[PATCH v3] pretty: add %D format specifier

[Harry Jeffery <harry@exec64.co.uk>]

Add a new format specifier, '%D' that is identical in behaviour to '%d',
except that it does not include the ' (' prefix or ')' suffix provided
by '%d'.

Signed-off-by: Harry Jeffery <harry@exec64.co.uk>
---
 Documentation/pretty-formats.txt |  6 ++++--
 log-tree.c                       | 24 +++++++++++++-----------
 log-tree.h                       |  8 +++++++-
 pretty.c                         |  4 ++++
 t/t4205-log-pretty-formats.sh    | 11 +++++++++++
 5 files changed, 39 insertions(+), 14 deletions(-)

diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
index eac7909..2632e1a 100644
--- a/Documentation/pretty-formats.txt
+++ b/Documentation/pretty-formats.txt
@@ -128,6 +128,7 @@ The placeholders are:
 - '%ct': committer date, UNIX timestamp
 - '%ci': committer date, ISO 8601 format
 - '%d': ref names, like the --decorate option of linkgit:git-log[1]
+- '%D': ref names without the " (", ")" wrapping.
 - '%e': encoding
 - '%s': subject
 - '%f': sanitized subject line, suitable for a filename
@@ -182,8 +183,9 @@ The placeholders are:
 NOTE: Some placeholders may depend on other options given to the
 revision traversal engine. For example, the `%g*` reflog options will
 insert an empty string unless we are traversing reflog entries (e.g., by
-`git log -g`). The `%d` placeholder will use the "short" decoration
-format if `--decorate` was not already provided on the command line.
+`git log -g`). The `%d` and `%D` placeholders will use the "short"
+decoration format if `--decorate` was not already provided on the command
+line.
 
 If you add a `+` (plus sign) after '%' of a placeholder, a line-feed
 is inserted immediately before the expansion if and only if the
diff --git a/log-tree.c b/log-tree.c
index 95e9b1d..61d1dea 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -179,14 +179,16 @@ static void show_children(struct rev_info *opt, struct commit *commit, int abbre
 }
 
 /*
- * The caller makes sure there is no funny color before
- * calling. format_decorations makes sure the same after return.
+ * The caller makes sure there is no funny color before calling.
+ * format_decorations_extended makes sure the same after return.
  */
-void format_decorations(struct strbuf *sb,
+void format_decorations_extended(struct strbuf *sb,
 			const struct commit *commit,
-			int use_color)
+			int use_color,
+			const char *prefix,
+			const char *separator,
+			const char *suffix)
 {
-	const char *prefix;
 	struct name_decoration *decoration;
 	const char *color_commit =
 		diff_get_color(use_color, DIFF_COMMIT);
@@ -196,20 +198,20 @@ void format_decorations(struct strbuf *sb,
 	decoration = lookup_decoration(&name_decoration, &commit->object);
 	if (!decoration)
 		return;
-	prefix = " (";
+	strbuf_addstr(sb, color_commit);
+	strbuf_addstr(sb, prefix);
 	while (decoration) {
-		strbuf_addstr(sb, color_commit);
-		strbuf_addstr(sb, prefix);
 		strbuf_addstr(sb, decorate_get_color(use_color, decoration->type));
 		if (decoration->type == DECORATION_REF_TAG)
 			strbuf_addstr(sb, "tag: ");
 		strbuf_addstr(sb, decoration->name);
 		strbuf_addstr(sb, color_reset);
-		prefix = ", ";
+		strbuf_addstr(sb, color_commit);
+		if (decoration->next)
+			strbuf_addstr(sb, separator);
 		decoration = decoration->next;
 	}
-	strbuf_addstr(sb, color_commit);
-	strbuf_addch(sb, ')');
+	strbuf_addstr(sb, suffix);
 	strbuf_addstr(sb, color_reset);
 }
 
diff --git a/log-tree.h b/log-tree.h
index d6ecd4d..b26160c 100644
--- a/log-tree.h
+++ b/log-tree.h
@@ -13,7 +13,13 @@ int log_tree_diff_flush(struct rev_info *);
 int log_tree_commit(struct rev_info *, struct commit *);
 int log_tree_opt_parse(struct rev_info *, const char **, int);
 void show_log(struct rev_info *opt);
-void format_decorations(struct strbuf *sb, const struct commit *commit, int use_color);
+void format_decorations_extended(struct strbuf *sb, const struct commit *commit,
+			     int use_color,
+			     const char *prefix,
+			     const char *separator,
+			     const char *suffix);
+#define format_decorations(strbuf, commit, color) \
+			     format_decorations_extended((strbuf), (commit), (color), " (", ", ", ")")
 void show_decorations(struct rev_info *opt, struct commit *commit);
 void log_write_email_headers(struct rev_info *opt, struct commit *commit,
 			     const char **subject_p,
diff --git a/pretty.c b/pretty.c
index 44b9f64..46d65b9 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1197,6 +1197,10 @@ static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
 		load_ref_decorations(DECORATE_SHORT_REFS);
 		format_decorations(sb, commit, c->auto_color);
 		return 1;
+	case 'D':
+		load_ref_decorations(DECORATE_SHORT_REFS);
+		format_decorations_extended(sb, commit, c->auto_color, "", ", ", "");
+		return 1;
 	case 'g':		/* reflog info */
 		switch(placeholder[1]) {
 		case 'd':	/* reflog selector */
diff --git a/t/t4205-log-pretty-formats.sh b/t/t4205-log-pretty-formats.sh
index de0cc4a..38148c1 100755
--- a/t/t4205-log-pretty-formats.sh
+++ b/t/t4205-log-pretty-formats.sh
@@ -457,4 +457,15 @@ EOF
 	test_cmp expected actual1
 '
 
+test_expect_success 'clean log decoration' '
+	git log --no-walk --tags --pretty="%H %D" --decorate=full >actual &&
+	cat <<EOF >expected &&
+$head1 tag: refs/tags/tag2
+$head2 tag: refs/tags/message-one
+$old_head1 tag: refs/tags/message-two
+EOF
+	sort actual >actual1 &&
+	test_cmp expected actual1
+'
+
 test_done
-- 
2.1.0