Merge branch '2.1.x'

Closes gh-17552

spring-boot-project/spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/web/servlet/MockMvcPrintOnlyOnFailureTestExecutionListener.java

@@ -36,11 +36,12 @@ class MockMvcPrintOnlyOnFailureTestExecutionListener extends AbstractTestExecuti
 
 	@Override
 	public void afterTestMethod(TestContext testContext) throws Exception {
-		if (testContext.getTestException() != null) {
-			DeferredLinesWriter writer = DeferredLinesWriter.get(testContext.getApplicationContext());
-			if (writer != null) {
+		DeferredLinesWriter writer = DeferredLinesWriter.get(testContext.getApplicationContext());
+		if (writer != null) {
+			if (testContext.getTestException() != null) {
 				writer.writeDeferredResult();
 			}
+			writer.clear();
 		}
 
 	}

spring-boot-project/spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/web/servlet/SpringBootMockMvcBuilderCustomizer.java

@@ -253,6 +253,10 @@ public class SpringBootMockMvcBuilderCustomizer implements MockMvcBuilderCustomi
 			}
 		}
 
+		void clear() {
+			this.lines.clear();
+		}
+
 	}
 
 	/**

spring-boot-project/spring-boot-test-autoconfigure/src/test/java/org/springframework/boot/test/autoconfigure/web/servlet/mockmvc/WebMvcTestPrintDefaultIntegrationTests.java

@@ -16,7 +16,9 @@
 
 package org.springframework.boot.test.autoconfigure.web.servlet.mockmvc;
 
+import org.junit.jupiter.api.MethodOrderer;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.TestMethodOrder;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.junit.platform.engine.discovery.DiscoverySelectors;
 
@@ -43,6 +45,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
  * @author Andy Wilkinson
  */
 @ExtendWith(OutputCaptureExtension.class)
+@TestMethodOrder(MethodOrderer.Alphanumeric.class)
 class WebMvcTestPrintDefaultIntegrationTests {
 
 	@Test
@@ -54,7 +57,7 @@ class WebMvcTestPrintDefaultIntegrationTests {
 	@Test
 	void shouldPrint(CapturedOutput output) throws Throwable {
 		executeTests(ShouldPrint.class);
-		assertThat(output).contains("HTTP Method");
+		assertThat(output).containsOnlyOnce("HTTP Method");
 	}
 
 	private void executeTests(Class<?> testClass) throws Throwable {