win32 debug build memory access violation

[Mihai Hanor]

Win32 debug build of svn 35386, VS2010, QT 4.7.1, CRT retail libs, full pageheap enabled

After starting a VM, by opening and then closing the VboxDbg Statistics window (Debug menu), it always stops with memory access violation (2nd chance), the VboxDbgBaseWindow object (*this) is not accessible. If the pageheap is disabled, nothing is reported.

VBoxDbg!VBoxDbgBaseWindow::vPolishSizeAndPos(void)+0x1f [f:\vbox\src\vbox\debugger\vboxdbgbase.cpp @ 217]
VBoxDbg!VBoxDbgBaseWindow::event(
			class QEvent * a_pEvt = 0x0012d3ec)+0x39 [f:\vbox\src\vbox\debugger\vboxdbgbase.cpp @ 208]
QtGui4!QApplicationPrivate::notify_helper(
			class QObject * receiver = 0x671086bd, 
			class QEvent * e = 0x08cb4fb0)+0xb9 [f:\qt\4.7.1\src\gui\kernel\qapplication.cpp @ 4446]
QtGui4!QApplication::notify(
			class QObject * receiver = 0x08cb4fb0, 
			class QEvent * e = 0x0012d3ec)+0x12cc [f:\qt\4.7.1\src\gui\kernel\qapplication.cpp @ 4410]
MSVCR100!malloc(
			unsigned int size = 0x390cfc8)+0x4b [f:\dd\vctools\crt_bld\self_x86\crt\src\malloc.c @ 89]
QtCore4!QCoreApplication::notifyInternal(
			class QObject * receiver = 0x0390cfc8, 
			class QEvent * event = 0x0012d3ec)+0x8d [f:\qt\4.7.1\src\corelib\kernel\qcoreapplication.cpp @ 745]
QtCore4!QCoreApplication::sendSpontaneousEvent(
			class QObject * receiver = <Memory access error>, 
			class QEvent * event = <Memory access error>)+0x22 [f:\qt\4.7.1\src\corelib\kernel\qcoreapplication.h @ 218]
QtGui4!QWidgetPrivate::close_helper(
			QWidgetPrivate::CloseMode mode = <Memory access error>)+0xb9 [f:\qt\4.7.1\src\gui\kernel\qwidget.cpp @ 7765]
QtGui4!QtWndProc(
			struct HWND__ * hwnd = <Memory access error>, 
			unsigned int message = <Memory access error>, 
			unsigned int wParam = <Memory access error>, 
			long lParam = <Memory access error>)+0xdbc [f:\qt\4.7.1\src\gui\kernel\qapplication_win.cpp @ 2154]
USER32!InternalCallWinProc+0x28
USER32!UserCallWinProcCheckWow+0x150
USER32!DispatchClientMessage+0xa3
USER32!__fnDWORD+0x24
ntdll!KiUserCallbackDispatcher+0x13
USER32!NtUserMessageCall+0xc
USER32!RealDefWindowProcW+0x47
USER32!DefWindowProcW+0x72
QtGui4!QWinInputContext::DefWindowProcW(
			struct HWND__ * hwnd = <Memory access error>, 
			unsigned int msg = <Memory access error>, 
			unsigned int wParam = <Memory access error>, 
			long lParam = <Memory access error>)+0x40 [f:\qt\4.7.1\src\gui\inputmethod\qwininputcontext_win.cpp @ 365]
QtGui4!QtWndProc(
			struct HWND__ * hwnd = <Memory access error>, 
			unsigned int message = <Memory access error>, 
			unsigned int wParam = <Memory access error>, 
			long lParam = <Memory access error>)+0x219f [f:\qt\4.7.1\src\gui\kernel\qapplication_win.cpp @ 2636]
USER32!InternalCallWinProc+0x28
USER32!UserCallWinProcCheckWow+0x150
USER32!DispatchClientMessage+0xa3
USER32!__fnDWORD+0x24
ntdll!KiUserCallbackDispatcher+0x13
USER32!NtUserMessageCall+0xc
USER32!RealDefWindowProcW+0x47
USER32!DefWindowProcW+0x72
QtGui4!QWinInputContext::DefWindowProcW(
			struct HWND__ * hwnd = <Memory access error>, 
			unsigned int msg = <Memory access error>, 
			unsigned int wParam = <Memory access error>, 
			long lParam = <Memory access error>)+0x40 [f:\qt\4.7.1\src\gui\inputmethod\qwininputcontext_win.cpp @ 365]
QtGui4!QtWndProc(
			struct HWND__ * hwnd = <Memory access error>, 
			unsigned int message = <Memory access error>, 
			unsigned int wParam = <Memory access error>, 
			long lParam = <Memory access error>)+0x219f [f:\qt\4.7.1\src\gui\kernel\qapplication_win.cpp @ 2636]
USER32!InternalCallWinProc+0x28
USER32!UserCallWinProcCheckWow+0x150
USER32!DispatchMessageWorker+0x306
USER32!DispatchMessageW+0xf
QtCore4!QEventDispatcherWin32::processEvents(
			class QFlags<enum QEventLoop::ProcessEventsFlag> flags = class QFlags<enum QEventLoop::ProcessEventsFlag>)+0x5d1 [f:\qt\4.7.1\src\corelib\kernel\qeventdispatcher_win.cpp @ 807]
QtGui4!QGuiEventDispatcherWin32::processEvents(
			class QFlags<enum QEventLoop::ProcessEventsFlag> flags = class QFlags<enum QEventLoop::ProcessEventsFlag>)+0xf [f:\qt\4.7.1\src\gui\kernel\qapplication_win.cpp @ 1170]
QtCore4!QEventLoop::exec(
			class QFlags<enum QEventLoop::ProcessEventsFlag> flags = class QFlags<enum QEventLoop::ProcessEventsFlag>)+0x100 [f:\qt\4.7.1\src\corelib\kernel\qeventloop.cpp @ 201]
*** WARNING: Unable to verify checksum for VirtualBox.exe
QtCore4!QCoreApplication::exec(void)+0x106 [f:\qt\4.7.1\src\corelib\kernel\qcoreapplication.cpp @ 1009]
VirtualBox!TrustedMain(
			int argc = 0n3, 
			char ** argv = 0x02ccafb0, 
			char ** __formal = 0x0217ef68)+0x4c9 [f:\vbox\src\vbox\frontends\virtualbox\src\main.cpp @ 496]
VirtualBox!main(
			int argc = 0n3, 
			char ** argv = 0x02ccafb0, 
			char ** envp = 0x0217ef68)+0x3b0 [f:\vbox\src\vbox\frontends\virtualbox\src\main.cpp @ 647]
VirtualBox!__tmainCRTStartup(void)+0x122 [f:\dd\vctools\crt_bld\self_x86\crt\src\crtexe.c @ 555]
kernel32!BaseProcessStart+0x23