Bugzilla Bug 82825

sendmail is not built with NIS support even if nis is included
in the system's USE variable.

Reproducible: Always
Steps to Reproduce:
1. add "nis" to USE variable
2. emerge sendmail
3.

Actual Results:  
sendmail is built without NIS support and cannot reference
NIS based databases (such as aliases files)

Expected Results:  
if the nis flag is in the system's USE variable sendmail should be
built with NIS database support.

Bug #18578 reported this bug for the sendmail-8.12.9.ebuild
only. This should be fixed for all present and future ebuilds.
In order to properly add NIS support to the sendmail ebuilds I
think two changes should be made. First "nis" should be added to
the IUSE string.

  IUSE="ssl ldap sasl tcpd mbox milter mailwrapper ipv6 nis"

Second, the following line should be added so that the sendmail
binary is compiled with NIS support if nis is in the system's USE variable.

        use ipv6 && confENVDEF="${confENVDEF} -DNETINET6"
      + use nis && confMAPDEF="${confMAPDEF} -DNIS"

Committed 8.13.8 with USE="nis" flag.