[
https://issues.apache.org/jira/browse/FLINK-37245?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Maximilian Michels updated FLINK-37245:
---------------------------------------
Fix Version/s: 2.1.0
> RowData#createFieldGetter can resurrect null values for non-null fields
> -----------------------------------------------------------------------
>
> Key: FLINK-37245
> URL: https://issues.apache.org/jira/browse/FLINK-37245
> Project: Flink
> Issue Type: Bug
> Components: Table SQL / API, Table SQL / Runtime
> Affects Versions: 1.20.0, 1.19.1
> Reporter: Maximilian Michels
> Assignee: Maximilian Michels
> Priority: Major
> Labels: pull-request-available
> Fix For: 2.1.0
>
>
> {{RowData#createFieldGetter}} is the go-to method for creating field getters
> for a given field type and position. The method
> {{FieldGetter#getFieldOrNull}} suggests that null is returned if the field
> has been nulled. But that is not always the case.
> When using BinaryRowData with a non-null field, which has been set to null, a
> call to {{FieldGetter#getFieldOrNull}} will return a non-null value,
> interpreting whatever bytes are backing the field as an actual value instead
> of null.
> Example:
> {noformat}
> public static void main(String[] args) {
> IntType nullableIntType = new IntType(true);
> IntType nonNullableIntType = new IntType(false);
> RowDataSerializer rowDataSerializer = new RowDataSerializer(
> nullableIntType, nonNullableIntType
> );
> BinaryRowData binaryRow =
> rowDataSerializer.toBinaryRow(GenericRowData.of(null, null));
> RowData.FieldGetter fieldGetter1 =
> RowData.createFieldGetter(nullableIntType, 0);
> RowData.FieldGetter fieldGetter2 =
> RowData.createFieldGetter(nonNullableIntType, 1);
> System.out.println(fieldGetter1.getFieldOrNull(binaryRow));
> System.out.println(fieldGetter2.getFieldOrNull(binaryRow));
> }
> {noformat}
> Output is:
> {noformat}
> null
> 0
> {noformat}
> The expected output would be that the second non-null field also returns
> null, or raises a NullPointerException directly. That's not the case because
> {{RowData#createFieldGetter}} only checks for null values (via a call to
> {{{}Rowdata#isNullAt(pos){}}}) when the type is nullable (see
> [https://github.com/apache/flink/blob/b86fdf906c06af8fc2841bca3d98dd3944bb5031/flink-table/flink-table-common/src/main/java/org/apache/flink/table/data/RowData.java#L289]).
> It seems fair to always check for null fields, instead of deferring this easy
> to forget check to the caller.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
