net/http: error unwrapping broken on some transport errors

[mraerino]

What version of Go are you using (go version)?

$ go version
go version go1.19.2 linux/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/circleci/.cache/go-build"
GOENV="/home/circleci/.config/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/circleci/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/circleci/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="go1.19.2"
GCCGO="gccgo"
GOAMD64="v1"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/dev/null"
GOWORK=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build2218043753=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Here's my repro that only seems to work on Linux: https://go.dev/play/p/k305YHkn2QM
You can run it a couple of times to get results like this:

Get "http://localhost:35633": write tcp 127.0.0.1:52368->127.0.0.1:35633: use of closed network connection
in chain: false
Get "http://localhost:35633": read tcp 127.0.0.1:52368->127.0.0.1:35633: use of closed network connection
in chain: true
Get "http://localhost:35633": read tcp 127.0.0.1:52368->127.0.0.1:35633: use of closed network connection
in chain: true
Get "http://localhost:35633": readLoopPeekFailLocked: read tcp 127.0.0.1:52368->127.0.0.1:35633: use of closed network connection
in chain: false
Get "http://localhost:35633": write tcp 127.0.0.1:52368->127.0.0.1:35633: use of closed network connection
in chain: false

What did you expect to see?

I expected net.ErrClosed to always be part of the error chain

What did you see instead?

It looks like for the write tcp and readLoopPeekFailLocked the error chain can't be unwrapped entirely.

[mraerino]

i can make a PR for this!

[heschi]

cc @neild

[neild]

These code paths all long predate error wrapping.

I'm happy to review a CL fixing the wrapping in places where we're getting it wrong now.

[mraerino]

PR is here: #56451

[gopherbot]

Change https://go.dev/cl/445775 mentions this issue: net/http: build error chains in transport that can be unwrapped