Cursor is vanished when type through input method in QWebView

Repro steps
1. install Korean language in 'Language Support'
2. set Keyboard input method system to 'Ibus'
3. Add Korean input method system at 'Keyboard Input Methods'
4. run attached test.py
5. type in English at the first line in dialog
6. There's no problem in cursor
7. Change your input method Korean-Korean at input method switcher in tray of Ubuntu
8. repeat step 5

Expected

• Cursor has to be displayed

Actual

• Cursor is vanished after type in