Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

net/http/httputil: new resp.Body returned by dump* is nocloser #67950

Closed
NewUserHa opened this issue Jun 12, 2024 · 5 comments
Closed

net/http/httputil: new resp.Body returned by dump* is nocloser #67950

NewUserHa opened this issue Jun 12, 2024 · 5 comments
Labels
NeedsInvestigation Someone must examine and confirm this is a valid issue and not a duplicate of an existing one.

Comments

@NewUserHa
Copy link

NewUserHa commented Jun 12, 2024 •
edited
Loading

Go version

go version go1.22.0 windows/amd64

Output of go env in your module/workspace:

set GO111MODULE=
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\user\AppData\Local\go-build
set GOENV=C:\Users\user\AppData\Roaming\go\env
set GOEXE=.exe
set GOEXPERIMENT=
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GOMODCACHE=C:\Users\user\go\pkg\mod
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=C:\Users\user\go
set GOPRIVATE=
set GOPROXY=https://goproxy.io,direct
set GOROOT=C:\Program Files\Go
set GOSUMDB=sum.golang.org
set GOTMPDIR=
set GOTOOLCHAIN=auto
set GOTOOLDIR=C:\Program Files\Go\pkg\tool\windows_amd64
set GOVCS=
set GOVERSION=go1.22.0
set GCCGO=gccgo
set GOAMD64=v1
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=0
set GOMOD=NUL
set GOWORK=
set CGO_CFLAGS=-O2 -g
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-O2 -g
set CGO_FFLAGS=-O2 -g
set CGO_LDFLAGS=-O2 -g
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -fno-caret-diagnostics -Qunused-arguments -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=C:\Users\user\AppData\Local\Temp\go-build1134552419=/tmp/go-build -gno-record-gcc-switches

What did you do?

		test, err := httputil.DumpResponse(resp, true)
		resp.Body.Close()
		test, err = io.ReadAll(resp.Body)
		fmt.Println(string(test), err)

What did you see happen?

test is still readable.

What did you expect to see?

the resp.Body is closed.

go/src/net/http/httputil/dump.go

Line 322 in 97bc577

save, resp.Body, err = drainBody(resp.Body)
this line return both new and old resp are nopcloser

should I open a PR?
@gabyhelp
Copy link

Similar Issues

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

@prattmic prattmic added the NeedsInvestigation Someone must examine and confirm this is a valid issue and not a duplicate of an existing one. label Jun 13, 2024
@prattmic
Copy link
Member

cc @neild

@neild
Copy link
Contributor

neild commented Jun 13, 2024

I'm not certain if I understand correctly, but I think you're saying that closing the body should cause further reads to return an error.

httputil.Dump* just replace the body with a bytes.Reader wrapped in an io.NopCloser. Is there really a need for anything more complicated?

@NewUserHa
Copy link
Author

according to the document, the response.Body should be closed, even the new body is just a bytes.Reader wrapped in an io.NopCloser, it may not cause real issue, but it should keep the same behavior as the real response.Body

https://go.dev/src/net/http/response.go
	// The http Client and Transport guarantee that Body is always
	// non-nil, even on responses without a body or responses with
	// a zero-length body. It is the caller's responsibility to
	// close Body. The default HTTP client's Transport may not
	// reuse HTTP/1.x "keep-alive" TCP connections if the Body is
	// not read to completion and closed.

@rsc
Copy link
Contributor

rsc commented Jun 28, 2024

There is no requirement about how exactly a body implementation responds to misuse such as Read after Close.
It is perfectly valid to use io.NopCloser, which implements Close as a no-op, in which case Read after Close does work.
You cannot rely on an error from Read after Close.

@rsc rsc closed this as completed Jun 28, 2024
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
NeedsInvestigation Someone must examine and confirm this is a valid issue and not a duplicate of an existing one.
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
5 participants
@neild @rsc @prattmic @NewUserHa @gabyhelp