[git] How to change the commit author for one specific commit?

I want to change the author of one specific commit in the history. It's not the last commit.

I know about this question - How do I change the author of a commit in git?

But I am thinking about something, where I identify the commit by hash or short-hash.

SOLUTION

1. Install git filter-repo (Git project recommends filter-repo over filter-branch)

   $ PACKAGE_TOOL install git-filter-repo
   

2. Create a file .mailmap in the root of the git repository containing

   New Name <[email protected]> <[email protected]>
   

3. Run git filter-repo --use-mailmap

MORE DETAILS

• git-filter-repo lists this as an example in their docs
• Instead of replacing both name and email based on email filter as in example above, take a look at additional examples in git mailmap documentation
• Instead of using default .mailmap file you can specify your own by invoking git filter-repo with argument --mailmap <filename>.
• Many more examples on how to further filter branch/tag/whatever can be found in git-filter-repo project's README.md.

For the merge commit message, I found that I cannot amend it by using rebase, at least on gitlab. It shows the merge as a commit but I cannot rebase onto that #sha. I found this post is helpful.

git checkout <sha of merge>
git commit --amend # edit message
git rebase HEAD previous_branch

This three lines of code did the job for changing the merge commit message (like author).

The accepted answer to this question is a wonderfully clever use of interactive rebase, but it unfortunately exhibits conflicts if the commit we are trying to change the author of used to be on a branch which was subsequently merged in. More generally, it does not work when handling messy histories.

Since I am apprehensive about running scripts which depend on setting and unsetting environment variables to rewrite git history, I am writing a new answer based on this post which is similar to this answer but is more complete.

The following is tested and working, unlike the linked answer. Assume for clarity of exposition that 03f482d6 is the commit whose author we are trying to replace, and 42627abe is the commit with the new author.

1. Checkout the commit we are trying to modify.

   git checkout 03f482d6
   

2. Make the author change.

   git commit --amend --author "New Author Name <New Author Email>"
   

   Now we have a new commit with hash assumed to be 42627abe.

3. Checkout the original branch.

4. Replace the old commit with the new one locally.

   git replace 03f482d6 42627abe
   

5. Rewrite all future commits based on the replacement.

   git filter-branch -- --all
   

6. Remove the replacement for cleanliness.

   git replace -d 03f482d6
   

7. Push the new history (only use --force if the below fails, and only after sanity checking with git log and/or git diff).

   git push --force-with-lease
   

Instead of 4-6 you can just rebase onto new commit:

git rebase -i 42627abe

OPTIONAL: Make sure to stash your local changes if you don't want to send them to remote.

$ git status
$ git stash

Update the author for the last commit.

$ git log   // Old author in local and remote
$ git commit --amend --author="Author Name <[email protected]>"
$ git log   // New Author in local
$ git push origin <branch> --force-with-lease 
$ git log   // New Author in remote

Then, if you used git stash then recovers your staged changes

$ git stash pop
$ git status

Then, you should to update the configuration for the next commits of the current project.

$ git config user.name "Author Name"
$ git config user.email "<[email protected]>"

And check or also edit this with git config --edit

Clarification: In the rare case that you lose commits using $ ggpush -f you can recover them with reflog. Anyway using --force-with-lease you are protected even more than if you use only -f

GL

• Source
• ZSH

The answers in the question to which you linked are good answers and cover your situation (the other question is more general since it involves rewriting multiple commits).

As an excuse to try out git filter-branch, I wrote a script to rewrite the Author Name and/or Author Email for a given commit:

#!/bin/sh

#
# Change the author name and/or email of a single commit.
#
# change-author [-f] commit-to-change [branch-to-rewrite [new-name [new-email]]]
#
#     If -f is supplied it is passed to "git filter-branch".
#
#     If <branch-to-rewrite> is not provided or is empty HEAD will be used.
#     Use "--all" or a space separated list (e.g. "master next") to rewrite
#     multiple branches.
#
#     If <new-name> (or <new-email>) is not provided or is empty, the normal
#     user.name (user.email) Git configuration value will be used.
#

force=''
if test "x$1" = "x-f"; then
    force='-f'
    shift
fi

die() {
    printf '%s\n' "$@"
    exit 128
}
targ="$(git rev-parse --verify "$1" 2>/dev/null)" || die "$1 is not a commit"
br="${2:-HEAD}"

TARG_COMMIT="$targ"
TARG_NAME="${3-}"
TARG_EMAIL="${4-}"
export TARG_COMMIT TARG_NAME TARG_EMAIL

filt='

    if test "$GIT_COMMIT" = "$TARG_COMMIT"; then
        if test -n "$TARG_EMAIL"; then
            GIT_AUTHOR_EMAIL="$TARG_EMAIL"
            export GIT_AUTHOR_EMAIL
        else
            unset GIT_AUTHOR_EMAIL
        fi
        if test -n "$TARG_NAME"; then
            GIT_AUTHOR_NAME="$TARG_NAME"
            export GIT_AUTHOR_NAME
        else
            unset GIT_AUTHOR_NAME
        fi
    fi

'

git filter-branch $force --env-filter "$filt" -- $br

Steps to rename author name after commit pushed

1. First type "git log" to get the commit id and more details

2. git rebase i HEAD~10 (10 is the total commit to display on rebase)

   If you Get anything like below

   fatal: It seems that there is already a rebase-merge directory, and I wonder if you are in the middle of another rebase. If that is the case, please try

   git rebase (--continue | --abort | --skip) If that is not the case, please rm -fr ".git/rebase-merge" and run me again. I am stopping in case you still have something valuable there.

3. Then type "git rebase --continue" or "git rebase --abort" as per your need

   • now your will rebase window opened, click "i" key from keyboard
   • then you will get list of commits to 10 [because we have passed 10 commit above] Like below

   pick 897fe9e simplify code a little

   pick abb60f9 add new feature

   pick dc18f70 bugfix

4. Now you need to add below command just below of the commit you want to edit, like below

   pick 897fe9e simplify code a little exec git commit --amend --author 'Author Name <[email protected]>' pick abb60f9 add new feature exec git commit --amend --author 'Author Name <[email protected]>' pick dc18f70 bugfix exec git commit --amend --author 'Author Name <[email protected]>'

   5. That's it, now just press ESC, :wq and you are all set

   6. Then git push origin HEAD:BRANCH NAME -f [please take care of -f Force push]

   like git push -f or git push origin HEAD: dev -f

Commit before:

To fix author for all commits you can apply command from @Amber's answer:

git commit --amend --author="Author Name <[email protected]>"

Or to reuse your name and email you can just write:

git commit --amend --author=Eugen

Commit after the command:

For example to change all starting from 4025621:

You must run:

git rebase --onto 4025621 --exec "git commit --amend --author=Eugen" 4025621

Note: To include an author containing spaces such as a name and email address, the author must be surrounded by escaped quotes. For example:

git rebase --onto 4025621 --exec "git commit --amend --author=\"Foo Bar <[email protected]>\"" 4025621

or add this alias into ~/.gitconfig:

[alias]
    reauthor = !bash -c 'git rebase --onto $1 --exec \"git commit --amend --author=$2\" $1' --

And then run:

git reauthor 4025621 Eugen

Find a way that can change user quickly and has no side effect to others commits.

Simple and clear way:

git config user.name "New User"
git config user.email "[email protected]"

git log
git rebase -i 1f1357
# change the word 'pick' to 'edit', save and exit

git commit --amend --reset-author --no-edit
git rebase --continue

git push --force-with-lease

detailed operations

• show commit logs and find out the commit id that ahead of your commit which you want to change:

git log

• git rebase start from the chosed commit id to the recent reversely:

git config user.name "New User"
git config user.email "[email protected]"
git rebase -i 1f1357

# change word pick to edit, save and exit
edit 809b8f7 change code order 
pick 9baaae5 add prometheus monitor kubernetes
edit 5d726c3 fix liquid escape issue   
edit 3a5f98f update tags
pick 816e21c add prometheus monitor kubernetes

• rebase will Stopped at next commit id, output:

Stopped at 809b8f7...  change code order 
You can amend the commit now, with
  git commit --amend 

Once you are satisfied with your changes, run

  git rebase --continue

• comfirm and continue your rebase untill it successfully to refs/heads/master.

# each continue will show you an amend message
# use git commit --amend --reset-author --no-edit to comfirm
# use git rebase --skip to skip
git commit --amend --reset-author --no-edit
git rebase --continue
git commit --amend --reset-author --no-edit
...
git rebase --continue
Successfully rebased and updated refs/heads/master.

• git push to update

git push --force-with-lease

• Reset your email to the config globally:

  git config --global user.email [email protected]

• Now reset the author of your commit without edit required:

  git commit --amend --reset-author --no-edit

You can change author of last commit using the command below.

git commit --amend --author="Author Name <[email protected]>"

However, if you want to change more than one commits author name, it's a bit tricky. You need to start an interactive rebase then mark commits as edit then amend them one by one and finish.

Start rebasing with git rebase -i. It will show you something like this.

Change the pick keyword to edit for the commits you want to change the author name.

Then close the editor. For the beginners, hit Escape then type :wq and hit Enter.

Then you will see your terminal like nothing happened. Actually you are in the middle of an interactive rebase. Now it's time to amend your commit's author name using the command above. It will open the editor again. Quit and continue rebase with git rebase --continue. Repeat the same for the commit count you want to edit. You can make sure that interactive rebase finished when you get the No rebase in progress? message.

There is also a lazy approach to this problem, especially if you have more than one commit that you want to change. In my case, I had a new branch with several commits with a wrong author, so what helped me:

Go to your original branch:

git checkout develop

Create new branch from it:

git checkout -b myFeature develop 

Merge it without commit info as one commit:

git merge --no-commit --squash branchWrongAuthor

You might also want to stage changes:

git stage .

Change the name of the author and commit changes:

git commit --amend --author "New Author Name <New Author Email>" -m "new feature added"

And that's it, you can push the changes.

git push

You can delete the branch with a wrong author after that.

In furtherance to Eugen Konkov answer, to start from the root commit, use --root flag. The --no-edit flag is helpful too, because with it you are not prompted into an editor for each commit.

git rebase --root --exec "git commit --amend --author='name <email>' --no-edit"

If the commit that you want to change is not the last commit, then follow the below steps. If your commit is in different branch then first switch to that branch.

git checkout branch_name

Find commit before the commit that you want to change and find its hash. Then issue rebase command.

git rebase -i -p hash of commit

Then an editor will open and enter 'edit' for the commits that you want to change. Leave others with default 'pick' option. Once changed enter 'esc' key and wq! to exit.

Then issue git commit command with amendment option.

git commit --amend --author="Username email" --no-edit

Then issue the following command.

git rebase --continue

Once commit author is updated in the local repository, push the changes to the remote repository.

you can use these commands from official page of github

https://help.github.com/en/github/using-git/changing-author-info

here is the commands

#!/bin/sh

git filter-branch --env-filter '

OLD_EMAIL="[email protected]"
CORRECT_NAME="Your Correct Name"
CORRECT_EMAIL="[email protected]"

if [ "$GIT_COMMITTER_EMAIL" = "$OLD_EMAIL" ]
then
export GIT_COMMITTER_NAME="$CORRECT_NAME"
export GIT_COMMITTER_EMAIL="$CORRECT_EMAIL"
fi
if [ "$GIT_AUTHOR_EMAIL" = "$OLD_EMAIL" ]
then
export GIT_AUTHOR_NAME="$CORRECT_NAME"
export GIT_AUTHOR_EMAIL="$CORRECT_EMAIL"
fi
' --tag-name-filter cat -- --branches --tags

here u can change the old email to ur new user name and email address.

Github documentation contains a script that replaces the committer info for all commits in a branch.

• Run the following script from terminal after changing the variable values

  #!/bin/sh
  
  git filter-branch --env-filter '
  
  OLD_EMAIL="[email protected]"
  CORRECT_NAME="Your Correct Name"
  CORRECT_EMAIL="[email protected]"
  
  if [ "$GIT_COMMITTER_EMAIL" = "$OLD_EMAIL" ]
  then
      export GIT_COMMITTER_NAME="$CORRECT_NAME"
      export GIT_COMMITTER_EMAIL="$CORRECT_EMAIL"
  fi
  if [ "$GIT_AUTHOR_EMAIL" = "$OLD_EMAIL" ]
  then
      export GIT_AUTHOR_NAME="$CORRECT_NAME"
      export GIT_AUTHOR_EMAIL="$CORRECT_EMAIL"
  fi
  ' --tag-name-filter cat -- --branches --tags
  

• Push the corrected history to GitHub:

  git push --force --tags origin 'refs/heads/*'
  

  OR if you like to push selected references of the branches then use

  git push --force --tags origin 'refs/heads/develop'
  

If what you need to change is the AUTHOR OF THE LAST commit and no other is using your repository, you may undo your last commit with:

git push -f origin last_commit_hash:branch_name 

change the author name of your commit with:

git commit --amend --author "type new author here"

Exit the editor that opens and push again your code:

git push

There is one additional step to Amber's answer if you're using a centralized repository:

git push -f to force the update of the central repository.

Be careful that there are not a lot of people working on the same branch because it can ruin consistency.

Changing Your Committer Name & Email Globally:

$ git config --global user.name "John Doe"
$ git config --global user.email "[email protected]"

Changing Your Committer Name & Email per Repository:

$ git config user.name "John Doe"
$ git config user.email "[email protected]"

Changing the Author Information Just for the Next Commit:

$ git commit --author="John Doe <[email protected]>"

Hint: For other situation and read more information read the post reference.

When doing git rebase -i there is this interesting bit in the doc:

If you want to fold two or more commits into one, replace the command "pick" for the second and subsequent commits with "squash" or "fixup". If the commits had different authors, the folded commit will be attributed to the author of the first commit. The suggested commit message for the folded commit is the concatenation of the commit messages of the first commit and of those with the "squash" command, but omits the commit messages of commits with the "fixup" command.

• If you have an history of A-B-C-D-E-F,
• and you want to change commits B and D (= 2 commits),

then you can do:

• git config user.name "Correct new name"
• git config user.email "[email protected]"
• create empty commits (one for each commit):
  • you need a message for rebase purpose
  • git commit --allow-empty -m "empty"
• start the rebase operation
  • git rebase -i B^
  • B^ selects the parent of B.
• you will want to put one empty commit before each commit to modify
• you will want to change pick to squash for those.

Example of what git rebase -i B^ will give you:

pick sha-commit-B some message
pick sha-commit-C some message
pick sha-commit-D some message
pick sha-commit-E some message
pick sha-commit-F some message
# pick sha-commit-empty1 empty
# pick sha-commit-empty2 empty

change that to:

# change commit B's author
pick sha-commit-empty1 empty
squash sha-commit-B some message
# leave commit C alone
pick sha-commit-C some message
# change commit D's author
pick sha-commit-empty2 empty
squash sha-commit-D some message
# leave commit E-F alone
pick sha-commit-E some message
pick sha-commit-F some message

It will prompt you to edit the messages:

# This is a combination of 2 commits.
# The first commit's message is:

empty

# This is the 2nd commit message:

...some useful commit message there...

and you can just remove the first few lines.