Show usage and exit non-zero for unsupported option in sccmap

Towards https://gitlab.com/graphviz/graphviz/-/issues/1843.

diff --git a/doc/libgraph/sccmap.c b/doc/libgraph/sccmap.c
index 6808462b64be67de478fd377a4ad99271db84981..0c37efc2ea8dfc979164bf348d2dd2dbc132b87d 100644 (file)
--- a/doc/libgraph/sccmap.c
+++ b/doc/libgraph/sccmap.c
@@ -313,9 +313,11 @@ static void scanArgs(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;
                }
        }