Occassionally with HTTP2, server does not send "End Stream" flag as True when all the data has been sent in response

[saudawar]

Hypercorn Version: 0.16.0
Python Version: 3.9.18
Operating system: Oracle linux 8
Environment: Kubernetes

We have observed that when HTTP2 protocol is used, then server occassionally does not set the "End Stream" in the last datagram of the response.

From application point of view, complete data (JSON formatted) has been sent over multiple datagrams. It is expected that the server must set End Stream flag to True to indicate to client that complete data has been sent but this is not observed some times.

This has mostly been observed when response data size is large and spans over multiple datagrams as depicted in the attached screenshot.

In packet 4256, all the data is complete as verified from the sent bytes but the appropriate flags are not set.