fix single message behaviour

data/glade/single_message_window.glade

@@ -21,6 +21,7 @@
   <property name="focus_on_map">True</property>
   <signal name="key_press_event" handler="on_single_message_window_key_press_event" last_modification_time="Tue, 05 Jul 2005 22:02:15 GMT"/>
   <signal name="delete_event" handler="on_single_message_window_delete_event" last_modification_time="Mon, 17 Oct 2005 15:32:50 GMT"/>
+  <signal name="destroy" handler="on_single_message_window_destroy"/>
 
   <child>
     <widget class="GtkVBox" id="vbox97">
@@ -544,5 +545,4 @@
     </widget>
   </child>
 </widget>
-
 </glade-interface>

src/dialogs.py

@@ -1481,8 +1481,11 @@ class SingleMessageWindow:
 	singled message depending on action argument which can be 'send'
 	or 'receive'.
 	'''
+	# Keep a reference on windows so garbage collector don't restroy them
+	instances = []
 	def __init__(self, account, to = '', action = '', from_whom = '',
 	subject = '', message = '', resource = ''):
+		self.instances.append(self)
 		self.account = account
 		self.action = action
 
@@ -1581,6 +1584,9 @@ class SingleMessageWindow:
 				gajim.config.get('single-msg-height'))
 		self.window.show_all()
 
+	def on_single_message_window_destroy(self, widget):
+		self.instances.remove(self)
+
 	def set_cursor_to_end(self):
 			end_iter = self.message_tv_buffer.get_end_iter()
 			self.message_tv_buffer.place_cursor(end_iter)