Reviewed by Kenneth Rohde Christiansen.

        [Qt] Null QObjects properties cause Segmentation Fault
        https://bugs.webkit.org/show_bug.cgi?id=34730

        QObjects exported to the QWebkit javascript with properties that are
        a null "QObject*" cause Segmentation Fault.

        If an QObject is added to the javascript context and it contains
        properties of the type QObject* with NULL value, calling the property
        causes Segmentation Fault.
        So now the code below properly checks for null pointers:

        * bridge/qt/qt_instance.cpp:
        (JSC::Bindings::QtInstance::getClass): may return NULL
        (JSC::Bindings::QtInstance::getMethod): may return jsNull()
        (JSC::Bindings::QtInstance::stringValue): may return jsNull()
        (JSC::Bindings::QtInstance::booleanValue): may return false
        * bridge/qt/qt_runtime.cpp:
        (JSC::Bindings::convertValueToQVariant):
        (JSC::Bindings::convertQVariantToValue): May return jsNull on QObjectStar
2010-04-15  Bruno Schmidt  <bruno.schmidt@gmail.com>

        Reviewed by Kenneth Rohde Christiansen.

        [Qt] Null QObjects properties cause Segmentation Fault
        https://bugs.webkit.org/show_bug.cgi?id=34730

        QObjects exported to the QWebkit javascript with properties that are
        a null "QObject*" cause Segmentation Fault.

        If an QObject is added to the javascript context and it contains
        properties of the type QObject* with NULL value, calling the property
        causes Segmentation Fault.

        Follow the tests for the corrections done over WebCore.

        * tests/qwebframe/tst_qwebframe.cpp:
        (MyQObject::MyQObject): init the field m_objectStar
        (MyQObject::objectStarProperty): read the Object* prop
        (MyQObject::setObjectStarProperty): write the Object* prop
        (tst_QWebFrame::getSetStaticProperty): new tests for the new prop

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@57638 268f45cc-cd09-0410-ab3c-d52691b4dbfc