Merge branch '5.3.x'

# Conflicts:
#	build.gradle

build.gradle

@@ -170,14 +170,14 @@ configure(allprojects) { project ->
 			dependency "org.junit.support:testng-engine:1.0.1"
 			dependency "org.hamcrest:hamcrest:2.1"
 			dependency "org.awaitility:awaitility:3.1.6"
-			dependency "org.assertj:assertj-core:3.21.0"
+			dependency "org.assertj:assertj-core:3.22.0"
-			dependencySet(group: 'org.xmlunit', version: '2.8.3') {
+			dependencySet(group: 'org.xmlunit', version: '2.8.4') {
 				entry 'xmlunit-assertj'
 				entry('xmlunit-matchers') {
 					exclude group: "org.hamcrest", name: "hamcrest-core"
 				}
 			}
-			dependencySet(group: 'org.mockito', version: '4.1.0') {
+			dependencySet(group: 'org.mockito', version: '4.2.0') {
 				entry('mockito-core') {
 					exclude group: "org.hamcrest", name: "hamcrest-core"
 				}
@@ -185,10 +185,10 @@ configure(allprojects) { project ->
 			}
 			dependency "io.mockk:mockk:1.12.1"
 
-			dependency("net.sourceforge.htmlunit:htmlunit:2.55.0") {
+			dependency("net.sourceforge.htmlunit:htmlunit:2.56.0") {
 				exclude group: "commons-logging", name: "commons-logging"
 			}
-			dependency("org.seleniumhq.selenium:htmlunit-driver:2.55.0") {
+			dependency("org.seleniumhq.selenium:htmlunit-driver:2.56.0") {
 				exclude group: "commons-logging", name: "commons-logging"
 			}
 			dependency("org.seleniumhq.selenium:selenium-java:3.141.59") {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -42,6 +42,7 @@ import org.springframework.lang.Nullable;
  *
  * @author Sebastien Deleuze
  * @author Rossen Stoyanchev
+ * @author Juergen Hoeller
  * @since 5.0
  */
 public class ServerSentEventHttpMessageReader implements HttpMessageReader<Object> {
@@ -140,22 +141,23 @@ public class ServerSentEventHttpMessageReader implements HttpMessageReader<Objec
 	private Object buildEvent(List<String> lines, ResolvableType valueType, boolean shouldWrap,
 			Map<String, Object> hints) {
 
-		ServerSentEvent.Builder<Object> sseBuilder = shouldWrap ? ServerSentEvent.builder() : null;
+		ServerSentEvent.Builder<Object> sseBuilder = (shouldWrap ? ServerSentEvent.builder() : null);
 		StringBuilder data = null;
 		StringBuilder comment = null;
 
 		for (String line : lines) {
 			if (line.startsWith("data:")) {
-				data = (data != null ? data : new StringBuilder());
+				int length = line.length();
-				if (line.charAt(5) != ' ') {
+				if (length > 5) {
-					data.append(line, 5, line.length());
+					int index = (line.charAt(5) != ' ' ? 5 : 6);
+					if (length > index) {
+						data = (data != null ? data : new StringBuilder());
+						data.append(line, index, line.length());
+						data.append('\n');
+					}
 				}
-				else {
-					data.append(line, 6, line.length());
-				}
-				data.append('\n');
 			}
-			if (shouldWrap) {
+			else if (shouldWrap) {
 				if (line.startsWith("id:")) {
 					sseBuilder.id(line.substring(3).trim());
 				}

spring-web/src/test/java/org/springframework/http/codec/ServerSentEventHttpMessageReaderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -40,6 +40,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  * Unit tests for {@link ServerSentEventHttpMessageReader}.
  *
  * @author Sebastien Deleuze
+ * @author Juergen Hoeller
  */
 public class ServerSentEventHttpMessageReaderTests extends AbstractLeakCheckingTests {
 
@@ -66,7 +67,7 @@ public class ServerSentEventHttpMessageReaderTests extends AbstractLeakCheckingT
 		MockServerHttpRequest request = MockServerHttpRequest.post("/")
 				.body(Mono.just(stringBuffer(
 						"id:c42\nevent:foo\nretry:123\n:bla\n:bla bla\n:bla bla bla\ndata:bar\n\n" +
-						"id:c43\nevent:bar\nretry:456\ndata:baz\n\n")));
+						"id:c43\nevent:bar\nretry:456\ndata:baz\n\ndata:\n\ndata: \n\n")));
 
 		Flux<ServerSentEvent> events = this.reader
 				.read(ResolvableType.forClassWithGenerics(ServerSentEvent.class, String.class),
@@ -87,6 +88,8 @@ public class ServerSentEventHttpMessageReaderTests extends AbstractLeakCheckingT
 					assertThat(event.comment()).isNull();
 					assertThat(event.data()).isEqualTo("baz");
 				})
+				.consumeNextWith(event -> assertThat(event.data()).isNull())
+				.consumeNextWith(event -> assertThat(event.data()).isNull())
 				.expectComplete()
 				.verify();
 	}
@@ -175,7 +178,7 @@ public class ServerSentEventHttpMessageReaderTests extends AbstractLeakCheckingT
 				.verify();
 	}
 
-	@Test // gh-24389
+	@Test  // gh-24389
 	void readPojoWithCommentOnly() {
 		MockServerHttpRequest request = MockServerHttpRequest.post("/")
 				.body(Flux.just(stringBuffer(":ping\n"), stringBuffer("\n")));
@@ -221,7 +224,6 @@ public class ServerSentEventHttpMessageReaderTests extends AbstractLeakCheckingT
 
 	@Test
 	public void maxInMemoryLimit() {
-
 		this.reader.setMaxInMemorySize(17);
 
 		MockServerHttpRequest request = MockServerHttpRequest.post("/")
@@ -235,9 +237,8 @@ public class ServerSentEventHttpMessageReaderTests extends AbstractLeakCheckingT
 				.verify();
 	}
 
-	@Test // gh-24312
+	@Test  // gh-24312
 	public void maxInMemoryLimitAllowsReadingPojoLargerThanDefaultSize() {
-
 		int limit = this.jsonDecoder.getMaxInMemorySize();
 
 		String fooValue = getStringOfSize(limit) + "and then some more";
@@ -259,13 +260,6 @@ public class ServerSentEventHttpMessageReaderTests extends AbstractLeakCheckingT
 				.verify();
 	}
 
-	private static String getStringOfSize(long size) {
-		StringBuilder content = new StringBuilder("Aa");
-		while (content.length() < size) {
-			content.append(content);
-		}
-		return content.toString();
-	}
 
 	private DataBuffer stringBuffer(String value) {
 		byte[] bytes = value.getBytes(StandardCharsets.UTF_8);
@@ -274,4 +268,12 @@ public class ServerSentEventHttpMessageReaderTests extends AbstractLeakCheckingT
 		return buffer;
 	}
 
+	private static String getStringOfSize(long size) {
+		StringBuilder content = new StringBuilder("Aa");
+		while (content.length() < size) {
+			content.append(content);
+		}
+		return content.toString();
+	}
+
 }

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/AbstractMessageConverterMethodArgumentResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -167,7 +167,7 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 		HttpMethod httpMethod = (inputMessage instanceof HttpRequest ? ((HttpRequest) inputMessage).getMethod() : null);
 		Object body = NO_VALUE;
 
-		EmptyBodyCheckingHttpInputMessage message;
+		EmptyBodyCheckingHttpInputMessage message = null;
 		try {
 			message = new EmptyBodyCheckingHttpInputMessage(inputMessage);
 
@@ -194,6 +194,11 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 		catch (IOException ex) {
 			throw new HttpMessageNotReadableException("I/O error while reading input message", ex, inputMessage);
 		}
+		finally {
+			if (message != null && message.hasBody()) {
+				closeStreamIfNecessary(message.getBody());
+			}
+		}
 
 		if (body == NO_VALUE) {
 			if (httpMethod == null || !SUPPORTED_METHODS.contains(httpMethod) ||
@@ -296,6 +301,15 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 		return arg;
 	}
 
+	/**
+	 * Allow for closing the body stream if necessary,
+	 * e.g. for part streams in a multipart request.
+	 */
+	void closeStreamIfNecessary(InputStream body) {
+		// No-op by default: A standard HttpInputMessage exposes the HTTP request stream
+		// (ServletRequest#getInputStream), with its lifecycle managed by the container.
+	}
+
 
 	private static class EmptyBodyCheckingHttpInputMessage implements HttpInputMessage {
 

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestPartMethodArgumentResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.web.servlet.mvc.method.annotation;
 
+import java.io.IOException;
+import java.io.InputStream;
 import java.util.List;
 
 import jakarta.servlet.http.HttpServletRequest;
@@ -180,4 +182,17 @@ public class RequestPartMethodArgumentResolver extends AbstractMessageConverterM
 		return partName;
 	}
 
+	@Override
+	void closeStreamIfNecessary(InputStream body) {
+		// RequestPartServletServerHttpRequest exposes individual part streams,
+		// potentially from temporary files -> explicit close call after resolution
+		// in order to prevent file descriptor leaks.
+		try {
+			body.close();
+		}
+		catch (IOException ex) {
+			// ignore
+		}
+	}
+
 }

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/RequestPartMethodArgumentResolverTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -16,6 +16,9 @@
 
 package org.springframework.web.servlet.mvc.method.annotation;
 
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
 import java.lang.reflect.Method;
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
@@ -82,6 +85,8 @@ public class RequestPartMethodArgumentResolverTests {
 
 	private MultipartFile multipartFile2;
 
+	private CloseTrackingInputStream trackedStream;
+
 	private MockMultipartHttpServletRequest multipartRequest;
 
 	private NativeWebRequest webRequest;
@@ -115,7 +120,14 @@ public class RequestPartMethodArgumentResolverTests {
 		reset(messageConverter);
 
 		byte[] content = "doesn't matter as long as not empty".getBytes(StandardCharsets.UTF_8);
-		multipartFile1 = new MockMultipartFile("requestPart", "", "text/plain", content);
+		multipartFile1 = new MockMultipartFile("requestPart", "", "text/plain", content) {
+			@Override
+			public InputStream getInputStream() throws IOException {
+				CloseTrackingInputStream in = new CloseTrackingInputStream(super.getInputStream());
+				trackedStream = in;
+				return in;
+			}
+		};
 		multipartFile2 = new MockMultipartFile("requestPart", "", "text/plain", content);
 		multipartRequest = new MockMultipartHttpServletRequest();
 		multipartRequest.addFile(multipartFile1);
@@ -181,8 +193,7 @@ public class RequestPartMethodArgumentResolverTests {
 	@Test
 	public void resolveMultipartFileList() throws Exception {
 		Object actual = resolver.resolveArgument(paramMultipartFileList, null, webRequest, null);
-		boolean condition = actual instanceof List;
+		assertThat(actual instanceof List).isTrue();
-		assertThat(condition).isTrue();
 		assertThat(actual).isEqualTo(Arrays.asList(multipartFile1, multipartFile2));
 	}
 
@@ -190,8 +201,7 @@ public class RequestPartMethodArgumentResolverTests {
 	public void resolveMultipartFileArray() throws Exception {
 		Object actual = resolver.resolveArgument(paramMultipartFileArray, null, webRequest, null);
 		assertThat(actual).isNotNull();
-		boolean condition = actual instanceof MultipartFile[];
+		assertThat(actual instanceof MultipartFile[]).isTrue();
-		assertThat(condition).isTrue();
 		MultipartFile[] parts = (MultipartFile[]) actual;
 		assertThat(parts.length).isEqualTo(2);
 		assertThat(multipartFile1).isEqualTo(parts[0]);
@@ -208,8 +218,7 @@ public class RequestPartMethodArgumentResolverTests {
 
 		Object result = resolver.resolveArgument(paramMultipartFileNotAnnot, null, webRequest, null);
 
-		boolean condition = result instanceof MultipartFile;
+		assertThat(result instanceof MultipartFile).isTrue();
-		assertThat(condition).isTrue();
 		assertThat(result).as("Invalid result").isEqualTo(expected);
 	}
 
@@ -224,8 +233,7 @@ public class RequestPartMethodArgumentResolverTests {
 		webRequest = new ServletWebRequest(request);
 
 		Object result = resolver.resolveArgument(paramPart, null, webRequest, null);
-		boolean condition = result instanceof Part;
+		assertThat(result instanceof Part).isTrue();
-		assertThat(condition).isTrue();
 		assertThat(result).as("Invalid result").isEqualTo(expected);
 	}
 
@@ -242,8 +250,7 @@ public class RequestPartMethodArgumentResolverTests {
 		webRequest = new ServletWebRequest(request);
 
 		Object result = resolver.resolveArgument(paramPartList, null, webRequest, null);
-		boolean condition = result instanceof List;
+		assertThat(result instanceof List).isTrue();
-		assertThat(condition).isTrue();
 		assertThat(result).isEqualTo(Arrays.asList(part1, part2));
 	}
 
@@ -260,8 +267,7 @@ public class RequestPartMethodArgumentResolverTests {
 		webRequest = new ServletWebRequest(request);
 
 		Object result = resolver.resolveArgument(paramPartArray, null, webRequest, null);
-		boolean condition = result instanceof Part[];
+		assertThat(result instanceof Part[]).isTrue();
-		assertThat(condition).isTrue();
 		Part[] parts = (Part[]) result;
 		assertThat(parts.length).isEqualTo(2);
 		assertThat(part1).isEqualTo(parts[0]);
@@ -356,8 +362,7 @@ public class RequestPartMethodArgumentResolverTests {
 		assertThat(((Optional<?>) actualValue).get()).as("Invalid result").isEqualTo(expected);
 
 		actualValue = resolver.resolveArgument(optionalMultipartFile, null, webRequest, null);
-		boolean condition = actualValue instanceof Optional;
+		assertThat(actualValue instanceof Optional).isTrue();
-		assertThat(condition).isTrue();
 		assertThat(((Optional<?>) actualValue).get()).as("Invalid result").isEqualTo(expected);
 	}
 
@@ -398,8 +403,7 @@ public class RequestPartMethodArgumentResolverTests {
 		assertThat(((Optional<?>) actualValue).get()).as("Invalid result").isEqualTo(Collections.singletonList(expected));
 
 		actualValue = resolver.resolveArgument(optionalMultipartFileList, null, webRequest, null);
-		boolean condition = actualValue instanceof Optional;
+		assertThat(actualValue instanceof Optional).isTrue();
-		assertThat(condition).isTrue();
 		assertThat(((Optional<?>) actualValue).get()).as("Invalid result").isEqualTo(Collections.singletonList(expected));
 	}
 
@@ -442,8 +446,7 @@ public class RequestPartMethodArgumentResolverTests {
 		assertThat(((Optional<?>) actualValue).get()).as("Invalid result").isEqualTo(expected);
 
 		actualValue = resolver.resolveArgument(optionalPart, null, webRequest, null);
-		boolean condition = actualValue instanceof Optional;
+		assertThat(actualValue instanceof Optional).isTrue();
-		assertThat(condition).isTrue();
 		assertThat(((Optional<?>) actualValue).get()).as("Invalid result").isEqualTo(expected);
 	}
 
@@ -488,8 +491,7 @@ public class RequestPartMethodArgumentResolverTests {
 		assertThat(((Optional<?>) actualValue).get()).as("Invalid result").isEqualTo(Collections.singletonList(expected));
 
 		actualValue = resolver.resolveArgument(optionalPartList, null, webRequest, null);
-		boolean condition = actualValue instanceof Optional;
+		assertThat(actualValue instanceof Optional).isTrue();
-		assertThat(condition).isTrue();
 		assertThat(((Optional<?>) actualValue).get()).as("Invalid result").isEqualTo(Collections.singletonList(expected));
 	}
 
@@ -571,6 +573,7 @@ public class RequestPartMethodArgumentResolverTests {
 		Object actualValue = resolver.resolveArgument(parameter, mavContainer, webRequest, new ValidatingBinderFactory());
 		assertThat(actualValue).as("Invalid argument value").isEqualTo(argValue);
 		assertThat(mavContainer.isRequestHandled()).as("The requestHandled flag shouldn't change").isFalse();
+		assertThat(trackedStream != null && trackedStream.closed).isTrue();
 	}
 
 
@@ -590,7 +593,7 @@ public class RequestPartMethodArgumentResolverTests {
 	}
 
 
-	private final class ValidatingBinderFactory implements WebDataBinderFactory {
+	private static class ValidatingBinderFactory implements WebDataBinderFactory {
 
 		@Override
 		public WebDataBinder createBinder(NativeWebRequest webRequest, @Nullable Object target,
@@ -605,6 +608,21 @@ public class RequestPartMethodArgumentResolverTests {
 	}
 
 
+	private static class CloseTrackingInputStream extends FilterInputStream {
+
+		public boolean closed = false;
+
+		public CloseTrackingInputStream(InputStream in) {
+			super(in);
+		}
+
+		@Override
+		public void close() {
+			this.closed = true;
+		}
+	}
+
+
 	@SuppressWarnings("unused")
 	public void handle(
 			@RequestPart SimpleBean requestPart,