os: The result of UserHomeDir and User.HomeDir is inconsistent.

[Dreamacro]

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

$ go version
go version go1.12 darwin/amd64

Does this issue reproduce with the latest release?

yes.

What did you do?

Before go 1.12, I used os/user to get homedir.

current, _ := user.Current()
current.HomeDir

After new release, I used new function UserHomeDir

homeDir, _ := os.UserHomeDir()

However, they may return different values under same environment. For example, when I used termux on android, the former returns $HOME while the latter returns /.

The root case because of the UserHomeDir returns / directly but user.Current() read env "$HOME" first.

• https://golang.org/src/os/file.go?s=11606:11640#L397
• https://github.com/golang/go/blob/go1.12.1/src/os/user/lookup_stubs.go#L34

I prefer the previous implementation. So how do you plan to deal with the inconsistency between the two implementation?

[cuonglm]

With commit bedb6a1 , the result is now consistent. But not when HOME is not set.:

• current.HomeDir is /sdcard
• os.UserHomeDir() returns /

[Dreamacro]

Great! But will this patch be released on 1.12.2? this is a long time for me to wait until 1.13 release 🤔

[gopherbot]

Change https://golang.org/cl/169540 mentions this issue: os/user: keep user.HomeDir sync with os.UserHomeDir when HOME not set

[cuonglm]

@Dreamacro I don't know, you should ask the core team cc @bradfitz @mvdan

Not sure this issue is urgent for a cherry pick.

[bradfitz]

/cc @eliasnaur

[mvdan]

But will this patch be released on 1.12.2? this is a long time for me to wait until 1.13 release

Cherry-picks are generally reserved for regressions, security bugs, or really bad bugs like runtime crashes, so I don't think this qualifies. If anyone really wants the fix before 1.13 is released, copy-pasting a bit of code from master should be pretty easy.

I think what @Gnouc said in his first comment makes sense. os/user depends on os, so perhaps we could even make it call os.UserHomeDir to deduplicate the logic.