feat(lobby): Handle disabling lobby. (#16770)

* feat(lobby): Handle disabling lobby.

* squash: rename field.

resources/prosody-plugins/README.md

@@ -6,6 +6,7 @@
 - breakout_rooms - A table containing breakout rooms created in the main room. The keys are the JIDs of the breakout rooms, and the values are their subjects.
 - breakout_rooms_active - Whether there was a breakout room created in the main room.
 - breakout_rooms_counter - A counter for breakout rooms created in the main room.
+- lobby_disabled - Whether lobby was disabled for the room by the backend.
 - flip_participant_nick - Used in mod_muc_flip, when flipping a participant we store the nick of the second device/participant. Same processing as kicked_participant_nick.
 - hideDisplayNameForGuests - When set to true, the display name of participants is hidden for guests.
 - jicofo_lock - A boolean value, when set to true the room is locked waiting for Jicofo to join. All attempts to join will be queued until Jicofo joins.

resources/prosody-plugins/mod_muc_lobby_rooms.lua

@@ -413,11 +413,16 @@ function process_lobby_muc_loaded(lobby_muc, host_module)
     host_module:hook('host-disco-info-node', function (event)
         local session, reply, node = event.origin, event.reply, event.node;
         if node == LOBBY_IDENTITY_TYPE
-            and session.jitsi_web_query_room
-            and check_display_name_required then
+            and session.jitsi_web_query_room then
             local room = get_room_by_name_and_subdomain(session.jitsi_web_query_room, session.jitsi_web_query_prefix);
 
-            if room and room._data.lobbyroom then
+            if room and room._data.lobby_disabled then
+                -- we cannot remove the child from the stanza so let's just change the type
+                local lobby_identity = reply:get_child_with_attr('identity', nil, 'type', LOBBY_IDENTITY_TYPE);
+                lobby_identity.attr.type = 'DISABLED_'..LOBBY_IDENTITY_TYPE;
+            end
+
+            if check_display_name_required and room and room._data.lobbyroom then
                 reply:tag('feature', { var = DISPLAY_NAME_REQUIRED_FEATURE }):up();
             end
         end
@@ -489,6 +494,11 @@ process_host_module(main_muc_component_config, function(host_module, host)
         end
         local members_only = event.fields['muc#roomconfig_membersonly'] and true or nil;
         if members_only then
+            -- if lobby disabled just ignore and return
+            if room._data.lobby_disabled then
+                module:log('warn', 'Lobby is disabled for room %s, cannot enable members only', room.jid);
+                return;
+            end
             local lobby_created = attach_lobby_room(room, actor);
             if lobby_created then
                 module:fire_event('jitsi-lobby-enabled', { room = room; });