Bug 153507 Bogus error when bad data set column referenced in group key
Run attached report design. Its group key binding column, "groupkey", is defined to refer to a non-existing data set column: dataSetRow["bad"]. However the actual error seen when previewing the report in BIRT designer: Table (id = 6): + A BIRT exception occurred: Error evaluating Javascript expression. Script engine error: TypeError: valueOf is not a function. Script source: null, line: 0, text: <compiled script>. See next exception for more information. Error evaluating Javascript expression. Script engine error: TypeError: valueOf is not a function. Script source: null, line: 0, text: <compiled script> This error is completely irrelevant to the actual cause of the problem.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/QueryExecutor.java
{
			return DataType.UNKNOWN_TYPE;
		}
		return ( (IBaseExpression) baseExpr ).getDataType( );
	}
	
	/**
	 * @param src
	 * @return
	 */
	private String getGroupKeyExpression( IGroupDefinition src )
	{
		String expr = src.getKeyColumn( );
		if ( expr == null )
		{
			expr = src.getKeyExpression( );
		}
		else
		{
			expr = getColumnRefExpression( expr );
		}
		return expr;
	}
	/**
	 * 
	 * @param expr
	 * @return
	 */
	private String getColumnRefExpression( String expr )
	{