Bug 155943 "Restore Properties" is always enabled for extended chart
Steps to reproduce: 1.New a report, includes a library, extends lib.chart 2.Choose the chart Expected result: "Restore Properties" is disabled untill set/change any local properties for the chart Actual result: "Restore Properties" is always enabled
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/writer/ModuleWriter.java
return;
		writer.conditionalStartElement( DesignSchemaConstants.STRUCTURE_TAG );
		writer.attribute( DesignSchemaConstants.NAME_ATTRIB, memberName );
		Iterator iter = structDefn.propertiesIterator( );
		while ( iter.hasNext( ) )
		{
			StructPropertyDefn strcutPropDefn = (StructPropertyDefn) iter
					.next( );
			property( memberStruct, strcutPropDefn.getName( ) );
		}
		writer.endElement( );
	}
	/**
	 * Writes the structure list of the give property definition for given
	 * design element.
	 * 
	 * @param obj
	 *            the design element to write
	 * @param propName
	 *            the name of the structure list property to write
	 */
	protected void writeStructureList( DesignElement obj, String propName )
	{
		PropertyDefn prop = (ElementPropertyDefn) obj.getDefn( ).getProperty(
				propName );
		assert prop != null;
		assert prop.getTypeCode( ) == PropertyType.STRUCT_TYPE && prop.isList( );
		List list = (List) obj.getLocalProperty( getModule( ), propName );
		if ( list == null || list.size( ) == 0 )
			return;