From cc0cac4a49b678e0c2b41020581036381385db5e Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Tue, 6 Mar 2007 22:45:16 +0000
Subject: [PATCH] Fix oversight in original coding of inline_function(): since
check_sql_fn_retval allows binary-compatibility cases, the expression
extracted from an inline-able SQL function might have a type that is only
binary-compatible with the declared function result type. To avoid possibly
changing the semantics of the expression, we should insert a RelabelType node
in such cases. This has only been shown to have bad consequences in recent
8.1 and up releases, but I suspect there may be failure cases in the older
branches too, so patch it all the way back. Per bug #3116 from Greg Mullane.
Along the way, fix an omission in eval_const_expressions_mutator: it failed
to copy the relabelformat field when processing a RelabelType. No known
observable failures from this, but it definitely isn't intended behavior.
---
src/backend/optimizer/util/clauses.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 852b0f533e7..0f8231c4f91 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.236 2007/02/22 22:00:24 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.237 2007/03/06 22:45:16 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@@ -1976,6 +1976,7 @@ eval_const_expressions_mutator(Node *node,
newrelabel->arg = (Expr *) arg;
newrelabel->resulttype = relabel->resulttype;
newrelabel->resulttypmod = relabel->resulttypmod;
+ newrelabel->relabelformat = relabel->relabelformat;
return (Node *) newrelabel;
}
}
@@ -2929,7 +2930,8 @@ inline_function(Oid funcid, Oid result_type, List *args,
* no rewriting was needed; that's probably not important, but let's be
* careful.
*/
- (void) check_sql_fn_retval(funcid, result_type, querytree_list, NULL);
+ if (check_sql_fn_retval(funcid, result_type, querytree_list, NULL))
+ goto fail; /* reject whole-tuple-result cases */
/*
* Additional validity checks on the expression. It mustn't return a set,
@@ -3014,6 +3016,21 @@ inline_function(Oid funcid, Oid result_type, List *args,
MemoryContextDelete(mycxt);
+ /*
+ * Since check_sql_fn_retval allows binary-compatibility cases, the
+ * expression we now have might return some type that's only binary
+ * compatible with the original expression result type. To avoid
+ * confusing matters, insert a RelabelType in such cases.
+ */
+ if (exprType(newexpr) != funcform->prorettype)
+ {
+ Assert(IsBinaryCoercible(exprType(newexpr), funcform->prorettype));
+ newexpr = (Node *) makeRelabelType((Expr *) newexpr,
+ funcform->prorettype,
+ -1,
+ COERCE_IMPLICIT_CAST);
+ }
+
/*
* Recursively try to simplify the modified expression. Here we must add
* the current function to the context list of active functions.
--
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