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
* the basic principle is just copying the property value into the clone,
	 * the other things, like container references, child list references,
	 * listener references will not be cloned; that is, the clone is isolated
	 * from the design tree until it is added into a target design tree.
	 * 
	 * <p>
	 * When inserting the cloned element into the design tree, user needs to
	 * care about the element name confliction; that is, the client needs to
	 * call the method
	 * <code>{@link ReportDesignHandle#rename( DesignElementHandle )}</code>
	 * to change the element names.
	 * 
	 * @return Object the cloned design element.
	 * @throws CloneNotSupportedException
	 *             if clone is not supported.
	 * 
	 */
	final public Object clone( ) throws CloneNotSupportedException
	{
		return doClone( CopyForPastePolicy.getInstance( ) );
	}
	/**
	 * Generates a clone copy of this element. When a report element is cloned,
	 * the basic principle is just copying the property value into the clone,
	 * the other things, like container references, child list references,
	 * listener references will not be cloned; that is, the clone is isolated
	 * from the design tree until it is added into a target design tree. As for
	 * the extends reference to the parent, which is in library, the copy policy
	 * will be responsible for the specific dealing.
	 *