Kotlin codegen generates invalid code when a parameterized mapped superclass is used

[jpmsilva]

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Describe the bug

When using a parameterized mapped superclass the generated Q-classes are invalid with respect to the generic parameters.

To Reproduce

A test example can be seen at https://github.com/jpmsilva/openfeign-querydsl/tree/kotlin-codegen-generic-supertype (branched from the 6.10.1 release).

Running clean package -P quickbuild from the folder querydsl-examples/querydsl-example-kotlin-codegen shows the issue:

[INFO] --- kotlin:2.1.0:compile (compile) @ querydsl-example-kotlin-codegen ---
[INFO] Applied plugin: 'jpa'
[WARNING] Duplicate source root: querydsl/querydsl-examples/querydsl-example-kotlin-codegen/target/generated-sources/kapt/compile
[WARNING] Duplicate source root: querydsl/querydsl-examples/querydsl-example-kotlin-codegen/target/generated-sources/kaptKotlin/compile
[ERROR] querydsl/querydsl-examples/querydsl-example-kotlin-codegen/target/generated-sources/kaptKotlin/compile/com/querydsl/examples/kotlin/entity/QExampleBaseEntity.kt: (23, 42) None of the following candidates is applicable:
constructor<T : Any!>(p0: Class<out T!>!, p1: String!): EntityPathBase<T>
constructor<T : Any!>(p0: Class<out T!>!, p1: PathMetadata!): EntityPathBase<T>
[ERROR] querydsl/querydsl-examples/querydsl-example-kotlin-codegen/target/generated-sources/kaptKotlin/compile/com/querydsl/examples/kotlin/entity/QExampleBaseEntity.kt: (27, 48) None of the following candidates is applicable:
constructor<T : Any!>(p0: Class<out T!>!, p1: String!): EntityPathBase<T>
constructor<T : Any!>(p0: Class<out T!>!, p1: PathMetadata!): EntityPathBase<T>
[ERROR] querydsl/querydsl-examples/querydsl-example-kotlin-codegen/target/generated-sources/kaptKotlin/compile/com/querydsl/examples/kotlin/entity/QExampleEntity.kt: (27, 5) None of the following candidates is applicable:
constructor(variable: String): QExampleBaseEntity
constructor(path: Path<out ExampleBaseEntity<Serializable>>): QExampleBaseEntity
constructor(metadata: PathMetadata): QExampleBaseEntity

Expected behavior
Build should complete without errors.

Screenshots
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Additional context
I might be able to submit a PR to properly set the out keyword in the superclass parameters of the generated Q-classes. This aligns the generated Kotlin Q-classes with the Java Q-classes with regards to entity parameters, when they are used.

When using the Java codegen variant these generic mapped superclass types are properly handled. The issue only happens in the Kotlin codegen module.

[jpmsilva]

Please note that I also tested the same scenario using the KSP codegen, but it results in a different error. Unfortunately I am not able to properly diagnose that issue, as KSP is not something I know how to work with:

e: [ksp] java.lang.IllegalStateException: Error processing com.querydsl.example.ksp.BaseEntity.id: Type was not recognised, This may be an entity that has not been annotated with @Entity, or maybe you are using javax instead of jakarta.

Do let me know if you'd like a separate issue filed for the KSP codegen issue, but please take note that I won't be able to assist in that case.