bug#7112: 24.0.50; [PATCH] `ls-lisp-insert-directory' should be no-op for empty FILE

[Drew Adams]

> dired.el should not be asking ls-lisp to list a directory called "",
> which is obviously something that should generate an error.

`ls-lisp-insert-directory' should not raise a low-level, Args out of range
error.  It should itself DTRT for an empty file name.  Maybe it should raise an
error, but not that low-level error.  Or maybe it should, as the Subject line
suggests, ignore empty file names.  I obviously think the latter is preferable,
but I suppose it's open for discussion.

> >> What's the backtrace for this bug?
> >
> > Why not try it yourself, using the emacs -Q recipe:
> >
> > M-: (dired '("foobar" "111.el" ""))
> 
> Why would you call this function with an empty string as a parameter?

Because you can?  No experienced programmer takes refuge behind the argument
"Why would anyone ever do that?" or "Don't worry; no one would ever do that."

Sooner or later programmers learn that users will do anything they can, and code
should be prepared.  There is never any value in making excuses that blame
"stupid" users (or "stupid" caller code).