SQLite

  if( pKey ){
    assert( nKey==(i64)(int)nKey );
    pIdxKey = sqlite3VdbeAllocUnpackedRecord(pCur->pKeyInfo);
    if( pIdxKey==0 ) return SQLITE_NOMEM_BKPT;
    sqlite3VdbeRecordUnpack(pCur->pKeyInfo, (int)nKey, pKey, pIdxKey);
    if( pIdxKey->nField==0 ){
      rc = SQLITE_CORRUPT_PGNO(pCur->apPage[pCur->iPage]->pgno);
      goto moveto_done;
    }
  }else{
    pIdxKey = 0;
  }
  rc = sqlite3BtreeMovetoUnpacked(pCur, pIdxKey, nKey, bias, pRes);
moveto_done:

  }
  assert( offset <= (int)pBt->usableSize-5 );
  assert( pEType!=0 );
  *pEType = pPtrmap[offset];
  if( pPgno ) *pPgno = get4byte(&pPtrmap[offset+1]);

  sqlite3PagerUnref(pDbPage);
  if( *pEType<1 || *pEType>5 ) return SQLITE_CORRUPT_PGNO(iPtrmap);
  return SQLITE_OK;
}

#else /* if defined SQLITE_OMIT_AUTOVACUUM */
  #define ptrmapPut(w,x,y,z,rc)
  #define ptrmapGet(w,x,y,z) SQLITE_OK
  #define ptrmapPutOvflPtr(x, y, rc)

      if( 0==iFree2 || (data[iFree2]==0 && data[iFree2+1]==0) ){
        u8 *pEnd = &data[cellOffset + nCell*2];
        u8 *pAddr;
        int sz2 = 0;
        int sz = get2byte(&data[iFree+2]);
        int top = get2byte(&data[hdr+5]);
        if( iFree2 ){
          if( iFree+sz>iFree2 ) return SQLITE_CORRUPT_PGNO(pPage->pgno);
          sz2 = get2byte(&data[iFree2+2]);
          assert( iFree+sz+sz2+iFree2-(iFree+sz) <= usableSize );
          memmove(&data[iFree+sz+sz2], &data[iFree+sz], iFree2-(iFree+sz));
          sz += sz2;
        }
        cbrk = top+sz;
        assert( cbrk+(iFree-top) <= usableSize );

    pc = get2byte(pAddr);
    testcase( pc==iCellFirst );
    testcase( pc==iCellLast );
    /* These conditions have already been verified in btreeInitPage()
    ** if PRAGMA cell_size_check=ON.
    */
    if( pc<iCellFirst || pc>iCellLast ){
      return SQLITE_CORRUPT_PGNO(pPage->pgno);
    }
    assert( pc>=iCellFirst && pc<=iCellLast );
    size = pPage->xCellSize(pPage, &src[pc]);
    cbrk -= size;
    if( cbrk<iCellFirst || pc+size>usableSize ){
      return SQLITE_CORRUPT_PGNO(pPage->pgno);
    }
    assert( cbrk+size<=usableSize && cbrk>=iCellFirst );
    testcase( cbrk+size==usableSize );
    testcase( pc+size==usableSize );
    put2byte(pAddr, cbrk);
    if( temp==0 ){
      int x;
      if( cbrk==pc ) continue;
      temp = sqlite3PagerTempSpace(pPage->pBt->pPager);
      x = get2byte(&data[hdr+5]);
      memcpy(&temp[x], &data[x], (cbrk+size) - x);
      src = temp;
    }
    memcpy(&data[cbrk], &src[pc], size);
  }
  data[hdr+7] = 0;

 defragment_out:
  if( data[hdr+7]+cbrk-iCellFirst!=pPage->nFree ){
    return SQLITE_CORRUPT_PGNO(pPage->pgno);
  }
  assert( cbrk>=iCellFirst );
  put2byte(&data[hdr+5], cbrk);
  data[hdr+1] = 0;
  data[hdr+2] = 0;
  memset(&data[iCellFirst], 0, cbrk-iCellFirst);
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );

  assert( pc>0 );
  do{
    int size;            /* Size of the free slot */
    /* EVIDENCE-OF: R-06866-39125 Freeblocks are always connected in order of
    ** increasing offset. */
    if( pc>usableSize-4 || pc<iAddr+4 ){
      *pRc = SQLITE_CORRUPT_PGNO(pPg->pgno);
      return 0;
    }
    /* EVIDENCE-OF: R-22710-53328 The third and fourth bytes of each
    ** freeblock form a big-endian integer which is the size of the freeblock
    ** in bytes, including the 4-byte header. */
    size = get2byte(&aData[pc+2]);
    if( (x = size - nByte)>=0 ){
      testcase( x==4 );
      testcase( x==3 );
      if( pc < pPg->cellOffset+2*pPg->nCell || size+pc > usableSize ){
        *pRc = SQLITE_CORRUPT_PGNO(pPg->pgno);
        return 0;
      }else if( x<4 ){
        /* EVIDENCE-OF: R-11498-58022 In a well-formed b-tree page, the total
        ** number of bytes in fragments may not exceed 60. */
        if( aData[hdr+7]>57 ) return 0;

        /* Remove the slot from the free-list. Update the number of

  ** integer, so a value of 0 is used in its place. */
  top = get2byte(&data[hdr+5]);
  assert( top<=(int)pPage->pBt->usableSize ); /* Prevent by getAndInitPage() */
  if( gap>top ){
    if( top==0 && pPage->pBt->usableSize==65536 ){
      top = 65536;
    }else{
      return SQLITE_CORRUPT_PGNO(pPage->pgno);
    }
  }

  /* If there is enough space between gap and top for one more cell pointer
  ** array entry offset, and if the freelist is not empty, then search the
  ** freelist looking for a free slot big enough to satisfy the request.
  */

  iPtr = hdr + 1;
  if( data[iPtr+1]==0 && data[iPtr]==0 ){
    iFreeBlk = 0;  /* Shortcut for the case when the freelist is empty */
  }else{
    while( (iFreeBlk = get2byte(&data[iPtr]))<iStart ){
      if( iFreeBlk<iPtr+4 ){
        if( iFreeBlk==0 ) break;
        return SQLITE_CORRUPT_PGNO(pPage->pgno);
      }
      iPtr = iFreeBlk;
    }
    if( iFreeBlk>iLast ) return SQLITE_CORRUPT_PGNO(pPage->pgno);
    assert( iFreeBlk>iPtr || iFreeBlk==0 );
  
    /* At this point:
    **    iFreeBlk:   First freeblock after iStart, or zero if none
    **    iPtr:       The address of a pointer to iFreeBlk
    **
    ** Check to see if iFreeBlk should be coalesced onto the end of iStart.
    */
    if( iFreeBlk && iEnd+3>=iFreeBlk ){
      nFrag = iFreeBlk - iEnd;
      if( iEnd>iFreeBlk ) return SQLITE_CORRUPT_PGNO(pPage->pgno);
      iEnd = iFreeBlk + get2byte(&data[iFreeBlk+2]);
      if( iEnd > pPage->pBt->usableSize ){
        return SQLITE_CORRUPT_PGNO(pPage->pgno);
      }
      iSize = iEnd - iStart;
      iFreeBlk = get2byte(&data[iFreeBlk]);
    }
  
    /* If iPtr is another freeblock (that is, if iPtr is not the freelist
    ** pointer in the page header) then check to see if iStart should be
    ** coalesced onto the end of iPtr.
    */
    if( iPtr>hdr+1 ){
      int iPtrEnd = iPtr + get2byte(&data[iPtr+2]);
      if( iPtrEnd+3>=iStart ){
        if( iPtrEnd>iStart ) return SQLITE_CORRUPT_PGNO(pPage->pgno);
        nFrag += iStart - iPtrEnd;
        iSize = iEnd - iPtr;
        iStart = iPtr;
      }
    }
    if( nFrag>data[hdr+7] ) return SQLITE_CORRUPT_PGNO(pPage->pgno);
    data[hdr+7] -= nFrag;
  }
  if( iStart==get2byte(&data[hdr+5]) ){
    /* The new freeblock is at the beginning of the cell content area,
    ** so just extend the cell content area rather than create another
    ** freelist entry */
    if( iPtr!=hdr+1 ) return SQLITE_CORRUPT_PGNO(pPage->pgno);
    put2byte(&data[hdr+1], iFreeBlk);
    put2byte(&data[hdr+5], iEnd);
  }else{
    /* Insert the new freeblock into the freelist */
    put2byte(&data[iPtr], iStart);
    put2byte(&data[iStart], iFreeBlk);
    put2byte(&data[iStart+2], iSize);

    pPage->intKeyLeaf = 0;
    pPage->xParseCell = btreeParseCellPtrIndex;
    pPage->maxLocal = pBt->maxLocal;
    pPage->minLocal = pBt->minLocal;
  }else{
    /* EVIDENCE-OF: R-47608-56469 Any other value for the b-tree page type is
    ** an error. */
    return SQLITE_CORRUPT_PGNO(pPage->pgno);
  }
  pPage->max1bytePayload = pBt->max1bytePayload;
  return SQLITE_OK;
}

/*
** Initialize the auxiliary information for a disk block.

  assert( pPage->isInit==0 );

  pBt = pPage->pBt;
  hdr = pPage->hdrOffset;
  data = pPage->aData;
  /* EVIDENCE-OF: R-28594-02890 The one-byte flag at offset 0 indicating
  ** the b-tree page type. */
  if( decodeFlags(pPage, data[hdr]) ){
    return SQLITE_CORRUPT_PGNO(pPage->pgno);
  }
  assert( pBt->pageSize>=512 && pBt->pageSize<=65536 );
  pPage->maskPage = (u16)(pBt->pageSize - 1);
  pPage->nOverflow = 0;
  usableSize = pBt->usableSize;
  pPage->cellOffset = cellOffset = hdr + 8 + pPage->childPtrSize;
  pPage->aDataEnd = &data[usableSize];
  pPage->aCellIdx = &data[cellOffset];
  pPage->aDataOfst = &data[pPage->childPtrSize];
  /* EVIDENCE-OF: R-58015-48175 The two-byte integer at offset 5 designates
  ** the start of the cell content area. A zero value for this integer is
  ** interpreted as 65536. */
  top = get2byteNotZero(&data[hdr+5]);
  /* EVIDENCE-OF: R-37002-32774 The two-byte integer at offset 3 gives the
  ** number of cells on the page. */
  pPage->nCell = get2byte(&data[hdr+3]);
  if( pPage->nCell>MX_CELL(pBt) ){
    /* To many cells for a single page.  The page must be corrupt */
    return SQLITE_CORRUPT_PGNO(pPage->pgno);
  }
  testcase( pPage->nCell==MX_CELL(pBt) );
  /* EVIDENCE-OF: R-24089-57979 If a page contains no cells (which is only
  ** possible for a root page of a table that contains no rows) then the
  ** offset to the cell content area will equal the page size minus the
  ** bytes of reserved space. */
  assert( pPage->nCell>0 || top==usableSize || CORRUPT_DB );

    if( !pPage->leaf ) iCellLast--;
    for(i=0; i<pPage->nCell; i++){
      pc = get2byteAligned(&data[cellOffset+i*2]);
      testcase( pc==iCellFirst );
      testcase( pc==iCellLast );
      if( pc<iCellFirst || pc>iCellLast ){
        return SQLITE_CORRUPT_PGNO(pPage->pgno);
      }
      sz = pPage->xCellSize(pPage, &data[pc]);
      testcase( pc+sz==usableSize );
      if( pc+sz>usableSize ){
        return SQLITE_CORRUPT_PGNO(pPage->pgno);
      }
    }
    if( !pPage->leaf ) iCellLast++;
  }  

  /* Compute the total free space on the page
  ** EVIDENCE-OF: R-23588-34450 The two-byte integer at offset 1 gives the
  ** start of the first freeblock on the page, or is zero if there are no
  ** freeblocks. */
  pc = get2byte(&data[hdr+1]);
  nFree = data[hdr+7] + top;  /* Init nFree to non-freeblock free space */
  if( pc>0 ){
    u32 next, size;
    if( pc<iCellFirst ){
      /* EVIDENCE-OF: R-55530-52930 In a well-formed b-tree page, there will
      ** always be at least one cell before the first freeblock.
      */
      return SQLITE_CORRUPT_PGNO(pPage->pgno); 
    }
    while( 1 ){
      if( pc>iCellLast ){
        /* Freeblock off the end of the page */
        return SQLITE_CORRUPT_PGNO(pPage->pgno);
      }
      next = get2byte(&data[pc]);
      size = get2byte(&data[pc+2]);
      nFree = nFree + size;
      if( next<=pc+size+3 ) break;
      pc = next;
    }
    if( next>0 ){
      /* Freeblock not in ascending order */
      return SQLITE_CORRUPT_PGNO(pPage->pgno);
    }
    if( pc+size>(unsigned int)usableSize ){
      /* Last freeblock extends past page end */
      return SQLITE_CORRUPT_PGNO(pPage->pgno);
    }
  }

  /* At this point, nFree contains the sum of the offset to the start
  ** of the cell-content area plus the number of free bytes within
  ** the cell-content area. If this is greater than the usable-size
  ** of the page, then the page must be corrupted. This check also
  ** serves to verify that the offset to the start of the cell-content
  ** area, according to the page header, lies within the page.
  */
  if( nFree>usableSize ){
    return SQLITE_CORRUPT_PGNO(pPage->pgno);
  }
  pPage->nFree = (u16)(nFree - iCellFirst);
  pPage->isInit = 1;
  return SQLITE_OK;
}

/*

  }
  assert( (*ppPage)->pgno==pgno );
  assert( (*ppPage)->aData==sqlite3PagerGetData(pDbPage) );

  /* If obtaining a child page for a cursor, we must verify that the page is
  ** compatible with the root page. */
  if( pCur && ((*ppPage)->nCell<1 || (*ppPage)->intKey!=pCur->curIntKey) ){
    rc = SQLITE_CORRUPT_PGNO(pgno);
    releasePage(*ppPage);
    goto getAndInitPage_error;
  }
  return SQLITE_OK;

getAndInitPage_error:
  if( pCur ) pCur->iPage--;

*/
static int modifyPagePointer(MemPage *pPage, Pgno iFrom, Pgno iTo, u8 eType){
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  if( eType==PTRMAP_OVERFLOW2 ){
    /* The pointer is always the first 4 bytes of the page in this case.  */
    if( get4byte(pPage->aData)!=iFrom ){
      return SQLITE_CORRUPT_PGNO(pPage->pgno);
    }
    put4byte(pPage->aData, iTo);
  }else{
    int i;
    int nCell;
    int rc;

    rc = pPage->isInit ? SQLITE_OK : btreeInitPage(pPage);
    if( rc ) return rc;
    nCell = pPage->nCell;

    for(i=0; i<nCell; i++){
      u8 *pCell = findCell(pPage, i);
      if( eType==PTRMAP_OVERFLOW1 ){
        CellInfo info;
        pPage->xParseCell(pPage, pCell, &info);
        if( info.nLocal<info.nPayload ){
          if( pCell+info.nSize > pPage->aData+pPage->pBt->usableSize ){
            return SQLITE_CORRUPT_PGNO(pPage->pgno);
          }
          if( iFrom==get4byte(pCell+info.nSize-4) ){
            put4byte(pCell+info.nSize-4, iTo);
            break;
          }
        }
      }else{
        if( get4byte(pCell)==iFrom ){
          put4byte(pCell, iTo);
          break;
        }
      }
    }
  
    if( i==nCell ){
      if( eType!=PTRMAP_BTREE || 
          get4byte(&pPage->aData[pPage->hdrOffset+8])!=iFrom ){
        return SQLITE_CORRUPT_PGNO(pPage->pgno);
      }
      put4byte(&pPage->aData[pPage->hdrOffset+8], iTo);
    }
  }
  return SQLITE_OK;
}

  assert( aPayload > pPage->aData );
  if( (uptr)(aPayload - pPage->aData) > (pBt->usableSize - pCur->info.nLocal) ){
    /* Trying to read or write past the end of the data is an error.  The
    ** conditional above is really:
    **    &aPayload[pCur->info.nLocal] > &pPage->aData[pBt->usableSize]
    ** but is recast into its current form to avoid integer overflow problems
    */
    return SQLITE_CORRUPT_PGNO(pPage->pgno);
  }

  /* Check if data must be read/written to/from the btree page itself. */
  if( offset<pCur->info.nLocal ){
    int a = amt;
    if( a+offset>pCur->info.nLocal ){
      a = pCur->info.nLocal - offset;

      }
      if( rc ) break;
      iIdx++;
    }
  }

  if( rc==SQLITE_OK && amt>0 ){
    /* Overflow chain ends prematurely */
    return SQLITE_CORRUPT_PGNO(pPage->pgno);
  }
  return rc;
}

/*
** Read part of the payload for the row at which that cursor pCur is currently
** pointing.  "amt" bytes will be transferred into pBuf[].  The transfer

  ** Earlier versions of SQLite assumed that this test could not fail
  ** if the root page was already loaded when this function was called (i.e.
  ** if pCur->iPage>=0). But this is not so if the database is corrupted 
  ** in such a way that page pRoot is linked into a second b-tree table 
  ** (or the freelist).  */
  assert( pRoot->intKey==1 || pRoot->intKey==0 );
  if( pRoot->isInit==0 || (pCur->pKeyInfo==0)!=pRoot->intKey ){
    return SQLITE_CORRUPT_PGNO(pCur->apPage[pCur->iPage]->pgno);
  }

skip_init:  
  pCur->ix = 0;
  pCur->info.nSize = 0;
  pCur->curFlags &= ~(BTCF_AtLast|BTCF_ValidNKey|BTCF_ValidOvfl);

    pCur->ix = (u16)idx;
    if( xRecordCompare==0 ){
      for(;;){
        i64 nCellKey;
        pCell = findCellPastPtr(pPage, idx);
        if( pPage->intKeyLeaf ){
          while( 0x80 <= *(pCell++) ){
            if( pCell>=pPage->aDataEnd ){
              return SQLITE_CORRUPT_PGNO(pPage->pgno);
            }
          }
        }
        getVarint(pCell, (u64*)&nCellKey);
        if( nCellKey<intKey ){
          lwr = idx+1;
          if( lwr>upr ){ c = -1; break; }
        }else if( nCellKey>intKey ){

          pPage->xParseCell(pPage, pCellBody, &pCur->info);
          nCell = (int)pCur->info.nKey;
          testcase( nCell<0 );   /* True if key size is 2^32 or more */
          testcase( nCell==0 );  /* Invalid key size:  0x80 0x80 0x00 */
          testcase( nCell==1 );  /* Invalid key size:  0x80 0x80 0x01 */
          testcase( nCell==2 );  /* Minimum legal index key size */
          if( nCell<2 ){
            rc = SQLITE_CORRUPT_PGNO(pPage->pgno);
            goto moveto_finish;
          }
          pCellKey = sqlite3Malloc( nCell+18 );
          if( pCellKey==0 ){
            rc = SQLITE_NOMEM_BKPT;
            goto moveto_finish;
          }

        /* EVIDENCE-OF: R-59841-13798 The 4-byte big-endian integer at offset 32
        ** stores the page number of the first page of the freelist, or zero if
        ** the freelist is empty. */
        iTrunk = get4byte(&pPage1->aData[32]);
      }
      testcase( iTrunk==mxPage );
      if( iTrunk>mxPage || nSearch++ > n ){
        rc = SQLITE_CORRUPT_PGNO(pPrevTrunk->pgno);
      }else{
        rc = btreeGetUnusedPage(pBt, iTrunk, &pTrunk, 0);
      }
      if( rc ){
        pTrunk = 0;
        goto end_allocate_page;
      }

        *pPgno = iTrunk;
        memcpy(&pPage1->aData[32], &pTrunk->aData[0], 4);
        *ppPage = pTrunk;
        pTrunk = 0;
        TRACE(("ALLOCATE: %d trunk - %d free pages left\n", *pPgno, n-1));
      }else if( k>(u32)(pBt->usableSize/4 - 2) ){
        /* Value of k is out of range.  Database corruption */
        rc = SQLITE_CORRUPT_PGNO(iTrunk);
        goto end_allocate_page;
#ifndef SQLITE_OMIT_AUTOVACUUM
      }else if( searchList 
            && (nearby==iTrunk || (iTrunk<nearby && eMode==BTALLOC_LE)) 
      ){
        /* The list is being searched and this trunk page is the page
        ** to allocate, regardless of whether it has leaves.

          /* The trunk page is required by the caller but it contains 
          ** pointers to free-list leaves. The first leaf becomes a trunk
          ** page in this case.
          */
          MemPage *pNewTrunk;
          Pgno iNewTrunk = get4byte(&pTrunk->aData[8]);
          if( iNewTrunk>mxPage ){ 
            rc = SQLITE_CORRUPT_PGNO(iTrunk);
            goto end_allocate_page;
          }
          testcase( iNewTrunk==mxPage );
          rc = btreeGetUnusedPage(pBt, iNewTrunk, &pNewTrunk, 0);
          if( rc!=SQLITE_OK ){
            goto end_allocate_page;
          }

        }else{
          closest = 0;
        }

        iPage = get4byte(&aData[8+closest*4]);
        testcase( iPage==mxPage );
        if( iPage>mxPage ){
          rc = SQLITE_CORRUPT_PGNO(iTrunk);
          goto end_allocate_page;
        }
        testcase( iPage==mxPage );
        if( !searchList 
         || (iPage==nearby || (iPage<nearby && eMode==BTALLOC_LE)) 
        ){
          int noContent;

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  pPage->xParseCell(pPage, pCell, pInfo);
  if( pInfo->nLocal==pInfo->nPayload ){
    return SQLITE_OK;  /* No overflow pages. Return without doing anything */
  }
  if( pCell+pInfo->nSize-1 > pPage->aData+pPage->maskPage ){
    /* Cell extends past end of page */
    return SQLITE_CORRUPT_PGNO(pPage->pgno);
  }
  ovflPgno = get4byte(pCell + pInfo->nSize - 4);
  assert( pBt->usableSize > 4 );
  ovflPageSize = pBt->usableSize - 4;
  nOvfl = (pInfo->nPayload - pInfo->nLocal + ovflPageSize - 1)/ovflPageSize;
  assert( nOvfl>0 || 
    (CORRUPT_DB && (pInfo->nPayload + ovflPageSize)<ovflPageSize)

      goto end_insert;
    }
    oldCell = findCell(pPage, idx);
    if( !pPage->leaf ){
      memcpy(newCell, oldCell, 4);
    }
    rc = clearCell(pPage, oldCell, &info);
    if( info.nSize==szNew && info.nLocal==info.nPayload 
     && (!ISAUTOVACUUM || szNew<pPage->minLocal)
    ){
      /* Overwrite the old cell with the new if they are the same size.
      ** We could also try to do this if the old cell is smaller, then add
      ** the leftover space to the free list.  But experiments show that
      ** doing that is no faster then skipping this optimization and just
      ** calling dropCell() and insertCell(). 
      **
      ** This optimization cannot be used on an autovacuum database if the
      ** new entry uses overflow pages, as the insertCell() call below is
      ** necessary to add the PTRMAP_OVERFLOW1 pointer-map entry.  */
      assert( rc==SQLITE_OK ); /* clearCell never fails when nLocal==nPayload */
      if( oldCell+szNew > pPage->aDataEnd ) return SQLITE_CORRUPT_BKPT;
      memcpy(oldCell, newCell, szNew);
      return SQLITE_OK;
    }
    dropCell(pPage, idx, info.nSize, &rc);
    if( rc ) goto end_insert;

  return reportError(SQLITE_MISUSE, lineno, "misuse");
}
int sqlite3CantopenError(int lineno){
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return reportError(SQLITE_CANTOPEN, lineno, "cannot open file");
}
#ifdef SQLITE_DEBUG
int sqlite3CorruptPgnoError(int lineno, Pgno pgno){
  char zMsg[100];
  sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return reportError(SQLITE_CORRUPT, lineno, zMsg);
}
int sqlite3NomemError(int lineno){
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return reportError(SQLITE_NOMEM, lineno, "OOM");
}
int sqlite3IoerrnomemError(int lineno){
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return reportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");

  }else
#endif

  if( c=='s' && n>=4 && strncmp(azArg[0],"selftest",n)==0 ){
    int bIsInit = 0;         /* True to initialize the SELFTEST table */
    int bVerbose = 0;        /* Verbose output */
    int bSelftestExists;     /* True if SELFTEST already exists */



    int i, k;                /* Loop counters */
    int nTest = 0;           /* Number of tests runs */
    int nErr = 0;            /* Number of errors seen */
    ShellText str;           /* Answer for a query */


    sqlite3_stmt *pStmt = 0; /* Query against the SELFTEST table */




    open_db(p,0);
    for(i=1; i<nArg; i++){
      const char *z = azArg[i];
      if( z[0]=='-' && z[1]=='-' ) z++;
      if( strcmp(z,"-init")==0 ){
        bIsInit = 1;

    }else{
      bSelftestExists = 1;
    }
    if( bIsInit ){
      createSelftestTable(p);
      bSelftestExists = 1;
    }
    initText(&str);
    appendText(&str, "x", 0);
    for(k=bSelftestExists; k>=0; k--){
      if( k==1 ){
        rc = sqlite3_prepare_v2(p->db,
            "SELECT tno,op,cmd,ans FROM selftest ORDER BY tno",
            -1, &pStmt, 0);
      }else{
        rc = sqlite3_prepare_v2(p->db,
          "VALUES(0,'memo','Missing SELFTEST table - default checks only',''),"
          "      (1,'run','PRAGMA integrity_check','ok')",
          -1, &pStmt, 0);
      }
      if( rc ){
        raw_printf(stderr, "Error querying the selftest table\n");
        rc = 1;
        sqlite3_finalize(pStmt);
        goto meta_command_exit;




      }






      for(i=1; sqlite3_step(pStmt)==SQLITE_ROW; i++){
        int tno = sqlite3_column_int(pStmt, 0);
        const char *zOp = (const char*)sqlite3_column_text(pStmt, 1);
        const char *zSql = (const char*)sqlite3_column_text(pStmt, 2);
        const char *zAns = (const char*)sqlite3_column_text(pStmt, 3);

        k = 0;
        if( bVerbose>0 ){
          char *zQuote = sqlite3_mprintf("%q", zSql);
          printf("%d: %s %s\n", tno, zOp, zSql);
          sqlite3_free(zQuote);
        }
        if( strcmp(zOp,"memo")==0 ){
          utf8_printf(p->out, "%s\n", zSql);
        }else
        if( strcmp(zOp,"run")==0 ){
          char *zErrMsg = 0;
          str.n = 0;
          str.z[0] = 0;
          rc = sqlite3_exec(p->db, zSql, captureOutputCallback, &str, &zErrMsg);
          nTest++;
          if( bVerbose ){
            utf8_printf(p->out, "Result: %s\n", str.z);
          }
          if( rc || zErrMsg ){
            nErr++;
            rc = 1;
            utf8_printf(p->out, "%d: error-code-%d: %s\n", tno, rc, zErrMsg);
            sqlite3_free(zErrMsg);
          }else if( strcmp(zAns,str.z)!=0 ){
            nErr++;
            rc = 1;
            utf8_printf(p->out, "%d: Expected: [%s]\n", tno, zAns);
            utf8_printf(p->out, "%d:      Got: [%s]\n", tno, str.z);
          }
        }else
        {
          utf8_printf(stderr,
            "Unknown operation \"%s\" on selftest line %d\n", zOp, tno);
          rc = 1;
          break;
        }
      } /* End loop over rows of content from SELFTEST */
      sqlite3_finalize(pStmt);
    } /* End loop over k */
    freeText(&str);

    utf8_printf(p->out, "%d errors out of %d tests\n", nErr, nTest);
  }else

  if( c=='s' && strncmp(azArg[0], "separator", n)==0 ){
    if( nArg<2 || nArg>3 ){
      raw_printf(stderr, "Usage: .separator COL ?ROW?\n");
      rc = 1;

** interface returns SQLITE_OK and fills in the non-NULL pointers in
** the final five arguments with appropriate values if the specified
** column exists.  ^The sqlite3_table_column_metadata() interface returns
** SQLITE_ERROR and if the specified column does not exist.
** ^If the column-name parameter to sqlite3_table_column_metadata() is a
** NULL pointer, then this routine simply checks for the existence of the
** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
** does not.  If the table name parameter T in a call to
** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
** undefined behavior.
**
** ^The column is identified by the second, third and fourth parameters to
** this function. ^(The second parameter is either the name of the database
** (i.e. "main", "temp", or an attached database) containing the specified
** table or NULL.)^ ^If it is NULL, then all attached databases are searched
** for the table using the same algorithm used by the database engine to
** resolve unqualified table references.

int sqlite3CantopenError(int);
#define SQLITE_CORRUPT_BKPT sqlite3CorruptError(__LINE__)
#define SQLITE_MISUSE_BKPT sqlite3MisuseError(__LINE__)
#define SQLITE_CANTOPEN_BKPT sqlite3CantopenError(__LINE__)
#ifdef SQLITE_DEBUG
  int sqlite3NomemError(int);
  int sqlite3IoerrnomemError(int);
  int sqlite3CorruptPgnoError(int,Pgno);
# define SQLITE_NOMEM_BKPT sqlite3NomemError(__LINE__)
# define SQLITE_IOERR_NOMEM_BKPT sqlite3IoerrnomemError(__LINE__)
# define SQLITE_CORRUPT_PGNO(P) sqlite3CorruptPgnoError(__LINE__,(P))
#else
# define SQLITE_NOMEM_BKPT SQLITE_NOMEM
# define SQLITE_IOERR_NOMEM_BKPT SQLITE_IOERR_NOMEM
# define SQLITE_CORRUPT_PGNO(P) sqlite3CorruptError(__LINE__)
#endif

/*
** FTS3 and FTS4 both require virtual table support
*/
#if defined(SQLITE_OMIT_VIRTUALTABLE)
# undef SQLITE_ENABLE_FTS3

    char *z;

    /* Make an entry in the sqlite_master table */
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) goto triggerfinish_cleanup;
    sqlite3BeginWriteOperation(pParse, 0, iDb);
    z = sqlite3DbStrNDup(db, (char*)pAll->z, pAll->n);
    testcase( z==0 );
    sqlite3NestedParse(pParse,
       "INSERT INTO %Q.%s VALUES('trigger',%Q,%Q,0,'CREATE TRIGGER %q')",
       db->aDb[iDb].zDbSName, MASTER_NAME, zName,
       pTrig->table, z);
    sqlite3DbFree(db, z);
    sqlite3ChangeCookie(pParse, iDb);
    sqlite3VdbeAddParseSchemaOp(v, iDb,

  execsql { INSERT INTO t1 SELECT NULL, randstr(50,50) FROM t1 }
} {}
do_test autovacuum-9.5 {
  execsql { DELETE FROM t1 WHERE rowid > (SELECT max(a)/2 FROM t1) }
  file size test.db
} $::sqlite_pending_byte
 
do_execsql_test autovacuum-10.1 {
  DROP TABLE t1;
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
  INSERT INTO t1 VALUES(25, randomblob(104));
  REPLACE INTO t1 VALUES(25, randomblob(1117));
  PRAGMA integrity_check;
} {ok}

finish_test