webengine/osswebengine/JavaScriptCore/pcre/pcre_compile.c
changeset 0 dd21522fd290
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/webengine/osswebengine/JavaScriptCore/pcre/pcre_compile.c	Mon Mar 30 12:54:55 2009 +0300
@@ -0,0 +1,5314 @@
+/*************************************************
+*      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) 1997-2005 University of Cambridge
+           Copyright (c) 2004, 2005 Apple Computer, Inc.
+
+-----------------------------------------------------------------------------
+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. */
+
+
+#include "pcre_internal.h"
+
+
+/* WARNING: These macros evaluate their parameters more than once. */
+#if PCRE_UTF16
+#define CTYPES(cd, x) ((x) <= 255 ? (cd)->ctypes[(x)] : 0)
+#define DIGITAB(x) ((x) <= 255 ? digitab[(x)] : 0)
+#else
+#define CTYPES(cd, x) cd->ctypes[(x)]
+#define DIGITAB(x) digitab[(x)]
+#endif
+
+
+/* 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
+
+
+
+/*************************************************
+*      Code parameters and static tables         *
+*************************************************/
+
+/* Maximum number of items on the nested bracket stacks at compile time. This
+applies to the nesting of all kinds of parentheses. It does not limit
+un-nested, non-capturing parentheses. This number can be made bigger if
+necessary - it is used to dimension one int and one unsigned char vector at
+compile time. */
+
+#define BRASTACK_SIZE 200
+
+
+/* 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. */
+
+#if JAVASCRIPT   /* This is the "JavaScript" table for ASCII systems */
+static const short int escapes[] = {
+     0,      0,      0,      0,      0,      0,      0,      0,   /* 0 - 7 */
+     0,      0,    ':',    ';',    '<',    '=',    '>',    '?',   /* 8 - ? */
+   '@',      0, -ESC_B,      0, -ESC_D,      0,      0,      0,   /* @ - G */
+     0,      0,      0,      0,      0,      0,      0,      0,   /* H - O */
+     0,      0,      0, -ESC_S,      0,      0,      0, -ESC_W,   /* P - W */
+     0,      0,      0,    '[',   '\\',    ']',    '^',    '_',   /* X - _ */
+   '`',      7, -ESC_b,      0, -ESC_d,      0,  ESC_f,      0,   /* ` - g */
+     0,      0,      0,      0,      0,      0,  ESC_n,      0,   /* h - o */
+     0,      0,  ESC_r, -ESC_s,  ESC_tee,    0,  ESC_v, -ESC_w,   /* p - w */
+     0,      0,      0                                            /* x - z */
+};
+#else
+#if !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 */
+     0,      0,      0,      0,      0,      0,      0,      0,   /* H - O */
+-ESC_P, -ESC_Q,      0, -ESC_S,      0,      0,      0, -ESC_W,   /* P - W */
+-ESC_X,      0, -ESC_Z,    '[',   '\\',    ']',    '^',    '_',   /* X - _ */
+   '`',      7, -ESC_b,      0, -ESC_d,  ESC_e,  ESC_f,      0,   /* ` - g */
+     0,      0,      0,      0,      0,      0,  ESC_n,      0,   /* h - o */
+-ESC_p,      0,  ESC_r, -ESC_s,  ESC_tee,    0,      0, -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 */     0,     0,      0,     '{',      0,     0,      0,      0,
+/*  90 */     0,     0,      0,     'l',      0, ESC_n,      0, -ESC_p,
+/*  98 */     0, ESC_r,      0,     '}',      0,     0,      0,      0,
+/*  A0 */     0,   '~', -ESC_s, ESC_tee,      0,     0, -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 */     0,     0,      0,       0,      0,     0,      0,      0,
+/*  D0 */   '}',     0,      0,       0,      0,     0,      0, -ESC_P,
+/*  D8 */-ESC_Q,     0,      0,       0,      0,     0,      0,      0,
+/*  E0 */  '\\',     0, -ESC_S,       0,      0,     0, -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
+#endif
+
+
+/* Tables of names of POSIX character classes and their lengths. The list is
+terminated by a zero length entry. The first three must be alpha, upper, lower,
+as this is assumed for handling case independence. */
+
+static const char * const posix_names[] = {
+  "alpha", "lower", "upper",
+  "alnum", "ascii", "blank", "cntrl", "digit", "graph",
+  "print", "punct", "space", "word",  "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; up to three may be combined
+to form the class. The table for [:blank:] is dynamically modified to remove
+the vertical space characters. */
+
+static const int posix_class_maps[] = {
+  cbit_lower, cbit_upper, -1,             /* alpha */
+  cbit_lower, -1,         -1,             /* lower */
+  cbit_upper, -1,         -1,             /* upper */
+  cbit_digit, cbit_lower, cbit_upper,     /* alnum */
+  cbit_print, cbit_cntrl, -1,             /* ascii */
+  cbit_space, -1,         -1,             /* blank - a GNU extension */
+  cbit_cntrl, -1,         -1,             /* cntrl */
+  cbit_digit, -1,         -1,             /* digit */
+  cbit_graph, -1,         -1,             /* graph */
+  cbit_print, -1,         -1,             /* print */
+  cbit_punct, -1,         -1,             /* punct */
+  cbit_space, -1,         -1,             /* space */
+  cbit_word,  -1,         -1,             /* word - a Perl extension */
+  cbit_xdigit,-1,         -1              /* xdigit */
+};
+
+
+/* The texts of compile-time error messages. These are "char *" because they
+are passed to the outside world. */
+
+static const char * const error_texts[] = {
+  "no error",
+  "\\ at end of pattern",
+  "\\c at end of pattern",
+  "unrecognized character follows \\",
+  "numbers out of order in {} quantifier",
+  /* 5 */
+  "number too big in {} quantifier",
+  "missing terminating ] for character class",
+  "invalid escape sequence in character class",
+  "range out of order in character class",
+  "nothing to repeat",
+  /* 10 */
+  "operand of unlimited repeat could match the empty string",
+  "internal error: unexpected repeat",
+  "unrecognized character after (?",
+  "POSIX named classes are supported only within a class",
+  "missing )",
+  /* 15 */
+  "reference to non-existent subpattern",
+  "erroffset passed as NULL",
+  "unknown option bit(s) set",
+  "missing ) after comment",
+  "parentheses nested too deeply",
+  /* 20 */
+  "regular expression too large",
+  "failed to get memory",
+  "unmatched parentheses",
+  "internal error: code overflow",
+  "unrecognized character after (?<",
+  /* 25 */
+  "lookbehind assertion is not fixed length",
+  "malformed number after (?(",
+  "conditional group contains more than two branches",
+  "assertion expected after (?(",
+  "(?R or (?digits must be followed by )",
+  /* 30 */
+  "unknown POSIX class name",
+  "POSIX collating elements are not supported",
+  "this version of PCRE is not compiled with PCRE_UTF8 support",
+  "spare error",
+  "character value in \\x{...} sequence is too large",
+  /* 35 */
+  "invalid condition (?(0)",
+  "\\C not allowed in lookbehind assertion",
+  "PCRE does not support \\L, \\l, \\N, \\U, or \\u",
+  "number after (?C is > 255",
+  "closing ) for (?C expected",
+  /* 40 */
+  "recursive call could loop indefinitely",
+  "unrecognized character after (?P",
+  "syntax error after (?P",
+  "two named groups have the same name",
+#if PCRE_UTF16
+  "invalid UTF-16 string",
+#else
+  "invalid UTF-8 string",
+#endif
+  /* 45 */
+  "support for \\P, \\p, and \\X has not been compiled",
+  "malformed \\P or \\p sequence",
+  "unknown property name after \\P or \\p"
+};
+
+
+/* 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. */
+
+#if !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- 0xAC  */
+  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- 0xAC */
+  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, int *, uschar **, const pcre_uchar **, const pcre_uchar *, int *, BOOL, int,
+    int *, int *, branch_chain *, compile_data *);
+
+
+
+/*************************************************
+*            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. 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, errorptr is set
+*/
+
+static int
+check_escape(const pcre_uchar **ptrptr, const pcre_uchar *patternEnd, int *errorcodeptr, int bracount,
+  int options, BOOL isclass)
+{
+const pcre_uchar *ptr = *ptrptr;
+int c, i;
+
+/* If backslash is at the end of the pattern, it's an error. */
+
+if (++ptr == patternEnd) {
+    *errorcodeptr = ERR1;
+    *ptrptr = ptr;
+    return 0;
+}
+
+c = *ptr;
+
+/* Non-alphamerics 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. */
+
+#if !EBCDIC    /* ASCII coding */
+if (c < '0' || c > 'z') {}                           /* Not alphameric */
+else if ((i = escapes[c - '0']) != 0) c = i;
+
+#else          /* EBCDIC coding */
+if (c < 'a' || (ebcdic_chartab[c] & 0x0E) == 0) {}   /* Not alphameric */
+else if ((i = escapes[c - 0x48]) != 0)  c = i;
+#endif
+
+/* Escapes that need further processing, or are illegal. */
+
+else
+  {
+  const pcre_uchar *oldptr;
+  switch (c)
+    {
+    /* A number of Perl escapes are not handled by PCRE. We give an explicit
+    error. */
+
+#if !JAVASCRIPT
+    case 'l':
+    case 'L':
+    case 'N':
+    case 'u':
+    case 'U':
+    *errorcodeptr = ERR37;
+    break;
+#endif
+
+    /* 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 (ptr + 1 < patternEnd && (DIGITAB(ptr[1]) & ctype_digit) != 0)
+        c = c * 10 + *(++ptr) - '0';
+      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. */
+
+    case '0':
+    c -= '0';
+    while (i++ < 2 && ptr + 1 < patternEnd && ptr[1] >= '0' && ptr[1] <= '7')
+        c = c * 8 + *(++ptr) - '0';
+    c &= 255;     /* Take least significant 8 bits */
+    break;
+
+    /* \x is complicated when UTF-8 is enabled. \x{ddd} is a character number
+    which can be greater than 0xff, but only if the ddd are hex digits. */
+
+    case 'x':
+#ifdef SUPPORT_UTF8
+    if (ptr + 1 < patternEnd && ptr[1] == '{' && (options & PCRE_UTF8) != 0)
+      {
+      const pcre_uchar *pt = ptr + 2;
+      register int count = 0;
+      c = 0;
+      while (pt < patternEnd && (DIGITAB(*pt) & ctype_xdigit) != 0)
+        {
+        int cc = *pt++;
+        count++;
+#if !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 >= 'a' && cc <= 'z') cc += 64;  /* Convert to upper case */
+        c = c * 16 + cc - ((cc >= '0')? '0' : ('A' - 10));
+#endif
+        }
+      if (pt < patternEnd && *pt == '}')
+        {
+        if (c < 0 || count > 8 || (c >= 0xd800 && c <= 0xdbff) || (c >= 0xfdd0 && c <= 0xfdef) || c == 0xfffe || c == 0xffff || c > 0x10FFFF) *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. */
+      }
+#endif
+
+    /* Read just a single hex char */
+
+    c = 0;
+    while (i++ < 2 && ptr + 1 < patternEnd && (DIGITAB(ptr[1]) & ctype_xdigit) != 0)
+      {
+      int cc;                               /* Some compilers don't like ++ */
+      cc = *(++ptr);                        /* in initializers */
+#if !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;
+
+#if JAVASCRIPT
+    case 'u':
+    c = 0;
+    while (i++ < 4 && ptr + 1 < patternEnd && (DIGITAB(ptr[1]) & ctype_xdigit) != 0)
+      {
+      int cc;                               /* Some compilers don't like ++ */
+      cc = *(++ptr);                        /* in initializers */
+#if !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;
+#endif
+
+    /* Other special escapes not starting with a digit are straightforward */
+
+    case 'c':
+    if (++ptr == patternEnd)
+      {
+      *errorcodeptr = ERR2;
+      return 0;
+      }
+    c = *ptr;
+
+    /* A 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.) */
+
+#if !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 alphameric 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;
+}
+
+
+
+#if !JAVASCRIPT
+#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
+  errorcodeptr   points to the error code variable
+
+Returns:     value from ucp_type_table, or -1 for an invalid type
+*/
+
+static int
+get_ucp(const pcre_uchar **ptrptr, const pcre_uchar *patternEnd, BOOL *negptr, int *errorcodeptr)
+{
+int c, i, bot, top;
+const pcre_uchar *ptr = *ptrptr;
+char name[4];
+
+if (++ptr == patternEnd) goto ERROR_RETURN;
+c = *ptr;
+
+*negptr = FALSE;
+
+/* \P or \p can be followed by a one- or two-character name in {}, optionally
+preceded by ^ for negation. */
+
+if (c == '{')
+  {
+  if (ptr + 1 < patternEnd && ptr[1] == '^')
+    {
+    *negptr = TRUE;
+    ptr++;
+    }
+  for (i = 0; i <= 2; i++)
+    {
+    if (++ptr == patternEnd) goto ERROR_RETURN;
+    c = *ptr;
+    if (c == '}') break;
+    if (c > 127) goto ERROR_RETURN;
+    name[i] = c;
+    }
+  if (c !='}')   /* Try to distinguish error cases */
+    {
+    while (++ptr < patternEnd && *ptr != '}')
+        ;
+    if (*ptr == '}') goto UNKNOWN_RETURN; else goto ERROR_RETURN;
+    }
+  name[i] = 0;
+  }
+
+/* Otherwise there is just one following character */
+
+else
+  {
+  if (c > 127) goto ERROR_RETURN;
+  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)/2;
+  c = strcmp(name, _pcre_utt[i].name);
+  if (c == 0) return _pcre_utt[i].value;
+  if (c > 0) bot = i + 1; else top = i;
+  }
+
+UNKNOWN_RETURN:
+*errorcodeptr = ERR47;
+*ptrptr = ptr;
+return -1;
+
+ERROR_RETURN:
+*errorcodeptr = ERR46;
+*ptrptr = ptr;
+return -1;
+}
+#endif
+#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 pcre_uchar *p, const pcre_uchar *patternEnd)
+{
+if (p >= patternEnd || (DIGITAB(*p) & ctype_digit) == 0)
+    return FALSE;
+p++;
+while (p < patternEnd && (DIGITAB(*p) & ctype_digit) != 0)
+    p++;
+if (p < patternEnd && *p == '}')
+    return TRUE;
+
+if (p >= patternEnd || *p++ != ',')
+    return FALSE;
+if (p < patternEnd && *p == '}')
+    return TRUE;
+
+if (p >= patternEnd || (DIGITAB(*p) & ctype_digit) == 0)
+    return FALSE;
+p++;
+while (p < patternEnd && (DIGITAB(*p) & ctype_digit) != 0)
+    p++;
+
+return (p < patternEnd && *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 pcre_uchar *
+read_repeat_counts(const pcre_uchar *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 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_BRANUMBER:
+    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;
+  if (op >= OP_BRA) op = OP_BRA;
+
+  switch (op)
+    {
+    case OP_BRA:
+    case OP_ONCE:
+    case OP_COND:
+    d = find_fixedlength(cc, 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_BRANUMBER:
+    case OP_CREF:
+    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:
+    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);
+    cc += 4;
+    break;
+
+    /* Handle single-char matchers */
+
+    case OP_PROP:
+    case OP_NOTPROP:
+    cc++;
+    /* 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:
+    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
+*/
+
+#if !JAVASCRIPT
+
+static const uschar *
+find_bracket(const uschar *code, BOOL utf8, int number)
+{
+#ifndef SUPPORT_UTF8
+utf8 = utf8;               /* Stop pedantic compilers complaining */
+#endif
+
+for (;;)
+  {
+  register int c = *code;
+  if (c == OP_END) return NULL;
+  else if (c > OP_BRA)
+    {
+    int n = c - OP_BRA;
+    if (n > EXTRACT_BASIC_MAX) n = GET2(code, 2+LINK_SIZE);
+    if (n == number) return (uschar *)code;
+    code += _pcre_OP_lengths[OP_BRA];
+    }
+  else
+    {
+    code += _pcre_OP_lengths[c];
+
+#ifdef SUPPORT_UTF8
+
+    /* 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 scan along to skip the extra bytes. All opcodes are less than 128, so we
+    can use relatively efficient code. */
+
+    if (utf8) switch(c)
+      {
+      case OP_CHAR:
+      case OP_CHARNC:
+      case OP_EXACT:
+      case OP_UPTO:
+      case OP_MINUPTO:
+      case OP_STAR:
+      case OP_MINSTAR:
+      case OP_PLUS:
+      case OP_MINPLUS:
+      case OP_QUERY:
+      case OP_MINQUERY:
+      while ((*code & 0xc0) == 0x80) code++;
+      break;
+
+      /* 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. */
+
+      case OP_XCLASS:
+      code += GET(code, 1) + 1;
+      break;
+      }
+#endif
+    }
+  }
+}
+
+#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)
+{
+#ifndef SUPPORT_UTF8
+utf8 = utf8;               /* Stop pedantic compilers complaining */
+#endif
+
+for (;;)
+  {
+  register int c = *code;
+  if (c == OP_END) return NULL;
+  else if (c == OP_RECURSE) return code;
+  else if (c > OP_BRA)
+    {
+    code += _pcre_OP_lengths[OP_BRA];
+    }
+  else
+    {
+    code += _pcre_OP_lengths[c];
+
+#ifdef SUPPORT_UTF8
+
+    /* 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 scan along to skip the extra bytes. All opcodes are less than 128, so we
+    can use relatively efficient code. */
+
+    if (utf8) switch(c)
+      {
+      case OP_CHAR:
+      case OP_CHARNC:
+      case OP_EXACT:
+      case OP_UPTO:
+      case OP_MINUPTO:
+      case OP_STAR:
+      case OP_MINSTAR:
+      case OP_PLUS:
+      case OP_MINPLUS:
+      case OP_QUERY:
+      case OP_MINQUERY:
+      while ((*code & 0xc0) == 0x80) code++;
+      break;
+
+      /* 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. */
+
+      case OP_XCLASS:
+      code += GET(code, 1) + 1;
+      break;
+      }
+#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 only from could_be_empty()
+below. Note that first_significant_code() skips over assertions. 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 + 1 + LINK_SIZE, NULL, 0, TRUE);
+     code < endcode;
+     code = first_significant_code(code + _pcre_OP_lengths[c], NULL, 0, TRUE))
+  {
+  const uschar *ccode;
+
+  c = *code;
+
+  if (c >= OP_BRA)
+    {
+    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 */
+    code += 1 + LINK_SIZE;
+    c = *code;
+    }
+
+  else switch (c)
+    {
+    /* Check for quantifiers after a class */
+
+#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_ANYBYTE:
+    case OP_CHAR:
+    case OP_CHARNC:
+    case OP_NOT:
+    case OP_PLUS:
+    case OP_MINPLUS:
+    case OP_EXACT:
+    case OP_NOTPLUS:
+    case OP_NOTMINPLUS:
+    case OP_NOTEXACT:
+    case OP_TYPEPLUS:
+    case OP_TYPEMINPLUS:
+    case OP_TYPEEXACT:
+    return FALSE;
+
+    /* End of branch */
+
+    case OP_KET:
+    case OP_KETRMAX:
+    case OP_KETRMIN:
+    case OP_ALT:
+    return TRUE;
+
+    /* In UTF-8 mode, STAR, MINSTAR, QUERY, MINQUERY, UPTO, and MINUPTO  may be
+    followed by a multibyte character */
+
+#ifdef SUPPORT_UTF8
+    case OP_STAR:
+    case OP_MINSTAR:
+    case OP_QUERY:
+    case OP_MINQUERY:
+    case OP_UPTO:
+    case OP_MINUPTO:
+    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
+*/
+
+#if !JAVASCRIPT
+
+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;
+}
+
+#endif
+
+
+
+/*************************************************
+*           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 an
+optional ^ and then a sequence of letters, terminated by a matching ":]" or
+".]" or "=]".
+
+Argument:
+  ptr      pointer to the initial [
+  endptr   where to return the end pointer
+  cd       pointer to compile data
+
+Returns:   TRUE or FALSE
+*/
+
+#if !JAVASCRIPT
+
+static BOOL
+check_posix_syntax(const pcre_uchar *ptr, const pcre_uchar *patternEnd, const pcre_uchar **endptr, compile_data *cd)
+{
+int terminator;          /* Don't combine these lines; the Solaris cc */
+terminator = *(++ptr);   /* compiler warns about "non-constant" initializer. */
+if (*(++ptr) == '^') ptr++;
+while (ptr < patternEnd && (CTYPES(cd, *ptr) & ctype_letter) != 0)
+    ptr++;
+if (ptr + 1 < patternEnd && *ptr == terminator && ptr[1] == ']')
+  {
+  *endptr = ptr;
+  return TRUE;
+  }
+return FALSE;
+}
+
+#endif
+
+#if PCRE_UTF16
+
+static __inline BOOL strequal(const pcre_uchar *str1, int len, const char *str2)
+{
+  int i;
+  for (i = 0; i < len; i++)
+    if (str1[i] != str2[i])
+      return FALSE;
+  return TRUE;
+}
+
+#define STREQUAL(str1, len, str2) strequal((str1), (len), (str2))
+
+#else
+
+#define STREQUAL(str1, len, str2) (strncmp((const char *)(str1), (str2), (len)) == 0)
+
+#endif
+
+/*************************************************
+*          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
+*/
+
+#if !JAVASCRIPT
+
+static int
+check_posix_name(const pcre_uchar *ptr, int len)
+{
+register int yield = 0;
+while (posix_name_lengths[yield] != 0)
+  {
+  if (len == posix_name_lengths[yield] &&
+    STREQUAL(ptr, len, posix_names[yield])) return yield;
+  yield++;
+  }
+return -1;
+}
+
+#endif
+
+
+/*************************************************
+*    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 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 is the job of this function. Before it is called, the
+partially compiled regex must be temporarily terminated with OP_END.
+
+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.
+
+Returns:     nothing
+*/
+
+static void
+adjust_recurse(uschar *group, int adjust, BOOL utf8, compile_data *cd)
+{
+uschar *ptr = group;
+while ((ptr = (uschar *)find_recurse(ptr, utf8)) != NULL)
+  {
+  int 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 pcre_uchar *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 pcre_uchar *ptr, compile_data *cd)
+{
+int length = INT_CAST(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(int *cptr, int d, int *ocptr, int *odptr)
+{
+int c, chartype, othercase = 0, next;
+
+for (c = *cptr; c <= d; c++)
+  {
+  if (_pcre_ucp_findchar(c, &chartype, &othercase) == ucp_L && othercase != 0)
+    break;
+  }
+
+if (c > d) return FALSE;
+
+*ocptr = othercase;
+next = othercase + 1;
+
+for (++c; c <= d; c++)
+  {
+  if (_pcre_ucp_findchar(c, &chartype, &othercase) != ucp_L ||
+        othercase != next)
+    break;
+  next++;
+  }
+
+*odptr = next - 1;
+*cptr = c;
+
+return TRUE;
+}
+#endif  /* SUPPORT_UCP */
+
+
+/*************************************************
+*           Compile one branch                   *
+*************************************************/
+
+/* Scan the pattern, compiling it into the code vector. If the options are
+changed during the branch, the pointer is used to change the external options
+bits.
+
+Arguments:
+  optionsptr     pointer to the option bits
+  brackets       points to number of extracting brackets used
+  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.
+
+Returns:         TRUE on success
+                 FALSE, with *errorcodeptr set non-zero on error
+*/
+
+static BOOL
+compile_branch(int *optionsptr, int *brackets, uschar **codeptr,
+  const pcre_uchar **ptrptr, const pcre_uchar *patternEnd, int *errorcodeptr, int *firstbyteptr,
+  int *reqbyteptr, branch_chain *bcptr, compile_data *cd)
+{
+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 condcount = 0;
+int options = *optionsptr;
+int after_manual_callout = 0;
+register int c;
+register uschar *code = *codeptr;
+uschar *tempcode;
+BOOL inescq = FALSE;
+BOOL groupsetfirstbyte = FALSE;
+const pcre_uchar *ptr = *ptrptr;
+const pcre_uchar *tempptr;
+uschar *previous = NULL;
+uschar *previous_callout = NULL;
+uschar classbits[32];
+
+#ifdef SUPPORT_UTF8
+BOOL class_utf8;
+BOOL utf8 = (options & PCRE_UTF8) != 0;
+uschar *class_utf8data;
+uschar utf8_char[6];
+#else
+BOOL utf8 = FALSE;
+#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 possessive_quantifier;
+  BOOL is_quantifier;
+  int class_charcount;
+  int class_lastchar;
+  int newoptions;
+#if !JAVASCRIPT
+  int recno;
+#endif
+  int skipbytes;
+  int subreqbyte;
+  int subfirstbyte;
+  int mclength;
+  uschar mcbuffer[8];
+
+  /* Next byte in the pattern */
+
+  c = ptr < patternEnd ? *ptr : 0;
+
+#if !JAVASCRIPT
+  /* If in \Q...\E, check for the end; if not, we have a literal */
+
+  if (inescq && ptr < patternEnd)
+    {
+    if (c == '\\' && ptr + 1 < patternEnd && ptr[1] == 'E')
+      {
+      inescq = FALSE;
+      ptr++;
+      continue;
+      }
+    else
+      {
+      if (previous_callout != NULL)
+        {
+        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;
+      }
+    }
+#endif
+
+  /* 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, patternEnd));
+
+  if (!is_quantifier && previous_callout != NULL &&
+       after_manual_callout-- <= 0)
+    {
+    complete_callout(previous_callout, ptr, cd);
+    previous_callout = NULL;
+    }
+
+  /* In extended mode, skip white space and comments */
+
+  if ((options & PCRE_EXTENDED) != 0)
+    {
+    if ((CTYPES(cd, c) & ctype_space) != 0) continue;
+    if (c == '#')
+      {
+      while (++ptr < patternEnd && (c = *ptr) != NEWLINE)
+          ;
+      if (ptr < patternEnd)
+          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)
+    {
+    /* The branch terminates at end of string, |, or ). */
+
+    case 0:
+        if (ptr < patternEnd)
+            goto NORMAL_CHAR;
+        // End of string; fall through
+    case '|':
+    case ')':
+    *firstbyteptr = firstbyte;
+    *reqbyteptr = reqbyte;
+    *codeptr = code;
+    *ptrptr = ptr;
+    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++ = OP_ANY;
+    break;
+
+    /* Character classes. If the included characters are all < 255 in value, 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.
+    */
+
+    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 !JAVASCRIPT
+    if ((ptr[1] == ':' || ptr[1] == '.' || ptr[1] == '=') &&
+        check_posix_syntax(ptr, patternEnd, &tempptr, cd))
+      {
+      *errorcodeptr = (ptr[1] == ':')? ERR13 : ERR31;
+      goto FAILED;
+      }
+#endif
+
+    /* If the first character is '^', set the negation flag and skip it. */
+
+    if ((c = *(++ptr)) == '^')
+      {
+      negate_class = TRUE;
+      c = *(++ptr);
+      }
+    else
+      {
+      negate_class = 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). For higher valued UTF-8
+    characters, we don't yet do any optimization. */
+
+    class_charcount = 0;
+    class_lastchar = -1;
+
+#ifdef SUPPORT_UTF8
+    class_utf8 = FALSE;                       /* No chars >= 256 */
+    class_utf8data = code + LINK_SIZE + 34;   /* For UTF-8 items */
+#endif
+
+    /* Initialize the 32-char bit map to all zeros. We have to build the
+    map in a temporary bit of store, in case the class contains only 1
+    character (< 256), because in that case the compiled code doesn't use the
+    bit map. */
+
+    memset(classbits, 0, 32 * sizeof(uschar));
+
+    /* Process characters until ] is reached. By writing this as a "do" it
+    means that an initial ] is taken as a data character. The first pass
+    through the regex checked the overall syntax, so we don't need to be very
+    strict here. At the start of the loop, c contains the first byte of the
+    character. */
+
+    do
+      {
+#ifdef SUPPORT_UTF8
+      if (utf8 && c > 127)
+        {                           /* Braces are required because the */
+        GETCHARLEN(c, ptr, ptr);    /* macro generates multiple statements */
+        }
+#endif
+
+#if !JAVASCRIPT
+
+      /* Inside \Q...\E everything is literal except \E */
+
+      if (inescq)
+        {
+        if (c == '\\' && ptr[1] == 'E')
+          {
+          inescq = FALSE;
+          ptr++;
+          continue;
+          }
+        else goto LONE_SINGLE_CHARACTER;
+        }
+
+      /* 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, patternEnd, &tempptr, cd))
+        {
+        BOOL local_negate = FALSE;
+        int posix_class, i, namelen;
+        register const uschar *cbits = cd->cbits;
+
+        if (ptr[1] != ':')
+          {
+          *errorcodeptr = ERR31;
+          goto FAILED;
+          }
+
+        ptr += 2;
+        if (*ptr == '^')
+          {
+          local_negate = TRUE;
+          ptr++;
+          }
+
+        namelen = INT_CAST(tempptr - ptr);
+        posix_class = check_posix_name(ptr, namelen);
+        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;
+
+        /* Or into the map we are building up to 3 of the static class
+        tables, or their negations. The [:blank:] class sets up the same
+        chars as the [:space:] class (all white space). We remove the vertical
+        white space chars afterwards. */
+
+        posix_class *= 3;
+        for (i = 0; i < 3; i++)
+          {
+          BOOL blankclass = ptr + 5 <= patternEnd && STREQUAL(ptr, 5, "blank");
+          int taboffset = posix_class_maps[posix_class + i];
+          if (taboffset < 0) break;
+          if (local_negate)
+            {
+            if (i == 0)
+              for (c = 0; c < 32; c++) classbits[c] |= ~cbits[c+taboffset];
+            else
+              for (c = 0; c < 32; c++) classbits[c] &= ~cbits[c+taboffset];
+            if (blankclass) classbits[1] |= 0x3c;
+            }
+          else
+            {
+            for (c = 0; c < 32; c++) classbits[c] |= cbits[c+taboffset];
+            if (blankclass) classbits[1] &= ~0x3c;
+            }
+          }
+
+        ptr = tempptr + 1;
+        class_charcount = 10;  /* Set > 1; assumes more than 1 per class */
+        continue;    /* End of POSIX syntax handling */
+        }
+
+#endif
+
+      /* Backslash may introduce a single character, or it may introduce one
+      of the specials, which just set a flag. Escaped items are checked for
+      validity in the pre-compiling pass. 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, patternEnd, errorcodeptr, *brackets, options, TRUE);
+
+        if (-c == ESC_b) c = '\b';       /* \b is backslash in a class */
+        else if (-c == ESC_X) c = 'X';   /* \X is literal X in a class */
+        else if (-c == ESC_Q)            /* Handle start of quoted string */
+          {
+          if (ptr + 2 < patternEnd && ptr[1] == '\\' && ptr[2] == 'E')
+            {
+            ptr += 2; /* avoid empty string */
+            }
+          else inescq = TRUE;
+          continue;
+          }
+
+        if (c < 0)
+          {
+          register const uschar *cbits = cd->cbits;
+          class_charcount += 2;     /* Greater than 1 is what matters */
+          switch (-c)
+            {
+            case ESC_d:
+            for (c = 0; c < 32; c++) classbits[c] |= cbits[c+cbit_digit];
+            continue;
+
+            case ESC_D:
+            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:
+            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];
+#if !JAVASCRIPT
+            classbits[1] &= ~0x08;   /* Perl 5.004 onwards omits VT from \s */
+#endif
+            continue;
+
+            case ESC_S:
+            for (c = 0; c < 32; c++) classbits[c] |= ~cbits[c+cbit_space];
+#if !JAVASCRIPT
+            classbits[1] |= 0x08;    /* Perl 5.004 onwards omits VT from \s */
+#endif
+            continue;
+
+#if !JAVASCRIPT
+#ifdef SUPPORT_UCP
+            case ESC_p:
+            case ESC_P:
+              {
+              BOOL negated;
+              int property = get_ucp(&ptr, patternEnd, &negated, errorcodeptr);
+              if (property < 0) goto FAILED;
+              class_utf8 = TRUE;
+              *class_utf8data++ = ((-c == ESC_p) != negated)?
+                XCL_PROP : XCL_NOTPROP;
+              *class_utf8data++ = property;
+              class_charcount -= 2;   /* Not a < 256 character */
+              }
+            continue;
+#endif
+#endif
+
+            /* Unrecognized escapes are faulted if PCRE is running in its
+            strict mode. By default, for compatibility with Perl, they are
+            treated as literals. */
+
+            default:
+            if ((options & PCRE_EXTRA) != 0)
+              {
+              *errorcodeptr = ERR7;
+              goto FAILED;
+              }
+            c = *ptr;              /* The final character */
+            class_charcount -= 2;  /* Undo the default count from above */
+            }
+          }
+
+        /* Fall through if we have a single character (c >= 0). This may be
+        > 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
+      here is treated as a literal. */
+
+      if (ptr[1] == '-' && ptr[2] != ']')
+        {
+        int d;
+        ptr += 2;
+
+#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 (d == '\\')
+          {
+          const pcre_uchar *oldptr = ptr;
+          d = check_escape(&ptr, patternEnd, errorcodeptr, *brackets, options, TRUE);
+
+          /* \b is backslash; \X is literal X; any other special means the '-'
+          was literal */
+
+          if (d < 0)
+            {
+            if (d == -ESC_b) d = '\b';
+            else if (d == -ESC_X) d = 'X'; else
+              {
+              ptr = oldptr - 2;
+              goto LONE_SINGLE_CHARACTER;  /* A few lines below */
+              }
+            }
+          }
+
+        /* The check that the two values are in the correct order happens in
+        the pre-pass. Optimize one-character ranges */
+
+        if (d == c) goto LONE_SINGLE_CHARACTER;  /* A few lines below */
+
+        /* 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)
+            {
+            int occ, ocd;
+            int cc = c;
+            int origd = d;
+            while (get_othercase_range(&cc, origd, &occ, &ocd))
+              {
+              if (occ >= c && ocd <= d) continue;  /* Skip embedded ranges */
+
+              if (occ < c  && ocd >= 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 > d && occ <= 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. */
+
+        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));
+            }
+          class_charcount++;                /* in case a one-char range */
+          class_lastchar = c;
+          }
+
+        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)
+          {
+          int chartype;
+          int othercase;
+          if (_pcre_ucp_findchar(c, &chartype, &othercase) == ucp_L &&
+               othercase > 0)
+            {
+            *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; the check for end of string happens inside the
+    loop. This "while" is the end of the "do" above. */
+
+    while ((c = *(++ptr)) != ']' || inescq);
+
+    /* If class_charcount is 1, we saw precisely one character whose value is
+    less than 256. In non-UTF-8 mode we can always 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 &&
+          (!utf8 ||
+          (!class_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. If there are no characters < 256,
+    we can omit the bitmap. */
+
+#ifdef SUPPORT_UTF8
+    if (class_utf8)
+      {
+      *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, install it, and move on to the end of
+      the extra data */
+
+      if (class_charcount > 0)
+        {
+        *code++ |= XCL_MAP;
+        memcpy(code, classbits, 32);
+        code = class_utf8data;
+        }
+
+      /* If the map is not required, slide down the extra data. */
+
+      else
+        {
+        int len = INT_CAST(class_utf8data - (code + 33));
+        memmove(code + 1, code + 33, len);
+        code += len + 1;
+        }
+
+      /* 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, negate the 32-byte map if necessary,
+    and copy it into the code vector. 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 (negate_class)
+      {
+      *code++ = OP_NCLASS;
+      for (c = 0; c < 32; c++) code[c] = ~classbits[c];
+      }
+    else
+      {
+      *code++ = OP_CLASS;
+      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 < patternEnd && ptr[1] == '+')
+      {
+      repeat_type = 0;                  /* Force greedy */
+      possessive_quantifier = TRUE;
+      ptr++;
+      }
+    else if (ptr + 1 < patternEnd && ptr[1] == '?')
+      {
+      repeat_type = greedy_non_default;
+      ptr++;
+      }
+    else repeat_type = greedy_default;
+
+    /* If previous was a recursion, we need to wrap it inside brackets so that
+    it can be replicated if necessary. */
+
+    if (*previous == OP_RECURSE)
+      {
+      memmove(previous + 1 + LINK_SIZE, previous, 1 + LINK_SIZE);
+      code += 1 + LINK_SIZE;
+      *previous = OP_BRA;
+      PUT(previous, 1, code - previous);
+      *code = OP_KET;
+      PUT(code, 1, code - previous);
+      code += 1 + LINK_SIZE;
+      }
+
+    /* 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 = INT_CAST(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;
+        }
+
+      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. 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];
+      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;
+      op_type = OP_TYPESTAR - OP_STAR;  /* Use type opcodes */
+      c = *previous;
+
+      OUTPUT_SINGLE_REPEAT:
+      prop_type = (*previous == OP_PROP || *previous == OP_NOTPROP)?
+        previous[1] : -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->nopartial = TRUE;
+
+      /* 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 it
+      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 is an extra byte that defines 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++ = 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. */
+
+        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;
+          repeat_max -= repeat_min;
+          *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 is an extra byte that
+      defines the required property. */
+
+#ifdef SUPPORT_UCP
+      if (prop_type >= 0) *code++ = prop_type;
+#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->nopartial = TRUE;
+
+      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_ONCE ||
+             *previous == OP_COND)
+      {
+      register int i;
+      int ketoffset = 0;
+      int len = INT_CAST(code - previous);
+      uschar *bralink = NULL;
+
+      /* 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 = INT_CAST(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 just omit the group from the output
+        altogether. */
+
+        if (repeat_max == 0)
+          {
+          code = previous;
+          goto END_REPEAT;
+          }
+
+        /* 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 group, because the offset is from the start of the whole
+        regex. Temporarily terminate the pattern while doing this. */
+
+        if (repeat_max <= 1)
+          {
+          *code = OP_END;
+          adjust_recurse(previous, 1, utf8, cd);
+          memmove(previous+1, previous, len);
+          code++;
+          *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, tmpoffset;
+          *code = OP_END;
+          adjust_recurse(previous, 2 + LINK_SIZE, utf8, cd);
+          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. */
+
+          tmpoffset = INT_CAST(previous - bralink);
+          offset = (bralink == NULL)? 0 : tmpoffset;
+          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. */
+
+      else
+        {
+        if (repeat_min > 1)
+          {
+          if (groupsetfirstbyte && reqbyte < 0) reqbyte = firstbyte;
+          for (i = 1; i < repeat_min; i++)
+            {
+            memcpy(code, previous, len);
+            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. */
+
+      if (repeat_max >= 0)
+        {
+        for (i = repeat_max - 1; i >= 0; i--)
+          {
+          *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, tmpoffset;
+            *code++ = OP_BRA;
+            tmpoffset = INT_CAST(code - bralink);
+            offset = (bralink == NULL)? 0 : tmpoffset;
+            bralink = code;
+            PUTINC(code, 0, offset);
+            }
+
+          memcpy(code, previous, len);
+          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 = INT_CAST(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. */
+
+      else code[-ketoffset] = OP_KETRMAX + repeat_type;
+      }
+
+    /* Else there's some kind of shambles */
+
+    else
+      {
+      *errorcodeptr = ERR11;
+      goto FAILED;
+      }
+
+    /* If the character following a repeat is '+', we wrap the entire repeated
+    item inside OP_ONCE brackets. This is just syntactic sugar, taken from
+    Sun's Java package. The repeated item starts at tempcode, not at previous,
+    which might be the first part of a string whose (former) last char we
+    repeated. However, we don't support '+' after a greediness '?'. */
+
+    if (possessive_quantifier)
+      {
+      int len = INT_CAST(code - tempcode);
+      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);
+      }
+
+    /* 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 bracket sub-expression, or comment or lookahead or
+    lookbehind or option setting or condition. First deal with special things
+    that can come after a bracket; all are introduced by ?, and the appearance
+    of any of them means that this is not a referencing group. They were
+    checked for validity in the first pass over the string, so we don't have to
+    check for syntax errors here.  */
+
+    case '(':
+    newoptions = options;
+    skipbytes = 0;
+
+    if (*(++ptr) == '?')
+      {
+#if !JAVASCRIPT
+      int set, unset;
+      int *optset;
+#endif
+
+      switch (*(++ptr))
+        {
+#if !JAVASCRIPT
+        case '#':                 /* Comment; skip to ket */
+        ptr++;
+        while (*ptr != ')') ptr++;
+        continue;
+#endif
+
+        case ':':                 /* Non-extracting bracket */
+        bravalue = OP_BRA;
+        ptr++;
+        break;
+
+#if !JAVASCRIPT
+        case '(':
+        bravalue = OP_COND;       /* Conditional group */
+
+        /* Condition to test for recursion */
+
+        if (ptr[1] == 'R')
+          {
+          code[1+LINK_SIZE] = OP_CREF;
+          PUT2(code, 2+LINK_SIZE, CREF_RECURSE);
+          skipbytes = 3;
+          ptr += 3;
+          }
+
+        /* Condition to test for a numbered subpattern match. We know that
+        if a digit follows ( then there will just be digits until ) because
+        the syntax was checked in the first pass. */
+
+        else if ((DIGITAB(ptr[1]) && ctype_digit) != 0)
+          {
+          int condref;                 /* Don't amalgamate; some compilers */
+          condref = *(++ptr) - '0';    /* grumble at autoincrement in declaration */
+          while (*(++ptr) != ')') condref = condref*10 + *ptr - '0';
+          if (condref == 0)
+            {
+            *errorcodeptr = ERR35;
+            goto FAILED;
+            }
+          ptr++;
+          code[1+LINK_SIZE] = OP_CREF;
+          PUT2(code, 2+LINK_SIZE, condref);
+          skipbytes = 3;
+          }
+        /* For conditions that are assertions, we just fall through, having
+        set bravalue above. */
+        break;
+#endif
+
+        case '=':                 /* Positive lookahead */
+        bravalue = OP_ASSERT;
+        ptr++;
+        break;
+
+        case '!':                 /* Negative lookahead */
+        bravalue = OP_ASSERT_NOT;
+        ptr++;
+        break;
+
+#if !JAVASCRIPT
+        case '<':                 /* Lookbehinds */
+        switch (*(++ptr))
+          {
+          case '=':               /* Positive lookbehind */
+          bravalue = OP_ASSERTBACK;
+          ptr++;
+          break;
+
+          case '!':               /* Negative lookbehind */
+          bravalue = OP_ASSERTBACK_NOT;
+          ptr++;
+          break;
+          }
+        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;     /* Already checked that the terminating */
+          {                       /* closing parenthesis is present. */
+          int n = 0;
+          ++ptr;
+          while ((DIGITAB(*ptr) & ctype_digit) != 0)
+            {
+            n = n * 10 + *ptr - '0';
+            ++ptr;
+            }
+          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':                 /* Named subpattern handling */
+        if (*(++ptr) == '<')      /* Definition */
+          {
+          int i, namelen;
+          uschar *slot = cd->name_table;
+          const pcre_uchar *name; /* Don't amalgamate; some compilers */
+          name = ++ptr;           /* grumble at autoincrement in declaration */
+
+          while (*ptr++ != '>');
+          namelen = INT_CAST(ptr - name - 1);
+
+          /* FIXME: This won't work for UTF-16. */
+          for (i = 0; i < cd->names_found; i++)
+            {
+            int crc = memcmp(name, slot+2, namelen);
+            if (crc == 0)
+              {
+              if (slot[2+namelen] == 0)
+                {
+                *errorcodeptr = ERR43;
+                goto FAILED;
+                }
+              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, *brackets + 1);
+          memcpy(slot + 2, name, namelen);
+          slot[2+namelen] = 0;
+          cd->names_found++;
+          goto NUMBERED_GROUP;
+          }
+
+        if (*ptr == '=' || *ptr == '>')  /* Reference or recursion */
+          {
+          int i, namelen;
+          int type = *ptr++;
+          const pcre_uchar *name = ptr;
+          uschar *slot = cd->name_table;
+
+          while (*ptr != ')') ptr++;
+          namelen = INT_CAST(ptr - name);
+
+          for (i = 0; i < cd->names_found; i++)
+            {
+            if (STREQUAL(name, namelen, (char *)slot+2)) break;
+            slot += cd->name_entry_size;
+            }
+          if (i >= cd->names_found)
+            {
+            *errorcodeptr = ERR15;
+            goto FAILED;
+            }
+
+          recno = GET2(slot, 0);
+
+          if (type == '>') goto HANDLE_RECURSION;  /* A few lines below */
+
+          /* Back reference */
+
+          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;
+          continue;
+          }
+
+        /* Should never happen */
+        break;
+
+        case 'R':                 /* Pattern recursion */
+        ptr++;                    /* Same as (?0)      */
+        /* Fall through */
+
+        /* Recursion or "subroutine" call */
+
+        case '0': case '1': case '2': case '3': case '4':
+        case '5': case '6': case '7': case '8': case '9':
+          {
+          const uschar *called;
+          recno = 0;
+          while((DIGITAB(*ptr) & ctype_digit) != 0)
+            recno = recno * 10 + *ptr++ - '0';
+
+          /* Come here from code above that handles a named recursion */
+
+          HANDLE_RECURSION:
+
+          previous = code;
+
+          /* Find the bracket that is being referenced. Temporarily end the
+          regex in case it doesn't exist. */
+
+          *code = OP_END;
+          called = (recno == 0)?
+            cd->start_code : find_bracket(cd->start_code, utf8, recno);
+
+          if (called == NULL)
+            {
+            *errorcodeptr = ERR15;
+            goto FAILED;
+            }
+
+          /* If 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. */
+
+          if (GET(called, 1) == 0 && could_be_empty(called, code, bcptr, utf8))
+            {
+            *errorcodeptr = ERR40;
+            goto FAILED;
+            }
+
+          /* Insert the recursion/subroutine item */
+
+          *code = OP_RECURSE;
+          PUT(code, 1, called - cd->start_code);
+          code += 1 + LINK_SIZE;
+          }
+        continue;
+#endif
+
+        /* Character after (? not specially recognized */
+
+        default:                  /* Option setting */
+#if JAVASCRIPT
+        *errorcodeptr = ERR12;
+        goto FAILED;
+#else
+        set = unset = 0;
+        optset = &set;
+
+        while (*ptr != ')' && *ptr != ':')
+          {
+          switch (*ptr++)
+            {
+            case '-': optset = &unset; 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;
+            }
+          }
+
+        /* 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. Compile
+        code to change the ims options if this setting actually changes any of
+        them. We also pass the new setting back so that it can be put at the
+        start of any following branches, and when this group ends (if we are in
+        a group), a resetting item can be compiled.
+
+        Note that if this item is right at the start of the pattern, the
+        options will have been abstracted and made global, so there will be no
+        change to compile. */
+
+        if (*ptr == ')')
+          {
+          if ((options & PCRE_IMS) != (newoptions & PCRE_IMS))
+            {
+            *code++ = OP_OPT;
+            *code++ = newoptions & PCRE_IMS;
+            }
+
+          /* Change options at this level, and pass them back for use
+          in subsequent branches. Reset the greedy defaults and the case
+          value for firstbyte and reqbyte. */
+
+          *optionsptr = options = newoptions;
+          greedy_default = ((newoptions & PCRE_UNGREEDY) != 0);
+          greedy_non_default = greedy_default ^ 1;
+          req_caseopt = ((options & PCRE_CASELESS) != 0)? REQ_CASELESS : 0;
+
+          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++;
+#endif
+        }
+      }
+
+    /* 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 referencing group; adjust the opcode. If the bracket
+    number is greater than EXTRACT_BASIC_MAX, we set the opcode one higher, and
+    arrange for the true number to follow later, in an OP_BRANUMBER item. */
+
+    else
+      {
+#if !JAVASCRIPT
+      NUMBERED_GROUP:
+#endif
+      if (++(*brackets) > EXTRACT_BASIC_MAX)
+        {
+        bravalue = OP_BRA + EXTRACT_BASIC_MAX + 1;
+        code[1+LINK_SIZE] = OP_BRANUMBER;
+        PUT2(code, 2+LINK_SIZE, *brackets);
+        skipbytes = 3;
+        }
+      else bravalue = OP_BRA + *brackets;
+      }
+
+    /* Process nested bracketed re. Assertions may not be repeated, but other
+    kinds can be. 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 */
+
+    if (!compile_regex(
+         newoptions,                   /* The complete new option state */
+         options & PCRE_IMS,           /* The previous ims option state */
+         brackets,                     /* Extracting bracket count */
+         &tempcode,                    /* Where to put code (updated) */
+         &ptr,                         /* Input pointer (updated) */
+         patternEnd,
+         errorcodeptr,                 /* Where to put an error message */
+         (bravalue == OP_ASSERTBACK ||
+          bravalue == OP_ASSERTBACK_NOT), /* TRUE if back assert */
+         skipbytes,                    /* Skip over OP_COND/OP_BRANUMBER */
+         &subfirstbyte,                /* For possible first char */
+         &subreqbyte,                  /* For possible last char */
+         bcptr,                        /* Current branch chain */
+         cd))                          /* Tables block */
+      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. */
+
+    else if (bravalue == OP_COND)
+      {
+      uschar *tc = code;
+      condcount = 0;
+
+      do {
+         condcount++;
+         tc += GET(tc,1);
+         }
+      while (*tc != OP_KET);
+
+      if (condcount > 2)
+        {
+        *errorcodeptr = ERR27;
+        goto FAILED;
+        }
+
+      /* 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. */
+
+      if (condcount == 1) subfirstbyte = subreqbyte = REQ_NONE;
+      }
+
+    /* Handle updating of the required and first characters. 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_BRA || bravalue == OP_ONCE || bravalue == OP_COND)
+      {
+      /* 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;
+
+    /* Now update the main code pointer to the end of the group. */
+
+    code = tempcode;
+
+    /* Error if hit end of pattern */
+
+    if (ptr > patternEnd || *ptr != ')')
+      {
+      *errorcodeptr = ERR14;
+      goto FAILED;
+      }
+    break;
+
+    /* Check \ for being a real metacharacter; if not, fall through and handle
+    it as a data character at the start of a string. Escape items are checked
+    for validity in the pre-compiling pass. */
+
+    case '\\':
+    tempptr = ptr;
+    c = check_escape(&ptr, patternEnd, errorcodeptr, *brackets, options, FALSE);
+
+    /* Handle metacharacters 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. */
+
+    if (c < 0)
+      {
+      if (-c == ESC_Q)            /* Handle start of quoted string */
+        {
+        if (ptr + 2 < patternEnd && ptr[1] == '\\' && ptr[2] == 'E') ptr += 2; /* avoid empty string */
+          else inescq = TRUE;
+        continue;
+        }
+
+      /* 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;
+
+      /* Back references are handled specially */
+
+      if (-c >= ESC_REF)
+        {
+        int number = -c - ESC_REF;
+        previous = code;
+        *code++ = OP_REF;
+        PUT2INC(code, 0, number);
+        }
+
+      /* So are Unicode property matches, if supported. We know that get_ucp
+      won't fail because it was tested in the pre-pass. */
+
+#if !JAVASCRIPT
+#ifdef SUPPORT_UCP
+      else if (-c == ESC_P || -c == ESC_p)
+        {
+        BOOL negated = 0;
+        int value = get_ucp(&ptr, patternEnd, &negated, errorcodeptr);
+        previous = code;
+        *code++ = ((-c == ESC_p) != negated)? OP_PROP : OP_NOTPROP;
+        *code++ = value;
+        }
+#endif
+#endif
+
+      /* For the rest, 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:
+#if PCRE_UTF16
+    if (c < 128)
+      {
+       mclength = 1;
+       mcbuffer[0] = c;
+     }
+    else
+      mclength = _pcre_ord2utf8(c, mcbuffer);
+#else
+    mclength = 1;
+    mcbuffer[0] = c;
+
+#ifdef SUPPORT_UTF8
+    if (utf8 && (c & 0xc0) == 0xc0)
+      {
+      while (ptr + 1 < patternEnd && (ptr[1] & 0xc0) == 0x80)
+        mcbuffer[mclength++] = *(++ptr);
+      }
+#endif
+#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];
+
+    /* 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.
+
+Argument:
+  options        option bits, including any changes for this subpattern
+  oldims         previous settings of ims option bits
+  brackets       -> int containing the number of extracting brackets used
+  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
+  skipbytes      skip this many bytes at start (for OP_COND, OP_BRANUMBER)
+  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.
+
+Returns:      TRUE on success
+*/
+
+static BOOL
+compile_regex(int options, int oldims, int *brackets, uschar **codeptr,
+  const pcre_uchar **ptrptr, const pcre_uchar *patternEnd, int *errorcodeptr, BOOL lookbehind, int skipbytes,
+  int *firstbyteptr, int *reqbyteptr, branch_chain *bcptr, compile_data *cd)
+{
+const pcre_uchar *ptr = *ptrptr;
+uschar *code = *codeptr;
+uschar *last_branch = code;
+uschar *start_bracket = code;
+uschar *reverse_count = NULL;
+int firstbyte, reqbyte;
+int branchfirstbyte, branchreqbyte;
+branch_chain bc;
+
+bc.outer = bcptr;
+bc.current = code;
+
+firstbyte = reqbyte = REQ_UNSET;
+
+/* 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 */
+
+for (;;)
+  {
+  /* Handle a change of ims options at the start of the branch */
+
+  if ((options & PCRE_IMS) != oldims)
+    {
+    *code++ = OP_OPT;
+    *code++ = options & PCRE_IMS;
+    }
+
+  /* Set up dummy OP_REVERSE if lookbehind assertion */
+
+  if (lookbehind)
+    {
+    *code++ = OP_REVERSE;
+    reverse_count = code;
+    PUTINC(code, 0, 0);
+    }
+
+  /* Now compile the branch */
+
+  if (!compile_branch(&options, brackets, &code, &ptr, patternEnd, errorcodeptr,
+        &branchfirstbyte, &branchreqbyte, &bc, cd))
+    {
+    *ptrptr = ptr;
+    return FALSE;
+    }
+
+  /* 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 length;
+    *code = OP_END;
+    length = find_fixedlength(last_branch, options);
+    DPRINTF(("fixed length = %d\n", length));
+    if (length < 0)
+      {
+      *errorcodeptr = (length == -2)? ERR36 : ERR25;
+      *ptrptr = ptr;
+      return FALSE;
+      }
+    PUT(reverse_count, 0, length);
+    }
+
+  /* Reached end of expression, either ')' or end of pattern. 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 >= patternEnd || *ptr != '|')
+    {
+    int length = INT_CAST(code - last_branch);
+    do
+      {
+      int prev_length = GET(last_branch, 1);
+      PUT(last_branch, 1, length);
+      length = prev_length;
+      last_branch -= length;
+      }
+    while (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 < patternEnd && *ptr == ')')
+      {
+      *code++ = OP_OPT;
+      *code++ = oldims;
+      }
+
+    /* Set values to pass back */
+
+    *codeptr = code;
+    *ptrptr = ptr;
+    *firstbyteptr = firstbyte;
+    *reqbyteptr = reqbyte;
+    return TRUE;
+    }
+
+  /* Another branch follows; insert an "or" 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. */
+
+  *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 + 1+LINK_SIZE, options, PCRE_MULTILINE, FALSE);
+   register int op = *scode;
+
+   /* Capturing brackets */
+
+   if (op > OP_BRA)
+     {
+     int new_map;
+     op -= OP_BRA;
+     if (op > EXTRACT_BASIC_MAX) op = GET2(scode, 2+LINK_SIZE);
+     new_map = bracket_map | ((op < 32)? (1 << op) : 1);
+     if (!is_anchored(scode, options, new_map, backref_map)) return FALSE;
+     }
+
+   /* Other brackets */
+
+   else if (op == OP_BRA || 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 and it isn't in brackets that
+   are or may be referenced. */
+
+   else if ((op == OP_TYPESTAR || op == OP_TYPEMINSTAR) &&
+            (*options & PCRE_DOTALL) != 0)
+     {
+     if (scode[1] != OP_ANY || (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 + 1+LINK_SIZE, NULL, 0,
+     FALSE);
+   register int op = *scode;
+
+   /* Capturing brackets */
+
+   if (op > OP_BRA)
+     {
+     int new_map;
+     op -= OP_BRA;
+     if (op > EXTRACT_BASIC_MAX) op = GET2(scode, 2+LINK_SIZE);
+     new_map = bracket_map | ((op < 32)? (1 << op) : 1);
+     if (!is_startline(scode, new_map, backref_map)) return FALSE;
+     }
+
+   /* Other brackets */
+
+   else if (op == OP_BRA || 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)
+     {
+     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;
+
+   if (op >= OP_BRA) op = OP_BRA;
+
+   switch(op)
+     {
+     default:
+     return -1;
+
+     case OP_BRA:
+     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:
+     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_EXPORT pcre *
+pcre_compile(const pcre_char *pattern, int patternLength, int options, const char **errorptr,
+  int *erroroffset, const unsigned char *tables)
+{
+return pcre_compile2(pattern, patternLength, options, NULL, errorptr, erroroffset, tables);
+}
+
+
+PCRE_EXPORT pcre *
+pcre_compile2(const pcre_char *pattern, int patternLength, int options, int *errorcodeptr,
+  const char **errorptr, int *erroroffset, const unsigned char *tables)
+{
+real_pcre *re;
+int length = 1 + LINK_SIZE;      /* For initial BRA plus length */
+int c, firstbyte, reqbyte;
+int bracount = 0;
+int branch_extra = 0;
+int branch_newextra;
+int item_count = -1;
+int name_count = 0;
+int max_name_size = 0;
+int lastitemlength = 0;
+int errorcode = 0;
+#ifdef SUPPORT_UTF8
+BOOL utf8;
+BOOL class_utf8;
+#endif
+BOOL inescq = FALSE;
+BOOL capturing;
+unsigned int brastackptr = 0;
+size_t size;
+uschar *code;
+const uschar *codestart;
+const pcre_uchar *ptr;
+const pcre_uchar *patternEnd;
+compile_data compile_block;
+int brastack[BRASTACK_SIZE];
+uschar bralenstack[BRASTACK_SIZE];
+
+/* 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_RETURN;
+  }
+
+*erroroffset = 0;
+
+/* Always set the UTF-8 flag if we're compiled for UTF-16; saves on ifdefs. */
+
+#if PCRE_UTF16
+options |= PCRE_UTF8;
+#endif
+
+/* Can't support UTF8 unless PCRE has been compiled to include the code. */
+
+#ifdef SUPPORT_UTF8
+utf8 = (options & PCRE_UTF8) != 0;
+#if !PCRE_UTF16
+if (utf8 && (options & PCRE_NO_UTF8_CHECK) == 0 &&
+     (*erroroffset = _pcre_valid_utf8((pcre_uchar *)pattern, -1)) >= 0)
+  {
+  errorcode = ERR44;
+  goto PCRE_EARLY_ERROR_RETURN;
+  }
+#endif
+#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;
+compile_block.lcc = tables + lcc_offset;
+compile_block.fcc = tables + fcc_offset;
+compile_block.cbits = tables + cbits_offset;
+compile_block.ctypes = tables + ctypes_offset;
+
+/* Maximum back reference and backref bitmap. This is updated for numeric
+references during the first pass, but for named references during the actual
+compile pass. The bitmap records up to 31 back references to help in deciding
+whether (.*) can be treated as anchored or not. */
+
+compile_block.top_backref = 0;
+compile_block.backref_map = 0;
+
+/* Reflect pattern for debugging output */
+
+DPRINTF(("------------------------------------------------------------------\n"));
+#if !PCRE_UTF16
+DPRINTF(("%s\n", pattern));
+#endif
+
+/* The first thing to do is to make a pass over the pattern to compute the
+amount of store required to hold the compiled code. This does not have to be
+perfect as long as errors are overestimates. At the same time we can detect any
+flag settings right at the start, and extract them. Make an attempt to correct
+for any counted white space if an "extended" flag setting appears late in the
+pattern. We can't be so clever for #-comments. */
+
+ptr = (const pcre_uchar *)(pattern - 1);
+patternEnd = (const pcre_uchar *)(pattern + patternLength);
+
+while (++ptr < patternEnd)
+  {
+  int min = 0, max = 0;
+  int class_optcount;
+  int bracket_length;
+  int duplength;
+
+  c = *ptr;
+  
+  /* If we are inside a \Q...\E sequence, all chars are literal */
+
+  if (inescq)
+    {
+    if ((options & PCRE_AUTO_CALLOUT) != 0) length += 2 + 2*LINK_SIZE;
+    goto NORMAL_CHAR;
+    }
+
+  /* Otherwise, first check for ignored whitespace and comments */
+
+  if ((options & PCRE_EXTENDED) != 0)
+    {
+    if ((CTYPES(&compile_block, c) & ctype_space) != 0) continue;
+    if (c == '#')
+      {
+      while (++ptr < patternEnd && (c = *ptr) != NEWLINE)
+        ;
+      if (ptr == patternEnd)
+        break;
+      continue;
+      }
+    }
+
+  item_count++;    /* Is zero for the first non-comment item */
+
+  /* Allow space for auto callout before every item except quantifiers. */
+
+  if ((options & PCRE_AUTO_CALLOUT) != 0 &&
+       c != '*' && c != '+' && c != '?' &&
+       (c != '{' || !is_counted_repeat(ptr + 1, patternEnd)))
+    length += 2 + 2*LINK_SIZE;
+
+  switch(c)
+    {
+    /* A backslashed item may be an escaped data character or it may be a
+    character type. */
+
+    case '\\':
+    c = check_escape(&ptr, patternEnd, &errorcode, bracount, options, FALSE);
+    if (errorcode != 0) goto PCRE_ERROR_RETURN;
+
+    lastitemlength = 1;     /* Default length of last item for repeats */
+
+    if (c >= 0)             /* Data character */
+      {
+      length += 2;          /* For a one-byte character */
+
+#ifdef SUPPORT_UTF8
+      if (utf8 && c > 127)
+        {
+        int i;
+        for (i = 0; i < _pcre_utf8_table1_size; i++)
+          if (c <= _pcre_utf8_table1[i]) break;
+        length += i;
+        lastitemlength += i;
+        }
+#endif
+
+      continue;
+      }
+
+#if !JAVASCRIPT
+
+    /* If \Q, enter "literal" mode */
+
+    if (-c == ESC_Q)
+      {
+      inescq = TRUE;
+      continue;
+      }
+
+    /* \X is supported only if Unicode property support is compiled */
+
+#ifndef SUPPORT_UCP
+    if (-c == ESC_X)
+      {
+      errorcode = ERR45;
+      goto PCRE_ERROR_RETURN;
+      }
+#endif
+
+    /* \P and \p are for Unicode properties, but only when the support has
+    been compiled. Each item needs 2 bytes. */
+
+    else if (-c == ESC_P || -c == ESC_p)
+      {
+#ifdef SUPPORT_UCP
+      BOOL negated;
+      length += 2;
+      lastitemlength = 2;
+      if (get_ucp(&ptr, patternEnd, &negated, &errorcode) < 0) goto PCRE_ERROR_RETURN;
+      continue;
+#else
+      errorcode = ERR45;
+      goto PCRE_ERROR_RETURN;
+#endif
+      }
+
+#endif
+
+    /* Other escapes need one byte */
+
+    length++;
+
+    /* A back reference needs an additional 2 bytes, plus either one or 5
+    bytes for a repeat. We also need to keep the value of the highest
+    back reference. */
+
+    if (c <= -ESC_REF)
+      {
+      int refnum = -c - ESC_REF;
+      compile_block.backref_map |= (refnum < 32)? (1 << refnum) : 1;
+      if (refnum > compile_block.top_backref)
+        compile_block.top_backref = refnum;
+      length += 2;   /* For single back reference */
+      if (ptr + 1 < patternEnd && ptr[1] == '{' && is_counted_repeat(ptr+2, patternEnd))
+        {
+        ptr = read_repeat_counts(ptr+2, &min, &max, &errorcode);
+        if (errorcode != 0) goto PCRE_ERROR_RETURN;
+        if ((min == 0 && (max == 1 || max == -1)) ||
+          (min == 1 && max == -1))
+            length++;
+        else length += 5;
+        if (ptr + 1 < patternEnd && ptr[1] == '?')
+            ptr++;
+        }
+      }
+    continue;
+
+    case '^':     /* Single-byte metacharacters */
+    case '.':
+    case '$':
+    length++;
+    lastitemlength = 1;
+    continue;
+
+    case '*':            /* These repeats won't be after brackets; */
+    case '+':            /* those are handled separately */
+    case '?':
+    length++;
+    goto POSESSIVE;      /* A few lines below */
+
+    /* This covers the cases of braced repeats after a single char, metachar,
+    class, or back reference. */
+
+    case '{':
+    if (!is_counted_repeat(ptr+1, patternEnd))
+        goto NORMAL_CHAR;
+    ptr = read_repeat_counts(ptr+1, &min, &max, &errorcode);
+    if (errorcode != 0) goto PCRE_ERROR_RETURN;
+
+    /* These special cases just insert one extra opcode */
+
+    if ((min == 0 && (max == 1 || max == -1)) ||
+      (min == 1 && max == -1))
+        length++;
+
+    /* These cases might insert additional copies of a preceding character. */
+
+    else
+      {
+      if (min != 1)
+        {
+        length -= lastitemlength;   /* Uncount the original char or metachar */
+        if (min > 0) length += 3 + lastitemlength;
+        }
+      length += lastitemlength + ((max > 0)? 3 : 1);
+      }
+
+    if (ptr + 1 < patternEnd && ptr[1] == '?')
+        ptr++;                     /* Needs no extra length */
+
+    POSESSIVE:                     /* Test for possessive quantifier */
+    if (ptr + 1 < patternEnd && ptr[1] == '+')
+      {
+      ptr++;
+      length += 2 + 2*LINK_SIZE;   /* Allow for atomic brackets */
+      }
+    continue;
+
+    /* An alternation contains an offset to the next branch or ket. If any ims
+    options changed in the previous branch(es), and/or if we are in a
+    lookbehind assertion, extra space will be needed at the start of the
+    branch. This is handled by branch_extra. */
+
+    case '|':
+    length += 1 + LINK_SIZE + branch_extra;
+    continue;
+
+    /* A character class uses 33 characters provided that all the character
+    values are less than 256. Otherwise, it uses a bit map for low valued
+    characters, and individual items for others. Don't worry about character
+    types that aren't allowed in classes - they'll get picked up during the
+    compile. A character class that contains only one single-byte character
+    uses 2 or 3 bytes, depending on whether it is negated or not. Notice this
+    where we can. (In UTF-8 mode we can do this only for chars < 128.) */
+
+    case '[':
+    if (++ptr < patternEnd && *ptr == '^')
+      {
+      class_optcount = 10;  /* Greater than one */
+      ptr++;
+      }
+    else class_optcount = 0;
+
+#ifdef SUPPORT_UTF8
+    class_utf8 = FALSE;
+#endif
+
+    /* Written as a "do" so that an initial ']' is taken as data */
+
+    if (ptr < patternEnd) do
+      {
+      /* Inside \Q...\E everything is literal except \E */
+
+      if (inescq)
+        {
+        if (*ptr != '\\' || ptr + 1 >= patternEnd || ptr[1] != 'E')
+            goto GET_ONE_CHARACTER;
+        inescq = FALSE;
+        ptr += 1;
+        continue;
+        }
+
+      /* Outside \Q...\E, check for escapes */
+
+      if (*ptr == '\\')
+        {
+        c = check_escape(&ptr, patternEnd, &errorcode, bracount, options, TRUE);
+        if (errorcode != 0) goto PCRE_ERROR_RETURN;
+
+        /* \b is backspace inside a class; \X is literal */
+
+        if (-c == ESC_b) c = '\b';
+        else if (-c == ESC_X) c = 'X';
+
+        /* \Q enters quoting mode */
+
+        else if (-c == ESC_Q)
+          {
+          inescq = TRUE;
+          continue;
+          }
+
+        /* Handle escapes that turn into characters */
+
+        if (c >= 0) goto NON_SPECIAL_CHARACTER;
+
+        /* Escapes that are meta-things. The normal ones just affect the
+        bit map, but Unicode properties require an XCLASS extended item. */
+
+        else
+          {
+          class_optcount = 10;         /* \d, \s etc; make sure > 1 */
+#ifdef SUPPORT_UTF8
+          if (-c == ESC_p || -c == ESC_P)
+            {
+            if (!class_utf8)
+              {
+              class_utf8 = TRUE;
+              length += LINK_SIZE + 2;
+              }
+            length += 2;
+            }
+#endif
+          }
+        }
+
+#if !JAVASCRIPT
+
+      /* Check the syntax for POSIX stuff. The bits we actually handle are
+      checked during the real compile phase. */
+
+      else if (*ptr == '[' && ptr + 2 < patternEnd && (ptr[1] == ':' || ptr[1] == '.' || ptr[1] == '=') && check_posix_syntax(ptr, patternEnd, &ptr, &compile_block))
+        {
+        ptr++;
+        class_optcount = 10;    /* Make sure > 1 */
+        }
+
+#endif
+
+      /* Anything else increments the possible optimization count. We have to
+      detect ranges here so that we can compute the number of extra ranges for
+      caseless wide characters when UCP support is available. If there are wide
+      characters, we are going to have to use an XCLASS, even for single
+      characters. */
+
+      else
+        {
+        int d;
+
+        GET_ONE_CHARACTER:
+
+#ifdef SUPPORT_UTF8
+        if (utf8)
+          {
+          int extra = 0;
+          GETCHARLENEND(c, ptr, patternEnd, extra);
+          ptr += extra;
+          }
+        else c = *ptr;
+#else
+        c = *ptr;
+#endif
+
+        /* Come here from handling \ above when it escapes to a char value */
+
+        NON_SPECIAL_CHARACTER:
+        class_optcount++;
+
+        d = -1;
+        if (ptr + 1 < patternEnd && ptr[1] == '-')
+          {
+          pcre_uchar const *hyptr = ptr++;
+          if (ptr + 1 < patternEnd) {
+              if (ptr[1] == '\\')
+                {
+                ptr++;
+                d = check_escape(&ptr, patternEnd, &errorcode, bracount, options, TRUE);
+                if (errorcode != 0) goto PCRE_ERROR_RETURN;
+                if (-d == ESC_b) d = '\b';        /* backspace */
+                else if (-d == ESC_X) d = 'X';    /* literal X in a class */
+                }
+              else if (ptr[1] != ']')
+                {
+                ptr++;
+    #ifdef SUPPORT_UTF8
+                if (utf8)
+                  {
+                  int extra = 0;
+                  GETCHARLENEND(d, ptr, patternEnd, extra);
+                  ptr += extra;
+                  }
+                else
+    #endif
+                d = *ptr;
+                }
+          }
+          if (d < 0) ptr = hyptr;      /* go back to hyphen as data */
+          }
+
+        /* If d >= 0 we have a range. In UTF-8 mode, if the end is > 255, or >
+        127 for caseless matching, we will need to use an XCLASS. */
+
+        if (d >= 0)
+          {
+          class_optcount = 10;     /* Ensure > 1 */
+          if (d < c)
+            {
+            errorcode = ERR8;
+            goto PCRE_ERROR_RETURN;
+            }
+
+#ifdef SUPPORT_UTF8
+          if (utf8 && (d > 255 || ((options & PCRE_CASELESS) != 0 && d > 127)))
+            {
+            uschar buffer[6];
+            if (!class_utf8)         /* Allow for XCLASS overhead */
+              {
+              class_utf8 = TRUE;
+              length += LINK_SIZE + 2;
+              }
+
+#ifdef SUPPORT_UCP
+            /* If we have UCP support, find out how many extra ranges are
+            needed to map the other case of characters within this range. We
+            have to mimic the range optimization here, because extending the
+            range upwards might push d over a boundary that makes is use
+            another byte in the UTF-8 representation. */
+
+            if ((options & PCRE_CASELESS) != 0)
+              {
+              int occ, ocd;
+              int cc = c;
+              int origd = d;
+              while (get_othercase_range(&cc, origd, &occ, &ocd))
+                {
+                if (occ >= c && ocd <= d) continue;   /* Skip embedded */
+
+                if (occ < c  && ocd >= 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 > d && occ <= d + 1)   /* always shorter than    */
+                  {                            /* the basic range.       */
+                  d = ocd;
+                  continue;
+                  }
+
+                /* An extra item is needed */
+
+                length += 1 + _pcre_ord2utf8(occ, buffer) +
+                  ((occ == ocd)? 0 : _pcre_ord2utf8(ocd, buffer));
+                }
+              }
+#endif  /* SUPPORT_UCP */
+
+            /* The length of the (possibly extended) range */
+
+            length += 1 + _pcre_ord2utf8(c, buffer) + _pcre_ord2utf8(d, buffer);
+            }
+#endif  /* SUPPORT_UTF8 */
+
+          }
+
+        /* We have a single character. There is nothing to be done unless we
+        are in UTF-8 mode. If the char is > 255, or 127 when caseless, we must
+        allow for an XCL_SINGLE item, doubled for caselessness if there is UCP
+        support. */
+
+        else
+          {
+#ifdef SUPPORT_UTF8
+          if (utf8 && (c > 255 || ((options & PCRE_CASELESS) != 0 && c > 127)))
+            {
+            uschar buffer[6];
+            class_optcount = 10;     /* Ensure > 1 */
+            if (!class_utf8)         /* Allow for XCLASS overhead */
+              {
+              class_utf8 = TRUE;
+              length += LINK_SIZE + 2;
+              }
+#ifdef SUPPORT_UCP
+            length += (((options & PCRE_CASELESS) != 0)? 2 : 1) *
+              (1 + _pcre_ord2utf8(c, buffer));
+#else   /* SUPPORT_UCP */
+            length += 1 + _pcre_ord2utf8(c, buffer);
+#endif  /* SUPPORT_UCP */
+            }
+#endif  /* SUPPORT_UTF8 */
+          }
+        }
+      }
+    while (++ptr < patternEnd && (inescq || *ptr != ']')); /* Concludes "do" above */
+
+    if (ptr >= patternEnd)                          /* Missing terminating ']' */
+      {
+      errorcode = ERR6;
+      goto PCRE_ERROR_RETURN;
+      }
+
+    /* We can optimize when there was only one optimizable character. Repeats
+    for positive and negated single one-byte chars are handled by the general
+    code. Here, we handle repeats for the class opcodes. */
+
+    if (class_optcount == 1) length += 3; else
+      {
+      length += 33;
+
+      /* A repeat needs either 1 or 5 bytes. If it is a possessive quantifier,
+      we also need extra for wrapping the whole thing in a sub-pattern. */
+
+      if (ptr + 1 < patternEnd && ptr[1] == '{' && is_counted_repeat(ptr+2, patternEnd))
+        {
+        ptr = read_repeat_counts(ptr+2, &min, &max, &errorcode);
+        if (errorcode != 0) goto PCRE_ERROR_RETURN;
+        if ((min == 0 && (max == 1 || max == -1)) ||
+          (min == 1 && max == -1))
+            length++;
+        else length += 5;
+        if (ptr + 1 < patternEnd) {
+            if (ptr[1] == '+')
+              {
+              ptr++;
+              length += 2 + 2*LINK_SIZE;
+              }
+            else if (ptr[1] == '?')
+                ptr++;
+        }
+        }
+      }
+    continue;
+
+    /* Brackets may be genuine groups or special things */
+
+    case '(':
+    branch_newextra = 0;
+    bracket_length = 1 + LINK_SIZE;
+    capturing = FALSE;
+
+    /* Handle special forms of bracket, which all start (? */
+
+    if (ptr + 1 < patternEnd && ptr[1] == '?')
+      {
+#if !JAVASCRIPT
+      int set, unset;
+      int *optset;
+#endif
+
+      switch (c = (ptr + 2 < patternEnd ? ptr[2] : 0))
+        {
+#if !JAVASCRIPT
+        /* Skip over comments entirely */
+        case '#':
+        ptr += 3;
+        while (ptr < patternEnd && *ptr != ')')
+            ptr++;
+        if (ptr == patternEnd)
+          {
+          errorcode = ERR18;
+          goto PCRE_ERROR_RETURN;
+          }
+        continue;
+#endif
+
+        /* Non-referencing groups and lookaheads just move the pointer on, and
+        then behave like a non-special bracket, except that they don't increment
+        the count of extracting brackets. Ditto for the "once only" bracket,
+        which is in Perl from version 5.005. */
+
+        case ':':
+        case '=':
+        case '!':
+#if !JAVASCRIPT
+        case '>':
+#endif
+        ptr += 2;
+        break;
+
+        /* (?R) specifies a recursive call to the regex, which is an extension
+        to provide the facility which can be obtained by (?p{perl-code}) in
+        Perl 5.6. In Perl 5.8 this has become (??{perl-code}).
+
+        From PCRE 4.00, items such as (?3) specify subroutine-like "calls" to
+        the appropriate numbered brackets. This includes both recursive and
+        non-recursive calls. (?R) is now synonymous with (?0). */
+
+#if !JAVASCRIPT
+
+        case 'R':
+        ptr++;
+
+        case '0': case '1': case '2': case '3': case '4':
+        case '5': case '6': case '7': case '8': case '9':
+        ptr += 2;
+        if (c != 'R')
+          {
+          ++ptr;
+          while (ptr < patternEnd && (DIGITAB(*ptr) & ctype_digit) != 0)
+            ++ptr;
+          }
+        if (ptr >= patternEnd || *ptr != ')')
+          {
+          errorcode = ERR29;
+          goto PCRE_ERROR_RETURN;
+          }
+        length += 1 + LINK_SIZE;
+
+        /* If this item is quantified, it will get wrapped inside brackets so
+        as to use the code for quantified brackets. We jump down and use the
+        code that handles this for real brackets. */
+
+        if (ptr + 1 < patternEnd && (ptr[1] == '+' || ptr[1] == '*' || ptr[1] == '?' || ptr[1] == '{'))
+          {
+          length += 2 + 2 * LINK_SIZE;       /* to make bracketed */
+          duplength = 5 + 3 * LINK_SIZE;
+          goto HANDLE_QUANTIFIED_BRACKETS;
+          }
+        continue;
+
+        /* (?C) is an extension which provides "callout" - to provide a bit of
+        the functionality of the Perl (?{...}) feature. An optional number may
+        follow (default is zero). */
+
+        case 'C':
+        ptr += 3;
+        while (ptr < patternEnd && (DIGITAB(*ptr) & ctype_digit) != 0)
+          ++ptr;
+        if (ptr >= patternEnd || *ptr != ')')
+          {
+          errorcode = ERR39;
+          goto PCRE_ERROR_RETURN;
+          }
+        length += 2 + 2*LINK_SIZE;
+        continue;
+
+        /* Named subpatterns are an extension copied from Python */
+
+        case 'P':
+        ptr += 3;
+
+        /* Handle the definition of a named subpattern */
+
+        if (ptr < patternEnd) {
+            if (*ptr == '<')
+              {
+              const pcre_uchar *p;    /* Don't amalgamate; some compilers */
+              p = ++ptr;          /* grumble at autoincrement in declaration */
+              while (ptr < patternEnd && (CTYPES(&compile_block, *ptr) & ctype_word) != 0)
+                  ptr++;
+              if (ptr >= patternEnd || *ptr != '>')
+                {
+                errorcode = ERR42;
+                goto PCRE_ERROR_RETURN;
+                }
+              name_count++;
+              if (ptr - p > max_name_size) max_name_size = INT_CAST(ptr - p);
+              capturing = TRUE;   /* Named parentheses are always capturing */
+              break;
+              }
+
+            /* Handle back references and recursive calls to named subpatterns */
+
+            if (*ptr == '=' || *ptr == '>')
+              {
+              ++ptr;
+              while (ptr < patternEnd && (CTYPES(&compile_block, *ptr) & ctype_word) != 0)
+                ++ptr;
+              if (ptr >= patternEnd || *ptr != ')')
+                {
+                errorcode = ERR42;
+                goto PCRE_ERROR_RETURN;
+                }
+              break;
+              }
+        }
+
+        /* Unknown character after (?P */
+
+        errorcode = ERR41;
+        goto PCRE_ERROR_RETURN;
+
+        /* Lookbehinds are in Perl from version 5.005 */
+
+        case '<':
+        ptr += 3;
+        if (ptr < patternEnd && (*ptr == '=' || *ptr == '!'))
+          {
+          branch_newextra = 1 + LINK_SIZE;
+          length += 1 + LINK_SIZE;         /* For the first branch */
+          break;
+          }
+        errorcode = ERR24;
+        goto PCRE_ERROR_RETURN;
+
+        /* Conditionals are in Perl from version 5.005. The bracket must either
+        be followed by a number (for bracket reference) or by an assertion
+        group, or (a PCRE extension) by 'R' for a recursion test. */
+
+        case '(':
+        if (ptr + 4 < patternEnd && ptr[3] == 'R' && ptr[4] == ')')
+          {
+          ptr += 4;
+          length += 3;
+          }
+        else if (ptr + 3 < patternEnd && (DIGITAB(ptr[3]) & ctype_digit) != 0)
+          {
+          ptr += 4;
+          length += 3;
+          while (ptr < patternEnd && (DIGITAB(*ptr) & ctype_digit) != 0)
+              ptr++;
+          if (ptr >= patternEnd || *ptr != ')')
+            {
+            errorcode = ERR26;
+            goto PCRE_ERROR_RETURN;
+            }
+          }
+        else   /* An assertion must follow */
+          {
+          ptr++;   /* Can treat like ':' as far as spacing is concerned */
+          if (ptr + 3 >= patternEnd || ptr[2] != '?' ||
+             (ptr[3] != '=' && ptr[3] != '!' && ptr[3] != '<') )
+            {
+            ptr += 2;    /* To get right offset in message */
+            errorcode = ERR28;
+            goto PCRE_ERROR_RETURN;
+            }
+          }
+        break;
+
+#endif
+
+        /* Else loop checking valid options until ) is met. Anything else is an
+        error. If we are without any brackets, i.e. at top level, the settings
+        act as if specified in the options, so massage the options immediately.
+        This is for backward compatibility with Perl 5.004. */
+
+        default:
+#if JAVASCRIPT
+        errorcode = ERR12;
+        goto PCRE_ERROR_RETURN;
+#else
+        set = unset = 0;
+        optset = &set;
+        ptr += 2;
+
+        for (;; ptr++)
+          {
+          c = ptr < patternEnd ? *ptr : 0;
+          switch (c)
+            {
+            case 'i':
+            *optset |= PCRE_CASELESS;
+            continue;
+
+            case 'm':
+            *optset |= PCRE_MULTILINE;
+            continue;
+
+            case 's':
+            *optset |= PCRE_DOTALL;
+            continue;
+
+            case 'x':
+            *optset |= PCRE_EXTENDED;
+            continue;
+
+            case 'X':
+            *optset |= PCRE_EXTRA;
+            continue;
+
+            case 'U':
+            *optset |= PCRE_UNGREEDY;
+            continue;
+
+            case '-':
+            optset = &unset;
+            continue;
+
+            /* A termination by ')' indicates an options-setting-only item; if
+            this is at the very start of the pattern (indicated by item_count
+            being zero), we use it to set the global options. This is helpful
+            when analyzing the pattern for first characters, etc. Otherwise
+            nothing is done here and it is handled during the compiling
+            process.
+
+            We allow for more than one options setting at the start. If such
+            settings do not change the existing options, nothing is compiled.
+            However, we must leave space just in case something is compiled.
+            This can happen for pathological sequences such as (?i)(?-i)
+            because the global options will end up with -i set. The space is
+            small and not significant. (Before I did this there was a reported
+            bug with (?i)(?-i) in a machine-generated pattern.)
+
+            [Historical note: Up to Perl 5.8, options settings at top level
+            were always global settings, wherever they appeared in the pattern.
+            That is, they were equivalent to an external setting. From 5.8
+            onwards, they apply only to what follows (which is what you might
+            expect).] */
+
+            case ')':
+            if (item_count == 0)
+              {
+              options = (options | set) & (~unset);
+              set = unset = 0;     /* To save length */
+              item_count--;        /* To allow for several */
+              length += 2;
+              }
+
+            /* Fall through */
+
+            /* A termination by ':' indicates the start of a nested group with
+            the given options set. This is again handled at compile time, but
+            we must allow for compiled space if any of the ims options are
+            set. We also have to allow for resetting space at the end of
+            the group, which is why 4 is added to the length and not just 2.
+            If there are several changes of options within the same group, this
+            will lead to an over-estimate on the length, but this shouldn't
+            matter very much. We also have to allow for resetting options at
+            the start of any alternations, which we do by setting
+            branch_newextra to 2. Finally, we record whether the case-dependent
+            flag ever changes within the regex. This is used by the "required
+            character" code. */
+
+            case ':':
+            if (((set|unset) & PCRE_IMS) != 0)
+              {
+              length += 4;
+              branch_newextra = 2;
+              if (((set|unset) & PCRE_CASELESS) != 0) options |= PCRE_ICHANGED;
+              }
+            goto END_OPTIONS;
+
+            /* Unrecognized option character */
+
+            default:
+            errorcode = ERR12;
+            goto PCRE_ERROR_RETURN;
+            }
+          }
+
+        /* If we hit a closing bracket, that's it - this is a freestanding
+        option-setting. We need to ensure that branch_extra is updated if
+        necessary. The only values branch_newextra can have here are 0 or 2.
+        If the value is 2, then branch_extra must either be 2 or 5, depending
+        on whether this is a lookbehind group or not. */
+
+        END_OPTIONS:
+        if (c == ')')
+          {
+          if (branch_newextra == 2 &&
+              (branch_extra == 0 || branch_extra == 1+LINK_SIZE))
+            branch_extra += branch_newextra;
+          continue;
+          }
+
+        /* If options were terminated by ':' control comes here. This is a
+        non-capturing group with an options change. There is nothing more that
+        needs to be done because "capturing" is already set FALSE by default;
+        we can just fall through. */
+#endif
+        }
+      }
+
+    /* Ordinary parentheses, not followed by '?', are capturing unless
+    PCRE_NO_AUTO_CAPTURE is set. */
+
+    else capturing = (options & PCRE_NO_AUTO_CAPTURE) == 0;
+
+    /* Capturing brackets must be counted so we can process escapes in a
+    Perlish way. If the number exceeds EXTRACT_BASIC_MAX we are going to need
+    an additional 3 bytes of memory per capturing bracket. */
+
+    if (capturing)
+      {
+      bracount++;
+      if (bracount > EXTRACT_BASIC_MAX) bracket_length += 3;
+      }
+
+    /* Save length for computing whole length at end if there's a repeat that
+    requires duplication of the group. Also save the current value of
+    branch_extra, and start the new group with the new value. If non-zero, this
+    will either be 2 for a (?imsx: group, or 3 for a lookbehind assertion. */
+
+    if (brastackptr >= sizeof(brastack)/sizeof(int))
+      {
+      errorcode = ERR19;
+      goto PCRE_ERROR_RETURN;
+      }
+
+    bralenstack[brastackptr] = branch_extra;
+    branch_extra = branch_newextra;
+
+    brastack[brastackptr++] = length;
+    length += bracket_length;
+    continue;
+
+    /* Handle ket. Look for subsequent max/min; for certain sets of values we
+    have to replicate this bracket up to that many times. If brastackptr is
+    0 this is an unmatched bracket which will generate an error, but take care
+    not to try to access brastack[-1] when computing the length and restoring
+    the branch_extra value. */
+
+    case ')':
+    length += 1 + LINK_SIZE;
+    if (brastackptr > 0)
+      {
+      duplength = length - brastack[--brastackptr];
+      branch_extra = bralenstack[brastackptr];
+      }
+    else duplength = 0;
+
+    /* The following code is also used when a recursion such as (?3) is
+    followed by a quantifier, because in that case, it has to be wrapped inside
+    brackets so that the quantifier works. The value of duplength must be
+    set before arrival. */
+
+#if !JAVASCRIPT
+    HANDLE_QUANTIFIED_BRACKETS:
+#endif
+
+    /* Leave ptr at the final char; for read_repeat_counts this happens
+    automatically; for the others we need an increment. */
+
+    if (ptr + 1 < patternEnd && (c = ptr[1]) == '{' && is_counted_repeat(ptr+2, patternEnd))
+      {
+      ptr = read_repeat_counts(ptr+2, &min, &max, &errorcode);
+      if (errorcode != 0) goto PCRE_ERROR_RETURN;
+      }
+    else if (c == '*') { min = 0; max = -1; ptr++; }
+    else if (c == '+') { min = 1; max = -1; ptr++; }
+    else if (c == '?') { min = 0; max = 1;  ptr++; }
+    else { min = 1; max = 1; }
+
+    /* If the minimum is zero, we have to allow for an OP_BRAZERO before the
+    group, and if the maximum is greater than zero, we have to replicate
+    maxval-1 times; each replication acquires an OP_BRAZERO plus a nesting
+    bracket set. */
+
+    if (min == 0)
+      {
+      length++;
+      if (max > 0) length += (max - 1) * (duplength + 3 + 2*LINK_SIZE);
+      }
+
+    /* When the minimum is greater than zero, we have to replicate up to
+    minval-1 times, with no additions required in the copies. Then, if there
+    is a limited maximum we have to replicate up to maxval-1 times allowing
+    for a BRAZERO item before each optional copy and nesting brackets for all
+    but one of the optional copies. */
+
+    else
+      {
+      length += (min - 1) * duplength;
+      if (max > min)   /* Need this test as max=-1 means no limit */
+        length += (max - min) * (duplength + 3 + 2*LINK_SIZE)
+          - (2 + 2*LINK_SIZE);
+      }
+
+    /* Allow space for once brackets for "possessive quantifier" */
+
+    if (ptr + 1 < patternEnd && ptr[1] == '+')
+      {
+      ptr++;
+      length += 2 + 2*LINK_SIZE;
+      }
+    continue;
+
+    /* Non-special character. It won't be space or # in extended mode, so it is
+    always a genuine character. If we are in a \Q...\E sequence, check for the
+    end; if not, we have a literal. */
+
+    default:
+    NORMAL_CHAR:
+
+    if (inescq && c == '\\' && ptr + 1 < patternEnd && ptr[1] == 'E')
+      {
+      inescq = FALSE;
+      ptr++;
+      continue;
+      }
+
+    length += 2;          /* For a one-byte character */
+    lastitemlength = 1;   /* Default length of last item for repeats */
+
+    /* In UTF-8 mode, check for additional bytes. */
+
+#if PCRE_UTF16
+    if (c > 127)
+      {
+        if (IS_LEADING_SURROGATE(c))
+          {
+          c = DECODE_SURROGATE_PAIR(c, ptr < patternEnd ? *ptr : 0);
+          ++ptr;
+          }
+
+        {
+          int i;
+          for (i = 0; i < _pcre_utf8_table1_size; i++)
+            if (c <= _pcre_utf8_table1[i]) break;
+          length += i;
+          lastitemlength += i;
+        }
+      }
+#else
+#ifdef SUPPORT_UTF8
+    if (utf8 && (c & 0xc0) == 0xc0)
+      {
+      while (ptr + 1 < patternEnd && (ptr[1] & 0xc0) == 0x80)         /* Can't flow over the end */
+        {                                     /* because the end is marked */
+        lastitemlength++;                     /* by a zero byte. */
+        length++;
+        ptr++;
+        }
+      }
+#endif
+#endif
+
+    continue;
+    }
+  }
+
+length += 2 + LINK_SIZE;    /* For final KET and END */
+
+if ((options & PCRE_AUTO_CALLOUT) != 0)
+  length += 2 + 2*LINK_SIZE;  /* For final callout */
+
+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. */
+
+size = length + sizeof(real_pcre) + name_count * (max_name_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, options, 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 = (pcre_uint32)MAGIC_NUMBER;
+re->size = (pcre_uint32)size;
+re->options = options;
+re->dummy1 = 0;
+re->name_table_offset = sizeof(real_pcre);
+re->name_entry_size = max_name_size + 3;
+re->name_count = name_count;
+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. */
+
+compile_block.names_found = 0;
+compile_block.name_entry_size = max_name_size + 3;
+compile_block.name_table = (uschar *)re + re->name_table_offset;
+codestart = compile_block.name_table + re->name_entry_size * re->name_count;
+compile_block.start_code = codestart;
+compile_block.start_pattern = (const pcre_uchar *)pattern;
+compile_block.req_varyopt = 0;
+compile_block.nopartial = 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 pcre_uchar *)pattern;
+code = (uschar *)codestart;
+*code = OP_BRA;
+bracount = 0;
+(void)compile_regex(options, options & PCRE_IMS, &bracount, &code, &ptr, patternEnd,
+  &errorcode, FALSE, 0, &firstbyte, &reqbyte, NULL, &compile_block);
+re->top_bracket = bracount;
+re->top_backref = compile_block.top_backref;
+
+if (compile_block.nopartial) re->options |= PCRE_NOPARTIAL;
+
+/* If not reached end of pattern on success, there's an excess bracket. */
+
+if (errorcode == 0 && ptr < patternEnd) 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
+
+/* Give an error if there's back reference to a non-existent capturing
+subpattern. */
+
+if (re->top_backref > re->top_bracket) errorcode = ERR15;
+
+/* Failed to compile, or error while post-processing */
+
+if (errorcode != 0)
+  {
+  (pcre_free)(re);
+  PCRE_ERROR_RETURN:
+  *erroroffset = INT_CAST(ptr - (const pcre_uchar *)pattern);
+  PCRE_EARLY_ERROR_RETURN:
+  *errorptr = error_texts[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 character 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 ((options & PCRE_ANCHORED) == 0)
+  {
+  int temp_options = options;
+  if (is_anchored(codestart, &temp_options, 0, compile_block.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;
+#if PCRE_UTF16
+      if (ch < 127)
+#endif
+        {
+        re->first_byte = ((firstbyte & REQ_CASELESS) != 0 &&
+           compile_block.fcc[ch] == ch)? ch : firstbyte;
+        re->options |= PCRE_FIRSTSET;
+        }
+      }
+    else if (is_startline(codestart, 0, compile_block.backref_map))
+      re->options |= 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;
+#if PCRE_UTF16
+  if (ch < 127)
+#endif
+    {
+    re->req_byte = ((reqbyte & REQ_CASELESS) != 0 &&
+      compile_block.fcc[ch] == ch)? (reqbyte & ~REQ_CASELESS) : reqbyte;
+    re->options |= 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);
+
+if (re->options != 0)
+  {
+  printf("%s%s%s%s%s%s%s%s%s%s\n",
+    ((re->options & PCRE_NOPARTIAL) != 0)? "nopartial " : "",
+    ((re->options & PCRE_ANCHORED) != 0)? "anchored " : "",
+    ((re->options & PCRE_CASELESS) != 0)? "caseless " : "",
+    ((re->options & PCRE_ICHANGED) != 0)? "case state changed " : "",
+    ((re->options & PCRE_EXTENDED) != 0)? "extended " : "",
+    ((re->options & PCRE_MULTILINE) != 0)? "multiline " : "",
+    ((re->options & PCRE_DOTALL) != 0)? "dotall " : "",
+    ((re->options & PCRE_DOLLAR_ENDONLY) != 0)? "endonly " : "",
+    ((re->options & PCRE_EXTRA) != 0)? "extra " : "",
+    ((re->options & PCRE_UNGREEDY) != 0)? "ungreedy " : "");
+  }
+
+if ((re->options & 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->options & 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);
+
+/* 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 = error_texts[ERR23];
+  *erroroffset = ptr - (pcre_uchar *)pattern;
+  if (errorcodeptr != NULL) *errorcodeptr = ERR23;
+  return NULL;
+  }
+#endif
+
+return (pcre *)re;
+}
+
+/* End of pcre_compile.c */