Comment 24 for bug 256429

Unsure. It uses the workaround patch previously posted (adding a dummy KEY_A key capability to the uinput device). Without the workaround, the uinput device doesn't even show up in "xinput list". For some reason, a keyboard uinput device with only a KEY_ENTER is not sufficient to be registered.

So while it's more of a workaround than a fix, it does indeed resolve the issue and has absolutely zero side effects.