Comment 2 for bug 851383

StacktraceTop:
 g_assertion_message (domain=<optimized out>, file=<optimized out>, line=<optimized out>, func=0x7f3d76eb0b20 "gtk_file_chooser_default_initial_focus", message=0x160a7d0 "assertion failed: (widget != NULL)") at /build/buildd/glib2.0-2.29.90/./glib/gtestutils.c:1425
 g_assertion_message_expr (domain=0x7f3d76e9b17b "Gtk", file=0x7f3d76eb1c18 "/build/buildd/gtk+2.0-2.24.6/gtk/gtkfilechooserdefault.c", line=8750, func=0x7f3d76eb0b20 "gtk_file_chooser_default_initial_focus", expr=<optimized out>) at /build/buildd/glib2.0-2.29.90/./glib/gtestutils.c:1436
 gtk_file_chooser_default_initial_focus (chooser_embed=<optimized out>) at /build/buildd/gtk+2.0-2.24.6/gtk/gtkfilechooserdefault.c:8750
 gtk_file_chooser_dialog_map (widget=<optimized out>) at /build/buildd/gtk+2.0-2.24.6/gtk/gtkfilechooserdialog.c:359
 g_closure_invoke (closure=0xbf4470, return_value=0x0, n_param_values=1, param_values=0x15290c0, invocation_hint=<optimized out>) at /build/buildd/glib2.0-2.29.90/./gobject/gclosure.c:774