Bug 164764 Joint data set does not work properly using attached flatfile
The data set preview keep empty in joint data set. Step to reproduce: 1.Create two data sets based on attached flat file 2.Make an inner join using joint data set with key "A". 3.Preview data set in data set editor. Expect result: The data set preview correctly Actual result: The data set preview is empty.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/script/ScriptEvalUtil.java
* @param op2
	 * @return A Boolean result
	 * @throws DataException
	 */
	public static Object evalConditionalExpr( Object obj,
			int operator, Object o1, Object o2 )
			throws DataException
	{
		ExprTextAndValue op1 = createExprTextAndValueInstance( o1 );
		ExprTextAndValue op2 = createExprTextAndValueInstance( o2 );
		
		Object resultObject = obj;
		Object resultOp1 = op1.value;
		Object resultOp2 = op2.value;
		Object[] obArray = MiscUtil.isComparable( obj, operator, op1, op2 );
		if ( obArray != null )
		{
			resultObject = obArray[0];
			resultOp1 = obArray[1];
			resultOp2 = obArray[2];
		}
		
		if ( logger.isLoggable( Level.FINER ) )
			logger.entering( 
				ScriptEvalUtil.class.getName( ),
				"evalConditionalExpr",
				"evalConditionalExpr() resultObject="
				+ LogUtil.toString( resultObject )
				+ ", operator=" + operator
				+ ( resultOp1 == null? null: ( ", resultOp1=" + LogUtil.toString( resultOp1 ) ) )