fix: respect pushDefault config option

[eekhof]

This fixes #322 , so that if no remote to push to is set, the default option set by

[remote]
	pushDefault = origin

Is used instead.

[altsem]

I'm a bit confused, so had a look at the man git config.

       remote.pushDefault
           The remote to push to by default. Overrides branch.<name>.remote for all branches, and is
           overridden by branch.<name>.pushRemote for specific branches.

What does Overrides branch.<name>.remote for all branches actually mean? 🤔

       branch.<name>.remote
           When on branch <name>, it tells git fetch and git push which remote to fetch from or push to.
           The remote to push to may be overridden with remote.pushDefault (for all branches). The
           remote to push to, for the current branch, may be further overridden by
           branch.<name>.pushRemote. If no remote is configured, or if you are not on any branch and
           there is more than one remote defined in the repository, it defaults to origin for fetching
           and remote.pushDefault for pushing. Additionally, . (a period) is the current local
           repository (a dot-repository), see branch.<name>.merge's final note below.

       branch.<name>.pushRemote
           When on branch <name>, it overrides branch.<name>.remote for pushing. It also overrides
           remote.pushDefault for pushing from branch <name>. When you pull from one place (e.g. your
           upstream) and push to another place (e.g. your own publishing repository), you would want to
           set remote.pushDefault to specify the remote to push to for all branches, and use this option
           to override it for a specific branch.

It feels like a can of worm has opened up since the introduction of the two remotes (upstream/pushRemote). 😅

update:

Nevermind. I found this in Magit. Let's stick with how you've prioritized them (branch.<name>.remote over remote.pushDefault)

[altsem]

Some tests are failing (cargo test).
It's also possible to add a test like (in src/tests/push.rs):

#[test]
fn push_doesnt_prompt_for_remote_when_default_set() {
    let ctx = TestContext::setup_clone();
    run(ctx.dir.path(), &["git", "checkout", "-b", "new-branch"]);
    commit(ctx.dir.path(), "new-file", "");
    run(
        ctx.dir.path(),
        &["git", "config", "remote.pushDefault", "origin"],
    );

    snapshot!(ctx, "Pp<enter>");
}

[altsem]

Suggested change

	Err("Neither pushRemote nor push.default is configured".into())
	Err("Neither branch.<name>.pushRemote nor remote.pushDefault is configured".into())

[altsem]

push.default is something else (Defaults to "simple" etc.)