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/metadata/ElementDefn.java
* Returns whether this element has the requested slot given the numeric
	 * identifier of the slot.
	 * 
	 * @param slotID
	 *            The slotID to check.
	 * @return True if the slotID exists, false otherwise.
	 */
	public boolean hasSlot( int slotID )
	{
		if ( slots == null )
			return false;
		return slotID >= 0 && slotID < slots.size( );
	}
	/**
	 * Returns the meta-data definition for a slot given its numeric slot
	 * identifier.
	 * 
	 * @param slotID
	 *            The slot identifier.
	 * @return The slot information. Returns null if this element is not a
	 *         container, or if the ID is not valid for this container.
	 */
	public ISlotDefn getSlot( int slotID )
	{
		if ( slots == null )
			return null;
		if ( slotID < 0 || slotID >= slots.size( ) )
			return null;
		return (SlotDefn) slots.get( slotID );
	}