bug#62621: 29.0.60; uniquify can't make buffers unique based on things other than filename

[Eli Zaretskii]

> Date: Tue, 18 Jul 2023 03:34:06 +0300
> Cc: sbaugh@janestreet.com, 62621@debbugs.gnu.org
> From: Dmitry Gutov <dmitry@gutov.dev>
> 
> > Repeat after me: Use options whose values are functions
> > are hard on our users, because they require them to be Lisp
> > programmers.
> 
> That doesn't have to be the case. If the defcustom's docstring mentions 
> several functions that can be used, and the :type widget includes them 
> as well, the user can decide to switch to any of them without writing 
> any Lisp (or having to understand the implementations).

But that was not so in this particular case.