Unfortunately, on my machine Xwayland immediately crashes when I try to
start it. gdb backtrace:
#0 0x00007ffff74f0e79 in wl_proxy_marshal () from target:/lib64/libwayland-client.so.0
#1 0x0000000000413172 in zwp_confined_pointer_v1_destroy (zwp_confined_pointer_v1=0x700000000)
at hw/xwayland/Xwayland@exe/pointer-constraints-unstable-v1-client-protocol.h:612
#2 0x0000000000418bc0 in xwl_seat_destroy_confined_pointer (xwl_seat=0x8ba2a0)
at /home/lyudess/Projects/xserver/hw/xwayland/xwayland-input.c:2839
#3 0x0000000000418c09 in xwl_seat_unconfine_pointer (xwl_seat=0x8ba2a0)
at /home/lyudess/Projects/xserver/hw/xwayland/xwayland-input.c:2849
#4 0x0000000000410d97 in xwl_cursor_confined_to (device=0xa5a000, screen=0x8b9d80, window=0x9bdb70)
at /home/lyudess/Projects/xserver/hw/xwayland/xwayland.c:328
#5 0x00000000004a8571 in ConfineCursorToWindow (pDev=0xa5a000, pWin=0x9bdb70, generateEvents=1,
confineToScreen=0) at /home/lyudess/Projects/xserver/dix/events.c:900
#6 0x00000000004a94b7 in ScreenRestructured (pScreen=0x8b9d80)
at /home/lyudess/Projects/xserver/dix/events.c:1387
#7 0x0000000000502386 in RRScreenSizeNotify (pScreen=0x8b9d80)
at /home/lyudess/Projects/xserver/randr/rrscreen.c:160
#8 0x000000000041a83c in update_screen_size (xwl_output=0x8e7670, width=3840, height=2160)
at /home/lyudess/Projects/xserver/hw/xwayland/xwayland-output.c:203
#9 0x000000000041a9f0 in apply_output_change (xwl_output=0x8e7670)
at /home/lyudess/Projects/xserver/hw/xwayland/xwayland-output.c:252
#10 0x000000000041aaeb in xdg_output_handle_done (data=0x8e7670, xdg_output=0x8e7580)
at /home/lyudess/Projects/xserver/hw/xwayland/xwayland-output.c:307
#11 0x00007ffff50e9d1e in ffi_call_unix64 () at ../src/x86/unix64.S:76
#12 0x00007ffff50e968f in ffi_call (cif=<optimized out>, fn=<optimized out>, rvalue=<optimized out>,
avalue=<optimized out>) at ../src/x86/ffi64.c:525
#13 0x00007ffff74f3d8b in wl_closure_invoke () from target:/lib64/libwayland-client.so.0
#14 0x00007ffff74f0928 in dispatch_event.isra () from target:/lib64/libwayland-client.so.0
#15 0x00007ffff74f1be4 in wl_display_dispatch_queue_pending () from target:/lib64/libwayland-client.so.0
#16 0x00007ffff74f200b in wl_display_roundtrip_queue () from target:/lib64/libwayland-client.so.0
#17 0x0000000000418cad in InitInput (argc=12, argv=0x7fffffffd9c8)
at /home/lyudess/Projects/xserver/hw/xwayland/xwayland-input.c:2867
#18 0x00000000004a20e3 in dix_main (argc=12, argv=0x7fffffffd9c8, envp=0x7fffffffda30)
at /home/lyudess/Projects/xserver/dix/main.c:250
#19 0x0000000000420cb2 in main (argc=12, argv=0x7fffffffd9c8, envp=0x7fffffffda30)
at /home/lyudess/Projects/xserver/dix/stubmain.c:34
This appears to be the result of xwl_cursor_confined_to() and
xwl_screen_get_default_seat(). While not against protocol, mutter ends
up sending xdg_output before wl_seat. xwl_screen_get_default_seat()
makes the naïve assumption that we always have a valid seat, we end up
returning a pointer to the empty list itself instead of an actual seat
and causing ourselves to segfault.
So, actually return NULL in xwl_screen_get_default_seat() if the seat
list is empty, and skip any pointer confinement processing in
xwl_cursor_confined_to() when we don't have a seat setup yet.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
98edb9a35e