Restore thread interrupt flag in DefaultMvcResult

awaitAsyncDispatch() catches InterruptedException, returns false, and
discards the interruption. Catching InterruptedException without
rethrowing should restore the interrupt status (as is done across the
framework's main sources), so re-assert it before returning false.

Closes gh-36876

Signed-off-by: leestana01 <leestana01@naver.com>

spring-test/src/test/java/org/springframework/test/web/servlet/DefaultMvcResultTests.java

@@ -22,6 +22,7 @@ import org.junit.jupiter.api.Test;
 
 import org.springframework.mock.web.MockHttpServletRequest;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
@@ -46,4 +47,19 @@ class DefaultMvcResultTests {
 				this.mvcResult.getAsyncResult(0));
 	}
 
+	@Test
+	void getAsyncResultRestoresInterruptStatusWhenInterrupted() {
+		this.mvcResult.setAsyncDispatchLatch(new CountDownLatch(1));
+		Thread.currentThread().interrupt();
+		try {
+			assertThatIllegalStateException().isThrownBy(() ->
+					this.mvcResult.getAsyncResult(1000));
+			assertThat(Thread.currentThread().isInterrupted()).isTrue();
+		}
+		finally {
+			// Clear the interrupt status so it does not leak to other tests.
+			Thread.interrupted();
+		}
+	}
+
 }