Subject: Re: bug#57020: 29.0.50; Mouse wheel stops working

From: Po Lu <[email-masked]>
Date: Mon, 08 Aug 2022 10:36:23 +0800

Michael Heerdegen <[email-masked]> writes:

> Po Lu <[email-masked]> writes:
>
>> 		      printf ("%g\n", delta);
>>
>> afterwards?  Then, please see if any (and what) values are printed once
>> the mouse wheel stops working.
>
> Short answer: nothing is printed.
>
> Before the issue starts happening, I see -1 and +1 for each wheel
> "click" and lots of 1.79769e+308 values when moving the mouse.
>
> Once scrolling stopped working, mouse wheel turning leads to no output
> any more (but the 1.79769e+308 values are still printed).
>
> What I was also noticing: when turning the mouse wheel over the scroll
> bar, there is a visual feedback: it looks like the scroll bar would lead
> to a scroll (the bar moves), but scrolling is not happening, the buffer
> text stands still.  Also that is happening without output for DELTA.
>
> Michael.

Hmm, thanks.  Could you also add the following instrumentation to that
code, like such:

	      device = xi_device_from_id (dpyinfo, xev->deviceid);

	      if (!device)
		{
		  fprintf (stderr, "device not found, %d\n", xev->deviceid);
		  goto XI_OTHER;
		}

and see if that is ever printed when wheel movement stops working?