Fix NPE when GzipHandler is writing and an exception is thrown by the wrapping's Response.write()

jetty-core/jetty-server/src/main/java/org/eclipse/jetty/server/handler/gzip/GzipResponseAndCallback.java

@@ -326,6 +326,7 @@ protected void onCompleteFailure(Throwable x)
         {
             if (_deflaterEntry != null)
             {
+                _state.set(GZState.FINISHED);
                 _deflaterEntry.release();
                 _deflaterEntry = null;
             }
@@ -381,6 +382,7 @@ private void cleanup()
         {
             if (_deflaterEntry != null)
             {
+                _state.set(GZState.FINISHED);
                 _deflaterEntry.release();
                 _deflaterEntry = null;
             }

jetty-core/jetty-server/src/test/java/org/eclipse/jetty/server/handler/gzip/GzipHandlerTest.java

@@ -59,6 +59,7 @@
 import org.eclipse.jetty.server.Server;
 import org.eclipse.jetty.server.ServerConnector;
 import org.eclipse.jetty.server.handler.ContextHandler;
+import org.eclipse.jetty.server.handler.ErrorHandler;
 import org.eclipse.jetty.server.handler.ResourceHandler;
 import org.eclipse.jetty.toolchain.test.FS;
 import org.eclipse.jetty.toolchain.test.MavenPaths;
@@ -194,6 +195,61 @@ public void init() throws Exception
         _gzipHandler.setHandler(_contextHandler);
     }
 
+    @Test
+    public void testFailureDuringGzipWrite() throws Exception
+    {
+        Handler leafHandler = new Handler.Abstract()
+        {
+            @Override
+            public boolean handle(Request request, Response response, Callback callback) throws Exception
+            {
+                try (var out = Content.Sink.asOutputStream(response))
+                {
+                    out.write("Hello, Jetty".getBytes(StandardCharsets.UTF_8));
+                }
+                return true;
+            }
+        };
+        Handler rootHandler = new Handler.Wrapper(new GzipHandler(leafHandler))
+        {
+            @Override
+            public boolean handle(Request request, Response response, Callback callback) throws Exception
+            {
+                return super.handle(request, new Response.Wrapper(request, response)
+                {
+                    @Override
+                    public void write(boolean last, ByteBuffer byteBuffer, Callback callback)
+                    {
+                        throw new StacklessException("expected");
+                    }
+                }, callback);
+            }
+        };
+        _server.setHandler(rootHandler);
+        ErrorHandler errorHandler = new ErrorHandler();
+        errorHandler.setShowStacks(true);
+        errorHandler.setShowCauses(true);
+        _server.setErrorHandler(errorHandler);
+        _server.start();
+
+        // generated and parsed test
+        HttpTester.Request request = HttpTester.newRequest();
+        HttpTester.Response response;
+
+        request.setMethod("GET");
+        request.setURI("/");
+        request.setVersion("HTTP/1.0");
+        request.setHeader("Host", "tester");
+        request.setHeader("accept-encoding", "gzip");
+
+        response = HttpTester.parseResponse(_connector.getResponse(request.generate()));
+
+        assertThat(response.getStatus(), is(500));
+        String content = response.getContent();
+        assertThat(content, containsString("StacklessException: expected"));
+        assertThat(content, not(containsString("Suppressed: ")));
+    }
+
     @Test
     public void testAddIncludePaths()
     {
@@ -2053,4 +2109,18 @@ else if (request.getLength() >= 0)
             return super.handle(request, response, callback);
         }
     }
+
+    public static class StacklessException extends RuntimeException
+    {
+        public StacklessException(String message)
+        {
+            super(message);
+        }
+
+        @Override
+        public synchronized Throwable fillInStackTrace()
+        {
+            return this;
+        }
+    }
 }