/**
   * Gets info of the given commit and checks if it was a RENAME. If yes, returns the older file
   * path, which file was renamed from. If it's not a rename, returns null.
   */
  @Nullable
  private static FilePath getFirstCommitRenamePath(
      Project project, VirtualFile root, String commit, FilePath filePath) throws VcsException {
    // 'git show -M --name-status <commit hash>' returns the information about commit and detects
    // renames.
    // NB: we can't specify the filepath, because then rename detection will work only with the
    // '--follow' option, which we don't wanna use.
    final GitSimpleHandler h = new GitSimpleHandler(project, root, GitCommand.SHOW);
    final GitLogParser parser =
        new GitLogParser(project, GitLogParser.NameStatus.STATUS, HASH, COMMIT_TIME, SHORT_PARENTS);
    h.setNoSSH(true);
    h.setStdoutSuppressed(true);
    h.addParameters("-M", "--name-status", parser.getPretty(), "--encoding=UTF-8", commit);
    h.endOptions();
    final String output = h.run();
    final List<GitLogRecord> records = parser.parse(output);

    if (records.isEmpty()) return null;
    // we have information about all changed files of the commit. Extracting information about the
    // file we need.
    final List<Change> changes = records.get(0).parseChanges(project, root);
    for (Change change : changes) {
      if ((change.isMoved() || change.isRenamed())
          && filePath.equals(change.getAfterRevision().getFile())) {
        return change.getBeforeRevision().getFile();
      }
    }
    return null;
  }
  /**
   * Get history for the file
   *
   * @param project the context project
   * @param path the file path
   * @return the list of the revisions
   * @throws VcsException if there is problem with running git
   */
  public static List<VcsFileRevision> history(
      final Project project, FilePath path, final VirtualFile root, final String... parameters)
      throws VcsException {
    final List<VcsFileRevision> rc = new ArrayList<VcsFileRevision>();
    final List<VcsException> exceptions = new ArrayList<VcsException>();

    history(
        project,
        path,
        root,
        new Consumer<GitFileRevision>() {
          @Override
          public void consume(GitFileRevision gitFileRevision) {
            rc.add(gitFileRevision);
          }
        },
        new Consumer<VcsException>() {
          @Override
          public void consume(VcsException e) {
            exceptions.add(e);
          }
        },
        parameters);
    if (!exceptions.isEmpty()) {
      throw exceptions.get(0);
    }
    return rc;
  }
 /**
  * Get current revision for the file under git
  *
  * @param project a project
  * @param filePath a file path
  * @return a revision number or null if the file is unversioned or new
  * @throws VcsException if there is problem with running git
  */
 @Nullable
 public static ItemLatestState getLastRevision(final Project project, FilePath filePath)
     throws VcsException {
   VirtualFile root = GitUtil.getGitRoot(filePath);
   GitBranch c = GitBranch.current(project, root);
   GitBranch t = c == null ? null : c.tracked(project, root);
   if (t == null) {
     return new ItemLatestState(getCurrentRevision(project, filePath, null), true, false);
   }
   filePath = getLastCommitName(project, filePath);
   GitSimpleHandler h = new GitSimpleHandler(project, root, GitCommand.LOG);
   GitLogParser parser =
       new GitLogParser(project, GitLogParser.NameStatus.STATUS, HASH, COMMIT_TIME, SHORT_PARENTS);
   h.setNoSSH(true);
   h.setSilent(true);
   h.addParameters("-n1", parser.getPretty(), "--name-status", t.getFullName());
   h.endOptions();
   h.addRelativePaths(filePath);
   String result = h.run();
   if (result.length() == 0) {
     return null;
   }
   GitLogRecord record = parser.parseOneRecord(result);
   if (record == null) {
     return null;
   }
   final List<Change> changes = record.parseChanges(project, root);
   boolean exists = !FileStatus.DELETED.equals(changes.get(0).getFileStatus());
   record.setUsedHandler(h);
   return new ItemLatestState(
       new GitRevisionNumber(record.getHash(), record.getDate()), exists, false);
 }
  @Nullable
  public static Pair<AbstractHash, AbstractHash> getStashTop(
      @NotNull Project project, @NotNull VirtualFile root) throws VcsException {
    GitSimpleHandler h = new GitSimpleHandler(project, root, GitCommand.STASH.readLockingCommand());
    GitLogParser parser = new GitLogParser(project, SHORT_HASH, SHORT_PARENTS);
    h.setSilent(true);
    h.setNoSSH(true);
    h.addParameters("list");
    h.addParameters("-n1");
    h.addParameters(parser.getPretty());

    String out;
    h.setCharset(Charset.forName(GitConfigUtil.getLogEncoding(project, root)));
    out = h.run();
    final List<GitLogRecord> gitLogRecords = parser.parse(out);
    for (GitLogRecord gitLogRecord : gitLogRecords) {
      ProgressManager.checkCanceled();

      GitSimpleHandler h1 = new GitSimpleHandler(project, root, GitCommand.LOG);
      GitLogParser parser1 = new GitLogParser(project, SHORT_HASH, SHORT_PARENTS, SUBJECT);
      h1.setSilent(true);
      h1.setNoSSH(true);
      h1.addParameters("-n1");
      h1.addParameters(parser1.getPretty());
      // h1.endOptions();
      h1.addParameters(gitLogRecord.getShortHash());

      String out1;
      out1 = h1.run();
      final List<GitLogRecord> gitLogRecords1 = parser1.parse(out1);
      assert gitLogRecords1.size() == 1;
      final GitLogRecord logRecord = gitLogRecords1.get(0);
      final String[] parentsShortHashes = logRecord.getParentsShortHashes();
      String indexCommit = null;
      // heuristics
      if (parentsShortHashes.length == 2) {
        if (logRecord.getSubject().contains(parentsShortHashes[0])) {
          indexCommit = parentsShortHashes[1];
        }
        if (logRecord.getSubject().contains(parentsShortHashes[1])) {
          indexCommit = parentsShortHashes[0];
        }
      }
      return new Pair<AbstractHash, AbstractHash>(
          AbstractHash.create(gitLogRecord.getShortHash()),
          indexCommit == null ? null : AbstractHash.create(indexCommit));
    }
    return null;
  }