Accept REQUIRES_NEW on non-async transactional event listeners

See gh-30679

spring-tx/src/main/java/org/springframework/transaction/event/TransactionalApplicationListenerMethodAdapter.java

@@ -26,6 +26,7 @@ import org.springframework.context.event.EventListener;
 import org.springframework.context.event.GenericApplicationListener;
 import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.scheduling.annotation.Async;
+import org.springframework.transaction.annotation.Propagation;
 import org.springframework.transaction.annotation.Transactional;
 import org.springframework.transaction.support.TransactionSynchronizationManager;
 import org.springframework.util.Assert;
@@ -65,18 +66,19 @@ public class TransactionalApplicationListenerMethodAdapter extends ApplicationLi
 	 */
 	public TransactionalApplicationListenerMethodAdapter(String beanName, Class<?> targetClass, Method method) {
 		super(beanName, targetClass, method);
-		TransactionalEventListener ann =
+		TransactionalEventListener eventAnn =
 				AnnotatedElementUtils.findMergedAnnotation(method, TransactionalEventListener.class);
-		if (ann == null) {
+		if (eventAnn == null) {
 			throw new IllegalStateException("No TransactionalEventListener annotation found on method: " + method);
 		}
-		if (AnnotatedElementUtils.hasAnnotation(method, Transactional.class) &&
+		Transactional txAnn = AnnotatedElementUtils.findMergedAnnotation(method, Transactional.class);
+		if (txAnn != null && txAnn.propagation() != Propagation.REQUIRES_NEW &&
 				!AnnotatedElementUtils.hasAnnotation(method, Async.class)) {
-			throw new IllegalStateException("@TransactionalEventListener method must not be annotated " +
-					"with @Transactional, unless when declared as @Async: " + method);
+			throw new IllegalStateException("@TransactionalEventListener method must not be annotated with " +
+					"@Transactional unless when marked as REQUIRES_NEW or declared as @Async: " + method);
 		}
-		this.annotation = ann;
-		this.transactionPhase = ann.phase();
+		this.annotation = eventAnn;
+		this.transactionPhase = eventAnn.phase();
 	}
 
 

spring-tx/src/test/java/org/springframework/transaction/event/TransactionalApplicationListenerMethodAdapterTests.java

@@ -25,6 +25,7 @@ import org.springframework.context.event.ApplicationListenerMethodAdapter;
 import org.springframework.core.ResolvableType;
 import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.scheduling.annotation.Async;
+import org.springframework.transaction.annotation.Propagation;
 import org.springframework.transaction.annotation.Transactional;
 import org.springframework.transaction.support.TransactionSynchronization;
 import org.springframework.transaction.support.TransactionSynchronizationManager;
@@ -132,6 +133,13 @@ public class TransactionalApplicationListenerMethodAdapterTests {
 		assertThatIllegalStateException().isThrownBy(() -> createTestInstance(m));
 	}
 
+	@Test
+	public void withTransactionalRequiresNewAnnotation() {
+		Method m = ReflectionUtils.findMethod(SampleEvents.class, "withTransactionalRequiresNewAnnotation", String.class);
+		supportsEventType(true, m, createGenericEventType(String.class));
+		supportsEventType(false, m, createGenericEventType(Double.class));
+	}
+
 	@Test
 	public void withAsyncTransactionalAnnotation() {
 		Method m = ReflectionUtils.findMethod(SampleEvents.class, "withAsyncTransactionalAnnotation", String.class);
@@ -216,6 +224,11 @@ public class TransactionalApplicationListenerMethodAdapterTests {
 		public void withTransactionalAnnotation(String data) {
 		}
 
+		@TransactionalEventListener
+		@Transactional(propagation = Propagation.REQUIRES_NEW)
+		public void withTransactionalRequiresNewAnnotation(String data) {
+		}
+
 		@TransactionalEventListener
 		@Async @Transactional
 		public void withAsyncTransactionalAnnotation(String data) {