[sfntdiff] Fix exit codes

Fixes #348

Author: miguelsousa

c/sfntdiff/source/Dmain.c

@@ -54,7 +54,6 @@ static void printUsage(void) {
 /* Show usage information */
 static void showUsage(void) {
     printUsage();
-    quit(0);
 }
 
 /* Show usage and help information */
@@ -85,7 +84,6 @@ static void showHelp(void) {
         "        e.g., -i cmap,name\n"
         "        will inspect/compare ONLY the 'cmap' and 'name' tables\n");
     printf("    -i and -x switches are exclusive of each other.\n");
-    quit(1);
 }
 
 /* Main program */
@@ -115,16 +113,20 @@ IntN main(IntN argc, Byte8 *argv[]) {
 
     argi = opt_Scan(argc, argv, opt_NOPTS(opt), opt, NULL, NULL);
 
+    if (opt_Present("-u") || opt_Present("-h")) return 0;
+
     if (opt_Present("-x") && opt_Present("-i")) {
         printf("ERROR: '-x' switch and '-i' switch are exclusive of each other.\n");
         showUsage();
+        return 1;
     }
 
     if (level > 4) level = 4;
 
     if ((argc - argi) < 2) {
         printf("ERROR: not enough files/directories specified.\n");
         showUsage();
+        return 1;
     }
 
     filename1 = argv[argi];
@@ -303,8 +305,7 @@ IntN main(IntN argc, Byte8 *argv[]) {
     } else {
         printf("ERROR: Incorrect/insufficient files/directories specified.\n");
         showUsage();
+        return 1;
     }
-
-    /*printf( "\nDone.\n");*/
     return 0;
 }

c/sfntdiff/source/Dopt.c

@@ -8,6 +8,7 @@
 
 #include <stdio.h>
 #include <string.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include "Dopt.h"
 
@@ -99,6 +100,16 @@ void opt_Error(int error, opt_Option *opt, char *arg) {
     global.error += global.handler(error, opt, arg, global.client);
 }
 
+bool is_known_option(char *arg) {
+    const char *known_options[] = {"-u", "-h", "-T", "-d", "-x", "-i", "-X"};
+    int num_opts = sizeof(known_options) / sizeof(known_options[0]);
+    int i;
+    for (i = 0; i < num_opts; i++)
+        if (strcmp(arg, known_options[i]) == 0)
+            return true;
+    return false;
+}
+
 /* Process argument list */
 int opt_Scan(int argc, char *argv[],
              int nOpts, opt_Option *opts, opt_Handler handler, void *client) {
@@ -138,6 +149,10 @@ int opt_Scan(int argc, char *argv[],
     argi = 1;
     while (argi < argc) {
         char *arg = argv[argi];
+        if (arg[0] == '-' && !is_known_option(arg)) {
+            opt_Error(opt_Unknown, NULL, arg);
+            exit(1);
+        }
         opt_Option *opt = lookup(arg, matchWhole);
         if (opt != NULL)
             /* Whole argument matched option */

tests/sfntdiff_test.py

@@ -1,6 +1,7 @@
 from __future__ import print_function, division, absolute_import
 
 import os
+import subprocess32 as subprocess
 import pytest
 
 from .runner import main as runner
@@ -19,6 +20,21 @@ def _get_expected_path(file_name):
 # Tests
 # -----
 
+def test_exit_no_option():
+    # When ran by itself, 'sfntdiff' prints the usage
+    assert subprocess.call([TOOL]) == 1
+
+
+@pytest.mark.parametrize('arg', ['-h', '-u'])
+def test_exit_known_option(arg):
+    assert subprocess.call([TOOL, arg]) == 0
+
+
+@pytest.mark.parametrize('arg', ['-j', '--bogus'])
+def test_exit_unknown_option(arg):
+    assert subprocess.call([TOOL, arg]) == 1
+
+
 @pytest.mark.parametrize('args, txt_filename', [
     ([], 'dflt.txt'),
     (['T'], 'dflt.txt'),  # default diff with timestamp