--- \dll\postgresql-12.0\a\backend\commands\event_trigger.c	Mon Sep 30 17:06:55 2019
+++ event_trigger.c	Tue Nov 12 08:34:30 2019
@@ -171,7 +171,7 @@
 	HeapTuple	tuple;
 	Oid			funcoid;
 	Oid			funcrettype;
-	Oid			fargtypes[1];	/* dummy */
+	Oid			fargtypes[1] = {InvalidOid};	/* dummy */
 	Oid			evtowner = GetUserId();
 	ListCell   *lc;
 	List	   *tags = NULL;