sway/cursor: SEGFAULT

[nearffxx]

After upgrading sway to version 1.0-alpha.4-85-g1a9179db (Jul 24 2018, branch 'master'), it started SEGFAULTing randomly, mostly after a click. I didn't had the issue with the version from yesterday, so I presume maybe the problem came from #2342, but it's just a supposition.

(gdb) bt full
#0  0x0000558dee7482aa in find_resize_edge (cont=0x0, cursor=0x558defa6deb0) at ../sway/input/cursor.c:148
        view = 0x86a4d803afd83e00
        edge = (WLR_EDGE_BOTTOM | WLR_EDGE_LEFT | unknown: 19638224)
#1  0x0000558dee749775 in dispatch_cursor_button (cursor=0x558defa6deb0, time_msec=19638237, button=272, state=WLR_BUTTON_PRESSED) at ../sway/input/cursor.c:567
        surface = 0x558defd60320
        sx = 33.268037470822037
        sy = 10.6720169657155
        cont = 0x0
        on_border = false
        on_contents = false
        on_titlebar = false
        keyboard = 0x7f90a1c0662e <wlr_idle_notify_activity+39>
        modifiers = 0
        binding = 0x0
#2  0x0000558dee749b33 in handle_cursor_button (listener=0x558defa6df18, data=0x7ffe0aa93d80) at ../sway/input/cursor.c:631
        cursor = 0x558defa6deb0
        event = 0x7ffe0aa93d80
#3  0x00007f90a1c1dffc in wlr_signal_emit_safe (signal=0x558defa6e0c8, data=0x7ffe0aa93d80) at ../util/signal.c:29
        pos = 0x558defa6df18
        l = 0x558defa6df18
        cursor = {link = {prev = 0x558defa6df18, next = 0x7ffe0aa93c90}, notify = 0x7f90a1c1df46 <handle_noop>}
        end = {link = {prev = 0x7ffe0aa93c70, next = 0x558defa6e0c8}, notify = 0x7f90a1c1df46 <handle_noop>}
#4  0x00007f90a1c038f9 in handle_pointer_button (listener=0x558defc70a10, data=0x7ffe0aa93d80) at ../types/wlr_cursor.c:409
        event = 0x7ffe0aa93d80
        device = 0x558defc709b0
#5  0x00007f90a1c1dffc in wlr_signal_emit_safe (signal=0x558defc5d078, data=0x7ffe0aa93d80) at ../util/signal.c:29
        pos = 0x558defc70a10
        l = 0x558defc70a10
        cursor = {link = {prev = 0x558defc70a10, next = 0x7ffe0aa93d30}, notify = 0x7f90a1c1df46 <handle_noop>}
        end = {link = {prev = 0x7ffe0aa93d10, next = 0x558defc5d078}, notify = 0x7f90a1c1df46 <handle_noop>}
#6  0x00007f90a1be1083 in handle_pointer_button (event=0x558defd5be60, libinput_dev=0x558defc03b10) at ../backend/libinput/pointer.c:84
        wlr_dev = 0x558defc41ed0
        pevent = 0x558defd5be60
        wlr_event = {device = 0x558defc41ed0, time_msec = 19638237, button = 272, state = WLR_BUTTON_PRESSED}
#7  0x00007f90a1be0953 in handle_libinput_event (backend=0x558def7ade00, event=0x558defd5be60) at ../backend/libinput/events.c:222
        __PRETTY_FUNCTION__ = "handle_libinput_event"
        libinput_dev = 0x558defc03b10
        event_type = LIBINPUT_EVENT_POINTER_BUTTON
#8  0x00007f90a1bdf80f in handle_libinput_readable (fd=22, mask=1, _backend=0x558def7ade00) at ../backend/libinput/backend.c:35
        backend = 0x558def7ade00
        event = 0x558defd5be60
#9  0x00007f90a1e53a42 in wl_event_loop_dispatch () at /usr/lib/libwayland-server.so.0
#10 0x00007f90a1e5214c in wl_display_run () at /usr/lib/libwayland-server.so.0
#11 0x0000558dee72ea76 in server_run (server=0x558dee983920 <server>) at ../sway/server.c:154
#12 0x0000558dee72e2d5 in main (argc=1, argv=0x7ffe0aa94198) at ../sway/main.c:455
        verbose = 0
        debug = 0
        validate = 0
        long_options = 
            {{name = 0x558dee76e3bc "help", has_arg = 0, flag = 0x0, val = 104}, {name = 0x558dee76e3c1 "config", has_arg = 1, flag = 0x0, val = 99}, {name = 0x558dee76e3c8 "validate", has_arg = 0, flag = 0x0, val = 67}, {name = 0x558dee76e3d1 "debug", has_arg = 0, flag = 0x0, val = 100}, {name = 0x558dee76e3d7 "version", has_arg = 0, flag = 0x0, val = 118}, {name = 0x558dee76e3df "verbose", has_arg = 0, flag = 0x0, val = 86}, {name = 0x558dee76e3e7 "get-socketpath", has_arg = 0, flag = 0x0, val = 112}, {name = 0x0, has_arg = 0, flag = 0x0, val = 0}}
        config_path = 0x0
        usage = 0x558dee76df40 "Usage: sway [options] [command]\n\n  -h, --help", ' ' <repeats 13 times>, "Show help message and quit.\n  -c, --config <config>  Specify a config file.\n  -C, --validate         Check the validity of the config file, th"...
        c = -1
        suid = false