Comment 5 for bug 1283966

 * Including the self.app.select_single('GeditWindow') in the loop (as property, or just inline) crashes, while calling it once before the loop ("mw = self.app.select_single('GeditWindow')") does not crash.

 * Merely looping over self.app.select_single('GeditWindow'), and dropping the EditUndo select still crashes. That happens even earlier, at ~ 360 iterations.

 * Each iteration causes

   [GLib-GObject] UNKNOWN: g_value_set_enum: assertion 'G_VALUE_HOLDS_ENUM (value)' failed

   which becomes easier/faster to see with G_DEBUG=fatal-criticals

This should be investigated first, to either see if that's the cause of memory corruption or to get it out of the way.