bug#61704: 29.0.60; Crash in get_narrowed_begv

[martin rudalics]

Which BTW is not entirely trivial to do.
> The problem here is that Emacs should not crash, no matter what some
> other X client, such as the WM, does.

Right.  Even if we have no proof that frame resizing is the culprit
here.

> X programs are traditionally expected to not crash when run under a
> window manager that leaves features unimplemented, but to provide some
> kind of graceful fallback instead.

Right again.  And that's why I said that

> and OTOH the redisplay engine should be able to handle zero window
> sizes to avoid crashes the window code cannot prevent.

martin