Bolder, italic and "stroke through" don't work for multiple lines

[changsheng230]

For example :

When I selected the following two lines, and marked as bold
Line 1
Line 2

It will change to
Line 1
Line 2

Rather than
Line 1
Line 2

[thisisbhaskar]

I have also observed this, looks like a bug.

Raised a JIRA error @ http://bugreports.qt.nokia.com/browse/QTWEBSITE-262