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 The list of user properties.
	 */
	public List getUserProperties( )
	{
		List props = new ArrayList( );
		DesignElement e = this;
		while ( e != null )
		{
			List prop = e.getLocalUserProperties( );
			if ( prop != null )
			{
				props.addAll( prop );
			}
			e = e.getExtendsElement( );
		}
		return props;
	}
	/**
	 * Returns a list of user properties that are defined only on this element.
	 * 
	 * @return The list of user properties.
	 */
	public List getLocalUserProperties( )
	{
		if ( userProperties == null )
			return Collections.EMPTY_LIST;
		return new ArrayList( userProperties.values( ) );
	}
	/**