Merge pull request #335 from weiss/avoid-carbon-dups

Avoid duplicates of carbon copies

src/mod_carboncopy.erl

@@ -167,6 +167,10 @@ remove_connection(User, Server, Resource, _Status)->
 send_copies(JID, To, Packet, Direction)->
     {U, S, R} = jlib:jid_tolower(JID),
     PrioRes = ejabberd_sm:get_user_present_resources(U, S),
+    {MaxPrio, MaxRes} = case catch lists:max(PrioRes) of
+	{Prio, Res} -> {Prio, Res};
+	_ -> {0, undefined}
+    end,
 
     IsBareTo = case {Direction, To} of
 	{received, #jid{lresource = <<>>}} -> true;
@@ -180,15 +184,19 @@ send_copies(JID, To, Packet, Direction)->
     end,
     %% list of JIDs that should receive a carbon copy of this message (excluding the
     %% receiver(s) of the original message
-    TargetJIDs = if IsBareTo ->
-	    MaxPrio = case catch lists:max(PrioRes) of
-		{Prio, _Res} -> Prio;
-		_ -> 0
-	    end,
+    TargetJIDs = case {IsBareTo, R} of
+	{true, MaxRes} ->
 	    OrigTo = fun(Res) -> lists:member({MaxPrio, Res}, PrioRes) end,
 	    [ {jlib:make_jid({U, S, CCRes}), CC_Version}
 	     || {CCRes, CC_Version} <- list(U, S), not OrigTo(CCRes) ];
-	true ->
+	{true, _} ->
+	    %% The message was sent to our bare JID, and we currently have
+	    %% multiple resources with the same highest priority, so the session
+	    %% manager routes the message to each of them. We create carbon
+	    %% copies only from one of those resources (the one where R equals
+	    %% MaxRes) in order to avoid duplicates.
+	    [];
+	{false, _} ->
 	    [ {jlib:make_jid({U, S, CCRes}), CC_Version}
 	     || {CCRes, CC_Version} <- list(U, S), CCRes /= R ]
 	    %TargetJIDs = lists:delete(JID, [ jlib:make_jid({U, S, CCRes}) || CCRes <- list(U, S) ]),