From: Junio C Hamano <gitster@pobox.com>
Date: Sat, 23 Jan 2010 20:04:00 GMT
Subject: Re: [PATCH] Handle double slashes in make_relative_path()
Message-ID: <7vwrz8bnbj.fsf@alter.siamese.dyndns.org>
In-Reply-To: <201001231409.30706.j6t@kdbg.org>

Johannes Sixt <j6t@kdbg.org> writes:

> On Samstag, 23. Januar 2010, Robin Rosenberg wrote:
>> It seems this function does something unhealthy when you pass a path of the
>> form //server/share. On windows dropping the double // at the beginning
>> makes it a different path since // is the UNC prefix.
>
> There is no problem in practice.
>
> The function returns either the input unmodified, or it strips also at least 
> one directory component, except when base is only "/" (or "//" or "///"...). 
> I said in practice, because on Windows it does not make sense to invoke git 
> with (literally)
>
>    git --git-dir=//server/share/repo.git --work-tree=/ ...
>
> i.e., without a drive prefix before the slash of --work-tree.

If you did this:

    git --git-dir=//reposerver/repo.git --work-tree=//buildserver/workarea

then we would say "one is not a prefix of the other", so it would be
fine.  At least I don't think the "recover from unintentionally doubled
slashes in user supplied path" fix is introducing any new problem in that
case.

If on the other hand, if you did this:

    git --git-dir=//server/repo.git --work-tree=//server/workarea

that also would be Ok.

I think one issue is what happens when you did this:

    cd //server
    git --git-dir=//server/repo/repo.git --work-tree=repo

Does msysgit implementation figures out that the work tree is located at
"//server/repo" when get_git_work_tree() is asked to produce an absolute
path so that it can be compared with //server/repo/repo.git with the code?
If it does (with the leading double slash), then "doubled slahses fix" is
a regression we should do something about it.  If it doesn't, then it
probably doesn't matter.