[PyQt] Crash with QAxContainer.QAxWidget

[Patrick Hartling]

I have been tracking down a crash when using QAxContainer.QAxWidget  
from PyQt 4.4.3 built against Qt 4.4.1. At this point, I believe that  
there is an issue with how a meta object gets associated with  
sipQAxContainerQAxWidget. Specifically, the sipTypeDef instantiated at  
the end of the generated file QAxContainer/ 
sipQAxContainerQAxWidget.cpp gets its td_qt data member initialized  
with the value 0. The result is that  
sipQAxContainerQAxWidget::metaObject() returns NULL, and since  
QMetaObject::cast() expects to get back a non-NULL value, a crash  
occurs. The behavior can be seen by running the web browser example in  
examples/activeqt/webbrowser in the PyQt source tree. The C++ version  
of web browser example from Qt works without problems.

If I modify qaxbase.h to make QAxBase::staticMetaObject public,  
rebuild Qt, and then change the generated QAxContainer/ 
sipQAxContainerQAxWidget.cpp so that the td_qt data member is  
initialized to the address of QAxBase::staticMetaObject, then the  
crash is fixed. However, I get the following warnings at run time from  
Qt:

Object::connect: No such slot QWidget::GoBack()
Object::connect:  (sender name:   'actionBack')
Object::connect:  (receiver name: 'WebBrowser')
Object::connect: No such slot QWidget::GoForward()
Object::connect:  (sender name:   'actionForward')
Object::connect:  (receiver name: 'WebBrowser')
Object::connect: No such slot QWidget::Stop()
Object::connect:  (sender name:   'actionStop')
Object::connect:  (receiver name: 'WebBrowser')
Object::connect: No such slot QWidget::Refresh()
Object::connect:  (sender name:   'actionRefresh')
Object::connect:  (receiver name: 'WebBrowser')
Object::connect: No such slot QWidget::GoHome()
Object::connect:  (sender name:   'actionHome')
Object::connect:  (receiver name: 'WebBrowser')
Object::connect: No such slot QWidget::GoSearch()
Object::connect:  (sender name:   'actionSearch')
Object::connect:  (receiver name: 'WebBrowser')

That suggests that I am still not quite on the right track. I also  
tried using the address of QWidget::staticMetaObject, and that gives  
the same results. It has the benefit of not requiring a modification  
to the Qt source.

I realize that this is a lot of conjecture on my part. Has anyone seen  
problems with QAxContainer.QAxWidget? Is there some other way of  
handling the problem that I described above with the initialization of  
the sipTypeDef in QAxContainer/sipQxContainerQAxWidget.cpp?

  -Patrick


--
Patrick L. Hartling
Senior Software Engineer, Priority 5
http://www.priority5.com/

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