From: Torsten Bögershausen <tboegi@web.de>
Date: Fri, 13 Sep 2013 13:59:46 GMT
Subject: Re: [PATCH 1/2] relative_path should honor dos_drive_prefix
Message-ID: <52331A52.3010300@web.de>
In-Reply-To: <CANYiYbE6nT+9LrekWp7mryJ13RxQBSQ+p6EyQspAKBMj7oG0zQ@mail.gmail.com>

On 13.09.13 06:55, Jiang Xin wrote:
> 2013/9/13 Junio C Hamano <gitster@pobox.com>:
>> For systems that need POSIX escape hatch for Apollo Domain ;-), we
>> would need a bit more work.  When both path1 and path2 begin with a
>> double-dash, we would need to check if they match up to the next
>> slash, so that
>>
>>  - //host1/usr/src and //host1/usr/lib share the same root and the
>>    former can be made to ../src relative to the latter;
>>
>>  - //host1/usr/src and //host2/usr/lib are of separate roots.
>>
>> or something.
>>
>>
> But how could we know which platform supports network pathnames and
> needs such implementation.
Similar to the has_dos_drive_prefix:

For Windows/Mingw we do like this

mingw.h
#define has_dos_drive_prefix(path) (isalpha(*(path)) && (path)[1] == ':')

And all other platforms defines has_dos_drive_prefix() to be 0 here
git-compat-util.h
#ifndef has_dos_drive_prefix
#define has_dos_drive_prefix(path) 0
#endif

mingw.h:
#define has_unc_path_prefix(path) ((path)[0] == '/' && (path)[1] == '/')
(Or may be)
#define has_unc_path_prefix(path) (is_dir_sep((path)[0])   && is_dir_sep((path)[1]))