Catch EOFException in IntrospectingClientHttpResponse

Prior to this commit, the `IntrospectingClientHttpResponse` would try
and read the HTTP response stream in order to check for the presence of
a non-empty message body.

Developers reported that in some cases, an `EOFException` is thrown
instead of returning -1 from the `read()` method. This commit ensures
that this case is taken into account and that we report the response as
an empty body in these cases.

Closes gh-35361

spring-web/src/test/java/org/springframework/web/client/IntrospectingClientHttpResponseTests.java

@@ -17,11 +17,18 @@
 package org.springframework.web.client;
 
 import java.io.ByteArrayInputStream;
+import java.io.EOFException;
 import java.io.InputStream;
+import java.util.stream.Stream;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
 
+import org.springframework.http.HttpStatus;
+import org.springframework.http.HttpStatusCode;
 import org.springframework.http.client.ClientHttpResponse;
+import org.springframework.web.testfixture.http.client.MockClientHttpResponse;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.BDDMockito.given;
@@ -30,27 +37,57 @@ import static org.mockito.Mockito.mock;
 /**
  * Tests for {@link IntrospectingClientHttpResponse}.
  *
- * @since 5.3.10
- * @author Yin-Jui Liao
+ * @author Brian Clozel
  */
 class IntrospectingClientHttpResponseTests {
 
-	private final ClientHttpResponse response = mock();
 
-	private final IntrospectingClientHttpResponse wrappedResponse = new IntrospectingClientHttpResponse(response);
+	@ParameterizedTest
+	@MethodSource("noBodyHttpStatus")
+	void noMessageBodyWhenStatus(HttpStatus status) throws Exception {
+		var response = new MockClientHttpResponse(new byte[0], status);
+		var wrapped = new IntrospectingClientHttpResponse(response);
 
+		assertThat(wrapped.hasMessageBody()).isFalse();
+	}
+
+	static Stream<HttpStatusCode> noBodyHttpStatus() {
+		return Stream.of(HttpStatus.NO_CONTENT, HttpStatus.EARLY_HINTS, HttpStatus.NOT_MODIFIED);
+	}
 
 	@Test
-	void messageBodyDoesNotExist() throws Exception {
-		given(response.getBody()).willReturn(null);
-		assertThat(wrappedResponse.hasEmptyMessageBody()).isTrue();
+	void noMessageBodyWhenContentLength0() throws Exception {
+		var response = new MockClientHttpResponse(new byte[0], HttpStatus.OK);
+		response.getHeaders().setContentLength(0);
+		var wrapped = new IntrospectingClientHttpResponse(response);
+
+		assertThat(wrapped.hasMessageBody()).isFalse();
+	}
+
+	@Test
+	void emptyMessageWhenNullInputStream() throws Exception {
+		ClientHttpResponse mockResponse = mock();
+		given(mockResponse.getBody()).willReturn(null);
+		var wrappedMock = new IntrospectingClientHttpResponse(mockResponse);
+		assertThat(wrappedMock.hasEmptyMessageBody()).isTrue();
 	}
 
 	@Test
 	void messageBodyExists() throws Exception {
-		InputStream stream = new ByteArrayInputStream("content".getBytes());
-		given(response.getBody()).willReturn(stream);
-		assertThat(wrappedResponse.hasEmptyMessageBody()).isFalse();
+		var stream = new ByteArrayInputStream("content".getBytes());
+		var response = new MockClientHttpResponse(stream, HttpStatus.OK);
+		var wrapped = new IntrospectingClientHttpResponse(response);
+		assertThat(wrapped.hasEmptyMessageBody()).isFalse();
+	}
+
+	@Test
+	void emptyMessageWhenEOFException() throws Exception {
+		ClientHttpResponse mockResponse = mock();
+		InputStream stream = mock();
+		given(mockResponse.getBody()).willReturn(stream);
+		given(stream.read()).willThrow(new EOFException());
+		var wrappedMock = new IntrospectingClientHttpResponse(mockResponse);
+		assertThat(wrappedMock.hasEmptyMessageBody()).isTrue();
 	}
 
 }