Bug 123726 "Top n", "Bottom n" in highlight dialog doesn't work.
Description: "Top n", "Bottom n" in highlight dialog doesn't work. Steps to reproduce: 1. Add a highlight for a table. 2. Set highlight rule: "account_id", "top n", "3", let its font color red. 3. Preview the report, it doesn't work. Attached is design file.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/PreparedQuery.java
IConditionalExpression ce = (IConditionalExpression) expr;
	    	prepareExpression( ce.getExpression(), groupLevel, cx, reg );
	    	if ( ce.getOperand1() != null )
		    	prepareExpression( ce.getOperand1(), groupLevel, cx, reg );
	    	if ( ce.getOperand2() != null )
		    	prepareExpression( ce.getOperand2(), groupLevel, cx, reg );
	    	 
	    	
	    	expr.setHandle( expr );
	    	expr.setID( IDUtil.nextExprID( ) );
	    }
	    else
	    {
	    	
	    	assert false;
	    }
	}
	
	/**
	 * Convert IGroupDefn to IQuery.GroupSpec
	 * 
	 * @param cx
	 * @param src
	 * @return
	 * @throws DataException
	 */
	protected IQuery.GroupSpec groupDefnToSpec( Context cx,
			IGroupDefinition src, String columnName, int index )
			throws DataException
	{