1. visit http://www.jboss.org/books/
2. Type 'java' in the search box
3. Observe that only java books are displayed
4. delete 'java' from the search box
5. Observe that only two results are shown and the spinning wheel stays on the page

See:

https://www.dropbox.com/s/fm76zfwa59c8fip/Screenshot%202015-04-28%2010.05.45.png?dl=0

Also, this error is displayed in the console:

Uncaught ReferenceError: sys_url_view is not defined