bug#45041: 27.1; Emacs hangs if the cited message contains some specific text

[Lars Ingebrigtsen]

Pratyush Yadav <me@yadavpratyush.com> writes:

>> More information was requested, but no response was given within a 
>> month, so I'm closing this bug report.  If the problem still exists,
>> please respond to this email and we'll reopen the bug report.
>
> Sorry, forgot to reply. The backtrace is pasted below.

Thanks; reopening.

>   looking-at("^\\(\\([ \11]*\\(\\w\\|[_.]\\)+>+\\|[ \11]*[>|]\\)+\\)?
> *>>>>> ...")
>   gnus-cite-parse()

This must come from:

      (when (and (< guess-limit (+ begin gnus-cite-max-prefix))
                 (looking-at gnus-supercite-regexp))

And that's the default value of `gnus-supercite-regexp', I think?

"^\\(\\([       ]*\\(\\w\\|[_.]\\)+>+\\|[       ]*[>|]\\)+\\)? *>>>>> +\"\\([^\"
]+\\)\" +=="

(Only printed differently.)

But I'm not able to reproduce this bug.  When I try looking at this
message, I don't get a hang, unfortunately.  I've tried in Emacs 27, and
I don't get it there, either.

Your simpler report, that

(looking-at gnus-supercite-regexp)

"> ___________________________________________________________________________"

(without the quotes) hang, I'm not able to reproduce either (on Emacs
27.1 or Emacs 28).

Anybody guess what's going on?  Our systems look pretty similar, but I'm
on Debian, and the reported is on Arch.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no