[PATCHv8] nss_db: protect against empty mappings

[Florian Weimer]

* DJ Delorie:

> diff --git a/ChangeLog b/ChangeLog
> index aece032385..37be9a998a 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -1,3 +1,19 @@
> +2019-06-28  DJ Delorie  <dj@redhat.com>
> +	    Sergei Trofimovich <slyfox@inbox.ru>
> +
> +	[BZ #24696]
> +	[BZ #24695]
> +	* nss/nss_db/db-open.c (internal_endent): Protect against NULL
> +	mappings.
> +	* nss/tst-nss-db-endgrent.c: New.
> +	* nss/tst-nss-db-endgrent.root: New.
> +	* nss/tst-nss-db-endpwent.c: New.
> +	* nss/tst-nss-db-endpwent.root: New.
> +	* nss/Makefile: Add new tests.
> +	* support/links-dso-program-c.c: Add selinux dependency.
> +	* support/links-dso-program.cc: Add selinux dependency.
> +	* support/Makefile: Build those with -lselinux if enabled.
> +

This version looks okay to me.  Thanks.

Florian