else if (!strcmp(argv[1], "--no-summary"))
                        merge_summary = 0;
                else if (!strcmp(argv[1], "-F") || !strcmp(argv[1], "--file")) {
-                       if (argc < 2)
+                       if (argc < 3)
                                die ("Which file?");
                        if (!strcmp(argv[2], "-"))
                                in = stdin;
                        else {
                                fclose(in);
                                in = fopen(argv[2], "r");
+                               if (!in)
+                                       die("cannot open %s", argv[2]);
                        }
                        argc--; argv++;
                } else
 
        return 0;
 }
-