Merge branch 'nd/the-index' into md/list-objects-filter-by-depth
[gitweb.git] / sequencer.c
index f388405b4e0d2c260f74777323a738ac845195e0..b68bca0bef927f0ebb2d8762f658946be7107fcb 100644 (file)
@@ -30,6 +30,8 @@
 #include "oidset.h"
 #include "commit-slab.h"
 #include "alias.h"
+#include "commit-reach.h"
+#include "rebase-interactive.h"
 
 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
 
@@ -52,7 +54,10 @@ 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
@@ -140,7 +145,7 @@ 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")
@@ -152,6 +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 int git_sequencer_config(const char *k, const char *v, void *cb)
 {
@@ -350,7 +356,8 @@ static void free_message(struct commit *commit, struct commit_message *msg)
        unuse_commit_buffer(commit, msg->message);
 }
 
-static void print_advice(int show_hint, struct replay_opts *opts)
+static void print_advice(struct repository *r, int show_hint,
+                        struct replay_opts *opts)
 {
        char *msg = getenv("GIT_CHERRY_PICK_HELP");
 
@@ -361,7 +368,7 @@ static void print_advice(int show_hint, struct replay_opts *opts)
                 * (typically rebase --interactive) wants to take care
                 * of the commit itself so remove CHERRY_PICK_HEAD
                 */
-               unlink(git_path_cherry_pick_head(the_repository));
+               unlink(git_path_cherry_pick_head(r));
                return;
        }
 
@@ -376,8 +383,8 @@ 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;
 
@@ -434,14 +441,14 @@ static int read_oneliner(struct strbuf *buf,
        return 1;
 }
 
-static struct tree *empty_tree(void)
+static struct tree *empty_tree(struct repository *r)
 {
-       return lookup_tree(the_repository, the_repository->hash_algo->empty_tree);
+       return lookup_tree(r, the_hash_algo->empty_tree);
 }
 
-static int error_dirty_index(struct replay_opts *opts)
+static int error_dirty_index(struct index_state *istate, struct replay_opts *opts)
 {
-       if (read_cache_unmerged())
+       if (read_index_unmerged(istate))
                return error_resolve_conflict(_(action_name(opts)));
 
        error(_("your local changes would be overwritten by %s."),
@@ -466,15 +473,18 @@ static void update_abort_safety_file(void)
                write_file(git_path_abort_safety_file(), "%s", "");
 }
 
-static int fast_forward_to(const struct object_id *to, const struct object_id *from,
-                       int unborn, struct replay_opts *opts)
+static int fast_forward_to(struct repository *r,
+                          const struct object_id *to,
+                          const struct object_id *from,
+                          int unborn,
+                          struct replay_opts *opts)
 {
        struct ref_transaction *transaction;
        struct strbuf sb = STRBUF_INIT;
        struct strbuf err = STRBUF_INIT;
 
-       read_cache();
-       if (checkout_fast_forward(from, to, 1))
+       read_index(r->index);
+       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)));
@@ -500,24 +510,26 @@ static int fast_forward_to(const struct object_id *to, const struct object_id *f
        return 0;
 }
 
-void append_conflicts_hint(struct strbuf *msgbuf)
+void append_conflicts_hint(struct index_state *istate,
+                          struct strbuf *msgbuf)
 {
        int i;
 
        strbuf_addch(msgbuf, '\n');
        strbuf_commented_addf(msgbuf, "Conflicts:\n");
-       for (i = 0; i < active_nr;) {
-               const struct cache_entry *ce = active_cache[i++];
+       for (i = 0; i < istate->cache_nr;) {
+               const struct cache_entry *ce = istate->cache[i++];
                if (ce_stage(ce)) {
                        strbuf_commented_addf(msgbuf, "\t%s\n", ce->name);
-                       while (i < active_nr && !strcmp(ce->name,
-                                                       active_cache[i]->name))
+                       while (i < istate->cache_nr &&
+                              !strcmp(ce->name, istate->cache[i]->name))
                                i++;
                }
        }
 }
 
-static int do_recursive_merge(struct commit *base, struct commit *next,
+static int do_recursive_merge(struct repository *r,
+                             struct commit *base, struct commit *next,
                              const char *base_label, const char *next_label,
                              struct object_id *head, struct strbuf *msgbuf,
                              struct replay_opts *opts)
@@ -531,7 +543,7 @@ static int do_recursive_merge(struct commit *base, struct commit *next,
        if (hold_locked_index(&index_lock, LOCK_REPORT_ON_ERROR) < 0)
                return -1;
 
-       read_cache();
+       read_index(r->index);
 
        init_merge_options(&o);
        o.ancestor = base ? base_label : "(empty tree)";
@@ -542,8 +554,8 @@ static int do_recursive_merge(struct commit *base, struct commit *next,
        o.show_rename_progress = 1;
 
        head_tree = parse_tree_indirect(head);
-       next_tree = next ? get_commit_tree(next) : empty_tree();
-       base_tree = base ? get_commit_tree(base) : empty_tree();
+       next_tree = next ? get_commit_tree(next) : empty_tree(r);
+       base_tree = base ? get_commit_tree(base) : empty_tree(r);
 
        for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
                parse_merge_opt(&o, *xopt);
@@ -560,7 +572,7 @@ static int do_recursive_merge(struct commit *base, struct commit *next,
                return clean;
        }
 
-       if (write_locked_index(&the_index, &index_lock,
+       if (write_locked_index(r->index, &index_lock,
                               COMMIT_LOCK | SKIP_IF_UNCHANGED))
                /*
                 * TRANSLATORS: %s will be "revert", "cherry-pick" or
@@ -570,34 +582,35 @@ static int do_recursive_merge(struct commit *base, struct commit *next,
                        _(action_name(opts)));
 
        if (!clean)
-               append_conflicts_hint(msgbuf);
+               append_conflicts_hint(r->index, msgbuf);
 
        return !clean;
 }
 
-static struct object_id *get_cache_tree_oid(void)
+static struct object_id *get_cache_tree_oid(struct index_state *istate)
 {
-       if (!active_cache_tree)
-               active_cache_tree = cache_tree();
+       if (!istate->cache_tree)
+               istate->cache_tree = cache_tree();
 
-       if (!cache_tree_fully_valid(active_cache_tree))
-               if (cache_tree_update(&the_index, 0)) {
+       if (!cache_tree_fully_valid(istate->cache_tree))
+               if (cache_tree_update(istate, 0)) {
                        error(_("unable to update cache tree"));
                        return NULL;
                }
 
-       return &active_cache_tree->oid;
+       return &istate->cache_tree->oid;
 }
 
-static int is_index_unchanged(void)
+static int is_index_unchanged(struct repository *r)
 {
        struct object_id head_oid, *cache_tree_oid;
        struct commit *head_commit;
+       struct index_state *istate = r->index;
 
        if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
                return error(_("could not resolve HEAD commit"));
 
-       head_commit = lookup_commit(the_repository, &head_oid);
+       head_commit = lookup_commit(r, &head_oid);
 
        /*
         * If head_commit is NULL, check_commit, called from
@@ -610,10 +623,10 @@ 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 !oidcmp(cache_tree_oid, get_commit_tree_oid(head_commit));
+       return oideq(cache_tree_oid, get_commit_tree_oid(head_commit));
 }
 
 static int write_author_script(const char *message)
@@ -663,55 +676,131 @@ static int write_author_script(const char *message)
        return res;
 }
 
+/**
+ * Take a series of KEY='VALUE' lines where VALUE part is
+ * sq-quoted, and append <KEY, VALUE> at the end of the string list
+ */
+static int parse_key_value_squoted(char *buf, struct string_list *list)
+{
+       while (*buf) {
+               struct string_list_item *item;
+               char *np;
+               char *cp = strchr(buf, '=');
+               if (!cp) {
+                       np = strchrnul(buf, '\n');
+                       return error(_("no key present in '%.*s'"),
+                                    (int) (np - buf), buf);
+               }
+               np = strchrnul(cp, '\n');
+               *cp++ = '\0';
+               item = string_list_append(list, buf);
+
+               buf = np + (*np == '\n');
+               *np = '\0';
+               cp = sq_dequote(cp);
+               if (!cp)
+                       return error(_("unable to dequote value of '%s'"),
+                                    item->string);
+               item->util = xstrdup(cp);
+       }
+       return 0;
+}
 
-/*
- * write_author_script() used to fail to terminate the last line with a "'" and
- * also escaped "'" incorrectly as "'\\\\''" rather than "'\\''". We check for
- * the terminating "'" on the last line to see how "'" has been escaped in case
- * git was upgraded while rebase was stopped.
+/**
+ * Reads and parses the state directory's "author-script" file, and sets name,
+ * email and date accordingly.
+ * Returns 0 on success, -1 if the file could not be parsed.
+ *
+ * The author script is of the format:
+ *
+ *     GIT_AUTHOR_NAME='$author_name'
+ *     GIT_AUTHOR_EMAIL='$author_email'
+ *     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
+ * 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.
  */
-static int quoting_is_broken(const char *s, size_t n)
+int read_author_script(const char *path, char **name, char **email, char **date,
+                      int allow_missing)
 {
-       /* Skip any empty lines in case the file was hand edited */
-       while (n > 0 && s[--n] == '\n')
-               ; /* empty */
-       if (n > 0 && s[n] != '\'')
-               return 1;
+       struct strbuf buf = STRBUF_INIT;
+       struct string_list kv = STRING_LIST_INIT_DUP;
+       int retval = -1; /* assume failure */
+       int i, name_i = -2, email_i = -2, date_i = -2, err = 0;
 
-       return 0;
+       if (strbuf_read_file(&buf, path, 256) <= 0) {
+               strbuf_release(&buf);
+               if (errno == ENOENT && allow_missing)
+                       return 0;
+               else
+                       return error_errno(_("could not open '%s' for reading"),
+                                          path);
+       }
+
+       if (parse_key_value_squoted(buf.buf, &kv))
+               goto finish;
+
+       for (i = 0; i < kv.nr; i++) {
+               if (!strcmp(kv.items[i].string, "GIT_AUTHOR_NAME")) {
+                       if (name_i != -2)
+                               name_i = error(_("'GIT_AUTHOR_NAME' already given"));
+                       else
+                               name_i = i;
+               } else if (!strcmp(kv.items[i].string, "GIT_AUTHOR_EMAIL")) {
+                       if (email_i != -2)
+                               email_i = error(_("'GIT_AUTHOR_EMAIL' already given"));
+                       else
+                               email_i = i;
+               } else if (!strcmp(kv.items[i].string, "GIT_AUTHOR_DATE")) {
+                       if (date_i != -2)
+                               date_i = error(_("'GIT_AUTHOR_DATE' already given"));
+                       else
+                               date_i = i;
+               } else {
+                       err = error(_("unknown variable '%s'"),
+                                   kv.items[i].string);
+               }
+       }
+       if (name_i == -2)
+               error(_("missing 'GIT_AUTHOR_NAME'"));
+       if (email_i == -2)
+               error(_("missing 'GIT_AUTHOR_EMAIL'"));
+       if (date_i == -2)
+               error(_("missing 'GIT_AUTHOR_DATE'"));
+       if (date_i < 0 || email_i < 0 || date_i < 0 || err)
+               goto finish;
+       *name = kv.items[name_i].util;
+       *email = kv.items[email_i].util;
+       *date = kv.items[date_i].util;
+       retval = 0;
+finish:
+       string_list_clear(&kv, !!retval);
+       strbuf_release(&buf);
+       return retval;
 }
 
 /*
- * Read a list of environment variable assignments (such as the author-script
- * file) into an environment block. Returns -1 on error, 0 otherwise.
+ * Read a GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL AND GIT_AUTHOR_DATE from a
+ * file with shell quoting into struct argv_array. Returns -1 on
+ * error, 0 otherwise.
  */
 static int read_env_script(struct argv_array *env)
 {
-       struct strbuf script = STRBUF_INIT;
-       int i, count = 0, sq_bug;
-       const char *p2;
-       char *p;
+       char *name, *email, *date;
 
-       if (strbuf_read_file(&script, rebase_path_author_script(), 256) <= 0)
+       if (read_author_script(rebase_path_author_script(),
+                              &name, &email, &date, 0))
                return -1;
-       /* write_author_script() used to quote incorrectly */
-       sq_bug = quoting_is_broken(script.buf, script.len);
-       for (p = script.buf; *p; p++)
-               if (sq_bug && skip_prefix(p, "'\\\\''", &p2))
-                       strbuf_splice(&script, p - script.buf, p2 - p, "'", 1);
-               else if (skip_prefix(p, "'\\''", &p2))
-                       strbuf_splice(&script, p - script.buf, p2 - p, "'", 1);
-               else if (*p == '\'')
-                       strbuf_splice(&script, p-- - script.buf, 1, "", 0);
-               else if (*p == '\n') {
-                       *p = '\0';
-                       count++;
-               }
 
-       for (i = 0, p = script.buf; i < count; i++) {
-               argv_array_push(env, p);
-               p += strlen(p) + 1;
-       }
+       argv_array_pushf(env, "GIT_AUTHOR_NAME=%s", name);
+       argv_array_pushf(env, "GIT_AUTHOR_EMAIL=%s", email);
+       argv_array_pushf(env, "GIT_AUTHOR_DATE=%s", date);
+       free(name);
+       free(email);
+       free(date);
 
        return 0;
 }
@@ -731,54 +820,28 @@ static char *get_author(const char *message)
 /* Read author-script and return an ident line (author <email> timestamp) */
 static const char *read_author_ident(struct strbuf *buf)
 {
-       const char *keys[] = {
-               "GIT_AUTHOR_NAME=", "GIT_AUTHOR_EMAIL=", "GIT_AUTHOR_DATE="
-       };
        struct strbuf out = STRBUF_INIT;
-       char *in, *eol;
-       const char *val[3];
-       int i = 0;
-
-       if (strbuf_read_file(buf, rebase_path_author_script(), 256) <= 0)
-               return NULL;
-
-       /* dequote values and construct ident line in-place */
-       for (in = buf->buf; i < 3 && in - buf->buf < buf->len; i++) {
-               if (!skip_prefix(in, keys[i], (const char **)&in)) {
-                       warning(_("could not parse '%s' (looking for '%s')"),
-                               rebase_path_author_script(), keys[i]);
-                       return NULL;
-               }
-
-               eol = strchrnul(in, '\n');
-               *eol = '\0';
-               if (!sq_dequote(in)) {
-                       warning(_("bad quoting on %s value in '%s'"),
-                               keys[i], rebase_path_author_script());
-                       return NULL;
-               }
-               val[i] = in;
-               in = eol + 1;
-       }
+       char *name, *email, *date;
 
-       if (i < 3) {
-               warning(_("could not parse '%s' (looking for '%s')"),
-                       rebase_path_author_script(), keys[i]);
+       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(val[2], &out)){
+       if (parse_date(date, &out)){
                warning(_("invalid date format '%s' in '%s'"),
-                       val[2], rebase_path_author_script());
+                       date, rebase_path_author_script());
                strbuf_release(&out);
                return NULL;
        }
 
        strbuf_reset(&out);
-       strbuf_addstr(&out, fmt_ident(val[0], val[1], val[2], 0));
+       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;
 }
 
@@ -803,6 +866,23 @@ 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
@@ -815,7 +895,9 @@ N_("you have staged changes in your working tree\n"
  * 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;
@@ -838,7 +920,7 @@ static int run_git_commit(const char *defmsg, struct replay_opts *opts,
                if (!defmsg)
                        BUG("root commit without message");
 
-               if (!(cache_tree_oid = get_cache_tree_oid()))
+               if (!(cache_tree_oid = get_cache_tree_oid(r->index)))
                        res = -1;
 
                if (!res)
@@ -864,18 +946,11 @@ 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 (is_rebase_i(opts) && read_env_script(&cmd.env_array)) {
+               const char *gpg_opt = gpg_sign_opt_quoted(opts);
 
-               if (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");
@@ -905,21 +980,10 @@ static int run_git_commit(const char *defmsg, struct replay_opts *opts,
        if (!(flags & EDIT_MSG))
                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)
@@ -1065,7 +1129,9 @@ void commit_post_rewrite(const struct commit *old_head,
        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;
@@ -1075,7 +1141,7 @@ static int run_prepare_commit_msg_hook(struct strbuf *msg, const char *commit)
        if (write_message(msg->buf, msg->len, name, 0))
                return -1;
 
-       argv_array_pushf(&hook_env, "GIT_INDEX_FILE=%s", get_index_file());
+       argv_array_pushf(&hook_env, "GIT_INDEX_FILE=%s", r->index_file);
        argv_array_push(&hook_env, "GIT_EDITOR=:");
        if (commit)
                ret = run_hook_le(hook_env.argv, "prepare-commit-msg", name,
@@ -1131,7 +1197,9 @@ 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;
@@ -1142,7 +1210,7 @@ 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))
@@ -1175,7 +1243,7 @@ void print_commit_summary(const char *prefix, const struct object_id *oid,
        strbuf_release(&author_ident);
        strbuf_release(&committer_ident);
 
-       init_revisions(&rev, prefix);
+       repo_init_revisions(r, &rev, prefix);
        setup_revisions(0, NULL, &rev, NULL);
 
        rev.diff = 1;
@@ -1209,7 +1277,7 @@ 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;
@@ -1217,10 +1285,10 @@ 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 (oidcmp(&oid, &current_head->object.oid)) {
+               if (!oideq(&oid, &current_head->object.oid)) {
                        warning(_("HEAD %s is not a commit!"),
                                oid_to_hex(&oid));
                }
@@ -1241,7 +1309,8 @@ static int parse_head(struct commit **head)
  *   0 - success
  *   1 - run 'git commit'
  */
-static int try_to_commit(struct strbuf *msg, const char *author,
+static int try_to_commit(struct repository *r,
+                        struct strbuf *msg, const char *author,
                         struct replay_opts *opts, unsigned int flags,
                         struct object_id *oid)
 {
@@ -1256,7 +1325,7 @@ 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) {
@@ -1285,20 +1354,20 @@ static int try_to_commit(struct strbuf *msg, const char *author,
                commit_list_insert(current_head, &parents);
        }
 
-       if (write_index_as_tree(&tree, &the_index, get_index_file(), 0, NULL)) {
+       if (write_index_as_tree(&tree, r->index, r->index_file, 0, NULL)) {
                res = error(_("git write-tree failed to write a tree"));
                goto out;
        }
 
-       if (!(flags & ALLOW_EMPTY) && !oidcmp(current_head ?
-                                             get_commit_tree_oid(current_head) :
-                                             the_hash_algo->empty_tree, &tree)) {
+       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 (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(),
@@ -1347,7 +1416,8 @@ static int try_to_commit(struct strbuf *msg, const char *author,
        return res;
 }
 
-static int do_commit(const char *msg_file, const char *author,
+static int do_commit(struct repository *r,
+                    const char *msg_file, const char *author,
                     struct replay_opts *opts, unsigned int flags)
 {
        int res = 1;
@@ -1362,20 +1432,20 @@ 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;
 }
@@ -1397,13 +1467,15 @@ static int is_original_commit_empty(struct commit *commit)
                ptree_oid = the_hash_algo->empty_tree; /* commit is root */
        }
 
-       return !oidcmp(ptree_oid, get_commit_tree_oid(commit));
+       return oideq(ptree_oid, get_commit_tree_oid(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;
 
@@ -1420,7 +1492,7 @@ 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)
@@ -1453,6 +1525,7 @@ enum todo_command {
        TODO_SQUASH,
        /* commands that do something else than handling a single commit */
        TODO_EXEC,
+       TODO_BREAK,
        TODO_LABEL,
        TODO_RESET,
        TODO_MERGE,
@@ -1474,6 +1547,7 @@ static struct {
        { 'f', "fixup" },
        { 's', "squash" },
        { 'x', "exec" },
+       { 'b', "break" },
        { 'l', "label" },
        { 't', "reset" },
        { 'm', "merge" },
@@ -1522,8 +1596,10 @@ static int is_pick_or_similar(enum todo_command command)
        }
 }
 
-static int update_squash_messages(enum todo_command command,
-               struct commit *commit, struct replay_opts *opts)
+static int update_squash_messages(struct repository *r,
+                                 enum todo_command command,
+                                 struct commit *commit,
+                                 struct replay_opts *opts)
 {
        struct strbuf buf = STRBUF_INIT;
        int res;
@@ -1552,7 +1628,7 @@ static int update_squash_messages(enum todo_command command,
 
                if (get_oid("HEAD", &head))
                        return error(_("need a HEAD to fixup"));
-               if (!(head_commit = lookup_commit_reference(the_repository, &head)))
+               if (!(head_commit = lookup_commit_reference(r, &head)))
                        return error(_("could not read HEAD"));
                if (!(head_message = get_commit_buffer(head_commit, NULL)))
                        return error(_("could not read HEAD's commit message"));
@@ -1651,11 +1727,14 @@ static void record_in_rewritten(struct object_id *oid,
                flush_rewritten_pending();
 }
 
-static int do_pick_commit(enum todo_command command, struct commit *commit,
-               struct replay_opts *opts, int final_fixup)
+static int do_pick_commit(struct repository *r,
+                         enum todo_command command,
+                         struct commit *commit,
+                         struct replay_opts *opts,
+                         int final_fixup)
 {
        unsigned int flags = opts->edit ? EDIT_MSG : 0;
-       const char *msg_file = opts->edit ? NULL : git_path_merge_msg(the_repository);
+       const char *msg_file = opts->edit ? NULL : git_path_merge_msg(r);
        struct object_id head;
        struct commit *base, *next, *parent;
        const char *base_label, *next_label;
@@ -1671,24 +1750,24 @@ 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);
                /* Do we want to generate a root commit? */
                if (is_pick_or_similar(command) && opts->have_squash_onto &&
-                   !oidcmp(&head, &opts->squash_onto)) {
+                   oideq(&head, &opts->squash_onto)) {
                        if (is_fixup(command))
                                return error(_("cannot fixup root commit"));
                        flags |= CREATE_ROOT_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->index, opts);
        }
-       discard_cache();
+       discard_index(r->index);
 
        if (!commit->parents)
                parent = NULL;
@@ -1720,11 +1799,11 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
                        oid_to_hex(&commit->object.oid));
 
        if (opts->allow_ff && !is_fixup(command) &&
-           ((parent && !oidcmp(&parent->object.oid, &head)) ||
+           ((parent && oideq(&parent->object.oid, &head)) ||
             (!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;
@@ -1788,7 +1867,7 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
        if (command == TODO_REWORD)
                flags |= EDIT_MSG | VERIFY_MSG;
        else if (is_fixup(command)) {
-               if (update_squash_messages(command, commit, opts))
+               if (update_squash_messages(r, command, commit, opts))
                        return -1;
                flags |= AMEND_MSG;
                if (!final_fixup)
@@ -1797,12 +1876,12 @@ 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;
                }
@@ -1814,23 +1893,23 @@ 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(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);
@@ -1858,12 +1937,12 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
                      ? _("could not revert %s... %s")
                      : _("could not apply %s... %s"),
                      short_commit_name(commit), msg.subject);
-               print_advice(res == 1, opts);
-               rerere(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;
@@ -1872,7 +1951,7 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
        if (!opts->no_commit) {
 fast_forward_edit:
                if (author || command == TODO_REVERT || (flags & AMEND_MSG))
-                       res = do_commit(msg_file, author, opts, flags);
+                       res = do_commit(r, msg_file, author, opts, flags);
                else
                        res = error(_("unable to parse commit author"));
        }
@@ -1908,18 +1987,19 @@ 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_preload(&the_index, NULL) < 0) {
+       if (read_index(r->index) < 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)));
@@ -1964,7 +2044,8 @@ static struct todo_item *append_new_todo(struct todo_list *todo_list)
        return todo_list->items + todo_list->nr++;
 }
 
-static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
+static int parse_insn_line(struct repository *r, struct todo_item *item,
+                          const char *bol, char *eol)
 {
        struct object_id commit_oid;
        char *end_of_object_name;
@@ -1987,7 +2068,8 @@ static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
                if (skip_prefix(bol, todo_command_info[i].str, &bol)) {
                        item->command = i;
                        break;
-               } else if (bol[1] == ' ' && *bol == todo_command_info[i].c) {
+               } else if ((bol + 1 == eol || bol[1] == ' ') &&
+                          *bol == todo_command_info[i].c) {
                        bol++;
                        item->command = i;
                        break;
@@ -1999,7 +2081,7 @@ static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
        padding = strspn(bol, " \t");
        bol += padding;
 
-       if (item->command == TODO_NOOP) {
+       if (item->command == TODO_NOOP || item->command == TODO_BREAK) {
                if (bol != eol)
                        return error(_("%s does not accept arguments: '%s'"),
                                     command_to_string(item->command), bol);
@@ -2048,11 +2130,12 @@ static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
        if (status < 0)
                return -1;
 
-       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)
+static int parse_insn_buffer(struct repository *r, char *buf,
+                            struct todo_list *todo_list)
 {
        struct todo_item *item;
        char *p = buf, *next_p;
@@ -2068,7 +2151,7 @@ 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, p, eol)) {
                        res = error(_("invalid line %d: %.*s"),
                                i, (int)(eol - p), p);
                        item->command = TODO_NOOP;
@@ -2129,8 +2212,9 @@ static ssize_t strbuf_read_file_or_whine(struct strbuf *sb, const char *path)
        return len;
 }
 
-static int read_populate_todo(struct todo_list *todo_list,
-                       struct replay_opts *opts)
+static int read_populate_todo(struct repository *r,
+                             struct todo_list *todo_list,
+                             struct replay_opts *opts)
 {
        struct stat st;
        const char *todo_file = get_todo_path(opts);
@@ -2145,7 +2229,7 @@ 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 = parse_insn_buffer(r, todo_list->buf.buf, todo_list);
        if (res) {
                if (is_rebase_i(opts))
                        return error(_("please fix this using "
@@ -2176,7 +2260,7 @@ static int read_populate_todo(struct todo_list *todo_list,
                FILE *f = fopen_or_warn(rebase_path_msgtotal(), "w");
 
                if (strbuf_read_file(&done.buf, rebase_path_done(), 0) > 0 &&
-                               !parse_insn_buffer(done.buf.buf, &done))
+                   !parse_insn_buffer(r, done.buf.buf, &done))
                        todo_list->done_nr = count_commands(&done);
                else
                        todo_list->done_nr = 0;
@@ -2243,21 +2327,14 @@ 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;
-
-       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;
+       char *strategy_opts_string = raw_opts;
 
-       strategy_opts_string = buf->buf;
        if (*strategy_opts_string == ' ')
                strategy_opts_string++;
+
        opts->xopts_nr = split_cmdline(strategy_opts_string,
                                       (const char ***)&opts->xopts);
        for (i = 0; i < opts->xopts_nr; i++) {
@@ -2268,6 +2345,18 @@ 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)) {
@@ -2335,6 +2424,55 @@ 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(), "%s", "");
+       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)
 {
@@ -2425,7 +2563,7 @@ static int rollback_is_safe(void)
        if (get_oid("HEAD", &actual_head))
                oidclr(&actual_head);
 
-       return !oidcmp(&actual_head, &expected_head);
+       return oideq(&actual_head, &expected_head);
 }
 
 static int reset_for_rollback(const struct object_id *oid)
@@ -2439,12 +2577,12 @@ static int reset_for_rollback(const struct object_id *oid)
        return run_command_v_opt(argv, RUN_GIT_CMD);
 }
 
-static int rollback_single_pick(void)
+static int rollback_single_pick(struct repository *r)
 {
        struct object_id head_oid;
 
-       if (!file_exists(git_path_cherry_pick_head(the_repository)) &&
-           !file_exists(git_path_revert_head(the_repository)))
+       if (!file_exists(git_path_cherry_pick_head(r)) &&
+           !file_exists(git_path_revert_head(r)))
                return error(_("no cherry-pick or revert in progress"));
        if (read_ref_full("HEAD", 0, &head_oid, NULL))
                return error(_("cannot resolve HEAD"));
@@ -2453,7 +2591,7 @@ static int rollback_single_pick(void)
        return reset_for_rollback(&head_oid);
 }
 
-int sequencer_rollback(struct replay_opts *opts)
+int sequencer_rollback(struct repository *r, struct replay_opts *opts)
 {
        FILE *f;
        struct object_id oid;
@@ -2467,7 +2605,7 @@ 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());
@@ -2582,7 +2720,9 @@ static int save_opts(struct replay_opts *opts)
        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;
@@ -2598,7 +2738,7 @@ 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));
-       init_revisions(&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;
@@ -2638,17 +2778,19 @@ 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())
@@ -2679,21 +2821,24 @@ 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 };
@@ -2708,10 +2853,10 @@ 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 || read_index(r->index) < 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"
@@ -2777,9 +2922,9 @@ 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;
@@ -2820,7 +2965,9 @@ 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;
@@ -2828,7 +2975,7 @@ static int do_reset(const char *name, int len, struct replay_opts *opts)
        struct tree_desc desc;
        struct tree *tree;
        struct unpack_trees_options unpack_tree_opts;
-       int ret = 0, i;
+       int ret = 0;
 
        if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
                return -1;
@@ -2848,10 +2995,13 @@ static int do_reset(const char *name, int len, struct replay_opts *opts)
                }
                oidcpy(&oid, &opts->squash_onto);
        } else {
+               int i;
+
                /* Determine the length of the label */
                for (i = 0; i < len; i++)
                        if (isspace(name[i]))
-                               len = i;
+                               break;
+               len = i;
 
                strbuf_addf(&ref_name, "refs/rewritten/%.*s", len, name);
                if (get_oid(ref_name.buf, &oid) &&
@@ -2866,13 +3016,13 @@ static int do_reset(const char *name, int len, struct replay_opts *opts)
        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
        setup_unpack_trees_porcelain(&unpack_tree_opts, "reset");
        unpack_tree_opts.head_idx = 1;
-       unpack_tree_opts.src_index = &the_index;
-       unpack_tree_opts.dst_index = &the_index;
+       unpack_tree_opts.src_index = r->index;
+       unpack_tree_opts.dst_index = r->index;
        unpack_tree_opts.fn = oneway_merge;
        unpack_tree_opts.merge = 1;
        unpack_tree_opts.update = 1;
 
-       if (read_cache_unmerged()) {
+       if (read_index_unmerged(r->index)) {
                rollback_lock_file(&lock);
                strbuf_release(&ref_name);
                return error_resolve_conflict(_(action_name(opts)));
@@ -2894,9 +3044,9 @@ 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);
 
@@ -2929,7 +3079,9 @@ 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) ?
@@ -2986,7 +3138,7 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
        }
 
        if (opts->have_squash_onto &&
-           !oidcmp(&head_commit->object.oid, &opts->squash_onto)) {
+           oideq(&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.
@@ -2996,7 +3148,7 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
                        ret = error(_("octopus merge cannot be executed on "
                                      "top of a [new root]"));
                else
-                       ret = fast_forward_to(&to_merge->item->object.oid,
+                       ret = fast_forward_to(r, &to_merge->item->object.oid,
                                              &head_commit->object.oid, 0,
                                              opts);
                goto leave_merge;
@@ -3015,11 +3167,11 @@ 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 {
@@ -3041,11 +3193,11 @@ 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;
                }
        }
@@ -3055,8 +3207,8 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
         * commit, we cannot fast-forward.
         */
        can_fast_forward = opts->allow_ff && commit && commit->parents &&
-               !oidcmp(&commit->parents->item->object.oid,
-                       &head_commit->object.oid);
+               oideq(&commit->parents->item->object.oid,
+                     &head_commit->object.oid);
 
        /*
         * If any merge head is different from the original one, we cannot
@@ -3066,7 +3218,7 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
                struct commit_list *p = commit->parents->next;
 
                for (j = to_merge; j && p; j = j->next, p = p->next)
-                       if (oidcmp(&j->item->object.oid,
+                       if (!oideq(&j->item->object.oid,
                                   &p->item->object.oid)) {
                                can_fast_forward = 0;
                                break;
@@ -3081,7 +3233,7 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
 
        if (can_fast_forward) {
                rollback_lock_file(&lock);
-               ret = fast_forward_to(&commit->object.oid,
+               ret = fast_forward_to(r, &commit->object.oid,
                                      &head_commit->object.oid, 0, opts);
                goto leave_merge;
        }
@@ -3106,7 +3258,7 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
                argv_array_push(&cmd.args, "--no-log");
                argv_array_push(&cmd.args, "--no-stat");
                argv_array_push(&cmd.args, "-F");
-               argv_array_push(&cmd.args, git_path_merge_msg(the_repository));
+               argv_array_push(&cmd.args, git_path_merge_msg(r));
                if (opts->gpg_sign)
                        argv_array_push(&cmd.args, opts->gpg_sign);
 
@@ -3116,36 +3268,37 @@ 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 ||
+                            read_index(r->index) < 0))
                        ret = error(_("could not read index"));
                goto leave_merge;
        }
 
        merge_commit = to_merge->item;
-       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);
-
        bases = get_merge_bases(head_commit, merge_commit);
-       if (bases && !oidcmp(&merge_commit->object.oid,
-                            &bases->item->object.oid)) {
+       if (bases && oideq(&merge_commit->object.oid,
+                          &bases->item->object.oid)) {
                ret = 0;
                /* skip merging an ancestor of HEAD */
                goto leave_merge;
        }
 
+       write_message(oid_to_hex(&merge_commit->object.oid), GIT_SHA1_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();
+       read_index(r->index);
        init_merge_options(&o);
        o.branch1 = "HEAD";
        o.branch2 = ref_name.buf;
@@ -3170,23 +3323,23 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
         */
        ret = !ret;
 
-       if (active_cache_changed &&
-           write_locked_index(&the_index, &lock, COMMIT_LOCK)) {
+       if (r->index->cache_changed &&
+           write_locked_index(r->index, &lock, COMMIT_LOCK)) {
                ret = error(_("merge: Unable to write new index file"));
                goto leave_merge;
        }
 
        rollback_lock_file(&lock);
        if (ret)
-               rerere(opts->allow_rerere_auto);
+               repo_rerere(r, opts->allow_rerere_auto);
        else
                /*
                 * In case of problems, we now want to return a positive
                 * value (a negative one would indicate that the `merge`
                 * command needs to be rescheduled).
                 */
-               ret = !!run_git_commit(git_path_merge_msg(the_repository), opts,
-                                    run_commit_flags);
+               ret = !!run_git_commit(r, git_path_merge_msg(r), opts,
+                                      run_commit_flags);
 
 leave_merge:
        strbuf_release(&ref_name);
@@ -3285,6 +3438,73 @@ 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 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(r, &head)) ||
+           parse_commit(commit) || get_message(commit, &message))
+               fprintf(stderr, _("Stopped at HEAD\n"));
+       else {
+               fprintf(stderr, _("Stopped at %s\n"), message.label);
+               free_message(commit, &message);
+       }
+       return 0;
+
+}
+
 static const char rescheduled_advice[] =
 N_("Could not execute the todo command\n"
 "\n"
@@ -3296,7 +3516,9 @@ 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;
 
@@ -3304,7 +3526,7 @@ 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) {
@@ -3330,14 +3552,18 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                        unlink(rebase_path_author_script());
                        unlink(rebase_path_stopped_sha());
                        unlink(rebase_path_amend());
+                       unlink(git_path_merge_head(the_repository));
                        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
+
+                       if (item->command == TODO_BREAK)
+                               return stopped_at_head(r);
                }
                if (item->command <= TODO_SQUASH) {
                        if (is_rebase_i(opts))
                                setenv("GIT_REFLOG_ACTION", reflog_message(opts,
                                        command_to_string(item->command), NULL),
                                        1);
-                       res = do_pick_commit(item->command, item->commit,
+                       res = do_pick_commit(r, item->command, item->commit,
                                        opts, is_final_fixup(todo_list));
                        if (is_rebase_i(opts) && res < 0) {
                                /* Reschedule */
@@ -3357,7 +3583,7 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                                                _("Stopped at %s...  %.*s\n"),
                                                short_commit_name(commit),
                                                item->arg_len, item->arg);
-                               return error_with_patch(commit,
+                               return error_with_patch(r, commit,
                                        item->arg, item->arg_len, opts, res,
                                        !res);
                        }
@@ -3367,7 +3593,7 @@ 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,
+                               return error_failed_squash(r, item->commit, opts,
                                        item->arg_len, item->arg);
                        } else if (res && is_rebase_i(opts) && item->commit) {
                                int to_amend = 0;
@@ -3381,12 +3607,12 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                                 */
                                if (item->command == TODO_REWORD &&
                                    !get_oid("HEAD", &oid) &&
-                                   (!oidcmp(&item->commit->object.oid, &oid) ||
+                                   (oideq(&item->commit->object.oid, &oid) ||
                                     (opts->have_squash_onto &&
-                                     !oidcmp(&opts->squash_onto, &oid))))
+                                     oideq(&opts->squash_onto, &oid))))
                                        to_amend = 1;
 
-                               return res | error_with_patch(item->commit,
+                               return res | error_with_patch(r, item->commit,
                                                item->arg, item->arg_len, opts,
                                                res, to_amend);
                        }
@@ -3396,7 +3622,7 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                        struct stat st;
 
                        *end_of_arg = '\0';
-                       res = do_exec(item->arg);
+                       res = do_exec(r, item->arg);
                        *end_of_arg = saved;
 
                        /* Reread the todo file if it has changed. */
@@ -3407,19 +3633,19 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                                                  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))
+                               if (read_populate_todo(r, todo_list, opts))
                                        res = -1; /* message was printed */
                                /* `current` will be incremented below */
                                todo_list->current = -1;
                        }
                } else if (item->command == TODO_LABEL) {
-                       if ((res = do_label(item->arg, item->arg_len)))
+                       if ((res = do_label(r, item->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, item->arg, item->arg_len, opts)))
                                reschedule = 1;
                } else if (item->command == TODO_MERGE) {
-                       if ((res = do_merge(item->commit,
+                       if ((res = do_merge(r, item->commit,
                                            item->arg, item->arg_len,
                                            item->flags, opts)) < 0)
                                reschedule = 1;
@@ -3428,7 +3654,7 @@ 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,
+                               return error_with_patch(r, item->commit,
                                                        item->arg,
                                                        item->arg_len, opts,
                                                        res, 0);
@@ -3444,7 +3670,8 @@ 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,
+                               return error_with_patch(r,
+                                                       item->commit,
                                                        item->arg,
                                                        item->arg_len, opts,
                                                        res, 0);
@@ -3509,7 +3736,7 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                        struct object_id orig, head;
 
                        memset(&log_tree_opt, 0, sizeof(log_tree_opt));
-                       init_revisions(&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;
@@ -3566,26 +3793,27 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
        return sequencer_remove_state(opts);
 }
 
-static int continue_single_pick(void)
+static int continue_single_pick(struct repository *r)
 {
        const char *argv[] = { "commit", NULL };
 
-       if (!file_exists(git_path_cherry_pick_head(the_repository)) &&
-           !file_exists(git_path_revert_head(the_repository)))
+       if (!file_exists(git_path_cherry_pick_head(r)) &&
+           !file_exists(git_path_revert_head(r)))
                return error(_("no cherry-pick or revert in progress"));
        return run_command_v_opt(argv, RUN_GIT_CMD);
 }
 
-static int commit_staged_changes(struct replay_opts *opts,
+static int commit_staged_changes(struct repository *r,
+                                struct replay_opts *opts,
                                 struct todo_list *todo_list)
 {
        unsigned int flags = ALLOW_EMPTY | EDIT_MSG;
        unsigned int final_fixup = 0, is_clean;
 
-       if (has_unstaged_changes(1))
+       if (has_unstaged_changes(r, 1))
                return error(_("cannot rebase: You have unstaged changes."));
 
-       is_clean = !has_uncommitted_changes(0);
+       is_clean = !has_uncommitted_changes(r, 0);
 
        if (file_exists(rebase_path_amend())) {
                struct strbuf rev = STRBUF_INIT;
@@ -3598,7 +3826,7 @@ 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 (!is_clean && oidcmp(&head, &to_amend))
+               if (!is_clean && !oideq(&head, &to_amend))
                        return error(_("\nYou have uncommitted changes in your "
                                       "working tree. Please, commit them\n"
                                       "first and then run 'git rebase "
@@ -3612,7 +3840,7 @@ static int commit_staged_changes(struct replay_opts *opts,
                 */
                if (!is_clean || !opts->current_fixup_count)
                        ; /* this is not the final fixup */
-               else if (oidcmp(&head, &to_amend) ||
+               else if (!oideq(&head, &to_amend) ||
                         !file_exists(rebase_path_stopped_sha())) {
                        /* was a final fixup or squash done manually? */
                        if (!is_fixup(peek_command(todo_list, 0))) {
@@ -3669,7 +3897,7 @@ static int commit_staged_changes(struct replay_opts *opts,
                                struct commit *commit;
                                const char *path = rebase_path_squash_msg();
 
-                               if (parse_head(&commit) ||
+                               if (parse_head(r, &commit) ||
                                    !(p = get_commit_buffer(commit, NULL)) ||
                                    write_message(p, strlen(p), path, 0)) {
                                        unuse_commit_buffer(commit, p);
@@ -3685,7 +3913,7 @@ 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"));
@@ -3693,10 +3921,11 @@ 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));
        if (final_fixup) {
                unlink(rebase_path_fixup_msg());
                unlink(rebase_path_squash_msg());
@@ -3713,36 +3942,36 @@ static int commit_staged_changes(struct replay_opts *opts,
        return 0;
 }
 
-int sequencer_continue(struct replay_opts *opts)
+int sequencer_continue(struct repository *r, struct replay_opts *opts)
 {
        struct todo_list todo_list = TODO_LIST_INIT;
        int res;
 
-       if (read_and_refresh_cache(opts))
+       if (read_and_refresh_cache(r, opts))
                return -1;
 
        if (read_populate_opts(opts))
                return -1;
        if (is_rebase_i(opts)) {
-               if ((res = read_populate_todo(&todo_list, opts)))
+               if ((res = read_populate_todo(r, &todo_list, opts)))
                        goto release_todo_list;
-               if (commit_staged_changes(opts, &todo_list))
+               if (commit_staged_changes(r, opts, &todo_list))
                        return -1;
        } else if (!file_exists(get_todo_path(opts)))
-               return continue_single_pick();
-       else if ((res = read_populate_todo(&todo_list, opts)))
+               return continue_single_pick(r);
+       else if ((res = read_populate_todo(r, &todo_list, opts)))
                goto release_todo_list;
 
        if (!is_rebase_i(opts)) {
                /* Verify that the conflict has been resolved */
-               if (file_exists(git_path_cherry_pick_head(the_repository)) ||
-                   file_exists(git_path_revert_head(the_repository))) {
-                       res = continue_single_pick();
+               if (file_exists(git_path_cherry_pick_head(r)) ||
+                   file_exists(git_path_revert_head(r))) {
+                       res = continue_single_pick(r);
                        if (res)
                                goto release_todo_list;
                }
-               if (index_differs_from("HEAD", NULL, 0)) {
-                       res = error_dirty_index(opts);
+               if (index_differs_from(r, "HEAD", NULL, 0)) {
+                       res = error_dirty_index(r->index, opts);
                        goto release_todo_list;
                }
                todo_list.current++;
@@ -3756,27 +3985,30 @@ int sequencer_continue(struct replay_opts *opts)
                strbuf_release(&buf);
        }
 
-       res = pick_commits(&todo_list, opts);
+       res = pick_commits(r, &todo_list, opts);
 release_todo_list:
        todo_list_release(&todo_list);
        return res;
 }
 
-static int single_pick(struct commit *cmit, struct replay_opts *opts)
+static int single_pick(struct repository *r,
+                      struct commit *cmit,
+                      struct replay_opts *opts)
 {
        setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
-       return do_pick_commit(opts->action == REPLAY_PICK ?
+       return do_pick_commit(r, opts->action == REPLAY_PICK ?
                TODO_PICK : TODO_REVERT, cmit, opts, 0);
 }
 
-int sequencer_pick_revisions(struct replay_opts *opts)
+int sequencer_pick_revisions(struct repository *r,
+                            struct replay_opts *opts)
 {
        struct todo_list todo_list = TODO_LIST_INIT;
        struct object_id oid;
        int i, res;
 
        assert(opts->revs);
-       if (read_and_refresh_cache(opts))
+       if (read_and_refresh_cache(r, opts))
                return -1;
 
        for (i = 0; i < opts->revs->pending.nr; i++) {
@@ -3788,8 +4020,8 @@ 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"),
@@ -3818,7 +4050,7 @@ 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);
        }
 
        /*
@@ -3837,7 +4069,7 @@ 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;
 }
@@ -4145,9 +4377,7 @@ static int make_script_with_merges(struct pretty_print_context *pp,
                        struct object_id *oid = &parent->item->object.oid;
                        if (!oidset_contains(&interesting, oid))
                                continue;
-                       if (!oidset_contains(&child_seen, oid))
-                               oidset_insert(&child_seen, oid);
-                       else
+                       if (oidset_insert(&child_seen, oid))
                                label_oid(oid, "branch-point", &state);
                }
 
@@ -4243,7 +4473,8 @@ static int make_script_with_merges(struct pretty_print_context *pp,
        return 0;
 }
 
-int sequencer_make_script(FILE *out, int argc, const char **argv,
+int sequencer_make_script(struct repository *r, FILE *out,
+                         int argc, const char **argv,
                          unsigned flags)
 {
        char *format = NULL;
@@ -4255,7 +4486,7 @@ int sequencer_make_script(FILE *out, int argc, const char **argv,
        const char *insn = flags & TODO_LIST_ABBREVIATE_CMDS ? "p" : "pick";
        int rebase_merges = flags & TODO_LIST_REBASE_MERGES;
 
-       init_revisions(&revs, NULL);
+       repo_init_revisions(r, &revs, NULL);
        revs.verbose_header = 1;
        if (!rebase_merges)
                revs.max_parents = 1;
@@ -4308,7 +4539,8 @@ 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)
+int sequencer_add_exec_commands(struct repository *r,
+                               const char *commands)
 {
        const char *todo_file = rebase_path_todo();
        struct todo_list todo_list = TODO_LIST_INIT;
@@ -4319,7 +4551,7 @@ int sequencer_add_exec_commands(const char *commands)
        if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
                return error(_("could not read '%s'."), todo_file);
 
-       if (parse_insn_buffer(todo_list.buf.buf, &todo_list)) {
+       if (parse_insn_buffer(r, todo_list.buf.buf, &todo_list)) {
                todo_list_release(&todo_list);
                return error(_("unusable todo list: '%s'"), todo_file);
        }
@@ -4364,7 +4596,7 @@ int sequencer_add_exec_commands(const char *commands)
        return i;
 }
 
-int transform_todos(unsigned flags)
+int transform_todos(struct repository *r, unsigned flags)
 {
        const char *todo_file = rebase_path_todo();
        struct todo_list todo_list = TODO_LIST_INIT;
@@ -4375,7 +4607,7 @@ int transform_todos(unsigned flags)
        if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
                return error(_("could not read '%s'."), todo_file);
 
-       if (parse_insn_buffer(todo_list.buf.buf, &todo_list)) {
+       if (parse_insn_buffer(r, todo_list.buf.buf, &todo_list)) {
                todo_list_release(&todo_list);
                return error(_("unusable todo list: '%s'"), todo_file);
        }
@@ -4421,24 +4653,20 @@ 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);
@@ -4448,9 +4676,9 @@ define_commit_slab(commit_seen, unsigned char);
  * Check if there is an unrecognized command or a
  * bad SHA-1 in a command.
  */
-int check_todo_list(void)
+int check_todo_list(struct repository *r)
 {
-       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;
@@ -4465,9 +4693,9 @@ int check_todo_list(void)
                goto leave_check;
        }
        advise_to_edit_todo = res =
-               parse_insn_buffer(todo_list.buf.buf, &todo_list);
+               parse_insn_buffer(r, 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 */
@@ -4484,7 +4712,7 @@ int check_todo_list(void)
                goto leave_check;
        }
        strbuf_release(&todo_file);
-       res = !!parse_insn_buffer(todo_list.buf.buf, &todo_list);
+       res = !!parse_insn_buffer(r, todo_list.buf.buf, &todo_list);
 
        /* Find commits in git-rebase-todo.backup yet unseen */
        for (i = todo_list.nr - 1; i >= 0; i--) {
@@ -4502,7 +4730,7 @@ 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,
@@ -4548,17 +4776,17 @@ 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 repository *r, 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"));
        }
@@ -4566,7 +4794,7 @@ int skip_unnecessary_picks(void)
 
        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) {
+       if (parse_insn_buffer(r, todo_list.buf.buf, &todo_list) < 0) {
                todo_list_release(&todo_list);
                return -1;
        }
@@ -4588,9 +4816,9 @@ 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 (!oideq(parent_oid, output_oid))
                        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);
@@ -4619,15 +4847,114 @@ 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 repository *r, struct replay_opts *opts, unsigned flags,
+                   const char *shortrevisions, const char *onto_name,
+                   const char *onto, const char *orig_head, const char *cmd,
+                   unsigned autosquash)
+{
+       const char *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(r))
+               return -1;
+
+       if (cmd && *cmd)
+               sequencer_add_exec_commands(r, cmd);
+
+       if (strbuf_read_file(buf, todo_file, 0) < 0)
+               return error_errno(_("could not read '%s'."), todo_file);
+
+       if (parse_insn_buffer(r, buf->buf, &todo_list)) {
+               todo_list_release(&todo_list);
+               return error(_("unusable todo list: '%s'"), todo_file);
+       }
+
+       if (count_commands(&todo_list) == 0) {
+               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(r, flags | TODO_LIST_SHORTEN_IDS))
+               return error(_("could not transform the todo list"));
+
+       strbuf_reset(buf);
+
+       if (launch_sequence_editor(todo_file, buf, NULL)) {
+               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(r)) {
+               checkout_onto(opts, onto_name, onto, orig_head);
+               return -1;
+       }
+
+       if (transform_todos(r, flags & ~(TODO_LIST_SHORTEN_IDS)))
+               return error(_("could not transform the todo list"));
+
+       if (opts->allow_ff && skip_unnecessary_picks(r, &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(r, "rebase", "", 1, 1))
+               return -1;
+
+       return sequencer_continue(r, opts);
+}
+
 struct subject2item_entry {
        struct hashmap_entry entry;
        int i;
@@ -4652,7 +4979,7 @@ define_commit_slab(commit_todo_item, struct todo_item *);
  * message will have to be retrieved from the commit (as the oneline in the
  * script cannot be trusted) in order to normalize the autosquash arrangement.
  */
-int rearrange_squash(void)
+int rearrange_squash(struct repository *r)
 {
        const char *todo_file = rebase_path_todo();
        struct todo_list todo_list = TODO_LIST_INIT;
@@ -4663,7 +4990,7 @@ int rearrange_squash(void)
 
        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) {
+       if (parse_insn_buffer(r, todo_list.buf.buf, &todo_list) < 0) {
                todo_list_release(&todo_list);
                return -1;
        }