I have been working on optimising Actions workflows and only today noticed that actions/checkout when called on a PR without any options checks out a merge branch:
git checkout --progress --force refs/remotes/pull/3048/merge
It is also mentioned here:
PR merge branch
Can someone tell me what exactly this is? Intuitively it sounds like it is just merges target branch into the PR branch and runs the Actions. But is there some more documentation I can find for this? I would like to know what happens when there is merge conflict between the target branch and the PR branch.