bug#58464: 28.1; browse-url-emacs doesn't work for local files on Windows

[Eli Zaretskii]

> Date: Thu, 13 Oct 2022 09:40:54 -0700
> Cc: pquessev@gmail.com, 58464@debbugs.gnu.org
> From: Paul Eggert <eggert@cs.ucla.edu>
> 
> >>    -  if (NILP (handler) && !NILP (visit) && 
> >> current_buffer->modtime.tv_nsec < 0)
> >>    +  if (save_errno != 0)
> >>
> >> might cause us signal an error when VISIT is nil, something that
> >> didn't happen before.
> 
> We should be OK there. If VISIT is nil, SAVE_ERRNO must be zero.
> 
> >> (I also am not sure it is 100% reliable to rely on save_errno being
> >> non-zero whenever we encounter an error, especially in the
> >> file-handlers case.)
> 
> Should be OK here too. In the file-handlers case, SAVE_ERRNO is zero.

Famous last words.