archive/zip: AddFS omits trailing slash in directory names

[jba]

Go version

go version go1.24-20241213-RC00 cl/706019355 +e39e965e0e X:fieldtrack,boringcrypto linux/amd64

Output of go env in your module/workspace:

AR='ar'
CC='clang'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='clang++'
GCCGO='gccgo'
GO111MODULE='on'
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/usr/local/google/home/jba/.cache/go-build'
GODEBUG=''
GOENV='/usr/local/google/home/jba/.config/go/env'
GOEXE=''
GOEXPERIMENT='fieldtrack,boringcrypto'
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build2446417499=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/usr/local/google/home/jba/repos/go/src/go.mod'
GOMODCACHE='/usr/local/google/home/jba/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/usr/local/google/home/jba/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org'
GOROOT='/usr/lib/google-golang'
GOSUMDB='sum.golang.org'
GOTELEMETRY='on'
GOTELEMETRYDIR='/usr/local/google/home/jba/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/lib/google-golang/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.24-20241213-RC00 cl/706019355 +e39e965e0e X:fieldtrack,boringcrypto'
GOWORK=''
PKG_CONFIG='pkg-config'

What did you do?

The doc for zip.FileHeader.Name says "A trailing slash indicates that this file is a directory."
When change https://go.dev/cl/578415 added directories, it did not include the trailing slashes.

repro: https://go.dev/play/p/9C5y2uZ1A2U?v=gotip

What did you see happen?

dir
dir/file

What did you expect to see?

dir/
dir/file

[gabyhelp]

Related Issues

• archive/zip: fs.WalkDir fails if archive contains a directory without a trailing slash #50390 (closed)
• archive/{zip,tar}: (*Writer).AddFS omits empty directories #66831 (closed)
• archive/zip: duplicate entries in FS interface #45345 (closed)
• archive/zip: produces incorrect zip archives #30627 (closed)
• archive/zip: Reader.Open lies about directory fs.FileMode #48106
• archive/zip: FileHeader struct lacks Unicode Path Extra Field (0x7075) #36760
• os: `Lstat` on `darwin` sometimes fails to expand symlinks in paths with trailing slashes #59586
• io/fs,os: fs.ReadDir with an os.DirFS can produce invalid paths #44166 (closed)

Related Code Changes

• archive/tar: improve handling of directory paths
• archive/zip: improve Writer.Create documentation on how to add directories

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

[dmitshur]

CC @songgao, @ianlancetaylor.

[gopherbot]

Change https://go.dev/cl/642375 mentions this issue: archive/zip: dir add slash

[h9jiang]

As hana pointed out, this issue might be related to the issue happens in vscode-go causing the test failure.

CL 642479

I'm not very familiar with the go release process (about code freeze). Is this CL going to merge in gotip and released in go 1.24? (If it can merge in gotip, I will just drop my CL and wait for the fix here)

[jba]

@h9jiang it will be in 1.24.

[gopherbot]

Change https://go.dev/cl/644075 mentions this issue: archive/zip: add trailing slash to directory names for Writer.AddFS