Lock the Avahi thread before stopping it and tearing down the Avahi objects.

ChangeLog

@@ -1,3 +1,7 @@
+2008-06-06  Julien Blache <jb@jblache.org>
+	* backend/net.c: lock the Avahi thread before stopping it and
+	tearing down the Avahi objects.
+
 2008-06-03  Stéphane Voltz <stef.dev@free.fr>
 	* backend/genesys_gl646.c: fixed wrong offset for start
 	  of scanarea for MD6471 scanner.

backend/net.c

@@ -922,6 +922,7 @@ net_avahi_cleanup (void)
   if (!avahi_thread)
     return;
 
+  avahi_threaded_poll_lock (avahi_thread);
   avahi_threaded_poll_stop (avahi_thread);
 
   if (avahi_browser)