rebase --abort/--quit: cleanup refs/rewritten
[gitweb.git] / sequencer.c
index 7798f93b23f2250e61564951b6a467ae19746b36..258e5831565cb0782344eeffd2aa71eb161317df 100644 (file)
@@ -35,7 +35,7 @@
 
 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
 
-const char sign_off_header[] = "Signed-off-by: ";
+static const char sign_off_header[] = "Signed-off-by: ";
 static const char cherry_picked_prefix[] = "(cherry picked from commit ";
 
 GIT_PATH_FUNC(git_path_commit_editmsg, "COMMIT_EDITMSG")
@@ -55,8 +55,7 @@ static GIT_PATH_FUNC(rebase_path, "rebase-merge")
  * file and written to the tail of 'done'.
  */
 GIT_PATH_FUNC(rebase_path_todo, "rebase-merge/git-rebase-todo")
-static GIT_PATH_FUNC(rebase_path_todo_backup,
-                    "rebase-merge/git-rebase-todo.backup")
+GIT_PATH_FUNC(rebase_path_todo_backup, "rebase-merge/git-rebase-todo.backup")
 
 /*
  * The rebase command lines that have already been processed. A line
@@ -150,6 +149,7 @@ static GIT_PATH_FUNC(rebase_path_refs_to_delete, "rebase-merge/refs-to-delete")
 static GIT_PATH_FUNC(rebase_path_gpg_sign_opt, "rebase-merge/gpg_sign_opt")
 static GIT_PATH_FUNC(rebase_path_orig_head, "rebase-merge/orig-head")
 static GIT_PATH_FUNC(rebase_path_verbose, "rebase-merge/verbose")
+static GIT_PATH_FUNC(rebase_path_quiet, "rebase-merge/quiet")
 static GIT_PATH_FUNC(rebase_path_signoff, "rebase-merge/signoff")
 static GIT_PATH_FUNC(rebase_path_head_name, "rebase-merge/head-name")
 static GIT_PATH_FUNC(rebase_path_onto, "rebase-merge/onto")
@@ -157,7 +157,7 @@ static GIT_PATH_FUNC(rebase_path_autostash, "rebase-merge/autostash")
 static GIT_PATH_FUNC(rebase_path_strategy, "rebase-merge/strategy")
 static GIT_PATH_FUNC(rebase_path_strategy_opts, "rebase-merge/strategy_opts")
 static GIT_PATH_FUNC(rebase_path_allow_rerere_autoupdate, "rebase-merge/allow_rerere_autoupdate")
-static GIT_PATH_FUNC(rebase_path_quiet, "rebase-merge/quiet")
+static GIT_PATH_FUNC(rebase_path_reschedule_failed_exec, "rebase-merge/reschedule-failed-exec")
 
 static int git_sequencer_config(const char *k, const char *v, void *cb)
 {
@@ -274,7 +274,7 @@ static const char *gpg_sign_opt_quoted(struct replay_opts *opts)
 int sequencer_remove_state(struct replay_opts *opts)
 {
        struct strbuf buf = STRBUF_INIT;
-       int i;
+       int i, ret = 0;
 
        if (is_rebase_i(opts) &&
            strbuf_read_file(&buf, rebase_path_refs_to_delete(), 0) > 0) {
@@ -283,8 +283,10 @@ int sequencer_remove_state(struct replay_opts *opts)
                        char *eol = strchr(p, '\n');
                        if (eol)
                                *eol = '\0';
-                       if (delete_ref("(rebase -i) cleanup", p, NULL, 0) < 0)
+                       if (delete_ref("(rebase -i) cleanup", p, NULL, 0) < 0) {
                                warning(_("could not delete '%s'"), p);
+                               ret = -1;
+                       }
                        if (!eol)
                                break;
                        p = eol + 1;
@@ -300,10 +302,11 @@ int sequencer_remove_state(struct replay_opts *opts)
 
        strbuf_reset(&buf);
        strbuf_addstr(&buf, get_dir(opts));
-       remove_dir_recursively(&buf, 0);
+       if (remove_dir_recursively(&buf, 0))
+               ret = error(_("could not remove '%s'"), buf.buf);
        strbuf_release(&buf);
 
-       return 0;
+       return ret;
 }
 
 static const char *action_name(const struct replay_opts *opts)
@@ -383,8 +386,8 @@ static void print_advice(struct repository *r, int show_hint,
        }
 }
 
-int write_message(const void *buf, size_t len, const char *filename,
-                 int append_eol)
+static int write_message(const void *buf, size_t len, const char *filename,
+                        int append_eol)
 {
        struct lock_file msg_file = LOCK_INIT;
 
@@ -446,9 +449,9 @@ static struct tree *empty_tree(struct repository *r)
        return lookup_tree(r, the_hash_algo->empty_tree);
 }
 
-static int error_dirty_index(struct index_state *istate, struct replay_opts *opts)
+static int error_dirty_index(struct repository *repo, struct replay_opts *opts)
 {
-       if (read_index_unmerged(istate))
+       if (repo_read_index_unmerged(repo))
                return error_resolve_conflict(_(action_name(opts)));
 
        error(_("your local changes would be overwritten by %s."),
@@ -483,7 +486,7 @@ static int fast_forward_to(struct repository *r,
        struct strbuf sb = STRBUF_INIT;
        struct strbuf err = STRBUF_INIT;
 
-       read_index(r->index);
+       repo_read_index(r);
        if (checkout_fast_forward(r, from, to, 1))
                return -1; /* the callee should have complained already */
 
@@ -540,12 +543,12 @@ static int do_recursive_merge(struct repository *r,
        char **xopt;
        struct lock_file index_lock = LOCK_INIT;
 
-       if (hold_locked_index(&index_lock, LOCK_REPORT_ON_ERROR) < 0)
+       if (repo_hold_locked_index(r, &index_lock, LOCK_REPORT_ON_ERROR) < 0)
                return -1;
 
-       read_index(r->index);
+       repo_read_index(r);
 
-       init_merge_options(&o);
+       init_merge_options(&o, r);
        o.ancestor = base ? base_label : "(empty tree)";
        o.branch1 = "HEAD";
        o.branch2 = next ? next_label : "(empty tree)";
@@ -836,7 +839,7 @@ static const char *read_author_ident(struct strbuf *buf)
        }
 
        strbuf_reset(&out);
-       strbuf_addstr(&out, fmt_ident(name, email, date, 0));
+       strbuf_addstr(&out, fmt_ident(name, email, WANT_AUTHOR_IDENT, date, 0));
        strbuf_swap(buf, &out);
        strbuf_release(&out);
        free(name);
@@ -1102,6 +1105,7 @@ static int run_rewrite_hook(const struct object_id *oldoid,
        proc.argv = argv;
        proc.in = -1;
        proc.stdout_to_stderr = 1;
+       proc.trace2_hook_name = "post-rewrite";
 
        code = start_command(&proc);
        if (code)
@@ -1115,7 +1119,8 @@ static int run_rewrite_hook(const struct object_id *oldoid,
        return finish_command(&proc);
 }
 
-void commit_post_rewrite(const struct commit *old_head,
+void commit_post_rewrite(struct repository *r,
+                        const struct commit *old_head,
                         const struct object_id *new_head)
 {
        struct notes_rewrite_cfg *cfg;
@@ -1124,7 +1129,7 @@ void commit_post_rewrite(const struct commit *old_head,
        if (cfg) {
                /* we are amending, so old_head is not NULL */
                copy_note_for_rewrite(cfg, &old_head->object.oid, new_head);
-               finish_copy_notes_for_rewrite(cfg, "Notes added by 'git commit --amend'");
+               finish_copy_notes_for_rewrite(r, cfg, "Notes added by 'git commit --amend'");
        }
        run_rewrite_hook(&old_head->object.oid, new_head);
 }
@@ -1405,7 +1410,7 @@ static int try_to_commit(struct repository *r,
        }
 
        if (flags & AMEND_MSG)
-               commit_post_rewrite(current_head, oid);
+               commit_post_rewrite(r, current_head, oid);
 
 out:
        free_commit_extra_headers(extra);
@@ -1663,7 +1668,8 @@ static int update_squash_messages(struct repository *r,
        return res;
 }
 
-static void flush_rewritten_pending(void) {
+static void flush_rewritten_pending(void)
+{
        struct strbuf buf = STRBUF_INIT;
        struct object_id newoid;
        FILE *out;
@@ -1688,7 +1694,8 @@ static void flush_rewritten_pending(void) {
 }
 
 static void record_in_rewritten(struct object_id *oid,
-               enum todo_command next_command) {
+               enum todo_command next_command)
+{
        FILE *out = fopen_or_warn(rebase_path_rewritten_pending(), "a");
 
        if (!out)
@@ -1739,7 +1746,7 @@ static int do_pick_commit(struct repository *r,
                        oidcpy(&head, the_hash_algo->empty_tree);
                if (index_differs_from(r, unborn ? empty_tree_oid_hex() : "HEAD",
                                       NULL, 0))
-                       return error_dirty_index(r->index, opts);
+                       return error_dirty_index(r, opts);
        }
        discard_index(r->index);
 
@@ -1762,9 +1769,13 @@ static int do_pick_commit(struct repository *r,
                        return error(_("commit %s does not have parent %d"),
                                oid_to_hex(&commit->object.oid), opts->mainline);
                parent = p->item;
-       } else if (0 < opts->mainline)
-               return error(_("mainline was specified but commit %s is not a merge."),
-                       oid_to_hex(&commit->object.oid));
+       } else if (1 < opts->mainline)
+               /*
+                *  Non-first parent explicitly specified as mainline for
+                *  non-merge commit
+                */
+               return error(_("commit %s does not have parent %d"),
+                            oid_to_hex(&commit->object.oid), opts->mainline);
        else
                parent = commit->parents->item;
 
@@ -1965,8 +1976,8 @@ static int read_and_refresh_cache(struct repository *r,
                                  struct replay_opts *opts)
 {
        struct lock_file index_lock = LOCK_INIT;
-       int index_fd = hold_locked_index(&index_lock, 0);
-       if (read_index(r->index) < 0) {
+       int index_fd = repo_hold_locked_index(r, &index_lock, 0);
+       if (repo_read_index(r) < 0) {
                rollback_lock_file(&index_lock);
                return error(_("git %s: failed to read the index"),
                        _(action_name(opts)));
@@ -2350,11 +2361,17 @@ static int read_populate_opts(struct replay_opts *opts)
                if (file_exists(rebase_path_verbose()))
                        opts->verbose = 1;
 
+               if (file_exists(rebase_path_quiet()))
+                       opts->quiet = 1;
+
                if (file_exists(rebase_path_signoff())) {
                        opts->allow_ff = 0;
                        opts->signoff = 1;
                }
 
+               if (file_exists(rebase_path_reschedule_failed_exec()))
+                       opts->reschedule_failed_exec = 1;
+
                read_strategy_opts(opts, &buf);
                strbuf_release(&buf);
 
@@ -2404,22 +2421,20 @@ static void write_strategy_opts(struct replay_opts *opts)
 }
 
 int write_basic_state(struct replay_opts *opts, const char *head_name,
-                     const char *onto, const char *orig_head)
+                     struct commit *onto, const char *orig_head)
 {
        const char *quiet = getenv("GIT_QUIET");
 
        if (head_name)
                write_file(rebase_path_head_name(), "%s\n", head_name);
        if (onto)
-               write_file(rebase_path_onto(), "%s\n", onto);
+               write_file(rebase_path_onto(), "%s\n",
+                          oid_to_hex(&onto->object.oid));
        if (orig_head)
                write_file(rebase_path_orig_head(), "%s\n", orig_head);
 
        if (quiet)
                write_file(rebase_path_quiet(), "%s\n", quiet);
-       else
-               write_file(rebase_path_quiet(), "\n");
-
        if (opts->verbose)
                write_file(rebase_path_verbose(), "%s", "");
        if (opts->strategy)
@@ -2436,6 +2451,8 @@ int write_basic_state(struct replay_opts *opts, const char *head_name,
                write_file(rebase_path_gpg_sign_opt(), "-S%s\n", opts->gpg_sign);
        if (opts->signoff)
                write_file(rebase_path_signoff(), "--signoff\n");
+       if (opts->reschedule_failed_exec)
+               write_file(rebase_path_reschedule_failed_exec(), "%s", "");
 
        return 0;
 }
@@ -2820,7 +2837,7 @@ static int do_exec(struct repository *r, const char *command_line)
                                          child_env.argv);
 
        /* force re-reading of the cache */
-       if (discard_index(r->index) < 0 || read_index(r->index) < 0)
+       if (discard_index(r->index) < 0 || repo_read_index(r) < 0)
                return error(_("could not read index"));
 
        dirty = require_clean_work_tree(r, "rebase", NULL, 1, 1);
@@ -2944,7 +2961,7 @@ static int do_reset(struct repository *r,
        struct unpack_trees_options unpack_tree_opts;
        int ret = 0;
 
-       if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
+       if (repo_hold_locked_index(r, &lock, LOCK_REPORT_ON_ERROR) < 0)
                return -1;
 
        if (len == 10 && !strncmp("[new root]", name, len)) {
@@ -2989,7 +3006,7 @@ static int do_reset(struct repository *r,
        unpack_tree_opts.merge = 1;
        unpack_tree_opts.update = 1;
 
-       if (read_index_unmerged(r->index)) {
+       if (repo_read_index_unmerged(r)) {
                rollback_lock_file(&lock);
                strbuf_release(&ref_name);
                return error_resolve_conflict(_(action_name(opts)));
@@ -3062,7 +3079,7 @@ static int do_merge(struct repository *r,
        static struct lock_file lock;
        const char *p;
 
-       if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
+       if (repo_hold_locked_index(r, &lock, LOCK_REPORT_ON_ERROR) < 0) {
                ret = -1;
                goto leave_merge;
        }
@@ -3243,7 +3260,7 @@ static int do_merge(struct repository *r,
 
                /* force re-reading of the cache */
                if (!ret && (discard_index(r->index) < 0 ||
-                            read_index(r->index) < 0))
+                            repo_read_index(r) < 0))
                        ret = error(_("could not read index"));
                goto leave_merge;
        }
@@ -3265,8 +3282,8 @@ static int do_merge(struct repository *r,
                commit_list_insert(j->item, &reversed);
        free_commit_list(bases);
 
-       read_index(r->index);
-       init_merge_options(&o);
+       repo_read_index(r);
+       init_merge_options(&o, r);
        o.branch1 = "HEAD";
        o.branch2 = ref_name.buf;
        o.buffer_output = 2;
@@ -3405,10 +3422,11 @@ static const char *reflog_message(struct replay_opts *opts,
        return buf.buf;
 }
 
-static int run_git_checkout(struct replay_opts *opts, const char *commit,
-                           const char *action)
+static int run_git_checkout(struct repository *r, struct replay_opts *opts,
+                           const char *commit, const char *action)
 {
        struct child_process cmd = CHILD_PROCESS_INIT;
+       int ret;
 
        cmd.git_cmd = 1;
 
@@ -3417,26 +3435,32 @@ static int run_git_checkout(struct replay_opts *opts, const char *commit,
        argv_array_pushf(&cmd.env_array, GIT_REFLOG_ACTION "=%s", action);
 
        if (opts->verbose)
-               return run_command(&cmd);
+               ret = run_command(&cmd);
        else
-               return run_command_silent_on_success(&cmd);
+               ret = run_command_silent_on_success(&cmd);
+
+       if (!ret)
+               discard_index(r->index);
+
+       return ret;
 }
 
-int prepare_branch_to_be_rebased(struct replay_opts *opts, const char *commit)
+int prepare_branch_to_be_rebased(struct repository *r, struct replay_opts *opts,
+                                const char *commit)
 {
        const char *action;
 
        if (commit && *commit) {
                action = reflog_message(opts, "start", "checkout %s", commit);
-               if (run_git_checkout(opts, commit, action))
+               if (run_git_checkout(r, opts, commit, action))
                        return error(_("could not checkout %s"), commit);
        }
 
        return 0;
 }
 
-static int checkout_onto(struct replay_opts *opts,
-                        const char *onto_name, const char *onto,
+static int checkout_onto(struct repository *r, struct replay_opts *opts,
+                        const char *onto_name, const struct object_id *onto,
                         const char *orig_head)
 {
        struct object_id oid;
@@ -3445,7 +3469,7 @@ static int checkout_onto(struct replay_opts *opts,
        if (get_oid(orig_head, &oid))
                return error(_("%s: not a valid OID"), orig_head);
 
-       if (run_git_checkout(opts, onto, action)) {
+       if (run_git_checkout(r, opts, oid_to_hex(onto), action)) {
                apply_autostash(opts);
                sequencer_remove_state(opts);
                return error(_("could not detach HEAD"));
@@ -3512,10 +3536,11 @@ static int pick_commits(struct repository *r,
                                        fprintf(f, "%d\n", todo_list->done_nr);
                                        fclose(f);
                                }
-                               fprintf(stderr, "Rebasing (%d/%d)%s",
-                                       todo_list->done_nr,
-                                       todo_list->total_nr,
-                                       opts->verbose ? "\n" : "\r");
+                               if (!opts->quiet)
+                                       fprintf(stderr, "Rebasing (%d/%d)%s",
+                                               todo_list->done_nr,
+                                               todo_list->total_nr,
+                                               opts->verbose ? "\n" : "\r");
                        }
                        unlink(rebase_path_message());
                        unlink(rebase_path_author_script());
@@ -3594,9 +3619,10 @@ static int pick_commits(struct repository *r,
                        *end_of_arg = saved;
 
                        /* Reread the todo file if it has changed. */
-                       if (res)
-                               ; /* fall through */
-                       else if (stat(get_todo_path(opts), &st))
+                       if (res) {
+                               if (opts->reschedule_failed_exec)
+                                       reschedule = 1;
+                       } else if (stat(get_todo_path(opts), &st))
                                res = error_errno(_("could not stat '%s'"),
                                                  get_todo_path(opts));
                        else if (match_stat_data(&todo_list->stat, &st)) {
@@ -3737,6 +3763,7 @@ static int pick_commits(struct repository *r,
                                hook.in = open(rebase_path_rewritten_list(),
                                        O_RDONLY);
                                hook.stdout_to_stderr = 1;
+                               hook.trace2_hook_name = "post-rewrite";
                                argv_array_push(&hook.args, post_rewrite_hook);
                                argv_array_push(&hook.args, "rebase");
                                /* we don't care if this hook failed */
@@ -3745,8 +3772,10 @@ static int pick_commits(struct repository *r,
                }
                apply_autostash(opts);
 
-               fprintf(stderr, "Successfully rebased and updated %s.\n",
-                       head_ref.buf);
+               if (!opts->quiet)
+                       fprintf(stderr,
+                               "Successfully rebased and updated %s.\n",
+                               head_ref.buf);
 
                strbuf_release(&buf);
                strbuf_release(&head_ref);
@@ -3937,7 +3966,7 @@ int sequencer_continue(struct repository *r, struct replay_opts *opts)
                                goto release_todo_list;
                }
                if (index_differs_from(r, "HEAD", NULL, 0)) {
-                       res = error_dirty_index(r->index, opts);
+                       res = error_dirty_index(r, opts);
                        goto release_todo_list;
                }
                todo_list.current++;
@@ -4047,8 +4076,7 @@ void append_signoff(struct strbuf *msgbuf, size_t ignore_footer, unsigned flag)
        int has_footer;
 
        strbuf_addstr(&sob, sign_off_header);
-       strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
-                               getenv("GIT_COMMITTER_EMAIL")));
+       strbuf_addstr(&sob, fmt_name(WANT_COMMITTER_IDENT));
        strbuf_addch(&sob, '\n');
 
        if (!ignore_footer)
@@ -4215,7 +4243,7 @@ static const char *label_oid(struct object_id *oid, const char *label,
 }
 
 static int make_script_with_merges(struct pretty_print_context *pp,
-                                  struct rev_info *revs, FILE *out,
+                                  struct rev_info *revs, struct strbuf *out,
                                   unsigned flags)
 {
        int keep_empty = flags & TODO_LIST_KEEP_EMPTY;
@@ -4360,7 +4388,7 @@ static int make_script_with_merges(struct pretty_print_context *pp,
         * gathering commits not yet shown, reversing the list on the fly,
         * then outputting that list (labeling revisions as needed).
         */
-       fprintf(out, "%s onto\n", cmd_label);
+       strbuf_addf(out, "%s onto\n", cmd_label);
        for (iter = tips; iter; iter = iter->next) {
                struct commit_list *list = NULL, *iter2;
 
@@ -4370,9 +4398,9 @@ static int make_script_with_merges(struct pretty_print_context *pp,
                entry = oidmap_get(&state.commit2label, &commit->object.oid);
 
                if (entry)
-                       fprintf(out, "\n%c Branch %s\n", comment_line_char, entry->string);
+                       strbuf_addf(out, "\n%c Branch %s\n", comment_line_char, entry->string);
                else
-                       fprintf(out, "\n");
+                       strbuf_addch(out, '\n');
 
                while (oidset_contains(&interesting, &commit->object.oid) &&
                       !oidset_contains(&shown, &commit->object.oid)) {
@@ -4385,8 +4413,8 @@ static int make_script_with_merges(struct pretty_print_context *pp,
                }
 
                if (!commit)
-                       fprintf(out, "%s %s\n", cmd_reset,
-                               rebase_cousins ? "onto" : "[new root]");
+                       strbuf_addf(out, "%s %s\n", cmd_reset,
+                                   rebase_cousins ? "onto" : "[new root]");
                else {
                        const char *to = NULL;
 
@@ -4399,12 +4427,12 @@ static int make_script_with_merges(struct pretty_print_context *pp,
                                               &state);
 
                        if (!to || !strcmp(to, "onto"))
-                               fprintf(out, "%s onto\n", cmd_reset);
+                               strbuf_addf(out, "%s onto\n", cmd_reset);
                        else {
                                strbuf_reset(&oneline);
                                pretty_print_commit(pp, commit, &oneline);
-                               fprintf(out, "%s %s # %s\n",
-                                       cmd_reset, to, oneline.buf);
+                               strbuf_addf(out, "%s %s # %s\n",
+                                           cmd_reset, to, oneline.buf);
                        }
                }
 
@@ -4413,11 +4441,11 @@ static int make_script_with_merges(struct pretty_print_context *pp,
                        entry = oidmap_get(&commit2todo, oid);
                        /* only show if not already upstream */
                        if (entry)
-                               fprintf(out, "%s\n", entry->string);
+                               strbuf_addf(out, "%s\n", entry->string);
                        entry = oidmap_get(&state.commit2label, oid);
                        if (entry)
-                               fprintf(out, "%s %s\n",
-                                       cmd_label, entry->string);
+                               strbuf_addf(out, "%s %s\n",
+                                           cmd_label, entry->string);
                        oidset_insert(&shown, oid);
                }
 
@@ -4439,13 +4467,11 @@ static int make_script_with_merges(struct pretty_print_context *pp,
        return 0;
 }
 
-int sequencer_make_script(struct repository *r, FILE *out,
-                         int argc, const char **argv,
-                         unsigned flags)
+int sequencer_make_script(struct repository *r, struct strbuf *out, int argc,
+                         const char **argv, unsigned flags)
 {
        char *format = NULL;
        struct pretty_print_context pp = {0};
-       struct strbuf buf = STRBUF_INIT;
        struct rev_info revs;
        struct commit *commit;
        int keep_empty = flags & TODO_LIST_KEEP_EMPTY;
@@ -4488,16 +4514,13 @@ int sequencer_make_script(struct repository *r, FILE *out,
 
                if (!is_empty && (commit->object.flags & PATCHSAME))
                        continue;
-               strbuf_reset(&buf);
                if (!keep_empty && is_empty)
-                       strbuf_addf(&buf, "%c ", comment_line_char);
-               strbuf_addf(&buf, "%s %s ", insn,
+                       strbuf_addf(out, "%c ", comment_line_char);
+               strbuf_addf(out, "%s %s ", insn,
                            oid_to_hex(&commit->object.oid));
-               pretty_print_commit(&pp, commit, &buf);
-               strbuf_addch(&buf, '\n');
-               fputs(buf.buf, out);
+               pretty_print_commit(&pp, commit, out);
+               strbuf_addch(out, '\n');
        }
-       strbuf_release(&buf);
        return 0;
 }
 
@@ -4505,8 +4528,8 @@ int sequencer_make_script(struct repository *r, FILE *out,
  * Add commands after pick and (series of) squash/fixup commands
  * in the todo list.
  */
-static void todo_list_add_exec_commands(struct todo_list *todo_list,
-                                       struct string_list *commands)
+void todo_list_add_exec_commands(struct todo_list *todo_list,
+                                struct string_list *commands)
 {
        struct strbuf *buf = &todo_list->buf;
        size_t base_offset = buf->len;
@@ -4572,30 +4595,6 @@ static void todo_list_add_exec_commands(struct todo_list *todo_list,
        todo_list->alloc = alloc;
 }
 
-int sequencer_add_exec_commands(struct repository *r,
-                               struct string_list *commands)
-{
-       const char *todo_file = rebase_path_todo();
-       struct todo_list todo_list = TODO_LIST_INIT;
-       int res;
-
-       if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
-               return error_errno(_("could not read '%s'."), todo_file);
-
-       if (todo_list_parse_insn_buffer(r, todo_list.buf.buf, &todo_list)) {
-               todo_list_release(&todo_list);
-               return error(_("unusable todo list: '%s'"), todo_file);
-       }
-
-       todo_list_add_exec_commands(&todo_list, commands);
-       res = todo_list_write_to_file(r, &todo_list, todo_file, NULL, NULL, -1, 0);
-       todo_list_release(&todo_list);
-
-       if (res)
-               return error_errno(_("could not write '%s'."), todo_file);
-       return 0;
-}
-
 static void todo_list_to_strbuf(struct repository *r, struct todo_list *todo_list,
                                struct strbuf *buf, int num, unsigned flags)
 {
@@ -4648,22 +4647,13 @@ int todo_list_write_to_file(struct repository *r, struct todo_list *todo_list,
                            const char *file, const char *shortrevisions,
                            const char *shortonto, int num, unsigned flags)
 {
-       int edit_todo = !(shortrevisions && shortonto), res;
+       int res;
        struct strbuf buf = STRBUF_INIT;
 
        todo_list_to_strbuf(r, todo_list, &buf, num, flags);
-
-       if (flags & TODO_LIST_APPEND_TODO_HELP) {
-               int command_count = count_commands(todo_list);
-               if (!edit_todo) {
-                       strbuf_addch(&buf, '\n');
-                       strbuf_commented_addf(&buf, Q_("Rebase %s onto %s (%d command)",
-                                                      "Rebase %s onto %s (%d commands)",
-                                                      command_count),
-                                             shortrevisions, shortonto, command_count);
-               }
-               append_todo_help(edit_todo, flags & TODO_LIST_KEEP_EMPTY, &buf);
-       }
+       if (flags & TODO_LIST_APPEND_TODO_HELP)
+               append_todo_help(flags & TODO_LIST_KEEP_EMPTY, count_commands(todo_list),
+                                shortrevisions, shortonto, &buf);
 
        res = write_message(buf.buf, buf.len, file, 0);
        strbuf_release(&buf);
@@ -4671,29 +4661,6 @@ int todo_list_write_to_file(struct repository *r, struct todo_list *todo_list,
        return res;
 }
 
-int transform_todo_file(struct repository *r, unsigned flags)
-{
-       const char *todo_file = rebase_path_todo();
-       struct todo_list todo_list = TODO_LIST_INIT;
-       int res;
-
-       if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
-               return error_errno(_("could not read '%s'."), todo_file);
-
-       if (todo_list_parse_insn_buffer(r, todo_list.buf.buf, &todo_list)) {
-               todo_list_release(&todo_list);
-               return error(_("unusable todo list: '%s'"), todo_file);
-       }
-
-       res = todo_list_write_to_file(r, &todo_list, todo_file,
-                                     NULL, NULL, -1, flags);
-       todo_list_release(&todo_list);
-
-       if (res)
-               return error_errno(_("could not write '%s'."), todo_file);
-       return 0;
-}
-
 static const char edit_todo_list_advice[] =
 N_("You can fix this with 'git rebase --edit-todo' "
 "and then run 'git rebase --continue'.\n"
@@ -4729,52 +4696,22 @@ int check_todo_list_from_file(struct repository *r)
        return res;
 }
 
-static int rewrite_file(const char *path, const char *buf, size_t len)
-{
-       int rc = 0;
-       int fd = open(path, O_WRONLY | O_TRUNC);
-       if (fd < 0)
-               return error_errno(_("could not open '%s' for writing"), path);
-       if (write_in_full(fd, buf, len) < 0)
-               rc = error_errno(_("could not write to '%s'"), path);
-       if (close(fd) && !rc)
-               rc = error_errno(_("could not close '%s'"), path);
-       return rc;
-}
-
 /* skip picking commits whose parents are unchanged */
-static int skip_unnecessary_picks(struct repository *r, struct object_id *output_oid)
+static int skip_unnecessary_picks(struct repository *r,
+                                 struct todo_list *todo_list,
+                                 struct object_id *base_oid)
 {
-       const char *todo_file = rebase_path_todo();
-       struct strbuf buf = STRBUF_INIT;
-       struct todo_list todo_list = TODO_LIST_INIT;
        struct object_id *parent_oid;
-       int fd, i;
-
-       if (!read_oneliner(&buf, rebase_path_onto(), 0))
-               return error(_("could not read 'onto'"));
-       if (get_oid(buf.buf, output_oid)) {
-               strbuf_release(&buf);
-               return error(_("need a HEAD to fixup"));
-       }
-       strbuf_release(&buf);
-
-       if (strbuf_read_file_or_whine(&todo_list.buf, todo_file) < 0)
-               return -1;
-       if (todo_list_parse_insn_buffer(r, todo_list.buf.buf, &todo_list) < 0) {
-               todo_list_release(&todo_list);
-               return -1;
-       }
+       int i;
 
-       for (i = 0; i < todo_list.nr; i++) {
-               struct todo_item *item = todo_list.items + i;
+       for (i = 0; i < todo_list->nr; i++) {
+               struct todo_item *item = todo_list->items + i;
 
                if (item->command >= TODO_NOOP)
                        continue;
                if (item->command != TODO_PICK)
                        break;
                if (parse_commit(item->commit)) {
-                       todo_list_release(&todo_list);
                        return error(_("could not parse commit '%s'"),
                                oid_to_hex(&item->commit->object.oid));
                }
@@ -4783,137 +4720,103 @@ static int skip_unnecessary_picks(struct repository *r, struct object_id *output
                if (item->commit->parents->next)
                        break; /* merge commit */
                parent_oid = &item->commit->parents->item->object.oid;
-               if (!oideq(parent_oid, output_oid))
+               if (!oideq(parent_oid, base_oid))
                        break;
-               oidcpy(output_oid, &item->commit->object.oid);
+               oidcpy(base_oid, &item->commit->object.oid);
        }
        if (i > 0) {
-               int offset = get_item_line_offset(&todo_list, i);
                const char *done_path = rebase_path_done();
 
-               fd = open(done_path, O_CREAT | O_WRONLY | O_APPEND, 0666);
-               if (fd < 0) {
-                       error_errno(_("could not open '%s' for writing"),
-                                   done_path);
-                       todo_list_release(&todo_list);
-                       return -1;
-               }
-               if (write_in_full(fd, todo_list.buf.buf, offset) < 0) {
+               if (todo_list_write_to_file(r, todo_list, done_path, NULL, NULL, i, 0)) {
                        error_errno(_("could not write to '%s'"), done_path);
-                       todo_list_release(&todo_list);
-                       close(fd);
                        return -1;
                }
-               close(fd);
 
-               if (rewrite_file(rebase_path_todo(), todo_list.buf.buf + offset,
-                                todo_list.buf.len - offset) < 0) {
-                       todo_list_release(&todo_list);
-                       return -1;
-               }
+               MOVE_ARRAY(todo_list->items, todo_list->items + i, todo_list->nr - i);
+               todo_list->nr -= i;
+               todo_list->current = 0;
 
-               todo_list.current = i;
-               if (is_fixup(peek_command(&todo_list, 0)))
-                       record_in_rewritten(output_oid, peek_command(&todo_list, 0));
+               if (is_fixup(peek_command(todo_list, 0)))
+                       record_in_rewritten(base_oid, peek_command(todo_list, 0));
        }
 
-       todo_list_release(&todo_list);
-
        return 0;
 }
 
 int complete_action(struct repository *r, struct replay_opts *opts, unsigned flags,
                    const char *shortrevisions, const char *onto_name,
-                   const char *onto, const char *orig_head, struct string_list *commands,
-                   unsigned autosquash)
+                   struct commit *onto, const char *orig_head,
+                   struct string_list *commands, unsigned autosquash,
+                   struct todo_list *todo_list)
 {
        const char *shortonto, *todo_file = rebase_path_todo();
-       struct todo_list todo_list = TODO_LIST_INIT;
-       struct strbuf *buf = &(todo_list.buf);
-       struct object_id oid;
-       struct stat st;
+       struct todo_list new_todo = TODO_LIST_INIT;
+       struct strbuf *buf = &todo_list->buf;
+       struct object_id oid = onto->object.oid;
+       int res;
 
-       get_oid(onto, &oid);
        shortonto = find_unique_abbrev(&oid, DEFAULT_ABBREV);
 
-       if (!lstat(todo_file, &st) && st.st_size == 0 &&
-           write_message("noop\n", 5, todo_file, 0))
-               return -1;
+       if (buf->len == 0) {
+               struct todo_item *item = append_new_todo(todo_list);
+               item->command = TODO_NOOP;
+               item->commit = NULL;
+               item->arg_len = item->arg_offset = item->flags = item->offset_in_buf = 0;
+       }
 
-       if (autosquash && rearrange_squash_in_todo_file(r))
+       if (autosquash && todo_list_rearrange_squash(todo_list))
                return -1;
 
        if (commands->nr)
-               sequencer_add_exec_commands(r, commands);
-
-       if (strbuf_read_file(buf, todo_file, 0) < 0)
-               return error_errno(_("could not read '%s'."), todo_file);
+               todo_list_add_exec_commands(todo_list, commands);
 
-       if (todo_list_parse_insn_buffer(r, buf->buf, &todo_list)) {
-               todo_list_release(&todo_list);
-               return error(_("unusable todo list: '%s'"), todo_file);
-       }
-
-       if (count_commands(&todo_list) == 0) {
+       if (count_commands(todo_list) == 0) {
                apply_autostash(opts);
                sequencer_remove_state(opts);
-               todo_list_release(&todo_list);
 
                return error(_("nothing to do"));
        }
 
-       strbuf_addch(buf, '\n');
-       strbuf_commented_addf(buf, Q_("Rebase %s onto %s (%d command)",
-                                     "Rebase %s onto %s (%d commands)",
-                                     count_commands(&todo_list)),
-                             shortrevisions, shortonto, count_commands(&todo_list));
-       append_todo_help(0, flags & TODO_LIST_KEEP_EMPTY, buf);
-
-       if (write_message(buf->buf, buf->len, todo_file, 0)) {
-               todo_list_release(&todo_list);
+       res = edit_todo_list(r, todo_list, &new_todo, shortrevisions,
+                            shortonto, flags);
+       if (res == -1)
                return -1;
-       }
-
-       if (copy_file(rebase_path_todo_backup(), todo_file, 0666))
-               return error(_("could not copy '%s' to '%s'."), todo_file,
-                            rebase_path_todo_backup());
-
-       if (transform_todo_file(r, flags | TODO_LIST_SHORTEN_IDS))
-               return error(_("could not transform the todo list"));
-
-       strbuf_reset(buf);
-
-       if (launch_sequence_editor(todo_file, buf, NULL)) {
+       else if (res == -2) {
                apply_autostash(opts);
                sequencer_remove_state(opts);
-               todo_list_release(&todo_list);
 
                return -1;
-       }
-
-       strbuf_stripspace(buf, 1);
-       if (buf->len == 0) {
+       } else if (res == -3) {
                apply_autostash(opts);
                sequencer_remove_state(opts);
-               todo_list_release(&todo_list);
+               todo_list_release(&new_todo);
 
                return error(_("nothing to do"));
        }
 
-       todo_list_release(&todo_list);
+       if (todo_list_parse_insn_buffer(r, new_todo.buf.buf, &new_todo) ||
+           todo_list_check(todo_list, &new_todo)) {
+               fprintf(stderr, _(edit_todo_list_advice));
+               checkout_onto(r, opts, onto_name, &onto->object.oid, orig_head);
+               todo_list_release(&new_todo);
 
-       if (check_todo_list_from_file(r)) {
-               checkout_onto(opts, onto_name, onto, orig_head);
                return -1;
        }
 
-       if (transform_todo_file(r, flags & ~(TODO_LIST_SHORTEN_IDS)))
-               return error(_("could not transform the todo list"));
-
-       if (opts->allow_ff && skip_unnecessary_picks(r, &oid))
+       if (opts->allow_ff && skip_unnecessary_picks(r, &new_todo, &oid)) {
+               todo_list_release(&new_todo);
                return error(_("could not skip unnecessary pick commands"));
+       }
+
+       if (todo_list_write_to_file(r, &new_todo, todo_file, NULL, NULL, -1,
+                                   flags & ~(TODO_LIST_SHORTEN_IDS))) {
+               todo_list_release(&new_todo);
+               return error_errno(_("could not write '%s'"), todo_file);
+       }
+
+       todo_list_release(&new_todo);
 
-       if (checkout_onto(opts, onto_name, oid_to_hex(&oid), orig_head))
+       if (checkout_onto(r, opts, onto_name, &oid, orig_head))
                return -1;
 
        if (require_clean_work_tree(r, "rebase", "", 1, 1))
@@ -4946,7 +4849,7 @@ define_commit_slab(commit_todo_item, struct todo_item *);
  * message will have to be retrieved from the commit (as the oneline in the
  * script cannot be trusted) in order to normalize the autosquash arrangement.
  */
-static int todo_list_rearrange_squash(struct todo_list *todo_list)
+int todo_list_rearrange_squash(struct todo_list *todo_list)
 {
        struct hashmap subject2item;
        int rearranged = 0, *next, *tail, i, nr = 0, alloc = 0;
@@ -5084,27 +4987,3 @@ static int todo_list_rearrange_squash(struct todo_list *todo_list)
 
        return 0;
 }
-
-int rearrange_squash_in_todo_file(struct repository *r)
-{
-       const char *todo_file = rebase_path_todo();
-       struct todo_list todo_list = TODO_LIST_INIT;
-       int res = 0;
-
-       if (strbuf_read_file_or_whine(&todo_list.buf, todo_file) < 0)
-               return -1;
-       if (todo_list_parse_insn_buffer(r, todo_list.buf.buf, &todo_list) < 0) {
-               todo_list_release(&todo_list);
-               return -1;
-       }
-
-       res = todo_list_rearrange_squash(&todo_list);
-       if (!res)
-               res = todo_list_write_to_file(r, &todo_list, todo_file, NULL, NULL, -1, 0);
-
-       todo_list_release(&todo_list);
-
-       if (res)
-               return error_errno(_("could not write '%s'."), todo_file);
-       return 0;
-}