Response not ended on edge error cases (#2909) (#2915)

* Always end the response

* Add tests

* Reset connection in case of already written response

* Test headWritten then reset the connction rather than catching an exception

* Renaming

* Fix imports

* Fix style

* Fix style

* Fix style

Co-authored-by: olivierayache <olivier.ayache@gmail.com>

Author: tsegismont

vertx-web/src/main/java/io/vertx/ext/web/impl/RoutingContextImplBase.java

@@ -256,14 +256,21 @@ protected void unhandledFailure(int statusCode, Throwable failure, RouterImpl ro
 
     if (!response().ended() && !response().closed()) {
       try {
-        response().setStatusCode(code);
+        if (response().headWritten()) {
+          response().reset(code);
+        } else {
+          response().setStatusCode(code);
+        }
       } catch (IllegalArgumentException e) {
         // means that there are invalid chars in the status message
         response()
             .setStatusMessage(HttpResponseStatus.valueOf(code).reasonPhrase())
             .setStatusCode(code);
+      } finally {
+        if (!response().headWritten()) {
+          response().end(response().getStatusMessage());
+        }
       }
-      response().end(response().getStatusMessage());
     }
   }
 

vertx-web/src/test/java/io/vertx/ext/web/handler/BodyHandlerTest.java

@@ -21,6 +21,7 @@
 import io.vertx.core.buffer.Buffer;
 import io.vertx.core.http.HttpHeaders;
 import io.vertx.core.http.HttpMethod;
+import io.vertx.core.http.HttpServerResponse;
 import io.vertx.core.http.RequestOptions;
 import io.vertx.core.json.JsonObject;
 import io.vertx.ext.web.FileUpload;
@@ -39,6 +40,7 @@
 import java.util.Base64;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Function;
 
 /**
@@ -432,6 +434,42 @@ private void sendFileUploadRequest(Buffer fileData,
     }, statusCode, statusMessage, null);
   }
 
+  @Test
+  public void testRoutingContextFailedBeforeDownloaded() throws Exception {
+    router.get("/failed-download")
+      .handler((e) -> {
+        HttpServerResponse response = e.response();
+        response.setChunked(true);
+        response.putHeader(HttpHeaders.CONTENT_TYPE, "application/octet-stream");
+        AtomicInteger count = new AtomicInteger();
+        vertx.setPeriodic(200, id -> {
+          response.write(Buffer.buffer(new byte[1024]));
+          if (count.incrementAndGet() == 5) {
+            vertx.cancelTimer(id);
+            e.fail(500, new RuntimeException("Download exception"));
+          }
+        });
+      });
+
+    RequestOptions requestOptions = new RequestOptions()
+      .setHost("localhost")
+      .setPort(8080)
+      .setMethod(HttpMethod.GET)
+      .setURI("/failed-download");
+
+    client.request(requestOptions).onComplete(onSuccess(req -> {
+      req.response(onSuccess(resp -> {
+        assertEquals(200, resp.statusCode());
+        resp.exceptionHandler(t -> {
+          testComplete();
+        });
+      }));
+      req.end();
+    }));
+
+    await();
+  }
+
   @Test
   public void testRoutingContextFailedBeforeFileIsFullyUploaded() throws Exception {
     String uploadsDirectory = tempUploads.newFolder().getPath();