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
{
			if ( tmpContainer instanceof ListingElement
					|| tmpContainer instanceof MasterPage )
			{
				List errors = tmpContainer.checkContent( module, this, slotId,
						defn );
				return errors.isEmpty( );
			}
			tmpContainer = tmpContainer.getContainer( );
		}
		return retValue;
	}
	/**
	 * Checks whether a type of elements can reside in the given slot of the
	 * current element. Besides the type check, it also checks the cardinality
	 * of this slot.
	 * 
	 * @param slotId
	 *            the slot id of the current element
	 * @param defn
	 *            the element definition
	 * 
	 * @return <code>true</code> if elements with the definition
	 *         <code>defn</code> can reside in the given slot. Otherwise
	 *         <code>false</code>.
	 */
	private boolean canContainInRom( int slotId, IElementDefn defn )
	{
		if ( slotId < 0 || slotId >= getDefn( ).getSlotCount( ) )
			return false;