Qt5WebKitd.dll!WTFCrash - full page heap checking enabled (intermittent crash)

qtdev12345

Hi Qt

I am hoping to get some help / advise on this.
We are using Qt5WebKit in our project, it is almost identical to the FancyBrowser example.

I have executed this example with releases
5.3.1
5.3.2

I browse to the website "ndtv.com" (known to crash) and wait for the page to load. If it has not crashed at this point, click the movies link and wait for it to load.

The problem is the issue is intermittent, it might crash, it might not.
I thought this was an issue in our module so I enabled full page heap checking
http://msdn.microsoft.com/en-us/library/windows/hardware/ff543094(v=vs.85).aspx

gflags /p /enable fancybrowser.exe /full
gflags /i fancybrowser.exe +hpa
gflags /i fancybrowser.exe +02000000

This always point to a memory issue within Qt5WebKitd! or Qt5WebKit
Although the stack traces are always slightly different, they always point to a memory operation.

In the trace below, I compiled the example FancyBrowser and executed it on windows 8 32 bit with full page heap checking.

I think there is a heap corruption bug in Qt5WebKit and it only shows up randomly.
If you enable full heap checking, it is possible to see it all the time.

I am still fairly new to QT so feel free to double check anything with me.
I am currently using QT version 5.3.2 and visual studio 2013 express.
Although I have seen the same issue with vs 2008.

Thanks ( post limited to 6000 chars, I will copy the stack trace later)

qtdev12345

Qt5WebKitd!WTFCrash+17 [c:\work\build\qt5_workdir\w\s\qtwebkit\source\wtf\wtf\assertions.cpp @ 345]
6377b417 c705efbeadbb00000000 mov dword ptr ds:[0BBADBEEFh],0

EXCEPTION_RECORD: ffffffff -- (.exr 0xffffffffffffffff)
ExceptionAddress: 6377b417 (Qt5WebKitd!WTFCrash+0x00000017)
ExceptionCode: c0000005 (Access violation)
ExceptionFlags: 00000000
NumberParameters: 2
Parameter[0]: 00000001
Parameter[1]: bbadbeef
Attempt to write to address bbadbeef

00eebd3c 627ec68d 0054e2d8 00eebd7c 631f9265 Qt5WebKitd!WTFCrash+0x17
00eebd48 631f9265 04687fa0 00eebd64 627ec0c2 Qt5WebKitd!WTF::OwnPtrWebCore::ImageBuffer::operator->+0x2d
00eebd7c 631fd835 5a54ef48 39518de0 00eebd98 Qt5WebKitd!WebCore::BitmapTextureImageBuffer::updateContents+0x15
00eebdcc 631f830f 5a54ef48 39518de0 00eebde4 Qt5WebKitd!WebCore::TextureMapperTile::updateContents+0x115

qtdev12345

Bad Formatting

qtdev12345

Does anyone have any advise on this issue?

I am just after trying with 5.4 and the same issue is present.

coquetangler

The only solution us to go back to Qt 4.8. Qt 5 is a mess.