The patch was tested using two examples which I've run across recently:
* [xf86-input-joystick](https://www.x.org/releases/individual/driver/xf86-input-joystick-1.6.3.tar.gz) ([signature](https://www.x.org/releases/individual/driver/xf86-input-joystick-1.6.3.tar.gz.sig))
* `file`: ftp://ftp.astron.com/pub/file/file-5.37.tar.gz{,.asc}
Without the patch, `gpg --verify $sigfile` fails with "No public key." With the patch, the same command retrieves the public key used for the signature and successfully verifies it.