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+git-rebase(1)
+=============
+
+NAME
+----
+git-rebase - Reapply commits on top of another base tip
+
+SYNOPSIS
+--------
+[verse]
+'git rebase' [-i | --interactive] [<options>] [--exec <cmd>]
+ [--onto <newbase> | --keep-base] [<upstream> [<branch>]]
+'git rebase' [-i | --interactive] [<options>] [--exec <cmd>] [--onto <newbase>]
+ --root [<branch>]
+'git rebase' (--continue | --skip | --abort | --quit | --edit-todo | --show-current-patch)
+
+DESCRIPTION
+-----------
+If `<branch>` is specified, `git rebase` will perform an automatic
+`git switch <branch>` before doing anything else. Otherwise
+it remains on the current branch.
+
+If `<upstream>` is not specified, the upstream configured in
+`branch.<name>.remote` and `branch.<name>.merge` options will be used (see
+linkgit:git-config[1] for details) and the `--fork-point` option is
+assumed. If you are currently not on any branch or if the current
+branch does not have a configured upstream, the rebase will abort.
+
+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 by
+`git log 'fork_point'..HEAD`, if `--fork-point` is active (see the
+description on `--fork-point` below); or by `git log HEAD`, if the
+`--root` option 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 check out 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
+------------
+
+*NOTE:* The latter form is just a short-hand of `git checkout topic`
+followed by `git rebase master`. When rebase exits `topic` will
+remain the checked-out branch.
+
+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 and warnings will be issued (if the 'merge' backend is
+used). 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
+
+OPTIONS
+-------
+--onto <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.
+
+--keep-base::
+ Set the starting point at which to create the new commits to the
+ merge base of `<upstream>` and `<branch>`. Running
+ `git rebase --keep-base <upstream> <branch>` is equivalent to
+ running
+ `git rebase --reapply-cherry-picks --no-fork-point --onto <upstream>...<branch> <upstream> <branch>`.
++
+This option is useful in the case where one is developing a feature on
+top of an upstream branch. While the feature is being worked on, the
+upstream branch may advance and it may not be the best idea to keep
+rebasing on top of the upstream but to keep the base commit as-is. As
+the base commit is unchanged this option implies `--reapply-cherry-picks`
+to avoid losing commits.
++
+Although both this option and `--fork-point` find the merge base between
+`<upstream>` and `<branch>`, this option uses the merge base as the _starting
+point_ on which new commits will be created, whereas `--fork-point` uses
+the merge base to determine the _set of commits_ which will be rebased.
++
+See also INCOMPATIBLE OPTIONS below.
+
+<upstream>::
+ Upstream branch to compare against. May be any valid commit,
+ not just an existing branch name. Defaults to the configured
+ upstream for the current branch.
+
+<branch>::
+ Working branch; defaults to `HEAD`.
+
+--continue::
+ Restart the rebasing process after having resolved a merge conflict.
+
+--abort::
+ Abort the rebase operation and reset HEAD to the original
+ branch. If `<branch>` was provided when the rebase operation was
+ started, then `HEAD` will be reset to `<branch>`. Otherwise `HEAD`
+ will be reset to where it was when the rebase operation was
+ started.
+
+--quit::
+ Abort the rebase operation but `HEAD` is not reset back to the
+ original branch. The index and working tree are also left
+ unchanged as a result. If a temporary stash entry was created
+ using `--autostash`, it will be saved to the stash list.
+
+--apply::
+ Use applying strategies to rebase (calling `git-am`
+ internally). This option may become a no-op in the future
+ once the merge backend handles everything the apply one does.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--empty={drop,keep,ask}::
+ How to handle commits that are not empty to start and are not
+ clean cherry-picks of any upstream commit, but which become
+ empty after rebasing (because they contain a subset of already
+ upstream changes). With drop (the default), commits that
+ become empty are dropped. With keep, such commits are kept.
+ With ask (implied by `--interactive`), the rebase will halt when
+ an empty commit is applied allowing you to choose whether to
+ drop it, edit files more, or just commit the empty changes.
+ Other options, like `--exec`, will use the default of drop unless
+ `-i`/`--interactive` is explicitly specified.
++
+Note that commits which start empty are kept (unless `--no-keep-empty`
+is specified), and commits which are clean cherry-picks (as determined
+by `git log --cherry-mark ...`) are detected and dropped as a
+preliminary step (unless `--reapply-cherry-picks` or `--keep-base` is
+passed).
++
+See also INCOMPATIBLE OPTIONS below.
+
+--no-keep-empty::
+--keep-empty::
+ Do not keep commits that start empty before the rebase
+ (i.e. that do not change anything from its parent) in the
+ result. The default is to keep commits which start empty,
+ since creating such commits requires passing the `--allow-empty`
+ override flag to `git commit`, signifying that a user is very
+ intentionally creating such a commit and thus wants to keep
+ it.
++
+Usage of this flag will probably be rare, since you can get rid of
+commits that start empty by just firing up an interactive rebase and
+removing the lines corresponding to the commits you don't want. This
+flag exists as a convenient shortcut, such as for cases where external
+tools generate many empty commits and you want them all removed.
++
+For commits which do not start empty but become empty after rebasing,
+see the `--empty` flag.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--reapply-cherry-picks::
+--no-reapply-cherry-picks::
+ Reapply all clean cherry-picks of any upstream commit instead
+ of preemptively dropping them. (If these commits then become
+ empty after rebasing, because they contain a subset of already
+ upstream changes, the behavior towards them is controlled by
+ the `--empty` flag.)
++
+
+In the absence of `--keep-base` (or if `--no-reapply-cherry-picks` is
+given), these commits will be automatically dropped. Because this
+necessitates reading all upstream commits, this can be expensive in
+repositories with a large number of upstream commits that need to be
+read. When using the 'merge' backend, warnings will be issued for each
+dropped commit (unless `--quiet` is given). Advice will also be issued
+unless `advice.skippedCherryPicks` is set to false (see
+linkgit:git-config[1]).
+
++
+`--reapply-cherry-picks` allows rebase to forgo reading all upstream
+commits, potentially improving performance.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--allow-empty-message::
+ No-op. Rebasing commits with an empty message used to fail
+ and this option would override that behavior, allowing commits
+ with empty messages to be rebased. Now commits with an empty
+ message do not cause rebasing to halt.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--skip::
+ Restart the rebasing process by skipping the current patch.
+
+--edit-todo::
+ Edit the todo list during an interactive rebase.
+
+--show-current-patch::
+ Show the current patch in an interactive rebase or when rebase
+ is stopped because of conflicts. This is the equivalent of
+ `git show REBASE_HEAD`.
+
+-m::
+--merge::
+ Using merging strategies to rebase (default).
++
+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.
++
+See also INCOMPATIBLE OPTIONS below.
+
+-s <strategy>::
+--strategy=<strategy>::
+ Use the given merge strategy, instead of the default `ort`.
+ 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 empties all patches from the `<branch>`,
+which makes little sense.
++
+See also INCOMPATIBLE OPTIONS below.
+
+-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 ort`. Note the reversal of 'ours' and
+ 'theirs' as noted above for the `-m` option.
++
+See also INCOMPATIBLE OPTIONS below.
+
+include::rerere-options.txt[]
+
+-S[<keyid>]::
+--gpg-sign[=<keyid>]::
+--no-gpg-sign::
+ GPG-sign commits. The `keyid` argument is optional and
+ defaults to the committer identity; if specified, it must be
+ stuck to the option without a space. `--no-gpg-sign` is useful to
+ countermand both `commit.gpgSign` configuration variable, and
+ earlier `--gpg-sign`.
+
+-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 linkgit:githooks[5].
+
+--verify::
+ Allows the pre-rebase hook to run, which is the default. This option can
+ be used to override `--no-verify`. See also linkgit: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. Implies `--apply`.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--no-ff::
+--force-rebase::
+-f::
+ Individually replay 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.
++
+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
+link:howto/revert-a-faulty-merge.html[revert-a-faulty-merge How-To] for
+details).
+
+--fork-point::
+--no-fork-point::
+ Use reflog to find a better common ancestor between `<upstream>`
+ and `<branch>` when calculating which commits have been
+ introduced by `<branch>`.
++
+When `--fork-point` is active, 'fork_point' will be used instead of
+`<upstream>` to calculate the set of commits to rebase, where
+'fork_point' is the result of `git merge-base --fork-point <upstream>
+<branch>` command (see linkgit:git-merge-base[1]). If 'fork_point'
+ends up being empty, the `<upstream>` will be used as a fallback.
++
+If `<upstream>` or `--keep-base` is given on the command line, then
+the default is `--no-fork-point`, otherwise the default is
+`--fork-point`. See also `rebase.forkpoint` in linkgit:git-config[1].
++
+If your branch was based on `<upstream>` but `<upstream>` was rewound and
+your branch contains commits which were dropped, this option can be used
+with `--keep-base` in order to drop those commits from your branch.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--ignore-whitespace::
+ Ignore whitespace differences when trying to reconcile
+ differences. Currently, each backend implements an approximation of
+ this behavior:
++
+apply backend;;
+ When applying a patch, ignore changes in whitespace in context
+ lines. Unfortunately, this means that if the "old" lines being
+ replaced by the patch differ only in whitespace from the existing
+ file, you will get a merge conflict instead of a successful patch
+ application.
++
+merge backend;;
+ Treat lines with only whitespace changes as unchanged when merging.
+ Unfortunately, this means that any patch hunks that were intended
+ to modify whitespace and nothing else will be dropped, even if the
+ other side had no changes that conflicted.
+
+--whitespace=<option>::
+ This flag is passed to the `git apply` program
+ (see linkgit:git-apply[1]) that applies the patch.
+ Implies `--apply`.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--committer-date-is-author-date::
+ Instead of using the current time as the committer date, use
+ the author date of the commit being rebased as the committer
+ date. This option implies `--force-rebase`.
+
+--ignore-date::
+--reset-author-date::
+ Instead of using the author date of the original commit, use
+ the current time as the author date of the rebased commit. This
+ option implies `--force-rebase`.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--signoff::
+ Add a `Signed-off-by` trailer to all the rebased commits. Note
+ that if `--interactive` is given then only commits marked to be
+ picked, edited or reworded will have the trailer added.
++
+See also INCOMPATIBLE OPTIONS below.
+
+-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).
++
+The commit list format can be changed by setting the configuration option
+rebase.instructionFormat. A customized instruction format will automatically
+have the long commit hash prepended to the format.
++
+See also INCOMPATIBLE OPTIONS below.
+
+-r::
+--rebase-merges[=(rebase-cousins|no-rebase-cousins)]::
+ By default, a rebase will simply drop merge commits from the todo
+ list, and put the rebased commits into a single, linear branch.
+ With `--rebase-merges`, the rebase will instead try to preserve
+ the branching structure within the commits that are to be rebased,
+ by recreating the merge commits. Any resolved merge conflicts or
+ manual amendments in these merge commits will have to be
+ resolved/re-applied manually.
++
+By default, or when `no-rebase-cousins` was specified, commits which do not
+have `<upstream>` as direct ancestor will keep their original branch point,
+i.e. commits that would be excluded by linkgit:git-log[1]'s
+`--ancestry-path` option will keep their original ancestry by default. If
+the `rebase-cousins` mode is turned on, such commits are instead rebased
+onto `<upstream>` (or `<onto>`, if specified).
++
+It is currently only possible to recreate the merge commits using the
+`ort` merge strategy; different merge strategies can be used only via
+explicit `exec git merge -s <strategy> [...]` commands.
++
+See also REBASING MERGES and INCOMPATIBLE OPTIONS below.
+
+-x <cmd>::
+--exec <cmd>::
+ Append "exec <cmd>" after each line creating a commit in the
+ final history. `<cmd>` will be interpreted as one or more shell
+ commands. Any command that fails will interrupt the rebase,
+ with exit code 1.
++
+You may execute several commands by either using one instance of `--exec`
+with several commands:
++
+ git rebase -i --exec "cmd1 && cmd2 && ..."
++
+or by giving more than one `--exec`:
++
+ git rebase -i --exec "cmd1" --exec "cmd2" --exec ...
++
+If `--autosquash` is used, `exec` lines will not be appended for
+the intermediate commits, and will only appear at the end of each
+squash/fixup series.
++
+This uses the `--interactive` machinery internally, but it can be run
+without an explicit `--interactive`.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--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. When used with `--onto`, it
+ will skip changes already contained in `<newbase>` (instead of
+ `<upstream>`) whereas without `--onto` it will operate on every
+ change.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--autosquash::
+--no-autosquash::
+ When the commit log message begins with "squash! ..." or "fixup! ..."
+ or "amend! ...", and there is already a commit in the todo list that
+ matches 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` or `fixup -C` respectively. A commit
+ matches the `...` if the commit subject matches, or if the `...` refers
+ to the commit's hash. As a fall-back, partial matches of the commit
+ subject work, too. The recommended way to create fixup/amend/squash
+ commits is by using the `--fixup`, `--fixup=amend:` or `--fixup=reword:`
+ and `--squash` options respectively of linkgit:git-commit[1].
++
+If the `--autosquash` option is enabled by default using the
+configuration variable `rebase.autoSquash`, this option can be
+used to override and disable this setting.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--autostash::
+--no-autostash::
+ Automatically create a temporary stash entry before the operation
+ begins, and apply it after the operation ends. This means
+ that you can run rebase on a dirty worktree. However, use
+ with care: the final stash application after a successful
+ rebase might result in non-trivial conflicts.
+
+--reschedule-failed-exec::
+--no-reschedule-failed-exec::
+ Automatically reschedule `exec` commands that failed. This only makes
+ sense in interactive mode (or when an `--exec` option was provided).
++
+Even though this option applies once a rebase is started, it's set for
+the whole rebase at the start based on either the
+`rebase.rescheduleFailedExec` configuration (see linkgit:git-config[1]
+or "CONFIGURATION" below) or whether this option is
+provided. Otherwise an explicit `--no-reschedule-failed-exec` at the
+start would be overridden by the presence of
+`rebase.rescheduleFailedExec=true` configuration.
+
+--update-refs::
+--no-update-refs::
+ Automatically force-update any branches that point to commits that
+ are being rebased. Any branches that are checked out in a worktree
+ are not updated in this way.
++
+If the configuration variable `rebase.updateRefs` is set, then this option
+can be used to override and disable this setting.
+
+INCOMPATIBLE OPTIONS
+--------------------
+
+The following options:
+
+ * --apply
+ * --whitespace
+ * -C
+
+are incompatible with the following options:
+
+ * --merge
+ * --strategy
+ * --strategy-option
+ * --allow-empty-message
+ * --[no-]autosquash
+ * --rebase-merges
+ * --interactive
+ * --exec
+ * --no-keep-empty
+ * --empty=
+ * --reapply-cherry-picks
+ * --edit-todo
+ * --update-refs
+ * --root when used in combination with --onto
+
+In addition, the following pairs of options are incompatible:
+
+ * --keep-base and --onto
+ * --keep-base and --root
+ * --fork-point and --root
+
+BEHAVIORAL DIFFERENCES
+-----------------------
+
+`git rebase` has two primary backends: 'apply' and 'merge'. (The 'apply'
+backend used to be known as the 'am' backend, but the name led to
+confusion as it looks like a verb instead of a noun. Also, the 'merge'
+backend used to be known as the interactive backend, but it is now
+used for non-interactive cases as well. Both were renamed based on
+lower-level functionality that underpinned each.) There are some
+subtle differences in how these two backends behave:
+
+Empty commits
+~~~~~~~~~~~~~
+
+The 'apply' backend unfortunately drops intentionally empty commits, i.e.
+commits that started empty, though these are rare in practice. It
+also drops commits that become empty and has no option for controlling
+this behavior.
+
+The 'merge' backend keeps intentionally empty commits by default (though
+with `-i` they are marked as empty in the todo list editor, or they can
+be dropped automatically with `--no-keep-empty`).
+
+Similar to the apply backend, by default the merge backend drops
+commits that become empty unless `-i`/`--interactive` is specified (in
+which case it stops and asks the user what to do). The merge backend
+also has an `--empty={drop,keep,ask}` option for changing the behavior
+of handling commits that become empty.
+
+Directory rename detection
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Due to the lack of accurate tree information (arising from
+constructing fake ancestors with the limited information available in
+patches), directory rename detection is disabled in the 'apply' backend.
+Disabled directory rename detection means that if one side of history
+renames a directory and the other adds new files to the old directory,
+then the new files will be left behind in the old directory without
+any warning at the time of rebasing that you may want to move these
+files into the new directory.
+
+Directory rename detection works with the 'merge' backend to provide you
+warnings in such cases.
+
+Context
+~~~~~~~
+
+The 'apply' backend works by creating a sequence of patches (by calling
+`format-patch` internally), and then applying the patches in sequence
+(calling `am` internally). Patches are composed of multiple hunks,
+each with line numbers, a context region, and the actual changes. The
+line numbers have to be taken with some fuzz, since the other side
+will likely have inserted or deleted lines earlier in the file. The
+context region is meant to help find how to adjust the line numbers in
+order to apply the changes to the right lines. However, if multiple
+areas of the code have the same surrounding lines of context, the
+wrong one can be picked. There are real-world cases where this has
+caused commits to be reapplied incorrectly with no conflicts reported.
+Setting `diff.context` to a larger value may prevent such types of
+problems, but increases the chance of spurious conflicts (since it
+will require more lines of matching context to apply).
+
+The 'merge' backend works with a full copy of each relevant file,
+insulating it from these types of problems.
+
+Labelling of conflicts markers
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+When there are content conflicts, the merge machinery tries to
+annotate each side's conflict markers with the commits where the
+content came from. Since the 'apply' backend drops the original
+information about the rebased commits and their parents (and instead
+generates new fake commits based off limited information in the
+generated patches), those commits cannot be identified; instead it has
+to fall back to a commit summary. Also, when `merge.conflictStyle` is
+set to `diff3` or `zdiff3`, the 'apply' backend will use "constructed merge
+base" to label the content from the merge base, and thus provide no
+information about the merge base commit whatsoever.
+
+The 'merge' backend works with the full commits on both sides of history
+and thus has no such limitations.
+
+Hooks
+~~~~~
+
+The 'apply' backend has not traditionally called the post-commit hook,
+while the 'merge' backend has. Both have called the post-checkout hook,
+though the 'merge' backend has squelched its output. Further, both
+backends only call the post-checkout hook with the starting point
+commit of the rebase, not the intermediate commits nor the final
+commit. In each case, the calling of these hooks was by accident of
+implementation rather than by design (both backends were originally
+implemented as shell scripts and happened to invoke other commands
+like `git checkout` or `git commit` that would call the hooks). Both
+backends should have the same behavior, though it is not entirely
+clear which, if any, is correct. We will likely make rebase stop
+calling either of these hooks in the future.
+
+Interruptability
+~~~~~~~~~~~~~~~~
+
+The 'apply' backend has safety problems with an ill-timed interrupt; if
+the user presses Ctrl-C at the wrong time to try to abort the rebase,
+the rebase can enter a state where it cannot be aborted with a
+subsequent `git rebase --abort`. The 'merge' backend does not appear to
+suffer from the same shortcoming. (See
+https://lore.kernel.org/git/20200207132152.GC2868@szeder.dev/ for
+details.)
+
+Commit Rewording
+~~~~~~~~~~~~~~~~
+
+When a conflict occurs while rebasing, rebase stops and asks the user
+to resolve. Since the user may need to make notable changes while
+resolving conflicts, after conflicts are resolved and the user has run
+`git rebase --continue`, the rebase should open an editor and ask the
+user to update the commit message. The 'merge' backend does this, while
+the 'apply' backend blindly applies the original commit message.
+
+Miscellaneous differences
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+There are a few more behavioral differences that most folks would
+probably consider inconsequential but which are mentioned for
+completeness:
+
+* Reflog: The two backends will use different wording when describing
+ the changes made in the reflog, though both will make use of the
+ word "rebase".
+
+* Progress, informational, and error messages: The two backends
+ provide slightly different progress and informational messages.
+ Also, the apply backend writes error messages (such as "Your files
+ would be overwritten...") to stdout, while the merge backend writes
+ them to stderr.
+
+* State directories: The two backends keep their state in different
+ directories under `.git/`
+
+include::merge-strategies.txt[]
+
+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 rebase 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
+
+a) regular use
+
+ 1. finish something worthy of a commit
+ 2. commit
+
+b) 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.
+
+To interrupt the rebase (just like an "edit" command would do, but without
+cherry-picking any commit first), use the "break" command.
+
+If you just want to edit the commit message for a commit, replace the
+command "pick" with the command "reword".
+
+To drop a commit, replace the command "pick" with "drop", or just
+delete the matching line.
+
+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 first
+commit's message with those identified by "squash" commands, omitting the
+messages of commits identified by "fixup" commands, unless "fixup -c"
+is used. In that case the suggested commit message is only the message
+of the "fixup -c" commit, and an editor is opened allowing you to edit
+the message. The contents (patch) of the "fixup -c" commit are still
+incorporated into the folded commit. If there is more than one "fixup -c"
+commit, the message from the final one is used. You can also use
+"fixup -C" to get the same behavior as "fixup -c" except without opening
+an editor.
+
+`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 recreate merge commits, e.g. 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 -r --onto Q O
+-----------------------------
+
+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:
+
+-------------------------------------------
+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
+...
+-------------------------------------------
+
+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.
+
+----------------------------------
+$ git rebase -i --exec "make test"
+----------------------------------
+
+This command lets you check that intermediate commits are compilable.
+The todo list becomes like that:
+
+--------------------
+pick 5928aea one
+exec make test
+pick 04d0fda two
+exec make test
+pick ba46169 three
+exec make test
+pick f4593f9 four
+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 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
+ a full history rewriting command like
+ https://github.com/newren/git-filter-repo[`filter-repo`].
+
+
+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 (unless
+`--reapply-cherry-picks` is given). 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!
+
+REBASING MERGES
+---------------
+
+The interactive rebase command was originally designed to handle
+individual patch series. As such, it makes sense to exclude merge
+commits from the todo list, as the developer may have merged the
+then-current `master` while working on the branch, only to rebase
+all the commits onto `master` eventually (skipping the merge
+commits).
+
+However, there are legitimate reasons why a developer may want to
+recreate merge commits: to keep the branch structure (or "commit
+topology") when working on multiple, inter-related branches.
+
+In the following example, the developer works on a topic branch that
+refactors the way buttons are defined, and on another topic branch
+that uses that refactoring to implement a "Report a bug" button. The
+output of `git log --graph --format=%s -5` may look like this:
+
+------------
+* Merge branch 'report-a-bug'
+|\
+| * Add the feedback button
+* | Merge branch 'refactor-button'
+|\ \
+| |/
+| * Use the Button class for all buttons
+| * Extract a generic Button class from the DownloadButton one
+------------
+
+The developer might want to rebase those commits to a newer `master`
+while keeping the branch topology, for example when the first topic
+branch is expected to be integrated into `master` much earlier than the
+second one, say, to resolve merge conflicts with changes to the
+DownloadButton class that made it into `master`.
+
+This rebase can be performed using the `--rebase-merges` option.
+It will generate a todo list looking like this:
+
+------------
+label onto
+
+# Branch: refactor-button
+reset onto
+pick 123456 Extract a generic Button class from the DownloadButton one
+pick 654321 Use the Button class for all buttons
+label refactor-button
+
+# Branch: report-a-bug
+reset refactor-button # Use the Button class for all buttons
+pick abcdef Add the feedback button
+label report-a-bug
+
+reset onto
+merge -C a1b2c3 refactor-button # Merge 'refactor-button'
+merge -C 6f5e4d report-a-bug # Merge 'report-a-bug'
+------------
+
+In contrast to a regular interactive rebase, there are `label`, `reset`
+and `merge` commands in addition to `pick` ones.
+
+The `label` command associates a label with the current HEAD when that
+command is executed. These labels are created as worktree-local refs
+(`refs/rewritten/<label>`) that will be deleted when the rebase
+finishes. That way, rebase operations in multiple worktrees linked to
+the same repository do not interfere with one another. If the `label`
+command fails, it is rescheduled immediately, with a helpful message how
+to proceed.
+
+The `reset` command resets the HEAD, index and worktree to the specified
+revision. It is similar to an `exec git reset --hard <label>`, but
+refuses to overwrite untracked files. If the `reset` command fails, it is
+rescheduled immediately, with a helpful message how to edit the todo list
+(this typically happens when a `reset` command was inserted into the todo
+list manually and contains a typo).
+
+The `merge` command will merge the specified revision(s) into whatever
+is HEAD at that time. With `-C <original-commit>`, the commit message of
+the specified merge commit will be used. When the `-C` is changed to
+a lower-case `-c`, the message will be opened in an editor after a
+successful merge so that the user can edit the message.
+
+If a `merge` command fails for any reason other than merge conflicts (i.e.
+when the merge operation did not even start), it is rescheduled immediately.
+
+By default, the `merge` command will use the `ort` merge strategy for
+regular merges, and `octopus` for octopus merges. One can specify a
+default strategy for all merges using the `--strategy` argument when
+invoking rebase, or can override specific merges in the interactive
+list of commands by using an `exec` command to call `git merge`
+explicitly with a `--strategy` argument. Note that when calling `git
+merge` explicitly like this, you can make use of the fact that the
+labels are worktree-local refs (the ref `refs/rewritten/onto` would
+correspond to the label `onto`, for example) in order to refer to the
+branches you want to merge.
+
+Note: the first command (`label onto`) labels the revision onto which
+the commits are rebased; The name `onto` is just a convention, as a nod
+to the `--onto` option.
+
+It is also possible to introduce completely new merge commits from scratch
+by adding a command of the form `merge <merge-head>`. This form will
+generate a tentative commit message and always open an editor to let the
+user edit it. This can be useful e.g. when a topic branch turns out to
+address more than a single concern and wants to be split into two or
+even more topic branches. Consider this todo list:
+
+------------
+pick 192837 Switch from GNU Makefiles to CMake
+pick 5a6c7e Document the switch to CMake
+pick 918273 Fix detection of OpenSSL in CMake
+pick afbecd http: add support for TLS v1.3
+pick fdbaec Fix detection of cURL in CMake on Windows
+------------
+
+The one commit in this list that is not related to CMake may very well
+have been motivated by working on fixing all those bugs introduced by
+switching to CMake, but it addresses a different concern. To split this
+branch into two topic branches, the todo list could be edited like this:
+
+------------
+label onto
+
+pick afbecd http: add support for TLS v1.3
+label tlsv1.3
+
+reset onto
+pick 192837 Switch from GNU Makefiles to CMake
+pick 918273 Fix detection of OpenSSL in CMake
+pick fdbaec Fix detection of cURL in CMake on Windows
+pick 5a6c7e Document the switch to CMake
+label cmake
+
+reset onto
+merge tlsv1.3
+merge cmake
+------------
+
+CONFIGURATION
+-------------
+
+include::includes/cmd-config-section-all.txt[]
+
+include::config/rebase.txt[]
+include::config/sequencer.txt[]
+
+GIT
+---
+Part of the linkgit:git[1] suite