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
ElementRefValue oldRef = (ElementRefValue) propValues
					.get( propName );
			updateReference( oldRef, (ElementRefValue) value, prop );
		}
		
		if ( prop.getTypeCode( ) == PropertyType.STRUCT_REF_TYPE )
		{
			StructRefValue oldRef = (StructRefValue) propValues.get( propName );
			updateReference( oldRef, (StructRefValue) value, prop );
		}
		
		if ( value == null )
			propValues.remove( propName );
		else
			propValues.put( propName, value );
	}
	/**
	 * Returns the mask of the given property. If the mask of one property has
	 * not been found, looks for its parent or any ancestor.
	 * <p>
	 * Note that this method is only for internal usage. DO NOT call this method
	 * outside the org.eclipse.birt.report.model package.
	 * 
	 * @param module
	 *            the module
	 * @param propName
	 *            the name of the property
	 * 
	 * @return the mask of the given property
	 */