In my master page I have a placeholder where a Html.RenderPartial() will render a collection of (bread)crumbs which are effectively a list of links I build up using action, controller names and RouteValueDictionary's.
I have an action that is called from multiple places to view a short-list and so when building the list of breadcrumbs for this actions view to display. Ideally I'd like to use Request.UrlReferer as the penultimate crumb.
Before unconditionally using this URL I want to check that it will actually match at least 1 route so I can be sure if the user clicks it they will get a view from my app and if they don't I will simply use the home page instead.
Any suggestions how I would go about this?