Spanner - PK fields which can be null - Save entity with @Interleaved field

[agustintabarez]

Describe the bug
The error occurs when inserting an entity that has an interleaved relationship with another table, and at least one shared primary key is null.

Versions:
spring-cloud-gcp-dependencies: 5.0.3
spring-boot: 3.2.2

Sample

@Table
public class Parent { 

  @PrimaryKey
  @Column
  private String keyOne;

  @PrimaryKey(keyOrder = 2)
  @Column
  private Long keyTwo;

  @Interleaved
  private List<Child> children;

  // More fields
}

@Table
public class Child { 

  @PrimaryKey
  @Column
  private String keyOne;

  @PrimaryKey(keyOrder = 2)
  @Column
  private Long keyTwo;

  @PrimaryKey(keyOrder = 3)
  @Column
  private Long keyThree;

  // More fields
}

var keyOne = "keyOne";
var keyTwo = null;
var keyThree = "keyThree";
List<Child> children = List.of(new Child(keyOne, keyTwo, keyThree));

Parent parent = new Parent(keyOne, keyTwo, children);
parentRepository.save(parent) // extends SpannerRepository

Error:

Cannot invoke "Object.equals(Object)" because the return value of "java.util.Iterator.next()" is null

[agustintabarez]

Following the same example, also an error occurs when retrieving an entity that has some PK field null.

1. Find All
   parentRepository.findAll(); // parentRepository extends SpannerRepository<Parent, Object[]>

It only throws error when using @Interleaved(lazy = true).

2. Find By ID

Object[] keys = new Object[2];
keys[0] = "not-null-key";
keys[1] = null; // Also tried not to send this key
this.parentRepository.findById(keys);