summaryrefslogtreecommitdiff
path: root/replay.c
AgeCommit message (Collapse)AuthorFilesLines
3 daysMerge branch 'en/midx-missing-pack-fallback'Junio C Hamano1-0/+7
The object lookup machinery has been taught to gracefully recover when a multi-pack-index points to an owning pack that was removed during a concurrent geometric repack, and 'git replay' has been fixed to not segfault when reading such missing objects. * en/midx-missing-pack-fallback: packfile: recover when a multi-pack-index names a removed pack mktree: do not use OBJECT_INFO_QUICK when checking objects mktree: plug per-tree leak in --batch mode replay: fail gracefully when a merge input is unreadable
13 daysreplay: offer an option to linearize the commit topologyToon Claes1-17/+37
One of the stated goals of git-replay(1) is to allow implementing the git-rebase(1) functionality on the server side. The default mode of git-rebase(1) is to act as if `--no-rebase-merges` was given. This mode drops merge commits instead of replaying them, and linearizes the history into a sequence of regular (single-parent) commits. Add option `--linearize` to git-replay(1) to do the same. Each replayed commit is stacked on top of the previously replayed one. When a merge is encountered, the commits reachable from all of its sides are replayed into the single line and the merge itself is dropped. If a ref was pointing to a merge commit, that ref is updated to the merge's last replayed ancestor. git-replay(1) accepts multiple branches, for example: $ git replay --onto main topic1 topic2 Without `--linearize` this replays 'topic1' and 'topic2' onto 'main' (keeping shared portions of history shared and divergent parts divergent) and updates both refs. Due to current implementation limitations, replaying multiple branches with `--linearize` is disallowed to avoid concatenating unrelated histories into a single line. For the same reason disallow the use of `--contained` with `--linearize`. Users who want to linearize multiple branches are advised to do this in separate git-replay(1) invocations. Linearizing multiple branches at once might be added later. Note that `--linearize` is not modeled after git-rebase(1)'s `--rebase-merges[=<mode>]` interface. Recreating merges, by preserving their topology, is a distinct operation that would be a separate mode. `--linearize` only drops merges and replays commits linearly. So git-replay(1) uses its own option rather than reusing that interface. Based-on-patches-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Toon Claes <toon@iotcl.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
13 daysreplay: resolve the replay base outside pick_regular_commit()Toon Claes1-13/+21
Depending on what gets passed into the function pick_regular_commit(), it decides the new base for the replayed commit. It first tries to find the replayed results of `pickme`'s parent in the `replayed_commits` map. If not found, it falls back to `onto`. When using git-replay(1) with --onto, the fallback is the revision passed in with this option, but when using --revert, the fallback is `last_commit`. It's rather confusing the base is decided partly inside pick_regular_commit() and partly by its caller. Move the base selection completely into the caller: replay_revisions(). This bundles all the logic of deciding on the base together. Also, this reduces the number of parameters of pick_regular_commit(), making its interface cleaner. This refactoring doesn't bring any behavior changes. Signed-off-by: Toon Claes <toon@iotcl.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
13 daysreplay: add helper to put entry into replayed_commitsToon Claes1-11/+20
The function replay_revisions() in replay.c is rather lengthy. Extract the logic to put a commit entry into a `struct mapped_commits` into a helper function put_mapped_commit(). While at it, rename mapped_commit() to get_mapped_commit() to pair with this new function. Signed-off-by: Toon Claes <toon@iotcl.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
14 daysreplay: fail gracefully when a merge input is unreadableElijah Newren1-0/+7
When objects involved in the merge cannot be read, the merge machinery will return early with result.clean = -1, and result.tree left as NULL. pick_regular_commit() tested only "if (!result->clean)", ignoring the case where "clean < 0". That causes the code to try to use result->tree, resulting in a SIGSEGV. Handle clean < 0 explicitly; the merge machinery will already have printed messages such as "Could not read <object>" and "collecting merge info failed for trees...", so we don't need to add much detail beyond the fact that the merge failed. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-07-19Merge branch 'js/coverity-fixes-null-safety'Junio C Hamano1-2/+6
Various code paths have been hardened against potential NULL-pointer dereferences and invalid file descriptor accesses flagged by Coverity. * js/coverity-fixes-null-safety: shallow: give write_one_shallow() its own hex buffer shallow: fix NULL dereference bisect: ensure non-NULL `head` before using it pack-bitmap: handle missing bitmap for base MIDX revision: avoid dereferencing NULL in `add_parents_only()` replay: die when --onto does not peel to a commit bisect: handle NULL commit in `bisect_successful()` mailsplit: move NULL check before first use of file handle reftable/stack: guard against NULL list_file in stack_destroy remote: guard `remote_tracking()` against NULL remote diff: handle NULL return from repo_get_commit_tree() diffcore-break: guard against NULLed queue entries in merge loop
2026-07-15Merge branch 'ps/history-drop'Junio C Hamano1-4/+4
The experimental 'git history' command has been taught a new 'drop' subcommand to remove a commit, with its descendants replayed onto its parent. * ps/history-drop: builtin/history: implement "drop" subcommand builtin/history: split handling of ref updates into two phases replay: expose `replay_result_queue_update()` reset: stop assuming that the caller passes in a clean index reset: allow the caller to specify the current HEAD object reset: introduce ability to skip updating HEAD reset: introduce dry-run mode reset: modernize flags passed to `reset_working_tree()` reset: rename `reset_head()` reset: drop `USE_THE_REPOSITORY_VARIABLE` read-cache: split out function to drop unmerged entries to stage 0
2026-07-10replay: die when --onto does not peel to a commitJohannes Schindelin1-2/+6
The `peel_committish()` function calls `repo_peel_to_type()` to convert the given object to a commit, but does not check the return value. When the object exists but cannot be peeled to a commit (e.g., a tree or blob OID is passed as --onto), the return value is NULL. Add an explicit NULL check and die with a descriptive message in that case. Pointed out by Coverity. Assisted-by: Claude Opus 4.6 Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-07-03replay: expose `replay_result_queue_update()`Patrick Steinhardt1-4/+4
Expose `replay_result_queue_update()`, which is used to append another reference update to the replay result. This function will be used in a subsequent commit. Suggested-by: Christian Couder <christian.couder@gmail.com> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-07Merge branch 'kh/free-commit-list'Junio C Hamano1-1/+1
Code clean-up. * kh/free-commit-list: commit: remove deprecated functions *: replace deprecated free_commit_list
2026-05-29*: replace deprecated free_commit_listKristoffer Haugsbakk1-1/+1
Replace `free_commit_list` with `commit_list_free`. The former was deprecated in 9f18d089 (commit: rename `free_commit_list()` to conform to coding guidelines, 2026-01-15). This allows us to remove all the deprecated functions in the next commit: • `copy_commit_list` • `reverse_commit_list` • `free_commit_list` Acked-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-04-27replay: allow callers to control what happens with empty commitsPatrick Steinhardt1-5/+24
When replaying commits it may happen that some of the commits become empty relative to their parent. Such commits are for now automatically dropped by the replay subsystem without much control from the user. Introduce a new enum that allows the caller to drop, keep or abort in this case. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-04-08Merge branch 'tc/replay-ref'Junio C Hamano1-8/+27
The experimental `git replay` command learned the `--ref=<ref>` option to allow specifying which ref to update, overriding the default behavior. * tc/replay-ref: replay: allow to specify a ref with option --ref replay: use stuck form in documentation and help message builtin/replay: mark options as not negatable
2026-04-06Merge branch 'tc/replay-down-to-root'Junio C Hamano1-10/+17
git replay now supports replaying down to the root commit. * tc/replay-down-to-root: replay: support replaying down from root commit
2026-04-03Merge branch 'sa/replay-revert'Junio C Hamano1-41/+116
"git replay" (experimental) learns, in addition to "pick" and "replay", a new operating mode "revert". * sa/replay-revert: replay: add --revert mode to reverse commit changes sequencer: extract revert message formatting into shared function
2026-04-01replay: allow to specify a ref with option --refToon Claes1-8/+27
When option '--onto' is passed to git-replay(1), the command will update refs from the <revision-range> passed to the command. When using option '--advance' or '--revert', the argument of that option is a ref that will be updated. To enable users to specify which ref to update, add option '--ref'. When using option '--ref', the refs described above are left untouched and instead the argument of this option is updated instead. Because this introduces code paths in replay.c that jump to `out` before init_basic_merge_options() is called on `merge_opt`, zero-initialize the struct. Signed-off-by: Toon Claes <toon@iotcl.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-03-25Merge branch 'sa/replay-revert' into tc/replay-refJunio C Hamano1-41/+116
* sa/replay-revert: replay: add --revert mode to reverse commit changes sequencer: extract revert message formatting into shared function
2026-03-25replay: add --revert mode to reverse commit changesSiddharth Asthana1-41/+116
Add a `--revert <branch>` mode to git replay that undoes the changes introduced by the specified commits. Like --onto and --advance, --revert is a standalone mode: it takes a branch argument and updates that branch with the newly created revert commits. At GitLab, we need this in Gitaly for reverting commits directly on bare repositories without requiring a working tree checkout. The approach is the same as sequencer.c's do_pick_commit() -- cherry-pick and revert are just the same three-way merge with swapped arguments: - Cherry-pick: merge(ancestor=parent, ours=current, theirs=commit) - Revert: merge(ancestor=commit, ours=current, theirs=parent) We swap the base and pickme trees passed to merge_incore_nonrecursive() to reverse the diff direction. Reverts are processed newest-first (matching git revert behavior) to reduce conflicts by peeling off changes from the top. Each revert builds on the result of the previous one via the last_commit fallback in the main replay loop, rather than relying on the parent-mapping used for cherry-pick. Revert commit messages follow the usual git revert conventions: prefixed with "Revert" (or "Reapply" when reverting a revert), and including "This reverts commit <hash>.". The author is set to the current user rather than preserving the original author, matching git revert behavior. Helped-by: Christian Couder <christian.couder@gmail.com> Helped-by: Patrick Steinhardt <ps@pks.im> Helped-by: Elijah Newren <newren@gmail.com> Helped-by: Phillip Wood <phillip.wood123@gmail.com> Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Helped-by: Junio C Hamano <gitster@pobox.com> Helped-by: Toon Claes <toon@iotcl.com> Signed-off-by: Siddharth Asthana <siddharthasthana31@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-03-24replay: support replaying down from root commitToon Claes1-10/+17
git-replay(1) doesn't allow replaying commits all the way down to the root commit. Fix that. Signed-off-by: Toon Claes <toon@iotcl.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-02-21replay: prevent the_repository from coming backElijah Newren1-0/+6
Due to the use of DEFAULT_ABBREV, we cannot get rid of our usage of USE_THE_REPOSITORY_VARIABLE. We have removed all other uses of the_repository before, but without removing that definition, they keep coming back. Define the_repository to make it a compilation error so that they don't come back any more; the repo parameter plumbed through the various functions can be used instead. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-13replay: drop commits that become emptyPhillip Wood1-3/+7
If the changes in a commit being replayed are already in the branch that the commits are being replayed onto, then "git replay" creates an empty commit. This is confusing because the commit message no longer matches the contents of the commit. Drop the commit instead. Commits that start off empty are not dropped. This matches the behavior of "git rebase --reapply-cherry-pick --empty=drop" and "git cherry-pick --empty-drop". If a branch points to a commit that is dropped it will be updated to point to the last commit that was not dropped. This can be seen in the new test where "topic1" is updated to point to the rebased "C" as "F" is dropped because it is already upstream. While this is a breaking change, "git replay" is marked as experimental to allow improvements like this that change the behavior. Helped-by: Elijah Newren <newren@gmail.com> Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-13replay: support updating detached HEADPatrick Steinhardt1-14/+33
In a subsequent commit we're about to introduce a new git-history(1) command, which will by default work on all local branches and HEAD. This is already well-supported by the replay machinery for most of the part: updating branches is one of its prime use cases, and the HEAD ref is also updated in case it points to any of the branches. However, what's not supported yet is to update HEAD in case it is not a symbolic ref. We determine the refs that need to be updated by iterating through the decorations of the original commit, but we only update those refs that are `DECORATION_REF_LOCAL`, which covers local branches. Address this gap by also handling `DECORATION_REF_HEAD`. Note though that this needs to only happen in case we're working on a detached HEAD. If HEAD is pointing to a branch, then we'd already update that branch via `DECORATION_REF_LOCAL`. Refactor the loop that iterates through the decorations a bit to make the individual conditions easier to understand. Based-on-patch-by: Elijah Newren <newren@gmail.com> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-13replay: support empty commit rangesPatrick Steinhardt1-2/+3
In a subsequent commit we're about to introduce a new user of the replay subsystem. With that new user, the range of commits that we'll want to replay will be identified implicitly via a single commit, and will include all descendants of that commit to any branch. If that commit has no descendants (because it's the tip of some branch), then the range of revisions that we're asked to replay becomes empty. This case does not make sense with git-replay(1), but with the new command it will. This case is not currently supported by `replay_revisions()` though because we zero-initialize `struct merge_result`. This includes its `.clean` member, which indicates whether the merge ran into a conflict or not. But given that we don't have any revision to replay, we won't ever perform any merge at all, and consequently that member will never be set to `1`. We thus later think that there's been a merge conflict and return an error from `replay_commits()`. Address this issue by initializing the `.clean` member to `1`. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-13replay: small set of cleanupsPatrick Steinhardt1-7/+4
Perform a small set of cleanups so that the "replay" logic compiles with "-Wsign-compare" and doesn't use `the_repository` anymore. Note that there are still some implicit dependencies on `the_repository`, e.g. because we use `get_commit_output_encoding()`. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-13builtin/replay: move core logic into "libgit.a"Patrick Steinhardt1-0/+354
Move the core logic used to replay commits into "libgit.a" so that it can be easily reused by other commands. It will be used in a subsequent commit where we're about to introduce a new git-history(1) command. Note that with this change we have no sign-comparison warnings anymore, and neither do we depend on `the_repository`. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>