SQLite

      pUnpack = vdbeUnpackRecord(&p->keyinfo, pData->n, pData->z);
      if( !pUnpack ){
        rc = SQLITE_NOMEM;
        goto preupdate_new_out;
      }
      p->pNewUnpacked = pUnpack;
    }



    pMem = &pUnpack->aMem[iIdx];
    if( iIdx==p->pTab->iPKey ){
      sqlite3VdbeMemSetInt64(pMem, p->iKey2);

    }else if( iIdx>=pUnpack->nField ){
      pMem = (sqlite3_value *)columnNullValue();
    }
  }else{
    /* For an UPDATE, memory cell (p->iNewReg+1+iIdx) contains the required
    ** value. Make a copy of the cell contents and return a pointer to it.
    ** It is not safe to return a pointer to the memory cell itself as the
    ** caller may modify the value text encoding.
    */

** If the second argument is not NULL, release any allocations associated 
** with the memory cells in the p->aMem[] array. Also free the UnpackedRecord
** structure itself, using sqlite3DbFree().
**
** This function is used to free UnpackedRecord structures allocated by
** the vdbeUnpackRecord() function found in vdbeapi.c.
*/
static void vdbeFreeUnpacked(sqlite3 *db, int nField, UnpackedRecord *p){
  if( p ){
    int i;
    for(i=0; i<nField; i++){
      Mem *pMem = &p->aMem[i];
      if( pMem->zMalloc ) sqlite3VdbeMemRelease(pMem);
    }
    sqlite3DbFree(db, p);
  }
}
#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

  preupdate.iKey2 = iKey2;
  preupdate.pTab = pTab;

  db->pPreUpdate = &preupdate;
  db->xPreUpdateCallback(db->pPreUpdateArg, db, op, zDb, zTbl, iKey1, iKey2);
  db->pPreUpdate = 0;
  sqlite3DbFree(db, preupdate.aRecord);
  vdbeFreeUnpacked(db, preupdate.keyinfo.nField+1, preupdate.pUnpacked);
  vdbeFreeUnpacked(db, preupdate.keyinfo.nField+1, preupdate.pNewUnpacked);
  if( preupdate.aNew ){
    int i;
    for(i=0; i<pCsr->nField; i++){
      sqlite3VdbeMemRelease(&preupdate.aNew[i]);
    }
    sqlite3DbFree(db, preupdate.aNew);
  }
}
#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

}

# No preupdate callbacks for modifying sqlite_master.
do_preupdate_test 8.1 {
  CREATE TABLE x1(x, y);
} {
}

#-------------------------------------------------------------------------
reset_db
db preupdate hook preupdate_hook
do_execsql_test 9.0 {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c);
  CREATE TABLE t2(a, b INTEGER PRIMARY KEY);
}
do_preupdate_test 9.1 {
  INSERT INTO t1 VALUES(456, NULL, NULL);
} {
  INSERT main t1 456 456  0  456 {} {}
}
do_execsql_test 9.2 {
  ALTER TABLE t1 ADD COLUMN d;
}
do_preupdate_test 9.3 {
  INSERT INTO t1(a, b, c) VALUES(457, NULL, NULL);
} {
  INSERT main t1 457 457  0  457 {} {} {}
}
do_preupdate_test 9.4 {
  DELETE FROM t1 WHERE a=456
} {
  DELETE main t1 456 456  0  456 {} {} {}
}
do_preupdate_test 9.5 {
  INSERT INTO t2 DEFAULT VALUES;
} {
  INSERT main t2 1 1  0  {} 1
} 
do_preupdate_test 9.6 {
  INSERT INTO t1 DEFAULT VALUES;
} {
  INSERT main t1 458 458  0  458 {} {} {}
} 

finish_test

        foreach {dummy cmdlinearg(malloctrace)} [split $a =] break
        if {$cmdlinearg(malloctrace)} {
          sqlite3_memdebug_log start
        }
      }
      {^-+backtrace=.+$} {
        foreach {dummy cmdlinearg(backtrace)} [split $a =] break
        sqlite3_memdebug_backtrace $cmdlinearg(backtrace)
      }
      {^-+binarylog=.+$} {
        foreach {dummy cmdlinearg(binarylog)} [split $a =] break
        set cmdlinearg(binarylog) [file normalize $cmdlinearg(binarylog)]
      }
      {^-+soak=.+$} {
        foreach {dummy cmdlinearg(soak)} [split $a =] break