Major Description
Padded DATA frames lead to PROTOCOL_ERROR because of wrong data size calculation.
https://github.com/apache/trafficserver/blob/6.0.x/proxy/http2/Http2ConnectionState.cc#L88
The size should be sum of real data sizes without padding but not payload sizes.
How to reproduce:
$ nghttp -v --padding=123 -d foo http://localhost:8080/