Qt apps on N8 cannot display Chinese characters correctly

All Qt apps on N8 cannot display Chinese characters correctly after I flashed N8 with the latest image.

I made a small Qt app, which simply has a line edit to demo this bug.

I installed the app on my N8. After I clicked the line edit on the app, the VKB showed up, then I input two Chinese characters "你好"(see the attached VKB.png), and finally finished inputting. Then we got back to the app, and find the line edit shown two unreadable and strange characters, they are not Simplified Chinese words (see the attached lineedit.png)

and if I install the app LineEdit.sis to other N8 with older version, the Qt app does not have this problem.

Please check the attached demo.