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/ReferencableStructure.java
* 
	 * @see org.eclipse.birt.report.model.core.IReferencable#addClient(org.eclipse.birt.report.model.core.DesignElement,
	 *      java.lang.String)
	 */
	public void addClient( DesignElement client, String propName )
	{
		clients.add( new BackRef( client, propName ) );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.core.IReferencable#dropClient(org.eclipse.birt.report.model.core.DesignElement)
	 */
	public void dropClient( DesignElement client )
	{
		for ( int i = 0; i < clients.size( ); i++ )
		{
			if ( ( (BackRef) clients.get( i ) ).element == client )
			{
				clients.remove( i );
				return;
			}
		}
		assert false;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.core.IReferencable#getClientList()
	 */