* Open a fileselector i Open mode
* Control-l to open Location entry
* Make sure the mouse cursor is not placed within the location entry dialog
(this is very common since the location entry dialog is so tiny)
* Type something that will give a list of completions
* At some point while typing, the location entry will lose focus and the window
where the mouse cursor is, will be focused
* Typing regular characters is still possible, but things like tab-completion
stops working

Note, this is with 'Select windows when the mouse moves over them' selected in
Windows Preferences.