title: Assigning to document.location.href without clobbering history
body: <p>In testing document.location.href, I have observed that when the user initiates an action that results in javascript that assigns to document.location.href, the new URL is added to the history.</p>
  
  <p>However, if the call is initiated by javascript that is result of, say, state change of an XMLHTTPRequest, the entry for the current page in the history is over-written. Have I characterized this correctly? Is there a way to get the page change to be reflected in the history in this latter case?</p>