bug#47207: 28.0.50; decode_next_window_args crash

[martin rudalics]

> Could you please look at my patch (below).  It seems to fix the bug you
> gave a recipe for a couple of posts back.  I'm hoping it can be
> committed as it is.

It fixes that bug.  I'll check in a fix for the original Bug#47207 in a
couple of days.

Thanks, martin