HandlerMappingIntrospector handles attribute changes properly

Closes gh-26833

spring-webmvc/src/test/java/org/springframework/web/servlet/handler/HandlerMappingIntrospectorTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 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 +40,10 @@ import org.springframework.web.context.support.StaticWebApplicationContext;
 import org.springframework.web.cors.CorsConfiguration;
 import org.springframework.web.servlet.HandlerExecutionChain;
 import org.springframework.web.servlet.HandlerMapping;
+import org.springframework.web.servlet.function.RouterFunction;
+import org.springframework.web.servlet.function.RouterFunctions;
+import org.springframework.web.servlet.function.ServerResponse;
+import org.springframework.web.servlet.function.support.RouterFunctionMapping;
 import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping;
 import org.springframework.web.testfixture.servlet.MockHttpServletRequest;
 import org.springframework.web.util.ServletRequestPathUtils;
@@ -99,16 +103,6 @@ public class HandlerMappingIntrospectorTests {
 		assertThat(actual).isEqualTo(expected);
 	}
 
-	void defaultHandlerMappings() {
-		StaticWebApplicationContext context = new StaticWebApplicationContext();
-		context.refresh();
-		List<HandlerMapping> actual = initIntrospector(context).getHandlerMappings();
-
-		assertThat(actual.size()).isEqualTo(2);
-		assertThat(actual.get(0).getClass()).isEqualTo(BeanNameUrlHandlerMapping.class);
-		assertThat(actual.get(1).getClass()).isEqualTo(RequestMappingHandlerMapping.class);
-	}
-
 	@ParameterizedTest
 	@ValueSource(booleans = {true, false})
 	void getMatchable(boolean usePathPatterns) throws Exception {
@@ -151,6 +145,22 @@ public class HandlerMappingIntrospectorTests {
 		assertThatIllegalStateException().isThrownBy(() -> initIntrospector(cxt).getMatchableHandlerMapping(request));
 	}
 
+	@Test // gh-26833
+	void getMatchablePreservesRequestAttributes() throws Exception {
+		AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
+		context.register(TestConfig.class);
+		context.refresh();
+
+		MockHttpServletRequest request = new MockHttpServletRequest("POST", "/path");
+		request.setAttribute("name", "value");
+
+		MatchableHandlerMapping matchable = initIntrospector(context).getMatchableHandlerMapping(request);
+		assertThat(matchable).isNotNull();
+
+		// RequestPredicates.restoreAttributes clears and re-adds attributes
+		assertThat(request.getAttribute("name")).isEqualTo("value");
+	}
+
 	@Test
 	void getCorsConfigurationPreFlight() {
 		AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
@@ -204,15 +214,29 @@ public class HandlerMappingIntrospectorTests {
 	@Configuration
 	static class TestConfig {
 
+		@Bean
+		public RouterFunctionMapping routerFunctionMapping() {
+			RouterFunctionMapping mapping = new RouterFunctionMapping();
+			mapping.setOrder(1);
+			return mapping;
+		}
+
 		@Bean
 		public RequestMappingHandlerMapping handlerMapping() {
-			return new RequestMappingHandlerMapping();
+			RequestMappingHandlerMapping mapping = new RequestMappingHandlerMapping();
+			mapping.setOrder(2);
+			return mapping;
 		}
 
 		@Bean
 		public TestController testController() {
 			return new TestController();
 		}
+
+		@Bean
+		public RouterFunction<?> routerFunction() {
+			return RouterFunctions.route().GET("/fn-path", request -> ServerResponse.ok().build()).build();
+		}
 	}