Re: [PATCH] fix pushing to //server/share/dir paths on Windows

[Junio C Hamano <gitster@pobox.com>]

Johannes Sixt <j6t@kdbg.org> writes:

> There is a change in behavior: \\server\share is not transformed
> into //server/share anymore, but all subsequent directory separators
> are rewritten to '/'. This should not make a difference; Windows can
> handle the mix.

I saw Dscho had a similar "windows can handle the mix" change in an
earlier development cycle, I think, and this is being consistent.

>  Another long-standing bug uncovered by the quarantine series.
>
>  Dscho, it looks like this could fix the original report at
>  https://github.com/git-for-windows/git/issues/979
>
>  This patch should cook well because of the change in behavior.
>  I would not be surprised if there is some fall-out.
>
>  The other bug I'm alluding to, I still have to investigate. I do
>  not think that it can be counted as fall-out.
>
>  path.c | 24 +++++++++++++++---------
>  1 file changed, 15 insertions(+), 9 deletions(-)

Thanks.

> diff --git a/path.c b/path.c
> index 52d889c88e..02dc70fb92 100644
> --- a/path.c
> +++ b/path.c
> @@ -991,7 +991,7 @@ const char *remove_leading_path(const char *in, const char *prefix)
>   *
>   * Performs the following normalizations on src, storing the result in dst:
>   * - Ensures that components are separated by '/' (Windows only)
> - * - Squashes sequences of '/'.
> + * - Squashes sequences of '/' except "//server/share" on Windows

"on windows" because offset_1st_component() does the magic only
there?  Makes sense.

>   * - Removes "." components.
>   * - Removes ".." components, and the components the precede them.
>   * Returns failure (non-zero) if a ".." component appears as first path
> @@ -1014,17 +1014,23 @@ const char *remove_leading_path(const char *in, const char *prefix)
>  int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
>  {
>  	char *dst0;
> -	int i;
> -
> -	for (i = has_dos_drive_prefix(src); i > 0; i--)
> -		*dst++ = *src++;
> -	dst0 = dst;
> +	int offset;
>  
> -	if (is_dir_sep(*src)) {
> +	/*
> +	 * Handle initial part of absolute path: "/", "C:/", "\\server\share/".
> +	 */
> +	offset = offset_1st_component(src);
> +	if (offset) {
> +		/* Convert the trailing separator to '/' on Windows. */
> +		memcpy(dst, src, offset - 1);
> +		dst += offset - 1;
>  		*dst++ = '/';
> -		while (is_dir_sep(*src))
> -			src++;
> +		src += offset;
>  	}
> +	dst0 = dst;

By resetting dst0 here, we ensure that up_one that is triggered by
seeing "../" will not escape the \\server\share\ part, which makes
sense to me.

> +	while (is_dir_sep(*src))
> +		src++;
>  
>  	for (;;) {
>  		char c = *src;