bug#81559: 31.0.91; speedbar does not follow Dired and shell-dirtrack-mode

Eli Zaretskii <[email protected]> writes:

>> From: Daniel Mendler <[email protected]>
>> Cc: [email protected]
>> Date: Sun, 09 Aug 2026 18:10:03 +0200
>> 
>> Eli Zaretskii <[email protected]> writes:
>> 
>> >> From: Daniel Mendler <[email protected]>
>> >> Cc: [email protected]
>> >> Date: Wed, 05 Aug 2026 19:26:41 +0200
>> >> 
>> >> Eli Zaretskii <[email protected]> writes:
>> >> 
>> >> >> Date: Wed, 05 Aug 2026 17:40:01 +0200
>> >> >> From: Daniel Mendler via "Bug reports for GNU Emacs,
>> >> >>  the Swiss army knife of text editors" <[email protected]>
>> >> >> 
>> >> >> The speedbar does not follow the current shell directory, nor does it
>> >> >> follow the current directory in Dired. In order to test:
>> >> >> 
>> >> >> 1. emacs -Q
>> >> >> 2. M-x speedbar
>> >> >> 3. M-x shell and then cd to change directories => speedbar does not follow
>> >> >> 4. M-x dired, chose various directories => speedbar does not follow
>> >> >
>> >> > Did Speedbar ever react to Dired and shell directory changes?  If yes,
>> >> > in which version of Emacs?  If it never did, this is a request for an
>> >> > enhancement, right?  And I think the way to add such an enhancement is
>> >> > described the node "Extending" of the Speedbar manual.
>> >> 
>> >> Yes, as far as I can tell, this has never worked. It is a feature
>> >> request.
>> >
>> > Thanks, marked it as such.  Patches welcome.
>> 
>> The following simple patch ensures that Speedbar reacts also on buffers
>> which are not backed by files (e.g. Shell with dirtrack mode or Dired).
>> This should go to the master branch and we might want to guard it behind
>> an option (e.g., speedbar-update-file-buffer). Eli, what do you think?
>
> Is this useful?  I'd think we could do something more sophisticated.
> E.g., just showing the files in a directory already displayed in Dired
> doesn't seem to add any information, does it?

Yes, it is useful, but more so for shell-dirtrack-mode, and in other
non-file backed buffers. Dired is just a an example for such a buffer,
but there speedbar does not add much value. One can also explicitly
exclude dired-mode via speedbar-ignored-modes.

Daniel