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Overview
Comment:Fix a faulty assert() in the validation logic for the LEFT JOIN strength reduction optimization. Problem found by OSSFuzz.
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SHA3-256: 2fd62fccd13e326dbd7dd730112542c6faa56e466bf4f7b8e22ced543031280c
User & Date: drh 2018-09-23 02:01:42.716
Context
2018-09-24
19:32
Fix a faulty assert() in the validation logic for the LEFT JOIN strength reduction optimization. Problem found by OSSFuzz. (check-in: 8694c3d565 user: drh tags: branch-3.25)
10:47
Increase the initial value of WhereLoopBuilder.iPlanLimit to 20K. Issue a warning if the iPlanLimit reaches zero. (check-in: 3dd35f5118 user: drh tags: trunk)
2018-09-23
02:01
Fix a faulty assert() in the validation logic for the LEFT JOIN strength reduction optimization. Problem found by OSSFuzz. (check-in: 2fd62fccd1 user: drh tags: trunk)
2018-09-22
15:05
Enhance WhereLoopBuilder.iPlanLimit to handle a case involving the OR optimization discovered overnight by OSSFuzz. (check-in: 7b59930a1d user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/expr.c.
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  }
  return 0;
}

/*
** This is the Expr node callback for sqlite3ExprImpliesNotNullRow().
** If the expression node requires that the table at pWalker->iCur
** have a non-NULL column, then set pWalker->eCode to 1 and abort.




*/
static int impliesNotNullRow(Walker *pWalker, Expr *pExpr){
  /* This routine is only called for WHERE clause expressions and so it
  ** cannot have any TK_AGG_COLUMN entries because those are only found
  ** in HAVING clauses.  We can get a TK_AGG_FUNCTION in a WHERE clause,
  ** but that is an illegal construct and the query will be rejected at
  ** a later stage of processing, so the TK_AGG_FUNCTION case does not
  ** need to be considered here. */
  assert( pExpr->op!=TK_AGG_COLUMN );
  testcase( pExpr->op==TK_AGG_FUNCTION );

  if( ExprHasProperty(pExpr, EP_FromJoin) ) return WRC_Prune;
  switch( pExpr->op ){
    case TK_ISNOT:
    case TK_NOT:
    case TK_ISNULL:
    case TK_IS:
    case TK_OR:








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>
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>
>


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<








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  }
  return 0;
}

/*
** This is the Expr node callback for sqlite3ExprImpliesNotNullRow().
** If the expression node requires that the table at pWalker->iCur
** have one or more non-NULL column, then set pWalker->eCode to 1 and abort.
**
** This routine controls an optimization.  False positives (setting
** pWalker->eCode to 1 when it should not be) are deadly, but false-negatives
** (never setting pWalker->eCode) is a harmless missed optimization.
*/
static int impliesNotNullRow(Walker *pWalker, Expr *pExpr){






  testcase( pExpr->op==TK_AGG_COLUMN );
  testcase( pExpr->op==TK_AGG_FUNCTION );

  if( ExprHasProperty(pExpr, EP_FromJoin) ) return WRC_Prune;
  switch( pExpr->op ){
    case TK_ISNOT:
    case TK_NOT:
    case TK_ISNULL:
    case TK_IS:
    case TK_OR:
︙︙
Changes to test/fuzzdata5.db.

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