From a4aec0607b67f8d2b5d2da2893f2cca381c6d722 Mon Sep 17 00:00:00 2001
From: Gwenhael Le Moine <gwenhael.le.moine@gmail.com>
Date: Tue, 19 Sep 2023 19:25:54 +0200
Subject: [PATCH] explicit -u

---
 src/runtime_options.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/runtime_options.c b/src/runtime_options.c
index a8a1b1d..4c961f2 100644
--- a/src/runtime_options.c
+++ b/src/runtime_options.c
@@ -193,8 +193,12 @@ int parse_args( int argc, char* argv[] ) {
                     frontend_type = FRONTEND_SDL;
                 else if ( strcmp( optarg, "text" ) == 0 )
                     frontend_type = FRONTEND_TEXT;
-                else
+                else if ( strcmp( optarg, "x11" ) == 0 )
                     frontend_type = FRONTEND_X11;
+                else {
+                    fprintf( stderr, "Error: unknown frontend '%s'\n", optarg );
+                    exit( 1 );
+                }
                 break;
             case 'V':
                 verbose = 1;