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Diffstat (limited to 'Documentation/git-rebase.txt')
| -rw-r--r-- | Documentation/git-rebase.txt | 316 |
1 files changed, 285 insertions, 31 deletions
diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt index 8a861c1e0d..1fbc6ebcde 100644 --- a/Documentation/git-rebase.txt +++ b/Documentation/git-rebase.txt @@ -8,11 +8,11 @@ git-rebase - Reapply commits on top of another base tip SYNOPSIS -------- [verse] -'git rebase' [-i | --interactive] [options] [--exec <cmd>] [--onto <newbase>] +'git rebase' [-i | --interactive] [<options>] [--exec <cmd>] [--onto <newbase>] [<upstream> [<branch>]] -'git rebase' [-i | --interactive] [options] [--exec <cmd>] [--onto <newbase>] +'git rebase' [-i | --interactive] [<options>] [--exec <cmd>] [--onto <newbase>] --root [<branch>] -'git rebase' --continue | --skip | --abort | --quit | --edit-todo +'git rebase' --continue | --skip | --abort | --quit | --edit-todo | --show-current-patch DESCRIPTION ----------- @@ -243,6 +243,15 @@ leave out at most one of A and B, in which case it defaults to HEAD. --keep-empty:: Keep the commits that do not change anything from its parents in the result. ++ +See also INCOMPATIBLE OPTIONS below. + +--allow-empty-message:: + By default, rebasing commits with an empty message will fail. + This option overrides that behavior, allowing commits with empty + messages to be rebased. ++ +See also INCOMPATIBLE OPTIONS below. --skip:: Restart the rebasing process by skipping the current patch. @@ -250,6 +259,11 @@ leave out at most one of A and B, in which case it defaults to HEAD. --edit-todo:: Edit the todo list during an interactive rebase. +--show-current-patch:: + Show the current patch in an interactive rebase or when rebase + is stopped because of conflicts. This is the equivalent of + `git show REBASE_HEAD`. + -m:: --merge:: Use merging strategies to rebase. When the recursive (default) merge @@ -261,6 +275,8 @@ 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>:: @@ -270,8 +286,10 @@ other words, the sides are swapped. + 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>, +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>:: @@ -279,6 +297,8 @@ which makes little sense. 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. ++ +See also INCOMPATIBLE OPTIONS below. -S[<keyid>]:: --gpg-sign[=<keyid>]:: @@ -314,17 +334,21 @@ which makes little sense. and after each change. When fewer lines of surrounding context exist they all must match. By default no context is ever ignored. ++ +See also INCOMPATIBLE OPTIONS below. --f:: +--no-ff:: --force-rebase:: - Force a rebase even if the current branch is up to date and - the command without `--force` would return without doing anything. +-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 (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 -link:howto/revert-a-faulty-merge.html[revert-a-faulty-merge How-To] for details). +You may find this helpful after reverting a topic branch merge, as this option +recreates the topic branch with fresh commits so it can be remerged +successfully without needing to "revert the reversion" (see the +link:howto/revert-a-faulty-merge.html[revert-a-faulty-merge How-To] for +details). --fork-point:: --no-fork-point:: @@ -345,18 +369,22 @@ default is `--no-fork-point`, otherwise the default is `--fork-point`. --whitespace=<option>:: These flag are passed to the 'git apply' program (see linkgit:git-apply[1]) that applies the patch. - Incompatible with the --interactive option. ++ +See also INCOMPATIBLE OPTIONS below. --committer-date-is-author-date:: --ignore-date:: These flags are passed to 'git am' to easily change the dates of the rebased commits (see linkgit:git-am[1]). - Incompatible with the --interactive option. ++ +See also INCOMPATIBLE OPTIONS below. --signoff:: - This flag is passed to 'git am' to sign off all the rebased - commits (see linkgit:git-am[1]). Incompatible with the - --interactive option. + 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:: @@ -367,6 +395,35 @@ default is `--no-fork-point`, otherwise the default is `--fork-point`. The commit list format can be changed by setting the configuration option rebase.instructionFormat. A customized instruction format will automatically have the long commit hash prepended to the format. ++ +See also INCOMPATIBLE OPTIONS below. + +-r:: +--rebase-merges[=(rebase-cousins|no-rebase-cousins)]:: + By default, a rebase will simply drop merge commits from the todo + list, and put the rebased commits into a single, linear branch. + With `--rebase-merges`, the rebase will instead try to preserve + the branching structure within the commits that are to be rebased, + by recreating the merge commits. Any resolved merge conflicts or + manual amendments in these merge commits will have to be + resolved/re-applied manually. ++ +By default, or when `no-rebase-cousins` was specified, commits which do not +have `<upstream>` as direct ancestor will keep their original branch point, +i.e. commits that would be excluded by gitlink:git-log[1]'s +`--ancestry-path` option will keep their original ancestry by default. If +the `rebase-cousins` mode is turned on, such commits are instead rebased +onto `<upstream>` (or `<onto>`, if specified). ++ +The `--rebase-merges` mode is similar in spirit to `--preserve-merges`, but +in contrast to that option works well in interactive rebases: commits can be +reordered, inserted and dropped at will. ++ +It is currently only possible to recreate the merge commits using the +`recursive` 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. -p:: --preserve-merges:: @@ -377,6 +434,8 @@ have the long commit hash prepended to the format. 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). ++ +See also INCOMPATIBLE OPTIONS below. -x <cmd>:: --exec <cmd>:: @@ -399,6 +458,8 @@ 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 @@ -409,6 +470,8 @@ without an explicit `--interactive`. When used together with both --onto and --preserve-merges, 'all' root commits will be rewritten to have <newbase> as parent instead. ++ +See also INCOMPATIBLE OPTIONS below. --autosquash:: --no-autosquash:: @@ -423,11 +486,11 @@ without an explicit `--interactive`. too. The recommended way to create fixup/squash commits is by using the `--fixup`/`--squash` options of linkgit:git-commit[1]. + -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. ++ +See also INCOMPATIBLE OPTIONS below. --autostash:: --no-autostash:: @@ -437,17 +500,73 @@ used to override and disable this setting. 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 -link:howto/revert-a-faulty-merge.html[revert-a-faulty-merge How-To] for details). +INCOMPATIBLE OPTIONS +-------------------- + +git-rebase has many flags that are incompatible with each other, +predominantly due to the fact that it has three different underlying +implementations: + + * one based on linkgit:git-am[1] (the default) + * one based on git-merge-recursive (merge backend) + * one based on linkgit:git-cherry-pick[1] (interactive backend) + +Flags only understood by the am backend: + + * --committer-date-is-author-date + * --ignore-date + * --whitespace + * --ignore-whitespace + * -C + +Flags understood by both merge and interactive backends: + + * --merge + * --strategy + * --strategy-option + * --allow-empty-message + +Flags only understood by the interactive backend: + + * --[no-]autosquash + * --rebase-merges + * --preserve-merges + * --interactive + * --exec + * --keep-empty + * --autosquash + * --edit-todo + * --root when used in combination with --onto + +Other incompatible flag pairs: + + * --preserve-merges and --interactive + * --preserve-merges and --signoff + * --preserve-merges and --rebase-merges + * --rebase-merges and --strategy + * --rebase-merges and --strategy-option + +BEHAVIORAL DIFFERENCES +----------------------- + + * empty commits: + + am-based rebase will drop any "empty" commits, whether the + commit started empty (had no changes relative to its parent to + start with) or ended empty (all changes were already applied + upstream in other commits). + + merge-based rebase does the same. + + interactive-based rebase will by default drop commits that + started empty and halt if it hits a commit that ended up empty. + The `--keep-empty` option exists for interactive rebases to allow + it to keep commits that started empty. + + * directory rename detection: + + merge-based and interactive-based rebases work fine with + directory rename detection. am-based rebases sometimes do not. include::merge-strategies.txt[] @@ -765,12 +884,147 @@ 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 isimilar 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. + +At this time, the `merge` command will *always* use the `recursive` +merge strategy for regular merges, and `octopus` for octopus merges, +strategy, with no way to choose a different one. To work around +this, an `exec` command can be used to call `git merge` explicitly, +using the fact that the labels are worktree-local refs (the ref +`refs/rewritten/onto` would correspond to the label `onto`, for example). + +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 +------------ + BUGS ---- The todo list presented by `--preserve-merges --interactive` does not represent the topology of the revision graph. Editing commits and rewording their commit messages should work fine, but attempts to -reorder commits tend to produce counterintuitive results. +reorder commits tend to produce counterintuitive results. Use +`--rebase-merges` in such scenarios instead. For example, an attempt to rearrange ------------ |