This adds a `SendRequestExt` trait to h2-support, with a `get` method
that does a lot of the repeated request building stuff many test cases
were doing.
As a first step, the cleans up stream_states tests to use it.
[Trailers without EOS](https://httpwg.org/specs/rfc7540.html#HttpSequence):
> An endpoint that receives a HEADERS frame without the END_STREAM flag set after receiving a final (non-informational) status code MUST treat the corresponding request or response as malformed (Section 8.1.2.6).
[Malformed messages](https://httpwg.org/specs/rfc7540.html#malformed):
> Malformed requests or responses that are detected MUST be treated as a stream error (Section 5.4.2) of type PROTOCOL_ERROR.
Currently, there are many cases where `h2` will fail a connection or
stream with a PROTOCOL_ERROR, without recording why the protocol error
occurred. Since protocol errors may result from a bug in `h2` or from a
misbehaving peer, it is important to be able to debug the cause of
protocol errors.
This branch adds a log line to almost all cases where a protocol error
occurs. I've tried to make the new log lines consistent with the
existing logging, and in some cases, changed existing log lines to make
them internally consistent with other log lines in that module. All
receive-side errors that would send a reset are now logged at the debug
level, using a formatting based on the format used in `framed_read`.
Signed-off-by: Eliza Weisman <eliza@buoyant.io>
- Removes incrementing counter, instead just using the StreamId as a
slab ABA guard.
- Adjusts Ptr::deref to use Store::index, as before it was skipping to
check the ABA guard.
- Rename fields and types to clarify it actually is an ABA guard.
- Improve panic message in case a dangling Ptr is accessed.
