IsDeviceUsable in IOhidapi.cpp uses errno to detect if hid_write failed because of an unconnected Wiimote on a Dolphinbar (it expects errno == EPIPE in this case).
macOS’s implementation of hid_write detected this specific error (IOHIDDeviceSetReport returns kUSBHostReturnPipeStalled) but didn’t set errno so the check failed.
This add errno assignment to failure cases of macOS’s hid_write.
If available, use the system-generated unique ID for HID device paths instead of a transport/vid/pid/location tuple.
The Mayflash Dolphinbar registers four HID devices (regardless of the number of connected Wiimotes) which had the same path with the previous path building method, causing a bit of confusion when detecting and connecting to Wiimotes.
The unique IDs do not change if the computer is suspended and resumed, but do change if the HID device is unplugged/replugged.
Based on ca0c2efe7a. Credits go to flacs.
However, unlike the original commit, hidapi does not completely replace
the current implementations, so we can still connect Wiimotes with 1+2
(without pairing).
Also, it is only used on Linux and OS X for now. This removes the
advantage of having only one implementation but there is no other
choice: using hidapi on Windows is currently impossible because
hid_write() is implemented in a way that won't work with Wiimotes.
Additionally:
* We now check for the device name in addition to the PID/VID so we can
support the Balance Board and maybe third-party Wiimotes too. This
doesn't achieve anything with the DolphinBar but it does with hidraw.
* Added a check to not connect to the same device more than once.
