On Wed, 2014-05-07 at 10:46 -0700, Junio C Hamano wrote:
> David Turner <dturner@xxxxxxxxxxxxxxxx> writes:
>
> > On Wed, 2014-05-07 at 08:17 +0200, Johannes Sixt wrote:
> >> > } else if (cache_name_pos(src, length) < 0)
> >> > bad = _("not under version control");
> >> > - else if (lstat(dst, &st) == 0) {
> >> > + else if (lstat(dst, &dst_st) == 0 &&
> >> > + (src_st.st_ino != dst_st.st_ino ||
> >> > + (src_st.st_ino == 0 && strcasecmp(src, dst)))) {
> >>
> >> Don't do that. st_ino is zero on Windows only because we do not spend time
> >> to fill in the field. Don't use it as an indicator for a case-insensitive
> >> file system; zero may be a valid inode number on other systems.
> >
> > I don't think it is a problem if zero is a valid inode. The only thing
> > that happens when there is a zero inode, is that we have to compare
> > filenames. The inode check is just an optimization to avoid doing a
> > bunch of strcasecmp on systems that don't have to.
>
> Am I correct to rephrase you that the code assumes that any
> filesystem that cannot give unique inum to different files will use
> 0 as the placeholder inum, so if src/dst share the same non-zero
> inum, it is guaranteed that is not a placeholder and we know they
> are different files without comparing the two paths?
Yes, this is indeed a fair rephrasing. In fact, the entire zero-check
should not be necessary, as POSIX requires that the st_ino field has a
"meaningful" value. So in the case that this ever runs into a problem,
we ought to wrap the lstat call with a compatibility layer anyway.
But maybe there is an OS I'm not thinking of which fills in st_ino with
something else?
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html