embed: embed directive does not add _ and . directories recursivley

[SimonBaeumer]

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

$ go version
go version go1.16.1 darwin/amd64

Does this issue reproduce with the latest release?

Yes

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

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/simon/Library/Caches/go-build"
GOENV="/Users/simon/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/simon/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/simon/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/Cellar/go/1.16.1/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.16.1/libexec/pkg/tool/darwin_amd64"
GOVCS=""
GOVERSION="go1.16.1"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/simon/go/src/github.com/stackrox/rox/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -arch x86_64 -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/np/bn9w387j4ll0xly59mf3p6140000gn/T/go-build3155111729=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

• Want to print all directories, including the ones prefixed with _ and .
• Add // go:embed embed/* directive and store it into a embed.FS variable
• Print all directories included in the embed.FS variable

Create the directory structure:

// To create the directory structure run:
// $ echo "embed/.invisible embed/_underscore embed/recursive/.invisible embed/recursive/_underscore embed/recursive/visible" | xargs mkdir -p
/*
embed
├── .invisible
├── _underscore
├── recursive
│   ├── .invisible
│   ├── _underscore
│   └── visible
└── visible
*/

//go:embed embed/*
var FS embed.FS
func main() {
	fs.WalkDir(FS, ".", func(p string, d fs.DirEntry, err error) error {
		fmt.Println(p)
		return nil
	})
}

Play golang: https://play.golang.org/p/ui10fGMnItQ

What did you expect to see?

Directories prefixed with . and _ under recursive should be displayed too.

.
embed
embed/.invisible
embed/_underscore
embed/recursive
embed/recursive/.invisible
embed/recursive/_underscore
embed/visible

What did you see instead?

.
embed
embed/.invisible
embed/_underscore
embed/recursive
embed/recursive/visible
embed/visible

[cherrymui]

See also #42321 and #43854.

cc @rsc

Feel free to close as a dup.

It looks a bit weird to me that the top-level . and _ files are included.

[seankhliao]

Duplicate of #43854

The * pattern matches everything directly in the directory including . and _, the usual policy of ignoring . and _ then applies to all matched directories