Bug 172273 Grid insert to masterpage dosen't display propertily [05]
Build Number: 2.2.0.v20070131-1050 Description: As the screenshot, insert a grid (3*3) in the master page.It can't be display propertily. Step to reproduce: 1. new a report and switch to masterpage 2. insert a grid (3*3) Actual result: Please refer to the screenshot, it's abnormal.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
* Sets the parent element. This version should be used to implement a
	 * command to change the parent element. The caller must have validated that
	 * the new parent is valid for this element.
	 * <p>
	 * Part of: Inheritance system.
	 * 
	 * @param base
	 *            The new parent element, or null if the element is to have no
	 *            base element.
	 */
	public void setExtendsElement( DesignElement base )
	{
		DesignElement oldExtends = getExtendsElement( );
		if ( base == oldExtends && base != null )
			return;
		if ( oldExtends != null )
			oldExtends.dropDerived( this );
		if ( base == null )
		{
			extendsRef = null;
		}
		else
		{
			
			assert base.getDefn( ) == getDefn( );
			
			assert base.getName( ) != null;
			String namespace = null;
			Module root = base.getRoot( );
			if ( root instanceof Library )