abuild: implement automatic -lang subpackages

abuild.in

@@ -478,6 +478,21 @@ prepare_subpackages() {
 	fi
 }
 
+default_lang() {
+	pkgname="Languages for package $pkgname"
+	install_if="$pkgname=$pkgver-r$pkgrel lang"
+	arch="noarch"
+	local dir
+	for dir in ${langdir:-/usr/share/locale}; do
+		mkdir -p "$subpkgdir"/${dir%/*}
+		mv "$pkgdir"/"$dir" "$subpkgdir"/"$dir" || return 1
+	done
+}
+
+lang() {
+	default_lang
+}
+
 default_lang_subpkg() {
 	if [ -z "$lang" ]; then
 		error "lang is not set"