Problem with broken wiki page and Markdown file

Created by: ldath

Error log

Started GET "/test1/master/tree" for 192.168.5.239 at 2012-09-18 13:43:01 +0200
Processing by RefsController#tree as HTML
  Parameters: {"project_id"=>"test1", "id"=>"master"}
  Rendered refs/_head.html.haml (3.1ms)
  Rendered refs/_tree_item.html.haml (142.0ms)
  Rendered refs/_tree.html.haml (311.7ms)
  Rendered refs/tree.html.haml within layouts/project (335.0ms)
Completed 500 Internal Server Error in 402ms

ActionView::Template::Error (ClassNotFound: no lexer for alias 'txt' found):
    45:         .file_content.wiki
    46:           - if content.name =~ /\.(md|markdown)$/i
    47:             = preserve do
    48:               = markdown(content.data)
    49:           - else
    50:             = simple_format(content.data)
    51: 
  lib/redcarpet/render/gitlab_html.rb:14:in `block_code'
  app/helpers/gitlab_markdown_helper.rb:68:in `render'
  app/helpers/gitlab_markdown_helper.rb:68:in `markdown'
  app/views/refs/_tree.html.haml:48:in `block in  _app_views_refs__tree_html_haml___2604746595127003284_38330500'
  app/views/refs/_tree.html.haml:47:in `_app_views_refs__tree_html_haml___2604746595127003284_38330500'
  app/views/refs/tree.html.haml:2:in `_app_views_refs_tree_html_haml__2263099346269022960_27911560'
  app/controllers/refs_controller.rb:40:in `tree'

To reproduce this bug README.md was used.