XWikiExplorer throws a JavaScript exception when inputing a page with an unexisting parent

Here are the steps to reproduce:

• create a new page X.Y and set its parent to X.Z, making sure X.Z doesn't exist
• go to Main.AllDocs and open the Tree tab
• you should see the X space in the tree, but not the Y page, which is normal considering its parent doesn't exist
• type X.Y in the input below the tree
• you should get a JavaScript exception

  mismatched tag. Expected: </br>.
  http://localhost:8080/xwiki/bin/view/Main/AllDocs?view=tree
  Line 8
  

  and also notice the failed request:

  GET http://localhost:8080/xwiki/rest/wikis/xwiki/spaces/X/pages/Z 404 Not Found 5ms
  

This issue can be reproduced in the new WYSIWYG editor following this steps:

• create a new page X.Y with xwiki/2.0 syntax and set its parent to X.Z, making sure X.Z doesn't exist
• save the X.Y page
• edit in WYSIWYG mode
• type some text "abc" and select it
• go to the Link menu and choose "Wiki page"
• you should see the tree loaded, but with a JavaScript exception in the Firebug console