diff -r 5f8e5adbbed9 -r 29cda98b007e engine/sqlite/src/prepare.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/engine/sqlite/src/prepare.cpp	Thu Feb 25 14:29:19 2010 +0000
@@ -0,0 +1,763 @@
+/*
+** 2005 May 25
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains the implementation of the sqlite3_prepare()
+** interface, and routines that contribute to loading the database schema
+** from disk.
+**
+** $Id: prepare.cpp 1282 2008-11-13 09:31:33Z LarsPson $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+
+/*
+** Fill the InitData structure with an error message that indicates
+** that the database is corrupt.
+*/
+static void corruptSchema(InitData *pData, const char *zExtra){
+  if( !pData->db->mallocFailed ){
+    sqlite3SetString(pData->pzErrMsg, "malformed database schema",
+       zExtra!=0 && zExtra[0]!=0 ? " - " : (char*)0, zExtra, (char*)0);
+  }
+  pData->rc = SQLITE_CORRUPT;
+}
+
+/*
+** This is the callback routine for the code that initializes the
+** database.  See sqlite3Init() below for additional information.
+** This routine is also called from the OP_ParseSchema opcode of the VDBE.
+**
+** Each callback contains the following information:
+**
+**     argv[0] = name of thing being created
+**     argv[1] = root page number for table or index. 0 for trigger or view.
+**     argv[2] = SQL text for the CREATE statement.
+**
+*/
+int sqlite3InitCallback(void *pInit, int argc, char **argv, char **azColName){
+  InitData *pData = (InitData*)pInit;
+  sqlite3 *db = pData->db;
+  int iDb = pData->iDb;
+
+  assert( sqlite3_mutex_held(db->mutex) );
+  pData->rc = SQLITE_OK;
+  DbClearProperty(db, iDb, DB_Empty);
+  if( db->mallocFailed ){
+    corruptSchema(pData, 0);
+    return SQLITE_NOMEM;
+  }
+
+  assert( argc==3 );
+  if( argv==0 ) return 0;   /* Might happen if EMPTY_RESULT_CALLBACKS are on */
+  if( argv[1]==0 ){
+    corruptSchema(pData, 0);
+    return 1;
+  }
+  assert( iDb>=0 && iDb<db->nDb );
+  if( argv[2] && argv[2][0] ){
+    /* Call the parser to process a CREATE TABLE, INDEX or VIEW.
+    ** But because db->init.busy is set to 1, no VDBE code is generated
+    ** or executed.  All the parser does is build the internal data
+    ** structures that describe the table, index, or view.
+    */
+    char *zErr;
+    int rc;
+    assert( db->init.busy );
+    db->init.iDb = iDb;
+    db->init.newTnum = atoi(argv[1]);
+    rc = sqlite3_exec(db, argv[2], 0, 0, &zErr);
+    db->init.iDb = 0;
+    assert( rc!=SQLITE_OK || zErr==0 );
+    if( SQLITE_OK!=rc ){
+      pData->rc = rc;
+      if( rc==SQLITE_NOMEM ){
+        db->mallocFailed = 1;
+      }else if( rc!=SQLITE_INTERRUPT ){
+        corruptSchema(pData, zErr);
+      }
+      sqlite3_free(zErr);
+      return 1;
+    }
+  }else{
+    /* If the SQL column is blank it means this is an index that
+    ** was created to be the PRIMARY KEY or to fulfill a UNIQUE
+    ** constraint for a CREATE TABLE.  The index should have already
+    ** been created when we processed the CREATE TABLE.  All we have
+    ** to do here is record the root page number for that index.
+    */
+    Index *pIndex;
+    pIndex = sqlite3FindIndex(db, argv[0], db->aDb[iDb].zName);
+    if( pIndex==0 || pIndex->tnum!=0 ){
+      /* This can occur if there exists an index on a TEMP table which
+      ** has the same name as another index on a permanent index.  Since
+      ** the permanent table is hidden by the TEMP table, we can also
+      ** safely ignore the index on the permanent table.
+      */
+      /* Do Nothing */;
+    }else{
+      pIndex->tnum = atoi(argv[1]);
+    }
+  }
+  return 0;
+}
+
+/*
+** Attempt to read the database schema and initialize internal
+** data structures for a single database file.  The index of the
+** database file is given by iDb.  iDb==0 is used for the main
+** database.  iDb==1 should never be used.  iDb>=2 is used for
+** auxiliary databases.  Return one of the SQLITE_ error codes to
+** indicate success or failure.
+*/
+static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
+  int rc;
+  BtCursor *curMain;
+  int size;
+  Table *pTab;
+  Db *pDb;
+  char const *azArg[4];
+  int meta[10];
+  InitData initData;
+  char const *zMasterSchema;
+  char const *zMasterName = SCHEMA_TABLE(iDb);
+
+  /*
+  ** The master database table has a structure like this
+  */
+  static const char master_schema[] = 
+     "CREATE TABLE sqlite_master(\n"
+     "  type text,\n"
+     "  name text,\n"
+     "  tbl_name text,\n"
+     "  rootpage integer,\n"
+     "  sql text\n"
+     ")"
+  ;
+#ifndef SQLITE_OMIT_TEMPDB
+  static const char temp_master_schema[] = 
+     "CREATE TEMP TABLE sqlite_temp_master(\n"
+     "  type text,\n"
+     "  name text,\n"
+     "  tbl_name text,\n"
+     "  rootpage integer,\n"
+     "  sql text\n"
+     ")"
+  ;
+#else
+  #define temp_master_schema 0
+#endif
+
+  assert( iDb>=0 && iDb<db->nDb );
+  assert( db->aDb[iDb].pSchema );
+  assert( sqlite3_mutex_held(db->mutex) );
+
+  /* zMasterSchema and zInitScript are set to point at the master schema
+  ** and initialisation script appropriate for the database being
+  ** initialised. zMasterName is the name of the master table.
+  */
+  if( !OMIT_TEMPDB && iDb==1 ){
+    zMasterSchema = temp_master_schema;
+  }else{
+    zMasterSchema = master_schema;
+  }
+  zMasterName = SCHEMA_TABLE(iDb);
+
+  /* Construct the schema tables.  */
+  sqlite3SafetyOff(db);
+  azArg[0] = zMasterName;
+  azArg[1] = "1";
+  azArg[2] = zMasterSchema;
+  azArg[3] = 0;
+  initData.db = db;
+  initData.iDb = iDb;
+  initData.pzErrMsg = pzErrMsg;
+  rc = sqlite3InitCallback(&initData, 3, (char **)azArg, 0);
+  if( rc ){
+    sqlite3SafetyOn(db);
+    rc = initData.rc;
+    goto error_out;
+  }
+  pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName);
+  if( pTab ){
+    pTab->readOnly = 1;
+  }
+  sqlite3SafetyOn(db);
+
+  /* Create a cursor to hold the database open
+  */
+  pDb = &db->aDb[iDb];
+  if( pDb->pBt==0 ){
+    if( !OMIT_TEMPDB && iDb==1 ){
+      DbSetProperty(db, 1, DB_SchemaLoaded);
+    }
+    return SQLITE_OK;
+  }
+  sqlite3BtreeEnter(pDb->pBt);
+  rc = sqlite3BtreeCursor(pDb->pBt, MASTER_ROOT, 0, 0, 0, &curMain);
+  if( rc!=SQLITE_OK && rc!=SQLITE_EMPTY ){
+    sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
+    sqlite3BtreeLeave(pDb->pBt);
+    goto error_out;
+  }
+
+  /* Get the database meta information.
+  **
+  ** Meta values are as follows:
+  **    meta[0]   Schema cookie.  Changes with each schema change.
+  **    meta[1]   File format of schema layer.
+  **    meta[2]   Size of the page cache.
+  **    meta[3]   Use freelist if 0.  Autovacuum if greater than zero.
+  **    meta[4]   Db text encoding. 1:UTF-8 2:UTF-16LE 3:UTF-16BE
+  **    meta[5]   The user cookie. Used by the application.
+  **    meta[6]   Incremental-vacuum flag.
+  **    meta[7]
+  **    meta[8]
+  **    meta[9]
+  **
+  ** Note: The #defined SQLITE_UTF* symbols in sqliteInt.h correspond to
+  ** the possible values of meta[4].
+  */
+  if( rc==SQLITE_OK ){
+    int i;
+    for(i=0; rc==SQLITE_OK && i<sizeof(meta)/sizeof(meta[0]); i++){
+      rc = sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]);
+    }
+    if( rc ){
+      sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
+      sqlite3BtreeCloseCursor(curMain);
+      sqlite3BtreeLeave(pDb->pBt);
+      goto error_out;
+    }
+  }else{
+    memset(meta, 0, sizeof(meta));
+  }
+  pDb->pSchema->schema_cookie = meta[0];
+
+  /* If opening a non-empty database, check the text encoding. For the
+  ** main database, set sqlite3.enc to the encoding of the main database.
+  ** For an attached db, it is an error if the encoding is not the same
+  ** as sqlite3.enc.
+  */
+  if( meta[4] ){  /* text encoding */
+    if( iDb==0 ){
+      /* If opening the main database, set ENC(db). */
+      ENC(db) = (u8)meta[4];
+      db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 6, 0);
+    }else{
+      /* If opening an attached database, the encoding much match ENC(db) */
+      if( meta[4]!=ENC(db) ){
+        sqlite3BtreeCloseCursor(curMain);
+        sqlite3SetString(pzErrMsg, "attached databases must use the same"
+            " text encoding as main database", (char*)0);
+        sqlite3BtreeLeave(pDb->pBt);
+        return SQLITE_ERROR;
+      }
+    }
+  }else{
+    DbSetProperty(db, iDb, DB_Empty);
+  }
+  pDb->pSchema->enc = ENC(db);
+
+  size = meta[2];
+  if( size==0 ){ size = SQLITE_DEFAULT_CACHE_SIZE; }
+  pDb->pSchema->cache_size = size;
+  sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
+
+  /*
+  ** file_format==1    Version 3.0.0.
+  ** file_format==2    Version 3.1.3.  // ALTER TABLE ADD COLUMN
+  ** file_format==3    Version 3.1.4.  // ditto but with non-NULL defaults
+  ** file_format==4    Version 3.3.0.  // DESC indices.  Boolean constants
+  */
+  pDb->pSchema->file_format = meta[1];
+  if( pDb->pSchema->file_format==0 ){
+    pDb->pSchema->file_format = 1;
+  }
+  if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){
+    sqlite3BtreeCloseCursor(curMain);
+    sqlite3SetString(pzErrMsg, "unsupported file format", (char*)0);
+    sqlite3BtreeLeave(pDb->pBt);
+    return SQLITE_ERROR;
+  }
+
+  /* Ticket #2804:  When we open a database in the newer file format,
+  ** clear the legacy_file_format pragma flag so that a VACUUM will
+  ** not downgrade the database and thus invalidate any descending
+  ** indices that the user might have created.
+  */
+  if( iDb==0 && meta[1]>=4 ){
+    db->flags &= ~SQLITE_LegacyFileFmt;
+  }
+
+  /* Read the schema information out of the schema tables
+  */
+  assert( db->init.busy );
+  if( rc==SQLITE_EMPTY ){
+    /* For an empty database, there is nothing to read */
+    rc = SQLITE_OK;
+  }else{
+    char *zSql;
+    zSql = sqlite3MPrintf(db, 
+        "SELECT name, rootpage, sql FROM '%q'.%s",
+        db->aDb[iDb].zName, zMasterName);
+    sqlite3SafetyOff(db);
+#ifndef SQLITE_OMIT_AUTHORIZATION
+    {
+      int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
+      xAuth = db->xAuth;
+      db->xAuth = 0;
+#endif
+      rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
+#ifndef SQLITE_OMIT_AUTHORIZATION
+      db->xAuth = xAuth;
+    }
+#endif
+    if( rc==SQLITE_ABORT ) rc = initData.rc;
+    sqlite3SafetyOn(db);
+    sqlite3_free(zSql);
+#ifndef SQLITE_OMIT_ANALYZE
+    if( rc==SQLITE_OK ){
+      sqlite3AnalysisLoad(db, iDb);
+    }
+#endif
+    sqlite3BtreeCloseCursor(curMain);
+  }
+  if( db->mallocFailed ){
+    /* sqlite3SetString(pzErrMsg, "out of memory", (char*)0); */
+    rc = SQLITE_NOMEM;
+    sqlite3ResetInternalSchema(db, 0);
+  }
+  if( rc==SQLITE_OK || (db->flags&SQLITE_RecoveryMode)){
+    /* Black magic: If the SQLITE_RecoveryMode flag is set, then consider
+    ** the schema loaded, even if errors occured. In this situation the 
+    ** current sqlite3_prepare() operation will fail, but the following one
+    ** will attempt to compile the supplied statement against whatever subset
+    ** of the schema was loaded before the error occured. The primary
+    ** purpose of this is to allow access to the sqlite_master table
+    ** even when its contents have been corrupted.
+    */
+    DbSetProperty(db, iDb, DB_SchemaLoaded);
+    rc = SQLITE_OK;
+  }
+  sqlite3BtreeLeave(pDb->pBt);
+
+error_out:
+  if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
+    db->mallocFailed = 1;
+  }
+  return rc;
+}
+
+/*
+** Initialize all database files - the main database file, the file
+** used to store temporary tables, and any additional database files
+** created using ATTACH statements.  Return a success code.  If an
+** error occurs, write an error message into *pzErrMsg.
+**
+** After a database is initialized, the DB_SchemaLoaded bit is set
+** bit is set in the flags field of the Db structure. If the database
+** file was of zero-length, then the DB_Empty flag is also set.
+*/
+int sqlite3Init(sqlite3 *db, char **pzErrMsg){
+  int i, rc;
+  int commit_internal = !(db->flags&SQLITE_InternChanges);
+  
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( db->init.busy ) return SQLITE_OK;
+  rc = SQLITE_OK;
+  db->init.busy = 1;
+  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
+    if( DbHasProperty(db, i, DB_SchemaLoaded) || i==1 ) continue;
+    rc = sqlite3InitOne(db, i, pzErrMsg);
+    if( rc ){
+      sqlite3ResetInternalSchema(db, i);
+    }
+  }
+
+  /* Once all the other databases have been initialised, load the schema
+  ** for the TEMP database. This is loaded last, as the TEMP database
+  ** schema may contain references to objects in other databases.
+  */
+#ifndef SQLITE_OMIT_TEMPDB
+  if( rc==SQLITE_OK && db->nDb>1 && !DbHasProperty(db, 1, DB_SchemaLoaded) ){
+    rc = sqlite3InitOne(db, 1, pzErrMsg);
+    if( rc ){
+      sqlite3ResetInternalSchema(db, 1);
+    }
+  }
+#endif
+
+  db->init.busy = 0;
+  if( rc==SQLITE_OK && commit_internal ){
+    sqlite3CommitInternalChanges(db);
+  }
+
+  return rc; 
+}
+
+/*
+** This routine is a no-op if the database schema is already initialised.
+** Otherwise, the schema is loaded. An error code is returned.
+*/
+int sqlite3ReadSchema(Parse *pParse){
+  int rc = SQLITE_OK;
+  sqlite3 *db = pParse->db;
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( !db->init.busy ){
+    rc = sqlite3Init(db, &pParse->zErrMsg);
+  }
+  if( rc!=SQLITE_OK ){
+    pParse->rc = rc;
+    pParse->nErr++;
+  }
+  return rc;
+}
+
+
+/*
+** Check schema cookies in all databases.  If any cookie is out
+** of date, return 0.  If all schema cookies are current, return 1.
+*/
+static int schemaIsValid(sqlite3 *db){
+  int iDb;
+  int rc;
+  BtCursor *curTemp;
+  int cookie;
+  int allOk = 1;
+
+  assert( sqlite3_mutex_held(db->mutex) );
+  for(iDb=0; allOk && iDb<db->nDb; iDb++){
+    Btree *pBt;
+    pBt = db->aDb[iDb].pBt;
+    if( pBt==0 ) continue;
+    rc = sqlite3BtreeCursor(pBt, MASTER_ROOT, 0, 0, 0, &curTemp);
+    if( rc==SQLITE_OK ){
+      rc = sqlite3BtreeGetMeta(pBt, 1, (u32 *)&cookie);
+      if( rc==SQLITE_OK && cookie!=db->aDb[iDb].pSchema->schema_cookie ){
+        allOk = 0;
+      }
+      sqlite3BtreeCloseCursor(curTemp);
+    }
+    if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
+      db->mallocFailed = 1;
+    }
+  }
+  return allOk;
+}
+
+/*
+** Convert a schema pointer into the iDb index that indicates
+** which database file in db->aDb[] the schema refers to.
+**
+** If the same database is attached more than once, the first
+** attached database is returned.
+*/
+int sqlite3SchemaToIndex(sqlite3 *db, Schema *pSchema){
+  int i = -1000000;
+
+  /* If pSchema is NULL, then return -1000000. This happens when code in 
+  ** expr.c is trying to resolve a reference to a transient table (i.e. one
+  ** created by a sub-select). In this case the return value of this 
+  ** function should never be used.
+  **
+  ** We return -1000000 instead of the more usual -1 simply because using
+  ** -1000000 as incorrectly using -1000000 index into db->aDb[] is much 
+  ** more likely to cause a segfault than -1 (of course there are assert()
+  ** statements too, but it never hurts to play the odds).
+  */
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( pSchema ){
+    for(i=0; i<db->nDb; i++){
+      if( db->aDb[i].pSchema==pSchema ){
+        break;
+      }
+    }
+    assert( i>=0 &&i>=0 &&  i<db->nDb );
+  }
+  return i;
+}
+
+/*
+** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
+*/
+int sqlite3Prepare(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  int saveSqlFlag,          /* True to copy SQL text into the sqlite3_stmt */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+){
+  Parse sParse;
+  char *zErrMsg = 0;
+  int rc = SQLITE_OK;
+  int i;
+
+  assert( ppStmt );
+  *ppStmt = 0;
+  if( sqlite3SafetyOn(db) ){
+    return SQLITE_MISUSE;
+  }
+  assert( !db->mallocFailed );
+  assert( sqlite3_mutex_held(db->mutex) );
+
+  /* If any attached database schemas are locked, do not proceed with
+  ** compilation. Instead return SQLITE_LOCKED immediately.
+  */
+  for(i=0; i<db->nDb; i++) {
+    Btree *pBt = db->aDb[i].pBt;
+    if( pBt ){
+      int rc;
+      rc = sqlite3BtreeSchemaLocked(pBt);
+      if( rc ){
+        const char *zDb = db->aDb[i].zName;
+        sqlite3Error(db, SQLITE_LOCKED, "database schema is locked: %s", zDb);
+        sqlite3SafetyOff(db);
+        return SQLITE_LOCKED;
+      }
+    }
+  }
+  
+  memset(&sParse, 0, sizeof(sParse));
+  sParse.db = db;
+  if( nBytes>=0 && zSql[nBytes]!=0 ){
+    char *zSqlCopy;
+    if( nBytes>SQLITE_MAX_SQL_LENGTH ){
+      return SQLITE_TOOBIG;
+    }
+    zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes);
+    if( zSqlCopy ){
+      sqlite3RunParser(&sParse, zSqlCopy, &zErrMsg);
+      sqlite3_free(zSqlCopy);
+    }
+    sParse.zTail = &zSql[nBytes];
+  }else{
+    sqlite3RunParser(&sParse, zSql, &zErrMsg);
+  }
+
+  if( db->mallocFailed ){
+    sParse.rc = SQLITE_NOMEM;
+  }
+  if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK;
+  if( sParse.checkSchema && !schemaIsValid(db) ){
+    sParse.rc = SQLITE_SCHEMA;
+  }
+  if( sParse.rc==SQLITE_SCHEMA ){
+    sqlite3ResetInternalSchema(db, 0);
+  }
+  if( db->mallocFailed ){
+    sParse.rc = SQLITE_NOMEM;
+  }
+  if( pzTail ){
+    *pzTail = sParse.zTail;
+  }
+  rc = sParse.rc;
+
+#ifndef SQLITE_OMIT_EXPLAIN
+  if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){
+    if( sParse.explain==2 ){
+      sqlite3VdbeSetNumCols(sParse.pVdbe, 3);
+      sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "order", P3_STATIC);
+      sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "from", P3_STATIC);
+      sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "detail", P3_STATIC);
+    }else{
+      sqlite3VdbeSetNumCols(sParse.pVdbe, 5);
+      sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "addr", P3_STATIC);
+      sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "opcode", P3_STATIC);
+      sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "p1", P3_STATIC);
+      sqlite3VdbeSetColName(sParse.pVdbe, 3, COLNAME_NAME, "p2", P3_STATIC);
+      sqlite3VdbeSetColName(sParse.pVdbe, 4, COLNAME_NAME, "p3", P3_STATIC);
+    }
+  }
+#endif
+
+  if( sqlite3SafetyOff(db) ){
+    rc = SQLITE_MISUSE;
+  }
+
+  if( saveSqlFlag ){
+    sqlite3VdbeSetSql(sParse.pVdbe, zSql, sParse.zTail - zSql);
+  }
+  if( rc!=SQLITE_OK || db->mallocFailed ){
+    sqlite3_finalize((sqlite3_stmt*)sParse.pVdbe);
+    assert(!(*ppStmt));
+  }else{
+    *ppStmt = (sqlite3_stmt*)sParse.pVdbe;
+  }
+
+  if( zErrMsg ){
+    sqlite3Error(db, rc, "%s", zErrMsg);
+    sqlite3_free(zErrMsg);
+  }else{
+    sqlite3Error(db, rc, 0);
+  }
+
+  rc = sqlite3ApiExit(db, rc);
+  /* sqlite3ReleaseThreadData(); */
+  assert( (rc&db->errMask)==rc );
+  return rc;
+}
+static int sqlite3LockAndPrepare(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  int saveSqlFlag,          /* True to copy SQL text into the sqlite3_stmt */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+){
+  int rc;
+  if( sqlite3SafetyCheck(db) ){
+    return SQLITE_MISUSE;
+  }
+  sqlite3_mutex_enter(db->mutex);
+  sqlite3BtreeEnterAll(db);
+  rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, ppStmt, pzTail);
+  sqlite3BtreeLeaveAll(db);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** Rerun the compilation of a statement after a schema change.
+** Return true if the statement was recompiled successfully.
+** Return false if there is an error of some kind.
+*/
+int sqlite3Reprepare(Vdbe *p){
+  int rc;
+  sqlite3_stmt *pNew;
+  const char *zSql;
+  sqlite3 *db;
+
+  assert( sqlite3_mutex_held(sqlite3VdbeDb(p)->mutex) );
+  zSql = sqlite3_sql((sqlite3_stmt *)p);
+  if( zSql==0 ){
+    return 0;
+  }
+  db = sqlite3VdbeDb(p);
+  assert( sqlite3_mutex_held(db->mutex) );
+  rc = sqlite3LockAndPrepare(db, zSql, -1, 0, &pNew, 0);
+  if( rc ){
+    if( rc==SQLITE_NOMEM ){
+      db->mallocFailed = 1;
+    }
+    assert( pNew==0 );
+    return 0;
+  }else{
+    assert( pNew!=0 );
+  }
+  sqlite3VdbeSwap((Vdbe*)pNew, p);
+  sqlite3_transfer_bindings(pNew, (sqlite3_stmt*)p);
+  sqlite3VdbeResetStepResult((Vdbe*)pNew);
+  sqlite3VdbeFinalize((Vdbe*)pNew);
+  return 1;
+}
+
+
+/*
+** Two versions of the official API.  Legacy and new use.  In the legacy
+** version, the original SQL text is not saved in the prepared statement
+** and so if a schema change occurs, SQLITE_SCHEMA is returned by
+** sqlite3_step().  In the new version, the original SQL text is retained
+** and the statement is automatically recompiled if an schema change
+** occurs.
+*/
+EXPORT_C int sqlite3_prepare(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+){
+  return sqlite3LockAndPrepare(db,zSql,nBytes,0,ppStmt,pzTail);
+}
+EXPORT_C int sqlite3_prepare_v2(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+){
+  return sqlite3LockAndPrepare(db,zSql,nBytes,1,ppStmt,pzTail);
+}
+
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Compile the UTF-16 encoded SQL statement zSql into a statement handle.
+*/
+static int sqlite3Prepare16(
+  sqlite3 *db,              /* Database handle. */ 
+  const void *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  int saveSqlFlag,          /* True to save SQL text into the sqlite3_stmt */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const void **pzTail       /* OUT: End of parsed string */
+){
+  /* This function currently works by first transforming the UTF-16
+  ** encoded string to UTF-8, then invoking sqlite3_prepare(). The
+  ** tricky bit is figuring out the pointer to return in *pzTail.
+  */
+  char *zSql8;
+  const char *zTail8 = 0;
+  int rc = SQLITE_OK;
+
+  if( sqlite3SafetyCheck(db) ){
+    return SQLITE_MISUSE;
+  }
+  sqlite3_mutex_enter(db->mutex);
+  zSql8 = sqlite3Utf16to8(db, zSql, nBytes);
+  if( zSql8 ){
+    rc = sqlite3LockAndPrepare(db, zSql8, -1, saveSqlFlag, ppStmt, &zTail8);
+  }
+
+  if( zTail8 && pzTail ){
+    /* If sqlite3_prepare returns a tail pointer, we calculate the
+    ** equivalent pointer into the UTF-16 string by counting the unicode
+    ** characters between zSql8 and zTail8, and then returning a pointer
+    ** the same number of characters into the UTF-16 string.
+    */
+    int chars_parsed = sqlite3Utf8CharLen(zSql8, zTail8-zSql8);
+    *pzTail = (u8 *)zSql + sqlite3Utf16ByteLen(zSql, chars_parsed);
+  }
+  sqlite3_free(zSql8); 
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** Two versions of the official API.  Legacy and new use.  In the legacy
+** version, the original SQL text is not saved in the prepared statement
+** and so if a schema change occurs, SQLITE_SCHEMA is returned by
+** sqlite3_step().  In the new version, the original SQL text is retained
+** and the statement is automatically recompiled if an schema change
+** occurs.
+*/
+EXPORT_C int sqlite3_prepare16(
+  sqlite3 *db,              /* Database handle. */ 
+  const void *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const void **pzTail       /* OUT: End of parsed string */
+){
+  return sqlite3Prepare16(db,zSql,nBytes,0,ppStmt,pzTail);
+}
+EXPORT_C int sqlite3_prepare16_v2(
+  sqlite3 *db,              /* Database handle. */ 
+  const void *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const void **pzTail       /* OUT: End of parsed string */
+){
+  return sqlite3Prepare16(db,zSql,nBytes,1,ppStmt,pzTail);
+}
+
+#endif /* SQLITE_OMIT_UTF16 */