bug#81589: 31.0.91; Regression: window-buffer-change-functions no longer firing on set-window-configuration

> From: "J.D. Smith" <[email protected]>
> Cc: [email protected],  [email protected]
> Date: Sun, 09 Aug 2026 11:07:56 -0400
> 
> Eli Zaretskii <[email protected]> writes:
> 
> >> From: "J.D. Smith" <[email protected]>
> >> Date: Sun, 09 Aug 2026 08:16:30 -0400
> >> 
> >> 
> >> In the latest v31, upon using `set-window-configuration' (e.g. via
> >> `tab-bar-history-back') to change the buffer in a window, the
> >> `window-buffer-change-functions' are not run.  Neither global nor
> >> buffer-local values of this hook are run, in contrast to earlier
> >> versions.
> >> 
> >> I have verified that this is a recent regression caused by commit
> >> d6f7b2d99bd in bug#81097.  With this commit, the hook does not run.
> >> Without it, it does.
> >
> > You already reported this in that bug, so I wonder what was the
> > purpose of submitting another bug report with the same information?
> 
> I received a report that the bug was closed and archived

It can be unarchived with a single debbugs command in your email
message, see admin/notes/bugtracker.

> and concluded a new report would be more visible, given the pending
> v31 release.

There's no basis for this conclusion.  Both Sean and myself receive
all the messages sent to debbugs and treat them all equally.

It isn't a catastrophe, of course, but each extra bug makes their
management a tad harder.  Please keep this in mind.