private static boolean enabled(final AnActionEvent e) {
    final Project project = e.getData(CommonDataKeys.PROJECT);
    if (project == null) return false;
    final VirtualFile revisionVirtualFile = e.getData(VcsDataKeys.VCS_VIRTUAL_FILE);
    if (revisionVirtualFile == null) return false;
    final VcsFileRevision revision = e.getData(VcsDataKeys.VCS_FILE_REVISION);
    if (revision == null) return false;
    if (! (revision instanceof SvnFileRevision)) return false;
    return ! ((SvnFileRevision) revision).getMergeSources().isEmpty();
  }
private static boolean enabled(final AnActionEvent e)