git-clone: do not forget to create origin branch.

The newly cloned repository by default had .git/remotes/origin
set up to track the remote master to origin, but forgot to
create the origin branch ourselves.  Also it hardcoded the
assumption that the remote HEAD points at "master", which may
not always be true.

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

git-clone.sh

@@ -196,10 +196,17 @@ cd $D || exit
 
 if test -f ".git/HEAD"
 then
-	mkdir -p .git/remotes || exit
-	echo >.git/remotes/origin \
-	"URL: $repo
-Pull: master:origin"
+	head_points_at=`git-symbolic-ref HEAD`
+	case "$head_points_at" in
+	refs/heads/*)
+		head_points_at=`expr "$head_points_at" : 'refs/heads/\(.*\)'`
+		mkdir -p .git/remotes &&
+		echo >.git/remotes/origin \
+		"URL: $repo
+Pull: $head_points_at:origin"
+		cp ".git/refs/heads/$head_points_at" .git/refs/heads/origin
+	esac
+
 	case "$no_checkout" in
 	'')
 		git checkout