GIT-REBASE(1)

NAME

git-rebase - Forward-port local commits to the updated upstream head

SYNOPSIS

git rebase [-i | --interactive] [options] [--onto <newbase>]
        <upstream> [<branch>]
git rebase [-i | --interactive] [options] --onto <newbase>
        --root [<branch>]


git rebase --continue | --skip | --abort

DESCRIPTION

If <branch> is specified, git rebase will perform an automatic git checkout <branch> before doing anything else. Otherwise it remains on
the current branch.

All changes made by commits in the current branch but that are not in
<upstream> are saved to a temporary area. This is the same set of
commits that would be shown by git log <upstream>..HEAD (or git log
HEAD, if --root is specified).

The current branch is reset to <upstream>, or <newbase> if the --onto
option was supplied. This has the exact same effect as git reset --hard <upstream> (or <newbase>). ORIG_HEAD is set to point at the tip of the branch before the reset.

The commits that were previously saved into the temporary area are then reapplied to the current branch, one by one, in order. Note that any
commits in HEAD which introduce the same textual changes as a commit in HEAD..<upstream> are omitted (i.e., a patch already accepted upstream
with a different commit message or timestamp will be skipped).

It is possible that a merge failure will prevent this process from
being completely automatic. You will have to resolve any such merge
failure and run git rebase --continue. Another option is to bypass the commit that caused the merge failure with git rebase --skip. To restore the original <branch> and remove the .git/rebase-apply working files,
use the command git rebase --abort instead.

Assume the following history exists and the current branch is "topic":: A---B---C topic
/
D---E---F---G master
From this point, the result of either of the following commands:: git rebase master
git rebase master topic
would be:: A'--B'--C' topic
/
D---E---F---G master
The latter form is just a short-hand of git checkout topic followed by git rebase master.
If the upstream branch already contains a change you have made (e.g., because you mailed a patch which was applied upstream), then that commit will be skipped. For example, running 'git rebase master` on the following history (in which A' and A introduce the same set of changes, but have different committer information):: A---B---C topic
/
D---E---A'---F master
will result in:: B'---C' topic
/
D---E---A'---F master
Here is how you would transplant a topic branch based on one branch to another, to pretend that you forked the topic branch from the latter branch, using rebase --onto.
First let's assume your topic is based on branch next. For example, a feature developed in topic depends on some functionality which is found in next.: o---o---o---o---o master
\
o---o---o---o---o next
\
o---o---o topic
We want to make topic forked from branch master; for example, because the functionality on which topic depends was merged into the more stable master branch. We want our tree to look like this:: o---o---o---o---o master
| \
| o'--o'--o' topic
\
o---o---o---o---o next
We can get this using the following command:: git rebase --onto master next topic
Another example of --onto option is to rebase part of a branch. If we have the following situation:: H---I---J topicB
/
E---F---G topicA
/
A---B---C---D master
then the command: git rebase --onto master topicA topicB
would result in:: H'--I'--J' topicB
/ | E---F---G topicA |/
A---B---C---D master
This is useful when topicB does not depend on topicA.
A range of commits could also be removed with rebase. If we have the following situation:: E---F---G---H---I---J topicA
then the command: git rebase --onto topicA~5 topicA~3 topicA
would result in the removal of commits F and G:: E---H'---I'---J' topicA
This is useful if F and G were flawed in some way, or should not be part of topicA. Note that the argument to --onto and the <upstream> parameter can be any valid commit-ish.
In case of conflict, git rebase will stop at the first problematic commit and leave conflict markers in the tree. You can use git diff to locate the markers (<<<<<<) and make edits to resolve the conflict. For each file you edit, you need to tell git that the conflict has been resolved, typically this would be done with: git add <filename>
After resolving the conflict manually and updating the index with the desired resolution, you can continue the rebasing process with: git rebase --continue
Alternatively, you can undo the git rebase with: git rebase --abort

CONFIGURATION

rebase.stat: Whether to show a diffstat of what changed upstream since the last rebase. False by default.

OPTIONS

<newbase>: Starting point at which to create the new commits. If the --onto
option is not specified, the starting point is <upstream>. May be
any valid commit, and not just an existing branch name.
<upstream>: Upstream branch to compare against. May be any valid commit, not
just an existing branch name.
<branch>: Working branch; defaults to HEAD.
--continue: Restart the rebasing process after having resolved a merge
conflict.
--abort: Restore the original branch and abort the rebase operation.
--skip: Restart the rebasing process by skipping the current patch.
-m, --merge: Use merging strategies to rebase. When the recursive (default)
merge strategy is used, this allows rebase to be aware of renames
on the upstream side.; Note that a rebase merge works by replaying each commit from the
working branch on top of the <upstream> branch. Because of this,
when a merge conflict happens, the side reported as ours is the so-far rebased series, starting with <upstream>, and theirs is the working branch. In other words, the sides are swapped.
-s <strategy>, --strategy=<strategy>: Use the given merge strategy. If there is no -s option git
merge-recursive is used instead. This implies --merge.; Because git rebase replays each commit from the working branch on top of the <upstream> branch using the given strategy, using the
ours strategy simply discards all patches from the <branch>, which makes little sense.
-q, --quiet: Be quiet. Implies --no-stat.
-v, --verbose: Be verbose. Implies --stat.
--stat: Show a diffstat of what changed upstream since the last rebase. The diffstat is also controlled by the configuration option
rebase.stat.
-n, --no-stat: Do not show a diffstat as part of the rebase process.
--no-verify: This option bypasses the pre-rebase hook. See also githooks(5).
-C<n>: Ensure at least <n> lines of surrounding context match before and
after each change. When fewer lines of surrounding context exist
they all must match. By default no context is ever ignored.
-f, --force-rebase: Force the rebase even if the current branch is a descendant of the commit you are rebasing onto. Normally non-interactive rebase will exit with the message "Current branch is up to date" in such a
situation. Incompatible with the --interactive option.; You may find this (or --no-ff with an interactive rebase) helpful
after reverting a topic branch merge, as this option recreates the topic branch with fresh commits so it can be remerged successfully without needing to "revert the reversion" (see the
revert-a-faulty-merge How-To[1] for details).
--ignore-whitespace, --whitespace=<option>: These flag are passed to the git apply program (see git-apply(1)) that applies the patch. Incompatible with the --interactive option.
--committer-date-is-author-date, --ignore-date: These flags are passed to git am to easily change the dates of the rebased commits (see git-am(1)).
-i, --interactive: Make a list of the commits which are about to be rebased. Let the
user edit that list before rebasing. This mode can also be used to split commits (see SPLITTING COMMITS below).
-p, --preserve-merges: Instead of ignoring merges, try to recreate them.
--root: Rebase all commits reachable from <branch>, instead of limiting
them with an <upstream>. This allows you to rebase the root
commit(s) on a branch. Must be used with --onto, and will skip
changes already contained in <newbase> (instead of <upstream>).
When used together with --preserve-merges, all root commits will be rewritten to have <newbase> as parent instead.
--autosquash: When the commit log message begins with "squash! ..." (or "fixup!
..."), and there is a commit whose title begins with the same ..., automatically modify the todo list of rebase -i so that the commit marked for squashing comes right after the commit to be modified,
and change the action of the moved commit from pick to squash (or
fixup).; This option is only valid when the --interactive option is used.
--no-ff: With --interactive, cherry-pick all rebased commits instead of
fast-forwarding over the unchanged ones. This ensures that the
entire history of the rebased branch is composed of new commits.; Without --interactive, this is a synonym for --force-rebase.; You may find this helpful after reverting a topic branch merge, as this option recreates the topic branch with fresh commits so it can be remerged successfully without needing to "revert the reversion" (see the revert-a-faulty-merge How-To[1] for details).

MERGE STRATEGIES

The merge mechanism (git-merge and git-pull commands) allows the backend merge strategies to be chosen with -s option. Some strategies can also take their own options, which can be passed by giving
-X<option> arguments to git-merge and/or git-pull.

resolve: This can only resolve two heads (i.e. the current branch and
another branch you pulled from) using a 3-way merge algorithm. It
tries to carefully detect criss-cross merge ambiguities and is
considered generally safe and fast.
recursive: This can only resolve two heads using a 3-way merge algorithm. When there is more than one common ancestor that can be used for 3-way
merge, it creates a merged tree of the common ancestors and uses
that as the reference tree for the 3-way merge. This has been
reported to result in fewer merge conflicts without causing
mis-merges by tests done on actual merge commits taken from Linux
2.6 kernel development history. Additionally this can detect and
handle merges involving renames. This is the default merge strategy when pulling or merging one branch.; The recursive strategy can take the following options:; ours
This option forces conflicting hunks to be auto-resolved
cleanly by favoring our version. Changes from the other tree that do not conflict with our side are reflected to the merge
result.

This should not be confused with the ours merge strategy, which does not even look at what the other tree contains at all. It
discards everything the other tree did, declaring our history contains all that happened in it.; theirs
This is opposite of ours.; subtree[=path]
This option is a more advanced form of subtree strategy, where the strategy makes a guess on how two trees must be shifted to match with each other when merging. Instead, the specified path is prefixed (or stripped from the beginning) to make the shape of two trees to match.
octopus: This resolves cases with more than two heads, but refuses to do a
complex merge that needs manual resolution. It is primarily meant
to be used for bundling topic branch heads together. This is the
default merge strategy when pulling or merging more than one
branch.
ours: This resolves any number of heads, but the resulting tree of the
merge is always that of the current branch head, effectively
ignoring all changes from all other branches. It is meant to be
used to supersede old development history of side branches. Note
that this is different from the -Xours option to the recursive merge strategy.
subtree: This is a modified recursive strategy. When merging trees A and B, if B corresponds to a subtree of A, B is first adjusted to match
the tree structure of A, instead of reading the trees at the same
level. This adjustment is also done to the common ancestor tree.

NOTES

You should understand the implications of using git rebase on a repository that you share. See also RECOVERING FROM UPSTREAM REBASE
below.

When the git-rebase command is run, it will first execute a
"pre-rebase" hook if one exists. You can use this hook to do sanity
checks and reject the rebase if it isn't appropriate. Please see the
template pre-rebase hook script for an example.

Upon completion, <branch> will be the current branch.

INTERACTIVE MODE

Rebasing interactively means that you have a chance to edit the commits which are rebased. You can reorder the commits, and you can remove them (weeding out bad or otherwise unwanted patches).

The interactive mode is meant for this type of workflow:: 1. have a wonderful idea; 2. hack on the code; 3. prepare a series for submission; 4. submit
where point 2. consists of several instances of: 1. regular use

1. finish something worthy of a commit

2. commit

2. independent fixup

1. realize that something does not work

2. fix that

3. commit it

Sometimes the thing fixed in b.2. cannot be amended to the not-quite
perfect commit it fixes, because that commit is buried deeply in a
patch series. That is exactly what interactive rebase is for: use it
after plenty of "a"s and "b"s, by rearranging and editing commits, and squashing multiple commits into one.

Start it with the last commit you want to retain as-is:

git rebase -i <after-this-commit>

An editor will be fired up with all the commits in your current branch (ignoring merge commits), which come after the given commit. You can
reorder the commits in this list to your heart's content, and you can
remove them. The list looks more or less like this:

pick deadbee The oneline of this commit
pick fa1afe1 The oneline of the next commit
...

The oneline descriptions are purely for your pleasure; git rebase will not look at them but at the commit names ("deadbee" and "fa1afe1" in
this example), so do not delete or edit the names.

By replacing the command "pick" with the command "edit", you can tell
git rebase to stop after applying that commit, so that you can edit the files and/or the commit message, amend the commit, and continue
rebasing.

If you just want to edit the commit message for a commit, replace the
command "pick" with the command "reword".

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.

git rebase will stop when "pick" has been replaced with "edit" or when a command fails due to merge errors. When you are done editing and/or
resolving conflicts you can continue with git rebase --continue.

For example, if you want to reorder the last 5 commits, such that what was HEAD~4 becomes the new HEAD. To achieve that, you would call git rebase like this:

$ git rebase -i HEAD~5

And move the first patch to the end of the list.

You might want to preserve merges, if you have a history like this:

X
\

A---M---B; /
---o---O---P---Q
Suppose you want to rebase the side branch starting at "A" to "Q". Make sure that the current HEAD is "B", and call: $ git rebase -i -p --onto Q O

SPLITTING COMMITS

In interactive mode, you can mark commits with the action "edit".
However, this does not necessarily mean that git rebase expects the result of this edit to be exactly one commit. Indeed, you can undo the commit, or you can add other commits. This can be used to split a
commit into two:

o Start an interactive rebase with git rebase -i <commit>^, where: <commit> is the commit you want to split. In fact, any commit range will do, as long as it contains that commit.
o Mark the commit you want to split with the action "edit".
o When it comes to editing that commit, execute git reset HEAD^. The effect is that the HEAD is rewound by one, and the index follows suit. However, the working tree stays the same.
o Now add the changes to the index that you want to have in the first commit. You can use git add (possibly interactively) or git gui (or both) to do that.
o Commit the now-current index with whatever commit message is appropriate now.
o Repeat the last two steps until your working tree is clean.
o Continue the rebase with git rebase --continue.
If you are not absolutely sure that the intermediate revisions are consistent (they compile, pass the testsuite, etc.) you should use git stash to stash away the not-yet-committed changes after each commit, test, and amend the commit if fixes are necessary.

RECOVERING FROM UPSTREAM REBASE

Rebasing (or any other form of rewriting) a branch that others have
based work on is a bad idea: anyone downstream of it is forced to
manually fix their history. This section explains how to do the fix
from the downstream's point of view. The real fix, however, would be to avoid rebasing the upstream in the first place.

To illustrate, suppose you are in a situation where someone develops a subsystem branch, and you are working on a topic that is dependent on this subsystem. You might end up with a history like the following:: o---o---o---o---o---o---o---o---o master
\
o---o---o---o---o subsystem
\
*---*---* topic
If subsystem is rebased against master, the following happens:: o---o---o---o---o---o---o---o master
\ \
o---o---o---o---o o'--o'--o'--o'--o' subsystem
\
*---*---* topic
If you now continue development as usual, and eventually merge topic to subsystem, the commits from subsystem will remain duplicated forever:: o---o---o---o---o---o---o---o master
\ \
o---o---o---o---o o'--o'--o'--o'--o'--M subsystem \ /
*---*---*-..........-*--* topic
Such duplicates are generally frowned upon because they clutter up history, making it harder to follow. To clean things up, you need to transplant the commits on topic to the new subsystem tip, i.e., rebase topic. This becomes a ripple effect: anyone downstream from topic is forced to rebase too, and so on!
There are two kinds of fixes, discussed in the following subsections:
Easy case: The changes are literally the same. This happens if the subsystem rebase was a simple rebase and had no conflicts.
Hard case: The changes are not the same. This happens if the subsystem rebase had conflicts, or used --interactive to omit, edit, squash, or fixup commits; or if the upstream used one of commit --amend, reset, or filter-branch.
The easy case
Only works if the changes (patch IDs based on the diff contents) on
subsystem are literally the same before and after the rebase subsystem did.
In that case, the fix is easy because git rebase knows to skip changes that are already present in the new upstream. So if you say (assuming you're on topic): $ git rebase subsystem
you will end up with the fixed history: o---o---o---o---o---o---o---o master
\
o'--o'--o'--o'--o' subsystem
\
*---*---* topic
The hard case
Things get more complicated if the subsystem changes do not exactly correspond to the ones before the rebase.: Note
While an "easy case recovery" sometimes appears to be successful
even in the hard case, it may have unintended consequences. For
example, a commit that was removed via git rebase --interactive
will be resurrected!
The idea is to manually tell git rebase "where the old subsystem ended and your topic began", that is, what the old merge-base between them was. You will have to find a way to name the last commit of the old subsystem, for example:
o With the subsystem reflog: after git fetch, the old tip of subsystem is at subsystem@{1}. Subsequent fetches will increase the number. (See git-reflog(1).)
o Relative to the tip of topic: knowing that your topic has three commits, the old tip of subsystem must be topic~3.
You can then transplant the old subsystem..topic to the new tip by saying (for the reflog case, and assuming you are on topic already):: $ git rebase --onto subsystem subsystem@{1}
The ripple effect of a "hard case" recovery is especially bad: everyone downstream from topic will now have to perform a "hard case" recovery too!

AUTHORS

Written by Junio C Hamano <gitster@pobox.com[2]> and Johannes E. Schindelin <johannes.schindelin@gmx.de[3]>

DOCUMENTATION

Documentation by Junio C Hamano and the git-list
<git@vger.kernel.org[4]>.

GIT

Part of the git(1) suite

NOTES

1. revert-a-faulty-merge How-To: file:///usr/share/doc/git-doc/howto/revert-a-faulty-merge.txt; 2. gitster@pobox.com
mailto:gitster@pobox.com; 3. johannes.schindelin@gmx.de
mailto:johannes.schindelin@gmx.de; 4. git@vger.kernel.org
mailto:git@vger.kernel.org

docs.sk

comprehensive documentation repository

See also

GIT-REBASE(1)

NAME

SYNOPSIS

DESCRIPTION

CONFIGURATION

OPTIONS

MERGE STRATEGIES

NOTES

INTERACTIVE MODE

SPLITTING COMMITS

RECOVERING FROM UPSTREAM REBASE

AUTHORS

DOCUMENTATION

GIT

NOTES