Merge branch 'nd/diff-parseopt-3'

Third batch to teach the diff machinery to use the parse-options
API.

* nd/diff-parseopt-3:
  diff-parseopt: convert --submodule
  diff-parseopt: convert --ignore-submodules
  diff-parseopt: convert --textconv
  diff-parseopt: convert --ext-diff
  diff-parseopt: convert --quiet
  diff-parseopt: convert --exit-code
  diff-parseopt: convert --color-words
  diff-parseopt: convert --word-diff-regex
  diff-parseopt: convert --word-diff
  diff-parseopt: convert --[no-]color
  diff-parseopt: convert --[no-]follow
  diff-parseopt: convert -R
  diff-parseopt: convert -a|--text
  diff-parseopt: convert --full-index
  diff-parseopt: convert --binary
  diff-parseopt: convert --anchored
  diff-parseopt: convert --diff-algorithm
  diff-parseopt: convert --histogram
  diff-parseopt: convert --patience
  diff-parseopt: convert --[no-]indent-heuristic
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index 5ebc568..09faee3 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -436,7 +436,7 @@
 
 --binary::
 	In addition to `--full-index`, output a binary diff that
-	can be applied with `git-apply`.
+	can be applied with `git-apply`. Implies `--patch`.
 
 --abbrev[=<n>]::
 	Instead of showing the full 40-byte hexadecimal object
diff --git a/diff.c b/diff.c
index ec5c095..6dfad79 100644
--- a/diff.c
+++ b/diff.c
@@ -4788,14 +4788,6 @@
 	return 1;
 }
 
-static int parse_submodule_opt(struct diff_options *options, const char *value)
-{
-	if (parse_submodule_params(options, value))
-		die(_("Failed to parse --submodule option parameter: '%s'"),
-			value);
-	return 1;
-}
-
 static const char diff_status_letters[] = {
 	DIFF_STATUS_ADDED,
 	DIFF_STATUS_COPIED,
@@ -4906,6 +4898,31 @@
 	return 1;
 }
 
+static int diff_opt_anchored(const struct option *opt,
+			     const char *arg, int unset)
+{
+	struct diff_options *options = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+	options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
+	ALLOC_GROW(options->anchors, options->anchors_nr + 1,
+		   options->anchors_alloc);
+	options->anchors[options->anchors_nr++] = xstrdup(arg);
+	return 0;
+}
+
+static int diff_opt_binary(const struct option *opt,
+			   const char *arg, int unset)
+{
+	struct diff_options *options = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
+	enable_patch_output(&options->output_format);
+	options->flags.binary = 1;
+	return 0;
+}
+
 static int diff_opt_break_rewrites(const struct option *opt,
 				   const char *arg, int unset)
 {
@@ -4943,6 +4960,18 @@
 	return 0;
 }
 
+static int diff_opt_color_words(const struct option *opt,
+				const char *arg, int unset)
+{
+	struct diff_options *options = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+	options->use_color = 1;
+	options->word_diff = DIFF_WORDS_COLOR;
+	options->word_regex = arg;
+	return 0;
+}
+
 static int diff_opt_compact_summary(const struct option *opt,
 				    const char *arg, int unset)
 {
@@ -4958,6 +4987,24 @@
 	return 0;
 }
 
+static int diff_opt_diff_algorithm(const struct option *opt,
+				   const char *arg, int unset)
+{
+	struct diff_options *options = opt->value;
+	long value = parse_algorithm_value(arg);
+
+	BUG_ON_OPT_NEG(unset);
+	if (value < 0)
+		return error(_("option diff-algorithm accepts \"myers\", "
+			       "\"minimal\", \"patience\" and \"histogram\""));
+
+	/* clear out previous settings */
+	DIFF_XDL_CLR(options, NEED_MINIMAL);
+	options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
+	options->xdl_opts |= value;
+	return 0;
+}
+
 static int diff_opt_dirstat(const struct option *opt,
 			    const char *arg, int unset)
 {
@@ -5010,6 +5057,34 @@
 	return 0;
 }
 
+static int diff_opt_follow(const struct option *opt,
+			   const char *arg, int unset)
+{
+	struct diff_options *options = opt->value;
+
+	BUG_ON_OPT_ARG(arg);
+	if (unset) {
+		options->flags.follow_renames = 0;
+		options->flags.default_follow_renames = 0;
+	} else {
+		options->flags.follow_renames = 1;
+	}
+	return 0;
+}
+
+static int diff_opt_ignore_submodules(const struct option *opt,
+				      const char *arg, int unset)
+{
+	struct diff_options *options = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+	if (!arg)
+		arg = "all";
+	options->flags.override_submodule_config = 1;
+	handle_ignore_submodules_arg(options, arg);
+	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)
@@ -5027,6 +5102,26 @@
 	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)
 {
@@ -5039,6 +5134,35 @@
 	return 0;
 }
 
+static int diff_opt_submodule(const struct option *opt,
+			      const char *arg, int unset)
+{
+	struct diff_options *options = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+	if (!arg)
+		arg = "log";
+	if (parse_submodule_params(options, arg))
+		return error(_("failed to parse --submodule option parameter: '%s'"),
+			     arg);
+	return 0;
+}
+
+static int diff_opt_textconv(const struct option *opt,
+			     const char *arg, int unset)
+{
+	struct diff_options *options = opt->value;
+
+	BUG_ON_OPT_ARG(arg);
+	if (unset) {
+		options->flags.allow_textconv = 0;
+	} else {
+		options->flags.allow_textconv = 1;
+		options->flags.textconv_set_via_cmdline = 1;
+	}
+	return 0;
+}
+
 static int diff_opt_unified(const struct option *opt,
 			    const char *arg, int unset)
 {
@@ -5055,6 +5179,44 @@
 	return 0;
 }
 
+static int diff_opt_word_diff(const struct option *opt,
+			      const char *arg, int unset)
+{
+	struct diff_options *options = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+	if (arg) {
+		if (!strcmp(arg, "plain"))
+			options->word_diff = DIFF_WORDS_PLAIN;
+		else if (!strcmp(arg, "color")) {
+			options->use_color = 1;
+			options->word_diff = DIFF_WORDS_COLOR;
+		}
+		else if (!strcmp(arg, "porcelain"))
+			options->word_diff = DIFF_WORDS_PORCELAIN;
+		else if (!strcmp(arg, "none"))
+			options->word_diff = DIFF_WORDS_NONE;
+		else
+			return error(_("bad --word-diff argument: %s"), arg);
+	} else {
+		if (options->word_diff == DIFF_WORDS_NONE)
+			options->word_diff = DIFF_WORDS_PLAIN;
+	}
+	return 0;
+}
+
+static int diff_opt_word_diff_regex(const struct option *opt,
+				    const char *arg, int unset)
+{
+	struct diff_options *options = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+	if (options->word_diff == DIFF_WORDS_NONE)
+		options->word_diff = DIFF_WORDS_PLAIN;
+	options->word_regex = arg;
+	return 0;
+}
+
 static void prep_parse_options(struct diff_options *options)
 {
 	struct option parseopts[] = {
@@ -5132,6 +5294,13 @@
 		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, "binary", options, NULL,
+			       N_("output a binary diff that can be applied"),
+			       PARSE_OPT_NONEG | PARSE_OPT_NOARG, diff_opt_binary),
+		OPT_BOOL(0, "full-index", &options->flags.full_index,
+			 N_("show full pre- and post-image object names on the \"index\" lines")),
+		OPT_COLOR_FLAG(0, "color", &options->use_color,
+			       N_("show colored diff")),
 		OPT_CALLBACK_F(0, "output-indicator-new",
 			       &options->output_indicators[OUTPUT_INDICATOR_NEW],
 			       N_("<char>"),
@@ -5171,6 +5340,9 @@
 			      0, PARSE_OPT_NONEG),
 		OPT_BOOL(0, "rename-empty", &options->flags.rename_empty,
 			 N_("use empty blobs as rename source")),
+		OPT_CALLBACK_F(0, "follow", options, NULL,
+			       N_("continue listing the history of a file beyond renames"),
+			       PARSE_OPT_NOARG, diff_opt_follow),
 
 		OPT_GROUP(N_("Diff algorithm options")),
 		OPT_BIT(0, "minimal", &options->xdl_opts,
@@ -5191,12 +5363,58 @@
 		OPT_BIT_F(0, "ignore-blank-lines", &options->xdl_opts,
 			  N_("ignore changes whose lines are all blank"),
 			  XDF_IGNORE_BLANK_LINES, PARSE_OPT_NONEG),
+		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_BITOP(0, "histogram", &options->xdl_opts,
+			  N_("generate diff using the \"histogram diff\" algorithm"),
+			  XDF_HISTOGRAM_DIFF, XDF_DIFF_ALGORITHM_MASK),
+		OPT_CALLBACK_F(0, "diff-algorithm", options, N_("<algorithm>"),
+			       N_("choose a diff algorithm"),
+			       PARSE_OPT_NONEG, diff_opt_diff_algorithm),
+		OPT_CALLBACK_F(0, "anchored", options, N_("<text>"),
+			       N_("generate diff using the \"anchored diff\" algorithm"),
+			       PARSE_OPT_NONEG, diff_opt_anchored),
+		OPT_CALLBACK_F(0, "word-diff", options, N_("<mode>"),
+			       N_("show word diff, using <mode> to delimit changed words"),
+			       PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_word_diff),
+		OPT_CALLBACK_F(0, "word-diff-regex", options, N_("<regex>"),
+			       N_("use <regex> to decide what a word is"),
+			       PARSE_OPT_NONEG, diff_opt_word_diff_regex),
+		OPT_CALLBACK_F(0, "color-words", options, N_("<regex>"),
+			       N_("equivalent to --word-diff=color --word-diff-regex=<regex>"),
+			       PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_color_words),
 
 		OPT_GROUP(N_("Diff other options")),
 		OPT_CALLBACK_F(0, "relative", options, N_("<prefix>"),
 			       N_("when run from subdir, exclude changes outside and show relative paths"),
 			       PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
 			       diff_opt_relative),
+		OPT_BOOL('a', "text", &options->flags.text,
+			 N_("treat all files as text")),
+		OPT_BOOL('R', NULL, &options->flags.reverse_diff,
+			 N_("swap two inputs, reverse the diff")),
+		OPT_BOOL(0, "exit-code", &options->flags.exit_with_status,
+			 N_("exit with 1 if there were differences, 0 otherwise")),
+		OPT_BOOL(0, "quiet", &options->flags.quick,
+			 N_("disable all output of the program")),
+		OPT_BOOL(0, "ext-diff", &options->flags.allow_external,
+			 N_("allow an external diff helper to be executed")),
+		OPT_CALLBACK_F(0, "textconv", options, NULL,
+			       N_("run external text conversion filters when comparing binary files"),
+			       PARSE_OPT_NOARG, diff_opt_textconv),
+		OPT_CALLBACK_F(0, "ignore-submodules", options, N_("<when>"),
+			       N_("ignore changes to submodules in the diff generation"),
+			       PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
+			       diff_opt_ignore_submodules),
+		OPT_CALLBACK_F(0, "submodule", options, N_("<format>"),
+			       N_("specify how differences in submodules are shown"),
+			       PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
+			       diff_opt_submodule),
 		{ OPTION_CALLBACK, 0, "output", options, N_("<file>"),
 		  N_("Output to a specific file"),
 		  PARSE_OPT_NONEG, NULL, 0, diff_opt_output },
@@ -5228,66 +5446,8 @@
 	if (ac)
 		return ac;
 
-	/* xdiff options */
-	if (!strcmp(arg, "--indent-heuristic"))
-		DIFF_XDL_SET(options, INDENT_HEURISTIC);
-	else if (!strcmp(arg, "--no-indent-heuristic"))
-		DIFF_XDL_CLR(options, INDENT_HEURISTIC);
-	else 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"))
-		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);
-		if (value < 0)
-			return error("option diff-algorithm accepts \"myers\", "
-				     "\"minimal\", \"patience\" and \"histogram\"");
-		/* clear out previous settings */
-		DIFF_XDL_CLR(options, NEED_MINIMAL);
-		options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
-		options->xdl_opts |= value;
-		return argcount;
-	} else if (skip_prefix(arg, "--anchored=", &arg)) {
-		options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
-		ALLOC_GROW(options->anchors, options->anchors_nr + 1,
-			   options->anchors_alloc);
-		options->anchors[options->anchors_nr++] = xstrdup(arg);
-	}
-
 	/* flags options */
-	else if (!strcmp(arg, "--binary")) {
-		enable_patch_output(&options->output_format);
-		options->flags.binary = 1;
-	}
-	else if (!strcmp(arg, "--full-index"))
-		options->flags.full_index = 1;
-	else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
-		options->flags.text = 1;
-	else if (!strcmp(arg, "-R"))
-		options->flags.reverse_diff = 1;
-	else if (!strcmp(arg, "--follow"))
-		options->flags.follow_renames = 1;
-	else if (!strcmp(arg, "--no-follow")) {
-		options->flags.follow_renames = 0;
-		options->flags.default_follow_renames = 0;
-	} else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
-		int value = git_config_colorbool(NULL, arg);
-		if (value < 0)
-			return error("option `color' expects \"always\", \"auto\", or \"never\"");
-		options->use_color = value;
-	}
-	else if (!strcmp(arg, "--no-color"))
-		options->use_color = 0;
-	else if (!strcmp(arg, "--color-moved")) {
+	if (!strcmp(arg, "--color-moved")) {
 		if (diff_color_moved_default)
 			options->color_moved = diff_color_moved_default;
 		if (options->color_moved == COLOR_MOVED_NO)
@@ -5306,53 +5466,7 @@
 		if (cm & COLOR_MOVED_WS_ERROR)
 			return -1;
 		options->color_moved_ws_handling = cm;
-	} else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
-		options->use_color = 1;
-		options->word_diff = DIFF_WORDS_COLOR;
-	}
-	else if (!strcmp(arg, "--word-diff")) {
-		if (options->word_diff == DIFF_WORDS_NONE)
-			options->word_diff = DIFF_WORDS_PLAIN;
-	}
-	else if (skip_prefix(arg, "--word-diff=", &arg)) {
-		if (!strcmp(arg, "plain"))
-			options->word_diff = DIFF_WORDS_PLAIN;
-		else if (!strcmp(arg, "color")) {
-			options->use_color = 1;
-			options->word_diff = DIFF_WORDS_COLOR;
-		}
-		else if (!strcmp(arg, "porcelain"))
-			options->word_diff = DIFF_WORDS_PORCELAIN;
-		else if (!strcmp(arg, "none"))
-			options->word_diff = DIFF_WORDS_NONE;
-		else
-			die("bad --word-diff argument: %s", arg);
-	}
-	else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
-		if (options->word_diff == DIFF_WORDS_NONE)
-			options->word_diff = DIFF_WORDS_PLAIN;
-		options->word_regex = optarg;
-		return argcount;
-	}
-	else if (!strcmp(arg, "--exit-code"))
-		options->flags.exit_with_status = 1;
-	else if (!strcmp(arg, "--quiet"))
-		options->flags.quick = 1;
-	else if (!strcmp(arg, "--ext-diff"))
-		options->flags.allow_external = 1;
-	else if (!strcmp(arg, "--no-ext-diff"))
-		options->flags.allow_external = 0;
-	else if (!strcmp(arg, "--textconv")) {
-		options->flags.allow_textconv = 1;
-		options->flags.textconv_set_via_cmdline = 1;
-	} else if (!strcmp(arg, "--no-textconv"))
-		options->flags.allow_textconv = 0;
-	else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
-		options->flags.override_submodule_config = 1;
-		handle_ignore_submodules_arg(options, arg);
-	} else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
-		return parse_submodule_opt(options, arg);
-	else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
+	} else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
 		return parse_ws_error_highlight_opt(options, arg);
 	else if (!strcmp(arg, "--ita-invisible-in-index"))
 		options->ita_invisible_in_index = 1;