bug#10489: 24.0.92; dired-do-copy may create infinite directory hierarchy

[Stefan Monnier]

>> If you don't create "test1" and file-subdir-of-p is unable to handle a
>> non--existing directory,I don't understand how you want to do.
> I was saying that files-equal-p returns unexpected results in case both
> files do not exist. I haven't spoken about file-subdir-of-p.

Exactly.  I don't think noexist is needed for subdir-p (it should accept
a non-existing dir for the `dir1' argument, without any need for
a noexist arg and it should reject a non-existing dir2), but I can live
with it, but file-equal-p only makes sense for existing files and should
not have a `noexist' argument.


        Stefan