Re: [PATCH 1/1] mingw: fix launching of externals from Unicode paths

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

"Adam Roben via GitGitGadget" <gitgitgadget@gmail.com> writes:

> Note that the only problem in this function was calling
> `GetFileAttributes()` instead of `GetFileAttributesW()`. The calls to
> `access()` were fine because `access()` is a macro which resolves to
> `mingw_access()`, which already handles Unicode correctly. But
> `lookup_prog()` was changed to use `_waccess()` directly so that we only
> convert the path to UTF-16 once.

Nicely explained.  Thanks.

>
> To make things work correctly, we have to maintain UTF-8 and UTF-16
> versions in tandem in `lookup_prog()`.
>
> Signed-off-by: Adam Roben <adam@roben.org>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>  compat/mingw.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/compat/mingw.c b/compat/mingw.c
> index 8141f77189..9f02403ebf 100644
> --- a/compat/mingw.c
> +++ b/compat/mingw.c
> @@ -1161,14 +1161,21 @@ static char *lookup_prog(const char *dir, int dirlen, const char *cmd,
>  			 int isexe, int exe_only)
>  {
>  	char path[MAX_PATH];
> +	wchar_t wpath[MAX_PATH];
>  	snprintf(path, sizeof(path), "%.*s\\%s.exe", dirlen, dir, cmd);
>  
> -	if (!isexe && access(path, F_OK) == 0)
> +	if (xutftowcs_path(wpath, path) < 0)
> +		return NULL;
> +
> +	if (!isexe && _waccess(wpath, F_OK) == 0)
>  		return xstrdup(path);
> -	path[strlen(path)-4] = '\0';
> -	if ((!exe_only || isexe) && access(path, F_OK) == 0)
> -		if (!(GetFileAttributes(path) & FILE_ATTRIBUTE_DIRECTORY))
> +	wpath[wcslen(wpath)-4] = '\0';
> +	if ((!exe_only || isexe) && _waccess(wpath, F_OK) == 0) {
> +		if (!(GetFileAttributesW(wpath) & FILE_ATTRIBUTE_DIRECTORY)) {
> +			path[strlen(path)-4] = '\0';
>  			return xstrdup(path);
> +		}
> +	}
>  	return NULL;
>  }