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
/**
	 * Support for inheritance. Represents the resolved or unresolved element
	 * that this element extends.
	 */
	protected ElementRefValue extendsRef = null;
	/**
	 * Inverse of the extends relationship: parent-->derived. Very few elements
	 * are extended, so we create this list only when needed.
	 */
	protected ArrayList derived = null;
	/**
	 * The unique ID assigned to this element when it is added to the design.
	 * Allows web applications to refer to the element by ID.
	 */
	protected long id = NO_ID;
	/**
	 * Cached element definition. Cached for speed since the definition cannot
	 * change.
	 */
	protected IElementDefn cachedDefn = null;
	/**
	 * Indicates whether the element is valid. The initial value is true.
	 */
	protected boolean isValid = true;
	/**
	 * API handle for this element.
	 */
	protected DesignElementHandle handle = null;
	/**
	 * The validation error list, each of which is the instance of