SQLite

      if( p->eType==SQLITE_TEXT || p->eType==SQLITE_BLOB ){
        sqlite3DbFree(db, p->u.z);
      }
    }
    sqlite3DbFree(db, pIdx->aSample);
  }
#else
  UNUSED_PARAMETER(db);
  UNUSED_PARAMETER(pIdx);
#endif
}

/*
** Load the content of the sqlite_stat1 and sqlite_stat2 tables. The
** contents of sqlite_stat1 are used to populate the Index.aiRowEst[]

  */
  nPage = nPageHeader = get4byte(28+(u8*)pPage1->aData);
  sqlite3PagerPagecount(pBt->pPager, &nPageFile);
  if( nPage==0 || memcmp(24+(u8*)pPage1->aData, 92+(u8*)pPage1->aData,4)!=0 ){
    nPage = nPageFile;
  }
  if( nPage>0 ){
    u32 pageSize;
    u32 usableSize;
    u8 *page1 = pPage1->aData;
    rc = SQLITE_NOTADB;
    if( memcmp(page1, zMagicHeader, 16)!=0 ){
      goto page1_init_failed;
    }

#ifdef SQLITE_OMIT_WAL

      /* After reading the first page of the database assuming a page size
      ** of BtShared.pageSize, we have discovered that the page-size is
      ** actually pageSize. Unlock the database, leave pBt->pPage1 at
      ** zero and return SQLITE_OK. The caller will call this function
      ** again with the correct page-size.
      */
      releasePage(pPage1);
      pBt->usableSize = usableSize;
      pBt->pageSize = pageSize;
      freeTempSpace(pBt);
      rc = sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize,
                                   pageSize-usableSize);
      return rc;
    }
    if( nPageHeader>nPageFile ){
      rc = SQLITE_CORRUPT_BKPT;
      goto page1_init_failed;
    }
    if( usableSize<480 ){
      goto page1_init_failed;
    }
    pBt->pageSize = pageSize;
    pBt->usableSize = usableSize;
#ifndef SQLITE_OMIT_AUTOVACUUM
    pBt->autoVacuum = (get4byte(&page1[36 + 4*4])?1:0);
    pBt->incrVacuum = (get4byte(&page1[36 + 7*4])?1:0);
#endif
  }

  /* maxLocal is the maximum amount of payload to store locally for

** the cell content has been copied someplace else.  This routine just
** removes the reference to the cell from pPage.
**
** "sz" must be the number of bytes in the cell.
*/
static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
  int i;          /* Loop counter */
  u32 pc;         /* Offset to cell content of cell being deleted */
  u8 *data;       /* pPage->aData */
  u8 *ptr;        /* Used to move bytes around within data[] */
  int rc;         /* The return code */
  int hdr;        /* Beginning of the header.  0 most pages.  100 page 1 */

  if( *pRC ) return;

  assert( idx>=0 && idx<pPage->nCell );
  assert( sz==cellSize(pPage, idx) );
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  data = pPage->aData;
  ptr = &data[pPage->cellOffset + 2*idx];
  pc = get2byte(ptr);
  hdr = pPage->hdrOffset;
  testcase( pc==get2byte(&data[hdr+5]) );
  testcase( pc+sz==pPage->pBt->usableSize );
  if( pc < (u32)get2byte(&data[hdr+5]) || pc+sz > pPage->pBt->usableSize ){
    *pRC = SQLITE_CORRUPT_BKPT;
    return;
  }
  rc = freeSpace(pPage, pc, sz);
  if( rc ){
    *pRC = rc;
    return;

      ** Unless SQLite is compiled in secure-delete mode. In this case,
      ** the dropCell() routine will overwrite the entire cell with zeroes.
      ** In this case, temporarily copy the cell into the aOvflSpace[]
      ** buffer. It will be copied out again as soon as the aSpace[] buffer
      ** is allocated.  */
      if( pBt->secureDelete ){
        int iOff = SQLITE_PTR_TO_INT(apDiv[i]) - SQLITE_PTR_TO_INT(pParent->aData);
        if( (iOff+szNew[i])>(int)pBt->usableSize ){
          rc = SQLITE_CORRUPT_BKPT;
          memset(apOld, 0, (i+1)*sizeof(MemPage*));
          goto balance_cleanup;
        }else{
          memcpy(&aOvflSpace[iOff], apDiv[i], szNew[i]);
          apDiv[i] = &aOvflSpace[apDiv[i]-pParent->aData];
        }

    if( isFreeList ){
      int n = get4byte(&pOvflData[4]);
#ifndef SQLITE_OMIT_AUTOVACUUM
      if( pCheck->pBt->autoVacuum ){
        checkPtrmap(pCheck, iPage, PTRMAP_FREEPAGE, 0, zContext);
      }
#endif
      if( n>(int)pCheck->pBt->usableSize/4-2 ){
        checkAppendMsg(pCheck, zContext,
           "freelist leaf count too big on page %d", iPage);
        N--;
      }else{
        for(i=0; i<n; i++){
          Pgno iFreePage = get4byte(&pOvflData[8+i*4]);
#ifndef SQLITE_OMIT_AUTOVACUUM

    for(i=0; i<nCell; i++){
      int pc = get2byte(&data[cellStart+i*2]);
      u32 size = 65536;
      int j;
      if( pc<=usableSize-4 ){
        size = cellSizePtr(pPage, &data[pc]);
      }
      if( (int)(pc+size-1)>=usableSize ){
        checkAppendMsg(pCheck, 0, 
            "Corruption detected in cell %d on page %d",i,iPage);
      }else{
        for(j=pc+size-1; j>=pc; j--) hit[j]++;
      }
    }
    i = get2byte(&data[hdr+1]);

** - 4 bytes: Database page size.
** 
** Followed by (JOURNAL_HDR_SZ - 28) bytes of unused space.
*/
static int writeJournalHdr(Pager *pPager){
  int rc = SQLITE_OK;                 /* Return code */
  char *zHeader = pPager->pTmpSpace;  /* Temporary space used to build header */
  u32 nHeader = (u32)pPager->pageSize;/* Size of buffer pointed to by zHeader */
  u32 nWrite;                         /* Bytes of header sector written */
  int ii;                             /* Loop counter */

  assert( isOpen(pPager->jfd) );      /* Journal file must be open. */

  if( nHeader>JOURNAL_HDR_SZ(pPager) ){
    nHeader = JOURNAL_HDR_SZ(pPager);

  ** is a no-op for that case anyhow.
  */

  u32 pageSize = *pPageSize;
  assert( pageSize==0 || (pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE) );
  if( (pPager->memDb==0 || pPager->dbSize==0)
   && sqlite3PcacheRefCount(pPager->pPCache)==0 
   && pageSize && pageSize!=(u32)pPager->pageSize 
  ){
    char *pNew;                 /* New temp space */
    i64 nByte = 0;

    if( pPager->eState>PAGER_OPEN && isOpen(pPager->fd) ){
      rc = sqlite3OsFileSize(pPager->fd, &nByte);
    }

    /* The maximum page number is 2^31. Return SQLITE_CORRUPT if a page
    ** number greater than this, or the unused locking-page, is requested. */
    if( pgno>PAGER_MAX_PGNO || pgno==PAGER_MJ_PGNO(pPager) ){
      rc = SQLITE_CORRUPT_BKPT;
      goto pager_acquire_err;
    }

    if( MEMDB || pPager->dbSize<pgno || noContent || !isOpen(pPager->fd) ){
      if( pgno>pPager->mxPgno ){
        rc = SQLITE_FULL;
        goto pager_acquire_err;
      }
      if( noContent ){
        /* Failure to set the bits in the InJournal bit-vectors is benign.
        ** It merely means that we might do some extra work to journal a