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
if ( element instanceof ExtendedItem )
		{
			if ( prop.isExtended( ) )
				assert ( (ExtendedItem) element ).getExtendedElement( ) != null;
		}
	}
	/**
	 * Private method to validate the value of a property.
	 * 
	 * @param prop
	 *            definition of the property to validate
	 * @param value
	 *            the value to validate
	 * @return the value to store for the property
	 * @throws PropertyValueException
	 *             if the value is not valid
	 */
	private Object validateValue( ElementPropertyDefn prop, Object value )
			throws SemanticException
	{
		
		if ( value == null )
			return null;
		Object input = value;
		
		if ( value instanceof DesignElementHandle )
		{
			DesignElementHandle elementHandle = (DesignElementHandle) value;
			Module root = elementHandle.getModule( );
			input = ReferenceValueUtil.needTheNamespacePrefix( elementHandle