From: Elijah Newren via GitGitGadget Date: Thu, 27 Aug 2026 01:02:11 GMT Subject: [PATCH v2 0/3] commit: refuse to amend during conflict resolution Message-ID: In-Reply-To: Both git commit --amend and a partial commit (git commit ) are foot-guns while the user is in the middle of an operation that resolves conflicts on top of HEAD: recording a conflict resolution is about capturing the state of the whole tree as a new commit, not about rewriting HEAD or committing a subset of paths. Historically we only rejected these during a merge or a cherry-pick or when resolving an empty pick during a rebase. The same hazard exists for am, revert, and rebase conflict stops, none of which were covered. This series extends the refusal to all of them. The three patches: 1. reword the two pre-existing "empty commit" rebase messages, which were misleadingly generic 2. refuse git commit --amend during these additional operations 3. refuse partial commits during the same operations. Elijah Newren (3): commit: reword the empty-commit rebase errors commit: refuse to amend during conflict resolution commit: refuse partial commits during conflict resolution builtin/commit.c | 51 +++++++++---- sequencer.c | 65 +++++++++++++++++ sequencer.h | 24 ++++++ t/t3404-rebase-interactive.sh | 125 +++++++++++++++++++++++++++++++- t/t3507-cherry-pick-conflict.sh | 22 ++++++ t/t4151-am-abort.sh | 22 ++++++ 6 files changed, 293 insertions(+), 16 deletions(-) base-commit: 2c3adbb2c475981e340c79fdc5e7f4f9b5d9054e Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2389%2Fnewren%2Frefuse-amend-during-conflicts-v2 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2389/newren/refuse-amend-during-conflicts-v2 Pull-Request: https://github.com/git/git/pull/2389 Range-diff vs v1: -: ---------- > 1: 65c48ed3cb commit: reword the empty-commit rebase errors 1: a3d6b059c6 ! 2: 4a1461e527 commit: refuse to amend during conflict resolution @@ Commit message Signed-off-by: Elijah Newren ## builtin/commit.c ## -@@ - #include "path.h" - #include "preload-index.h" - #include "read-cache.h" -+#include "refs.h" - #include "repository.h" - #include "string-list.h" - #include "rerere.h" @@ builtin/commit.c: static int parse_and_validate_options(int argc, const char *argv[], - else if (whence == FROM_REBASE_PICK) - die(_("You are in the middle of a rebase -- cannot amend.")); + use_editor = 0; + + /* Sanity check options */ +- if (amend && !current_head) +- die(_("You have nothing to amend.")); +- if (amend && whence != FROM_COMMIT) { +- if (whence == FROM_MERGE) ++ if (amend) { ++ if (!current_head) ++ die(_("You have nothing to amend.")); ++ /* ++ * Refuse to amend in the middle of any operation that is ++ * meant to record its result as a new commit on top of HEAD ++ * rather than by rewriting HEAD. ++ */ ++ switch (sequencer_ongoing_operation(s->repo, whence)) { ++ case ONGOING_NONE: ++ break; ++ case ONGOING_MERGE: + die(_("You are in the middle of a merge -- cannot amend.")); +- else if (is_from_cherry_pick(whence)) ++ case ONGOING_CHERRY_PICK: + die(_("You are in the middle of a cherry-pick -- cannot amend.")); +- else if (whence == FROM_REBASE_PICK) ++ case ONGOING_REBASE_EMPTY: + die(_("You are resolving a commit that became empty -- cannot amend.")); ++ case ONGOING_REVERT: ++ die(_("You are in the middle of a revert -- cannot amend.")); ++ case ONGOING_AM: ++ die(_("You are in the middle of an am session -- cannot amend.")); ++ case ONGOING_REBASE_CONFLICT: ++ die(_("You are resolving conflicts during a rebase -- cannot amend.")); ++ } } -+ if (amend && whence == FROM_COMMIT) { -+ char *applying, *apply_dir, *stopped_sha, *amend_marker; -+ int in_am, conflicted_stop; + if (fixup_message && squash_message) + die(_("options '%s' and '%s' cannot be used together"), "--squash", "--fixup"); + + ## sequencer.c ## +@@ sequencer.c: int sequencer_determine_whence(struct repository *r, enum commit_whence *whence) + return 0; + } + ++enum ongoing_operation sequencer_ongoing_operation(struct repository *r, ++ enum commit_whence whence) ++{ ++ char *path; ++ int found; + -+ /* Check middle of revert */ -+ if (refs_ref_exists(get_main_ref_store(the_repository), -+ "REVERT_HEAD")) -+ die(_("You are in the middle of a revert -- cannot amend.")); ++ /* ++ * The merge, cherry-pick, and (empty) rebase-pick stops are already ++ * distinguished by 'whence'. ++ */ ++ switch (whence) { ++ case FROM_MERGE: ++ return ONGOING_MERGE; ++ case FROM_CHERRY_PICK_SINGLE: ++ case FROM_CHERRY_PICK_MULTI: ++ return ONGOING_CHERRY_PICK; ++ case FROM_REBASE_PICK: ++ return ONGOING_REBASE_EMPTY; ++ case FROM_COMMIT: ++ break; ++ } + -+ /* Check middle of `am` */ -+ applying = repo_git_path(the_repository, -+ "rebase-apply/applying"); -+ in_am = file_exists(applying); ++ /* ++ * 'whence' is FROM_COMMIT, but we may still be in the middle of an ++ * operation that records its result on top of HEAD; detect those ++ * from their on-disk state. ++ */ + -+ free(applying); -+ if (in_am) -+ die(_("You are in the middle of an am session -- cannot amend.")); ++ /* In the middle of a revert? */ ++ if (refs_ref_exists(get_main_ref_store(r), "REVERT_HEAD")) ++ return ONGOING_REVERT; + -+ /* Check middle of rebase specifically stopped for conflicts */ -+ apply_dir = repo_git_path(the_repository, -+ "rebase-apply"); -+ stopped_sha = repo_git_path(the_repository, -+ "rebase-merge/stopped-sha"); -+ amend_marker = repo_git_path(the_repository, -+ "rebase-merge/amend"); -+ /* -+ * The apply backend only ever stops for conflicts; the -+ * merge backend writes stopped-sha but omits `amend`, -+ * which it writes only at a clean edit/reword stop. -+ */ -+ conflicted_stop = -+ file_exists(apply_dir) || -+ (file_exists(stopped_sha) && !file_exists(amend_marker)); ++ /* In the middle of an `am`? */ ++ path = repo_git_path(r, "rebase-apply/applying"); ++ found = file_exists(path); ++ free(path); ++ if (found) ++ return ONGOING_AM; ++ ++ /* ++ * In the middle of a rebase that stopped for conflict resolution? ++ * The apply backend only ever stops for conflicts, so the presence ++ * of its state directory is enough. The merge backend writes ++ * stopped-sha whenever it hands control back to the user, but omits ++ * `amend` unless it stopped with HEAD already pointing at the commit ++ * to be amended (a clean edit/reword stop); its absence therefore ++ * marks a conflicted stop. ++ */ ++ path = repo_git_path(r, "rebase-apply"); ++ found = file_exists(path); ++ free(path); ++ if (!found) { ++ char *stopped_sha = repo_git_path(r, "rebase-merge/stopped-sha"); ++ char *amend_marker = repo_git_path(r, "rebase-merge/amend"); + -+ free(apply_dir); ++ found = file_exists(stopped_sha) && !file_exists(amend_marker); + free(stopped_sha); + free(amend_marker); -+ if (conflicted_stop) -+ die(_("You are resolving conflicts during a rebase -- cannot amend.")); + } - if (fixup_message && squash_message) - die(_("options '%s' and '%s' cannot be used together"), "--squash", "--fixup"); - die_for_incompatible_opt4(!!use_message, "-C", ++ if (found) ++ return ONGOING_REBASE_CONFLICT; ++ ++ return ONGOING_NONE; ++} ++ + int sequencer_get_update_refs_state(const char *wt_dir, + struct string_list *refs) + { + + ## sequencer.h ## +@@ sequencer.h: int sequencer_get_last_command(struct repository* r, + enum replay_action *action); + int sequencer_determine_whence(struct repository *r, enum commit_whence *whence); + ++/* ++ * An in-progress operation that records its result (often a conflict ++ * resolution) as a new commit on top of HEAD, during which amending ++ * HEAD via "git commit --amend" is almost always a mistake. ++ */ ++enum ongoing_operation { ++ ONGOING_NONE = 0, ++ ONGOING_MERGE, ++ ONGOING_CHERRY_PICK, ++ ONGOING_REBASE_EMPTY, ++ ONGOING_REVERT, ++ ONGOING_AM, ++ ONGOING_REBASE_CONFLICT ++}; ++ ++/* ++ * Return which in-progress operation, if any, is underway; see enum ++ * ongoing_operation. 'whence' is the origin already computed for the ++ * pending commit. ++ */ ++enum ongoing_operation sequencer_ongoing_operation(struct repository *r, ++ enum commit_whence whence); ++ + /** + * Append the set of ref-OID pairs that are currently stored for the 'git + * rebase --update-refs' feature if such a rebase is currently happening. ## t/t3404-rebase-interactive.sh ## @@ t/t3404-rebase-interactive.sh: test_expect_success 'correct error message for commit --amend after empty pick' - test_grep "middle of a rebase -- cannot amend." err + test_grep "resolving a commit that became empty -- cannot amend." err ' +test_expect_success 'commit --amend is refused at a rebase conflict stop' ' -: ---------- > 3: e0be8cdf63 commit: refuse partial commits during conflict resolution -- gitgitgadget