From cc3a4f0c5f5a37b8026a0b04bb773677cb3a5a31 Mon Sep 17 00:00:00 2001
From: JianBo He <heeejianbo@gmail.com>
Date: Tue, 22 Feb 2022 14:42:10 +0800
Subject: [PATCH] chore: don't send subscribe msg if topic list is empty

---
 apps/emqx_auto_subscribe/src/emqx_auto_subscribe.erl | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/apps/emqx_auto_subscribe/src/emqx_auto_subscribe.erl b/apps/emqx_auto_subscribe/src/emqx_auto_subscribe.erl
index 134248920..03bacca68 100644
--- a/apps/emqx_auto_subscribe/src/emqx_auto_subscribe.erl
+++ b/apps/emqx_auto_subscribe/src/emqx_auto_subscribe.erl
@@ -60,8 +60,12 @@ test(_) ->
 %% hook
 
 on_client_connected(ClientInfo, ConnInfo, {TopicHandler, Options}) ->
-    TopicTables = erlang:apply(TopicHandler, handle, [ClientInfo, ConnInfo, Options]),
-    self() ! {subscribe, TopicTables};
+    case erlang:apply(TopicHandler, handle, [ClientInfo, ConnInfo, Options]) of
+        [] -> ok;
+        TopicTables ->
+            _ = self() ! {subscribe, TopicTables},
+            ok
+    end;
 on_client_connected(_, _, _) ->
     ok.