bug#41261: 27.0.90; Dired default file operation target no longer guessed

[Eli Zaretskii <eliz@gnu.org>]

> From: Kévin Le Gouguec <kevin.legouguec@gmail.com>
> Date: Thu, 14 May 2020 17:20:10 +0200
> Cc: 41261@debbugs.gnu.org
> 
> Wojciech Siewierski <wojciech.siewierski@onet.pl> writes:
> 
> > Test scenario, from 'emacs -Q':
> > 1. Open two dired buffers in two windows.
> > 2. Try moving a file by pressing 'R'.
> > 3. The currently suggested directory should be the file's original
> >    directory, that's expected.
> > 4. Press M-n.
> > 5. The currently suggested directory should be the directory of the
> >    second buffer window.
> >
> > That was the case in Emacs 26.3 but not in Emacs 27.0.90 which now
> > changes the moved file's directory into its full current path upon
> > pressing M-n.  Just to be clear, I do not want the second directory to
> > be the initial default (i.e. what setting dired-dwim-target to t would
> > do), I only expect this behavior after pressing M-n.
> 
> If I'm not mistaken, this change in behaviour has been introduced in
> bug#35385.

I'm not sure I understand how that could be possible, since the change
for bug#35385 didn't change any behaviors, it just added new functions
that can be optionally used as values of dired-dwim-target.

Could you please bisect to see what change broke this?  This behavior
wasn't supposed to change in Emacs 27.

Thanks.