Make argument quotation compatible with cygwin/msys2/gitbash on Windows

[arixmkii]

It is the same situation like in https://github.com/lima-vm/lima/blob/786c1f5f3c6e8ff276c0c5d6789cdd9243d70f49/pkg/sshutil/sshutil.go#L271

Windows based tooling can't correctly escape ".

The implemented workaround probably will not work for some extreme cases, but at least it is not failing outright from the start.

It has been tested to work on Windows with Git Bash and WSL2 based tooling.

[arixmkii]

@AkihiroSuda could you take a look?

[AkihiroSuda]

Could you add a comment to explain the reason?

Also, can we have a unit test and/or an integration test?

[arixmkii]

I will try to sketch the unit test. It will take some time, I will ping you, when it is done.

[arixmkii]

I managed to get a reproducer with a command line example. The command is extracted using recording processes started on the host.

"C:\Program Files\Git\usr\bin\ssh.exe" -i /c/Users/User/.local/share/containers/podman/machine/machine -p 60251 core@localhost -- mkdir -p \"/c/Users/runneradmin\"
bash: -c: line 1: unexpected EOF while looking for matching `"'

I don't think this can be reasonably covered by integration test - this would recover spinning VM just for that test.

And the method in question is not unit testable as it actually executes the resulting external commands within itself.

It would be only possible to cover private addQuotes with a unit test, which is actually a single standard library call on all platforms other than Windows, but I will add it and add the comment.

[arixmkii]

Added basic unit test and also extended test matrix to include Windows.

[AkihiroSuda]

Thanks