Bug 181880 – [MSE] Null de-ref of m_playbackWithoutUserGestureStartedTime

• Status: NEW
• Component: Media

[Alicia Boya García]

I've encountered this at least a couple of times in GTK.

#0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
#1  0x00007fffdc137381 in __GI_abort () at abort.c:79
#2  0x00007fffdc12d8fa in __assert_fail_base (fmt=0x7fffdc2a8ba8 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=assertion@entry=0x7ffff55f74e8 "initialized()", 
    file=file@entry=0x7ffff55f74c8 "../../Source/WTF/wtf/Optional.h", line=line@entry=590, 
    function=function@entry=0x7ffff5609220 <std::optional<WTF::MediaTime>::operator->()::__PRETTY_FUNCTION__> "T* std::optional<T>::operator->() [with T = WTF::MediaTime]") at assert.c:92
#3  0x00007fffdc12d972 in __GI___assert_fail (assertion=0x7ffff55f74e8 "initialized()", file=0x7ffff55f74c8 "../../Source/WTF/wtf/Optional.h", line=590, 
    function=0x7ffff5609220 <std::optional<WTF::MediaTime>::operator->()::__PRETTY_FUNCTION__> "T* std::optional<T>::operator->() [with T = WTF::MediaTime]") at assert.c:101
#4  0x00007ffff3214a09 in std::optional<WTF::MediaTime>::operator-> (this=0x7fff5948bdd8) at ../../Source/WTF/wtf/Optional.h:590
#5  0x00007ffff31fe6d8 in WebCore::HTMLMediaElement::playbackProgressTimerFired (this=0x7fff5948b780) at ../../Source/WebCore/html/HTMLMediaElement.cpp:3800
#6  0x00007ffff32293d0 in std::__invoke_impl<void, void (WebCore::HTMLMediaElement::*&)(), WebCore::HTMLMediaElement*&> (
    __f=@0x7fff59491bc8: (void (WebCore::HTMLMediaElement::*)(WebCore::HTMLMediaElement * const)) 0x7ffff31fe450 <WebCore::HTMLMediaElement::playbackProgressTimerFired()>, __t=@0x7fff59491bd8: 0x7fff5948b780)
    at /usr/include/c++/7/bits/invoke.h:73
#7  0x00007ffff32292bd in std::__invoke<void (WebCore::HTMLMediaElement::*&)(), WebCore::HTMLMediaElement*&> (
    __fn=@0x7fff59491bc8: (void (WebCore::HTMLMediaElement::*)(WebCore::HTMLMediaElement * const)) 0x7ffff31fe450 <WebCore::HTMLMediaElement::playbackProgressTimerFired()>, __args#0=@0x7fff59491bd8: 0x7fff5948b780)
    at /usr/include/c++/7/bits/invoke.h:95
#8  0x00007ffff3229012 in std::_Bind<void (WebCore::HTMLMediaElement::*(WebCore::HTMLMediaElement*))()>::__call<void, , 0ul>(std::tuple<>&&, std::_Index_tuple<0ul>) (this=0x7fff59491bc8, __args=...)
    at /usr/include/c++/7/functional:467
#9  0x00007ffff32289ae in std::_Bind<void (WebCore::HTMLMediaElement::*(WebCore::HTMLMediaElement*))()>::operator()<, void>() (this=0x7fff59491bc8) at /usr/include/c++/7/functional:551
#10 0x00007ffff322873e in WTF::Function<void ()>::CallableWrapper<std::_Bind<void (WebCore::HTMLMediaElement::*(WebCore::HTMLMediaElement*))()> >::call() (this=0x7fff59491bc0) at ../../Source/WTF/wtf/Function.h:101
#11 0x00007ffff160dece in WTF::Function<void ()>::operator()() const (this=0x7fff5948b910) at ../../Source/WTF/wtf/Function.h:56
#12 0x00007ffff1618fc6 in WebCore::Timer::fired (this=0x7fff5948b8d8) at ../../Source/WebCore/platform/Timer.h:133
#13 0x00007ffff3694232 in WebCore::ThreadTimers::sharedTimerFiredInternal (this=0x7fffd4afd190) at ../../Source/WebCore/platform/ThreadTimers.cpp:118
#14 0x00007ffff3693d5f in WebCore::ThreadTimers::<lambda()>::operator()(void) const (__closure=0x7fffd4afa348) at ../../Source/WebCore/platform/ThreadTimers.cpp:70
#15 0x00007ffff3696b90 in WTF::Function<void()>::CallableWrapper<WebCore::ThreadTimers::setSharedTimer(WebCore::SharedTimer*)::<lambda()> >::call(void) (this=0x7fffd4afa340) at ../../Source/WTF/wtf/Function.h:101
#16 0x00007ffff160dece in WTF::Function<void ()>::operator()() const (this=0x7ffff7dc5788 <WebCore::MainThreadSharedTimer::singleton()::instance+8>) at ../../Source/WTF/wtf/Function.h:56
#17 0x00007ffff367cd65 in WebCore::MainThreadSharedTimer::fired (this=0x7ffff7dc5780 <WebCore::MainThreadSharedTimer::singleton()::instance>) at ../../Source/WebCore/platform/MainThreadSharedTimer.cpp:54
#18 0x00007ffff367e134 in WTF::RunLoop::Timer<WebCore::MainThreadSharedTimer>::fired (this=0x7ffff7dc5790 <WebCore::MainThreadSharedTimer::singleton()::instance+16>) at ../../Source/WTF/wtf/RunLoop.h:152
#19 0x00007fffe860ff4d in WTF::RunLoop::TimerBase::<lambda(gpointer)>::operator()(gpointer) const (__closure=0x0, userData=0x7ffff7dc5790 <WebCore::MainThreadSharedTimer::singleton()::instance+16>)
    at ../../Source/WTF/wtf/glib/RunLoopGLib.cpp:166
#20 0x00007fffe860ff89 in WTF::RunLoop::TimerBase::<lambda(gpointer)>::_FUN(gpointer) () at ../../Source/WTF/wtf/glib/RunLoopGLib.cpp:170
#21 0x00007fffe860f6c2 in WTF::<lambda(GSource*, GSourceFunc, gpointer)>::operator()(GSource *, GSourceFunc, gpointer) const (__closure=0x0, source=0x560640, 
    callback=0x7fffe860ff6c <WTF::RunLoop::TimerBase::<lambda(gpointer)>::_FUN(gpointer)>, userData=0x7ffff7dc5790 <WebCore::MainThreadSharedTimer::singleton()::instance+16>) at ../../Source/WTF/wtf/glib/RunLoopGLib.cpp:45
#22 0x00007fffe860f6f1 in WTF::<lambda(GSource*, GSourceFunc, gpointer)>::_FUN(GSource *, GSourceFunc, gpointer) () at ../../Source/WTF/wtf/glib/RunLoopGLib.cpp:46
#23 0x00007fffe121c563 in g_main_dispatch (context=context@entry=0x4611d0) at /webkit/WebKitBuild/DependenciesGTK/Source/glib-2.52.1/glib/gmain.c:3212
#24 0x00007fffe121ee85 in g_main_context_dispatch (context=context@entry=0x4611d0) at /webkit/WebKitBuild/DependenciesGTK/Source/glib-2.52.1/glib/gmain.c:3865
#25 0x00007fffe121efe3 in g_main_context_iterate (context=0x4611d0, block=block@entry=1, dispatch=dispatch@entry=1, self=self@entry=0x4cd500) at /webkit/WebKitBuild/DependenciesGTK/Source/glib-2.52.1/glib/gmain.c:3938
#26 0x00007fffe121f397 in g_main_loop_run (loop=0x51e360) at /webkit/WebKitBuild/DependenciesGTK/Source/glib-2.52.1/glib/gmain.c:4134
#27 0x00007fffe860fc10 in WTF::RunLoop::run () at ../../Source/WTF/wtf/glib/RunLoopGLib.cpp:96
#28 0x00007ffff1e7a261 in WebKit::ChildProcessMain<WebKit::WebProcess, WebKit::WebProcessMain> (argc=2, argv=0x7fffffff74d8) at ../../Source/WebKit/Shared/unix/ChildProcessMain.h:61
#29 0x00007ffff1e7a113 in WebKit::WebProcessMainUnix (argc=2, argv=0x7fffffff74d8) at ../../Source/WebKit/WebProcess/gtk/WebProcessMainGtk.cpp:69
#30 0x0000000000400d42 in main (argc=2, argv=0x7fffffff74d8) at ../../Source/WebKit/WebProcess/EntryPoint/unix/WebProcessMain.cpp:52

(gdb) p (bool)m_playbackWithoutUserGestureStartedTime
$2 = false