add performance test for dtext, fixes #2051

app/logical/d_text.rb

@@ -19,6 +19,7 @@ class DText
     str.gsub!(/\[i\](.+?)\[\/i\]/i, '<em>\1</em>')
     str.gsub!(/\[s\](.+?)\[\/s\]/i, '<s>\1</s>')
     str.gsub!(/\[u\](.+?)\[\/u\]/i, '<u>\1</u>')
+    str.gsub!(/\[tn\](.+?)\[\/tn\]/i, '<p class="tn">\1</p>')
 
     str = parse_links(str)
     str = parse_aliased_wiki_links(str)