QWebFrame-> toHtml() Ошибка сегментации

Question

Я использую QT 5.4 и имею некоторые проблемы. Иногда, когда я пытаюсь прочитать загруженные данные в QWebView, используя myBrowser->page()->mainFrame()->toHtml(); - у меня возникла ошибка сегментации. Как это решить?

Существует трассировку:

0 WTFCrash C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xb9bfcf3 
1 WTF::fastRealloc(void*, unsigned int) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xb9b05e9 
2 WTF::StringImpl::reallocate(WTF::PassRefPtr<WTF::StringImpl>, unsigned int, wchar_t*&) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xb991d2e 
3 void WTF::StringBuilder::reallocateBuffer<wchar_t>(unsigned int) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xb996e04 
4 wchar_t* WTF::StringBuilder::appendUninitializedSlow<wchar_t>(unsigned int) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xbb17957 
5 WTF::StringBuilder::append(unsigned char const*, unsigned int) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xb99720a 
6 WebCore::MarkupAccumulator::appendCharactersReplacingEntities(WTF::StringBuilder&, WTF::String const&, unsigned int, unsigned int, WebCore::EntityMask) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1974fe 
7 WebCore::MarkupAccumulator::appendAttributeValue(WTF::StringBuilder&, WTF::String const&, bool) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa19795d 
8 WebCore::MarkupAccumulator::appendAttribute(WTF::StringBuilder&, WebCore::Element*, WebCore::Attribute const&, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e458b 
9 WebCore::MarkupAccumulator::appendElement(WTF::StringBuilder&, WebCore::Element*, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e4768 
10 WebCore::MarkupAccumulator::appendStartMarkup(WTF::StringBuilder&, WebCore::Node const*, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1c9672 
11 WebCore::MarkupAccumulator::appendStartTag(WebCore::Node*, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e0792 
12 WebCore::MarkupAccumulator::serializeNodesWithNamespaces(WebCore::Node*, WebCore::Node*, WebCore::EChildrenOnly, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>> const*, WTF::Vector<WebCore::QualifiedName, 0u, WTF::CrashOnOverflow>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e3a01 
13 WebCore::MarkupAccumulator::serializeNodesWithNamespaces(WebCore::Node*, WebCore::Node*, WebCore::EChildrenOnly, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>> const*, WTF::Vector<WebCore::QualifiedName, 0u, WTF::CrashOnOverflow>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e38d0 
14 WebCore::MarkupAccumulator::serializeNodesWithNamespaces(WebCore::Node*, WebCore::Node*, WebCore::EChildrenOnly, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>> const*, WTF::Vector<WebCore::QualifiedName, 0u, WTF::CrashOnOverflow>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e38d0 
15 WebCore::MarkupAccumulator::serializeNodesWithNamespaces(WebCore::Node*, WebCore::Node*, WebCore::EChildrenOnly, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>> const*, WTF::Vector<WebCore::QualifiedName, 0u, WTF::CrashOnOverflow>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e38d0 
16 WebCore::MarkupAccumulator::serializeNodesWithNamespaces(WebCore::Node*, WebCore::Node*, WebCore::EChildrenOnly, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>> const*, WTF::Vector<WebCore::QualifiedName, 0u, WTF::CrashOnOverflow>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e38d0 
17 WebCore::MarkupAccumulator::serializeNodesWithNamespaces(WebCore::Node*, WebCore::Node*, WebCore::EChildrenOnly, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>> const*, WTF::Vector<WebCore::QualifiedName, 0u, WTF::CrashOnOverflow>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e38d0 
18 WebCore::MarkupAccumulator::serializeNodesWithNamespaces(WebCore::Node*, WebCore::Node*, WebCore::EChildrenOnly, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>> const*, WTF::Vector<WebCore::QualifiedName, 0u, WTF::CrashOnOverflow>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e38d0 
19 WebCore::MarkupAccumulator::serializeNodesWithNamespaces(WebCore::Node*, WebCore::Node*, WebCore::EChildrenOnly, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>> const*, WTF::Vector<WebCore::QualifiedName, 0u, WTF::CrashOnOverflow>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e38d0 
20 WebCore::MarkupAccumulator::serializeNodesWithNamespaces(WebCore::Node*, WebCore::Node*, WebCore::EChildrenOnly, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>> const*, WTF::Vector<WebCore::QualifiedName, 0u, WTF::CrashOnOverflow>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e38d0 
21 WebCore::MarkupAccumulator::serializeNodesWithNamespaces(WebCore::Node*, WebCore::Node*, WebCore::EChildrenOnly, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>> const*, WTF::Vector<WebCore::QualifiedName, 0u, WTF::CrashOnOverflow>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e38d0 
22 WebCore::MarkupAccumulator::serializeNodesWithNamespaces(WebCore::Node*, WebCore::Node*, WebCore::EChildrenOnly, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>> const*, WTF::Vector<WebCore::QualifiedName, 0u, WTF::CrashOnOverflow>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e38d0 
23 WebCore::MarkupAccumulator::serializeNodesWithNamespaces(WebCore::Node*, WebCore::Node*, WebCore::EChildrenOnly, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>> const*, WTF::Vector<WebCore::QualifiedName, 0u, WTF::CrashOnOverflow>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e38d0 
24 WebCore::MarkupAccumulator::serializeNodesWithNamespaces(WebCore::Node*, WebCore::Node*, WebCore::EChildrenOnly, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>> const*, WTF::Vector<WebCore::QualifiedName, 0u, WTF::CrashOnOverflow>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e38d0 
25 WebCore::MarkupAccumulator::serializeNodesWithNamespaces(WebCore::Node*, WebCore::Node*, WebCore::EChildrenOnly, WTF::HashMap<WTF::AtomicStringImpl*, WTF::AtomicStringImpl*, WTF::PtrHash<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>, WTF::HashTraits<WTF::AtomicStringImpl*>> const*, WTF::Vector<WebCore::QualifiedName, 0u, WTF::CrashOnOverflow>*) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e38d0 
26 WebCore::createMarkup(WebCore::Node const*, WebCore::EChildrenOnly, WTF::Vector<WebCore::Node*, 0u, WTF::CrashOnOverflow>*, WebCore::EAbsoluteURLs, WTF::Vector<WebCore::QualifiedName, 0u, WTF::CrashOnOverflow>*, WebCore::EFragmentSerialization) C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0xa1e3bb5 
27 QWebFrameAdapter::toHtml() const C:\QT\5.4\mingw491_32\bin\Qt5WebKitd.dll  0x9cf0f10 
28 QWebFrame::toHtml  268 0xe404824 
29 VBSearshMachine::movingToNextPage VBSearshMachine.cpp 200 0x40e59e  
30 VBSearshMachine::qt_static_metacall moc_VBSearshMachine.cpp 233 0x42ff0b  
31 QMetaObject::activate  3716 0x6b95a0c0 
32 QMetaObject::activate  3582 0x6b959a1a 
33 QSingleShotTimer::timeout  122 0x6b95e452 
34 QSingleShotTimer::timerEvent  318 0x6b95de0b 
35 QObject::event  1226 0x6b9543ec 
36 QApplicationPrivate::notify_helper  3720 0xf08f4dd 
37 QApplication::notify  3164 0xf08ceb0 
38 QCoreApplication::notifyInternal  935 0x6b92ee90 
39 QCoreApplication::sendEvent  228 0x6b9d4e9f 
40 QEventDispatcherWin32Private::sendTimerEvent  615 0x6b97e0c5 
41 qt_internal_proc(HWND__*, unsigned int, unsigned int, long)*16  417 0x6b97d682 
42 USER32!CallNextHookEx C:\Windows\SYSTEM32\user32.dll  0x771d8e71 
43 USER32!CallNextHookEx C:\Windows\SYSTEM32\user32.dll  0x771d90d1 
44 USER32!GetMessageW C:\Windows\SYSTEM32\user32.dll  0x771da66f 
45 USER32!DispatchMessageW C:\Windows\SYSTEM32\user32.dll  0x771da6e0 
46 QEventDispatcherWin32::processEvents  806 0x6b97ed24 
47 QWindowsGuiEventDispatcher::processEvents  73 0x2ccce774 
48 QEventLoop::processEvents  128 0x6b92cf14 
49 QEventLoop::exec  204 0x6b92d1a7 
50 QCoreApplication::exec  1188 0x6b92f4d3 
51 QGuiApplication::exec  1507 0x1326bac 
52 QApplication::exec  2956 0xf08c7ef 
53 qMain main.cpp 108 0x401ec9  
54 WinMain*16  112 0x434a38  
55 main   0x46069d  

Answer 1

Вы разыменования нулевого указателя где-то в этом выражении. Вы должны проверить их все за то, что они не были пустым, прежде чем вы их используете:

Q_ASSERT(myBrowser); 
if (myBrowser->page() && myBrowser->page()->mainFrame()) { 
    auto html = myBrowser->page()->mainFrame()->toHtml(); 
    ... 
}