Fix compilation: use 9.4 version of SyncRepGetStandbyPriority

Author: Asim R P

src/backend/replication/syncrep.c

@@ -856,8 +856,10 @@ SyncRepGetSyncStandbys(bool *am_sync)
 static int
 SyncRepGetStandbyPriority(void)
 {
-	const char *standby_name;
-	int			priority;
+	char	   *rawstring;
+	List	   *elemlist;
+	ListCell   *l;
+	int			priority = 0;
 	bool		found = false;
 
 	/*
@@ -867,29 +869,37 @@ SyncRepGetStandbyPriority(void)
 	if (am_cascading_walsender)
 		return 0;
 
-	if (!SyncStandbysDefined() || SyncRepConfig == NULL)
+	/* Need a modifiable copy of string */
+	rawstring = pstrdup(SyncRepStandbyNames);
+
+	/* Parse string into list of identifiers */
+	if (!SplitIdentifierString(rawstring, ',', &elemlist))
+	{
+		/* syntax error in list */
+		pfree(rawstring);
+		list_free(elemlist);
+		/* GUC machinery will have already complained - no need to do again */
 		return 0;
+	}
 
-	standby_name = SyncRepConfig->member_names;
-	for (priority = 1; priority <= SyncRepConfig->nmembers; priority++)
+	foreach(l, elemlist)
 	{
+		char	   *standby_name = (char *) lfirst(l);
+
+		priority++;
+
 		if (pg_strcasecmp(standby_name, application_name) == 0 ||
-			strcmp(standby_name, "*") == 0)
+			pg_strcasecmp(standby_name, "*") == 0)
 		{
 			found = true;
 			break;
 		}
-		standby_name += strlen(standby_name) + 1;
 	}
 
-	if (!found)
-		return 0;
+	pfree(rawstring);
+	list_free(elemlist);
 
-	/*
-	 * In quorum-based sync replication, all the standbys in the list have the
-	 * same priority, one.
-	 */
-	return (SyncRepConfig->syncrep_method == SYNC_REP_PRIORITY) ? priority : 1;
+	return (found ? priority : 0);
 }
 
 /*