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
property( obj, GraphicMasterPage.COLUMN_SPACING_PROP );
		writeContents( obj, GraphicMasterPage.CONTENT_SLOT,
				DesignSchemaConstants.CONTENTS_TAG );
		writer.endElement( );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.design.elements.DesignVisitor#visitSimpleMasterPage(org.eclipse.birt.report.model.design.elements.SimpleMasterPage)
	 */
	public void visitSimpleMasterPage( SimpleMasterPage obj )
	{
		writer.startElement( DesignSchemaConstants.SIMPLE_MASTER_PAGE_TAG );
		super.visitSimpleMasterPage( obj );
		property( obj, SimpleMasterPage.SHOW_HEADER_ON_FIRST_PROP );
		property( obj, SimpleMasterPage.SHOW_FOOTER_ON_LAST_PROP );
		property( obj, SimpleMasterPage.FLOATING_FOOTER );
		property( obj, SimpleMasterPage.HEADER_HEIGHT_PROP );
		property( obj, SimpleMasterPage.FOOTER_HEIGHT_PROP );
		writeContents( obj, SimpleMasterPage.PAGE_HEADER_SLOT,
				DesignSchemaConstants.PAGE_HEADER_TAG );
		writeContents( obj, SimpleMasterPage.PAGE_FOOTER_SLOT,
				DesignSchemaConstants.PAGE_FOOTER_TAG );
		writer.endElement( );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.design.elements.DesignVisitor#visitParameterGroup(org.eclipse.birt.report.model.design.elements.ParameterGroup)
	 */