Remove empty ref directories that prevent creating a ref.

This patch also adds test cases from Linus and Junio.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

git-branch.sh

@@ -112,6 +112,16 @@ rev=$(git-rev-parse --verify "$head") || exit
 git-check-ref-format "heads/$branchname" ||
 	die "we do not like '$branchname' as a branch name."
 
+if [ -d "$GIT_DIR/refs/heads/$branchname" ]
+then
+	for refdir in `cd "$GIT_DIR" && \
+		find "refs/heads/$branchname" -type d | sort -r`
+	do
+		rmdir "$GIT_DIR/$refdir" || \
+		    die "Could not delete '$refdir', there may still be a ref there."
+	done
+fi
+
 if [ -e "$GIT_DIR/refs/heads/$branchname" ]
 then
 	if test '' = "$force"

t/t3200-branch.sh

@@ -61,4 +61,16 @@ test_expect_success \
 	 test -f .git/logs/refs/heads/g/h/i &&
 	 diff expect .git/logs/refs/heads/g/h/i'
 
+test_expect_success \
+    'git branch j/k should work after branch j has been deleted' \
+       'git-branch j &&
+        git-branch -d j &&
+        git-branch j/k'
+
+test_expect_success \
+    'git branch l should work after branch l/m has been deleted' \
+       'git-branch l/m &&
+        git-branch -d l/m &&
+        git-branch l'
+
 test_done