Git

Staging

Stage only part of a new/untracked file

git add -N <file>
git add -p <file>

git add's -N flag record only the fact that the path will be added later.

Stash

Checking out a single file from the stash

git checkout stash@{0} -- <file>

Alternatively one can create a copy of a stashed file using git show:

git show stash@{0}:<stashed-file> > <file>

Branches

Remove obsolete tracking branches

After deleting a local branch with git branch -d and deleting the remote branch with git push origin --delete, other machines may still have "obsolete tracking branches". To get rid of these do

git fetch --all --prune

Log

List commits since certain commit

To list all commits made since a certain commit, use git log <hash>.., where <hash> represents the commit hash you want to start listing from, ensuring to include the two dots for correct range specification:

git log origin/main..

GitHub

Edit PR as maintainer

Let's say contributor has submitted a pull request to project/repo. They have made changes on their feature branch and proposed to merge this into origin/main. A maintainer can edit (i.e., pushing commits or rebasing) the pull request if maintainer edits are enabled.

To do that, as maintainer you must first add their fork as a remote

git remote add contributor git@github.com:contributor/repo

such that:

git remote -v
origin        https://github.com/project/repo (fetch)
origin        https://github.com/project/repo (push)
contributor   https://github.com/contributor/repo  (fetch)
contributor   https://github.com/contributor/repo  (push)

Next, pull down their list of branches with

git fetch contributor

and create a new branch contributor-feature from the branch that they have created the PR from:

git checkout -b contributor-feature contributor/feature

Now make any changes you need to make on this branch and finally push the changes back to the PR by pushing their branch

git push contributor contributor-feature:feature

Note that if a rebase was performed, a push --force is necessary.