http2: don't send trailers on a closed connection

There is a race condition between onStreamCloseResponse(), which removes the wantTrailers listener, and Http2Stream.close(), which will invalidate the connection. IE, sendTrailers can be called on a closed connection which would crash with a: Error [ERR_HTTP2_INVALID_STREAM]: The stream has been destroyed PR-URL: #23146 Reviewed-By: James M Snell <[email protected]> Reviewed-By: Trivikram Kamat <[email protected]>

Author: edevil

lib/internal/http2/core.js

@@ -330,7 +330,7 @@ function tryClose(fd){
 functiononStreamTrailers(){
 conststream=this[kOwner];
 stream[kState].trailersReady=true;
-if(stream.destroyed)
+if(stream.destroyed||stream.closed)
 return;
 if(!stream.emit('wantTrailers')){
 // There are no listeners, send empty trailing HEADERS frame and close.