Downgrade errors in object_ownercheck() to internal

petere · petere · commit de9037d0d085 · 2025-01-15T16:58:44.000+01:00
The "does not exist" errors in object_ownership() were written as ereport(), suggesting that they are user-facing. But no code path except one can reach this function without first checking that the object exists. If this were actually a user-facing error message, then there would be some problems: get_object_class_descr() is meant to be for internal errors only and does not support translation. The one case that can reach this without first checking the object existence is from be_lo_unlink(). (This makes some sense since large objects are referred to by their OID directly.) In this one case, we can add a line of code to check the object existence explicitly, consistent with other LO code. For the rest, downgrade the error messages to elog()s. The new message wordings are the same as in DropObjectById(). Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://www.postgresql.org/message-id/flat/da2f8942-be6d-48d0-ac1c-a053370a6b1f@eisentraut.org
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
@@ -4082,9 +4082,8 @@ object_ownercheck(Oid classid, Oid objectid, Oid roleid)
 
 		tuple = SearchSysCache1(cacheid, ObjectIdGetDatum(objectid));
 		if (!HeapTupleIsValid(tuple))
-			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_OBJECT),
-					 errmsg("%s with OID %u does not exist", get_object_class_descr(classid), objectid)));
+			elog(ERROR, "cache lookup failed for %s %u",
+				 get_object_class_descr(classid), objectid);
 
 		ownerId = DatumGetObjectId(SysCacheGetAttrNotNull(cacheid,
 														  tuple,
@@ -4113,9 +4112,8 @@ object_ownercheck(Oid classid, Oid objectid, Oid roleid)
 
 		tuple = systable_getnext(scan);
 		if (!HeapTupleIsValid(tuple))
-			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_OBJECT),
-					 errmsg("%s with OID %u does not exist", get_object_class_descr(classid), objectid)));
+			elog(ERROR, "could not find tuple for %s %u",
+				 get_object_class_descr(classid), objectid);
 
 		ownerId = DatumGetObjectId(heap_getattr(tuple,
 												get_object_attnum_owner(classid),
diff --git a/src/backend/libpq/be-fsstubs.c b/src/backend/libpq/be-fsstubs.c
@@ -317,6 +317,11 @@ be_lo_unlink(PG_FUNCTION_ARGS)
 
 	PreventCommandIfReadOnly("lo_unlink()");
 
+	if (!LargeObjectExists(lobjId))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("large object %u does not exist", lobjId)));
+
 	/*
 	 * Must be owner of the large object.  It would be cleaner to check this
 	 * in inv_drop(), but we want to throw the error before not after closing
