wl_resource_for_each_safe isn't safe to use here because it accesses
the list's head memory one last time at the end of the loop. Work
around this by breaking out early.
==19880==ERROR: AddressSanitizer: heap-use-after-free on address 0x60d0000e6368 at pc 0x7fab68619de2 bp 0x7ffd5c91cee0 sp 0x7ffd5c91ced0
READ of size 8 at 0x60d0000e6368 thread T0
#0 0x7fab68619de1 in wlr_seat_destroy ../types/seat/wlr_seat.c:179
#1 0x7fab68619fb9 in handle_display_destroy ../types/seat/wlr_seat.c:196
#2 0x7fab688e4f8f in wl_priv_signal_emit src/wayland-server.c:2024
#3 0x7fab688e56ca in wl_display_destroy src/wayland-server.c:1092
#4 0x40c11e in server_fini ../sway/server.c:138
#5 0x40b1a8 in main ../sway/main.c:438
#6 0x7fab67b5e18a in __libc_start_main ../csu/libc-start.c:308
#7 0x409359 in _start (/opt/wayland/bin/sway+0x409359)
0x60d0000e6368 is located 24 bytes inside of 144-byte region [0x60d0000e6350,0x60d0000e63e0)
freed by thread T0 here:
#0 0x7fab6a7d6880 in __interceptor_free (/lib64/libasan.so.5+0xee880)
#1 0x7fab68619805 in seat_client_handle_resource_destroy ../types/seat/wlr_seat.c:97
#2 0x7fab688e5025 in destroy_resource src/wayland-server.c:688
previously allocated by thread T0 here:
#0 0x7fab6a7d6e50 in calloc (/lib64/libasan.so.5+0xeee50)
#1 0x7fab686198df in seat_handle_bind ../types/seat/wlr_seat.c:127
#2 0x7fab6530503d in ffi_call_unix64 (/lib64/libffi.so.6+0x603d)
It is common to want to iterate an xdg-surface's popups separately from
the toplevel and subsurfaces. For example, popups are typically rendered
on top of most other surfaces.
wlr_xdg_surface_for_each_surface continues to iterate both surfaces and
popups to maintain backwards compatibility.
We cannot handle just one of the two being NULL later down the road
(e.g. divide by zero in matrix projection code),
just ignore any such configure request.
Found through static analysis
Guido Günther
Drew DeVault
emersion
Dominique Martinet
Armin Preiml
Ilia Bozhinov
Ryan Dwyer
Vincent Vanlaer