Bug 148747 Design become invalid when I extend a masterpage from Library
The attachment contains a report file and a library file. Reproduce: 1. Deploy the library("lib"), and open the report. 2. Drag Masterpage("page1") from "lib" to report. 3. Reopen the report, it become invalid.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/writer/ModuleWriter.java
* @param obj
	 *            the element that has user properties.
	 */
	protected void writeOverridenPropertyValues( DesignElement obj )
	{
		
		if ( obj.getExtendsElement( ) == null )
			return;
		writer
				.conditionalStartElement( DesignSchemaConstants.OVERRIDDEN_VALUES_TAG );
		Iterator iter = new ContentIterator( obj );
		while ( iter.hasNext( ) ) 
		{
			DesignElement virtualElement = (DesignElement) iter.next( );
			if ( !virtualElement.hasLocalPropertyValues( )
					&& virtualElement.getStyle( ) == null
					&& StringUtil.isBlank( virtualElement.getName( ) ) )
				continue;
			writer
					.conditionalStartElement( DesignSchemaConstants.REF_ENTRY_TAG );
			long baseId = virtualElement.getBaseId( );
			writer.attribute( DesignSchemaConstants.BASE_ID_ATTRIB, new Long(
					baseId ).toString( ) );
			writer.attribute( DesignSchemaConstants.NAME_ATTRIB, virtualElement
					.getName( ) );
			assert virtualElement.getExtendsElement( ) == null;
			List propDefns = null;
			if ( virtualElement instanceof ExtendedItem )
			{
				propDefns = ( (ExtendedItem) virtualElement ).getExtDefn( )