wminput crashes on classic controller button click

[HaraldKorneliussen]

Hi,

Great to see this project is maintained again, I pulled the latest version to see if a certain bug was fixed, sadly it wasn't.

What I do is this:

1. Edit the gamepad config file, change the line CLASSIC.A = BTN_A to CLASSIC.A = KEY_A.
2. Start wminput (I just run it with sudo to work around uinput permissions issue - maybe not the best idea) and connect successfully to wiimote with Classic controller attached (it works fine with wmgui)
3. Press the A button on the classic controller
4. Whoops, X crashes.

What I really wanted to do was make one of the analog sticks work as a mouse, but I couldn't get it to register anything at all. The moment I change anything in the config file, this happens.

[tuomasjjrasanen]

Confirmed but unfortunately it has nothing to do with libcwiid nor wminput. I just experimented a bit, and it seems that it's a bug in Xorg. I was able to reproduce the crash without any dependency to cwiid whatsoever.

Steps to reproduce:

1. Create an uinput device.
2. Enable a relative or an absolute axis.
3. Enable a key from AT key set. (KEY_ prefixes).
4. Send a EV_KEY event.

If any AT key is enabled, the device is handled as a keyboard.

If a relative axis was enabled, crashing can be avoided by registering one standard mouse button (BTN_MOUSE for example). It seems, that whenever a device has two relative axes and at least one mouse button, it is handled as mouse. However, I have no idea why this affects the crash behavior. It is quite odd that just enabling some capabilities causes the device to become a crash cannon..

There is something really wrong in Xorg's capability checking.. this should be reported to Xorg.

[HaraldKorneliussen]

Big thanks for confirming this and tracking it down! I'm not sure I do the workaround correctly, though. I change Classic.Home to BTN_MOUSE, and remove the ones with KEY_ prefixes, but I can still crash it - whether the axes are set to relative or not.