MUC: Don't default room name to JID localpart (API breaking change)

Behavior with turning empty name into localpart was originally introduced
in 711eb5bf94b4

This has caused some problems for clients, making it difficult to
differentiate between a room actually named like the localpart from a
room without a name.

Breaking:
The function signature of the :get_name() method changes from always
returning a string to optional string.

1 files changed, 13 insertions, 3 deletions

diff --git a/plugins/muc/mod_muc.lua b/plugins/muc/mod_muc.lua
index d911de08..e9fd1521 100644
--- a/plugins/muc/mod_muc.lua
+++ b/plugins/muc/mod_muc.lua
@@ -137,7 +137,12 @@ local room_items_cache = {};
 local function room_save(room, forced, savestate)
 	local node = jid_split(room.jid);
 	local is_persistent = persistent.get(room);
-	room_items_cache[room.jid] = room:get_public() and room:get_name() or nil;
+	if room:get_public() then
+		room_items_cache[room.jid] = room:get_name() or "";
+	else
+		room_items_cache[room.jid] = nil;
+	end
+
 	if is_persistent or savestate then
 		persistent_rooms:set(nil, room.jid, true);
 		local data, state = room:freeze(savestate);
@@ -163,7 +168,11 @@ local rooms = cache.new(max_rooms or max_live_rooms, function (jid, room)
 	end
 	module:log("debug", "Evicting room %s", jid);
 	room_eviction();
-	room_items_cache[room.jid] = room:get_public() and room:get_name() or nil;
+	if room:get_public() then
+		room_items_cache[room.jid] = room:get_name() or "";
+	else
+		room_items_cache[room.jid] = nil;
+	end
 	local ok, err = room_save(room, nil, true); -- Force to disk
 	if not ok then
 		module:log("error", "Failed to swap inactive room %s to disk: %s", jid, err);
@@ -337,13 +346,14 @@ module:hook("host-disco-items", function(event)
 	module:log("debug", "host-disco-items called");
 	if next(room_items_cache) ~= nil then
 		for jid, room_name in pairs(room_items_cache) do
+			if room_name == "" then room_name = nil; end
 			reply:tag("item", { jid = jid, name = room_name }):up();
 		end
 	else
 		for room in all_rooms() do
 			if not room:get_hidden() then
 				local jid, room_name = room.jid, room:get_name();
-				room_items_cache[jid] = room_name;
+				room_items_cache[jid] = room_name or "";
 				reply:tag("item", { jid = jid, name = room_name }):up();
 			end
 		end