Bug 134216 [regression] add a report item to library does not work properly
steps to reproduce: - create a library - add report items, say label - add 1st label - add 2nd laebl expected behavior: - everytime i drag a label to Outline->ReportItems, the label will be added actual behavior: - for the 1st label, it worked out fine - for the 2nd label, i had to drag a label twice to complete the operation note that this happened with other report items as well
UI/org.eclipse.birt.report.designer.ui.lib/src/org/eclipse/birt/report/designer/internal/lib/views/outline/dnd/LibraryDropListener.java
* @see org.eclipse.birt.report.designer.internal.ui.dnd.DesignElementDropAdapter#validateTarget(java.lang.Object,
	 *      java.lang.Object)
	 */
	protected boolean validateTarget( Object target, Object transfer )
	{
		
		boolean retValue = super.validateTarget( target, transfer );
		if ( !retValue )
		{
			retValue = isSupportPalletType( target, transfer )
					&& getCurrentLocation( ) == LOCATION_ON;
		}
		return retValue;
	}
	
	private boolean validateSameParent(Object targetObj, Object transferData)
	{
		if ( targetObj == null || transferData == null )
			return false;
		if (transferData instanceof String)
		{
			return true;
		}
		if (!(targetObj instanceof DesignElementHandle))
		{
			return false;
		}
		if ( transferData instanceof StructuredSelection )
		{
			return validateSameParent( targetObj,