bug#39188: 28.0.50; w32 cursor redisplay problem

[Eli Zaretskii]

> From: Fabrice Popineau <fabrice.popineau@gmail.com>
> Date: Sun, 19 Jan 2020 17:32:17 +0100
> Cc: 39188@debbugs.gnu.org
> 
>  Sorry, I don't.  I only see one or 2 artefacts in the window, as I
>  described.
> 
> I should have added : try the cursor in column 12 or so, not at bol. 

That's what I did.

> Like the one after Summary here? The cursor being at Manual, 1st line.
> What is annoying is that it gets worse with my usual setting. It seems like 
> a race condition with something else.

It's "your usual case" that I cannot reproduce.  I only see 1 or 2
traces in a window.  I'll try to see how to avoid those traces, but no
promises, as I know almost nothing about the Windows GUI programming.

> OTOH and luckily, there is nothing like that if w32-use-visible-system-caret 
> is set to nil.

I actually am surprised you are using that, it's main use case is for
people who use a speech synthesizer.