net/http: request.Clone doesn't deep copy TransferEncoding #41907
Description
What version of Go are you using (go version)?
$ go version go version go1.14.5 darwin/amd64
Does this issue reproduce with the latest release?
yes, bug exists in master: https://github.com/golang/go/blob/master/src/net/http/request.go#L385
What operating system and processor architecture are you using (go env)?
go env Output
$ go env GO111MODULE="" GOARCH="amd64" GOBIN="" GOCACHE="/Users/david/Library/Caches/go-build" GOENV="/Users/david/Library/Application Support/go/env" GOEXE="" GOFLAGS="" GOHOSTARCH="amd64" GOHOSTOS="darwin" GOINSECURE="" GONOPROXY="" GONOSUMDB="" GOOS="darwin" GOPATH="/Users/david/cs/go" GOPRIVATE="" GOPROXY="https://proxy.golang.org,direct" GOROOT="/usr/local/Cellar/go/1.14.5/libexec" GOSUMDB="sum.golang.org" GOTMPDIR="" GOTOOLDIR="/usr/local/Cellar/go/1.14.5/libexec/pkg/tool/darwin_amd64" GCCGO="gccgo" AR="ar" CC="clang" CXX="clang++" CGO_ENABLED="1" GOMOD="" 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 -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/5r/35kn30hd119486nmd0sjcy8c0000gn/T/go-build221526405=/tmp/go-build -gno-record-gcc-switches -fno-common"
What did you do?
- initialize http.Request with TransferEncoding
- clone request
- modify original request TransferEncoding
https://play.golang.org/p/aSFm22u_TGZ
What did you expect to see?
cloned request TransferEncoding should not changed by changes to the original request after it has been copied.
What did you see instead?
cloned request TransferEncoding was modified by changing original request TransferEncoding