Subject: bug#78474: 31.0.50; Wrong char insertion in rxvt

From: Eli Zaretskii <[email-masked]>
Date: Thu, 24 Jul 2025 09:40:43 +0300

> Date: Wed, 23 Jul 2025 22:29:30 +0200
> From: Samuel Thibault <[email-masked]>
> Cc: [email-masked], [email-masked], [email-masked],
> 	[email-masked], [email-masked]
> 
> Eli Zaretskii, le mer. 23 juil. 2025 20:06:57 +0300, a ecrit:
> > Evaluate this in an interactive session, then visit src/xdisp.c, and
> > invoke the command.  Wait until it finishes scrolling and record the
> > time it shows.
> 
> Ok, thanks.
> 
> > Note: you need to run this in a fresh Emacs session, i.e. never run
> > the benchmark twice in the same session.
> 
> Yes, sure.
> 
> I performed 10 measurements with the venerable xterm, and a couple
> measurements with the vte-based mate-terminal, rxvt, and Eterm.
> The choice of terminal hardly changes anything at all. It's emacs that
> consumes one core 100%, while the terminal consumes 1-3% only.
> 
> Here are the measurements:
> 
> With \e[C:
> 
> xterm
> 18.515394
> 18.516340
> 18.453698
> 18.576480
> 18.454190
> 18.530091
> 18.392103
> 18.484421
> 18.422035
> 18.469797
> 
> mate
> 18.595872
> 18.501546
> 
> rxvt
> 18.500069
> 18.423311
> 
> Eterm
> 18.428876
> 18.460808
> 
> With \t\b:
> 
> xterm
> 18.310599
> 18.583103
> 18.464580
> 18.516165
> 18.424753
> 18.498778
> 18.377242
> 18.445612
> 18.407960
> 18.505874
> 
> mate
> 18.551353
> 18.503176
> 
> rxvt
> 18.396504
> 18.340624
> 
> Eterm
> 18.544554
> 18.423233
> 
> So the average difference on xterm (0.03s) is completely inside the standard deviation (~0.06s)...

Thanks.

I'd encourage others to run similar benchmarks on these and other
terminals.  Gnome-terminal, alacritty, kitty, screen, tmux, and the
Linux console come to mind.  Also, if someone can test this in a
remote-login session, especially over a slow connection, those numbers
would be important to have.