gitview: Read tag and branch information using git ls-remote

This fix the below bug

Junio C Hamano <junkio@cox.net> writes:

>
> It does not work in my repository, since you do not seem to
> handle branch and tag names with slashes in them.  All of my
> topic branches live in directories with two-letter names
> (e.g. ak/gitview).

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

contrib/gitview/gitview

@@ -56,20 +56,6 @@ def show_date(epoch, tz):
 
 	return time.strftime("%Y-%m-%d %H:%M:%S", time.gmtime(secs))
 
-def get_sha1_from_tags(line):
-	fp = os.popen("git cat-file -t " + line)
-	entry = string.strip(fp.readline())
-	fp.close()
-	if (entry == "commit"):
-		return line
-	elif (entry == "tag"):
-		fp = os.popen("git cat-file tag "+ line)
-		entry = string.strip(fp.readline())
-		fp.close()
-		obj = re.split(" ", entry)
-		if (obj[0] == "object"):
-			return obj[1]
-	return None
 
 class CellRendererGraph(gtk.GenericCellRenderer):
 	"""Cell renderer for directed graph.
@@ -465,32 +451,24 @@ class GitView:
 		respective sha1 details """
 
 		self.bt_sha1 = { }
+		ls_remote = re.compile('^(.{40})\trefs/([^^]+)(?:\\^(..))?$');
 		git_dir = os.getenv("GIT_DIR")
 		if (git_dir == None):
 			git_dir = ".git"
 
-		#FIXME the path seperator
-		ref_files = os.listdir(git_dir + "/refs/tags")
-		for file in ref_files:
-			fp = open(git_dir + "/refs/tags/"+file)
-			sha1 = get_sha1_from_tags(string.strip(fp.readline()))
-			try:
-				self.bt_sha1[sha1].append(file)
-			except KeyError:
-				self.bt_sha1[sha1] = [file]
-			fp.close()
-
-
-		#FIXME the path seperator
-		ref_files = os.listdir(git_dir + "/refs/heads")
-		for file in ref_files:
-			fp = open(git_dir + "/refs/heads/" + file)
-			sha1 = get_sha1_from_tags(string.strip(fp.readline()))
-			try:
-				self.bt_sha1[sha1].append(file)
-			except KeyError:
-				self.bt_sha1[sha1] = [file]
-			fp.close()
+		fp = os.popen('git ls-remote ' + git_dir)
+		while 1:
+			line = string.strip(fp.readline())
+			if line == '':
+				break
+			m = ls_remote.match(line)
+			if not m:
+				continue
+			(sha1, name) = (m.group(1), m.group(2))
+			if not self.bt_sha1.has_key(sha1):
+				self.bt_sha1[sha1] = []
+			self.bt_sha1[sha1].append(name)
+		fp.close()
 
 
 	def construct(self):