Fix bogus CALLED_AS_TRIGGER() defenses.

contrib/lo's lo_manage() thought it could use
trigdata->tg_trigger->tgname in its error message about
not being called as a trigger.  That naturally led to a core dump.

unique_key_recheck() figured it could Assert that fcinfo->context
is a TriggerData node in advance of having checked that it's
being called as a trigger.  That's harmless in production builds,
and perhaps not that easy to reach in any case, but it's logically
wrong.

The first of these per bug #16340 from William Crowell;
the second from manual inspection of other CALLED_AS_TRIGGER
call sites.

Back-patch the lo.c change to all supported branches, the
other to v10 where the thinko crept in.

Discussion: https://postgr.es/m/16340-591c7449dc7c8c47@postgresql.org

diff --git a/contrib/lo/lo.c b/contrib/lo/lo.c
index 953659305fbde7b13c4be23dfbd9aea1b6a3c93e..2b450b8ea8c6739aae904da18e3eb7e9b7ccd306 100644 (file)
--- a/contrib/lo/lo.c
+++ b/contrib/lo/lo.c
@@ -35,8 +35,7 @@ lo_manage(PG_FUNCTION_ARGS)
        HeapTuple       trigtuple;              /* The original value of tuple  */
 
        if (!CALLED_AS_TRIGGER(fcinfo))         /* internal error */
-               elog(ERROR, "%s: not fired by trigger manager",
-                        trigdata->tg_trigger->tgname);
+               elog(ERROR, "lo_manage: not fired by trigger manager");
 
        if (!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))         /* internal error */
                elog(ERROR, "%s: must be fired for row",