QGraphicsTextItem::setDefaultTextColor doesn't check whether input is the same as the current value

QGraphicsTextItem::setDefaultTextColor does not check whether the given color is already the defaultTextColor. On some systems, this results in infinite loops if the paintEvent calls setDefaultTextColor. This is for example necessary when the QGraphicsTextItem is colored with a KStatefulBrush. See http://websvn.kde.org/?view=rev&revision=1054334 for an example of where this issue occurs, and how a workaround solved the problem.