QTabBar: elide text should result in tab with equal size

When QTabBar is in ellide mode, the text should be ellided in a way all the tab have an equal size.

Let's say we have a QTabBar with thoeses label,

111111111111111
222222222222
333333333

It should become

1111...
2222...
3333...

and not

111111111...
222222...
333...

Test case main.cpp to aid in reproducing issue
=============================================
#include <QtGui>
int main(int argc, char** argv)
{
QApplication a(argc, argv);
QTabWidget w;
w.show();
w.addTab(new QWidget, "111111111111111111111111111111111" );
w.addTab(new QWidget, "222222222222222222" );
w.addTab(new QWidget, "3333333333" );
w.setElideMode(Qt::ElideRight);
w.resize(400,400);
return a.exec();
}