The documentation for wayland-server.h says:
> Use of this header file is discouraged. Prefer including
> wayland-server-core.h instead, which does not include the server protocol
> header and as such only defines the library PI, excluding the deprecated API
> below.
Replacing wayland-server.h with wayland-server-core.h allows us to drop the
WL_HIDE_DEPRECATED declaration.
When the surface is destroyed clear it's reference but wait for the up
event to destroy the touch point via wlr_seat_touch_notify_up().
If the surface is destroyed before the up event we end up with
incomplete sequences sent to the client like
[915821.276] wl_touch@3.down(146, 2475027, wl_surface@38, 0, 236.000000, 515.000000)
[915821.608] wl_touch@3.frame()
[915821.637] wl_touch@3.motion(2475027, 0, 236.000000, 515.000000)
[915821.779] wl_touch@3.frame()
so there's never an up event. While it should be something like
[2461229.051] wl_touch@3.down(81, 3236959, wl_surface@34, 0, 218.000000, 478.000000)
[2461229.435] wl_touch@3.frame()
[2461229.484] wl_touch@3.motion(3236959, 0, 218.000000, 478.000000)
[2461229.636] wl_touch@3.frame()
[2461277.520] wl_touch@3.up(82, 3237007, 0)
[2461277.681] wl_touch@3.frame()
this confuses toolkits intepreting the next down event incorrectly. So
don't destroy the touch point too early.
This change tracks, for each wlr_seat_client, the most recent serial
numbers which were sent to the client. When the client makes a
selection request, wlroots now verifies that the serial number
associated with the selection request was actually provided to that
specific client. This ensures that the client that was most
recently interacted with always has priority for its copy selection
requests, and that no other clients can incorrectly use a larger serial
value and "steal" the role of having the copy selection.
Also, the code used to determine when a given selection is superseded
by a newer request uses < instead of <= to allow clients to make
multiple selection requests with the same serial number and have the
last one hold.
To limit memory use, a ring buffer is used to store runs of sequential
serial numbers, and all serial numbers earlier than the start of the
ring buffer are assumed to be valid. Faking very old serials is
unlikely to be disruptive.
Assuming all clients are correctly written, the only additional
constraint which this patch should impose is that serial numbers
are now bound to seats: clients may not receive a serial number
from an input event on one seat and then use that to request
copy-selection on another seat.