Re: [GSoC][PATCH v5 2/7] clone: better handle symlinked files at .git/objects/

>
> On 03/30, Matheus Tavares wrote:
> > There is currently an odd behaviour when locally cloning a repository
> > with symlinks at .git/objects: using --no-hardlinks all symlinks are
> > dereferenced but without it, Git will try to hardlink the files with the
> > link() function, which has an OS-specific behaviour on symlinks. On OSX
> > and NetBSD, it creates a hardlink to the file pointed by the symlink
> > whilst on GNU/Linux, it creates a hardlink to the symlink itself.
> >
> > On Manjaro GNU/Linux:
> >     $ touch a
> >     $ ln -s a b
> >     $ link b c
> >     $ ls -li a b c
> >     155 [...] a
> >     156 [...] b -> a
> >     156 [...] c -> a
> >
> > But on NetBSD:
> >     $ ls -li a b c
> >     2609160 [...] a
> >     2609164 [...] b -> a
> >     2609160 [...] c
> >
> > It's not good to have the result of a local clone to be OS-dependent and
> > besides that, the current behaviour on GNU/Linux may result in broken
> > symlinks. So let's standardize this by making the hardlinks always point
> > to dereferenced paths, instead of the symlinks themselves. Also, add
> > tests for symlinked files at .git/objects/.
> >
> > Note: Git won't create symlinks at .git/objects itself, but it's better
> > to handle this case and be friendly with users who manually create them.
> >
> > Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
> > Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> > Co-authored-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> > ---
> >  builtin/clone.c            |  5 ++++-
> >  t/t5604-clone-reference.sh | 27 ++++++++++++++++++++-------
> >  2 files changed, 24 insertions(+), 8 deletions(-)
> >
> > diff --git a/builtin/clone.c b/builtin/clone.c
> > index 50bde99618..f975b509f1 100644
> > --- a/builtin/clone.c
> > +++ b/builtin/clone.c
> > @@ -443,7 +443,10 @@ static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
> >               if (unlink(dest->buf) && errno != ENOENT)
> >                       die_errno(_("failed to unlink '%s'"), dest->buf);
> >               if (!option_no_hardlinks) {
> > -                     if (!link(src->buf, dest->buf))
> > +                     char *resolved_path = real_pathdup(src->buf, 1);
> > +                     int status = link(resolved_path, dest->buf);
> > +                     free(resolved_path);
> > +                     if (!status)
>
> Is there any reason why we can't use 'real_path()' here?  As I
> mentioned in [*1*], 'real_path()' doesn't require the callers to free
> any memory, so the above could become much simpler, and could just be
>
> +                       if (!link(real_path(src->buf), dest->buf))
>

> *1*: <20190330192738.GQ32487@hank.intra.tgummerer.com>
>
> >                               continue;
> >                       if (option_local > 0)
> >                               die_errno(_("failed to create link '%s'"), dest->buf);