[HHH-16122] Add test to reproduce problem

hibernate-core/src/test/java/org/hibernate/orm/test/annotations/HHH16122Test.java

@@ -0,0 +1,58 @@
+package org.hibernate.orm.test.annotations;
+
+import jakarta.persistence.AttributeConverter;
+import jakarta.persistence.Converter;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.MappedSuperclass;
+import org.hibernate.orm.test.jpa.BaseEntityManagerFunctionalTestCase;
+import org.hibernate.testing.TestForIssue;
+import org.junit.Test;
+
+@TestForIssue( jiraKey = "HHH-16122" )
+public class HHH16122Test extends BaseEntityManagerFunctionalTestCase {
+    @Override
+    protected Class<?>[] getAnnotatedClasses() {
+        return new Class[] { ValueConverter.class, SuperClass.class, SubClass.class };
+    }
+
+    @Test
+    public void testGenericSuperClassWithConverter() {
+        // The test is successful if the entity manager factory can be built.
+    }
+
+    public static class ConvertedValue {
+        public final long value;
+        public ConvertedValue(long value) {
+            this.value = value;
+        }
+    }
+
+    @Converter(autoApply = true)
+    public static class ValueConverter implements AttributeConverter<ConvertedValue, Long> {
+        @Override
+        public Long convertToDatabaseColumn( ConvertedValue value ) {
+            return value.value;
+        }
+        @Override
+        public ConvertedValue convertToEntityAttribute( Long value ) {
+            return new ConvertedValue(value);
+        }
+    }
+
+    @MappedSuperclass
+    public static abstract class SuperClass<S extends SuperClass> {
+        @Id
+        private String id;
+        public ConvertedValue convertedValue = new ConvertedValue( 1 );
+        public ConvertedValue getConvertedValue() {
+            return convertedValue;
+        }
+        public void setConvertedValue(ConvertedValue convertedValue) {
+            this.convertedValue = convertedValue;
+        }
+    }
+
+    @Entity(name = "SubClass")
+    public static class SubClass extends SuperClass<SubClass> {}
+}