User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:36.0) Gecko/20100101 Firefox/36.0 Build ID: 20150212154903 Steps to reproduce: 1. Open Firefox 2. Type "filetype:pdf" in URL bar (not search bar) 3. Hit Enter 4. If first time, choose to open this type of link with firefox.exe Actual results: Firefox enters into an infinite loop of opening new tabs i.e New Tabs keep on opening until you force-close it. Expected results: Should've made a search query using default search engine.