MontrealDevOne
MontrealDevOne

Reputation: 1044

Git overwrite master and keep history

I would like to overwrite the master branch and keep the history of the files.

I have an API that I generate code. Everytime I generate the code for the API, I would like to overwrite the master branch, and remove any files that I do not have locally from the remote master branch. The files that I do have locally, I would like to track their history once I push them.

I used git push --set-upstream origin master -f and this deleted the history of all files.

Upvotes: 0

Views: 620

Answers (1)

CodeWizard
CodeWizard

Reputation: 142402

Few options:

git reset

You can tag your current HEAD and once it's tagged you can revert any prior commit since git will keep the full history


git checkout <backup branch>

Backup the current branch history into a new branch


git revert <sha-1>

"Undo" the given commit or commit range.
The reset command will "undo" any changes made in the given commit.
A new commit with the undo patch will be committed while the original commit will remain in the history as well.

# add new commit with the undoing of the original one.
# the <sha-1> can be any commit(s) or commit range
git revert <sha-1>

Full answer: Choose the one which suits your choice - I added some extra info as well so you can have the full picture


Before answering let's add some background, explaining what is this HEAD.

First of all what is HEAD?

HEAD is simply a reference to the current commit (latest) on the current branch.
There can only be a single HEAD at any given time. (excluding git worktree)

The content of HEAD is stored inside .git/HEAD and it contains the 40 bytes SHA-1 of the current commit.


detached HEAD

If you are not on the latest commit - meaning that HEAD is pointing to a prior commit in history its called detached HEAD.

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On the command line, it will look like this- SHA-1 instead of the branch name since the HEAD is not pointing to the tip of the current branch

enter image description here

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A few options on how to recover from a detached HEAD - or in your case how to keep the history in git


git checkout

git checkout <commit_id>
git checkout -b <new branch> <commit_id>
git checkout HEAD~X // x is the number of commits t go back

This will checkout new branch pointing to the desired commit.
This command will checkout to a given commit.
At this point, you can create a branch and start to work from this point on.

# Checkout a given commit. 
# Doing so will result in a `detached HEAD` which mean that the `HEAD`
# is not pointing to the latest so you will need to checkout branch
# in order to be able to update the code.
git checkout <commit-id>

# create a new branch forked to the given commit
git checkout -b <branch name>

git reflog

You can always use the reflog as well.
git reflog will display any change which updated the HEAD and checking out the desired reflog entry will set the HEAD back to this commit.

Every time the HEAD is modified there will be a new entry in the reflog

git reflog
git checkout HEAD@{...}

This will get you back to your desired commit

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git reset --hard <commit_id>

"Move" your HEAD back to the desired commit.

# This will destroy any local modifications.
# Don't do it if you have uncommitted work you want to keep.
git reset --hard 0d1d7fc32

# Alternatively, if there's work to keep:
git stash
git reset --hard 0d1d7fc32
git stash pop
# This saves the modifications, then reapplies that patch after resetting.
# You could get merge conflicts if you've modified things which were
# changed since the commit you reset to.
  • Note: (Since Git 2.7)
    you can also use the git rebase --no-autostash as well.

git revert <sha-1>

"Undo" the given commit or commit range.
The reset command will "undo" any changes made in the given commit.
A new commit with the undo patch will be committed while the original commit will remain in the history as well.

# add new commit with the undo of the original one.
# the <sha-1> can be any commit(s) or commit range
git revert <sha-1>

This schema illustrates which command does what.
As you can see there reset && checkout modify the HEAD.

enter image description here

Upvotes: 1

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