1. Windows10 default Chinese and Japanese IME (No any other setting)
2. Widget API fails, Quick API work fine
3. Qt 5.6 and 5.7 work fine
4. Other Qt based application work fine.
5. The URL bar work fine

relates to: QTBUG-58362

steps to reproduce:
1. open qt demo browser with 5.9.0 and navigate to https://www.google.com
2. Try to typing any word into the google’s search box by Chinese or Japanese IME, that doesn't work and just display English character. There may be other IME was also affected.
You can't also switch to Chinese status by Shift key or cursor click.