Re: [GSoC][PATCH v7 06/10] dir-iterator: add flags parameter to dir_iterator_begin

From: Matheus Tavares Bernardino <matheus.bernardino@usp.br>
Date: Jun 27, 2019, 17:23 UTC
Message-ID: <CAHd-oW5zea9wzobAQG4FzN-KSS5BsRoM5vf_x_F83=yqGRfUQw@mail.gmail.com>
In-Reply-To: <xmqqwoh8cjeg.fsf@gitster-ct.c.googlers.com>

On Wed, Jun 26, 2019 at 3:04 PM Junio C Hamano <gitster@pobox.com> wrote:

Show 29 quoted lines

>
> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
>
> > Hi Matheus,
> >
> > On Tue, 18 Jun 2019, Matheus Tavares wrote:
> >
> >>[...]
> >> +/*
> >> + * Look for a recursive symlink at iter->base.path pointing to any directory on
> >> + * the previous stack levels. If it is found, return 1. If not, return 0.
> >> + */
> >> +static int find_recursive_symlinks(struct dir_iterator_int *iter)
> >> +{
> >> +    int i;
> >> +
> >> +    if (!(iter->flags & DIR_ITERATOR_FOLLOW_SYMLINKS) ||
> >> +        !S_ISDIR(iter->base.st.st_mode))
> >> +            return 0;
> >>
> >> +    for (i = 0; i < iter->levels_nr; ++i)
> >> +            if (iter->base.st.st_ino == iter->levels[i].ino)
> >
> > This does not work on Windows. [[ Windows port does not have
> > usable st_ino field ]]]
>
> And if you cross mountpoint, st_ino alone does not guarantee
> uniqueness; you'd need to combine it with st_dev, I would think,
> even on POSIX systems.

Ok, thanks for letting me know. I'm trying to think of another approach to test for recursive symlinks that does not rely on inode: Given any symlink, we could get its real_path() and compare it with the path of the directory current being iterated. If the first is a prefix of the second, than we mark it as a recursive symlink.

What do you think of this idea?