Version:            (using KDE 4.1.2)
Installed from:    SuSE RPMs

If you have a KTextEdit created like that:

KTextEdit *kte = new KTextEdit(this);
kte->setTextInteractionFlags(Qt::NoTextInteraction);

and then right-click on the edit field, the method KTextEdit::mousePopupMenu() gets called (http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/ktextedit_8cpp-source.html#l00394)

By defining that we want no interaction, Qt returns a NP at createStandardContextMenu();

The application crashes when calling connect():

QObject::connect: Cannot connect (null)::triggered ( QAction* ) to KTextEdit::menuActivated( QAction* )

I don't have a recent SVN checkout here to provide a patch, but it should be done with a simple check for a NP.