Merge branch 'jk/empty-pick-fix'
authorJunio C Hamano <gitster@pobox.com>
Tue, 24 Jul 2018 21:50:48 +0000 (14:50 -0700)
committerJunio C Hamano <gitster@pobox.com>
Tue, 24 Jul 2018 21:50:48 +0000 (14:50 -0700)
Handling of an empty range by "git cherry-pick" was inconsistent
depending on how the range ended up to be empty, which has been
corrected.

* jk/empty-pick-fix:
sequencer: don't say BUG on bogus input
sequencer: handle empty-set cases consistently

1  2 
sequencer.c
t/t3510-cherry-pick-sequence.sh
diff --combined sequencer.c
index 349ae04ffd66968a0641ca04508eceea0c8a2b8b,5bf91b18e2c80ddc90a57214137d2d0586675ae7..b89d5f2e34f960fc8d171ecb4862a65e841221de
@@@ -1,14 -1,13 +1,14 @@@
  #include "cache.h"
  #include "config.h"
  #include "lockfile.h"
 -#include "sequencer.h"
  #include "dir.h"
 +#include "object-store.h"
  #include "object.h"
  #include "commit.h"
 +#include "sequencer.h"
  #include "tag.h"
  #include "run-command.h"
 -#include "exec_cmd.h"
 +#include "exec-cmd.h"
  #include "utf8.h"
  #include "cache-tree.h"
  #include "diff.h"
  #include "log-tree.h"
  #include "wt-status.h"
  #include "hashmap.h"
 +#include "notes-utils.h"
 +#include "sigchain.h"
 +#include "unpack-trees.h"
 +#include "worktree.h"
 +#include "oidmap.h"
 +#include "oidset.h"
 +#include "commit-slab.h"
 +#include "alias.h"
  
  #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
  
  const char sign_off_header[] = "Signed-off-by: ";
  static const char cherry_picked_prefix[] = "(cherry picked from commit ";
  
 +GIT_PATH_FUNC(git_path_commit_editmsg, "COMMIT_EDITMSG")
 +
  GIT_PATH_FUNC(git_path_seq_dir, "sequencer")
  
  static GIT_PATH_FUNC(git_path_todo_file, "sequencer/todo")
@@@ -63,12 -52,12 +63,12 @@@ static GIT_PATH_FUNC(rebase_path_done, 
   * The file to keep track of how many commands were already processed (e.g.
   * for the prompt).
   */
 -static GIT_PATH_FUNC(rebase_path_msgnum, "rebase-merge/msgnum");
 +static GIT_PATH_FUNC(rebase_path_msgnum, "rebase-merge/msgnum")
  /*
   * The file to keep track of how many commands are to be processed in total
   * (e.g. for the prompt).
   */
 -static GIT_PATH_FUNC(rebase_path_msgtotal, "rebase-merge/end");
 +static GIT_PATH_FUNC(rebase_path_msgtotal, "rebase-merge/end")
  /*
   * The commit message that is planned to be used for any changes that
   * need to be committed following a user interaction.
@@@ -81,6 -70,13 +81,6 @@@ static GIT_PATH_FUNC(rebase_path_messag
   * previous commit and from the first squash/fixup commit are written
   * to it. The commit message for each subsequent squash/fixup commit
   * is appended to the file as it is processed.
 - *
 - * The first line of the file is of the form
 - *     # This is a combination of $count commits.
 - * where $count is the number of commits whose messages have been
 - * written to the file so far (including the initial "pick" commit).
 - * Each time that a commit message is processed, this line is read and
 - * updated. It is deleted just before the combined commit is made.
   */
  static GIT_PATH_FUNC(rebase_path_squash_msg, "rebase-merge/message-squash")
  /*
   * commit without opening the editor.)
   */
  static GIT_PATH_FUNC(rebase_path_fixup_msg, "rebase-merge/message-fixup")
 +/*
 + * This file contains the list fixup/squash commands that have been
 + * accumulated into message-fixup or message-squash so far.
 + */
 +static GIT_PATH_FUNC(rebase_path_current_fixups, "rebase-merge/current-fixups")
  /*
   * A script to set the GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
   * GIT_AUTHOR_DATE that will be used for the commit that is currently
@@@ -125,19 -116,6 +125,19 @@@ static GIT_PATH_FUNC(rebase_path_stoppe
  static GIT_PATH_FUNC(rebase_path_rewritten_list, "rebase-merge/rewritten-list")
  static GIT_PATH_FUNC(rebase_path_rewritten_pending,
        "rebase-merge/rewritten-pending")
 +
 +/*
 + * The path of the file containig the OID of the "squash onto" commit, i.e.
 + * the dummy commit used for `reset [new root]`.
 + */
 +static GIT_PATH_FUNC(rebase_path_squash_onto, "rebase-merge/squash-onto")
 +
 +/*
 + * The path of the file listing refs that need to be deleted after the rebase
 + * finishes. This is used by the `label` command to record the need for cleanup.
 + */
 +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).
  static GIT_PATH_FUNC(rebase_path_gpg_sign_opt, "rebase-merge/gpg_sign_opt")
  static GIT_PATH_FUNC(rebase_path_orig_head, "rebase-merge/orig-head")
  static GIT_PATH_FUNC(rebase_path_verbose, "rebase-merge/verbose")
 +static GIT_PATH_FUNC(rebase_path_signoff, "rebase-merge/signoff")
  static GIT_PATH_FUNC(rebase_path_head_name, "rebase-merge/head-name")
  static GIT_PATH_FUNC(rebase_path_onto, "rebase-merge/onto")
  static GIT_PATH_FUNC(rebase_path_autostash, "rebase-merge/autostash")
@@@ -153,52 -130,6 +153,52 @@@ static GIT_PATH_FUNC(rebase_path_strate
  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 int git_sequencer_config(const char *k, const char *v, void *cb)
 +{
 +      struct replay_opts *opts = cb;
 +      int status;
 +
 +      if (!strcmp(k, "commit.cleanup")) {
 +              const char *s;
 +
 +              status = git_config_string(&s, k, v);
 +              if (status)
 +                      return status;
 +
 +              if (!strcmp(s, "verbatim"))
 +                      opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_NONE;
 +              else if (!strcmp(s, "whitespace"))
 +                      opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_SPACE;
 +              else if (!strcmp(s, "strip"))
 +                      opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_ALL;
 +              else if (!strcmp(s, "scissors"))
 +                      opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_SPACE;
 +              else
 +                      warning(_("invalid commit message cleanup mode '%s'"),
 +                                s);
 +
 +              free((char *)s);
 +              return status;
 +      }
 +
 +      if (!strcmp(k, "commit.gpgsign")) {
 +              opts->gpg_sign = git_config_bool(k, v) ? xstrdup("") : NULL;
 +              return 0;
 +      }
 +
 +      status = git_gpg_config(k, v, NULL);
 +      if (status)
 +              return status;
 +
 +      return git_diff_basic_config(k, v, NULL);
 +}
 +
 +void sequencer_init_config(struct replay_opts *opts)
 +{
 +      opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_NONE;
 +      git_config(git_sequencer_config, opts);
 +}
 +
  static inline int is_rebase_i(const struct replay_opts *opts)
  {
        return opts->action == REPLAY_INTERACTIVE_REBASE;
@@@ -264,35 -195,18 +264,35 @@@ static const char *gpg_sign_opt_quoted(
  
  int sequencer_remove_state(struct replay_opts *opts)
  {
 -      struct strbuf dir = STRBUF_INIT;
 +      struct strbuf buf = STRBUF_INIT;
        int i;
  
 +      if (is_rebase_i(opts) &&
 +          strbuf_read_file(&buf, rebase_path_refs_to_delete(), 0) > 0) {
 +              char *p = buf.buf;
 +              while (*p) {
 +                      char *eol = strchr(p, '\n');
 +                      if (eol)
 +                              *eol = '\0';
 +                      if (delete_ref("(rebase -i) cleanup", p, NULL, 0) < 0)
 +                              warning(_("could not delete '%s'"), p);
 +                      if (!eol)
 +                              break;
 +                      p = eol + 1;
 +              }
 +      }
 +
        free(opts->gpg_sign);
        free(opts->strategy);
        for (i = 0; i < opts->xopts_nr; i++)
                free(opts->xopts[i]);
        free(opts->xopts);
 +      strbuf_release(&opts->current_fixups);
  
 -      strbuf_addstr(&dir, get_dir(opts));
 -      remove_dir_recursively(&dir, 0);
 -      strbuf_release(&dir);
 +      strbuf_reset(&buf);
 +      strbuf_addstr(&buf, get_dir(opts));
 +      remove_dir_recursively(&buf, 0);
 +      strbuf_release(&buf);
  
        return 0;
  }
@@@ -319,7 -233,7 +319,7 @@@ struct commit_message 
  
  static const char *short_commit_name(struct commit *commit)
  {
 -      return find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV);
 +      return find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV);
  }
  
  static int get_message(struct commit *commit, struct commit_message *out)
@@@ -358,7 -272,7 +358,7 @@@ static void print_advice(int show_hint
                 * (typically rebase --interactive) wants to take care
                 * of the commit itself so remove CHERRY_PICK_HEAD
                 */
 -              unlink(git_path_cherry_pick_head());
 +              unlink(git_path_cherry_pick_head(the_repository));
                return;
        }
  
  static int write_message(const void *buf, size_t len, const char *filename,
                         int append_eol)
  {
 -      static struct lock_file msg_file;
 +      struct lock_file msg_file = LOCK_INIT;
  
        int msg_fd = hold_lock_file_for_update(&msg_file, filename, 0);
        if (msg_fd < 0)
                return error_errno(_("could not lock '%s'"), filename);
        if (write_in_full(msg_fd, buf, len) < 0) {
 +              error_errno(_("could not write to '%s'"), filename);
                rollback_lock_file(&msg_file);
 -              return error_errno(_("could not write to '%s'"), filename);
 +              return -1;
        }
        if (append_eol && write(msg_fd, "\n", 1) < 0) {
 +              error_errno(_("could not write eol to '%s'"), filename);
                rollback_lock_file(&msg_file);
 -              return error_errno(_("could not write eol to '%s'"), filename);
 -      }
 -      if (commit_lock_file(&msg_file) < 0) {
 -              rollback_lock_file(&msg_file);
 -              return error(_("failed to finalize '%s'."), filename);
 +              return -1;
        }
 +      if (commit_lock_file(&msg_file) < 0)
 +              return error(_("failed to finalize '%s'"), filename);
  
        return 0;
  }
@@@ -479,8 -393,7 +479,8 @@@ static int fast_forward_to(const struc
        transaction = ref_transaction_begin(&err);
        if (!transaction ||
            ref_transaction_update(transaction, "HEAD",
 -                                 to, unborn ? &null_oid : from,
 +                                 to, unborn && !is_rebase_i(opts) ?
 +                                 &null_oid : from,
                                   0, sb.buf, &err) ||
            ref_transaction_commit(transaction, &err)) {
                ref_transaction_free(transaction);
@@@ -523,7 -436,7 +523,7 @@@ static int do_recursive_merge(struct co
        struct tree *result, *next_tree, *base_tree, *head_tree;
        int clean;
        char **xopt;
 -      static struct lock_file index_lock;
 +      struct lock_file index_lock = LOCK_INIT;
  
        if (hold_locked_index(&index_lock, LOCK_REPORT_ON_ERROR) < 0)
                return -1;
        o.show_rename_progress = 1;
  
        head_tree = parse_tree_indirect(head);
 -      next_tree = next ? next->tree : empty_tree();
 -      base_tree = base ? base->tree : empty_tree();
 +      next_tree = next ? get_commit_tree(next) : empty_tree();
 +      base_tree = base ? get_commit_tree(base) : empty_tree();
  
        for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
                parse_merge_opt(&o, *xopt);
                fputs(o.obuf.buf, stdout);
        strbuf_release(&o.obuf);
        diff_warn_rename_limit("merge.renamelimit", o.needed_rename_limit, 0);
 -      if (clean < 0)
 +      if (clean < 0) {
 +              rollback_lock_file(&index_lock);
                return clean;
 +      }
  
 -      if (active_cache_changed &&
 -          write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
 +      if (write_locked_index(&the_index, &index_lock,
 +                             COMMIT_LOCK | SKIP_IF_UNCHANGED))
                /*
                 * TRANSLATORS: %s will be "revert", "cherry-pick" or
                 * "rebase -i".
                 */
                return error(_("%s: Unable to write new index file"),
                        _(action_name(opts)));
 -      rollback_lock_file(&index_lock);
 -
 -      if (opts->signoff)
 -              append_signoff(msgbuf, 0, 0);
  
        if (!clean)
                append_conflicts_hint(msgbuf);
        return !clean;
  }
  
 +static struct object_id *get_cache_tree_oid(void)
 +{
 +      if (!active_cache_tree)
 +              active_cache_tree = cache_tree();
 +
 +      if (!cache_tree_fully_valid(active_cache_tree))
 +              if (cache_tree_update(&the_index, 0)) {
 +                      error(_("unable to update cache tree"));
 +                      return NULL;
 +              }
 +
 +      return &active_cache_tree->oid;
 +}
 +
  static int is_index_unchanged(void)
  {
 -      struct object_id head_oid;
 +      struct object_id head_oid, *cache_tree_oid;
        struct commit *head_commit;
  
        if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
        if (parse_commit(head_commit))
                return -1;
  
 -      if (!active_cache_tree)
 -              active_cache_tree = cache_tree();
 -
 -      if (!cache_tree_fully_valid(active_cache_tree))
 -              if (cache_tree_update(&the_index, 0))
 -                      return error(_("unable to update cache tree"));
 +      if (!(cache_tree_oid = get_cache_tree_oid()))
 +              return -1;
  
 -      return !oidcmp(&active_cache_tree->oid,
 -                     &head_commit->tree->object.oid);
 +      return !oidcmp(cache_tree_oid, get_commit_tree_oid(head_commit));
  }
  
  static int write_author_script(const char *message)
@@@ -690,64 -596,6 +690,64 @@@ static int read_env_script(struct argv_
        return 0;
  }
  
 +static char *get_author(const char *message)
 +{
 +      size_t len;
 +      const char *a;
 +
 +      a = find_commit_header(message, "author", &len);
 +      if (a)
 +              return xmemdupz(a, len);
 +
 +      return NULL;
 +}
 +
 +/* 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="
 +      };
 +      char *in, *out, *eol;
 +      int i = 0, len;
 +
 +      if (strbuf_read_file(buf, rebase_path_author_script(), 256) <= 0)
 +              return NULL;
 +
 +      /* dequote values and construct ident line in-place */
 +      for (in = out = 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';
 +              sq_dequote(in);
 +              len = strlen(in);
 +
 +              if (i > 0) /* separate values by spaces */
 +                      *(out++) = ' ';
 +              if (i == 1) /* email needs to be surrounded by <...> */
 +                      *(out++) = '<';
 +              memmove(out, in, len);
 +              out += len;
 +              if (i == 1) /* email needs to be surrounded by <...> */
 +                      *(out++) = '>';
 +              in = eol + 1;
 +      }
 +
 +      if (i < 3) {
 +              warning("could not parse '%s' (looking for '%s')",
 +                      rebase_path_author_script(), keys[i]);
 +              return NULL;
 +      }
 +
 +      buf->len = out - buf->buf;
 +      return buf->buf;
 +}
 +
  static const char staged_changes_advice[] =
  N_("you have staged changes in your working tree\n"
  "If these changes are meant to be squashed into the previous commit, run:\n"
  #define AMEND_MSG   (1<<2)
  #define CLEANUP_MSG (1<<3)
  #define VERIFY_MSG  (1<<4)
 +#define CREATE_ROOT_COMMIT (1<<5)
  
  /*
   * If we are cherry-pick, and if the merge did not result in
@@@ -787,40 -634,6 +787,40 @@@ static int run_git_commit(const char *d
        struct child_process cmd = CHILD_PROCESS_INIT;
        const char *value;
  
 +      if ((flags & CREATE_ROOT_COMMIT) && !(flags & AMEND_MSG)) {
 +              struct strbuf msg = STRBUF_INIT, script = STRBUF_INIT;
 +              const char *author = is_rebase_i(opts) ?
 +                      read_author_ident(&script) : NULL;
 +              struct object_id root_commit, *cache_tree_oid;
 +              int res = 0;
 +
 +              if (!defmsg)
 +                      BUG("root commit without message");
 +
 +              if (!(cache_tree_oid = get_cache_tree_oid()))
 +                      res = -1;
 +
 +              if (!res)
 +                      res = strbuf_read_file(&msg, defmsg, 0);
 +
 +              if (res <= 0)
 +                      res = error_errno(_("could not read '%s'"), defmsg);
 +              else
 +                      res = commit_tree(msg.buf, msg.len, cache_tree_oid,
 +                                        NULL, &root_commit, author,
 +                                        opts->gpg_sign);
 +
 +              strbuf_release(&msg);
 +              strbuf_release(&script);
 +              if (!res) {
 +                      update_ref(NULL, "CHERRY_PICK_HEAD", &root_commit, NULL,
 +                                 REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR);
 +                      res = update_ref(NULL, "HEAD", &root_commit, NULL, 0,
 +                                       UPDATE_REFS_MSG_ON_ERR);
 +              }
 +              return res < 0 ? error(_("writing root commit")) : 0;
 +      }
 +
        cmd.git_cmd = 1;
  
        if (is_rebase_i(opts)) {
                argv_array_push(&cmd.args, "--amend");
        if (opts->gpg_sign)
                argv_array_pushf(&cmd.args, "-S%s", opts->gpg_sign);
 -      if (opts->signoff)
 -              argv_array_push(&cmd.args, "-s");
        if (defmsg)
                argv_array_pushl(&cmd.args, "-F", defmsg, NULL);
 +      else if (!(flags & EDIT_MSG))
 +              argv_array_pushl(&cmd.args, "-C", "HEAD", NULL);
        if ((flags & CLEANUP_MSG))
                argv_array_push(&cmd.args, "--cleanup=strip");
        if ((flags & EDIT_MSG))
        return run_command(&cmd);
  }
  
 +static int rest_is_empty(const struct strbuf *sb, int start)
 +{
 +      int i, eol;
 +      const char *nl;
 +
 +      /* Check if the rest is just whitespace and Signed-off-by's. */
 +      for (i = start; i < sb->len; i++) {
 +              nl = memchr(sb->buf + i, '\n', sb->len - i);
 +              if (nl)
 +                      eol = nl - sb->buf;
 +              else
 +                      eol = sb->len;
 +
 +              if (strlen(sign_off_header) <= eol - i &&
 +                  starts_with(sb->buf + i, sign_off_header)) {
 +                      i = eol;
 +                      continue;
 +              }
 +              while (i < eol)
 +                      if (!isspace(sb->buf[i++]))
 +                              return 0;
 +      }
 +
 +      return 1;
 +}
 +
 +/*
 + * Find out if the message in the strbuf contains only whitespace and
 + * Signed-off-by lines.
 + */
 +int message_is_empty(const struct strbuf *sb,
 +                   enum commit_msg_cleanup_mode cleanup_mode)
 +{
 +      if (cleanup_mode == COMMIT_MSG_CLEANUP_NONE && sb->len)
 +              return 0;
 +      return rest_is_empty(sb, 0);
 +}
 +
 +/*
 + * See if the user edited the message in the editor or left what
 + * was in the template intact
 + */
 +int template_untouched(const struct strbuf *sb, const char *template_file,
 +                     enum commit_msg_cleanup_mode cleanup_mode)
 +{
 +      struct strbuf tmpl = STRBUF_INIT;
 +      const char *start;
 +
 +      if (cleanup_mode == COMMIT_MSG_CLEANUP_NONE && sb->len)
 +              return 0;
 +
 +      if (!template_file || strbuf_read_file(&tmpl, template_file, 0) <= 0)
 +              return 0;
 +
 +      strbuf_stripspace(&tmpl, cleanup_mode == COMMIT_MSG_CLEANUP_ALL);
 +      if (!skip_prefix(sb->buf, tmpl.buf, &start))
 +              start = sb->buf;
 +      strbuf_release(&tmpl);
 +      return rest_is_empty(sb, start - sb->buf);
 +}
 +
 +int update_head_with_reflog(const struct commit *old_head,
 +                          const struct object_id *new_head,
 +                          const char *action, const struct strbuf *msg,
 +                          struct strbuf *err)
 +{
 +      struct ref_transaction *transaction;
 +      struct strbuf sb = STRBUF_INIT;
 +      const char *nl;
 +      int ret = 0;
 +
 +      if (action) {
 +              strbuf_addstr(&sb, action);
 +              strbuf_addstr(&sb, ": ");
 +      }
 +
 +      nl = strchr(msg->buf, '\n');
 +      if (nl) {
 +              strbuf_add(&sb, msg->buf, nl + 1 - msg->buf);
 +      } else {
 +              strbuf_addbuf(&sb, msg);
 +              strbuf_addch(&sb, '\n');
 +      }
 +
 +      transaction = ref_transaction_begin(err);
 +      if (!transaction ||
 +          ref_transaction_update(transaction, "HEAD", new_head,
 +                                 old_head ? &old_head->object.oid : &null_oid,
 +                                 0, sb.buf, err) ||
 +          ref_transaction_commit(transaction, err)) {
 +              ret = -1;
 +      }
 +      ref_transaction_free(transaction);
 +      strbuf_release(&sb);
 +
 +      return ret;
 +}
 +
 +static int run_rewrite_hook(const struct object_id *oldoid,
 +                          const struct object_id *newoid)
 +{
 +      struct child_process proc = CHILD_PROCESS_INIT;
 +      const char *argv[3];
 +      int code;
 +      struct strbuf sb = STRBUF_INIT;
 +
 +      argv[0] = find_hook("post-rewrite");
 +      if (!argv[0])
 +              return 0;
 +
 +      argv[1] = "amend";
 +      argv[2] = NULL;
 +
 +      proc.argv = argv;
 +      proc.in = -1;
 +      proc.stdout_to_stderr = 1;
 +
 +      code = start_command(&proc);
 +      if (code)
 +              return code;
 +      strbuf_addf(&sb, "%s %s\n", oid_to_hex(oldoid), oid_to_hex(newoid));
 +      sigchain_push(SIGPIPE, SIG_IGN);
 +      write_in_full(proc.in, sb.buf, sb.len);
 +      close(proc.in);
 +      strbuf_release(&sb);
 +      sigchain_pop(SIGPIPE);
 +      return finish_command(&proc);
 +}
 +
 +void commit_post_rewrite(const struct commit *old_head,
 +                       const struct object_id *new_head)
 +{
 +      struct notes_rewrite_cfg *cfg;
 +
 +      cfg = init_copy_notes_for_rewrite("amend");
 +      if (cfg) {
 +              /* we are amending, so old_head is not NULL */
 +              copy_note_for_rewrite(cfg, &old_head->object.oid, new_head);
 +              finish_copy_notes_for_rewrite(cfg, "Notes added by 'git commit --amend'");
 +      }
 +      run_rewrite_hook(&old_head->object.oid, new_head);
 +}
 +
 +static int run_prepare_commit_msg_hook(struct strbuf *msg, const char *commit)
 +{
 +      struct argv_array hook_env = ARGV_ARRAY_INIT;
 +      int ret;
 +      const char *name;
 +
 +      name = git_path_commit_editmsg();
 +      if (write_message(msg->buf, msg->len, name, 0))
 +              return -1;
 +
 +      argv_array_pushf(&hook_env, "GIT_INDEX_FILE=%s", get_index_file());
 +      argv_array_push(&hook_env, "GIT_EDITOR=:");
 +      if (commit)
 +              ret = run_hook_le(hook_env.argv, "prepare-commit-msg", name,
 +                                "commit", commit, NULL);
 +      else
 +              ret = run_hook_le(hook_env.argv, "prepare-commit-msg", name,
 +                                "message", NULL);
 +      if (ret)
 +              ret = error(_("'prepare-commit-msg' hook failed"));
 +      argv_array_clear(&hook_env);
 +
 +      return ret;
 +}
 +
 +static const char implicit_ident_advice_noconfig[] =
 +N_("Your name and email address were configured automatically based\n"
 +"on your username and hostname. Please check that they are accurate.\n"
 +"You can suppress this message by setting them explicitly. Run the\n"
 +"following command and follow the instructions in your editor to edit\n"
 +"your configuration file:\n"
 +"\n"
 +"    git config --global --edit\n"
 +"\n"
 +"After doing this, you may fix the identity used for this commit with:\n"
 +"\n"
 +"    git commit --amend --reset-author\n");
 +
 +static const char implicit_ident_advice_config[] =
 +N_("Your name and email address were configured automatically based\n"
 +"on your username and hostname. Please check that they are accurate.\n"
 +"You can suppress this message by setting them explicitly:\n"
 +"\n"
 +"    git config --global user.name \"Your Name\"\n"
 +"    git config --global user.email you@example.com\n"
 +"\n"
 +"After doing this, you may fix the identity used for this commit with:\n"
 +"\n"
 +"    git commit --amend --reset-author\n");
 +
 +static const char *implicit_ident_advice(void)
 +{
 +      char *user_config = expand_user_path("~/.gitconfig", 0);
 +      char *xdg_config = xdg_config_home("config");
 +      int config_exists = file_exists(user_config) || file_exists(xdg_config);
 +
 +      free(user_config);
 +      free(xdg_config);
 +
 +      if (config_exists)
 +              return _(implicit_ident_advice_config);
 +      else
 +              return _(implicit_ident_advice_noconfig);
 +
 +}
 +
 +void print_commit_summary(const char *prefix, const struct object_id *oid,
 +                        unsigned int flags)
 +{
 +      struct rev_info rev;
 +      struct commit *commit;
 +      struct strbuf format = STRBUF_INIT;
 +      const char *head;
 +      struct pretty_print_context pctx = {0};
 +      struct strbuf author_ident = STRBUF_INIT;
 +      struct strbuf committer_ident = STRBUF_INIT;
 +
 +      commit = lookup_commit(oid);
 +      if (!commit)
 +              die(_("couldn't look up newly created commit"));
 +      if (parse_commit(commit))
 +              die(_("could not parse newly created commit"));
 +
 +      strbuf_addstr(&format, "format:%h] %s");
 +
 +      format_commit_message(commit, "%an <%ae>", &author_ident, &pctx);
 +      format_commit_message(commit, "%cn <%ce>", &committer_ident, &pctx);
 +      if (strbuf_cmp(&author_ident, &committer_ident)) {
 +              strbuf_addstr(&format, "\n Author: ");
 +              strbuf_addbuf_percentquote(&format, &author_ident);
 +      }
 +      if (flags & SUMMARY_SHOW_AUTHOR_DATE) {
 +              struct strbuf date = STRBUF_INIT;
 +
 +              format_commit_message(commit, "%ad", &date, &pctx);
 +              strbuf_addstr(&format, "\n Date: ");
 +              strbuf_addbuf_percentquote(&format, &date);
 +              strbuf_release(&date);
 +      }
 +      if (!committer_ident_sufficiently_given()) {
 +              strbuf_addstr(&format, "\n Committer: ");
 +              strbuf_addbuf_percentquote(&format, &committer_ident);
 +              if (advice_implicit_identity) {
 +                      strbuf_addch(&format, '\n');
 +                      strbuf_addstr(&format, implicit_ident_advice());
 +              }
 +      }
 +      strbuf_release(&author_ident);
 +      strbuf_release(&committer_ident);
 +
 +      init_revisions(&rev, prefix);
 +      setup_revisions(0, NULL, &rev, NULL);
 +
 +      rev.diff = 1;
 +      rev.diffopt.output_format =
 +              DIFF_FORMAT_SHORTSTAT | DIFF_FORMAT_SUMMARY;
 +
 +      rev.verbose_header = 1;
 +      rev.show_root_diff = 1;
 +      get_commit_format(format.buf, &rev);
 +      rev.always_show_header = 0;
 +      rev.diffopt.detect_rename = DIFF_DETECT_RENAME;
 +      rev.diffopt.break_opt = 0;
 +      diff_setup_done(&rev.diffopt);
 +
 +      head = resolve_ref_unsafe("HEAD", 0, NULL, NULL);
 +      if (!head)
 +              die_errno(_("unable to resolve HEAD after creating commit"));
 +      if (!strcmp(head, "HEAD"))
 +              head = _("detached HEAD");
 +      else
 +              skip_prefix(head, "refs/heads/", &head);
 +      printf("[%s%s ", head, (flags & SUMMARY_INITIAL_COMMIT) ?
 +                                              _(" (root-commit)") : "");
 +
 +      if (!log_tree_commit(&rev, commit)) {
 +              rev.always_show_header = 1;
 +              rev.use_terminator = 1;
 +              log_tree_commit(&rev, commit);
 +      }
 +
 +      strbuf_release(&format);
 +}
 +
 +static int parse_head(struct commit **head)
 +{
 +      struct commit *current_head;
 +      struct object_id oid;
 +
 +      if (get_oid("HEAD", &oid)) {
 +              current_head = NULL;
 +      } else {
 +              current_head = lookup_commit_reference(&oid);
 +              if (!current_head)
 +                      return error(_("could not parse HEAD"));
 +              if (oidcmp(&oid, &current_head->object.oid)) {
 +                      warning(_("HEAD %s is not a commit!"),
 +                              oid_to_hex(&oid));
 +              }
 +              if (parse_commit(current_head))
 +                      return error(_("could not parse HEAD commit"));
 +      }
 +      *head = current_head;
 +
 +      return 0;
 +}
 +
 +/*
 + * Try to commit without forking 'git commit'. In some cases we need
 + * to run 'git commit' to display an error message
 + *
 + * Returns:
 + *  -1 - error unable to commit
 + *   0 - success
 + *   1 - run 'git commit'
 + */
 +static int try_to_commit(struct strbuf *msg, const char *author,
 +                       struct replay_opts *opts, unsigned int flags,
 +                       struct object_id *oid)
 +{
 +      struct object_id tree;
 +      struct commit *current_head;
 +      struct commit_list *parents = NULL;
 +      struct commit_extra_header *extra = NULL;
 +      struct strbuf err = STRBUF_INIT;
 +      struct strbuf commit_msg = STRBUF_INIT;
 +      char *amend_author = NULL;
 +      const char *hook_commit = NULL;
 +      enum commit_msg_cleanup_mode cleanup;
 +      int res = 0;
 +
 +      if (parse_head(&current_head))
 +              return -1;
 +
 +      if (flags & AMEND_MSG) {
 +              const char *exclude_gpgsig[] = { "gpgsig", NULL };
 +              const char *out_enc = get_commit_output_encoding();
 +              const char *message = logmsg_reencode(current_head, NULL,
 +                                                    out_enc);
 +
 +              if (!msg) {
 +                      const char *orig_message = NULL;
 +
 +                      find_commit_subject(message, &orig_message);
 +                      msg = &commit_msg;
 +                      strbuf_addstr(msg, orig_message);
 +                      hook_commit = "HEAD";
 +              }
 +              author = amend_author = get_author(message);
 +              unuse_commit_buffer(current_head, message);
 +              if (!author) {
 +                      res = error(_("unable to parse commit author"));
 +                      goto out;
 +              }
 +              parents = copy_commit_list(current_head->parents);
 +              extra = read_commit_extra_headers(current_head, exclude_gpgsig);
 +      } else if (current_head) {
 +              commit_list_insert(current_head, &parents);
 +      }
 +
 +      if (write_cache_as_tree(&tree, 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)) {
 +              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);
 +              if (res)
 +                      goto out;
 +              if (strbuf_read_file(&commit_msg, git_path_commit_editmsg(),
 +                                   2048) < 0) {
 +                      res = error_errno(_("unable to read commit message "
 +                                            "from '%s'"),
 +                                          git_path_commit_editmsg());
 +                      goto out;
 +              }
 +              msg = &commit_msg;
 +      }
 +
 +      cleanup = (flags & CLEANUP_MSG) ? COMMIT_MSG_CLEANUP_ALL :
 +                                        opts->default_msg_cleanup;
 +
 +      if (cleanup != COMMIT_MSG_CLEANUP_NONE)
 +              strbuf_stripspace(msg, cleanup == COMMIT_MSG_CLEANUP_ALL);
 +      if (!opts->allow_empty_message && message_is_empty(msg, cleanup)) {
 +              res = 1; /* run 'git commit' to display error message */
 +              goto out;
 +      }
 +
 +      reset_ident_date();
 +
 +      if (commit_tree_extended(msg->buf, msg->len, &tree, parents,
 +                               oid, author, opts->gpg_sign, extra)) {
 +              res = error(_("failed to write commit object"));
 +              goto out;
 +      }
 +
 +      if (update_head_with_reflog(current_head, oid,
 +                                  getenv("GIT_REFLOG_ACTION"), msg, &err)) {
 +              res = error("%s", err.buf);
 +              goto out;
 +      }
 +
 +      if (flags & AMEND_MSG)
 +              commit_post_rewrite(current_head, oid);
 +
 +out:
 +      free_commit_extra_headers(extra);
 +      strbuf_release(&err);
 +      strbuf_release(&commit_msg);
 +      free(amend_author);
 +
 +      return res;
 +}
 +
 +static int do_commit(const char *msg_file, const char *author,
 +                   struct replay_opts *opts, unsigned int flags)
 +{
 +      int res = 1;
 +
 +      if (!(flags & EDIT_MSG) && !(flags & VERIFY_MSG) &&
 +          !(flags & CREATE_ROOT_COMMIT)) {
 +              struct object_id oid;
 +              struct strbuf sb = STRBUF_INIT;
 +
 +              if (msg_file && strbuf_read_file(&sb, msg_file, 2048) < 0)
 +                      return error_errno(_("unable to read commit message "
 +                                           "from '%s'"),
 +                                         msg_file);
 +
 +              res = try_to_commit(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));
 +                      if (!is_rebase_i(opts))
 +                              print_commit_summary(NULL, &oid,
 +                                              SUMMARY_SHOW_AUTHOR_DATE);
 +                      return res;
 +              }
 +      }
 +      if (res == 1)
 +              return run_git_commit(msg_file, opts, flags);
 +
 +      return res;
 +}
 +
  static int is_original_commit_empty(struct commit *commit)
  {
        const struct object_id *ptree_oid;
                if (parse_commit(parent))
                        return error(_("could not parse parent commit %s"),
                                oid_to_hex(&parent->object.oid));
 -              ptree_oid = &parent->tree->object.oid;
 +              ptree_oid = get_commit_tree_oid(parent);
        } else {
                ptree_oid = the_hash_algo->empty_tree; /* commit is root */
        }
  
 -      return !oidcmp(ptree_oid, &commit->tree->object.oid);
 +      return !oidcmp(ptree_oid, get_commit_tree_oid(commit));
  }
  
  /*
@@@ -1412,9 -767,6 +1412,9 @@@ enum todo_command 
        TODO_SQUASH,
        /* commands that do something else than handling a single commit */
        TODO_EXEC,
 +      TODO_LABEL,
 +      TODO_RESET,
 +      TODO_MERGE,
        /* commands that do nothing but are counted for reporting progress */
        TODO_NOOP,
        TODO_DROP,
@@@ -1433,9 -785,6 +1433,9 @@@ static struct 
        { 'f', "fixup" },
        { 's', "squash" },
        { 'x', "exec" },
 +      { 'l', "label" },
 +      { 't', "reset" },
 +      { 'm', "merge" },
        { 0,   "noop" },
        { 'd', "drop" },
        { 0,   NULL }
@@@ -1465,43 -814,38 +1465,43 @@@ static int is_fixup(enum todo_command c
        return command == TODO_FIXUP || command == TODO_SQUASH;
  }
  
 +/* Does this command create a (non-merge) commit? */
 +static int is_pick_or_similar(enum todo_command command)
 +{
 +      switch (command) {
 +      case TODO_PICK:
 +      case TODO_REVERT:
 +      case TODO_EDIT:
 +      case TODO_REWORD:
 +      case TODO_FIXUP:
 +      case TODO_SQUASH:
 +              return 1;
 +      default:
 +              return 0;
 +      }
 +}
 +
  static int update_squash_messages(enum todo_command command,
                struct commit *commit, struct replay_opts *opts)
  {
        struct strbuf buf = STRBUF_INIT;
 -      int count, res;
 +      int res;
        const char *message, *body;
  
 -      if (file_exists(rebase_path_squash_msg())) {
 +      if (opts->current_fixup_count > 0) {
                struct strbuf header = STRBUF_INIT;
 -              char *eol, *p;
 +              char *eol;
  
 -              if (strbuf_read_file(&buf, rebase_path_squash_msg(), 2048) <= 0)
 +              if (strbuf_read_file(&buf, rebase_path_squash_msg(), 9) <= 0)
                        return error(_("could not read '%s'"),
                                rebase_path_squash_msg());
  
 -              p = buf.buf + 1;
 -              eol = strchrnul(buf.buf, '\n');
 -              if (buf.buf[0] != comment_line_char ||
 -                  (p += strcspn(p, "0123456789\n")) == eol)
 -                      return error(_("unexpected 1st line of squash message:"
 -                                     "\n\n\t%.*s"),
 -                                   (int)(eol - buf.buf), buf.buf);
 -              count = strtol(p, NULL, 10);
 -
 -              if (count < 1)
 -                      return error(_("invalid 1st line of squash message:\n"
 -                                     "\n\t%.*s"),
 -                                   (int)(eol - buf.buf), buf.buf);
 +              eol = buf.buf[0] != comment_line_char ?
 +                      buf.buf : strchrnul(buf.buf, '\n');
  
                strbuf_addf(&header, "%c ", comment_line_char);
 -              strbuf_addf(&header,
 -                          _("This is a combination of %d commits."), ++count);
 +              strbuf_addf(&header, _("This is a combination of %d commits."),
 +                          opts->current_fixup_count + 2);
                strbuf_splice(&buf, 0, eol - buf.buf, header.buf, header.len);
                strbuf_release(&header);
        } else {
                                     rebase_path_fixup_msg());
                }
  
 -              count = 2;
                strbuf_addf(&buf, "%c ", comment_line_char);
 -              strbuf_addf(&buf, _("This is a combination of %d commits."),
 -                          count);
 +              strbuf_addf(&buf, _("This is a combination of %d commits."), 2);
                strbuf_addf(&buf, "\n%c ", comment_line_char);
                strbuf_addstr(&buf, _("This is the 1st commit message:"));
                strbuf_addstr(&buf, "\n\n");
        if (command == TODO_SQUASH) {
                unlink(rebase_path_fixup_msg());
                strbuf_addf(&buf, "\n%c ", comment_line_char);
 -              strbuf_addf(&buf, _("This is the commit message #%d:"), count);
 +              strbuf_addf(&buf, _("This is the commit message #%d:"),
 +                          ++opts->current_fixup_count);
                strbuf_addstr(&buf, "\n\n");
                strbuf_addstr(&buf, body);
        } else if (command == TODO_FIXUP) {
                strbuf_addf(&buf, "\n%c ", comment_line_char);
                strbuf_addf(&buf, _("The commit message #%d will be skipped:"),
 -                          count);
 +                          ++opts->current_fixup_count);
                strbuf_addstr(&buf, "\n\n");
                strbuf_add_commented_lines(&buf, body, strlen(body));
        } else
  
        res = write_message(buf.buf, buf.len, rebase_path_squash_msg(), 0);
        strbuf_release(&buf);
 +
 +      if (!res) {
 +              strbuf_addf(&opts->current_fixups, "%s%s %s",
 +                          opts->current_fixups.len ? "\n" : "",
 +                          command_to_string(command),
 +                          oid_to_hex(&commit->object.oid));
 +              res = write_message(opts->current_fixups.buf,
 +                                  opts->current_fixups.len,
 +                                  rebase_path_current_fixups(), 0);
 +      }
 +
        return res;
  }
  
@@@ -1614,11 -948,10 +1614,11 @@@ static int do_pick_commit(enum todo_com
                struct replay_opts *opts, int final_fixup)
  {
        unsigned int flags = opts->edit ? EDIT_MSG : 0;
 -      const char *msg_file = opts->edit ? NULL : git_path_merge_msg();
 +      const char *msg_file = opts->edit ? NULL : git_path_merge_msg(the_repository);
        struct object_id head;
        struct commit *base, *next, *parent;
        const char *base_label, *next_label;
 +      char *author = NULL;
        struct commit_message msg = { NULL, NULL, NULL, NULL };
        struct strbuf msgbuf = STRBUF_INIT;
        int res, unborn = 0, allow;
                 * that represents the "current" state for merge-recursive
                 * to work on.
                 */
 -              if (write_cache_as_tree(head.hash, 0, NULL))
 +              if (write_cache_as_tree(&head, 0, NULL))
                        return error(_("your index file is unmerged."));
        } else {
                unborn = get_oid("HEAD", &head);
 -              if (unborn)
 +              /* Do we want to generate a root commit? */
 +              if (is_pick_or_similar(command) && opts->have_squash_onto &&
 +                  !oidcmp(&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_SHA1_HEX : "HEAD",
 +              if (index_differs_from(unborn ? empty_tree_oid_hex() : "HEAD",
                                       NULL, 0))
                        return error_dirty_index(opts);
        }
                        strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
                        strbuf_addstr(&msgbuf, ")\n");
                }
 +              if (!is_fixup(command))
 +                      author = get_author(msg.message);
        }
  
        if (command == TODO_REWORD)
                        flags |= CLEANUP_MSG;
                        msg_file = rebase_path_fixup_msg();
                } else {
 -                      const char *dest = git_path_squash_msg();
 +                      const char *dest = git_path_squash_msg(the_repository);
                        unlink(dest);
                        if (copy_file(dest, rebase_path_squash_msg(), 0666))
                                return error(_("could not rename '%s' to '%s'"),
                                             rebase_path_squash_msg(), dest);
 -                      unlink(git_path_merge_msg());
 +                      unlink(git_path_merge_msg(the_repository));
                        msg_file = dest;
                        flags |= EDIT_MSG;
                }
        }
  
 +      if (opts->signoff && !is_fixup(command))
 +              append_signoff(&msgbuf, 0, 0);
 +
        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,
                                         &head, &msgbuf, opts);
                if (res < 0)
 -                      return res;
 -              res |= write_message(msgbuf.buf, msgbuf.len,
 -                                   git_path_merge_msg(), 0);
 +                      goto leave;
 +
 +              res |= write_message(msgbuf.buf, msgbuf.len,
 +                                   git_path_merge_msg(the_repository), 0);
        } else {
                struct commit_list *common = NULL;
                struct commit_list *remotes = NULL;
  
                res = write_message(msgbuf.buf, msgbuf.len,
 -                                  git_path_merge_msg(), 0);
 +                                  git_path_merge_msg(the_repository), 0);
  
                commit_list_insert(base, &common);
                commit_list_insert(next, &remotes);
                goto leave;
        } else if (allow)
                flags |= ALLOW_EMPTY;
 -      if (!opts->no_commit)
 +      if (!opts->no_commit) {
  fast_forward_edit:
 -              res = run_git_commit(msg_file, opts, flags);
 +              if (author || command == TODO_REVERT || (flags & AMEND_MSG))
 +                      res = do_commit(msg_file, author, opts, flags);
 +              else
 +                      res = error(_("unable to parse commit author"));
 +      }
  
        if (!res && final_fixup) {
                unlink(rebase_path_fixup_msg());
                unlink(rebase_path_squash_msg());
 +              unlink(rebase_path_current_fixups());
 +              strbuf_reset(&opts->current_fixups);
 +              opts->current_fixup_count = 0;
        }
  
  leave:
        free_message(commit, &msg);
 +      free(author);
        update_abort_safety_file();
  
        return res;
@@@ -1864,14 -1176,12 +1864,12 @@@ static int prepare_revs(struct replay_o
        if (prepare_revision_walk(opts->revs))
                return error(_("revision walk setup failed"));
  
-       if (!opts->revs->commits)
-               return error(_("empty commit set passed"));
        return 0;
  }
  
  static int read_and_refresh_cache(struct replay_opts *opts)
  {
 -      static struct lock_file index_lock;
 +      struct lock_file index_lock = LOCK_INIT;
        int index_fd = hold_locked_index(&index_lock, 0);
        if (read_index_preload(&the_index, NULL) < 0) {
                rollback_lock_file(&index_lock);
                        _(action_name(opts)));
        }
        refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 -      if (the_index.cache_changed && index_fd >= 0) {
 -              if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK)) {
 +      if (index_fd >= 0) {
 +              if (write_locked_index(&the_index, &index_lock,
 +                                     COMMIT_LOCK | SKIP_IF_UNCHANGED)) {
                        return error(_("git %s: failed to refresh the index"),
                                _(action_name(opts)));
                }
        }
 -      rollback_lock_file(&index_lock);
        return 0;
  }
  
 +enum todo_item_flags {
 +      TODO_EDIT_MERGE_MSG = 1
 +};
 +
  struct todo_item {
        enum todo_command command;
        struct commit *commit;
 +      unsigned int flags;
        const char *arg;
        int arg_len;
        size_t offset_in_buf;
@@@ -1931,8 -1236,6 +1929,8 @@@ static int parse_insn_line(struct todo_
        char *end_of_object_name;
        int i, saved, status, padding;
  
 +      item->flags = 0;
 +
        /* left-trim */
        bol += strspn(bol, " \t");
  
                return error(_("missing arguments for %s"),
                             command_to_string(item->command));
  
 -      if (item->command == TODO_EXEC) {
 +      if (item->command == TODO_EXEC || item->command == TODO_LABEL ||
 +          item->command == TODO_RESET) {
                item->commit = NULL;
                item->arg = bol;
                item->arg_len = (int)(eol - bol);
                return 0;
        }
  
 +      if (item->command == TODO_MERGE) {
 +              if (skip_prefix(bol, "-C", &bol))
 +                      bol += strspn(bol, " \t");
 +              else if (skip_prefix(bol, "-c", &bol)) {
 +                      bol += strspn(bol, " \t");
 +                      item->flags |= TODO_EDIT_MERGE_MSG;
 +              } else {
 +                      item->flags |= TODO_EDIT_MERGE_MSG;
 +                      item->commit = NULL;
 +                      item->arg = bol;
 +                      item->arg_len = (int)(eol - bol);
 +                      return 0;
 +              }
 +      }
 +
        end_of_object_name = (char *) bol + strcspn(bol, " \t\n");
        saved = *end_of_object_name;
        *end_of_object_name = '\0';
@@@ -2058,48 -1345,22 +2056,48 @@@ static int count_commands(struct todo_l
        return count;
  }
  
 +static int get_item_line_offset(struct todo_list *todo_list, int index)
 +{
 +      return index < todo_list->nr ?
 +              todo_list->items[index].offset_in_buf : todo_list->buf.len;
 +}
 +
 +static const char *get_item_line(struct todo_list *todo_list, int index)
 +{
 +      return todo_list->buf.buf + get_item_line_offset(todo_list, index);
 +}
 +
 +static int get_item_line_length(struct todo_list *todo_list, int index)
 +{
 +      return get_item_line_offset(todo_list, index + 1)
 +              -  get_item_line_offset(todo_list, index);
 +}
 +
 +static ssize_t strbuf_read_file_or_whine(struct strbuf *sb, const char *path)
 +{
 +      int fd;
 +      ssize_t len;
 +
 +      fd = open(path, O_RDONLY);
 +      if (fd < 0)
 +              return error_errno(_("could not open '%s'"), path);
 +      len = strbuf_read(sb, fd, 0);
 +      close(fd);
 +      if (len < 0)
 +              return error(_("could not read '%s'."), path);
 +      return len;
 +}
 +
  static int read_populate_todo(struct todo_list *todo_list,
                        struct replay_opts *opts)
  {
        struct stat st;
        const char *todo_file = get_todo_path(opts);
 -      int fd, res;
 +      int res;
  
        strbuf_reset(&todo_list->buf);
 -      fd = open(todo_file, O_RDONLY);
 -      if (fd < 0)
 -              return error_errno(_("could not open '%s'"), todo_file);
 -      if (strbuf_read(&todo_list->buf, fd, 0) < 0) {
 -              close(fd);
 -              return error(_("could not read '%s'."), todo_file);
 -      }
 -      close(fd);
 +      if (strbuf_read_file_or_whine(&todo_list->buf, todo_file) < 0)
 +              return -1;
  
        res = stat(todo_file, &st);
        if (res)
@@@ -2207,7 -1468,6 +2205,7 @@@ static int populate_opts_cb(const char 
  static void read_strategy_opts(struct replay_opts *opts, struct strbuf *buf)
  {
        int i;
 +      char *strategy_opts_string;
  
        strbuf_reset(buf);
        if (!read_oneliner(buf, rebase_path_strategy(), 0))
        if (!read_oneliner(buf, rebase_path_strategy_opts(), 0))
                return;
  
 -      opts->xopts_nr = split_cmdline(buf->buf, (const char ***)&opts->xopts);
 +      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++) {
                const char *arg = opts->xopts[i];
  
@@@ -2255,30 -1511,9 +2253,30 @@@ static int read_populate_opts(struct re
                if (file_exists(rebase_path_verbose()))
                        opts->verbose = 1;
  
 +              if (file_exists(rebase_path_signoff())) {
 +                      opts->allow_ff = 0;
 +                      opts->signoff = 1;
 +              }
 +
                read_strategy_opts(opts, &buf);
                strbuf_release(&buf);
  
 +              if (read_oneliner(&opts->current_fixups,
 +                                rebase_path_current_fixups(), 1)) {
 +                      const char *p = opts->current_fixups.buf;
 +                      opts->current_fixup_count = 1;
 +                      while ((p = strchr(p, '\n'))) {
 +                              opts->current_fixup_count++;
 +                              p++;
 +                      }
 +              }
 +
 +              if (read_oneliner(&buf, rebase_path_squash_onto(), 0)) {
 +                      if (get_oid_hex(buf.buf, &opts->squash_onto) < 0)
 +                              return error(_("unusable squash-onto"));
 +                      opts->have_squash_onto = 1;
 +              }
 +
                return 0;
        }
  
@@@ -2323,6 -1558,10 +2321,10 @@@ static int walk_revs_populate_todo(stru
                        short_commit_name(commit), subject_len, subject);
                unuse_commit_buffer(commit, commit_buffer);
        }
+       if (!todo_list->nr)
+               return error(_("empty commit set passed"));
        return 0;
  }
  
@@@ -2340,24 -1579,28 +2342,24 @@@ static int create_seq_dir(void
  
  static int save_head(const char *head)
  {
 -      static struct lock_file head_lock;
 +      struct lock_file head_lock = LOCK_INIT;
        struct strbuf buf = STRBUF_INIT;
        int fd;
        ssize_t written;
  
        fd = hold_lock_file_for_update(&head_lock, git_path_head_file(), 0);
 -      if (fd < 0) {
 -              rollback_lock_file(&head_lock);
 +      if (fd < 0)
                return error_errno(_("could not lock HEAD"));
 -      }
        strbuf_addf(&buf, "%s\n", head);
        written = write_in_full(fd, buf.buf, buf.len);
        strbuf_release(&buf);
        if (written < 0) {
 +              error_errno(_("could not write to '%s'"), git_path_head_file());
                rollback_lock_file(&head_lock);
 -              return error_errno(_("could not write to '%s'"),
 -                                 git_path_head_file());
 -      }
 -      if (commit_lock_file(&head_lock) < 0) {
 -              rollback_lock_file(&head_lock);
 -              return error(_("failed to finalize '%s'."), git_path_head_file());
 +              return -1;
        }
 +      if (commit_lock_file(&head_lock) < 0)
 +              return error(_("failed to finalize '%s'"), git_path_head_file());
        return 0;
  }
  
@@@ -2400,8 -1643,8 +2402,8 @@@ static int rollback_single_pick(void
  {
        struct object_id head_oid;
  
 -      if (!file_exists(git_path_cherry_pick_head()) &&
 -          !file_exists(git_path_revert_head()))
 +      if (!file_exists(git_path_cherry_pick_head(the_repository)) &&
 +          !file_exists(git_path_revert_head(the_repository)))
                return error(_("no cherry-pick or revert in progress"));
        if (read_ref_full("HEAD", 0, &head_oid, NULL))
                return error(_("cannot resolve HEAD"));
@@@ -2461,7 -1704,7 +2463,7 @@@ fail
  
  static int save_todo(struct todo_list *todo_list, struct replay_opts *opts)
  {
 -      static struct lock_file todo_lock;
 +      struct lock_file todo_lock = LOCK_INIT;
        const char *todo_path = get_todo_path(opts);
        int next = todo_list->current, offset, fd;
  
        fd = hold_lock_file_for_update(&todo_lock, todo_path, 0);
        if (fd < 0)
                return error_errno(_("could not lock '%s'"), todo_path);
 -      offset = next < todo_list->nr ?
 -              todo_list->items[next].offset_in_buf : todo_list->buf.len;
 +      offset = get_item_line_offset(todo_list, next);
        if (write_in_full(fd, todo_list->buf.buf + offset,
                        todo_list->buf.len - offset) < 0)
                return error_errno(_("could not write to '%s'"), todo_path);
        if (commit_lock_file(&todo_lock) < 0)
 -              return error(_("failed to finalize '%s'."), todo_path);
 +              return error(_("failed to finalize '%s'"), todo_path);
  
 -      if (is_rebase_i(opts)) {
 -              const char *done_path = rebase_path_done();
 -              int fd = open(done_path, O_CREAT | O_WRONLY | O_APPEND, 0666);
 -              int prev_offset = !next ? 0 :
 -                      todo_list->items[next - 1].offset_in_buf;
 +      if (is_rebase_i(opts) && next > 0) {
 +              const char *done = rebase_path_done();
 +              int fd = open(done, O_CREAT | O_WRONLY | O_APPEND, 0666);
 +              int ret = 0;
  
 -              if (fd >= 0 && offset > prev_offset &&
 -                  write_in_full(fd, todo_list->buf.buf + prev_offset,
 -                                offset - prev_offset) < 0) {
 -                      close(fd);
 -                      return error_errno(_("could not write to '%s'"),
 -                                         done_path);
 -              }
 -              if (fd >= 0)
 -                      close(fd);
 +              if (fd < 0)
 +                      return 0;
 +              if (write_in_full(fd, get_item_line(todo_list, next - 1),
 +                                get_item_line_length(todo_list, next - 1))
 +                  < 0)
 +                      ret = error_errno(_("could not write to '%s'"), done);
 +              if (close(fd) < 0)
 +                      ret = error_errno(_("failed to finalize '%s'"), done);
 +              return ret;
        }
        return 0;
  }
@@@ -2549,9 -1794,6 +2551,9 @@@ static int make_patch(struct commit *co
        p = short_commit_name(commit);
        if (write_message(p, strlen(p), rebase_path_stopped_sha(), 1) < 0)
                return -1;
 +      if (update_ref("rebase", "REBASE_HEAD", &commit->object.oid,
 +                     NULL, REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR))
 +              res |= error(_("could not update %s"), "REBASE_HEAD");
  
        strbuf_addf(&buf, "%s/patch", get_dir(opts));
        memset(&log_tree_opt, 0, sizeof(log_tree_opt));
@@@ -2623,14 -1865,14 +2625,14 @@@ static int error_with_patch(struct comm
  static int error_failed_squash(struct commit *commit,
        struct replay_opts *opts, int subject_len, const char *subject)
  {
 -      if (rename(rebase_path_squash_msg(), rebase_path_message()))
 -              return error(_("could not rename '%s' to '%s'"),
 +      if (copy_file(rebase_path_message(), rebase_path_squash_msg(), 0666))
 +              return error(_("could not copy '%s' to '%s'"),
                        rebase_path_squash_msg(), rebase_path_message());
 -      unlink(rebase_path_fixup_msg());
 -      unlink(git_path_merge_msg());
 -      if (copy_file(git_path_merge_msg(), rebase_path_message(), 0666))
 +      unlink(git_path_merge_msg(the_repository));
 +      if (copy_file(git_path_merge_msg(the_repository), rebase_path_message(), 0666))
                return error(_("could not copy '%s' to '%s'"),
 -                           rebase_path_message(), git_path_merge_msg());
 +                           rebase_path_message(),
 +                           git_path_merge_msg(the_repository));
        return error_with_patch(commit, subject, subject_len, opts, 1, 0);
  }
  
@@@ -2679,377 -1921,6 +2681,377 @@@ static int do_exec(const char *command_
        return status;
  }
  
 +static int safe_append(const char *filename, const char *fmt, ...)
 +{
 +      va_list ap;
 +      struct lock_file lock = LOCK_INIT;
 +      int fd = hold_lock_file_for_update(&lock, filename,
 +                                         LOCK_REPORT_ON_ERROR);
 +      struct strbuf buf = STRBUF_INIT;
 +
 +      if (fd < 0)
 +              return -1;
 +
 +      if (strbuf_read_file(&buf, filename, 0) < 0 && errno != ENOENT) {
 +              error_errno(_("could not read '%s'"), filename);
 +              rollback_lock_file(&lock);
 +              return -1;
 +      }
 +      strbuf_complete(&buf, '\n');
 +      va_start(ap, fmt);
 +      strbuf_vaddf(&buf, fmt, ap);
 +      va_end(ap);
 +
 +      if (write_in_full(fd, buf.buf, buf.len) < 0) {
 +              error_errno(_("could not write to '%s'"), filename);
 +              strbuf_release(&buf);
 +              rollback_lock_file(&lock);
 +              return -1;
 +      }
 +      if (commit_lock_file(&lock) < 0) {
 +              strbuf_release(&buf);
 +              rollback_lock_file(&lock);
 +              return error(_("failed to finalize '%s'"), filename);
 +      }
 +
 +      strbuf_release(&buf);
 +      return 0;
 +}
 +
 +static int do_label(const char *name, int len)
 +{
 +      struct ref_store *refs = get_main_ref_store(the_repository);
 +      struct ref_transaction *transaction;
 +      struct strbuf ref_name = STRBUF_INIT, err = STRBUF_INIT;
 +      struct strbuf msg = STRBUF_INIT;
 +      int ret = 0;
 +      struct object_id head_oid;
 +
 +      if (len == 1 && *name == '#')
 +              return error("Illegal label name: '%.*s'", len, name);
 +
 +      strbuf_addf(&ref_name, "refs/rewritten/%.*s", len, name);
 +      strbuf_addf(&msg, "rebase -i (label) '%.*s'", len, name);
 +
 +      transaction = ref_store_transaction_begin(refs, &err);
 +      if (!transaction) {
 +              error("%s", err.buf);
 +              ret = -1;
 +      } else if (get_oid("HEAD", &head_oid)) {
 +              error(_("could not read HEAD"));
 +              ret = -1;
 +      } else if (ref_transaction_update(transaction, ref_name.buf, &head_oid,
 +                                        NULL, 0, msg.buf, &err) < 0 ||
 +                 ref_transaction_commit(transaction, &err)) {
 +              error("%s", err.buf);
 +              ret = -1;
 +      }
 +      ref_transaction_free(transaction);
 +      strbuf_release(&err);
 +      strbuf_release(&msg);
 +
 +      if (!ret)
 +              ret = safe_append(rebase_path_refs_to_delete(),
 +                                "%s\n", ref_name.buf);
 +      strbuf_release(&ref_name);
 +
 +      return ret;
 +}
 +
 +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)
 +{
 +      struct strbuf ref_name = STRBUF_INIT;
 +      struct object_id oid;
 +      struct lock_file lock = LOCK_INIT;
 +      struct tree_desc desc;
 +      struct tree *tree;
 +      struct unpack_trees_options unpack_tree_opts;
 +      int ret = 0, i;
 +
 +      if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
 +              return -1;
 +
 +      if (len == 10 && !strncmp("[new root]", name, len)) {
 +              if (!opts->have_squash_onto) {
 +                      const char *hex;
 +                      if (commit_tree("", 0, the_hash_algo->empty_tree,
 +                                      NULL, &opts->squash_onto,
 +                                      NULL, NULL))
 +                              return error(_("writing fake root commit"));
 +                      opts->have_squash_onto = 1;
 +                      hex = oid_to_hex(&opts->squash_onto);
 +                      if (write_message(hex, strlen(hex),
 +                                        rebase_path_squash_onto(), 0))
 +                              return error(_("writing squash-onto"));
 +              }
 +              oidcpy(&oid, &opts->squash_onto);
 +      } else {
 +              /* Determine the length of the label */
 +              for (i = 0; i < len; i++)
 +                      if (isspace(name[i]))
 +                              len = i;
 +
 +              strbuf_addf(&ref_name, "refs/rewritten/%.*s", len, name);
 +              if (get_oid(ref_name.buf, &oid) &&
 +                  get_oid(ref_name.buf + strlen("refs/rewritten/"), &oid)) {
 +                      error(_("could not read '%s'"), ref_name.buf);
 +                      rollback_lock_file(&lock);
 +                      strbuf_release(&ref_name);
 +                      return -1;
 +              }
 +      }
 +
 +      memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 +      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.fn = oneway_merge;
 +      unpack_tree_opts.merge = 1;
 +      unpack_tree_opts.update = 1;
 +
 +      if (read_cache_unmerged()) {
 +              rollback_lock_file(&lock);
 +              strbuf_release(&ref_name);
 +              return error_resolve_conflict(_(action_name(opts)));
 +      }
 +
 +      if (!fill_tree_descriptor(&desc, &oid)) {
 +              error(_("failed to find tree of %s"), oid_to_hex(&oid));
 +              rollback_lock_file(&lock);
 +              free((void *)desc.buffer);
 +              strbuf_release(&ref_name);
 +              return -1;
 +      }
 +
 +      if (unpack_trees(1, &desc, &unpack_tree_opts)) {
 +              rollback_lock_file(&lock);
 +              free((void *)desc.buffer);
 +              strbuf_release(&ref_name);
 +              return -1;
 +      }
 +
 +      tree = parse_tree_indirect(&oid);
 +      prime_cache_tree(&the_index, tree);
 +
 +      if (write_locked_index(&the_index, &lock, COMMIT_LOCK) < 0)
 +              ret = error(_("could not write index"));
 +      free((void *)desc.buffer);
 +
 +      if (!ret)
 +              ret = update_ref(reflog_message(opts, "reset", "'%.*s'",
 +                                              len, name), "HEAD", &oid,
 +                               NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 +
 +      strbuf_release(&ref_name);
 +      return ret;
 +}
 +
 +static int do_merge(struct commit *commit, const char *arg, int arg_len,
 +                  int flags, struct replay_opts *opts)
 +{
 +      int run_commit_flags = (flags & TODO_EDIT_MERGE_MSG) ?
 +              EDIT_MSG | VERIFY_MSG : 0;
 +      struct strbuf ref_name = STRBUF_INIT;
 +      struct commit *head_commit, *merge_commit, *i;
 +      struct commit_list *bases, *j, *reversed = NULL;
 +      struct merge_options o;
 +      int merge_arg_len, oneline_offset, can_fast_forward, ret;
 +      static struct lock_file lock;
 +      const char *p;
 +
 +      if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 +              ret = -1;
 +              goto leave_merge;
 +      }
 +
 +      head_commit = lookup_commit_reference_by_name("HEAD");
 +      if (!head_commit) {
 +              ret = error(_("cannot merge without a current revision"));
 +              goto leave_merge;
 +      }
 +
 +      oneline_offset = arg_len;
 +      merge_arg_len = strcspn(arg, " \t\n");
 +      p = arg + merge_arg_len;
 +      p += strspn(p, " \t\n");
 +      if (*p == '#' && (!p[1] || isspace(p[1]))) {
 +              p += 1 + strspn(p + 1, " \t\n");
 +              oneline_offset = p - arg;
 +      } else if (p - arg < arg_len)
 +              BUG("octopus merges are not supported yet: '%s'", p);
 +
 +      strbuf_addf(&ref_name, "refs/rewritten/%.*s", merge_arg_len, arg);
 +      merge_commit = lookup_commit_reference_by_name(ref_name.buf);
 +      if (!merge_commit) {
 +              /* fall back to non-rewritten ref or commit */
 +              strbuf_splice(&ref_name, 0, strlen("refs/rewritten/"), "", 0);
 +              merge_commit = lookup_commit_reference_by_name(ref_name.buf);
 +      }
 +
 +      if (!merge_commit) {
 +              ret = error(_("could not resolve '%s'"), ref_name.buf);
 +              goto leave_merge;
 +      }
 +
 +      if (opts->have_squash_onto &&
 +          !oidcmp(&head_commit->object.oid, &opts->squash_onto)) {
 +              /*
 +               * When the user tells us to "merge" something into a
 +               * "[new root]", let's simply fast-forward to the merge head.
 +               */
 +              rollback_lock_file(&lock);
 +              ret = fast_forward_to(&merge_commit->object.oid,
 +                                     &head_commit->object.oid, 0, opts);
 +              goto leave_merge;
 +      }
 +
 +      if (commit) {
 +              const char *message = get_commit_buffer(commit, NULL);
 +              const char *body;
 +              int len;
 +
 +              if (!message) {
 +                      ret = error(_("could not get commit message of '%s'"),
 +                                  oid_to_hex(&commit->object.oid));
 +                      goto leave_merge;
 +              }
 +              write_author_script(message);
 +              find_commit_subject(message, &body);
 +              len = strlen(body);
 +              ret = write_message(body, len, git_path_merge_msg(the_repository), 0);
 +              unuse_commit_buffer(commit, message);
 +              if (ret) {
 +                      error_errno(_("could not write '%s'"),
 +                                  git_path_merge_msg(the_repository));
 +                      goto leave_merge;
 +              }
 +      } else {
 +              struct strbuf buf = STRBUF_INIT;
 +              int len;
 +
 +              strbuf_addf(&buf, "author %s", git_author_info(0));
 +              write_author_script(buf.buf);
 +              strbuf_reset(&buf);
 +
 +              if (oneline_offset < arg_len) {
 +                      p = arg + oneline_offset;
 +                      len = arg_len - oneline_offset;
 +              } else {
 +                      strbuf_addf(&buf, "Merge branch '%.*s'",
 +                                  merge_arg_len, arg);
 +                      p = buf.buf;
 +                      len = buf.len;
 +              }
 +
 +              ret = write_message(p, len, git_path_merge_msg(the_repository), 0);
 +              strbuf_release(&buf);
 +              if (ret) {
 +                      error_errno(_("could not write '%s'"),
 +                                  git_path_merge_msg(the_repository));
 +                      goto leave_merge;
 +              }
 +      }
 +
 +      /*
 +       * If HEAD is not identical to the first parent of the original merge
 +       * commit, we cannot fast-forward.
 +       */
 +      can_fast_forward = opts->allow_ff && commit && commit->parents &&
 +              !oidcmp(&commit->parents->item->object.oid,
 +                      &head_commit->object.oid);
 +
 +      /*
 +       * If the merge head is different from the original one, we cannot
 +       * fast-forward.
 +       */
 +      if (can_fast_forward) {
 +              struct commit_list *second_parent = commit->parents->next;
 +
 +              if (second_parent && !second_parent->next &&
 +                  oidcmp(&merge_commit->object.oid,
 +                         &second_parent->item->object.oid))
 +                      can_fast_forward = 0;
 +      }
 +
 +      if (can_fast_forward && commit->parents->next &&
 +          !commit->parents->next->next &&
 +          !oidcmp(&commit->parents->next->item->object.oid,
 +                  &merge_commit->object.oid)) {
 +              rollback_lock_file(&lock);
 +              ret = fast_forward_to(&commit->object.oid,
 +                                    &head_commit->object.oid, 0, opts);
 +              goto leave_merge;
 +      }
 +
 +      write_message(oid_to_hex(&merge_commit->object.oid), GIT_SHA1_HEXSZ,
 +                    git_path_merge_head(the_repository), 0);
 +      write_message("no-ff", 5, git_path_merge_mode(the_repository), 0);
 +
 +      bases = get_merge_bases(head_commit, merge_commit);
 +      if (bases && !oidcmp(&merge_commit->object.oid,
 +                           &bases->item->object.oid)) {
 +              ret = 0;
 +              /* skip merging an ancestor of HEAD */
 +              goto leave_merge;
 +      }
 +
 +      for (j = bases; j; j = j->next)
 +              commit_list_insert(j->item, &reversed);
 +      free_commit_list(bases);
 +
 +      read_cache();
 +      init_merge_options(&o);
 +      o.branch1 = "HEAD";
 +      o.branch2 = ref_name.buf;
 +      o.buffer_output = 2;
 +
 +      ret = merge_recursive(&o, head_commit, merge_commit, reversed, &i);
 +      if (ret <= 0)
 +              fputs(o.obuf.buf, stdout);
 +      strbuf_release(&o.obuf);
 +      if (ret < 0) {
 +              error(_("could not even attempt to merge '%.*s'"),
 +                    merge_arg_len, arg);
 +              goto leave_merge;
 +      }
 +      /*
 +       * The return value of merge_recursive() is 1 on clean, and 0 on
 +       * unclean merge.
 +       *
 +       * Let's reverse that, so that do_merge() returns 0 upon success and
 +       * 1 upon failed merge (keeping the return value -1 for the cases where
 +       * we will want to reschedule the `merge` command).
 +       */
 +      ret = !ret;
 +
 +      if (active_cache_changed &&
 +          write_locked_index(&the_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);
 +      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);
 +
 +leave_merge:
 +      strbuf_release(&ref_name);
 +      rollback_lock_file(&lock);
 +      return ret;
 +}
 +
  static int is_final_fixup(struct todo_list *todo_list)
  {
        int i = todo_list->current;
@@@ -3140,20 -2011,9 +3142,20 @@@ static const char *reflog_message(struc
        return buf.buf;
  }
  
 +static const char rescheduled_advice[] =
 +N_("Could not execute the todo command\n"
 +"\n"
 +"    %.*s"
 +"\n"
 +"It has been rescheduled; To edit the command before continuing, please\n"
 +"edit the todo list first:\n"
 +"\n"
 +"    git rebase --edit-todo\n"
 +"    git rebase --continue\n");
 +
  static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
  {
 -      int res = 0;
 +      int res = 0, reschedule = 0;
  
        setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
        if (opts->allow_ff)
                        unlink(rebase_path_author_script());
                        unlink(rebase_path_stopped_sha());
                        unlink(rebase_path_amend());
 +                      delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
                }
                if (item->command <= TODO_SQUASH) {
                        if (is_rebase_i(opts))
                                        opts, is_final_fixup(todo_list));
                        if (is_rebase_i(opts) && res < 0) {
                                /* Reschedule */
 +                              advise(_(rescheduled_advice),
 +                                     get_item_line_length(todo_list,
 +                                                          todo_list->current),
 +                                     get_item_line(todo_list,
 +                                                   todo_list->current));
                                todo_list->current--;
                                if (save_todo(todo_list, opts))
                                        return -1;
                                        intend_to_amend();
                                return error_failed_squash(item->commit, opts,
                                        item->arg_len, item->arg);
 -                      } else if (res && is_rebase_i(opts))
 +                      } else if (res && is_rebase_i(opts) && item->commit) {
 +                              int to_amend = 0;
 +                              struct object_id oid;
 +
 +                              /*
 +                               * If we are rewording and have either
 +                               * fast-forwarded already, or are about to
 +                               * create a new root commit, we want to amend,
 +                               * otherwise we do not.
 +                               */
 +                              if (item->command == TODO_REWORD &&
 +                                  !get_oid("HEAD", &oid) &&
 +                                  (!oidcmp(&item->commit->object.oid, &oid) ||
 +                                   (opts->have_squash_onto &&
 +                                    !oidcmp(&opts->squash_onto, &oid))))
 +                                      to_amend = 1;
 +
                                return res | error_with_patch(item->commit,
 -                                      item->arg, item->arg_len, opts, res,
 -                                      item->command == TODO_REWORD);
 +                                              item->arg, item->arg_len, opts,
 +                                              res, to_amend);
 +                      }
                } else if (item->command == TODO_EXEC) {
                        char *end_of_arg = (char *)(item->arg + item->arg_len);
                        int saved = *end_of_arg;
                                /* `current` will be incremented below */
                                todo_list->current = -1;
                        }
 +              } else if (item->command == TODO_LABEL) {
 +                      if ((res = do_label(item->arg, item->arg_len)))
 +                              reschedule = 1;
 +              } else if (item->command == TODO_RESET) {
 +                      if ((res = do_reset(item->arg, item->arg_len, opts)))
 +                              reschedule = 1;
 +              } else if (item->command == TODO_MERGE) {
 +                      if ((res = do_merge(item->commit,
 +                                          item->arg, item->arg_len,
 +                                          item->flags, opts)) < 0)
 +                              reschedule = 1;
 +                      else if (item->commit)
 +                              record_in_rewritten(&item->commit->object.oid,
 +                                                  peek_command(todo_list, 1));
 +                      if (res > 0)
 +                              /* failed with merge conflicts */
 +                              return error_with_patch(item->commit,
 +                                                      item->arg,
 +                                                      item->arg_len, opts,
 +                                                      res, 0);
                } else if (!is_noop(item->command))
                        return error(_("unknown command %d"), item->command);
  
 +              if (reschedule) {
 +                      advise(_(rescheduled_advice),
 +                             get_item_line_length(todo_list,
 +                                                  todo_list->current),
 +                             get_item_line(todo_list, todo_list->current));
 +                      todo_list->current--;
 +                      if (save_todo(todo_list, opts))
 +                              return -1;
 +                      if (item->commit)
 +                              return error_with_patch(item->commit,
 +                                                      item->arg,
 +                                                      item->arg_len, opts,
 +                                                      res, 0);
 +              }
 +
                todo_list->current++;
                if (res)
                        return res;
@@@ -3425,22 -2227,25 +3427,22 @@@ static int continue_single_pick(void
  {
        const char *argv[] = { "commit", NULL };
  
 -      if (!file_exists(git_path_cherry_pick_head()) &&
 -          !file_exists(git_path_revert_head()))
 +      if (!file_exists(git_path_cherry_pick_head(the_repository)) &&
 +          !file_exists(git_path_revert_head(the_repository)))
                return error(_("no cherry-pick or revert in progress"));
        return run_command_v_opt(argv, RUN_GIT_CMD);
  }
  
 -static int commit_staged_changes(struct replay_opts *opts)
 +static int commit_staged_changes(struct replay_opts *opts,
 +                               struct todo_list *todo_list)
  {
        unsigned int flags = ALLOW_EMPTY | EDIT_MSG;
 +      unsigned int final_fixup = 0, is_clean;
  
        if (has_unstaged_changes(1))
                return error(_("cannot rebase: You have unstaged changes."));
 -      if (!has_uncommitted_changes(0)) {
 -              const char *cherry_pick_head = git_path_cherry_pick_head();
  
 -              if (file_exists(cherry_pick_head) && unlink(cherry_pick_head))
 -                      return error(_("could not remove CHERRY_PICK_HEAD"));
 -              return 0;
 -      }
 +      is_clean = !has_uncommitted_changes(0);
  
        if (file_exists(rebase_path_amend())) {
                struct strbuf rev = STRBUF_INIT;
                if (get_oid_hex(rev.buf, &to_amend))
                        return error(_("invalid contents: '%s'"),
                                rebase_path_amend());
 -              if (oidcmp(&head, &to_amend))
 +              if (!is_clean && oidcmp(&head, &to_amend))
                        return error(_("\nYou have uncommitted changes in your "
                                       "working tree. Please, commit them\n"
                                       "first and then run 'git rebase "
                                       "--continue' again."));
 +              /*
 +               * When skipping a failed fixup/squash, we need to edit the
 +               * commit message, the current fixup list and count, and if it
 +               * was the last fixup/squash in the chain, we need to clean up
 +               * the commit message and if there was a squash, let the user
 +               * edit it.
 +               */
 +              if (is_clean && !oidcmp(&head, &to_amend) &&
 +                  opts->current_fixup_count > 0 &&
 +                  file_exists(rebase_path_stopped_sha())) {
 +                      const char *p = opts->current_fixups.buf;
 +                      int len = opts->current_fixups.len;
 +
 +                      opts->current_fixup_count--;
 +                      if (!len)
 +                              BUG("Incorrect current_fixups:\n%s", p);
 +                      while (len && p[len - 1] != '\n')
 +                              len--;
 +                      strbuf_setlen(&opts->current_fixups, len);
 +                      if (write_message(p, len, rebase_path_current_fixups(),
 +                                        0) < 0)
 +                              return error(_("could not write file: '%s'"),
 +                                           rebase_path_current_fixups());
 +
 +                      /*
 +                       * If a fixup/squash in a fixup/squash chain failed, the
 +                       * commit message is already correct, no need to commit
 +                       * it again.
 +                       *
 +                       * Only if it is the final command in the fixup/squash
 +                       * chain, and only if the chain is longer than a single
 +                       * fixup/squash command (which was just skipped), do we
 +                       * actually need to re-commit with a cleaned up commit
 +                       * message.
 +                       */
 +                      if (opts->current_fixup_count > 0 &&
 +                          !is_fixup(peek_command(todo_list, 0))) {
 +                              final_fixup = 1;
 +                              /*
 +                               * If there was not a single "squash" in the
 +                               * chain, we only need to clean up the commit
 +                               * message, no need to bother the user with
 +                               * opening the commit message in the editor.
 +                               */
 +                              if (!starts_with(p, "squash ") &&
 +                                  !strstr(p, "\nsquash "))
 +                                      flags = (flags & ~EDIT_MSG) | CLEANUP_MSG;
 +                      } else if (is_fixup(peek_command(todo_list, 0))) {
 +                              /*
 +                               * We need to update the squash message to skip
 +                               * the latest commit message.
 +                               */
 +                              struct commit *commit;
 +                              const char *path = rebase_path_squash_msg();
 +
 +                              if (parse_head(&commit) ||
 +                                  !(p = get_commit_buffer(commit, NULL)) ||
 +                                  write_message(p, strlen(p), path, 0)) {
 +                                      unuse_commit_buffer(commit, p);
 +                                      return error(_("could not write file: "
 +                                                     "'%s'"), path);
 +                              }
 +                              unuse_commit_buffer(commit, p);
 +                      }
 +              }
  
                strbuf_release(&rev);
                flags |= AMEND_MSG;
        }
  
 -      if (run_git_commit(rebase_path_message(), opts, flags))
 +      if (is_clean) {
 +              const char *cherry_pick_head = git_path_cherry_pick_head(the_repository);
 +
 +              if (file_exists(cherry_pick_head) && unlink(cherry_pick_head))
 +                      return error(_("could not remove CHERRY_PICK_HEAD"));
 +              if (!final_fixup)
 +                      return 0;
 +      }
 +
 +      if (run_git_commit(final_fixup ? NULL : rebase_path_message(),
 +                         opts, flags))
                return error(_("could not commit staged changes."));
        unlink(rebase_path_amend());
 +      if (final_fixup) {
 +              unlink(rebase_path_fixup_msg());
 +              unlink(rebase_path_squash_msg());
 +      }
 +      if (opts->current_fixup_count > 0) {
 +              /*
 +               * Whether final fixup or not, we just cleaned up the commit
 +               * message...
 +               */
 +              unlink(rebase_path_current_fixups());
 +              strbuf_reset(&opts->current_fixups);
 +              opts->current_fixup_count = 0;
 +      }
        return 0;
  }
  
@@@ -3565,22 -2282,20 +3567,22 @@@ int sequencer_continue(struct replay_op
        if (read_and_refresh_cache(opts))
                return -1;
  
 +      if (read_populate_opts(opts))
 +              return -1;
        if (is_rebase_i(opts)) {
 -              if (commit_staged_changes(opts))
 +              if ((res = read_populate_todo(&todo_list, opts)))
 +                      goto release_todo_list;
 +              if (commit_staged_changes(opts, &todo_list))
                        return -1;
        } else if (!file_exists(get_todo_path(opts)))
                return continue_single_pick();
 -      if (read_populate_opts(opts))
 -              return -1;
 -      if ((res = read_populate_todo(&todo_list, opts)))
 +      else if ((res = read_populate_todo(&todo_list, opts)))
                goto release_todo_list;
  
        if (!is_rebase_i(opts)) {
                /* Verify that the conflict has been resolved */
 -              if (file_exists(git_path_cherry_pick_head()) ||
 -                  file_exists(git_path_revert_head())) {
 +              if (file_exists(git_path_cherry_pick_head(the_repository)) ||
 +                  file_exists(git_path_revert_head(the_repository))) {
                        res = continue_single_pick();
                        if (res)
                                goto release_todo_list;
@@@ -3633,11 -2348,9 +3635,11 @@@ int sequencer_pick_revisions(struct rep
  
                if (!get_oid(name, &oid)) {
                        if (!lookup_commit_reference_gently(&oid, 1)) {
 -                              enum object_type type = sha1_object_info(oid.hash, NULL);
 +                              enum object_type type = oid_object_info(the_repository,
 +                                                                      &oid,
 +                                                                      NULL);
                                return error(_("%s: can't cherry-pick a %s"),
 -                                      name, typename(type));
 +                                      name, type_name(type));
                        }
                } else
                        return error(_("%s: bad revision"), name);
                if (prepare_revision_walk(opts->revs))
                        return error(_("revision walk setup failed"));
                cmit = get_revision(opts->revs);
-               if (!cmit || get_revision(opts->revs))
-                       return error("BUG: expected exactly one commit from walk");
+               if (!cmit)
+                       return error(_("empty commit set passed"));
+               if (get_revision(opts->revs))
+                       BUG("unexpected extra commit from walk");
                return single_pick(cmit, opts);
        }
  
@@@ -3745,348 -2460,6 +3749,348 @@@ void append_signoff(struct strbuf *msgb
        strbuf_release(&sob);
  }
  
 +struct labels_entry {
 +      struct hashmap_entry entry;
 +      char label[FLEX_ARRAY];
 +};
 +
 +static int labels_cmp(const void *fndata, const struct labels_entry *a,
 +                    const struct labels_entry *b, const void *key)
 +{
 +      return key ? strcmp(a->label, key) : strcmp(a->label, b->label);
 +}
 +
 +struct string_entry {
 +      struct oidmap_entry entry;
 +      char string[FLEX_ARRAY];
 +};
 +
 +struct label_state {
 +      struct oidmap commit2label;
 +      struct hashmap labels;
 +      struct strbuf buf;
 +};
 +
 +static const char *label_oid(struct object_id *oid, const char *label,
 +                           struct label_state *state)
 +{
 +      struct labels_entry *labels_entry;
 +      struct string_entry *string_entry;
 +      struct object_id dummy;
 +      size_t len;
 +      int i;
 +
 +      string_entry = oidmap_get(&state->commit2label, oid);
 +      if (string_entry)
 +              return string_entry->string;
 +
 +      /*
 +       * For "uninteresting" commits, i.e. commits that are not to be
 +       * rebased, and which can therefore not be labeled, we use a unique
 +       * abbreviation of the commit name. This is slightly more complicated
 +       * than calling find_unique_abbrev() because we also need to make
 +       * sure that the abbreviation does not conflict with any other
 +       * label.
 +       *
 +       * We disallow "interesting" commits to be labeled by a string that
 +       * is a valid full-length hash, to ensure that we always can find an
 +       * abbreviation for any uninteresting commit's names that does not
 +       * clash with any other label.
 +       */
 +      if (!label) {
 +              char *p;
 +
 +              strbuf_reset(&state->buf);
 +              strbuf_grow(&state->buf, GIT_SHA1_HEXSZ);
 +              label = p = state->buf.buf;
 +
 +              find_unique_abbrev_r(p, oid, default_abbrev);
 +
 +              /*
 +               * We may need to extend the abbreviated hash so that there is
 +               * no conflicting label.
 +               */
 +              if (hashmap_get_from_hash(&state->labels, strihash(p), p)) {
 +                      size_t i = strlen(p) + 1;
 +
 +                      oid_to_hex_r(p, oid);
 +                      for (; i < GIT_SHA1_HEXSZ; i++) {
 +                              char save = p[i];
 +                              p[i] = '\0';
 +                              if (!hashmap_get_from_hash(&state->labels,
 +                                                         strihash(p), p))
 +                                      break;
 +                              p[i] = save;
 +                      }
 +              }
 +      } else if (((len = strlen(label)) == the_hash_algo->hexsz &&
 +                  !get_oid_hex(label, &dummy)) ||
 +                 (len == 1 && *label == '#') ||
 +                 hashmap_get_from_hash(&state->labels,
 +                                       strihash(label), label)) {
 +              /*
 +               * If the label already exists, or if the label is a valid full
 +               * OID, or the label is a '#' (which we use as a separator
 +               * between merge heads and oneline), we append a dash and a
 +               * number to make it unique.
 +               */
 +              struct strbuf *buf = &state->buf;
 +
 +              strbuf_reset(buf);
 +              strbuf_add(buf, label, len);
 +
 +              for (i = 2; ; i++) {
 +                      strbuf_setlen(buf, len);
 +                      strbuf_addf(buf, "-%d", i);
 +                      if (!hashmap_get_from_hash(&state->labels,
 +                                                 strihash(buf->buf),
 +                                                 buf->buf))
 +                              break;
 +              }
 +
 +              label = buf->buf;
 +      }
 +
 +      FLEX_ALLOC_STR(labels_entry, label, label);
 +      hashmap_entry_init(labels_entry, strihash(label));
 +      hashmap_add(&state->labels, labels_entry);
 +
 +      FLEX_ALLOC_STR(string_entry, string, label);
 +      oidcpy(&string_entry->entry.oid, oid);
 +      oidmap_put(&state->commit2label, string_entry);
 +
 +      return string_entry->string;
 +}
 +
 +static int make_script_with_merges(struct pretty_print_context *pp,
 +                                 struct rev_info *revs, FILE *out,
 +                                 unsigned flags)
 +{
 +      int keep_empty = flags & TODO_LIST_KEEP_EMPTY;
 +      int rebase_cousins = flags & TODO_LIST_REBASE_COUSINS;
 +      struct strbuf buf = STRBUF_INIT, oneline = STRBUF_INIT;
 +      struct strbuf label = STRBUF_INIT;
 +      struct commit_list *commits = NULL, **tail = &commits, *iter;
 +      struct commit_list *tips = NULL, **tips_tail = &tips;
 +      struct commit *commit;
 +      struct oidmap commit2todo = OIDMAP_INIT;
 +      struct string_entry *entry;
 +      struct oidset interesting = OIDSET_INIT, child_seen = OIDSET_INIT,
 +              shown = OIDSET_INIT;
 +      struct label_state state = { OIDMAP_INIT, { NULL }, STRBUF_INIT };
 +
 +      int abbr = flags & TODO_LIST_ABBREVIATE_CMDS;
 +      const char *cmd_pick = abbr ? "p" : "pick",
 +              *cmd_label = abbr ? "l" : "label",
 +              *cmd_reset = abbr ? "t" : "reset",
 +              *cmd_merge = abbr ? "m" : "merge";
 +
 +      oidmap_init(&commit2todo, 0);
 +      oidmap_init(&state.commit2label, 0);
 +      hashmap_init(&state.labels, (hashmap_cmp_fn) labels_cmp, NULL, 0);
 +      strbuf_init(&state.buf, 32);
 +
 +      if (revs->cmdline.nr && (revs->cmdline.rev[0].flags & BOTTOM)) {
 +              struct object_id *oid = &revs->cmdline.rev[0].item->oid;
 +              FLEX_ALLOC_STR(entry, string, "onto");
 +              oidcpy(&entry->entry.oid, oid);
 +              oidmap_put(&state.commit2label, entry);
 +      }
 +
 +      /*
 +       * First phase:
 +       * - get onelines for all commits
 +       * - gather all branch tips (i.e. 2nd or later parents of merges)
 +       * - label all branch tips
 +       */
 +      while ((commit = get_revision(revs))) {
 +              struct commit_list *to_merge;
 +              int is_octopus;
 +              const char *p1, *p2;
 +              struct object_id *oid;
 +              int is_empty;
 +
 +              tail = &commit_list_insert(commit, tail)->next;
 +              oidset_insert(&interesting, &commit->object.oid);
 +
 +              is_empty = is_original_commit_empty(commit);
 +              if (!is_empty && (commit->object.flags & PATCHSAME))
 +                      continue;
 +
 +              strbuf_reset(&oneline);
 +              pretty_print_commit(pp, commit, &oneline);
 +
 +              to_merge = commit->parents ? commit->parents->next : NULL;
 +              if (!to_merge) {
 +                      /* non-merge commit: easy case */
 +                      strbuf_reset(&buf);
 +                      if (!keep_empty && is_empty)
 +                              strbuf_addf(&buf, "%c ", comment_line_char);
 +                      strbuf_addf(&buf, "%s %s %s", cmd_pick,
 +                                  oid_to_hex(&commit->object.oid),
 +                                  oneline.buf);
 +
 +                      FLEX_ALLOC_STR(entry, string, buf.buf);
 +                      oidcpy(&entry->entry.oid, &commit->object.oid);
 +                      oidmap_put(&commit2todo, entry);
 +
 +                      continue;
 +              }
 +
 +              is_octopus = to_merge && to_merge->next;
 +
 +              if (is_octopus)
 +                      BUG("Octopus merges not yet supported");
 +
 +              /* Create a label */
 +              strbuf_reset(&label);
 +              if (skip_prefix(oneline.buf, "Merge ", &p1) &&
 +                  (p1 = strchr(p1, '\'')) &&
 +                  (p2 = strchr(++p1, '\'')))
 +                      strbuf_add(&label, p1, p2 - p1);
 +              else if (skip_prefix(oneline.buf, "Merge pull request ",
 +                                   &p1) &&
 +                       (p1 = strstr(p1, " from ")))
 +                      strbuf_addstr(&label, p1 + strlen(" from "));
 +              else
 +                      strbuf_addbuf(&label, &oneline);
 +
 +              for (p1 = label.buf; *p1; p1++)
 +                      if (isspace(*p1))
 +                              *(char *)p1 = '-';
 +
 +              strbuf_reset(&buf);
 +              strbuf_addf(&buf, "%s -C %s",
 +                          cmd_merge, oid_to_hex(&commit->object.oid));
 +
 +              /* label the tip of merged branch */
 +              oid = &to_merge->item->object.oid;
 +              strbuf_addch(&buf, ' ');
 +
 +              if (!oidset_contains(&interesting, oid))
 +                      strbuf_addstr(&buf, label_oid(oid, NULL, &state));
 +              else {
 +                      tips_tail = &commit_list_insert(to_merge->item,
 +                                                      tips_tail)->next;
 +
 +                      strbuf_addstr(&buf, label_oid(oid, label.buf, &state));
 +              }
 +              strbuf_addf(&buf, " # %s", oneline.buf);
 +
 +              FLEX_ALLOC_STR(entry, string, buf.buf);
 +              oidcpy(&entry->entry.oid, &commit->object.oid);
 +              oidmap_put(&commit2todo, entry);
 +      }
 +
 +      /*
 +       * Second phase:
 +       * - label branch points
 +       * - add HEAD to the branch tips
 +       */
 +      for (iter = commits; iter; iter = iter->next) {
 +              struct commit_list *parent = iter->item->parents;
 +              for (; parent; parent = parent->next) {
 +                      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
 +                              label_oid(oid, "branch-point", &state);
 +              }
 +
 +              /* Add HEAD as implict "tip of branch" */
 +              if (!iter->next)
 +                      tips_tail = &commit_list_insert(iter->item,
 +                                                      tips_tail)->next;
 +      }
 +
 +      /*
 +       * Third phase: output the todo list. This is a bit tricky, as we
 +       * want to avoid jumping back and forth between revisions. To
 +       * accomplish that goal, we walk backwards from the branch tips,
 +       * gathering commits not yet shown, reversing the list on the fly,
 +       * then outputting that list (labeling revisions as needed).
 +       */
 +      fprintf(out, "%s onto\n", cmd_label);
 +      for (iter = tips; iter; iter = iter->next) {
 +              struct commit_list *list = NULL, *iter2;
 +
 +              commit = iter->item;
 +              if (oidset_contains(&shown, &commit->object.oid))
 +                      continue;
 +              entry = oidmap_get(&state.commit2label, &commit->object.oid);
 +
 +              if (entry)
 +                      fprintf(out, "\n# Branch %s\n", entry->string);
 +              else
 +                      fprintf(out, "\n");
 +
 +              while (oidset_contains(&interesting, &commit->object.oid) &&
 +                     !oidset_contains(&shown, &commit->object.oid)) {
 +                      commit_list_insert(commit, &list);
 +                      if (!commit->parents) {
 +                              commit = NULL;
 +                              break;
 +                      }
 +                      commit = commit->parents->item;
 +              }
 +
 +              if (!commit)
 +                      fprintf(out, "%s %s\n", cmd_reset,
 +                              rebase_cousins ? "onto" : "[new root]");
 +              else {
 +                      const char *to = NULL;
 +
 +                      entry = oidmap_get(&state.commit2label,
 +                                         &commit->object.oid);
 +                      if (entry)
 +                              to = entry->string;
 +                      else if (!rebase_cousins)
 +                              to = label_oid(&commit->object.oid, NULL,
 +                                             &state);
 +
 +                      if (!to || !strcmp(to, "onto"))
 +                              fprintf(out, "%s onto\n", cmd_reset);
 +                      else {
 +                              strbuf_reset(&oneline);
 +                              pretty_print_commit(pp, commit, &oneline);
 +                              fprintf(out, "%s %s # %s\n",
 +                                      cmd_reset, to, oneline.buf);
 +                      }
 +              }
 +
 +              for (iter2 = list; iter2; iter2 = iter2->next) {
 +                      struct object_id *oid = &iter2->item->object.oid;
 +                      entry = oidmap_get(&commit2todo, oid);
 +                      /* only show if not already upstream */
 +                      if (entry)
 +                              fprintf(out, "%s\n", entry->string);
 +                      entry = oidmap_get(&state.commit2label, oid);
 +                      if (entry)
 +                              fprintf(out, "%s %s\n",
 +                                      cmd_label, entry->string);
 +                      oidset_insert(&shown, oid);
 +              }
 +
 +              free_commit_list(list);
 +      }
 +
 +      free_commit_list(commits);
 +      free_commit_list(tips);
 +
 +      strbuf_release(&label);
 +      strbuf_release(&oneline);
 +      strbuf_release(&buf);
 +
 +      oidmap_free(&commit2todo, 1);
 +      oidmap_free(&state.commit2label, 1);
 +      hashmap_free(&state.labels, 1);
 +      strbuf_release(&state.buf);
 +
 +      return 0;
 +}
 +
  int sequencer_make_script(FILE *out, int argc, const char **argv,
                          unsigned flags)
  {
        struct commit *commit;
        int keep_empty = flags & TODO_LIST_KEEP_EMPTY;
        const char *insn = flags & TODO_LIST_ABBREVIATE_CMDS ? "p" : "pick";
 +      int rebase_merges = flags & TODO_LIST_REBASE_MERGES;
  
        init_revisions(&revs, NULL);
        revs.verbose_header = 1;
 -      revs.max_parents = 1;
 -      revs.cherry_pick = 1;
 +      if (!rebase_merges)
 +              revs.max_parents = 1;
 +      revs.cherry_mark = 1;
        revs.limited = 1;
        revs.reverse = 1;
        revs.right_only = 1;
        if (prepare_revision_walk(&revs) < 0)
                return error(_("make_script: error preparing revisions"));
  
 +      if (rebase_merges)
 +              return make_script_with_merges(&pp, &revs, out, flags);
 +
        while ((commit = get_revision(&revs))) {
 +              int is_empty  = is_original_commit_empty(commit);
 +
 +              if (!is_empty && (commit->object.flags & PATCHSAME))
 +                      continue;
                strbuf_reset(&buf);
 -              if (!keep_empty && is_original_commit_empty(commit))
 +              if (!keep_empty && is_empty)
                        strbuf_addf(&buf, "%c ", comment_line_char);
                strbuf_addf(&buf, "%s %s ", insn,
                            oid_to_hex(&commit->object.oid));
@@@ -4223,16 -2587,8 +4227,16 @@@ int transform_todos(unsigned flags
                                          short_commit_name(item->commit) :
                                          oid_to_hex(&item->commit->object.oid);
  
 +                      if (item->command == TODO_MERGE) {
 +                              if (item->flags & TODO_EDIT_MERGE_MSG)
 +                                      strbuf_addstr(&buf, " -c");
 +                              else
 +                                      strbuf_addstr(&buf, " -C");
 +                      }
 +
                        strbuf_addf(&buf, " %s", oid);
                }
 +
                /* add all the rest */
                if (!item->arg_len)
                        strbuf_addch(&buf, '\n');
@@@ -4265,7 -2621,6 +4269,7 @@@ static enum check_level get_missing_com
        return CHECK_IGNORE;
  }
  
 +define_commit_slab(commit_seen, unsigned char);
  /*
   * Check if the user dropped some commits by mistake
   * Behaviour determined by rebase.missingCommitsCheck.
@@@ -4278,16 -2633,20 +4282,16 @@@ int check_todo_list(void
        struct strbuf todo_file = STRBUF_INIT;
        struct todo_list todo_list = TODO_LIST_INIT;
        struct strbuf missing = STRBUF_INIT;
 -      int advise_to_edit_todo = 0, res = 0, fd, i;
 +      int advise_to_edit_todo = 0, res = 0, i;
 +      struct commit_seen commit_seen;
 +
 +      init_commit_seen(&commit_seen);
  
        strbuf_addstr(&todo_file, rebase_path_todo());
 -      fd = open(todo_file.buf, O_RDONLY);
 -      if (fd < 0) {
 -              res = error_errno(_("could not open '%s'"), todo_file.buf);
 -              goto leave_check;
 -      }
 -      if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
 -              close(fd);
 -              res = error(_("could not read '%s'."), todo_file.buf);
 +      if (strbuf_read_file_or_whine(&todo_list.buf, todo_file.buf) < 0) {
 +              res = -1;
                goto leave_check;
        }
 -      close(fd);
        advise_to_edit_todo = res =
                parse_insn_buffer(todo_list.buf.buf, &todo_list);
  
        for (i = 0; i < todo_list.nr; i++) {
                struct commit *commit = todo_list.items[i].commit;
                if (commit)
 -                      commit->util = (void *)1;
 +                      *commit_seen_at(&commit_seen, commit) = 1;
        }
  
        todo_list_release(&todo_list);
        strbuf_addstr(&todo_file, ".backup");
 -      fd = open(todo_file.buf, O_RDONLY);
 -      if (fd < 0) {
 -              res = error_errno(_("could not open '%s'"), todo_file.buf);
 -              goto leave_check;
 -      }
 -      if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
 -              close(fd);
 -              res = error(_("could not read '%s'."), todo_file.buf);
 +      if (strbuf_read_file_or_whine(&todo_list.buf, todo_file.buf) < 0) {
 +              res = -1;
                goto leave_check;
        }
 -      close(fd);
        strbuf_release(&todo_file);
        res = !!parse_insn_buffer(todo_list.buf.buf, &todo_list);
  
        for (i = todo_list.nr - 1; i >= 0; i--) {
                struct todo_item *item = todo_list.items + i;
                struct commit *commit = item->commit;
 -              if (commit && !commit->util) {
 +              if (commit && !*commit_seen_at(&commit_seen, commit)) {
                        strbuf_addf(&missing, " - %s %.*s\n",
                                    short_commit_name(commit),
                                    item->arg_len, item->arg);
 -                      commit->util = (void *)1;
 +                      *commit_seen_at(&commit_seen, commit) = 1;
                }
        }
  
                "The possible behaviours are: ignore, warn, error.\n\n"));
  
  leave_check:
 +      clear_commit_seen(&commit_seen);
        strbuf_release(&todo_file);
        todo_list_release(&todo_list);
  
@@@ -4388,8 -2753,15 +4392,8 @@@ int skip_unnecessary_picks(void
        }
        strbuf_release(&buf);
  
 -      fd = open(todo_file, O_RDONLY);
 -      if (fd < 0) {
 -              return error_errno(_("could not open '%s'"), todo_file);
 -      }
 -      if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
 -              close(fd);
 -              return error(_("could not read '%s'."), todo_file);
 -      }
 -      close(fd);
 +      if (strbuf_read_file_or_whine(&todo_list.buf, todo_file) < 0)
 +              return -1;
        if (parse_insn_buffer(todo_list.buf.buf, &todo_list) < 0) {
                todo_list_release(&todo_list);
                return -1;
                oid = &item->commit->object.oid;
        }
        if (i > 0) {
 -              int offset = i < todo_list.nr ?
 -                      todo_list.items[i].offset_in_buf : todo_list.buf.len;
 +              int offset = get_item_line_offset(&todo_list, i);
                const char *done_path = rebase_path_done();
  
                fd = open(done_path, O_CREAT | O_WRONLY | O_APPEND, 0666);
@@@ -4465,8 -2838,6 +4469,8 @@@ static int subject2item_cmp(const void 
        return key ? strcmp(a->subject, key) : strcmp(a->subject, b->subject);
  }
  
 +define_commit_slab(commit_todo_item, struct todo_item *);
 +
  /*
   * Rearrange the todo list that has both "pick commit-id msg" and "pick
   * commit-id fixup!/squash! msg" in it so that the latter is put immediately
@@@ -4481,18 -2852,22 +4485,18 @@@ int rearrange_squash(void
        const char *todo_file = rebase_path_todo();
        struct todo_list todo_list = TODO_LIST_INIT;
        struct hashmap subject2item;
 -      int res = 0, rearranged = 0, *next, *tail, fd, i;
 +      int res = 0, rearranged = 0, *next, *tail, i;
        char **subjects;
 +      struct commit_todo_item commit_todo;
  
 -      fd = open(todo_file, O_RDONLY);
 -      if (fd < 0)
 -              return error_errno(_("could not open '%s'"), todo_file);
 -      if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
 -              close(fd);
 -              return error(_("could not read '%s'."), todo_file);
 -      }
 -      close(fd);
 +      if (strbuf_read_file_or_whine(&todo_list.buf, todo_file) < 0)
 +              return -1;
        if (parse_insn_buffer(todo_list.buf.buf, &todo_list) < 0) {
                todo_list_release(&todo_list);
                return -1;
        }
  
 +      init_commit_todo_item(&commit_todo);
        /*
         * The hashmap maps onelines to the respective todo list index.
         *
                struct subject2item_entry *entry;
  
                next[i] = tail[i] = -1;
 -              if (item->command >= TODO_EXEC) {
 +              if (!item->commit || item->command == TODO_DROP) {
                        subjects[i] = NULL;
                        continue;
                }
  
                if (is_fixup(item->command)) {
                        todo_list_release(&todo_list);
 +                      clear_commit_todo_item(&commit_todo);
                        return error(_("the script was already rearranged."));
                }
  
 -              item->commit->util = item;
 +              *commit_todo_item_at(&commit_todo, item->commit) = item;
  
                parse_commit(item->commit);
                commit_buffer = get_commit_buffer(item->commit, NULL);
                        else if (!strchr(p, ' ') &&
                                 (commit2 =
                                  lookup_commit_reference_by_name(p)) &&
 -                               commit2->util)
 +                               *commit_todo_item_at(&commit_todo, commit2))
                                /* found by commit name */
 -                              i2 = (struct todo_item *)commit2->util
 +                              i2 = *commit_todo_item_at(&commit_todo, commit2)
                                        - todo_list.items;
                        else {
                                /* copy can be a prefix of the commit subject */
                                continue;
  
                        while (cur >= 0) {
 -                              int offset = todo_list.items[cur].offset_in_buf;
 -                              int end_offset = cur + 1 < todo_list.nr ?
 -                                      todo_list.items[cur + 1].offset_in_buf :
 -                                      todo_list.buf.len;
 -                              char *bol = todo_list.buf.buf + offset;
 -                              char *eol = todo_list.buf.buf + end_offset;
 +                              const char *bol =
 +                                      get_item_line(&todo_list, cur);
 +                              const char *eol =
 +                                      get_item_line(&todo_list, cur + 1);
  
                                /* replace 'pick', by 'fixup' or 'squash' */
                                command = todo_list.items[cur].command;
        hashmap_free(&subject2item, 1);
        todo_list_release(&todo_list);
  
 +      clear_commit_todo_item(&commit_todo);
        return res;
  }
index b42cd66d3a574138148a311b34472506b433c286,6987bbfee5ff62410f94a337464225a1213ceda0..3505b6aa14e630a98062558ed30270c98e5a920f
@@@ -122,7 -122,7 +122,7 @@@ test_expect_success '--quit keeps HEAD 
        {
                git rev-list HEAD |
                git diff-tree --root --stdin |
 -              sed "s/$_x40/OBJID/g"
 +              sed "s/$OID_REGEX/OBJID/g"
        } >actual &&
        test_cmp expect actual
  '
@@@ -220,7 -220,7 +220,7 @@@ test_expect_success 'cherry-pick still 
        {
                git rev-list HEAD |
                git diff-tree --root --stdin |
 -              sed "s/$_x40/OBJID/g"
 +              sed "s/$OID_REGEX/OBJID/g"
        } >actual &&
        cat >expect <<-\EOF &&
        OBJID
@@@ -247,9 -247,9 +247,9 @@@ test_expect_success '--abort after las
  test_expect_success 'cherry-pick does not implicitly stomp an existing operation' '
        pristine_detach initial &&
        test_expect_code 1 git cherry-pick base..anotherpick &&
 -      test-chmtime -v +0 .git/sequencer >expect &&
 +      test-tool chmtime --get .git/sequencer >expect &&
        test_expect_code 128 git cherry-pick unrelatedpick &&
 -      test-chmtime -v +0 .git/sequencer >actual &&
 +      test-tool chmtime --get .git/sequencer >actual &&
        test_cmp expect actual
  '
  
@@@ -317,7 -317,7 +317,7 @@@ test_expect_success '--continue after r
        {
                git rev-list HEAD |
                git diff-tree --root --stdin |
 -              sed "s/$_x40/OBJID/g"
 +              sed "s/$OID_REGEX/OBJID/g"
        } >actual.log &&
        test_cmp expect foo &&
        test_cmp expect.log actual.log
@@@ -334,7 -334,7 +334,7 @@@ test_expect_success '--continue after r
        {
                git rev-list HEAD |
                git diff-tree --root --stdin |
 -              sed "s/$_x40/OBJID/g"
 +              sed "s/$OID_REGEX/OBJID/g"
        } >actual &&
        cat >expect <<-\EOF &&
        OBJID
@@@ -480,11 -480,16 +480,16 @@@ test_expect_success 'malformed instruct
        test_expect_code 128 git cherry-pick --continue
  '
  
- test_expect_success 'empty commit set' '
+ test_expect_success 'empty commit set (no commits to walk)' '
        pristine_detach initial &&
        test_expect_code 128 git cherry-pick base..base
  '
  
+ test_expect_success 'empty commit set (culled during walk)' '
+       pristine_detach initial &&
+       test_expect_code 128 git cherry-pick -2 --author=no.such.author base
+ '
  test_expect_success 'malformed instruction sheet 3' '
        pristine_detach initial &&
        test_expect_code 1 git cherry-pick base..anotherpick &&