When I type "-" (minus) in FileBrowser's Path dropdown and press enter, minus is appended to the path instead of changing path to current buffer. When I choose "Directory of current buffer" from commands menu, it works ok. ~ and / options are working fine. There is also small inconsistency, because in search and replace dialog to current buffer points empty dropdown, not minus. Maybe in FileBrowser it should as well, but for now neither minus nor empty field points to current directory.