Re: [PATCH] git mv: do not keep slash in `git mv dir non-existing-dir/`

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Junio,

On Fri, 5 Aug 2016, Junio C Hamano wrote:

> Johannes Schindelin <johannes.schindelin@gmx.de> writes:
> 
> > When calling `rename("dir", "non-existing-dir/")` on Linux, it silently
> > succeeds, stripping the trailing slash of the second argument.
> >
> > This is all good and dandy but this behavior disagrees with the specs at
> >
> > http://pubs.opengroup.org/onlinepubs/9699919799/functions/rename.html
> >
> > that state clearly regarding the 2nd parameter (called `new`):
> >
> > 	If the `new` argument does not resolve to an existing directory
> > 	entry for a file of type directory and the `new` argument
> > 	contains at least one non- <slash> character and ends with one
> > 	or more trailing <slash> characters after all symbolic links
> > 	have been processed, `rename()` shall fail.
> 
> I agree with all of the above.  But
> 
> > Of course, we would like `git mv dir non-existing-dir/` to succeed (and
> > rename the directory "dir" to "non-existing-dir").
> 
> I do not think I want that.  When I say "mv A B/", I want it to fail
> if I made a typo for B; the trailing slash after B is an explicit
> statement "I expect B to exist and I want A to appear at B/A".

Please note that t7001 *specifically* tests for the opposite of what you
want, then ;-)

	https://github.com/git/git/blob/v2.9.2/t/t7001-mv.sh#L79-L80

> Current Git behaviour on Linux seems to allow "git mv dir no-such-dir/"
> but "dir" is renamed to "no-such-dir", which fails two expectations,
> and I think this is broken.  If Windows port does not share this
> breakage, that is a good thing.  We should fix Git behaviour on Linux
> instead, I would think.

To be precise, Git for Windows displays the same behavior as Git on Linux,
because rename("dir", "no-such-dir/") succeeds.

The breakage fixed by this here patch happens when running plain Linux Git
in "Bash on Windows" (i.e. Bash on Ubuntu on Windows, the new Linux
subsystem of Windows, allowing to run unmodified Linux binaries on Windows
without the need for a Virtual Machine).

Ciao,
Dscho