Most likely to occur when:

• Apply https://codereview.qt-project.org/#change,79074 to Active Qt
• Launch browser, type some invalid login name, press enter
• click link to go back
• Click at address line edit , try to type: Note line edit does not have focus

The webbrowser grabs the focus itself, resulting in an WM_SETFOCUS for the AxHostWidget, which Qt translates to the mainwindow in QApplicationPrivate::notifyActiveWindowChange() , which in turn messes up focus handling since the active window never changes.