Back off from Kotlin BeanInfo creation for interfaces.

KotlinBeanInfoFactory no longer creates a BeanInfo for interfaces to follow general BeanInfo semantics.

Closes #2964

src/main/java/org/springframework/data/util/KotlinBeanInfoFactory.java

@@ -48,10 +48,15 @@ public class KotlinBeanInfoFactory implements BeanInfoFactory, Ordered {
 	@Override
 	public BeanInfo getBeanInfo(Class<?> beanClass) throws IntrospectionException {
 
+		if (beanClass.isInterface()) {
+			return null; // back-off to leave interface-based properties to the default mechanism.
+		}
+
 		if (!KotlinDetector.isKotlinReflectPresent() || !KotlinDetector.isKotlinType(beanClass)) {
 			return null;
 		}
 
+
 		KClass<?> kotlinClass = JvmClassMappingKt.getKotlinClass(beanClass);
 		List<PropertyDescriptor> pds = new ArrayList<>();
 

src/test/kotlin/org/springframework/data/util/KotlinBeanInfoFactoryUnitTests.kt

@@ -65,6 +65,14 @@ class KotlinBeanInfoFactoryUnitTests {
 		assertThat(pds[0].writeMethod).isNull()
 	}
 
+	@Test // GH-2964
+	internal fun backsOffForInterfaces() {
+
+		val pds = BeanUtils.getPropertyDescriptors(FirstnameOnly::class.java)
+
+		assertThat(pds).hasSize(1).extracting("name").containsOnly("firstname")
+	}
+
 	data class SimpleDataClass(val id: String, var name: String)
 
 	@JvmInline
@@ -74,4 +82,8 @@ class KotlinBeanInfoFactoryUnitTests {
 
 	data class WithOptionalValueClass(val address: EmailAddress? = EmailAddress("un@known"))
 
+	interface FirstnameOnly {
+		fun getFirstname(): String
+	}
+
 }