Merge branch 'rr/submodule-diff-config'

Allow "git diff --submodule=log" to set to be the default via
configuration.

* rr/submodule-diff-config:
  submodule: display summary header in bold
  diff: rename "set" variable
  diff: introduce diff.submodule configuration variable
  Documentation: move diff.wordRegex from config.txt to diff-config.txt

Documentation/config.txt

@@ -962,12 +962,6 @@ difftool.<tool>.cmd::
 difftool.prompt::
 	Prompt before each invocation of the diff tool.
 
-diff.wordRegex::
-	A POSIX Extended Regular Expression used to determine what is a "word"
-	when performing word-by-word difference calculations.  Character
-	sequences that match the regular expression are "words", all other
-	characters are *ignorable* whitespace.
-
 fetch.recurseSubmodules::
 	This option can be either set to a boolean value or to 'on-demand'.
 	Setting it to a boolean changes the behavior of fetch and pull to

Documentation/diff-config.txt

@@ -107,6 +107,19 @@ diff.suppressBlankEmpty::
 	A boolean to inhibit the standard behavior of printing a space
 	before each empty output line. Defaults to false.
 
+diff.submodule::
+	Specify the format in which differences in submodules are
+	shown.  The "log" format lists the commits in the range like
+	linkgit:git-submodule[1] `summary` does.  The "short" format
+	format just shows the names of the commits at the beginning
+	and end of the range.  Defaults to short.
+
+diff.wordRegex::
+	A POSIX Extended Regular Expression used to determine what is a "word"
+	when performing word-by-word difference calculations.  Character
+	sequences that match the regular expression are "words", all other
+	characters are *ignorable* whitespace.
+
 diff.<driver>.command::
 	The custom diff driver command.  See linkgit:gitattributes[5]
 	for details.

Documentation/diff-options.txt

@@ -170,7 +170,8 @@ any of those replacements occurred.
 	the commits in the range like linkgit:git-submodule[1] `summary` does.
 	Omitting the `--submodule` option or specifying `--submodule=short`,
 	uses the 'short' format. This format just shows the names of the commits
-	at the beginning and end of the range.
+	at the beginning and end of the range.  Can be tweaked via the
+	`diff.submodule` configuration variable.
 
 --color[=<when>]::
 	Show colored diff.

diff.c

@@ -123,6 +123,17 @@ static int parse_dirstat_params(struct diff_options *options, const char *params
 	return ret;
 }
 
+static int parse_submodule_params(struct diff_options *options, const char *value)
+{
+	if (!strcmp(value, "log"))
+		DIFF_OPT_SET(options, SUBMODULE_LOG);
+	else if (!strcmp(value, "short"))
+		DIFF_OPT_CLR(options, SUBMODULE_LOG);
+	else
+		return -1;
+	return 0;
+}
+
 static int git_config_rename(const char *var, const char *value)
 {
 	if (!value)
@@ -178,6 +189,13 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
 	if (!strcmp(var, "diff.ignoresubmodules"))
 		handle_ignore_submodules_arg(&default_diff_options, value);
 
+	if (!strcmp(var, "diff.submodule")) {
+		if (parse_submodule_params(&default_diff_options, value))
+			warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
+				value);
+		return 0;
+	}
+
 	if (git_color_config(var, value, cb) < 0)
 		return -1;
 
@@ -2223,7 +2241,7 @@ static void builtin_diff(const char *name_a,
 	mmfile_t mf1, mf2;
 	const char *lbl[2];
 	char *a_one, *b_two;
-	const char *set = diff_get_color_opt(o, DIFF_METAINFO);
+	const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
 	const char *reset = diff_get_color_opt(o, DIFF_RESET);
 	const char *a_prefix, *b_prefix;
 	struct userdiff_driver *textconv_one = NULL;
@@ -2244,7 +2262,7 @@ static void builtin_diff(const char *name_a,
 		const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
 		show_submodule_summary(o->file, one ? one->path : two->path,
 				one->sha1, two->sha1, two->dirty_submodule,
-				del, add, reset);
+				meta, del, add, reset);
 		return;
 	}
 
@@ -2270,24 +2288,24 @@ static void builtin_diff(const char *name_a,
 	b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
 	lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
 	lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
-	strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
+	strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
 	if (lbl[0][0] == '/') {
 		/* /dev/null */
-		strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
+		strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
 		if (xfrm_msg)
 			strbuf_addstr(&header, xfrm_msg);
 		must_show_header = 1;
 	}
 	else if (lbl[1][0] == '/') {
-		strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
+		strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
 		if (xfrm_msg)
 			strbuf_addstr(&header, xfrm_msg);
 		must_show_header = 1;
 	}
 	else {
 		if (one->mode != two->mode) {
-			strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
-			strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
+			strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
+			strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
 			must_show_header = 1;
 		}
 		if (xfrm_msg)
@@ -3480,6 +3498,14 @@ static int parse_dirstat_opt(struct diff_options *options, const char *params)
 	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;
+}
+
 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 {
 	const char *arg = av[0];
@@ -3660,10 +3686,8 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		handle_ignore_submodules_arg(options, arg + 20);
 	} else if (!strcmp(arg, "--submodule"))
 		DIFF_OPT_SET(options, SUBMODULE_LOG);
-	else if (!prefixcmp(arg, "--submodule=")) {
-		if (!strcmp(arg + 12, "log"))
-			DIFF_OPT_SET(options, SUBMODULE_LOG);
-	}
+	else if (!prefixcmp(arg, "--submodule="))
+		return parse_submodule_opt(options, arg + 12);
 
 	/* misc options */
 	else if (!strcmp(arg, "-z"))

submodule.c

@@ -258,7 +258,7 @@ int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg)
 
 void show_submodule_summary(FILE *f, const char *path,
 		unsigned char one[20], unsigned char two[20],
-		unsigned dirty_submodule,
+		unsigned dirty_submodule, const char *meta,
 		const char *del, const char *add, const char *reset)
 {
 	struct rev_info rev;
@@ -292,15 +292,15 @@ void show_submodule_summary(FILE *f, const char *path,
 		return;
 	}
 
-	strbuf_addf(&sb, "Submodule %s %s..", path,
+	strbuf_addf(&sb, "%sSubmodule %s %s..", meta, path,
 			find_unique_abbrev(one, DEFAULT_ABBREV));
 	if (!fast_backward && !fast_forward)
 		strbuf_addch(&sb, '.');
 	strbuf_addf(&sb, "%s", find_unique_abbrev(two, DEFAULT_ABBREV));
 	if (message)
-		strbuf_addf(&sb, " %s\n", message);
+		strbuf_addf(&sb, " %s%s\n", message, reset);
 	else
-		strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
+		strbuf_addf(&sb, "%s:%s\n", fast_backward ? " (rewind)" : "", reset);
 	fwrite(sb.buf, sb.len, 1, f);
 
 	if (!message) {

submodule.h

@@ -20,7 +20,7 @@ void handle_ignore_submodules_arg(struct diff_options *diffopt, const char *);
 int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg);
 void show_submodule_summary(FILE *f, const char *path,
 		unsigned char one[20], unsigned char two[20],
-		unsigned dirty_submodule,
+		unsigned dirty_submodule, const char *meta,
 		const char *del, const char *add, const char *reset);
 void set_config_fetch_recurse_submodules(int value);
 void check_for_new_submodule_commits(unsigned char new_sha1[20]);

t/t4041-diff-submodule-option.sh

@@ -33,6 +33,7 @@ test_create_repo sm1 &&
 add_file . foo >/dev/null
 
 head1=$(add_file sm1 foo1 foo2)
+fullhead1=$(cd sm1; git rev-list --max-count=1 $head1)
 
 test_expect_success 'added submodule' "
 	git add sm1 &&
@@ -43,6 +44,48 @@ EOF
 	test_cmp expected actual
 "
 
+test_expect_success 'added submodule, set diff.submodule' "
+	git config diff.submodule log &&
+	git add sm1 &&
+	git diff --cached >actual &&
+	cat >expected <<-EOF &&
+Submodule sm1 0000000...$head1 (new submodule)
+EOF
+	git config --unset diff.submodule &&
+	test_cmp expected actual
+"
+
+test_expect_success '--submodule=short overrides diff.submodule' "
+	test_config diff.submodule log &&
+	git add sm1 &&
+	git diff --submodule=short --cached >actual &&
+	cat >expected <<-EOF &&
+diff --git a/sm1 b/sm1
+new file mode 160000
+index 0000000..a2c4dab
+--- /dev/null
++++ b/sm1
+@@ -0,0 +1 @@
++Subproject commit $fullhead1
+EOF
+	test_cmp expected actual
+"
+
+test_expect_success 'diff.submodule does not affect plumbing' '
+	test_config diff.submodule log &&
+	git diff-index -p HEAD >actual &&
+	cat >expected <<-EOF &&
+	diff --git a/sm1 b/sm1
+	new file mode 160000
+	index 0000000..a2c4dab
+	--- /dev/null
+	+++ b/sm1
+	@@ -0,0 +1 @@
+	+Subproject commit $fullhead1
+	EOF
+	test_cmp expected actual
+'
+
 commit_file sm1 &&
 head2=$(add_file sm1 foo3)
 
@@ -73,7 +116,6 @@ EOF
 	test_cmp expected actual
 "
 
-fullhead1=$(cd sm1; git rev-list --max-count=1 $head1)
 fullhead2=$(cd sm1; git rev-list --max-count=1 $head2)
 test_expect_success 'modified submodule(forward) --submodule=short' "
 	git diff --submodule=short >actual &&