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
MoveListItemRecord record = new MoveListItemRecord( element, ref, list,
				oldPosn, adjustedNewPosn );
		stack.execute( record );
		stack.commit( );
	}
	/**
	 * The top level element property referenced by a member reference can be a
	 * list property or a structure property.
	 * <p>
	 * <li>If references a list property, the method will check to see if the
	 * current element has the local list value, if it has, the method returns,
	 * otherwise, a copy of the list value inherited from container or parent
	 * will be set locally on the element itself.
	 * <li>If references a structure property, the method will check to see if
	 * the current element has the local structure value, if it has, the method
	 * returns, otherwise, a copy of the structure value inherited from
	 * container or parent will be set locally on the element itself.
	 * <p>
	 * This method is supposed to be used when we need to change the value of a
	 * composite property( a list property or a structure property ). These kind
	 * of property is inherited as a whole, so when the value changed from a
	 * child element. This method will be called to ensure that a local copy
	 * will be made, so change to the child won't affect the original value in
	 * the parent.
	 * 
	 * @param ref
	 *            a reference to a list property or member.
	 */
	void makeLocalCompositeValue( MemberRef ref )
	{