Fixes #2284

src/core.py

@@ -1505,14 +1505,15 @@ class Core(object):
                 self.information_win.refresh()
                 self.current_tab().input.refresh()
 
-    def disconnect(self, msg=None, reconnect=False):
+    def disconnect(self, msg='', reconnect=False):
         """
         Disconnect from remote server and correctly set the states of all
         parts of the client (for example, set the MucTabs as not joined, etc)
         """
+        msg = msg or ''
         for tab in self.tabs:
-            if isinstance(tab, tabs.MucTab):
-                muc.leave_groupchat(self.xmpp, tab.name, tab.own_nick, msg)
+            if isinstance(tab, tabs.MucTab) and tab.joined:
+                tab.command_part(msg)
         roster.empty()
         self.save_config()
         # Ugly fix thanks to gmail servers

src/tabs.py

@@ -570,9 +570,9 @@ class MucTab(ChatTab):
             msg = None
         if self.joined:
             muc.leave_groupchat(self.core.xmpp, self.name, self.own_nick, arg)
-            self.joined = False
             self.add_message(_("\x195}You left the chatroom\x193}"))
-            self.refresh()
+            if self == self.core.current_tab():
+                self.refresh()
             self.core.doupdate()
         self.core.disable_private_tabs(self.name)