epm-downgrade: fix downgrade a package

bin/epm

@@ -331,7 +331,6 @@ check_command()
         ;;
     downgrade)                # HELPCMD: downgrade [all] packages to the repo state
         epm_cmd=downgrade
-        direct_args=1
         ;;
     download)                 # HELPCMD: download package(s) file to the current dir
         epm_cmd=download

bin/epm-downgrade

@@ -78,9 +78,14 @@ epm_downgrade()
 	apt-rpm)
 		local APTOPTIONS="$(subst_option non_interactive -y)"
 		__epm_add_alt_apt_downgrade_preferences || return
-		load_helper epm-upgrade
 		# pass pkg_filenames too
+		if [ -n "$pkg_names" ] ; then
+			load_helper epm-install
+			(pkg_names=$pkg_names epm_install)
+		else
+			load_helper epm-upgrade
 			epm_upgrade "$@"
+		fi
 		__epm_remove_apt_downgrade_preferences
 		;;
 	apt-dpkg)