diff: allow --patch & cie to override -s/--no-patch

All options that trigger a patch output now override --no-patch.

The case of --binary deserves extra attention: the name may suggest that
it turns a normal patch into a binary patch, but it actually already
enables patch output when normally disabled (e.g. "git log --binary"
displays a patch), hence it makes sense for "git show --no-patch
--binary" to display the binary patch.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff.c

@@ -3497,22 +3497,27 @@ static int parse_submodule_opt(struct diff_options *options, const char *value)
 	return 1;
 }
 
+static void enable_patch_output(int *fmt) {
+	*fmt &= ~DIFF_FORMAT_NO_OUTPUT;
+	*fmt |= DIFF_FORMAT_PATCH;
+}
+
 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 {
 	const char *arg = av[0];
 	const char *optarg;
 	int argcount;
 
 	/* Output format options */
-	if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
-		options->output_format |= DIFF_FORMAT_PATCH;
-	else if (opt_arg(arg, 'U', "unified", &options->context))
-		options->output_format |= DIFF_FORMAT_PATCH;
+	if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
+	    || opt_arg(arg, 'U', "unified", &options->context))
+		enable_patch_output(&options->output_format);
 	else if (!strcmp(arg, "--raw"))
 		options->output_format |= DIFF_FORMAT_RAW;
-	else if (!strcmp(arg, "--patch-with-raw"))
-		options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
-	else if (!strcmp(arg, "--numstat"))
+	else if (!strcmp(arg, "--patch-with-raw")) {
+		enable_patch_output(&options->output_format);
+		options->output_format |= DIFF_FORMAT_RAW;
+	} else if (!strcmp(arg, "--numstat"))
 		options->output_format |= DIFF_FORMAT_NUMSTAT;
 	else if (!strcmp(arg, "--shortstat"))
 		options->output_format |= DIFF_FORMAT_SHORTSTAT;
@@ -3534,9 +3539,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		options->output_format |= DIFF_FORMAT_CHECKDIFF;
 	else if (!strcmp(arg, "--summary"))
 		options->output_format |= DIFF_FORMAT_SUMMARY;
-	else if (!strcmp(arg, "--patch-with-stat"))
-		options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
-	else if (!strcmp(arg, "--name-only"))
+	else if (!strcmp(arg, "--patch-with-stat")) {
+		enable_patch_output(&options->output_format);
+		options->output_format |= DIFF_FORMAT_DIFFSTAT;
+	} else if (!strcmp(arg, "--name-only"))
 		options->output_format |= DIFF_FORMAT_NAME;
 	else if (!strcmp(arg, "--name-status"))
 		options->output_format |= DIFF_FORMAT_NAME_STATUS;
@@ -3611,7 +3617,7 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 
 	/* flags options */
 	else if (!strcmp(arg, "--binary")) {
-		options->output_format |= DIFF_FORMAT_PATCH;
+		enable_patch_output(&options->output_format);
 		DIFF_OPT_SET(options, BINARY);
 	}
 	else if (!strcmp(arg, "--full-index"))

t/t4000-diff-format.sh

@@ -71,4 +71,22 @@ test_expect_success 'git diff-files --no-patch as synonym for -s' '
 	test_must_be_empty err
 '
 
+test_expect_success 'git diff-files --no-patch --patch shows the patch' '
+	git diff-files --no-patch --patch >actual &&
+	compare_diff_patch expected actual
+'
+
+test_expect_success 'git diff-files --no-patch --patch-with-raw shows the patch and raw data' '
+	git diff-files --no-patch --patch-with-raw >actual &&
+	grep -q "^:100644 100755 .* 0000000000000000000000000000000000000000 M	path0\$" actual &&
+	tail -n +4 actual >actual-patch &&
+	compare_diff_patch expected actual-patch
+'
+
+test_expect_success 'git diff-files --patch --no-patch does not show the patch' '
+	git diff-files --patch --no-patch >actual 2>err &&
+	test_must_be_empty actual &&
+	test_must_be_empty err
+'
+
 test_done