IntrospectingClientHttpResponse#hasEmptyMessageBody

should not throw an exception when the response body
is an empty lazy gzip stream.

spring-web/src/main/java/org/springframework/web/client/IntrospectingClientHttpResponse.java

@@ -16,6 +16,8 @@
 
 package org.springframework.web.client;
 
+import java.io.ByteArrayInputStream;
+import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.PushbackInputStream;
@@ -96,14 +98,20 @@ public boolean hasEmptyMessageBody() throws IOException {
 			}
 		}
 		else {
-			this.pushbackInputStream = new PushbackInputStream(body);
-			int b = this.pushbackInputStream.read();
-			if (b == -1) {
-				return true;
+			try {
+				this.pushbackInputStream = new PushbackInputStream(body);
+				int b = this.pushbackInputStream.read();
+				if (b == -1) {
+					return true;
+				}
+				else {
+					this.pushbackInputStream.unread(b);
+					return false;
+				}
 			}
-			else {
-				this.pushbackInputStream.unread(b);
-				return false;
+			catch (EOFException ex) {
+				this.pushbackInputStream = new PushbackInputStream(new ByteArrayInputStream(new byte[0]));
+				return true;
 			}
 		}
 	}

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

@@ -18,9 +18,11 @@
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.lang.reflect.Type;
 import java.util.Arrays;
 import java.util.List;
+import java.util.zip.GZIPInputStream;
 
 import org.junit.jupiter.api.Test;
 
@@ -114,6 +116,22 @@ void emptyMessageBody() throws IOException {
 		assertThat(result).isNull();
 	}
 
+	@Test
+	void emptyLazyGzipMessageBody() throws IOException {
+		given(response.getStatusCode()).willReturn(HttpStatus.BAD_REQUEST);
+		given(response.getHeaders()).willReturn(responseHeaders);
+		given(response.getBody()).willReturn(new InputStream() {
+			@Override
+			public int read() throws IOException {
+				// Simulates lazy gzip stream reading
+				return new GZIPInputStream(new ByteArrayInputStream("".getBytes())).read();
+			}
+		});
+
+		Object result = extractor.extractData(response);
+		assertThat(result).isNull();
+	}
+
 	@Test // gh-22265
 	void nullMessageBody() throws IOException {
 		given(response.getStatusCode()).willReturn(HttpStatus.OK);