Add GitLab support

[JakeWharton]

No description provided.

[JakeWharton]

Can't go through GraphQL yet because of https://gitlab.com/gitlab-org/gitlab/-/issues/196170

[JakeWharton]

v4 REST API should be usable, but perhaps punt for a while

[johnjohndoe]

I was confused for a bit because the configuration specification in the README.md contains:

# Repos not on GitHub to synchronize.
[git.repos]
asm = "https://gitlab.ow2.org/asm/asm.git"

This led me to try to gitout some GitLab repositories. Once I cloned them and checked with git log this error is output:

$ git log
fatal: your current branch 'master' does not have any commits yet

Maybe, the README.md should clarify that GitLab doesn't work yet or replace the example URL?

[JakeWharton]

Does git log work in bare repositories?

This feature is for discovering your repositories through your GitLab username. You're always able to clone any git repo from anywhere if you list the full URL.

[johnjohndoe]

Does git log work in bare repositories?

Yes. If I clone a repository (e.g. git clone --bare https://github.com/JakeWharton/gitout.git) then I can successfully invoke git log.

This feature is for discovering your repositories through your GitLab username.

Thanks for the clarification.

You're always able to clone any git repo from anywhere if you list the full URL.

The full URL, e.g. https://gitlab.com/oeffi/oeffi or https://gitlab.com/oeffi/oeffi.git works for cloning it seems but then git log fails as stated before.

Here is the configuration file - just in case:

version = 0

[git.repos]
gitout = "https://github.com/JakeWharton/gitout.git" # git log doesn't work here
oeffi = "https://gitlab.com/oeffi/oeffi.git" # git log doesn't work here

[JakeWharton]

Thanks I'll play with it. We delegate everything to libgit2 which can have differing behavior from git proper. At worst, I just create a repro and file a bug upstream.