I tested a full-symbol version and found that tar segfaulted due to 'argp'.
Tar is using its own internal implementation of argp, instead of linking to
the one most musl-based distros are using - argp-standalone. In other
words, that internal implementation is not compatible with musl and there's
no actual bug in tar.

I am satisfied with add -largp, but one more question: what's the reason
for not adding argp to musl? I can understand execinfo is hard to add (from
mail)and fts is waiting for changes of API(in wiki). They're not portable
for adding, so what's wrong with argp then? I did not find any mail related
to this question. And I am sorry if i missed anything.

He X

2017-03-25 2:36 GMT+08:00 Rich Felker <dalias@libc.org>:

> On Thu, Mar 23, 2017 at 01:05:55PM +0800, He X wrote:
> > Hi, rich, happy that you merged the changes related to dcngettext(). But
> > you seems forget this simple patch and did not get it with those changes.
> > So i bump it again now. Hope you do not mind if you still remember it.
> >
> > He X
> >
> > 2017-03-04 16:08 GMT+08:00 He X <xw897002528@gmail.com>:
> >
> > > following http://www.openwall.com/lists/musl/2017/02/13/8 ,
> > > http://www.openwall.com/lists/musl/2017/03/04/1 and
> > > http://www.openwall.com/lists/musl/2017/02/13/5:
> > >
> > > > gnu tar showed me segfaults, because he passed a zero msgid1 causing
> > > __mo_lookup segfault, we should add a check in dcngettext to avoid
> it(if
> > > (!msgid1) goto notrans;):
> > >
> > >  #2  0x00007ffff7d82a6f in dcngettext (domainname=0x6737a0 "tar",
> > > msgid1=0x0, msgid2=0x0, n=1,
> > >     category=5) at src/locale/dcngettext.c:211
>
> Indeed, I did forget. But looking at it more closely, according to the
> GNU gettext manual I think this is a bug in GNU tar:
>
>     "If the argument is NULL the result is undefined."
>
> https://www.gnu.org/software/gettext/manual/html_node/
> Interface-to-gettext.html
>
> Whether we commit this patch or not, I think it should be reported as
> a bug in GNU tar.
>
> Given that the API documentation says a NULL pointer is not valid
> here, my leaning, in alignment with existing musl practice, is _not_
> to make it silently "work" but to leave it crashing, so that this sort
> of bug is caught. But if the documentation is wrong and the practice
> of passing null pointers here is widely accepted we can reconsider.
>
> Rich
>