bug#29189: 25.3; Dired does not work with binary filenames

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 11 Nov 2017 10:20:36 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: schwab@suse.de, 29189@debbugs.gnu.org
> 
> > Without -b, the filename in Dired is two binary characters, \300 and
> > \265.  With -b, the filename in Dired is four characters, \265
> 
> Sorry, it seems I was confused.  You didn't originally say what file
> name you expected to see in Dired.  If the expected file name is \265,
> a single byte, but you see \300\265 instead, then the problem is not
> in deletion, the problem is in how Dired prepares file names for
> display.  I will look into that when I have time, if no one beats me
> to it.

The problem is in insert-directory.  It manually decodes each file
name which was output by 'ls', and that produces strangely
inconsistent results when the file name includes raw bytes: sometimes
we get the 2-byte sequence starting with \300, sometimes the original
byte survives unchanged, and sometimes I see the sequence \301\200
instead of a lone \300 in the file name.  I'm trying to understand
what's going on and find a solution to that.

CC'ing Handa-san in the hope that he could comment on this or provide
some suggestions.