int ii;            /* Iterator variable */
    int nNew;          /* Number of remaining savepoints after this op. */

    /* Figure out how many savepoints will still be active after this
    ** operation. Store this value in nNew. Then free resources associated 
    ** with any savepoints that are destroyed by this operation.
    */
    nNew = iSavepoint + (op==SAVEPOINT_ROLLBACK);
    for(ii=nNew; ii<pPager->nSavepoint; ii++){
      sqlite3BitvecDestroy(pPager->aSavepoint[ii].pInSavepoint);
    }
    pPager->nSavepoint = nNew;












    /* If this is a rollback operation, playback the specified savepoint.
    ** If this is a temp-file, it is possible that the journal file has
    ** not yet been opened. In this case there have been no changes to
    ** the database file, so the playback operation can be skipped.
    */
    if( op==SAVEPOINT_ROLLBACK && isOpen(pPager->jfd) ){
      PagerSavepoint *pSavepoint = (nNew==0)?0:&pPager->aSavepoint[nNew-1];
      rc = pagerPlaybackSavepoint(pPager, pSavepoint);
      assert(rc!=SQLITE_DONE);
    }
  
    /* If this is a release of the outermost savepoint, truncate 
    ** the sub-journal to zero bytes in size. */
    if( nNew==0 && op==SAVEPOINT_RELEASE && isOpen(pPager->sjfd) ){
      assert( rc==SQLITE_OK );
      rc = sqlite3OsTruncate(pPager->sjfd, 0);
      pPager->nSubRec = 0;
    }
  }
  return rc;
}

/*
** Return the full pathname of the database file.
*/

    int ii;            /* Iterator variable */
    int nNew;          /* Number of remaining savepoints after this op. */

    /* Figure out how many savepoints will still be active after this
    ** operation. Store this value in nNew. Then free resources associated 
    ** with any savepoints that are destroyed by this operation.
    */
    nNew = iSavepoint + (( op==SAVEPOINT_RELEASE ) ? 0 : 1);
    for(ii=nNew; ii<pPager->nSavepoint; ii++){
      sqlite3BitvecDestroy(pPager->aSavepoint[ii].pInSavepoint);
    }
    pPager->nSavepoint = nNew;

    /* If this is a release of the outermost savepoint, truncate 
    ** the sub-journal to zero bytes in size. */
    if( op==SAVEPOINT_RELEASE ){
      if( nNew==0 && isOpen(pPager->sjfd) ){
        /* Only truncate if it is an in-memory sub-journal. */
        if( sqlite3IsMemJournal(pPager->sjfd) ){
          rc = sqlite3OsTruncate(pPager->sjfd, 0);
        }
        pPager->nSubRec = 0;
      }
    }
    /* Else this is a rollback operation, playback the specified savepoint.
    ** If this is a temp-file, it is possible that the journal file has
    ** not yet been opened. In this case there have been no changes to
    ** the database file, so the playback operation can be skipped.
    */
    else if( isOpen(pPager->jfd) ){
      PagerSavepoint *pSavepoint = (nNew==0)?0:&pPager->aSavepoint[nNew-1];
      rc = pagerPlaybackSavepoint(pPager, pSavepoint);
      assert(rc!=SQLITE_DONE);
    }
  







  }
  return rc;
}

/*
** Return the full pathname of the database file.
*/

    ** unreferenced dirty page.
    */
    expensive_assert( pcacheCheckSynced(pCache) );
    for(pPg=pCache->pSynced; 
        pPg && (pPg->nRef || (pPg->flags&PGHDR_NEED_SYNC)); 
        pPg=pPg->pDirtyPrev
    );

    if( !pPg ){
      for(pPg=pCache->pDirtyTail; pPg && pPg->nRef; pPg=pPg->pDirtyPrev);
    }
    if( pPg ){
      int rc;
      rc = pCache->xStress(pCache->pStress, pPg);
      if( rc!=SQLITE_OK && rc!=SQLITE_BUSY ){

    ** unreferenced dirty page.
    */
    expensive_assert( pcacheCheckSynced(pCache) );
    for(pPg=pCache->pSynced; 
        pPg && (pPg->nRef || (pPg->flags&PGHDR_NEED_SYNC)); 
        pPg=pPg->pDirtyPrev
    );
    pCache->pSynced = pPg;
    if( !pPg ){
      for(pPg=pCache->pDirtyTail; pPg && pPg->nRef; pPg=pPg->pDirtyPrev);
    }
    if( pPg ){
      int rc;
      rc = pCache->xStress(pCache->pStress, pPg);
      if( rc!=SQLITE_OK && rc!=SQLITE_BUSY ){

  int i;             /* Loop counter */
  char *zData;       /* Part of the record being decoded */
  Mem *pDest;        /* Where to write the extracted value */
  Mem sMem;          /* For storing the record being decoded */
  u8 *zIdx;          /* Index into header */
  u8 *zEndHdr;       /* Pointer to first byte after the header */
  u32 offset;        /* Offset into the data */
  u64 offset64;      /* 64-bit offset.  64 bits needed to catch overflow */
  int szHdr;         /* Size of the header size field at start of record */
  int avail;         /* Number of bytes of available data */
  Mem *pReg;         /* PseudoTable input register */


  p1 = pOp->p1;
  p2 = pOp->p2;
................................................................................
    zIdx = (u8 *)&zData[szHdr];

    /* Scan the header and use it to fill in the aType[] and aOffset[]
    ** arrays.  aType[i] will contain the type integer for the i-th
    ** column and aOffset[i] will contain the offset from the beginning
    ** of the record to the start of the data for the i-th column
    */
    offset64 = offset;
    for(i=0; i<nField; i++){
      if( zIdx<zEndHdr ){
        aOffset[i] = (u32)offset64;
        zIdx += getVarint32(zIdx, aType[i]);
        offset64 += sqlite3VdbeSerialTypeLen(aType[i]);





      }else{
        /* If i is less that nField, then there are less fields in this
        ** record than SetNumColumns indicated there are columns in the
        ** table. Set the offset for any extra columns not present in
        ** the record to 0. This tells code below to store a NULL
        ** instead of deserializing a value from the record.
        */
................................................................................

    /* If we have read more header data than was contained in the header,
    ** or if the end of the last field appears to be past the end of the
    ** record, or if the end of the last field appears to be before the end
    ** of the record (when all fields present), then we must be dealing 
    ** with a corrupt database.
    */
    if( (zIdx > zEndHdr)|| (offset64 > payloadSize)
     || (zIdx==zEndHdr && offset64!=(u64)payloadSize) ){
      rc = SQLITE_CORRUPT_BKPT;
      goto op_column_out;
    }
  }

  /* Get the column information. If aOffset[p2] is non-zero, then 
  ** deserialize the value from the record. If aOffset[p2] is zero,

  int i;             /* Loop counter */
  char *zData;       /* Part of the record being decoded */
  Mem *pDest;        /* Where to write the extracted value */
  Mem sMem;          /* For storing the record being decoded */
  u8 *zIdx;          /* Index into header */
  u8 *zEndHdr;       /* Pointer to first byte after the header */
  u32 offset;        /* Offset into the data */
  u32 szField;       /* Number of bytes in the content of a field */
  int szHdr;         /* Size of the header size field at start of record */
  int avail;         /* Number of bytes of available data */
  Mem *pReg;         /* PseudoTable input register */


  p1 = pOp->p1;
  p2 = pOp->p2;
................................................................................
    zIdx = (u8 *)&zData[szHdr];

    /* Scan the header and use it to fill in the aType[] and aOffset[]
    ** arrays.  aType[i] will contain the type integer for the i-th
    ** column and aOffset[i] will contain the offset from the beginning
    ** of the record to the start of the data for the i-th column
    */

    for(i=0; i<nField; i++){
      if( zIdx<zEndHdr ){
        aOffset[i] = offset;
        zIdx += getVarint32(zIdx, aType[i]);
        szField = sqlite3VdbeSerialTypeLen(aType[i]);
        offset += szField;
        if( offset<szField ){  /* True if offset overflows */
          zIdx = &zEndHdr[1];  /* Forces SQLITE_CORRUPT return below */
          break;
        }
      }else{
        /* If i is less that nField, then there are less fields in this
        ** record than SetNumColumns indicated there are columns in the
        ** table. Set the offset for any extra columns not present in
        ** the record to 0. This tells code below to store a NULL
        ** instead of deserializing a value from the record.
        */
................................................................................

    /* If we have read more header data than was contained in the header,
    ** or if the end of the last field appears to be past the end of the
    ** record, or if the end of the last field appears to be before the end
    ** of the record (when all fields present), then we must be dealing 
    ** with a corrupt database.
    */
    if( (zIdx > zEndHdr) || (offset > payloadSize)
         || (zIdx==zEndHdr && offset!=payloadSize) ){
      rc = SQLITE_CORRUPT_BKPT;
      goto op_column_out;
    }
  }

  /* Get the column information. If aOffset[p2] is non-zero, then 
  ** deserialize the value from the record. If aOffset[p2] is zero,