www-client/firefox: add eme-free use flag to buildtime-disable all DRM plugin loading

For those wanting to ensure firefox will never load any closed DRM content plugins
or allow any user on the system to do so in their profile, USE="eme-free" now
triggers --disable-eme in the build configuration, which entirely removes the
capability of DRM plugin loading.  This flag nullifies the effect that
USE=-gmp-autoupdate performs but a REQUIRED_USE was not implemented as
forcing package.use modifications seems overkill for what becomes a do-nothing
flag.

3 files changed, 11 insertions, 6 deletions

diff --git a/www-client/firefox/firefox-52.4.0.ebuild b/www-client/firefox/firefox-52.4.0.ebuild
index ab4e45da..ebd29fbf 100644
--- a/www-client/firefox/firefox-52.4.0.ebuild
+++ b/www-client/firefox/firefox-52.4.0.ebuild
@@ -39,7 +39,7 @@ KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~ia64 ~ppc ~ppc64 ~x86 ~amd64-linux ~x86-lin
 
 SLOT="0"
 LICENSE="MPL-2.0 GPL-2 LGPL-2.1"
-IUSE="bindist +gmp-autoupdate hardened hwaccel jack pgo rust selinux test"
+IUSE="bindist eme-free +gmp-autoupdate hardened hwaccel jack pgo rust selinux test"
 RESTRICT="!bindist? ( bindist )"
 
 PATCH_URIS=( https://dev.gentoo.org/~{anarchy,axs,polynomial-c}/mozilla/patchsets/${PATCH}.tar.xz )
@@ -204,6 +204,8 @@ src_configure() {
 	# enable JACK, bug 600002
 	mozconfig_use_enable jack
 
+	use eme-free && mozconfig_annotate '+eme-free' --disable-eme
+
 	# It doesn't compile on alpha without this LDFLAGS
 	use alpha && append-ldflags "-Wl,--no-relax"
 
@@ -298,7 +300,7 @@ src_install() {
 		|| die
 
 	local plugin
-	use gmp-autoupdate || for plugin in "${GMP_PLUGIN_LIST[@]}" ; do
+	use gmp-autoupdate || || use eme-free || for plugin in "${GMP_PLUGIN_LIST[@]}" ; do
 		echo "pref(\"media.${plugin}.autoupdate\", false);" >> \
 			"${BUILD_OBJ_DIR}/dist/bin/browser/defaults/preferences/all-gentoo.js" \
 			|| die
@@ -386,7 +388,7 @@ pkg_postinst() {
 	xdg_desktop_database_update
 	gnome2_icon_cache_update
 
-	if ! use gmp-autoupdate ; then
+	if ! use gmp-autoupdate && ! use eme-free ; then
 		elog "USE='-gmp-autoupdate' has disabled the following plugins from updating or"
 		elog "installing into new profiles:"
 		local plugin
diff --git a/www-client/firefox/firefox-56.0.ebuild b/www-client/firefox/firefox-56.0.ebuild
index 144ad8f8..b970878d 100644
--- a/www-client/firefox/firefox-56.0.ebuild
+++ b/www-client/firefox/firefox-56.0.ebuild
@@ -38,7 +38,7 @@ KEYWORDS="~amd64 ~x86"
 
 SLOT="0"
 LICENSE="MPL-2.0 GPL-2 LGPL-2.1"
-IUSE="bindist +gmp-autoupdate hardened hwaccel jack nsplugin pgo selinux test"
+IUSE="bindist eme-free +gmp-autoupdate hardened hwaccel jack nsplugin pgo selinux test"
 RESTRICT="!bindist? ( bindist )"
 
 PATCH_URIS=( https://dev.gentoo.org/~{anarchy,axs,polynomial-c}/mozilla/patchsets/${PATCH}.tar.xz )
@@ -195,6 +195,8 @@ src_configure() {
 	# enable JACK, bug 600002
 	mozconfig_use_enable jack
 
+	use eme-free && mozconfig_annotate '+eme-free' --disable-eme
+
 	# It doesn't compile on alpha without this LDFLAGS
 	use alpha && append-ldflags "-Wl,--no-relax"
 
@@ -292,7 +294,7 @@ src_install() {
 	fi
 
 	local plugin
-	use gmp-autoupdate || for plugin in "${GMP_PLUGIN_LIST[@]}" ; do
+	use gmp-autoupdate || use eme-free || for plugin in "${GMP_PLUGIN_LIST[@]}" ; do
 		echo "pref(\"media.${plugin}.autoupdate\", false);" >> \
 			"${BUILD_OBJ_DIR}/dist/bin/browser/defaults/preferences/all-gentoo.js" \
 			|| die
@@ -380,7 +382,7 @@ pkg_postinst() {
 	xdg_desktop_database_update
 	gnome2_icon_cache_update
 
-	if ! use gmp-autoupdate ; then
+	if ! use gmp-autoupdate && ! use eme-free ; then
 		elog "USE='-gmp-autoupdate' has disabled the following plugins from updating or"
 		elog "installing into new profiles:"
 		local plugin
diff --git a/www-client/firefox/metadata.xml b/www-client/firefox/metadata.xml
index 56f49272..a338b442 100644
--- a/www-client/firefox/metadata.xml
+++ b/www-client/firefox/metadata.xml
@@ -10,6 +10,7 @@
 		are not binary-redistributable according to upstream.</flag>
 	<flag name="custom-optimization">Build with user-specified compiler optimizations
 		(-Os, -O0, -O1, -O2, -O3) from CFLAGS (unsupported)</flag>
+	<flag name="eme-free">Disable EME (DRM plugin) cabability at build time</flag>
 	<flag name="gtk2">Use the cairo-gtk2 rendering engine</flag>
 	<flag name="gmp-autoupdate">Allow Gecko Media Plugins (binary blobs) to be automatically
 		downloaded and kept up-to-date in user profiles</flag>