NAME | SYNOPSIS | DESCRIPTION | CONFIGURATION | OPTIONS | MERGE STRATEGIES | NOTES | INTERACTIVE MODE | SPLITTING COMMITS | RECOVERING FROM UPSTREAM REBASE | BUGS | GIT | NOTES | COLOPHON

GIT-REBASE(1)                    Git Manual                    GIT-REBASE(1)

NAME         top

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

SYNOPSIS         top

       git rebase [-i | --interactive] [options] [--exec <cmd>] [--onto <newbase>]
               [<upstream> [<branch>]]
       git rebase [-i | --interactive] [options] [--exec <cmd>] [--onto <newbase>]
               --root [<branch>]
       git rebase --continue | --skip | --abort | --quit | --edit-todo

DESCRIPTION         top

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

CONFIGURATION         top

       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
           If set to true enable --autostash option by default.
       rebase.missingCommitsCheck
           If set to "warn", print warnings about removed commits in
           interactive mode. If set to "error", print the warnings and stop
           the rebase. If set to "ignore", no checking is done. "ignore" by
           default.
       rebase.instructionFormat
           Custom commit list format to use during an --interactive rebase.

OPTIONS         top

       --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.
       <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.
       --keep-empty
           Keep the commits that do not change anything from its parents in
           the result.
       --skip
           Restart the rebasing process by skipping the current patch.
       --edit-todo
           Edit the todo list during an interactive rebase.
       -m, --merge
           Use merging strategies to rebase. When the recursive (default)
           merge strategy is used, this allows rebase to be aware of renames
           on the upstream side.
           Note that a rebase merge works by replaying each commit from the
           working branch on top of the <upstream> branch. Because of this,
           when a merge conflict happens, the side reported as ours is the
           so-far rebased series, starting with <upstream>, and theirs is
           the working branch. In other words, the sides are swapped.
       -s <strategy>, --strategy=<strategy>
           Use the given merge strategy. If there is no -s option git
           merge-recursive is used instead. This implies --merge.
           Because git rebase replays each commit from the working branch on
           top of the <upstream> branch using the given strategy, using the
           ours strategy simply discards all patches from the <branch>,
           which makes little sense.
       -X <strategy-option>, --strategy-option=<strategy-option>
           Pass the <strategy-option> through to the merge strategy. This
           implies --merge and, if no strategy has been specified, -s
           recursive. Note the reversal of ours and theirs as noted above
           for the -m option.
       -S[<keyid>], --gpg-sign[=<keyid>]
           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.
       -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.
       -f, --force-rebase
           Force a rebase even if the current branch is up-to-date and the
           command without --force would return without doing anything.
           You may find this (or --no-ff with an interactive rebase) helpful
           after reverting a topic branch merge, as this option recreates
           the topic branch with fresh commits so it can be remerged
           successfully without needing to "revert the reversion" (see the
           revert-a-faulty-merge How-To[1] for details).
       --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 either <upstream> or --root is given on the command line, then
           the default is --no-fork-point, otherwise the default is
           --fork-point.
       --ignore-whitespace, --whitespace=<option>
           These flag are passed to the git apply program (see git-apply(1))
           that applies the patch. Incompatible with the --interactive
           option.
       --committer-date-is-author-date, --ignore-date
           These flags are passed to git am to easily change the dates of
           the rebased commits (see git-am(1)). Incompatible with the
           --interactive option.
       --signoff
           This flag is passed to git am to sign off all the rebased commits
           (see git-am(1)). Incompatible with the --interactive option.
       -i, --interactive
           Make a list of the commits which are about to be rebased. Let the
           user edit that list before rebasing. This mode can also be used
           to split commits (see SPLITTING COMMITS below).
           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.
       -p, --preserve-merges
           Recreate merge commits instead of flattening the history by
           replaying commits a merge commit introduces. Merge conflict
           resolutions or manual amendments to merge commits are not
           preserved.
           This uses the --interactive machinery internally, but combining
           it with the --interactive option explicitly is generally not a
           good idea unless you know what you are doing (see BUGS below).
       -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.
           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.
       --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. When used
           together with both --onto and --preserve-merges, all root commits
           will be rewritten to have <newbase> as parent instead.
       --autosquash, --no-autosquash
           When the commit log message begins with "squash! ..." (or "fixup!
           ..."), and there is a commit whose title begins with the same
           ..., automatically modify the todo list of rebase -i so that the
           commit marked for squashing comes right after the commit to be
           modified, and change the action of the moved commit from pick to
           squash (or fixup). Ignores subsequent "fixup! " or "squash! "
           after the first, in case you referred to an earlier fixup/squash
           with git commit --fixup/--squash.
           This option is only valid when the --interactive option is used.
           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.
       --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.
       --no-ff
           With --interactive, cherry-pick all rebased commits instead of
           fast-forwarding over the unchanged ones. This ensures that the
           entire history of the rebased branch is composed of new commits.
           Without --interactive, this is a synonym for --force-rebase.
           You may find this helpful after reverting a topic branch merge,
           as this option recreates the topic branch with fresh commits so
           it can be remerged successfully without needing to "revert the
           reversion" (see the revert-a-faulty-merge How-To[1] for details).

MERGE STRATEGIES         top

       The merge mechanism (git merge and git pull commands) allows the
       backend merge strategies to be chosen with -s option. Some strategies
       can also take their own options, which can be passed by giving
       -X<option> arguments to git merge and/or git pull.
       resolve
           This can only resolve two heads (i.e. the current branch and
           another branch you pulled from) using a 3-way merge algorithm. It
           tries to carefully detect criss-cross merge ambiguities and is
           considered generally safe and fast.
       recursive
           This can only resolve two heads using a 3-way merge algorithm.
           When there is more than one common ancestor that can be used for
           3-way merge, it creates a merged tree of the common ancestors and
           uses that as the reference tree for the 3-way merge. This has
           been reported to result in fewer merge conflicts without causing
           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. This is the default merge
           strategy when pulling or merging one branch.
           The recursive strategy can take the following options:
           ours
               This option forces conflicting hunks to be auto-resolved
               cleanly by favoring our version. Changes from the other tree
               that do not conflict with our side are reflected to the merge
               result. 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.
           patience
               With this option, merge-recursive spends a little extra time
               to avoid mismerges that sometimes occur due to unimportant
               matching lines (e.g., braces from distinct functions). Use
               this when the branches to be merged have diverged wildly. See
               also git-diff(1)--patience.
           diff-algorithm=[patience|minimal|histogram|myers]
               Tells merge-recursive to use a different diff algorithm,
               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.
           ignore-space-change, ignore-all-space, ignore-space-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, and --ignore-space-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.
           no-renames
               Turn off rename detection. See also git-diff(1)--no-renames.
           find-renames[=<n>]
               Turn on rename detection, optionally setting the similarity
               threshold. This is the default. 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.
       octopus
           This resolves cases with more than two heads, but refuses to do a
           complex merge that needs manual resolution. It is primarily meant
           to be used for bundling topic branch heads together. This is the
           default merge strategy when pulling or merging more than one
           branch.
       ours
           This resolves any number of heads, but the resulting tree of the
           merge is always that of the current branch head, effectively
           ignoring all changes from all other branches. It is meant to be
           used to supersede old development history of side branches. Note
           that this is different from the -Xours option to the recursive
           merge strategy.
       subtree
           This is a modified recursive strategy. When merging trees A and
           B, if B corresponds to a subtree of A, B is first adjusted to
           match the tree structure of A, instead of reading the trees at
           the same level. This adjustment is also done to the common
           ancestor tree.
       With the strategies that use 3-way merge (including the default,
       recursive), 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         top

       You should understand the implications of using git rebase on a
       repository that you share. See also RECOVERING FROM UPSTREAM REBASE
       below.
       When the git-rebase command is run, it will first execute a
       "pre-rebase" hook if one exists. You can use this hook to do sanity
       checks and reject the rebase if it isn’t appropriate. Please see the
       template pre-rebase hook script for an example.
       Upon completion, <branch> will be the current branch.

INTERACTIVE MODE         top

       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.
       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 commit
       messages of the first commit and of those with the "squash" command,
       but omits the commit messages of commits with the "fixup" command.
       git rebase will stop when "pick" has been replaced with "edit" or
       when a command fails due to merge errors. When you are done editing
       and/or resolving conflicts you can continue with git rebase
       --continue.
       For example, if you want to reorder the last 5 commits, such that
       what was HEAD~4 becomes the new HEAD. To achieve that, you would call
       git rebase like this:
           $ git rebase -i HEAD~5
       And move the first patch to the end of the list.
       You might want to preserve merges, if you have a history like this:
                      X
                       \
                    A---M---B
                   /
           ---o---O---P---Q
       Suppose you want to rebase the side branch starting at "A" to "Q".
       Make sure that the current HEAD is "B", and call
           $ git rebase -i -p --onto Q O
       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         top

       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         top

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

BUGS         top

       The todo list presented by --preserve-merges --interactive does not
       represent the topology of the revision graph. Editing commits and
       rewording their commit messages should work fine, but attempts to
       reorder commits tend to produce counterintuitive results.
       For example, an attempt to rearrange
           1 --- 2 --- 3 --- 4 --- 5
       to
           1 --- 2 --- 4 --- 3 --- 5
       by moving the "pick 4" line will result in the following history:
                   3
                  /
           1 --- 2 --- 4 --- 5

GIT         top

       Part of the git(1) suite

NOTES         top

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

COLOPHON         top

       This page is part of the git (Git distributed version control system)
       project.  Information about the project can be found at 
       ⟨http://git-scm.com/⟩.  If you have a bug report for this manual page,
       see ⟨http://git-scm.com/community⟩.  This page was obtained from the
       project's upstream Git repository ⟨https://github.com/git/git.git⟩ on
       2017-07-05.  If you discover any rendering problems in this HTML ver‐
       sion of the page, or you believe there is a better or more up-to-date
       source for the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original man‐
       ual page), send a mail to man-pages@man7.org
Git 2.13.2.556.g5116f7           07/05/2017                    GIT-REBASE(1)

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