net/http: upon http redirect, Request.GetBody is always nil

[maruel]

Go version

go version devel go1.25-252c939445 Fri Apr 18 08:30:30 2025 -0700 linux/amd64

Output of go env in your module/workspace:

AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE=''
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/home/maruel/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/home/maruel/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build432130765=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/home/maruel/src-oth/golang/src/go.mod'
GOMODCACHE='/home/maruel/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/home/maruel/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/home/maruel/src-oth/golang'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/home/maruel/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/home/maruel/src-oth/golang/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='devel go1.25-252c939445 Fri Apr 18 08:30:30 2025 -0700'
GOWORK=''
PKG_CONFIG='pkg-config'

What did you do?

Implement a http.RoundTripper that leverages http.Request.GetBody. Handle a server that returns 307/308 on a POST.

What did you see happen?

http.Request.GetBody is always nil after a HTTP redirect.

What did you expect to see?

http.Request.GetBody is copied over so the RoundTripper can rewind the request body if needed.

[maruel]

Fix: https://go-review.googlesource.com/c/go/+/666735

[gopherbot]

Change https://go.dev/cl/666735 mentions this issue: net/http: upon http redirect, copy Request.GetBody in new request

[gabyhelp]

Related Issues

• net/http: NewFileTransport does not populate Response.Request on redirect #51562
• net/http: should not reuse body following redirects after method is changed to GET #70180 (closed)
• net/http, x/net/http2: client loses the request body when retrying after HTTP2 server close connection gracefully(GOAWAY) #39086 (closed)
• http/client - edge case on POST and redirect #70174 (closed)
• net/http: Request body is not closed by Transport.RoundTrip on some net.Conn errors #49621 (closed)
• net/http: request.Body.Close() can be called after RoundTrip() returns #58521 (closed)
• net/http: Unexpected "define Request.GetBody to avoid this error" error after setting Request.GetBody #69412
• net/http: use 308 instead of 301 in Server to preserve POST payload in redirects #50243
• net/http: Re-connect with upgraded HTTP2 connection fails to send Request.body #32441 (closed)

Related Code Changes

• net/http: don't send body on redirects for 301, 302, 303 when GetBody is set

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[JunyangShao]

@neild