`NullPointerException` when loading deeply nested embedded entities

[IvanPriests]

During updating spring from 3.1.5 to 3.2.0 our crud jdbc repository method that returning custom response started failing with NPE.
We got method like this:

@Query("""
           SELECT *, 5 as extend_value FROM entity_table
        """)
    fun getExtendedEntities(): List<ExtendEntity>
    
    data class ExtendEntity(
    @Embedded.Nullable
    val entity: Entity,
    val extendValue: Int,
)

Entity example:

@Table("entity_table")
data class Entity(
    @Embedded.Nullable
    val nestedEntity: NestedEntity,
    @Id
    val id: EntityId = EntityId.new(),
    val time: Instant,
) {
    @PersistenceCreator
    constructor(
        id: Ulid,
        time: Instant,
        nestedEntity: NestedEntity,
    ) : this(
        nestedEntity,
        EntityId(id),
        time
    )
}

Exception stacktrace:

Cannot invoke "org.springframework.data.relational.core.mapping.AggregatePath$ColumnInfo.alias()" because the return value of "org.springframework.data.relational.core.mapping.AggregatePath$TableInfo.reverseColumnInfo()" is null
java.lang.NullPointerException: Cannot invoke "org.springframework.data.relational.core.mapping.AggregatePath$ColumnInfo.alias()" because the return value of "org.springframework.data.relational.core.mapping.AggregatePath$TableInfo.reverseColumnInfo()" is null
  at org.springframework.data.jdbc.core.convert.MappingJdbcConverter$ResolvingRelationalPropertyValueProvider.hasValue(MappingJdbcConverter.java:424)
  at org.springframework.data.relational.core.conversion.MappingRelationalConverter.shouldReadEmbeddable(MappingRelationalConverter.java:586)
  at org.springframework.data.relational.core.conversion.MappingRelationalConverter.readEmbedded(MappingRelationalConverter.java:565)
  at org.springframework.data.relational.core.conversion.MappingRelationalConverter$2.getPropertyValue(MappingRelationalConverter.java:490)
  at org.springframework.data.relational.core.conversion.MappingRelationalConverter$2.getPropertyValue(MappingRelationalConverter.java:475)
  at org.springframework.data.mapping.model.PersistentEntityParameterValueProvider.getParameterValue(PersistentEntityParameterValueProvider.java:71)
  at org.springframework.data.relational.core.conversion.MappingRelationalConverter$ConvertingParameterValueProvider.getParameterValue(MappingRelationalConverter.java:1161)
  at org.springframework.data.mapping.model.SpELExpressionParameterValueProvider.getParameterValue(SpELExpressionParameterValueProvider.java:49)
  at org.springframework.data.mapping.model.ClassGeneratingEntityInstantiator.extractInvocationArguments(ClassGeneratingEntityInstantiator.java:301)
  at org.springframework.data.mapping.model.ClassGeneratingEntityInstantiator$EntityInstantiatorAdapter.createInstance(ClassGeneratingEntityInstantiator.java:273)
  at org.springframework.data.mapping.model.ClassGeneratingEntityInstantiator.createInstance(ClassGeneratingEntityInstantiator.java:98)
  at org.springframework.data.relational.core.conversion.MappingRelationalConverter.read(MappingRelationalConverter.java:454)
  at org.springframework.data.relational.core.conversion.MappingRelationalConverter.readAggregate(MappingRelationalConverter.java:348)
  at org.springframework.data.relational.core.conversion.MappingRelationalConverter.readAggregate(MappingRelationalConverter.java:311)
  at org.springframework.data.jdbc.core.convert.MappingJdbcConverter.readAndResolve(MappingJdbcConverter.java:287)
  at org.springframework.data.jdbc.core.convert.JdbcConverter.readAndResolve(JdbcConverter.java:106)
  at org.springframework.data.jdbc.core.convert.EntityRowMapper.mapRow(EntityRowMapper.java:82)
  at org.springframework.data.jdbc.repository.support.JdbcQueryLookupStrategy$PostProcessingRowMapper.mapRow(JdbcQueryLookupStrategy.java:335)
  at org.springframework.data.jdbc.repository.query.AbstractJdbcQuery$ConvertingRowMapper.mapRow(AbstractJdbcQuery.java:196)
  at org.springframework.jdbc.core.RowMapperResultSetExtractor.extractData(RowMapperResultSetExtractor.java:94)
  at org.springframework.jdbc.core.RowMapperResultSetExtractor.extractData(RowMapperResultSetExtractor.java:61)
  at org.springframework.jdbc.core.JdbcTemplate$1.doInPreparedStatement(JdbcTemplate.java:733)
  at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:658)
  at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:723)
  at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:748)
  at org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate.query(NamedParameterJdbcTemplate.java:178)
  at org.springframework.data.jdbc.repository.query.AbstractJdbcQuery.lambda$createSingleReadingQueryExecution$3(AbstractJdbcQuery.java:165)
  at org.springframework.data.jdbc.repository.query.StringBasedJdbcQuery.execute(StringBasedJdbcQuery.java:145)
  at org.springframework.data.repository.core.support.RepositoryMethodInvoker.doInvoke(RepositoryMethodInvoker.java:170)
  at org.springframework.data.repository.core.support.RepositoryMethodInvoker.invoke(RepositoryMethodInvoker.java:158)
  at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.doInvoke(QueryExecutorMethodInterceptor.java:164)
  at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.invoke(QueryExecutorMethodInterceptor.java:143)
  at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184)
  at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:123)
  at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:385)
  at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:119)
  at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184)
  at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:137)
  at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184)
  at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:97)
  at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184)
  at org.springframework.data.repository.core.support.MethodInvocationValidator.invoke(MethodInvocationValidator.java:95)
  at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184)
  at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:249)
  at jdk.proxy3/jdk.proxy3.$Proxy116.getExtendedEntities(Unknown Source)
  at com.example.demo.entity.RepoTests.selectExtended(RepoTests.kt:15)

On 3.1.5 this case worked. Shared test project with failing scenario.

Versions:
Kotlin 1.9.20
JVM Target 21
Spring Data JDBC 3.2.0

[schauder]

Thanks for reporting this. This is a bug triggered when there are multiple levels of embedded entities, with @Embedded.Nullable annotation and we need to check the presence of a lower level in order to decide if we need to load the upper level.