[BROWSEUI] filebrowsers adress-bar-combobox interaction destroys full path

r75675 gcc dbg:

Since r75670 we have the adressbar 'populated' in file-browser.
Usually we display the full adress-path in the combobox, but after expanding, the full path gets erroneously replaced by current-folder-name only and the error persists after collapsing the combobox.
see fullPathNotRestored.webm

This is different to 2k3 where the full path stays visible the whole time when expanded (and also later when collapsed again).