os: Stat on a symlink fails when path has a trailing slash

[AudriusButkevicius]

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

go version go1.11 windows/amd64

Does this issue reproduce with the latest release?

Yes

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

Windows 10 with Developer mode enabled (allowing to create symlinks for unprivileged users)

What did you do?

c:\temp>type test.go
package main

import (
  "os"
  "fmt"
)

func main() {
  fmt.Println(os.Lstat(`c:\temp\b`))
  fmt.Println(os.Lstat(`c:\temp\b\`))
}

c:\temp>mkdir a

c:\temp>mklink /D b a
symbolic link created for b <<===>> a

c:\temp>cmd /c "set GOROOT=c:\go1.10.4&& c:\go1.10.4\bin\go.exe run test.go"
&{b {1040 {477620318 30686378} {477620318 30686378} {477620318 30686378} 0 0} 0 {0 0} c:\temp\b 0 0 0 false} <nil>
&{b {1040 {477620318 30686378} {477620318 30686378} {477620318 30686378} 0 0} 0 {0 0} c:\temp\b\ 0 0 0 false} <nil>

c:\temp>cmd /c "set GOROOT=c:\go&& c:\go\bin\go.exe run test.go"
&{b 1040 {477620318 30686378} {477620318 30686378} {477620318 30686378} 0 0 2684354572 0 {0 0} c:\temp\b 0 0 0 false} <nil>
<nil> FindFirstFile c:\temp\b\: The system cannot find the file specified.

Same issue between Stat and Lstat

What did you expect to see?

Stat to succeed, like it did in Go 1.10.4

What did you see instead?

Stat failed

[mvdan]

Does this only happen on Windows?

[AudriusButkevicius]

Yes, as far as I found.

[bradfitz]

/cc @alexbrainman

[alexbrainman]

@AudriusButkevicius thank you for reporting the issue. I will investigate when I have time.

Alex

[gopherbot]

Change https://golang.org/cl/134195 mentions this issue: os: use FILE_FLAG_OPEN_REPARSE_POINT in SameFile

[gopherbot]

Change https://golang.org/cl/143578 mentions this issue: os: use CreateFile for Stat of symlinks

[alexbrainman]

@AudriusButkevicius please try https://go-review.googlesource.com/c/go/+/143578

Does it fixes your problem?

Thank you.

Alex

[AudriusButkevicius]

I won't be able to try it out as I have no pc access for 3-4 weeks. Ping @calmh, @imsodin who might be able to help.

[alexbrainman]

I won't be able to try it out as I have no pc access for 3-4 weeks.

Never mind that. You will try when you can.

Alex