Bug 93245 [Dialogs] Error messages show up in two locations in the properties dialog
Force an error message: 1) select a Java project 2) open the properties dialog 3) navigate to Java Compiler>Building 4) enable project specific settings 5) enter a letter into the maximum number of problems field ->the error message shows up at the bottom 6) resize the dialog ->the error message also shows up in the banner
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferencePage.java
* @return the size of the preference page encoded as
     *   <code>new Point(width,height)</code>
     */
    protected Point doComputeSize() {
        if (descriptionLabel != null && body != null) {
            Point bodySize = body.computeSize(SWT.DEFAULT, SWT.DEFAULT, true);
            GridData gd = (GridData) descriptionLabel.getLayoutData();
            gd.widthHint = bodySize.x;
            descriptionLabel.getParent().layout(true);
        }
        return getControl().computeSize(SWT.DEFAULT, SWT.DEFAULT, true);
    }
    /**
     * Returns the preference store of this preference page.
     * <p>
     * This is a framework hook method for subclasses to return a
     * page-specific preference store. The default implementation
     * returns <code>null</code>.
     * </p>
     *
     * @return the preference store, or <code>null</code> if none
     */
    protected IPreferenceStore doGetPreferenceStore() {
        return null;
    }
    /**
     * Returns the container of this page.
     *
     * @return the preference page container, or <code>null</code> if this
     *   page has yet to be added to a container