bug#57020: 29.0.50; Mouse wheel stops working

[Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Michael Heerdegen <michael_heerdegen@web.de> writes:

> Po Lu <luangruo@yahoo.com> writes:
>
>> mouse-4/mouse-5 or wheel-up/wheel-down?
>>
>> Please be clear here, since they are handled separately under XInput
>> 2.
>
> You are right, the force of habit: When the events are considered they
> are named "wheel-up/wheel-down" - I'm sorry.
>
> Michael.

Could you instrument this chunk of xterm.c:

		      /* See the comment on top of x_cache_xi_devices
			 for more details on how scroll wheel movement
			 is reported on XInput 2.  */
		      delta = x_get_scroll_valuator_delta (dpyinfo, device,
							   i, *values, &val);
		      values++;

by adding:

		      printf ("%g\n", delta);

afterwards?  Then, please see if any (and what) values are printed once
the mouse wheel stops working.