[pacman-dev] [PATCH] libalpm: fix documentation for alpm_pkg_mtree_next

[Morgan Adamiec]

On Thu, 20 Jun 2019 at 05:46, Allan McRae <allan at archlinux.org> wrote:
>
> On 14/6/19 11:26 pm, Dave Reisner wrote:
> > On Fri, Jun 14, 2019 at 02:19:52PM +0100, Morgan Adamiec wrote:
> >> On Fri, 14 Jun 2019 at 14:09, Dave Reisner <d at falconindy.com> wrote:
> >>>
> >>> On Fri, Jun 14, 2019 at 02:51:14AM +0100, morganamilo wrote:
> >>>> libarchive uses 1 for EOF, not 0. Instead of using the actual ints, use
> >>>> libarchive's error codes.
> >>>> ---
> >>>>
> >>>> By the way, not familiar with doxygen. Is my wording fine or is there
> >>>> some built in "see also" functionality?
> >>>>
> >>>> diff --git a/lib/libalpm/alpm.h b/lib/libalpm/alpm.h
> >>>> index ffb2ad96..ece894cf 100644
> >>>> --- a/lib/libalpm/alpm.h
> >>>> +++ b/lib/libalpm/alpm.h
> >>>> @@ -1326,7 +1326,8 @@ struct archive *alpm_pkg_mtree_open(alpm_pkg_t *pkg);
> >>>>   * @param pkg the package that the mtree file is being read from
> >>>>   * @param archive the archive structure reading from the mtree file
> >>>>   * @param entry an archive_entry to store the entry header information
> >>>> - * @return 0 if end of archive is reached, non-zero otherwise.
> >>>> + * @return ARCHIVE_OK on success, ARCHIVE_EOF if end of archive is reached,
> >>>> + * otherwise an error occured (see archive.h).
> >>>
> >>> Please, no. Let's not leak details from libarchive in our own API.
> >>>
> >>>>   */
> >>>>  int alpm_pkg_mtree_next(const alpm_pkg_t *pkg, struct archive *archive,
> >>>>               struct archive_entry **entry);
> >>>> --
> >>>> 2.21.0
> >>
> >> Why not? The return value is exactly that. If libarchive's return
> >> codes suddenly changed then so would libalpms's. Plus pacman itself
> >> already uses ARCHIVE_OK to check the return code. And finally if we
> >> did not depend on magic numbers then the doc wouldn't be wrong in the
> >> first place.
> >
> > Because users of libalpm should only need to understand libalpm and not
> > concern themselves with details of libarchive. Exposing ARCHIVE_* in
> > libalpm is a leaky abstraction.
> >
> > If the code is broken (and it sounds like it is), then it should be
> > fixed along with the documentation.
> >
>
> Agreed.   Not this is the only place in pacman we use an ARCHIVE_*
> value, so this is broken.
>
> src/pacman/check.c:     while(alpm_pkg_mtree_next(pkg, mtree, &entry) ==
> ARCHIVE_OK) {

Would is then also make sense to do `typedef struct archive
alpm_mtree_t` or something similar?