Fixed issue with slash separated paths on windows

[felicienfrancois]

No description provided.

[felicienfrancois]

Tested with the following paths:

path\to\some\dir=> path\to\some
path\to\some\dir\ => path\to\some\dir
path/to/some/dir=> path\to\some
path/to/some/dir/ => path\to\some\dir
dir => .
dir\ => dir
dir/ => dir

[jprichardson]

I'd like to accept this, but I can't until I get all of the other Windows issues currently fixed as reported by Appveyor.

[jprichardson]

OK, all Appveyor Windows tests are passing now. It's not quite clear to me what problem this is solving?

[felicienfrancois]

Before the fix, the copy method were not working correctly when the dest path was slash separated instead of anti-slash separated.
Additionally, using the copy method with a relative dir without any separator were not working

Before the processing of dest dir was:
"path\to\some\dir" => "path\to\some" OK
"path\to\some\dir\" => "path\to\some\dir" OK
"path/to/some/dir" => "" FAIL
"path/to/some/dir/" => "" FAIL
"dir" => "" FAIL
"dir\" => "dir" OK
"dir/" => "" FAIL

Now it is:
`"path\to\some\dir"` => `"path\to\some"`        OK
`"path\to\some\dir\"` => `"path\to\some\dir"`  OK
`"path/to/some/dir"` => `"path\to\some"`        OK
`"path/to/some/dir/"` => "path\to\some\dir"     OK
`"dir"` => "."     OK
`"dir\"` => "dir"     OK
`"dir/"` => "dir"     OK

This was due to the use of split(path.sep) (IE \ on windows) on a possibly not normalized path.
The || "." addition fix the bug for relative dir without separator

[RyanZim]

@jprichardson ping?

[jprichardson]

@jprichardson ping?

I'm not sure here. Maybe we need to normalize the paths now? This issue is pretty old.

[RyanZim]

Closing this PR since resolving the merge conflicts would be more work than re-implementing. If anyone has a similar issue, please open an issue in the issue tracker with a reduced test case; we can go from there.