Bug 149251 Inconsistent Handling of a Non-inheritable ROM Property
For a ROM property defined to be non-inheritable, an empty string property value should be consistently handled as an empty string, not as null. For example, an oda.dataSource extension defines a data source property with canInherit=false. When a oda-data-source handle get saved in a report design, it correctly includes the tag for such property, even when an empty string value is specified. <oda-data-source extensionID="my.oda.plugin" name="my Data Source" id="24"> ... <property name="ApplicationServer"></property> </oda-data-source> However, later when using the DE API to read its property value, a null is returned. Then when the report design is subsequently saved, the property tag is lost. Expects that an empty string value of a non-inhertiable property should be preserved.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/PropertyCommand.java
IExtendedItemModel.EXTENSION_NAME_PROP,
					value,
					PropertyValueException.DESIGN_EXCEPTION_EXTENSION_SETTING_FORBIDDEN );
		}
		String mask = element.getPropertyMask( module, prop.getName( ) );
		if ( DesignChoiceConstants.PROPERTY_MASK_TYPE_LOCK
				.equalsIgnoreCase( mask ) )
		{
			throw new PropertyValueException( element, prop, value,
					PropertyValueException.DESIGN_EXCEPTION_VALUE_LOCKED );
		}
		
		
		if ( element.isVirtualElement( ) && element instanceof Cell )
		{
			String propName = prop.getName( );
			if ( Cell.COL_SPAN_PROP.equalsIgnoreCase( propName )
					|| Cell.ROW_SPAN_PROP.equalsIgnoreCase( propName )
					|| Cell.DROP_PROP.equalsIgnoreCase( propName )
					|| Cell.COLUMN_PROP.equalsIgnoreCase( propName ) )
			{
				throw new PropertyValueException(
						element,
						prop,
						value,
						PropertyValueException.DESIGN_EXCEPTION_PROPERTY_CHANGE_FORBIDDEN );
			}
		}
		if ( element instanceof MasterPage )
		{