mod_mam: Don't route error bounces to clients

mod_mam/src/mod_mam.erl

@@ -52,7 +52,8 @@
 %% ejabberd_hooks callbacks.
 -export([receive_stanza/4,
 	 send_stanza/3,
-	 remove_user/2]).
+	 remove_user/2,
+	 drop_mam_error/4]).
 
 %% gen_iq_handler callback.
 -export([handle_iq/3]).
@@ -201,6 +202,8 @@ init({Host, Opts}) ->
 		       remove_user, 50),
     ejabberd_hooks:add(anonymous_purge_hook, Host, ?MODULE,
 		       remove_user, 50),
+    ejabberd_hooks:add(c2s_filter_packet_in, Host, ?MODULE,
+		       drop_mam_error, 50),
     AccessMaxMsgs =
 	gen_mod:get_opt(access_max_user_messages, Opts,
 			fun(A) when is_atom(A) -> A end, max_user_mam_messages),
@@ -246,7 +249,9 @@ terminate(Reason, #state{host = Host}) ->
     ejabberd_hooks:delete(remove_user, Host, ?MODULE,
 			  remove_user, 50),
     ejabberd_hooks:delete(anonymous_purge_hook, Host, ?MODULE,
-			  remove_user, 50).
+			  remove_user, 50),
+    ejabberd_hooks:delete(c2s_filter_packet_in, Host, ?MODULE,
+			  drop_mam_error, 50).
 
 -spec code_change({down, _} | _, state(), _) -> {ok, state()}.
 
@@ -1258,3 +1263,33 @@ remove_user(LUser, LServer, mnesia) ->
 	end,
     {atomic, ok} = mnesia:sync_transaction(Remove),
     manage_mnesia_fragments(true).
+
+%%--------------------------------------------------------------------
+%% Drop MAM error bounces.
+%%--------------------------------------------------------------------
+
+drop_mam_error(#xmlel{name = <<"message">>, attrs = Attrs} = Message, _JID,
+	       From, #jid{lresource = <<"">>} = To) ->
+    case xml:get_attr_s(<<"type">>, Attrs) of
+      <<"error">> ->
+	  case xml:get_subtag_with_xmlns(Message, <<"result">>, ?NS_MAM) of
+	    #xmlel{} ->
+		?DEBUG("Dropping MAM result error message from ~s to ~s",
+		       [jlib:jid_to_string(From),
+			jlib:jid_to_string(To)]),
+		drop;
+	    false ->
+		case xml:get_subtag_with_xmlns(Message, <<"fin">>, ?NS_MAM) of
+		  #xmlel{} ->
+		      ?DEBUG("Dropping MAM fin error message from ~s to ~s",
+			     [jlib:jid_to_string(From),
+			      jlib:jid_to_string(To)]),
+		      drop;
+		  false ->
+		      Message
+		end
+	  end;
+      _ ->
+	  Message
+    end;
+drop_mam_error(Acc, _JID, _From, _To) -> Acc.