FS2 Open Coding - The Source Code Project (SCP) / Re: RELEASE: wxLauncher 0.10.1 beta [Updated 2015/09/26]« Last post by jg18 on May 26, 2017, 12:30:38 am »
wxL itself never manually sets the GUID to zero (that is, a long string of zeroes). It sets the GUID to an empty string on error, which will cause FSO to ignore the GUID entirely AFAICT.
AFAICT the only case where the GUID gets set to 0 is in SDL itself, from the SDL wiki page:
Returns the GUID of the given joystick. If called on an invalid index, this function returns a zero GUID; call
SDL_GetError() for more information.
Therefore wxL may be specifying the wrong index when getting the joystick GUID for XInput devices? That's one thought. I need to compare more carefully to the FSO SDL joystick code. That's what I have so far.