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2020-04-29Merge branch 'dl/merge-autostash-rebase-quit-fix'Libravatar Junio C Hamano1-0/+1
The stash entry created by "git rebase --autosquash" to keep the initial dirty state were discarded by mistake upon "git rebase --quit", which has been corrected. * dl/merge-autostash-rebase-quit-fix: rebase: save autostash entry into stash reflog on --quit
2020-04-29Merge branch 'dl/merge-autostash'Libravatar Junio C Hamano1-264/+44
"git merge" learns the "--autostash" option. * dl/merge-autostash: (22 commits) pull: pass --autostash to merge t5520: make test_pull_autostash() accept expect_parent_num merge: teach --autostash option sequencer: implement apply_autostash_oid() sequencer: implement save_autostash() sequencer: unlink autostash in apply_autostash() sequencer: extract perform_autostash() from rebase rebase: generify create_autostash() rebase: extract create_autostash() reset: extract reset_head() from rebase rebase: generify reset_head() rebase: use apply_autostash() from sequencer.c sequencer: rename stash_sha1 to stash_oid sequencer: make apply_autostash() accept a path rebase: use read_oneliner() sequencer: make read_oneliner() extern sequencer: configurably warn on non-existent files sequencer: make read_oneliner() accept flags sequencer: make file exists check more efficient sequencer: stop leaking buf ...
2020-04-28rebase: save autostash entry into stash reflog on --quitLibravatar Denton Liu1-0/+1
In a03b55530a (merge: teach --autostash option, 2020-04-07), the --autostash option was introduced for `git merge`. Notably, when `git merge --quit` is run with an autostash entry present, it is saved into the stash reflog. This is contrasted with the current behaviour of `git rebase --quit` where the autostash entry is simply just dropped out of existence. Adopt the behaviour of `git merge --quit` in `git rebase --quit` and save the autostash entry into the stash reflog instead of just deleting it. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-22Merge branch 'jt/rebase-allow-duplicate'Libravatar Junio C Hamano1-0/+7
Allow "git rebase" to reapply all local commits, even if the may be already in the upstream, without checking first. * jt/rebase-allow-duplicate: rebase --merge: optionally skip upstreamed commits
2020-04-22Merge branch 'en/rebase-no-keep-empty'Libravatar Junio C Hamano1-7/+10
"git rebase" (again) learns to honor "--no-keep-empty", which lets the user to discard commits that are empty from the beginning (as opposed to the ones that become empty because of rebasing). The interactive rebase also marks commits that are empty in the todo. * en/rebase-no-keep-empty: rebase: fix an incompatible-options error message rebase: reinstate --no-keep-empty rebase -i: mark commits that begin empty in todo editor
2020-04-22Merge branch 'dd/no-gpg-sign'Libravatar Junio C Hamano1-3/+4
"git rebase" learned the "--no-gpg-sign" option to countermand commit.gpgSign the user may have. * dd/no-gpg-sign: Documentation: document merge option --no-gpg-sign Documentation: merge commit-tree --[no-]gpg-sign Documentation: reword commit --no-gpg-sign Documentation: document am --no-gpg-sign cherry-pick/revert: honour --no-gpg-sign in all case rebase.c: honour --no-gpg-sign
2020-04-11rebase --merge: optionally skip upstreamed commitsLibravatar Jonathan Tan1-0/+7
When rebasing against an upstream that has had many commits since the original branch was created: O -- O -- ... -- O -- O (upstream) \ -- O (my-dev-branch) it must read the contents of every novel upstream commit, in addition to the tip of the upstream and the merge base, because "git rebase" attempts to exclude commits that are duplicates of upstream ones. This can be a significant performance hit, especially in a partial clone, wherein a read of an object may end up being a fetch. Add a flag to "git rebase" to allow suppression of this feature. This flag only works when using the "merge" backend. This flag changes the behavior of sequencer_make_script(), called from do_interactive_rebase() <- run_rebase_interactive() <- run_specific_rebase() <- cmd_rebase(). With this flag, limit_list() (indirectly called from sequencer_make_script() through prepare_revision_walk()) will no longer call cherry_pick_list(), and thus PATCHSAME is no longer set. Refraining from setting PATCHSAME both means that the intermediate commits in upstream are no longer read (as shown by the test) and means that no PATCHSAME-caused skipping of commits is done by sequencer_make_script(), either directly or through make_script_with_merges(). Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-11rebase: fix an incompatible-options error messageLibravatar Elijah Newren1-1/+1
When the user specifies the apply backend with options that only work with the merge backend, such as git rebase --apply --exec /bin/true HEAD~3 the error message has always been fatal: --exec requires an interactive rebase This error message is misleading and was one of the reasons we renamed the interactive backend to the merge backend. Update the error message to state that these options merely require use of the merge backend. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-11rebase: reinstate --no-keep-emptyLibravatar Elijah Newren1-6/+9
Commit d48e5e21da ("rebase (interactive-backend): make --keep-empty the default", 2020-02-15) turned --keep-empty (for keeping commits which start empty) into the default. The logic underpinning that commit was: 1) 'git commit' errors out on the creation of empty commits without an override flag 2) Once someone determines that the override is worthwhile, it's annoying and/or harmful to required them to take extra steps in order to keep such commits around (and to repeat such steps with every rebase). While the logic on which the decision was made is sound, the result was a bit of an overcorrection. Instead of jumping to having --keep-empty being the default, it jumped to making --keep-empty the only available behavior. There was a simple workaround, though, which was thought to be good enough at the time. People could still drop commits which started empty the same way the could drop any commits: by firing up an interactive rebase and picking out the commits they didn't want from the list. However, there are cases where external tools might create enough empty commits that picking all of them out is painful. As such, having a flag to automatically remove start-empty commits may be beneficial. Provide users a way to drop commits which start empty using a flag that existed for years: --no-keep-empty. Interpret --keep-empty as countermanding any previous --no-keep-empty, but otherwise leaving --keep-empty as the default. This might lead to some slight weirdness since commands like git rebase --empty=drop --keep-empty git rebase --empty=keep --no-keep-empty look really weird despite making perfect sense (the first will drop commits which become empty, but keep commits that started empty; the second will keep commits which become empty, but drop commits which started empty). However, --no-keep-empty was named years ago and we are predominantly keeping it for backward compatibility; also we suspect it will only be used rarely since folks already have a simple way to drop commits they don't want with an interactive rebase. Reported-by: Bryan Turner <bturner@atlassian.com> Reported-by: Sami Boukortt <sami@boukortt.com> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10merge: teach --autostash optionLibravatar Denton Liu1-2/+1
In rebase, one can pass the `--autostash` option to cause the worktree to be automatically stashed before continuing with the rebase. This option is missing in merge, however. Implement the `--autostash` option and corresponding `merge.autoStash` option in merge which stashes before merging and then pops after. This option is useful when a developer has some local changes on a topic branch but they realize that their work depends on another branch. Previously, they had to run something like git fetch ... git stash push git merge FETCH_HEAD git stash pop but now, that is reduced to git fetch ... git merge --autostash FETCH_HEAD When an autostash is generated, it is automatically reapplied to the worktree only in three explicit situations: 1. An incomplete merge is commit using `git commit`. 2. A merge completes successfully. 3. A merge is aborted using `git merge --abort`. In all other situations where the merge state is removed using remove_merge_branch_state() such as aborting a merge via `git reset --hard`, the autostash is saved into the stash reflog instead keeping the worktree clean. Helped-by: Phillip Wood <phillip.wood@dunelm.org.uk> Suggested-by: Alban Gruin <alban.gruin@gmail.com> Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10sequencer: extract perform_autostash() from rebaseLibravatar Denton Liu1-49/+0
Lib-ify the autostash code by extracting perform_autostash() from rebase into sequencer. In a future commit, this will be used to implement `--autostash` in other builtins. This patch is best viewed with `--color-moved`. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10rebase: generify create_autostash()Libravatar Denton Liu1-16/+16
In the future, we plan on lib-ifying create_autostash() so we need it to be more generic. Make it more generic by making it accept a `struct repository` argument instead of implicitly using the non-repo functions and `the_repository`. Also, make it accept a `path` argument so that we no longer rely have to rely on `struct rebase_options`. Finally, make it accept a `default_reflog_action` argument so we no longer have to rely on `DEFAULT_REFLOG_ACTION`. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10rebase: extract create_autostash()Libravatar Denton Liu1-44/+50
In a future commit, we will lib-ify this code. In preparation for this, extract the code into the create_autostash() function so that it can be cleaned up before it is finally lib-ified. This patch is best viewed with `--color-moved` and `--color-moved-ws=allow-indentation-change`. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10reset: extract reset_head() from rebaseLibravatar Denton Liu1-138/+1
Continue the process of lib-ifying the autostash code. In a future commit, this will be used to implement `--autostash` in other builtins. This patch is best viewed with `--color-moved`. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10rebase: generify reset_head()Libravatar Denton Liu1-27/+37
In the future, we plan on lib-ifying reset_head() so we need it to be more generic. Make it more generic by making it accept a `struct repository` argument instead of implicitly using the non-repo functions. Also, make it accept a `const char *default_reflog_action` argument so that the default action of "rebase" isn't hardcoded in. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10rebase: use apply_autostash() from sequencer.cLibravatar Denton Liu1-47/+2
The apply_autostash() function in builtin/rebase.c is similar enough to the apply_autostash() function in sequencer.c that they are almost interchangeable, except for the type of arg they accept. Make the sequencer.c version extern and use it in rebase. The rebase version was introduced in 6defce2b02 (builtin rebase: support `--autostash` option, 2018-09-04) as part of the shell to C conversion. It opted to duplicate the function because, at the time, there was another in-progress project converting interactive rebase from shell to C as well and they did not want to clash with them by refactoring sequencer.c version of apply_autostash(). Since both efforts are long done, we can freely combine them together now. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10rebase: use read_oneliner()Libravatar Denton Liu1-20/+17
Since in sequencer.c, read_one() basically duplicates the functionality of read_oneliner(), reduce code duplication by replacing read_one() with read_oneliner(). This was done with the following Coccinelle script @@ expression a, b; @@ - read_one(a, b) + !read_oneliner(b, a, READ_ONELINER_WARN_MISSING) and long lines were manually broken up. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-03rebase.c: honour --no-gpg-signLibravatar Đoàn Trần Công Danh1-3/+4
Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-26Merge branch 'bc/filter-process'Libravatar Junio C Hamano1-0/+1
Provide more information (e.g. the object of the tree-ish in which the blob being converted appears, in addition to its path, which has already been given) to smudge/clean conversion filters. * bc/filter-process: t0021: test filter metadata for additional cases builtin/reset: compute checkout metadata for reset builtin/rebase: compute checkout metadata for rebases builtin/clone: compute checkout metadata for clones builtin/checkout: compute checkout metadata for checkouts convert: provide additional metadata to filters convert: permit passing additional metadata to filter processes builtin/checkout: pass branch info down to checkout_worktree
2020-03-16builtin/rebase: compute checkout metadata for rebasesLibravatar brian m. carlson1-0/+1
Signed-off-by: brian m. carlson <bk2204@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-12Merge branch 'en/rebase-backend'Libravatar Junio C Hamano1-1/+1
Band-aid fixes for two fallouts from switching the default "rebase" backend. * en/rebase-backend: git-rebase.txt: highlight backend differences with commit rewording sequencer: clear state upon dropping a become-empty commit i18n: unmark a message in rebase.c
2020-03-11i18n: unmark a message in rebase.cLibravatar Jiang Xin1-1/+1
Commit v2.25.0-4-ge98c4269c8 (rebase (interactive-backend): fix handling of commits that become empty, 2020-02-15) marked "{drop,keep,ask}" for translation, but this message should not be changed. Signed-off-by: Jiang Xin <worldhello.net@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-05Merge branch 'ag/rebase-remove-redundant-code'Libravatar Junio C Hamano1-9/+1
Code reduction. * ag/rebase-remove-redundant-code: builtin/rebase: remove a call to get_oid() on `options.switch_to'
2020-03-05Merge branch 'es/do-not-let-rebase-switch-to-protected-branch'Libravatar Junio C Hamano1-2/+3
"git rebase BASE BRANCH" rebased/updated the tip of BRANCH and checked it out, even when the BRANCH is checked out in a different worktree. This has been corrected. * es/do-not-let-rebase-switch-to-protected-branch: rebase: refuse to switch to branch already checked out elsewhere t3400: make test clean up after itself
2020-03-02Merge branch 'en/rebase-backend'Libravatar Junio C Hamano1-78/+179
"git rebase" has learned to use the merge backend (i.e. the machinery that drives "rebase -i") by default, while allowing "--apply" option to use the "apply" backend (e.g. the moral equivalent of "format-patch piped to am"). The rebase.backend configuration variable can be set to customize. * en/rebase-backend: rebase: rename the two primary rebase backends rebase: change the default backend from "am" to "merge" rebase: make the backend configurable via config setting rebase tests: repeat some tests using the merge backend instead of am rebase tests: mark tests specific to the am-backend with --am rebase: drop '-i' from the reflog for interactive-based rebases git-prompt: change the prompt for interactive-based rebases rebase: add an --am option rebase: move incompatibility checks between backend options a bit earlier git-rebase.txt: add more details about behavioral differences of backends rebase: allow more types of rebases to fast-forward t3432: make these tests work with either am or merge backends rebase: fix handling of restrict_revision rebase: make sure to pass along the quiet flag to the sequencer rebase, sequencer: remove the broken GIT_QUIET handling t3406: simplify an already simple test rebase (interactive-backend): fix handling of commits that become empty rebase (interactive-backend): make --keep-empty the default t3404: directly test the behavior of interest git-rebase.txt: update description of --allow-empty-message
2020-02-26builtin/rebase: remove a call to get_oid() on `options.switch_to'Libravatar Alban Gruin1-9/+1
When `options.switch_to' is set, `options.orig_head' is populated right after with the object name the ref/commit argument points at. Therefore, there is no need to parse `switch_to' again. Signed-off-by: Alban Gruin <alban.gruin@gmail.com> Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24rebase: refuse to switch to branch already checked out elsewhereLibravatar Eric Sunshine1-2/+3
The invocation "git rebase <upstream> <branch>" switches to <branch> before performing the rebase operation. However, unlike git-switch, git-checkout, and git-worktree which all refuse to switch to a branch that is already checked out in some other worktree, git-rebase switches to <branch> unconditionally. Curb this careless behavior by making git-rebase also refuse to switch to a branch checked out elsewhere. Reported-by: Mike Hommey <mh@glandium.org> Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16rebase: rename the two primary rebase backendsLibravatar Elijah Newren1-52/+47
Two related changes, with separate rationale for each: Rename the 'interactive' backend to 'merge' because: * 'interactive' as a name caused confusion; this backend has been used for many kinds of non-interactive rebases, and will probably be used in the future for more non-interactive rebases than interactive ones given that we are making it the default. * 'interactive' is not the underlying strategy; merging is. * the directory where state is stored is not called .git/rebase-interactive but .git/rebase-merge. Rename the 'am' backend to 'apply' because: * Few users are familiar with git-am as a reference point. * Related to the above, the name 'am' makes sentences in the documentation harder for users to read and comprehend (they may read it as the verb from "I am"); avoiding this difficult places a large burden on anyone writing documentation about this backend to be very careful with quoting and sentence structure and often forces annoying redundancy to try to avoid such problems. * Users stumble over pronunciation ("am" as in "I am a person not a backend" or "am" as in "the first and thirteenth letters in the alphabet in order are "A-M"); this may drive confusion when one user tries to explain to another what they are doing. * While "am" is the tool driving this backend, the tool driving git-am is git-apply, and since we are driving towards lower-level tools for the naming of the merge backend we may as well do so here too. * The directory where state is stored has never been called .git/rebase-am, it was always called .git/rebase-apply. For all the reasons listed above: * Modify the documentation to refer to the backends with the new names * Provide a brief note in the documentation connecting the new names to the old names in case users run across the old names anywhere (e.g. in old release notes or older versions of the documentation) * Change the (new) --am command line flag to --apply * Rename some enums, variables, and functions to reinforce the new backend names for us as well. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16rebase: change the default backend from "am" to "merge"Libravatar Elijah Newren1-2/+2
The am-backend drops information and thus limits what we can do: * lack of full tree information from the original commits means we cannot do directory rename detection and warn users that they might want to move some of their new files that they placed in old directories to prevent their becoming orphaned.[1] * reduction in context from only having a few lines beyond those changed means that when context lines are non-unique we can apply patches incorrectly.[2] * lack of access to original commits means that conflict marker annotation has less information available. * the am backend has safety problems with an ill-timed interrupt. Also, the merge/interactive backend have far more abilities, appear to currently have a slight performance advantage[3] and have room for more optimizations than the am backend[4] (and work is underway to take advantage of some of those possibilities). [1] https://lore.kernel.org/git/xmqqh8jeh1id.fsf@gitster-ct.c.googlers.com/ [2] https://lore.kernel.org/git/CABPp-BGiu2nVMQY_t-rnFR5GQUz_ipyEE8oDocKeO+h+t4Mn4A@mail.gmail.com/ [3] https://public-inbox.org/git/CABPp-BF=ev03WgODk6TMQmuNoatg2kiEe5DR__gJ0OTVqHSnfQ@mail.gmail.com/ [4] https://lore.kernel.org/git/CABPp-BGh7yW69QwxQb13K0HM38NKmQif3A6C6UULEKYnkEJ5vA@mail.gmail.com/ Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16rebase: make the backend configurable via config settingLibravatar Elijah Newren1-7/+24
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16rebase: drop '-i' from the reflog for interactive-based rebasesLibravatar Elijah Newren1-1/+1
A large variety of rebase types are supported by the interactive machinery, not just the explicitly interactive ones. These all share the same code and write the same reflog messages, but the "-i" moniker in those messages doesn't really have much meaning. It also becomes somewhat distracting once we switch the default from the am-backend to the interactive one. Just remove the "-i" from these messages. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16rebase: add an --am optionLibravatar Elijah Newren1-1/+17
Currently, this option doesn't do anything except error out if any options requiring the interactive-backend are also passed. However, when we make the default backend configurable later in this series, this flag will provide a way to override the config setting. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16rebase: move incompatibility checks between backend options a bit earlierLibravatar Elijah Newren1-11/+11
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16rebase: allow more types of rebases to fast-forwardLibravatar Elijah Newren1-4/+14
In the past, we dis-allowed rebases using the interactive backend from performing a fast-forward to short-circuit the rebase operation. This made sense for explicitly interactive rebases and some implicitly interactive rebases, but certainly became overly stringent when the merge backend was re-implemented via the interactive backend. Just as the am-based rebase has always had to disable the fast-forward based on a variety of conditions or flags (e.g. --signoff, --whitespace, etc.), we need to do the same but now with a few more options. However, continuing to use REBASE_FORCE for tracking this is problematic because the interactive backend used it for a different purpose. (When REBASE_FORCE wasn't set, the interactive backend would not fast-forward the whole series but would fast-forward individual "pick" commits at the beginning of the todo list, and then a squash or something would cause it to start generating new commits.) So, introduce a new allow_preemptive_ff flag contained within cmd_rebase() and use it to track whether we are going to allow a pre-emptive fast-forward that short-circuits the whole rebase. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16rebase: fix handling of restrict_revisionLibravatar Elijah Newren1-2/+2
restrict_revision in the original shell script was an excluded revision range. It is also treated that way by the am-backend. In the conversion from shell to C (see commit 6ab54d17be3f ("rebase -i: implement the logic to initialize $revisions in C", 2018-08-28)), the interactive-backend accidentally treated it as a positive revision rather than a negated one. This was missed as there were no tests in the testsuite that tested an interactive rebase with fork-point behavior. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16rebase: make sure to pass along the quiet flag to the sequencerLibravatar Elijah Newren1-1/+2
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16rebase, sequencer: remove the broken GIT_QUIET handlingLibravatar Elijah Newren1-4/+2
The GIT_QUIET environment variable was used to signal the non-am backends that the rebase should perform quietly. The preserve-merges backend does not make use of the quiet flag anywhere (other than to write out its state whenever it writes state), and this mechanism was broken in the conversion from shell to C. Since this environment variable was specifically designed for scripts and the only backend that would still use it is no longer a script, just gut this code. A subsequent commit will fix --quiet for the interactive/merge backend in a different way. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16rebase (interactive-backend): fix handling of commits that become emptyLibravatar Elijah Newren1-0/+52
As established in the previous commit and commit b00bf1c9a8dd (git-rebase: make --allow-empty-message the default, 2018-06-27), the behavior for rebase with different backends in various edge or corner cases is often more happenstance than design. This commit addresses another such corner case: commits which "become empty". A careful reader may note that there are two types of commits which would become empty due to a rebase: * [clean cherry-pick] Commits which are clean cherry-picks of upstream commits, as determined by `git log --cherry-mark ...`. Re-applying these commits would result in an empty set of changes and a duplicative commit message; i.e. these are commits that have "already been applied" upstream. * [become empty] Commits which are not empty to start, are not clean cherry-picks of upstream commits, but which still become empty after being rebased. This happens e.g. when a commit has changes which are a strict subset of the changes in an upstream commit, or when the changes of a commit can be found spread across or among several upstream commits. Clearly, in both cases the changes in the commit in question are found upstream already, but the commit message may not be in the latter case. When cherry-mark can determine a commit is already upstream, then because of how cherry-mark works this means the upstream commit message was about the *exact* same set of changes. Thus, the commit messages can be assumed to be fully interchangeable (and are in fact likely to be completely identical). As such, the clean cherry-pick case represents a case when there is no information to be gained by keeping the extra commit around. All rebase types have always dropped these commits, and no one to my knowledge has ever requested that we do otherwise. For many of the become empty cases (and likely even most), we will also be able to drop the commit without loss of information -- but this isn't quite always the case. Since these commits represent cases that were not clean cherry-picks, there is no upstream commit message explaining the same set of changes. Projects with good commit message hygiene will likely have the explanation from our commit message contained within or spread among the relevant upstream commits, but not all projects run that way. As such, the commit message of the commit being rebased may have reasoning that suggests additional changes that should be made to adapt to the new base, or it may have information that someone wants to add as a note to another commit, or perhaps someone even wants to create an empty commit with the commit message as-is. Junio commented on the "become-empty" types of commits as follows[1]: WRT a change that ends up being empty (as opposed to a change that is empty from the beginning), I'd think that the current behaviour is desireable one. "am" based rebase is solely to transplant an existing history and want to stop much less than "interactive" one whose purpose is to polish a series before making it publishable, and asking for confirmation ("this has become empty--do you want to drop it?") is more appropriate from the workflow point of view. [1] https://lore.kernel.org/git/xmqqfu1fswdh.fsf@gitster-ct.c.googlers.com/ I would simply add that his arguments for "am"-based rebases actually apply to all non-explicitly-interactive rebases. Also, since we are stating that different cases should have different defaults, it may be worth providing a flag to allow users to select which behavior they want for these commits. Introduce a new command line flag for selecting the desired behavior: --empty={drop,keep,ask} with the definitions: drop: drop commits which become empty keep: keep commits which become empty ask: provide the user a chance to interact and pick what to do with commits which become empty on a case-by-case basis In line with Junio's suggestion, if the --empty flag is not specified, pick defaults as follows: explicitly interactive: ask otherwise: drop Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16rebase (interactive-backend): make --keep-empty the defaultLibravatar Elijah Newren1-9/+19
Different rebase backends have different treatment for commits which start empty (i.e. have no changes relative to their parent), and the --keep-empty option was added at some point to allow adjusting behavior. The handling of commits which start empty is actually quite similar to commit b00bf1c9a8dd (git-rebase: make --allow-empty-message the default, 2018-06-27), which pointed out that the behavior for various backends is often more happenstance than design. The specific change made in that commit is actually quite relevant as well and much of the logic there directly applies here. It makes a lot of sense in 'git commit' to error out on the creation of empty commits, unless an override flag is provided. However, once someone determines that there is a rare case that merits using the manual override to create such a commit, it is somewhere between annoying and harmful to have to take extra steps to keep such intentional commits around. Granted, empty commits are quite rare, which is why handling of them doesn't get considered much and folks tend to defer to existing (accidental) behavior and assume there was a reason for it, leading them to just add flags (--keep-empty in this case) that allow them to override the bad defaults. Fix the interactive backend so that --keep-empty is the default, much like we did with --allow-empty-message. The am backend should also be fixed to have --keep-empty semantics for commits that start empty, but that is not included in this patch other than a testcase documenting the failure. Note that there was one test in t3421 which appears to have been written expecting --keep-empty to not be the default as correct behavior. This test was introduced in commit 00b8be5a4d38 ("add tests for rebasing of empty commits", 2013-06-06), which was part of a series focusing on rebase topology and which had an interesting original cover letter at https://lore.kernel.org/git/1347949878-12578-1-git-send-email-martinvonz@gmail.com/ which noted Your input especially appreciated on whether you agree with the intent of the test cases. and then went into a long example about how one of the many tests added had several questions about whether it was correct. As such, I believe most the tests in that series were about testing rebase topology with as many different flags as possible and were not trying to state in general how those flags should behave otherwise. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-14Merge branch 'ag/rebase-avoid-unneeded-checkout'Libravatar Junio C Hamano1-13/+5
"git rebase -i" (and friends) used to unnecessarily check out the tip of the branch to be rebased, which has been corrected. * ag/rebase-avoid-unneeded-checkout: rebase -i: stop checking out the tip of the branch to rebase
2020-01-24rebase -i: stop checking out the tip of the branch to rebaseLibravatar Alban Gruin1-13/+5
One of the first things done when using a sequencer-based rebase (ie. `rebase -i', `rebase -r', or `rebase -m') is to make a todo list. This requires knowledge of the commit range to rebase. To get the oid of the last commit of the range, the tip of the branch to rebase is checked out with prepare_branch_to_be_rebased(), then the oid of the head is read. After this, the tip of the branch is not even modified. The `am' backend, on the other hand, does not check out the branch. On big repositories, it's a performance penalty: with `rebase -i', the user may have to wait before editing the todo list while git is extracting the branch silently, and "quiet" rebases will be slower than `am'. Since we already have the oid of the tip of the branch in `opts->orig_head', it's useless to switch to this commit. This removes the call to prepare_branch_to_be_rebased() in do_interactive_rebase(), and adds a `orig_head' parameter to get_revision_ranges(). prepare_branch_to_be_rebased() is removed as it is no longer used. This introduces a visible change: as we do not switch on the tip of the branch to rebase, no reflog entry is created at the beginning of the rebase for it. Unscientific performance measurements, performed on linux.git, are as follow: Before this patch: $ time git rebase -m --onto v4.18 463fa44eec2fef50~ 463fa44eec2fef50 real 0m8,940s user 0m6,830s sys 0m2,121s After this patch: $ time git rebase -m --onto v4.18 463fa44eec2fef50~ 463fa44eec2fef50 real 0m1,834s user 0m0,916s sys 0m0,206s Reported-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Alban Gruin <alban.gruin@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-17git-rebase.txt: update description of --allow-empty-messageLibravatar Elijah Newren1-5/+7
Commit b00bf1c9a8dd ("git-rebase: make --allow-empty-message the default", 2018-06-27) made --allow-empty-message the default and thus turned --allow-empty-message into a no-op but did not update the documentation to reflect this. Update the documentation now, and hide the option from the normal -h output since it is not useful. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-12Revert "Merge branch 'ra/rebase-i-more-options'"Libravatar Junio C Hamano1-37/+12
This reverts commit 5d9324e0f4210bb7d52bcb79efe3935703083f72, reversing changes made to c58ae96fc4bb11916b62a96940bb70bb85ea5992. The topic turns out to be too buggy for real use. cf. <f2fe7437-8a48-3315-4d3f-8d51fe4bb8f1@gmail.com>
2020-01-02Merge branch 'en/rebase-signoff-fix'Libravatar Junio C Hamano1-1/+1
"git rebase --signoff" stopped working when the command was written in C, which has been corrected. * en/rebase-signoff-fix: rebase: fix saving of --signoff state for am-based rebases
2019-12-20rebase: fix saving of --signoff state for am-based rebasesLibravatar Elijah Newren1-1/+1
This was an error introduced in the conversion from shell in commit 21853626eac5 ("built-in rebase: call `git am` directly", 2019-01-18), which was noticed by a random browsing of the code. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-16Merge branch 'dl/rebase-with-autobase'Libravatar Junio C Hamano1-1/+2
"git rebase" did not work well when format.useAutoBase configuration variable is set, which has been corrected. * dl/rebase-with-autobase: rebase: fix format.useAutoBase breakage format-patch: teach --no-base t4014: use test_config() format-patch: fix indentation t3400: demonstrate failure with format.useAutoBase
2019-12-16Merge branch 'ag/sequencer-todo-updates'Libravatar Junio C Hamano1-0/+6
Reduce unnecessary reading of state variables back from the disk during sequencer operation. * ag/sequencer-todo-updates: sequencer: directly call pick_commits() from complete_action() rebase: fill `squash_onto' in get_replay_opts() sequencer: move the code writing total_nr on the disk to a new function sequencer: update `done_nr' when skipping commands in a todo list sequencer: update `total_nr' when adding an item to a todo list
2019-12-10Merge branch 'ra/rebase-i-more-options'Libravatar Junio C Hamano1-12/+36
"git rebase -i" learned a few options that are known by "git rebase" proper. * ra/rebase-i-more-options: rebase -i: finishing touches to --reset-author-date rebase: add --reset-author-date rebase -i: support --ignore-date sequencer: rename amend_author to author_to_rename rebase -i: support --committer-date-is-author-date sequencer: allow callers of read_author_script() to ignore fields rebase -i: add --ignore-whitespace flag
2019-12-05rebase: fix format.useAutoBase breakageLibravatar Denton Liu1-1/+2
With `format.useAutoBase = true`, running rebase resulted in an error: fatal: failed to get upstream, if you want to record base commit automatically, please use git branch --set-upstream-to to track a remote branch. Or you could specify base commit by --base=<base-commit-id> manually error: git encountered an error while preparing the patches to replay these revisions: ede2467cdedc63784887b587a61c36b7850ebfac..d8f581194799ae29bf5fa72a98cbae98a1198b12 As a result, git cannot rebase them. Fix this by always passing `--no-base` to format-patch from rebase so that the effect of `format.useAutoBase` is negated. Reported-by: Christian Biesinger <cbiesinger@google.com> Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-25rebase -i: finishing touches to --reset-author-dateLibravatar Junio C Hamano1-3/+3
Clarify the way the `--reset-author-date` option is described, and mark its usage string translatable. Signed-off-by: Junio C Hamano <gitster@pobox.com>