libraries/spcre/libpcre/pcre/pcre_compile.c
changeset 0 7f656887cf89
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libraries/spcre/libpcre/pcre/pcre_compile.c	Wed Jun 23 15:52:26 2010 +0100
@@ -0,0 +1,6382 @@
+/*************************************************
+*      Perl-Compatible Regular Expressions       *
+*************************************************/
+
+/* PCRE is a library of functions to support regular expressions whose syntax
+and semantics are as close as possible to those of the Perl 5 language.
+
+                       Written by Philip Hazel
+           Copyright (c) 1997-2008 University of Cambridge
+
+-----------------------------------------------------------------------------
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright notice,
+      this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+
+    * Neither the name of the University of Cambridge nor the names of its
+      contributors may be used to endorse or promote products derived from
+      this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+-----------------------------------------------------------------------------
+*/
+
+
+/* This module contains the external function pcre_compile(), along with
+supporting internal functions that are not used by other modules. */
+
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#define NLBLOCK cd             /* Block containing newline information */
+#define PSSTART start_pattern  /* Field containing processed string start */
+#define PSEND   end_pattern    /* Field containing processed string end */
+
+#include "pcre_internal.h"
+
+
+/* When DEBUG is defined, we need the pcre_printint() function, which is also
+used by pcretest. DEBUG is not defined when building a production library. */
+
+#ifdef DEBUG
+#include "pcre_printint.src"
+#endif
+
+
+/* Macro for setting individual bits in class bitmaps. */
+
+#define SETBIT(a,b) a[b/8] |= (1 << (b%8))
+
+/* Maximum length value to check against when making sure that the integer that
+holds the compiled pattern length does not overflow. We make it a bit less than
+INT_MAX to allow for adding in group terminating bytes, so that we don't have
+to check them every time. */
+
+#define OFLOW_MAX (INT_MAX - 20)
+
+
+/*************************************************
+*      Code parameters and static tables         *
+*************************************************/
+
+/* This value specifies the size of stack workspace that is used during the
+first pre-compile phase that determines how much memory is required. The regex
+is partly compiled into this space, but the compiled parts are discarded as
+soon as they can be, so that hopefully there will never be an overrun. The code
+does, however, check for an overrun. The largest amount I've seen used is 218,
+so this number is very generous.
+
+The same workspace is used during the second, actual compile phase for
+remembering forward references to groups so that they can be filled in at the
+end. Each entry in this list occupies LINK_SIZE bytes, so even when LINK_SIZE
+is 4 there is plenty of room. */
+
+#define COMPILE_WORK_SIZE (4096)
+
+
+/* Table for handling escaped characters in the range '0'-'z'. Positive returns
+are simple data values; negative values are for special things like \d and so
+on. Zero means further processing is needed (for things like \x), or the escape
+is invalid. */
+
+#ifndef EBCDIC  /* This is the "normal" table for ASCII systems */
+static const short int escapes[] = {
+     0,      0,      0,      0,      0,      0,      0,      0,   /* 0 - 7 */
+     0,      0,    ':',    ';',    '<',    '=',    '>',    '?',   /* 8 - ? */
+   '@', -ESC_A, -ESC_B, -ESC_C, -ESC_D, -ESC_E,      0, -ESC_G,   /* @ - G */
+-ESC_H,      0,      0, -ESC_K,      0,      0,      0,      0,   /* H - O */
+-ESC_P, -ESC_Q, -ESC_R, -ESC_S,      0,      0, -ESC_V, -ESC_W,   /* P - W */
+-ESC_X,      0, -ESC_Z,    '[',   '\\',    ']',    '^',    '_',   /* X - _ */
+   '`',      7, -ESC_b,      0, -ESC_d,  ESC_e,  ESC_f,      0,   /* ` - g */
+-ESC_h,      0,      0, -ESC_k,      0,      0,  ESC_n,      0,   /* h - o */
+-ESC_p,      0,  ESC_r, -ESC_s,  ESC_tee,    0, -ESC_v, -ESC_w,   /* p - w */
+     0,      0, -ESC_z                                            /* x - z */
+};
+
+#else           /* This is the "abnormal" table for EBCDIC systems */
+static const short int escapes[] = {
+/*  48 */     0,     0,      0,     '.',    '<',   '(',    '+',    '|',
+/*  50 */   '&',     0,      0,       0,      0,     0,      0,      0,
+/*  58 */     0,     0,    '!',     '$',    '*',   ')',    ';',    '~',
+/*  60 */   '-',   '/',      0,       0,      0,     0,      0,      0,
+/*  68 */     0,     0,    '|',     ',',    '%',   '_',    '>',    '?',
+/*  70 */     0,     0,      0,       0,      0,     0,      0,      0,
+/*  78 */     0,   '`',    ':',     '#',    '@',  '\'',    '=',    '"',
+/*  80 */     0,     7, -ESC_b,       0, -ESC_d, ESC_e,  ESC_f,      0,
+/*  88 */-ESC_h,     0,      0,     '{',      0,     0,      0,      0,
+/*  90 */     0,     0, -ESC_k,     'l',      0, ESC_n,      0, -ESC_p,
+/*  98 */     0, ESC_r,      0,     '}',      0,     0,      0,      0,
+/*  A0 */     0,   '~', -ESC_s, ESC_tee,      0,-ESC_v, -ESC_w,      0,
+/*  A8 */     0,-ESC_z,      0,       0,      0,   '[',      0,      0,
+/*  B0 */     0,     0,      0,       0,      0,     0,      0,      0,
+/*  B8 */     0,     0,      0,       0,      0,   ']',    '=',    '-',
+/*  C0 */   '{',-ESC_A, -ESC_B,  -ESC_C, -ESC_D,-ESC_E,      0, -ESC_G,
+/*  C8 */-ESC_H,     0,      0,       0,      0,     0,      0,      0,
+/*  D0 */   '}',     0, -ESC_K,       0,      0,     0,      0, -ESC_P,
+/*  D8 */-ESC_Q,-ESC_R,      0,       0,      0,     0,      0,      0,
+/*  E0 */  '\\',     0, -ESC_S,       0,      0,-ESC_V, -ESC_W, -ESC_X,
+/*  E8 */     0,-ESC_Z,      0,       0,      0,     0,      0,      0,
+/*  F0 */     0,     0,      0,       0,      0,     0,      0,      0,
+/*  F8 */     0,     0,      0,       0,      0,     0,      0,      0
+};
+#endif
+
+
+/* Table of special "verbs" like (*PRUNE). This is a short table, so it is
+searched linearly. Put all the names into a single string, in order to reduce
+the number of relocations when a shared library is dynamically linked. */
+
+typedef struct verbitem {
+  int   len;
+  int   op;
+} verbitem;
+
+static const char verbnames[] =
+  "ACCEPT\0"
+  "COMMIT\0"
+  "F\0"
+  "FAIL\0"
+  "PRUNE\0"
+  "SKIP\0"
+  "THEN";
+
+static const verbitem verbs[] = {
+  { 6, OP_ACCEPT },
+  { 6, OP_COMMIT },
+  { 1, OP_FAIL },
+  { 4, OP_FAIL },
+  { 5, OP_PRUNE },
+  { 4, OP_SKIP  },
+  { 4, OP_THEN  }
+};
+
+static const int verbcount = sizeof(verbs)/sizeof(verbitem);
+
+
+/* Tables of names of POSIX character classes and their lengths. The names are
+now all in a single string, to reduce the number of relocations when a shared
+library is dynamically loaded. The list of lengths is terminated by a zero
+length entry. The first three must be alpha, lower, upper, as this is assumed
+for handling case independence. */
+
+static const char posix_names[] =
+  "alpha\0"  "lower\0"  "upper\0"  "alnum\0"  "ascii\0"  "blank\0"
+  "cntrl\0"  "digit\0"  "graph\0"  "print\0"  "punct\0"  "space\0"
+  "word\0"   "xdigit";
+
+static const uschar posix_name_lengths[] = {
+  5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 4, 6, 0 };
+
+/* Table of class bit maps for each POSIX class. Each class is formed from a
+base map, with an optional addition or removal of another map. Then, for some
+classes, there is some additional tweaking: for [:blank:] the vertical space
+characters are removed, and for [:alpha:] and [:alnum:] the underscore
+character is removed. The triples in the table consist of the base map offset,
+second map offset or -1 if no second map, and a non-negative value for map
+addition or a negative value for map subtraction (if there are two maps). The
+absolute value of the third field has these meanings: 0 => no tweaking, 1 =>
+remove vertical space characters, 2 => remove underscore. */
+
+static const int posix_class_maps[] = {
+  cbit_word,  cbit_digit, -2,             /* alpha */
+  cbit_lower, -1,          0,             /* lower */
+  cbit_upper, -1,          0,             /* upper */
+  cbit_word,  -1,          2,             /* alnum - word without underscore */
+  cbit_print, cbit_cntrl,  0,             /* ascii */
+  cbit_space, -1,          1,             /* blank - a GNU extension */
+  cbit_cntrl, -1,          0,             /* cntrl */
+  cbit_digit, -1,          0,             /* digit */
+  cbit_graph, -1,          0,             /* graph */
+  cbit_print, -1,          0,             /* print */
+  cbit_punct, -1,          0,             /* punct */
+  cbit_space, -1,          0,             /* space */
+  cbit_word,  -1,          0,             /* word - a Perl extension */
+  cbit_xdigit,-1,          0              /* xdigit */
+};
+
+
+#define STRING(a)  # a
+#define XSTRING(s) STRING(s)
+
+/* The texts of compile-time error messages. These are "char *" because they
+are passed to the outside world. Do not ever re-use any error number, because
+they are documented. Always add a new error instead. Messages marked DEAD below
+are no longer used. This used to be a table of strings, but in order to reduce
+the number of relocations needed when a shared library is loaded dynamically,
+it is now one long string. We cannot use a table of offsets, because the
+lengths of inserts such as XSTRING(MAX_NAME_SIZE) are not known. Instead, we
+simply count through to the one we want - this isn't a performance issue
+because these strings are used only when there is a compilation error. */
+
+static const char error_texts[] =
+  "no error\0"
+  "\\ at end of pattern\0"
+  "\\c at end of pattern\0"
+  "unrecognized character follows \\\0"
+  "numbers out of order in {} quantifier\0"
+  /* 5 */
+  "number too big in {} quantifier\0"
+  "missing terminating ] for character class\0"
+  "invalid escape sequence in character class\0"
+  "range out of order in character class\0"
+  "nothing to repeat\0"
+  /* 10 */
+  "operand of unlimited repeat could match the empty string\0"  /** DEAD **/
+  "internal error: unexpected repeat\0"
+  "unrecognized character after (? or (?-\0"
+  "POSIX named classes are supported only within a class\0"
+  "missing )\0"
+  /* 15 */
+  "reference to non-existent subpattern\0"
+  "erroffset passed as NULL\0"
+  "unknown option bit(s) set\0"
+  "missing ) after comment\0"
+  "parentheses nested too deeply\0"  /** DEAD **/
+  /* 20 */
+  "regular expression is too large\0"
+  "failed to get memory\0"
+  "unmatched parentheses\0"
+  "internal error: code overflow\0"
+  "unrecognized character after (?<\0"
+  /* 25 */
+  "lookbehind assertion is not fixed length\0"
+  "malformed number or name after (?(\0"
+  "conditional group contains more than two branches\0"
+  "assertion expected after (?(\0"
+  "(?R or (?[+-]digits must be followed by )\0"
+  /* 30 */
+  "unknown POSIX class name\0"
+  "POSIX collating elements are not supported\0"
+  "this version of PCRE is not compiled with PCRE_UTF8 support\0"
+  "spare error\0"  /** DEAD **/
+  "character value in \\x{...} sequence is too large\0"
+  /* 35 */
+  "invalid condition (?(0)\0"
+  "\\C not allowed in lookbehind assertion\0"
+  "PCRE does not support \\L, \\l, \\N, \\U, or \\u\0"
+  "number after (?C is > 255\0"
+  "closing ) for (?C expected\0"
+  /* 40 */
+  "recursive call could loop indefinitely\0"
+  "unrecognized character after (?P\0"
+  "syntax error in subpattern name (missing terminator)\0"
+  "two named subpatterns have the same name\0"
+  "invalid UTF-8 string\0"
+  /* 45 */
+  "support for \\P, \\p, and \\X has not been compiled\0"
+  "malformed \\P or \\p sequence\0"
+  "unknown property name after \\P or \\p\0"
+  "subpattern name is too long (maximum " XSTRING(MAX_NAME_SIZE) " characters)\0"
+  "too many named subpatterns (maximum " XSTRING(MAX_NAME_COUNT) ")\0"
+  /* 50 */
+  "repeated subpattern is too long\0"    /** DEAD **/
+  "octal value is greater than \\377 (not in UTF-8 mode)\0"
+  "internal error: overran compiling workspace\0"
+  "internal error: previously-checked referenced subpattern not found\0"
+  "DEFINE group contains more than one branch\0"
+  /* 55 */
+  "repeating a DEFINE group is not allowed\0"
+  "inconsistent NEWLINE options\0"
+  "\\g is not followed by a braced, angle-bracketed, or quoted name/number or by a plain number\0"
+  "a numbered reference must not be zero\0"
+  "(*VERB) with an argument is not supported\0"
+  /* 60 */
+  "(*VERB) not recognized\0"
+  "number is too big\0"
+  "subpattern name expected\0"
+  "digit expected after (?+\0"
+  "] is an invalid data character in JavaScript compatibility mode";
+
+
+/* Table to identify digits and hex digits. This is used when compiling
+patterns. Note that the tables in chartables are dependent on the locale, and
+may mark arbitrary characters as digits - but the PCRE compiling code expects
+to handle only 0-9, a-z, and A-Z as digits when compiling. That is why we have
+a private table here. It costs 256 bytes, but it is a lot faster than doing
+character value tests (at least in some simple cases I timed), and in some
+applications one wants PCRE to compile efficiently as well as match
+efficiently.
+
+For convenience, we use the same bit definitions as in chartables:
+
+  0x04   decimal digit
+  0x08   hexadecimal digit
+
+Then we can use ctype_digit and ctype_xdigit in the code. */
+
+#ifndef EBCDIC  /* This is the "normal" case, for ASCII systems */
+static const unsigned char digitab[] =
+  {
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*   0-  7 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*   8- 15 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  16- 23 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  24- 31 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*    - '  */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  ( - /  */
+  0x0c,0x0c,0x0c,0x0c,0x0c,0x0c,0x0c,0x0c, /*  0 - 7  */
+  0x0c,0x0c,0x00,0x00,0x00,0x00,0x00,0x00, /*  8 - ?  */
+  0x00,0x08,0x08,0x08,0x08,0x08,0x08,0x00, /*  @ - G  */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  H - O  */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  P - W  */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  X - _  */
+  0x00,0x08,0x08,0x08,0x08,0x08,0x08,0x00, /*  ` - g  */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  h - o  */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  p - w  */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  x -127 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 128-135 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 136-143 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 144-151 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 152-159 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 160-167 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 168-175 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 176-183 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 184-191 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 192-199 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 200-207 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 208-215 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 216-223 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 224-231 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 232-239 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 240-247 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};/* 248-255 */
+
+#else           /* This is the "abnormal" case, for EBCDIC systems */
+static const unsigned char digitab[] =
+  {
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*   0-  7  0 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*   8- 15    */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  16- 23 10 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  24- 31    */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  32- 39 20 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  40- 47    */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  48- 55 30 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  56- 63    */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*    - 71 40 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  72- |     */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  & - 87 50 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  88- 95    */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  - -103 60 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 104- ?     */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 112-119 70 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 120- "     */
+  0x00,0x08,0x08,0x08,0x08,0x08,0x08,0x00, /* 128- g  80 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  h -143    */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 144- p  90 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  q -159    */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 160- x  A0 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  y -175    */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  ^ -183 B0 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 184-191    */
+  0x00,0x08,0x08,0x08,0x08,0x08,0x08,0x00, /*  { - G  C0 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  H -207    */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  } - P  D0 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  Q -223    */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  \ - X  E0 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  Y -239    */
+  0x0c,0x0c,0x0c,0x0c,0x0c,0x0c,0x0c,0x0c, /*  0 - 7  F0 */
+  0x0c,0x0c,0x00,0x00,0x00,0x00,0x00,0x00};/*  8 -255    */
+
+static const unsigned char ebcdic_chartab[] = { /* chartable partial dup */
+  0x80,0x00,0x00,0x00,0x00,0x01,0x00,0x00, /*   0-  7 */
+  0x00,0x00,0x00,0x00,0x01,0x01,0x00,0x00, /*   8- 15 */
+  0x00,0x00,0x00,0x00,0x00,0x01,0x00,0x00, /*  16- 23 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  24- 31 */
+  0x00,0x00,0x00,0x00,0x00,0x01,0x00,0x00, /*  32- 39 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  40- 47 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  48- 55 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  56- 63 */
+  0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*    - 71 */
+  0x00,0x00,0x00,0x80,0x00,0x80,0x80,0x80, /*  72- |  */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  & - 87 */
+  0x00,0x00,0x00,0x80,0x80,0x80,0x00,0x00, /*  88- 95 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  - -103 */
+  0x00,0x00,0x00,0x00,0x00,0x10,0x00,0x80, /* 104- ?  */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 112-119 */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 120- "  */
+  0x00,0x1a,0x1a,0x1a,0x1a,0x1a,0x1a,0x12, /* 128- g  */
+  0x12,0x12,0x00,0x00,0x00,0x00,0x00,0x00, /*  h -143 */
+  0x00,0x12,0x12,0x12,0x12,0x12,0x12,0x12, /* 144- p  */
+  0x12,0x12,0x00,0x00,0x00,0x00,0x00,0x00, /*  q -159 */
+  0x00,0x00,0x12,0x12,0x12,0x12,0x12,0x12, /* 160- x  */
+  0x12,0x12,0x00,0x00,0x00,0x00,0x00,0x00, /*  y -175 */
+  0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  ^ -183 */
+  0x00,0x00,0x80,0x00,0x00,0x00,0x00,0x00, /* 184-191 */
+  0x80,0x1a,0x1a,0x1a,0x1a,0x1a,0x1a,0x12, /*  { - G  */
+  0x12,0x12,0x00,0x00,0x00,0x00,0x00,0x00, /*  H -207 */
+  0x00,0x12,0x12,0x12,0x12,0x12,0x12,0x12, /*  } - P  */
+  0x12,0x12,0x00,0x00,0x00,0x00,0x00,0x00, /*  Q -223 */
+  0x00,0x00,0x12,0x12,0x12,0x12,0x12,0x12, /*  \ - X  */
+  0x12,0x12,0x00,0x00,0x00,0x00,0x00,0x00, /*  Y -239 */
+  0x1c,0x1c,0x1c,0x1c,0x1c,0x1c,0x1c,0x1c, /*  0 - 7  */
+  0x1c,0x1c,0x00,0x00,0x00,0x00,0x00,0x00};/*  8 -255 */
+#endif
+
+
+/* Definition to allow mutual recursion */
+
+static BOOL
+  compile_regex(int, int, uschar **, const uschar **, int *, BOOL, BOOL, int,
+    int *, int *, branch_chain *, compile_data *, int *);
+
+
+
+/*************************************************
+*            Find an error text                  *
+*************************************************/
+
+/* The error texts are now all in one long string, to save on relocations. As
+some of the text is of unknown length, we can't use a table of offsets.
+Instead, just count through the strings. This is not a performance issue
+because it happens only when there has been a compilation error.
+
+Argument:   the error number
+Returns:    pointer to the error string
+*/
+
+static const char *
+find_error_text(int n)
+{
+const char *s = error_texts;
+for (; n > 0; n--) while (*s++ != 0) {};
+return s;
+}
+
+
+/*************************************************
+*            Handle escapes                      *
+*************************************************/
+
+/* This function is called when a \ has been encountered. It either returns a
+positive value for a simple escape such as \n, or a negative value which
+encodes one of the more complicated things such as \d. A backreference to group
+n is returned as -(ESC_REF + n); ESC_REF is the highest ESC_xxx macro. When
+UTF-8 is enabled, a positive value greater than 255 may be returned. On entry,
+ptr is pointing at the \. On exit, it is on the final character of the escape
+sequence.
+
+Arguments:
+  ptrptr         points to the pattern position pointer
+  errorcodeptr   points to the errorcode variable
+  bracount       number of previous extracting brackets
+  options        the options bits
+  isclass        TRUE if inside a character class
+
+Returns:         zero or positive => a data character
+                 negative => a special escape sequence
+                 on error, errorcodeptr is set
+*/
+
+static int
+check_escape(const uschar **ptrptr, int *errorcodeptr, int bracount,
+  int options, BOOL isclass)
+{
+BOOL utf8 = (options & PCRE_UTF8) != 0;
+const uschar *ptr = *ptrptr + 1;
+int c, i;
+
+GETCHARINCTEST(c, ptr);           /* Get character value, increment pointer */
+ptr--;                            /* Set pointer back to the last byte */
+
+/* If backslash is at the end of the pattern, it's an error. */
+
+if (c == 0) *errorcodeptr = ERR1;
+
+/* Non-alphanumerics are literals. For digits or letters, do an initial lookup
+in a table. A non-zero result is something that can be returned immediately.
+Otherwise further processing may be required. */
+
+#ifndef EBCDIC  /* ASCII coding */
+else if (c < '0' || c > 'z') {}                           /* Not alphanumeric */
+else if ((i = escapes[c - '0']) != 0) c = i;
+
+#else           /* EBCDIC coding */
+else if (c < 'a' || (ebcdic_chartab[c] & 0x0E) == 0) {}   /* Not alphanumeric */
+else if ((i = escapes[c - 0x48]) != 0)  c = i;
+#endif
+
+/* Escapes that need further processing, or are illegal. */
+
+else
+  {
+  const uschar *oldptr;
+  BOOL braced, negated;
+
+  switch (c)
+    {
+    /* A number of Perl escapes are not handled by PCRE. We give an explicit
+    error. */
+
+    case 'l':
+    case 'L':
+    case 'N':
+    case 'u':
+    case 'U':
+    *errorcodeptr = ERR37;
+    break;
+
+    /* \g must be followed by one of a number of specific things:
+
+    (1) A number, either plain or braced. If positive, it is an absolute
+    backreference. If negative, it is a relative backreference. This is a Perl
+    5.10 feature.
+
+    (2) Perl 5.10 also supports \g{name} as a reference to a named group. This
+    is part of Perl's movement towards a unified syntax for back references. As
+    this is synonymous with \k{name}, we fudge it up by pretending it really
+    was \k.
+
+    (3) For Oniguruma compatibility we also support \g followed by a name or a
+    number either in angle brackets or in single quotes. However, these are
+    (possibly recursive) subroutine calls, _not_ backreferences. Just return
+    the -ESC_g code (cf \k). */
+
+    case 'g':
+    if (ptr[1] == '<' || ptr[1] == '\'')
+      {
+      c = -ESC_g;
+      break;
+      }
+
+    /* Handle the Perl-compatible cases */
+
+    if (ptr[1] == '{')
+      {
+      const uschar *p;
+      for (p = ptr+2; *p != 0 && *p != '}'; p++)
+        if (*p != '-' && (digitab[*p] & ctype_digit) == 0) break;
+      if (*p != 0 && *p != '}')
+        {
+        c = -ESC_k;
+        break;
+        }
+      braced = TRUE;
+      ptr++;
+      }
+    else braced = FALSE;
+
+    if (ptr[1] == '-')
+      {
+      negated = TRUE;
+      ptr++;
+      }
+    else negated = FALSE;
+
+    c = 0;
+    while ((digitab[ptr[1]] & ctype_digit) != 0)
+      c = c * 10 + *(++ptr) - '0';
+
+    if (c < 0)   /* Integer overflow */
+      {
+      *errorcodeptr = ERR61;
+      break;
+      }
+
+    if (braced && *(++ptr) != '}')
+      {
+      *errorcodeptr = ERR57;
+      break;
+      }
+
+    if (c == 0)
+      {
+      *errorcodeptr = ERR58;
+      break;
+      }
+
+    if (negated)
+      {
+      if (c > bracount)
+        {
+        *errorcodeptr = ERR15;
+        break;
+        }
+      c = bracount - (c - 1);
+      }
+
+    c = -(ESC_REF + c);
+    break;
+
+    /* The handling of escape sequences consisting of a string of digits
+    starting with one that is not zero is not straightforward. By experiment,
+    the way Perl works seems to be as follows:
+
+    Outside a character class, the digits are read as a decimal number. If the
+    number is less than 10, or if there are that many previous extracting
+    left brackets, then it is a back reference. Otherwise, up to three octal
+    digits are read to form an escaped byte. Thus \123 is likely to be octal
+    123 (cf \0123, which is octal 012 followed by the literal 3). If the octal
+    value is greater than 377, the least significant 8 bits are taken. Inside a
+    character class, \ followed by a digit is always an octal number. */
+
+    case '1': case '2': case '3': case '4': case '5':
+    case '6': case '7': case '8': case '9':
+
+    if (!isclass)
+      {
+      oldptr = ptr;
+      c -= '0';
+      while ((digitab[ptr[1]] & ctype_digit) != 0)
+        c = c * 10 + *(++ptr) - '0';
+      if (c < 0)    /* Integer overflow */
+        {
+        *errorcodeptr = ERR61;
+        break;
+        }
+      if (c < 10 || c <= bracount)
+        {
+        c = -(ESC_REF + c);
+        break;
+        }
+      ptr = oldptr;      /* Put the pointer back and fall through */
+      }
+
+    /* Handle an octal number following \. If the first digit is 8 or 9, Perl
+    generates a binary zero byte and treats the digit as a following literal.
+    Thus we have to pull back the pointer by one. */
+
+    if ((c = *ptr) >= '8')
+      {
+      ptr--;
+      c = 0;
+      break;
+      }
+
+    /* \0 always starts an octal number, but we may drop through to here with a
+    larger first octal digit. The original code used just to take the least
+    significant 8 bits of octal numbers (I think this is what early Perls used
+    to do). Nowadays we allow for larger numbers in UTF-8 mode, but no more
+    than 3 octal digits. */
+
+    case '0':
+    c -= '0';
+    while(i++ < 2 && ptr[1] >= '0' && ptr[1] <= '7')
+        c = c * 8 + *(++ptr) - '0';
+    if (!utf8 && c > 255) *errorcodeptr = ERR51;
+    break;
+
+    /* \x is complicated. \x{ddd} is a character number which can be greater
+    than 0xff in utf8 mode, but only if the ddd are hex digits. If not, { is
+    treated as a data character. */
+
+    case 'x':
+    if (ptr[1] == '{')
+      {
+      const uschar *pt = ptr + 2;
+      int count = 0;
+
+      c = 0;
+      while ((digitab[*pt] & ctype_xdigit) != 0)
+        {
+        register int cc = *pt++;
+        if (c == 0 && cc == '0') continue;     /* Leading zeroes */
+        count++;
+
+#ifndef EBCDIC  /* ASCII coding */
+        if (cc >= 'a') cc -= 32;               /* Convert to upper case */
+        c = (c << 4) + cc - ((cc < 'A')? '0' : ('A' - 10));
+#else           /* EBCDIC coding */
+        if (cc >= 'a' && cc <= 'z') cc += 64;  /* Convert to upper case */
+        c = (c << 4) + cc - ((cc >= '0')? '0' : ('A' - 10));
+#endif
+        }
+
+      if (*pt == '}')
+        {
+        if (c < 0 || count > (utf8? 8 : 2)) *errorcodeptr = ERR34;
+        ptr = pt;
+        break;
+        }
+
+      /* If the sequence of hex digits does not end with '}', then we don't
+      recognize this construct; fall through to the normal \x handling. */
+      }
+
+    /* Read just a single-byte hex-defined char */
+
+    c = 0;
+    while (i++ < 2 && (digitab[ptr[1]] & ctype_xdigit) != 0)
+      {
+      int cc;                               /* Some compilers don't like ++ */
+      cc = *(++ptr);                        /* in initializers */
+#ifndef EBCDIC  /* ASCII coding */
+      if (cc >= 'a') cc -= 32;              /* Convert to upper case */
+      c = c * 16 + cc - ((cc < 'A')? '0' : ('A' - 10));
+#else           /* EBCDIC coding */
+      if (cc <= 'z') cc += 64;              /* Convert to upper case */
+      c = c * 16 + cc - ((cc >= '0')? '0' : ('A' - 10));
+#endif
+      }
+    break;
+
+    /* For \c, a following letter is upper-cased; then the 0x40 bit is flipped.
+    This coding is ASCII-specific, but then the whole concept of \cx is
+    ASCII-specific. (However, an EBCDIC equivalent has now been added.) */
+
+    case 'c':
+    c = *(++ptr);
+    if (c == 0)
+      {
+      *errorcodeptr = ERR2;
+      break;
+      }
+
+#ifndef EBCDIC  /* ASCII coding */
+    if (c >= 'a' && c <= 'z') c -= 32;
+    c ^= 0x40;
+#else           /* EBCDIC coding */
+    if (c >= 'a' && c <= 'z') c += 64;
+    c ^= 0xC0;
+#endif
+    break;
+
+    /* PCRE_EXTRA enables extensions to Perl in the matter of escapes. Any
+    other alphanumeric following \ is an error if PCRE_EXTRA was set;
+    otherwise, for Perl compatibility, it is a literal. This code looks a bit
+    odd, but there used to be some cases other than the default, and there may
+    be again in future, so I haven't "optimized" it. */
+
+    default:
+    if ((options & PCRE_EXTRA) != 0) switch(c)
+      {
+      default:
+      *errorcodeptr = ERR3;
+      break;
+      }
+    break;
+    }
+  }
+
+*ptrptr = ptr;
+return c;
+}
+
+
+
+#ifdef SUPPORT_UCP
+/*************************************************
+*               Handle \P and \p                 *
+*************************************************/
+
+/* This function is called after \P or \p has been encountered, provided that
+PCRE is compiled with support for Unicode properties. On entry, ptrptr is
+pointing at the P or p. On exit, it is pointing at the final character of the
+escape sequence.
+
+Argument:
+  ptrptr         points to the pattern position pointer
+  negptr         points to a boolean that is set TRUE for negation else FALSE
+  dptr           points to an int that is set to the detailed property value
+  errorcodeptr   points to the error code variable
+
+Returns:         type value from ucp_type_table, or -1 for an invalid type
+*/
+
+static int
+get_ucp(const uschar **ptrptr, BOOL *negptr, int *dptr, int *errorcodeptr)
+{
+int c, i, bot, top;
+const uschar *ptr = *ptrptr;
+char name[32];
+
+c = *(++ptr);
+if (c == 0) goto ERROR_RETURN;
+
+*negptr = FALSE;
+
+/* \P or \p can be followed by a name in {}, optionally preceded by ^ for
+negation. */
+
+if (c == '{')
+  {
+  if (ptr[1] == '^')
+    {
+    *negptr = TRUE;
+    ptr++;
+    }
+  for (i = 0; i < (int)sizeof(name) - 1; i++)
+    {
+    c = *(++ptr);
+    if (c == 0) goto ERROR_RETURN;
+    if (c == '}') break;
+    name[i] = c;
+    }
+  if (c !='}') goto ERROR_RETURN;
+  name[i] = 0;
+  }
+
+/* Otherwise there is just one following character */
+
+else
+  {
+  name[0] = c;
+  name[1] = 0;
+  }
+
+*ptrptr = ptr;
+
+/* Search for a recognized property name using binary chop */
+
+bot = 0;
+top = _pcre_utt_size;
+
+while (bot < top)
+  {
+  i = (bot + top) >> 1;
+  c = strcmp(name, _pcre_utt_names + _pcre_utt[i].name_offset);
+  if (c == 0)
+    {
+    *dptr = _pcre_utt[i].value;
+    return _pcre_utt[i].type;
+    }
+  if (c > 0) bot = i + 1; else top = i;
+  }
+
+*errorcodeptr = ERR47;
+*ptrptr = ptr;
+return -1;
+
+ERROR_RETURN:
+*errorcodeptr = ERR46;
+*ptrptr = ptr;
+return -1;
+}
+#endif
+
+
+
+
+/*************************************************
+*            Check for counted repeat            *
+*************************************************/
+
+/* This function is called when a '{' is encountered in a place where it might
+start a quantifier. It looks ahead to see if it really is a quantifier or not.
+It is only a quantifier if it is one of the forms {ddd} {ddd,} or {ddd,ddd}
+where the ddds are digits.
+
+Arguments:
+  p         pointer to the first char after '{'
+
+Returns:    TRUE or FALSE
+*/
+
+static BOOL
+is_counted_repeat(const uschar *p)
+{
+if ((digitab[*p++] & ctype_digit) == 0) return FALSE;
+while ((digitab[*p] & ctype_digit) != 0) p++;
+if (*p == '}') return TRUE;
+
+if (*p++ != ',') return FALSE;
+if (*p == '}') return TRUE;
+
+if ((digitab[*p++] & ctype_digit) == 0) return FALSE;
+while ((digitab[*p] & ctype_digit) != 0) p++;
+
+return (*p == '}');
+}
+
+
+
+/*************************************************
+*         Read repeat counts                     *
+*************************************************/
+
+/* Read an item of the form {n,m} and return the values. This is called only
+after is_counted_repeat() has confirmed that a repeat-count quantifier exists,
+so the syntax is guaranteed to be correct, but we need to check the values.
+
+Arguments:
+  p              pointer to first char after '{'
+  minp           pointer to int for min
+  maxp           pointer to int for max
+                 returned as -1 if no max
+  errorcodeptr   points to error code variable
+
+Returns:         pointer to '}' on success;
+                 current ptr on error, with errorcodeptr set non-zero
+*/
+
+static const uschar *
+read_repeat_counts(const uschar *p, int *minp, int *maxp, int *errorcodeptr)
+{
+int min = 0;
+int max = -1;
+
+/* Read the minimum value and do a paranoid check: a negative value indicates
+an integer overflow. */
+
+while ((digitab[*p] & ctype_digit) != 0) min = min * 10 + *p++ - '0';
+if (min < 0 || min > 65535)
+  {
+  *errorcodeptr = ERR5;
+  return p;
+  }
+
+/* Read the maximum value if there is one, and again do a paranoid on its size.
+Also, max must not be less than min. */
+
+if (*p == '}') max = min; else
+  {
+  if (*(++p) != '}')
+    {
+    max = 0;
+    while((digitab[*p] & ctype_digit) != 0) max = max * 10 + *p++ - '0';
+    if (max < 0 || max > 65535)
+      {
+      *errorcodeptr = ERR5;
+      return p;
+      }
+    if (max < min)
+      {
+      *errorcodeptr = ERR4;
+      return p;
+      }
+    }
+  }
+
+/* Fill in the required variables, and pass back the pointer to the terminating
+'}'. */
+
+*minp = min;
+*maxp = max;
+return p;
+}
+
+
+
+/*************************************************
+*       Find forward referenced subpattern       *
+*************************************************/
+
+/* This function scans along a pattern's text looking for capturing
+subpatterns, and counting them. If it finds a named pattern that matches the
+name it is given, it returns its number. Alternatively, if the name is NULL, it
+returns when it reaches a given numbered subpattern. This is used for forward
+references to subpatterns. We know that if (?P< is encountered, the name will
+be terminated by '>' because that is checked in the first pass.
+
+Arguments:
+  ptr          current position in the pattern
+  cd           compile background data
+  name         name to seek, or NULL if seeking a numbered subpattern
+  lorn         name length, or subpattern number if name is NULL
+  xmode        TRUE if we are in /x mode
+
+Returns:       the number of the named subpattern, or -1 if not found
+*/
+
+static int
+find_parens(const uschar *ptr, compile_data *cd, const uschar *name, int lorn,
+  BOOL xmode)
+{
+const uschar *thisname;
+int count = cd->bracount;
+
+for (; *ptr != 0; ptr++)
+  {
+  int term;
+
+  /* Skip over backslashed characters and also entire \Q...\E */
+
+  if (*ptr == '\\')
+    {
+    if (*(++ptr) == 0) return -1;
+    if (*ptr == 'Q') for (;;)
+      {
+      while (*(++ptr) != 0 && *ptr != '\\') {};
+      if (*ptr == 0) return -1;
+      if (*(++ptr) == 'E') break;
+      }
+    continue;
+    }
+
+  /* Skip over character classes; this logic must be similar to the way they
+  are handled for real. If the first character is '^', skip it. Also, if the
+  first few characters (either before or after ^) are \Q\E or \E we skip them
+  too. This makes for compatibility with Perl. */
+
+  if (*ptr == '[')
+    {
+    BOOL negate_class = FALSE;
+    for (;;)
+      {
+      int c = *(++ptr);
+      if (c == '\\')
+        {
+        if (ptr[1] == 'E') ptr++;
+          else if (strncmp((const char *)ptr+1, "Q\\E", 3) == 0) ptr += 3;
+            else break;
+        }
+      else if (!negate_class && c == '^')
+        negate_class = TRUE;
+      else break;
+      }
+
+    /* If the next character is ']', it is a data character that must be
+    skipped, except in JavaScript compatibility mode. */
+
+    if (ptr[1] == ']' && (cd->external_options & PCRE_JAVASCRIPT_COMPAT) == 0)
+      ptr++;
+
+    while (*(++ptr) != ']')
+      {
+      if (*ptr == 0) return -1;
+      if (*ptr == '\\')
+        {
+        if (*(++ptr) == 0) return -1;
+        if (*ptr == 'Q') for (;;)
+          {
+          while (*(++ptr) != 0 && *ptr != '\\') {};
+          if (*ptr == 0) return -1;
+          if (*(++ptr) == 'E') break;
+          }
+        continue;
+        }
+      }
+    continue;
+    }
+
+  /* Skip comments in /x mode */
+
+  if (xmode && *ptr == '#')
+    {
+    while (*(++ptr) != 0 && *ptr != '\n') {};
+    if (*ptr == 0) return -1;
+    continue;
+    }
+
+  /* An opening parens must now be a real metacharacter */
+
+  if (*ptr != '(') continue;
+  if (ptr[1] != '?' && ptr[1] != '*')
+    {
+    count++;
+    if (name == NULL && count == lorn) return count;
+    continue;
+    }
+
+  ptr += 2;
+  if (*ptr == 'P') ptr++;                      /* Allow optional P */
+
+  /* We have to disambiguate (?<! and (?<= from (?<name> */
+
+  if ((*ptr != '<' || ptr[1] == '!' || ptr[1] == '=') &&
+       *ptr != '\'')
+    continue;
+
+  count++;
+
+  if (name == NULL && count == lorn) return count;
+  term = *ptr++;
+  if (term == '<') term = '>';
+  thisname = ptr;
+  while (*ptr != term) ptr++;
+  if (name != NULL && lorn == ptr - thisname &&
+      strncmp((const char *)name, (const char *)thisname, lorn) == 0)
+    return count;
+  }
+
+return -1;
+}
+
+
+
+/*************************************************
+*      Find first significant op code            *
+*************************************************/
+
+/* This is called by several functions that scan a compiled expression looking
+for a fixed first character, or an anchoring op code etc. It skips over things
+that do not influence this. For some calls, a change of option is important.
+For some calls, it makes sense to skip negative forward and all backward
+assertions, and also the \b assertion; for others it does not.
+
+Arguments:
+  code         pointer to the start of the group
+  options      pointer to external options
+  optbit       the option bit whose changing is significant, or
+                 zero if none are
+  skipassert   TRUE if certain assertions are to be skipped
+
+Returns:       pointer to the first significant opcode
+*/
+
+static const uschar*
+first_significant_code(const uschar *code, int *options, int optbit,
+  BOOL skipassert)
+{
+for (;;)
+  {
+  switch ((int)*code)
+    {
+    case OP_OPT:
+    if (optbit > 0 && ((int)code[1] & optbit) != (*options & optbit))
+      *options = (int)code[1];
+    code += 2;
+    break;
+
+    case OP_ASSERT_NOT:
+    case OP_ASSERTBACK:
+    case OP_ASSERTBACK_NOT:
+    if (!skipassert) return code;
+    do code += GET(code, 1); while (*code == OP_ALT);
+    code += _pcre_OP_lengths[*code];
+    break;
+
+    case OP_WORD_BOUNDARY:
+    case OP_NOT_WORD_BOUNDARY:
+    if (!skipassert) return code;
+    /* Fall through */
+
+    case OP_CALLOUT:
+    case OP_CREF:
+    case OP_RREF:
+    case OP_DEF:
+    code += _pcre_OP_lengths[*code];
+    break;
+
+    default:
+    return code;
+    }
+  }
+/* Control never reaches here */
+}
+
+
+
+
+/*************************************************
+*        Find the fixed length of a pattern      *
+*************************************************/
+
+/* Scan a pattern and compute the fixed length of subject that will match it,
+if the length is fixed. This is needed for dealing with backward assertions.
+In UTF8 mode, the result is in characters rather than bytes.
+
+Arguments:
+  code     points to the start of the pattern (the bracket)
+  options  the compiling options
+
+Returns:   the fixed length, or -1 if there is no fixed length,
+             or -2 if \C was encountered
+*/
+
+static int
+find_fixedlength(uschar *code, int options)
+{
+int length = -1;
+
+register int branchlength = 0;
+register uschar *cc = code + 1 + LINK_SIZE;
+
+/* Scan along the opcodes for this branch. If we get to the end of the
+branch, check the length against that of the other branches. */
+
+for (;;)
+  {
+  int d;
+  register int op = *cc;
+  switch (op)
+    {
+    case OP_CBRA:
+    case OP_BRA:
+    case OP_ONCE:
+    case OP_COND:
+    d = find_fixedlength(cc + ((op == OP_CBRA)? 2:0), options);
+    if (d < 0) return d;
+    branchlength += d;
+    do cc += GET(cc, 1); while (*cc == OP_ALT);
+    cc += 1 + LINK_SIZE;
+    break;
+
+    /* Reached end of a branch; if it's a ket it is the end of a nested
+    call. If it's ALT it is an alternation in a nested call. If it is
+    END it's the end of the outer call. All can be handled by the same code. */
+
+    case OP_ALT:
+    case OP_KET:
+    case OP_KETRMAX:
+    case OP_KETRMIN:
+    case OP_END:
+    if (length < 0) length = branchlength;
+      else if (length != branchlength) return -1;
+    if (*cc != OP_ALT) return length;
+    cc += 1 + LINK_SIZE;
+    branchlength = 0;
+    break;
+
+    /* Skip over assertive subpatterns */
+
+    case OP_ASSERT:
+    case OP_ASSERT_NOT:
+    case OP_ASSERTBACK:
+    case OP_ASSERTBACK_NOT:
+    do cc += GET(cc, 1); while (*cc == OP_ALT);
+    /* Fall through */
+
+    /* Skip over things that don't match chars */
+
+    case OP_REVERSE:
+    case OP_CREF:
+    case OP_RREF:
+    case OP_DEF:
+    case OP_OPT:
+    case OP_CALLOUT:
+    case OP_SOD:
+    case OP_SOM:
+    case OP_EOD:
+    case OP_EODN:
+    case OP_CIRC:
+    case OP_DOLL:
+    case OP_NOT_WORD_BOUNDARY:
+    case OP_WORD_BOUNDARY:
+    cc += _pcre_OP_lengths[*cc];
+    break;
+
+    /* Handle literal characters */
+
+    case OP_CHAR:
+    case OP_CHARNC:
+    case OP_NOT:
+    branchlength++;
+    cc += 2;
+#ifdef SUPPORT_UTF8
+    if ((options & PCRE_UTF8) != 0)
+      {
+      while ((*cc & 0xc0) == 0x80) cc++;
+      }
+#endif
+    break;
+
+    /* Handle exact repetitions. The count is already in characters, but we
+    need to skip over a multibyte character in UTF8 mode.  */
+
+    case OP_EXACT:
+    branchlength += GET2(cc,1);
+    cc += 4;
+#ifdef SUPPORT_UTF8
+    if ((options & PCRE_UTF8) != 0)
+      {
+      while((*cc & 0x80) == 0x80) cc++;
+      }
+#endif
+    break;
+
+    case OP_TYPEEXACT:
+    branchlength += GET2(cc,1);
+    if (cc[3] == OP_PROP || cc[3] == OP_NOTPROP) cc += 2;
+    cc += 4;
+    break;
+
+    /* Handle single-char matchers */
+
+    case OP_PROP:
+    case OP_NOTPROP:
+    cc += 2;
+    /* Fall through */
+
+    case OP_NOT_DIGIT:
+    case OP_DIGIT:
+    case OP_NOT_WHITESPACE:
+    case OP_WHITESPACE:
+    case OP_NOT_WORDCHAR:
+    case OP_WORDCHAR:
+    case OP_ANY:
+    case OP_ALLANY:
+    branchlength++;
+    cc++;
+    break;
+
+    /* The single-byte matcher isn't allowed */
+
+    case OP_ANYBYTE:
+    return -2;
+
+    /* Check a class for variable quantification */
+
+#ifdef SUPPORT_UTF8
+    case OP_XCLASS:
+    cc += GET(cc, 1) - 33;
+    /* Fall through */
+#endif
+
+    case OP_CLASS:
+    case OP_NCLASS:
+    cc += 33;
+
+    switch (*cc)
+      {
+      case OP_CRSTAR:
+      case OP_CRMINSTAR:
+      case OP_CRQUERY:
+      case OP_CRMINQUERY:
+      return -1;
+
+      case OP_CRRANGE:
+      case OP_CRMINRANGE:
+      if (GET2(cc,1) != GET2(cc,3)) return -1;
+      branchlength += GET2(cc,1);
+      cc += 5;
+      break;
+
+      default:
+      branchlength++;
+      }
+    break;
+
+    /* Anything else is variable length */
+
+    default:
+    return -1;
+    }
+  }
+/* Control never gets here */
+}
+
+
+
+
+/*************************************************
+*    Scan compiled regex for numbered bracket    *
+*************************************************/
+
+/* This little function scans through a compiled pattern until it finds a
+capturing bracket with the given number.
+
+Arguments:
+  code        points to start of expression
+  utf8        TRUE in UTF-8 mode
+  number      the required bracket number
+
+Returns:      pointer to the opcode for the bracket, or NULL if not found
+*/
+
+static const uschar *
+find_bracket(const uschar *code, BOOL utf8, int number)
+{
+for (;;)
+  {
+  register int c = *code;
+  if (c == OP_END) return NULL;
+
+  /* XCLASS is used for classes that cannot be represented just by a bit
+  map. This includes negated single high-valued characters. The length in
+  the table is zero; the actual length is stored in the compiled code. */
+
+  if (c == OP_XCLASS) code += GET(code, 1);
+
+  /* Handle capturing bracket */
+
+  else if (c == OP_CBRA)
+    {
+    int n = GET2(code, 1+LINK_SIZE);
+    if (n == number) return (uschar *)code;
+    code += _pcre_OP_lengths[c];
+    }
+
+  /* Otherwise, we can get the item's length from the table, except that for
+  repeated character types, we have to test for \p and \P, which have an extra
+  two bytes of parameters. */
+
+  else
+    {
+    switch(c)
+      {
+      case OP_TYPESTAR:
+      case OP_TYPEMINSTAR:
+      case OP_TYPEPLUS:
+      case OP_TYPEMINPLUS:
+      case OP_TYPEQUERY:
+      case OP_TYPEMINQUERY:
+      case OP_TYPEPOSSTAR:
+      case OP_TYPEPOSPLUS:
+      case OP_TYPEPOSQUERY:
+      if (code[1] == OP_PROP || code[1] == OP_NOTPROP) code += 2;
+      break;
+
+      case OP_TYPEUPTO:
+      case OP_TYPEMINUPTO:
+      case OP_TYPEEXACT:
+      case OP_TYPEPOSUPTO:
+      if (code[3] == OP_PROP || code[3] == OP_NOTPROP) code += 2;
+      break;
+      }
+
+    /* Add in the fixed length from the table */
+
+    code += _pcre_OP_lengths[c];
+
+  /* In UTF-8 mode, opcodes that are followed by a character may be followed by
+  a multi-byte character. The length in the table is a minimum, so we have to
+  arrange to skip the extra bytes. */
+
+#ifdef SUPPORT_UTF8
+    if (utf8) switch(c)
+      {
+      case OP_CHAR:
+      case OP_CHARNC:
+      case OP_EXACT:
+      case OP_UPTO:
+      case OP_MINUPTO:
+      case OP_POSUPTO:
+      case OP_STAR:
+      case OP_MINSTAR:
+      case OP_POSSTAR:
+      case OP_PLUS:
+      case OP_MINPLUS:
+      case OP_POSPLUS:
+      case OP_QUERY:
+      case OP_MINQUERY:
+      case OP_POSQUERY:
+      if (code[-1] >= 0xc0) code += _pcre_utf8_table4[code[-1] & 0x3f];
+      break;
+      }
+#else
+    (void)(utf8);  /* Keep compiler happy by referencing function argument */
+#endif
+    }
+  }
+}
+
+
+
+/*************************************************
+*   Scan compiled regex for recursion reference  *
+*************************************************/
+
+/* This little function scans through a compiled pattern until it finds an
+instance of OP_RECURSE.
+
+Arguments:
+  code        points to start of expression
+  utf8        TRUE in UTF-8 mode
+
+Returns:      pointer to the opcode for OP_RECURSE, or NULL if not found
+*/
+
+static const uschar *
+find_recurse(const uschar *code, BOOL utf8)
+{
+for (;;)
+  {
+  register int c = *code;
+  if (c == OP_END) return NULL;
+  if (c == OP_RECURSE) return code;
+
+  /* XCLASS is used for classes that cannot be represented just by a bit
+  map. This includes negated single high-valued characters. The length in
+  the table is zero; the actual length is stored in the compiled code. */
+
+  if (c == OP_XCLASS) code += GET(code, 1);
+
+  /* Otherwise, we can get the item's length from the table, except that for
+  repeated character types, we have to test for \p and \P, which have an extra
+  two bytes of parameters. */
+
+  else
+    {
+    switch(c)
+      {
+      case OP_TYPESTAR:
+      case OP_TYPEMINSTAR:
+      case OP_TYPEPLUS:
+      case OP_TYPEMINPLUS:
+      case OP_TYPEQUERY:
+      case OP_TYPEMINQUERY:
+      case OP_TYPEPOSSTAR:
+      case OP_TYPEPOSPLUS:
+      case OP_TYPEPOSQUERY:
+      if (code[1] == OP_PROP || code[1] == OP_NOTPROP) code += 2;
+      break;
+
+      case OP_TYPEPOSUPTO:
+      case OP_TYPEUPTO:
+      case OP_TYPEMINUPTO:
+      case OP_TYPEEXACT:
+      if (code[3] == OP_PROP || code[3] == OP_NOTPROP) code += 2;
+      break;
+      }
+
+    /* Add in the fixed length from the table */
+
+    code += _pcre_OP_lengths[c];
+
+    /* In UTF-8 mode, opcodes that are followed by a character may be followed
+    by a multi-byte character. The length in the table is a minimum, so we have
+    to arrange to skip the extra bytes. */
+
+#ifdef SUPPORT_UTF8
+    if (utf8) switch(c)
+      {
+      case OP_CHAR:
+      case OP_CHARNC:
+      case OP_EXACT:
+      case OP_UPTO:
+      case OP_MINUPTO:
+      case OP_POSUPTO:
+      case OP_STAR:
+      case OP_MINSTAR:
+      case OP_POSSTAR:
+      case OP_PLUS:
+      case OP_MINPLUS:
+      case OP_POSPLUS:
+      case OP_QUERY:
+      case OP_MINQUERY:
+      case OP_POSQUERY:
+      if (code[-1] >= 0xc0) code += _pcre_utf8_table4[code[-1] & 0x3f];
+      break;
+      }
+#else
+    (void)(utf8);  /* Keep compiler happy by referencing function argument */
+#endif
+    }
+  }
+}
+
+
+
+/*************************************************
+*    Scan compiled branch for non-emptiness      *
+*************************************************/
+
+/* This function scans through a branch of a compiled pattern to see whether it
+can match the empty string or not. It is called from could_be_empty()
+below and from compile_branch() when checking for an unlimited repeat of a
+group that can match nothing. Note that first_significant_code() skips over
+backward and negative forward assertions when its final argument is TRUE. If we
+hit an unclosed bracket, we return "empty" - this means we've struck an inner
+bracket whose current branch will already have been scanned.
+
+Arguments:
+  code        points to start of search
+  endcode     points to where to stop
+  utf8        TRUE if in UTF8 mode
+
+Returns:      TRUE if what is matched could be empty
+*/
+
+static BOOL
+could_be_empty_branch(const uschar *code, const uschar *endcode, BOOL utf8)
+{
+register int c;
+for (code = first_significant_code(code + _pcre_OP_lengths[*code], NULL, 0, TRUE);
+     code < endcode;
+     code = first_significant_code(code + _pcre_OP_lengths[c], NULL, 0, TRUE))
+  {
+  const uschar *ccode;
+
+  c = *code;
+
+  /* Skip over forward assertions; the other assertions are skipped by
+  first_significant_code() with a TRUE final argument. */
+
+  if (c == OP_ASSERT)
+    {
+    do code += GET(code, 1); while (*code == OP_ALT);
+    c = *code;
+    continue;
+    }
+
+  /* Groups with zero repeats can of course be empty; skip them. */
+
+  if (c == OP_BRAZERO || c == OP_BRAMINZERO || c == OP_SKIPZERO)
+    {
+    code += _pcre_OP_lengths[c];
+    do code += GET(code, 1); while (*code == OP_ALT);
+    c = *code;
+    continue;
+    }
+
+  /* For other groups, scan the branches. */
+
+  if (c == OP_BRA || c == OP_CBRA || c == OP_ONCE || c == OP_COND)
+    {
+    BOOL empty_branch;
+    if (GET(code, 1) == 0) return TRUE;    /* Hit unclosed bracket */
+
+    /* Scan a closed bracket */
+
+    empty_branch = FALSE;
+    do
+      {
+      if (!empty_branch && could_be_empty_branch(code, endcode, utf8))
+        empty_branch = TRUE;
+      code += GET(code, 1);
+      }
+    while (*code == OP_ALT);
+    if (!empty_branch) return FALSE;   /* All branches are non-empty */
+    c = *code;
+    continue;
+    }
+
+  /* Handle the other opcodes */
+
+  switch (c)
+    {
+    /* Check for quantifiers after a class. XCLASS is used for classes that
+    cannot be represented just by a bit map. This includes negated single
+    high-valued characters. The length in _pcre_OP_lengths[] is zero; the
+    actual length is stored in the compiled code, so we must update "code"
+    here. */
+
+#ifdef SUPPORT_UTF8
+    case OP_XCLASS:
+    ccode = code += GET(code, 1);
+    goto CHECK_CLASS_REPEAT;
+#endif
+
+    case OP_CLASS:
+    case OP_NCLASS:
+    ccode = code + 33;
+
+#ifdef SUPPORT_UTF8
+    CHECK_CLASS_REPEAT:
+#endif
+
+    switch (*ccode)
+      {
+      case OP_CRSTAR:            /* These could be empty; continue */
+      case OP_CRMINSTAR:
+      case OP_CRQUERY:
+      case OP_CRMINQUERY:
+      break;
+
+      default:                   /* Non-repeat => class must match */
+      case OP_CRPLUS:            /* These repeats aren't empty */
+      case OP_CRMINPLUS:
+      return FALSE;
+
+      case OP_CRRANGE:
+      case OP_CRMINRANGE:
+      if (GET2(ccode, 1) > 0) return FALSE;  /* Minimum > 0 */
+      break;
+      }
+    break;
+
+    /* Opcodes that must match a character */
+
+    case OP_PROP:
+    case OP_NOTPROP:
+    case OP_EXTUNI:
+    case OP_NOT_DIGIT:
+    case OP_DIGIT:
+    case OP_NOT_WHITESPACE:
+    case OP_WHITESPACE:
+    case OP_NOT_WORDCHAR:
+    case OP_WORDCHAR:
+    case OP_ANY:
+    case OP_ALLANY:
+    case OP_ANYBYTE:
+    case OP_CHAR:
+    case OP_CHARNC:
+    case OP_NOT:
+    case OP_PLUS:
+    case OP_MINPLUS:
+    case OP_POSPLUS:
+    case OP_EXACT:
+    case OP_NOTPLUS:
+    case OP_NOTMINPLUS:
+    case OP_NOTPOSPLUS:
+    case OP_NOTEXACT:
+    case OP_TYPEPLUS:
+    case OP_TYPEMINPLUS:
+    case OP_TYPEPOSPLUS:
+    case OP_TYPEEXACT:
+    return FALSE;
+
+    /* These are going to continue, as they may be empty, but we have to
+    fudge the length for the \p and \P cases. */
+
+    case OP_TYPESTAR:
+    case OP_TYPEMINSTAR:
+    case OP_TYPEPOSSTAR:
+    case OP_TYPEQUERY:
+    case OP_TYPEMINQUERY:
+    case OP_TYPEPOSQUERY:
+    if (code[1] == OP_PROP || code[1] == OP_NOTPROP) code += 2;
+    break;
+
+    /* Same for these */
+
+    case OP_TYPEUPTO:
+    case OP_TYPEMINUPTO:
+    case OP_TYPEPOSUPTO:
+    if (code[3] == OP_PROP || code[3] == OP_NOTPROP) code += 2;
+    break;
+
+    /* End of branch */
+
+    case OP_KET:
+    case OP_KETRMAX:
+    case OP_KETRMIN:
+    case OP_ALT:
+    return TRUE;
+
+    /* In UTF-8 mode, STAR, MINSTAR, POSSTAR, QUERY, MINQUERY, POSQUERY, UPTO,
+    MINUPTO, and POSUPTO may be followed by a multibyte character */
+
+#ifdef SUPPORT_UTF8
+    case OP_STAR:
+    case OP_MINSTAR:
+    case OP_POSSTAR:
+    case OP_QUERY:
+    case OP_MINQUERY:
+    case OP_POSQUERY:
+    case OP_UPTO:
+    case OP_MINUPTO:
+    case OP_POSUPTO:
+    if (utf8) while ((code[2] & 0xc0) == 0x80) code++;
+    break;
+#endif
+    }
+  }
+
+return TRUE;
+}
+
+
+
+/*************************************************
+*    Scan compiled regex for non-emptiness       *
+*************************************************/
+
+/* This function is called to check for left recursive calls. We want to check
+the current branch of the current pattern to see if it could match the empty
+string. If it could, we must look outwards for branches at other levels,
+stopping when we pass beyond the bracket which is the subject of the recursion.
+
+Arguments:
+  code        points to start of the recursion
+  endcode     points to where to stop (current RECURSE item)
+  bcptr       points to the chain of current (unclosed) branch starts
+  utf8        TRUE if in UTF-8 mode
+
+Returns:      TRUE if what is matched could be empty
+*/
+
+static BOOL
+could_be_empty(const uschar *code, const uschar *endcode, branch_chain *bcptr,
+  BOOL utf8)
+{
+while (bcptr != NULL && bcptr->current >= code)
+  {
+  if (!could_be_empty_branch(bcptr->current, endcode, utf8)) return FALSE;
+  bcptr = bcptr->outer;
+  }
+return TRUE;
+}
+
+
+
+/*************************************************
+*           Check for POSIX class syntax         *
+*************************************************/
+
+/* This function is called when the sequence "[:" or "[." or "[=" is
+encountered in a character class. It checks whether this is followed by a
+sequence of characters terminated by a matching ":]" or ".]" or "=]". If we
+reach an unescaped ']' without the special preceding character, return FALSE.
+
+Originally, this function only recognized a sequence of letters between the
+terminators, but it seems that Perl recognizes any sequence of characters,
+though of course unknown POSIX names are subsequently rejected. Perl gives an
+"Unknown POSIX class" error for [:f\oo:] for example, where previously PCRE
+didn't consider this to be a POSIX class. Likewise for [:1234:].
+
+The problem in trying to be exactly like Perl is in the handling of escapes. We
+have to be sure that [abc[:x\]pqr] is *not* treated as containing a POSIX
+class, but [abc[:x\]pqr:]] is (so that an error can be generated). The code
+below handles the special case of \], but does not try to do any other escape
+processing. This makes it different from Perl for cases such as [:l\ower:]
+where Perl recognizes it as the POSIX class "lower" but PCRE does not recognize
+"l\ower". This is a lesser evil that not diagnosing bad classes when Perl does,
+I think.
+
+Arguments:
+  ptr      pointer to the initial [
+  endptr   where to return the end pointer
+
+Returns:   TRUE or FALSE
+*/
+
+static BOOL
+check_posix_syntax(const uschar *ptr, const uschar **endptr)
+{
+int terminator;          /* Don't combine these lines; the Solaris cc */
+terminator = *(++ptr);   /* compiler warns about "non-constant" initializer. */
+for (++ptr; *ptr != 0; ptr++)
+  {
+  if (*ptr == '\\' && ptr[1] == ']') ptr++; else
+    {
+    if (*ptr == ']') return FALSE;
+    if (*ptr == terminator && ptr[1] == ']')
+      {
+      *endptr = ptr;
+      return TRUE;
+      }
+    }
+  }
+return FALSE;
+}
+
+
+
+
+/*************************************************
+*          Check POSIX class name                *
+*************************************************/
+
+/* This function is called to check the name given in a POSIX-style class entry
+such as [:alnum:].
+
+Arguments:
+  ptr        points to the first letter
+  len        the length of the name
+
+Returns:     a value representing the name, or -1 if unknown
+*/
+
+static int
+check_posix_name(const uschar *ptr, int len)
+{
+const char *pn = posix_names;
+register int yield = 0;
+while (posix_name_lengths[yield] != 0)
+  {
+  if (len == posix_name_lengths[yield] &&
+    strncmp((const char *)ptr, pn, len) == 0) return yield;
+  pn += posix_name_lengths[yield] + 1;
+  yield++;
+  }
+return -1;
+}
+
+
+/*************************************************
+*    Adjust OP_RECURSE items in repeated group   *
+*************************************************/
+
+/* OP_RECURSE items contain an offset from the start of the regex to the group
+that is referenced. This means that groups can be replicated for fixed
+repetition simply by copying (because the recursion is allowed to refer to
+earlier groups that are outside the current group). However, when a group is
+optional (i.e. the minimum quantifier is zero), OP_BRAZERO or OP_SKIPZERO is
+inserted before it, after it has been compiled. This means that any OP_RECURSE
+items within it that refer to the group itself or any contained groups have to
+have their offsets adjusted. That one of the jobs of this function. Before it
+is called, the partially compiled regex must be temporarily terminated with
+OP_END.
+
+This function has been extended with the possibility of forward references for
+recursions and subroutine calls. It must also check the list of such references
+for the group we are dealing with. If it finds that one of the recursions in
+the current group is on this list, it adjusts the offset in the list, not the
+value in the reference (which is a group number).
+
+Arguments:
+  group      points to the start of the group
+  adjust     the amount by which the group is to be moved
+  utf8       TRUE in UTF-8 mode
+  cd         contains pointers to tables etc.
+  save_hwm   the hwm forward reference pointer at the start of the group
+
+Returns:     nothing
+*/
+
+static void
+adjust_recurse(uschar *group, int adjust, BOOL utf8, compile_data *cd,
+  uschar *save_hwm)
+{
+uschar *ptr = group;
+
+while ((ptr = (uschar *)find_recurse(ptr, utf8)) != NULL)
+  {
+  int offset;
+  uschar *hc;
+
+  /* See if this recursion is on the forward reference list. If so, adjust the
+  reference. */
+
+  for (hc = save_hwm; hc < cd->hwm; hc += LINK_SIZE)
+    {
+    offset = GET(hc, 0);
+    if (cd->start_code + offset == ptr + 1)
+      {
+      PUT(hc, 0, offset + adjust);
+      break;
+      }
+    }
+
+  /* Otherwise, adjust the recursion offset if it's after the start of this
+  group. */
+
+  if (hc >= cd->hwm)
+    {
+    offset = GET(ptr, 1);
+    if (cd->start_code + offset >= group) PUT(ptr, 1, offset + adjust);
+    }
+
+  ptr += 1 + LINK_SIZE;
+  }
+}
+
+
+
+/*************************************************
+*        Insert an automatic callout point       *
+*************************************************/
+
+/* This function is called when the PCRE_AUTO_CALLOUT option is set, to insert
+callout points before each pattern item.
+
+Arguments:
+  code           current code pointer
+  ptr            current pattern pointer
+  cd             pointers to tables etc
+
+Returns:         new code pointer
+*/
+
+static uschar *
+auto_callout(uschar *code, const uschar *ptr, compile_data *cd)
+{
+*code++ = OP_CALLOUT;
+*code++ = 255;
+PUT(code, 0, ptr - cd->start_pattern);  /* Pattern offset */
+PUT(code, LINK_SIZE, 0);                /* Default length */
+return code + 2*LINK_SIZE;
+}
+
+
+
+/*************************************************
+*         Complete a callout item                *
+*************************************************/
+
+/* A callout item contains the length of the next item in the pattern, which
+we can't fill in till after we have reached the relevant point. This is used
+for both automatic and manual callouts.
+
+Arguments:
+  previous_callout   points to previous callout item
+  ptr                current pattern pointer
+  cd                 pointers to tables etc
+
+Returns:             nothing
+*/
+
+static void
+complete_callout(uschar *previous_callout, const uschar *ptr, compile_data *cd)
+{
+int length = ptr - cd->start_pattern - GET(previous_callout, 2);
+PUT(previous_callout, 2 + LINK_SIZE, length);
+}
+
+
+
+#ifdef SUPPORT_UCP
+/*************************************************
+*           Get othercase range                  *
+*************************************************/
+
+/* This function is passed the start and end of a class range, in UTF-8 mode
+with UCP support. It searches up the characters, looking for internal ranges of
+characters in the "other" case. Each call returns the next one, updating the
+start address.
+
+Arguments:
+  cptr        points to starting character value; updated
+  d           end value
+  ocptr       where to put start of othercase range
+  odptr       where to put end of othercase range
+
+Yield:        TRUE when range returned; FALSE when no more
+*/
+
+static BOOL
+get_othercase_range(unsigned int *cptr, unsigned int d, unsigned int *ocptr,
+  unsigned int *odptr)
+{
+unsigned int c, othercase, next;
+
+for (c = *cptr; c <= d; c++)
+  { if ((othercase = UCD_OTHERCASE(c)) != c) break; }
+
+if (c > d) return FALSE;
+
+*ocptr = othercase;
+next = othercase + 1;
+
+for (++c; c <= d; c++)
+  {
+  if (UCD_OTHERCASE(c) != next) break;
+  next++;
+  }
+
+*odptr = next - 1;
+*cptr = c;
+
+return TRUE;
+}
+#endif  /* SUPPORT_UCP */
+
+
+
+/*************************************************
+*     Check if auto-possessifying is possible    *
+*************************************************/
+
+/* This function is called for unlimited repeats of certain items, to see
+whether the next thing could possibly match the repeated item. If not, it makes
+sense to automatically possessify the repeated item.
+
+Arguments:
+  op_code       the repeated op code
+  this          data for this item, depends on the opcode
+  utf8          TRUE in UTF-8 mode
+  utf8_char     used for utf8 character bytes, NULL if not relevant
+  ptr           next character in pattern
+  options       options bits
+  cd            contains pointers to tables etc.
+
+Returns:        TRUE if possessifying is wanted
+*/
+
+static BOOL
+check_auto_possessive(int op_code, int item, BOOL utf8, uschar *utf8_char,
+  const uschar *ptr, int options, compile_data *cd)
+{
+int next;
+
+/* Skip whitespace and comments in extended mode */
+
+if ((options & PCRE_EXTENDED) != 0)
+  {
+  for (;;)
+    {
+    while ((cd->ctypes[*ptr] & ctype_space) != 0) ptr++;
+    if (*ptr == '#')
+      {
+      while (*(++ptr) != 0)
+        if (IS_NEWLINE(ptr)) { ptr += cd->nllen; break; }
+      }
+    else break;
+    }
+  }
+
+/* If the next item is one that we can handle, get its value. A non-negative
+value is a character, a negative value is an escape value. */
+
+if (*ptr == '\\')
+  {
+  int temperrorcode = 0;
+  next = check_escape(&ptr, &temperrorcode, cd->bracount, options, FALSE);
+  if (temperrorcode != 0) return FALSE;
+  ptr++;    /* Point after the escape sequence */
+  }
+
+else if ((cd->ctypes[*ptr] & ctype_meta) == 0)
+  {
+#ifdef SUPPORT_UTF8
+  if (utf8) { GETCHARINC(next, ptr); } else
+#endif
+  next = *ptr++;
+  }
+
+else return FALSE;
+
+/* Skip whitespace and comments in extended mode */
+
+if ((options & PCRE_EXTENDED) != 0)
+  {
+  for (;;)
+    {
+    while ((cd->ctypes[*ptr] & ctype_space) != 0) ptr++;
+    if (*ptr == '#')
+      {
+      while (*(++ptr) != 0)
+        if (IS_NEWLINE(ptr)) { ptr += cd->nllen; break; }
+      }
+    else break;
+    }
+  }
+
+/* If the next thing is itself optional, we have to give up. */
+
+if (*ptr == '*' || *ptr == '?' || strncmp((char *)ptr, "{0,", 3) == 0)
+  return FALSE;
+
+/* Now compare the next item with the previous opcode. If the previous is a
+positive single character match, "item" either contains the character or, if
+"item" is greater than 127 in utf8 mode, the character's bytes are in
+utf8_char. */
+
+
+/* Handle cases when the next item is a character. */
+
+if (next >= 0) switch(op_code)
+  {
+  case OP_CHAR:
+#ifdef SUPPORT_UTF8
+  if (utf8 && item > 127) { GETCHAR(item, utf8_char); }
+#else
+  (void)(utf8_char);  /* Keep compiler happy by referencing function argument */
+#endif
+  return item != next;
+
+  /* For CHARNC (caseless character) we must check the other case. If we have
+  Unicode property support, we can use it to test the other case of
+  high-valued characters. */
+
+  case OP_CHARNC:
+#ifdef SUPPORT_UTF8
+  if (utf8 && item > 127) { GETCHAR(item, utf8_char); }
+#endif
+  if (item == next) return FALSE;
+#ifdef SUPPORT_UTF8
+  if (utf8)
+    {
+    unsigned int othercase;
+    if (next < 128) othercase = cd->fcc[next]; else
+#ifdef SUPPORT_UCP
+    othercase = UCD_OTHERCASE((unsigned int)next);
+#else
+    othercase = NOTACHAR;
+#endif
+    return (unsigned int)item != othercase;
+    }
+  else
+#endif  /* SUPPORT_UTF8 */
+  return (item != cd->fcc[next]);  /* Non-UTF-8 mode */
+
+  /* For OP_NOT, "item" must be a single-byte character. */
+
+  case OP_NOT:
+  if (item == next) return TRUE;
+  if ((options & PCRE_CASELESS) == 0) return FALSE;
+#ifdef SUPPORT_UTF8
+  if (utf8)
+    {
+    unsigned int othercase;
+    if (next < 128) othercase = cd->fcc[next]; else
+#ifdef SUPPORT_UCP
+    othercase = UCD_OTHERCASE(next);
+#else
+    othercase = NOTACHAR;
+#endif
+    return (unsigned int)item == othercase;
+    }
+  else
+#endif  /* SUPPORT_UTF8 */
+  return (item == cd->fcc[next]);  /* Non-UTF-8 mode */
+
+  case OP_DIGIT:
+  return next > 127 || (cd->ctypes[next] & ctype_digit) == 0;
+
+  case OP_NOT_DIGIT:
+  return next <= 127 && (cd->ctypes[next] & ctype_digit) != 0;
+
+  case OP_WHITESPACE:
+  return next > 127 || (cd->ctypes[next] & ctype_space) == 0;
+
+  case OP_NOT_WHITESPACE:
+  return next <= 127 && (cd->ctypes[next] & ctype_space) != 0;
+
+  case OP_WORDCHAR:
+  return next > 127 || (cd->ctypes[next] & ctype_word) == 0;
+
+  case OP_NOT_WORDCHAR:
+  return next <= 127 && (cd->ctypes[next] & ctype_word) != 0;
+
+  case OP_HSPACE:
+  case OP_NOT_HSPACE:
+  switch(next)
+    {
+    case 0x09:
+    case 0x20:
+    case 0xa0:
+    case 0x1680:
+    case 0x180e:
+    case 0x2000:
+    case 0x2001:
+    case 0x2002:
+    case 0x2003:
+    case 0x2004:
+    case 0x2005:
+    case 0x2006:
+    case 0x2007:
+    case 0x2008:
+    case 0x2009:
+    case 0x200A:
+    case 0x202f:
+    case 0x205f:
+    case 0x3000:
+    return op_code != OP_HSPACE;
+    default:
+    return op_code == OP_HSPACE;
+    }
+
+  case OP_VSPACE:
+  case OP_NOT_VSPACE:
+  switch(next)
+    {
+    case 0x0a:
+    case 0x0b:
+    case 0x0c:
+    case 0x0d:
+    case 0x85:
+    case 0x2028:
+    case 0x2029:
+    return op_code != OP_VSPACE;
+    default:
+    return op_code == OP_VSPACE;
+    }
+
+  default:
+  return FALSE;
+  }
+
+
+/* Handle the case when the next item is \d, \s, etc. */
+
+switch(op_code)
+  {
+  case OP_CHAR:
+  case OP_CHARNC:
+#ifdef SUPPORT_UTF8
+  if (utf8 && item > 127) { GETCHAR(item, utf8_char); }
+#endif
+  switch(-next)
+    {
+    case ESC_d:
+    return item > 127 || (cd->ctypes[item] & ctype_digit) == 0;
+
+    case ESC_D:
+    return item <= 127 && (cd->ctypes[item] & ctype_digit) != 0;
+
+    case ESC_s:
+    return item > 127 || (cd->ctypes[item] & ctype_space) == 0;
+
+    case ESC_S:
+    return item <= 127 && (cd->ctypes[item] & ctype_space) != 0;
+
+    case ESC_w:
+    return item > 127 || (cd->ctypes[item] & ctype_word) == 0;
+
+    case ESC_W:
+    return item <= 127 && (cd->ctypes[item] & ctype_word) != 0;
+
+    case ESC_h:
+    case ESC_H:
+    switch(item)
+      {
+      case 0x09:
+      case 0x20:
+      case 0xa0:
+      case 0x1680:
+      case 0x180e:
+      case 0x2000:
+      case 0x2001:
+      case 0x2002:
+      case 0x2003:
+      case 0x2004:
+      case 0x2005:
+      case 0x2006:
+      case 0x2007:
+      case 0x2008:
+      case 0x2009:
+      case 0x200A:
+      case 0x202f:
+      case 0x205f:
+      case 0x3000:
+      return -next != ESC_h;
+      default:
+      return -next == ESC_h;
+      }
+
+    case ESC_v:
+    case ESC_V:
+    switch(item)
+      {
+      case 0x0a:
+      case 0x0b:
+      case 0x0c:
+      case 0x0d:
+      case 0x85:
+      case 0x2028:
+      case 0x2029:
+      return -next != ESC_v;
+      default:
+      return -next == ESC_v;
+      }
+
+    default:
+    return FALSE;
+    }
+
+  case OP_DIGIT:
+  return next == -ESC_D || next == -ESC_s || next == -ESC_W ||
+         next == -ESC_h || next == -ESC_v;
+
+  case OP_NOT_DIGIT:
+  return next == -ESC_d;
+
+  case OP_WHITESPACE:
+  return next == -ESC_S || next == -ESC_d || next == -ESC_w;
+
+  case OP_NOT_WHITESPACE:
+  return next == -ESC_s || next == -ESC_h || next == -ESC_v;
+
+  case OP_HSPACE:
+  return next == -ESC_S || next == -ESC_H || next == -ESC_d || next == -ESC_w;
+
+  case OP_NOT_HSPACE:
+  return next == -ESC_h;
+
+  /* Can't have \S in here because VT matches \S (Perl anomaly) */
+  case OP_VSPACE:
+  return next == -ESC_V || next == -ESC_d || next == -ESC_w;
+
+  case OP_NOT_VSPACE:
+  return next == -ESC_v;
+
+  case OP_WORDCHAR:
+  return next == -ESC_W || next == -ESC_s || next == -ESC_h || next == -ESC_v;
+
+  case OP_NOT_WORDCHAR:
+  return next == -ESC_w || next == -ESC_d;
+
+  default:
+  return FALSE;
+  }
+
+/* Control does not reach here */
+}
+
+
+
+/*************************************************
+*           Compile one branch                   *
+*************************************************/
+
+/* Scan the pattern, compiling it into the a vector. If the options are
+changed during the branch, the pointer is used to change the external options
+bits. This function is used during the pre-compile phase when we are trying
+to find out the amount of memory needed, as well as during the real compile
+phase. The value of lengthptr distinguishes the two phases.
+
+Arguments:
+  optionsptr     pointer to the option bits
+  codeptr        points to the pointer to the current code point
+  ptrptr         points to the current pattern pointer
+  errorcodeptr   points to error code variable
+  firstbyteptr   set to initial literal character, or < 0 (REQ_UNSET, REQ_NONE)
+  reqbyteptr     set to the last literal character required, else < 0
+  bcptr          points to current branch chain
+  cd             contains pointers to tables etc.
+  lengthptr      NULL during the real compile phase
+                 points to length accumulator during pre-compile phase
+
+Returns:         TRUE on success
+                 FALSE, with *errorcodeptr set non-zero on error
+*/
+
+static BOOL
+compile_branch(int *optionsptr, uschar **codeptr, const uschar **ptrptr,
+  int *errorcodeptr, int *firstbyteptr, int *reqbyteptr, branch_chain *bcptr,
+  compile_data *cd, int *lengthptr)
+{
+int repeat_type, op_type;
+int repeat_min = 0, repeat_max = 0;      /* To please picky compilers */
+int bravalue = 0;
+int greedy_default, greedy_non_default;
+int firstbyte, reqbyte;
+int zeroreqbyte, zerofirstbyte;
+int req_caseopt, reqvary, tempreqvary;
+int options = *optionsptr;
+int after_manual_callout = 0;
+int length_prevgroup = 0;
+register int c;
+register uschar *code = *codeptr;
+uschar *last_code = code;
+uschar *orig_code = code;
+uschar *tempcode;
+BOOL inescq = FALSE;
+BOOL groupsetfirstbyte = FALSE;
+const uschar *ptr = *ptrptr;
+const uschar *tempptr;
+uschar *previous = NULL;
+uschar *previous_callout = NULL;
+uschar *save_hwm = NULL;
+uschar classbits[32];
+
+#ifdef SUPPORT_UTF8
+BOOL class_utf8;
+BOOL utf8 = (options & PCRE_UTF8) != 0;
+uschar *class_utf8data;
+uschar *class_utf8data_base;
+uschar utf8_char[6];
+#else
+BOOL utf8 = FALSE;
+uschar *utf8_char = NULL;
+#endif
+
+#ifdef DEBUG
+if (lengthptr != NULL) DPRINTF((">> start branch\n"));
+#endif
+
+/* Set up the default and non-default settings for greediness */
+
+greedy_default = ((options & PCRE_UNGREEDY) != 0);
+greedy_non_default = greedy_default ^ 1;
+
+/* Initialize no first byte, no required byte. REQ_UNSET means "no char
+matching encountered yet". It gets changed to REQ_NONE if we hit something that
+matches a non-fixed char first char; reqbyte just remains unset if we never
+find one.
+
+When we hit a repeat whose minimum is zero, we may have to adjust these values
+to take the zero repeat into account. This is implemented by setting them to
+zerofirstbyte and zeroreqbyte when such a repeat is encountered. The individual
+item types that can be repeated set these backoff variables appropriately. */
+
+firstbyte = reqbyte = zerofirstbyte = zeroreqbyte = REQ_UNSET;
+
+/* The variable req_caseopt contains either the REQ_CASELESS value or zero,
+according to the current setting of the caseless flag. REQ_CASELESS is a bit
+value > 255. It is added into the firstbyte or reqbyte variables to record the
+case status of the value. This is used only for ASCII characters. */
+
+req_caseopt = ((options & PCRE_CASELESS) != 0)? REQ_CASELESS : 0;
+
+/* Switch on next character until the end of the branch */
+
+for (;; ptr++)
+  {
+  BOOL negate_class;
+  BOOL should_flip_negation;
+  BOOL possessive_quantifier;
+  BOOL is_quantifier;
+  BOOL is_recurse;
+  BOOL reset_bracount;
+  int class_charcount;
+  int class_lastchar;
+  int newoptions;
+  int recno;
+  int refsign;
+  int skipbytes;
+  int subreqbyte;
+  int subfirstbyte;
+  int terminator;
+  int mclength;
+  uschar mcbuffer[8];
+
+  /* Get next byte in the pattern */
+
+  c = *ptr;
+
+  /* If we are in the pre-compile phase, accumulate the length used for the
+  previous cycle of this loop. */
+
+  if (lengthptr != NULL)
+    {
+#ifdef DEBUG
+    if (code > cd->hwm) cd->hwm = code;                 /* High water info */
+#endif
+    if (code > cd->start_workspace + COMPILE_WORK_SIZE) /* Check for overrun */
+      {
+      *errorcodeptr = ERR52;
+      goto FAILED;
+      }
+
+    /* There is at least one situation where code goes backwards: this is the
+    case of a zero quantifier after a class (e.g. [ab]{0}). At compile time,
+    the class is simply eliminated. However, it is created first, so we have to
+    allow memory for it. Therefore, don't ever reduce the length at this point.
+    */
+
+    if (code < last_code) code = last_code;
+
+    /* Paranoid check for integer overflow */
+
+    if (OFLOW_MAX - *lengthptr < code - last_code)
+      {
+      *errorcodeptr = ERR20;
+      goto FAILED;
+      }
+
+    *lengthptr += code - last_code;
+    DPRINTF(("length=%d added %d c=%c\n", *lengthptr, code - last_code, c));
+
+    /* If "previous" is set and it is not at the start of the work space, move
+    it back to there, in order to avoid filling up the work space. Otherwise,
+    if "previous" is NULL, reset the current code pointer to the start. */
+
+    if (previous != NULL)
+      {
+      if (previous > orig_code)
+        {
+        memmove(orig_code, previous, code - previous);
+        code -= previous - orig_code;
+        previous = orig_code;
+        }
+      }
+    else code = orig_code;
+
+    /* Remember where this code item starts so we can pick up the length
+    next time round. */
+
+    last_code = code;
+    }
+
+  /* In the real compile phase, just check the workspace used by the forward
+  reference list. */
+
+  else if (cd->hwm > cd->start_workspace + COMPILE_WORK_SIZE)
+    {
+    *errorcodeptr = ERR52;
+    goto FAILED;
+    }
+
+  /* If in \Q...\E, check for the end; if not, we have a literal */
+
+  if (inescq && c != 0)
+    {
+    if (c == '\\' && ptr[1] == 'E')
+      {
+      inescq = FALSE;
+      ptr++;
+      continue;
+      }
+    else
+      {
+      if (previous_callout != NULL)
+        {
+        if (lengthptr == NULL)  /* Don't attempt in pre-compile phase */
+          complete_callout(previous_callout, ptr, cd);
+        previous_callout = NULL;
+        }
+      if ((options & PCRE_AUTO_CALLOUT) != 0)
+        {
+        previous_callout = code;
+        code = auto_callout(code, ptr, cd);
+        }
+      goto NORMAL_CHAR;
+      }
+    }
+
+  /* Fill in length of a previous callout, except when the next thing is
+  a quantifier. */
+
+  is_quantifier = c == '*' || c == '+' || c == '?' ||
+    (c == '{' && is_counted_repeat(ptr+1));
+
+  if (!is_quantifier && previous_callout != NULL &&
+       after_manual_callout-- <= 0)
+    {
+    if (lengthptr == NULL)      /* Don't attempt in pre-compile phase */
+      complete_callout(previous_callout, ptr, cd);
+    previous_callout = NULL;
+    }
+
+  /* In extended mode, skip white space and comments */
+
+  if ((options & PCRE_EXTENDED) != 0)
+    {
+    if ((cd->ctypes[c] & ctype_space) != 0) continue;
+    if (c == '#')
+      {
+      while (*(++ptr) != 0)
+        {
+        if (IS_NEWLINE(ptr)) { ptr += cd->nllen - 1; break; }
+        }
+      if (*ptr != 0) continue;
+
+      /* Else fall through to handle end of string */
+      c = 0;
+      }
+    }
+
+  /* No auto callout for quantifiers. */
+
+  if ((options & PCRE_AUTO_CALLOUT) != 0 && !is_quantifier)
+    {
+    previous_callout = code;
+    code = auto_callout(code, ptr, cd);
+    }
+
+  switch(c)
+    {
+    /* ===================================================================*/
+    case 0:                        /* The branch terminates at string end */
+    case '|':                      /* or | or ) */
+    case ')':
+    *firstbyteptr = firstbyte;
+    *reqbyteptr = reqbyte;
+    *codeptr = code;
+    *ptrptr = ptr;
+    if (lengthptr != NULL)
+      {
+      if (OFLOW_MAX - *lengthptr < code - last_code)
+        {
+        *errorcodeptr = ERR20;
+        goto FAILED;
+        }
+      *lengthptr += code - last_code;   /* To include callout length */
+      DPRINTF((">> end branch\n"));
+      }
+    return TRUE;
+
+
+    /* ===================================================================*/
+    /* Handle single-character metacharacters. In multiline mode, ^ disables
+    the setting of any following char as a first character. */
+
+    case '^':
+    if ((options & PCRE_MULTILINE) != 0)
+      {
+      if (firstbyte == REQ_UNSET) firstbyte = REQ_NONE;
+      }
+    previous = NULL;
+    *code++ = OP_CIRC;
+    break;
+
+    case '$':
+    previous = NULL;
+    *code++ = OP_DOLL;
+    break;
+
+    /* There can never be a first char if '.' is first, whatever happens about
+    repeats. The value of reqbyte doesn't change either. */
+
+    case '.':
+    if (firstbyte == REQ_UNSET) firstbyte = REQ_NONE;
+    zerofirstbyte = firstbyte;
+    zeroreqbyte = reqbyte;
+    previous = code;
+    *code++ = ((options & PCRE_DOTALL) != 0)? OP_ALLANY: OP_ANY;
+    break;
+
+
+    /* ===================================================================*/
+    /* Character classes. If the included characters are all < 256, we build a
+    32-byte bitmap of the permitted characters, except in the special case
+    where there is only one such character. For negated classes, we build the
+    map as usual, then invert it at the end. However, we use a different opcode
+    so that data characters > 255 can be handled correctly.
+
+    If the class contains characters outside the 0-255 range, a different
+    opcode is compiled. It may optionally have a bit map for characters < 256,
+    but those above are are explicitly listed afterwards. A flag byte tells
+    whether the bitmap is present, and whether this is a negated class or not.
+
+    In JavaScript compatibility mode, an isolated ']' causes an error. In
+    default (Perl) mode, it is treated as a data character. */
+
+    case ']':
+    if ((cd->external_options & PCRE_JAVASCRIPT_COMPAT) != 0)
+      {
+      *errorcodeptr = ERR64;
+      goto FAILED;
+      }
+    goto NORMAL_CHAR;
+
+    case '[':
+    previous = code;
+
+    /* PCRE supports POSIX class stuff inside a class. Perl gives an error if
+    they are encountered at the top level, so we'll do that too. */
+
+    if ((ptr[1] == ':' || ptr[1] == '.' || ptr[1] == '=') &&
+        check_posix_syntax(ptr, &tempptr))
+      {
+      *errorcodeptr = (ptr[1] == ':')? ERR13 : ERR31;
+      goto FAILED;
+      }
+
+    /* If the first character is '^', set the negation flag and skip it. Also,
+    if the first few characters (either before or after ^) are \Q\E or \E we
+    skip them too. This makes for compatibility with Perl. */
+
+    negate_class = FALSE;
+    for (;;)
+      {
+      c = *(++ptr);
+      if (c == '\\')
+        {
+        if (ptr[1] == 'E') ptr++;
+          else if (strncmp((const char *)ptr+1, "Q\\E", 3) == 0) ptr += 3;
+            else break;
+        }
+      else if (!negate_class && c == '^')
+        negate_class = TRUE;
+      else break;
+      }
+
+    /* Empty classes are allowed in JavaScript compatibility mode. Otherwise,
+    an initial ']' is taken as a data character -- the code below handles
+    that. In JS mode, [] must always fail, so generate OP_FAIL, whereas
+    [^] must match any character, so generate OP_ALLANY. */
+
+    if (c ==']' && (cd->external_options & PCRE_JAVASCRIPT_COMPAT) != 0)
+      {
+      *code++ = negate_class? OP_ALLANY : OP_FAIL;
+      if (firstbyte == REQ_UNSET) firstbyte = REQ_NONE;
+      zerofirstbyte = firstbyte;
+      break;
+      }
+
+    /* If a class contains a negative special such as \S, we need to flip the
+    negation flag at the end, so that support for characters > 255 works
+    correctly (they are all included in the class). */
+
+    should_flip_negation = FALSE;
+
+    /* Keep a count of chars with values < 256 so that we can optimize the case
+    of just a single character (as long as it's < 256). However, For higher
+    valued UTF-8 characters, we don't yet do any optimization. */
+
+    class_charcount = 0;
+    class_lastchar = -1;
+
+    /* Initialize the 32-char bit map to all zeros. We build the map in a
+    temporary bit of memory, in case the class contains only 1 character (less
+    than 256), because in that case the compiled code doesn't use the bit map.
+    */
+
+    memset(classbits, 0, 32 * sizeof(uschar));
+
+#ifdef SUPPORT_UTF8
+    class_utf8 = FALSE;                       /* No chars >= 256 */
+    class_utf8data = code + LINK_SIZE + 2;    /* For UTF-8 items */
+    class_utf8data_base = class_utf8data;     /* For resetting in pass 1 */
+#endif
+
+    /* Process characters until ] is reached. By writing this as a "do" it
+    means that an initial ] is taken as a data character. At the start of the
+    loop, c contains the first byte of the character. */
+
+    if (c != 0) do
+      {
+      const uschar *oldptr;
+
+#ifdef SUPPORT_UTF8
+      if (utf8 && c > 127)
+        {                           /* Braces are required because the */
+        GETCHARLEN(c, ptr, ptr);    /* macro generates multiple statements */
+        }
+
+      /* In the pre-compile phase, accumulate the length of any UTF-8 extra
+      data and reset the pointer. This is so that very large classes that
+      contain a zillion UTF-8 characters no longer overwrite the work space
+      (which is on the stack). */
+
+      if (lengthptr != NULL)
+        {
+        *lengthptr += class_utf8data - class_utf8data_base;
+        class_utf8data = class_utf8data_base;
+        }
+
+#endif
+
+      /* Inside \Q...\E everything is literal except \E */
+
+      if (inescq)
+        {
+        if (c == '\\' && ptr[1] == 'E')     /* If we are at \E */
+          {
+          inescq = FALSE;                   /* Reset literal state */
+          ptr++;                            /* Skip the 'E' */
+          continue;                         /* Carry on with next */
+          }
+        goto CHECK_RANGE;                   /* Could be range if \E follows */
+        }
+
+      /* Handle POSIX class names. Perl allows a negation extension of the
+      form [:^name:]. A square bracket that doesn't match the syntax is
+      treated as a literal. We also recognize the POSIX constructions
+      [.ch.] and [=ch=] ("collating elements") and fault them, as Perl
+      5.6 and 5.8 do. */
+
+      if (c == '[' &&
+          (ptr[1] == ':' || ptr[1] == '.' || ptr[1] == '=') &&
+          check_posix_syntax(ptr, &tempptr))
+        {
+        BOOL local_negate = FALSE;
+        int posix_class, taboffset, tabopt;
+        register const uschar *cbits = cd->cbits;
+        uschar pbits[32];
+
+        if (ptr[1] != ':')
+          {
+          *errorcodeptr = ERR31;
+          goto FAILED;
+          }
+
+        ptr += 2;
+        if (*ptr == '^')
+          {
+          local_negate = TRUE;
+          should_flip_negation = TRUE;  /* Note negative special */
+          ptr++;
+          }
+
+        posix_class = check_posix_name(ptr, tempptr - ptr);
+        if (posix_class < 0)
+          {
+          *errorcodeptr = ERR30;
+          goto FAILED;
+          }
+
+        /* If matching is caseless, upper and lower are converted to
+        alpha. This relies on the fact that the class table starts with
+        alpha, lower, upper as the first 3 entries. */
+
+        if ((options & PCRE_CASELESS) != 0 && posix_class <= 2)
+          posix_class = 0;
+
+        /* We build the bit map for the POSIX class in a chunk of local store
+        because we may be adding and subtracting from it, and we don't want to
+        subtract bits that may be in the main map already. At the end we or the
+        result into the bit map that is being built. */
+
+        posix_class *= 3;
+
+        /* Copy in the first table (always present) */
+
+        memcpy(pbits, cbits + posix_class_maps[posix_class],
+          32 * sizeof(uschar));
+
+        /* If there is a second table, add or remove it as required. */
+
+        taboffset = posix_class_maps[posix_class + 1];
+        tabopt = posix_class_maps[posix_class + 2];
+
+        if (taboffset >= 0)
+          {
+          if (tabopt >= 0)
+            for (c = 0; c < 32; c++) pbits[c] |= cbits[c + taboffset];
+          else
+            for (c = 0; c < 32; c++) pbits[c] &= ~cbits[c + taboffset];
+          }
+
+        /* Not see if we need to remove any special characters. An option
+        value of 1 removes vertical space and 2 removes underscore. */
+
+        if (tabopt < 0) tabopt = -tabopt;
+        if (tabopt == 1) pbits[1] &= ~0x3c;
+          else if (tabopt == 2) pbits[11] &= 0x7f;
+
+        /* Add the POSIX table or its complement into the main table that is
+        being built and we are done. */
+
+        if (local_negate)
+          for (c = 0; c < 32; c++) classbits[c] |= ~pbits[c];
+        else
+          for (c = 0; c < 32; c++) classbits[c] |= pbits[c];
+
+        ptr = tempptr + 1;
+        class_charcount = 10;  /* Set > 1; assumes more than 1 per class */
+        continue;    /* End of POSIX syntax handling */
+        }
+
+      /* Backslash may introduce a single character, or it may introduce one
+      of the specials, which just set a flag. The sequence \b is a special
+      case. Inside a class (and only there) it is treated as backspace.
+      Elsewhere it marks a word boundary. Other escapes have preset maps ready
+      to 'or' into the one we are building. We assume they have more than one
+      character in them, so set class_charcount bigger than one. */
+
+      if (c == '\\')
+        {
+        c = check_escape(&ptr, errorcodeptr, cd->bracount, options, TRUE);
+        if (*errorcodeptr != 0) goto FAILED;
+
+        if (-c == ESC_b) c = '\b';       /* \b is backspace in a class */
+        else if (-c == ESC_X) c = 'X';   /* \X is literal X in a class */
+        else if (-c == ESC_R) c = 'R';   /* \R is literal R in a class */
+        else if (-c == ESC_Q)            /* Handle start of quoted string */
+          {
+          if (ptr[1] == '\\' && ptr[2] == 'E')
+            {
+            ptr += 2; /* avoid empty string */
+            }
+          else inescq = TRUE;
+          continue;
+          }
+        else if (-c == ESC_E) continue;  /* Ignore orphan \E */
+
+        if (c < 0)
+          {
+          register const uschar *cbits = cd->cbits;
+          class_charcount += 2;     /* Greater than 1 is what matters */
+
+          /* Save time by not doing this in the pre-compile phase. */
+
+          if (lengthptr == NULL) switch (-c)
+            {
+            case ESC_d:
+            for (c = 0; c < 32; c++) classbits[c] |= cbits[c+cbit_digit];
+            continue;
+
+            case ESC_D:
+            should_flip_negation = TRUE;
+            for (c = 0; c < 32; c++) classbits[c] |= ~cbits[c+cbit_digit];
+            continue;
+
+            case ESC_w:
+            for (c = 0; c < 32; c++) classbits[c] |= cbits[c+cbit_word];
+            continue;
+
+            case ESC_W:
+            should_flip_negation = TRUE;
+            for (c = 0; c < 32; c++) classbits[c] |= ~cbits[c+cbit_word];
+            continue;
+
+            case ESC_s:
+            for (c = 0; c < 32; c++) classbits[c] |= cbits[c+cbit_space];
+            classbits[1] &= ~0x08;   /* Perl 5.004 onwards omits VT from \s */
+            continue;
+
+            case ESC_S:
+            should_flip_negation = TRUE;
+            for (c = 0; c < 32; c++) classbits[c] |= ~cbits[c+cbit_space];
+            classbits[1] |= 0x08;    /* Perl 5.004 onwards omits VT from \s */
+            continue;
+
+            default:    /* Not recognized; fall through */
+            break;      /* Need "default" setting to stop compiler warning. */
+            }
+
+          /* In the pre-compile phase, just do the recognition. */
+
+          else if (c == -ESC_d || c == -ESC_D || c == -ESC_w ||
+                   c == -ESC_W || c == -ESC_s || c == -ESC_S) continue;
+
+          /* We need to deal with \H, \h, \V, and \v in both phases because
+          they use extra memory. */
+
+          if (-c == ESC_h)
+            {
+            SETBIT(classbits, 0x09); /* VT */
+            SETBIT(classbits, 0x20); /* SPACE */
+            SETBIT(classbits, 0xa0); /* NSBP */
+#ifdef SUPPORT_UTF8
+            if (utf8)
+              {
+              class_utf8 = TRUE;
+              *class_utf8data++ = XCL_SINGLE;
+              class_utf8data += _pcre_ord2utf8(0x1680, class_utf8data);
+              *class_utf8data++ = XCL_SINGLE;
+              class_utf8data += _pcre_ord2utf8(0x180e, class_utf8data);
+              *class_utf8data++ = XCL_RANGE;
+              class_utf8data += _pcre_ord2utf8(0x2000, class_utf8data);
+              class_utf8data += _pcre_ord2utf8(0x200A, class_utf8data);
+              *class_utf8data++ = XCL_SINGLE;
+              class_utf8data += _pcre_ord2utf8(0x202f, class_utf8data);
+              *class_utf8data++ = XCL_SINGLE;
+              class_utf8data += _pcre_ord2utf8(0x205f, class_utf8data);
+              *class_utf8data++ = XCL_SINGLE;
+              class_utf8data += _pcre_ord2utf8(0x3000, class_utf8data);
+              }
+#endif
+            continue;
+            }
+
+          if (-c == ESC_H)
+            {
+            for (c = 0; c < 32; c++)
+              {
+              int x = 0xff;
+              switch (c)
+                {
+                case 0x09/8: x ^= 1 << (0x09%8); break;
+                case 0x20/8: x ^= 1 << (0x20%8); break;
+                case 0xa0/8: x ^= 1 << (0xa0%8); break;
+                default: break;
+                }
+              classbits[c] |= x;
+              }
+
+#ifdef SUPPORT_UTF8
+            if (utf8)
+              {
+              class_utf8 = TRUE;
+              *class_utf8data++ = XCL_RANGE;
+              class_utf8data += _pcre_ord2utf8(0x0100, class_utf8data);
+              class_utf8data += _pcre_ord2utf8(0x167f, class_utf8data);
+              *class_utf8data++ = XCL_RANGE;
+              class_utf8data += _pcre_ord2utf8(0x1681, class_utf8data);
+              class_utf8data += _pcre_ord2utf8(0x180d, class_utf8data);
+              *class_utf8data++ = XCL_RANGE;
+              class_utf8data += _pcre_ord2utf8(0x180f, class_utf8data);
+              class_utf8data += _pcre_ord2utf8(0x1fff, class_utf8data);
+              *class_utf8data++ = XCL_RANGE;
+              class_utf8data += _pcre_ord2utf8(0x200B, class_utf8data);
+              class_utf8data += _pcre_ord2utf8(0x202e, class_utf8data);
+              *class_utf8data++ = XCL_RANGE;
+              class_utf8data += _pcre_ord2utf8(0x2030, class_utf8data);
+              class_utf8data += _pcre_ord2utf8(0x205e, class_utf8data);
+              *class_utf8data++ = XCL_RANGE;
+              class_utf8data += _pcre_ord2utf8(0x2060, class_utf8data);
+              class_utf8data += _pcre_ord2utf8(0x2fff, class_utf8data);
+              *class_utf8data++ = XCL_RANGE;
+              class_utf8data += _pcre_ord2utf8(0x3001, class_utf8data);
+              class_utf8data += _pcre_ord2utf8(0x7fffffff, class_utf8data);
+              }
+#endif
+            continue;
+            }
+
+          if (-c == ESC_v)
+            {
+            SETBIT(classbits, 0x0a); /* LF */
+            SETBIT(classbits, 0x0b); /* VT */
+            SETBIT(classbits, 0x0c); /* FF */
+            SETBIT(classbits, 0x0d); /* CR */
+            SETBIT(classbits, 0x85); /* NEL */
+#ifdef SUPPORT_UTF8
+            if (utf8)
+              {
+              class_utf8 = TRUE;
+              *class_utf8data++ = XCL_RANGE;
+              class_utf8data += _pcre_ord2utf8(0x2028, class_utf8data);
+              class_utf8data += _pcre_ord2utf8(0x2029, class_utf8data);
+              }
+#endif
+            continue;
+            }
+
+          if (-c == ESC_V)
+            {
+            for (c = 0; c < 32; c++)
+              {
+              int x = 0xff;
+              switch (c)
+                {
+                case 0x0a/8: x ^= 1 << (0x0a%8);
+                             x ^= 1 << (0x0b%8);
+                             x ^= 1 << (0x0c%8);
+                             x ^= 1 << (0x0d%8);
+                             break;
+                case 0x85/8: x ^= 1 << (0x85%8); break;
+                default: break;
+                }
+              classbits[c] |= x;
+              }
+
+#ifdef SUPPORT_UTF8
+            if (utf8)
+              {
+              class_utf8 = TRUE;
+              *class_utf8data++ = XCL_RANGE;
+              class_utf8data += _pcre_ord2utf8(0x0100, class_utf8data);
+              class_utf8data += _pcre_ord2utf8(0x2027, class_utf8data);
+              *class_utf8data++ = XCL_RANGE;
+              class_utf8data += _pcre_ord2utf8(0x2029, class_utf8data);
+              class_utf8data += _pcre_ord2utf8(0x7fffffff, class_utf8data);
+              }
+#endif
+            continue;
+            }
+
+          /* We need to deal with \P and \p in both phases. */
+
+#ifdef SUPPORT_UCP
+          if (-c == ESC_p || -c == ESC_P)
+            {
+            BOOL negated;
+            int pdata;
+            int ptype = get_ucp(&ptr, &negated, &pdata, errorcodeptr);
+            if (ptype < 0) goto FAILED;
+            class_utf8 = TRUE;
+            *class_utf8data++ = ((-c == ESC_p) != negated)?
+              XCL_PROP : XCL_NOTPROP;
+            *class_utf8data++ = ptype;
+            *class_utf8data++ = pdata;
+            class_charcount -= 2;   /* Not a < 256 character */
+            continue;
+            }
+#endif
+          /* Unrecognized escapes are faulted if PCRE is running in its
+          strict mode. By default, for compatibility with Perl, they are
+          treated as literals. */
+
+          if ((options & PCRE_EXTRA) != 0)
+            {
+            *errorcodeptr = ERR7;
+            goto FAILED;
+            }
+
+          class_charcount -= 2;  /* Undo the default count from above */
+          c = *ptr;              /* Get the final character and fall through */
+          }
+
+        /* Fall through if we have a single character (c >= 0). This may be
+        greater than 256 in UTF-8 mode. */
+
+        }   /* End of backslash handling */
+
+      /* A single character may be followed by '-' to form a range. However,
+      Perl does not permit ']' to be the end of the range. A '-' character
+      at the end is treated as a literal. Perl ignores orphaned \E sequences
+      entirely. The code for handling \Q and \E is messy. */
+
+      CHECK_RANGE:
+      while (ptr[1] == '\\' && ptr[2] == 'E')
+        {
+        inescq = FALSE;
+        ptr += 2;
+        }
+
+      oldptr = ptr;
+
+      /* Remember \r or \n */
+
+      if (c == '\r' || c == '\n') cd->external_flags |= PCRE_HASCRORLF;
+
+      /* Check for range */
+
+      if (!inescq && ptr[1] == '-')
+        {
+        int d;
+        ptr += 2;
+        while (*ptr == '\\' && ptr[1] == 'E') ptr += 2;
+
+        /* If we hit \Q (not followed by \E) at this point, go into escaped
+        mode. */
+
+        while (*ptr == '\\' && ptr[1] == 'Q')
+          {
+          ptr += 2;
+          if (*ptr == '\\' && ptr[1] == 'E') { ptr += 2; continue; }
+          inescq = TRUE;
+          break;
+          }
+
+        if (*ptr == 0 || (!inescq && *ptr == ']'))
+          {
+          ptr = oldptr;
+          goto LONE_SINGLE_CHARACTER;
+          }
+
+#ifdef SUPPORT_UTF8
+        if (utf8)
+          {                           /* Braces are required because the */
+          GETCHARLEN(d, ptr, ptr);    /* macro generates multiple statements */
+          }
+        else
+#endif
+        d = *ptr;  /* Not UTF-8 mode */
+
+        /* The second part of a range can be a single-character escape, but
+        not any of the other escapes. Perl 5.6 treats a hyphen as a literal
+        in such circumstances. */
+
+        if (!inescq && d == '\\')
+          {
+          d = check_escape(&ptr, errorcodeptr, cd->bracount, options, TRUE);
+          if (*errorcodeptr != 0) goto FAILED;
+
+          /* \b is backspace; \X is literal X; \R is literal R; any other
+          special means the '-' was literal */
+
+          if (d < 0)
+            {
+            if (d == -ESC_b) d = '\b';
+            else if (d == -ESC_X) d = 'X';
+            else if (d == -ESC_R) d = 'R'; else
+              {
+              ptr = oldptr;
+              goto LONE_SINGLE_CHARACTER;  /* A few lines below */
+              }
+            }
+          }
+
+        /* Check that the two values are in the correct order. Optimize
+        one-character ranges */
+
+        if (d < c)
+          {
+          *errorcodeptr = ERR8;
+          goto FAILED;
+          }
+
+        if (d == c) goto LONE_SINGLE_CHARACTER;  /* A few lines below */
+
+        /* Remember \r or \n */
+
+        if (d == '\r' || d == '\n') cd->external_flags |= PCRE_HASCRORLF;
+
+        /* In UTF-8 mode, if the upper limit is > 255, or > 127 for caseless
+        matching, we have to use an XCLASS with extra data items. Caseless
+        matching for characters > 127 is available only if UCP support is
+        available. */
+
+#ifdef SUPPORT_UTF8
+        if (utf8 && (d > 255 || ((options & PCRE_CASELESS) != 0 && d > 127)))
+          {
+          class_utf8 = TRUE;
+
+          /* With UCP support, we can find the other case equivalents of
+          the relevant characters. There may be several ranges. Optimize how
+          they fit with the basic range. */
+
+#ifdef SUPPORT_UCP
+          if ((options & PCRE_CASELESS) != 0)
+            {
+            unsigned int occ, ocd;
+            unsigned int cc = c;
+            unsigned int origd = d;
+            while (get_othercase_range(&cc, origd, &occ, &ocd))
+              {
+              if (occ >= (unsigned int)c &&
+                  ocd <= (unsigned int)d)
+                continue;                          /* Skip embedded ranges */
+
+              if (occ < (unsigned int)c  &&
+                  ocd >= (unsigned int)c - 1)      /* Extend the basic range */
+                {                                  /* if there is overlap,   */
+                c = occ;                           /* noting that if occ < c */
+                continue;                          /* we can't have ocd > d  */
+                }                                  /* because a subrange is  */
+              if (ocd > (unsigned int)d &&
+                  occ <= (unsigned int)d + 1)      /* always shorter than    */
+                {                                  /* the basic range.       */
+                d = ocd;
+                continue;
+                }
+
+              if (occ == ocd)
+                {
+                *class_utf8data++ = XCL_SINGLE;
+                }
+              else
+                {
+                *class_utf8data++ = XCL_RANGE;
+                class_utf8data += _pcre_ord2utf8(occ, class_utf8data);
+                }
+              class_utf8data += _pcre_ord2utf8(ocd, class_utf8data);
+              }
+            }
+#endif  /* SUPPORT_UCP */
+
+          /* Now record the original range, possibly modified for UCP caseless
+          overlapping ranges. */
+
+          *class_utf8data++ = XCL_RANGE;
+          class_utf8data += _pcre_ord2utf8(c, class_utf8data);
+          class_utf8data += _pcre_ord2utf8(d, class_utf8data);
+
+          /* With UCP support, we are done. Without UCP support, there is no
+          caseless matching for UTF-8 characters > 127; we can use the bit map
+          for the smaller ones. */
+
+#ifdef SUPPORT_UCP
+          continue;    /* With next character in the class */
+#else
+          if ((options & PCRE_CASELESS) == 0 || c > 127) continue;
+
+          /* Adjust upper limit and fall through to set up the map */
+
+          d = 127;
+
+#endif  /* SUPPORT_UCP */
+          }
+#endif  /* SUPPORT_UTF8 */
+
+        /* We use the bit map for all cases when not in UTF-8 mode; else
+        ranges that lie entirely within 0-127 when there is UCP support; else
+        for partial ranges without UCP support. */
+
+        class_charcount += d - c + 1;
+        class_lastchar = d;
+
+        /* We can save a bit of time by skipping this in the pre-compile. */
+
+        if (lengthptr == NULL) for (; c <= d; c++)
+          {
+          classbits[c/8] |= (1 << (c&7));
+          if ((options & PCRE_CASELESS) != 0)
+            {
+            int uc = cd->fcc[c];           /* flip case */
+            classbits[uc/8] |= (1 << (uc&7));
+            }
+          }
+
+        continue;   /* Go get the next char in the class */
+        }
+
+      /* Handle a lone single character - we can get here for a normal
+      non-escape char, or after \ that introduces a single character or for an
+      apparent range that isn't. */
+
+      LONE_SINGLE_CHARACTER:
+
+      /* Handle a character that cannot go in the bit map */
+
+#ifdef SUPPORT_UTF8
+      if (utf8 && (c > 255 || ((options & PCRE_CASELESS) != 0 && c > 127)))
+        {
+        class_utf8 = TRUE;
+        *class_utf8data++ = XCL_SINGLE;
+        class_utf8data += _pcre_ord2utf8(c, class_utf8data);
+
+#ifdef SUPPORT_UCP
+        if ((options & PCRE_CASELESS) != 0)
+          {
+          unsigned int othercase;
+          if ((othercase = UCD_OTHERCASE(c)) != c)
+            {
+            *class_utf8data++ = XCL_SINGLE;
+            class_utf8data += _pcre_ord2utf8(othercase, class_utf8data);
+            }
+          }
+#endif  /* SUPPORT_UCP */
+
+        }
+      else
+#endif  /* SUPPORT_UTF8 */
+
+      /* Handle a single-byte character */
+        {
+        classbits[c/8] |= (1 << (c&7));
+        if ((options & PCRE_CASELESS) != 0)
+          {
+          c = cd->fcc[c];   /* flip case */
+          classbits[c/8] |= (1 << (c&7));
+          }
+        class_charcount++;
+        class_lastchar = c;
+        }
+      }
+
+    /* Loop until ']' reached. This "while" is the end of the "do" above. */
+
+    while ((c = *(++ptr)) != 0 && (c != ']' || inescq));
+
+    if (c == 0)                          /* Missing terminating ']' */
+      {
+      *errorcodeptr = ERR6;
+      goto FAILED;
+      }
+
+
+/* This code has been disabled because it would mean that \s counts as
+an explicit \r or \n reference, and that's not really what is wanted. Now
+we set the flag only if there is a literal "\r" or "\n" in the class. */
+
+#if 0
+    /* Remember whether \r or \n are in this class */
+
+    if (negate_class)
+      {
+      if ((classbits[1] & 0x24) != 0x24) cd->external_flags |= PCRE_HASCRORLF;
+      }
+    else
+      {
+      if ((classbits[1] & 0x24) != 0) cd->external_flags |= PCRE_HASCRORLF;
+      }
+#endif
+
+
+    /* If class_charcount is 1, we saw precisely one character whose value is
+    less than 256. As long as there were no characters >= 128 and there was no
+    use of \p or \P, in other words, no use of any XCLASS features, we can
+    optimize.
+
+    In UTF-8 mode, we can optimize the negative case only if there were no
+    characters >= 128 because OP_NOT and the related opcodes like OP_NOTSTAR
+    operate on single-bytes only. This is an historical hangover. Maybe one day
+    we can tidy these opcodes to handle multi-byte characters.
+
+    The optimization throws away the bit map. We turn the item into a
+    1-character OP_CHAR[NC] if it's positive, or OP_NOT if it's negative. Note
+    that OP_NOT does not support multibyte characters. In the positive case, it
+    can cause firstbyte to be set. Otherwise, there can be no first char if
+    this item is first, whatever repeat count may follow. In the case of
+    reqbyte, save the previous value for reinstating. */
+
+#ifdef SUPPORT_UTF8
+    if (class_charcount == 1 && !class_utf8 &&
+      (!utf8 || !negate_class || class_lastchar < 128))
+#else
+    if (class_charcount == 1)
+#endif
+      {
+      zeroreqbyte = reqbyte;
+
+      /* The OP_NOT opcode works on one-byte characters only. */
+
+      if (negate_class)
+        {
+        if (firstbyte == REQ_UNSET) firstbyte = REQ_NONE;
+        zerofirstbyte = firstbyte;
+        *code++ = OP_NOT;
+        *code++ = class_lastchar;
+        break;
+        }
+
+      /* For a single, positive character, get the value into mcbuffer, and
+      then we can handle this with the normal one-character code. */
+
+#ifdef SUPPORT_UTF8
+      if (utf8 && class_lastchar > 127)
+        mclength = _pcre_ord2utf8(class_lastchar, mcbuffer);
+      else
+#endif
+        {
+        mcbuffer[0] = class_lastchar;
+        mclength = 1;
+        }
+      goto ONE_CHAR;
+      }       /* End of 1-char optimization */
+
+    /* The general case - not the one-char optimization. If this is the first
+    thing in the branch, there can be no first char setting, whatever the
+    repeat count. Any reqbyte setting must remain unchanged after any kind of
+    repeat. */
+
+    if (firstbyte == REQ_UNSET) firstbyte = REQ_NONE;
+    zerofirstbyte = firstbyte;
+    zeroreqbyte = reqbyte;
+
+    /* If there are characters with values > 255, we have to compile an
+    extended class, with its own opcode, unless there was a negated special
+    such as \S in the class, because in that case all characters > 255 are in
+    the class, so any that were explicitly given as well can be ignored. If
+    (when there are explicit characters > 255 that must be listed) there are no
+    characters < 256, we can omit the bitmap in the actual compiled code. */
+
+#ifdef SUPPORT_UTF8
+    if (class_utf8 && !should_flip_negation)
+      {
+      *class_utf8data++ = XCL_END;    /* Marks the end of extra data */
+      *code++ = OP_XCLASS;
+      code += LINK_SIZE;
+      *code = negate_class? XCL_NOT : 0;
+
+      /* If the map is required, move up the extra data to make room for it;
+      otherwise just move the code pointer to the end of the extra data. */
+
+      if (class_charcount > 0)
+        {
+        *code++ |= XCL_MAP;
+        memmove(code + 32, code, class_utf8data - code);
+        memcpy(code, classbits, 32);
+        code = class_utf8data + 32;
+        }
+      else code = class_utf8data;
+
+      /* Now fill in the complete length of the item */
+
+      PUT(previous, 1, code - previous);
+      break;   /* End of class handling */
+      }
+#endif
+
+    /* If there are no characters > 255, set the opcode to OP_CLASS or
+    OP_NCLASS, depending on whether the whole class was negated and whether
+    there were negative specials such as \S in the class. Then copy the 32-byte
+    map into the code vector, negating it if necessary. */
+
+    *code++ = (negate_class == should_flip_negation) ? OP_CLASS : OP_NCLASS;
+    if (negate_class)
+      {
+      if (lengthptr == NULL)    /* Save time in the pre-compile phase */
+        for (c = 0; c < 32; c++) code[c] = ~classbits[c];
+      }
+    else
+      {
+      memcpy(code, classbits, 32);
+      }
+    code += 32;
+    break;
+
+
+    /* ===================================================================*/
+    /* Various kinds of repeat; '{' is not necessarily a quantifier, but this
+    has been tested above. */
+
+    case '{':
+    if (!is_quantifier) goto NORMAL_CHAR;
+    ptr = read_repeat_counts(ptr+1, &repeat_min, &repeat_max, errorcodeptr);
+    if (*errorcodeptr != 0) goto FAILED;
+    goto REPEAT;
+
+    case '*':
+    repeat_min = 0;
+    repeat_max = -1;
+    goto REPEAT;
+
+    case '+':
+    repeat_min = 1;
+    repeat_max = -1;
+    goto REPEAT;
+
+    case '?':
+    repeat_min = 0;
+    repeat_max = 1;
+
+    REPEAT:
+    if (previous == NULL)
+      {
+      *errorcodeptr = ERR9;
+      goto FAILED;
+      }
+
+    if (repeat_min == 0)
+      {
+      firstbyte = zerofirstbyte;    /* Adjust for zero repeat */
+      reqbyte = zeroreqbyte;        /* Ditto */
+      }
+
+    /* Remember whether this is a variable length repeat */
+
+    reqvary = (repeat_min == repeat_max)? 0 : REQ_VARY;
+
+    op_type = 0;                    /* Default single-char op codes */
+    possessive_quantifier = FALSE;  /* Default not possessive quantifier */
+
+    /* Save start of previous item, in case we have to move it up to make space
+    for an inserted OP_ONCE for the additional '+' extension. */
+
+    tempcode = previous;
+
+    /* If the next character is '+', we have a possessive quantifier. This
+    implies greediness, whatever the setting of the PCRE_UNGREEDY option.
+    If the next character is '?' this is a minimizing repeat, by default,
+    but if PCRE_UNGREEDY is set, it works the other way round. We change the
+    repeat type to the non-default. */
+
+    if (ptr[1] == '+')
+      {
+      repeat_type = 0;                  /* Force greedy */
+      possessive_quantifier = TRUE;
+      ptr++;
+      }
+    else if (ptr[1] == '?')
+      {
+      repeat_type = greedy_non_default;
+      ptr++;
+      }
+    else repeat_type = greedy_default;
+
+    /* If previous was a character match, abolish the item and generate a
+    repeat item instead. If a char item has a minumum of more than one, ensure
+    that it is set in reqbyte - it might not be if a sequence such as x{3} is
+    the first thing in a branch because the x will have gone into firstbyte
+    instead.  */
+
+    if (*previous == OP_CHAR || *previous == OP_CHARNC)
+      {
+      /* Deal with UTF-8 characters that take up more than one byte. It's
+      easier to write this out separately than try to macrify it. Use c to
+      hold the length of the character in bytes, plus 0x80 to flag that it's a
+      length rather than a small character. */
+
+#ifdef SUPPORT_UTF8
+      if (utf8 && (code[-1] & 0x80) != 0)
+        {
+        uschar *lastchar = code - 1;
+        while((*lastchar & 0xc0) == 0x80) lastchar--;
+        c = code - lastchar;            /* Length of UTF-8 character */
+        memcpy(utf8_char, lastchar, c); /* Save the char */
+        c |= 0x80;                      /* Flag c as a length */
+        }
+      else
+#endif
+
+      /* Handle the case of a single byte - either with no UTF8 support, or
+      with UTF-8 disabled, or for a UTF-8 character < 128. */
+
+        {
+        c = code[-1];
+        if (repeat_min > 1) reqbyte = c | req_caseopt | cd->req_varyopt;
+        }
+
+      /* If the repetition is unlimited, it pays to see if the next thing on
+      the line is something that cannot possibly match this character. If so,
+      automatically possessifying this item gains some performance in the case
+      where the match fails. */
+
+      if (!possessive_quantifier &&
+          repeat_max < 0 &&
+          check_auto_possessive(*previous, c, utf8, utf8_char, ptr + 1,
+            options, cd))
+        {
+        repeat_type = 0;    /* Force greedy */
+        possessive_quantifier = TRUE;
+        }
+
+      goto OUTPUT_SINGLE_REPEAT;   /* Code shared with single character types */
+      }
+
+    /* If previous was a single negated character ([^a] or similar), we use
+    one of the special opcodes, replacing it. The code is shared with single-
+    character repeats by setting opt_type to add a suitable offset into
+    repeat_type. We can also test for auto-possessification. OP_NOT is
+    currently used only for single-byte chars. */
+
+    else if (*previous == OP_NOT)
+      {
+      op_type = OP_NOTSTAR - OP_STAR;  /* Use "not" opcodes */
+      c = previous[1];
+      if (!possessive_quantifier &&
+          repeat_max < 0 &&
+          check_auto_possessive(OP_NOT, c, utf8, NULL, ptr + 1, options, cd))
+        {
+        repeat_type = 0;    /* Force greedy */
+        possessive_quantifier = TRUE;
+        }
+      goto OUTPUT_SINGLE_REPEAT;
+      }
+
+    /* If previous was a character type match (\d or similar), abolish it and
+    create a suitable repeat item. The code is shared with single-character
+    repeats by setting op_type to add a suitable offset into repeat_type. Note
+    the the Unicode property types will be present only when SUPPORT_UCP is
+    defined, but we don't wrap the little bits of code here because it just
+    makes it horribly messy. */
+
+    else if (*previous < OP_EODN)
+      {
+      uschar *oldcode;
+      int prop_type, prop_value;
+      op_type = OP_TYPESTAR - OP_STAR;  /* Use type opcodes */
+      c = *previous;
+
+      if (!possessive_quantifier &&
+          repeat_max < 0 &&
+          check_auto_possessive(c, 0, utf8, NULL, ptr + 1, options, cd))
+        {
+        repeat_type = 0;    /* Force greedy */
+        possessive_quantifier = TRUE;
+        }
+
+      OUTPUT_SINGLE_REPEAT:
+      if (*previous == OP_PROP || *previous == OP_NOTPROP)
+        {
+        prop_type = previous[1];
+        prop_value = previous[2];
+        }
+      else prop_type = prop_value = -1;
+
+      oldcode = code;
+      code = previous;                  /* Usually overwrite previous item */
+
+      /* If the maximum is zero then the minimum must also be zero; Perl allows
+      this case, so we do too - by simply omitting the item altogether. */
+
+      if (repeat_max == 0) goto END_REPEAT;
+
+      /* All real repeats make it impossible to handle partial matching (maybe
+      one day we will be able to remove this restriction). */
+
+      if (repeat_max != 1) cd->external_flags |= PCRE_NOPARTIAL;
+
+      /* Combine the op_type with the repeat_type */
+
+      repeat_type += op_type;
+
+      /* A minimum of zero is handled either as the special case * or ?, or as
+      an UPTO, with the maximum given. */
+
+      if (repeat_min == 0)
+        {
+        if (repeat_max == -1) *code++ = OP_STAR + repeat_type;
+          else if (repeat_max == 1) *code++ = OP_QUERY + repeat_type;
+        else
+          {
+          *code++ = OP_UPTO + repeat_type;
+          PUT2INC(code, 0, repeat_max);
+          }
+        }
+
+      /* A repeat minimum of 1 is optimized into some special cases. If the
+      maximum is unlimited, we use OP_PLUS. Otherwise, the original item is
+      left in place and, if the maximum is greater than 1, we use OP_UPTO with
+      one less than the maximum. */
+
+      else if (repeat_min == 1)
+        {
+        if (repeat_max == -1)
+          *code++ = OP_PLUS + repeat_type;
+        else
+          {
+          code = oldcode;                 /* leave previous item in place */
+          if (repeat_max == 1) goto END_REPEAT;
+          *code++ = OP_UPTO + repeat_type;
+          PUT2INC(code, 0, repeat_max - 1);
+          }
+        }
+
+      /* The case {n,n} is just an EXACT, while the general case {n,m} is
+      handled as an EXACT followed by an UPTO. */
+
+      else
+        {
+        *code++ = OP_EXACT + op_type;  /* NB EXACT doesn't have repeat_type */
+        PUT2INC(code, 0, repeat_min);
+
+        /* If the maximum is unlimited, insert an OP_STAR. Before doing so,
+        we have to insert the character for the previous code. For a repeated
+        Unicode property match, there are two extra bytes that define the
+        required property. In UTF-8 mode, long characters have their length in
+        c, with the 0x80 bit as a flag. */
+
+        if (repeat_max < 0)
+          {
+#ifdef SUPPORT_UTF8
+          if (utf8 && c >= 128)
+            {
+            memcpy(code, utf8_char, c & 7);
+            code += c & 7;
+            }
+          else
+#endif
+            {
+            *code++ = c;
+            if (prop_type >= 0)
+              {
+              *code++ = prop_type;
+              *code++ = prop_value;
+              }
+            }
+          *code++ = OP_STAR + repeat_type;
+          }
+
+        /* Else insert an UPTO if the max is greater than the min, again
+        preceded by the character, for the previously inserted code. If the
+        UPTO is just for 1 instance, we can use QUERY instead. */
+
+        else if (repeat_max != repeat_min)
+          {
+#ifdef SUPPORT_UTF8
+          if (utf8 && c >= 128)
+            {
+            memcpy(code, utf8_char, c & 7);
+            code += c & 7;
+            }
+          else
+#endif
+          *code++ = c;
+          if (prop_type >= 0)
+            {
+            *code++ = prop_type;
+            *code++ = prop_value;
+            }
+          repeat_max -= repeat_min;
+
+          if (repeat_max == 1)
+            {
+            *code++ = OP_QUERY + repeat_type;
+            }
+          else
+            {
+            *code++ = OP_UPTO + repeat_type;
+            PUT2INC(code, 0, repeat_max);
+            }
+          }
+        }
+
+      /* The character or character type itself comes last in all cases. */
+
+#ifdef SUPPORT_UTF8
+      if (utf8 && c >= 128)
+        {
+        memcpy(code, utf8_char, c & 7);
+        code += c & 7;
+        }
+      else
+#endif
+      *code++ = c;
+
+      /* For a repeated Unicode property match, there are two extra bytes that
+      define the required property. */
+
+#ifdef SUPPORT_UCP
+      if (prop_type >= 0)
+        {
+        *code++ = prop_type;
+        *code++ = prop_value;
+        }
+#endif
+      }
+
+    /* If previous was a character class or a back reference, we put the repeat
+    stuff after it, but just skip the item if the repeat was {0,0}. */
+
+    else if (*previous == OP_CLASS ||
+             *previous == OP_NCLASS ||
+#ifdef SUPPORT_UTF8
+             *previous == OP_XCLASS ||
+#endif
+             *previous == OP_REF)
+      {
+      if (repeat_max == 0)
+        {
+        code = previous;
+        goto END_REPEAT;
+        }
+
+      /* All real repeats make it impossible to handle partial matching (maybe
+      one day we will be able to remove this restriction). */
+
+      if (repeat_max != 1) cd->external_flags |= PCRE_NOPARTIAL;
+
+      if (repeat_min == 0 && repeat_max == -1)
+        *code++ = OP_CRSTAR + repeat_type;
+      else if (repeat_min == 1 && repeat_max == -1)
+        *code++ = OP_CRPLUS + repeat_type;
+      else if (repeat_min == 0 && repeat_max == 1)
+        *code++ = OP_CRQUERY + repeat_type;
+      else
+        {
+        *code++ = OP_CRRANGE + repeat_type;
+        PUT2INC(code, 0, repeat_min);
+        if (repeat_max == -1) repeat_max = 0;  /* 2-byte encoding for max */
+        PUT2INC(code, 0, repeat_max);
+        }
+      }
+
+    /* If previous was a bracket group, we may have to replicate it in certain
+    cases. */
+
+    else if (*previous == OP_BRA  || *previous == OP_CBRA ||
+             *previous == OP_ONCE || *previous == OP_COND)
+      {
+      register int i;
+      int ketoffset = 0;
+      int len = code - previous;
+      uschar *bralink = NULL;
+
+      /* Repeating a DEFINE group is pointless */
+
+      if (*previous == OP_COND && previous[LINK_SIZE+1] == OP_DEF)
+        {
+        *errorcodeptr = ERR55;
+        goto FAILED;
+        }
+
+      /* If the maximum repeat count is unlimited, find the end of the bracket
+      by scanning through from the start, and compute the offset back to it
+      from the current code pointer. There may be an OP_OPT setting following
+      the final KET, so we can't find the end just by going back from the code
+      pointer. */
+
+      if (repeat_max == -1)
+        {
+        register uschar *ket = previous;
+        do ket += GET(ket, 1); while (*ket != OP_KET);
+        ketoffset = code - ket;
+        }
+
+      /* The case of a zero minimum is special because of the need to stick
+      OP_BRAZERO in front of it, and because the group appears once in the
+      data, whereas in other cases it appears the minimum number of times. For
+      this reason, it is simplest to treat this case separately, as otherwise
+      the code gets far too messy. There are several special subcases when the
+      minimum is zero. */
+
+      if (repeat_min == 0)
+        {
+        /* If the maximum is also zero, we used to just omit the group from the
+        output altogether, like this:
+
+        ** if (repeat_max == 0)
+        **   {
+        **   code = previous;
+        **   goto END_REPEAT;
+        **   }
+
+        However, that fails when a group is referenced as a subroutine from
+        elsewhere in the pattern, so now we stick in OP_SKIPZERO in front of it
+        so that it is skipped on execution. As we don't have a list of which
+        groups are referenced, we cannot do this selectively.
+
+        If the maximum is 1 or unlimited, we just have to stick in the BRAZERO
+        and do no more at this point. However, we do need to adjust any
+        OP_RECURSE calls inside the group that refer to the group itself or any
+        internal or forward referenced group, because the offset is from the
+        start of the whole regex. Temporarily terminate the pattern while doing
+        this. */
+
+        if (repeat_max <= 1)    /* Covers 0, 1, and unlimited */
+          {
+          *code = OP_END;
+          adjust_recurse(previous, 1, utf8, cd, save_hwm);
+          memmove(previous+1, previous, len);
+          code++;
+          if (repeat_max == 0)
+            {
+            *previous++ = OP_SKIPZERO;
+            goto END_REPEAT;
+            }
+          *previous++ = OP_BRAZERO + repeat_type;
+          }
+
+        /* If the maximum is greater than 1 and limited, we have to replicate
+        in a nested fashion, sticking OP_BRAZERO before each set of brackets.
+        The first one has to be handled carefully because it's the original
+        copy, which has to be moved up. The remainder can be handled by code
+        that is common with the non-zero minimum case below. We have to
+        adjust the value or repeat_max, since one less copy is required. Once
+        again, we may have to adjust any OP_RECURSE calls inside the group. */
+
+        else
+          {
+          int offset;
+          *code = OP_END;
+          adjust_recurse(previous, 2 + LINK_SIZE, utf8, cd, save_hwm);
+          memmove(previous + 2 + LINK_SIZE, previous, len);
+          code += 2 + LINK_SIZE;
+          *previous++ = OP_BRAZERO + repeat_type;
+          *previous++ = OP_BRA;
+
+          /* We chain together the bracket offset fields that have to be
+          filled in later when the ends of the brackets are reached. */
+
+          offset = (bralink == NULL)? 0 : previous - bralink;
+          bralink = previous;
+          PUTINC(previous, 0, offset);
+          }
+
+        repeat_max--;
+        }
+
+      /* If the minimum is greater than zero, replicate the group as many
+      times as necessary, and adjust the maximum to the number of subsequent
+      copies that we need. If we set a first char from the group, and didn't
+      set a required char, copy the latter from the former. If there are any
+      forward reference subroutine calls in the group, there will be entries on
+      the workspace list; replicate these with an appropriate increment. */
+
+      else
+        {
+        if (repeat_min > 1)
+          {
+          /* In the pre-compile phase, we don't actually do the replication. We
+          just adjust the length as if we had. Do some paranoid checks for
+          potential integer overflow. */
+
+          if (lengthptr != NULL)
+            {
+            int delta = (repeat_min - 1)*length_prevgroup;
+            if ((double)(repeat_min - 1)*(double)length_prevgroup >
+                                                            (double)INT_MAX ||
+                OFLOW_MAX - *lengthptr < delta)
+              {
+              *errorcodeptr = ERR20;
+              goto FAILED;
+              }
+            *lengthptr += delta;
+            }
+
+          /* This is compiling for real */
+
+          else
+            {
+            if (groupsetfirstbyte && reqbyte < 0) reqbyte = firstbyte;
+            for (i = 1; i < repeat_min; i++)
+              {
+              uschar *hc;
+              uschar *this_hwm = cd->hwm;
+              memcpy(code, previous, len);
+              for (hc = save_hwm; hc < this_hwm; hc += LINK_SIZE)
+                {
+                PUT(cd->hwm, 0, GET(hc, 0) + len);
+                cd->hwm += LINK_SIZE;
+                }
+              save_hwm = this_hwm;
+              code += len;
+              }
+            }
+          }
+
+        if (repeat_max > 0) repeat_max -= repeat_min;
+        }
+
+      /* This code is common to both the zero and non-zero minimum cases. If
+      the maximum is limited, it replicates the group in a nested fashion,
+      remembering the bracket starts on a stack. In the case of a zero minimum,
+      the first one was set up above. In all cases the repeat_max now specifies
+      the number of additional copies needed. Again, we must remember to
+      replicate entries on the forward reference list. */
+
+      if (repeat_max >= 0)
+        {
+        /* In the pre-compile phase, we don't actually do the replication. We
+        just adjust the length as if we had. For each repetition we must add 1
+        to the length for BRAZERO and for all but the last repetition we must
+        add 2 + 2*LINKSIZE to allow for the nesting that occurs. Do some
+        paranoid checks to avoid integer overflow. */
+
+        if (lengthptr != NULL && repeat_max > 0)
+          {
+          int delta = repeat_max * (length_prevgroup + 1 + 2 + 2*LINK_SIZE) -
+                      2 - 2*LINK_SIZE;   /* Last one doesn't nest */
+          if ((double)repeat_max *
+                (double)(length_prevgroup + 1 + 2 + 2*LINK_SIZE)
+                  > (double)INT_MAX ||
+              OFLOW_MAX - *lengthptr < delta)
+            {
+            *errorcodeptr = ERR20;
+            goto FAILED;
+            }
+          *lengthptr += delta;
+          }
+
+        /* This is compiling for real */
+
+        else for (i = repeat_max - 1; i >= 0; i--)
+          {
+          uschar *hc;
+          uschar *this_hwm = cd->hwm;
+
+          *code++ = OP_BRAZERO + repeat_type;
+
+          /* All but the final copy start a new nesting, maintaining the
+          chain of brackets outstanding. */
+
+          if (i != 0)
+            {
+            int offset;
+            *code++ = OP_BRA;
+            offset = (bralink == NULL)? 0 : code - bralink;
+            bralink = code;
+            PUTINC(code, 0, offset);
+            }
+
+          memcpy(code, previous, len);
+          for (hc = save_hwm; hc < this_hwm; hc += LINK_SIZE)
+            {
+            PUT(cd->hwm, 0, GET(hc, 0) + len + ((i != 0)? 2+LINK_SIZE : 1));
+            cd->hwm += LINK_SIZE;
+            }
+          save_hwm = this_hwm;
+          code += len;
+          }
+
+        /* Now chain through the pending brackets, and fill in their length
+        fields (which are holding the chain links pro tem). */
+
+        while (bralink != NULL)
+          {
+          int oldlinkoffset;
+          int offset = code - bralink + 1;
+          uschar *bra = code - offset;
+          oldlinkoffset = GET(bra, 1);
+          bralink = (oldlinkoffset == 0)? NULL : bralink - oldlinkoffset;
+          *code++ = OP_KET;
+          PUTINC(code, 0, offset);
+          PUT(bra, 1, offset);
+          }
+        }
+
+      /* If the maximum is unlimited, set a repeater in the final copy. We
+      can't just offset backwards from the current code point, because we
+      don't know if there's been an options resetting after the ket. The
+      correct offset was computed above.
+
+      Then, when we are doing the actual compile phase, check to see whether
+      this group is a non-atomic one that could match an empty string. If so,
+      convert the initial operator to the S form (e.g. OP_BRA -> OP_SBRA) so
+      that runtime checking can be done. [This check is also applied to
+      atomic groups at runtime, but in a different way.] */
+
+      else
+        {
+        uschar *ketcode = code - ketoffset;
+        uschar *bracode = ketcode - GET(ketcode, 1);
+        *ketcode = OP_KETRMAX + repeat_type;
+        if (lengthptr == NULL && *bracode != OP_ONCE)
+          {
+          uschar *scode = bracode;
+          do
+            {
+            if (could_be_empty_branch(scode, ketcode, utf8))
+              {
+              *bracode += OP_SBRA - OP_BRA;
+              break;
+              }
+            scode += GET(scode, 1);
+            }
+          while (*scode == OP_ALT);
+          }
+        }
+      }
+
+    /* If previous is OP_FAIL, it was generated by an empty class [] in
+    JavaScript mode. The other ways in which OP_FAIL can be generated, that is
+    by (*FAIL) or (?!) set previous to NULL, which gives a "nothing to repeat"
+    error above. We can just ignore the repeat in JS case. */
+
+    else if (*previous == OP_FAIL) goto END_REPEAT;
+
+    /* Else there's some kind of shambles */
+
+    else
+      {
+      *errorcodeptr = ERR11;
+      goto FAILED;
+      }
+
+    /* If the character following a repeat is '+', or if certain optimization
+    tests above succeeded, possessive_quantifier is TRUE. For some of the
+    simpler opcodes, there is an special alternative opcode for this. For
+    anything else, we wrap the entire repeated item inside OP_ONCE brackets.
+    The '+' notation is just syntactic sugar, taken from Sun's Java package,
+    but the special opcodes can optimize it a bit. The repeated item starts at
+    tempcode, not at previous, which might be the first part of a string whose
+    (former) last char we repeated.
+
+    Possessifying an 'exact' quantifier has no effect, so we can ignore it. But
+    an 'upto' may follow. We skip over an 'exact' item, and then test the
+    length of what remains before proceeding. */
+
+    if (possessive_quantifier)
+      {
+      int len;
+      if (*tempcode == OP_EXACT || *tempcode == OP_TYPEEXACT ||
+          *tempcode == OP_NOTEXACT)
+        tempcode += _pcre_OP_lengths[*tempcode] +
+          ((*tempcode == OP_TYPEEXACT &&
+             (tempcode[3] == OP_PROP || tempcode[3] == OP_NOTPROP))? 2:0);
+      len = code - tempcode;
+      if (len > 0) switch (*tempcode)
+        {
+        case OP_STAR:  *tempcode = OP_POSSTAR; break;
+        case OP_PLUS:  *tempcode = OP_POSPLUS; break;
+        case OP_QUERY: *tempcode = OP_POSQUERY; break;
+        case OP_UPTO:  *tempcode = OP_POSUPTO; break;
+
+        case OP_TYPESTAR:  *tempcode = OP_TYPEPOSSTAR; break;
+        case OP_TYPEPLUS:  *tempcode = OP_TYPEPOSPLUS; break;
+        case OP_TYPEQUERY: *tempcode = OP_TYPEPOSQUERY; break;
+        case OP_TYPEUPTO:  *tempcode = OP_TYPEPOSUPTO; break;
+
+        case OP_NOTSTAR:  *tempcode = OP_NOTPOSSTAR; break;
+        case OP_NOTPLUS:  *tempcode = OP_NOTPOSPLUS; break;
+        case OP_NOTQUERY: *tempcode = OP_NOTPOSQUERY; break;
+        case OP_NOTUPTO:  *tempcode = OP_NOTPOSUPTO; break;
+
+        default:
+        memmove(tempcode + 1+LINK_SIZE, tempcode, len);
+        code += 1 + LINK_SIZE;
+        len += 1 + LINK_SIZE;
+        tempcode[0] = OP_ONCE;
+        *code++ = OP_KET;
+        PUTINC(code, 0, len);
+        PUT(tempcode, 1, len);
+        break;
+        }
+      }
+
+    /* In all case we no longer have a previous item. We also set the
+    "follows varying string" flag for subsequently encountered reqbytes if
+    it isn't already set and we have just passed a varying length item. */
+
+    END_REPEAT:
+    previous = NULL;
+    cd->req_varyopt |= reqvary;
+    break;
+
+
+    /* ===================================================================*/
+    /* Start of nested parenthesized sub-expression, or comment or lookahead or
+    lookbehind or option setting or condition or all the other extended
+    parenthesis forms.  */
+
+    case '(':
+    newoptions = options;
+    skipbytes = 0;
+    bravalue = OP_CBRA;
+    save_hwm = cd->hwm;
+    reset_bracount = FALSE;
+
+    /* First deal with various "verbs" that can be introduced by '*'. */
+
+    if (*(++ptr) == '*' && (cd->ctypes[ptr[1]] & ctype_letter) != 0)
+      {
+      int i, namelen;
+      const char *vn = verbnames;
+      const uschar *name = ++ptr;
+      previous = NULL;
+      while ((cd->ctypes[*++ptr] & ctype_letter) != 0) {};
+      if (*ptr == ':')
+        {
+        *errorcodeptr = ERR59;   /* Not supported */
+        goto FAILED;
+        }
+      if (*ptr != ')')
+        {
+        *errorcodeptr = ERR60;
+        goto FAILED;
+        }
+      namelen = ptr - name;
+      for (i = 0; i < verbcount; i++)
+        {
+        if (namelen == verbs[i].len &&
+            strncmp((char *)name, vn, namelen) == 0)
+          {
+          *code = verbs[i].op;
+          if (*code++ == OP_ACCEPT) cd->had_accept = TRUE;
+          break;
+          }
+        vn += verbs[i].len + 1;
+        }
+      if (i < verbcount) continue;
+      *errorcodeptr = ERR60;
+      goto FAILED;
+      }
+
+    /* Deal with the extended parentheses; all are introduced by '?', and the
+    appearance of any of them means that this is not a capturing group. */
+
+    else if (*ptr == '?')
+      {
+      int i, set, unset, namelen;
+      int *optset;
+      const uschar *name;
+      uschar *slot;
+
+      switch (*(++ptr))
+        {
+        case '#':                 /* Comment; skip to ket */
+        ptr++;
+        while (*ptr != 0 && *ptr != ')') ptr++;
+        if (*ptr == 0)
+          {
+          *errorcodeptr = ERR18;
+          goto FAILED;
+          }
+        continue;
+
+
+        /* ------------------------------------------------------------ */
+        case '|':                 /* Reset capture count for each branch */
+        reset_bracount = TRUE;
+        /* Fall through */
+
+        /* ------------------------------------------------------------ */
+        case ':':                 /* Non-capturing bracket */
+        bravalue = OP_BRA;
+        ptr++;
+        break;
+
+
+        /* ------------------------------------------------------------ */
+        case '(':
+        bravalue = OP_COND;       /* Conditional group */
+
+        /* A condition can be an assertion, a number (referring to a numbered
+        group), a name (referring to a named group), or 'R', referring to
+        recursion. R<digits> and R&name are also permitted for recursion tests.
+
+        There are several syntaxes for testing a named group: (?(name)) is used
+        by Python; Perl 5.10 onwards uses (?(<name>) or (?('name')).
+
+        There are two unfortunate ambiguities, caused by history. (a) 'R' can
+        be the recursive thing or the name 'R' (and similarly for 'R' followed
+        by digits), and (b) a number could be a name that consists of digits.
+        In both cases, we look for a name first; if not found, we try the other
+        cases. */
+
+        /* For conditions that are assertions, check the syntax, and then exit
+        the switch. This will take control down to where bracketed groups,
+        including assertions, are processed. */
+
+        if (ptr[1] == '?' && (ptr[2] == '=' || ptr[2] == '!' || ptr[2] == '<'))
+          break;
+
+        /* Most other conditions use OP_CREF (a couple change to OP_RREF
+        below), and all need to skip 3 bytes at the start of the group. */
+
+        code[1+LINK_SIZE] = OP_CREF;
+        skipbytes = 3;
+        refsign = -1;
+
+        /* Check for a test for recursion in a named group. */
+
+        if (ptr[1] == 'R' && ptr[2] == '&')
+          {
+          terminator = -1;
+          ptr += 2;
+          code[1+LINK_SIZE] = OP_RREF;    /* Change the type of test */
+          }
+
+        /* Check for a test for a named group's having been set, using the Perl
+        syntax (?(<name>) or (?('name') */
+
+        else if (ptr[1] == '<')
+          {
+          terminator = '>';
+          ptr++;
+          }
+        else if (ptr[1] == '\'')
+          {
+          terminator = '\'';
+          ptr++;
+          }
+        else
+          {
+          terminator = 0;
+          if (ptr[1] == '-' || ptr[1] == '+') refsign = *(++ptr);
+          }
+
+        /* We now expect to read a name; any thing else is an error */
+
+        if ((cd->ctypes[ptr[1]] & ctype_word) == 0)
+          {
+          ptr += 1;  /* To get the right offset */
+          *errorcodeptr = ERR28;
+          goto FAILED;
+          }
+
+        /* Read the name, but also get it as a number if it's all digits */
+
+        recno = 0;
+        name = ++ptr;
+        while ((cd->ctypes[*ptr] & ctype_word) != 0)
+          {
+          if (recno >= 0)
+            recno = ((digitab[*ptr] & ctype_digit) != 0)?
+              recno * 10 + *ptr - '0' : -1;
+          ptr++;
+          }
+        namelen = ptr - name;
+
+        if ((terminator > 0 && *ptr++ != terminator) || *ptr++ != ')')
+          {
+          ptr--;      /* Error offset */
+          *errorcodeptr = ERR26;
+          goto FAILED;
+          }
+
+        /* Do no further checking in the pre-compile phase. */
+
+        if (lengthptr != NULL) break;
+
+        /* In the real compile we do the work of looking for the actual
+        reference. If the string started with "+" or "-" we require the rest to
+        be digits, in which case recno will be set. */
+
+        if (refsign > 0)
+          {
+          if (recno <= 0)
+            {
+            *errorcodeptr = ERR58;
+            goto FAILED;
+            }
+          recno = (refsign == '-')?
+            cd->bracount - recno + 1 : recno +cd->bracount;
+          if (recno <= 0 || recno > cd->final_bracount)
+            {
+            *errorcodeptr = ERR15;
+            goto FAILED;
+            }
+          PUT2(code, 2+LINK_SIZE, recno);
+          break;
+          }
+
+        /* Otherwise (did not start with "+" or "-"), start by looking for the
+        name. */
+
+        slot = cd->name_table;
+        for (i = 0; i < cd->names_found; i++)
+          {
+          if (strncmp((char *)name, (char *)slot+2, namelen) == 0) break;
+          slot += cd->name_entry_size;
+          }
+
+        /* Found a previous named subpattern */
+
+        if (i < cd->names_found)
+          {
+          recno = GET2(slot, 0);
+          PUT2(code, 2+LINK_SIZE, recno);
+          }
+
+        /* Search the pattern for a forward reference */
+
+        else if ((i = find_parens(ptr, cd, name, namelen,
+                        (options & PCRE_EXTENDED) != 0)) > 0)
+          {
+          PUT2(code, 2+LINK_SIZE, i);
+          }
+
+        /* If terminator == 0 it means that the name followed directly after
+        the opening parenthesis [e.g. (?(abc)...] and in this case there are
+        some further alternatives to try. For the cases where terminator != 0
+        [things like (?(<name>... or (?('name')... or (?(R&name)... ] we have
+        now checked all the possibilities, so give an error. */
+
+        else if (terminator != 0)
+          {
+          *errorcodeptr = ERR15;
+          goto FAILED;
+          }
+
+        /* Check for (?(R) for recursion. Allow digits after R to specify a
+        specific group number. */
+
+        else if (*name == 'R')
+          {
+          recno = 0;
+          for (i = 1; i < namelen; i++)
+            {
+            if ((digitab[name[i]] & ctype_digit) == 0)
+              {
+              *errorcodeptr = ERR15;
+              goto FAILED;
+              }
+            recno = recno * 10 + name[i] - '0';
+            }
+          if (recno == 0) recno = RREF_ANY;
+          code[1+LINK_SIZE] = OP_RREF;      /* Change test type */
+          PUT2(code, 2+LINK_SIZE, recno);
+          }
+
+        /* Similarly, check for the (?(DEFINE) "condition", which is always
+        false. */
+
+        else if (namelen == 6 && strncmp((char *)name, "DEFINE", 6) == 0)
+          {
+          code[1+LINK_SIZE] = OP_DEF;
+          skipbytes = 1;
+          }
+
+        /* Check for the "name" actually being a subpattern number. We are
+        in the second pass here, so final_bracount is set. */
+
+        else if (recno > 0 && recno <= cd->final_bracount)
+          {
+          PUT2(code, 2+LINK_SIZE, recno);
+          }
+
+        /* Either an unidentified subpattern, or a reference to (?(0) */
+
+        else
+          {
+          *errorcodeptr = (recno == 0)? ERR35: ERR15;
+          goto FAILED;
+          }
+        break;
+
+
+        /* ------------------------------------------------------------ */
+        case '=':                 /* Positive lookahead */
+        bravalue = OP_ASSERT;
+        ptr++;
+        break;
+
+
+        /* ------------------------------------------------------------ */
+        case '!':                 /* Negative lookahead */
+        ptr++;
+        if (*ptr == ')')          /* Optimize (?!) */
+          {
+          *code++ = OP_FAIL;
+          previous = NULL;
+          continue;
+          }
+        bravalue = OP_ASSERT_NOT;
+        break;
+
+
+        /* ------------------------------------------------------------ */
+        case '<':                 /* Lookbehind or named define */
+        switch (ptr[1])
+          {
+          case '=':               /* Positive lookbehind */
+          bravalue = OP_ASSERTBACK;
+          ptr += 2;
+          break;
+
+          case '!':               /* Negative lookbehind */
+          bravalue = OP_ASSERTBACK_NOT;
+          ptr += 2;
+          break;
+
+          default:                /* Could be name define, else bad */
+          if ((cd->ctypes[ptr[1]] & ctype_word) != 0) goto DEFINE_NAME;
+          ptr++;                  /* Correct offset for error */
+          *errorcodeptr = ERR24;
+          goto FAILED;
+          }
+        break;
+
+
+        /* ------------------------------------------------------------ */
+        case '>':                 /* One-time brackets */
+        bravalue = OP_ONCE;
+        ptr++;
+        break;
+
+
+        /* ------------------------------------------------------------ */
+        case 'C':                 /* Callout - may be followed by digits; */
+        previous_callout = code;  /* Save for later completion */
+        after_manual_callout = 1; /* Skip one item before completing */
+        *code++ = OP_CALLOUT;
+          {
+          int n = 0;
+          while ((digitab[*(++ptr)] & ctype_digit) != 0)
+            n = n * 10 + *ptr - '0';
+          if (*ptr != ')')
+            {
+            *errorcodeptr = ERR39;
+            goto FAILED;
+            }
+          if (n > 255)
+            {
+            *errorcodeptr = ERR38;
+            goto FAILED;
+            }
+          *code++ = n;
+          PUT(code, 0, ptr - cd->start_pattern + 1);  /* Pattern offset */
+          PUT(code, LINK_SIZE, 0);                    /* Default length */
+          code += 2 * LINK_SIZE;
+          }
+        previous = NULL;
+        continue;
+
+
+        /* ------------------------------------------------------------ */
+        case 'P':                 /* Python-style named subpattern handling */
+        if (*(++ptr) == '=' || *ptr == '>')  /* Reference or recursion */
+          {
+          is_recurse = *ptr == '>';
+          terminator = ')';
+          goto NAMED_REF_OR_RECURSE;
+          }
+        else if (*ptr != '<')    /* Test for Python-style definition */
+          {
+          *errorcodeptr = ERR41;
+          goto FAILED;
+          }
+        /* Fall through to handle (?P< as (?< is handled */
+
+
+        /* ------------------------------------------------------------ */
+        DEFINE_NAME:    /* Come here from (?< handling */
+        case '\'':
+          {
+          terminator = (*ptr == '<')? '>' : '\'';
+          name = ++ptr;
+
+          while ((cd->ctypes[*ptr] & ctype_word) != 0) ptr++;
+          namelen = ptr - name;
+
+          /* In the pre-compile phase, just do a syntax check. */
+
+          if (lengthptr != NULL)
+            {
+            if (*ptr != terminator)
+              {
+              *errorcodeptr = ERR42;
+              goto FAILED;
+              }
+            if (cd->names_found >= MAX_NAME_COUNT)
+              {
+              *errorcodeptr = ERR49;
+              goto FAILED;
+              }
+            if (namelen + 3 > cd->name_entry_size)
+              {
+              cd->name_entry_size = namelen + 3;
+              if (namelen > MAX_NAME_SIZE)
+                {
+                *errorcodeptr = ERR48;
+                goto FAILED;
+                }
+              }
+            }
+
+          /* In the real compile, create the entry in the table */
+
+          else
+            {
+            slot = cd->name_table;
+            for (i = 0; i < cd->names_found; i++)
+              {
+              int crc = memcmp(name, slot+2, namelen);
+              if (crc == 0)
+                {
+                if (slot[2+namelen] == 0)
+                  {
+                  if ((options & PCRE_DUPNAMES) == 0)
+                    {
+                    *errorcodeptr = ERR43;
+                    goto FAILED;
+                    }
+                  }
+                else crc = -1;      /* Current name is substring */
+                }
+              if (crc < 0)
+                {
+                memmove(slot + cd->name_entry_size, slot,
+                  (cd->names_found - i) * cd->name_entry_size);
+                break;
+                }
+              slot += cd->name_entry_size;
+              }
+
+            PUT2(slot, 0, cd->bracount + 1);
+            memcpy(slot + 2, name, namelen);
+            slot[2+namelen] = 0;
+            }
+          }
+
+        /* In both cases, count the number of names we've encountered. */
+
+        ptr++;                    /* Move past > or ' */
+        cd->names_found++;
+        goto NUMBERED_GROUP;
+
+
+        /* ------------------------------------------------------------ */
+        case '&':                 /* Perl recursion/subroutine syntax */
+        terminator = ')';
+        is_recurse = TRUE;
+        /* Fall through */
+
+        /* We come here from the Python syntax above that handles both
+        references (?P=name) and recursion (?P>name), as well as falling
+        through from the Perl recursion syntax (?&name). We also come here from
+        the Perl \k<name> or \k'name' back reference syntax and the \k{name}
+        .NET syntax, and the Oniguruma \g<...> and \g'...' subroutine syntax. */
+
+        NAMED_REF_OR_RECURSE:
+        name = ++ptr;
+        while ((cd->ctypes[*ptr] & ctype_word) != 0) ptr++;
+        namelen = ptr - name;
+
+        /* In the pre-compile phase, do a syntax check and set a dummy
+        reference number. */
+
+        if (lengthptr != NULL)
+          {
+          if (namelen == 0)
+            {
+            *errorcodeptr = ERR62;
+            goto FAILED;
+            }
+          if (*ptr != terminator)
+            {
+            *errorcodeptr = ERR42;
+            goto FAILED;
+            }
+          if (namelen > MAX_NAME_SIZE)
+            {
+            *errorcodeptr = ERR48;
+            goto FAILED;
+            }
+          recno = 0;
+          }
+
+        /* In the real compile, seek the name in the table. We check the name
+        first, and then check that we have reached the end of the name in the
+        table. That way, if the name that is longer than any in the table,
+        the comparison will fail without reading beyond the table entry. */
+
+        else
+          {
+          slot = cd->name_table;
+          for (i = 0; i < cd->names_found; i++)
+            {
+            if (strncmp((char *)name, (char *)slot+2, namelen) == 0 &&
+                slot[2+namelen] == 0)
+              break;
+            slot += cd->name_entry_size;
+            }
+
+          if (i < cd->names_found)         /* Back reference */
+            {
+            recno = GET2(slot, 0);
+            }
+          else if ((recno =                /* Forward back reference */
+                    find_parens(ptr, cd, name, namelen,
+                      (options & PCRE_EXTENDED) != 0)) <= 0)
+            {
+            *errorcodeptr = ERR15;
+            goto FAILED;
+            }
+          }
+
+        /* In both phases, we can now go to the code than handles numerical
+        recursion or backreferences. */
+
+        if (is_recurse) goto HANDLE_RECURSION;
+          else goto HANDLE_REFERENCE;
+
+
+        /* ------------------------------------------------------------ */
+        case 'R':                 /* Recursion */
+        ptr++;                    /* Same as (?0)      */
+        /* Fall through */
+
+
+        /* ------------------------------------------------------------ */
+        case '-': case '+':
+        case '0': case '1': case '2': case '3': case '4':   /* Recursion or */
+        case '5': case '6': case '7': case '8': case '9':   /* subroutine */
+          {
+          const uschar *called;
+          terminator = ')';
+
+          /* Come here from the \g<...> and \g'...' code (Oniguruma
+          compatibility). However, the syntax has been checked to ensure that
+          the ... are a (signed) number, so that neither ERR63 nor ERR29 will
+          be called on this path, nor with the jump to OTHER_CHAR_AFTER_QUERY
+          ever be taken. */
+
+          HANDLE_NUMERICAL_RECURSION:
+
+          if ((refsign = *ptr) == '+')
+            {
+            ptr++;
+            if ((digitab[*ptr] & ctype_digit) == 0)
+              {
+              *errorcodeptr = ERR63;
+              goto FAILED;
+              }
+            }
+          else if (refsign == '-')
+            {
+            if ((digitab[ptr[1]] & ctype_digit) == 0)
+              goto OTHER_CHAR_AFTER_QUERY;
+            ptr++;
+            }
+
+          recno = 0;
+          while((digitab[*ptr] & ctype_digit) != 0)
+            recno = recno * 10 + *ptr++ - '0';
+
+          if (*ptr != terminator)
+            {
+            *errorcodeptr = ERR29;
+            goto FAILED;
+            }
+
+          if (refsign == '-')
+            {
+            if (recno == 0)
+              {
+              *errorcodeptr = ERR58;
+              goto FAILED;
+              }
+            recno = cd->bracount - recno + 1;
+            if (recno <= 0)
+              {
+              *errorcodeptr = ERR15;
+              goto FAILED;
+              }
+            }
+          else if (refsign == '+')
+            {
+            if (recno == 0)
+              {
+              *errorcodeptr = ERR58;
+              goto FAILED;
+              }
+            recno += cd->bracount;
+            }
+
+          /* Come here from code above that handles a named recursion */
+
+          HANDLE_RECURSION:
+
+          previous = code;
+          called = cd->start_code;
+
+          /* When we are actually compiling, find the bracket that is being
+          referenced. Temporarily end the regex in case it doesn't exist before
+          this point. If we end up with a forward reference, first check that
+          the bracket does occur later so we can give the error (and position)
+          now. Then remember this forward reference in the workspace so it can
+          be filled in at the end. */
+
+          if (lengthptr == NULL)
+            {
+            *code = OP_END;
+            if (recno != 0) called = find_bracket(cd->start_code, utf8, recno);
+
+            /* Forward reference */
+
+            if (called == NULL)
+              {
+              if (find_parens(ptr, cd, NULL, recno,
+                    (options & PCRE_EXTENDED) != 0) < 0)
+                {
+                *errorcodeptr = ERR15;
+                goto FAILED;
+                }
+              called = cd->start_code + recno;
+              PUTINC(cd->hwm, 0, code + 2 + LINK_SIZE - cd->start_code);
+              }
+
+            /* If not a forward reference, and the subpattern is still open,
+            this is a recursive call. We check to see if this is a left
+            recursion that could loop for ever, and diagnose that case. */
+
+            else if (GET(called, 1) == 0 &&
+                     could_be_empty(called, code, bcptr, utf8))
+              {
+              *errorcodeptr = ERR40;
+              goto FAILED;
+              }
+            }
+
+          /* Insert the recursion/subroutine item, automatically wrapped inside
+          "once" brackets. Set up a "previous group" length so that a
+          subsequent quantifier will work. */
+
+          *code = OP_ONCE;
+          PUT(code, 1, 2 + 2*LINK_SIZE);
+          code += 1 + LINK_SIZE;
+
+          *code = OP_RECURSE;
+          PUT(code, 1, called - cd->start_code);
+          code += 1 + LINK_SIZE;
+
+          *code = OP_KET;
+          PUT(code, 1, 2 + 2*LINK_SIZE);
+          code += 1 + LINK_SIZE;
+
+          length_prevgroup = 3 + 3*LINK_SIZE;
+          }
+
+        /* Can't determine a first byte now */
+
+        if (firstbyte == REQ_UNSET) firstbyte = REQ_NONE;
+        continue;
+
+
+        /* ------------------------------------------------------------ */
+        default:              /* Other characters: check option setting */
+        OTHER_CHAR_AFTER_QUERY:
+        set = unset = 0;
+        optset = &set;
+
+        while (*ptr != ')' && *ptr != ':')
+          {
+          switch (*ptr++)
+            {
+            case '-': optset = &unset; break;
+
+            case 'J':    /* Record that it changed in the external options */
+            *optset |= PCRE_DUPNAMES;
+            cd->external_flags |= PCRE_JCHANGED;
+            break;
+
+            case 'i': *optset |= PCRE_CASELESS; break;
+            case 'm': *optset |= PCRE_MULTILINE; break;
+            case 's': *optset |= PCRE_DOTALL; break;
+            case 'x': *optset |= PCRE_EXTENDED; break;
+            case 'U': *optset |= PCRE_UNGREEDY; break;
+            case 'X': *optset |= PCRE_EXTRA; break;
+
+            default:  *errorcodeptr = ERR12;
+                      ptr--;    /* Correct the offset */
+                      goto FAILED;
+            }
+          }
+
+        /* Set up the changed option bits, but don't change anything yet. */
+
+        newoptions = (options | set) & (~unset);
+
+        /* If the options ended with ')' this is not the start of a nested
+        group with option changes, so the options change at this level. If this
+        item is right at the start of the pattern, the options can be
+        abstracted and made external in the pre-compile phase, and ignored in
+        the compile phase. This can be helpful when matching -- for instance in
+        caseless checking of required bytes.
+
+        If the code pointer is not (cd->start_code + 1 + LINK_SIZE), we are
+        definitely *not* at the start of the pattern because something has been
+        compiled. In the pre-compile phase, however, the code pointer can have
+        that value after the start, because it gets reset as code is discarded
+        during the pre-compile. However, this can happen only at top level - if
+        we are within parentheses, the starting BRA will still be present. At
+        any parenthesis level, the length value can be used to test if anything
+        has been compiled at that level. Thus, a test for both these conditions
+        is necessary to ensure we correctly detect the start of the pattern in
+        both phases.
+
+        If we are not at the pattern start, compile code to change the ims
+        options if this setting actually changes any of them, and reset the
+        greedy defaults and the case value for firstbyte and reqbyte. */
+
+        if (*ptr == ')')
+          {
+          if (code == cd->start_code + 1 + LINK_SIZE &&
+               (lengthptr == NULL || *lengthptr == 2 + 2*LINK_SIZE))
+            {
+            cd->external_options = newoptions;
+            }
+         else
+            {
+            if ((options & PCRE_IMS) != (newoptions & PCRE_IMS))
+              {
+              *code++ = OP_OPT;
+              *code++ = newoptions & PCRE_IMS;
+              }
+            greedy_default = ((newoptions & PCRE_UNGREEDY) != 0);
+            greedy_non_default = greedy_default ^ 1;
+            req_caseopt = ((newoptions & PCRE_CASELESS) != 0)? REQ_CASELESS : 0;
+            }
+
+          /* Change options at this level, and pass them back for use
+          in subsequent branches. When not at the start of the pattern, this
+          information is also necessary so that a resetting item can be
+          compiled at the end of a group (if we are in a group). */
+
+          *optionsptr = options = newoptions;
+          previous = NULL;       /* This item can't be repeated */
+          continue;              /* It is complete */
+          }
+
+        /* If the options ended with ':' we are heading into a nested group
+        with possible change of options. Such groups are non-capturing and are
+        not assertions of any kind. All we need to do is skip over the ':';
+        the newoptions value is handled below. */
+
+        bravalue = OP_BRA;
+        ptr++;
+        }     /* End of switch for character following (? */
+      }       /* End of (? handling */
+
+    /* Opening parenthesis not followed by '?'. If PCRE_NO_AUTO_CAPTURE is set,
+    all unadorned brackets become non-capturing and behave like (?:...)
+    brackets. */
+
+    else if ((options & PCRE_NO_AUTO_CAPTURE) != 0)
+      {
+      bravalue = OP_BRA;
+      }
+
+    /* Else we have a capturing group. */
+
+    else
+      {
+      NUMBERED_GROUP:
+      cd->bracount += 1;
+      PUT2(code, 1+LINK_SIZE, cd->bracount);
+      skipbytes = 2;
+      }
+
+    /* Process nested bracketed regex. Assertions may not be repeated, but
+    other kinds can be. All their opcodes are >= OP_ONCE. We copy code into a
+    non-register variable in order to be able to pass its address because some
+    compilers complain otherwise. Pass in a new setting for the ims options if
+    they have changed. */
+
+    previous = (bravalue >= OP_ONCE)? code : NULL;
+    *code = bravalue;
+    tempcode = code;
+    tempreqvary = cd->req_varyopt;     /* Save value before bracket */
+    length_prevgroup = 0;              /* Initialize for pre-compile phase */
+
+    if (!compile_regex(
+         newoptions,                   /* The complete new option state */
+         options & PCRE_IMS,           /* The previous ims option state */
+         &tempcode,                    /* Where to put code (updated) */
+         &ptr,                         /* Input pointer (updated) */
+         errorcodeptr,                 /* Where to put an error message */
+         (bravalue == OP_ASSERTBACK ||
+          bravalue == OP_ASSERTBACK_NOT), /* TRUE if back assert */
+         reset_bracount,               /* True if (?| group */
+         skipbytes,                    /* Skip over bracket number */
+         &subfirstbyte,                /* For possible first char */
+         &subreqbyte,                  /* For possible last char */
+         bcptr,                        /* Current branch chain */
+         cd,                           /* Tables block */
+         (lengthptr == NULL)? NULL :   /* Actual compile phase */
+           &length_prevgroup           /* Pre-compile phase */
+         ))
+      goto FAILED;
+
+    /* At the end of compiling, code is still pointing to the start of the
+    group, while tempcode has been updated to point past the end of the group
+    and any option resetting that may follow it. The pattern pointer (ptr)
+    is on the bracket. */
+
+    /* If this is a conditional bracket, check that there are no more than
+    two branches in the group, or just one if it's a DEFINE group. We do this
+    in the real compile phase, not in the pre-pass, where the whole group may
+    not be available. */
+
+    if (bravalue == OP_COND && lengthptr == NULL)
+      {
+      uschar *tc = code;
+      int condcount = 0;
+
+      do {
+         condcount++;
+         tc += GET(tc,1);
+         }
+      while (*tc != OP_KET);
+
+      /* A DEFINE group is never obeyed inline (the "condition" is always
+      false). It must have only one branch. */
+
+      if (code[LINK_SIZE+1] == OP_DEF)
+        {
+        if (condcount > 1)
+          {
+          *errorcodeptr = ERR54;
+          goto FAILED;
+          }
+        bravalue = OP_DEF;   /* Just a flag to suppress char handling below */
+        }
+
+      /* A "normal" conditional group. If there is just one branch, we must not
+      make use of its firstbyte or reqbyte, because this is equivalent to an
+      empty second branch. */
+
+      else
+        {
+        if (condcount > 2)
+          {
+          *errorcodeptr = ERR27;
+          goto FAILED;
+          }
+        if (condcount == 1) subfirstbyte = subreqbyte = REQ_NONE;
+        }
+      }
+
+    /* Error if hit end of pattern */
+
+    if (*ptr != ')')
+      {
+      *errorcodeptr = ERR14;
+      goto FAILED;
+      }
+
+    /* In the pre-compile phase, update the length by the length of the group,
+    less the brackets at either end. Then reduce the compiled code to just a
+    set of non-capturing brackets so that it doesn't use much memory if it is
+    duplicated by a quantifier.*/
+
+    if (lengthptr != NULL)
+      {
+      if (OFLOW_MAX - *lengthptr < length_prevgroup - 2 - 2*LINK_SIZE)
+        {
+        *errorcodeptr = ERR20;
+        goto FAILED;
+        }
+      *lengthptr += length_prevgroup - 2 - 2*LINK_SIZE;
+      *code++ = OP_BRA;
+      PUTINC(code, 0, 1 + LINK_SIZE);
+      *code++ = OP_KET;
+      PUTINC(code, 0, 1 + LINK_SIZE);
+      break;    /* No need to waste time with special character handling */
+      }
+
+    /* Otherwise update the main code pointer to the end of the group. */
+
+    code = tempcode;
+
+    /* For a DEFINE group, required and first character settings are not
+    relevant. */
+
+    if (bravalue == OP_DEF) break;
+
+    /* Handle updating of the required and first characters for other types of
+    group. Update for normal brackets of all kinds, and conditions with two
+    branches (see code above). If the bracket is followed by a quantifier with
+    zero repeat, we have to back off. Hence the definition of zeroreqbyte and
+    zerofirstbyte outside the main loop so that they can be accessed for the
+    back off. */
+
+    zeroreqbyte = reqbyte;
+    zerofirstbyte = firstbyte;
+    groupsetfirstbyte = FALSE;
+
+    if (bravalue >= OP_ONCE)
+      {
+      /* If we have not yet set a firstbyte in this branch, take it from the
+      subpattern, remembering that it was set here so that a repeat of more
+      than one can replicate it as reqbyte if necessary. If the subpattern has
+      no firstbyte, set "none" for the whole branch. In both cases, a zero
+      repeat forces firstbyte to "none". */
+
+      if (firstbyte == REQ_UNSET)
+        {
+        if (subfirstbyte >= 0)
+          {
+          firstbyte = subfirstbyte;
+          groupsetfirstbyte = TRUE;
+          }
+        else firstbyte = REQ_NONE;
+        zerofirstbyte = REQ_NONE;
+        }
+
+      /* If firstbyte was previously set, convert the subpattern's firstbyte
+      into reqbyte if there wasn't one, using the vary flag that was in
+      existence beforehand. */
+
+      else if (subfirstbyte >= 0 && subreqbyte < 0)
+        subreqbyte = subfirstbyte | tempreqvary;
+
+      /* If the subpattern set a required byte (or set a first byte that isn't
+      really the first byte - see above), set it. */
+
+      if (subreqbyte >= 0) reqbyte = subreqbyte;
+      }
+
+    /* For a forward assertion, we take the reqbyte, if set. This can be
+    helpful if the pattern that follows the assertion doesn't set a different
+    char. For example, it's useful for /(?=abcde).+/. We can't set firstbyte
+    for an assertion, however because it leads to incorrect effect for patterns
+    such as /(?=a)a.+/ when the "real" "a" would then become a reqbyte instead
+    of a firstbyte. This is overcome by a scan at the end if there's no
+    firstbyte, looking for an asserted first char. */
+
+    else if (bravalue == OP_ASSERT && subreqbyte >= 0) reqbyte = subreqbyte;
+    break;     /* End of processing '(' */
+
+
+    /* ===================================================================*/
+    /* Handle metasequences introduced by \. For ones like \d, the ESC_ values
+    are arranged to be the negation of the corresponding OP_values. For the
+    back references, the values are ESC_REF plus the reference number. Only
+    back references and those types that consume a character may be repeated.
+    We can test for values between ESC_b and ESC_Z for the latter; this may
+    have to change if any new ones are ever created. */
+
+    case '\\':
+    tempptr = ptr;
+    c = check_escape(&ptr, errorcodeptr, cd->bracount, options, FALSE);
+    if (*errorcodeptr != 0) goto FAILED;
+
+    if (c < 0)
+      {
+      if (-c == ESC_Q)            /* Handle start of quoted string */
+        {
+        if (ptr[1] == '\\' && ptr[2] == 'E') ptr += 2; /* avoid empty string */
+          else inescq = TRUE;
+        continue;
+        }
+
+      if (-c == ESC_E) continue;  /* Perl ignores an orphan \E */
+
+      /* For metasequences that actually match a character, we disable the
+      setting of a first character if it hasn't already been set. */
+
+      if (firstbyte == REQ_UNSET && -c > ESC_b && -c < ESC_Z)
+        firstbyte = REQ_NONE;
+
+      /* Set values to reset to if this is followed by a zero repeat. */
+
+      zerofirstbyte = firstbyte;
+      zeroreqbyte = reqbyte;
+
+      /* \g<name> or \g'name' is a subroutine call by name and \g<n> or \g'n'
+      is a subroutine call by number (Oniguruma syntax). In fact, the value
+      -ESC_g is returned only for these cases. So we don't need to check for <
+      or ' if the value is -ESC_g. For the Perl syntax \g{n} the value is
+      -ESC_REF+n, and for the Perl syntax \g{name} the result is -ESC_k (as
+      that is a synonym for a named back reference). */
+
+      if (-c == ESC_g)
+        {
+        const uschar *p;
+        save_hwm = cd->hwm;   /* Normally this is set when '(' is read */
+        terminator = (*(++ptr) == '<')? '>' : '\'';
+
+        /* These two statements stop the compiler for warning about possibly
+        unset variables caused by the jump to HANDLE_NUMERICAL_RECURSION. In
+        fact, because we actually check for a number below, the paths that
+        would actually be in error are never taken. */
+
+        skipbytes = 0;
+        reset_bracount = FALSE;
+
+        /* Test for a name */
+
+        if (ptr[1] != '+' && ptr[1] != '-')
+          {
+          BOOL isnumber = TRUE;
+          for (p = ptr + 1; *p != 0 && *p != terminator; p++)
+            {
+            if ((cd->ctypes[*p] & ctype_digit) == 0) isnumber = FALSE;
+            if ((cd->ctypes[*p] & ctype_word) == 0) break;
+            }
+          if (*p != terminator)
+            {
+            *errorcodeptr = ERR57;
+            break;
+            }
+          if (isnumber)
+            {
+            ptr++;
+            goto HANDLE_NUMERICAL_RECURSION;
+            }
+          is_recurse = TRUE;
+          goto NAMED_REF_OR_RECURSE;
+          }
+
+        /* Test a signed number in angle brackets or quotes. */
+
+        p = ptr + 2;
+        while ((digitab[*p] & ctype_digit) != 0) p++;
+        if (*p != terminator)
+          {
+          *errorcodeptr = ERR57;
+          break;
+          }
+        ptr++;
+        goto HANDLE_NUMERICAL_RECURSION;
+        }
+
+      /* \k<name> or \k'name' is a back reference by name (Perl syntax).
+      We also support \k{name} (.NET syntax) */
+
+      if (-c == ESC_k && (ptr[1] == '<' || ptr[1] == '\'' || ptr[1] == '{'))
+        {
+        is_recurse = FALSE;
+        terminator = (*(++ptr) == '<')? '>' : (*ptr == '\'')? '\'' : '}';
+        goto NAMED_REF_OR_RECURSE;
+        }
+
+      /* Back references are handled specially; must disable firstbyte if
+      not set to cope with cases like (?=(\w+))\1: which would otherwise set
+      ':' later. */
+
+      if (-c >= ESC_REF)
+        {
+        recno = -c - ESC_REF;
+
+        HANDLE_REFERENCE:    /* Come here from named backref handling */
+        if (firstbyte == REQ_UNSET) firstbyte = REQ_NONE;
+        previous = code;
+        *code++ = OP_REF;
+        PUT2INC(code, 0, recno);
+        cd->backref_map |= (recno < 32)? (1 << recno) : 1;
+        if (recno > cd->top_backref) cd->top_backref = recno;
+        }
+
+      /* So are Unicode property matches, if supported. */
+
+#ifdef SUPPORT_UCP
+      else if (-c == ESC_P || -c == ESC_p)
+        {
+        BOOL negated;
+        int pdata;
+        int ptype = get_ucp(&ptr, &negated, &pdata, errorcodeptr);
+        if (ptype < 0) goto FAILED;
+        previous = code;
+        *code++ = ((-c == ESC_p) != negated)? OP_PROP : OP_NOTPROP;
+        *code++ = ptype;
+        *code++ = pdata;
+        }
+#else
+
+      /* If Unicode properties are not supported, \X, \P, and \p are not
+      allowed. */
+
+      else if (-c == ESC_X || -c == ESC_P || -c == ESC_p)
+        {
+        *errorcodeptr = ERR45;
+        goto FAILED;
+        }
+#endif
+
+      /* For the rest (including \X when Unicode properties are supported), we
+      can obtain the OP value by negating the escape value. */
+
+      else
+        {
+        previous = (-c > ESC_b && -c < ESC_Z)? code : NULL;
+        *code++ = -c;
+        }
+      continue;
+      }
+
+    /* We have a data character whose value is in c. In UTF-8 mode it may have
+    a value > 127. We set its representation in the length/buffer, and then
+    handle it as a data character. */
+
+#ifdef SUPPORT_UTF8
+    if (utf8 && c > 127)
+      mclength = _pcre_ord2utf8(c, mcbuffer);
+    else
+#endif
+
+     {
+     mcbuffer[0] = c;
+     mclength = 1;
+     }
+    goto ONE_CHAR;
+
+
+    /* ===================================================================*/
+    /* Handle a literal character. It is guaranteed not to be whitespace or #
+    when the extended flag is set. If we are in UTF-8 mode, it may be a
+    multi-byte literal character. */
+
+    default:
+    NORMAL_CHAR:
+    mclength = 1;
+    mcbuffer[0] = c;
+
+#ifdef SUPPORT_UTF8
+    if (utf8 && c >= 0xc0)
+      {
+      while ((ptr[1] & 0xc0) == 0x80)
+        mcbuffer[mclength++] = *(++ptr);
+      }
+#endif
+
+    /* At this point we have the character's bytes in mcbuffer, and the length
+    in mclength. When not in UTF-8 mode, the length is always 1. */
+
+    ONE_CHAR:
+    previous = code;
+    *code++ = ((options & PCRE_CASELESS) != 0)? OP_CHARNC : OP_CHAR;
+    for (c = 0; c < mclength; c++) *code++ = mcbuffer[c];
+
+    /* Remember if \r or \n were seen */
+
+    if (mcbuffer[0] == '\r' || mcbuffer[0] == '\n')
+      cd->external_flags |= PCRE_HASCRORLF;
+
+    /* Set the first and required bytes appropriately. If no previous first
+    byte, set it from this character, but revert to none on a zero repeat.
+    Otherwise, leave the firstbyte value alone, and don't change it on a zero
+    repeat. */
+
+    if (firstbyte == REQ_UNSET)
+      {
+      zerofirstbyte = REQ_NONE;
+      zeroreqbyte = reqbyte;
+
+      /* If the character is more than one byte long, we can set firstbyte
+      only if it is not to be matched caselessly. */
+
+      if (mclength == 1 || req_caseopt == 0)
+        {
+        firstbyte = mcbuffer[0] | req_caseopt;
+        if (mclength != 1) reqbyte = code[-1] | cd->req_varyopt;
+        }
+      else firstbyte = reqbyte = REQ_NONE;
+      }
+
+    /* firstbyte was previously set; we can set reqbyte only the length is
+    1 or the matching is caseful. */
+
+    else
+      {
+      zerofirstbyte = firstbyte;
+      zeroreqbyte = reqbyte;
+      if (mclength == 1 || req_caseopt == 0)
+        reqbyte = code[-1] | req_caseopt | cd->req_varyopt;
+      }
+
+    break;            /* End of literal character handling */
+    }
+  }                   /* end of big loop */
+
+
+/* Control never reaches here by falling through, only by a goto for all the
+error states. Pass back the position in the pattern so that it can be displayed
+to the user for diagnosing the error. */
+
+FAILED:
+*ptrptr = ptr;
+return FALSE;
+}
+
+
+
+
+/*************************************************
+*     Compile sequence of alternatives           *
+*************************************************/
+
+/* On entry, ptr is pointing past the bracket character, but on return it
+points to the closing bracket, or vertical bar, or end of string. The code
+variable is pointing at the byte into which the BRA operator has been stored.
+If the ims options are changed at the start (for a (?ims: group) or during any
+branch, we need to insert an OP_OPT item at the start of every following branch
+to ensure they get set correctly at run time, and also pass the new options
+into every subsequent branch compile.
+
+This function is used during the pre-compile phase when we are trying to find
+out the amount of memory needed, as well as during the real compile phase. The
+value of lengthptr distinguishes the two phases.
+
+Arguments:
+  options        option bits, including any changes for this subpattern
+  oldims         previous settings of ims option bits
+  codeptr        -> the address of the current code pointer
+  ptrptr         -> the address of the current pattern pointer
+  errorcodeptr   -> pointer to error code variable
+  lookbehind     TRUE if this is a lookbehind assertion
+  reset_bracount TRUE to reset the count for each branch
+  skipbytes      skip this many bytes at start (for brackets and OP_COND)
+  firstbyteptr   place to put the first required character, or a negative number
+  reqbyteptr     place to put the last required character, or a negative number
+  bcptr          pointer to the chain of currently open branches
+  cd             points to the data block with tables pointers etc.
+  lengthptr      NULL during the real compile phase
+                 points to length accumulator during pre-compile phase
+
+Returns:         TRUE on success
+*/
+
+static BOOL
+compile_regex(int options, int oldims, uschar **codeptr, const uschar **ptrptr,
+  int *errorcodeptr, BOOL lookbehind, BOOL reset_bracount, int skipbytes,
+  int *firstbyteptr, int *reqbyteptr, branch_chain *bcptr, compile_data *cd,
+  int *lengthptr)
+{
+const uschar *ptr = *ptrptr;
+uschar *code = *codeptr;
+uschar *last_branch = code;
+uschar *start_bracket = code;
+uschar *reverse_count = NULL;
+int firstbyte, reqbyte;
+int branchfirstbyte, branchreqbyte;
+int length;
+int orig_bracount;
+int max_bracount;
+branch_chain bc;
+
+bc.outer = bcptr;
+bc.current = code;
+
+firstbyte = reqbyte = REQ_UNSET;
+
+/* Accumulate the length for use in the pre-compile phase. Start with the
+length of the BRA and KET and any extra bytes that are required at the
+beginning. We accumulate in a local variable to save frequent testing of
+lenthptr for NULL. We cannot do this by looking at the value of code at the
+start and end of each alternative, because compiled items are discarded during
+the pre-compile phase so that the work space is not exceeded. */
+
+length = 2 + 2*LINK_SIZE + skipbytes;
+
+/* WARNING: If the above line is changed for any reason, you must also change
+the code that abstracts option settings at the start of the pattern and makes
+them global. It tests the value of length for (2 + 2*LINK_SIZE) in the
+pre-compile phase to find out whether anything has yet been compiled or not. */
+
+/* Offset is set zero to mark that this bracket is still open */
+
+PUT(code, 1, 0);
+code += 1 + LINK_SIZE + skipbytes;
+
+/* Loop for each alternative branch */
+
+orig_bracount = max_bracount = cd->bracount;
+for (;;)
+  {
+  /* For a (?| group, reset the capturing bracket count so that each branch
+  uses the same numbers. */
+
+  if (reset_bracount) cd->bracount = orig_bracount;
+
+  /* Handle a change of ims options at the start of the branch */
+
+  if ((options & PCRE_IMS) != oldims)
+    {
+    *code++ = OP_OPT;
+    *code++ = options & PCRE_IMS;
+    length += 2;
+    }
+
+  /* Set up dummy OP_REVERSE if lookbehind assertion */
+
+  if (lookbehind)
+    {
+    *code++ = OP_REVERSE;
+    reverse_count = code;
+    PUTINC(code, 0, 0);
+    length += 1 + LINK_SIZE;
+    }
+
+  /* Now compile the branch; in the pre-compile phase its length gets added
+  into the length. */
+
+  if (!compile_branch(&options, &code, &ptr, errorcodeptr, &branchfirstbyte,
+        &branchreqbyte, &bc, cd, (lengthptr == NULL)? NULL : &length))
+    {
+    *ptrptr = ptr;
+    return FALSE;
+    }
+
+  /* Keep the highest bracket count in case (?| was used and some branch
+  has fewer than the rest. */
+
+  if (cd->bracount > max_bracount) max_bracount = cd->bracount;
+
+  /* In the real compile phase, there is some post-processing to be done. */
+
+  if (lengthptr == NULL)
+    {
+    /* If this is the first branch, the firstbyte and reqbyte values for the
+    branch become the values for the regex. */
+
+    if (*last_branch != OP_ALT)
+      {
+      firstbyte = branchfirstbyte;
+      reqbyte = branchreqbyte;
+      }
+
+    /* If this is not the first branch, the first char and reqbyte have to
+    match the values from all the previous branches, except that if the
+    previous value for reqbyte didn't have REQ_VARY set, it can still match,
+    and we set REQ_VARY for the regex. */
+
+    else
+      {
+      /* If we previously had a firstbyte, but it doesn't match the new branch,
+      we have to abandon the firstbyte for the regex, but if there was
+      previously no reqbyte, it takes on the value of the old firstbyte. */
+
+      if (firstbyte >= 0 && firstbyte != branchfirstbyte)
+        {
+        if (reqbyte < 0) reqbyte = firstbyte;
+        firstbyte = REQ_NONE;
+        }
+
+      /* If we (now or from before) have no firstbyte, a firstbyte from the
+      branch becomes a reqbyte if there isn't a branch reqbyte. */
+
+      if (firstbyte < 0 && branchfirstbyte >= 0 && branchreqbyte < 0)
+          branchreqbyte = branchfirstbyte;
+
+      /* Now ensure that the reqbytes match */
+
+      if ((reqbyte & ~REQ_VARY) != (branchreqbyte & ~REQ_VARY))
+        reqbyte = REQ_NONE;
+      else reqbyte |= branchreqbyte;   /* To "or" REQ_VARY */
+      }
+
+    /* If lookbehind, check that this branch matches a fixed-length string, and
+    put the length into the OP_REVERSE item. Temporarily mark the end of the
+    branch with OP_END. */
+
+    if (lookbehind)
+      {
+      int fixed_length;
+      *code = OP_END;
+      fixed_length = find_fixedlength(last_branch, options);
+      DPRINTF(("fixed length = %d\n", fixed_length));
+      if (fixed_length < 0)
+        {
+        *errorcodeptr = (fixed_length == -2)? ERR36 : ERR25;
+        *ptrptr = ptr;
+        return FALSE;
+        }
+      PUT(reverse_count, 0, fixed_length);
+      }
+    }
+
+  /* Reached end of expression, either ')' or end of pattern. In the real
+  compile phase, go back through the alternative branches and reverse the chain
+  of offsets, with the field in the BRA item now becoming an offset to the
+  first alternative. If there are no alternatives, it points to the end of the
+  group. The length in the terminating ket is always the length of the whole
+  bracketed item. If any of the ims options were changed inside the group,
+  compile a resetting op-code following, except at the very end of the pattern.
+  Return leaving the pointer at the terminating char. */
+
+  if (*ptr != '|')
+    {
+    if (lengthptr == NULL)
+      {
+      int branch_length = code - last_branch;
+      do
+        {
+        int prev_length = GET(last_branch, 1);
+        PUT(last_branch, 1, branch_length);
+        branch_length = prev_length;
+        last_branch -= branch_length;
+        }
+      while (branch_length > 0);
+      }
+
+    /* Fill in the ket */
+
+    *code = OP_KET;
+    PUT(code, 1, code - start_bracket);
+    code += 1 + LINK_SIZE;
+
+    /* Resetting option if needed */
+
+    if ((options & PCRE_IMS) != oldims && *ptr == ')')
+      {
+      *code++ = OP_OPT;
+      *code++ = oldims;
+      length += 2;
+      }
+
+    /* Retain the highest bracket number, in case resetting was used. */
+
+    cd->bracount = max_bracount;
+
+    /* Set values to pass back */
+
+    *codeptr = code;
+    *ptrptr = ptr;
+    *firstbyteptr = firstbyte;
+    *reqbyteptr = reqbyte;
+    if (lengthptr != NULL)
+      {
+      if (OFLOW_MAX - *lengthptr < length)
+        {
+        *errorcodeptr = ERR20;
+        return FALSE;
+        }
+      *lengthptr += length;
+      }
+    return TRUE;
+    }
+
+  /* Another branch follows. In the pre-compile phase, we can move the code
+  pointer back to where it was for the start of the first branch. (That is,
+  pretend that each branch is the only one.)
+
+  In the real compile phase, insert an ALT node. Its length field points back
+  to the previous branch while the bracket remains open. At the end the chain
+  is reversed. It's done like this so that the start of the bracket has a
+  zero offset until it is closed, making it possible to detect recursion. */
+
+  if (lengthptr != NULL)
+    {
+    code = *codeptr + 1 + LINK_SIZE + skipbytes;
+    length += 1 + LINK_SIZE;
+    }
+  else
+    {
+    *code = OP_ALT;
+    PUT(code, 1, code - last_branch);
+    bc.current = last_branch = code;
+    code += 1 + LINK_SIZE;
+    }
+
+  ptr++;
+  }
+/* Control never reaches here */
+}
+
+
+
+
+/*************************************************
+*          Check for anchored expression         *
+*************************************************/
+
+/* Try to find out if this is an anchored regular expression. Consider each
+alternative branch. If they all start with OP_SOD or OP_CIRC, or with a bracket
+all of whose alternatives start with OP_SOD or OP_CIRC (recurse ad lib), then
+it's anchored. However, if this is a multiline pattern, then only OP_SOD
+counts, since OP_CIRC can match in the middle.
+
+We can also consider a regex to be anchored if OP_SOM starts all its branches.
+This is the code for \G, which means "match at start of match position, taking
+into account the match offset".
+
+A branch is also implicitly anchored if it starts with .* and DOTALL is set,
+because that will try the rest of the pattern at all possible matching points,
+so there is no point trying again.... er ....
+
+.... except when the .* appears inside capturing parentheses, and there is a
+subsequent back reference to those parentheses. We haven't enough information
+to catch that case precisely.
+
+At first, the best we could do was to detect when .* was in capturing brackets
+and the highest back reference was greater than or equal to that level.
+However, by keeping a bitmap of the first 31 back references, we can catch some
+of the more common cases more precisely.
+
+Arguments:
+  code           points to start of expression (the bracket)
+  options        points to the options setting
+  bracket_map    a bitmap of which brackets we are inside while testing; this
+                  handles up to substring 31; after that we just have to take
+                  the less precise approach
+  backref_map    the back reference bitmap
+
+Returns:     TRUE or FALSE
+*/
+
+static BOOL
+is_anchored(register const uschar *code, int *options, unsigned int bracket_map,
+  unsigned int backref_map)
+{
+do {
+   const uschar *scode = first_significant_code(code + _pcre_OP_lengths[*code],
+     options, PCRE_MULTILINE, FALSE);
+   register int op = *scode;
+
+   /* Non-capturing brackets */
+
+   if (op == OP_BRA)
+     {
+     if (!is_anchored(scode, options, bracket_map, backref_map)) return FALSE;
+     }
+
+   /* Capturing brackets */
+
+   else if (op == OP_CBRA)
+     {
+     int n = GET2(scode, 1+LINK_SIZE);
+     int new_map = bracket_map | ((n < 32)? (1 << n) : 1);
+     if (!is_anchored(scode, options, new_map, backref_map)) return FALSE;
+     }
+
+   /* Other brackets */
+
+   else if (op == OP_ASSERT || op == OP_ONCE || op == OP_COND)
+     {
+     if (!is_anchored(scode, options, bracket_map, backref_map)) return FALSE;
+     }
+
+   /* .* is not anchored unless DOTALL is set (which generates OP_ALLANY) and
+   it isn't in brackets that are or may be referenced. */
+
+   else if ((op == OP_TYPESTAR || op == OP_TYPEMINSTAR ||
+             op == OP_TYPEPOSSTAR))
+     {
+     if (scode[1] != OP_ALLANY || (bracket_map & backref_map) != 0)
+       return FALSE;
+     }
+
+   /* Check for explicit anchoring */
+
+   else if (op != OP_SOD && op != OP_SOM &&
+           ((*options & PCRE_MULTILINE) != 0 || op != OP_CIRC))
+     return FALSE;
+   code += GET(code, 1);
+   }
+while (*code == OP_ALT);   /* Loop for each alternative */
+return TRUE;
+}
+
+
+
+/*************************************************
+*         Check for starting with ^ or .*        *
+*************************************************/
+
+/* This is called to find out if every branch starts with ^ or .* so that
+"first char" processing can be done to speed things up in multiline
+matching and for non-DOTALL patterns that start with .* (which must start at
+the beginning or after \n). As in the case of is_anchored() (see above), we
+have to take account of back references to capturing brackets that contain .*
+because in that case we can't make the assumption.
+
+Arguments:
+  code           points to start of expression (the bracket)
+  bracket_map    a bitmap of which brackets we are inside while testing; this
+                  handles up to substring 31; after that we just have to take
+                  the less precise approach
+  backref_map    the back reference bitmap
+
+Returns:         TRUE or FALSE
+*/
+
+static BOOL
+is_startline(const uschar *code, unsigned int bracket_map,
+  unsigned int backref_map)
+{
+do {
+   const uschar *scode = first_significant_code(code + _pcre_OP_lengths[*code],
+     NULL, 0, FALSE);
+   register int op = *scode;
+
+   /* Non-capturing brackets */
+
+   if (op == OP_BRA)
+     {
+     if (!is_startline(scode, bracket_map, backref_map)) return FALSE;
+     }
+
+   /* Capturing brackets */
+
+   else if (op == OP_CBRA)
+     {
+     int n = GET2(scode, 1+LINK_SIZE);
+     int new_map = bracket_map | ((n < 32)? (1 << n) : 1);
+     if (!is_startline(scode, new_map, backref_map)) return FALSE;
+     }
+
+   /* Other brackets */
+
+   else if (op == OP_ASSERT || op == OP_ONCE || op == OP_COND)
+     { if (!is_startline(scode, bracket_map, backref_map)) return FALSE; }
+
+   /* .* means "start at start or after \n" if it isn't in brackets that
+   may be referenced. */
+
+   else if (op == OP_TYPESTAR || op == OP_TYPEMINSTAR || op == OP_TYPEPOSSTAR)
+     {
+     if (scode[1] != OP_ANY || (bracket_map & backref_map) != 0) return FALSE;
+     }
+
+   /* Check for explicit circumflex */
+
+   else if (op != OP_CIRC) return FALSE;
+
+   /* Move on to the next alternative */
+
+   code += GET(code, 1);
+   }
+while (*code == OP_ALT);  /* Loop for each alternative */
+return TRUE;
+}
+
+
+
+/*************************************************
+*       Check for asserted fixed first char      *
+*************************************************/
+
+/* During compilation, the "first char" settings from forward assertions are
+discarded, because they can cause conflicts with actual literals that follow.
+However, if we end up without a first char setting for an unanchored pattern,
+it is worth scanning the regex to see if there is an initial asserted first
+char. If all branches start with the same asserted char, or with a bracket all
+of whose alternatives start with the same asserted char (recurse ad lib), then
+we return that char, otherwise -1.
+
+Arguments:
+  code       points to start of expression (the bracket)
+  options    pointer to the options (used to check casing changes)
+  inassert   TRUE if in an assertion
+
+Returns:     -1 or the fixed first char
+*/
+
+static int
+find_firstassertedchar(const uschar *code, int *options, BOOL inassert)
+{
+register int c = -1;
+do {
+   int d;
+   const uschar *scode =
+     first_significant_code(code + 1+LINK_SIZE, options, PCRE_CASELESS, TRUE);
+   register int op = *scode;
+
+   switch(op)
+     {
+     default:
+     return -1;
+
+     case OP_BRA:
+     case OP_CBRA:
+     case OP_ASSERT:
+     case OP_ONCE:
+     case OP_COND:
+     if ((d = find_firstassertedchar(scode, options, op == OP_ASSERT)) < 0)
+       return -1;
+     if (c < 0) c = d; else if (c != d) return -1;
+     break;
+
+     case OP_EXACT:       /* Fall through */
+     scode += 2;
+
+     case OP_CHAR:
+     case OP_CHARNC:
+     case OP_PLUS:
+     case OP_MINPLUS:
+     case OP_POSPLUS:
+     if (!inassert) return -1;
+     if (c < 0)
+       {
+       c = scode[1];
+       if ((*options & PCRE_CASELESS) != 0) c |= REQ_CASELESS;
+       }
+     else if (c != scode[1]) return -1;
+     break;
+     }
+
+   code += GET(code, 1);
+   }
+while (*code == OP_ALT);
+return c;
+}
+
+
+
+/*************************************************
+*        Compile a Regular Expression            *
+*************************************************/
+
+/* This function takes a string and returns a pointer to a block of store
+holding a compiled version of the expression. The original API for this
+function had no error code return variable; it is retained for backwards
+compatibility. The new function is given a new name.
+
+Arguments:
+  pattern       the regular expression
+  options       various option bits
+  errorcodeptr  pointer to error code variable (pcre_compile2() only)
+                  can be NULL if you don't want a code value
+  errorptr      pointer to pointer to error text
+  erroroffset   ptr offset in pattern where error was detected
+  tables        pointer to character tables or NULL
+
+Returns:        pointer to compiled data block, or NULL on error,
+                with errorptr and erroroffset set
+*/
+
+PCRE_EXP_DEFN pcre * PCRE_CALL_CONVENTION
+pcre_compile(const char *pattern, int options, const char **errorptr,
+  int *erroroffset, const unsigned char *tables)
+{
+return pcre_compile2(pattern, options, NULL, errorptr, erroroffset, tables);
+}
+
+
+PCRE_EXP_DEFN pcre * PCRE_CALL_CONVENTION
+pcre_compile2(const char *pattern, int options, int *errorcodeptr,
+  const char **errorptr, int *erroroffset, const unsigned char *tables)
+{
+real_pcre *re;
+int length = 1;  /* For final END opcode */
+int firstbyte, reqbyte, newline;
+int errorcode = 0;
+int skipatstart = 0;
+#ifdef SUPPORT_UTF8
+BOOL utf8;
+#endif
+size_t size;
+uschar *code;
+const uschar *codestart;
+const uschar *ptr;
+compile_data compile_block;
+compile_data *cd = &compile_block;
+
+/* This space is used for "compiling" into during the first phase, when we are
+computing the amount of memory that is needed. Compiled items are thrown away
+as soon as possible, so that a fairly large buffer should be sufficient for
+this purpose. The same space is used in the second phase for remembering where
+to fill in forward references to subpatterns. */
+
+uschar cworkspace[COMPILE_WORK_SIZE];
+
+/* Set this early so that early errors get offset 0. */
+
+ptr = (const uschar *)pattern;
+
+/* We can't pass back an error message if errorptr is NULL; I guess the best we
+can do is just return NULL, but we can set a code value if there is a code
+pointer. */
+
+if (errorptr == NULL)
+  {
+  if (errorcodeptr != NULL) *errorcodeptr = 99;
+  return NULL;
+  }
+
+*errorptr = NULL;
+if (errorcodeptr != NULL) *errorcodeptr = ERR0;
+
+/* However, we can give a message for this error */
+
+if (erroroffset == NULL)
+  {
+  errorcode = ERR16;
+  goto PCRE_EARLY_ERROR_RETURN2;
+  }
+
+*erroroffset = 0;
+
+/* Can't support UTF8 unless PCRE has been compiled to include the code. */
+
+#ifdef SUPPORT_UTF8
+utf8 = (options & PCRE_UTF8) != 0;
+if (utf8 && (options & PCRE_NO_UTF8_CHECK) == 0 &&
+     (*erroroffset = _pcre_valid_utf8((uschar *)pattern, -1)) >= 0)
+  {
+  errorcode = ERR44;
+  goto PCRE_EARLY_ERROR_RETURN2;
+  }
+#else
+if ((options & PCRE_UTF8) != 0)
+  {
+  errorcode = ERR32;
+  goto PCRE_EARLY_ERROR_RETURN;
+  }
+#endif
+
+if ((options & ~PUBLIC_OPTIONS) != 0)
+  {
+  errorcode = ERR17;
+  goto PCRE_EARLY_ERROR_RETURN;
+  }
+
+/* Set up pointers to the individual character tables */
+
+if (tables == NULL) tables = _pcre_default_tables;
+cd->lcc = tables + lcc_offset;
+cd->fcc = tables + fcc_offset;
+cd->cbits = tables + cbits_offset;
+cd->ctypes = tables + ctypes_offset;
+
+/* Check for global one-time settings at the start of the pattern, and remember
+the offset for later. */
+
+while (ptr[skipatstart] == '(' && ptr[skipatstart+1] == '*')
+  {
+  int newnl = 0;
+  int newbsr = 0;
+
+  if (strncmp((char *)(ptr+skipatstart+2), "CR)", 3) == 0)
+    { skipatstart += 5; newnl = PCRE_NEWLINE_CR; }
+  else if (strncmp((char *)(ptr+skipatstart+2), "LF)", 3)  == 0)
+    { skipatstart += 5; newnl = PCRE_NEWLINE_LF; }
+  else if (strncmp((char *)(ptr+skipatstart+2), "CRLF)", 5)  == 0)
+    { skipatstart += 7; newnl = PCRE_NEWLINE_CR + PCRE_NEWLINE_LF; }
+  else if (strncmp((char *)(ptr+skipatstart+2), "ANY)", 4) == 0)
+    { skipatstart += 6; newnl = PCRE_NEWLINE_ANY; }
+  else if (strncmp((char *)(ptr+skipatstart+2), "ANYCRLF)", 8)  == 0)
+    { skipatstart += 10; newnl = PCRE_NEWLINE_ANYCRLF; }
+
+  else if (strncmp((char *)(ptr+skipatstart+2), "BSR_ANYCRLF)", 12) == 0)
+    { skipatstart += 14; newbsr = PCRE_BSR_ANYCRLF; }
+  else if (strncmp((char *)(ptr+skipatstart+2), "BSR_UNICODE)", 12) == 0)
+    { skipatstart += 14; newbsr = PCRE_BSR_UNICODE; }
+
+  if (newnl != 0)
+    options = (options & ~PCRE_NEWLINE_BITS) | newnl;
+  else if (newbsr != 0)
+    options = (options & ~(PCRE_BSR_ANYCRLF|PCRE_BSR_UNICODE)) | newbsr;
+  else break;
+  }
+
+/* Check validity of \R options. */
+
+switch (options & (PCRE_BSR_ANYCRLF|PCRE_BSR_UNICODE))
+  {
+  case 0:
+  case PCRE_BSR_ANYCRLF:
+  case PCRE_BSR_UNICODE:
+  break;
+  default: errorcode = ERR56; goto PCRE_EARLY_ERROR_RETURN;
+  }
+
+/* Handle different types of newline. The three bits give seven cases. The
+current code allows for fixed one- or two-byte sequences, plus "any" and
+"anycrlf". */
+
+switch (options & PCRE_NEWLINE_BITS)
+  {
+  case 0: newline = NEWLINE; break;   /* Build-time default */
+  case PCRE_NEWLINE_CR: newline = '\r'; break;
+  case PCRE_NEWLINE_LF: newline = '\n'; break;
+  case PCRE_NEWLINE_CR+
+       PCRE_NEWLINE_LF: newline = ('\r' << 8) | '\n'; break;
+  case PCRE_NEWLINE_ANY: newline = -1; break;
+  case PCRE_NEWLINE_ANYCRLF: newline = -2; break;
+  default: errorcode = ERR56; goto PCRE_EARLY_ERROR_RETURN;
+  }
+
+if (newline == -2)
+  {
+  cd->nltype = NLTYPE_ANYCRLF;
+  }
+else if (newline < 0)
+  {
+  cd->nltype = NLTYPE_ANY;
+  }
+else
+  {
+  cd->nltype = NLTYPE_FIXED;
+  if (newline > 255)
+    {
+    cd->nllen = 2;
+    cd->nl[0] = (newline >> 8) & 255;
+    cd->nl[1] = newline & 255;
+    }
+  else
+    {
+    cd->nllen = 1;
+    cd->nl[0] = newline;
+    }
+  }
+
+/* Maximum back reference and backref bitmap. The bitmap records up to 31 back
+references to help in deciding whether (.*) can be treated as anchored or not.
+*/
+
+cd->top_backref = 0;
+cd->backref_map = 0;
+
+/* Reflect pattern for debugging output */
+
+DPRINTF(("------------------------------------------------------------------\n"));
+DPRINTF(("%s\n", pattern));
+
+/* Pretend to compile the pattern while actually just accumulating the length
+of memory required. This behaviour is triggered by passing a non-NULL final
+argument to compile_regex(). We pass a block of workspace (cworkspace) for it
+to compile parts of the pattern into; the compiled code is discarded when it is
+no longer needed, so hopefully this workspace will never overflow, though there
+is a test for its doing so. */
+
+cd->bracount = cd->final_bracount = 0;
+cd->names_found = 0;
+cd->name_entry_size = 0;
+cd->name_table = NULL;
+cd->start_workspace = cworkspace;
+cd->start_code = cworkspace;
+cd->hwm = cworkspace;
+cd->start_pattern = (const uschar *)pattern;
+cd->end_pattern = (const uschar *)(pattern + strlen(pattern));
+cd->req_varyopt = 0;
+cd->external_options = options;
+cd->external_flags = 0;
+
+/* Now do the pre-compile. On error, errorcode will be set non-zero, so we
+don't need to look at the result of the function here. The initial options have
+been put into the cd block so that they can be changed if an option setting is
+found within the regex right at the beginning. Bringing initial option settings
+outside can help speed up starting point checks. */
+
+ptr += skipatstart;
+code = cworkspace;
+*code = OP_BRA;
+(void)compile_regex(cd->external_options, cd->external_options & PCRE_IMS,
+  &code, &ptr, &errorcode, FALSE, FALSE, 0, &firstbyte, &reqbyte, NULL, cd,
+  &length);
+if (errorcode != 0) goto PCRE_EARLY_ERROR_RETURN;
+
+DPRINTF(("end pre-compile: length=%d workspace=%d\n", length,
+  cd->hwm - cworkspace));
+
+if (length > MAX_PATTERN_SIZE)
+  {
+  errorcode = ERR20;
+  goto PCRE_EARLY_ERROR_RETURN;
+  }
+
+/* Compute the size of data block needed and get it, either from malloc or
+externally provided function. Integer overflow should no longer be possible
+because nowadays we limit the maximum value of cd->names_found and
+cd->name_entry_size. */
+
+size = length + sizeof(real_pcre) + cd->names_found * (cd->name_entry_size + 3);
+re = (real_pcre *)(pcre_malloc)(size);
+
+if (re == NULL)
+  {
+  errorcode = ERR21;
+  goto PCRE_EARLY_ERROR_RETURN;
+  }
+
+/* Put in the magic number, and save the sizes, initial options, internal
+flags, and character table pointer. NULL is used for the default character
+tables. The nullpad field is at the end; it's there to help in the case when a
+regex compiled on a system with 4-byte pointers is run on another with 8-byte
+pointers. */
+
+re->magic_number = MAGIC_NUMBER;
+re->size = size;
+re->options = cd->external_options;
+re->flags = cd->external_flags;
+re->dummy1 = 0;
+re->first_byte = 0;
+re->req_byte = 0;
+re->name_table_offset = sizeof(real_pcre);
+re->name_entry_size = cd->name_entry_size;
+re->name_count = cd->names_found;
+re->ref_count = 0;
+re->tables = (tables == _pcre_default_tables)? NULL : tables;
+re->nullpad = NULL;
+
+/* The starting points of the name/number translation table and of the code are
+passed around in the compile data block. The start/end pattern and initial
+options are already set from the pre-compile phase, as is the name_entry_size
+field. Reset the bracket count and the names_found field. Also reset the hwm
+field; this time it's used for remembering forward references to subpatterns.
+*/
+
+cd->final_bracount = cd->bracount;  /* Save for checking forward references */
+cd->bracount = 0;
+cd->names_found = 0;
+cd->name_table = (uschar *)re + re->name_table_offset;
+codestart = cd->name_table + re->name_entry_size * re->name_count;
+cd->start_code = codestart;
+cd->hwm = cworkspace;
+cd->req_varyopt = 0;
+cd->had_accept = FALSE;
+
+/* Set up a starting, non-extracting bracket, then compile the expression. On
+error, errorcode will be set non-zero, so we don't need to look at the result
+of the function here. */
+
+ptr = (const uschar *)pattern + skipatstart;
+code = (uschar *)codestart;
+*code = OP_BRA;
+(void)compile_regex(re->options, re->options & PCRE_IMS, &code, &ptr,
+  &errorcode, FALSE, FALSE, 0, &firstbyte, &reqbyte, NULL, cd, NULL);
+re->top_bracket = cd->bracount;
+re->top_backref = cd->top_backref;
+re->flags = cd->external_flags;
+
+if (cd->had_accept) reqbyte = -1;   /* Must disable after (*ACCEPT) */
+
+/* If not reached end of pattern on success, there's an excess bracket. */
+
+if (errorcode == 0 && *ptr != 0) errorcode = ERR22;
+
+/* Fill in the terminating state and check for disastrous overflow, but
+if debugging, leave the test till after things are printed out. */
+
+*code++ = OP_END;
+
+#ifndef DEBUG
+if (code - codestart > length) errorcode = ERR23;
+#endif
+
+/* Fill in any forward references that are required. */
+
+while (errorcode == 0 && cd->hwm > cworkspace)
+  {
+  int offset, recno;
+  const uschar *groupptr;
+  cd->hwm -= LINK_SIZE;
+  offset = GET(cd->hwm, 0);
+  recno = GET(codestart, offset);
+  groupptr = find_bracket(codestart, (re->options & PCRE_UTF8) != 0, recno);
+  if (groupptr == NULL) errorcode = ERR53;
+    else PUT(((uschar *)codestart), offset, groupptr - codestart);
+  }
+
+/* Give an error if there's back reference to a non-existent capturing
+subpattern. */
+
+if (errorcode == 0 && re->top_backref > re->top_bracket) errorcode = ERR15;
+
+/* Failed to compile, or error while post-processing */
+
+if (errorcode != 0)
+  {
+  (pcre_free)(re);
+  PCRE_EARLY_ERROR_RETURN:
+  *erroroffset = ptr - (const uschar *)pattern;
+  PCRE_EARLY_ERROR_RETURN2:
+  *errorptr = find_error_text(errorcode);
+  if (errorcodeptr != NULL) *errorcodeptr = errorcode;
+  return NULL;
+  }
+
+/* If the anchored option was not passed, set the flag if we can determine that
+the pattern is anchored by virtue of ^ characters or \A or anything else (such
+as starting with .* when DOTALL is set).
+
+Otherwise, if we know what the first byte has to be, save it, because that
+speeds up unanchored matches no end. If not, see if we can set the
+PCRE_STARTLINE flag. This is helpful for multiline matches when all branches
+start with ^. and also when all branches start with .* for non-DOTALL matches.
+*/
+
+if ((re->options & PCRE_ANCHORED) == 0)
+  {
+  int temp_options = re->options;   /* May get changed during these scans */
+  if (is_anchored(codestart, &temp_options, 0, cd->backref_map))
+    re->options |= PCRE_ANCHORED;
+  else
+    {
+    if (firstbyte < 0)
+      firstbyte = find_firstassertedchar(codestart, &temp_options, FALSE);
+    if (firstbyte >= 0)   /* Remove caseless flag for non-caseable chars */
+      {
+      int ch = firstbyte & 255;
+      re->first_byte = ((firstbyte & REQ_CASELESS) != 0 &&
+         cd->fcc[ch] == ch)? ch : firstbyte;
+      re->flags |= PCRE_FIRSTSET;
+      }
+    else if (is_startline(codestart, 0, cd->backref_map))
+      re->flags |= PCRE_STARTLINE;
+    }
+  }
+
+/* For an anchored pattern, we use the "required byte" only if it follows a
+variable length item in the regex. Remove the caseless flag for non-caseable
+bytes. */
+
+if (reqbyte >= 0 &&
+     ((re->options & PCRE_ANCHORED) == 0 || (reqbyte & REQ_VARY) != 0))
+  {
+  int ch = reqbyte & 255;
+  re->req_byte = ((reqbyte & REQ_CASELESS) != 0 &&
+    cd->fcc[ch] == ch)? (reqbyte & ~REQ_CASELESS) : reqbyte;
+  re->flags |= PCRE_REQCHSET;
+  }
+
+/* Print out the compiled data if debugging is enabled. This is never the
+case when building a production library. */
+
+#ifdef DEBUG
+
+printf("Length = %d top_bracket = %d top_backref = %d\n",
+  length, re->top_bracket, re->top_backref);
+
+printf("Options=%08x\n", re->options);
+
+if ((re->flags & PCRE_FIRSTSET) != 0)
+  {
+  int ch = re->first_byte & 255;
+  const char *caseless = ((re->first_byte & REQ_CASELESS) == 0)?
+    "" : " (caseless)";
+  if (isprint(ch)) printf("First char = %c%s\n", ch, caseless);
+    else printf("First char = \\x%02x%s\n", ch, caseless);
+  }
+
+if ((re->flags & PCRE_REQCHSET) != 0)
+  {
+  int ch = re->req_byte & 255;
+  const char *caseless = ((re->req_byte & REQ_CASELESS) == 0)?
+    "" : " (caseless)";
+  if (isprint(ch)) printf("Req char = %c%s\n", ch, caseless);
+    else printf("Req char = \\x%02x%s\n", ch, caseless);
+  }
+
+pcre_printint(re, stdout, TRUE);
+
+/* This check is done here in the debugging case so that the code that
+was compiled can be seen. */
+
+if (code - codestart > length)
+  {
+  (pcre_free)(re);
+  *errorptr = find_error_text(ERR23);
+  *erroroffset = ptr - (uschar *)pattern;
+  if (errorcodeptr != NULL) *errorcodeptr = ERR23;
+  return NULL;
+  }
+#endif   /* DEBUG */
+
+return (pcre *)re;
+}
+
+/* End of pcre_compile.c */