From 8a84376a14488cf9e8cbbbae162bb782a6d378b9 Mon Sep 17 00:00:00 2001
From: Magnus Jacobsson <magnus.jacobsson@berotec.se>
Date: Sat, 3 Oct 2020 16:03:37 +0200
Subject: [PATCH] Show usage and exit non-zero for unsupported option in
 dijkstra

Towards https://gitlab.com/graphviz/graphviz/-/issues/1843.
---
 cmd/tools/dijkstra.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/cmd/tools/dijkstra.c b/cmd/tools/dijkstra.c
index 8269b9afd..ba12bc7ba 100644
--- a/cmd/tools/dijkstra.c
+++ b/cmd/tools/dijkstra.c
@@ -263,9 +263,11 @@ static void init(int argc, char *argv[])
 	case '?':
 	    if (optopt == '?')
 		usage(0);
-	    else
-		fprintf(stderr, "%s: option -%c unrecognized - ignored\n",
+	    else {
+		fprintf(stderr, "%s: option -%c unrecognized\n",
 			CmdName, optopt);
+		usage(1);
+	    }
 	    break;
 	}
     }
-- 
2.40.0