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For many years, we have rejected amending during conflict resolution in the middle of - a merge - a cherry-pick However, this was never extended to other operations that can also produce conflicts: - an `am` operation - a revert - a rebase Extend it to handle these other cases now. Extending to `am`, revert, and the apply backend of rebase are fairly straightforward. However, with the merge backend of rebase we have to be more careful, since it powers interactive rebases and - the interactive machinery internally uses `git commit --amend` for `squash` and `reword` directives - users are expected to `git commit --amend` after hitting an `edit` or `break` directive So, we need to be careful with rebase to only reject amending when doing conflict resolution. A few files under the rebase-merge/ directory provide us the necessary information: - stopped-sha is written only when the rebase stops and hands control back to the user, so its presence marks a genuine stop -- as opposed to the sequencer's own internal `git commit --amend` while applying a squash, fixup, or reword, during which no stopped-sha exists. - amend is written only when the rebase stops with HEAD already pointing at the commit the user is meant to amend: a clean `edit`, or a fast-forward `reword`. Its absence at a stop therefore means the commit did not apply, so HEAD is the previously-applied commit rather than the one being rebased -- exactly the case we refuse. So for the merge backend we die when stopped-sha exists and amend does not. This covers a plain conflicted pick as well as a conflicted `edit` (both leave HEAD on the previously-applied commit), while still allowing a clean `edit` or `reword` stop and a `break` stop (no stopped-sha). stopped-sha is unlinked at the start of the resume loop, so a resumed squash's internal amend is unaffected. Signed-off-by: Elijah Newren --- commit: refuse to amend during conflict resolution Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2389%2Fnewren%2Frefuse-amend-during-conflicts-v1 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2389/newren/refuse-amend-during-conflicts-v1 Pull-Request: https://github.com/git/git/pull/2389 builtin/commit.c | 41 ++++++++++++++++ t/t3404-rebase-interactive.sh | 87 +++++++++++++++++++++++++++++++++ t/t3507-cherry-pick-conflict.sh | 11 +++++ t/t4151-am-abort.sh | 11 +++++ 4 files changed, 150 insertions(+) diff --git a/builtin/commit.c b/builtin/commit.c index 28f6174503..a9fd04366e 100644 --- a/builtin/commit.c +++ b/builtin/commit.c @@ -30,6 +30,7 @@ #include "path.h" #include "preload-index.h" #include "read-cache.h" +#include "refs.h" #include "repository.h" #include "string-list.h" #include "rerere.h" @@ -1336,6 +1337,46 @@ 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.")); } + if (amend && whence == FROM_COMMIT) { + char *applying, *apply_dir, *stopped_sha, *amend_marker; + int in_am, conflicted_stop; + + /* 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.")); + + /* Check middle of `am` */ + applying = repo_git_path(the_repository, + "rebase-apply/applying"); + in_am = file_exists(applying); + + free(applying); + if (in_am) + die(_("You are in the middle of an am session -- cannot amend.")); + + /* 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)); + + free(apply_dir); + 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", diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh index ff11abb2f2..01d4735b3b 100755 --- a/t/t3404-rebase-interactive.sh +++ b/t/t3404-rebase-interactive.sh @@ -1884,6 +1884,93 @@ test_expect_success 'correct error message for commit --amend after empty pick' test_grep "middle of a rebase -- cannot amend." err ' +test_expect_success 'commit --amend is refused at a rebase conflict stop' ' + test_when_finished "git rebase --abort" && + git checkout --detach conflict-branch && + ( + set_fake_editor && + FAKE_LINES="1 3" && + export FAKE_LINES && + test_must_fail git rebase -i A + ) && + test_path_is_file .git/rebase-merge/patch && + test_path_is_missing .git/rebase-merge/amend && + echo resolved >conflict && + git add conflict && + test_must_fail git commit --amend --no-edit 2>err && + test_grep "You are resolving conflicts during a rebase -- cannot amend" err +' + +test_expect_success 'commit --amend is refused when an "edit" pick conflicts' ' + test_when_finished "git rebase --abort" && + git checkout --detach conflict-branch && + ( + set_fake_editor && + FAKE_LINES="1 edit 3" && + export FAKE_LINES && + test_must_fail git rebase -i A + ) && + test_path_is_file .git/rebase-merge/patch && + test_path_is_missing .git/rebase-merge/amend && + echo resolved >conflict && + git add conflict && + test_must_fail git commit --amend --no-edit 2>err && + test_grep "You are resolving conflicts during a rebase -- cannot amend" err +' + +test_expect_success 'commit --amend is allowed at a rebase edit stop' ' + test_when_finished "git rebase --abort" && + git checkout --detach no-conflict-branch && + ( + set_fake_editor && + FAKE_LINES="edit 1 2 3 4" && + export FAKE_LINES && + git rebase -i A + ) && + test_path_is_file .git/rebase-merge/amend && + echo tweak >fileJ && + git add fileJ && + git commit --amend --no-edit +' + +test_expect_success 'commit --amend is allowed at a rebase break stop' ' + test_when_finished "git rebase --abort" && + git checkout --detach no-conflict-branch && + ( + set_fake_editor && + FAKE_LINES="break 1 2 3 4" && + export FAKE_LINES && + git rebase -i A + ) && + test_must_fail git rev-parse --verify REBASE_HEAD && + echo tweak >fileJ && + git add fileJ && + git commit --amend --no-edit +' + +test_expect_success 'commit --amend is refused at an apply-backend conflict stop' ' + test_when_finished "rm -rf apply-backend" && + test_create_repo apply-backend && + ( + cd apply-backend && + test_commit base file && + git branch -M mainline && + test_commit upstream file upstream && + git checkout -b side mainline~1 && + test_commit conflicting file side && + test_commit unrelated other && + test_must_fail git rebase --apply mainline && + # the apply backend only ever stops for conflicts, and + # leaves HEAD on the previously-applied commit + test_path_is_dir .git/rebase-apply && + test_path_is_missing .git/rebase-apply/applying && + echo resolved >file && + git add file && + test_must_fail git commit --amend --no-edit 2>err && + test_grep "You are resolving conflicts during a rebase -- cannot amend" err + ) +' + test_expect_success 'todo has correct onto hash' ' GIT_SEQUENCE_EDITOR=cat git rebase -i no-conflict-branch~4 no-conflict-branch >actual && onto=$(git rev-parse --short HEAD~4) && diff --git a/t/t3507-cherry-pick-conflict.sh b/t/t3507-cherry-pick-conflict.sh index 44596cb1e8..42de398f76 100755 --- a/t/t3507-cherry-pick-conflict.sh +++ b/t/t3507-cherry-pick-conflict.sh @@ -364,6 +364,17 @@ test_expect_success 'failed revert sets REVERT_HEAD' ' test_cmp_rev picked REVERT_HEAD ' +test_expect_success 'commit --amend of revert fails' ' + pristine_detach initial && + + test_must_fail git revert picked && + echo resolved >foo && + git add foo && + test_must_fail git commit --amend 2>err && + + test_grep "in the middle of a revert -- cannot amend." err +' + test_expect_success 'successful revert does not set REVERT_HEAD' ' pristine_detach base && git revert base && diff --git a/t/t4151-am-abort.sh b/t/t4151-am-abort.sh index 8e1ecf8a68..9313a074b2 100755 --- a/t/t4151-am-abort.sh +++ b/t/t4151-am-abort.sh @@ -63,6 +63,17 @@ do done +test_expect_success 'commit --amend during a failed am fails' ' + git reset --hard initial && + cp file-2-expect file-2 && + test_must_fail git am 000[1245]-*.patch && + echo resolved >file-1 && + git add file-1 && + test_must_fail git commit --amend 2>err && + test_grep "in the middle of an am session -- cannot amend." err && + git am --abort +' + test_expect_success 'am -3 --skip removes otherfile-4' ' git reset --hard initial && test_must_fail git am -3 0003-*.patch && base-commit: 2c3adbb2c475981e340c79fdc5e7f4f9b5d9054e -- gitgitgadget