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
return baseId != NO_BASE_ID;
	}
	/**
	 * Copied the structure from the parent element to the element itself. Local
	 * properties of the contents will all be cleared.Please note that the
	 * containment relationship is kept while property values of the content
	 * elements are not copied.
	 * 
	 * @param module
	 *            the module
	 * 
	 * @return <code>true</code> if the refresh action is successful.
	 *         <code>false</code> othersize.
	 * 
	 */
	public boolean refreshStructureFromParent( Module module )
	{
		DesignElement parent = getExtendsElement( );
		if ( parent == null )
			return false;
		
		return ElementStructureUtil.updateStructureFromParent( this, parent );
	}
	/**
	 * Resolve and returns the virtual parent element. If the element is not
	 * virtual element, <code>null</code> will be returned. Otherwise, find
	 * and returns the virtual parent using the <code>baseId</code>.
	 * 
	 * @return the virtual parent element.
	 */