docs: def merge(config):
      """Merge the current branch into master."""
      repo = config.repo
  
      active_branch = repo.active_branch
      if active_branch.name == "master":
          error_out("You're already on the master branch.")
  
      if repo.is_dirty():
          error_out(
              'Repo is "dirty". ({})'.format(
                  ", ".join([repr(x.b_path) for x in repo.index.diff(None)])
              )
          )
  
      branch_name = active_branch.name
  
      state = read(config.configfile)
      origin_name = state.get("ORIGIN_NAME", "origin")
      upstream_remote = None
      for remote in repo.remotes:
          if remote.name == origin_name:
              upstream_remote = remote
              break
      if not upstream_remote:
          error_out("No remote called {!r} found".format(origin_name))
  
      repo.heads.master.checkout()
      upstream_remote.pull(repo.heads.master)
  
      repo.git.merge(branch_name)
      repo.git.branch("-d", branch_name)
      success_out("Branch {!r} deleted.".format(branch_name))
  
      info_out("NOW, you might want to run:\n")
      info_out("git push origin master\n\n")
  
      push_for_you = input("Run that push? [Y/n] ").lower().strip() != "n"
      if push_for_you:
          upstream_remote.push("master")
          success_out("Current master pushed to {}".format(upstream_remote.name))