rebase -i: rewrite init_basic_state() in C
[gitweb.git] / sequencer.c
index 0f017c058c0e42b810c25850fb836a3ee848f891..8dd6db5a017030da8468a48fe868d2982394699d 100644 (file)
@@ -2,6 +2,7 @@
 #include "config.h"
 #include "lockfile.h"
 #include "dir.h"
+#include "object-store.h"
 #include "object.h"
 #include "commit.h"
 #include "sequencer.h"
@@ -27,6 +28,9 @@
 #include "worktree.h"
 #include "oidmap.h"
 #include "oidset.h"
+#include "commit-slab.h"
+#include "alias.h"
+#include "rebase-interactive.h"
 
 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
 
@@ -49,7 +53,10 @@ static GIT_PATH_FUNC(rebase_path, "rebase-merge")
  * the lines are processed, they are removed from the front of this
  * file and written to the tail of 'done'.
  */
-static GIT_PATH_FUNC(rebase_path_todo, "rebase-merge/git-rebase-todo")
+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")
+
 /*
  * The rebase command lines that have already been processed. A line
  * is moved here when it is first handled, before any associated user
@@ -78,13 +85,6 @@ static GIT_PATH_FUNC(rebase_path_message, "rebase-merge/message")
  * previous commit and from the first squash/fixup commit are written
  * to it. The commit message for each subsequent squash/fixup commit
  * is appended to the file as it is processed.
- *
- * The first line of the file is of the form
- *     # This is a combination of $count commits.
- * where $count is the number of commits whose messages have been
- * written to the file so far (including the initial "pick" commit).
- * Each time that a commit message is processed, this line is read and
- * updated. It is deleted just before the combined commit is made.
  */
 static GIT_PATH_FUNC(rebase_path_squash_msg, "rebase-merge/message-squash")
 /*
@@ -95,6 +95,11 @@ static GIT_PATH_FUNC(rebase_path_squash_msg, "rebase-merge/message-squash")
  * commit without opening the editor.)
  */
 static GIT_PATH_FUNC(rebase_path_fixup_msg, "rebase-merge/message-fixup")
+/*
+ * This file contains the list fixup/squash commands that have been
+ * accumulated into message-fixup or message-squash so far.
+ */
+static GIT_PATH_FUNC(rebase_path_current_fixups, "rebase-merge/current-fixups")
 /*
  * A script to set the GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
  * GIT_AUTHOR_DATE that will be used for the commit that is currently
@@ -139,7 +144,7 @@ static GIT_PATH_FUNC(rebase_path_refs_to_delete, "rebase-merge/refs-to-delete")
 
 /*
  * The following files are written by git-rebase just after parsing the
- * command-line (and are only consumed, not modified, by the sequencer).
+ * command-line.
  */
 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")
@@ -151,6 +156,7 @@ 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 int git_sequencer_config(const char *k, const char *v, void *cb)
 {
@@ -176,6 +182,7 @@ static int git_sequencer_config(const char *k, const char *v, void *cb)
                        warning(_("invalid commit message cleanup mode '%s'"),
                                  s);
 
+               free((char *)s);
                return status;
        }
 
@@ -285,6 +292,7 @@ int sequencer_remove_state(struct replay_opts *opts)
        for (i = 0; i < opts->xopts_nr; i++)
                free(opts->xopts[i]);
        free(opts->xopts);
+       strbuf_release(&opts->current_fixups);
 
        strbuf_reset(&buf);
        strbuf_addstr(&buf, get_dir(opts));
@@ -355,7 +363,7 @@ 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());
+               unlink(git_path_cherry_pick_head(the_repository));
                return;
        }
 
@@ -370,8 +378,8 @@ static void print_advice(int show_hint, struct replay_opts *opts)
        }
 }
 
-static int write_message(const void *buf, size_t len, const char *filename,
-                        int append_eol)
+int write_message(const void *buf, size_t len, const char *filename,
+                 int append_eol)
 {
        struct lock_file msg_file = LOCK_INIT;
 
@@ -536,8 +544,8 @@ static int do_recursive_merge(struct commit *base, struct commit *next,
        o.show_rename_progress = 1;
 
        head_tree = parse_tree_indirect(head);
-       next_tree = next ? next->tree : empty_tree();
-       base_tree = base ? base->tree : empty_tree();
+       next_tree = next ? get_commit_tree(next) : empty_tree();
+       base_tree = base ? get_commit_tree(base) : empty_tree();
 
        for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
                parse_merge_opt(&o, *xopt);
@@ -607,7 +615,7 @@ static int is_index_unchanged(void)
        if (!(cache_tree_oid = get_cache_tree_oid()))
                return -1;
 
-       return !oidcmp(cache_tree_oid, &head_commit->tree->object.oid);
+       return !oidcmp(cache_tree_oid, get_commit_tree_oid(head_commit));
 }
 
 static int write_author_script(const char *message)
@@ -766,6 +774,23 @@ N_("you have staged changes in your working tree\n"
 #define VERIFY_MSG  (1<<4)
 #define CREATE_ROOT_COMMIT (1<<5)
 
+static int run_command_silent_on_success(struct child_process *cmd)
+{
+       struct strbuf buf = STRBUF_INIT;
+       int rc;
+
+       cmd->stdout_to_stderr = 1;
+       rc = pipe_command(cmd,
+                         NULL, 0,
+                         NULL, 0,
+                         &buf, 0);
+
+       if (rc)
+               fputs(buf.buf, stderr);
+       strbuf_release(&buf);
+       return rc;
+}
+
 /*
  * If we are cherry-pick, and if the merge did not result in
  * hand-editing, we will hit this commit and inherit the original
@@ -820,18 +845,11 @@ static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 
        cmd.git_cmd = 1;
 
-       if (is_rebase_i(opts)) {
-               if (!(flags & EDIT_MSG)) {
-                       cmd.stdout_to_stderr = 1;
-                       cmd.err = -1;
-               }
-
-               if (read_env_script(&cmd.env_array)) {
-                       const char *gpg_opt = gpg_sign_opt_quoted(opts);
+       if (is_rebase_i(opts) && read_env_script(&cmd.env_array)) {
+               const char *gpg_opt = gpg_sign_opt_quoted(opts);
 
-                       return error(_(staged_changes_advice),
-                                    gpg_opt, gpg_opt);
-               }
+               return error(_(staged_changes_advice),
+                            gpg_opt, gpg_opt);
        }
 
        argv_array_push(&cmd.args, "commit");
@@ -844,6 +862,8 @@ static int run_git_commit(const char *defmsg, struct replay_opts *opts,
                argv_array_pushf(&cmd.args, "-S%s", opts->gpg_sign);
        if (defmsg)
                argv_array_pushl(&cmd.args, "-F", defmsg, NULL);
+       else if (!(flags & EDIT_MSG))
+               argv_array_pushl(&cmd.args, "-C", "HEAD", NULL);
        if ((flags & CLEANUP_MSG))
                argv_array_push(&cmd.args, "--cleanup=strip");
        if ((flags & EDIT_MSG))
@@ -859,21 +879,10 @@ static int run_git_commit(const char *defmsg, struct replay_opts *opts,
        if (opts->allow_empty_message)
                argv_array_push(&cmd.args, "--allow-empty-message");
 
-       if (cmd.err == -1) {
-               /* hide stderr on success */
-               struct strbuf buf = STRBUF_INIT;
-               int rc = pipe_command(&cmd,
-                                     NULL, 0,
-                                     /* stdout is already redirected */
-                                     NULL, 0,
-                                     &buf, 0);
-               if (rc)
-                       fputs(buf.buf, stderr);
-               strbuf_release(&buf);
-               return rc;
-       }
-
-       return run_command(&cmd);
+       if (is_rebase_i(opts) && !(flags & EDIT_MSG))
+               return run_command_silent_on_success(&cmd);
+       else
+               return run_command(&cmd);
 }
 
 static int rest_is_empty(const struct strbuf *sb, int start)
@@ -1245,8 +1254,8 @@ static int try_to_commit(struct strbuf *msg, const char *author,
        }
 
        if (!(flags & ALLOW_EMPTY) && !oidcmp(current_head ?
-                                             &current_head->tree->object.oid :
-                                             &empty_tree_oid, &tree)) {
+                                             get_commit_tree_oid(current_head) :
+                                             the_hash_algo->empty_tree, &tree)) {
                res = 1; /* run 'git commit' to display error message */
                goto out;
        }
@@ -1275,6 +1284,8 @@ static int try_to_commit(struct strbuf *msg, const char *author,
                goto out;
        }
 
+       reset_ident_date();
+
        if (commit_tree_extended(msg->buf, msg->len, &tree, parents,
                                 oid, author, opts->gpg_sign, extra)) {
                res = error(_("failed to write commit object"));
@@ -1318,8 +1329,8 @@ static int do_commit(const char *msg_file, const char *author,
                                    &oid);
                strbuf_release(&sb);
                if (!res) {
-                       unlink(git_path_cherry_pick_head());
-                       unlink(git_path_merge_msg());
+                       unlink(git_path_cherry_pick_head(the_repository));
+                       unlink(git_path_merge_msg(the_repository));
                        if (!is_rebase_i(opts))
                                print_commit_summary(NULL, &oid,
                                                SUMMARY_SHOW_AUTHOR_DATE);
@@ -1344,12 +1355,12 @@ static int is_original_commit_empty(struct commit *commit)
                if (parse_commit(parent))
                        return error(_("could not parse parent commit %s"),
                                oid_to_hex(&parent->object.oid));
-               ptree_oid = &parent->tree->object.oid;
+               ptree_oid = get_commit_tree_oid(parent);
        } else {
                ptree_oid = the_hash_algo->empty_tree; /* commit is root */
        }
 
-       return !oidcmp(ptree_oid, &commit->tree->object.oid);
+       return !oidcmp(ptree_oid, get_commit_tree_oid(commit));
 }
 
 /*
@@ -1478,34 +1489,23 @@ static int update_squash_messages(enum todo_command command,
                struct commit *commit, struct replay_opts *opts)
 {
        struct strbuf buf = STRBUF_INIT;
-       int count, res;
+       int res;
        const char *message, *body;
 
-       if (file_exists(rebase_path_squash_msg())) {
+       if (opts->current_fixup_count > 0) {
                struct strbuf header = STRBUF_INIT;
-               char *eol, *p;
+               char *eol;
 
-               if (strbuf_read_file(&buf, rebase_path_squash_msg(), 2048) <= 0)
+               if (strbuf_read_file(&buf, rebase_path_squash_msg(), 9) <= 0)
                        return error(_("could not read '%s'"),
                                rebase_path_squash_msg());
 
-               p = buf.buf + 1;
-               eol = strchrnul(buf.buf, '\n');
-               if (buf.buf[0] != comment_line_char ||
-                   (p += strcspn(p, "0123456789\n")) == eol)
-                       return error(_("unexpected 1st line of squash message:"
-                                      "\n\n\t%.*s"),
-                                    (int)(eol - buf.buf), buf.buf);
-               count = strtol(p, NULL, 10);
-
-               if (count < 1)
-                       return error(_("invalid 1st line of squash message:\n"
-                                      "\n\t%.*s"),
-                                    (int)(eol - buf.buf), buf.buf);
+               eol = buf.buf[0] != comment_line_char ?
+                       buf.buf : strchrnul(buf.buf, '\n');
 
                strbuf_addf(&header, "%c ", comment_line_char);
-               strbuf_addf(&header,
-                           _("This is a combination of %d commits."), ++count);
+               strbuf_addf(&header, _("This is a combination of %d commits."),
+                           opts->current_fixup_count + 2);
                strbuf_splice(&buf, 0, eol - buf.buf, header.buf, header.len);
                strbuf_release(&header);
        } else {
@@ -1528,10 +1528,8 @@ static int update_squash_messages(enum todo_command command,
                                     rebase_path_fixup_msg());
                }
 
-               count = 2;
                strbuf_addf(&buf, "%c ", comment_line_char);
-               strbuf_addf(&buf, _("This is a combination of %d commits."),
-                           count);
+               strbuf_addf(&buf, _("This is a combination of %d commits."), 2);
                strbuf_addf(&buf, "\n%c ", comment_line_char);
                strbuf_addstr(&buf, _("This is the 1st commit message:"));
                strbuf_addstr(&buf, "\n\n");
@@ -1548,13 +1546,14 @@ static int update_squash_messages(enum todo_command command,
        if (command == TODO_SQUASH) {
                unlink(rebase_path_fixup_msg());
                strbuf_addf(&buf, "\n%c ", comment_line_char);
-               strbuf_addf(&buf, _("This is the commit message #%d:"), count);
+               strbuf_addf(&buf, _("This is the commit message #%d:"),
+                           ++opts->current_fixup_count);
                strbuf_addstr(&buf, "\n\n");
                strbuf_addstr(&buf, body);
        } else if (command == TODO_FIXUP) {
                strbuf_addf(&buf, "\n%c ", comment_line_char);
                strbuf_addf(&buf, _("The commit message #%d will be skipped:"),
-                           count);
+                           ++opts->current_fixup_count);
                strbuf_addstr(&buf, "\n\n");
                strbuf_add_commented_lines(&buf, body, strlen(body));
        } else
@@ -1563,6 +1562,17 @@ static int update_squash_messages(enum todo_command command,
 
        res = write_message(buf.buf, buf.len, rebase_path_squash_msg(), 0);
        strbuf_release(&buf);
+
+       if (!res) {
+               strbuf_addf(&opts->current_fixups, "%s%s %s",
+                           opts->current_fixups.len ? "\n" : "",
+                           command_to_string(command),
+                           oid_to_hex(&commit->object.oid));
+               res = write_message(opts->current_fixups.buf,
+                                   opts->current_fixups.len,
+                                   rebase_path_current_fixups(), 0);
+       }
+
        return res;
 }
 
@@ -1608,7 +1618,7 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
                struct replay_opts *opts, int final_fixup)
 {
        unsigned int flags = opts->edit ? EDIT_MSG : 0;
-       const char *msg_file = opts->edit ? NULL : git_path_merge_msg();
+       const char *msg_file = opts->edit ? NULL : git_path_merge_msg(the_repository);
        struct object_id head;
        struct commit *base, *next, *parent;
        const char *base_label, *next_label;
@@ -1637,7 +1647,7 @@ 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_SHA1_HEX : "HEAD",
+               if (index_differs_from(unborn ? empty_tree_oid_hex() : "HEAD",
                                       NULL, 0))
                        return error_dirty_index(opts);
        }
@@ -1750,12 +1760,12 @@ 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();
+                       const char *dest = git_path_squash_msg(the_repository);
                        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());
+                       unlink(git_path_merge_msg(the_repository));
                        msg_file = dest;
                        flags |= EDIT_MSG;
                }
@@ -1770,15 +1780,16 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
                res = do_recursive_merge(base, next, base_label, next_label,
                                         &head, &msgbuf, opts);
                if (res < 0)
-                       return res;
+                       goto leave;
+
                res |= write_message(msgbuf.buf, msgbuf.len,
-                                    git_path_merge_msg(), 0);
+                                    git_path_merge_msg(the_repository), 0);
        } else {
                struct commit_list *common = NULL;
                struct commit_list *remotes = NULL;
 
                res = write_message(msgbuf.buf, msgbuf.len,
-                                   git_path_merge_msg(), 0);
+                                   git_path_merge_msg(the_repository), 0);
 
                commit_list_insert(base, &common);
                commit_list_insert(next, &remotes);
@@ -1832,6 +1843,9 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
        if (!res && final_fixup) {
                unlink(rebase_path_fixup_msg());
                unlink(rebase_path_squash_msg());
+               unlink(rebase_path_current_fixups());
+               strbuf_reset(&opts->current_fixups);
+               opts->current_fixup_count = 0;
        }
 
 leave:
@@ -2194,18 +2208,16 @@ static int populate_opts_cb(const char *key, const char *value, void *data)
        return 0;
 }
 
-static void read_strategy_opts(struct replay_opts *opts, struct strbuf *buf)
+void parse_strategy_opts(struct replay_opts *opts, char *raw_opts)
 {
        int i;
+       char *strategy_opts_string = raw_opts;
 
-       strbuf_reset(buf);
-       if (!read_oneliner(buf, rebase_path_strategy(), 0))
-               return;
-       opts->strategy = strbuf_detach(buf, NULL);
-       if (!read_oneliner(buf, rebase_path_strategy_opts(), 0))
-               return;
+       if (*strategy_opts_string == ' ')
+               strategy_opts_string++;
 
-       opts->xopts_nr = split_cmdline(buf->buf, (const char ***)&opts->xopts);
+       opts->xopts_nr = split_cmdline(strategy_opts_string,
+                                      (const char ***)&opts->xopts);
        for (i = 0; i < opts->xopts_nr; i++) {
                const char *arg = opts->xopts[i];
 
@@ -2214,6 +2226,18 @@ static void read_strategy_opts(struct replay_opts *opts, struct strbuf *buf)
        }
 }
 
+static void read_strategy_opts(struct replay_opts *opts, struct strbuf *buf)
+{
+       strbuf_reset(buf);
+       if (!read_oneliner(buf, rebase_path_strategy(), 0))
+               return;
+       opts->strategy = strbuf_detach(buf, NULL);
+       if (!read_oneliner(buf, rebase_path_strategy_opts(), 0))
+               return;
+
+       parse_strategy_opts(opts, buf->buf);
+}
+
 static int read_populate_opts(struct replay_opts *opts)
 {
        if (is_rebase_i(opts)) {
@@ -2248,6 +2272,16 @@ static int read_populate_opts(struct replay_opts *opts)
                read_strategy_opts(opts, &buf);
                strbuf_release(&buf);
 
+               if (read_oneliner(&opts->current_fixups,
+                                 rebase_path_current_fixups(), 1)) {
+                       const char *p = opts->current_fixups.buf;
+                       opts->current_fixup_count = 1;
+                       while ((p = strchr(p, '\n'))) {
+                               opts->current_fixup_count++;
+                               p++;
+                       }
+               }
+
                if (read_oneliner(&buf, rebase_path_squash_onto(), 0)) {
                        if (get_oid_hex(buf.buf, &opts->squash_onto) < 0)
                                return error(_("unusable squash-onto"));
@@ -2271,6 +2305,55 @@ static int read_populate_opts(struct replay_opts *opts)
        return 0;
 }
 
+static void write_strategy_opts(struct replay_opts *opts)
+{
+       int i;
+       struct strbuf buf = STRBUF_INIT;
+
+       for (i = 0; i < opts->xopts_nr; ++i)
+               strbuf_addf(&buf, " --%s", opts->xopts[i]);
+
+       write_file(rebase_path_strategy_opts(), "%s\n", buf.buf);
+       strbuf_release(&buf);
+}
+
+int write_basic_state(struct replay_opts *opts, const char *head_name,
+                     const char *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);
+       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(), "");
+       if (opts->strategy)
+               write_file(rebase_path_strategy(), "%s\n", opts->strategy);
+       if (opts->xopts_nr > 0)
+               write_strategy_opts(opts);
+
+       if (opts->allow_rerere_auto == RERERE_AUTOUPDATE)
+               write_file(rebase_path_allow_rerere_autoupdate(), "--rerere-autoupdate\n");
+       else if (opts->allow_rerere_auto == RERERE_NOAUTOUPDATE)
+               write_file(rebase_path_allow_rerere_autoupdate(), "--no-rerere-autoupdate\n");
+
+       if (opts->gpg_sign)
+               write_file(rebase_path_gpg_sign_opt(), "-S%s\n", opts->gpg_sign);
+       if (opts->signoff)
+               write_file(rebase_path_signoff(), "--signoff\n");
+
+       return 0;
+}
+
 static int walk_revs_populate_todo(struct todo_list *todo_list,
                                struct replay_opts *opts)
 {
@@ -2375,8 +2458,8 @@ static int rollback_single_pick(void)
 {
        struct object_id head_oid;
 
-       if (!file_exists(git_path_cherry_pick_head()) &&
-           !file_exists(git_path_revert_head()))
+       if (!file_exists(git_path_cherry_pick_head(the_repository)) &&
+           !file_exists(git_path_revert_head(the_repository)))
                return error(_("no cherry-pick or revert in progress"));
        if (read_ref_full("HEAD", 0, &head_oid, NULL))
                return error(_("cannot resolve HEAD"));
@@ -2598,14 +2681,14 @@ static int error_with_patch(struct commit *commit,
 static int error_failed_squash(struct commit *commit,
        struct replay_opts *opts, int subject_len, const char *subject)
 {
-       if (rename(rebase_path_squash_msg(), rebase_path_message()))
-               return error(_("could not rename '%s' to '%s'"),
+       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(rebase_path_fixup_msg());
-       unlink(git_path_merge_msg());
-       if (copy_file(git_path_merge_msg(), rebase_path_message(), 0666))
+       unlink(git_path_merge_msg(the_repository));
+       if (copy_file(git_path_merge_msg(the_repository), rebase_path_message(), 0666))
                return error(_("could not copy '%s' to '%s'"),
-                            rebase_path_message(), git_path_merge_msg());
+                            rebase_path_message(),
+                            git_path_merge_msg(the_repository));
        return error_with_patch(commit, subject, subject_len, opts, 1, 0);
 }
 
@@ -2693,7 +2776,7 @@ static int safe_append(const char *filename, const char *fmt, ...)
 
 static int do_label(const char *name, int len)
 {
-       struct ref_store *refs = get_main_ref_store();
+       struct ref_store *refs = get_main_ref_store(the_repository);
        struct ref_transaction *transaction;
        struct strbuf ref_name = STRBUF_INIT, err = STRBUF_INIT;
        struct strbuf msg = STRBUF_INIT;
@@ -2747,18 +2830,34 @@ static int do_reset(const char *name, int len, struct replay_opts *opts)
        if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
                return -1;
 
-       /* Determine the length of the label */
-       for (i = 0; i < len; i++)
-               if (isspace(name[i]))
-                       len = i;
-
-       strbuf_addf(&ref_name, "refs/rewritten/%.*s", len, name);
-       if (get_oid(ref_name.buf, &oid) &&
-           get_oid(ref_name.buf + strlen("refs/rewritten/"), &oid)) {
-               error(_("could not read '%s'"), ref_name.buf);
-               rollback_lock_file(&lock);
-               strbuf_release(&ref_name);
-               return -1;
+       if (len == 10 && !strncmp("[new root]", name, len)) {
+               if (!opts->have_squash_onto) {
+                       const char *hex;
+                       if (commit_tree("", 0, the_hash_algo->empty_tree,
+                                       NULL, &opts->squash_onto,
+                                       NULL, NULL))
+                               return error(_("writing fake root commit"));
+                       opts->have_squash_onto = 1;
+                       hex = oid_to_hex(&opts->squash_onto);
+                       if (write_message(hex, strlen(hex),
+                                         rebase_path_squash_onto(), 0))
+                               return error(_("writing squash-onto"));
+               }
+               oidcpy(&oid, &opts->squash_onto);
+       } else {
+               /* Determine the length of the label */
+               for (i = 0; i < len; i++)
+                       if (isspace(name[i]))
+                               len = i;
+
+               strbuf_addf(&ref_name, "refs/rewritten/%.*s", len, name);
+               if (get_oid(ref_name.buf, &oid) &&
+                   get_oid(ref_name.buf + strlen("refs/rewritten/"), &oid)) {
+                       error(_("could not read '%s'"), ref_name.buf);
+                       rollback_lock_file(&lock);
+                       strbuf_release(&ref_name);
+                       return -1;
+               }
        }
 
        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
@@ -2854,6 +2953,18 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
                goto leave_merge;
        }
 
+       if (opts->have_squash_onto &&
+           !oidcmp(&head_commit->object.oid, &opts->squash_onto)) {
+               /*
+                * When the user tells us to "merge" something into a
+                * "[new root]", let's simply fast-forward to the merge head.
+                */
+               rollback_lock_file(&lock);
+               ret = fast_forward_to(&merge_commit->object.oid,
+                                      &head_commit->object.oid, 0, opts);
+               goto leave_merge;
+       }
+
        if (commit) {
                const char *message = get_commit_buffer(commit, NULL);
                const char *body;
@@ -2867,11 +2978,11 @@ 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(), 0);
+               ret = write_message(body, len, git_path_merge_msg(the_repository), 0);
                unuse_commit_buffer(commit, message);
                if (ret) {
                        error_errno(_("could not write '%s'"),
-                                   git_path_merge_msg());
+                                   git_path_merge_msg(the_repository));
                        goto leave_merge;
                }
        } else {
@@ -2892,11 +3003,11 @@ 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(), 0);
+               ret = write_message(p, len, git_path_merge_msg(the_repository), 0);
                strbuf_release(&buf);
                if (ret) {
                        error_errno(_("could not write '%s'"),
-                                   git_path_merge_msg());
+                                   git_path_merge_msg(the_repository));
                        goto leave_merge;
                }
        }
@@ -2933,8 +3044,8 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
        }
 
        write_message(oid_to_hex(&merge_commit->object.oid), GIT_SHA1_HEXSZ,
-                     git_path_merge_head(), 0);
-       write_message("no-ff", 5, git_path_merge_mode(), 0);
+                     git_path_merge_head(the_repository), 0);
+       write_message("no-ff", 5, git_path_merge_mode(the_repository), 0);
 
        bases = get_merge_bases(head_commit, merge_commit);
        if (bases && !oidcmp(&merge_commit->object.oid,
@@ -2988,7 +3099,7 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
                 * value (a negative one would indicate that the `merge`
                 * command needs to be rescheduled).
                 */
-               ret = !!run_git_commit(git_path_merge_msg(), opts,
+               ret = !!run_git_commit(git_path_merge_msg(the_repository), opts,
                                     run_commit_flags);
 
 leave_merge:
@@ -3087,6 +3198,55 @@ 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)
+{
+       struct child_process cmd = CHILD_PROCESS_INIT;
+
+       cmd.git_cmd = 1;
+
+       argv_array_push(&cmd.args, "checkout");
+       argv_array_push(&cmd.args, commit);
+       argv_array_pushf(&cmd.env_array, GIT_REFLOG_ACTION "=%s", action);
+
+       if (opts->verbose)
+               return run_command(&cmd);
+       else
+               return run_command_silent_on_success(&cmd);
+}
+
+int prepare_branch_to_be_rebased(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))
+                       return error(_("could not checkout %s"), commit);
+       }
+
+       return 0;
+}
+
+static int checkout_onto(struct replay_opts *opts,
+                        const char *onto_name, const char *onto,
+                        const char *orig_head)
+{
+       struct object_id oid;
+       const char *action = reflog_message(opts, "start", "checkout %s", onto_name);
+
+       if (get_oid(orig_head, &oid))
+               return error(_("%s: not a valid OID"), orig_head);
+
+       if (run_git_checkout(opts, onto, action)) {
+               apply_autostash(opts);
+               sequencer_remove_state(opts);
+               return error(_("could not detach HEAD"));
+       }
+
+       return update_ref(NULL, "ORIG_HEAD", &oid, NULL, 0, UPDATE_REFS_MSG_ON_ERR);
+}
+
 static const char rescheduled_advice[] =
 N_("Could not execute the todo command\n"
 "\n"
@@ -3171,10 +3331,27 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                                        intend_to_amend();
                                return error_failed_squash(item->commit, opts,
                                        item->arg_len, item->arg);
-                       } else if (res && is_rebase_i(opts) && item->commit)
+                       } else if (res && is_rebase_i(opts) && item->commit) {
+                               int to_amend = 0;
+                               struct object_id oid;
+
+                               /*
+                                * If we are rewording and have either
+                                * fast-forwarded already, or are about to
+                                * create a new root commit, we want to amend,
+                                * otherwise we do not.
+                                */
+                               if (item->command == TODO_REWORD &&
+                                   !get_oid("HEAD", &oid) &&
+                                   (!oidcmp(&item->commit->object.oid, &oid) ||
+                                    (opts->have_squash_onto &&
+                                     !oidcmp(&opts->squash_onto, &oid))))
+                                       to_amend = 1;
+
                                return res | error_with_patch(item->commit,
-                                       item->arg, item->arg_len, opts, res,
-                                       item->command == TODO_REWORD);
+                                               item->arg, item->arg_len, opts,
+                                               res, to_amend);
+                       }
                } else if (item->command == TODO_EXEC) {
                        char *end_of_arg = (char *)(item->arg + item->arg_len);
                        int saved = *end_of_arg;
@@ -3355,25 +3532,22 @@ static int continue_single_pick(void)
 {
        const char *argv[] = { "commit", NULL };
 
-       if (!file_exists(git_path_cherry_pick_head()) &&
-           !file_exists(git_path_revert_head()))
+       if (!file_exists(git_path_cherry_pick_head(the_repository)) &&
+           !file_exists(git_path_revert_head(the_repository)))
                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 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))
                return error(_("cannot rebase: You have unstaged changes."));
-       if (!has_uncommitted_changes(0)) {
-               const char *cherry_pick_head = git_path_cherry_pick_head();
 
-               if (file_exists(cherry_pick_head) && unlink(cherry_pick_head))
-                       return error(_("could not remove CHERRY_PICK_HEAD"));
-               return 0;
-       }
+       is_clean = !has_uncommitted_changes(0);
 
        if (file_exists(rebase_path_amend())) {
                struct strbuf rev = STRBUF_INIT;
@@ -3386,19 +3560,107 @@ static int commit_staged_changes(struct replay_opts *opts)
                if (get_oid_hex(rev.buf, &to_amend))
                        return error(_("invalid contents: '%s'"),
                                rebase_path_amend());
-               if (oidcmp(&head, &to_amend))
+               if (!is_clean && oidcmp(&head, &to_amend))
                        return error(_("\nYou have uncommitted changes in your "
                                       "working tree. Please, commit them\n"
                                       "first and then run 'git rebase "
                                       "--continue' again."));
+               /*
+                * When skipping a failed fixup/squash, we need to edit the
+                * commit message, the current fixup list and count, and if it
+                * was the last fixup/squash in the chain, we need to clean up
+                * the commit message and if there was a squash, let the user
+                * edit it.
+                */
+               if (is_clean && !oidcmp(&head, &to_amend) &&
+                   opts->current_fixup_count > 0 &&
+                   file_exists(rebase_path_stopped_sha())) {
+                       const char *p = opts->current_fixups.buf;
+                       int len = opts->current_fixups.len;
+
+                       opts->current_fixup_count--;
+                       if (!len)
+                               BUG("Incorrect current_fixups:\n%s", p);
+                       while (len && p[len - 1] != '\n')
+                               len--;
+                       strbuf_setlen(&opts->current_fixups, len);
+                       if (write_message(p, len, rebase_path_current_fixups(),
+                                         0) < 0)
+                               return error(_("could not write file: '%s'"),
+                                            rebase_path_current_fixups());
+
+                       /*
+                        * If a fixup/squash in a fixup/squash chain failed, the
+                        * commit message is already correct, no need to commit
+                        * it again.
+                        *
+                        * Only if it is the final command in the fixup/squash
+                        * chain, and only if the chain is longer than a single
+                        * fixup/squash command (which was just skipped), do we
+                        * actually need to re-commit with a cleaned up commit
+                        * message.
+                        */
+                       if (opts->current_fixup_count > 0 &&
+                           !is_fixup(peek_command(todo_list, 0))) {
+                               final_fixup = 1;
+                               /*
+                                * If there was not a single "squash" in the
+                                * chain, we only need to clean up the commit
+                                * message, no need to bother the user with
+                                * opening the commit message in the editor.
+                                */
+                               if (!starts_with(p, "squash ") &&
+                                   !strstr(p, "\nsquash "))
+                                       flags = (flags & ~EDIT_MSG) | CLEANUP_MSG;
+                       } else if (is_fixup(peek_command(todo_list, 0))) {
+                               /*
+                                * We need to update the squash message to skip
+                                * the latest commit message.
+                                */
+                               struct commit *commit;
+                               const char *path = rebase_path_squash_msg();
+
+                               if (parse_head(&commit) ||
+                                   !(p = get_commit_buffer(commit, NULL)) ||
+                                   write_message(p, strlen(p), path, 0)) {
+                                       unuse_commit_buffer(commit, p);
+                                       return error(_("could not write file: "
+                                                      "'%s'"), path);
+                               }
+                               unuse_commit_buffer(commit, p);
+                       }
+               }
 
                strbuf_release(&rev);
                flags |= AMEND_MSG;
        }
 
-       if (run_git_commit(rebase_path_message(), opts, flags))
+       if (is_clean) {
+               const char *cherry_pick_head = git_path_cherry_pick_head(the_repository);
+
+               if (file_exists(cherry_pick_head) && unlink(cherry_pick_head))
+                       return error(_("could not remove CHERRY_PICK_HEAD"));
+               if (!final_fixup)
+                       return 0;
+       }
+
+       if (run_git_commit(final_fixup ? NULL : rebase_path_message(),
+                          opts, flags))
                return error(_("could not commit staged changes."));
        unlink(rebase_path_amend());
+       if (final_fixup) {
+               unlink(rebase_path_fixup_msg());
+               unlink(rebase_path_squash_msg());
+       }
+       if (opts->current_fixup_count > 0) {
+               /*
+                * Whether final fixup or not, we just cleaned up the commit
+                * message...
+                */
+               unlink(rebase_path_current_fixups());
+               strbuf_reset(&opts->current_fixups);
+               opts->current_fixup_count = 0;
+       }
        return 0;
 }
 
@@ -3410,20 +3672,22 @@ int sequencer_continue(struct replay_opts *opts)
        if (read_and_refresh_cache(opts))
                return -1;
 
+       if (read_populate_opts(opts))
+               return -1;
        if (is_rebase_i(opts)) {
-               if (commit_staged_changes(opts))
+               if ((res = read_populate_todo(&todo_list, opts)))
+                       goto release_todo_list;
+               if (commit_staged_changes(opts, &todo_list))
                        return -1;
        } else if (!file_exists(get_todo_path(opts)))
                return continue_single_pick();
-       if (read_populate_opts(opts))
-               return -1;
-       if ((res = read_populate_todo(&todo_list, opts)))
+       else if ((res = read_populate_todo(&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()) ||
-                   file_exists(git_path_revert_head())) {
+               if (file_exists(git_path_cherry_pick_head(the_repository)) ||
+                   file_exists(git_path_revert_head(the_repository))) {
                        res = continue_single_pick();
                        if (res)
                                goto release_todo_list;
@@ -3476,7 +3740,8 @@ int sequencer_pick_revisions(struct replay_opts *opts)
 
                if (!get_oid(name, &oid)) {
                        if (!lookup_commit_reference_gently(&oid, 1)) {
-                               enum object_type type = oid_object_info(&oid,
+                               enum object_type type = oid_object_info(the_repository,
+                                                                       &oid,
                                                                        NULL);
                                return error(_("%s: can't cherry-pick a %s"),
                                        name, type_name(type));
@@ -3661,7 +3926,7 @@ static const char *label_oid(struct object_id *oid, const char *label,
                                p[i] = save;
                        }
                }
-       } else if (((len = strlen(label)) == GIT_SHA1_RAWSZ &&
+       } else if (((len = strlen(label)) == the_hash_algo->hexsz &&
                    !get_oid_hex(label, &dummy)) ||
                   (len == 1 && *label == '#') ||
                   hashmap_get_from_hash(&state->labels,
@@ -3875,7 +4140,8 @@ static int make_script_with_merges(struct pretty_print_context *pp,
                }
 
                if (!commit)
-                       fprintf(out, "%s onto\n", cmd_reset);
+                       fprintf(out, "%s %s\n", cmd_reset,
+                               rebase_cousins ? "onto" : "[new root]");
                else {
                        const char *to = NULL;
 
@@ -4086,26 +4352,23 @@ int transform_todos(unsigned flags)
        return i;
 }
 
-enum check_level {
-       CHECK_IGNORE = 0, CHECK_WARN, CHECK_ERROR
-};
-
-static enum check_level get_missing_commit_check_level(void)
+enum missing_commit_check_level get_missing_commit_check_level(void)
 {
        const char *value;
 
        if (git_config_get_value("rebase.missingcommitscheck", &value) ||
                        !strcasecmp("ignore", value))
-               return CHECK_IGNORE;
+               return MISSING_COMMIT_CHECK_IGNORE;
        if (!strcasecmp("warn", value))
-               return CHECK_WARN;
+               return MISSING_COMMIT_CHECK_WARN;
        if (!strcasecmp("error", value))
-               return CHECK_ERROR;
+               return MISSING_COMMIT_CHECK_ERROR;
        warning(_("unrecognized setting %s for option "
                  "rebase.missingCommitsCheck. Ignoring."), value);
-       return CHECK_IGNORE;
+       return MISSING_COMMIT_CHECK_IGNORE;
 }
 
+define_commit_slab(commit_seen, unsigned char);
 /*
  * Check if the user dropped some commits by mistake
  * Behaviour determined by rebase.missingCommitsCheck.
@@ -4114,11 +4377,14 @@ static enum check_level get_missing_commit_check_level(void)
  */
 int check_todo_list(void)
 {
-       enum check_level check_level = get_missing_commit_check_level();
+       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;
+
+       init_commit_seen(&commit_seen);
 
        strbuf_addstr(&todo_file, rebase_path_todo());
        if (strbuf_read_file_or_whine(&todo_list.buf, todo_file.buf) < 0) {
@@ -4128,14 +4394,14 @@ int check_todo_list(void)
        advise_to_edit_todo = res =
                parse_insn_buffer(todo_list.buf.buf, &todo_list);
 
-       if (res || check_level == CHECK_IGNORE)
+       if (res || check_level == MISSING_COMMIT_CHECK_IGNORE)
                goto leave_check;
 
        /* 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->util = (void *)1;
+                       *commit_seen_at(&commit_seen, commit) = 1;
        }
 
        todo_list_release(&todo_list);
@@ -4151,11 +4417,11 @@ int check_todo_list(void)
        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->util) {
+               if (commit && !*commit_seen_at(&commit_seen, commit)) {
                        strbuf_addf(&missing, " - %s %.*s\n",
                                    short_commit_name(commit),
                                    item->arg_len, item->arg);
-                       commit->util = (void *)1;
+                       *commit_seen_at(&commit_seen, commit) = 1;
                }
        }
 
@@ -4163,7 +4429,7 @@ int check_todo_list(void)
        if (!missing.len)
                goto leave_check;
 
-       if (check_level == CHECK_ERROR)
+       if (check_level == MISSING_COMMIT_CHECK_ERROR)
                advise_to_edit_todo = res = 1;
 
        fprintf(stderr,
@@ -4181,6 +4447,7 @@ int check_todo_list(void)
                "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);
 
@@ -4208,17 +4475,17 @@ static int rewrite_file(const char *path, const char *buf, size_t len)
 }
 
 /* skip picking commits whose parents are unchanged */
-int skip_unnecessary_picks(void)
+static int skip_unnecessary_picks(struct object_id *output_oid)
 {
        const char *todo_file = rebase_path_todo();
        struct strbuf buf = STRBUF_INIT;
        struct todo_list todo_list = TODO_LIST_INIT;
-       struct object_id onto_oid, *oid = &onto_oid, *parent_oid;
+       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, &onto_oid)) {
+       if (get_oid(buf.buf, output_oid)) {
                strbuf_release(&buf);
                return error(_("need a HEAD to fixup"));
        }
@@ -4248,9 +4515,9 @@ int skip_unnecessary_picks(void)
                if (item->commit->parents->next)
                        break; /* merge commit */
                parent_oid = &item->commit->parents->item->object.oid;
-               if (hashcmp(parent_oid->hash, oid->hash))
+               if (hashcmp(parent_oid->hash, output_oid->hash))
                        break;
-               oid = &item->commit->object.oid;
+               oidcpy(output_oid, &item->commit->object.oid);
        }
        if (i > 0) {
                int offset = get_item_line_offset(&todo_list, i);
@@ -4279,15 +4546,114 @@ int skip_unnecessary_picks(void)
 
                todo_list.current = i;
                if (is_fixup(peek_command(&todo_list, 0)))
-                       record_in_rewritten(oid, peek_command(&todo_list, 0));
+                       record_in_rewritten(output_oid, peek_command(&todo_list, 0));
        }
 
        todo_list_release(&todo_list);
-       printf("%s\n", oid_to_hex(oid));
 
        return 0;
 }
 
+int complete_action(struct replay_opts *opts, unsigned flags,
+                   const char *shortrevisions, const char *onto_name,
+                   const char *onto, const char *orig_head, const char *cmd,
+                   unsigned autosquash)
+{
+       const char *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;
+
+       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 (autosquash && rearrange_squash())
+               return -1;
+
+       if (cmd && *cmd)
+               sequencer_add_exec_commands(cmd);
+
+       if (strbuf_read_file(buf, todo_file, 0) < 0)
+               return error_errno(_("could not read '%s'."), todo_file);
+
+       if (parse_insn_buffer(buf->buf, &todo_list)) {
+               todo_list_release(&todo_list);
+               return error(_("unusable todo list: '%s'"), todo_file);
+       }
+
+       if (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);
+               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)) {
+               apply_autostash(opts);
+               sequencer_remove_state(opts);
+               todo_list_release(&todo_list);
+
+               return -1;
+       }
+
+       strbuf_stripspace(buf, 1);
+       if (buf->len == 0) {
+               apply_autostash(opts);
+               sequencer_remove_state(opts);
+               todo_list_release(&todo_list);
+
+               return error(_("nothing to do"));
+       }
+
+       todo_list_release(&todo_list);
+
+       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))
+               return error(_("could not skip unnecessary pick commands"));
+
+       if (checkout_onto(opts, onto_name, oid_to_hex(&oid), orig_head))
+               return -1;
+;
+       if (require_clean_work_tree("rebase", "", 1, 1))
+               return -1;
+
+       return sequencer_continue(opts);
+}
+
 struct subject2item_entry {
        struct hashmap_entry entry;
        int i;
@@ -4301,6 +4667,8 @@ static int subject2item_cmp(const void *fndata,
        return key ? strcmp(a->subject, key) : strcmp(a->subject, b->subject);
 }
 
+define_commit_slab(commit_todo_item, struct todo_item *);
+
 /*
  * Rearrange the todo list that has both "pick commit-id msg" and "pick
  * commit-id fixup!/squash! msg" in it so that the latter is put immediately
@@ -4317,6 +4685,7 @@ int rearrange_squash(void)
        struct hashmap subject2item;
        int res = 0, rearranged = 0, *next, *tail, i;
        char **subjects;
+       struct commit_todo_item commit_todo;
 
        if (strbuf_read_file_or_whine(&todo_list.buf, todo_file) < 0)
                return -1;
@@ -4325,6 +4694,7 @@ int rearrange_squash(void)
                return -1;
        }
 
+       init_commit_todo_item(&commit_todo);
        /*
         * The hashmap maps onelines to the respective todo list index.
         *
@@ -4355,10 +4725,11 @@ 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."));
                }
 
-               item->commit->util = item;
+               *commit_todo_item_at(&commit_todo, item->commit) = item;
 
                parse_commit(item->commit);
                commit_buffer = get_commit_buffer(item->commit, NULL);
@@ -4385,9 +4756,9 @@ int rearrange_squash(void)
                        else if (!strchr(p, ' ') &&
                                 (commit2 =
                                  lookup_commit_reference_by_name(p)) &&
-                                commit2->util)
+                                *commit_todo_item_at(&commit_todo, commit2))
                                /* found by commit name */
-                               i2 = (struct todo_item *)commit2->util
+                               i2 = *commit_todo_item_at(&commit_todo, commit2)
                                        - todo_list.items;
                        else {
                                /* copy can be a prefix of the commit subject */
@@ -4464,5 +4835,6 @@ int rearrange_squash(void)
        hashmap_free(&subject2item, 1);
        todo_list_release(&todo_list);
 
+       clear_commit_todo_item(&commit_todo);
        return res;
 }