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.
Previously, any streams that were dropped or closed while not having
consumed the inflight received window capacity would simply leak that
capacity for the connection. This could easily happen if a `RecvStream`
were dropped before fully consuming the data, and therefore a user would
have no idea how much capacity to release in the first place. This
resulted in stalled connections that would never have capacity again.
I believe this was an oversight - a stream that is reset can still have some
capacity assigned to it (e.g. if said capacity was assigned in the same poll as
the reset), which should be redistributed.
Because `send_reset` called `recv_err`, which calls `reclaim_all_capacity`,
which eventually calls `transition(stream, ..)` -- all of which happens _before_
the RESET frame is enqueued -- it was possible for the stream to get unlinked
from the store (if there was any connection-level capacity to reassign). This
could then cause the stream to get "leaked" on drop/EOF since it would no longer
be iterated.
Fix this by delaying the call to `reclaim_all_capacity` _after_ enqueueing the
RESET frame.
A test demonstrating the issue is included.
* Prevent `pending_open` streams from being released.
This fixes a panic that would otherwise occur in some cases. A test
demonstrating said panic is included.
* Clear the pending_open queue together with everything else.
There was a race condition in the test where the server connection
sometimes closed before the final client opereation. This triggered an
unwrap in the test.
This patch updates the test to ensuree that the mock server connection
stays open until the client test is complete.
