app-arch/7zip: add symlink useflag

goal is to allow packages which only use the 7z/7zr/7za binaries
to be able to depend on 7zip[symlink] rather than p7zip. this is
a step towards replacing the unmaintained p7zip.

Bug: https://bugs.gentoo.org/942397
Signed-off-by: NRK <nrk@disroot.org>
Signed-off-by: Sam James <sam@gentoo.org>

app-arch/7zip/7zip-24.09.ebuild

@@ -18,18 +18,20 @@ S="${WORKDIR}"
 LICENSE="LGPL-2 BSD rar? ( unRAR )"
 SLOT="0"
 KEYWORDS="amd64 arm64 ~ppc ~ppc64 ~riscv"
-IUSE="uasm jwasm rar"
+IUSE="uasm jwasm rar symlink"
 REQUIRED_USE="?? ( uasm jwasm )"
 
 DOCS=( readme.txt History.txt License.txt )
 HTML_DOCS=( MANUAL )
 
-DEPEND="${RDEPEND}"
 BDEPEND="
 	app-arch/xz-utils[extra-filters(+)]
 	uasm? ( dev-lang/uasm )
 	jwasm? ( dev-lang/jwasm )
 "
+RDEPEND="
+	symlink? ( !app-arch/p7zip )
+"
 
 PATCHES=(
 	"${FILESDIR}/${PN}-24.05-respect-build-env.patch"
@@ -107,5 +109,10 @@ src_compile() {
 
 src_install() {
 	dobin "./CPP/7zip/Bundles/Alone2/b/${bdir}/7zz"
+	if use symlink; then
+		dosym 7zz /usr/bin/7z
+		dosym 7zz /usr/bin/7za
+		dosym 7zz /usr/bin/7zr
+	fi
 	einstalldocs
 }

app-arch/7zip/metadata.xml

@@ -16,6 +16,7 @@
 		<flag name="rar">Enable support for non-free rar decoder</flag>
 		<flag name="uasm">Use <pkg>dev-lang/uasm</pkg> to include optimized code</flag>
 		<flag name="jwasm">Use <pkg>dev-lang/jwasm</pkg> to include optimized code (doesn't support AES)</flag>
+		<flag name="symlink">Install additional symlink to 7z, 7za and 7zr</flag>
 	</use>
 	<upstream>
 		<maintainer>