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