Squash and merge master into same branch

Question

Is there a way to squash and merge master into the same branch? Effectively taking all the pending commits and putting them into 1 commit?

My original idea is a script that takes my-branch and does a git checkout master && git pull && git checkout my-branch-squashed and then git merge --squash my-branch (deal with any merge conflicts) and then finally delete my-branch and rename my-branch-squash to my-branch

This seem very round-about and possibly bad, so I am trying to see if there is any other way. The intent I am trying to solve is that when I put branches on github and they are "squashed and merged" into master, the branch that exists on the local machine doesn't match the branch that was merged into master, so when using git branch --merged ${1-master} | grep -v " ${1-master}$" | xargs -r git branch -d; it doesnt correctly delete the branches that have already been merged into master. What I want is a way to auto-delete old branches that have been merged into master

Answer 1

You can do that using git rebase, and fixup the commits you want to merge:

$ git rebase -i HEAD~5

pick c2e2c87 commit 1
f 689d474 commit 2
f aa9d9b4 commit 3
f 888a009 commit 4
f d396e75 commit 5

# Rebase 2f7f53e..d396e75 onto 2f7f53e (5 commands)
#
# Commands:
# p, pick = use commit
# r, reword = use commit, but edit the commit message
# e, edit = use commit, but stop for amending
# s, squash = use commit, but meld into previous commit
# f, fixup = like "squash", but discard this commit's log message
# x, exec = run command (the rest of the line) using shell
# d, drop = remove commit
#
# These lines can be re-ordered; they are executed from top to bottom.
#
# If you remove a line here THAT COMMIT WILL BE LOST.
#
# However, if you remove everything, the rebase will be aborted.
#
# Note that empty commits are commented out

You can use git rebase -i --root in order to rebase from the first commit.

Answer 2

If all you really want is to squash your local development history before submitting a pull-request, the simplest way is to just develop on a local feature branch which is different from whatever upstream branch you want to affect.

Then, the procedure for squashing it onto master is

git checkout master
git merge --squash feature

(replace master with integration or whatever).

I'd use rebase -i for fine control, but for this simple case we can use git's knowledge of your history to figure out the last common ancestor automatically.