Avoid NPE when the default branch cannot be identified

Robin Rosenberg

2013-09-01 02ede7f11c6fb28ca53fc240905cd1b140236f08

 src/main/java/com/gitblit/utils/JGitUtils.java

@@ -566,6 +566,8 @@
      try {

         if (tree == null) {

            ObjectId object = getDefaultBranch(repository);

            if (object == null)

               return null;

            RevCommit commit = rw.parseCommit(object);

            tree = commit.getTree();

         }