bug#81295: 32.0.50; dired-auto-toggle-b-switch problem with subdirectory

> From: Stephen Berman <[email protected]>
> Cc: [email protected],  [email protected],  [email protected]
> Date: Wed, 29 Jul 2026 15:32:45 +0200
> 
> On Wed, 29 Jul 2026 15:36:51 +0300 Eli Zaretskii <[email protected]> wrote:
> 
> >> From: Stephen Berman <[email protected]>
> >> Cc: Filipp Gunbin <[email protected]>,  [email protected],  Eli
> >>  Zaretskii <[email protected]>
> >> Date: Wed, 29 Jul 2026 13:49:09 +0200
> >> 
> >> On Tue, 28 Jul 2026 13:19:56 +0100 Sean Whitton <[email protected]> wrote:
> >> 
> >> > Stephen Berman [28/Jul 11:51am +02] wrote:
> >> >> TL;DR for Eli and Sean: Should one of the attached patches for this
> >> >> bug be installed in master now, or should we wait for Filipp's
> >> >> alternative fix?  (Read on for more context.)
> >> >
> >> > It looks like you are still discussing, why would there be a need to
> >> > install something quickly?
> >> 
> >> The discussion seems to have reached an impasse.
> >
> > If there's something that you want Sean and myself to make a decision
> > about, would you mind spelling that out?  I'm afraid that I don't
> > understand which part(s) of the discussion require our decisions.
> 
> Here's a high-level summary (as I understand it, but if Filipp thinks
> I've missed or misrepresented anything, I'm sure he'll chime in):
> 
> - First Filipp opened this bug to report that the handling in Dired of
>   file names that containing a newline did not work with Dired subdirs.
>   
> - Through an iterative process of me posting patches and Filipp finding
>   further problems a point was reached where the handling in subdirs was
>   as good as in simple Dired buffers.
> 
> - But then Filipp found another problem: in a Dired buffer that lists no
>   file names containing a newline and also lists a directory entry, and
>   that directory does have a file whose name contains a newline, typing
>   `C-u i RET' on that directory (where the prefix argument allows adding
>   switches for displaying the subdir, but RET means just the default
>   switches -al are used) results in the subdir not being displayed in
>   the Dired buffer.
> 
> - I came up with a fix, so that the subdir was properly displayed, but
>   Filipp objected to the fix because it in effect makes the function
>   `dired-insert-subdir-validate' a no-op in the situation leading to the
>   bug.  The details are important for understanding the substance of the
>   objection, but I don't understand them well enough to give a useful
>   summary here (that's part of the current impasse); maybe Filipp can,
>   since he has an idea for a better solution, but doesn't have time to
>   implement it now.
> 
> So that's the current situation, and why I've turned to you and Sean for
> a decision on how to proceed: (i) install my changes to handle file
> names with newlines in Dired subdirs, including the change that "fixes"
> the bug with `C-u i'; (ii) install the changes except for the one that
> "fixes" the `C-u i' bug, thus leaving that unfixed for now; (iii) wait
> for Filipp's alternative implementation, which will hopefully fix that
> bug without circumventing validation of subdir switches.
> 
> My preference is (i), for the reasons I gave in my latest response to
> Filipp, repeated here: "It's not clear to me that if any bugs result
> from this change, they will be worse than the bug that the change fixes.
> It's also not clear to me why including this change along with the other
> changes now and later, if it is shown to cause other bugs, changing or
> replacing it, is worse than omitting the change and leaving a known bug
> unfixed for the time being.  But again, I'm fine with whatever the
> maintainers decide."

I tend to agree with Stephen's suggestion.

Let's hear what Sean thinks about this.