Re: GDI+ take 3

[Eli Zaretskii <eliz@gnu.org>]

> From: Juan José García-Ripoll
>  <juanjose.garciaripoll@gmail.com>
> Date: Sat, 18 Apr 2020 14:38:58 +0200
> 
> Juanma Barranquero <lekktu@gmail.com> writes:
> > Tiffs no longer crash for me and are correctly animated
> > GIFs still fail to animate correctly the first time. Juan José, are you
> > planning to look into it?
> 
> With my last mini-patch, I tried exactly the same lisp code with this image
> https://upload.wikimedia.org/wikipedia/commons/2/2c/Rotating_earth_%28large%29.gif
> and it animates just fine, exactly as emacs 26.3 with libgif.

I think I've just seen what Juanma describes -- but with libgif.  I
saw it only once, and couldn't reproduce afterwards.  But I think this
means that the problem is not with the w32image.c code, it's somewhere
else.

Juanma, if you still can reproduce the problem at will, please step
through the code which performs the animation, and tell what you see
there that causes the animation to stop prematurely.  Some of the
animation happens in Lisp, so it 's a bit tricky to "step through it",
but if you can reliably reproduce, just discovering what stops the
animation would be an important step forward.

TIA