Provided by: git-man_2.43.0-1ubuntu7.1_all bug

NAME

       git-rebase - Reapply commits on top of another base tip

SYNOPSIS

       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 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.

           Note
           ORIG_HEAD is not guaranteed to still point to the previous branch tip at the end of
           the rebase if other commands that write that pseudo-ref (e.g. git reset) are used
           during the rebase. The previous branch tip, however, is accessible using the reflog of
           the current branch (i.e. @{1}, see gitrevisions(7)).

       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

MODE OPTIONS

       The options in this section cannot be used with any other option, including not with each
       other:

       --continue
           Restart the rebasing process after having resolved a merge conflict.

       --skip
           Restart the rebasing process by skipping the current patch.

       --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.

       --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.

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.

       --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 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.

       -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.

       --rerere-autoupdate, --no-rerere-autoupdate
           After the rerere mechanism reuses a recorded resolution on the current conflict to
           update the files in the working tree, allow it to also update the index with the
           result of resolution.  --no-rerere-autoupdate is a good way to double-check what
           rerere did and catch potential mismerges, before committing the result to the index
           with a separate git add.

       -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 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 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 revert-a-faulty-merge How-To[1] 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 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
           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 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)], --no-rebase-merges
           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.
           --no-rebase-merges can be used to countermand both the rebase.rebaseMerges config
           option and a previous --rebase-merges.

           When rebasing merges, there are two modes: rebase-cousins and no-rebase-cousins. If
           the mode is not specified, it defaults to no-rebase-cousins. In no-rebase-cousins
           mode, commits which do not have <upstream> as direct ancestor will keep their original
           branch point, i.e. commits that would be excluded by git-log(1)'s --ancestry-path
           option will keep their original ancestry by default. In rebase-cousins mode, 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.

           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 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
           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.

           See also INCOMPATIBLE OPTIONS below.

INCOMPATIBLE OPTIONS

       The following options:

       •   --apply

       •   --whitespace

       •   -C

       are incompatible with the following options:

       •   --merge

       •   --strategy

       •   --strategy-option

       •   --autosquash

       •   --rebase-merges

       •   --interactive

       •   --exec

       •   --no-keep-empty

       •   --empty=

       •   --[no-]reapply-cherry-picks when used without --keep-base

       •   --update-refs

       •   --root when used without --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/

MERGE STRATEGIES

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

       ort
           This is the default merge strategy when pulling or merging one branch. This strategy
           can only resolve two heads using a 3-way merge algorithm. When there is more than one
           common ancestor that can be used for 3-way merge, it creates a merged tree of the
           common ancestors and uses that as the reference tree for the 3-way merge. This has
           been reported to result in fewer merge conflicts without causing mismerges by tests
           done on actual merge commits taken from Linux 2.6 kernel development history.
           Additionally this strategy can detect and handle merges involving renames. It does not
           make use of detected copies. The name for this algorithm is an acronym ("Ostensibly
           Recursive’s Twin") and came from the fact that it was written as a replacement for the
           previous default algorithm, recursive.

           The ort strategy can take the following options:

           ours
               This option forces conflicting hunks to be auto-resolved cleanly by favoring our
               version. Changes from the other tree that do not conflict with our side are
               reflected in the merge result. For a binary file, the entire contents are taken
               from our side.

               This should not be confused with the ours merge strategy, which does not even look
               at what the other tree contains at all. It discards everything the other tree did,
               declaring our history contains all that happened in it.

           theirs
               This is the opposite of ours; note that, unlike ours, there is no theirs merge
               strategy to confuse this merge option with.

           ignore-space-change, ignore-all-space, ignore-space-at-eol, ignore-cr-at-eol
               Treats lines with the indicated type of whitespace change as unchanged for the
               sake of a three-way merge. Whitespace changes mixed with other changes to a line
               are not ignored. See also git-diff(1) -b, -w, --ignore-space-at-eol, and
               --ignore-cr-at-eol.

               •   If their version only introduces whitespace changes to a line, our version is
                   used;

               •   If our version introduces whitespace changes but their version includes a
                   substantial change, their version is used;

               •   Otherwise, the merge proceeds in the usual way.

           renormalize
               This runs a virtual check-out and check-in of all three stages of a file when
               resolving a three-way merge. This option is meant to be used when merging branches
               with different clean filters or end-of-line normalization rules. See "Merging
               branches with differing checkin/checkout attributes" in gitattributes(5) for
               details.

           no-renormalize
               Disables the renormalize option. This overrides the merge.renormalize
               configuration variable.

           find-renames[=<n>]
               Turn on rename detection, optionally setting the similarity threshold. This is the
               default. This overrides the merge.renames configuration variable. See also git-
               diff(1) --find-renames.

           rename-threshold=<n>
               Deprecated synonym for find-renames=<n>.

           subtree[=<path>]
               This option is a more advanced form of subtree strategy, where the strategy makes
               a guess on how two trees must be shifted to match with each other when merging.
               Instead, the specified path is prefixed (or stripped from the beginning) to make
               the shape of two trees to match.

       recursive
           This can only resolve two heads using a 3-way merge algorithm. When there is more than
           one common ancestor that can be used for 3-way merge, it creates a merged tree of the
           common ancestors and uses that as the reference tree for the 3-way merge. This has
           been reported to result in fewer merge conflicts without causing mismerges by tests
           done on actual merge commits taken from Linux 2.6 kernel development history.
           Additionally this can detect and handle merges involving renames. It does not make use
           of detected copies. This was the default strategy for resolving two heads from Git
           v0.99.9k until v2.33.0.

           The recursive strategy takes the same options as ort. However, there are three
           additional options that ort ignores (not documented above) that are potentially useful
           with the recursive strategy:

           patience
               Deprecated synonym for diff-algorithm=patience.

           diff-algorithm=[patience|minimal|histogram|myers]
               Use a different diff algorithm while merging, which can help avoid mismerges that
               occur due to unimportant matching lines (such as braces from distinct functions).
               See also git-diff(1) --diff-algorithm. Note that ort specifically uses
               diff-algorithm=histogram, while recursive defaults to the diff.algorithm config
               setting.

           no-renames
               Turn off rename detection. This overrides the merge.renames configuration
               variable. See also git-diff(1) --no-renames.

       resolve
           This can only resolve two heads (i.e. the current branch and another branch you pulled
           from) using a 3-way merge algorithm. It tries to carefully detect criss-cross merge
           ambiguities. It does not handle renames.

       octopus
           This resolves cases with more than two heads, but refuses to do a complex merge that
           needs manual resolution. It is primarily meant to be used for bundling topic branch
           heads together. This is the default merge strategy when pulling or merging more than
           one branch.

       ours
           This resolves any number of heads, but the resulting tree of the merge is always that
           of the current branch head, effectively ignoring all changes from all other branches.
           It is meant to be used to supersede old development history of side branches. Note
           that this is different from the -Xours option to the recursive merge strategy.

       subtree
           This is a modified ort strategy. When merging trees A and B, if B corresponds to a
           subtree of A, B is first adjusted to match the tree structure of A, instead of reading
           the trees at the same level. This adjustment is also done to the common ancestor tree.

       With the strategies that use 3-way merge (including the default, ort), if a change is made
       on both branches, but later reverted on one of the branches, that change will be present
       in the merged result; some people find this behavior confusing. It occurs because only the
       heads and the merge base are considered when performing a merge, not the individual
       commits. The merge algorithm therefore considers the reverted change as no change at all,
       and substitutes the changed version instead.

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 filter-repo[2].

   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 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

       Everything below this line in this section is selectively included from the git-config(1)
       documentation. The content is the same as what’s found there:

       rebase.backend
           Default backend to use for rebasing. Possible choices are apply or merge. In the
           future, if the merge backend gains all remaining capabilities of the apply backend,
           this setting may become unused.

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

       rebase.autoSquash
           If set to true enable --autosquash option by default.

       rebase.autoStash
           When set to true, 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. This option can be overridden by the
           --no-autostash and --autostash options of git-rebase(1). Defaults to false.

       rebase.updateRefs
           If set to true enable --update-refs option by default.

       rebase.missingCommitsCheck
           If set to "warn", git rebase -i will print a warning if some commits are removed (e.g.
           a line was deleted), however the rebase will still proceed. If set to "error", it will
           print the previous warning and stop the rebase, git rebase --edit-todo can then be
           used to correct the error. If set to "ignore", no checking is done. To drop a commit
           without warning or error, use the drop command in the todo list. Defaults to "ignore".

       rebase.instructionFormat
           A format string, as specified in git-log(1), to be used for the todo list during an
           interactive rebase. The format will automatically have the long commit hash prepended
           to the format.

       rebase.abbreviateCommands
           If set to true, git rebase will use abbreviated command names in the todo list
           resulting in something like this:

                       p deadbee The oneline of the commit
                       p fa1afe1 The oneline of the next commit
                       ...

           instead of:

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

           Defaults to false.

       rebase.rescheduleFailedExec
           Automatically reschedule exec commands that failed. This only makes sense in
           interactive mode (or when an --exec option was provided). This is the same as
           specifying the --reschedule-failed-exec option.

       rebase.forkPoint
           If set to false set --no-fork-point option by default.

       rebase.rebaseMerges
           Whether and how to set the --rebase-merges option by default. Can be rebase-cousins,
           no-rebase-cousins, or a boolean. Setting to true or to no-rebase-cousins is equivalent
           to --rebase-merges=no-rebase-cousins, setting to rebase-cousins is equivalent to
           --rebase-merges=rebase-cousins, and setting to false is equivalent to
           --no-rebase-merges. Passing --rebase-merges on the command line, with or without an
           argument, overrides any rebase.rebaseMerges configuration.

       rebase.maxLabelLength
           When generating label names from commit subjects, truncate the names to this length.
           By default, the names are truncated to a little less than NAME_MAX (to allow e.g.
           .lock files to be written for the corresponding loose refs).

       sequence.editor
           Text editor used by git rebase -i for editing the rebase instruction file. The value
           is meant to be interpreted by the shell when it is used. It can be overridden by the
           GIT_SEQUENCE_EDITOR environment variable. When not configured, the default commit
           message editor is used instead.

GIT

       Part of the git(1) suite

NOTES

        1. revert-a-faulty-merge How-To
           file:///usr/share/doc/git/html/howto/revert-a-faulty-merge.html

        2. filter-repo
           https://github.com/newren/git-filter-repo