QFileDialog::getOpenFileName fails to use the "directory" argument properly

calling QFileDialog::getOpenFileName and passing a directory such as "/path/to/directory" files to show that directory by default on OSX. Instead it is necessary to append /, aka "/path/to/directory/". I could swear this worked in the past and I just didn't notice this regression for some time. Perhaps this slipped into the 4.7 series?