From f2be305a43deba50e5be308bace0be9918d467c5 Mon Sep 17 00:00:00 2001
From: Steve Ebersole <steve@hibernate.org>
Date: Tue, 28 Mar 2023 16:28:04 -0500
Subject: [PATCH] HHH-16391 - Incorrect mutability-plan resolution for
 converted collection-as-basic mappings

---
 .../model/process/internal/NamedConverterResolution.java   | 4 +++-
 .../asbasic/CommaDelimitedStringsConverter.java            | 7 ++++++-
 .../asbasic/CommaDelimitedStringsConverterTests.java       | 7 +++++++
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/hibernate-core/src/main/java/org/hibernate/boot/model/process/internal/NamedConverterResolution.java b/hibernate-core/src/main/java/org/hibernate/boot/model/process/internal/NamedConverterResolution.java
index 66d8b6ab60..3eff73136f 100644
--- a/hibernate-core/src/main/java/org/hibernate/boot/model/process/internal/NamedConverterResolution.java
+++ b/hibernate-core/src/main/java/org/hibernate/boot/model/process/internal/NamedConverterResolution.java
@@ -6,6 +6,7 @@
  */
 package org.hibernate.boot.model.process.internal;
 
+import java.util.Collection;
 import java.util.Map;
 import java.util.function.Function;
 
@@ -16,7 +17,6 @@ import org.hibernate.boot.model.convert.spi.JpaAttributeConverterCreationContext
 import org.hibernate.boot.registry.classloading.spi.ClassLoaderService;
 import org.hibernate.boot.spi.MetadataBuildingContext;
 import org.hibernate.mapping.BasicValue;
-import org.hibernate.mapping.Collection;
 import org.hibernate.metamodel.mapping.JdbcMapping;
 import org.hibernate.type.BasicType;
 import org.hibernate.type.descriptor.converter.internal.AttributeConverterMutabilityPlanImpl;
@@ -149,6 +149,8 @@ public class NamedConverterResolution<J> implements BasicValue.Resolution<J> {
 			return ImmutableMutabilityPlan.instance();
 		}
 
+		// if the domain JavaType is immutable, use the immutability plan
+		// 		- note : ignore this for collection-as-basic mappings.
 		if ( !domainJtd.getMutabilityPlan().isMutable()
 				&& !isCollection( domainJtd.getJavaTypeClass() ) ) {
 			return ImmutableMutabilityPlan.instance();
diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/mapping/collections/asbasic/CommaDelimitedStringsConverter.java b/hibernate-core/src/test/java/org/hibernate/orm/test/mapping/collections/asbasic/CommaDelimitedStringsConverter.java
index 931690191f..cf9cf982f2 100644
--- a/hibernate-core/src/test/java/org/hibernate/orm/test/mapping/collections/asbasic/CommaDelimitedStringsConverter.java
+++ b/hibernate-core/src/test/java/org/hibernate/orm/test/mapping/collections/asbasic/CommaDelimitedStringsConverter.java
@@ -6,12 +6,17 @@
  */
 package org.hibernate.orm.test.mapping.collections.asbasic;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
+import org.hibernate.internal.util.collections.CollectionHelper;
+
 import jakarta.persistence.AttributeConverter;
 
+
 import static org.hibernate.internal.util.StringHelper.join;
+import static org.hibernate.internal.util.collections.CollectionHelper.listOf;
 
 /**
  * @author Steve Ebersole
@@ -31,7 +36,7 @@ public class CommaDelimitedStringsConverter implements AttributeConverter<List<S
 		if ( dbData == null ) {
 			return null;
 		}
-		return Arrays.asList( dbData.split( "," ) );
+		return listOf( dbData.split( "," ) );
 	}
 }
 //end::ex-csv-converter[]
diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/mapping/collections/asbasic/CommaDelimitedStringsConverterTests.java b/hibernate-core/src/test/java/org/hibernate/orm/test/mapping/collections/asbasic/CommaDelimitedStringsConverterTests.java
index dfeacf18fa..dcf5ff65dd 100644
--- a/hibernate-core/src/test/java/org/hibernate/orm/test/mapping/collections/asbasic/CommaDelimitedStringsConverterTests.java
+++ b/hibernate-core/src/test/java/org/hibernate/orm/test/mapping/collections/asbasic/CommaDelimitedStringsConverterTests.java
@@ -63,6 +63,13 @@ public class CommaDelimitedStringsConverterTests {
 			final Person loaded = session.byId( Person.class ).load( 1 );
 			assertThat( loaded.nickNames ).hasSize( 2 );
 			assertThat( loaded.nickNames ).containsExactly( "John Q. Public", "Joe Public" );
+
+			loaded.nickNames.add( "Another one" );
+		} );
+
+		scope.inTransaction( (session) -> {
+			final Person reloaded = session.byId( Person.class ).load( 1 );
+			assertThat( reloaded.nickNames ).hasSize( 3 );
 		} );
 	}