Open a random folder in a nautilus browser window. Create a new folder in it.
Open with new folder. Using the path bar, go back to the parent folder.
Move the new folder in the trash.

The new, trashed folder still appears in the path bar. If you try to navigate to
it, you get an error message.

When nautilus deletes a folder, it should check if it's a part of the path bar,
and if it is, update the path bar accordingly.