bug#68390: Emacs display rendering problem

[Eli Zaretskii]

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> Date: Fri, 12 Jan 2024 22:23:39 +0000 (UTC)
> From: Sunil Matta <mattasunil@yahoo.com>
> 
> On Thursday, January 11, 2024 at 02:15:31 PM EST, Eli Zaretskii 
> <eliz@gnu.org> wrote: 
> 
> > 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?
> 
> This is in gui frames mode. I didnt realize that there was a text mode.
> I am running emacs in server mode and window-system == 'x'
> 
> > 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.
> 
> Yes, it shouldnt be an emacs problem. I too feel its a display driver issue, 
> but I'm only having this
> problem
> in emacs and not in other apps. 
> I do not have any optimizations set for my display and gnome window manager.
> 
> Seems like an interaction with the display driver and the latest Fedora 38 
> patch.
> I have posted to the fedora users group as well. No answers on that forum I'm 
> guessing cause its only
> happening in emacs.
> 
> Very odd. I have never seen this behavior in emacs before.
> 
> And really making my emacs unusable and killing my development time, so any 
> suggestions would
> be appreciated.
> 
> Thanks.
> 
> Sunil

I think we should wait for Fedora to resolve this.