bug#22300: 25.1.50; Dired -- renaming folders/files to CamelCase/UPPERCASE/lowercase.

[Eli Zaretskii]

> Date: Sun, 3 Jan 2016 17:37:37 -0800 (PST)
> From: Drew Adams <drew.adams@oracle.com>
> Cc: 22300-done@debbugs.gnu.org, Keith David Bershatsky <esq@lawlist.com>
> 
> > His description matches something I run into myself all the time, due to
> > Emacs's case insensitive filesystem:
> > 
> >     17:10:45 Vulcan:/tmp $ mv foo Foo
> >     mv: ‘foo’ and ‘Foo’ are the same file
> 
> Okay.  But (1) he _is_ able to do it using `mv foo Foo', and
> (2) MS Windows is also case-insensitive for files and folders,
> and I can easily use `R' to rename a directory `foo' to `FOO',
> and vice versa.  (Emacs asks me to confirm that I want to rename,
> but that's all.)

For some value of "easily", yes.  On the C source level, Emacs works
very hard (a.k.a. "jumps through hoops") to allow you doing that
easily, and it does that only for MS-Windows and MS-DOS, whose
filesystems are known to be case-insensitive.  OS X doesn't have that
privilege.

If OS X filesystems are always case-insensitive, perhaps the same code
should also be compiled on that system.  If some of OS X filesystems
are case-sensitive, we can only do that if Emacs can know which one is
it.