I've hit a snag thats got me stumped and I'm not sure if its a bug or just some limitation that I'm unaware of.

My issue is that I've made a html helper using MergeAttribute to generate a menu eg:
link.MergeAttribute("href", menuItem.URL);
It works as expected unless the URL includes a named anchor.

So '/testpage' correctly becomes '/en/testpage' but '/testpage#foo' just gets rendered as '/testpage#foo'

Could it be that the URL with the anchor is failing the regex in EarlyUrlLocalizer.cs? I'm hopeless at regex so I really can't tell (It's a dark art I've never managed to get my head around) or could something else be tripping it up?