Fix option parsing for unknown flags

mcd segfaulted on any unrecognised option (e.g. -V) because usage()
called strlen(pid_file) before compose_paths() had initialised it.
Fix by moving compose_paths() into usage() itself.

mctl silently showed help and exited 0 for unknown options because
'?' is also in the option string as a -? help alias, masking the
error.  Split case '?' to check optopt and add a default branch so
unrecognised options exit with code 1.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

Author: troglobit

src/main.c

@@ -49,12 +49,14 @@ static int compose_paths(void)
 
 static int usage(int code)
 {
-    char pidbuf[strlen(pid_file) + 10];
-    char ipcbuf[strlen(_PATH_MCD_SOCK) + 42];
+    char pidbuf[PATH_MAX];
+    char ipcbuf[PATH_MAX];
     char *nm = PACKAGE_NAME;
     char *sockfn = ipcbuf;
     char *pidfn = pidbuf;
 
+    compose_paths();
+
     if (pid_file[0] == '/')
 	pidfn = pid_file;
     else
@@ -122,7 +124,6 @@ int main(int argc, char *argv[])
 	    break;
 
 	case 'h':
-	    compose_paths();
 	    return usage(0);
 
 	case 'i':	/* --ident=NAME */

src/mctl.c

@@ -641,9 +641,12 @@ int main(int argc, char *argv[])
 			break;
 
 		case 'h':
-		case '?':
 			return usage(0);
 
+		case '?':
+			/* optopt is set for unrecognized options, clear for -? */
+			return usage(optopt ? 1 : 0);
+
 		case 'i':	/* --ident=NAME */
 			ident = optarg;
 			break;
@@ -666,6 +669,9 @@ int main(int argc, char *argv[])
 
 		case 'v':
 			return version();
+
+		default:
+			return usage(1);
 		}
 	}