anchor.diff:     * 6) cannot end with '.lock'.
     */
     static const BRANCH_PATTERN
  -      = r"^(?!/|.*([/.]\\.|//|@\\{|\\\\))[^\\x00-\\x20 ~^:?*\\[]+$";
  +      = r"^(?!build-|/|.*([/.][.]|//|@\\{|\\\\))[^\040\177 ~^:?*\\[]+$";
   
     static final branchRegex = new RegExp(BRANCH_PATTERN);
   
  
positive.code:     if (remoteBranchName != null && remoteBranchName.isNotEmpty) {
        return options.store.getRemoteHeadForRef(remoteBranchName).then((sha) {
          options.depth = 1;
          Fetch fetch = new Fetch(options);
            return fetch.fetch().then((_) {
              return store.createNewRef('refs/heads/' + branchName, sha);
          });
        });
      } else {
  
negative.code: import 'fetch.dart';
  import '../exception.dart';
  import '../objectstore.dart';
  import '../options.dart';
  
  /**
  