Ensure the functions that appear to be constant are not factored out of
expression that originate on the right-hand side of a LEFT JOIN.
Ticket [6710d2f7a13a2997]
FossilOrigin-Name: 500c9152daaf11cf69d778aa8592175f6088337c6667c59af6df3a24cd81eb0e
diff --git a/src/expr.c b/src/expr.c
index 8f02ae5..ef4221f 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -3994,10 +3994,23 @@
break;
}
+ /* TK_IF_NULL_ROW Expr nodes are inserted ahead of expressions
+ ** that derive from the right-hand table of a LEFT JOIN. The
+ ** Expr.iTable value is the table number for the right-hand table.
+ ** The expression is only evaluated if that table is not currently
+ ** on a LEFT JOIN NULL row.
+ */
case TK_IF_NULL_ROW: {
int addrINR;
+ u8 okConstFactor = pParse->okConstFactor;
addrINR = sqlite3VdbeAddOp1(v, OP_IfNullRow, pExpr->iTable);
+ /* Temporarily disable factoring of constant expressions, since
+ ** even though expressions may appear to be constant, they are not
+ ** really constant because they originate from the right-hand side
+ ** of a LEFT JOIN. */
+ pParse->okConstFactor = 0;
inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
+ pParse->okConstFactor = okConstFactor;
sqlite3VdbeJumpHere(v, addrINR);
sqlite3VdbeChangeP3(v, addrINR, inReg);
break;