Merge pull request #2836 from emqx/fix-discard

Fix case clause error

src/emqx_channel.erl

@@ -610,9 +610,6 @@ handle_call(Req, Channel) ->
 %% Handle cast
 %%--------------------------------------------------------------------
 
-handle_cast(discard, Channel) ->
-    {stop, {shutdown, discarded}, Channel};
-
 handle_cast(Msg, Channel) ->
     ?LOG(error, "Unexpected cast: ~p", [Msg]),
     {ok, Channel}.

src/emqx_cm.erl

@@ -233,7 +233,7 @@ discard_session(ClientId) when is_binary(ClientId) ->
 
 discard_session(ClientId, ChanPid) when node(ChanPid) == node() ->
     case get_chan_attrs(ClientId, ChanPid) of
-        #{conn_mod := ConnMod} ->
+        #{client := #{conn_mod := ConnMod}} ->
             ConnMod:discard(ChanPid);
         undefined -> ok
     end;