Repository: Extract run_command() function

[Turbo87]

This new function makes it easier to run arbitrary git commands in the working folder of the local index clone. It was extracted from the squash_index() background worker tasks, which uses it to run git push --force-with-lease, which is not yet supported by the git2 crate.

The main goal of this PR is to reduce the visibility of the checkout_path and credentials fields on the Repository, which outside code should ideally not have any access to.

Note that this includes the commits from and is based on #4363.

[locks]

@bors r+

[bors]

📌 Commit 4c63e20 has been approved by locks

[bors]

🔒 Merge conflict

This pull request and the master branch diverged in a way that cannot be automatically merged. Please rebase on top of the latest master branch, and let the reviewer approve again.

How do I rebase?

Assuming self is your fork and upstream is this repository, you can resolve the conflict following these steps:

1. git checkout git-run-command (switch to your branch)
2. git fetch upstream master (retrieve the latest master)
3. git rebase upstream/master -p (rebase on top of it)
4. Follow the on-screen instruction to resolve conflicts (check git status if you got lost).
5. git push self git-run-command --force-with-lease (update this PR)

You may also read Git Rebasing to Resolve Conflicts by Drew Blessing for a short tutorial.

Please avoid the "Resolve conflicts" button on GitHub. It uses git merge instead of git rebase which makes the PR commit history more difficult to read.

Sometimes step 4 will complete without asking for resolution. This is usually due to difference between how Cargo.lock conflict is handled during merge and rebase. This is normal, and you should still perform step 5 to update this PR.

Error message

Auto-merging src/git.rs
CONFLICT (content): Merge conflict in src/git.rs
Automatic merge failed; fix conflicts and then commit the result.

[bors]

☔ The latest upstream changes (presumably #4364) made this pull request unmergeable. Please resolve the merge conflicts.

[Turbo87]

@bors r=locks

[bors]

📌 Commit eb2f671 has been approved by locks

[bors]

⌛ Testing commit eb2f671 with merge 0409e47...

[bors]

☀️ Test successful - checks-actions
Approved by: locks
Pushing 0409e47 to master...