x/net/http2: unexpected custom errors when HTTP2.0 PUT request gets lesser content than the specified content-length

[harshavardhana]

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

$ go version
go version go1.12 linux/amd64

Does this issue reproduce with the latest release?

Yes with go1.12

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

go env Output

$ go env
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/harsha/.cache/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/harsha/mygo"
GOPROXY=""
GORACE=""
GOROOT="/home/harsha/.gimme/versions/go1.12.linux.amd64"
GOTMPDIR=""
GOTOOLDIR="/home/harsha/.gimme/versions/go1.12.linux.amd64/pkg/tool/linux_amd64"
GCCGO="/usr/bin/gccgo"
CC="gcc"
CXX="g++"
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 -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build150613686=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Set a high content-length and send shorter data leads to unexpected errors reported by the server

// endStream closes a Request.Body's pipe. It is called when a DATA
// frame says a request body is over (or after trailers).
func (st *http2stream) endStream() {
        sc := st.sc
        sc.serveG.check()

        if st.declBodyBytes != -1 && st.declBodyBytes != st.bodyBytes {
                st.body.CloseWithError(fmt.Errorf("request declared a Content-Length of %d but only wrote %d bytes",
                        st.declBodyBytes, st.bodyBytes))
        } else {
                st.body.closeWithErrorAndCode(io.EOF, st.copyTrailersToHandlerRequest)
                st.body.CloseWithError(io.EOF)
        }
        st.state = http2stateHalfClosedRemote
}

Should be ideally

// endStream closes a Request.Body's pipe. It is called when a DATA
// frame says a request body is over (or after trailers).
func (st *http2stream) endStream() {
        sc := st.sc
        sc.serveG.check()

        if st.declBodyBytes != -1 && st.declBodyBytes != st.bodyBytes {
                st.body.CloseWithError(io.ErrUnexpectedEOF)
        } else {
                st.body.closeWithErrorAndCode(io.EOF, st.copyTrailersToHandlerRequest)
                st.body.CloseWithError(io.EOF)
        }
        st.state = http2stateHalfClosedRemote
}

What did you expect to see?

Expected to see io.ErrUnexpectedEOF

What did you see instead?

request declared a Content-Length of %d but only wrote %d bytes

This behavior differs from HTTP 1.1 behavior.

[agnivade]

/cc @bradfitz @fraenkel

[fraenkel]

An example would help.
The http path has something similar, https://github.com/golang/go/blob/master/src/net/http/transfer.go#L387

[harshavardhana]

will do @fraenkel