Fix client disconnect logged as error in WebFlux

spring-web/src/main/java/org/springframework/web/server/adapter/HttpWebHandlerAdapter.java

@@ -362,15 +362,13 @@ private Mono<Void> handleUnresolvedError(
 		ServerHttpResponse response = exchange.getResponse();
 		String logPrefix = exchange.getLogPrefix();
 
-		// Sometimes a remote call error can look like a disconnected client.
-		// Try to set the response first before the "isDisconnectedClient" check.
-
-		if (response.setStatusCode(HttpStatus.INTERNAL_SERVER_ERROR)) {
-			logger.error(logPrefix + "500 Server Error for " + formatRequest(request), ex);
+		// Check for client disconnect first; DisconnectedClientHelper already excludes remote-call wrappers.
+		if (disconnectedClientHelper.checkAndLogClientDisconnectedException(ex)) {
+			observationContext.setConnectionAborted(true);
 			return Mono.empty();
 		}
-		else if (disconnectedClientHelper.checkAndLogClientDisconnectedException(ex)) {
-			observationContext.setConnectionAborted(true);
+		else if (response.setStatusCode(HttpStatus.INTERNAL_SERVER_ERROR)) {
+			logger.error(logPrefix + "500 Server Error for " + formatRequest(request), ex);
 			return Mono.empty();
 		}
 		else {

spring-web/src/test/java/org/springframework/web/server/adapter/HttpWebHandlerAdapterObservabilityTests.java

@@ -17,6 +17,7 @@
 package org.springframework.web.server.adapter;
 
 
+import java.io.IOException;
 import java.util.List;
 import java.util.Optional;
 
@@ -25,7 +26,10 @@
 import io.micrometer.observation.tck.TestObservationRegistry;
 import io.micrometer.observation.tck.TestObservationRegistryAssert;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
 import reactor.core.publisher.Mono;
+import reactor.netty.channel.AbortedException;
 import reactor.test.StepVerifier;
 
 import org.springframework.http.HttpStatus;
@@ -88,6 +92,36 @@ void handlerShouldRecordObservationWhenCancelled() {
 		assertThatHttpObservation().hasLowCardinalityKeyValue("outcome", "UNKNOWN");
 	}
 
+	@ParameterizedTest
+	@MethodSource("disconnectExceptions")
+	void handlerShouldMarkConnectionAbortedForClientDisconnect(Exception disconnectEx) {
+		// ThrowingExceptionWebHandler captures ServerRequestObservationContext from exchange
+		// attributes; handleUnresolvedError operates on the same object, so setConnectionAborted(true)
+		// is visible after block().
+		ThrowingExceptionWebHandler throwingHandler = new ThrowingExceptionWebHandler(disconnectEx);
+		createWebHandler(throwingHandler).handle(this.request, this.response).block();
+		assertThat(throwingHandler.observationContext).isPresent();
+		assertThat(throwingHandler.observationContext.get().isConnectionAborted()).isTrue();
+	}
+
+	static List<Exception> disconnectExceptions() {
+		// Verified by DisconnectedClientHelperTests.disconnectedExceptions() and exceptionPhrases()
+		return List.of(
+				new AbortedException(""),
+				new IOException("Broken pipe")
+		);
+	}
+
+	@Test
+	void handlerShouldNotMarkConnectionAbortedForServerError() {
+		ThrowingExceptionWebHandler throwingHandler =
+				new ThrowingExceptionWebHandler(new IllegalStateException("server error"));
+		createWebHandler(throwingHandler).handle(this.request, this.response).block();
+		assertThat(throwingHandler.observationContext).isPresent();
+		assertThat(throwingHandler.observationContext.get().isConnectionAborted()).isFalse();
+		assertThat(this.response.getStatusCode()).isEqualTo(HttpStatus.INTERNAL_SERVER_ERROR);
+	}
+
 	private HttpWebHandlerAdapter createWebHandler(WebHandler targetHandler) {
 		HttpWebHandlerAdapter handlerAdapter = new HttpWebHandlerAdapter(targetHandler);
 		handlerAdapter.setObservationRegistry(this.observationRegistry);