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 internal element type name for this element
	 */
	public abstract String getElementName( );
	/*
	 * (non-Javadoc)
	 * 
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	public boolean equals( Object obj )
	{
		if ( obj == null )
			return false;
		if ( obj == this )
			return true;
		if ( obj instanceof DesignElementHandle )
			return ( (DesignElementHandle) obj ).getElement( ) == this;
		return false;
	}
	/**
	 * Returns the slot that contains the given content element.
	 * 
	 * @param content
	 *            the element to find
	 * @return the number of the slot that contains the element, or -1 if this
	 *         element does not contain the content element.
	 */
	public int findSlotOf( DesignElement content )
	{
		if ( content == null || content.getContainer( ) != this )
			return NO_SLOT;