Git Rebasing
External
Internal
TODO
- https://www.atlassian.com/git/tutorials/merging-vs-rebasing
- “Rebase Commits” section from the O’Reilly book
- Understand merge really well, especially
- What happens if I have several commits on the topic branch?
- Read git rebase --help.
- Understand git pull --rebase.
Overview
There are two situations when rebasing is useful: on an individual branch, to coalesce several logically-related commits into one, or when two connected branches are involved, to shift head branch commits relative to the base branch commits. This last situation is useful when we intend to merge the branches and we want to avoid a merge commit - the base branch can simply be fast forwarded with the commits from the head branch.
Rebasing rewrites history, by removing the commits that are being rebased and creating new, equivalent ones.
Rewriting History
Rebasing removes the commits that are being rebased and creating new, equivalent ones.
Practical Use Cases
Squashing Commits
Shifting Head Branch Commits at the HEAD of the Base Branch
One might want to do that in preparation of a merge of those branches, by shifting the commits applied on the head branch at the top of the base branch - and modifying them in the process. The advantage of doing that is that when the merge occurs, is a simple fast forward merge, and no additional merge commit is created - the changes required by the merge are already worked into the commits that are rebased.
To Link To
Fixing a Merge Broken by Base Branch Rebase
Moving a Branch Forward
You are working on a feature branch, named "A", created when the "develop" branch HEAD was commit "ef5". You committed work on the "A" branch, and your commit is "3ba". After a while, you want to apply your changes on the HEAD of "develop", since "develop" has evolved and you want to try
On branch task/of/PLAT-15252 Your branch and 'origin/task/of/PLAT-15252' have diverged, and have 164 and 1 different commits each, respectively. (use "git pull" to merge the remote branch into yours)
Rebasing at the HEAD of the Base Branch
This procedure takes all commits from the head branch that diverged from the base branch, squashes them into one, and applies to the HEAD of the base branch.
You will be given the chance to squash extraneous commits. Change "pick" into "s" for the commits you want squashed into the previous (above) commits.
You will then be given the chance to edit comments.
If you don't want to squash, you can omit -i.
On branch topic/... Your branch and 'origin/topic/...' have diverged, and have 1 and 2 different commits each, respectively. (use "git pull" to merge the remote branch into yours)
git push --force
You can delete the branch (locally and remotely)