diff options
Diffstat (limited to 'src/backend/parser/parse_expr.c')
| -rw-r--r-- | src/backend/parser/parse_expr.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 65d03adc494..79328c99797 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -836,12 +836,15 @@ transformAExprOp(ParseState *pstate, A_Expr *a) /* * Special-case "foo = NULL" and "NULL = foo" for compatibility with * standards-broken products (like Microsoft's). Turn these into IS NULL - * exprs. + * exprs. (If either side is a CaseTestExpr, then the expression was + * generated internally from a CASE-WHEN expression, and + * transform_null_equals does not apply.) */ if (Transform_null_equals && list_length(a->name) == 1 && strcmp(strVal(linitial(a->name)), "=") == 0 && - (exprIsNullConstant(lexpr) || exprIsNullConstant(rexpr))) + (exprIsNullConstant(lexpr) || exprIsNullConstant(rexpr)) && + (!IsA(lexpr, CaseTestExpr) && !IsA(rexpr, CaseTestExpr))) { NullTest *n = makeNode(NullTest); |