cmd/go: support ~ in import paths

[gopherbot]

by henderson.bj:

What does 'go version' print?

go version go1.3.3 linux/amd64

What steps reproduce the problem?
If possible, include a link to a program on play.golang.org.

1. go get -d gitserver/~user/repo.git

What happened?

package gitserver/~user/repo.git: unrecognized import path
"gitserver/~user/repo.git"

What should have happened instead?

The repository should have been checked out.

Please provide any additional information below.

git ls-remote works on the supplied path, so it's a valid url.
I believe the relevant line is here:

https://code.google.com/p/go/source/browse/src/cmd/go/vcs.go?name=go1.3.3#618

This line in tip has not changed.

I tested manually checking out the repo into the same path and everything else (import,
build) seemed to work.

thank you,

[ianlancetaylor]

Comment 1:

Labels changed: added repo-main, release-go1.5.

[rsc]

Sadly I am postponing this to Go 1.6. It is too late to find out what the answer is here. I am worried about Windows in particular having unanticipated problems with the ~.

[stemar94]

@adg You should add Proposal Label here (I read you are going to do discussions about proposals).