On Fri, May 02, 2025 at 09:16:51PM -0700, Collin Funk wrote:
> As documented on NetBSD's man page, open with the O_NOFOLLOW flag and a
> symlink returns -1 and sets errno to EFTYPE which differs from POSIX.
>
> This patch fixes the following test failure:
>
> $ sh t0602-reffiles-fsck.sh --verbose
> --- expect 2025-05-02 23:05:23.920890147 +0000
> +++ err 2025-05-02 23:05:23.916794959 +0000
> @@ -1 +1 @@
> -error: packed-refs: badRefFiletype: not a regular file but a symlink
> +error: unable to open '.git/packed-refs': Inappropriate file type or format
> not ok 12 - the filetype of packed-refs should be checked
>
> FreeBSD has the same issue for EMLINK instead of EFTYPE.
>
> This portability issue was introduced in cfea2f2da8 (packed-backend:
> check whether the "packed-refs" is regular file, 2025-02-28)
Ok, makes sense.
> diff --git a/wrapper.c b/wrapper.c
> index 3c79778055..f74e3f7747 100644
> --- a/wrapper.c
> +++ b/wrapper.c
> @@ -737,7 +737,26 @@ int is_empty_or_missing_file(const char *filename)
> int open_nofollow(const char *path, int flags)
> {
> #ifdef O_NOFOLLOW
> - return open(path, flags | O_NOFOLLOW);
> + int ret = open(path, flags | O_NOFOLLOW);
> + /*
> + * NetBSD sets errno to EFTYPE when path is a symlink. The only other
> + * time this errno occurs when O_REGULAR is used. Since we don't use
> + * it anywhere we can avoid an lstat here. FreeBSD does the same with
> + * EMLINK.
> + */
> +#ifdef __NetBSD__
> +#define SYMLINK_ERRNO EFTYPE
> +#elif defined(__FreeBSD__)
> +#define SYMLINK_ERRNO EMLINK
> +#endif
Nit, to make this a bit easier to read: our style guide says that nested
preprocessor directives should be indented by one spaces. So this would
become:
# ifdef __NetBSD__
# define SYMLINK_ERRNO EFTYPE
# elif defined(__FreeBSD__)
# define SYMLINK_ERRNO EMLINK
# endif
Note that the `ifdef` itself would also be indented because we already
have a surrounding `#ifdef O_NOFOLLOW`.
> +#if SYMLINK_ERRNO
> + if (ret < 0 && errno == SYMLINK_ERRNO) {
> + errno = ELOOP;
> + return -1;
> + }
> +#undef SYMLINK_ERRNO
> +#endif
These three preprocessor defines should be indented, as well.
Patrick
