v2-0001-Use-ereport-rather-than-elog-in-WinCheckAndInitia.patch

From 976de4af0951a49e9fa55fad03f0582a4e77e7f5 Mon Sep 17 00:00:00 2001
From: Tatsuo Ishii <ishii@postgresql.org>
Date: Mon, 13 Oct 2025 14:32:01 +0900
Subject: [PATCH v2] Use ereport rather than elog in
 WinCheckAndInitializeNullTreatment.

Previously WinCheckAndInitializeNullTreatment() used elog() to emit an
error message. ereport() should be used instead because it's a
user-facing error. Also use existing get_func_name() to get a
function's name, rather than own implementation.

In addition to them, add an assertion to validate winobj parameter,
just like other window function API.

Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Author: Tatsuo Ishii <ishii@postgresql.org>
Reviewed-by: Chao Li <lic@highgo.com>
Discussion: https://postgr.es/m/2952409.1760023154%40sss.pgh.pa.us
---
 src/backend/executor/nodeWindowAgg.c | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c
index e6a53f95391..47e00be7b49 100644
--- a/src/backend/executor/nodeWindowAgg.c
+++ b/src/backend/executor/nodeWindowAgg.c
@@ -3538,24 +3538,20 @@ WinCheckAndInitializeNullTreatment(WindowObject winobj,
 								   bool allowNullTreatment,
 								   FunctionCallInfo fcinfo)
 {
+	Assert(WindowObjectIsValid(winobj));
 	if (winobj->ignore_nulls != NO_NULLTREATMENT && !allowNullTreatment)
 	{
-		HeapTuple	proctup;
-		Form_pg_proc procform;
-		Oid			funcid;
+		const char *funcname = get_func_name(fcinfo->flinfo->fn_oid);
 
-		funcid = fcinfo->flinfo->fn_oid;
-		proctup = SearchSysCache1(PROCOID,
-								  ObjectIdGetDatum(funcid));
-		if (!HeapTupleIsValid(proctup))
-			elog(ERROR, "cache lookup failed for function %u", funcid);
-		procform = (Form_pg_proc) GETSTRUCT(proctup);
-		elog(ERROR, "function %s does not allow RESPECT/IGNORE NULLS",
-			 NameStr(procform->proname));
+		if (!funcname)
+			elog(ERROR, "could not get function name");
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("function %s does not allow RESPECT/IGNORE NULLS",
+						funcname)));
 	}
 	else if (winobj->ignore_nulls == PARSER_IGNORE_NULLS)
 		winobj->ignore_nulls = IGNORE_NULLS;
-
 }
 
 /*
-- 
2.43.0