QT does not render missing characters in selected fonts with fallback fonts

Qt Fallback fonts does not work well.

When selected font does not have particular character. It should render that character from fallback font providing that characters.

gtk doing it very well.

Version-Release number of selected component (if applicable):
qt-4.8.4-19.fc19.x86_64

How reproducible:
Everytime

Steps to Reproduce:
1. open kwrite
2. paster "земли́" in kwrite
3. from Setting-> configure Editor-> Fonts & colors -> Font
4. Select Liberation Sans

Actual results:
acute accent (´) is displayed as square box

Expected results:
It should be render from fallback fonts and should not be shown as square box.

Additional info:
From reproducing bug with konqueror follow steps given in https://bugzilla.redhat.com/show_bug.cgi?id=952778