Linux Certif

Toute la documentation sur la certification Linux LPI

git-rebase

NAME

git-rebase - Forward-port local commits to the updated upstream head

SYNOPSIS

git-rebase [-v] [--merge] [-C<n>] [--onto <newbase>] <upstream> [<branch>]

git-rebase --continue | --skip | --abort

DESCRIPTION

If <branch> is specified, git-rebase will perform an automatic git checkout <branch> before doing anything else. Otherwise it remains on the current branch.

All changes made by commits in the current branch but that are not in <upstream> are saved to a temporary area. This is the same set of commits that would be shown by git log <upstream>..HEAD.

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>).

The commits that were previously saved into the temporary area are then reapplied to the current branch, one by one, in order.

It is possible that a merge failure will prevent this process from being completely automatic. You will have to resolve any such merge failure and run git rebase --continue. Another option is to bypass the commit that caused the merge failure with git rebase --skip. To restore the original <branch> and remove the .dotest 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

The latter form is just a short-hand of git checkout topic followed by git rebase 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 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 would want to make topic forked from branch master, for example because the functionality topic branch depend on got merged into more stable master branch, 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~2 topicA

would result in the removal of commits F and G:

    E---H'---I'---J'  topicA

This is useful if F and G were flawed in some way, or should not be part of topicA. Note that the argument to --onto and the <upstream> parameter can be any valid commit-ish.

In case of conflict, git-rebase will stop at the first problematic commit and leave conflict markers in the tree. You can use git diff to locate the markers (<<<<<<) and make edits to resolve the conflict. For each file you edit, you need to tell git that the conflict has been resolved, typically this would be done with

git add <filename>

After resolving the conflict manually and updating the index with the desired resolution, you can continue the rebasing process with

git rebase --continue

Alternatively, you can undo the git-rebase with

git rebase --abort

OPTIONS

<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.

<upstream>

Upstream branch to compare against. May be any valid commit, not just an existing branch name.

<branch>

Working branch; defaults to HEAD.

--continue

Restart the rebasing process after having resolved a merge conflict.

--abort

Restore the original branch and abort the rebase operation.

--skip

Restart the rebasing process by skipping the current patch.

--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.

-s <strategy>, --strategy=<strategy>

Use the given merge strategy; can be supplied more than once to specify them in the order they should be tried. If there is no -s option, a built-in list of strategies is used instead (git-merge-recursive when merging a single head, git-merge-octopus otherwise). This implies --merge.

-v, --verbose

Display a diffstat of what changed upstream since the last rebase.

-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.

MERGE STRATEGIES

resolve

This can only resolve two heads (i.e. the current branch and another branch you pulled from) using 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 3-way merge algorithm. When there are more than one common ancestors 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 mis-merges by tests done on actual merge commits taken from Linux 2.6 kernel development history. Additionally this can detect and handle merges involving renames. This is the default merge strategy when pulling or merging one branch.

octopus

This resolves more than two-head case, but refuses to do 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 branches.

ours

This resolves any number of heads, but the result of the merge is always the current branch head. It is meant to be used to supersede old development history of side branches.

NOTES

When you rebase a branch, you are changing its history in a way that will cause problems for anyone who already has a copy of the branch in their repository and tries to pull updates from you. You should understand the implications of using git rebase on a repository that you share.

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.

You must be in the top directory of your project to start (or continue) a rebase. Upon completion, <branch> will be the current branch.

AUTHOR

Written by Junio C Hamano <junkio@cox.net>

DOCUMENTATION

Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.

GIT

Part of the git(7) suite