bug#35158: 26.1; Display bugs: odd bits wrong in shell window

[Eli Zaretskii <eliz@gnu.org>]

> From: DJC <djc@resiak.org>
> Date: Fri, 5 Apr 2019 16:13:24 +0200
> 
> In the upper window of a frame I had several hundred lines containing the 
> full paths of filenames within quotation marks -- all containing non-ASCII 
> accented European characters -- and in the lower window a Windows shell. 
>  From the shell window I used a macro to change windows, grab a file name, 
> then return to the shell window and issue
> 
>      del {filename within quotation marks}
> 
> After confirming that this was working as desired, I issued a command to 
> repeat the macro indefinitely.  As lines scrolled in the shell window I 
> remarked some errors in the display there: certain improper bits were being 
> displayed rather consistently.  When the run was finished, I grabbed a 
> screen shot of the quiescent state (attached) showing some of these. 

You mean, those stray pixels after "5" in "HS2015"?  And also the
artifacts before the backslashes in last two lines you captured?

If so, I suggest to review the settings of your display driver, and if
there are any "optimization" options there, turn them off.

Thanks.