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
}
	/**
	 * Inserts an item to a structure list.
	 * <ul>
	 * <li>If the property is currently unset anywhere up the inheritance
	 * hierarchy, then a new list is created on this element, and the list
	 * contains the only the new item.</li>
	 * <li>If the property is currently set on this element, then the item is
	 * inserted into the existing list.</li>
	 * <li>If the list is not set on this element, but is set by an ancestor
	 * element, then the list is <strong>copied </strong> onto this element, and
	 * the new element is then inserted into the copy.</li>
	 * </ul>
	 * 
	 * @param ref
	 *            reference to the list into which to insert the new item
	 * @param item
	 *            the item to insert
	 * @param posn
	 *            the position at which to insert the item
	 * @throws SemanticException
	 *             if the item to add is invalid.
	 * @throws IndexOutOfBoundsException
	 *             if the given posn is out of range
	 *             <code>(index &lt; 0 || index &gt; list.size())</code>.
	 */
	public void insertItem( MemberRef ref, IStructure item, int posn )
			throws SemanticException
	{
		assert ref != null;