[C] Fix unwanted point moveage in VM

[Julian Bradfield]

In article <18149.58079.498563.234436 at puma.r.npc.de> Joachim Schrod <jschrod at acm.org> writes:
>>>>>> "MS" == Michael Sperber <sperber at informatik.uni-tuebingen.de> writes:
>MS> So before I sink more work into this: Can you confirm that the
>MS> "flicker" problem seen on 21.5 also occurs with the new VM?
>
>I don't know if I fully understood what Julian's "flicker" problem
>is actually... Thus, let me rephrase the situation as I observe it.
>
>When one moves from one message to another (i.e., evaluates
>#'vm-next-message), the frame goes completely white and is then
>rebuild. Is that the "flicker" problem of Julian? This is the same in
>VM 7.17/7.19 and VM 8.0. I'd think that this behaviour was already
>there when I still used XEmacs 21.4; I don't remember any change here. 
>AFAIU, that's done during the construction of the mail's presentation
>(MIME decoding and so).

Yes, I guess that's what I mean. On 21.5, it is very visible, and very
annoying - even on a tty frame, even on a very fast machine. On 21.4,
it's not visible at all on any machine I use, as far as I can see, so
I don't know whether it even happens.
I suppose I could put them under xscope to see what's actually
happening to the window!