Comment 1:

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

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 ~.

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

If someone wants to write a proposal document for this, I'd be happy to provide feedback.

Does this really need a full proposal? I'd say fix the regexp, test on Windows, and ship it if it works there?

The possible problems I expect on Windows are subtle (remember that ~ is how Windows shortens long path names to 8.3 format). "Test it once and ship it" is NOT okay.

It may be okay to accept ~ only at the beginning of a path element.

~ is a shellism, once the program (not just a go program) gets hold of the
values, they will have been expanded by the shell (unless escaped).

This proposal is about trying to make ~ expansion happen in the case where
the shell hasn't been able to do it. I think we should do the opposite and
fail early if ~ has leaked into GOPATH by accident.

On Sat, 24 Oct 2015, 13:55 Russ Cox notifications@github.com wrote:

The possible problems I expect on Windows are subtle (remember that ~ is
how Windows shortens long path names to 8.3 format). "Test it once and ship
it" is NOT okay.

It may be okay to accept ~ only at the beginning of a path element.

—
Reply to this email directly or view it on GitHub
#9193 (comment).

I don't see why ~ wouldn't work in windows paths:

C:\a>dir
 Volume in drive C has no label.
 Volume Serial Number is 1021-46BD

 Directory of C:\a

24/10/2015  07:14 PM    <DIR>          .
24/10/2015  07:14 PM    <DIR>          ..
               0 File(s)              0 bytes
               2 Dir(s)   4,800,569,344 bytes free

C:\a>echo > ~file

C:\a>echo > file~

C:\a>echo > fi~le

C:\a>echo > ~~~

C:\a>mkdir ~dir

C:\a>mkdir dir~

C:\a>mkdir d~ir

C:\a>mkdir ~~~~

C:\a>mkdir ~~~
A subdirectory or file ~~~ already exists.

C:\a>dir
 Volume in drive C has no label.
 Volume Serial Number is 1021-46BD

 Directory of C:\a

24/10/2015  07:15 PM    <DIR>          .
24/10/2015  07:15 PM    <DIR>          ..
24/10/2015  07:15 PM    <DIR>          dir~
24/10/2015  07:15 PM    <DIR>          d~ir
24/10/2015  07:15 PM                13 file~
24/10/2015  07:15 PM                13 fi~le
24/10/2015  07:15 PM    <DIR>          ~dir
24/10/2015  07:15 PM                13 ~file
24/10/2015  07:15 PM                13 ~~~
24/10/2015  07:15 PM    <DIR>          ~~~~
               4 File(s)             52 bytes
               6 Dir(s)   4,800,565,248 bytes free

C:\a>del file~

C:\a>rmdir dir~

C:\a>

Alex

@davecheney, are you sure this is about shell expansion? The initial report says go get -d gitserver/~user/repo.git, and shell expansion would not apply to a ~ unless it appeared at the beginning of an argument.

I thought this proposal was about supporting git servers that use the literal substring /~user/ in their git URLs. For example I thought launchpad.net did this, and in fact such examples are in our docs:

Launchpad (Bazaar)

    import "launchpad.net/project"
    import "launchpad.net/project/series"
    import "launchpad.net/project/series/sub/directory"

    import "launchpad.net/~user/project/branch"
    import "launchpad.net/~user/project/branch/sub/directory"

I don't have bzr installed and I don't know of any launchpad users to try looking for code. Can someone check what happens if you try to go get a launchpad.net/~user path?

If it doesn't work, we should fix that. We can do that by allowing ~ as the first character of a path element, but no in general.

@alexbrainman, what concerns me about Windows paths is the ambiguity it might introduce. It's true that if you create paths with ~ in them you can get to them, but on most systems you can also, for example, type "c:\progra~1" instead of "c:\program files", and it's that access to shortened names that I want to disallow.

I hear you @rsc. This program https://play.golang.org/p/PDKP6ZfV0X fails with:

C:\>u:\test
shortname="C:\\DOCUME~1\\brainman\\LOCALS~1\\Temp\\ALEX06~1\\DIRECT~1"
2015/10/30 10:30:22 mkdir C:\DOCUME~1\brainman\LOCALS~1\Temp\ALEX06~1\DIRECT~1: Cannot create a file when that file already exists.

C:\>```

Alex

@rogpeppe or @niemeyer, do either of you have or know of Go code on launchpad.net/~user repos? Can you check whether they work with go get today? Thanks.

This proposal is accepted provided it's only about leading ~ in path elements. I thought that worked already, and there are examples in the go command docs saying it should work, so that seems pretty unobjectionable. Would still like to hear whether it actually works.

CL https://golang.org/cl/17952 mentions this issue.