[HTTP/2] Reading data assert

[ManickaP]

https://github.com/dotnet/runtime/blame/a566fd59fc34d3f73da1b8eeaab613ab0c1fc9b5/src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Stream.cs#L1127-L1127

With a recent repro from an internal customer, I'm hitting assert at this line as I'm testing with Debug build. I can share repro privately.

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/ncl
See info in area-owners.md if you want to be subscribed.

[ManickaP]

So the problem is the server sending DATA frame containing only padding and no data at all. We do not handle this case at all and we will unblock the user pending read with 0-bytes read (despite not being at the end of the stream).

[karelz]

Fixed in main (9.0) in PR #99502, in 6.0.30 in PR #99678 and in 8.0.5 in PR #99677