Bug 142939 Invalid interval will cause incorrect group action.
Description: Invalid interval will cause incorrect group action. Steps to reproduce: 1. Insert a list 2. Add a group, key is string type column, set interval to year, range to 3 3. Preview Expected result: Error msg about invald interval and ignore the invalid interval. Actual result: No error msg and only return one group with all datarows.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/QueryExecutor.java
String name = columnInfo.getColumnName( );
					if ( name == null && index < 0 )
					{
						
						
						
						temporaryComputedColumns.add( new ComputedColumn( "_{$TEMP_FILTER_"
								+ i + "$}_",
								exprText,
								DataType.ANY_TYPE ) );
						it.remove( );
						result.add( new FilterDefinition( new ConditionalExpression( new ScriptExpression( String.valueOf( "dataSetRow[\"_{$TEMP_FILTER_"
								+ i + "$}_\"]" ) ),
								ce.getOperator( ),
								ce.getOperand1( ),
								ce.getOperand2( ) ) ) );
					}
				}
			}
		}
	}
	/**
	 * 
	 * @param filter
	 * @return
	 */
	private boolean isGroupFilter( IFilterDefinition filter )
	{
		IBaseExpression expr = filter.getExpression( );
		if ( expr instanceof IConditionalExpression )