Comment 2 for bug 1208405

StacktraceTop:
 g_type_check_instance (type_instance=type_instance@entry=0x2bb5dc0) at /build/buildd/glib2.0-2.37.3/./gobject/gtype.c:4082
 g_signal_handlers_disconnect_matched (instance=0x2bb5dc0, mask=mask@entry=(G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA), signal_id=signal_id@entry=0, detail=detail@entry=0, closure=closure@entry=0x0, func=func@entry=0x7fc349806c20 <toolbar_item_visiblity_notify_cb>, data=data@entry=0x2b29b50) at /build/buildd/glib2.0-2.37.3/./gobject/gsignal.c:2874
 toolbar_content_remove (content=content@entry=0x2c7e540, toolbar=toolbar@entry=0x2b29b50) at /build/buildd/gtk+3.0-3.8.2/./gtk/gtktoolbar.c:3315
 gtk_toolbar_stop_sliding (toolbar=toolbar@entry=0x2b29b50) at /build/buildd/gtk+3.0-3.8.2/./gtk/gtktoolbar.c:1389
 toolbar_content_new_tool_item (toolbar=0x2b29b50, item=item@entry=0x2b5ddd0, is_placeholder=is_placeholder@entry=0, pos=1) at /build/buildd/gtk+3.0-3.8.2/./gtk/gtktoolbar.c:3297