Fossil

        if( !bGlob ){
          appendText(&sSelect, " ESCAPE '\\' ", 0);
        }
        appendText(&sSelect, " AND ", 0);
        sqlite3_free(zQarg);
      }
      if( bNoSystemTabs ){
        appendText(&sSelect, "name NOT LIKE 'sqlite__%%' ESCAPE '_' AND ", 0);
      }
      appendText(&sSelect, "sql IS NOT NULL"
                           " ORDER BY snum, rowid", 0);
      if( bDebug ){
        sqlite3_fprintf(p->out, "SQL: %s;\n", sSelect.z);
      }else{
        rc = sqlite3_exec(p->db, sSelect.z, callback, &data, &zErrMsg);

** the text of this file.  Search for "Begin file sqlite3.h" to find the start
** of the embedded sqlite3.h header file.) Additional code files may be needed
** if you want a wrapper to interface SQLite with your choice of programming
** language. The code for the "sqlite3" command-line shell is also in a
** separate file. This file contains only code for the core SQLite library.
**
** The content in this amalgamation comes from Fossil check-in
** 6a5701e6c7be25cba93e55438f950966e1da with changes in files:
**
**    
*/
#ifndef SQLITE_AMALGAMATION
#define SQLITE_CORE 1
#define SQLITE_AMALGAMATION 1
#ifndef SQLITE_PRIVATE

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.51.0"
#define SQLITE_VERSION_NUMBER 3051000
#define SQLITE_SOURCE_ID      "2025-06-24 15:58:32 6a5701e6c7be25cba93e55438f950966e1dacb32eb2b23a8acc8ac53da6f0a85"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros

** (See how SQLite handles [invalid UTF] for exceptions to this rule.)
** ^(Memory to hold the error message string is managed internally.
** The application does not need to worry about freeing the result.
** However, the error string might be overwritten or deallocated by
** subsequent calls to other SQLite interface functions.)^
**
** ^The sqlite3_errstr(E) interface returns the English-language text
** that describes the [result code] E, as UTF-8, or NULL if E is not a
** result code for which a text error message is available.
** ^(Memory to hold the error message string is managed internally
** and must not be freed by the application)^.
**
** ^If the most recent error references a specific token in the input
** SQL, the sqlite3_error_offset() interface returns the byte offset
** of the start of that token.  ^The byte offset returned by
** sqlite3_error_offset() assumes that the input SQL is UTF-8.
** ^If the most recent error does not reference a specific token in the input
** SQL, then the sqlite3_error_offset() function returns -1.
**
** When the serialized [threading mode] is in use, it might be the
** case that a second error occurs on a separate thread in between
** the time of the first error and the call to these interfaces.
** When that happens, the second error will be reported since these

/*
** CAPI3REF: Run-Time Limit Categories
** KEYWORDS: {limit category} {*limit categories}
**
** These constants define various performance limits
** that can be lowered at run-time using [sqlite3_limit()].
** A concise description of these limits follows, and additional information
** is available at [limits | Limits in SQLite].
**
** <dl>
** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
**
** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
** <dd>The maximum length of an SQL statement, in bytes.</dd>)^

#define SQLITE_LIMIT_VARIABLE_NUMBER           9
#define SQLITE_LIMIT_TRIGGER_DEPTH            10
#define SQLITE_LIMIT_WORKER_THREADS           11

/*
** CAPI3REF: Prepare Flags
**
** These constants define various flags that can be passed into the
** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
** [sqlite3_prepare16_v3()] interfaces.
**
** New flags may be added in future releases of SQLite.
**
** <dl>
** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>

** up to the first zero terminator or until the nByte bytes have been read,
** whichever comes first.  ^If nByte is zero, then no prepared
** statement is generated.
** If the caller knows that the supplied string is nul-terminated, then
** there is a small performance advantage to passing an nByte parameter that
** is the number of bytes in the input string <i>including</i>
** the nul-terminator.
** Note that nByte measures the length of the input in bytes, not
** characters, even for the UTF-16 interfaces.
**
** ^If pzTail is not NULL then *pzTail is made to point to the first byte
** past the end of the first SQL statement in zSql.  These routines only
** compile the first statement in zSql, so *pzTail is left pointing to
** what remains uncompiled.
**

** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
** and parameter :xyz is unbound, then sqlite3_sql() will return
** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
** will return "SELECT 2345,NULL".)^
**
** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
** is available to hold the result, or if the result would exceed the
** maximum string length determined by the [SQLITE_LIMIT_LENGTH].
**
** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
** bound parameter expansions.  ^The [SQLITE_OMIT_TRACE] compile-time
** option causes sqlite3_expanded_sql() to always return NULL.
**
** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
** are managed by SQLite and are automatically freed when the prepared

typedef struct sqlite3_value sqlite3_value;

/*
** CAPI3REF: SQL Function Context Object
**
** The context in which an SQL function executes is stored in an
** sqlite3_context object.  ^A pointer to an sqlite3_context object
** is always the first parameter to [application-defined SQL functions].
** The application-defined SQL function implementation will pass this
** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
** [sqlite3_aggregate_context()], [sqlite3_user_data()],
** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
** and/or [sqlite3_set_auxdata()].
*/
typedef struct sqlite3_context sqlite3_context;

/*
** CAPI3REF: Destroy A Prepared Statement Object
** DESTRUCTOR: sqlite3_stmt
**
** ^The sqlite3_finalize() function is called to delete a [prepared statement].
** ^If the most recent evaluation of the statement encountered no errors
** or if the statement has never been evaluated, then sqlite3_finalize() returns
** SQLITE_OK.  ^If the most recent evaluation of statement S failed, then
** sqlite3_finalize(S) returns the appropriate [error code] or
** [extended error code].
**
** ^The sqlite3_finalize(S) routine can be called at any point during
** the life cycle of [prepared statement] S:
** before statement S is ever evaluated, after

  void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
  void(*xDestroy)(void*)
);

/*
** CAPI3REF: Text Encodings
**
** These constants define integer codes that represent the various
** text encodings supported by SQLite.
*/
#define SQLITE_UTF8           1    /* IMP: R-37514-35566 */
#define SQLITE_UTF16LE        2    /* IMP: R-03371-37637 */
#define SQLITE_UTF16BE        3    /* IMP: R-51971-34154 */
#define SQLITE_UTF16          4    /* Use native byte order */
#define SQLITE_ANY            5    /* Deprecated */

**
** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd>
** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call
** [sqlite3_result_subtype()] to cause a sub-type to be associated with its
** result.
** Every function that invokes [sqlite3_result_subtype()] should have this
** property.  If it does not, then the call to [sqlite3_result_subtype()]
** might become a no-op if the function is used as a term in an
** [expression index].  On the other hand, SQL functions that never invoke
** [sqlite3_result_subtype()] should avoid setting this property, as the
** purpose of this property is to disable certain optimizations that are
** incompatible with subtypes.
**
** [[SQLITE_SELFORDER1]] <dt>SQLITE_SELFORDER1</dt><dd>
** The SQLITE_SELFORDER1 flag indicates that the function is an aggregate

** then the conversion is performed.  Otherwise no conversion occurs.
** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
**
** ^Within the [xUpdate] method of a [virtual table], the
** sqlite3_value_nochange(X) interface returns true if and only if
** the column corresponding to X is unchanged by the UPDATE operation
** that the xUpdate method call was invoked to implement and if
** the prior [xColumn] method call that was invoked to extract
** the value for that column returned without setting a result (probably
** because it queried [sqlite3_vtab_nochange()] and found that the column
** was unchanging).  ^Within an [xUpdate] method, any value for which
** sqlite3_value_nochange(X) is true will in all other respects appear
** to be a NULL value.  If sqlite3_value_nochange(X) is invoked anywhere other
** than within an [xUpdate] method call for an UPDATE statement, then
** the return value is arbitrary and meaningless.

  ** SQLITE_UPDATE pre-update callback, and that iIdx is within range. */
  if( !p || p->op==SQLITE_INSERT ){
    rc = SQLITE_MISUSE_BKPT;
    goto preupdate_old_out;
  }
  if( p->pPk ){
    iStore = sqlite3TableColumnToIndex(p->pPk, iIdx);
  }else if( iIdx >= p->pTab->nCol ){
    rc = SQLITE_MISUSE_BKPT;
    goto preupdate_old_out;
  }else{
    iStore = sqlite3TableColumnToStorage(p->pTab, iIdx);
  }
  if( iStore>=p->pCsr->nField || iStore<0 ){
    rc = SQLITE_RANGE;
    goto preupdate_old_out;
  }

  /* Variables populated based on current entry. */
  Fts5Buffer term;                /* Current term */
  i64 iRowid;                     /* Current rowid */
  int nPos;                       /* Number of bytes in current position list */
  u8 bDel;                        /* True if the delete flag is set */
};

static int fts5IndexCorruptRowid(Fts5Index *pIdx, i64 iRowid){
  pIdx->rc = FTS5_CORRUPT;
  sqlite3Fts5ConfigErrmsg(pIdx->pConfig,
      "fts5: corruption found reading blob %lld from table \"%s\"",
      iRowid, pIdx->pConfig->zName
  );
  return SQLITE_CORRUPT_VTAB;
}
#define FTS5_CORRUPT_ROWID(pIdx, iRowid) fts5IndexCorruptRowid(pIdx, iRowid)

static int fts5IndexCorruptIter(Fts5Index *pIdx, Fts5SegIter *pIter){
  pIdx->rc = FTS5_CORRUPT;
  sqlite3Fts5ConfigErrmsg(pIdx->pConfig,
      "fts5: corruption on page %d, segment %d, table \"%s\"",
      pIter->iLeafPgno, pIter->pSeg->iSegid, pIdx->pConfig->zName
  );
  return SQLITE_CORRUPT_VTAB;
}
#define FTS5_CORRUPT_ITER(pIdx, pIter) fts5IndexCorruptIter(pIdx, pIter)

static int fts5IndexCorruptIdx(Fts5Index *pIdx){
  pIdx->rc = FTS5_CORRUPT;
  sqlite3Fts5ConfigErrmsg(pIdx->pConfig,
      "fts5: corruption in table \"%s\"", pIdx->pConfig->zName
  );
  return SQLITE_CORRUPT_VTAB;
}
#define FTS5_CORRUPT_IDX(pIdx) fts5IndexCorruptIdx(pIdx)


/*
** Array of tombstone pages. Reference counted.
*/
struct Fts5TombstoneArray {
  int nRef;                         /* Number of pointers to this object */
  int nTombstone;

    }

    /* If either of the sqlite3_blob_open() or sqlite3_blob_reopen() calls
    ** above returned SQLITE_ERROR, return SQLITE_CORRUPT_VTAB instead.
    ** All the reasons those functions might return SQLITE_ERROR - missing
    ** table, missing row, non-blob/text in block column - indicate
    ** backing store corruption.  */
    if( rc==SQLITE_ERROR ) rc = FTS5_CORRUPT_ROWID(p, iRowid);

    if( rc==SQLITE_OK ){
      u8 *aOut = 0;               /* Read blob data into this buffer */
      int nByte = sqlite3_blob_bytes(p->pReader);
      int szData = (sizeof(Fts5Data) + 7) & ~7;
      sqlite3_int64 nAlloc = szData + nByte + FTS5_DATA_PADDING;
      pRet = (Fts5Data*)sqlite3_malloc64(nAlloc);

  sqlite3_free(pData);
}

static Fts5Data *fts5LeafRead(Fts5Index *p, i64 iRowid){
  Fts5Data *pRet = fts5DataRead(p, iRowid);
  if( pRet ){
    if( pRet->nn<4 || pRet->szLeaf>pRet->nn ){
      FTS5_CORRUPT_ROWID(p, iRowid);
      fts5DataRelease(pRet);
      pRet = 0;
    }
  }
  return pRet;
}

  Fts5Data *pData;

  pData = fts5DataRead(p, FTS5_STRUCTURE_ROWID);
  if( p->rc==SQLITE_OK ){
    /* TODO: Do we need this if the leaf-index is appended? Probably... */
    memset(&pData->p[pData->nn], 0, FTS5_DATA_PADDING);
    p->rc = fts5StructureDecode(pData->p, pData->nn, &iCookie, &pRet);
    if( p->rc==SQLITE_OK ){
      if( (pConfig->pgsz==0 || pConfig->iCookie!=iCookie) ){
        p->rc = sqlite3Fts5ConfigLoad(pConfig, iCookie);
      }
    }else if( p->rc==SQLITE_CORRUPT_VTAB ){
      sqlite3Fts5ConfigErrmsg(p->pConfig,
          "fts5: corrupt structure record for table \"%s\"", p->pConfig->zName
      );
    }
    fts5DataRelease(pData);
    if( p->rc!=SQLITE_OK ){
      fts5StructureRelease(pRet);
      pRet = 0;
    }
  }

  u8 *a = pIter->pLeaf->p;        /* Buffer to read data from */
  i64 iOff = pIter->iLeafOffset;

  ASSERT_SZLEAF_OK(pIter->pLeaf);
  while( iOff>=pIter->pLeaf->szLeaf ){
    fts5SegIterNextPage(p, pIter);
    if( pIter->pLeaf==0 ){
      if( p->rc==SQLITE_OK ) FTS5_CORRUPT_ITER(p, pIter);
      return;
    }
    iOff = 4;
    a = pIter->pLeaf->p;
  }
  iOff += sqlite3Fts5GetVarint(&a[iOff], (u64*)&pIter->iRowid);
  pIter->iLeafOffset = iOff;

static void fts5SegIterLoadTerm(Fts5Index *p, Fts5SegIter *pIter, int nKeep){
  u8 *a = pIter->pLeaf->p;        /* Buffer to read data from */
  i64 iOff = pIter->iLeafOffset;  /* Offset to read at */
  int nNew;                       /* Bytes of new data */

  iOff += fts5GetVarint32(&a[iOff], nNew);
  if( iOff+nNew>pIter->pLeaf->szLeaf || nKeep>pIter->term.n || nNew==0 ){
    FTS5_CORRUPT_ITER(p, pIter);
    return;
  }
  pIter->term.n = nKeep;
  fts5BufferAppendBlob(&p->rc, &pIter->term, nNew, &a[iOff]);
  assert( pIter->term.n<=pIter->term.nSpace );
  iOff += nNew;
  pIter->iTermLeafOffset = iOff;

          pIter->iLeafOffset = pIter->iTermLeafOffset;
        }
      }else{
        int iRowidOff;
        iRowidOff = fts5LeafFirstRowidOff(pNew);
        if( iRowidOff ){
          if( iRowidOff>=pNew->szLeaf ){
            FTS5_CORRUPT_ITER(p, pIter);
          }else{
            pIter->pLeaf = pNew;
            pIter->iLeafOffset = iRowidOff;
          }
        }
      }

        );
        pIter->iLeafOffset = iOff;
        pIter->iEndofDoclist = iOff;
        bNewTerm = 1;
      }
      assert_nc( iOff<pLeaf->szLeaf );
      if( iOff>pLeaf->szLeaf ){
        FTS5_CORRUPT_ITER(p, pIter);
        return;
      }
    }
  }

  /* Check if the iterator is now at EOF. If so, return early. */
  if( pIter->pLeaf ){

  if( pLast ){
    int iOff;
    fts5DataRelease(pIter->pLeaf);
    pIter->pLeaf = pLast;
    pIter->iLeafPgno = pgnoLast;
    iOff = fts5LeafFirstRowidOff(pLast);
    if( iOff>pLast->szLeaf ){
      FTS5_CORRUPT_ITER(p, pIter);
      return;
    }
    iOff += fts5GetVarint(&pLast->p[iOff], (u64*)&pIter->iRowid);
    pIter->iLeafOffset = iOff;

    if( fts5LeafIsTermless(pLast) ){
      pIter->iEndofDoclist = pLast->nn+1;

  assert( p->rc==SQLITE_OK );

  iPgidx = (u32)pIter->pLeaf->szLeaf;
  iPgidx += fts5GetVarint32(&a[iPgidx], iTermOff);
  iOff = iTermOff;
  if( iOff>n ){
    FTS5_CORRUPT_ITER(p, pIter);
    return;
  }

  while( 1 ){

    /* Figure out how many new bytes are in this term */
    fts5FastGetVarint32(a, iOff, nNew);

    }

    iPgidx += fts5GetVarint32(&a[iPgidx], nKeep);
    iTermOff += nKeep;
    iOff = iTermOff;

    if( iOff>=n ){
      FTS5_CORRUPT_ITER(p, pIter);
      return;
    }

    /* Read the nKeep field of the next term. */
    fts5FastGetVarint32(a, iOff, nKeep);
  }

      fts5SegIterNextPage(p, pIter);
      if( pIter->pLeaf==0 ) return;
      a = pIter->pLeaf->p;
      if( fts5LeafIsTermless(pIter->pLeaf)==0 ){
        iPgidx = (u32)pIter->pLeaf->szLeaf;
        iPgidx += fts5GetVarint32(&pIter->pLeaf->p[iPgidx], iOff);
        if( iOff<4 || (i64)iOff>=pIter->pLeaf->szLeaf ){
          FTS5_CORRUPT_ITER(p, pIter);
          return;
        }else{
          nKeep = 0;
          iTermOff = iOff;
          n = (u32)pIter->pLeaf->nn;
          iOff += fts5GetVarint32(&a[iOff], nNew);
          break;
        }
      }
    }while( 1 );
  }

 search_success:
  if( (i64)iOff+nNew>n || nNew<1 ){
    FTS5_CORRUPT_ITER(p, pIter);
    return;
  }
  pIter->iLeafOffset = iOff + nNew;
  pIter->iTermLeafOffset = pIter->iLeafOffset;
  pIter->iTermLeafPgno = pIter->iLeafPgno;

  fts5BufferSet(&p->rc, &pIter->term, nKeep, pTerm);

  Fts5Index *p,                   /* FTS5 backend object */
  Fts5SegIter *pIter,             /* Iterator to advance */
  int iLeafPgno
){
  assert( iLeafPgno>pIter->iLeafPgno );

  if( iLeafPgno>pIter->pSeg->pgnoLast ){
    FTS5_CORRUPT_IDX(p);
  }else{
    fts5DataRelease(pIter->pNextLeaf);
    pIter->pNextLeaf = 0;
    pIter->iLeafPgno = iLeafPgno-1;

    while( p->rc==SQLITE_OK ){
      int iOff;
      fts5SegIterNextPage(p, pIter);
      if( pIter->pLeaf==0 ) break;
      iOff = fts5LeafFirstRowidOff(pIter->pLeaf);
      if( iOff>0 ){
        u8 *a = pIter->pLeaf->p;
        int n = pIter->pLeaf->szLeaf;
        if( iOff<4 || iOff>=n ){
          FTS5_CORRUPT_IDX(p);
        }else{
          iOff += fts5GetVarint(&a[iOff], (u64*)&pIter->iRowid);
          pIter->iLeafOffset = iOff;
          fts5SegIterLoadNPos(p, pIter);
        }
        break;
      }

  while( 1 ){
    xChunk(p, pCtx, pChunk, nChunk);
    nRem -= nChunk;
    fts5DataRelease(pData);
    if( nRem<=0 ){
      break;
    }else if( pSeg->pSeg==0 ){
      FTS5_CORRUPT_IDX(p);
      return;
    }else{
      pgno++;
      pData = fts5LeafRead(p, FTS5_SEGMENT_ROWID(pSeg->pSeg->iSegid, pgno));
      if( pData==0 ) break;
      pChunk = &pData->p[4];
      nChunk = MIN(nRem, pData->szLeaf - 4);

      pData = fts5LeafRead(p, iLeafRowid);
      if( pData ){
        if( iOff>pData->szLeaf ){
          /* This can occur if the pages that the segments occupy overlap - if
          ** a single page has been assigned to more than one segment. In
          ** this case a prior iteration of this loop may have corrupted the
          ** segment currently being trimmed.  */
          FTS5_CORRUPT_ROWID(p, iLeafRowid);
        }else{
          fts5BufferZero(&buf);
          fts5BufferGrow(&p->rc, &buf, pData->nn);
          fts5BufferAppendBlob(&p->rc, &buf, sizeof(aHdr), aHdr);
          fts5BufferAppendVarint(&p->rc, &buf, pSeg->term.n);
          fts5BufferAppendBlob(&p->rc, &buf, pSeg->term.n, pSeg->term.p);
          fts5BufferAppendBlob(&p->rc, &buf,pData->szLeaf-iOff,&pData->p[iOff]);

      assert_nc( bDetailNone==0 || pLeaf->nn==4 );
      if( bDetailNone==0 ) fts5DataWrite(p, iRowid, aEmpty, sizeof(aEmpty));
      fts5DataRelease(pLeaf);
      pLeaf = 0;
    }else if( bDetailNone ){
      break;
    }else if( iNext>=pLeaf->szLeaf || pLeaf->nn<pLeaf->szLeaf || iNext<4 ){
      FTS5_CORRUPT_ROWID(p, iRowid);
      break;
    }else{
      int nShift = iNext - 4;
      int nPg;

      int nIdx = 0;
      u8 *aIdx = 0;

      /* Unless the current page footer is 0 bytes in size (in which case
      ** the new page footer will be as well), allocate and populate a
      ** buffer containing the new page footer. Set stack variables aIdx
      ** and nIdx accordingly.  */
      if( pLeaf->nn>pLeaf->szLeaf ){
        int iFirst = 0;
        int i1 = pLeaf->szLeaf;
        int i2 = 0;

        i1 += fts5GetVarint32(&aPg[i1], iFirst);
        if( iFirst<iNext ){
          FTS5_CORRUPT_ROWID(p, iRowid);
          break;
        }
        aIdx = sqlite3Fts5MallocZero(&p->rc, (pLeaf->nn-pLeaf->szLeaf)+2);
        if( aIdx==0 ) break;
        i2 = sqlite3Fts5PutVarint(aIdx, iFirst-nShift);
        if( i1<pLeaf->nn ){
          memcpy(&aIdx[i2], &aPg[i1], pLeaf->nn-i1);

      }
      iKeyOff += fts5GetVarint32(&aPg[iKeyOff], nSuffix);

      nPrefix = MIN(nPrefix, nPrefix2);
      nSuffix = (nPrefix2 + nSuffix2) - nPrefix;

      if( (iKeyOff+nSuffix)>iPgIdx || (iNextOff+nSuffix2)>iPgIdx ){
        FTS5_CORRUPT_IDX(p);
      }else{
        if( iKey!=1 ){
          iOff += sqlite3Fts5PutVarint(&aPg[iOff], nPrefix);
        }
        iOff += sqlite3Fts5PutVarint(&aPg[iOff], nSuffix);
        if( nPrefix2>pSeg->term.n ){
          FTS5_CORRUPT_IDX(p);
        }else if( nPrefix2>nPrefix ){
          memcpy(&aPg[iOff], &pSeg->term.p[nPrefix], nPrefix2-nPrefix);
          iOff += (nPrefix2-nPrefix);
        }
        memmove(&aPg[iOff], &aPg[iNextOff], nSuffix2);
        iOff += nSuffix2;
        iNextOff += nSuffix2;

        nTmp += pSave->iter.nPoslist + 10;
        nMerge++;
        fts5PrefixMergerInsertByPosition(&pHead, pSave);
        pSave = pNext;
      }

      if( pHead==0 || pHead->pNext==0 ){
        FTS5_CORRUPT_IDX(p);
        break;
      }

      /* See the earlier comment in this function for an explanation of why
      ** corrupt input position lists might cause the output to consume
      ** at most nMerge*10 bytes of unexpected space. */
      if( sqlite3Fts5BufferSize(&p->rc, &tmp, nTmp+nMerge*10) ){

      }
      nTail = pHead->iter.nPoslist - pHead->iOff;

      /* WRITEPOSLISTSIZE */
      assert_nc( tmp.n+nTail<=nTmp );
      assert( tmp.n+nTail<=nTmp+nMerge*10 );
      if( tmp.n+nTail>nTmp-FTS5_DATA_ZERO_PADDING ){
        if( p->rc==SQLITE_OK ) FTS5_CORRUPT_IDX(p);
        break;
      }
      fts5BufferSafeAppendVarint(&out, (tmp.n+nTail) * 2);
      fts5BufferSafeAppendBlob(&out, tmp.p, tmp.n);
      if( nTail>0 ){
        fts5BufferSafeAppendBlob(&out, &pHead->aPos[pHead->iOff], nTail);
      }

  int i;

  /* Now check that the iter.nEmpty leaves following the current leaf
  ** (a) exist and (b) contain no terms. */
  for(i=iFirst; p->rc==SQLITE_OK && i<=iLast; i++){
    Fts5Data *pLeaf = fts5DataRead(p, FTS5_SEGMENT_ROWID(pSeg->iSegid, i));
    if( pLeaf ){
      if( !fts5LeafIsTermless(pLeaf)
       || (i>=iNoRowid && 0!=fts5LeafFirstRowidOff(pLeaf))
      ){
        FTS5_CORRUPT_ROWID(p, FTS5_SEGMENT_ROWID(pSeg->iSegid, i));
      }
    }
    fts5DataRelease(pLeaf);
  }
}

static void fts5IntegrityCheckPgidx(Fts5Index *p, i64 iRowid, Fts5Data *pLeaf){
  i64 iTermOff = 0;
  int ii;

  Fts5Buffer buf1 = {0,0,0};
  Fts5Buffer buf2 = {0,0,0};

  ii = pLeaf->szLeaf;
  while( ii<pLeaf->nn && p->rc==SQLITE_OK ){
    int res;
    i64 iOff;
    int nIncr;

    ii += fts5GetVarint32(&pLeaf->p[ii], nIncr);
    iTermOff += nIncr;
    iOff = iTermOff;

    if( iOff>=pLeaf->szLeaf ){
      FTS5_CORRUPT_ROWID(p, iRowid);
    }else if( iTermOff==nIncr ){
      int nByte;
      iOff += fts5GetVarint32(&pLeaf->p[iOff], nByte);
      if( (iOff+nByte)>pLeaf->szLeaf ){
        FTS5_CORRUPT_ROWID(p, iRowid);
      }else{
        fts5BufferSet(&p->rc, &buf1, nByte, &pLeaf->p[iOff]);
      }
    }else{
      int nKeep, nByte;
      iOff += fts5GetVarint32(&pLeaf->p[iOff], nKeep);
      iOff += fts5GetVarint32(&pLeaf->p[iOff], nByte);
      if( nKeep>buf1.n || (iOff+nByte)>pLeaf->szLeaf ){
        FTS5_CORRUPT_ROWID(p, iRowid);
      }else{
        buf1.n = nKeep;
        fts5BufferAppendBlob(&p->rc, &buf1, nByte, &pLeaf->p[iOff]);
      }

      if( p->rc==SQLITE_OK ){
        res = fts5BufferCompare(&buf1, &buf2);
        if( res<=0 ) FTS5_CORRUPT_ROWID(p, iRowid);
      }
    }
    fts5BufferSet(&p->rc, &buf2, buf1.n, buf1.p);
  }

  fts5BufferFree(&buf1);
  fts5BufferFree(&buf2);

       && pLeaf->nn==pLeaf->szLeaf
       && pLeaf->nn==4
      ){
        /* special case - the very first page in a segment keeps its %_idx
        ** entry even if all the terms are removed from it by secure-delete
        ** operations. */
      }else{
        FTS5_CORRUPT_ROWID(p, iRow);
      }

    }else{
      int iOff;                   /* Offset of first term on leaf */
      int iRowidOff;              /* Offset of first rowid on leaf */
      int nTerm;                  /* Size of term on leaf in bytes */
      int res;                    /* Comparison of term and split-key */

      iOff = fts5LeafFirstTermOff(pLeaf);
      iRowidOff = fts5LeafFirstRowidOff(pLeaf);
      if( iRowidOff>=iOff || iOff>=pLeaf->szLeaf ){
        FTS5_CORRUPT_ROWID(p, iRow);
      }else{
        iOff += fts5GetVarint32(&pLeaf->p[iOff], nTerm);
        res = fts5Memcmp(&pLeaf->p[iOff], zIdxTerm, MIN(nTerm, nIdxTerm));
        if( res==0 ) res = nTerm - nIdxTerm;
        if( res<0 ) FTS5_CORRUPT_ROWID(p, iRow);
      }

      fts5IntegrityCheckPgidx(p, iRow, pLeaf);
    }
    fts5DataRelease(pLeaf);
    if( p->rc ) break;

    /* Now check that the iter.nEmpty leaves following the current leaf
    ** (a) exist and (b) contain no terms. */
    fts5IndexIntegrityCheckEmpty(

      ){

        /* Check any rowid-less pages that occur before the current leaf. */
        for(iPg=iPrevLeaf+1; iPg<fts5DlidxIterPgno(pDlidx); iPg++){
          iKey = FTS5_SEGMENT_ROWID(iSegid, iPg);
          pLeaf = fts5DataRead(p, iKey);
          if( pLeaf ){
            if( fts5LeafFirstRowidOff(pLeaf)!=0 ) FTS5_CORRUPT_ROWID(p, iKey);
            fts5DataRelease(pLeaf);
          }
        }
        iPrevLeaf = fts5DlidxIterPgno(pDlidx);

        /* Check that the leaf page indicated by the iterator really does
        ** contain the rowid suggested by the same. */
        iKey = FTS5_SEGMENT_ROWID(iSegid, iPrevLeaf);
        pLeaf = fts5DataRead(p, iKey);
        if( pLeaf ){
          i64 iRowid;
          int iRowidOff = fts5LeafFirstRowidOff(pLeaf);
          ASSERT_SZLEAF_OK(pLeaf);
          if( iRowidOff>=pLeaf->szLeaf ){
            FTS5_CORRUPT_ROWID(p, iKey);
          }else if( bSecureDelete==0 || iRowidOff>0 ){
            i64 iDlRowid = fts5DlidxIterRowid(pDlidx);
            fts5GetVarint(&pLeaf->p[iRowidOff], (u64*)&iRowid);
            if( iRowid<iDlRowid || (bSecureDelete==0 && iRowid!=iDlRowid) ){
              FTS5_CORRUPT_ROWID(p, iKey);
            }
          }
          fts5DataRelease(pLeaf);
        }
      }

      iDlidxPrevLeaf = iPg;

        cksum2 ^= sqlite3Fts5IndexEntryCksum(iRowid, iCol, iTokOff, -1, z, n);
      }
    }
  }
  fts5TestTerm(p, &term, 0, 0, cksum2, &cksum3);

  fts5MultiIterFree(pIter);
  if( p->rc==SQLITE_OK && bUseCksum && cksum!=cksum2 ){
    p->rc = FTS5_CORRUPT;
    sqlite3Fts5ConfigErrmsg(p->pConfig,
        "fts5: checksum mismatch for table \"%s\"", p->pConfig->zName
    );
  }

  fts5StructureRelease(pStruct);
#ifdef SQLITE_DEBUG
  fts5BufferFree(&term);
#endif
  fts5BufferFree(&poslist);
  return fts5IndexReturn(p);

static void fts5SourceIdFunc(
  sqlite3_context *pCtx,          /* Function call context */
  int nArg,                       /* Number of args */
  sqlite3_value **apUnused        /* Function arguments */
){
  assert( nArg==0 );
  UNUSED_PARAM2(nArg, apUnused);
  sqlite3_result_text(pCtx, "fts5: 2025-06-24 15:58:32 6a5701e6c7be25cba93e55438f950966e1dacb32eb2b23a8acc8ac53da6f0a85", -1, SQLITE_TRANSIENT);
}

/*
** Implementation of fts5_locale(LOCALE, TEXT) function.
**
** If parameter LOCALE is NULL, or a zero-length string, then a copy of
** TEXT is returned. Otherwise, both LOCALE and TEXT are interpreted as

          zSchema, zTabname);
      rc = (*pzErr) ? SQLITE_OK : SQLITE_NOMEM;
    }else{
      *pzErr = sqlite3_mprintf("unable to validate the inverted index for"
          " FTS5 table %s.%s: %s",
          zSchema, zTabname, sqlite3_errstr(rc));
    }
  }else if( (rc&0xff)==SQLITE_CORRUPT ){
    rc = SQLITE_OK;
  }
  sqlite3Fts5IndexCloseReader(pTab->p.pIndex);
  pTab->p.pConfig->pzErrmsg = 0;

  return rc;
}

static int fts5Init(sqlite3 *db){

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.51.0"
#define SQLITE_VERSION_NUMBER 3051000
#define SQLITE_SOURCE_ID      "2025-06-24 15:58:32 6a5701e6c7be25cba93e55438f950966e1dacb32eb2b23a8acc8ac53da6f0a85"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros

** (See how SQLite handles [invalid UTF] for exceptions to this rule.)
** ^(Memory to hold the error message string is managed internally.
** The application does not need to worry about freeing the result.
** However, the error string might be overwritten or deallocated by
** subsequent calls to other SQLite interface functions.)^
**
** ^The sqlite3_errstr(E) interface returns the English-language text
** that describes the [result code] E, as UTF-8, or NULL if E is not a
** result code for which a text error message is available.
** ^(Memory to hold the error message string is managed internally
** and must not be freed by the application)^.
**
** ^If the most recent error references a specific token in the input
** SQL, the sqlite3_error_offset() interface returns the byte offset
** of the start of that token.  ^The byte offset returned by
** sqlite3_error_offset() assumes that the input SQL is UTF-8.
** ^If the most recent error does not reference a specific token in the input
** SQL, then the sqlite3_error_offset() function returns -1.
**
** When the serialized [threading mode] is in use, it might be the
** case that a second error occurs on a separate thread in between
** the time of the first error and the call to these interfaces.
** When that happens, the second error will be reported since these

/*
** CAPI3REF: Run-Time Limit Categories
** KEYWORDS: {limit category} {*limit categories}
**
** These constants define various performance limits
** that can be lowered at run-time using [sqlite3_limit()].
** A concise description of these limits follows, and additional information
** is available at [limits | Limits in SQLite].
**
** <dl>
** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
**
** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
** <dd>The maximum length of an SQL statement, in bytes.</dd>)^

#define SQLITE_LIMIT_VARIABLE_NUMBER           9
#define SQLITE_LIMIT_TRIGGER_DEPTH            10
#define SQLITE_LIMIT_WORKER_THREADS           11

/*
** CAPI3REF: Prepare Flags
**
** These constants define various flags that can be passed into the
** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
** [sqlite3_prepare16_v3()] interfaces.
**
** New flags may be added in future releases of SQLite.
**
** <dl>
** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>

** up to the first zero terminator or until the nByte bytes have been read,
** whichever comes first.  ^If nByte is zero, then no prepared
** statement is generated.
** If the caller knows that the supplied string is nul-terminated, then
** there is a small performance advantage to passing an nByte parameter that
** is the number of bytes in the input string <i>including</i>
** the nul-terminator.
** Note that nByte measures the length of the input in bytes, not
** characters, even for the UTF-16 interfaces.
**
** ^If pzTail is not NULL then *pzTail is made to point to the first byte
** past the end of the first SQL statement in zSql.  These routines only
** compile the first statement in zSql, so *pzTail is left pointing to
** what remains uncompiled.
**

** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
** and parameter :xyz is unbound, then sqlite3_sql() will return
** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
** will return "SELECT 2345,NULL".)^
**
** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
** is available to hold the result, or if the result would exceed the
** maximum string length determined by the [SQLITE_LIMIT_LENGTH].
**
** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
** bound parameter expansions.  ^The [SQLITE_OMIT_TRACE] compile-time
** option causes sqlite3_expanded_sql() to always return NULL.
**
** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
** are managed by SQLite and are automatically freed when the prepared

typedef struct sqlite3_value sqlite3_value;

/*
** CAPI3REF: SQL Function Context Object
**
** The context in which an SQL function executes is stored in an
** sqlite3_context object.  ^A pointer to an sqlite3_context object
** is always the first parameter to [application-defined SQL functions].
** The application-defined SQL function implementation will pass this
** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
** [sqlite3_aggregate_context()], [sqlite3_user_data()],
** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
** and/or [sqlite3_set_auxdata()].
*/
typedef struct sqlite3_context sqlite3_context;

/*
** CAPI3REF: Destroy A Prepared Statement Object
** DESTRUCTOR: sqlite3_stmt
**
** ^The sqlite3_finalize() function is called to delete a [prepared statement].
** ^If the most recent evaluation of the statement encountered no errors
** or if the statement has never been evaluated, then sqlite3_finalize() returns
** SQLITE_OK.  ^If the most recent evaluation of statement S failed, then
** sqlite3_finalize(S) returns the appropriate [error code] or
** [extended error code].
**
** ^The sqlite3_finalize(S) routine can be called at any point during
** the life cycle of [prepared statement] S:
** before statement S is ever evaluated, after

  void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
  void(*xDestroy)(void*)
);

/*
** CAPI3REF: Text Encodings
**
** These constants define integer codes that represent the various
** text encodings supported by SQLite.
*/
#define SQLITE_UTF8           1    /* IMP: R-37514-35566 */
#define SQLITE_UTF16LE        2    /* IMP: R-03371-37637 */
#define SQLITE_UTF16BE        3    /* IMP: R-51971-34154 */
#define SQLITE_UTF16          4    /* Use native byte order */
#define SQLITE_ANY            5    /* Deprecated */

**
** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd>
** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call
** [sqlite3_result_subtype()] to cause a sub-type to be associated with its
** result.
** Every function that invokes [sqlite3_result_subtype()] should have this
** property.  If it does not, then the call to [sqlite3_result_subtype()]
** might become a no-op if the function is used as a term in an
** [expression index].  On the other hand, SQL functions that never invoke
** [sqlite3_result_subtype()] should avoid setting this property, as the
** purpose of this property is to disable certain optimizations that are
** incompatible with subtypes.
**
** [[SQLITE_SELFORDER1]] <dt>SQLITE_SELFORDER1</dt><dd>
** The SQLITE_SELFORDER1 flag indicates that the function is an aggregate

** then the conversion is performed.  Otherwise no conversion occurs.
** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
**
** ^Within the [xUpdate] method of a [virtual table], the
** sqlite3_value_nochange(X) interface returns true if and only if
** the column corresponding to X is unchanged by the UPDATE operation
** that the xUpdate method call was invoked to implement and if
** the prior [xColumn] method call that was invoked to extract
** the value for that column returned without setting a result (probably
** because it queried [sqlite3_vtab_nochange()] and found that the column
** was unchanging).  ^Within an [xUpdate] method, any value for which
** sqlite3_value_nochange(X) is true will in all other respects appear
** to be a NULL value.  If sqlite3_value_nochange(X) is invoked anywhere other
** than within an [xUpdate] method call for an UPDATE statement, then
** the return value is arbitrary and meaningless.