Comment by neild
2 days ago
The "move a branch from one commit to another without changing anything" command is "git reset".
"git reset --hard" is "...and also change all the files in the working directory to match the new branch commit".
"git reset --soft" is "...but leave the working directory alone".
Actually, "git reset --soft" moves the current branch to another commit, without moving the index (aka staging area) along with it, whereas "git reset" (aka "git reset --mixed") moves the current branch AND the index to another commit. I really couldn't wrap my head around it before I had gone through "Reset demystified" [1] a couple times - it's not a quick read but I can strongly recommend it.
[1] https://git-scm.com/book/en/v2/Git-Tools-Reset-Demystified
git reset only works if you're on the branch you want to move, which is why every one of these example flows has you create your new branch, then do the reset, then switch to the new branch, instead of just allowing you to move a branch you're not on.