Makes sense, but I notice that InputEventJoypadButton::set_button_index (also mentioned in that proposal) doesn't do any validation of the parameter. Actually, almost none of the setters in InputEvent* classes do, aside from this one.

Makes me wonder if there should be parameters checking in the first place. It seems none of the InputEvent's business to question these values. If one were obsessed with performance, they could argue it even makes Godot's own created events a bit slower.

If it helps, the only reference to this error message I found online was someone confused because they were getting it and didn't know why (was just ERR_FAIL_INDEX at the time so it's slightly different): https://forum.godotengine.org/t/joy-axis-error-debug-spam/5634

The check was added here: 41c1cfe

Thanks!