GIT-REBASE(1)GIT-REBASE(1)NAMEgit-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 com-
mits 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":
.ft C
A---B---C topic
/
D---E---F---G master
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GIT-REBASE(1)GIT-REBASE(1)
.ft
From this point, the result of either of the following commands:
git rebase master
git rebase master topic
would be:
.ft C
A'--B'--C' topic
/
D---E---F---G master
.ft
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 com-
mit 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):
.ft C
A---B---C topic
/
D---E---A'---F master
.ft
will result in:
.ft C
B'---C' topic
/
D---E---A'---F master
.ft
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GIT-REBASE(1)GIT-REBASE(1)
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 exam-
ple, a feature developed in topic depends on some functionality which
is found in next.
.ft C
o---o---o---o---o master
\
o---o---o---o---o next
\
o---o---o topic
.ft
We want to make topic forked from branch master; for example, because
the functionality on which topic depends was merged into the more sta-
ble master branch. We want our tree to look like this:
.ft C
o---o---o---o---o master
| \
| o'--o'--o' topic
\
o---o---o---o---o next
.ft
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:
.ft C
H---I---J topicB
/
E---F---G topicA
/
3
GIT-REBASE(1)GIT-REBASE(1)
A---B---C---D master
.ft
then the command
git rebase --onto master topicA topicB
would result in:
.ft C
H'--I'--J' topicB
/
| E---F---G topicA
|/
A---B---C---D master
.ft
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:
.ft C
E---F---G---H---I---J topicA
.ft
then the command
git rebase --onto topicA~5 topicA~3 topicA
would result in the removal of commits F and G:
.ft C
E---H'---I'---J' topicA
.ft
4
GIT-REBASE(1)GIT-REBASE(1)
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 com-
mit 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.
rebase.autosquash
If set to true enable --autosquash option 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.
As a special case, you may use "A...B" as a shortcut for the
merge base of A and B if there is exactly one merge base. You
can leave out at most one of A and B, in which case it defaults
to HEAD.
<upstream>
Upstream branch to compare against. May be any valid commit, not
just an existing branch name.
<branch>
Working branch; defaults to HEAD.
5
GIT-REBASE(1)GIT-REBASE(1)--continue
Restart the rebasing process after having resolved a merge con-
flict.
--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.
-X <strategy-option>, --strategy-option=<strategy-option>
Pass the <strategy-option> through to the merge strategy. This
implies \--merge and, if no strategy has been specified, -s
recursive. Note the reversal of ours and theirs as noted in
above for the -m option.
-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.
6
GIT-REBASE(1)GIT-REBASE(1)-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) help-
ful after reverting a topic branch merge, as this option recre-
ates 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: howto/revert-a-faulty-merge.txt
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)). Incompatible with the
--interactive option.
-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.
This uses the --interactive machinery internally, but combining
it with the --interactive option explicitly is generally not a
good idea unless you know what you are doing (see BUGS below).
7
GIT-REBASE(1)GIT-REBASE(1)--root Rebase all commits reachable from <branch>, instead of limiting
them with an <upstream>. This allows you to rebase the root com-
mit(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, --no-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 com-
mit 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.
If the --autosquash option is enabled by default using the con-
figuration variable rebase.autosquash, this option can be used
to override and disable this setting.
--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: howto/revert-
a-faulty-merge.txt for details).
MERGE STRATEGIES
The merge mechanism (git-merge and git-pull commands) allows the back-
end 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
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GIT-REBASE(1)GIT-REBASE(1)
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.
renormalize
This runs a virtual check-out and check-in of all three
stages of a file when resolving a three-way merge. This
option is meant to be used when merging branches with
different clean filters or end-of-line normalization
rules. See "Merging branches with differing
checkin/checkout attributes" in gitattributes(5) for
details.
no-renormalize
Disables the renormalize option. This overrides the
merge.renormalize configuration variable.
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
9
GIT-REBASE(1)GIT-REBASE(1)
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 reposi-
tory 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
10
GIT-REBASE(1)GIT-REBASE(1)
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:
.ft C
pick deadbee The oneline of this commit
pick fa1afe1 The oneline of the next commit
...
.ft
The oneline descriptions are purely for your pleasure; git rebase will
11
GIT-REBASE(1)GIT-REBASE(1)
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 rebas-
ing.
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 mes-
sage 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:
.ft C
$ git rebase -i HEAD~5
.ft
And move the first patch to the end of the list.
You might want to preserve merges, if you have a history like this:
.ft C
X
\
A---M---B
/
---o---O---P---Q
12
GIT-REBASE(1)GIT-REBASE(1)
.ft
Suppose you want to rebase the side branch starting at "A" to "Q". Make
sure that the current HEAD is "B", and call
.ft C
$ git rebase -i -p --onto Q O
.ft
Reordering and editing commits usually creates untested intermediate
steps. You may want to check that your history editing did not break
anything by running a test, or at least recompiling at intermediate
points in history by using the "exec" command (shortcut "x"). You may
do so by creating a todo list like this one:
.ft C
pick deadbee Implement feature XXX
fixup f1a5c00 Fix to feature XXX
exec make
pick c0ffeee The oneline of the next commit
edit deadbab The oneline of the commit after
exec cd subdir; make test
...
.ft
The interactive rebase will stop when a command fails (i.e. exits with
non-0 status) to give you an opportunity to fix the problem. You can
continue with git rebase --continue.
The "exec" command launches the command in a shell (the one specified
in $SHELL, or the default shell if $SHELL is not set), so you can use
shell features (like "cd", ">", ";" ...). The command is run from the
root of the working tree.
SPLITTING COMMITS
In interactive mode, you can mark commits with the action "edit". How-
ever, 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
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GIT-REBASE(1)GIT-REBASE(1)
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 appro-
priate 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 con-
sistent (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 manu-
ally 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:
.ft C
o---o---o---o---o---o---o---o---o master
\
o---o---o---o---o subsystem
\
*---*---* topic
.ft
14
GIT-REBASE(1)GIT-REBASE(1)
If subsystem is rebased against master, the following happens:
.ft C
o---o---o---o---o---o---o---o master
\ \
o---o---o---o---o o'--o'--o'--o'--o' subsystem
\
*---*---* topic
.ft
If you now continue development as usual, and eventually merge topic to
subsystem, the commits from subsystem will remain duplicated forever:
.ft C
o---o---o---o---o---o---o---o master
\ \
o---o---o---o---o o'--o'--o'--o'--o'--M subsystem
\ /
*---*---*-..........-*--* topic
.ft
Such duplicates are generally frowned upon because they clutter up his-
tory, 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 fil-
ter-branch.
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GIT-REBASE(1)GIT-REBASE(1)
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)
.ft C
$ git rebase subsystem
.ft
you will end up with the fixed history
.ft C
o---o---o---o---o---o---o---o master
\
o'--o'--o'--o'--o' subsystem
\
*---*---* topic
.ft
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:
16
GIT-REBASE(1)GIT-REBASE(1)
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 com-
mits, the old tip of subsystem must be topic~3.
You can then transplant the old subsystem..topic to the new tip by say-
ing (for the reflog case, and assuming you are on topic already):
.ft C
$ git rebase --onto subsystem subsystem@{1}
.ft
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!
BUGS
The todo list presented by --preserve-merges --interactive does not
represent the topology of the revision graph. Editing commits and
rewording their commit messages should work fine, but attempts to
reorder commits tend to produce counterintuitive results.
For example, an attempt to rearrange
.ft C
1 --- 2 --- 3 --- 4 --- 5
.ft
to
.ft C
1 --- 2 --- 4 --- 3 --- 5
.ft
17
GIT-REBASE(1)GIT-REBASE(1)
by moving the "pick 4" line will result in the following history:
.ft C
3
/
1 --- 2 --- 4 --- 5
.ft
AUTHORS
Written by Junio C Hamano <gitster@pobox.com: mailto:gitster@pobox.com>
and Johannes E. Schindelin <johannes.schindelin@gmx.de:
mailto:johannes.schindelin@gmx.de>
DOCUMENTATION
Documentation by Junio C Hamano and the git-list <git@vger.kernel.org:
mailto:git@vger.kernel.org>.
GIT
Part of the git(1) suite
18
