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Overview
Comment:Fix a problem in vdbe.c that could cause a double-free of memory if the SQLITE_LIMIT_LENGTH is changed after a statement is prepared but before it is run. Also remove debugging statements from tkt3841.test. (CVS 6777)
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SHA1: 3d7327fd6af983d5ce9bc9a2ba869b23c44cc8e6
User & Date: drh 2009-06-17 21:42:34
Context
2009-06-17
22:50
Avoid an assertion fault if an out-of-memory error occurs while trying to run the string-concatentation operator on a zero-blob. (This is an absurd thing to do, but even so, we still should not fault.) (CVS 6778) check-in: 0def0b76 user: drh tags: trunk
21:42
Fix a problem in vdbe.c that could cause a double-free of memory if the SQLITE_LIMIT_LENGTH is changed after a statement is prepared but before it is run. Also remove debugging statements from tkt3841.test. (CVS 6777) check-in: 3d7327fd user: drh tags: trunk
16:20
Use caution to avoid integer overflow when doing real to integer affinity operations. Ticket #3922. (CVS 6776) check-in: 39255946 user: drh tags: trunk
Changes
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Changes to src/vdbe.c.

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**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.852 2009/06/17 16:20:04 drh Exp $
*/
#include "sqliteInt.h"
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor
** moves, either by the OP_SeekXX, OP_Next, or OP_Prev opcodes.  The test
................................................................................
case OP_String8: {         /* same as TK_STRING, out2-prerelease */
  assert( pOp->p4.z!=0 );
  pOp->opcode = OP_String;
  pOp->p1 = sqlite3Strlen30(pOp->p4.z);

#ifndef SQLITE_OMIT_UTF16
  if( encoding!=SQLITE_UTF8 ){
    sqlite3VdbeMemSetStr(pOut, pOp->p4.z, -1, SQLITE_UTF8, SQLITE_STATIC);

    if( SQLITE_OK!=sqlite3VdbeChangeEncoding(pOut, encoding) ) goto no_mem;
    if( SQLITE_OK!=sqlite3VdbeMemMakeWriteable(pOut) ) goto no_mem;


    pOut->zMalloc = 0;
    pOut->flags |= MEM_Static;
    pOut->flags &= ~MEM_Dyn;
    if( pOp->p4type==P4_DYNAMIC ){
      sqlite3DbFree(db, pOp->p4.z);
    }
    pOp->p4type = P4_DYNAMIC;
    pOp->p4.z = pOut->z;
    pOp->p1 = pOut->n;
    if( pOp->p1>db->aLimit[SQLITE_LIMIT_LENGTH] ){
      goto too_big;
    }
    UPDATE_MAX_BLOBSIZE(pOut);
    break;
  }
#endif
  if( pOp->p1>db->aLimit[SQLITE_LIMIT_LENGTH] ){
    goto too_big;
  }
  /* Fall through to the next case, OP_String */
}







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**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.853 2009/06/17 21:42:34 drh Exp $
*/
#include "sqliteInt.h"
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor
** moves, either by the OP_SeekXX, OP_Next, or OP_Prev opcodes.  The test
................................................................................
case OP_String8: {         /* same as TK_STRING, out2-prerelease */
  assert( pOp->p4.z!=0 );
  pOp->opcode = OP_String;
  pOp->p1 = sqlite3Strlen30(pOp->p4.z);

#ifndef SQLITE_OMIT_UTF16
  if( encoding!=SQLITE_UTF8 ){
    rc = sqlite3VdbeMemSetStr(pOut, pOp->p4.z, -1, SQLITE_UTF8, SQLITE_STATIC);
    if( rc==SQLITE_TOOBIG ) goto too_big;
    if( SQLITE_OK!=sqlite3VdbeChangeEncoding(pOut, encoding) ) goto no_mem;

    assert( pOut->zMalloc==pOut->z );
    assert( pOut->flags & MEM_Dyn );
    pOut->zMalloc = 0;
    pOut->flags |= MEM_Static;
    pOut->flags &= ~MEM_Dyn;
    if( pOp->p4type==P4_DYNAMIC ){
      sqlite3DbFree(db, pOp->p4.z);
    }
    pOp->p4type = P4_DYNAMIC;
    pOp->p4.z = pOut->z;
    pOp->p1 = pOut->n;





  }
#endif
  if( pOp->p1>db->aLimit[SQLITE_LIMIT_LENGTH] ){
    goto too_big;
  }
  /* Fall through to the next case, OP_String */
}

Changes to test/tkt3841.test.

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    INSERT INTO list VALUES ("a", 1);
    INSERT INTO list VALUES ("a", 2);
    INSERT INTO list VALUES ("a", 3);
    INSERT INTO list VALUES ("b", 4);
    INSERT INTO list VALUES ("b", 5);
    INSERT INTO list VALUES ("b", 6);

pragma vdbe_listing=on; pragma vdbe_trace=on;  
    SELECT
      table2.x,
      (SELECT group_concat(list.value)
        FROM list
        WHERE list.key = table2.key)
    FROM table2;
  }
} {alist 1,2,3 blist 4,5,6}

finish_test







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    INSERT INTO list VALUES ("a", 1);
    INSERT INTO list VALUES ("a", 2);
    INSERT INTO list VALUES ("a", 3);
    INSERT INTO list VALUES ("b", 4);
    INSERT INTO list VALUES ("b", 5);
    INSERT INTO list VALUES ("b", 6);


    SELECT
      table2.x,
      (SELECT group_concat(list.value)
        FROM list
        WHERE list.key = table2.key)
    FROM table2;
  }
} {alist 1,2,3 blist 4,5,6}

finish_test