revert: introduce --abort to cancel a failed cherry-pick

After running some ill-advised command like "git cherry-pick
HEAD..linux-next", the bewildered novice may want to return to more
familiar territory.  Introduce a "git cherry-pick --abort" command
that rolls back the entire cherry-pick sequence and places the
repository back on solid ground.

Just like "git merge --abort", this internally uses "git reset
--merge", so local changes not involved in the conflict resolution are
preserved.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-cherry-pick.txt b/Documentation/git-cherry-pick.txt
index 21998b820efbf3b600813bb1c7d32224f61e46c1..fed5097e00b4a031c2992ac3d421f6df975e6152 100644 (file)
--- a/Documentation/git-cherry-pick.txt
+++ b/Documentation/git-cherry-pick.txt
@@ -11,6 +11,7 @@ SYNOPSIS
 'git cherry-pick' [--edit] [-n] [-m parent-number] [-s] [-x] [--ff] <commit>...
 'git cherry-pick' --continue
 'git cherry-pick' --quit
+'git cherry-pick' --abort
 
 DESCRIPTION
 -----------

diff --git a/Documentation/git-revert.txt b/Documentation/git-revert.txt
index b0fcabc8b69ff65e00fc18aadf5644ac75786a7b..b699a3458eff439b05049dab94610a57ac62fc0a 100644 (file)
--- a/Documentation/git-revert.txt
+++ b/Documentation/git-revert.txt
@@ -11,6 +11,7 @@ SYNOPSIS
 'git revert' [--edit | --no-edit] [-n] [-m parent-number] [-s] <commit>...
 'git revert' --continue
 'git revert' --quit
+'git revert' --abort
 
 DESCRIPTION
 -----------

diff --git a/Documentation/sequencer.txt b/Documentation/sequencer.txt
index 75f8e869e82feb6ad2ff4327a7a95245b39584a8..5747f442f25e6271c7464db78496b85ee058d05f 100644 (file)
--- a/Documentation/sequencer.txt
+++ b/Documentation/sequencer.txt
@@ -7,3 +7,6 @@
        Forget about the current operation in progress.  Can be used
        to clear the sequencer state after a failed cherry-pick or
        revert.
+
+--abort::
+       Cancel the operation and return to the pre-sequence state.

diff --git a/builtin/revert.c b/builtin/revert.c
index f5ba67a50578b257c713b0d69d5c022f4e5f483b..70a5fbb672f14bec432447b37ce9b012577fe510 100644 (file)
--- a/builtin/revert.c
+++ b/builtin/revert.c
@@ -40,7 +40,12 @@ static const char * const cherry_pick_usage[] = {
 };
 
 enum replay_action { REVERT, CHERRY_PICK };
-enum replay_subcommand { REPLAY_NONE, REPLAY_REMOVE_STATE, REPLAY_CONTINUE };
+enum replay_subcommand {
+       REPLAY_NONE,
+       REPLAY_REMOVE_STATE,
+       REPLAY_CONTINUE,
+       REPLAY_ROLLBACK
+};
 
 struct replay_opts {
        enum replay_action action;
@@ -135,9 +140,11 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
        const char *me = action_name(opts);
        int remove_state = 0;
        int contin = 0;
+       int rollback = 0;
        struct option options[] = {
                OPT_BOOLEAN(0, "quit", &remove_state, "end revert or cherry-pick sequence"),
                OPT_BOOLEAN(0, "continue", &contin, "resume revert or cherry-pick sequence"),
+               OPT_BOOLEAN(0, "abort", &rollback, "cancel revert or cherry-pick sequence"),
                OPT_BOOLEAN('n', "no-commit", &opts->no_commit, "don't automatically commit"),
                OPT_BOOLEAN('e', "edit", &opts->edit, "edit the commit message"),
                OPT_NOOP_NOARG('r', NULL),
@@ -173,6 +180,7 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
        verify_opt_mutually_compatible(me,
                                "--quit", remove_state,
                                "--continue", contin,
+                               "--abort", rollback,
                                NULL);
 
        /* Set the subcommand */
@@ -180,6 +188,8 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
                opts->subcommand = REPLAY_REMOVE_STATE;
        else if (contin)
                opts->subcommand = REPLAY_CONTINUE;
+       else if (rollback)
+               opts->subcommand = REPLAY_ROLLBACK;
        else
                opts->subcommand = REPLAY_NONE;
 
@@ -188,8 +198,12 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
                char *this_operation;
                if (opts->subcommand == REPLAY_REMOVE_STATE)
                        this_operation = "--quit";
-               else
+               else if (opts->subcommand == REPLAY_CONTINUE)
                        this_operation = "--continue";
+               else {
+                       assert(opts->subcommand == REPLAY_ROLLBACK);
+                       this_operation = "--abort";
+               }
 
                verify_opt_compatible(me, this_operation,
                                "--no-commit", opts->no_commit,
@@ -850,7 +864,7 @@ static int create_seq_dir(void)
 
        if (file_exists(seq_dir)) {
                error(_("a cherry-pick or revert is already in progress"));
-               advise(_("try \"git cherry-pick (--continue | --quit)\""));
+               advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
                return -1;
        }
        else if (mkdir(seq_dir, 0777) < 0)
@@ -873,6 +887,71 @@ static void save_head(const char *head)
                die(_("Error wrapping up %s."), head_file);
 }
 
+static int reset_for_rollback(const unsigned char *sha1)
+{
+       const char *argv[4];    /* reset --merge <arg> + NULL */
+       argv[0] = "reset";
+       argv[1] = "--merge";
+       argv[2] = sha1_to_hex(sha1);
+       argv[3] = NULL;
+       return run_command_v_opt(argv, RUN_GIT_CMD);
+}
+
+static int rollback_single_pick(void)
+{
+       unsigned char head_sha1[20];
+
+       if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
+           !file_exists(git_path("REVERT_HEAD")))
+               return error(_("no cherry-pick or revert in progress"));
+       if (!resolve_ref("HEAD", head_sha1, 0, NULL))
+               return error(_("cannot resolve HEAD"));
+       if (is_null_sha1(head_sha1))
+               return error(_("cannot abort from a branch yet to be born"));
+       return reset_for_rollback(head_sha1);
+}
+
+static int sequencer_rollback(struct replay_opts *opts)
+{
+       const char *filename;
+       FILE *f;
+       unsigned char sha1[20];
+       struct strbuf buf = STRBUF_INIT;
+
+       filename = git_path(SEQ_HEAD_FILE);
+       f = fopen(filename, "r");
+       if (!f && errno == ENOENT) {
+               /*
+                * There is no multiple-cherry-pick in progress.
+                * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
+                * a single-cherry-pick in progress, abort that.
+                */
+               return rollback_single_pick();
+       }
+       if (!f)
+               return error(_("cannot open %s: %s"), filename,
+                                               strerror(errno));
+       if (strbuf_getline(&buf, f, '\n')) {
+               error(_("cannot read %s: %s"), filename, ferror(f) ?
+                       strerror(errno) : _("unexpected end of file"));
+               goto fail;
+       }
+       if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
+               error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
+                       filename);
+               goto fail;
+       }
+       if (reset_for_rollback(sha1))
+               goto fail;
+       strbuf_release(&buf);
+       fclose(f);
+       return 0;
+fail:
+       strbuf_release(&buf);
+       fclose(f);
+       return -1;
+}
+
 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 {
        const char *todo_file = git_path(SEQ_TODO_FILE);
@@ -977,6 +1056,8 @@ static int pick_revisions(struct replay_opts *opts)
                remove_sequencer_state(1);
                return 0;
        }
+       if (opts->subcommand == REPLAY_ROLLBACK)
+               return sequencer_rollback(opts);
        if (opts->subcommand == REPLAY_CONTINUE) {
                if (!file_exists(git_path(SEQ_TODO_FILE)))
                        return error(_("No %s in progress"), action_name(opts));

diff --git a/t/t3510-cherry-pick-sequence.sh b/t/t3510-cherry-pick-sequence.sh
index bb67cdcb5d8b0ddb611ea112258e6f9b35896851..e97397f96b29d9f20183c99999ec5bf7923549e7 100755 (executable)
--- a/t/t3510-cherry-pick-sequence.sh
+++ b/t/t3510-cherry-pick-sequence.sh
@@ -2,6 +2,7 @@
 
 test_description='Test cherry-pick continuation features
 
+  + yetanotherpick: rewrites foo to e
   + anotherpick: rewrites foo to d
   + picked: rewrites foo to c
   + unrelatedpick: rewrites unrelated to reallyunrelated
@@ -19,6 +20,12 @@ pristine_detach () {
        git clean -d -f -f -q -x
 }
 
+test_cmp_rev () {
+       git rev-parse --verify "$1" >expect.rev &&
+       git rev-parse --verify "$2" >actual.rev &&
+       test_cmp expect.rev actual.rev
+}
+
 test_expect_success setup '
        echo unrelated >unrelated &&
        git add unrelated &&
@@ -27,6 +34,7 @@ test_expect_success setup '
        test_commit unrelatedpick unrelated reallyunrelated &&
        test_commit picked foo c &&
        test_commit anotherpick foo d &&
+       test_commit yetanotherpick foo e &&
        git config advice.detachedhead false
 
 '
@@ -75,6 +83,11 @@ test_expect_success '--quit does not complain when no cherry-pick is in progress
        git cherry-pick --quit
 '
 
+test_expect_success '--abort requires cherry-pick in progress' '
+       pristine_detach initial &&
+       test_must_fail git cherry-pick --abort
+'
+
 test_expect_success '--quit cleans up sequencer state' '
        pristine_detach initial &&
        test_must_fail git cherry-pick base..picked &&
@@ -103,6 +116,79 @@ test_expect_success 'cherry-pick --reset (another name for --quit)' '
        test_cmp expect actual
 '
 
+test_expect_success '--abort to cancel multiple cherry-pick' '
+       pristine_detach initial &&
+       test_must_fail git cherry-pick base..anotherpick &&
+       git cherry-pick --abort &&
+       test_path_is_missing .git/sequencer &&
+       test_cmp_rev initial HEAD &&
+       git update-index --refresh &&
+       git diff-index --exit-code HEAD
+'
+
+test_expect_success '--abort to cancel single cherry-pick' '
+       pristine_detach initial &&
+       test_must_fail git cherry-pick picked &&
+       git cherry-pick --abort &&
+       test_path_is_missing .git/sequencer &&
+       test_cmp_rev initial HEAD &&
+       git update-index --refresh &&
+       git diff-index --exit-code HEAD
+'
+
+test_expect_success 'cherry-pick --abort to cancel multiple revert' '
+       pristine_detach anotherpick &&
+       test_must_fail git revert base..picked &&
+       git cherry-pick --abort &&
+       test_path_is_missing .git/sequencer &&
+       test_cmp_rev anotherpick HEAD &&
+       git update-index --refresh &&
+       git diff-index --exit-code HEAD
+'
+
+test_expect_success 'revert --abort works, too' '
+       pristine_detach anotherpick &&
+       test_must_fail git revert base..picked &&
+       git revert --abort &&
+       test_path_is_missing .git/sequencer &&
+       test_cmp_rev anotherpick HEAD
+'
+
+test_expect_success '--abort to cancel single revert' '
+       pristine_detach anotherpick &&
+       test_must_fail git revert picked &&
+       git revert --abort &&
+       test_path_is_missing .git/sequencer &&
+       test_cmp_rev anotherpick HEAD &&
+       git update-index --refresh &&
+       git diff-index --exit-code HEAD
+'
+
+test_expect_success '--abort keeps unrelated change, easy case' '
+       pristine_detach unrelatedpick &&
+       echo changed >expect &&
+       test_must_fail git cherry-pick picked..yetanotherpick &&
+       echo changed >unrelated &&
+       git cherry-pick --abort &&
+       test_cmp expect unrelated
+'
+
+test_expect_success '--abort refuses to clobber unrelated change, harder case' '
+       pristine_detach initial &&
+       echo changed >expect &&
+       test_must_fail git cherry-pick base..anotherpick &&
+       echo changed >unrelated &&
+       test_must_fail git cherry-pick --abort &&
+       test_cmp expect unrelated &&
+       git rev-list HEAD >log &&
+       test_line_count = 2 log &&
+       test_must_fail git update-index --refresh &&
+
+       git checkout unrelated &&
+       git cherry-pick --abort &&
+       test_cmp_rev initial HEAD
+'
+
 test_expect_success 'cherry-pick cleans up sequencer state when one commit is left' '
        pristine_detach initial &&
        test_must_fail git cherry-pick base..picked &&
@@ -127,6 +213,16 @@ test_expect_success 'cherry-pick cleans up sequencer state when one commit is le
        test_cmp expect actual
 '
 
+test_expect_failure '--abort after last commit in sequence' '
+       pristine_detach initial &&
+       test_must_fail git cherry-pick base..picked &&
+       git cherry-pick --abort &&
+       test_path_is_missing .git/sequencer &&
+       test_cmp_rev initial HEAD &&
+       git update-index --refresh &&
+       git diff-index --exit-code HEAD
+'
+
 test_expect_success 'cherry-pick does not implicitly stomp an existing operation' '
        pristine_detach initial &&
        test_must_fail git cherry-pick base..anotherpick &&