From: Michael Haggerty <mhagger@alum.mit.edu>
Date: Tue, 07 Jan 2014 09:26:44 GMT
Subject: Re: [PATCH v2 03/17] safe_create_leading_directories(): add explicit "slash" pointer
Message-ID: <52CBC854.2060602@alum.mit.edu>
In-Reply-To: <xmqqppo5hsf9.fsf@gitster.dls.corp.google.com>

On 01/06/2014 07:32 PM, Junio C Hamano wrote:
> Michael Haggerty <mhagger@alum.mit.edu> writes:
> 
>> Keep track of the position of the slash character independently of
>> "pos", thereby making the purpose of each variable clearer and
>> working towards other upcoming changes.
>>
>> Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
>> ---
> 
> This step has an interaction with $gmane/239878 where Windows folks
> want it to pay attention to is_dir_sep()---over there, a backslash
> could separate directory path components.
> 
> AFAIK, the function was meant to be used only on paths we internally
> generate, and the paths we internally generate all are slash
> separated, so it could be argued that feeding a path, whose path
> components are separated by backslashes, that we obtained from the
> end user without converting it to the internal form in some
> codepaths (e.g. "$there" in "git clone $url $there") are bugs we
> acquired over time that need to be fixed, but it is easy enough to
> use is_dir_sep() here to work it around, and doing so will
> not negatively affect
> 
>  1. UNIX-only projects by forbidding use of a byte with backslash in
>     it as a path component character (yes, I am imagining using
>     Shift-JIS that can use a backslash as the second byte of
>     two-byte character in the pathname on UNIX); and
> 
>  2. UNIX-and-Windows mixed projects, as you cannot sanely use such a
>     pathname with backslash as part of a path component if its tree
>     needs to be checked out on Windows.

I agree that it would be reasonable to use is_dir_sep() in the
implementation of this function, at least unless/until somebody does the
work to figure out whether callers should really only be passing it
forward-slash-normalized paths.

Please be careful, though, because I don't think this function is
capable of handling arbitrary Windows paths, like for example
//host/path format, either before or after my change.

Let me know if you would like me to merge or rebase the is_dir_sep()
changes into this patch series.

Michael

-- 
Michael Haggerty
mhagger@alum.mit.edu
http://softwareswirl.blogspot.com/