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
result = match( resultObject, resultOp1 );
				break;
			case IConditionalExpression.OP_NOT_MATCH :
				result = !match( resultObject, resultOp1 );
				break;
			default :
				throw new DataException(
						ResourceConstants.UNSUPPORTTED_COND_OPERATOR, new Integer(operator) );
		}
		
		logger.exiting( ScriptEvalUtil.class.getName( ),
				"evalConditionalExpr",
				new Boolean( result ) );
		return new Boolean( result );
	}
	/**
	 * @param o1
	 * @return
	 */
	private static ExprTextAndValue createExprTextAndValueInstance( Object o )
	{
		ExprTextAndValue op;
		if(! (o instanceof ExprTextAndValue ))
			op = ExprTextAndValue.newInstance( "", o );
		else
			op = (ExprTextAndValue)o;
		return op;
	}
	/**
	 * Most objects should already be formatted to the same type by method