app-backup/amanda: make NDMP optional

NDMP is an uncommon feature, and fails to build with newer glibc at this time; make it optional for now.

Closes: https://bugs.gentoo.org/376127
Closes: https://bugs.gentoo.org/636262
Closes: https://github.com/gentoo/gentoo/pull/6137
Closes: https://github.com/gentoo/gentoo/pull/6138
Closes: https://github.com/gentoo/gentoo/pull/6142
(cherry picked from commit 337a72935369e963b74b8293e3a9ecbce1383bd0)
Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>

app-backup/amanda/amanda-3.5.ebuild

@@ -10,7 +10,7 @@ SRC_URI="mirror://sourceforge/amanda/${P}.tar.gz"
 
 LICENSE="HPND BSD BSD-2 GPL-2+ GPL-3+"
 SLOT="0"
-IUSE="curl gnuplot ipv6 kerberos minimal nls readline s3 samba systemd xfs"
+IUSE="curl gnuplot ipv6 kerberos minimal ndmp nls readline s3 samba systemd xfs"
 
 KEYWORDS="~amd64 ~ppc ~ppc64 ~sparc ~x86"
 RDEPEND="sys-libs/readline:=
@@ -288,6 +288,9 @@ src_configure() {
 	# build manpages
 	myconf="${myconf} --enable-manpage-build"
 
+	# Bug #636262
+	myconf="${myconf} $(use_with ndmp ndmp)"
+
 	# bug #483120
 	tc-export AR
 

app-backup/amanda/metadata.xml

@@ -23,6 +23,7 @@
 	<use>
 		<flag name="xfs">Support for backing up raw XFS filesystems using xfsdump</flag>
 		<flag name="s3">Support for backing up to the Amazon S3 system</flag>
+		<flag name="ndmp">Support for the NDMP protocol</flag>
 	</use>
 	<upstream>
 		<remote-id type="sourceforge">amanda</remote-id>