Bug 134266 [Wizard] Page description not set if page message already set
Since page messages such as errors and warnings used to be displayed in the same widget as the page description, code was put in place in WizardDialog#updateDescriptionMessage() to avoid setting the page description if there was already a message. As of 3.2 M6 there is a separate widget for displaying error and warning messages and so the page description should always be set.
bundles/org.eclipse.jface/src/org/eclipse/jface/wizard/WizardDialog.java
*/
        public void layout(Composite composite, boolean force) {
            Rectangle rect = getClientArea(composite);
            Control[] children = composite.getChildren();
            for (int i = 0; i < children.length; i++) {
                children[i].setBounds(rect);
            }
        }
        /**
         * Lays outs the page according to this layout.
         *
         * @param w the control
         */
        public void layoutPage(Control w) {
            w.setBounds(getClientArea(w.getParent()));
        }
        /**
         * Sets the location of the page so that its origin is in the
         * upper left corner.
         *
         * @param w the control
         */
        public void setPageLocation(Control w) {
            w.setLocation(marginWidth, marginHeight);
        }
    }
    /**
     * Creates a new wizard dialog for the given wizard. 
     *
     * @param parentShell the parent shell