Merge branch 'jt/fetch-pack-wanted-refs-optim'
[gitweb.git] / sequencer.c
index e1a4dd15f1a826c7bd1bf4780c8f85c21117c43b..546f28189851875b4a881ef9ff8876528e5dc9f9 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)
 {
@@ -356,7 +356,8 @@ static void free_message(struct commit *commit, struct commit_message *msg)
        unuse_commit_buffer(commit, msg->message);
 }
 
-static void print_advice(int show_hint, struct replay_opts *opts)
+static void print_advice(struct repository *r, int show_hint,
+                        struct replay_opts *opts)
 {
        char *msg = getenv("GIT_CHERRY_PICK_HELP");
 
@@ -367,7 +368,7 @@ static void print_advice(int show_hint, struct replay_opts *opts)
                 * (typically rebase --interactive) wants to take care
                 * of the commit itself so remove CHERRY_PICK_HEAD
                 */
-               unlink(git_path_cherry_pick_head(the_repository));
+               unlink(git_path_cherry_pick_head(r));
                return;
        }
 
@@ -382,8 +383,8 @@ static void print_advice(int show_hint, struct replay_opts *opts)
        }
 }
 
-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;
 
@@ -440,14 +441,14 @@ static int read_oneliner(struct strbuf *buf,
        return 1;
 }
 
-static struct tree *empty_tree(void)
+static struct tree *empty_tree(struct repository *r)
 {
-       return lookup_tree(the_repository, the_repository->hash_algo->empty_tree);
+       return lookup_tree(r, the_hash_algo->empty_tree);
 }
 
-static int error_dirty_index(struct replay_opts *opts)
+static int error_dirty_index(struct repository *repo, struct replay_opts *opts)
 {
-       if (read_cache_unmerged())
+       if (repo_read_index_unmerged(repo))
                return error_resolve_conflict(_(action_name(opts)));
 
        error(_("your local changes would be overwritten by %s."),
@@ -472,15 +473,18 @@ static void update_abort_safety_file(void)
                write_file(git_path_abort_safety_file(), "%s", "");
 }
 
-static int fast_forward_to(const struct object_id *to, const struct object_id *from,
-                       int unborn, struct replay_opts *opts)
+static int fast_forward_to(struct repository *r,
+                          const struct object_id *to,
+                          const struct object_id *from,
+                          int unborn,
+                          struct replay_opts *opts)
 {
        struct ref_transaction *transaction;
        struct strbuf sb = STRBUF_INIT;
        struct strbuf err = STRBUF_INIT;
 
-       read_index(&the_index);
-       if (checkout_fast_forward(the_repository, from, to, 1))
+       repo_read_index(r);
+       if (checkout_fast_forward(r, from, to, 1))
                return -1; /* the callee should have complained already */
 
        strbuf_addf(&sb, _("%s: fast-forward"), _(action_name(opts)));
@@ -506,24 +510,26 @@ static int fast_forward_to(const struct object_id *to, const struct object_id *f
        return 0;
 }
 
-void append_conflicts_hint(struct strbuf *msgbuf)
+void append_conflicts_hint(struct index_state *istate,
+                          struct strbuf *msgbuf)
 {
        int i;
 
        strbuf_addch(msgbuf, '\n');
        strbuf_commented_addf(msgbuf, "Conflicts:\n");
-       for (i = 0; i < active_nr;) {
-               const struct cache_entry *ce = active_cache[i++];
+       for (i = 0; i < istate->cache_nr;) {
+               const struct cache_entry *ce = istate->cache[i++];
                if (ce_stage(ce)) {
                        strbuf_commented_addf(msgbuf, "\t%s\n", ce->name);
-                       while (i < active_nr && !strcmp(ce->name,
-                                                       active_cache[i]->name))
+                       while (i < istate->cache_nr &&
+                              !strcmp(ce->name, istate->cache[i]->name))
                                i++;
                }
        }
 }
 
-static int do_recursive_merge(struct commit *base, struct commit *next,
+static int do_recursive_merge(struct repository *r,
+                             struct commit *base, struct commit *next,
                              const char *base_label, const char *next_label,
                              struct object_id *head, struct strbuf *msgbuf,
                              struct replay_opts *opts)
@@ -534,12 +540,12 @@ static int do_recursive_merge(struct commit *base, struct commit *next,
        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_cache();
+       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)";
@@ -548,8 +554,8 @@ static int do_recursive_merge(struct commit *base, struct commit *next,
        o.show_rename_progress = 1;
 
        head_tree = parse_tree_indirect(head);
-       next_tree = next ? get_commit_tree(next) : empty_tree();
-       base_tree = base ? get_commit_tree(base) : empty_tree();
+       next_tree = next ? get_commit_tree(next) : empty_tree(r);
+       base_tree = base ? get_commit_tree(base) : empty_tree(r);
 
        for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
                parse_merge_opt(&o, *xopt);
@@ -566,7 +572,7 @@ static int do_recursive_merge(struct commit *base, struct commit *next,
                return clean;
        }
 
-       if (write_locked_index(&the_index, &index_lock,
+       if (write_locked_index(r->index, &index_lock,
                               COMMIT_LOCK | SKIP_IF_UNCHANGED))
                /*
                 * TRANSLATORS: %s will be "revert", "cherry-pick" or
@@ -576,34 +582,35 @@ static int do_recursive_merge(struct commit *base, struct commit *next,
                        _(action_name(opts)));
 
        if (!clean)
-               append_conflicts_hint(msgbuf);
+               append_conflicts_hint(r->index, msgbuf);
 
        return !clean;
 }
 
-static struct object_id *get_cache_tree_oid(void)
+static struct object_id *get_cache_tree_oid(struct index_state *istate)
 {
-       if (!active_cache_tree)
-               active_cache_tree = cache_tree();
+       if (!istate->cache_tree)
+               istate->cache_tree = cache_tree();
 
-       if (!cache_tree_fully_valid(active_cache_tree))
-               if (cache_tree_update(&the_index, 0)) {
+       if (!cache_tree_fully_valid(istate->cache_tree))
+               if (cache_tree_update(istate, 0)) {
                        error(_("unable to update cache tree"));
                        return NULL;
                }
 
-       return &active_cache_tree->oid;
+       return &istate->cache_tree->oid;
 }
 
-static int is_index_unchanged(void)
+static int is_index_unchanged(struct repository *r)
 {
        struct object_id head_oid, *cache_tree_oid;
        struct commit *head_commit;
+       struct index_state *istate = r->index;
 
        if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
                return error(_("could not resolve HEAD commit"));
 
-       head_commit = lookup_commit(the_repository, &head_oid);
+       head_commit = lookup_commit(r, &head_oid);
 
        /*
         * If head_commit is NULL, check_commit, called from
@@ -616,7 +623,7 @@ static int is_index_unchanged(void)
        if (parse_commit(head_commit))
                return -1;
 
-       if (!(cache_tree_oid = get_cache_tree_oid()))
+       if (!(cache_tree_oid = get_cache_tree_oid(istate)))
                return -1;
 
        return oideq(cache_tree_oid, get_commit_tree_oid(head_commit));
@@ -829,7 +836,7 @@ 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);
@@ -888,7 +895,9 @@ static int run_command_silent_on_success(struct child_process *cmd)
  * interactive rebase: in that case, we will want to retain the
  * author metadata.
  */
-static int run_git_commit(const char *defmsg, struct replay_opts *opts,
+static int run_git_commit(struct repository *r,
+                         const char *defmsg,
+                         struct replay_opts *opts,
                          unsigned int flags)
 {
        struct child_process cmd = CHILD_PROCESS_INIT;
@@ -911,7 +920,7 @@ static int run_git_commit(const char *defmsg, struct replay_opts *opts,
                if (!defmsg)
                        BUG("root commit without message");
 
-               if (!(cache_tree_oid = get_cache_tree_oid()))
+               if (!(cache_tree_oid = get_cache_tree_oid(r->index)))
                        res = -1;
 
                if (!res)
@@ -1093,6 +1102,7 @@ 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)
@@ -1106,7 +1116,8 @@ 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;
@@ -1115,12 +1126,14 @@ 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);
 }
 
-static int run_prepare_commit_msg_hook(struct strbuf *msg, const char *commit)
+static int run_prepare_commit_msg_hook(struct repository *r,
+                                      struct strbuf *msg,
+                                      const char *commit)
 {
        struct argv_array hook_env = ARGV_ARRAY_INIT;
        int ret;
@@ -1130,7 +1143,7 @@ static int run_prepare_commit_msg_hook(struct strbuf *msg, const char *commit)
        if (write_message(msg->buf, msg->len, name, 0))
                return -1;
 
-       argv_array_pushf(&hook_env, "GIT_INDEX_FILE=%s", get_index_file());
+       argv_array_pushf(&hook_env, "GIT_INDEX_FILE=%s", r->index_file);
        argv_array_push(&hook_env, "GIT_EDITOR=:");
        if (commit)
                ret = run_hook_le(hook_env.argv, "prepare-commit-msg", name,
@@ -1186,7 +1199,9 @@ static const char *implicit_ident_advice(void)
 
 }
 
-void print_commit_summary(const char *prefix, const struct object_id *oid,
+void print_commit_summary(struct repository *r,
+                         const char *prefix,
+                         const struct object_id *oid,
                          unsigned int flags)
 {
        struct rev_info rev;
@@ -1197,7 +1212,7 @@ void print_commit_summary(const char *prefix, const struct object_id *oid,
        struct strbuf author_ident = STRBUF_INIT;
        struct strbuf committer_ident = STRBUF_INIT;
 
-       commit = lookup_commit(the_repository, oid);
+       commit = lookup_commit(r, oid);
        if (!commit)
                die(_("couldn't look up newly created commit"));
        if (parse_commit(commit))
@@ -1230,7 +1245,7 @@ void print_commit_summary(const char *prefix, const struct object_id *oid,
        strbuf_release(&author_ident);
        strbuf_release(&committer_ident);
 
-       repo_init_revisions(the_repository, &rev, prefix);
+       repo_init_revisions(r, &rev, prefix);
        setup_revisions(0, NULL, &rev, NULL);
 
        rev.diff = 1;
@@ -1264,7 +1279,7 @@ void print_commit_summary(const char *prefix, const struct object_id *oid,
        strbuf_release(&format);
 }
 
-static int parse_head(struct commit **head)
+static int parse_head(struct repository *r, struct commit **head)
 {
        struct commit *current_head;
        struct object_id oid;
@@ -1272,7 +1287,7 @@ static int parse_head(struct commit **head)
        if (get_oid("HEAD", &oid)) {
                current_head = NULL;
        } else {
-               current_head = lookup_commit_reference(the_repository, &oid);
+               current_head = lookup_commit_reference(r, &oid);
                if (!current_head)
                        return error(_("could not parse HEAD"));
                if (!oideq(&oid, &current_head->object.oid)) {
@@ -1296,7 +1311,8 @@ static int parse_head(struct commit **head)
  *   0 - success
  *   1 - run 'git commit'
  */
-static int try_to_commit(struct strbuf *msg, const char *author,
+static int try_to_commit(struct repository *r,
+                        struct strbuf *msg, const char *author,
                         struct replay_opts *opts, unsigned int flags,
                         struct object_id *oid)
 {
@@ -1311,7 +1327,7 @@ static int try_to_commit(struct strbuf *msg, const char *author,
        enum commit_msg_cleanup_mode cleanup;
        int res = 0;
 
-       if (parse_head(&current_head))
+       if (parse_head(r, &current_head))
                return -1;
 
        if (flags & AMEND_MSG) {
@@ -1340,7 +1356,7 @@ static int try_to_commit(struct strbuf *msg, const char *author,
                commit_list_insert(current_head, &parents);
        }
 
-       if (write_index_as_tree(&tree, &the_index, get_index_file(), 0, NULL)) {
+       if (write_index_as_tree(&tree, r->index, r->index_file, 0, NULL)) {
                res = error(_("git write-tree failed to write a tree"));
                goto out;
        }
@@ -1353,7 +1369,7 @@ static int try_to_commit(struct strbuf *msg, const char *author,
        }
 
        if (find_hook("prepare-commit-msg")) {
-               res = run_prepare_commit_msg_hook(msg, hook_commit);
+               res = run_prepare_commit_msg_hook(r, msg, hook_commit);
                if (res)
                        goto out;
                if (strbuf_read_file(&commit_msg, git_path_commit_editmsg(),
@@ -1391,7 +1407,7 @@ static int try_to_commit(struct strbuf *msg, const char *author,
        }
 
        if (flags & AMEND_MSG)
-               commit_post_rewrite(current_head, oid);
+               commit_post_rewrite(r, current_head, oid);
 
 out:
        free_commit_extra_headers(extra);
@@ -1402,7 +1418,8 @@ static int try_to_commit(struct strbuf *msg, const char *author,
        return res;
 }
 
-static int do_commit(const char *msg_file, const char *author,
+static int do_commit(struct repository *r,
+                    const char *msg_file, const char *author,
                     struct replay_opts *opts, unsigned int flags)
 {
        int res = 1;
@@ -1417,20 +1434,20 @@ static int do_commit(const char *msg_file, const char *author,
                                             "from '%s'"),
                                           msg_file);
 
-               res = try_to_commit(msg_file ? &sb : NULL, author, opts, flags,
-                                   &oid);
+               res = try_to_commit(r, msg_file ? &sb : NULL,
+                                   author, opts, flags, &oid);
                strbuf_release(&sb);
                if (!res) {
-                       unlink(git_path_cherry_pick_head(the_repository));
-                       unlink(git_path_merge_msg(the_repository));
+                       unlink(git_path_cherry_pick_head(r));
+                       unlink(git_path_merge_msg(r));
                        if (!is_rebase_i(opts))
-                               print_commit_summary(NULL, &oid,
+                               print_commit_summary(r, NULL, &oid,
                                                SUMMARY_SHOW_AUTHOR_DATE);
                        return res;
                }
        }
        if (res == 1)
-               return run_git_commit(msg_file, opts, flags);
+               return run_git_commit(r, msg_file, opts, flags);
 
        return res;
 }
@@ -1458,7 +1475,9 @@ static int is_original_commit_empty(struct commit *commit)
 /*
  * Do we run "git commit" with "--allow-empty"?
  */
-static int allow_empty(struct replay_opts *opts, struct commit *commit)
+static int allow_empty(struct repository *r,
+                      struct replay_opts *opts,
+                      struct commit *commit)
 {
        int index_unchanged, empty_commit;
 
@@ -1475,7 +1494,7 @@ static int allow_empty(struct replay_opts *opts, struct commit *commit)
        if (!opts->allow_empty)
                return 0; /* let "git commit" barf as necessary */
 
-       index_unchanged = is_index_unchanged();
+       index_unchanged = is_index_unchanged(r);
        if (index_unchanged < 0)
                return index_unchanged;
        if (!index_unchanged)
@@ -1493,32 +1512,6 @@ static int allow_empty(struct replay_opts *opts, struct commit *commit)
                return 1;
 }
 
-/*
- * Note that ordering matters in this enum. Not only must it match the mapping
- * below, it is also divided into several sections that matter.  When adding
- * new commands, make sure you add it in the right section.
- */
-enum todo_command {
-       /* commands that handle commits */
-       TODO_PICK = 0,
-       TODO_REVERT,
-       TODO_EDIT,
-       TODO_REWORD,
-       TODO_FIXUP,
-       TODO_SQUASH,
-       /* commands that do something else than handling a single commit */
-       TODO_EXEC,
-       TODO_BREAK,
-       TODO_LABEL,
-       TODO_RESET,
-       TODO_MERGE,
-       /* commands that do nothing but are counted for reporting progress */
-       TODO_NOOP,
-       TODO_DROP,
-       /* comments (not counted for reporting progress) */
-       TODO_COMMENT
-};
-
 static struct {
        char c;
        const char *str;
@@ -1579,8 +1572,10 @@ static int is_pick_or_similar(enum todo_command command)
        }
 }
 
-static int update_squash_messages(enum todo_command command,
-               struct commit *commit, struct replay_opts *opts)
+static int update_squash_messages(struct repository *r,
+                                 enum todo_command command,
+                                 struct commit *commit,
+                                 struct replay_opts *opts)
 {
        struct strbuf buf = STRBUF_INIT;
        int res;
@@ -1609,7 +1604,7 @@ static int update_squash_messages(enum todo_command command,
 
                if (get_oid("HEAD", &head))
                        return error(_("need a HEAD to fixup"));
-               if (!(head_commit = lookup_commit_reference(the_repository, &head)))
+               if (!(head_commit = lookup_commit_reference(r, &head)))
                        return error(_("could not read HEAD"));
                if (!(head_message = get_commit_buffer(head_commit, NULL)))
                        return error(_("could not read HEAD's commit message"));
@@ -1670,7 +1665,8 @@ static int update_squash_messages(enum todo_command command,
        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;
@@ -1695,7 +1691,8 @@ 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)
@@ -1708,11 +1705,14 @@ static void record_in_rewritten(struct object_id *oid,
                flush_rewritten_pending();
 }
 
-static int do_pick_commit(enum todo_command command, struct commit *commit,
-               struct replay_opts *opts, int final_fixup)
+static int do_pick_commit(struct repository *r,
+                         enum todo_command command,
+                         struct commit *commit,
+                         struct replay_opts *opts,
+                         int final_fixup)
 {
        unsigned int flags = opts->edit ? EDIT_MSG : 0;
-       const char *msg_file = opts->edit ? NULL : git_path_merge_msg(the_repository);
+       const char *msg_file = opts->edit ? NULL : git_path_merge_msg(r);
        struct object_id head;
        struct commit *base, *next, *parent;
        const char *base_label, *next_label;
@@ -1728,7 +1728,7 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
                 * that represents the "current" state for merge-recursive
                 * to work on.
                 */
-               if (write_index_as_tree(&head, &the_index, get_index_file(), 0, NULL))
+               if (write_index_as_tree(&head, r->index, r->index_file, 0, NULL))
                        return error(_("your index file is unmerged."));
        } else {
                unborn = get_oid("HEAD", &head);
@@ -1741,11 +1741,11 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
                        unborn = 1;
                } else if (unborn)
                        oidcpy(&head, the_hash_algo->empty_tree);
-               if (index_differs_from(unborn ? empty_tree_oid_hex() : "HEAD",
+               if (index_differs_from(r, unborn ? empty_tree_oid_hex() : "HEAD",
                                       NULL, 0))
-                       return error_dirty_index(opts);
+                       return error_dirty_index(r, opts);
        }
-       discard_cache();
+       discard_index(r->index);
 
        if (!commit->parents)
                parent = NULL;
@@ -1766,9 +1766,13 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
                        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;
 
@@ -1781,7 +1785,7 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
             (!parent && unborn))) {
                if (is_rebase_i(opts))
                        write_author_script(msg.message);
-               res = fast_forward_to(&commit->object.oid, &head, unborn,
+               res = fast_forward_to(r, &commit->object.oid, &head, unborn,
                        opts);
                if (res || command != TODO_REWORD)
                        goto leave;
@@ -1845,7 +1849,7 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
        if (command == TODO_REWORD)
                flags |= EDIT_MSG | VERIFY_MSG;
        else if (is_fixup(command)) {
-               if (update_squash_messages(command, commit, opts))
+               if (update_squash_messages(r, command, commit, opts))
                        return -1;
                flags |= AMEND_MSG;
                if (!final_fixup)
@@ -1854,12 +1858,12 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
                        flags |= CLEANUP_MSG;
                        msg_file = rebase_path_fixup_msg();
                } else {
-                       const char *dest = git_path_squash_msg(the_repository);
+                       const char *dest = git_path_squash_msg(r);
                        unlink(dest);
                        if (copy_file(dest, rebase_path_squash_msg(), 0666))
                                return error(_("could not rename '%s' to '%s'"),
                                             rebase_path_squash_msg(), dest);
-                       unlink(git_path_merge_msg(the_repository));
+                       unlink(git_path_merge_msg(r));
                        msg_file = dest;
                        flags |= EDIT_MSG;
                }
@@ -1871,23 +1875,23 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
        if (is_rebase_i(opts) && write_author_script(msg.message) < 0)
                res = -1;
        else if (!opts->strategy || !strcmp(opts->strategy, "recursive") || command == TODO_REVERT) {
-               res = do_recursive_merge(base, next, base_label, next_label,
+               res = do_recursive_merge(r, base, next, base_label, next_label,
                                         &head, &msgbuf, opts);
                if (res < 0)
                        goto leave;
 
                res |= write_message(msgbuf.buf, msgbuf.len,
-                                    git_path_merge_msg(the_repository), 0);
+                                    git_path_merge_msg(r), 0);
        } else {
                struct commit_list *common = NULL;
                struct commit_list *remotes = NULL;
 
                res = write_message(msgbuf.buf, msgbuf.len,
-                                   git_path_merge_msg(the_repository), 0);
+                                   git_path_merge_msg(r), 0);
 
                commit_list_insert(base, &common);
                commit_list_insert(next, &remotes);
-               res |= try_merge_command(the_repository, opts->strategy,
+               res |= try_merge_command(r, opts->strategy,
                                         opts->xopts_nr, (const char **)opts->xopts,
                                        common, oid_to_hex(&head), remotes);
                free_commit_list(common);
@@ -1915,12 +1919,12 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
                      ? _("could not revert %s... %s")
                      : _("could not apply %s... %s"),
                      short_commit_name(commit), msg.subject);
-               print_advice(res == 1, opts);
-               repo_rerere(the_repository, opts->allow_rerere_auto);
+               print_advice(r, res == 1, opts);
+               repo_rerere(r, opts->allow_rerere_auto);
                goto leave;
        }
 
-       allow = allow_empty(opts, commit);
+       allow = allow_empty(r, opts, commit);
        if (allow < 0) {
                res = allow;
                goto leave;
@@ -1929,7 +1933,7 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
        if (!opts->no_commit) {
 fast_forward_edit:
                if (author || command == TODO_REVERT || (flags & AMEND_MSG))
-                       res = do_commit(msg_file, author, opts, flags);
+                       res = do_commit(r, msg_file, author, opts, flags);
                else
                        res = error(_("unable to parse commit author"));
        }
@@ -1965,18 +1969,19 @@ static int prepare_revs(struct replay_opts *opts)
        return 0;
 }
 
-static int read_and_refresh_cache(struct replay_opts *opts)
+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(&the_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)));
        }
-       refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
+       refresh_index(r->index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
        if (index_fd >= 0) {
-               if (write_locked_index(&the_index, &index_lock,
+               if (write_locked_index(r->index, &index_lock,
                                       COMMIT_LOCK | SKIP_IF_UNCHANGED)) {
                        return error(_("git %s: failed to refresh the index"),
                                _(action_name(opts)));
@@ -1989,26 +1994,7 @@ enum todo_item_flags {
        TODO_EDIT_MERGE_MSG = 1
 };
 
-struct todo_item {
-       enum todo_command command;
-       struct commit *commit;
-       unsigned int flags;
-       const char *arg;
-       int arg_len;
-       size_t offset_in_buf;
-};
-
-struct todo_list {
-       struct strbuf buf;
-       struct todo_item *items;
-       int nr, alloc, current;
-       int done_nr, total_nr;
-       struct stat_data stat;
-};
-
-#define TODO_LIST_INIT { STRBUF_INIT }
-
-static void todo_list_release(struct todo_list *todo_list)
+void todo_list_release(struct todo_list *todo_list)
 {
        strbuf_release(&todo_list->buf);
        FREE_AND_NULL(todo_list->items);
@@ -2021,7 +2007,14 @@ static struct todo_item *append_new_todo(struct todo_list *todo_list)
        return todo_list->items + todo_list->nr++;
 }
 
-static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
+const char *todo_item_get_arg(struct todo_list *todo_list,
+                             struct todo_item *item)
+{
+       return todo_list->buf.buf + item->arg_offset;
+}
+
+static int parse_insn_line(struct repository *r, struct todo_item *item,
+                          const char *buf, const char *bol, char *eol)
 {
        struct object_id commit_oid;
        char *end_of_object_name;
@@ -2035,7 +2028,7 @@ static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
        if (bol == eol || *bol == '\r' || *bol == comment_line_char) {
                item->command = TODO_COMMENT;
                item->commit = NULL;
-               item->arg = bol;
+               item->arg_offset = bol - buf;
                item->arg_len = eol - bol;
                return 0;
        }
@@ -2062,7 +2055,7 @@ static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
                        return error(_("%s does not accept arguments: '%s'"),
                                     command_to_string(item->command), bol);
                item->commit = NULL;
-               item->arg = bol;
+               item->arg_offset = bol - buf;
                item->arg_len = eol - bol;
                return 0;
        }
@@ -2074,7 +2067,7 @@ static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
        if (item->command == TODO_EXEC || item->command == TODO_LABEL ||
            item->command == TODO_RESET) {
                item->commit = NULL;
-               item->arg = bol;
+               item->arg_offset = bol - buf;
                item->arg_len = (int)(eol - bol);
                return 0;
        }
@@ -2088,7 +2081,7 @@ static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
                } else {
                        item->flags |= TODO_EDIT_MERGE_MSG;
                        item->commit = NULL;
-                       item->arg = bol;
+                       item->arg_offset = bol - buf;
                        item->arg_len = (int)(eol - bol);
                        return 0;
                }
@@ -2100,22 +2093,27 @@ static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
        status = get_oid(bol, &commit_oid);
        *end_of_object_name = saved;
 
-       item->arg = end_of_object_name + strspn(end_of_object_name, " \t");
-       item->arg_len = (int)(eol - item->arg);
+       bol = end_of_object_name + strspn(end_of_object_name, " \t");
+       item->arg_offset = bol - buf;
+       item->arg_len = (int)(eol - bol);
 
        if (status < 0)
-               return -1;
+               return error(_("could not parse '%.*s'"),
+                            (int)(end_of_object_name - bol), bol);
 
-       item->commit = lookup_commit_reference(the_repository, &commit_oid);
+       item->commit = lookup_commit_reference(r, &commit_oid);
        return !item->commit;
 }
 
-static int parse_insn_buffer(char *buf, struct todo_list *todo_list)
+int todo_list_parse_insn_buffer(struct repository *r, char *buf,
+                               struct todo_list *todo_list)
 {
        struct todo_item *item;
        char *p = buf, *next_p;
        int i, res = 0, fixup_okay = file_exists(rebase_path_done());
 
+       todo_list->current = todo_list->nr = 0;
+
        for (i = 1; *p; i++, p = next_p) {
                char *eol = strchrnul(p, '\n');
 
@@ -2126,10 +2124,13 @@ static int parse_insn_buffer(char *buf, struct todo_list *todo_list)
 
                item = append_new_todo(todo_list);
                item->offset_in_buf = p - todo_list->buf.buf;
-               if (parse_insn_line(item, p, eol)) {
+               if (parse_insn_line(r, item, buf, p, eol)) {
                        res = error(_("invalid line %d: %.*s"),
                                i, (int)(eol - p), p);
-                       item->command = TODO_NOOP;
+                       item->command = TODO_COMMENT + 1;
+                       item->arg_offset = p - buf;
+                       item->arg_len = (int)(eol - p);
+                       item->commit = NULL;
                }
 
                if (fixup_okay)
@@ -2187,8 +2188,9 @@ static ssize_t strbuf_read_file_or_whine(struct strbuf *sb, const char *path)
        return len;
 }
 
-static int read_populate_todo(struct todo_list *todo_list,
-                       struct replay_opts *opts)
+static int read_populate_todo(struct repository *r,
+                             struct todo_list *todo_list,
+                             struct replay_opts *opts)
 {
        struct stat st;
        const char *todo_file = get_todo_path(opts);
@@ -2203,7 +2205,7 @@ static int read_populate_todo(struct todo_list *todo_list,
                return error(_("could not stat '%s'"), todo_file);
        fill_stat_data(&todo_list->stat, &st);
 
-       res = parse_insn_buffer(todo_list->buf.buf, todo_list);
+       res = todo_list_parse_insn_buffer(r, todo_list->buf.buf, todo_list);
        if (res) {
                if (is_rebase_i(opts))
                        return error(_("please fix this using "
@@ -2234,7 +2236,7 @@ static int read_populate_todo(struct todo_list *todo_list,
                FILE *f = fopen_or_warn(rebase_path_msgtotal(), "w");
 
                if (strbuf_read_file(&done.buf, rebase_path_done(), 0) > 0 &&
-                               !parse_insn_buffer(done.buf.buf, &done))
+                   !todo_list_parse_insn_buffer(r, done.buf.buf, &done))
                        todo_list->done_nr = count_commands(&done);
                else
                        todo_list->done_nr = 0;
@@ -2273,6 +2275,15 @@ static int populate_opts_cb(const char *key, const char *value, void *data)
                opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
        else if (!strcmp(key, "options.edit"))
                opts->edit = git_config_bool_or_int(key, value, &error_flag);
+       else if (!strcmp(key, "options.allow-empty"))
+               opts->allow_empty =
+                       git_config_bool_or_int(key, value, &error_flag);
+       else if (!strcmp(key, "options.allow-empty-message"))
+               opts->allow_empty_message =
+                       git_config_bool_or_int(key, value, &error_flag);
+       else if (!strcmp(key, "options.keep-redundant-commits"))
+               opts->keep_redundant_commits =
+                       git_config_bool_or_int(key, value, &error_flag);
        else if (!strcmp(key, "options.signoff"))
                opts->signoff = git_config_bool_or_int(key, value, &error_flag);
        else if (!strcmp(key, "options.record-origin"))
@@ -2357,11 +2368,17 @@ 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);
 
@@ -2424,9 +2441,6 @@ int write_basic_state(struct replay_opts *opts, const char *head_name,
 
        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)
@@ -2443,6 +2457,8 @@ 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;
 }
@@ -2466,7 +2482,7 @@ static int walk_revs_populate_todo(struct todo_list *todo_list,
 
                item->command = command;
                item->commit = commit;
-               item->arg = NULL;
+               item->arg_offset = 0;
                item->arg_len = 0;
                item->offset_in_buf = todo_list->buf.len;
                subject_len = find_commit_subject(commit_buffer, &subject);
@@ -2551,12 +2567,12 @@ static int reset_for_rollback(const struct object_id *oid)
        return run_command_v_opt(argv, RUN_GIT_CMD);
 }
 
-static int rollback_single_pick(void)
+static int rollback_single_pick(struct repository *r)
 {
        struct object_id head_oid;
 
-       if (!file_exists(git_path_cherry_pick_head(the_repository)) &&
-           !file_exists(git_path_revert_head(the_repository)))
+       if (!file_exists(git_path_cherry_pick_head(r)) &&
+           !file_exists(git_path_revert_head(r)))
                return error(_("no cherry-pick or revert in progress"));
        if (read_ref_full("HEAD", 0, &head_oid, NULL))
                return error(_("cannot resolve HEAD"));
@@ -2565,7 +2581,7 @@ static int rollback_single_pick(void)
        return reset_for_rollback(&head_oid);
 }
 
-int sequencer_rollback(struct replay_opts *opts)
+int sequencer_rollback(struct repository *r, struct replay_opts *opts)
 {
        FILE *f;
        struct object_id oid;
@@ -2579,7 +2595,7 @@ int sequencer_rollback(struct replay_opts *opts)
                 * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
                 * a single-cherry-pick in progress, abort that.
                 */
-               return rollback_single_pick();
+               return rollback_single_pick(r);
        }
        if (!f)
                return error_errno(_("cannot open '%s'"), git_path_head_file());
@@ -2661,40 +2677,60 @@ static int save_opts(struct replay_opts *opts)
        int res = 0;
 
        if (opts->no_commit)
-               res |= git_config_set_in_file_gently(opts_file, "options.no-commit", "true");
+               res |= git_config_set_in_file_gently(opts_file,
+                                       "options.no-commit", "true");
        if (opts->edit)
-               res |= git_config_set_in_file_gently(opts_file, "options.edit", "true");
+               res |= git_config_set_in_file_gently(opts_file,
+                                       "options.edit", "true");
+       if (opts->allow_empty)
+               res |= git_config_set_in_file_gently(opts_file,
+                                       "options.allow-empty", "true");
+       if (opts->allow_empty_message)
+               res |= git_config_set_in_file_gently(opts_file,
+                               "options.allow-empty-message", "true");
+       if (opts->keep_redundant_commits)
+               res |= git_config_set_in_file_gently(opts_file,
+                               "options.keep-redundant-commits", "true");
        if (opts->signoff)
-               res |= git_config_set_in_file_gently(opts_file, "options.signoff", "true");
+               res |= git_config_set_in_file_gently(opts_file,
+                                       "options.signoff", "true");
        if (opts->record_origin)
-               res |= git_config_set_in_file_gently(opts_file, "options.record-origin", "true");
+               res |= git_config_set_in_file_gently(opts_file,
+                                       "options.record-origin", "true");
        if (opts->allow_ff)
-               res |= git_config_set_in_file_gently(opts_file, "options.allow-ff", "true");
+               res |= git_config_set_in_file_gently(opts_file,
+                                       "options.allow-ff", "true");
        if (opts->mainline) {
                struct strbuf buf = STRBUF_INIT;
                strbuf_addf(&buf, "%d", opts->mainline);
-               res |= git_config_set_in_file_gently(opts_file, "options.mainline", buf.buf);
+               res |= git_config_set_in_file_gently(opts_file,
+                                       "options.mainline", buf.buf);
                strbuf_release(&buf);
        }
        if (opts->strategy)
-               res |= git_config_set_in_file_gently(opts_file, "options.strategy", opts->strategy);
+               res |= git_config_set_in_file_gently(opts_file,
+                                       "options.strategy", opts->strategy);
        if (opts->gpg_sign)
-               res |= git_config_set_in_file_gently(opts_file, "options.gpg-sign", opts->gpg_sign);
+               res |= git_config_set_in_file_gently(opts_file,
+                                       "options.gpg-sign", opts->gpg_sign);
        if (opts->xopts) {
                int i;
                for (i = 0; i < opts->xopts_nr; i++)
                        res |= git_config_set_multivar_in_file_gently(opts_file,
-                                                       "options.strategy-option",
-                                                       opts->xopts[i], "^$", 0);
+                                       "options.strategy-option",
+                                       opts->xopts[i], "^$", 0);
        }
        if (opts->allow_rerere_auto)
-               res |= git_config_set_in_file_gently(opts_file, "options.allow-rerere-auto",
-                                                    opts->allow_rerere_auto == RERERE_AUTOUPDATE ?
-                                                    "true" : "false");
+               res |= git_config_set_in_file_gently(opts_file,
+                               "options.allow-rerere-auto",
+                               opts->allow_rerere_auto == RERERE_AUTOUPDATE ?
+                               "true" : "false");
        return res;
 }
 
-static int make_patch(struct commit *commit, struct replay_opts *opts)
+static int make_patch(struct repository *r,
+                     struct commit *commit,
+                     struct replay_opts *opts)
 {
        struct strbuf buf = STRBUF_INIT;
        struct rev_info log_tree_opt;
@@ -2710,7 +2746,7 @@ static int make_patch(struct commit *commit, struct replay_opts *opts)
 
        strbuf_addf(&buf, "%s/patch", get_dir(opts));
        memset(&log_tree_opt, 0, sizeof(log_tree_opt));
-       repo_init_revisions(the_repository, &log_tree_opt, NULL);
+       repo_init_revisions(r, &log_tree_opt, NULL);
        log_tree_opt.abbrev = 0;
        log_tree_opt.diff = 1;
        log_tree_opt.diffopt.output_format = DIFF_FORMAT_PATCH;
@@ -2750,17 +2786,19 @@ static int intend_to_amend(void)
        return write_message(p, strlen(p), rebase_path_amend(), 1);
 }
 
-static int error_with_patch(struct commit *commit,
-       const char *subject, int subject_len,
-       struct replay_opts *opts, int exit_code, int to_amend)
+static int error_with_patch(struct repository *r,
+                           struct commit *commit,
+                           const char *subject, int subject_len,
+                           struct replay_opts *opts,
+                           int exit_code, int to_amend)
 {
        if (commit) {
-               if (make_patch(commit, opts))
+               if (make_patch(r, commit, opts))
                        return -1;
        } else if (copy_file(rebase_path_message(),
-                            git_path_merge_msg(the_repository), 0666))
+                            git_path_merge_msg(r), 0666))
                return error(_("unable to copy '%s' to '%s'"),
-                            git_path_merge_msg(the_repository), rebase_path_message());
+                            git_path_merge_msg(r), rebase_path_message());
 
        if (to_amend) {
                if (intend_to_amend())
@@ -2791,21 +2829,24 @@ static int error_with_patch(struct commit *commit,
        return exit_code;
 }
 
-static int error_failed_squash(struct commit *commit,
-       struct replay_opts *opts, int subject_len, const char *subject)
+static int error_failed_squash(struct repository *r,
+                              struct commit *commit,
+                              struct replay_opts *opts,
+                              int subject_len,
+                              const char *subject)
 {
        if (copy_file(rebase_path_message(), rebase_path_squash_msg(), 0666))
                return error(_("could not copy '%s' to '%s'"),
                        rebase_path_squash_msg(), rebase_path_message());
-       unlink(git_path_merge_msg(the_repository));
-       if (copy_file(git_path_merge_msg(the_repository), rebase_path_message(), 0666))
+       unlink(git_path_merge_msg(r));
+       if (copy_file(git_path_merge_msg(r), rebase_path_message(), 0666))
                return error(_("could not copy '%s' to '%s'"),
                             rebase_path_message(),
-                            git_path_merge_msg(the_repository));
-       return error_with_patch(commit, subject, subject_len, opts, 1, 0);
+                            git_path_merge_msg(r));
+       return error_with_patch(r, commit, subject, subject_len, opts, 1, 0);
 }
 
-static int do_exec(const char *command_line)
+static int do_exec(struct repository *r, const char *command_line)
 {
        struct argv_array child_env = ARGV_ARRAY_INIT;
        const char *child_argv[] = { NULL, NULL };
@@ -2820,10 +2861,10 @@ static int do_exec(const char *command_line)
                                          child_env.argv);
 
        /* force re-reading of the cache */
-       if (discard_cache() < 0 || read_cache() < 0)
+       if (discard_index(r->index) < 0 || repo_read_index(r) < 0)
                return error(_("could not read index"));
 
-       dirty = require_clean_work_tree("rebase", NULL, 1, 1);
+       dirty = require_clean_work_tree(r, "rebase", NULL, 1, 1);
 
        if (status) {
                warning(_("execution failed: %s\n%s"
@@ -2889,9 +2930,9 @@ static int safe_append(const char *filename, const char *fmt, ...)
        return 0;
 }
 
-static int do_label(const char *name, int len)
+static int do_label(struct repository *r, const char *name, int len)
 {
-       struct ref_store *refs = get_main_ref_store(the_repository);
+       struct ref_store *refs = get_main_ref_store(r);
        struct ref_transaction *transaction;
        struct strbuf ref_name = STRBUF_INIT, err = STRBUF_INIT;
        struct strbuf msg = STRBUF_INIT;
@@ -2932,7 +2973,9 @@ static int do_label(const char *name, int len)
 static const char *reflog_message(struct replay_opts *opts,
        const char *sub_action, const char *fmt, ...);
 
-static int do_reset(const char *name, int len, struct replay_opts *opts)
+static int do_reset(struct repository *r,
+                   const char *name, int len,
+                   struct replay_opts *opts)
 {
        struct strbuf ref_name = STRBUF_INIT;
        struct object_id oid;
@@ -2942,7 +2985,7 @@ static int do_reset(const char *name, int len, struct replay_opts *opts)
        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)) {
@@ -2981,13 +3024,13 @@ static int do_reset(const char *name, int len, struct replay_opts *opts)
        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
        setup_unpack_trees_porcelain(&unpack_tree_opts, "reset");
        unpack_tree_opts.head_idx = 1;
-       unpack_tree_opts.src_index = &the_index;
-       unpack_tree_opts.dst_index = &the_index;
+       unpack_tree_opts.src_index = r->index;
+       unpack_tree_opts.dst_index = r->index;
        unpack_tree_opts.fn = oneway_merge;
        unpack_tree_opts.merge = 1;
        unpack_tree_opts.update = 1;
 
-       if (read_cache_unmerged()) {
+       if (repo_read_index_unmerged(r)) {
                rollback_lock_file(&lock);
                strbuf_release(&ref_name);
                return error_resolve_conflict(_(action_name(opts)));
@@ -3009,9 +3052,9 @@ static int do_reset(const char *name, int len, struct replay_opts *opts)
        }
 
        tree = parse_tree_indirect(&oid);
-       prime_cache_tree(&the_index, tree);
+       prime_cache_tree(r, r->index, tree);
 
-       if (write_locked_index(&the_index, &lock, COMMIT_LOCK) < 0)
+       if (write_locked_index(r->index, &lock, COMMIT_LOCK) < 0)
                ret = error(_("could not write index"));
        free((void *)desc.buffer);
 
@@ -3044,7 +3087,9 @@ static struct commit *lookup_label(const char *label, int len,
        return commit;
 }
 
-static int do_merge(struct commit *commit, const char *arg, int arg_len,
+static int do_merge(struct repository *r,
+                   struct commit *commit,
+                   const char *arg, int arg_len,
                    int flags, struct replay_opts *opts)
 {
        int run_commit_flags = (flags & TODO_EDIT_MERGE_MSG) ?
@@ -3058,7 +3103,7 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
        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;
        }
@@ -3111,7 +3156,7 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
                        ret = error(_("octopus merge cannot be executed on "
                                      "top of a [new root]"));
                else
-                       ret = fast_forward_to(&to_merge->item->object.oid,
+                       ret = fast_forward_to(r, &to_merge->item->object.oid,
                                              &head_commit->object.oid, 0,
                                              opts);
                goto leave_merge;
@@ -3130,11 +3175,11 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
                write_author_script(message);
                find_commit_subject(message, &body);
                len = strlen(body);
-               ret = write_message(body, len, git_path_merge_msg(the_repository), 0);
+               ret = write_message(body, len, git_path_merge_msg(r), 0);
                unuse_commit_buffer(commit, message);
                if (ret) {
                        error_errno(_("could not write '%s'"),
-                                   git_path_merge_msg(the_repository));
+                                   git_path_merge_msg(r));
                        goto leave_merge;
                }
        } else {
@@ -3156,11 +3201,11 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
                        len = buf.len;
                }
 
-               ret = write_message(p, len, git_path_merge_msg(the_repository), 0);
+               ret = write_message(p, len, git_path_merge_msg(r), 0);
                strbuf_release(&buf);
                if (ret) {
                        error_errno(_("could not write '%s'"),
-                                   git_path_merge_msg(the_repository));
+                                   git_path_merge_msg(r));
                        goto leave_merge;
                }
        }
@@ -3196,7 +3241,7 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
 
        if (can_fast_forward) {
                rollback_lock_file(&lock);
-               ret = fast_forward_to(&commit->object.oid,
+               ret = fast_forward_to(r, &commit->object.oid,
                                      &head_commit->object.oid, 0, opts);
                goto leave_merge;
        }
@@ -3221,7 +3266,7 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
                argv_array_push(&cmd.args, "--no-log");
                argv_array_push(&cmd.args, "--no-stat");
                argv_array_push(&cmd.args, "-F");
-               argv_array_push(&cmd.args, git_path_merge_msg(the_repository));
+               argv_array_push(&cmd.args, git_path_merge_msg(r));
                if (opts->gpg_sign)
                        argv_array_push(&cmd.args, opts->gpg_sign);
 
@@ -3231,14 +3276,15 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
                                        oid_to_hex(&j->item->object.oid));
 
                strbuf_release(&ref_name);
-               unlink(git_path_cherry_pick_head(the_repository));
+               unlink(git_path_cherry_pick_head(r));
                rollback_lock_file(&lock);
 
                rollback_lock_file(&lock);
                ret = run_command(&cmd);
 
                /* force re-reading of the cache */
-               if (!ret && (discard_cache() < 0 || read_cache() < 0))
+               if (!ret && (discard_index(r->index) < 0 ||
+                            repo_read_index(r) < 0))
                        ret = error(_("could not read index"));
                goto leave_merge;
        }
@@ -3253,15 +3299,15 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
        }
 
        write_message(oid_to_hex(&merge_commit->object.oid), GIT_SHA1_HEXSZ,
-                     git_path_merge_head(the_repository), 0);
-       write_message("no-ff", 5, git_path_merge_mode(the_repository), 0);
+                     git_path_merge_head(r), 0);
+       write_message("no-ff", 5, git_path_merge_mode(r), 0);
 
        for (j = bases; j; j = j->next)
                commit_list_insert(j->item, &reversed);
        free_commit_list(bases);
 
-       read_cache();
-       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;
@@ -3285,23 +3331,23 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
         */
        ret = !ret;
 
-       if (active_cache_changed &&
-           write_locked_index(&the_index, &lock, COMMIT_LOCK)) {
+       if (r->index->cache_changed &&
+           write_locked_index(r->index, &lock, COMMIT_LOCK)) {
                ret = error(_("merge: Unable to write new index file"));
                goto leave_merge;
        }
 
        rollback_lock_file(&lock);
        if (ret)
-               repo_rerere(the_repository, opts->allow_rerere_auto);
+               repo_rerere(r, opts->allow_rerere_auto);
        else
                /*
                 * In case of problems, we now want to return a positive
                 * value (a negative one would indicate that the `merge`
                 * command needs to be rescheduled).
                 */
-               ret = !!run_git_commit(git_path_merge_msg(the_repository), opts,
-                                    run_commit_flags);
+               ret = !!run_git_commit(r, git_path_merge_msg(r), opts,
+                                      run_commit_flags);
 
 leave_merge:
        strbuf_release(&ref_name);
@@ -3449,14 +3495,14 @@ static int checkout_onto(struct replay_opts *opts,
        return update_ref(NULL, "ORIG_HEAD", &oid, NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 }
 
-static int stopped_at_head(void)
+static int stopped_at_head(struct repository *r)
 {
        struct object_id head;
        struct commit *commit;
        struct commit_message message;
 
        if (get_oid("HEAD", &head) ||
-           !(commit = lookup_commit(the_repository, &head)) ||
+           !(commit = lookup_commit(r, &head)) ||
            parse_commit(commit) || get_message(commit, &message))
                fprintf(stderr, _("Stopped at HEAD\n"));
        else {
@@ -3478,7 +3524,9 @@ N_("Could not execute the todo command\n"
 "    git rebase --edit-todo\n"
 "    git rebase --continue\n");
 
-static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
+static int pick_commits(struct repository *r,
+                       struct todo_list *todo_list,
+                       struct replay_opts *opts)
 {
        int res = 0, reschedule = 0;
 
@@ -3486,11 +3534,13 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
        if (opts->allow_ff)
                assert(!(opts->signoff || opts->no_commit ||
                                opts->record_origin || opts->edit));
-       if (read_and_refresh_cache(opts))
+       if (read_and_refresh_cache(r, opts))
                return -1;
 
        while (todo_list->current < todo_list->nr) {
                struct todo_item *item = todo_list->items + todo_list->current;
+               const char *arg = todo_item_get_arg(todo_list, item);
+
                if (save_todo(todo_list, opts))
                        return -1;
                if (is_rebase_i(opts)) {
@@ -3503,10 +3553,11 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                                        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());
@@ -3516,14 +3567,14 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 
                        if (item->command == TODO_BREAK)
-                               return stopped_at_head();
+                               return stopped_at_head(r);
                }
                if (item->command <= TODO_SQUASH) {
                        if (is_rebase_i(opts))
                                setenv("GIT_REFLOG_ACTION", reflog_message(opts,
                                        command_to_string(item->command), NULL),
                                        1);
-                       res = do_pick_commit(item->command, item->commit,
+                       res = do_pick_commit(r, item->command, item->commit,
                                        opts, is_final_fixup(todo_list));
                        if (is_rebase_i(opts) && res < 0) {
                                /* Reschedule */
@@ -3542,10 +3593,9 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                                        fprintf(stderr,
                                                _("Stopped at %s...  %.*s\n"),
                                                short_commit_name(commit),
-                                               item->arg_len, item->arg);
-                               return error_with_patch(commit,
-                                       item->arg, item->arg_len, opts, res,
-                                       !res);
+                                               item->arg_len, arg);
+                               return error_with_patch(r, commit,
+                                       arg, item->arg_len, opts, res, !res);
                        }
                        if (is_rebase_i(opts) && !res)
                                record_in_rewritten(&item->commit->object.oid,
@@ -3553,8 +3603,8 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                        if (res && is_fixup(item->command)) {
                                if (res == 1)
                                        intend_to_amend();
-                               return error_failed_squash(item->commit, opts,
-                                       item->arg_len, item->arg);
+                               return error_failed_squash(r, item->commit, opts,
+                                       item->arg_len, arg);
                        } else if (res && is_rebase_i(opts) && item->commit) {
                                int to_amend = 0;
                                struct object_id oid;
@@ -3572,41 +3622,42 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                                      oideq(&opts->squash_onto, &oid))))
                                        to_amend = 1;
 
-                               return res | error_with_patch(item->commit,
-                                               item->arg, item->arg_len, opts,
+                               return res | error_with_patch(r, item->commit,
+                                               arg, item->arg_len, opts,
                                                res, to_amend);
                        }
                } else if (item->command == TODO_EXEC) {
-                       char *end_of_arg = (char *)(item->arg + item->arg_len);
+                       char *end_of_arg = (char *)(arg + item->arg_len);
                        int saved = *end_of_arg;
                        struct stat st;
 
                        *end_of_arg = '\0';
-                       res = do_exec(item->arg);
+                       res = do_exec(r, arg);
                        *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)) {
+                               /* Reread the todo file if it has changed. */
                                todo_list_release(todo_list);
-                               if (read_populate_todo(todo_list, opts))
+                               if (read_populate_todo(r, todo_list, opts))
                                        res = -1; /* message was printed */
                                /* `current` will be incremented below */
                                todo_list->current = -1;
                        }
                } else if (item->command == TODO_LABEL) {
-                       if ((res = do_label(item->arg, item->arg_len)))
+                       if ((res = do_label(r, arg, item->arg_len)))
                                reschedule = 1;
                } else if (item->command == TODO_RESET) {
-                       if ((res = do_reset(item->arg, item->arg_len, opts)))
+                       if ((res = do_reset(r, arg, item->arg_len, opts)))
                                reschedule = 1;
                } else if (item->command == TODO_MERGE) {
-                       if ((res = do_merge(item->commit,
-                                           item->arg, item->arg_len,
+                       if ((res = do_merge(r, item->commit,
+                                           arg, item->arg_len,
                                            item->flags, opts)) < 0)
                                reschedule = 1;
                        else if (item->commit)
@@ -3614,10 +3665,9 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                                                    peek_command(todo_list, 1));
                        if (res > 0)
                                /* failed with merge conflicts */
-                               return error_with_patch(item->commit,
-                                                       item->arg,
-                                                       item->arg_len, opts,
-                                                       res, 0);
+                               return error_with_patch(r, item->commit,
+                                                       arg, item->arg_len,
+                                                       opts, res, 0);
                } else if (!is_noop(item->command))
                        return error(_("unknown command %d"), item->command);
 
@@ -3630,10 +3680,10 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                        if (save_todo(todo_list, opts))
                                return -1;
                        if (item->commit)
-                               return error_with_patch(item->commit,
-                                                       item->arg,
-                                                       item->arg_len, opts,
-                                                       res, 0);
+                               return error_with_patch(r,
+                                                       item->commit,
+                                                       arg, item->arg_len,
+                                                       opts, res, 0);
                }
 
                todo_list->current++;
@@ -3695,7 +3745,7 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                        struct object_id orig, head;
 
                        memset(&log_tree_opt, 0, sizeof(log_tree_opt));
-                       repo_init_revisions(the_repository, &log_tree_opt, NULL);
+                       repo_init_revisions(r, &log_tree_opt, NULL);
                        log_tree_opt.diff = 1;
                        log_tree_opt.diffopt.output_format =
                                DIFF_FORMAT_DIFFSTAT;
@@ -3730,6 +3780,7 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                                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 */
@@ -3738,8 +3789,10 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                }
                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);
@@ -3752,26 +3805,27 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
        return sequencer_remove_state(opts);
 }
 
-static int continue_single_pick(void)
+static int continue_single_pick(struct repository *r)
 {
        const char *argv[] = { "commit", NULL };
 
-       if (!file_exists(git_path_cherry_pick_head(the_repository)) &&
-           !file_exists(git_path_revert_head(the_repository)))
+       if (!file_exists(git_path_cherry_pick_head(r)) &&
+           !file_exists(git_path_revert_head(r)))
                return error(_("no cherry-pick or revert in progress"));
        return run_command_v_opt(argv, RUN_GIT_CMD);
 }
 
-static int commit_staged_changes(struct replay_opts *opts,
+static int commit_staged_changes(struct repository *r,
+                                struct replay_opts *opts,
                                 struct todo_list *todo_list)
 {
        unsigned int flags = ALLOW_EMPTY | EDIT_MSG;
        unsigned int final_fixup = 0, is_clean;
 
-       if (has_unstaged_changes(1))
+       if (has_unstaged_changes(r, 1))
                return error(_("cannot rebase: You have unstaged changes."));
 
-       is_clean = !has_uncommitted_changes(0);
+       is_clean = !has_uncommitted_changes(r, 0);
 
        if (file_exists(rebase_path_amend())) {
                struct strbuf rev = STRBUF_INIT;
@@ -3855,7 +3909,7 @@ static int commit_staged_changes(struct replay_opts *opts,
                                struct commit *commit;
                                const char *path = rebase_path_squash_msg();
 
-                               if (parse_head(&commit) ||
+                               if (parse_head(r, &commit) ||
                                    !(p = get_commit_buffer(commit, NULL)) ||
                                    write_message(p, strlen(p), path, 0)) {
                                        unuse_commit_buffer(commit, p);
@@ -3871,7 +3925,7 @@ static int commit_staged_changes(struct replay_opts *opts,
        }
 
        if (is_clean) {
-               const char *cherry_pick_head = git_path_cherry_pick_head(the_repository);
+               const char *cherry_pick_head = git_path_cherry_pick_head(r);
 
                if (file_exists(cherry_pick_head) && unlink(cherry_pick_head))
                        return error(_("could not remove CHERRY_PICK_HEAD"));
@@ -3879,7 +3933,7 @@ static int commit_staged_changes(struct replay_opts *opts,
                        return 0;
        }
 
-       if (run_git_commit(final_fixup ? NULL : rebase_path_message(),
+       if (run_git_commit(r, final_fixup ? NULL : rebase_path_message(),
                           opts, flags))
                return error(_("could not commit staged changes."));
        unlink(rebase_path_amend());
@@ -3900,36 +3954,36 @@ static int commit_staged_changes(struct replay_opts *opts,
        return 0;
 }
 
-int sequencer_continue(struct replay_opts *opts)
+int sequencer_continue(struct repository *r, struct replay_opts *opts)
 {
        struct todo_list todo_list = TODO_LIST_INIT;
        int res;
 
-       if (read_and_refresh_cache(opts))
+       if (read_and_refresh_cache(r, opts))
                return -1;
 
        if (read_populate_opts(opts))
                return -1;
        if (is_rebase_i(opts)) {
-               if ((res = read_populate_todo(&todo_list, opts)))
+               if ((res = read_populate_todo(r, &todo_list, opts)))
                        goto release_todo_list;
-               if (commit_staged_changes(opts, &todo_list))
+               if (commit_staged_changes(r, opts, &todo_list))
                        return -1;
        } else if (!file_exists(get_todo_path(opts)))
-               return continue_single_pick();
-       else if ((res = read_populate_todo(&todo_list, opts)))
+               return continue_single_pick(r);
+       else if ((res = read_populate_todo(r, &todo_list, opts)))
                goto release_todo_list;
 
        if (!is_rebase_i(opts)) {
                /* Verify that the conflict has been resolved */
-               if (file_exists(git_path_cherry_pick_head(the_repository)) ||
-                   file_exists(git_path_revert_head(the_repository))) {
-                       res = continue_single_pick();
+               if (file_exists(git_path_cherry_pick_head(r)) ||
+                   file_exists(git_path_revert_head(r))) {
+                       res = continue_single_pick(r);
                        if (res)
                                goto release_todo_list;
                }
-               if (index_differs_from("HEAD", NULL, 0)) {
-                       res = error_dirty_index(opts);
+               if (index_differs_from(r, "HEAD", NULL, 0)) {
+                       res = error_dirty_index(r, opts);
                        goto release_todo_list;
                }
                todo_list.current++;
@@ -3943,27 +3997,30 @@ int sequencer_continue(struct replay_opts *opts)
                strbuf_release(&buf);
        }
 
-       res = pick_commits(&todo_list, opts);
+       res = pick_commits(r, &todo_list, opts);
 release_todo_list:
        todo_list_release(&todo_list);
        return res;
 }
 
-static int single_pick(struct commit *cmit, struct replay_opts *opts)
+static int single_pick(struct repository *r,
+                      struct commit *cmit,
+                      struct replay_opts *opts)
 {
        setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
-       return do_pick_commit(opts->action == REPLAY_PICK ?
+       return do_pick_commit(r, opts->action == REPLAY_PICK ?
                TODO_PICK : TODO_REVERT, cmit, opts, 0);
 }
 
-int sequencer_pick_revisions(struct replay_opts *opts)
+int sequencer_pick_revisions(struct repository *r,
+                            struct replay_opts *opts)
 {
        struct todo_list todo_list = TODO_LIST_INIT;
        struct object_id oid;
        int i, res;
 
        assert(opts->revs);
-       if (read_and_refresh_cache(opts))
+       if (read_and_refresh_cache(r, opts))
                return -1;
 
        for (i = 0; i < opts->revs->pending.nr; i++) {
@@ -3975,8 +4032,8 @@ int sequencer_pick_revisions(struct replay_opts *opts)
                        continue;
 
                if (!get_oid(name, &oid)) {
-                       if (!lookup_commit_reference_gently(the_repository, &oid, 1)) {
-                               enum object_type type = oid_object_info(the_repository,
+                       if (!lookup_commit_reference_gently(r, &oid, 1)) {
+                               enum object_type type = oid_object_info(r,
                                                                        &oid,
                                                                        NULL);
                                return error(_("%s: can't cherry-pick a %s"),
@@ -4005,7 +4062,7 @@ int sequencer_pick_revisions(struct replay_opts *opts)
                        return error(_("empty commit set passed"));
                if (get_revision(opts->revs))
                        BUG("unexpected extra commit from walk");
-               return single_pick(cmit, opts);
+               return single_pick(r, cmit, opts);
        }
 
        /*
@@ -4024,7 +4081,7 @@ int sequencer_pick_revisions(struct replay_opts *opts)
        if (save_opts(opts))
                return -1;
        update_abort_safety_file();
-       res = pick_commits(&todo_list, opts);
+       res = pick_commits(r, &todo_list, opts);
        todo_list_release(&todo_list);
        return res;
 }
@@ -4036,8 +4093,7 @@ 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)
@@ -4204,7 +4260,7 @@ 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;
@@ -4349,7 +4405,7 @@ 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;
 
@@ -4359,9 +4415,9 @@ 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)) {
@@ -4374,8 +4430,8 @@ 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;
 
@@ -4388,12 +4444,12 @@ 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);
                        }
                }
 
@@ -4402,11 +4458,11 @@ 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);
                }
 
@@ -4428,19 +4484,18 @@ static int make_script_with_merges(struct pretty_print_context *pp,
        return 0;
 }
 
-int sequencer_make_script(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;
        const char *insn = flags & TODO_LIST_ABBREVIATE_CMDS ? "p" : "pick";
        int rebase_merges = flags & TODO_LIST_REBASE_MERGES;
 
-       repo_init_revisions(the_repository, &revs, NULL);
+       repo_init_revisions(r, &revs, NULL);
        revs.verbose_header = 1;
        if (!rebase_merges)
                revs.max_parents = 1;
@@ -4476,16 +4531,13 @@ int sequencer_make_script(FILE *out, int argc, const char **argv,
 
                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;
 }
 
@@ -4493,90 +4545,95 @@ int sequencer_make_script(FILE *out, int argc, const char **argv,
  * Add commands after pick and (series of) squash/fixup commands
  * in the todo list.
  */
-int sequencer_add_exec_commands(const char *commands)
+void todo_list_add_exec_commands(struct todo_list *todo_list,
+                                struct string_list *commands)
 {
-       const char *todo_file = rebase_path_todo();
-       struct todo_list todo_list = TODO_LIST_INIT;
-       struct strbuf *buf = &todo_list.buf;
-       size_t offset = 0, commands_len = strlen(commands);
-       int i, insert;
+       struct strbuf *buf = &todo_list->buf;
+       size_t base_offset = buf->len;
+       int i, insert, nr = 0, alloc = 0;
+       struct todo_item *items = NULL, *base_items = NULL;
+
+       base_items = xcalloc(commands->nr, sizeof(struct todo_item));
+       for (i = 0; i < commands->nr; i++) {
+               size_t command_len = strlen(commands->items[i].string);
+
+               strbuf_addstr(buf, commands->items[i].string);
+               strbuf_addch(buf, '\n');
 
-       if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
-               return error(_("could not read '%s'."), todo_file);
+               base_items[i].command = TODO_EXEC;
+               base_items[i].offset_in_buf = base_offset;
+               base_items[i].arg_offset = base_offset + strlen("exec ");
+               base_items[i].arg_len = command_len - strlen("exec ");
 
-       if (parse_insn_buffer(todo_list.buf.buf, &todo_list)) {
-               todo_list_release(&todo_list);
-               return error(_("unusable todo list: '%s'"), todo_file);
+               base_offset += command_len + 1;
        }
 
        /*
         * Insert <commands> after every pick. Here, fixup/squash chains
         * are considered part of the pick, so we insert the commands *after*
         * those chains if there are any.
+        *
+        * As we insert the exec commands immediatly after rearranging
+        * any fixups and before the user edits the list, a fixup chain
+        * can never contain comments (any comments are empty picks that
+        * have been commented out because the user did not specify
+        * --keep-empty).  So, it is safe to insert an exec command
+        * without looking at the command following a comment.
         */
-       insert = -1;
-       for (i = 0; i < todo_list.nr; i++) {
-               enum todo_command command = todo_list.items[i].command;
-
-               if (insert >= 0) {
-                       /* skip fixup/squash chains */
-                       if (command == TODO_COMMENT)
-                               continue;
-                       else if (is_fixup(command)) {
-                               insert = i + 1;
-                               continue;
-                       }
-                       strbuf_insert(buf,
-                                     todo_list.items[insert].offset_in_buf +
-                                     offset, commands, commands_len);
-                       offset += commands_len;
-                       insert = -1;
+       insert = 0;
+       for (i = 0; i < todo_list->nr; i++) {
+               enum todo_command command = todo_list->items[i].command;
+               if (insert && !is_fixup(command)) {
+                       ALLOC_GROW(items, nr + commands->nr, alloc);
+                       COPY_ARRAY(items + nr, base_items, commands->nr);
+                       nr += commands->nr;
+
+                       insert = 0;
                }
 
+               ALLOC_GROW(items, nr + 1, alloc);
+               items[nr++] = todo_list->items[i];
+
                if (command == TODO_PICK || command == TODO_MERGE)
-                       insert = i + 1;
+                       insert = 1;
        }
 
        /* insert or append final <commands> */
-       if (insert >= 0 && insert < todo_list.nr)
-               strbuf_insert(buf, todo_list.items[insert].offset_in_buf +
-                             offset, commands, commands_len);
-       else if (insert >= 0 || !offset)
-               strbuf_add(buf, commands, commands_len);
+       if (insert || nr == todo_list->nr) {
+               ALLOC_GROW(items, nr + commands->nr, alloc);
+               COPY_ARRAY(items + nr, base_items, commands->nr);
+               nr += commands->nr;
+       }
 
-       i = write_message(buf->buf, buf->len, todo_file, 0);
-       todo_list_release(&todo_list);
-       return i;
+       free(base_items);
+       FREE_AND_NULL(todo_list->items);
+       todo_list->items = items;
+       todo_list->nr = nr;
+       todo_list->alloc = alloc;
 }
 
-int transform_todos(unsigned flags)
+static void todo_list_to_strbuf(struct repository *r, struct todo_list *todo_list,
+                               struct strbuf *buf, int num, unsigned flags)
 {
-       const char *todo_file = rebase_path_todo();
-       struct todo_list todo_list = TODO_LIST_INIT;
-       struct strbuf buf = STRBUF_INIT;
        struct todo_item *item;
-       int i;
+       int i, max = todo_list->nr;
 
-       if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
-               return error(_("could not read '%s'."), todo_file);
+       if (num > 0 && num < max)
+               max = num;
 
-       if (parse_insn_buffer(todo_list.buf.buf, &todo_list)) {
-               todo_list_release(&todo_list);
-               return error(_("unusable todo list: '%s'"), todo_file);
-       }
-
-       for (item = todo_list.items, i = 0; i < todo_list.nr; i++, item++) {
+       for (item = todo_list->items, i = 0; i < max; i++, item++) {
                /* if the item is not a command write it and continue */
                if (item->command >= TODO_COMMENT) {
-                       strbuf_addf(&buf, "%.*s\n", item->arg_len, item->arg);
+                       strbuf_addf(buf, "%.*s\n", item->arg_len,
+                                   todo_item_get_arg(todo_list, item));
                        continue;
                }
 
                /* add command to the buffer */
                if (flags & TODO_LIST_ABBREVIATE_CMDS)
-                       strbuf_addch(&buf, command_to_char(item->command));
+                       strbuf_addch(buf, command_to_char(item->command));
                else
-                       strbuf_addstr(&buf, command_to_string(item->command));
+                       strbuf_addstr(buf, command_to_string(item->command));
 
                /* add commit id */
                if (item->commit) {
@@ -4586,181 +4643,92 @@ int transform_todos(unsigned flags)
 
                        if (item->command == TODO_MERGE) {
                                if (item->flags & TODO_EDIT_MERGE_MSG)
-                                       strbuf_addstr(&buf, " -c");
+                                       strbuf_addstr(buf, " -c");
                                else
-                                       strbuf_addstr(&buf, " -C");
+                                       strbuf_addstr(buf, " -C");
                        }
 
-                       strbuf_addf(&buf, " %s", oid);
+                       strbuf_addf(buf, " %s", oid);
                }
 
                /* add all the rest */
                if (!item->arg_len)
-                       strbuf_addch(&buf, '\n');
+                       strbuf_addch(buf, '\n');
                else
-                       strbuf_addf(&buf, " %.*s\n", item->arg_len, item->arg);
+                       strbuf_addf(buf, " %.*s\n", item->arg_len,
+                                   todo_item_get_arg(todo_list, item));
        }
-
-       i = write_message(buf.buf, buf.len, todo_file, 0);
-       todo_list_release(&todo_list);
-       return i;
 }
 
-enum missing_commit_check_level get_missing_commit_check_level(void)
+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)
 {
-       const char *value;
+       int res;
+       struct strbuf buf = STRBUF_INIT;
 
-       if (git_config_get_value("rebase.missingcommitscheck", &value) ||
-                       !strcasecmp("ignore", value))
-               return MISSING_COMMIT_CHECK_IGNORE;
-       if (!strcasecmp("warn", value))
-               return MISSING_COMMIT_CHECK_WARN;
-       if (!strcasecmp("error", value))
-               return MISSING_COMMIT_CHECK_ERROR;
-       warning(_("unrecognized setting %s for option "
-                 "rebase.missingCommitsCheck. Ignoring."), value);
-       return MISSING_COMMIT_CHECK_IGNORE;
-}
+       todo_list_to_strbuf(r, todo_list, &buf, num, flags);
+       if (flags & TODO_LIST_APPEND_TODO_HELP)
+               append_todo_help(flags & TODO_LIST_KEEP_EMPTY, count_commands(todo_list),
+                                shortrevisions, shortonto, &buf);
 
-define_commit_slab(commit_seen, unsigned char);
-/*
- * Check if the user dropped some commits by mistake
- * Behaviour determined by rebase.missingCommitsCheck.
- * Check if there is an unrecognized command or a
- * bad SHA-1 in a command.
- */
-int check_todo_list(void)
-{
-       enum missing_commit_check_level check_level = get_missing_commit_check_level();
-       struct strbuf todo_file = STRBUF_INIT;
-       struct todo_list todo_list = TODO_LIST_INIT;
-       struct strbuf missing = STRBUF_INIT;
-       int advise_to_edit_todo = 0, res = 0, i;
-       struct commit_seen commit_seen;
+       res = write_message(buf.buf, buf.len, file, 0);
+       strbuf_release(&buf);
 
-       init_commit_seen(&commit_seen);
+       return res;
+}
 
-       strbuf_addstr(&todo_file, rebase_path_todo());
-       if (strbuf_read_file_or_whine(&todo_list.buf, todo_file.buf) < 0) {
-               res = -1;
-               goto leave_check;
-       }
-       advise_to_edit_todo = res =
-               parse_insn_buffer(todo_list.buf.buf, &todo_list);
+static const char edit_todo_list_advice[] =
+N_("You can fix this with 'git rebase --edit-todo' "
+"and then run 'git rebase --continue'.\n"
+"Or you can abort the rebase with 'git rebase"
+" --abort'.\n");
 
-       if (res || check_level == MISSING_COMMIT_CHECK_IGNORE)
-               goto leave_check;
+int check_todo_list_from_file(struct repository *r)
+{
+       struct todo_list old_todo = TODO_LIST_INIT, new_todo = TODO_LIST_INIT;
+       int res = 0;
 
-       /* Mark the commits in git-rebase-todo as seen */
-       for (i = 0; i < todo_list.nr; i++) {
-               struct commit *commit = todo_list.items[i].commit;
-               if (commit)
-                       *commit_seen_at(&commit_seen, commit) = 1;
+       if (strbuf_read_file_or_whine(&new_todo.buf, rebase_path_todo()) < 0) {
+               res = -1;
+               goto out;
        }
 
-       todo_list_release(&todo_list);
-       strbuf_addstr(&todo_file, ".backup");
-       if (strbuf_read_file_or_whine(&todo_list.buf, todo_file.buf) < 0) {
+       if (strbuf_read_file_or_whine(&old_todo.buf, rebase_path_todo_backup()) < 0) {
                res = -1;
-               goto leave_check;
-       }
-       strbuf_release(&todo_file);
-       res = !!parse_insn_buffer(todo_list.buf.buf, &todo_list);
-
-       /* Find commits in git-rebase-todo.backup yet unseen */
-       for (i = todo_list.nr - 1; i >= 0; i--) {
-               struct todo_item *item = todo_list.items + i;
-               struct commit *commit = item->commit;
-               if (commit && !*commit_seen_at(&commit_seen, commit)) {
-                       strbuf_addf(&missing, " - %s %.*s\n",
-                                   short_commit_name(commit),
-                                   item->arg_len, item->arg);
-                       *commit_seen_at(&commit_seen, commit) = 1;
-               }
+               goto out;
        }
 
-       /* Warn about missing commits */
-       if (!missing.len)
-               goto leave_check;
-
-       if (check_level == MISSING_COMMIT_CHECK_ERROR)
-               advise_to_edit_todo = res = 1;
-
-       fprintf(stderr,
-               _("Warning: some commits may have been dropped accidentally.\n"
-               "Dropped commits (newer to older):\n"));
-
-       /* Make the list user-friendly and display */
-       fputs(missing.buf, stderr);
-       strbuf_release(&missing);
-
-       fprintf(stderr, _("To avoid this message, use \"drop\" to "
-               "explicitly remove a commit.\n\n"
-               "Use 'git config rebase.missingCommitsCheck' to change "
-               "the level of warnings.\n"
-               "The possible behaviours are: ignore, warn, error.\n\n"));
-
-leave_check:
-       clear_commit_seen(&commit_seen);
-       strbuf_release(&todo_file);
-       todo_list_release(&todo_list);
-
-       if (advise_to_edit_todo)
-               fprintf(stderr,
-                       _("You can fix this with 'git rebase --edit-todo' "
-                         "and then run 'git rebase --continue'.\n"
-                         "Or you can abort the rebase with 'git rebase"
-                         " --abort'.\n"));
+       res = todo_list_parse_insn_buffer(r, old_todo.buf.buf, &old_todo);
+       if (!res)
+               res = todo_list_parse_insn_buffer(r, new_todo.buf.buf, &new_todo);
+       if (!res)
+               res = todo_list_check(&old_todo, &new_todo);
+       if (res)
+               fprintf(stderr, _(edit_todo_list_advice));
+out:
+       todo_list_release(&old_todo);
+       todo_list_release(&new_todo);
 
        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 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 (parse_insn_buffer(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));
                }
@@ -4769,143 +4737,109 @@ static int skip_unnecessary_picks(struct object_id *output_oid)
                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 replay_opts *opts, unsigned flags,
+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, const char *cmd,
-                   unsigned autosquash)
+                   const char *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 todo_list new_todo = TODO_LIST_INIT;
+       struct strbuf *buf = &todo_list->buf;
        struct object_id oid;
-       struct stat st;
+       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())
+       if (autosquash && todo_list_rearrange_squash(todo_list))
                return -1;
 
-       if (cmd && *cmd)
-               sequencer_add_exec_commands(cmd);
-
-       if (strbuf_read_file(buf, todo_file, 0) < 0)
-               return error_errno(_("could not read '%s'."), todo_file);
-
-       if (parse_insn_buffer(buf->buf, &todo_list)) {
-               todo_list_release(&todo_list);
-               return error(_("unusable todo list: '%s'"), todo_file);
-       }
+       if (commands->nr)
+               todo_list_add_exec_commands(todo_list, commands);
 
-       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_todos(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 (check_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(opts, onto_name, onto, orig_head);
+               todo_list_release(&new_todo);
+
                return -1;
        }
 
-       if (transform_todos(flags & ~(TODO_LIST_SHORTEN_IDS)))
-               return error(_("could not transform the todo list"));
-
-       if (opts->allow_ff && skip_unnecessary_picks(&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))
                return -1;
 
-       if (require_clean_work_tree("rebase", "", 1, 1))
+       if (require_clean_work_tree(r, "rebase", "", 1, 1))
                return -1;
 
-       return sequencer_continue(opts);
+       return sequencer_continue(r, opts);
 }
 
 struct subject2item_entry {
@@ -4932,21 +4866,13 @@ 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.
  */
-int rearrange_squash(void)
+int todo_list_rearrange_squash(struct todo_list *todo_list)
 {
-       const char *todo_file = rebase_path_todo();
-       struct todo_list todo_list = TODO_LIST_INIT;
        struct hashmap subject2item;
-       int res = 0, rearranged = 0, *next, *tail, i;
+       int rearranged = 0, *next, *tail, i, nr = 0, alloc = 0;
        char **subjects;
        struct commit_todo_item commit_todo;
-
-       if (strbuf_read_file_or_whine(&todo_list.buf, todo_file) < 0)
-               return -1;
-       if (parse_insn_buffer(todo_list.buf.buf, &todo_list) < 0) {
-               todo_list_release(&todo_list);
-               return -1;
-       }
+       struct todo_item *items = NULL;
 
        init_commit_todo_item(&commit_todo);
        /*
@@ -4959,13 +4885,13 @@ int rearrange_squash(void)
         * be moved to appear after the i'th.
         */
        hashmap_init(&subject2item, (hashmap_cmp_fn) subject2item_cmp,
-                    NULL, todo_list.nr);
-       ALLOC_ARRAY(next, todo_list.nr);
-       ALLOC_ARRAY(tail, todo_list.nr);
-       ALLOC_ARRAY(subjects, todo_list.nr);
-       for (i = 0; i < todo_list.nr; i++) {
+                    NULL, todo_list->nr);
+       ALLOC_ARRAY(next, todo_list->nr);
+       ALLOC_ARRAY(tail, todo_list->nr);
+       ALLOC_ARRAY(subjects, todo_list->nr);
+       for (i = 0; i < todo_list->nr; i++) {
                struct strbuf buf = STRBUF_INIT;
-               struct todo_item *item = todo_list.items + i;
+               struct todo_item *item = todo_list->items + i;
                const char *commit_buffer, *subject, *p;
                size_t subject_len;
                int i2 = -1;
@@ -4978,7 +4904,6 @@ int rearrange_squash(void)
                }
 
                if (is_fixup(item->command)) {
-                       todo_list_release(&todo_list);
                        clear_commit_todo_item(&commit_todo);
                        return error(_("the script was already rearranged."));
                }
@@ -5013,7 +4938,7 @@ int rearrange_squash(void)
                                 *commit_todo_item_at(&commit_todo, commit2))
                                /* found by commit name */
                                i2 = *commit_todo_item_at(&commit_todo, commit2)
-                                       - todo_list.items;
+                                       - todo_list->items;
                        else {
                                /* copy can be a prefix of the commit subject */
                                for (i2 = 0; i2 < i; i2++)
@@ -5026,7 +4951,7 @@ int rearrange_squash(void)
                }
                if (i2 >= 0) {
                        rearranged = 1;
-                       todo_list.items[i].command =
+                       todo_list->items[i].command =
                                starts_with(subject, "fixup!") ?
                                TODO_FIXUP : TODO_SQUASH;
                        if (next[i2] < 0)
@@ -5044,10 +4969,8 @@ int rearrange_squash(void)
        }
 
        if (rearranged) {
-               struct strbuf buf = STRBUF_INIT;
-
-               for (i = 0; i < todo_list.nr; i++) {
-                       enum todo_command command = todo_list.items[i].command;
+               for (i = 0; i < todo_list->nr; i++) {
+                       enum todo_command command = todo_list->items[i].command;
                        int cur = i;
 
                        /*
@@ -5058,37 +4981,26 @@ int rearrange_squash(void)
                                continue;
 
                        while (cur >= 0) {
-                               const char *bol =
-                                       get_item_line(&todo_list, cur);
-                               const char *eol =
-                                       get_item_line(&todo_list, cur + 1);
-
-                               /* replace 'pick', by 'fixup' or 'squash' */
-                               command = todo_list.items[cur].command;
-                               if (is_fixup(command)) {
-                                       strbuf_addstr(&buf,
-                                               todo_command_info[command].str);
-                                       bol += strcspn(bol, " \t");
-                               }
-
-                               strbuf_add(&buf, bol, eol - bol);
-
+                               ALLOC_GROW(items, nr + 1, alloc);
+                               items[nr++] = todo_list->items[cur];
                                cur = next[cur];
                        }
                }
 
-               res = rewrite_file(todo_file, buf.buf, buf.len);
-               strbuf_release(&buf);
+               FREE_AND_NULL(todo_list->items);
+               todo_list->items = items;
+               todo_list->nr = nr;
+               todo_list->alloc = alloc;
        }
 
        free(next);
        free(tail);
-       for (i = 0; i < todo_list.nr; i++)
+       for (i = 0; i < todo_list->nr; i++)
                free(subjects[i]);
        free(subjects);
        hashmap_free(&subject2item, 1);
-       todo_list_release(&todo_list);
 
        clear_commit_todo_item(&commit_todo);
-       return res;
+
+       return 0;
 }