744 lines
24 KiB
Plaintext
744 lines
24 KiB
Plaintext
git-rebase(1)
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=============
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NAME
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----
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git-rebase - Forward-port local commits to the updated upstream head
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SYNOPSIS
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--------
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[verse]
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'git rebase' [-i | --interactive] [options] [--exec <cmd>] [--onto <newbase>]
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[<upstream>] [<branch>]
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'git rebase' [-i | --interactive] [options] [--exec <cmd>] [--onto <newbase>]
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--root [<branch>]
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'git rebase' --continue | --skip | --abort
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DESCRIPTION
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-----------
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If <branch> is specified, 'git rebase' will perform an automatic
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`git checkout <branch>` before doing anything else. Otherwise
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it remains on the current branch.
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If <upstream> is not specified, the upstream configured in
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branch.<name>.remote and branch.<name>.merge options will be used; see
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linkgit:git-config[1] for details. If you are currently not on any
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branch or if the current branch does not have a configured upstream,
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the rebase will abort.
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All changes made by commits in the current branch but that are not
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in <upstream> are saved to a temporary area. This is the same set
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of commits that would be shown by `git log <upstream>..HEAD` (or
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`git log HEAD`, if --root is specified).
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The current branch is reset to <upstream>, or <newbase> if the
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--onto option was supplied. This has the exact same effect as
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`git reset --hard <upstream>` (or <newbase>). ORIG_HEAD is set
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to point at the tip of the branch before the reset.
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The commits that were previously saved into the temporary area are
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then reapplied to the current branch, one by one, in order. Note that
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any commits in HEAD which introduce the same textual changes as a commit
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in HEAD..<upstream> are omitted (i.e., a patch already accepted upstream
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with a different commit message or timestamp will be skipped).
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It is possible that a merge failure will prevent this process from being
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completely automatic. You will have to resolve any such merge failure
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and run `git rebase --continue`. Another option is to bypass the commit
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that caused the merge failure with `git rebase --skip`. To check out the
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original <branch> and remove the .git/rebase-apply working files, use the
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command `git rebase --abort` instead.
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Assume the following history exists and the current branch is "topic":
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------------
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A---B---C topic
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/
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D---E---F---G master
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------------
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From this point, the result of either of the following commands:
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git rebase master
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git rebase master topic
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would be:
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------------
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A'--B'--C' topic
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/
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D---E---F---G master
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------------
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*NOTE:* The latter form is just a short-hand of `git checkout topic`
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followed by `git rebase master`. When rebase exits `topic` will
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remain the checked-out branch.
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If the upstream branch already contains a change you have made (e.g.,
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because you mailed a patch which was applied upstream), then that commit
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will be skipped. For example, running `git rebase master` on the
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following history (in which A' and A introduce the same set of changes,
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but have different committer information):
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------------
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A---B---C topic
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/
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D---E---A'---F master
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------------
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will result in:
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------------
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B'---C' topic
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/
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D---E---A'---F master
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------------
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Here is how you would transplant a topic branch based on one
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branch to another, to pretend that you forked the topic branch
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from the latter branch, using `rebase --onto`.
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First let's assume your 'topic' is based on branch 'next'.
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For example, a feature developed in 'topic' depends on some
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functionality which is found in 'next'.
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------------
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o---o---o---o---o master
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\
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o---o---o---o---o next
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\
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o---o---o topic
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------------
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We want to make 'topic' forked from branch 'master'; for example,
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because the functionality on which 'topic' depends was merged into the
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more stable 'master' branch. We want our tree to look like this:
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------------
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o---o---o---o---o master
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| \
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| o'--o'--o' topic
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\
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o---o---o---o---o next
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------------
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We can get this using the following command:
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git rebase --onto master next topic
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Another example of --onto option is to rebase part of a
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branch. If we have the following situation:
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------------
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H---I---J topicB
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/
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E---F---G topicA
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/
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A---B---C---D master
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------------
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then the command
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git rebase --onto master topicA topicB
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would result in:
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------------
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H'--I'--J' topicB
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/
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| E---F---G topicA
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|/
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A---B---C---D master
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------------
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This is useful when topicB does not depend on topicA.
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A range of commits could also be removed with rebase. If we have
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the following situation:
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------------
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E---F---G---H---I---J topicA
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------------
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then the command
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git rebase --onto topicA~5 topicA~3 topicA
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would result in the removal of commits F and G:
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------------
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E---H'---I'---J' topicA
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------------
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This is useful if F and G were flawed in some way, or should not be
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part of topicA. Note that the argument to --onto and the <upstream>
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parameter can be any valid commit-ish.
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In case of conflict, 'git rebase' will stop at the first problematic commit
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and leave conflict markers in the tree. You can use 'git diff' to locate
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the markers (<<<<<<) and make edits to resolve the conflict. For each
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file you edit, you need to tell git that the conflict has been resolved,
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typically this would be done with
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git add <filename>
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After resolving the conflict manually and updating the index with the
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desired resolution, you can continue the rebasing process with
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git rebase --continue
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Alternatively, you can undo the 'git rebase' with
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git rebase --abort
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CONFIGURATION
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-------------
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rebase.stat::
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Whether to show a diffstat of what changed upstream since the last
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rebase. False by default.
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rebase.autosquash::
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If set to true enable '--autosquash' option by default.
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OPTIONS
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-------
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--onto <newbase>::
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Starting point at which to create the new commits. If the
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--onto option is not specified, the starting point is
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<upstream>. May be any valid commit, and not just an
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existing branch name.
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+
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As a special case, you may use "A\...B" as a shortcut for the
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merge base of A and B if there is exactly one merge base. You can
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leave out at most one of A and B, in which case it defaults to HEAD.
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<upstream>::
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Upstream branch to compare against. May be any valid commit,
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not just an existing branch name. Defaults to the configured
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upstream for the current branch.
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<branch>::
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Working branch; defaults to HEAD.
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--continue::
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Restart the rebasing process after having resolved a merge conflict.
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--abort::
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Abort the rebase operation and reset HEAD to the original
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branch. If <branch> was provided when the rebase operation was
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started, then HEAD will be reset to <branch>. Otherwise HEAD
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will be reset to where it was when the rebase operation was
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started.
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--keep-empty::
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Keep the commits that do not change anything from its
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parents in the result.
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--skip::
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Restart the rebasing process by skipping the current patch.
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-m::
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--merge::
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Use merging strategies to rebase. When the recursive (default) merge
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strategy is used, this allows rebase to be aware of renames on the
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upstream side.
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+
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Note that a rebase merge works by replaying each commit from the working
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branch on top of the <upstream> branch. Because of this, when a merge
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conflict happens, the side reported as 'ours' is the so-far rebased
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series, starting with <upstream>, and 'theirs' is the working branch. In
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other words, the sides are swapped.
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-s <strategy>::
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--strategy=<strategy>::
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Use the given merge strategy.
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If there is no `-s` option 'git merge-recursive' is used
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instead. This implies --merge.
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+
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Because 'git rebase' replays each commit from the working branch
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on top of the <upstream> branch using the given strategy, using
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the 'ours' strategy simply discards all patches from the <branch>,
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which makes little sense.
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-X <strategy-option>::
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--strategy-option=<strategy-option>::
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Pass the <strategy-option> through to the merge strategy.
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This implies `--merge` and, if no strategy has been
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specified, `-s recursive`. Note the reversal of 'ours' and
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'theirs' as noted above for the `-m` option.
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-q::
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--quiet::
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Be quiet. Implies --no-stat.
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-v::
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--verbose::
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Be verbose. Implies --stat.
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--stat::
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Show a diffstat of what changed upstream since the last rebase. The
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diffstat is also controlled by the configuration option rebase.stat.
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-n::
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--no-stat::
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Do not show a diffstat as part of the rebase process.
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--no-verify::
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This option bypasses the pre-rebase hook. See also linkgit:githooks[5].
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--verify::
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Allows the pre-rebase hook to run, which is the default. This option can
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be used to override --no-verify. See also linkgit:githooks[5].
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-C<n>::
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Ensure at least <n> lines of surrounding context match before
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and after each change. When fewer lines of surrounding
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context exist they all must match. By default no context is
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ever ignored.
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-f::
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--force-rebase::
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Force the rebase even if the current branch is a descendant
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of the commit you are rebasing onto. Normally non-interactive rebase will
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exit with the message "Current branch is up to date" in such a
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situation.
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Incompatible with the --interactive option.
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+
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You may find this (or --no-ff with an interactive rebase) helpful after
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reverting a topic branch merge, as this option recreates the topic branch with
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fresh commits so it can be remerged successfully without needing to "revert
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the reversion" (see the
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link:howto/revert-a-faulty-merge.txt[revert-a-faulty-merge How-To] for details).
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--ignore-whitespace::
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--whitespace=<option>::
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These flag are passed to the 'git apply' program
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(see linkgit:git-apply[1]) that applies the patch.
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Incompatible with the --interactive option.
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--committer-date-is-author-date::
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--ignore-date::
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These flags are passed to 'git am' to easily change the dates
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of the rebased commits (see linkgit:git-am[1]).
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Incompatible with the --interactive option.
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-i::
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--interactive::
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Make a list of the commits which are about to be rebased. Let the
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user edit that list before rebasing. This mode can also be used to
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split commits (see SPLITTING COMMITS below).
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-p::
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--preserve-merges::
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Instead of ignoring merges, try to recreate them.
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+
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This uses the `--interactive` machinery internally, but combining it
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with the `--interactive` option explicitly is generally not a good
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idea unless you know what you are doing (see BUGS below).
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-x <cmd>::
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--exec <cmd>::
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Append "exec <cmd>" after each line creating a commit in the
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final history. <cmd> will be interpreted as one or more shell
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commands.
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+
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This option can only be used with the `--interactive` option
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(see INTERACTIVE MODE below).
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+
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You may execute several commands by either using one instance of `--exec`
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with several commands:
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git rebase -i --exec "cmd1 && cmd2 && ..."
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+
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or by giving more than one `--exec`:
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+
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git rebase -i --exec "cmd1" --exec "cmd2" --exec ...
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+
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If `--autosquash` is used, "exec" lines will not be appended for
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the intermediate commits, and will only appear at the end of each
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squash/fixup series.
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--root::
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Rebase all commits reachable from <branch>, instead of
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limiting them with an <upstream>. This allows you to rebase
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the root commit(s) on a branch. When used with --onto, it
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will skip changes already contained in <newbase> (instead of
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<upstream>) whereas without --onto it will operate on every change.
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When used together with both --onto and --preserve-merges,
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'all' root commits will be rewritten to have <newbase> as parent
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instead.
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--autosquash::
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--no-autosquash::
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When the commit log message begins with "squash! ..." (or
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"fixup! ..."), and there is a commit whose title begins with
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the same ..., automatically modify the todo list of rebase -i
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so that the commit marked for squashing comes right after the
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commit to be modified, and change the action of the moved
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commit from `pick` to `squash` (or `fixup`).
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+
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This option is only valid when the '--interactive' option is used.
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+
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If the '--autosquash' option is enabled by default using the
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configuration variable `rebase.autosquash`, this option can be
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used to override and disable this setting.
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--no-ff::
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With --interactive, cherry-pick all rebased commits instead of
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fast-forwarding over the unchanged ones. This ensures that the
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entire history of the rebased branch is composed of new commits.
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+
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Without --interactive, this is a synonym for --force-rebase.
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+
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You may find this helpful after reverting a topic branch merge, as this option
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recreates the topic branch with fresh commits so it can be remerged
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successfully without needing to "revert the reversion" (see the
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link:howto/revert-a-faulty-merge.txt[revert-a-faulty-merge How-To] for details).
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include::merge-strategies.txt[]
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NOTES
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-----
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You should understand the implications of using 'git rebase' on a
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repository that you share. See also RECOVERING FROM UPSTREAM REBASE
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below.
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When the git-rebase command is run, it will first execute a "pre-rebase"
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hook if one exists. You can use this hook to do sanity checks and
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reject the rebase if it isn't appropriate. Please see the template
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pre-rebase hook script for an example.
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Upon completion, <branch> will be the current branch.
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INTERACTIVE MODE
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----------------
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Rebasing interactively means that you have a chance to edit the commits
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which are rebased. You can reorder the commits, and you can
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remove them (weeding out bad or otherwise unwanted patches).
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The interactive mode is meant for this type of workflow:
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1. have a wonderful idea
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2. hack on the code
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3. prepare a series for submission
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4. submit
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where point 2. consists of several instances of
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a) regular use
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1. finish something worthy of a commit
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2. commit
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b) independent fixup
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1. realize that something does not work
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2. fix that
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3. commit it
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Sometimes the thing fixed in b.2. cannot be amended to the not-quite
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perfect commit it fixes, because that commit is buried deeply in a
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patch series. That is exactly what interactive rebase is for: use it
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after plenty of "a"s and "b"s, by rearranging and editing
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commits, and squashing multiple commits into one.
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Start it with the last commit you want to retain as-is:
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git rebase -i <after-this-commit>
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An editor will be fired up with all the commits in your current branch
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(ignoring merge commits), which come after the given commit. You can
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reorder the commits in this list to your heart's content, and you can
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remove them. The list looks more or less like this:
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-------------------------------------------
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pick deadbee The oneline of this commit
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pick fa1afe1 The oneline of the next commit
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...
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-------------------------------------------
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The oneline descriptions are purely for your pleasure; 'git rebase' will
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not look at them but at the commit names ("deadbee" and "fa1afe1" in this
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example), so do not delete or edit the names.
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By replacing the command "pick" with the command "edit", you can tell
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'git rebase' to stop after applying that commit, so that you can edit
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the files and/or the commit message, amend the commit, and continue
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rebasing.
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If you just want to edit the commit message for a commit, replace the
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command "pick" with the command "reword".
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If you want to fold two or more commits into one, replace the command
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"pick" for the second and subsequent commits with "squash" or "fixup".
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If the commits had different authors, the folded commit will be
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attributed to the author of the first commit. The suggested commit
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message for the folded commit is the concatenation of the commit
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messages of the first commit and of those with the "squash" command,
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but omits the commit messages of commits with the "fixup" command.
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'git rebase' will stop when "pick" has been replaced with "edit" or
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when a command fails due to merge errors. When you are done editing
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and/or resolving conflicts you can continue with `git rebase --continue`.
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For example, if you want to reorder the last 5 commits, such that what
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was HEAD~4 becomes the new HEAD. To achieve that, you would call
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'git rebase' like this:
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----------------------
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$ git rebase -i HEAD~5
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----------------------
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And move the first patch to the end of the list.
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You might want to preserve merges, if you have a history like this:
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------------------
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X
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\
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A---M---B
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/
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---o---O---P---Q
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------------------
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Suppose you want to rebase the side branch starting at "A" to "Q". Make
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sure that the current HEAD is "B", and call
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-----------------------------
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$ git rebase -i -p --onto Q O
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-----------------------------
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Reordering and editing commits usually creates untested intermediate
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steps. You may want to check that your history editing did not break
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anything by running a test, or at least recompiling at intermediate
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points in history by using the "exec" command (shortcut "x"). You may
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do so by creating a todo list like this one:
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-------------------------------------------
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pick deadbee Implement feature XXX
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fixup f1a5c00 Fix to feature XXX
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exec make
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pick c0ffeee The oneline of the next commit
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edit deadbab The oneline of the commit after
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exec cd subdir; make test
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...
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-------------------------------------------
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The interactive rebase will stop when a command fails (i.e. exits with
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non-0 status) to give you an opportunity to fix the problem. You can
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continue with `git rebase --continue`.
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The "exec" command launches the command in a shell (the one specified
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|
in `$SHELL`, or the default shell if `$SHELL` is not set), so you can
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|
use shell features (like "cd", ">", ";" ...). The command is run from
|
|
the root of the working tree.
|
|
|
|
----------------------------------
|
|
$ git rebase -i --exec "make test"
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|
----------------------------------
|
|
|
|
This command lets you check that intermediate commits are compilable.
|
|
The todo list becomes like that:
|
|
|
|
--------------------
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|
pick 5928aea one
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|
exec make test
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|
pick 04d0fda two
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|
exec make test
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|
pick ba46169 three
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|
exec make test
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|
pick f4593f9 four
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|
exec make test
|
|
--------------------
|
|
|
|
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:
|
|
|
|
- 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.
|
|
|
|
- Mark the commit you want to split with the action "edit".
|
|
|
|
- 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.
|
|
|
|
- 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.
|
|
|
|
- Commit the now-current index with whatever commit message is appropriate
|
|
now.
|
|
|
|
- Repeat the last two steps until your working tree is clean.
|
|
|
|
- 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:
|
|
|
|
* With the 'subsystem' reflog: after 'git fetch', the old tip of
|
|
'subsystem' is at `subsystem@{1}`. Subsequent fetches will
|
|
increase the number. (See linkgit:git-reflog[1].)
|
|
|
|
* 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!
|
|
|
|
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
|
|
------------
|
|
1 --- 2 --- 3 --- 4 --- 5
|
|
------------
|
|
to
|
|
------------
|
|
1 --- 2 --- 4 --- 3 --- 5
|
|
------------
|
|
by moving the "pick 4" line will result in the following history:
|
|
------------
|
|
3
|
|
/
|
|
1 --- 2 --- 4 --- 5
|
|
------------
|
|
|
|
GIT
|
|
---
|
|
Part of the linkgit:git[1] suite
|