diff-parseopt: convert --patience

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff.c

@@ -4960,6 +4960,26 @@ static enum parse_opt_result diff_opt_output(struct parse_opt_ctx_t *ctx,
 	return 0;
 }
 
+static int diff_opt_patience(const struct option *opt,
+			     const char *arg, int unset)
+{
+	struct diff_options *options = opt->value;
+	int i;
+
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
+	options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
+	/*
+	 * Both --patience and --anchored use PATIENCE_DIFF
+	 * internally, so remove any anchors previously
+	 * specified.
+	 */
+	for (i = 0; i < options->anchors_nr; i++)
+		free(options->anchors[i]);
+	options->anchors_nr = 0;
+	return 0;
+}
+
 static int diff_opt_relative(const struct option *opt,
 			     const char *arg, int unset)
 {
@@ -5127,6 +5147,10 @@ static void prep_parse_options(struct diff_options *options)
 		OPT_BIT(0, "indent-heuristic", &options->xdl_opts,
 			N_("heuristic to shift diff hunk boundaries for easy reading"),
 			XDF_INDENT_HEURISTIC),
+		OPT_CALLBACK_F(0, "patience", options, NULL,
+			       N_("generate diff using the \"patience diff\" algorithm"),
+			       PARSE_OPT_NONEG | PARSE_OPT_NOARG,
+			       diff_opt_patience),
 
 		OPT_GROUP(N_("Diff other options")),
 		OPT_CALLBACK_F(0, "relative", options, N_("<prefix>"),
@@ -5165,18 +5189,7 @@ int diff_opt_parse(struct diff_options *options,
 		return ac;
 
 	/* xdiff options */
-	if (!strcmp(arg, "--patience")) {
-		int i;
-		options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
-		/*
-		 * Both --patience and --anchored use PATIENCE_DIFF
-		 * internally, so remove any anchors previously
-		 * specified.
-		 */
-		for (i = 0; i < options->anchors_nr; i++)
-			free(options->anchors[i]);
-		options->anchors_nr = 0;
-	} else if (!strcmp(arg, "--histogram"))
+	if (!strcmp(arg, "--histogram"))
 		options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
 	else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
 		long value = parse_algorithm_value(optarg);