Subject: Re: [PATCH v2 2/3] relative_path should honor dos_drive_prefix

From: Torsten Bögershausen <[email-masked]>
Date: Sat, 14 Sep 2013 08:11:31 +0200

On 13.09.13 07:08, Jiang Xin wrote:
> Tvangeste found that the "relative_path" function could not work
> properly on Windows if "in" and "prefix" have dos driver prefix.
> ($gmane/234434)
>
> e.g., When execute: test-path-utils relative_path "C:/a/b" "D:/x/y",
> should return "C:/a/b", but returns "../../C:/a/b", which is wrong.
>
> So make relative_path honor dos_drive_prefix, and add test cases
> for it in t0060.
>
> Reported-by: Tvangeste <[email-masked]>
> Helped-by: Johannes Sixt <[email-masked]>
> Signed-off-by: Jiang Xin <[email-masked]>
> ---
>  path.c                | 20 ++++++++++++++++++++
>  t/t0060-path-utils.sh |  4 ++++
>  2 files changed, 24 insertions(+)
>
> diff --git a/path.c b/path.c
> index 9fd28bcd..65d376d 100644
> --- a/path.c
> +++ b/path.c
> @@ -434,6 +434,16 @@ int adjust_shared_perm(const char *path)
>  	return 0;
>  }
>  
> +static int have_same_root(const char *path1, const char *path2)
> +{
> +	int is_abs1, is_abs2;
> +
> +	is_abs1 = is_absolute_path(path1);
> +	is_abs2 = is_absolute_path(path2);
> +	return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
> +	       (!is_abs1 && !is_abs2);
> +}
> +
I think the name of the fuction is somewhat misleading, as we are not sure if
they really have the same root.
And that is investigated further down.

may_have_same_root() could be a better name.

[snip]

>  	while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
>  		if (is_dir_sep(prefix[i])) {
>  			while (is_dir_sep(prefix[i]))
> diff --git a/t/t0060-path-utils.sh b/t/t0060-path-utils.sh
> index 82a6f21..0187d11 100755
> --- a/t/t0060-path-utils.sh
> +++ b/t/t0060-path-utils.sh
> @@ -210,6 +210,10 @@ relative_path foo/a/b/		foo/a/b		./
>  relative_path foo/a		foo/a/b		../
>  relative_path foo/x/y		foo/a/b		../../x/y
>  relative_path foo/a/c		foo/a/b		../c
> +relative_path foo/a/b		/foo/x/y	foo/a/b
> +relative_path /foo/a/b		foo/x/y		/foo/a/b
> +relative_path d:/a/b		D:/a/c		../b		MINGW
> +relative_path C:/a/b		D:/a/c		C:/a/b		MINGW
Side question:
What happens if we feed in a relative path with a dos drive?
like "c:foo" which is different from c:/foo.