bug#68390: Emacs display rendering problem

[Eli Zaretskii]

> Date: Thu, 11 Jan 2024 17:50:10 +0000 (UTC)
> From:  Sunil Matta via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> Issue: Emacs display is very buggy and unusable after latest Fedora 38 
> software updates.
> 
> Laptop:
> OS: Fedora 38 (patches updated as of 1/10/2024)
> cpu: Intel(R) Core™ i7-2670QM CPU @ 2.20GHz
> 
> Emacs: GNU Emacs 28.3 (build 1, x86_64-redhat-linux-gnu, GTK+ Version 
> 3.24.38, cairo version
> 1.17.8) of 2023-09-23
> 
> On my laptop, updated fedora version 38 with latest patches and
> getting very buggy behavior display rendering.

Is this on text-mode frames or on GUI frames?

> I am seeing these issues in my emacs editing sessions. Not sure if
> they happen outside of emacs just yet.
> Btw, I am using the emacs version that came with Fedora 38, as I
> usually do.
> 
> While editing buffers in emacs, the display is not updating properly.
> The point/cursor in multiple locations of the buffer as opposed to just
> one.
> Scrolling in a buffer displays remnant text that should have scrolled
> by on previous lines no longer on the screen.
> 
> Moving the point(cursor in a buffer), can make the display to go crazy
> and display the checker board pattern in the entire emacs window!
> In addition, this checkerboard pattern remains on the entire emacs window for 
> a few seconds!
> 
> PS: I have only seen this behavior in my emacs session as of this
> morning when I updated fedora with its regular updates for version 38.
> I did not upgrade to Fedora 39 just yet.

This is almost certainly not a problem with Emacs, but with your video
drivers and X libraries.  If you have some "optimization" features in
your display driver settings, try disabling them and see if the
problems go away.

Thanks.