Work Annoyance 1: Git Rebase

How many times the below thing happens to you?

1. You have created

   hotfix

   or patch branch in your work
2. You have pushed your commits to your work remote repo
3. There has been a update in master leaving your

   hotfix

   branch out-of-sync with master.
4. You will be forced to "Sync them"
5. Now is the question?

   git rebase

   or

   git merge

   ?

Though,

git rebase

is the keyword everyone uses and your managers will force you to rebase without knowing consequences.

Simply,

git rebase

won't work. Will explain you why.

git rebase

takes all the commits from your

hotfix

branch and applies on the new branch out of master as if that

hotfix

commit was never made.

It is like as if yourself

1. Takes all the changes in the first commit of

   hotfix

   branch and then applies the changes to the corresponding files manually via a code editor and then you commit them like usual in a new

   temp

   branch cut out of master.
2. You would repeat 1 for all the commits in your

   hotfix

   branch.
3. And then you would delete the old

   hotfix

   branch and rename the

   temp

   branch as your

   hotfix

   branch

git rebase

automates the above steps with optimisations. You can read about

git rebase

in here.

One thing you might have noticed that the old

hotfix

branch and new rebased

hotfix

branch are not the same, though their contents are. you can confirm them by

git log

. You will see the new datetimes and new hashids or commit ids compared to what you saw in the old

hotfix

.

So, now when you try to push the changes to

hotfix

branch, you will get an error similar to, "Updates were rejected because the tip of your current branch is behind its remote".

This is completely understandable since both branches have different ids in their history and no commit in common except for the base commit out of master.

And a normal

git push origin hotfix

cannot force the remote repo to override its

hotfix

branch.

Most often, Your organization would have disabled

force-push

, which lets u overwrite the

hotfix

branch.

Only working option u have is

git merge

.

git merge

is a very simple command. It adds a merge commit on top of current

hotfix

in addition to resolving any conflicts. You can read about it in here.

Now, you can easily push the branch because you are pushing only a single commit on top of existing

hotfix

branch without changing old commit ids.

So local

hotfix

is same as remote

hotfix

but one additional commit in local

hotfix

. But both

hotfixes

share the same history except for that one additional commit. Thereby, Remote can fast-forward its remote branch.

TLDR; don't use

git rebase

, if u have pushed your branch to remote. Always use

git merge

.