internal: url, support more scp-like URLs

[loderunner]

SCP-like URLs do not necessarily need to have a prefix followed by a / in the path.

For example, if a git repository is located at /test-repo.git on a remote, the following command is valid.

git clone user@remote:/test-repo.git

As long as user can use SSH to log into the remote (which might be described in SSH config), git will attempt to clone the repo at the given path.

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I removed the / as separator for the port as it interfered with this URL scheme, but I might have missed the rationale for this. Feel free to explain, and I will update the PR accordingly.

[mcuadros]

can you take a look to the testS?

[loderunner]

I rewrote some things in the tests.

• Fixed the regex to support port number in scp-like URL better
• Fixed the regex to support root paths better
• Fixed an assertion in internal/url/url_test.go
• Changed a test in plumbing/transport/common_test.go

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I tried my best, but I'm worried about breaking compatibility, here.

Investigating a bit deeper, I found that git does not support port numbers in SCP-like URLs.

On github (connection should be refused):

$ git clone git@github.com:2222:loderunner/go-git.git
Cloning into 'go-git'...
fatal: remote error:
   is not a valid repository name
  Visit https://support.github.com/ for help

With scrt.test defined as 127.0.0.1 in /etc/hosts:

$ git clone scrt@scrt.test:2222:repos/toto.git
Cloning into 'toto'...
ssh: connect to host scrt.test port 22: Connection refused
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

$ git clone scrt@127.0.0.1:2222:repos/toto.git
Cloning into 'toto'...
ssh: connect to host 127.0.0.1 port 22: Connection refused
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

You can see that git does not recognize my port, here, and tries to connect to 22.

Ran on my MacBook Pro, with an sshd running at port 2222

$ git --version
git version 2.24.3 (Apple Git-128)

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According the the scp manpage, git@github.com:9999/user/repository.git is not a valid path anyway:

The source and target may be specified as a local pathname, a remote host with
optional path in the form [user@]host:[path], or a URI in the form
scp://[user@]host[:port][/path].

What should I do: stick to git specification or maintain go-git backwards compatibility?

[mcuadros]

Support backward compatibility is the best in this case.

[b3n4kh]

My PR to this issue got closed as duplicate - this one is apparently dead. What is the way forward here?

[pjbgf]

Closing as this was fixed by #715.