show-branch: allow glob pattern to name branches to show.

With this, you can say "git-show-branch topic/* master" to show
all the topic branches you have under .git/refs/heads/topic/ and
your master branch.  Another example is "git-show-branch --list
v1.0*" to show all the v1.0 tags.  You can disambiguate by
saying "heads/topic/*" to show only topic branches if you have
tags under .git/refs/tags/topic/ as well.

Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git-show-branch.txt

@@ -7,18 +7,29 @@ git-show-branch - Show branches and their commits.
 
 SYNOPSIS
 --------
-'git-show-branch [--all] [--heads] [--tags] [--more=<n> | --list | --independent | --merge-base] [--no-name | --sha1-name] <reference>...'
+'git-show-branch [--all] [--heads] [--tags] [--more=<n> | --list | --independent | --merge-base] [--no-name | --sha1-name] [<rev> | <glob>]...'
 
 DESCRIPTION
 -----------
-Shows the head commits from the named <reference> (or all refs under
-$GIT_DIR/refs/heads), and displays concise list of commit logs
-to show their relationship semi-visually.
+
+Shows the commit ancestry graph starting from the commits named
+with <rev>s or <globs>s (or all refs under $GIT_DIR/refs/heads
+and/or $GIT_DIR/refs/tags) semi-visually.
+
+It cannot show more than 29 branches and commits at a time.
+
 
 OPTIONS
 -------
-<reference>::
-	Name of the reference under $GIT_DIR/refs/.
+<rev>::
+	Arbitrary extended SHA1 expression (see `git-rev-parse`)
+	that typically names a branch HEAD or a tag.
+
+<glob>::
+	A glob pattern that matches branch or tag names under
+	$GIT_DIR/refs.  For example, if you have many topic
+	branches under $GIT_DIR/refs/heads/topic, giving
+	`topic/*` would show all of them.
 
 --all --heads --tags::
 	Show all refs under $GIT_DIR/refs, $GIT_DIR/refs/heads,

show-branch.c

@@ -1,4 +1,5 @@
 #include <stdlib.h>
+#include <fnmatch.h>
 #include "cache.h"
 #include "commit.h"
 #include "refs.h"
@@ -332,6 +333,39 @@ static int append_tag_ref(const char *refname, const unsigned char *sha1)
 	return append_ref(refname + 5, sha1);
 }
 
+static const char *match_ref_pattern = NULL;
+static int match_ref_slash = 0;
+static int count_slash(const char *s)
+{
+	int cnt = 0;
+	while (*s)
+		if (*s++ == '/')
+			cnt++;
+	return cnt;
+}
+
+static int append_matching_ref(const char *refname, const unsigned char *sha1)
+{
+	/* we want to allow pattern hold/<asterisk> to show all
+	 * branches under refs/heads/hold/, and v0.99.9? to show
+	 * refs/tags/v0.99.9a and friends.
+	 */
+	const char *tail;
+	int slash = count_slash(refname);
+	for (tail = refname; *tail && match_ref_slash < slash; )
+		if (*tail++ == '/')
+			slash--;
+	if (!*tail)
+		return 0;
+	if (fnmatch(match_ref_pattern, tail, 0))
+		return 0;
+	if (!strncmp("refs/heads/", refname, 11))
+		return append_head_ref(refname, sha1);
+	if (!strncmp("refs/tags/", refname, 10))
+		return append_tag_ref(refname, sha1);
+	return append_ref(refname, sha1);
+}
+
 static void snarf_refs(int head, int tag)
 {
 	if (head) {
@@ -400,6 +434,27 @@ static int show_independent(struct commit **rev,
 	return 0;
 }
 
+static void append_one_rev(const char *av)
+{
+	unsigned char revkey[20];
+	if (!get_sha1(av, revkey)) {
+		append_ref(av, revkey);
+		return;
+	}
+	if (strchr(av, '*') || strchr(av, '?')) {
+		/* glob style match */
+		int saved_matches = ref_name_cnt;
+		match_ref_pattern = av;
+		match_ref_slash = count_slash(av);
+		for_each_ref(append_matching_ref);
+		if (saved_matches == ref_name_cnt &&
+		    ref_name_cnt < MAX_REVS)
+			error("no matching refs with %s", av);
+		return;
+	}
+	die("bad sha1 reference %s", av);
+}
+
 int main(int ac, char **av)
 {
 	struct commit *rev[MAX_REVS], *commit;
@@ -458,17 +513,20 @@ int main(int ac, char **av)
 	if (all_heads + all_tags)
 		snarf_refs(all_heads, all_tags);
 
-	while (0 < ac) {
-		unsigned char revkey[20];
-		if (get_sha1(*av, revkey))
-			die("bad sha1 reference %s", *av);
-		append_ref(*av, revkey);
-		ac--; av++;
+	if (ac) {
+		while (0 < ac) {
+			append_one_rev(*av);
+			ac--; av++;
+		}
 	}
-
-	/* If still no revs, then add heads */
-	if (!ref_name_cnt)
+	else {
+		/* If no revs given, then add heads */
 		snarf_refs(1, 0);
+	}
+	if (!ref_name_cnt) {
+		fprintf(stderr, "No revs to be shown.\n");
+		exit(0);
+	}
 
 	for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 		unsigned char revkey[20];