Created attachment 1172135 [details]
A backtrace from gdb attached to firefox

Version-Release number of selected component (if applicable):
firefox-47.0-7.wayland.fc24.x86_64
gtk3-3.20.6-1.fc24.x86_64

How reproducible:
Don't know

Steps to Reproduce:
1. go to youtube.com
2. play any video
3. open fullscreen mode

Actual results:
crash

Expected results:
no crash

Truncated backtrace:
#0  0x00007ffff5b12393 in delete_outdated_error_traps (display_x11=display_x11@entry=0x7ffff6b8f480 [GdkWaylandDisplay]) at gdkdisplay-x11.c:2598
#1  0x00007ffff5b123fe in gdk_x11_display_error_trap_push (display=display@entry=0x7ffff6b8f480 [GdkWaylandDisplay]) at gdkdisplay-x11.c:2637
#2  0x00007ffff5b211cc in get_net_supporting_wm_check (screen=screen@entry=0x7ffff6b64480 [GdkWaylandScreen], window=0x12c00000212) at gdkscreen-x11.c:1614
#3  0x00007ffff5b21306 in fetch_net_wm_check_window (screen=screen@entry=0x7ffff6b64480 [GdkWaylandScreen]) at gdkscreen-x11.c:1652
#4  0x00007ffff5b22773 in gdk_x11_screen_supports_net_wm_hint (screen=screen@entry=0x7ffff6b64480 [GdkWaylandScreen], property=0x58) at gdkscreen-x11.c:1732
#5  0x00007fffe92bb734 in nsWindow::MakeFullScreen(bool, nsIScreen*) (aShell=<optimized out>) at /usr/src/debug/firefox-47.0/firefox-47.0/widget/gtk/nsWindow.cpp:5042
#6  0x00007fffe92bb734 in nsWindow::MakeFullScreen(bool, nsIScreen*) (this=0x7fffc79d3000, aFullScreen=<optimized out>, aTargetScreen=<optimized out>) at /usr/src/debug/firefox-47.0/firefox-47.0/widget/gtk/nsWindow.cpp:5055
#7  0x00007fffe875bc55 in nsGlobalWindow::SetWidgetFullscreen(FullscreenReason, bool, nsIWidget*, nsIScreen*) (this=<optimized out>, aReason=aReason@entry=FullscreenReason::ForFullscreenAPI, aIsFullscreen=<optimized out>, aWidget=0x7fffc79d3000, aScreen=0x0) at /usr/src/debug/firefox-47.0/firefox-47.0/dom/base/nsGlobalWindow.cpp:6182
#8  0x00007fffe876e17d in FullscreenTransitionTask::Run() (this=0x7fffc1e63240) at /usr/src/debug/firefox-47.0/firefox-47.0/dom/base/nsGlobalWindow.cpp:5966
#9  0x00007fffe8018e45 in nsThread::ProcessNextEvent(bool, bool*) (this=0x7ffff6b66de0, aMayWait=<optimized out>, aResult=0x7fffffffc587) at /usr/src/debug/firefox-47.0/firefox-47.0/xpcom/threads/nsThread.cpp:994
#10 0x00007fffe80335d5 in NS_ProcessNextEvent(nsIThread*, bool) (aThread=<optimized out>, aMayWait=<optimized out>) at /usr/src/debug/firefox-47.0/firefox-47.0/xpcom/glue/nsThreadUtils.cpp:297
#11 0x00007fffe823576b in mozilla::ipc::MessagePump::Run(base::MessagePump::Delegate*) (this=0x7fffdb23eb80, aDelegate=0x7ffff6b959f0) at /usr/src/debug/firefox-47.0/firefox-47.0/ipc/glue/MessagePump.cpp:95
#12 0x00007fffe822055a in MessageLoop::Run() (this=<optimized out>) at /usr/src/debug/firefox-47.0/firefox-47.0/ipc/chromium/src/base/message_loop.cc:227
#13 0x00007fffe822055a in MessageLoop::Run() (this=<optimized out>) at /usr/src/debug/firefox-47.0/firefox-47.0/ipc/chromium/src/base/message_loop.cc:201
#14 0x00007fffe92a64dc in nsBaseAppShell::Run() (this=0x7fffd2654280) at /usr/src/debug/firefox-47.0/firefox-47.0/widget/nsBaseAppShell.cpp:156
#15 0x00007fffe989965c in nsAppStartup::Run() (this=0x7fffd264ab50) at /usr/src/debug/firefox-47.0/firefox-47.0/toolkit/components/startup/nsAppStartup.cpp:281
#16 0x00007fffe98cfdfd in XREMain::XRE_mainRun() (this=this@entry=0x7fffffffc828) at /usr/src/debug/firefox-47.0/firefox-47.0/toolkit/xre/nsAppRunner.cpp:4337
#17 0x00007fffe98d00b8 in XREMain::XRE_main(int, char**, nsXREAppData const*) (this=this@entry=0x7fffffffc828, argc=argc@entry=0x4, argv=argv@entry=0x7fffffffdd48, aAppData=aAppData@entry=0x7fffffffca28) at /usr/src/debug/firefox-47.0/firefox-47.0/toolkit/xre/nsAppRunner.cpp:4434
#18 0x00007fffe98d02e6 in XRE_main(int, char**, nsXREAppData const*, uint32_t) (argc=0x4, argv=0x7fffffffdd48, aAppData=0x7fffffffca28, aFlags=<optimized out>) at /usr/src/debug/firefox-47.0/firefox-47.0/toolkit/xre/nsAppRunner.cpp:4540
#19 0x00005555555590dc in do_main(int, char**, char**, nsIFile*) (argc=0x4, argv=0x7fffffffdd48, envp=<optimized out>, xreDirectory=0x7ffff6ba59c0) at /usr/src/debug/firefox-47.0/firefox-47.0/browser/app/nsBrowserApp.cpp:220
#20 0x000055555555877f in main(int, char**, char**) (argc=0x4, argv=0x7fffffffdd48, envp=0x7fffffffdd70) at /usr/src/debug/firefox-47.0/firefox-47.0/browser/app/nsBrowserApp.cpp:360