SQLite

  char *str = malloc(n + 1);
  memcpy(str, s, n);
  str[n] = '\0';
  return str;
}

/* Duplicate a string; the caller must free() the returned string.
 * (We don't use strdup() since it's not part of the standard C library and
 * may not be available everywhere.) */
static char *string_dup(const char *s){
  return string_dup_n(s, strlen(s));
}

/* Format a string, replacing each occurrence of the % character with
 * zDb.zName.  This may be more convenient than sqlite_mprintf()

  rc = content_update(v, pValues, iRow);  /* execute an SQL UPDATE */
  if( rc!=SQLITE_OK ) return rc;

  /* Now add positions for terms which appear in the updated row. */
  return insertTerms(v, pTerms, iRow, pValues);
}

/* This function implements the xUpdate callback; it's the top-level entry
 * point for inserting, deleting or updating a row in a full-text table. */
static int fulltextUpdate(sqlite3_vtab *pVtab, int nArg, sqlite3_value **ppArg,
                   sqlite_int64 *pRowid){
  fulltext_vtab *v = (fulltext_vtab *) pVtab;
  fts1Hash terms;   /* maps term string -> PosList */
  int rc;
  fts1HashElem *e;

  The ICU tokenizer implementation is very simple. It splits the input
  text according to the ICU rules for finding word boundaries and discards
  any tokens that consist entirely of white-space. This may be suitable
  for some applications in some locales, but not all. If more complex
  processing is required, for example to implement stemming or 
  discard punctuation, this can be done by creating a tokenizer 
  implementation that uses the ICU tokenizer as part of it's implementation.

  When using the ICU tokenizer this way, it is safe to overwrite the
  contents of the strings returned by the xNext() method (see
  fts2_tokenizer.h).

4. Sample code.

          if( sqlite3_column_type(pStmt, 0)==SQLITE_BLOB ){
            memcpy(pp, sqlite3_column_blob(pStmt, 0), sizeof(*pp));
          }
        }
      
        return sqlite3_finalize(pStmt);
      }

**
** This appears to have only a moderate impact on queries for very
** frequent terms (which are somewhat dominated by segment merge
** costs), and infrequent and non-existent terms still seem to be fast
** even with many segments.
**
** TODO(shess) That said, it would be nice to have a better query-side
** argument for MERGE_COUNT of 16.  Also, it's possible/likely that
** optimizations to things like doclist merging will swing the sweet
** spot around.
**
**
**
**** Handling of deletions and updates ****
** Since we're using a segmented structure, with no docid-oriented

}
static void dlrDestroy(DLReader *pReader){
  SCRAMBLE(pReader);
}

#ifndef NDEBUG
/* Verify that the doclist can be validly decoded.  Also returns the
** last docid found because it's convenient in other assertions for
** DLWriter.
*/
static void docListValidate(DocListType iType, const char *pData, int nData,
                            sqlite_int64 *pLastDocid){
  sqlite_int64 iPrevDocid = 0;
  assert( nData>0 );
  assert( pData!=0 );

  DLWriter dlw;
  PLWriter plw;
} DLCollector;

/* TODO(shess) This could also be done by calling plwTerminate() and
** dataBufferAppend().  I tried that, expecting nominal performance
** differences, but it seemed to pretty reliably be worth 1% to code
** it this way.  I suspect it's the incremental malloc overhead (some
** percentage of the plwTerminate() calls will cause a realloc), so
** this might be worth revisiting if the DataBuffer implementation
** changes.
*/
static void dlcAddDoclist(DLCollector *pCollector, DataBuffer *b){
  if( pCollector->dlw.iType>DL_DOCIDS ){
    char c[VARINT_MAX];

  char *str = malloc(n + 1);
  memcpy(str, s, n);
  str[n] = '\0';
  return str;
}

/* Duplicate a string; the caller must free() the returned string.
 * (We don't use strdup() since it's not part of the standard C library and
 * may not be available everywhere.) */
static char *string_dup(const char *s){
  return string_dup_n(s, strlen(s));
}

/* Format a string, replacing each occurrence of the % character with
 * zDb.zName.  This may be more convenient than sqlite_mprintf()

** interior node terms logically come between the blocks, so there is
** one more blockid than there are terms (that block contains terms >=
** the last interior-node term).
*/
/* TODO(shess) The calling code may already know that the end child is
** not worth calculating, because the end may be in a later sibling
** node.  Consider whether breaking symmetry is worthwhile.  I suspect
** it's not worthwhile.
*/
static void getChildrenContaining(const char *pData, int nData,
                                  const char *pTerm, int nTerm, int isPrefix,
                                  sqlite_int64 *piStartChild,
                                  sqlite_int64 *piEndChild){
  InteriorReader reader;

    fts2HashInit(&v->pendingTerms, FTS2_HASH_STRING, 1);
    v->nPendingData = 0;
  }
  v->iPrevDocid = iDocid;
  return SQLITE_OK;
}

/* This function implements the xUpdate callback; it's the top-level entry
 * point for inserting, deleting or updating a row in a full-text table. */
static int fulltextUpdate(sqlite3_vtab *pVtab, int nArg, sqlite3_value **ppArg,
                   sqlite_int64 *pRowid){
  fulltext_vtab *v = (fulltext_vtab *) pVtab;
  int rc;

  TRACE(("FTS2 Update %p\n", pVtab));

  The ICU tokenizer implementation is very simple. It splits the input
  text according to the ICU rules for finding word boundaries and discards
  any tokens that consist entirely of white-space. This may be suitable
  for some applications in some locales, but not all. If more complex
  processing is required, for example to implement stemming or 
  discard punctuation, this can be done by creating a tokenizer 
  implementation that uses the ICU tokenizer as part of it's implementation.

  When using the ICU tokenizer this way, it is safe to overwrite the
  contents of the strings returned by the xNext() method (see
  fts3_tokenizer.h).

4. Sample code.

          if( sqlite3_column_type(pStmt, 0)==SQLITE_BLOB ){
            memcpy(pp, sqlite3_column_blob(pStmt, 0), sizeof(*pp));
          }
        }
      
        return sqlite3_finalize(pStmt);
      }

**
** This appears to have only a moderate impact on queries for very
** frequent terms (which are somewhat dominated by segment merge
** costs), and infrequent and non-existent terms still seem to be fast
** even with many segments.
**
** TODO(shess) That said, it would be nice to have a better query-side
** argument for MERGE_COUNT of 16.  Also, it's possible/likely that
** optimizations to things like doclist merging will swing the sweet
** spot around.
**
**
**
**** Handling of deletions and updates ****
** Since we're using a segmented structure, with no docid-oriented

}
static void dlrDestroy(DLReader *pReader){
  SCRAMBLE(pReader);
}

#ifndef NDEBUG
/* Verify that the doclist can be validly decoded.  Also returns the
** last docid found because it's convenient in other assertions for
** DLWriter.
*/
static void docListValidate(DocListType iType, const char *pData, int nData,
                            sqlite_int64 *pLastDocid){
  sqlite_int64 iPrevDocid = 0;
  assert( nData>0 );
  assert( pData!=0 );

  DLWriter dlw;
  PLWriter plw;
} DLCollector;

/* TODO(shess) This could also be done by calling plwTerminate() and
** dataBufferAppend().  I tried that, expecting nominal performance
** differences, but it seemed to pretty reliably be worth 1% to code
** it this way.  I suspect it's the incremental malloc overhead (some
** percentage of the plwTerminate() calls will cause a realloc), so
** this might be worth revisiting if the DataBuffer implementation
** changes.
*/
static void dlcAddDoclist(DLCollector *pCollector, DataBuffer *b){
  if( pCollector->dlw.iType>DL_DOCIDS ){
    char c[VARINT_MAX];

  char *str = sqlite3_malloc(n + 1);
  memcpy(str, s, n);
  str[n] = '\0';
  return str;
}

/* Duplicate a string; the caller must free() the returned string.
 * (We don't use strdup() since it's not part of the standard C library and
 * may not be available everywhere.) */
static char *string_dup(const char *s){
  return string_dup_n(s, strlen(s));
}

/* Format a string, replacing each occurrence of the % character with
 * zDb.zName.  This may be more convenient than sqlite_mprintf()

** of the same phrase, or connected by the NEAR operator.
**
** If the QueryTerm.nNear variable is non-zero, then the token is followed 
** by a NEAR operator with span set to (nNear-1). For example, the 
** following query:
**
** The QueryTerm.iPhrase variable stores the index of the token within
** it's phrase, indexed starting at 1, or 1 if the token is not part 
** of any phrase.
**
** For example, the data structure used to represent the following query:
**
**     ... MATCH 'sqlite NEAR/5 google NEAR/2 "search engine"'
**
** is:

** interior node terms logically come between the blocks, so there is
** one more blockid than there are terms (that block contains terms >=
** the last interior-node term).
*/
/* TODO(shess) The calling code may already know that the end child is
** not worth calculating, because the end may be in a later sibling
** node.  Consider whether breaking symmetry is worthwhile.  I suspect
** it's not worthwhile.
*/
static void getChildrenContaining(const char *pData, int nData,
                                  const char *pTerm, int nTerm, int isPrefix,
                                  sqlite_int64 *piStartChild,
                                  sqlite_int64 *piEndChild){
  InteriorReader reader;

    fts3HashInit(&v->pendingTerms, FTS3_HASH_STRING, 1);
    v->nPendingData = 0;
  }
  v->iPrevDocid = iDocid;
  return SQLITE_OK;
}

/* This function implements the xUpdate callback; it's the top-level entry
 * point for inserting, deleting or updating a row in a full-text table. */
static int fulltextUpdate(sqlite3_vtab *pVtab, int nArg, sqlite3_value **ppArg,
                          sqlite_int64 *pRowid){
  fulltext_vtab *v = (fulltext_vtab *) pVtab;
  int rc;

  FTSTRACE(("FTS3 Update %p\n", pVtab));

/*
** 2007 May 6
**
** 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.
**
*************************************************************************
** $Id: icu.c,v 1.6 2007/06/22 15:21:16 danielk1977 Exp $
**
** This file implements an integration between the ICU library 
** ("International Components for Unicode", an open-source library 
** for handling unicode data) and SQLite. The integration uses 
** ICU to provide the following to SQLite:
**
**   * An implementation of the SQL regexp() function (and hence REGEXP

  /* Return 1 or 0. */
  sqlite3_result_int(p, res ? 1 : 0);
}

/*
** Implementations of scalar functions for case mapping - upper() and 
** lower(). Function upper() converts it's input to upper-case (ABC).
** Function lower() converts to lower-case (abc).
**
** ICU provides two types of case mapping, "general" case mapping and
** "language specific". Refer to ICU documentation for the differences
** between the two.
**
** To utilise "general" case mapping, the upper() or lower() scalar 

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that used to generate VDBE code
** that implements the ALTER TABLE command.
**
** $Id: alter.c,v 1.34 2007/12/13 08:15:31 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The code in this file only exists if we are not omitting the
** ALTER TABLE logic from the build.

      }

      /* Store the token that zCsr points to in tname. */
      tname.z = zCsr;
      tname.n = len;

      /* Advance zCsr to the next token. Store that token type in 'token',
      ** and it's length in 'len' (to be used next iteration of this loop).
      */
      do {
        zCsr += len;
        len = sqlite3GetToken(zCsr, &token);
      } while( token==TK_SPACE );
      assert( len>0 );
    } while( token!=TK_LP && token!=TK_USING );

      }

      /* Store the token that zCsr points to in tname. */
      tname.z = zCsr;
      tname.n = len;

      /* Advance zCsr to the next token. Store that token type in 'token',
      ** and it's length in 'len' (to be used next iteration of this loop).
      */
      do {
        zCsr += len;
        len = sqlite3GetToken(zCsr, &token);
      }while( token==TK_SPACE );
      assert( len>0 );

/*
** 2004 April 6
**
** 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.
**
*************************************************************************
** $Id: btree.c,v 1.432 2007/12/07 18:55:28 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"

** Restore the cursor to the position it was in (or as close to as possible)
** when saveCursorPosition() was called. Note that this call deletes the 
** saved position info stored by saveCursorPosition(), so there can be
** at most one effective restoreOrClearCursorPosition() call after each 
** saveCursorPosition().
**
** If the second argument argument - doSeek - is false, then instead of 
** returning the cursor to it's saved position, any saved position is deleted
** and the cursor state set to CURSOR_INVALID.
*/
int sqlite3BtreeRestoreOrClearCursorPosition(BtCursor *pCur){
  int rc;
  assert( cursorHoldsMutex(pCur) );
  assert( pCur->eState>=CURSOR_REQUIRESEEK );
  if( pCur->eState==CURSOR_FAULT ){

  int rc;

  assert( eType==PTRMAP_OVERFLOW2 || eType==PTRMAP_OVERFLOW1 || 
      eType==PTRMAP_BTREE || eType==PTRMAP_ROOTPAGE );
  assert( sqlite3_mutex_held(pBt->mutex) );
  assert( pDbPage->pBt==pBt );

  /* Move page iDbPage from it's current location to page number iFreePage */
  TRACE(("AUTOVACUUM: Moving %d to free page %d (ptr page %d type %d)\n", 
      iDbPage, iFreePage, iPtrPage, eType));
  rc = sqlite3PagerMovepage(pPager, pDbPage->pDbPage, iFreePage);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  pDbPage->pgno = iFreePage;

** linked list of overflow pages. If possible, it uses the auto-vacuum
** pointer-map data instead of reading the content of page ovfl to do so. 
**
** If an error occurs an SQLite error code is returned. Otherwise:
**
** Unless pPgnoNext is NULL, the page number of the next overflow 
** page in the linked list is written to *pPgnoNext. If page ovfl
** is the last page in it's linked list, *pPgnoNext is set to zero. 
**
** If ppPage is not NULL, *ppPage is set to the MemPage* handle
** for page ovfl. The underlying pager page may have been requested
** with the noContent flag set, so the page data accessable via
** this handle may not be trusted.
*/
static int getOverflowPage(

        pTemp = 0;
      }else{
        pCell -= 4;
        pTemp = &aSpace[iSpace];
        iSpace += sz;
        assert( iSpace<=pBt->pageSize*5 );
        /* Obscure case for non-leaf-data trees: If the cell at pCell was
        ** previously stored on a leaf node, and it's reported size was 4
        ** bytes, then it may actually be smaller than this 
        ** (see sqlite3BtreeParseCellPtr(), 4 bytes is the minimum size of
        ** any cell). But it's important to pass the correct size to 
        ** insertCell(), so reparse the cell now.
        **
        ** Note that this can never happen in an SQLite data file, as all
        ** cells are at least 4 bytes. It only happens in b-trees used
        ** to evaluate "IN (SELECT ...)" and similar clauses.
        */
        if( szCell[j]==4 ){

    (rc = restoreOrClearCursorPosition(pCur))!=0 ||
    (rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur))!=0 ||
    (rc = sqlite3PagerWrite(pPage->pDbPage))!=0
  ){
    return rc;
  }

  /* Locate the cell within it's page and leave pCell pointing to the
  ** data. The clearCell() call frees any overflow pages associated with the
  ** cell. The cell itself is still intact.
  */
  pCell = findCell(pPage, pCur->idx);
  if( !pPage->leaf ){
    pgnoChild = get4byte(pCell);
  }

int sqlite3BtreeIsInReadTrans(Btree *p){
  assert( sqlite3_mutex_held(p->db->mutex) );
  return (p && (p->inTrans!=TRANS_NONE));
}

/*
** This function returns a pointer to a blob of memory associated with
** a single shared-btree. The memory is used by client code for it's own
** purposes (for example, to store a high-level schema associated with 
** the shared-btree). The btree layer manages reference counting issues.
**
** The first time this is called on a shared-btree, nBytes bytes of memory
** are allocated, zeroed, and returned to the caller. For each subsequent 
** call the nBytes parameter is ignored and a pointer to the same blob
** of memory returned. 

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.318 2007/12/10 05:03:47 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**

  #define sqlite3_enable_in_opt 1
#endif

/*
** This function is used by the implementation of the IN (...) operator.
** It's job is to find or create a b-tree structure that may be used
** either to test for membership of the (...) set or to iterate through
** it's members, skipping duplicates.
**
** The cursor opened on the structure (database table, database index 
** or ephermal table) is stored in pX->iTable before this function returns.
** The returned value indicates the structure type, as follows:
**
**   IN_INDEX_ROWID - The cursor was opened on a database table.
**   IN_INDEX_INDEX - The cursor was opened on a database indec.
**   IN_INDEX_EPH -   The cursor was opened on a specially created and
**                    populated epheremal table.
**
** An existing structure may only be used if the SELECT is of the simple
** form:
**
**     SELECT <column> FROM <table>
**
** If the mustBeUnique parameter is false, the structure will be used 
** for fast set membership tests. In this case an epheremal table must 
** be used unless <column> is an INTEGER PRIMARY KEY or an index can 
** be found with <column> as it's left-most column.
**
** If mustBeUnique is true, then the structure will be used to iterate
** through the set members, skipping any duplicates. In this case an
** epheremal table must be used unless the selected <column> is guaranteed
** to be unique - either because it is an INTEGER PRIMARY KEY or it
** is unique by virtue of a constraint or implicit index.
*/

** This file contains the C functions that implement various SQL
** functions of SQLite.  
**
** There is only one exported symbol in this file - the function
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: func.c,v 1.180 2007/12/11 04:23:20 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include <stdlib.h>
#include <assert.h>
#include "vdbeInt.h"

  sqlite3_result_text(pCtx, zRet, 2*nArg-1, free_test_auxdata);
}
#endif /* SQLITE_TEST */

#ifdef SQLITE_TEST
/*
** A function to test error reporting from user functions. This function
** returns a copy of it's first argument as an error.
*/
static void test_error(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **argv
){
  sqlite3_result_error(pCtx, (char*)sqlite3_value_text(argv[0]), 0);

/*
** Return the sector size in bytes of the underlying block device for
** the specified file. This is almost always 512 bytes, but may be
** larger for some devices.
**
** SQLite code assumes this function cannot fail. It also assumes that
** if two files are created in the same file-system directory (i.e.
** a database and it's journal file) that the sector size will be the
** same for both.
*/
static int os2SectorSize(sqlite3_file *id){
  return SQLITE_DEFAULT_SECTOR_SIZE;
}

/*

# define O_BINARY 0
#endif

/*
** The DJGPP compiler environment looks mostly like Unix, but it
** lacks the fcntl() system call.  So redefine fcntl() to be something
** that always succeeds.  This means that locking does not occur under
** DJGPP.  But it's DOS - what did you expect?
*/
#ifdef __DJGPP__
# define fcntl(A,B,C) 0
#endif

/*
** The threadid macro resolves to the thread-id or to 0.  Used for

  */  
  return dotlockLockingStyle;
}

/* 
** Examines the f_fstypename entry in the statfs structure as returned by 
** stat() for the file system hosting the database file, assigns the 
** appropriate locking style based on it's value.  These values and 
** assignments are based on Darwin/OSX behavior and have not been tested on 
** other systems.
*/
static sqlite3LockingStyle sqlite3DetectLockingStyle(
  const char *filePath, 
  int fd
){

/*
** Return the sector size in bytes of the underlying block device for
** the specified file. This is almost always 512 bytes, but may be
** larger for some devices.
**
** SQLite code assumes this function cannot fail. It also assumes that
** if two files are created in the same file-system directory (i.e.
** a database and it's journal file) that the sector size will be the
** same for both.
*/
static int unixSectorSize(sqlite3_file *id){
  return SQLITE_DEFAULT_SECTOR_SIZE;
}

/*

/*
** Return the sector size in bytes of the underlying block device for
** the specified file. This is almost always 512 bytes, but may be
** larger for some devices.
**
** SQLite code assumes this function cannot fail. It also assumes that
** if two files are created in the same file-system directory (i.e.
** a database and it's journal file) that the sector size will be the
** same for both.
*/
static int winSectorSize(sqlite3_file *id){
  return SQLITE_DEFAULT_SECTOR_SIZE;
}

/*

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.399 2007/12/11 19:34:45 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include <assert.h>
#include <string.h>

/*

#define PAGERTRACE5(X,Y,Z,W,V)
#endif

/*
** The following two macros are used within the PAGERTRACEX() macros above
** to print out file-descriptors. 
**
** PAGERID() takes a pointer to a Pager struct as it's argument. The
** associated file-descriptor is returned. FILEHANDLEID() takes an sqlite3_file
** struct as it's argument.
*/
#define PAGERID(p) ((int)(p->fd))
#define FILEHANDLEID(fd) ((int)fd)

/*
** The page cache as a whole is always in one of the following
** states:

** pager structure for this purpose (variable Pager.lru).
**
** Additionally, if memory-management is enabled, all unreferenced pages 
** are stored in a global LRU list (global variable sqlite3LruPageList).
**
** In both cases, the PagerLruList.pFirstSynced variable points to
** the first page in the corresponding list that does not require an
** fsync() operation before it's memory can be reclaimed. If no such
** page exists, PagerLruList.pFirstSynced is set to NULL.
*/
typedef struct PagerLruList PagerLruList;
struct PagerLruList {
  PgHdr *pFirst;         /* First page in LRU list */
  PgHdr *pLast;          /* Last page in LRU list (the most recently used) */
  PgHdr *pFirstSynced;   /* First page in list with PgHdr.needSync==0 */

    */
    if( nRec==0 && !isHot &&
        pPager->journalHdr+JOURNAL_HDR_SZ(pPager)==pPager->journalOff ){
      nRec = (szJ - pPager->journalOff) / JOURNAL_PG_SZ(pPager);
    }

    /* If this is the first header read from the journal, truncate the
    ** database file back to it's original size.
    */
    if( pPager->journalOff==JOURNAL_HDR_SZ(pPager) ){
      rc = pager_truncate(pPager, mxPg);
      if( rc!=SQLITE_OK ){
        goto end_playback;
      }
    }

/*
** Forward declaration
*/
static int syncJournal(Pager*);

/*
** Unlink pPg from it's hash chain. Also set the page number to 0 to indicate
** that the page is not part of any hash chain. This is required because the
** sqlite3PagerMovepage() routine can leave a page in the 
** pNextFree/pPrevFree list that is not a part of any hash-chain.
*/
static void unlinkHashChain(Pager *pPager, PgHdr *pPg){
  if( pPg->pgno==0 ){
    assert( pPg->pNextHash==0 && pPg->pPrevHash==0 );

        ** EXCLUSIVE lock. If it were, another process might open the
        ** database file, detect the RESERVED lock, and conclude that the
        ** database is safe to read while this process is still rolling it 
        ** back.
        ** 
        ** Because the intermediate RESERVED lock is not requested, the
        ** second process will get to this point in the code and fail to
        ** obtain it's own EXCLUSIVE lock on the database file.
        */
        if( pPager->state<EXCLUSIVE_LOCK ){
          rc = sqlite3OsLock(pPager->fd, EXCLUSIVE_LOCK);
          if( rc!=SQLITE_OK ){
            pager_unlock(pPager);
            return pager_error(pPager, rc);
          }

    rc = sqlite3PagerTruncate(pPager, nTrunc);
  }

sync_exit:
  if( rc==SQLITE_IOERR_BLOCKED ){
    /* pager_incr_changecounter() may attempt to obtain an exclusive
     * lock to spill the cache and return IOERR_BLOCKED. But since 
     * there is no chance the cache is inconsistent, it's
     * better to return SQLITE_BUSY.
     */
    rc = SQLITE_BUSY;
  }
  pagerLeave(pPager);
  return rc;
}

  if( pPg->needSync ){
    needSyncPgno = pPg->pgno;
    assert( pPg->inJournal || (int)pgno>pPager->origDbSize );
    assert( pPg->dirty );
    assert( pPager->needSync );
  }

  /* Unlink pPg from it's hash-chain */
  unlinkHashChain(pPager, pPg);

  /* If the cache contains a page with page-number pgno, remove it
  ** from it's hash chain. Also, if the PgHdr.needSync was set for 
  ** page pgno before the 'move' operation, it needs to be retained 
  ** for the page moved there.
  */
  pPg->needSync = 0;
  pPgOld = pager_lookup(pPager, pgno);
  if( pPgOld ){
    assert( pPgOld->nRef==0 );

/*
** 2003 April 6
**
** 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 code used to implement the PRAGMA command.
**
** $Id: pragma.c,v 1.151 2007/12/05 01:38:24 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/* Ignore this whole file if pragmas are disabled
*/
#if !defined(SQLITE_OMIT_PRAGMA) && !defined(SQLITE_OMIT_PARSER)

#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

#ifndef SQLITE_OMIT_UTF16
  /*
  **   PRAGMA encoding
  **   PRAGMA encoding = "utf-8"|"utf-16"|"utf-16le"|"utf-16be"
  **
  ** In it's first form, this pragma returns the encoding of the main
  ** database. If the database is not initialized, it is initialized now.
  **
  ** The second form of this pragma is a no-op if the main database file
  ** has not already been initialized. In this case it sets the default
  ** encoding that will be used for the main database file if a new file
  ** is created. If an existing main database file is opened, then the
  ** default text encoding for the existing database is used.

**    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.c,v 1.65 2007/11/28 13:43:17 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.

  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 it's contents have been corrupted.
    */
    DbSetProperty(db, iDb, DB_SchemaLoaded);
    rc = SQLITE_OK;
  }
  sqlite3BtreeLeave(pDb->pBt);

error_out:

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.369 2007/12/13 19:15:03 danielk1977 Exp $
*/
#include "sqliteInt.h"


/*
** Delete all the content of a Select structure but do not deallocate
** the select structure itself.

  for(i=0; i<pEList->nExpr; i++){
    Expr *p = pEList->a[i].pExpr;
    const char *zOrigDb = 0;
    const char *zOrigTab = 0;
    const char *zOrigCol = 0;
    const char *zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol);

    /* The vdbe must make it's own copy of the column-type and other 
    ** column specific strings, in case the schema is reset before this
    ** virtual machine is deleted.
    */
    sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, P3_TRANSIENT);
    sqlite3VdbeSetColName(v, i, COLNAME_DATABASE, zOrigDb, P3_TRANSIENT);
    sqlite3VdbeSetColName(v, i, COLNAME_TABLE, zOrigTab, P3_TRANSIENT);
    sqlite3VdbeSetColName(v, i, COLNAME_COLUMN, zOrigCol, P3_TRANSIENT);

** on how SQLite interfaces are suppose to operate.
**
** The name of this file under configuration management is "sqlite.h.in".
** The makefile makes some minor changes to this file (such as inserting
** the version number) and changes its name to "sqlite3.h" as
** part of the build process.
**
** @(#) $Id: sqlite.h.in,v 1.277 2007/12/12 12:25:22 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.

int sqlite3_finalize(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Reset A Prepared Statement Object {F13330}
**
** The sqlite3_reset() function is called to reset a 
** [sqlite3_stmt | compiled SQL statement] object.
** back to it's initial state, ready to be re-executed.
** Any SQL statement variables that had values bound to them using
** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
** Use [sqlite3_clear_bindings()] to reset the bindings.
*/
int sqlite3_reset(sqlite3_stmt *pStmt);

/*

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** 
** This file defines various limits of what SQLite can process.
**
** @(#) $Id: sqliteLimit.h,v 1.4 2007/12/11 20:04:15 drh Exp $
*/

/*
** The maximum length of a TEXT or BLOB in bytes.   This also
** limits the size of a row in a table or index.
**
** The hard limit is the ability of a 32-bit signed integer

#endif

/*
** Ordinarily, if no value is explicitly provided, SQLite creates databases
** with page size SQLITE_DEFAULT_PAGE_SIZE. However, based on certain
** device characteristics (sector-size and atomic write() support),
** SQLite may choose a larger value. This constant is the maximum value
** SQLite will choose on it's own.
*/
#ifndef SQLITE_MAX_DEFAULT_PAGE_SIZE
# define SQLITE_MAX_DEFAULT_PAGE_SIZE 8192
#endif
#if SQLITE_MAX_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE
# undef SQLITE_MAX_DEFAULT_PAGE_SIZE
# define SQLITE_MAX_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing all sorts of SQLite interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test1.c,v 1.280 2007/11/29 17:05:18 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

/*

/*
** Implementation of tkt2213func(), a scalar function that takes exactly
** one argument. It has two interesting features:
**
** * It calls sqlite3_value_text() 3 times on the argument sqlite3_value*.
**   If the three pointers returned are not the same an SQL error is raised.
**
** * Otherwise it returns a copy of the text representation of it's 
**   argument in such a way as the VDBE representation is a Mem* cell 
**   with the MEM_Term flag clear. 
**
** Ticket #2213 can therefore be tested by evaluating the following
** SQL expression:
**
**   tkt2213func(tkt2213func('a string'));

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the virtual table interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test8.c,v 1.57 2007/09/03 15:03:21 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

** real table. For example, if the real table is declared as:
**
**     CREATE TABLE real(a, b, c);
**     CREATE INDEX real_index ON real(b);
**
** then the echo module handles WHERE or ORDER BY clauses that refer
** to the column "b", but not "a" or "c". If a multi-column index is
** present, only it's left most column is considered. 
**
** This xBestIndex method encodes the proposed search strategy as
** an SQL query on the real table underlying the virtual echo module 
** table and stores the query in sqlite3_index_info.idxStr. The SQL
** statement is of the form:
**
**   SELECT rowid, * FROM <real-table> ?<where-clause>? ?<order-by-clause>?

        /* Append length in bits and transform */
        ((uint32 *)ctx->in)[ 14 ] = ctx->bits[0];
        ((uint32 *)ctx->in)[ 15 ] = ctx->bits[1];

        MD5Transform(ctx->buf, (uint32 *)ctx->in);
        byteReverse((unsigned char *)ctx->buf, 4);
        memcpy(digest, ctx->buf, 16);
        memset(ctx, 0, sizeof(ctx));    /* In case it's sensitive */
}

/*
** Convert a digest into base-16.  digest should be declared as
** "unsigned char digest[16]" in the calling function.  The MD5
** digest is stored in the first 16 bytes.  zBuf should
** be "char zBuf[33]".

**
*************************************************************************
**
** This file contains the implementation of some Tcl commands used to
** test that sqlite3 database handles may be concurrently accessed by 
** multiple threads. Right now this only works on unix.
**
** $Id: test_thread.c,v 1.5 2007/12/13 18:29:36 drh Exp $
*/

#include "sqliteInt.h"
#include <tcl.h>

#if SQLITE_THREADSAFE && defined(TCL_THREADS)

  Tcl_DeleteInterp(interp);
  return;
}

/*
** sqlthread spawn VARNAME SCRIPT
**
**     Spawn a new thread with it's own Tcl interpreter and run the
**     specified SCRIPT(s) in it. The thread terminates after running
**     the script. The result of the script is stored in the variable
**     VARNAME.
**
**     The caller can wait for the script to terminate using [vwait VARNAME].
*/
static int sqlthread_spawn(

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.659 2007/12/12 22:24:13 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor

** entry is overwritten.  The data is the value on the top of the
** stack.  The key is the next value down on the stack.  The key must
** be an integer.  The stack is popped twice by this instruction.
**
** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
** incremented (otherwise not).  If the OPFLAG_LASTROWID flag of P2 is set,
** then rowid is stored for subsequent return by the
** sqlite3_last_insert_rowid() function (otherwise it's unmodified).
**
** Parameter P3 may point to a string containing the table-name, or
** may be NULL. If it is not NULL, then the update-hook 
** (sqlite3.xUpdateCallback) is invoked following a successful insert.
**
** This instruction only works on tables.  The equivalent instruction
** for indices is OP_IdxInsert.

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is testing the ATTACH and DETACH commands
# and related functionality.
#
# $Id: attach2.test,v 1.37 2007/10/09 08:29:32 danielk1977 Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !attach {
  finish_test

}

# A procedure to verify the status of locks on a database.
#
proc lock_status {testnum db expected_result} {
  # If the database was compiled with OMIT_TEMPDB set, then 
  # the lock_status list will not contain an entry for the temp
  # db. But the test code doesn't know this, so it's easiest 
  # to filter it out of the $expected_result list here.
  ifcapable !tempdb {
    set expected_result [concat \
        [lrange $expected_result 0 1] \
        [lrange $expected_result 4 end] \
    ]
  }

# 2003 January 29
#
# 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 implements regression tests for SQLite library.  The
# focus of this script testing the callback-free C/C++ API.
#
# $Id: capi3.test,v 1.56 2007/10/23 18:55:50 drh Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Return the UTF-16 representation of the supplied UTF-8 string $str.
# If $nt is true, append two 0x00 bytes as a nul terminator.

    COMMIT;
  }
} {0 {}}
do_test capi3-11.21 {
  sqlite3_finalize $STMT
} {SQLITE_OK}

# The following tests - capi3-12.* - check that it's Ok to start a
# transaction while other VMs are active, and that it's Ok to execute
# atomic updates in the same situation 
#
do_test capi3-12.1 {
  set STMT [sqlite3_prepare $DB "SELECT a FROM t2" -1 TAIL]
  sqlite3_step $STMT
} {SQLITE_ROW}
do_test capi3-12.2 {

#
#***********************************************************************
# This file implements regression tests for SQLite library.  
#
# This is a copy of the capi3.test file that has been adapted to
# test the new sqlite3_prepare_v2 interface.
#
# $Id: capi3c.test,v 1.12 2007/09/03 07:31:10 danielk1977 Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Return the UTF-16 representation of the supplied UTF-8 string $str.
# If $nt is true, append two 0x00 bytes as a nul terminator.

    COMMIT;
  }
} {0 {}}
do_test capi3c-11.21 {
  sqlite3_finalize $STMT
} {SQLITE_OK}

# The following tests - capi3c-12.* - check that it's Ok to start a
# transaction while other VMs are active, and that it's Ok to execute
# atomic updates in the same situation 
#
do_test capi3c-12.1 {
  set STMT [sqlite3_prepare_v2 $DB "SELECT a FROM t2" -1 TAIL]
  sqlite3_step $STMT
} {SQLITE_ROW}
do_test capi3c-12.2 {

# 2007 March 28
#
# The author disclaims copyright to this source code.
#
#*************************************************************************
# This file implements regression tests for SQLite library.  The focus
# of this script is testing isspace/isalnum/tolower problems with the
# FTS1 module.  Unfortunately, this code isn't a really principled set
# of tests, because it's impossible to know where new uses of these
# functions might appear.
#
# $Id: fts1k.test,v 1.1 2007/03/29 16:30:41 shess Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If SQLITE_ENABLE_FTS1 is defined, omit this file.
ifcapable !fts1 {

# 2007 March 28
#
# The author disclaims copyright to this source code.
#
#*************************************************************************
# This file implements regression tests for SQLite library.  The focus
# of this script is testing isspace/isalnum/tolower problems with the
# FTS2 module.  Unfortunately, this code isn't a really principled set
# of tests, because it's impossible to know where new uses of these
# functions might appear.
#
# $Id: fts2l.test,v 1.1 2007/03/29 16:30:41 shess Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If SQLITE_ENABLE_FTS2 is defined, omit this file.
ifcapable !fts2 {

# 2007 April 26
#
# The author disclaims copyright to this source code.
#
#*************************************************************************
# This file implements tests for prefix-searching in the fts2
# component of the SQLite library.
#
# $Id: fts2n.test,v 1.1 2007/05/01 18:25:53 shess Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If SQLITE_ENABLE_FTS2 is defined, omit this file.
ifcapable !fts2 {

} $ret

# TODO(shess) It would be useful to test a couple edge cases, but I
# don't know if we have the precision to manage it from here at this
# time.  Prefix hits can cross leaves, which the code above _should_
# hit by virtue of size.  There are two variations on this.  If the
# tree is 2 levels high, the code will find the leaf-node extent
# directly, but if it's higher, the code will have to follow two
# separate interior branches down the tree.  Both should be tested.

finish_test

# 2007 March 28
#
# The author disclaims copyright to this source code.
#
#*************************************************************************
# This file implements regression tests for SQLite library.  The focus
# of this script is testing isspace/isalnum/tolower problems with the
# FTS3 module.  Unfortunately, this code isn't a really principled set
# of tests, because it's impossible to know where new uses of these
# functions might appear.
#
# $Id: fts3al.test,v 1.1 2007/08/20 17:38:42 shess Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If SQLITE_ENABLE_FTS3 is defined, omit this file.
ifcapable !fts3 {

# 2007 April 26
#
# The author disclaims copyright to this source code.
#
#*************************************************************************
# This file implements tests for prefix-searching in the fts3
# component of the SQLite library.
#
# $Id: fts3an.test,v 1.1 2007/08/20 17:38:42 shess Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If SQLITE_ENABLE_FTS3 is defined, omit this file.
ifcapable !fts3 {

} $ret

# TODO(shess) It would be useful to test a couple edge cases, but I
# don't know if we have the precision to manage it from here at this
# time.  Prefix hits can cross leaves, which the code above _should_
# hit by virtue of size.  There are two variations on this.  If the
# tree is 2 levels high, the code will find the leaf-node extent
# directly, but if it's higher, the code will have to follow two
# separate interior branches down the tree.  Both should be tested.

finish_test

#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the incremental vacuum feature.
#
# Note: There are also some tests for incremental vacuum and IO 
# errors in incrvacuum_ioerr.test.
#
# $Id: incrvacuum.test,v 1.15 2007/12/10 05:03:48 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If this build of the library does not support auto-vacuum, omit this
# whole file.
ifcapable {!autovacuum || !pragma} {

  INSERT INTO t3 VALUES('hello', 'world');
  ROLLBACK;
} {
  INSERT INTO t3 VALUES('hello', 'world');
}
]

# If this build omit's subqueries, step 2 in the above list will not
# work. Replace it with "" in this case. 
#
ifcapable !subquery { lset TestScriptList 2 "" }

# Compare the contents of databases $A and $B.
#
proc compare_dbs {A B tname} {

# 2001 September 15
#
# 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 implements regression tests for SQLite library.  The
# focus of this script is database locks between competing processes.
#
# $Id: lock2.test,v 1.8 2007/08/12 20:07:59 drh Exp $


set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Launch another testfixture process to be controlled by this one. A
# channel name is returned that may be passed as the first argument to proc

    append r $line
  }
}

# Write the main loop for the child testfixture processes into file
# tf_main.tcl. The parent (this script) interacts with the child processes
# via a two way pipe. The parent writes a script to the stdin of the child
# process, followed by the word "OVER" on a line of it's own. The child
# process evaluates the script and writes the results to stdout, followed
# by an "OVER" of its own.
set f [open tf_main.tcl w]
puts $f {
  set l [open log w]
  set script ""
  while {![eof stdin]} {

#
#***********************************************************************
#
# This file contains tests to ensure that the library handles malloc() failures
# correctly. The emphasis of these tests are the _prepare(), _step() and
# _finalize() calls.
#
# $Id: malloc3.test,v 1.17 2007/10/09 08:29:33 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Only run these tests if memory debugging is turned on.
#
ifcapable !memdebug {

# NOTES ON TEST IMPLEMENTATION
#
# The tests in this file are implemented differently from those in other
# files. Instead, tests are specified using three primitives: SQL, PREP and
# TEST. Each primitive has a single argument. Primitives are processed in
# the order they are specified in the file.
#
# A TEST primitive specifies a TCL script as it's argument. When a TEST
# directive is encountered the Tcl script is evaluated. Usually, this Tcl
# script contains one or more calls to [do_test].
#
# A PREP primitive specifies an SQL script as it's argument. When a PREP
# directive is encountered the SQL is evaluated using database connection
# [db].
#
# The SQL primitives are where the action happens. An SQL primitive must
# contain a single, valid SQL statement as it's argument. When an SQL
# primitive is encountered, it is evaluated one or more times to test the
# behaviour of the system when malloc() fails during preparation or
# execution of said statement. The Nth time the statement is executed,
# the Nth malloc is said to fail. The statement is executed until it
# succeeds, i.e. (M+1) times, where M is the number of mallocs() required
# to prepare and execute the statement.
#

}
TEST 2 {
  do_test $testid.1 {
    execsql {SELECT tbl_name FROM sqlite_master;}
  } {abc}
}

# Insert a couple of rows into the table. each insert is in it's own
# transaction. test that the table is unpopulated before running the inserts
# (and hence after each failure of the first insert), and that it has been
# populated correctly after the final insert succeeds.
#
TEST 3 {
  do_test $testid.2 {
    execsql {SELECT * FROM abc}

# 2006 September 4
#
# 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 implements regression tests for SQLite library.
#
# $Id: misc7.test,v 1.16 2007/10/05 15:53:29 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

#do_test misc7-1 {
#  c_misuse_test
#} {}

  file mkdir mydir
  set rc [catch {
    sqlite3 db2 ./mydir
  } msg]
  list $rc $msg
} {1 {unable to open database file}}

# Try to open a file with a directory where it's journal file should be.
#
do_test misc7-5 {
  file delete mydir
  file mkdir mydir-journal
  sqlite3 db2 ./mydir
  catchsql {
    CREATE TABLE abc(a, b, c);

# 2005 December 30
#
# 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.
#
#***********************************************************************
#
# $Id: shared.test,v 1.28 2007/10/09 08:29:33 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl
db close

# These tests cannot be run without the ATTACH command.
#

  execsql {
    INSERT INTO t2 SELECT * FROM t1;
    COMMIT;
  }
} {}
do_test shared-$av.7.2 {
  # This test case deletes the contents of table t1 (the one at the start of
  # the file) while many cursors are open on table t2 and it's index. All of
  # the non-root pages will be moved from the end to the start of the file
  # when the DELETE is committed - this test verifies that moving the pages
  # does not disturb the open cursors.
  #

  proc lockrow {db tbl oids body} {
    set ret [list]

# 2006 June 10
#
# 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 implements regression tests for SQLite library.  The
# focus of this file is creating and dropping virtual tables.
#
# $Id: vtab1.test,v 1.49 2007/12/10 05:03:48 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !vtab||!schema_pragmas {
  finish_test
  return

  execsql { SELECT * FROM c }
} {3 G H}

# At one point (ticket #2759), a WHERE clause of the form "<column> IS NULL"
# on a virtual table was causing an assert() to fail in the compiler.
#
# "IS NULL" clauses should not be passed through to the virtual table
# implementation. They are handled by SQLite after the vtab returns it's
# data.
#
do_test vtab1.13-1 {
  execsql { 
    SELECT * FROM echo_c WHERE a IS NULL 
  }
} {}

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the ALTER TABLE ... RENAME TO
# command on virtual tables.
#
# $Id: vtab_alter.test,v 1.2 2007/09/01 18:24:55 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !vtab {
  finish_test
  return

do_test vtab_alter-1.5 {
  catchsql { SELECT * FROM t1echo }
} {1 {no such table: t1echo}}
do_test vtab_alter-1.6 {
  catchsql { SELECT * FROM new }
} {0 {}}

# Try to rename an echo table that renames it's base table. Make 
# sure nothing terrible happens.
#
do_test vtab_alter-2.1 {
  execsql { 
    DROP TABLE new;
    DROP TABLE t1;
    CREATE TABLE t1_base(a, b, c);

do_test vtab_alter-2.4 {
  execsql { SELECT * FROM x; }
} {1 2 3}
do_test vtab_alter-2.5 {
  execsql { SELECT * FROM x_base; }
} {1 2 3}

# Cause an error to occur when the echo module renames it's
# backing store table.
#
do_test vtab_alter-3.1 {
  execsql  { CREATE TABLE y_base(a, b, c) }
  catchsql { ALTER TABLE x RENAME TO y }
} {1 {SQL logic error or missing database}}
do_test vtab_alter-3.2 {
  execsql  { SELECT * FROM x }
} {1 2 3}

finish_test