QtWebEngine crashes in QTouchEvent::TouchPoint::pos()

The application uses PyQt5 packaged by PyInstaller.

The crash is intermittant and It does not happen on every machine that I have used it on. On the machines that have this crash it seems random as to when it will crash. Sometimes it's the first time a QtWebEngine browser dialog is opened, sometimes it's the fourth. I am currently working on isolating the problem.

Stack trace from OSX crash report.

OS Version: Mac OS X 10.10.5 (14F27)

Crashed Thread: 0 CrBrowserMain Dispatch queue: com.apple.main-thread

Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x000000000000000c

VM Regions Near 0xc:
-->
__TEXT 0000000000001000-0000000000007000 [ 24K] r-x/rwx SM=COW /Applications/MyApp.app/Contents/MacOS/MyApp

Thread 0 Crashed:: CrBrowserMain Dispatch queue: com.apple.main-thread
0 QtGui 0x0626aef1 QTouchEvent::TouchPoint::pos() const + 17
1 QtWebEngineCore 0x07b93135 QtWebEngineCore::MotionEventQt::GetX(unsigned long) const + 37
2 QtWebEngineCore 0x099f1faf ui::GestureEventDataPacket::FromTouch(ui::MotionEvent const&) + 79
3 QtWebEngineCore 0x099eff51 ui::FilteredGestureProvider::OnTouchEvent(ui::MotionEvent const&) + 81
4 QtWebEngineCore 0x07b91620 QtWebEngineCore::RenderWidgetHostViewQt::processMotionEvent(ui::MotionEvent const&) + 48
5 QtWebEngineCore 0x07b909a2 QtWebEngineCore::RenderWidgetHostViewQt::handleTouchEvent(QTouchEvent*) + 226
6 QtWebEngineCore 0x07b903b1 QtWebEngineCore::RenderWidgetHostViewQt::forwardEvent(QEvent*) + 401
7 QtWebEngineCore 0x07b9134d non-virtual thunk to QtWebEngineCore::RenderWidgetHostViewQt::forwardEvent(QEvent*) + 29
8 QtWebEngineWidgets 0x07711a4a QtWebEngineCore::RenderWidgetHostViewQtDelegateWidget::event(QEvent*) + 154
9 QtWidgets 0x05c0e835 QApplicationPrivate::notify_helper(QObject*, QEvent*) + 277
10 QtWidgets 0x05c11ba0 QApplication::notify(QObject*, QEvent*) + 8256
11 PyQt5.QtWidgets.so 0x06c1a90b meth_QApplication_notify(_object*, _object*) + 203
12 Python 0x0441ca7b PyCFunction_Call + 363
13 Python 0x0447d4c4 PyEval_EvalFrameEx + 19124
14 Python 0x044785ad PyEval_EvalCodeEx + 1453
15 Python 0x04402827 function_call + 375
16 Python 0x043db9a3 PyObject_Call + 99
17 Python 0x043e8b7c instancemethod_call + 220
18 Python 0x043db9a3 PyObject_Call + 99
19 Python 0x0447efc1 PyEval_CallObjectWithKeywords + 97
20 sip.so 0x057c7dfb sip_api_call_method + 81
21 PyQt5.QtCore.so 0x05093cbc sipVH_QtCore_26(PyGILState_STATE, void (_sipSimpleWrapper*, PyGILState_STATE), _sipSimpleWrapper*, _object*, QObject*, QEvent*) + 108
22 PyQt5.QtWidgets.so 0x06c195f5 sipQApplication::notify(QObject*, QEvent*) + 133
23 QtCore 0x053d94b0 QCoreApplication::notifyInternal(QObject*, QEvent*) + 112
24 QtWidgets 0x05c14c61 QApplicationPrivate::translateTouchCancel(QTouchDevice*, unsigned long) + 449
25 QtWidgets 0x05c71077 QWidgetWindow::event(QEvent*) + 279
26 QtWidgets 0x05c0e835 QApplicationPrivate::notify_helper(QObject*, QEvent*) + 277
27 QtWidgets 0x05c11ba0 QApplication::notify(QObject*, QEvent*) + 8256
28 PyQt5.QtWidgets.so 0x06c1a90b meth_QApplication_notify(_object*, _object*) + 203
29 Python 0x0441ca7b PyCFunction_Call + 363
30 Python 0x0447d4c4 PyEval_EvalFrameEx + 19124
31 Python 0x044785ad PyEval_EvalCodeEx + 1453
32 Python 0x04402827 function_call + 375
33 Python 0x043db9a3 PyObject_Call + 99
34 Python 0x043e8b7c instancemethod_call + 220
35 Python 0x043db9a3 PyObject_Call + 99
36 Python 0x0447efc1 PyEval_CallObjectWithKeywords + 97
37 sip.so 0x057c7dfb sip_api_call_method + 81
38 PyQt5.QtCore.so 0x05093cbc sipVH_QtCore_26(PyGILState_STATE, void (_sipSimpleWrapper*, PyGILState_STATE), _sipSimpleWrapper*, _object*, QObject*, QEvent*) + 108
39 PyQt5.QtWidgets.so 0x06c195f5 sipQApplication::notify(QObject*, QEvent*) + 133
40 QtCore 0x053d94b0 QCoreApplication::notifyInternal(QObject*, QEvent*) + 112
41 QtGui 0x06253155 QGuiApplicationPrivate::processTouchEvent(QWindowSystemInterfacePrivate::TouchEvent*) + 5189
42 QtGui 0x0623b44a QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) + 346
43 libqcocoa.dylib 0x100b3a19 QCocoaEventDispatcherPrivate::processPostedEvents() + 201
44 libqcocoa.dylib 0x100b431d QCocoaEventDispatcherPrivate::postedEventsSourceCallback(void*) + 29
45 com.apple.CoreFoundation 0x921f712f _CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION_ + 15
46 com.apple.CoreFoundation 0x921e8bbd __CFRunLoopDoSources0 + 253
47 com.apple.CoreFoundation 0x921e80f2 __CFRunLoopRun + 994
48 com.apple.CoreFoundation 0x921e7aa6 CFRunLoopRunSpecific + 390
49 com.apple.CoreFoundation 0x921e790b CFRunLoopRunInMode + 123
50 com.apple.HIToolbox 0x9a4a18f8 RunCurrentEventLoopInMode + 262
51 com.apple.HIToolbox 0x9a4a1503 ReceiveNextEventCommon + 192
52 com.apple.HIToolbox 0x9a4a142c _BlockUntilNextEventMatchingListInModeWithFilter + 99
53 com.apple.AppKit 0x969a3b41 _DPSNextEvent + 742
54 com.apple.AppKit 0x969a31e5 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 350
55 com.apple.AppKit 0x96b85445 -[NSApplication _realDoModalLoop:peek:] + 823
56 com.apple.AppKit 0x96b850ff -[NSApplication _doModalLoop:peek:] + 207
57 com.apple.AppKit 0x96dd59de -[NSApplication runModalSession:] + 121
58 libqcocoa.dylib 0x100b305e QCocoaEventDispatcher::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) + 2078
59 QtCore 0x053d6963 QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) + 435
60 QtCore 0x053d9a9e QCoreApplication::exec() + 334
61 PyQt5.QtWidgets.so 0x06c1a30c meth_QApplication_exec_(_object*, _object*) + 92
62 Python 0x0441ca7b PyCFunction_Call + 363
63 Python 0x0447d4c4 PyEval_EvalFrameEx + 19124
64 Python 0x0447f881 fast_function + 369
65 Python 0x0447b9de PyEval_EvalFrameEx + 12238
66 Python 0x044785ad PyEval_EvalCodeEx + 1453
67 Python 0x04477ff7 PyEval_EvalCode + 87
68 Python 0x0449fb1d PyRun_SimpleStringFlags + 157
69 Python 0x044a12f9 PyRun_SimpleString + 25
70 org.qt-project.Qt.QtWebEngineCore 0x00003257 0x1000 + 8791
71 org.qt-project.Qt.QtWebEngineCore 0x00003714 0x1000 + 10004
72 org.qt-project.Qt.QtWebEngineCore 0x00002115 0x1000 + 4373