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  1. Qt
  2. QTBUG-83387

EXCEPTION_ACCESS_VIOLATION_READ on windowHandle function on a window got from a QAccessibleWidget

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Details

    • Windows
    • 24a0303b9ed7d48c75c4567b93b327b731b2de3b

    Description

      We have sporadic crashes on multiple different Windows Machines relating to calling a function on a, presumably, null window object, taken from QAccessibleWidget::window().

      We have spent some time trying to figure out what causes this, and the only semi-related issue is that having "Touch Keyboard and Handwriting Panel Service" enabled seems to cause this. This is speculation, but it has been a common theme.

      We have multiple crash dumps and they all look exactly the same.

      Crash reason:  EXCEPTION_ACCESS_VIOLATION_READ
Crash address: 0x8
Process uptime: 634 seconds


Thread 0 (crashed)
 0  Qt5Widgets.dll!QWidget::windowHandle() [qwidget.cpp : 2656 + 0x0]
 1  Qt5Widgets.dll!QAccessibleWidget::window() [qaccessiblewidget.cpp : 229 + 0x8]
 2  qwindows.dll + 0x5ed4b
 3  qwindows.dll + 0x57c98
 4  Qt5Widgets.dll!QWindowsStyle::eventFilter(QObject *,QEvent *) [qwindowsstyle.cpp : 150 + 0x19]
 5  0x223ad3d1af8
 6  Qt5Widgets.dll!QWindowsStyle::eventFilter(QObject *,QEvent *) [qwindowsstyle.cpp : 150 + 0x19]
 7  0x7ffb0000000c
 8  UIAutomationCore.dll + 0x1fd000
 9  Qt5Gui.dll!QAccessible::queryAccessibleInterface(QObject *) [qaccessible.cpp : 678 + 0x5]
10  qwindows.dll + 0x5d6f
11  0x7ffc1f900000
12  UIAutomationCore.dll + 0x183348
13  qwindows.dll + 0x57835
14  UIAutomationCore.dll + 0x44053
15  ntdll.dll + 0xd997
16  Qt5Widgets.dll!QAccessibleWidget::window() [qaccessiblewidget.cpp : 231 + 0x8]
17  0x223b21bb280
18  UIAutomationCore.dll + 0x41931
19  UIAutomationCore.dll + 0x2013c0
20  UIAutomationCore.dll + 0x40636
21  qwindows.dll + 0x157b60
22  UIAutomationCore.dll + 0x404dc
23  ucrtbase.dll + 0xca26
24  Qt5Core.dll!QMetaObject::Connection::~Connection() [qobject.cpp : 5121 + 0x5]
25  qwindows.dll + 0x560c7
26  Qt5Widgets.dll!QWidget::hasFocus() [qwidget.cpp : 6475 + 0x5]
27  Qt5Core.dll!QMetaObject::cast(QObject *) [qmetaobject.cpp : 357 + 0xd]

      At this point, we have run out of options, short of compiling Qt ourselves without any accessibility features.

      Attachments

        1. GenerateTouchInputs.png
          0.7 kB
          Andreas Renz
        2. MicrosoftTouchSimulator.png
          49 kB
          Andreas Renz
        3. QObject_Disconnect_Qt5.12.7_Help.png
          14 kB
          Andreas Renz
        4. QTBUG-83387_MicrosoftTouchSimulator_TestProg_VS2017.gif
          1.74 MB
          Andreas Renz
        5. TestCrash_QTBUG-83387.zip
          6 kB
          Andreas Renz
        6. TestProgramStarted.png
          19 kB
          Andreas Renz
        7. VS2017WithTestProgramInMicrosoftTouchSimulator.png
          172 kB
          Andreas Renz

        Issue Links

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          Suggestion - Public suggestions QTBUG-108637 Deprecate QObject::disconnect(nullptr, nullptr, nullptr)

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            People

              mitch_curtis Mitch Curtis
              daniel_oxer Daniel Oxer
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              Dates

                Created:
                Updated:
                Resolved:

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