Revert "mod_mam: Don't route error bounces to clients"

This reverts commit 8b1eead24b.

As of ejabberd 15.04, the session manager won't deliver error messages
that were sent to bare JIDs anymore, so MAM error messages should no
longer arrive.  Also, the 'c2s_filter_packet_in' hook no longer exists.

mod_mam/src/mod_mam.erl

@@ -52,8 +52,7 @@
 %% ejabberd_hooks callbacks.
 -export([receive_stanza/4,
 	 send_stanza/3,
-	 remove_user/2,
-	 drop_mam_error/4]).
+	 remove_user/2]).
 
 %% gen_iq_handler callback.
 -export([handle_iq/3]).
@@ -202,8 +201,6 @@ 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),
@@ -249,9 +246,7 @@ 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),
-    ejabberd_hooks:delete(c2s_filter_packet_in, Host, ?MODULE,
-			  drop_mam_error, 50).
+			  remove_user, 50).
 
 -spec code_change({down, _} | _, state(), _) -> {ok, state()}.
 
@@ -1265,33 +1260,3 @@ 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.