]> git.ipfire.org Git - thirdparty/git.git/blobdiff - sequencer.c
mailinfo: factor out some repeated header handling
[thirdparty/git.git] / sequencer.c
index e1a4dd15f1a826c7bd1bf4780c8f85c21117c43b..b9dbf1adb078188a0163ad8ae29cce92c0587b88 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
@@ -132,7 +131,7 @@ static GIT_PATH_FUNC(rebase_path_rewritten_pending,
        "rebase-merge/rewritten-pending")
 
 /*
- * The path of the file containig the OID of the "squash onto" commit, i.e.
+ * The path of the file containing the OID of the "squash onto" commit, i.e.
  * the dummy commit used for `reset [new root]`.
  */
 static GIT_PATH_FUNC(rebase_path_squash_onto, "rebase-merge/squash-onto")
@@ -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)
 {
@@ -171,17 +171,22 @@ static int git_sequencer_config(const char *k, const char *v, void *cb)
                if (status)
                        return status;
 
-               if (!strcmp(s, "verbatim"))
+               if (!strcmp(s, "verbatim")) {
                        opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_NONE;
-               else if (!strcmp(s, "whitespace"))
+                       opts->explicit_cleanup = 1;
+               } else if (!strcmp(s, "whitespace")) {
                        opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_SPACE;
-               else if (!strcmp(s, "strip"))
+                       opts->explicit_cleanup = 1;
+               } else if (!strcmp(s, "strip")) {
                        opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_ALL;
-               else if (!strcmp(s, "scissors"))
-                       opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_SPACE;
-               else
+                       opts->explicit_cleanup = 1;
+               } else if (!strcmp(s, "scissors")) {
+                       opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_SCISSORS;
+                       opts->explicit_cleanup = 1;
+               } else {
                        warning(_("invalid commit message cleanup mode '%s'"),
                                  s);
+               }
 
                free((char *)s);
                return status;
@@ -274,7 +279,7 @@ static const char *gpg_sign_opt_quoted(struct replay_opts *opts)
 int sequencer_remove_state(struct replay_opts *opts)
 {
        struct strbuf buf = STRBUF_INIT;
-       int i;
+       int i, ret = 0;
 
        if (is_rebase_i(opts) &&
            strbuf_read_file(&buf, rebase_path_refs_to_delete(), 0) > 0) {
@@ -283,8 +288,10 @@ int sequencer_remove_state(struct replay_opts *opts)
                        char *eol = strchr(p, '\n');
                        if (eol)
                                *eol = '\0';
-                       if (delete_ref("(rebase -i) cleanup", p, NULL, 0) < 0)
+                       if (delete_ref("(rebase -i) cleanup", p, NULL, 0) < 0) {
                                warning(_("could not delete '%s'"), p);
+                               ret = -1;
+                       }
                        if (!eol)
                                break;
                        p = eol + 1;
@@ -300,10 +307,11 @@ int sequencer_remove_state(struct replay_opts *opts)
 
        strbuf_reset(&buf);
        strbuf_addstr(&buf, get_dir(opts));
-       remove_dir_recursively(&buf, 0);
+       if (remove_dir_recursively(&buf, 0))
+               ret = error(_("could not remove '%s'"), buf.buf);
        strbuf_release(&buf);
 
-       return 0;
+       return ret;
 }
 
 static const char *action_name(const struct replay_opts *opts)
@@ -356,7 +364,8 @@ 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 +376,7 @@ 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 +391,8 @@ 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 +449,14 @@ 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 +481,18 @@ 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)));
@@ -506,40 +518,85 @@ static int fast_forward_to(const struct object_id *to, const struct object_id *f
        return 0;
 }
 
-void append_conflicts_hint(struct strbuf *msgbuf)
+enum commit_msg_cleanup_mode get_cleanup_mode(const char *cleanup_arg,
+       int use_editor)
+{
+       if (!cleanup_arg || !strcmp(cleanup_arg, "default"))
+               return use_editor ? COMMIT_MSG_CLEANUP_ALL :
+                                   COMMIT_MSG_CLEANUP_SPACE;
+       else if (!strcmp(cleanup_arg, "verbatim"))
+               return COMMIT_MSG_CLEANUP_NONE;
+       else if (!strcmp(cleanup_arg, "whitespace"))
+               return COMMIT_MSG_CLEANUP_SPACE;
+       else if (!strcmp(cleanup_arg, "strip"))
+               return COMMIT_MSG_CLEANUP_ALL;
+       else if (!strcmp(cleanup_arg, "scissors"))
+               return use_editor ? COMMIT_MSG_CLEANUP_SCISSORS :
+                                   COMMIT_MSG_CLEANUP_SPACE;
+       else
+               die(_("Invalid cleanup mode %s"), cleanup_arg);
+}
+
+/*
+ * NB using int rather than enum cleanup_mode to stop clang's
+ * -Wtautological-constant-out-of-range-compare complaining that the comparison
+ * is always true.
+ */
+static const char *describe_cleanup_mode(int cleanup_mode)
+{
+       static const char *modes[] = { "whitespace",
+                                      "verbatim",
+                                      "scissors",
+                                      "strip" };
+
+       if (cleanup_mode < ARRAY_SIZE(modes))
+               return modes[cleanup_mode];
+
+       BUG("invalid cleanup_mode provided (%d)", cleanup_mode);
+}
+
+void append_conflicts_hint(struct index_state *istate,
+       struct strbuf *msgbuf, enum commit_msg_cleanup_mode cleanup_mode)
 {
        int i;
 
+       if (cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS) {
+               strbuf_addch(msgbuf, '\n');
+               wt_status_append_cut_line(msgbuf);
+               strbuf_addch(msgbuf, comment_line_char);
+       }
+
        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)
 {
        struct merge_options o;
-       struct tree *result, *next_tree, *base_tree, *head_tree;
+       struct tree *next_tree, *base_tree, *head_tree;
        int clean;
        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)";
@@ -548,25 +605,24 @@ 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);
 
        clean = merge_trees(&o,
                            head_tree,
-                           next_tree, base_tree, &result);
+                           next_tree, base_tree);
        if (is_rebase_i(opts) && clean <= 0)
                fputs(o.obuf.buf, stdout);
        strbuf_release(&o.obuf);
-       diff_warn_rename_limit("merge.renamelimit", o.needed_rename_limit, 0);
        if (clean < 0) {
                rollback_lock_file(&index_lock);
                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 +632,36 @@ 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,
+                                     opts->default_msg_cleanup);
 
        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 +674,7 @@ 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));
@@ -711,7 +769,7 @@ static int parse_key_value_squoted(char *buf, struct string_list *list)
  *     GIT_AUTHOR_DATE='$author_date'
  *
  * where $author_name, $author_email and $author_date are quoted. We are strict
- * with our parsing, as the file was meant to be eval'd in the old
+ * with our parsing, as the file was meant to be eval'd in the now-removed
  * git-am.sh/git-rebase--interactive.sh scripts, and thus if the file differs
  * from what this function expects, it is better to bail out than to do
  * something that the user does not expect.
@@ -810,34 +868,6 @@ static char *get_author(const char *message)
        return NULL;
 }
 
-/* Read author-script and return an ident line (author <email> timestamp) */
-static const char *read_author_ident(struct strbuf *buf)
-{
-       struct strbuf out = STRBUF_INIT;
-       char *name, *email, *date;
-
-       if (read_author_script(rebase_path_author_script(),
-                              &name, &email, &date, 0))
-               return NULL;
-
-       /* validate date since fmt_ident() will die() on bad value */
-       if (parse_date(date, &out)){
-               warning(_("invalid date format '%s' in '%s'"),
-                       date, rebase_path_author_script());
-               strbuf_release(&out);
-               return NULL;
-       }
-
-       strbuf_reset(&out);
-       strbuf_addstr(&out, fmt_ident(name, email, date, 0));
-       strbuf_swap(buf, &out);
-       strbuf_release(&out);
-       free(name);
-       free(email);
-       free(date);
-       return buf->buf;
-}
-
 static const char staged_changes_advice[] =
 N_("you have staged changes in your working tree\n"
 "If these changes are meant to be squashed into the previous commit, run:\n"
@@ -888,52 +918,12 @@ 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;
-       const char *value;
-
-       if ((flags & CREATE_ROOT_COMMIT) && !(flags & AMEND_MSG)) {
-               struct strbuf msg = STRBUF_INIT, script = STRBUF_INIT;
-               const char *author = NULL;
-               struct object_id root_commit, *cache_tree_oid;
-               int res = 0;
-
-               if (is_rebase_i(opts)) {
-                       author = read_author_ident(&script);
-                       if (!author) {
-                               strbuf_release(&script);
-                               return -1;
-                       }
-               }
-
-               if (!defmsg)
-                       BUG("root commit without message");
-
-               if (!(cache_tree_oid = get_cache_tree_oid()))
-                       res = -1;
-
-               if (!res)
-                       res = strbuf_read_file(&msg, defmsg, 0);
-
-               if (res <= 0)
-                       res = error_errno(_("could not read '%s'"), defmsg);
-               else
-                       res = commit_tree(msg.buf, msg.len, cache_tree_oid,
-                                         NULL, &root_commit, author,
-                                         opts->gpg_sign);
-
-               strbuf_release(&msg);
-               strbuf_release(&script);
-               if (!res) {
-                       update_ref(NULL, "CHERRY_PICK_HEAD", &root_commit, NULL,
-                                  REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR);
-                       res = update_ref(NULL, "HEAD", &root_commit, NULL, 0,
-                                        UPDATE_REFS_MSG_ON_ERR);
-               }
-               return res < 0 ? error(_("writing root commit")) : 0;
-       }
 
        cmd.git_cmd = 1;
 
@@ -962,7 +952,7 @@ static int run_git_commit(const char *defmsg, struct replay_opts *opts,
                argv_array_push(&cmd.args, "-e");
        else if (!(flags & CLEANUP_MSG) &&
                 !opts->signoff && !opts->record_origin &&
-                git_config_get_value("commit.cleanup", &value))
+                !opts->explicit_cleanup)
                argv_array_push(&cmd.args, "--cleanup=verbatim");
 
        if ((flags & ALLOW_EMPTY))
@@ -1003,6 +993,16 @@ static int rest_is_empty(const struct strbuf *sb, int start)
        return 1;
 }
 
+void cleanup_message(struct strbuf *msgbuf,
+       enum commit_msg_cleanup_mode cleanup_mode, int verbose)
+{
+       if (verbose || /* Truncate the message just before the diff, if any. */
+           cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS)
+               strbuf_setlen(msgbuf, wt_status_locate_end(msgbuf->buf, msgbuf->len));
+       if (cleanup_mode != COMMIT_MSG_CLEANUP_NONE)
+               strbuf_stripspace(msgbuf, cleanup_mode == COMMIT_MSG_CLEANUP_ALL);
+}
+
 /*
  * Find out if the message in the strbuf contains only whitespace and
  * Signed-off-by lines.
@@ -1093,6 +1093,7 @@ 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 +1107,8 @@ 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;
@@ -1115,32 +1117,31 @@ 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;
-       const char *name;
+       int ret = 0;
+       const char *name, *arg1 = NULL, *arg2 = NULL;
 
        name = git_path_commit_editmsg();
        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_push(&hook_env, "GIT_EDITOR=:");
-       if (commit)
-               ret = run_hook_le(hook_env.argv, "prepare-commit-msg", name,
-                                 "commit", commit, NULL);
-       else
-               ret = run_hook_le(hook_env.argv, "prepare-commit-msg", name,
-                                 "message", NULL);
-       if (ret)
+       if (commit) {
+               arg1 = "commit";
+               arg2 = commit;
+       } else {
+               arg1 = "message";
+       }
+       if (run_commit_hook(0, r->index_file, "prepare-commit-msg", name,
+                           arg1, arg2, NULL))
                ret = error(_("'prepare-commit-msg' hook failed"));
-       argv_array_clear(&hook_env);
 
        return ret;
 }
@@ -1186,7 +1187,9 @@ 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 +1200,7 @@ 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 +1233,7 @@ 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 +1267,7 @@ 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 +1275,7 @@ 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)) {
@@ -1296,12 +1299,13 @@ 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)
 {
        struct object_id tree;
-       struct commit *current_head;
+       struct commit *current_head = NULL;
        struct commit_list *parents = NULL;
        struct commit_extra_header *extra = NULL;
        struct strbuf err = STRBUF_INIT;
@@ -1311,7 +1315,7 @@ 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) {
@@ -1336,24 +1340,41 @@ static int try_to_commit(struct strbuf *msg, const char *author,
                }
                parents = copy_commit_list(current_head->parents);
                extra = read_commit_extra_headers(current_head, exclude_gpgsig);
-       } else if (current_head) {
+       } else if (current_head &&
+                  (!(flags & CREATE_ROOT_COMMIT) || (flags & AMEND_MSG))) {
                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;
        }
 
-       if (!(flags & ALLOW_EMPTY) && oideq(current_head ?
-                                           get_commit_tree_oid(current_head) :
-                                           the_hash_algo->empty_tree, &tree)) {
-               res = 1; /* run 'git commit' to display error message */
-               goto out;
+       if (!(flags & ALLOW_EMPTY)) {
+               struct commit *first_parent = current_head;
+
+               if (flags & AMEND_MSG) {
+                       if (current_head->parents) {
+                               first_parent = current_head->parents->item;
+                               if (repo_parse_commit(r, first_parent)) {
+                                       res = error(_("could not parse HEAD commit"));
+                                       goto out;
+                               }
+                       } else {
+                               first_parent = NULL;
+                       }
+               }
+               if (oideq(first_parent
+                         ? get_commit_tree_oid(first_parent)
+                         : the_hash_algo->empty_tree,
+                         &tree)) {
+                       res = 1; /* run 'git commit' to display error message */
+                       goto out;
+               }
        }
 
        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(),
@@ -1366,8 +1387,13 @@ static int try_to_commit(struct strbuf *msg, const char *author,
                msg = &commit_msg;
        }
 
-       cleanup = (flags & CLEANUP_MSG) ? COMMIT_MSG_CLEANUP_ALL :
-                                         opts->default_msg_cleanup;
+       if (flags & CLEANUP_MSG)
+               cleanup = COMMIT_MSG_CLEANUP_ALL;
+       else if ((opts->signoff || opts->record_origin) &&
+                !opts->explicit_cleanup)
+               cleanup = COMMIT_MSG_CLEANUP_SPACE;
+       else
+               cleanup = opts->default_msg_cleanup;
 
        if (cleanup != COMMIT_MSG_CLEANUP_NONE)
                strbuf_stripspace(msg, cleanup == COMMIT_MSG_CLEANUP_ALL);
@@ -1390,8 +1416,9 @@ static int try_to_commit(struct strbuf *msg, const char *author,
                goto out;
        }
 
+       run_commit_hook(0, r->index_file, "post-commit", NULL);
        if (flags & AMEND_MSG)
-               commit_post_rewrite(current_head, oid);
+               commit_post_rewrite(r, current_head, oid);
 
 out:
        free_commit_extra_headers(extra);
@@ -1402,13 +1429,13 @@ out:
        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;
 
-       if (!(flags & EDIT_MSG) && !(flags & VERIFY_MSG) &&
-           !(flags & CREATE_ROOT_COMMIT)) {
+       if (!(flags & EDIT_MSG) && !(flags & VERIFY_MSG)) {
                struct object_id oid;
                struct strbuf sb = STRBUF_INIT;
 
@@ -1417,20 +1444,20 @@ 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 +1485,9 @@ 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 +1504,7 @@ 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 +1522,6 @@ 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;
@@ -1579,12 +1582,15 @@ 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;
        const char *message, *body;
+       const char *encoding = get_commit_output_encoding();
 
        if (opts->current_fixup_count > 0) {
                struct strbuf header = STRBUF_INIT;
@@ -1609,9 +1615,9 @@ 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)))
+               if (!(head_message = logmsg_reencode(head_commit, NULL, encoding)))
                        return error(_("could not read HEAD's commit message"));
 
                find_commit_subject(head_message, &body);
@@ -1632,7 +1638,7 @@ static int update_squash_messages(enum todo_command command,
                unuse_commit_buffer(head_commit, head_message);
        }
 
-       if (!(message = get_commit_buffer(commit, NULL)))
+       if (!(message = logmsg_reencode(commit, NULL, encoding)))
                return error(_("could not read commit message of %s"),
                             oid_to_hex(&commit->object.oid));
        find_commit_subject(message, &body);
@@ -1670,7 +1676,8 @@ 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 +1702,8 @@ 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)
@@ -1708,18 +1716,21 @@ 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, int *check_todo)
 {
        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;
        char *author = NULL;
        struct commit_message msg = { NULL, NULL, NULL, NULL };
        struct strbuf msgbuf = STRBUF_INIT;
-       int res, unborn = 0, allow;
+       int res, unborn = 0, reword = 0, allow;
 
        if (opts->no_commit) {
                /*
@@ -1728,7 +1739,7 @@ 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 +1752,11 @@ 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 +1777,13 @@ 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;
 
@@ -1781,11 +1796,11 @@ 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;
-               flags |= EDIT_MSG | AMEND_MSG | VERIFY_MSG;
+               reword = 1;
                msg_file = NULL;
                goto fast_forward_edit;
        }
@@ -1843,9 +1858,9 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
        }
 
        if (command == TODO_REWORD)
-               flags |= EDIT_MSG | VERIFY_MSG;
+               reword = 1;
        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 +1869,12 @@ 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 +1886,23 @@ 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);
@@ -1915,25 +1930,33 @@ 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;
        } else if (allow)
                flags |= ALLOW_EMPTY;
        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"));
+               *check_todo = !!(flags & EDIT_MSG);
+               if (!res && reword) {
+fast_forward_edit:
+                       res = run_git_commit(r, NULL, opts, EDIT_MSG |
+                                            VERIFY_MSG | AMEND_MSG |
+                                            (flags & ALLOW_EMPTY));
+                       *check_todo = 1;
+               }
        }
 
+
        if (!res && final_fixup) {
                unlink(rebase_path_fixup_msg());
                unlink(rebase_path_squash_msg());
@@ -1965,18 +1988,19 @@ 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 +2013,7 @@ 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);
@@ -2018,10 +2023,30 @@ static void todo_list_release(struct todo_list *todo_list)
 static struct todo_item *append_new_todo(struct todo_list *todo_list)
 {
        ALLOC_GROW(todo_list->items, todo_list->nr + 1, todo_list->alloc);
+       todo_list->total_nr++;
        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 is_command(enum todo_command command, const char **bol)
+{
+       const char *str = todo_command_info[command].str;
+       const char nick = todo_command_info[command].c;
+       const char *p = *bol + 1;
+
+       return skip_prefix(*bol, str, bol) ||
+               ((nick && **bol == nick) &&
+                (*p == ' ' || *p == '\t' || *p == '\n' || *p == '\r' || !*p) &&
+                (*bol = p));
+}
+
+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;
@@ -2035,18 +2060,13 @@ 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;
        }
 
        for (i = 0; i < TODO_COMMENT; i++)
-               if (skip_prefix(bol, todo_command_info[i].str, &bol)) {
-                       item->command = i;
-                       break;
-               } else if ((bol + 1 == eol || bol[1] == ' ') &&
-                          *bol == todo_command_info[i].c) {
-                       bol++;
+               if (is_command(i, &bol)) {
                        item->command = i;
                        break;
                }
@@ -2062,7 +2082,7 @@ 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 +2094,7 @@ 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 +2108,7 @@ 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 +2120,54 @@ 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 sequencer_get_last_command(struct repository *r, enum replay_action *action)
+{
+       const char *todo_file, *bol;
+       struct strbuf buf = STRBUF_INIT;
+       int ret = 0;
+
+       todo_file = git_path_todo_file();
+       if (strbuf_read_file(&buf, todo_file, 0) < 0) {
+               if (errno == ENOENT || errno == ENOTDIR)
+                       return -1;
+               else
+                       return error_errno("unable to open '%s'", todo_file);
+       }
+       bol = buf.buf + strspn(buf.buf, " \t\r\n");
+       if (is_command(TODO_PICK, &bol) && (*bol == ' ' || *bol == '\t'))
+               *action = REPLAY_PICK;
+       else if (is_command(TODO_REVERT, &bol) &&
+                (*bol == ' ' || *bol == '\t'))
+               *action = REPLAY_REVERT;
+       else
+               ret = -1;
+
+       strbuf_release(&buf);
+
+       return ret;
+}
+
+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 +2178,13 @@ 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 +2242,72 @@ 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 have_finished_the_last_pick(void)
+{
+       struct strbuf buf = STRBUF_INIT;
+       const char *eol;
+       const char *todo_path = git_path_todo_file();
+       int ret = 0;
+
+       if (strbuf_read_file(&buf, todo_path, 0) < 0) {
+               if (errno == ENOENT) {
+                       return 0;
+               } else {
+                       error_errno("unable to open '%s'", todo_path);
+                       return 0;
+               }
+       }
+       /* If there is only one line then we are done */
+       eol = strchr(buf.buf, '\n');
+       if (!eol || !eol[1])
+               ret = 1;
+
+       strbuf_release(&buf);
+
+       return ret;
+}
+
+void sequencer_post_commit_cleanup(struct repository *r, int verbose)
+{
+       struct replay_opts opts = REPLAY_OPTS_INIT;
+       int need_cleanup = 0;
+
+       if (file_exists(git_path_cherry_pick_head(r))) {
+               if (!unlink(git_path_cherry_pick_head(r)) && verbose)
+                       warning(_("cancelling a cherry picking in progress"));
+               opts.action = REPLAY_PICK;
+               need_cleanup = 1;
+       }
+
+       if (file_exists(git_path_revert_head(r))) {
+               if (!unlink(git_path_revert_head(r)) && verbose)
+                       warning(_("cancelling a revert in progress"));
+               opts.action = REPLAY_REVERT;
+               need_cleanup = 1;
+       }
+
+       if (!need_cleanup)
+               return;
+
+       if (!have_finished_the_last_pick())
+               return;
+
+       sequencer_remove_state(&opts);
+}
+
+static void todo_list_write_total_nr(struct todo_list *todo_list)
+{
+       FILE *f = fopen_or_warn(rebase_path_msgtotal(), "w");
+
+       if (f) {
+               fprintf(f, "%d\n", todo_list->total_nr);
+               fclose(f);
+       }
+}
+
+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 +2322,7 @@ 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 "
@@ -2231,10 +2350,9 @@ static int read_populate_todo(struct todo_list *todo_list,
 
        if (is_rebase_i(opts)) {
                struct todo_list done = TODO_LIST_INIT;
-               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;
@@ -2243,10 +2361,7 @@ static int read_populate_todo(struct todo_list *todo_list,
                        + count_commands(todo_list);
                todo_list_release(&done);
 
-               if (f) {
-                       fprintf(f, "%d\n", todo_list->total_nr);
-                       fclose(f);
-               }
+               todo_list_write_total_nr(todo_list);
        }
 
        return 0;
@@ -2273,6 +2388,15 @@ 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"))
@@ -2292,7 +2416,10 @@ static int populate_opts_cb(const char *key, const char *value, void *data)
                opts->allow_rerere_auto =
                        git_config_bool_or_int(key, value, &error_flag) ?
                                RERERE_AUTOUPDATE : RERERE_NOAUTOUPDATE;
-       else
+       else if (!strcmp(key, "options.default-msg-cleanup")) {
+               opts->explicit_cleanup = 1;
+               opts->default_msg_cleanup = get_cleanup_mode(value, 1);
+       } else
                return error(_("invalid key: %s"), key);
 
        if (!error_flag)
@@ -2357,11 +2484,17 @@ 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);
 
@@ -2411,22 +2544,20 @@ static void write_strategy_opts(struct replay_opts *opts)
 }
 
 int write_basic_state(struct replay_opts *opts, const char *head_name,
-                     const char *onto, const char *orig_head)
+                     struct commit *onto, const char *orig_head)
 {
        const char *quiet = getenv("GIT_QUIET");
 
        if (head_name)
                write_file(rebase_path_head_name(), "%s\n", head_name);
        if (onto)
-               write_file(rebase_path_onto(), "%s\n", onto);
+               write_file(rebase_path_onto(), "%s\n",
+                          oid_to_hex(&onto->object.oid));
        if (orig_head)
                write_file(rebase_path_orig_head(), "%s\n", orig_head);
 
        if (quiet)
                write_file(rebase_path_quiet(), "%s\n", quiet);
-       else
-               write_file(rebase_path_quiet(), "\n");
-
        if (opts->verbose)
                write_file(rebase_path_verbose(), "%s", "");
        if (opts->strategy)
@@ -2443,6 +2574,8 @@ 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;
 }
@@ -2453,20 +2586,23 @@ static int walk_revs_populate_todo(struct todo_list *todo_list,
        enum todo_command command = opts->action == REPLAY_PICK ?
                TODO_PICK : TODO_REVERT;
        const char *command_string = todo_command_info[command].str;
+       const char *encoding;
        struct commit *commit;
 
        if (prepare_revs(opts))
                return -1;
 
+       encoding = get_log_output_encoding();
+
        while ((commit = get_revision(opts->revs))) {
                struct todo_item *item = append_new_todo(todo_list);
-               const char *commit_buffer = get_commit_buffer(commit, NULL);
+               const char *commit_buffer = logmsg_reencode(commit, NULL, encoding);
                const char *subject;
                int subject_len;
 
                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);
@@ -2481,15 +2617,41 @@ static int walk_revs_populate_todo(struct todo_list *todo_list,
        return 0;
 }
 
-static int create_seq_dir(void)
+static int create_seq_dir(struct repository *r)
 {
-       if (file_exists(git_path_seq_dir())) {
-               error(_("a cherry-pick or revert is already in progress"));
-               advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
+       enum replay_action action;
+       const char *in_progress_error = NULL;
+       const char *in_progress_advice = NULL;
+       unsigned int advise_skip = file_exists(git_path_revert_head(r)) ||
+                               file_exists(git_path_cherry_pick_head(r));
+
+       if (!sequencer_get_last_command(r, &action)) {
+               switch (action) {
+               case REPLAY_REVERT:
+                       in_progress_error = _("revert is already in progress");
+                       in_progress_advice =
+                       _("try \"git revert (--continue | %s--abort | --quit)\"");
+                       break;
+               case REPLAY_PICK:
+                       in_progress_error = _("cherry-pick is already in progress");
+                       in_progress_advice =
+                       _("try \"git cherry-pick (--continue | %s--abort | --quit)\"");
+                       break;
+               default:
+                       BUG("unexpected action in create_seq_dir");
+               }
+       }
+       if (in_progress_error) {
+               error("%s", in_progress_error);
+               if (advice_sequencer_in_use)
+                       advise(in_progress_advice,
+                               advise_skip ? "--skip | " : "");
                return -1;
-       } else if (mkdir(git_path_seq_dir(), 0777) < 0)
+       }
+       if (mkdir(git_path_seq_dir(), 0777) < 0)
                return error_errno(_("could not create sequencer directory '%s'"),
                                   git_path_seq_dir());
+
        return 0;
 }
 
@@ -2540,32 +2702,46 @@ static int rollback_is_safe(void)
        return oideq(&actual_head, &expected_head);
 }
 
-static int reset_for_rollback(const struct object_id *oid)
+static int reset_merge(const struct object_id *oid)
 {
-       const char *argv[4];    /* reset --merge <arg> + NULL */
+       int ret;
+       struct argv_array argv = ARGV_ARRAY_INIT;
 
-       argv[0] = "reset";
-       argv[1] = "--merge";
-       argv[2] = oid_to_hex(oid);
-       argv[3] = NULL;
-       return run_command_v_opt(argv, RUN_GIT_CMD);
+       argv_array_pushl(&argv, "reset", "--merge", NULL);
+
+       if (!is_null_oid(oid))
+               argv_array_push(&argv, oid_to_hex(oid));
+
+       ret = run_command_v_opt(argv.argv, RUN_GIT_CMD);
+       argv_array_clear(&argv);
+
+       return ret;
 }
 
-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"));
        if (is_null_oid(&head_oid))
                return error(_("cannot abort from a branch yet to be born"));
-       return reset_for_rollback(&head_oid);
+       return reset_merge(&head_oid);
+}
+
+static int skip_single_pick(void)
+{
+       struct object_id head;
+
+       if (read_ref_full("HEAD", 0, &head, NULL))
+               return error(_("cannot resolve HEAD"));
+       return reset_merge(&head);
 }
 
-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 +2755,7 @@ 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());
@@ -2605,7 +2781,7 @@ int sequencer_rollback(struct replay_opts *opts)
                warning(_("You seem to have moved HEAD. "
                          "Not rewinding, check your HEAD!"));
        } else
-       if (reset_for_rollback(&oid))
+       if (reset_merge(&oid))
                goto fail;
        strbuf_release(&buf);
        return sequencer_remove_state(opts);
@@ -2614,6 +2790,70 @@ fail:
        return -1;
 }
 
+int sequencer_skip(struct repository *r, struct replay_opts *opts)
+{
+       enum replay_action action = -1;
+       sequencer_get_last_command(r, &action);
+
+       /*
+        * Check whether the subcommand requested to skip the commit is actually
+        * in progress and that it's safe to skip the commit.
+        *
+        * opts->action tells us which subcommand requested to skip the commit.
+        * If the corresponding .git/<ACTION>_HEAD exists, we know that the
+        * action is in progress and we can skip the commit.
+        *
+        * Otherwise we check that the last instruction was related to the
+        * particular subcommand we're trying to execute and barf if that's not
+        * the case.
+        *
+        * Finally we check that the rollback is "safe", i.e., has the HEAD
+        * moved? In this case, it doesn't make sense to "reset the merge" and
+        * "skip the commit" as the user already handled this by committing. But
+        * we'd not want to barf here, instead give advice on how to proceed. We
+        * only need to check that when .git/<ACTION>_HEAD doesn't exist because
+        * it gets removed when the user commits, so if it still exists we're
+        * sure the user can't have committed before.
+        */
+       switch (opts->action) {
+       case REPLAY_REVERT:
+               if (!file_exists(git_path_revert_head(r))) {
+                       if (action != REPLAY_REVERT)
+                               return error(_("no revert in progress"));
+                       if (!rollback_is_safe())
+                               goto give_advice;
+               }
+               break;
+       case REPLAY_PICK:
+               if (!file_exists(git_path_cherry_pick_head(r))) {
+                       if (action != REPLAY_PICK)
+                               return error(_("no cherry-pick in progress"));
+                       if (!rollback_is_safe())
+                               goto give_advice;
+               }
+               break;
+       default:
+               BUG("unexpected action in sequencer_skip");
+       }
+
+       if (skip_single_pick())
+               return error(_("failed to skip the commit"));
+       if (!is_directory(git_path_seq_dir()))
+               return 0;
+
+       return sequencer_continue(r, opts);
+
+give_advice:
+       error(_("there is nothing to skip"));
+
+       if (advice_resolve_conflict) {
+               advise(_("have you committed already?\n"
+                        "try \"git %s --continue\""),
+                        action == REPLAY_REVERT ? "revert" : "cherry-pick");
+       }
+       return -1;
+}
+
 static int save_todo(struct todo_list *todo_list, struct replay_opts *opts)
 {
        struct lock_file todo_lock = LOCK_INIT;
@@ -2661,40 +2901,65 @@ 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");
+
+       if (opts->explicit_cleanup)
+               res |= git_config_set_in_file_gently(opts_file,
+                               "options.default-msg-cleanup",
+                               describe_cleanup_mode(opts->default_msg_cleanup));
        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 +2975,7 @@ 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;
@@ -2728,7 +2993,8 @@ static int make_patch(struct commit *commit, struct replay_opts *opts)
 
        strbuf_addf(&buf, "%s/message", get_dir(opts));
        if (!file_exists(buf.buf)) {
-               const char *commit_buffer = get_commit_buffer(commit, NULL);
+               const char *encoding = get_commit_output_encoding();
+               const char *commit_buffer = logmsg_reencode(commit, NULL, encoding);
                find_commit_subject(commit_buffer, &subject);
                res |= write_message(subject, strlen(subject), buf.buf, 1);
                unuse_commit_buffer(commit, commit_buffer);
@@ -2750,17 +3016,19 @@ 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 +3059,24 @@ 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 +3091,10 @@ 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 +3160,9 @@ 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 +3203,9 @@ 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 +3215,7 @@ 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)) {
@@ -2981,19 +3254,19 @@ 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)));
        }
 
-       if (!fill_tree_descriptor(&desc, &oid)) {
+       if (!fill_tree_descriptor(r, &desc, &oid)) {
                error(_("failed to find tree of %s"), oid_to_hex(&oid));
                rollback_lock_file(&lock);
                free((void *)desc.buffer);
@@ -3009,9 +3282,9 @@ 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 +3317,9 @@ 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) ?
@@ -3053,12 +3328,15 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
        struct commit *head_commit, *merge_commit, *i;
        struct commit_list *bases, *j, *reversed = NULL;
        struct commit_list *to_merge = NULL, **tail = &to_merge;
+       const char *strategy = !opts->xopts_nr &&
+               (!opts->strategy || !strcmp(opts->strategy, "recursive")) ?
+               NULL : opts->strategy;
        struct merge_options o;
        int merge_arg_len, oneline_offset, can_fast_forward, ret, k;
        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;
        }
@@ -3111,14 +3389,15 @@ 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;
        }
 
        if (commit) {
-               const char *message = get_commit_buffer(commit, NULL);
+               const char *encoding = get_commit_output_encoding();
+               const char *message = logmsg_reencode(commit, NULL, encoding);
                const char *body;
                int len;
 
@@ -3130,11 +3409,11 @@ 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 +3435,11 @@ 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;
                }
        }
@@ -3196,12 +3475,16 @@ 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);
+               if (flags & TODO_EDIT_MERGE_MSG) {
+                       run_commit_flags |= AMEND_MSG;
+                       goto fast_forward_edit;
+               }
                goto leave_merge;
        }
 
-       if (to_merge->next) {
+       if (strategy || to_merge->next) {
                /* Octopus merge */
                struct child_process cmd = CHILD_PROCESS_INIT;
 
@@ -3215,13 +3498,20 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
                cmd.git_cmd = 1;
                argv_array_push(&cmd.args, "merge");
                argv_array_push(&cmd.args, "-s");
-               argv_array_push(&cmd.args, "octopus");
+               if (!strategy)
+                       argv_array_push(&cmd.args, "octopus");
+               else {
+                       argv_array_push(&cmd.args, strategy);
+                       for (k = 0; k < opts->xopts_nr; k++)
+                               argv_array_pushf(&cmd.args,
+                                                "-X%s", opts->xopts[k]);
+               }
                argv_array_push(&cmd.args, "--no-edit");
                argv_array_push(&cmd.args, "--no-ff");
                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 +3521,15 @@ 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;
        }
@@ -3252,16 +3543,16 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
                goto leave_merge;
        }
 
-       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);
+       write_message(oid_to_hex(&merge_commit->object.oid), the_hash_algo->hexsz,
+                     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 +3576,24 @@ 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);
+       fast_forward_edit:
+               ret = !!run_git_commit(r, git_path_merge_msg(r), opts,
+                                      run_commit_flags);
 
 leave_merge:
        strbuf_release(&ref_name);
@@ -3400,10 +3692,11 @@ static const char *reflog_message(struct replay_opts *opts,
        return buf.buf;
 }
 
-static int run_git_checkout(struct replay_opts *opts, const char *commit,
-                           const char *action)
+static int run_git_checkout(struct repository *r, struct replay_opts *opts,
+                           const char *commit, const char *action)
 {
        struct child_process cmd = CHILD_PROCESS_INIT;
+       int ret;
 
        cmd.git_cmd = 1;
 
@@ -3412,26 +3705,32 @@ static int run_git_checkout(struct replay_opts *opts, const char *commit,
        argv_array_pushf(&cmd.env_array, GIT_REFLOG_ACTION "=%s", action);
 
        if (opts->verbose)
-               return run_command(&cmd);
+               ret = run_command(&cmd);
        else
-               return run_command_silent_on_success(&cmd);
+               ret = run_command_silent_on_success(&cmd);
+
+       if (!ret)
+               discard_index(r->index);
+
+       return ret;
 }
 
-int prepare_branch_to_be_rebased(struct replay_opts *opts, const char *commit)
+int prepare_branch_to_be_rebased(struct repository *r, struct replay_opts *opts,
+                                const char *commit)
 {
        const char *action;
 
        if (commit && *commit) {
                action = reflog_message(opts, "start", "checkout %s", commit);
-               if (run_git_checkout(opts, commit, action))
+               if (run_git_checkout(r, opts, commit, action))
                        return error(_("could not checkout %s"), commit);
        }
 
        return 0;
 }
 
-static int checkout_onto(struct replay_opts *opts,
-                        const char *onto_name, const char *onto,
+static int checkout_onto(struct repository *r, struct replay_opts *opts,
+                        const char *onto_name, const struct object_id *onto,
                         const char *orig_head)
 {
        struct object_id oid;
@@ -3440,7 +3739,7 @@ static int checkout_onto(struct replay_opts *opts,
        if (get_oid(orig_head, &oid))
                return error(_("%s: not a valid OID"), orig_head);
 
-       if (run_git_checkout(opts, onto, action)) {
+       if (run_git_checkout(r, opts, oid_to_hex(onto), action)) {
                apply_autostash(opts);
                sequencer_remove_state(opts);
                return error(_("could not detach HEAD"));
@@ -3449,14 +3748,14 @@ 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 +3777,9 @@ 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 +3787,14 @@ 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);
+               int check_todo = 0;
+
                if (save_todo(todo_list, opts))
                        return -1;
                if (is_rebase_i(opts)) {
@@ -3503,28 +3807,33 @@ 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());
                        unlink(rebase_path_stopped_sha());
                        unlink(rebase_path_amend());
-                       unlink(git_path_merge_head(the_repository));
+                       unlink(git_path_merge_head(r));
                        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 
-                       if (item->command == TODO_BREAK)
-                               return stopped_at_head();
+                       if (item->command == TODO_BREAK) {
+                               if (!opts->verbose)
+                                       term_clear_line();
+                               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,
-                                       opts, is_final_fixup(todo_list));
+                       res = do_pick_commit(r, item->command, item->commit,
+                                            opts, is_final_fixup(todo_list),
+                                            &check_todo);
                        if (is_rebase_i(opts) && res < 0) {
                                /* Reschedule */
                                advise(_(rescheduled_advice),
@@ -3538,14 +3847,16 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                        }
                        if (item->command == TODO_EDIT) {
                                struct commit *commit = item->commit;
-                               if (!res)
+                               if (!res) {
+                                       if (!opts->verbose)
+                                               term_clear_line();
                                        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 +3864,8 @@ 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 +3883,34 @@ 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;
 
+                       if (!opts->verbose)
+                               term_clear_line();
                        *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))
-                               res = error_errno(_("could not stat '%s'"),
-                                                 get_todo_path(opts));
-                       else if (match_stat_data(&todo_list->stat, &st)) {
-                               todo_list_release(todo_list);
-                               if (read_populate_todo(todo_list, opts))
-                                       res = -1; /* message was printed */
-                               /* `current` will be incremented below */
-                               todo_list->current = -1;
+                       if (res) {
+                               if (opts->reschedule_failed_exec)
+                                       reschedule = 1;
                        }
+                       check_todo = 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 +3918,9 @@ 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 +3933,24 @@ 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);
+               } else if (is_rebase_i(opts) && check_todo && !res) {
+                       struct stat st;
+
+                       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(r, todo_list, opts))
+                                       res = -1; /* message was printed */
+                               /* `current` will be incremented below */
+                               todo_list->current = -1;
+                       }
                }
 
                todo_list->current++;
@@ -3695,7 +4012,7 @@ cleanup_head_ref:
                        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 +4047,7 @@ cleanup_head_ref:
                                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 +4056,13 @@ cleanup_head_ref:
                }
                apply_autostash(opts);
 
-               fprintf(stderr, "Successfully rebased and updated %s.\n",
-                       head_ref.buf);
+               if (!opts->quiet) {
+                       if (!opts->verbose)
+                               term_clear_line();
+                       fprintf(stderr,
+                               "Successfully rebased and updated %s.\n",
+                               head_ref.buf);
+               }
 
                strbuf_release(&buf);
                strbuf_release(&head_ref);
@@ -3752,26 +4075,27 @@ cleanup_head_ref:
        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;
@@ -3854,9 +4178,10 @@ static int commit_staged_changes(struct replay_opts *opts,
                                 */
                                struct commit *commit;
                                const char *path = rebase_path_squash_msg();
+                               const char *encoding = get_commit_output_encoding();
 
-                               if (parse_head(&commit) ||
-                                   !(p = get_commit_buffer(commit, NULL)) ||
+                               if (parse_head(r, &commit) ||
+                                   !(p = logmsg_reencode(commit, NULL, encoding)) ||
                                    write_message(p, strlen(p), path, 0)) {
                                        unuse_commit_buffer(commit, p);
                                        return error(_("could not write file: "
@@ -3871,7 +4196,7 @@ 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"));
@@ -3879,11 +4204,11 @@ 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());
-       unlink(git_path_merge_head(the_repository));
+       unlink(git_path_merge_head(r));
        if (final_fixup) {
                unlink(rebase_path_fixup_msg());
                unlink(rebase_path_squash_msg());
@@ -3900,36 +4225,38 @@ 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))
-                       return -1;
+               if (commit_staged_changes(r, opts, &todo_list)) {
+                       res = -1;
+                       goto release_todo_list;
+               }
        } 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 +4270,33 @@ 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)
 {
+       int check_todo;
+
        setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
-       return do_pick_commit(opts->action == REPLAY_PICK ?
-               TODO_PICK : TODO_REVERT, cmit, opts, 0);
+       return do_pick_commit(r, opts->action == REPLAY_PICK ?
+                             TODO_PICK : TODO_REVERT, cmit, opts, 0,
+                             &check_todo);
 }
 
-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 +4308,8 @@ 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 +4338,7 @@ 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);
        }
 
        /*
@@ -4015,7 +4348,7 @@ int sequencer_pick_revisions(struct replay_opts *opts)
         */
 
        if (walk_revs_populate_todo(&todo_list, opts) ||
-                       create_seq_dir() < 0)
+                       create_seq_dir(r) < 0)
                return -1;
        if (get_oid("HEAD", &oid) && (opts->action == REPLAY_REVERT))
                return error(_("can't revert as initial commit"));
@@ -4024,7 +4357,7 @@ 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 +4369,7 @@ 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)
@@ -4095,9 +4427,14 @@ struct labels_entry {
        char label[FLEX_ARRAY];
 };
 
-static int labels_cmp(const void *fndata, const struct labels_entry *a,
-                     const struct labels_entry *b, const void *key)
+static int labels_cmp(const void *fndata, const struct hashmap_entry *eptr,
+                     const struct hashmap_entry *entry_or_key, const void *key)
 {
+       const struct labels_entry *a, *b;
+
+       a = container_of(eptr, const struct labels_entry, entry);
+       b = container_of(entry_or_key, const struct labels_entry, entry);
+
        return key ? strcmp(a->label, key) : strcmp(a->label, b->label);
 }
 
@@ -4118,7 +4455,6 @@ static const char *label_oid(struct object_id *oid, const char *label,
        struct labels_entry *labels_entry;
        struct string_entry *string_entry;
        struct object_id dummy;
-       size_t len;
        int i;
 
        string_entry = oidmap_get(&state->commit2label, oid);
@@ -4138,11 +4474,11 @@ static const char *label_oid(struct object_id *oid, const char *label,
         * abbreviation for any uninteresting commit's names that does not
         * clash with any other label.
         */
+       strbuf_reset(&state->buf);
        if (!label) {
                char *p;
 
-               strbuf_reset(&state->buf);
-               strbuf_grow(&state->buf, GIT_SHA1_HEXSZ);
+               strbuf_grow(&state->buf, GIT_MAX_HEXSZ);
                label = p = state->buf.buf;
 
                find_unique_abbrev_r(p, oid, default_abbrev);
@@ -4155,7 +4491,7 @@ static const char *label_oid(struct object_id *oid, const char *label,
                        size_t i = strlen(p) + 1;
 
                        oid_to_hex_r(p, oid);
-                       for (; i < GIT_SHA1_HEXSZ; i++) {
+                       for (; i < the_hash_algo->hexsz; i++) {
                                char save = p[i];
                                p[i] = '\0';
                                if (!hashmap_get_from_hash(&state->labels,
@@ -4164,37 +4500,60 @@ static const char *label_oid(struct object_id *oid, const char *label,
                                p[i] = save;
                        }
                }
-       } else if (((len = strlen(label)) == the_hash_algo->hexsz &&
-                   !get_oid_hex(label, &dummy)) ||
-                  (len == 1 && *label == '#') ||
-                  hashmap_get_from_hash(&state->labels,
-                                        strihash(label), label)) {
+       } else {
+               struct strbuf *buf = &state->buf;
+
                /*
-                * If the label already exists, or if the label is a valid full
-                * OID, or the label is a '#' (which we use as a separator
-                * between merge heads and oneline), we append a dash and a
-                * number to make it unique.
+                * Sanitize labels by replacing non-alpha-numeric characters
+                * (including white-space ones) by dashes, as they might be
+                * illegal in file names (and hence in ref names).
+                *
+                * Note that we retain non-ASCII UTF-8 characters (identified
+                * via the most significant bit). They should be all acceptable
+                * in file names. We do not validate the UTF-8 here, that's not
+                * the job of this function.
                 */
-               struct strbuf *buf = &state->buf;
+               for (; *label; label++)
+                       if ((*label & 0x80) || isalnum(*label))
+                               strbuf_addch(buf, *label);
+                       /* avoid leading dash and double-dashes */
+                       else if (buf->len && buf->buf[buf->len - 1] != '-')
+                               strbuf_addch(buf, '-');
+               if (!buf->len) {
+                       strbuf_addstr(buf, "rev-");
+                       strbuf_add_unique_abbrev(buf, oid, default_abbrev);
+               }
+               label = buf->buf;
 
-               strbuf_reset(buf);
-               strbuf_add(buf, label, len);
+               if ((buf->len == the_hash_algo->hexsz &&
+                    !get_oid_hex(label, &dummy)) ||
+                   (buf->len == 1 && *label == '#') ||
+                   hashmap_get_from_hash(&state->labels,
+                                         strihash(label), label)) {
+                       /*
+                        * If the label already exists, or if the label is a
+                        * valid full OID, or the label is a '#' (which we use
+                        * as a separator between merge heads and oneline), we
+                        * append a dash and a number to make it unique.
+                        */
+                       size_t len = buf->len;
 
-               for (i = 2; ; i++) {
-                       strbuf_setlen(buf, len);
-                       strbuf_addf(buf, "-%d", i);
-                       if (!hashmap_get_from_hash(&state->labels,
-                                                  strihash(buf->buf),
-                                                  buf->buf))
-                               break;
-               }
+                       for (i = 2; ; i++) {
+                               strbuf_setlen(buf, len);
+                               strbuf_addf(buf, "-%d", i);
+                               if (!hashmap_get_from_hash(&state->labels,
+                                                          strihash(buf->buf),
+                                                          buf->buf))
+                                       break;
+                       }
 
-               label = buf->buf;
+                       label = buf->buf;
+               }
        }
 
        FLEX_ALLOC_STR(labels_entry, label, label);
-       hashmap_entry_init(labels_entry, strihash(label));
-       hashmap_add(&state->labels, labels_entry);
+       hashmap_entry_init(&labels_entry->entry, strihash(label));
+       hashmap_add(&state->labels, &labels_entry->entry);
 
        FLEX_ALLOC_STR(string_entry, string, label);
        oidcpy(&string_entry->entry.oid, oid);
@@ -4204,11 +4563,12 @@ 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;
        int rebase_cousins = flags & TODO_LIST_REBASE_COUSINS;
+       int root_with_onto = flags & TODO_LIST_ROOT_WITH_ONTO;
        struct strbuf buf = STRBUF_INIT, oneline = STRBUF_INIT;
        struct strbuf label = STRBUF_INIT;
        struct commit_list *commits = NULL, **tail = &commits, *iter;
@@ -4228,14 +4588,19 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 
        oidmap_init(&commit2todo, 0);
        oidmap_init(&state.commit2label, 0);
-       hashmap_init(&state.labels, (hashmap_cmp_fn) labels_cmp, NULL, 0);
+       hashmap_init(&state.labels, labels_cmp, NULL, 0);
        strbuf_init(&state.buf, 32);
 
        if (revs->cmdline.nr && (revs->cmdline.rev[0].flags & BOTTOM)) {
+               struct labels_entry *onto_label_entry;
                struct object_id *oid = &revs->cmdline.rev[0].item->oid;
                FLEX_ALLOC_STR(entry, string, "onto");
                oidcpy(&entry->entry.oid, oid);
                oidmap_put(&state.commit2label, entry);
+
+               FLEX_ALLOC_STR(onto_label_entry, label, "onto");
+               hashmap_entry_init(&onto_label_entry->entry, strihash("onto"));
+               hashmap_add(&state.labels, &onto_label_entry->entry);
        }
 
        /*
@@ -4290,10 +4655,6 @@ static int make_script_with_merges(struct pretty_print_context *pp,
                else
                        strbuf_addbuf(&label, &oneline);
 
-               for (p1 = label.buf; *p1; p1++)
-                       if (isspace(*p1))
-                               *(char *)p1 = '-';
-
                strbuf_reset(&buf);
                strbuf_addf(&buf, "%s -C %s",
                            cmd_merge, oid_to_hex(&commit->object.oid));
@@ -4336,7 +4697,7 @@ static int make_script_with_merges(struct pretty_print_context *pp,
                                label_oid(oid, "branch-point", &state);
                }
 
-               /* Add HEAD as implict "tip of branch" */
+               /* Add HEAD as implicit "tip of branch" */
                if (!iter->next)
                        tips_tail = &commit_list_insert(iter->item,
                                                        tips_tail)->next;
@@ -4349,7 +4710,7 @@ 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 +4720,9 @@ 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 +4735,9 @@ 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 || root_with_onto ?
+                                   "onto" : "[new root]");
                else {
                        const char *to = NULL;
 
@@ -4388,12 +4750,12 @@ 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 +4764,11 @@ 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);
                }
 
@@ -4422,25 +4784,24 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 
        oidmap_free(&commit2todo, 1);
        oidmap_free(&state.commit2label, 1);
-       hashmap_free(&state.labels, 1);
+       hashmap_free_entries(&state.labels, struct labels_entry, entry);
        strbuf_release(&state.buf);
 
        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 +4837,13 @@ 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 +4851,95 @@ 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);
 
-       if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
-               return error(_("could not read '%s'."), todo_file);
+               strbuf_addstr(buf, commands->items[i].string);
+               strbuf_addch(buf, '\n');
 
-       if (parse_insn_buffer(todo_list.buf.buf, &todo_list)) {
-               todo_list_release(&todo_list);
-               return error(_("unusable todo list: '%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 ");
+
+               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 immediately 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;
-
-       if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
-               return error(_("could not read '%s'."), todo_file);
+       int i, max = todo_list->nr;
 
-       if (parse_insn_buffer(todo_list.buf.buf, &todo_list)) {
-               todo_list_release(&todo_list);
-               return error(_("unusable todo list: '%s'"), todo_file);
-       }
+       if (num > 0 && num < max)
+               max = num;
 
-       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 +4949,92 @@ 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 +5043,116 @@ 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->done_nr += i;
 
-               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)
+                   struct commit *onto, const char *orig_head,
+                   struct string_list *commands, unsigned autosquash,
+                   struct todo_list *todo_list)
 {
        const char *shortonto, *todo_file = rebase_path_todo();
-       struct todo_list todo_list = TODO_LIST_INIT;
-       struct strbuf *buf = &(todo_list.buf);
-       struct object_id oid;
-       struct stat st;
+       struct todo_list new_todo = TODO_LIST_INIT;
+       struct strbuf *buf = &todo_list->buf;
+       struct object_id oid = onto->object.oid;
+       int res;
 
-       get_oid(onto, &oid);
        shortonto = find_unique_abbrev(&oid, DEFAULT_ABBREV);
 
-       if (!lstat(todo_file, &st) && st.st_size == 0 &&
-           write_message("noop\n", 5, todo_file, 0))
-               return -1;
+       if (buf->len == 0) {
+               struct todo_item *item = append_new_todo(todo_list);
+               item->command = TODO_NOOP;
+               item->commit = NULL;
+               item->arg_len = item->arg_offset = item->flags = item->offset_in_buf = 0;
+       }
 
-       if (autosquash && rearrange_squash())
+       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 (commands->nr)
+               todo_list_add_exec_commands(todo_list, commands);
 
-       if (parse_insn_buffer(buf->buf, &todo_list)) {
-               todo_list_release(&todo_list);
-               return error(_("unusable todo list: '%s'"), todo_file);
-       }
-
-       if (count_commands(&todo_list) == 0) {
+       if (count_commands(todo_list) == 0) {
                apply_autostash(opts);
                sequencer_remove_state(opts);
-               todo_list_release(&todo_list);
 
                return error(_("nothing to do"));
        }
 
-       strbuf_addch(buf, '\n');
-       strbuf_commented_addf(buf, Q_("Rebase %s onto %s (%d command)",
-                                     "Rebase %s onto %s (%d commands)",
-                                     count_commands(&todo_list)),
-                             shortrevisions, shortonto, count_commands(&todo_list));
-       append_todo_help(0, flags & TODO_LIST_KEEP_EMPTY, buf);
-
-       if (write_message(buf->buf, buf->len, todo_file, 0)) {
-               todo_list_release(&todo_list);
+       res = edit_todo_list(r, todo_list, &new_todo, shortrevisions,
+                            shortonto, flags);
+       if (res == -1)
                return -1;
-       }
-
-       if (copy_file(rebase_path_todo_backup(), todo_file, 0666))
-               return error(_("could not copy '%s' to '%s'."), todo_file,
-                            rebase_path_todo_backup());
-
-       if (transform_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 (todo_list_parse_insn_buffer(r, new_todo.buf.buf, &new_todo) ||
+           todo_list_check(todo_list, &new_todo)) {
+               fprintf(stderr, _(edit_todo_list_advice));
+               checkout_onto(r, opts, onto_name, &onto->object.oid, orig_head);
+               todo_list_release(&new_todo);
 
-       if (check_todo_list()) {
-               checkout_onto(opts, onto_name, onto, orig_head);
                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 (checkout_onto(opts, onto_name, oid_to_hex(&oid), orig_head))
-               return -1;
+       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);
+       }
 
-       if (require_clean_work_tree("rebase", "", 1, 1))
-               return -1;
+       res = -1;
 
-       return sequencer_continue(opts);
+       if (checkout_onto(r, opts, onto_name, &oid, orig_head))
+               goto cleanup;
+
+       if (require_clean_work_tree(r, "rebase", "", 1, 1))
+               goto cleanup;
+
+       todo_list_write_total_nr(&new_todo);
+       res = pick_commits(r, &new_todo, opts);
+
+cleanup:
+       todo_list_release(&new_todo);
+
+       return res;
 }
 
 struct subject2item_entry {
@@ -4915,9 +5162,15 @@ struct subject2item_entry {
 };
 
 static int subject2item_cmp(const void *fndata,
-                           const struct subject2item_entry *a,
-                           const struct subject2item_entry *b, const void *key)
+                           const struct hashmap_entry *eptr,
+                           const struct hashmap_entry *entry_or_key,
+                           const void *key)
 {
+       const struct subject2item_entry *a, *b;
+
+       a = container_of(eptr, const struct subject2item_entry, entry);
+       b = container_of(entry_or_key, const struct subject2item_entry, entry);
+
        return key ? strcmp(a->subject, key) : strcmp(a->subject, b->subject);
 }
 
@@ -4932,21 +5185,13 @@ 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);
        /*
@@ -4958,14 +5203,13 @@ int rearrange_squash(void)
         * In that case, last[i] will indicate the index of the latest item to
         * 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++) {
+       hashmap_init(&subject2item, 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++) {
                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 +5222,6 @@ 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."));
                }
@@ -4986,7 +5229,7 @@ int rearrange_squash(void)
                *commit_todo_item_at(&commit_todo, item->commit) = item;
 
                parse_commit(item->commit);
-               commit_buffer = get_commit_buffer(item->commit, NULL);
+               commit_buffer = logmsg_reencode(item->commit, NULL, "UTF-8");
                find_commit_subject(commit_buffer, &subject);
                format_subject(&buf, subject, " ");
                subject = subjects[i] = strbuf_detach(&buf, &subject_len);
@@ -5003,8 +5246,11 @@ int rearrange_squash(void)
                                        break;
                        }
 
-                       if ((entry = hashmap_get_from_hash(&subject2item,
-                                                          strhash(p), p)))
+                       entry = hashmap_get_entry_from_hash(&subject2item,
+                                               strhash(p), p,
+                                               struct subject2item_entry,
+                                               entry);
+                       if (entry)
                                /* found by title */
                                i2 = entry->i;
                        else if (!strchr(p, ' ') &&
@@ -5013,7 +5259,7 @@ 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 +5272,7 @@ 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)
@@ -5038,16 +5284,15 @@ int rearrange_squash(void)
                                                strhash(subject), subject)) {
                        FLEX_ALLOC_MEM(entry, subject, subject, subject_len);
                        entry->i = i;
-                       hashmap_entry_init(entry, strhash(entry->subject));
-                       hashmap_put(&subject2item, entry);
+                       hashmap_entry_init(&entry->entry,
+                                       strhash(entry->subject));
+                       hashmap_put(&subject2item, &entry->entry);
                }
        }
 
        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 +5303,26 @@ 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);
+       hashmap_free_entries(&subject2item, struct subject2item_entry, entry);
 
        clear_commit_todo_item(&commit_todo);
-       return res;
+
+       return 0;
 }