Use NIL rather than NULL to represent an empty list.

robertmhaas · robertmhaas · commit 3106829513ab · 2017-06-06T11:21:22.000-04:00
Just to be tidy. Amit Langote Discussion: http://postgr.es/m/9297f80f-e4ab-7dda-33d4-8580bab6d634@lab.ntt.co.jp
diff --git a/src/backend/utils/cache/evtcache.c b/src/backend/utils/cache/evtcache.c
@@ -68,7 +68,7 @@ EventCacheLookup(EventTriggerEvent event)
 	if (EventTriggerCacheState != ETCS_VALID)
 		BuildEventTriggerCache();
 	entry = hash_search(EventTriggerCache, &event, HASH_FIND, NULL);
-	return entry != NULL ? entry->triggerlist : NULL;
+	return entry != NULL ? entry->triggerlist : NIL;
 }
 
 /*

Original file line number	Diff line number	Diff line change
`@@ -68,7 +68,7 @@ EventCacheLookup(EventTriggerEvent event)`
`68`	`68`	`if (EventTriggerCacheState != ETCS_VALID)`
`69`	`69`	`BuildEventTriggerCache();`
`70`	`70`	`entry = hash_search(EventTriggerCache, &event, HASH_FIND, NULL);`
`71`		`- return entry != NULL ? entry->triggerlist : NULL;`
	`71`	`+ return entry != NULL ? entry->triggerlist : NIL;`
`72`	`72`	`}`
`73`	`73`
`74`	`74`	`/*`