http2: handle errors on compat push response streams

lib/internal/http2/compat.js

@@ -162,9 +162,9 @@ function onStreamEnd() {
 
 function onStreamError(error) {
   // Mirror HTTP/1's IncomingMessage._destroy: forward 'error' to req
-  // only when a listener is attached.
+  // only when a listener is attached. Pushed streams have no request.
   const request = this[kRequest];
-  if (request !== undefined && request.listenerCount('error') > 0)
+  if (request != null && request.listenerCount('error') > 0)
     request.emit('error', error);
 }
 
@@ -928,6 +928,10 @@ class Http2ServerResponse extends Stream {
         callback(err);
         return;
       }
+      // Pushed streams have no Http2ServerRequest to install the stream
+      // 'error' handler, so attach it here. Otherwise a peer refusing the
+      // push (e.g. RST_STREAM with REFUSED_STREAM) would crash the process.
+      stream.on('error', onStreamError);
       callback(null, new Http2ServerResponse(stream));
     });
   }

test/parallel/test-http2-compat-serverresponse-createpushresponse-refused.js

@@ -0,0 +1,48 @@
+'use strict';
+
+const common = require('../common');
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+
+// A client refusing a push created through the compat API with
+// RST_STREAM(REFUSED_STREAM) must not crash the server with an unhandled
+// 'error' event on the pushed stream.
+
+const assert = require('assert');
+const http2 = require('http2');
+
+const server = http2.createServer(common.mustCall((req, res) => {
+  res.createPushResponse({ ':path': '/style.css' }, common.mustSucceed((pushRes) => {
+    pushRes.on('close', common.mustCall());
+    pushRes.setHeader('content-type', 'text/css');
+    pushRes.end('body { color: red }');
+  }));
+  res.end('hello');
+}));
+
+server.listen(0, common.mustCall(() => {
+  // A zero initial window keeps the pushed body from completing before the
+  // client refuses it, so the server sees a peer reset with its writable
+  // side still pending.
+  const client = http2.connect(`http://localhost:${server.address().port}`, {
+    settings: { initialWindowSize: 0 },
+  });
+
+  client.on('stream', common.mustCall((pushed) => {
+    pushed.on('error', common.expectsError({
+      code: 'ERR_HTTP2_STREAM_ERROR',
+    }));
+    pushed.close(http2.constants.NGHTTP2_REFUSED_STREAM);
+    // Reopen the window so the main response can complete.
+    client.settings({ initialWindowSize: 65535 });
+  }));
+
+  const req = client.request({ ':path': '/' });
+  req.resume();
+  req.on('close', common.mustCall(() => {
+    assert.strictEqual(req.rstCode, http2.constants.NGHTTP2_NO_ERROR);
+    client.close();
+    server.close();
+  }));
+  req.end();
+}));