app-shells/rc: only update /etc/shells when needed

diff --git a/app-shells/rc/rc-1.7.4.ebuild b/app-shells/rc/rc-1.7.4.ebuild
index 551f043253b4a7569a3b55b76abad7679ad70739..22f4fd6d069984481f36b1cdecbb4d90fcad4dfd 100644 (file)
--- a/app-shells/rc/rc-1.7.4.ebuild
+++ b/app-shells/rc/rc-1.7.4.ebuild
@@ -35,8 +35,9 @@ src_install() {
 }
 
 pkg_postinst() {
-       ebegin "Updating /etc/shells"
-       ( grep -v "^/bin/rcsh$" "${ROOT}"etc/shells; echo "/bin/rcsh" ) > "${T}"/shells
-       mv -f "${T}"/shells "${ROOT}"etc/shells
-       eend $?
+       if ! grep -q '^/bin/rcsh$' "${EROOT}"/etc/shells ; then
+               ebegin "Updating /etc/shells"
+               echo "/bin/rcsh" >> "${EROOT}"/etc/shells
+               eend $?
+       fi
 }