Merge pull request #117 from robinrosenberg/master

NPE fix in default branch determination & NPE fix when commit cache contains removed repo

src/main/java/com/gitblit/GitBlit.java

@@ -3603,7 +3603,7 @@ public class GitBlit implements ServletContextListener {
 			Date cutoff = CommitCache.instance().getCutoffDate();
 			for (String repositoryName : getRepositoryList()) {
 				RepositoryModel model = getRepositoryModel(repositoryName);
-				if (model.hasCommits && model.lastChange.after(cutoff)) {
+				if (model != null && model.hasCommits && model.lastChange.after(cutoff)) {
 					repoCount++;
 					Repository repository = getRepository(repositoryName);
 					for (RefModel ref : JGitUtils.getLocalBranches(repository, true, -1)) {

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

@@ -566,6 +566,8 @@ public class JGitUtils {
 		try {
 			if (tree == null) {
 				ObjectId object = getDefaultBranch(repository);
+				if (object == null)
+					return null;
 				RevCommit commit = rw.parseCommit(object);
 				tree = commit.getTree();
 			}