HHH-19076 Resolve member of MappedSuperclass specially

[beikov]

[Please describe here what your change is about]

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https://hibernate.atlassian.net/browse/HHH-19076

[Copilot]

Pull Request Overview

Adds tests and refactors how mapped-superclass members are resolved to address HHH-19076.

• Introduce two new tests (CompositeInheritanceWorkingTest and CompositeInheritanceFailTest) to illustrate working and failing composite‐ID inheritance cases.
• Simplify resolveMappedSuperclassMember and add special‐case handling for mapped‐superclass types in identifierMemberResolver and versionMemberResolver in AttributeFactory.
• Remove complex subtype‐inspection logic in favor of a direct getter lookup for mapped‐superclass members.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
hibernate-core/src/test/java/org/hibernate/orm/test/mapping/identifier/composite/CompositeInheritanceWorkingTest.java	New “working” test case for composite‐ID inheritance
hibernate-core/src/test/java/org/hibernate/orm/test/mapping/identifier/composite/CompositeInheritanceFailTest.java	New “failing” test case for composite‐ID inheritance
hibernate-core/src/main/java/org/hibernate/metamodel/internal/AttributeFactory.java	Simplify resolveMappedSuperclassMember and update identifier/version member resolvers to treat mapped‐superclass specially

Comments suppressed due to low confidence (3)

hibernate-core/src/test/java/org/hibernate/orm/test/mapping/identifier/composite/CompositeInheritanceWorkingTest.java:142

• [nitpick] This method returns the field otherId but is named myId(). For clarity and consistency, rename it to getOtherId() or change the field to myId.

		public String myId() {

hibernate-core/src/test/java/org/hibernate/orm/test/mapping/identifier/composite/CompositeInheritanceWorkingTest.java:165

• [nitpick] JavaBean conventions recommend getOid() instead of oid(), especially for JPA property access. Consider renaming this getter.

		public String oid() {

hibernate-core/src/main/java/org/hibernate/metamodel/internal/AttributeFactory.java:785

• The new branch for MappedSuperclassDomainType in the identifier resolver is not covered by existing tests. Consider adding a unit test to verify resolution when the owner type is a mapped superclass.

		if ( identifiableType instanceof MappedSuperclassDomainType<?> ) {

[Copilot]

Per the JPA spec, composite‐ID classes must implement equals() and hashCode() to ensure correct identity comparison. Consider adding those methods to CompositeIdClass.

[Copilot]

[nitpick] The same pattern (propertyMapping.getGetter(...).getMember()) is repeated in both identifier and version resolvers. Consider extracting this into a shared helper to reduce duplication.