test showing two problems with user types

hibernate-core/src/test/java/org/hibernate/orm/test/annotations/usertype/EnhancedUserTypeTest.java

@@ -0,0 +1,17 @@
+package org.hibernate.orm.test.annotations.usertype;
+
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.SessionFactory;
+import org.hibernate.testing.orm.junit.SessionFactoryScope;
+import org.junit.jupiter.api.Test;
+
+@SessionFactory
+@DomainModel(annotatedClasses = MyEntity.class)
+public class EnhancedUserTypeTest {
+
+    @Test
+    void test(SessionFactoryScope scope) {
+        scope.inTransaction(session -> session.persist(new MyEntity(new MyId("x1"), "hello world")));
+    }
+
+}

hibernate-core/src/test/java/org/hibernate/orm/test/annotations/usertype/MyEntity.java

@@ -0,0 +1,22 @@
+package org.hibernate.orm.test.annotations.usertype;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import org.hibernate.annotations.Type;
+
+@Entity
+class MyEntity {
+    @Id
+    @Type(MyType.class)
+    MyId id;
+
+    String content;
+
+    MyEntity(MyId id, String content) {
+        this.id = id;
+        this.content = content;
+    }
+
+    MyEntity() {
+    }
+}

hibernate-core/src/test/java/org/hibernate/orm/test/annotations/usertype/MyId.java

@@ -0,0 +1,9 @@
+package org.hibernate.orm.test.annotations.usertype;
+
+class MyId {
+    final String text;
+
+    MyId(String text) {
+        this.text = text;
+    }
+}

hibernate-core/src/test/java/org/hibernate/orm/test/annotations/usertype/MyType.java

@@ -0,0 +1,80 @@
+package org.hibernate.orm.test.annotations.usertype;
+
+import org.hibernate.HibernateException;
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
+import org.hibernate.type.SqlTypes;
+import org.hibernate.usertype.EnhancedUserType;
+
+import java.io.Serializable;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+class MyType implements EnhancedUserType<MyId> {
+    @Override
+    public String toSqlLiteral(MyId value) {
+        return "'" + value.text.replace("'", "''") + "'";
+    }
+
+    @Override
+    public String toString(MyId value) throws HibernateException {
+        return value.text;
+    }
+
+    @Override
+    public MyId fromStringValue(CharSequence sequence) throws HibernateException {
+        return new MyId(sequence.toString());
+    }
+
+    @Override
+    public int getSqlType() {
+        return SqlTypes.VARCHAR;
+    }
+
+    @Override
+    public Class<MyId> returnedClass() {
+        return MyId.class;
+    }
+
+    @Override
+    public boolean equals(MyId x, MyId y) {
+        return x != null && y != null && x.text.equals(y.text);
+    }
+
+    @Override
+    public int hashCode(MyId x) {
+        return x.text.hashCode();
+    }
+
+    @Override
+    public MyId nullSafeGet(ResultSet rs, int position, SharedSessionContractImplementor session, Object owner)
+            throws SQLException {
+        return new MyId(rs.getString(position));
+    }
+
+    @Override
+    public void nullSafeSet(PreparedStatement st, MyId value, int index, SharedSessionContractImplementor session)
+            throws SQLException {
+        st.setString(index, value.text);
+    }
+
+    @Override
+    public MyId deepCopy(MyId value) {
+        return value;
+    }
+
+    @Override
+    public boolean isMutable() {
+        return false;
+    }
+
+    @Override
+    public Serializable disassemble(MyId value) {
+        return value.text;
+    }
+
+    @Override
+    public MyId assemble(Serializable cached, Object owner) {
+        return new MyId((String) cached);
+    }
+}