http2: update checks for adding rst_stream to pending list

Author: kumarak

src/node_http2.cc

@@ -2196,11 +2196,13 @@ void Http2Stream::SubmitRstStream(const uint32_t code) {
   CHECK(!this->is_destroyed());
   code_ = code;
 
-  // If RST_STREAM is submitted with the cancel code, don't force purge the
-  // currently sending data. Instead add it to the pending stream list to
-  // avoid prioritizing over other operations.
+  // If RST_STREAM frame is received and stream is not writable
+  // because it is busy reading data, don't try force purging it.
+  // Instead add the stream to pending stream list and process
+  // the pending data when it is safe to do so. This is to avoid
+  // double free error due to unwanted behavior of nghttp2.
   // Ref:https://github.com/nodejs/node/issues/38964
-  if (code_ == NGHTTP2_CANCEL) {
+  if (!is_writable() && is_reading()) {
     session_->AddPendingRstStream(id_);
     return;
   }