Polishing

spring-beans/src/main/java/org/springframework/beans/factory/support/ConstructorResolver.java

@@ -486,7 +486,9 @@ class ConstructorResolver {
 				}
 			}
 
-			candidates.sort(AutowireUtils.EXECUTABLE_COMPARATOR);
+			if (candidates.size() > 1) {  // explicitly skip immutable singletonList
+				candidates.sort(AutowireUtils.EXECUTABLE_COMPARATOR);
+			}
 
 			ConstructorArgumentValues resolvedValues = null;
 			boolean autowiring = (mbd.getResolvedAutowireMode() == AutowireCapableBeanFactory.AUTOWIRE_CONSTRUCTOR);

spring-context/src/test/java/org/springframework/context/event/AnnotationDrivenEventListenerTests.java

@@ -850,9 +850,9 @@ public class AnnotationDrivenEventListenerTests {
 			this.eventCollector.addEvent(this, event);
 		}
 
-		@Override
 		@EventListener
 		@Async
+		@Override
 		public void handleAsync(AnotherTestEvent event) {
 			assertThat(Thread.currentThread().getName()).isNotEqualTo(event.content);
 			this.eventCollector.addEvent(this, event);
@@ -877,9 +877,9 @@ public class AnnotationDrivenEventListenerTests {
 			this.eventCollector.addEvent(this, event);
 		}
 
-		@Override
 		@EventListener
 		@Async
+		@Override
 		public void handleAsync(AnotherTestEvent event) {
 			assertThat(Thread.currentThread().getName()).isNotEqualTo(event.content);
 			this.eventCollector.addEvent(this, event);
@@ -994,20 +994,20 @@ public class AnnotationDrivenEventListenerTests {
 			super.handle(event);
 		}
 
-		@Override
 		@EventListener(condition = "#payload.startsWith('OK')")
+		@Override
 		public void handleString(String payload) {
 			super.handleString(payload);
 		}
 
-		@Override
 		@ConditionalEvent("#root.event.timestamp > #p0")
+		@Override
 		public void handleTimestamp(Long timestamp) {
 			collectEvent(timestamp);
 		}
 
-		@Override
 		@ConditionalEvent("@conditionEvaluator.valid(#p0)")
+		@Override
 		public void handleRatio(Double ratio) {
 			collectEvent(ratio);
 		}
@@ -1085,6 +1085,7 @@ public class AnnotationDrivenEventListenerTests {
 		}
 	}
 
+
 	@Configuration
 	@Import(UseMissingEventListener.class)
 	public static class MissingEventListener {
@@ -1095,6 +1096,7 @@ public class AnnotationDrivenEventListenerTests {
 		}
 	}
 
+
 	@Component
 	public static class MyEventListener {
 
@@ -1104,6 +1106,7 @@ public class AnnotationDrivenEventListenerTests {
 		}
 	}
 
+
 	public static class UseMissingEventListener {
 
 		@Inject

spring-core/src/main/java/org/springframework/core/codec/AbstractDataBufferDecoder.java

@@ -102,6 +102,7 @@ public abstract class AbstractDataBufferDecoder<T> extends AbstractDecoder<T> {
 	 * {@link #decode(DataBuffer, ResolvableType, MimeType, Map)} instead
 	 */
 	@Deprecated
+	@Nullable
 	protected T decodeDataBuffer(DataBuffer buffer, ResolvableType elementType,
 			@Nullable MimeType mimeType, @Nullable Map<String, Object> hints) {
 

spring-web/src/main/java/org/springframework/http/codec/ServerSentEventHttpMessageReader.java

@@ -155,6 +155,7 @@ public class ServerSentEventHttpMessageReader implements HttpMessageReader<Objec
 		}
 	}
 
+	@Nullable
 	private Object decodeData(String data, ResolvableType dataType, Map<String, Object> hints) {
 		if (String.class == dataType.resolve()) {
 			return data.substring(0, data.length() - 1);