Bug#660629: workaround for the bug

[Alan James]

I too suffered from this. Gnome-shell crashed whenever i tried to
search for an application.

The workaround was to empty the file ~/.local/share/recently-used.xbel
and then make it immutable with
sudo chattr +i ~/.local/share/recently-used.xbel

Now it doesn't crash, and I've only lost some functionality I didn't use.

Arch users are suffering too, and this is where I learned of the workaround:
https://bbs.archlinux.org/viewtopic.php?id=135826&p=1

Alan.