diff options
| author | drh <drh@noemail.net> | 2018-09-23 02:01:42 +0000 |
|---|---|---|
| committer | drh <drh@noemail.net> | 2018-09-23 02:01:42 +0000 |
| commit | f8937f9034e4df499734ec7bb330616a49ad6d1f (patch) | |
| tree | a0d384213bafc511254cf4da656a55bf467e73ee /src/expr.c | |
| parent | 2c3ba949697f5e4d2fe657c6bc49275a94ee2a25 (diff) | |
| download | sqlite-f8937f9034e4df499734ec7bb330616a49ad6d1f.tar.gz sqlite-f8937f9034e4df499734ec7bb330616a49ad6d1f.zip | |
Fix a faulty assert() in the validation logic for the LEFT JOIN strength
reduction optimization. Problem found by OSSFuzz.
FossilOrigin-Name: 2fd62fccd13e326dbd7dd730112542c6faa56e466bf4f7b8e22ced543031280c
Diffstat (limited to 'src/expr.c')
| -rw-r--r-- | src/expr.c | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/src/expr.c b/src/expr.c index 169282284..fa0bcd86a 100644 --- a/src/expr.c +++ b/src/expr.c @@ -4849,18 +4849,15 @@ int sqlite3ExprImpliesExpr(Parse *pParse, Expr *pE1, Expr *pE2, int iTab){ /* ** 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. +** 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){ - /* 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_COLUMN ); testcase( pExpr->op==TK_AGG_FUNCTION ); - if( ExprHasProperty(pExpr, EP_FromJoin) ) return WRC_Prune; switch( pExpr->op ){ case TK_ISNOT: |