Tablet pen proximity_out event not delivered if tablet has left surface

[Xyene]

With a mouse, if one does something like press down on a scrollbar and leave the window the scrollbar belongs to, and then release the mouse button, the scrollbar will be released.

If someone does the same with a tablet pen, the scrollbar is not released -- the tablet pen up event is not delivered. If the tablet pen re-enters the window while hovering, not pressed, the window remains under the impression that the pen is still down.

Running with WAYLAND_DEBUG shows that zwp_tablet_tool_v2.proximity_out is never sent if the pen left the window while the tablet pen is down. It's not sent after it's released in another window, either. The leave event is being sent, as is the eventual removed when I lift the pen.

[1517543.986] zwp_tablet_tool_v2@4278190084.proximity_in(3243, zwp_tablet_v2@4278190080, wl_surface@19)
[1520888.037] zwp_tablet_tool_v2@4278190084.proximity_in(3270, zwp_tablet_v2@4278190080, wl_surface@19)
[1521033.933] zwp_tablet_tool_v2@4278190084.proximity_out()

I've had this happen with every app I've tried (gedit, Firefox, kitty). gedit actually crashes a short while later in libwayland-client.so:wl_proxy_marshal, which I imagine is related as it doesn't happen when not trying to reproduce this issue.

I think this has to do with tablet v2 support. If the tablet is released over a surface supporting v2, the surface that is implicitly grabbed isn't notified of proximity_out. (For instance kitty does not support tablet v2, so releasing the pen over a kitty window works correctly, but releasing it over Firefox or gedit doesn't)