path/filepath: rename func VolumeName(path string) string

[ericwj]

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

$ go version
1..14.4

Does this issue reproduce with the latest release?

Yes.

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

Operating system and architecture independent.

What did you do?

Read the docs.

What did you expect to see?

func VolumeRoot(path string) string

or something similar that reflects what VolumeName actually returns.

-or-

Documentation to the effect that VolumeName in fact returns a volume name.

A volume name on Windows is also known as a volume label.

What did you see instead?

The function certainly does not return a volume name, hence either the name or its behavior and documentation are wrong.

Having VolumeName("C:\A") return "C:" is confusing and inconsistent. It could also be considered wrong, since "C:" is a relative path which would resolve to %CD% or C:. and Abs is also documented to never return C: for probably this reason. However this issue is about the function returning a path, not a name, as one would not be overly unjustified expect.

[ianlancetaylor]

We can update the docs, but we can't rename the function, because of the Go 1 compatibility guarantee (https://golang.org/doc/go1compat).

[ericwj]

Just punt it, I'm fine with that - I don't write go.

Try googling with Bing for Windows related stuff - seriously, the result are absolutely primary e.g. for 'volume name':

1. What Is a Volume Label of a Drive? - Lifewire.
2. How to Find a Drive's Volume Label or Serial Number
3. Naming a Volume - Win32 apps | Microsoft Docs

[alexbrainman]

VolumeName also works with UNC paths. See

https://golang.org/pkg/path/filepath/#VolumeName

for details.

Whatever this function does, we cannot change its name (as Ian explained).

Alex