Fix filtered HTTP headers in data binding

Prior to this commit, several common HTTP headers were ignored from the
data binding process when collecting property values, in gh-34039 and
gh-34182.

This commit completes the initial enhancement by ensuring that the
default header predicate is also considering cases where constructor
binding is applied and the Java type has a lowercase variant of the HTTP
header name to filter.

Fixes gh-34292

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/ExtendedWebExchangeDataBinder.java

@@ -17,6 +17,7 @@
 package org.springframework.web.reactive.result.method.annotation;
 
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.function.Predicate;
@@ -43,11 +44,11 @@
  */
 public class ExtendedWebExchangeDataBinder extends WebExchangeDataBinder {
 
-	private static final Set<String> FILTERED_HEADER_NAMES = Set.of("Accept", "Authorization", "Connection",
-			"Cookie", "From", "Host", "Origin", "Priority", "Range", "Referer", "Upgrade");
+	private static final Set<String> FILTERED_HEADER_NAMES = Set.of("accept", "authorization", "connection",
+			"cookie", "from", "host", "origin", "priority", "range", "referer", "upgrade");
 
 
-	private Predicate<String> headerPredicate = name -> !FILTERED_HEADER_NAMES.contains(name);
+	private Predicate<String> headerPredicate = name -> !FILTERED_HEADER_NAMES.contains(name.toLowerCase(Locale.ROOT));
 
 
 	public ExtendedWebExchangeDataBinder(@Nullable Object target, String objectName) {

spring-webflux/src/test/java/org/springframework/web/reactive/result/method/annotation/InitBinderBindingContextTests.java

@@ -224,7 +224,7 @@ void headerPredicate() throws Exception {
 
 	@ParameterizedTest
 	@ValueSource(strings = {"Accept", "Authorization", "Connection",
-			"Cookie", "From", "Host", "Origin", "Priority", "Range", "Referer", "Upgrade"})
+			"Cookie", "From", "Host", "Origin", "Priority", "Range", "Referer", "Upgrade", "priority"})
 	void filteredHeaders(String headerName) throws Exception {
 		MockServerHttpRequest request = MockServerHttpRequest.get("/path")
 				.header(headerName, "u1")

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

@@ -19,6 +19,7 @@
 import java.util.ArrayList;
 import java.util.Enumeration;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.function.Predicate;
@@ -39,7 +40,7 @@
  *
  * <p><strong>WARNING</strong>: Data binding can lead to security issues by exposing
  * parts of the object graph that are not meant to be accessed or modified by
- * external clients. Therefore the design and use of data binding should be considered
+ * external clients. Therefore, the design and use of data binding should be considered
  * carefully with regard to security. For more details, please refer to the dedicated
  * sections on data binding for
  * <a href="https://docs.spring.io/spring-framework/docs/current/reference/html/web.html#mvc-ann-initbinder-model-design">Spring Web MVC</a> and
@@ -53,11 +54,11 @@
  */
 public class ExtendedServletRequestDataBinder extends ServletRequestDataBinder {
 
-	private static final Set<String> FILTERED_HEADER_NAMES = Set.of("Accept", "Authorization", "Connection",
-			"Cookie", "From", "Host", "Origin", "Priority", "Range", "Referer", "Upgrade");
+	private static final Set<String> FILTERED_HEADER_NAMES = Set.of("accept", "authorization", "connection",
+			"cookie", "from", "host", "origin", "priority", "range", "referer", "upgrade");
 
 
-	private Predicate<String> headerPredicate = name -> !FILTERED_HEADER_NAMES.contains(name);
+	private Predicate<String> headerPredicate = name -> !FILTERED_HEADER_NAMES.contains(name.toLowerCase(Locale.ROOT));
 
 
 	/**

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

@@ -27,6 +27,7 @@
 import org.springframework.beans.MutablePropertyValues;
 import org.springframework.beans.testfixture.beans.TestBean;
 import org.springframework.core.ResolvableType;
+import org.springframework.validation.BindingResult;
 import org.springframework.web.bind.ServletRequestDataBinder;
 import org.springframework.web.bind.annotation.BindParam;
 import org.springframework.web.bind.support.BindParamNameResolver;
@@ -36,7 +37,7 @@
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
- * Test fixture for {@link ExtendedServletRequestDataBinder}.
+ * Tests for {@link ExtendedServletRequestDataBinder}.
  *
  * @author Rossen Stoyanchev
  */
@@ -136,6 +137,19 @@ void headerPredicateWithConstructorArgs() {
 		assertThat(bean.someIntArray()).isNull();
 	}
 
+	@Test
+	void filteredPriorityHeaderForConstructorBinding() {
+		TestBinder binder = new TestBinder();
+		binder.setTargetType(ResolvableType.forClass(TestTarget.class));
+		request.addHeader("Priority", "u1");
+
+		binder.construct(request);
+		BindingResult result = binder.getBindingResult();
+		TestTarget target = (TestTarget) result.getTarget();
+
+		assertThat(target.priority).isNull();
+	}
+
 	@Test
 	void headerPredicate() {
 		TestBinder binder = new TestBinder();
@@ -179,4 +193,14 @@ public void addBindValues(MutablePropertyValues mpvs, ServletRequest request) {
 		}
 	}
 
+	static class TestTarget {
+
+		final String priority;
+
+		public TestTarget(String priority) {
+			this.priority = priority;
+		}
+
+	}
+
 }