tree bc34910424167c68c976dd643d8b4f74e9a215c3
parent fd0948a1fd73cd775d1f4101399b4b8c796b9b00
author Alessandro Ghedini <alessandro@ghedini.me> 1603458037 +0100
committer Alessandro Ghedini <alessandro@ghedini.me> 1603460691 +0100

don't count dup data towards flow control limit

Currently we use the "raw" received STREAM frame length to check that
received data doesn't exceed the connection-level flow control limit.

However it can happen that the same data is received in two different
overlapping STREAM frames. In the current implementation this data ends
up being counted twice towards the flow control limit.

Instead use the difference between the frame's maximum offset and the
stream's maximum received offset.

This is consistent with §19.9 of the -transport draft:

   The sum of the final sizes on all streams - including streams in
   terminal states - MUST NOT exceed the value advertised by a receiver.