bug#39658: 26.3; can't edit file with terminal escape sequences

[Eli Zaretskii]

> Date: Tue, 18 Feb 2020 06:15:10 -0800
> From: frederik@ofb.net
> Cc: 39658@debbugs.gnu.org
> 
> >The problem is more likely to be the extremely long lines in the
> >file. If you have emacs-27 or emacs-master, you can try 'M-x
> >global-so-long-mode' before visiting the file, which attempts to
> >improve Emacs' behaviour in such cases.
> 
> Yes, the fact that it is all on one line is likely relevant. I haven't tried 
> installing Emacs 27, but I note that a file 10x as long as the one I 
> attached, consisting of the letter "t" repeated, can be opened and edited 
> without difficulty. My guess is that rendering the escape sequences in the 
> problem file is causing some kind of quadratic complexity.

Did you try "M-x find-file-literally RET"?  I'm guessing Emacs tries
to interpret the escape sequences as some variant of ISO-2022 encoding
or something.