bug#48657: Defvar delimiter for dired-copy-filename-as-kill

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Sun, 24 Oct 2021 00:11:28 -0700
> Cc: Rodrigo Morales <moralesrodrigo1100@gmail.com>, 48657@debbugs.gnu.org
> 
> >> I thought that it would be useful to have a defvar that allows
> >> specifying the delimiter for copied filenames through the mentioned
> >> function. Perhaps, its name could be "dired-copy-filename-delimiter".
> >
> > The only sane value for a reliable delimiter is the null byte, so
> > maybe it doesn't make much sense to customize it.
> 
> That's true, but on the other hand replacing space with the null byte as
> the hard-coded delimiter for dired-copy-filename-as-kill seems a
> bit... clunky.

I don't see why.  A number of GNU programs use the null byte as a
reliable delimiter in similar situations (Grep, xargs, etc.), so why
shouldn't we do the same?

> I've personally never had a problem with using space here, but you
> obviously will eventually run into problems.  So I think something
> should be done.

Why using a space when we know it will sometimes fail?  The null byte
will never fail, and Emacs is perfectly capable of handling strings
with embedded null bytes.