http2: avoid Transport hang with Connection: close and AllowHTTP

CL 111835 changed Transport stream ID numbering to start at
stream 3 when AllowHTTP is set. This was based on a
misunderstanding:

When a connection upgrades an HTTP/1.1 request to HTTP/2,
the initial HTTP/1.1 request occupies stream 1.
However, Transport does not perform HTTP protocol upgrades.
When using a Transport to send unencrypted HTTP/2 requests,
the entire connection uses HTTP/2, the first request is
sent as HTTP/2, and there is no reason not to use stream 1
for this request.

Starting from stream 3 is mostly harmless,
but ClientConn.idleStateLocked assumes that client streams
start from 1. This causes it to misidentify new single-use
connections as having already sent a request (when AllowHTTP
is set), and therefore not suitable for use.

Revert to always starting stream IDs at 1.

Fixes golang/go#67671

Change-Id: I97c89de4ae49623d916f9dbd200f8252d2fd4247
Reviewed-on: https://go-review.googlesource.com/c/net/+/591275
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
2 files changed
tree: f4032f2a929b90d0add685da2bd306db210594ba
  1. bpf/
  2. context/
  3. dict/
  4. dns/
  5. html/
  6. http/
  7. http2/
  8. icmp/
  9. idna/
  10. internal/
  11. ipv4/
  12. ipv6/
  13. lif/
  14. nettest/
  15. netutil/
  16. proxy/
  17. publicsuffix/
  18. quic/
  19. route/
  20. trace/
  21. webdav/
  22. websocket/
  23. xsrftoken/
  24. .gitattributes
  25. .gitignore
  26. codereview.cfg
  27. CONTRIBUTING.md
  28. go.mod
  29. go.sum
  30. LICENSE
  31. PATENTS
  32. README.md
README.md

Go Networking

Go Reference

This repository holds supplementary Go networking libraries.

Download/Install

The easiest way to install is to run go get -u golang.org/x/net. You can also manually git clone the repository to $GOPATH/src/golang.org/x/net.

Report Issues / Send Patches

This repository uses Gerrit for code changes. To learn how to submit changes to this repository, see https://golang.org/doc/contribute.html. The main issue tracker for the net repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/net:” in the subject line, so it is easy to find.