Initialize all constants at the very beginning of a prepared statement.
Do not allow constant initialization to occur once control flow has a chance
to diverge, to avoid the possibility of having uninitialized registers.
Ticket [80ba201079ea60807].
FossilOrigin-Name: c5c53152d68218bb5e7f922271dd7c50da2361c1
diff --git a/src/expr.c b/src/expr.c
index a88208b..d2fa682 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1655,6 +1655,7 @@
sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
dest.affinity = (u8)affinity;
assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
+ pExpr->x.pSelect->iLimit = 0;
if( sqlite3Select(pParse, pExpr->x.pSelect, &dest) ){
return 0;
}
@@ -1755,6 +1756,7 @@
sqlite3ExprDelete(pParse->db, pSel->pLimit);
pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0,
&sqlite3IntTokens[1]);
+ pSel->iLimit = 0;
if( sqlite3Select(pParse, pSel, &dest) ){
return 0;
}
@@ -3034,6 +3036,17 @@
return WRC_Continue;
}
+/* This routine is part of the parse-tree walker for
+** sqlite3ExprCodeConstants(). Simply return WRC_Continue so that
+** tree walker logic will extend constant extraction and precoding
+** into subqueires.
+*/
+static int evalConstSelect(Walker *pNotUsed1, Select *pNotUsed2){
+ UNUSED_PARAMETER(pNotUsed1);
+ UNUSED_PARAMETER(pNotUsed2);
+ return WRC_Continue;
+}
+
/*
** Preevaluate constant subexpressions within pExpr and store the
** results in registers. Modify pExpr so that the constant subexpresions
@@ -3041,8 +3054,9 @@
*/
void sqlite3ExprCodeConstants(Parse *pParse, Expr *pExpr){
Walker w;
+ if( pParse->cookieGoto ) return;
w.xExprCallback = evalConstExpr;
- w.xSelectCallback = 0;
+ w.xSelectCallback = evalConstSelect;
w.pParse = pParse;
sqlite3WalkExpr(&w, pExpr);
}