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

go version go1.17 windows/amd64

Does this issue reproduce with the latest release?

yes

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

set GO111MODULE=auto
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\xx\AppData\Local\go-build
set GOENV=C:\Users\xx\AppData\Roaming\go\env
set GOEXE=.exe
set GOEXPERIMENT=
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GOMODCACHE=C:\Users\xx\go\pkg\mod
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=C:\Users\xx\go
set GOPRIVATE=
set GOPROXY=https://goproxy.io,direct
set GOROOT=c:\go
set GOSUMDB=sum.golang.org
set GOTMPDIR=
set GOTOOLDIR=c:\go\pkg\tool\windows_amd64
set GOVCS=
set GOVERSION=go1.17
set GCCGO=gccgo
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=C:\Users\xx\AppData\Local\Temp\go-build2679503516=/tmp/go-build -gno-record-gcc-switches

What did you do?

package main

import (
	"bytes"
	"fmt"
	"mime/multipart"
	"net/http"
)

func main() {
	buf := new(bytes.Buffer)
	mw := multipart.NewWriter(buf)
	mw.Close()

	Request, _ := http.NewRequest("POST", "/", nil)
	Request.Header.Set("Content-Type", mw.FormDataContentType())

	f, fh, err := Request.FormFile("file")
	if err != nil {
		fmt.Printf("%#+v\n", err)
		return
	}
	f.Close()
	fmt.Printf("%#+v\n", fh)
	return
}

What did you expect to see?

I would like to see an error.

errors.New("missing form body")

What did you see instead?

panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xc0000005 code=0x0 addr=0x18 pc=0x77b632]

goroutine 1 [running]:
mime/multipart.(*stickyErrorReader).Read(0xc00005a500, {0xc0000da000, 0x927640, 0x0})
c:/go/src/mime/multipart/multipart.go:127 +0x32
bufio.(*Reader).fill(0xc000066180)
c:/go/src/bufio/bufio.go:101 +0x103
bufio.(*Reader).ReadSlice(0xc000066180, 0x98)
c:/go/src/bufio/bufio.go:360 +0x2f
mime/multipart.(*Reader).nextPart(0xc000022080, 0xf8)
c:/go/src/mime/multipart/multipart.go:335 +0xb6
mime/multipart.(*Reader).NextPart(...)
c:/go/src/mime/multipart/multipart.go:314
mime/multipart.(*Reader).readForm(0xc0000d4000, 0x2000000)
c:/go/src/mime/multipart/formdata.go:52 +0x178
mime/multipart.(*Reader).ReadForm(...)
c:/go/src/mime/multipart/formdata.go:31
net/http.(*Request).ParseMultipartForm(0xc0000d4000, 0x6ad007)
c:/go/src/net/http/request.go:1318 +0xa5
net/http.(*Request).FormFile(0xc0000d4000, {0x7e207c, 0x4})
c:/go/src/net/http/request.go:1376 +0x4f
main.main()
D:/gocode/src/ucenter/app/test/httpformfile/main.go:18 +0x1bb
exit status 2