Wayland: Mouse only scrolls up

[neonbyte1]

I encountered a problem with the mouse scrolling when switching from X11 + i3 to Wayland + Hyprland. At first I thought that this might be due to an outdated version of Looking Glass, as I was still using version B6 in my gaming VM. However, I performed a clean installation of my system last night, set up a new VM , but the problem was still there - even with the bleeding edge version.

Actual problem

I've noticed that the actual value of the value parameter in pointerAxisHandler is sometimes 0 while scrolling up or down. After looking at the implementation, you'll see why.

int button = value > 0 ?
  5 /* SPICE_MOUSE_BUTTON_DOWN */ :
  4 /* SPICE_MOUSE_BUTTON_UP */;
app_handleButtonPress(button);
app_handleButtonRelease(button);

Since the value is not greater than 0, the LookinGlass client will always handle the event as SPICE_MOUSE_BUTTON_UP.

Preview

https://i.imgur.com/A7eGpMb.mp4

Logs

Serial: 7067714, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067716, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067717, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067719, Axis: 0, Value: 3840, Double: 15.000000
Serial: 7067720, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067722, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067724, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067729, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067732, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067737, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067740, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067743, Axis: 0, Value: 3840, Double: 15.000000
Serial: 7067808, Axis: 0, Value: -3840, Double: -15.000000
Serial: 7067810, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067812, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067814, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067818, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067829, Axis: 0, Value: -3840, Double: -15.000000
Serial: 7067895, Axis: 0, Value: 3840, Double: 15.000000
Serial: 7067898, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067902, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067904, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067907, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067909, Axis: 0, Value: 3840, Double: 15.000000
Serial: 7067910, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067912, Axis: 0, Value: 0, Double: 0.000000
Serial: 7067976, Axis: 0, Value: -3840, Double: -15.000000

Solution

I've added an OR statement to the condition so that the events are only processed if the value is not 0.

[gnif]

Have you reported this as a bug to the Hyperland devs? A scroll value of 0 should really never be seen, it's a useless event.