Fix a regression in Cglib Kotlin proxies

The commit skips using UndeclaredThrowableStrategy for
Kotlin classes in CglibAopProxy in order to fix a
related regression caused by gh-32469.

See gh-33585

Author: sdeleuze

spring-aop/src/main/java/org/springframework/aop/framework/CglibAopProxy.java

@@ -206,7 +206,10 @@ private Object buildProxy(@Nullable ClassLoader classLoader, boolean classOnly)
 			enhancer.setInterfaces(AopProxyUtils.completeProxiedInterfaces(this.advised));
 			enhancer.setNamingPolicy(SpringNamingPolicy.INSTANCE);
 			enhancer.setAttemptLoad(true);
-			enhancer.setStrategy(new ClassLoaderAwareGeneratorStrategy(classLoader, undeclaredThrowableStrategy));
+			enhancer.setStrategy(KotlinDetector.isKotlinType(proxySuperClass) ?
+					new ClassLoaderAwareGeneratorStrategy(classLoader) :
+					new ClassLoaderAwareGeneratorStrategy(classLoader, undeclaredThrowableStrategy)
+			);
 
 			Callback[] callbacks = getCallbacks(rootClass);
 			Class<?>[] types = new Class<?>[callbacks.length];

spring-aop/src/test/kotlin/org/springframework/aop/framework/CglibAopProxyKotlinTests.kt

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2002-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.aop.framework
+
+import org.assertj.core.api.Assertions.assertThat
+import org.assertj.core.api.Assertions.assertThatThrownBy
+import org.junit.jupiter.api.Test
+
+/**
+ * Tests for Kotlin support in [CglibAopProxy].
+ *
+ * @author Sebastien Deleuze
+ */
+class CglibAopProxyKotlinTests {
+
+	@Test
+	fun proxiedInvocation() {
+		val proxyFactory = ProxyFactory(MyKotlinBean())
+		val proxy = proxyFactory.proxy as MyKotlinBean
+		assertThat(proxy.capitalize("foo")).isEqualTo("FOO")
+	}
+
+	@Test
+	fun proxiedUncheckedException() {
+		val proxyFactory = ProxyFactory(MyKotlinBean())
+		val proxy = proxyFactory.proxy as MyKotlinBean
+		assertThatThrownBy { proxy.uncheckedException() }.isInstanceOf(IllegalStateException::class.java)
+	}
+
+	@Test
+	fun proxiedCheckedException() {
+		val proxyFactory = ProxyFactory(MyKotlinBean())
+		val proxy = proxyFactory.proxy as MyKotlinBean
+		assertThatThrownBy { proxy.checkedException() }.isInstanceOf(CheckedException::class.java)
+	}
+
+
+	open class MyKotlinBean {
+
+		open fun capitalize(value: String) = value.uppercase()
+
+		open fun uncheckedException() {
+			throw IllegalStateException()
+		}
+
+		open fun checkedException() {
+			throw CheckedException()
+		}
+	}
+
+	class CheckedException() : Exception()
+}