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/core/DesignElement.java
* </li>
	 * <li>A non-style property is set if this element, or any of its ancestor
	 * elements, provide a value. It is also considered set if the system
	 * provides a default value.</li>
	 * <li>A property value is considered set only if it is set in the private
	 * style of this element or an ancestor element; it is not considered set if
	 * it is inherited from a shared style.</li>
	 * </ul>
	 * 
	 * @param module
	 *            module
	 * @param propName
	 *            name of the property
	 * @return the value of the property according to the rules explained above
	 */
	public Object getFactoryProperty( Module module, String propName )
	{
		ElementPropertyDefn prop = getPropertyDefn( propName );
		
		if ( prop == null )
			return null;
		return getFactoryProperty( module, prop );
	}
	/**
	 * Resolves a property element reference. The reference is the value of a
	 * property of type property element reference.
	 * 
	 * @param module
	 *            the module information needed for the check, and records any
	 *            errors