diff-parseopt: convert --output-*

This also validates that the user specifies a single character in
--output-indicator-*, not a string.

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

Documentation/diff-options.txt

@@ -41,6 +41,16 @@ ifndef::git-format-patch[]
 	Implies `-p`.
 endif::git-format-patch[]
 
+--output=<file>::
+	Output to a specific file instead of stdout.
+
+--output-indicator-new=<char>::
+--output-indicator-old=<char>::
+--output-indicator-context=<char>::
+	Specify the character used to indicate new, old or context
+	lines in the generated patch. Normally they are '+', '-' and
+	' ' respectively.
+
 ifndef::git-format-patch[]
 --raw::
 ifndef::git-log[]

diff.c

@@ -4841,6 +4841,19 @@ static int parse_objfind_opt(struct diff_options *opt, const char *arg)
 	return 1;
 }
 
+static int diff_opt_char(const struct option *opt,
+			 const char *arg, int unset)
+{
+	char *value = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+	if (arg[1])
+		return error(_("%s expects a character, got '%s'"),
+			     opt->long_name, arg);
+	*value = arg[0];
+	return 0;
+}
+
 static int diff_opt_compact_summary(const struct option *opt,
 				    const char *arg, int unset)
 {
@@ -4872,6 +4885,23 @@ static int diff_opt_dirstat(const struct option *opt,
 	return 0;
 }
 
+static enum parse_opt_result diff_opt_output(struct parse_opt_ctx_t *ctx,
+					     const struct option *opt,
+					     const char *arg, int unset)
+{
+	struct diff_options *options = opt->value;
+	char *path;
+
+	BUG_ON_OPT_NEG(unset);
+	path = prefix_filename(ctx->prefix, arg);
+	options->file = xfopen(path, "w");
+	options->close_file = 1;
+	if (options->use_color != GIT_COLOR_ALWAYS)
+		options->use_color = GIT_COLOR_NEVER;
+	free(path);
+	return 0;
+}
+
 static int diff_opt_unified(const struct option *opt,
 			    const char *arg, int unset)
 {
@@ -4965,6 +4995,27 @@ static void prep_parse_options(struct diff_options *options)
 		OPT_CALLBACK_F(0, "compact-summary", options, NULL,
 			       N_("generate compact summary in diffstat"),
 			       PARSE_OPT_NOARG, diff_opt_compact_summary),
+		OPT_CALLBACK_F(0, "output-indicator-new",
+			       &options->output_indicators[OUTPUT_INDICATOR_NEW],
+			       N_("<char>"),
+			       N_("specify the character to indicate a new line instead of '+'"),
+			       PARSE_OPT_NONEG, diff_opt_char),
+		OPT_CALLBACK_F(0, "output-indicator-old",
+			       &options->output_indicators[OUTPUT_INDICATOR_OLD],
+			       N_("<char>"),
+			       N_("specify the character to indicate an old line instead of '-'"),
+			       PARSE_OPT_NONEG, diff_opt_char),
+		OPT_CALLBACK_F(0, "output-indicator-context",
+			       &options->output_indicators[OUTPUT_INDICATOR_CONTEXT],
+			       N_("<char>"),
+			       N_("specify the character to indicate a context instead of ' '"),
+			       PARSE_OPT_NONEG, diff_opt_char),
+
+		OPT_GROUP(N_("Diff other options")),
+		{ OPTION_CALLBACK, 0, "output", options, N_("<file>"),
+		  N_("Output to a specific file"),
+		  PARSE_OPT_NONEG, NULL, 0, diff_opt_output },
+
 		OPT_END()
 	};
 
@@ -4992,16 +5043,8 @@ int diff_opt_parse(struct diff_options *options,
 	if (ac)
 		return ac;
 
-	/* Output format options */
-	if (skip_prefix(arg, "--output-indicator-new=", &arg))
-		options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
-	else if (skip_prefix(arg, "--output-indicator-old=", &arg))
-		options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
-	else if (skip_prefix(arg, "--output-indicator-context=", &arg))
-		options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
-
 	/* renames options */
-	else if (starts_with(arg, "-B") ||
+	if (starts_with(arg, "-B") ||
 		 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
 		if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
 			return error("invalid argument to -B: %s", arg+2);
@@ -5242,15 +5285,7 @@ int diff_opt_parse(struct diff_options *options,
 	else if (opt_arg(arg, '\0', "inter-hunk-context",
 			 &options->interhunkcontext))
 		;
-	else if ((argcount = parse_long_opt("output", av, &optarg))) {
+	else
-		char *path = prefix_filename(prefix, optarg);
-		options->file = xfopen(path, "w");
-		options->close_file = 1;
-		if (options->use_color != GIT_COLOR_ALWAYS)
-			options->use_color = GIT_COLOR_NEVER;
-		free(path);
-		return argcount;
-	} else
 		return 0;
 	return 1;
 }