From c12ecef56637a5d6c695fafe2a39b79710921415 Mon Sep 17 00:00:00 2001
From: Nunuhara Cabbage <nunuhara@haniwa.technology>
Date: Sun, 27 Mar 2022 13:55:07 -0700
Subject: [PATCH] Display error message for invalid argument

If the game can't be initialized with the given command line argument,
display an error message and exit.
---
 src/system4.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/system4.c b/src/system4.c
index b82784a..5e9bfb4 100644
--- a/src/system4.c
+++ b/src/system4.c
@@ -478,6 +478,9 @@ int main(int argc, char *argv[])
 		config_init_with_ini(argv[0]);
 	} else if (!strcasecmp(file_extension(argv[0]), "ain")) {
 		config_init_with_ain(argv[0]);
+	} else {
+		usage();
+		ERROR("Can't initialize game with argument '%s'", argv[0]);
 	}
 	ainfile = gamedir_path(config.ain_filename);