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

[Allan McRae]

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) {