Please describe the problem:
Navigate down a tree of empty folders. Go up a few levels, then delete the
folders. The location buttons stay put. Attempting to click them gives you a
"not found" error, and the button's state remains pressed. See attached
screenshot for clarification.

Steps to reproduce:
1. `mkdir -p test/test/test/test`
2. `gnome-open test/test/test/test`
3. Navigate up 3 levels.
4. Delete the "test" folder.


Actual results:
Location buttons remain intact and break when you click them.

Expected results:
Location buttons remove themselves.

Does this happen every time?
Yes.

Other information:
Maybe you'll have to open file monitoring on all of the folders the buttons
represent? Is that much of an issue?

Cheers guys. :)