Fix constructor resolution for Kotlin classes using unsigned types.

We now leniently skip parameter name resolution for types using unsigned types. The issue is caused by Kotlin's DefaultConstructorMarker that doesn't report a parameter name.

Closes #2215

Author: mp911de

src/main/java/org/springframework/data/mapping/model/PreferredConstructorDiscoverer.java

@@ -212,7 +212,7 @@ private static <T, P extends PersistentProperty<P>> PreferredConstructor<T, P> b
 
 			for (int i = 0; i < parameterTypes.size(); i++) {
 
-				String name = parameterNames == null ? null : parameterNames[i];
+				String name = parameterNames == null || parameterNames.length <= i ? null : parameterNames[i];
 				TypeInformation<?> type = parameterTypes.get(i);
 				Annotation[] annotations = parameterAnnotations[i];
 

src/test/kotlin/org/springframework/data/mapping/model/PreferredConstructorDiscovererUnitTests.kt

@@ -79,13 +79,27 @@ class PreferredConstructorDiscovererUnitTests {
 	@Suppress("UNCHECKED_CAST")
 	fun `should not resolve constructor for synthetic Kotlin class`() {
 
-		val c = Class.forName("org.springframework.data.mapping.model.TypeCreatingSyntheticClassKt") as Class<Any>
+		val c =
+			Class.forName("org.springframework.data.mapping.model.TypeCreatingSyntheticClassKt") as Class<Any>
 
-		val constructor = PreferredConstructorDiscoverer.discover<Any, SamplePersistentProperty>(c)
+		val constructor =
+			PreferredConstructorDiscoverer.discover<Any, SamplePersistentProperty>(c)
 
 		assertThat(constructor).isNull()
 	}
 
+	@Test // DATACMNS-1800, gh-2215
+	@ExperimentalUnsignedTypes
+	fun `should discover constructor for class using unsigned types`() {
+
+		val constructor =
+			PreferredConstructorDiscoverer.discover<UnsignedTypesEntity, SamplePersistentProperty>(
+				UnsignedTypesEntity::class.java
+			)
+
+		assertThat(constructor).isNotNull()
+	}
+
 	data class Simple(val firstname: String)
 
 	class TwoConstructorsWithoutDefault {
@@ -111,9 +125,23 @@ class PreferredConstructorDiscovererUnitTests {
 
 	class DefaultConstructor(val firstname: String = "foo")
 
-	class TwoDefaultConstructorsAnnotated(val firstname: String = "foo", val lastname: String = "bar") {
+	class TwoDefaultConstructorsAnnotated(
+		val firstname: String = "foo",
+		val lastname: String = "bar"
+	) {
 
 		@PersistenceConstructor
-		constructor(firstname: String = "foo", lastname: String = "bar", age: Int) : this(firstname, lastname)
+		constructor(firstname: String = "foo", lastname: String = "bar", age: Int) : this(
+			firstname,
+			lastname
+		)
 	}
+
+	@ExperimentalUnsignedTypes
+	data class UnsignedTypesEntity(
+		val id: String,
+		val a: UInt = 5u,
+		val b: Int = 5,
+		val c: Double = 1.5
+	)
 }