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
* <p>
	 * Part of: Property value system.
	 * 
	 * @param propName
	 *            The name of the property to set. Must be valid. Can be a
	 *            system-defined or user-defined property name.
	 */
	public void clearProperty( String propName )
	{
		setProperty( propName, null );
	}
	/**
	 * Returns the definition object for this element.
	 * <p>
	 * Part of: Meta data system.
	 * 
	 * @return The element definition. Will always be non-null in a valid build.
	 */
	public IElementDefn getDefn( )
	{
		if ( cachedDefn == null )
		{
			cachedDefn = MetaDataDictionary.getInstance( ).getElement(
					getElementName( ) );
			assert cachedDefn != null;
		}
		return cachedDefn;
	}
	/**
	 * Adds a user-defined property. The property must be unique within the