bug#45379: 28.0.50; Degraded Performance of describe-buffer-bindings

[Eli Zaretskii]

> From: handa <handa@gnu.org>
> Cc: stefan@marxist.se, styang@fastmail.com, juri@linkov.net, rudalics@gmx.at,
>       45379@debbugs.gnu.org, monnier@iro.umontreal.ca,
>       stephen.berman@gmx.net, handa@gnu.org
> Date: Sun, 07 Mar 2021 10:42:39 +0900
> 
> In article <83v9a4wve3.fsf@gnu.org>, Eli Zaretskii <eliz@gnu.org> writes:
> 
> > > From: Stefan Kangas <stefan@marxist.se>
> > > Date: Fri, 5 Mar 2021 20:44:33 -0800
> > > Cc: Juri Linkov <juri@linkov.net>, martin rudalics <rudalics@gmx.at>, Eli 
> > > Zaretskii <eliz@gnu.org>, 
> > >   45379@debbugs.gnu.org, Stefan Monnier <monnier@iro.umontreal.ca>, 
> > >   Stephen Berman <stephen.berman@gmx.net>
> > > 
> > > It turns out that we were doing unnecessary looping due to the above
> > > mentioned commit.
> 
> Could you show me what is "the above mentioned commit"?

This one, I guess:

> commit a6490343366f2b2331a91dcb693effb3a9dd78f5
> Author:     Stefan Kangas <stefan@marxist.se>
> AuthorDate: Fri Nov 13 15:28:29 2020 +0100
> Commit:     Stefan Kangas <stefan@marxist.se>
> CommitDate: Sun Nov 22 02:45:03 2020 +0100
> 
>     Don't show key ranges if shadowed by different commands
> 
>     * src/keymap.c (describe_vector): Make sure found consecutive keys
>     are either not shadowed or, if they are, that they are shadowed by
>     the same command.  (Bug#9293)
>     * test/src/keymap-tests.el
>     (help--describe-vector/bug-9293-one-shadowed-in-range): New test.

> > >  While working on this, I also found that we can get
> > > rid of an unnecessary call to char_table_ref_and_range, which should
> > > make this function run even faster.
> 
> Is the patch for the above improvement the one included in the file
> 0001-Fix-describe-buffer-bindings-performance-regression.patch?

Yes, it is.

> > > I'm also copying in Kenichi Handa, who was the last to touch this code.
> > > Handa-san, please let us know if you have any comments on this patch.
> > > Thanks in advance.
> 
> > AFAICT, you didn't CC Kenichi; I have now added him to the discussion.
> 
> It was more than 10 years ago that I last read keymap.c, and since then,
> the code has been changed a lot.  It will take some time to understand
> the latest code.

Thanks in advance.