Don't use double quotes. This is a bit of a gotcha. As a rule, when a filename is passed as a stand alone argument (i.e no switches or multiple filenames), double quotes are not supported. Commands like edit, which can be called like a function, requires double quoting because the argument is not just one filename (it's multiple filenames and switches). One less obvious function is file_match() which requires double quotes on the filename because that argument can have options in it. file_match is not one of the better designed functions. It's best to design functions (not commands) so double quoting is not necessary. There are a few functions which take a single filename argument which do strip double quotes. However, even I don't remember which ones do and which ones don't.