Merge branch 'bp/refresh-index-using-preload'
[git/git.git] / sequencer.c
index b46dd0f..0d87b07 100644 (file)
@@ -31,6 +31,7 @@
 #include "commit-slab.h"
 #include "alias.h"
 #include "commit-reach.h"
+#include "rebase-interactive.h"
 
 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
 
@@ -53,7 +54,10 @@ static GIT_PATH_FUNC(rebase_path, "rebase-merge")
  * the lines are processed, they are removed from the front of this
  * file and written to the tail of 'done'.
  */
-static GIT_PATH_FUNC(rebase_path_todo, "rebase-merge/git-rebase-todo")
+GIT_PATH_FUNC(rebase_path_todo, "rebase-merge/git-rebase-todo")
+static GIT_PATH_FUNC(rebase_path_todo_backup,
+                    "rebase-merge/git-rebase-todo.backup")
+
 /*
  * The rebase command lines that have already been processed. A line
  * is moved here when it is first handled, before any associated user
@@ -141,7 +145,7 @@ static GIT_PATH_FUNC(rebase_path_refs_to_delete, "rebase-merge/refs-to-delete")
 
 /*
  * The following files are written by git-rebase just after parsing the
- * command-line (and are only consumed, not modified, by the sequencer).
+ * command-line.
  */
 static GIT_PATH_FUNC(rebase_path_gpg_sign_opt, "rebase-merge/gpg_sign_opt")
 static GIT_PATH_FUNC(rebase_path_orig_head, "rebase-merge/orig-head")
@@ -153,6 +157,7 @@ static GIT_PATH_FUNC(rebase_path_autostash, "rebase-merge/autostash")
 static GIT_PATH_FUNC(rebase_path_strategy, "rebase-merge/strategy")
 static GIT_PATH_FUNC(rebase_path_strategy_opts, "rebase-merge/strategy_opts")
 static GIT_PATH_FUNC(rebase_path_allow_rerere_autoupdate, "rebase-merge/allow_rerere_autoupdate")
+static GIT_PATH_FUNC(rebase_path_quiet, "rebase-merge/quiet")
 
 static int git_sequencer_config(const char *k, const char *v, void *cb)
 {
@@ -377,8 +382,8 @@ static void print_advice(int show_hint, struct replay_opts *opts)
        }
 }
 
-static int write_message(const void *buf, size_t len, const char *filename,
-                        int append_eol)
+int write_message(const void *buf, size_t len, const char *filename,
+                 int append_eol)
 {
        struct lock_file msg_file = LOCK_INIT;
 
@@ -664,55 +669,131 @@ missing_author:
        return res;
 }
 
+/**
+ * Take a series of KEY='VALUE' lines where VALUE part is
+ * sq-quoted, and append <KEY, VALUE> at the end of the string list
+ */
+static int parse_key_value_squoted(char *buf, struct string_list *list)
+{
+       while (*buf) {
+               struct string_list_item *item;
+               char *np;
+               char *cp = strchr(buf, '=');
+               if (!cp) {
+                       np = strchrnul(buf, '\n');
+                       return error(_("no key present in '%.*s'"),
+                                    (int) (np - buf), buf);
+               }
+               np = strchrnul(cp, '\n');
+               *cp++ = '\0';
+               item = string_list_append(list, buf);
+
+               buf = np + (*np == '\n');
+               *np = '\0';
+               cp = sq_dequote(cp);
+               if (!cp)
+                       return error(_("unable to dequote value of '%s'"),
+                                    item->string);
+               item->util = xstrdup(cp);
+       }
+       return 0;
+}
 
-/*
- * write_author_script() used to fail to terminate the last line with a "'" and
- * also escaped "'" incorrectly as "'\\\\''" rather than "'\\''". We check for
- * the terminating "'" on the last line to see how "'" has been escaped in case
- * git was upgraded while rebase was stopped.
+/**
+ * Reads and parses the state directory's "author-script" file, and sets name,
+ * email and date accordingly.
+ * Returns 0 on success, -1 if the file could not be parsed.
+ *
+ * The author script is of the format:
+ *
+ *     GIT_AUTHOR_NAME='$author_name'
+ *     GIT_AUTHOR_EMAIL='$author_email'
+ *     GIT_AUTHOR_DATE='$author_date'
+ *
+ * where $author_name, $author_email and $author_date are quoted. We are strict
+ * with our parsing, as the file was meant to be eval'd in the old
+ * git-am.sh/git-rebase--interactive.sh scripts, and thus if the file differs
+ * from what this function expects, it is better to bail out than to do
+ * something that the user does not expect.
  */
-static int quoting_is_broken(const char *s, size_t n)
+int read_author_script(const char *path, char **name, char **email, char **date,
+                      int allow_missing)
 {
-       /* Skip any empty lines in case the file was hand edited */
-       while (n > 0 && s[--n] == '\n')
-               ; /* empty */
-       if (n > 0 && s[n] != '\'')
-               return 1;
+       struct strbuf buf = STRBUF_INIT;
+       struct string_list kv = STRING_LIST_INIT_DUP;
+       int retval = -1; /* assume failure */
+       int i, name_i = -2, email_i = -2, date_i = -2, err = 0;
 
-       return 0;
+       if (strbuf_read_file(&buf, path, 256) <= 0) {
+               strbuf_release(&buf);
+               if (errno == ENOENT && allow_missing)
+                       return 0;
+               else
+                       return error_errno(_("could not open '%s' for reading"),
+                                          path);
+       }
+
+       if (parse_key_value_squoted(buf.buf, &kv))
+               goto finish;
+
+       for (i = 0; i < kv.nr; i++) {
+               if (!strcmp(kv.items[i].string, "GIT_AUTHOR_NAME")) {
+                       if (name_i != -2)
+                               name_i = error(_("'GIT_AUTHOR_NAME' already given"));
+                       else
+                               name_i = i;
+               } else if (!strcmp(kv.items[i].string, "GIT_AUTHOR_EMAIL")) {
+                       if (email_i != -2)
+                               email_i = error(_("'GIT_AUTHOR_EMAIL' already given"));
+                       else
+                               email_i = i;
+               } else if (!strcmp(kv.items[i].string, "GIT_AUTHOR_DATE")) {
+                       if (date_i != -2)
+                               date_i = error(_("'GIT_AUTHOR_DATE' already given"));
+                       else
+                               date_i = i;
+               } else {
+                       err = error(_("unknown variable '%s'"),
+                                   kv.items[i].string);
+               }
+       }
+       if (name_i == -2)
+               error(_("missing 'GIT_AUTHOR_NAME'"));
+       if (email_i == -2)
+               error(_("missing 'GIT_AUTHOR_EMAIL'"));
+       if (date_i == -2)
+               error(_("missing 'GIT_AUTHOR_DATE'"));
+       if (date_i < 0 || email_i < 0 || date_i < 0 || err)
+               goto finish;
+       *name = kv.items[name_i].util;
+       *email = kv.items[email_i].util;
+       *date = kv.items[date_i].util;
+       retval = 0;
+finish:
+       string_list_clear(&kv, !!retval);
+       strbuf_release(&buf);
+       return retval;
 }
 
 /*
- * Read a list of environment variable assignments (such as the author-script
- * file) into an environment block. Returns -1 on error, 0 otherwise.
+ * Read a GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL AND GIT_AUTHOR_DATE from a
+ * file with shell quoting into struct argv_array. Returns -1 on
+ * error, 0 otherwise.
  */
 static int read_env_script(struct argv_array *env)
 {
-       struct strbuf script = STRBUF_INIT;
-       int i, count = 0, sq_bug;
-       const char *p2;
-       char *p;
+       char *name, *email, *date;
 
-       if (strbuf_read_file(&script, rebase_path_author_script(), 256) <= 0)
+       if (read_author_script(rebase_path_author_script(),
+                              &name, &email, &date, 0))
                return -1;
-       /* write_author_script() used to quote incorrectly */
-       sq_bug = quoting_is_broken(script.buf, script.len);
-       for (p = script.buf; *p; p++)
-               if (sq_bug && skip_prefix(p, "'\\\\''", &p2))
-                       strbuf_splice(&script, p - script.buf, p2 - p, "'", 1);
-               else if (skip_prefix(p, "'\\''", &p2))
-                       strbuf_splice(&script, p - script.buf, p2 - p, "'", 1);
-               else if (*p == '\'')
-                       strbuf_splice(&script, p-- - script.buf, 1, "", 0);
-               else if (*p == '\n') {
-                       *p = '\0';
-                       count++;
-               }
 
-       for (i = 0, p = script.buf; i < count; i++) {
-               argv_array_push(env, p);
-               p += strlen(p) + 1;
-       }
+       argv_array_pushf(env, "GIT_AUTHOR_NAME=%s", name);
+       argv_array_pushf(env, "GIT_AUTHOR_EMAIL=%s", email);
+       argv_array_pushf(env, "GIT_AUTHOR_DATE=%s", date);
+       free(name);
+       free(email);
+       free(date);
 
        return 0;
 }
@@ -732,54 +813,28 @@ static char *get_author(const char *message)
 /* Read author-script and return an ident line (author <email> timestamp) */
 static const char *read_author_ident(struct strbuf *buf)
 {
-       const char *keys[] = {
-               "GIT_AUTHOR_NAME=", "GIT_AUTHOR_EMAIL=", "GIT_AUTHOR_DATE="
-       };
        struct strbuf out = STRBUF_INIT;
-       char *in, *eol;
-       const char *val[3];
-       int i = 0;
+       char *name, *email, *date;
 
-       if (strbuf_read_file(buf, rebase_path_author_script(), 256) <= 0)
+       if (read_author_script(rebase_path_author_script(),
+                              &name, &email, &date, 0))
                return NULL;
 
-       /* dequote values and construct ident line in-place */
-       for (in = buf->buf; i < 3 && in - buf->buf < buf->len; i++) {
-               if (!skip_prefix(in, keys[i], (const char **)&in)) {
-                       warning(_("could not parse '%s' (looking for '%s')"),
-                               rebase_path_author_script(), keys[i]);
-                       return NULL;
-               }
-
-               eol = strchrnul(in, '\n');
-               *eol = '\0';
-               if (!sq_dequote(in)) {
-                       warning(_("bad quoting on %s value in '%s'"),
-                               keys[i], rebase_path_author_script());
-                       return NULL;
-               }
-               val[i] = in;
-               in = eol + 1;
-       }
-
-       if (i < 3) {
-               warning(_("could not parse '%s' (looking for '%s')"),
-                       rebase_path_author_script(), keys[i]);
-               return NULL;
-       }
-
        /* validate date since fmt_ident() will die() on bad value */
-       if (parse_date(val[2], &out)){
+       if (parse_date(date, &out)){
                warning(_("invalid date format '%s' in '%s'"),
-                       val[2], rebase_path_author_script());
+                       date, rebase_path_author_script());
                strbuf_release(&out);
                return NULL;
        }
 
        strbuf_reset(&out);
-       strbuf_addstr(&out, fmt_ident(val[0], val[1], val[2], 0));
+       strbuf_addstr(&out, fmt_ident(name, email, date, 0));
        strbuf_swap(buf, &out);
        strbuf_release(&out);
+       free(name);
+       free(email);
+       free(date);
        return buf->buf;
 }
 
@@ -804,6 +859,23 @@ N_("you have staged changes in your working tree\n"
 #define VERIFY_MSG  (1<<4)
 #define CREATE_ROOT_COMMIT (1<<5)
 
+static int run_command_silent_on_success(struct child_process *cmd)
+{
+       struct strbuf buf = STRBUF_INIT;
+       int rc;
+
+       cmd->stdout_to_stderr = 1;
+       rc = pipe_command(cmd,
+                         NULL, 0,
+                         NULL, 0,
+                         &buf, 0);
+
+       if (rc)
+               fputs(buf.buf, stderr);
+       strbuf_release(&buf);
+       return rc;
+}
+
 /*
  * If we are cherry-pick, and if the merge did not result in
  * hand-editing, we will hit this commit and inherit the original
@@ -865,18 +937,11 @@ static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 
        cmd.git_cmd = 1;
 
-       if (is_rebase_i(opts)) {
-               if (!(flags & EDIT_MSG)) {
-                       cmd.stdout_to_stderr = 1;
-                       cmd.err = -1;
-               }
-
-               if (read_env_script(&cmd.env_array)) {
-                       const char *gpg_opt = gpg_sign_opt_quoted(opts);
+       if (is_rebase_i(opts) && read_env_script(&cmd.env_array)) {
+               const char *gpg_opt = gpg_sign_opt_quoted(opts);
 
-                       return error(_(staged_changes_advice),
-                                    gpg_opt, gpg_opt);
-               }
+               return error(_(staged_changes_advice),
+                            gpg_opt, gpg_opt);
        }
 
        argv_array_push(&cmd.args, "commit");
@@ -906,21 +971,10 @@ static int run_git_commit(const char *defmsg, struct replay_opts *opts,
        if (!(flags & EDIT_MSG))
                argv_array_push(&cmd.args, "--allow-empty-message");
 
-       if (cmd.err == -1) {
-               /* hide stderr on success */
-               struct strbuf buf = STRBUF_INIT;
-               int rc = pipe_command(&cmd,
-                                     NULL, 0,
-                                     /* stdout is already redirected */
-                                     NULL, 0,
-                                     &buf, 0);
-               if (rc)
-                       fputs(buf.buf, stderr);
-               strbuf_release(&buf);
-               return rc;
-       }
-
-       return run_command(&cmd);
+       if (is_rebase_i(opts) && !(flags & EDIT_MSG))
+               return run_command_silent_on_success(&cmd);
+       else
+               return run_command(&cmd);
 }
 
 static int rest_is_empty(const struct strbuf *sb, int start)
@@ -1454,6 +1508,7 @@ enum todo_command {
        TODO_SQUASH,
        /* commands that do something else than handling a single commit */
        TODO_EXEC,
+       TODO_BREAK,
        TODO_LABEL,
        TODO_RESET,
        TODO_MERGE,
@@ -1475,6 +1530,7 @@ static struct {
        { 'f', "fixup" },
        { 's', "squash" },
        { 'x', "exec" },
+       { 'b', "break" },
        { 'l', "label" },
        { 't', "reset" },
        { 'm', "merge" },
@@ -1988,7 +2044,8 @@ static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
                if (skip_prefix(bol, todo_command_info[i].str, &bol)) {
                        item->command = i;
                        break;
-               } else if (bol[1] == ' ' && *bol == todo_command_info[i].c) {
+               } else if ((bol + 1 == eol || bol[1] == ' ') &&
+                          *bol == todo_command_info[i].c) {
                        bol++;
                        item->command = i;
                        break;
@@ -2000,7 +2057,7 @@ static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
        padding = strspn(bol, " \t");
        bol += padding;
 
-       if (item->command == TODO_NOOP) {
+       if (item->command == TODO_NOOP || item->command == TODO_BREAK) {
                if (bol != eol)
                        return error(_("%s does not accept arguments: '%s'"),
                                     command_to_string(item->command), bol);
@@ -2244,21 +2301,14 @@ static int populate_opts_cb(const char *key, const char *value, void *data)
        return 0;
 }
 
-static void read_strategy_opts(struct replay_opts *opts, struct strbuf *buf)
+void parse_strategy_opts(struct replay_opts *opts, char *raw_opts)
 {
        int i;
-       char *strategy_opts_string;
+       char *strategy_opts_string = raw_opts;
 
-       strbuf_reset(buf);
-       if (!read_oneliner(buf, rebase_path_strategy(), 0))
-               return;
-       opts->strategy = strbuf_detach(buf, NULL);
-       if (!read_oneliner(buf, rebase_path_strategy_opts(), 0))
-               return;
-
-       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++) {
@@ -2269,6 +2319,18 @@ static void read_strategy_opts(struct replay_opts *opts, struct strbuf *buf)
        }
 }
 
+static void read_strategy_opts(struct replay_opts *opts, struct strbuf *buf)
+{
+       strbuf_reset(buf);
+       if (!read_oneliner(buf, rebase_path_strategy(), 0))
+               return;
+       opts->strategy = strbuf_detach(buf, NULL);
+       if (!read_oneliner(buf, rebase_path_strategy_opts(), 0))
+               return;
+
+       parse_strategy_opts(opts, buf->buf);
+}
+
 static int read_populate_opts(struct replay_opts *opts)
 {
        if (is_rebase_i(opts)) {
@@ -2336,6 +2398,55 @@ static int read_populate_opts(struct replay_opts *opts)
        return 0;
 }
 
+static void write_strategy_opts(struct replay_opts *opts)
+{
+       int i;
+       struct strbuf buf = STRBUF_INIT;
+
+       for (i = 0; i < opts->xopts_nr; ++i)
+               strbuf_addf(&buf, " --%s", opts->xopts[i]);
+
+       write_file(rebase_path_strategy_opts(), "%s\n", buf.buf);
+       strbuf_release(&buf);
+}
+
+int write_basic_state(struct replay_opts *opts, const char *head_name,
+                     const char *onto, const char *orig_head)
+{
+       const char *quiet = getenv("GIT_QUIET");
+
+       if (head_name)
+               write_file(rebase_path_head_name(), "%s\n", head_name);
+       if (onto)
+               write_file(rebase_path_onto(), "%s\n", onto);
+       if (orig_head)
+               write_file(rebase_path_orig_head(), "%s\n", orig_head);
+
+       if (quiet)
+               write_file(rebase_path_quiet(), "%s\n", quiet);
+       else
+               write_file(rebase_path_quiet(), "\n");
+
+       if (opts->verbose)
+               write_file(rebase_path_verbose(), "%s", "");
+       if (opts->strategy)
+               write_file(rebase_path_strategy(), "%s\n", opts->strategy);
+       if (opts->xopts_nr > 0)
+               write_strategy_opts(opts);
+
+       if (opts->allow_rerere_auto == RERERE_AUTOUPDATE)
+               write_file(rebase_path_allow_rerere_autoupdate(), "--rerere-autoupdate\n");
+       else if (opts->allow_rerere_auto == RERERE_NOAUTOUPDATE)
+               write_file(rebase_path_allow_rerere_autoupdate(), "--no-rerere-autoupdate\n");
+
+       if (opts->gpg_sign)
+               write_file(rebase_path_gpg_sign_opt(), "-S%s\n", opts->gpg_sign);
+       if (opts->signoff)
+               write_file(rebase_path_signoff(), "--signoff\n");
+
+       return 0;
+}
+
 static int walk_revs_populate_todo(struct todo_list *todo_list,
                                struct replay_opts *opts)
 {
@@ -2829,7 +2940,7 @@ static int do_reset(const char *name, int len, struct replay_opts *opts)
        struct tree_desc desc;
        struct tree *tree;
        struct unpack_trees_options unpack_tree_opts;
-       int ret = 0, i;
+       int ret = 0;
 
        if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
                return -1;
@@ -2849,10 +2960,13 @@ static int do_reset(const char *name, int len, struct replay_opts *opts)
                }
                oidcpy(&oid, &opts->squash_onto);
        } else {
+               int i;
+
                /* Determine the length of the label */
                for (i = 0; i < len; i++)
                        if (isspace(name[i]))
-                               len = i;
+                               break;
+               len = i;
 
                strbuf_addf(&ref_name, "refs/rewritten/%.*s", len, name);
                if (get_oid(ref_name.buf, &oid) &&
@@ -3286,6 +3400,73 @@ static const char *reflog_message(struct replay_opts *opts,
        return buf.buf;
 }
 
+static int run_git_checkout(struct replay_opts *opts, const char *commit,
+                           const char *action)
+{
+       struct child_process cmd = CHILD_PROCESS_INIT;
+
+       cmd.git_cmd = 1;
+
+       argv_array_push(&cmd.args, "checkout");
+       argv_array_push(&cmd.args, commit);
+       argv_array_pushf(&cmd.env_array, GIT_REFLOG_ACTION "=%s", action);
+
+       if (opts->verbose)
+               return run_command(&cmd);
+       else
+               return run_command_silent_on_success(&cmd);
+}
+
+int prepare_branch_to_be_rebased(struct replay_opts *opts, const char *commit)
+{
+       const char *action;
+
+       if (commit && *commit) {
+               action = reflog_message(opts, "start", "checkout %s", commit);
+               if (run_git_checkout(opts, commit, action))
+                       return error(_("could not checkout %s"), commit);
+       }
+
+       return 0;
+}
+
+static int checkout_onto(struct replay_opts *opts,
+                        const char *onto_name, const char *onto,
+                        const char *orig_head)
+{
+       struct object_id oid;
+       const char *action = reflog_message(opts, "start", "checkout %s", onto_name);
+
+       if (get_oid(orig_head, &oid))
+               return error(_("%s: not a valid OID"), orig_head);
+
+       if (run_git_checkout(opts, onto, action)) {
+               apply_autostash(opts);
+               sequencer_remove_state(opts);
+               return error(_("could not detach HEAD"));
+       }
+
+       return update_ref(NULL, "ORIG_HEAD", &oid, NULL, 0, UPDATE_REFS_MSG_ON_ERR);
+}
+
+static int stopped_at_head(void)
+{
+       struct object_id head;
+       struct commit *commit;
+       struct commit_message message;
+
+       if (get_oid("HEAD", &head) ||
+           !(commit = lookup_commit(the_repository, &head)) ||
+           parse_commit(commit) || get_message(commit, &message))
+               fprintf(stderr, _("Stopped at HEAD\n"));
+       else {
+               fprintf(stderr, _("Stopped at %s\n"), message.label);
+               free_message(commit, &message);
+       }
+       return 0;
+
+}
+
 static const char rescheduled_advice[] =
 N_("Could not execute the todo command\n"
 "\n"
@@ -3332,6 +3513,9 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
                        unlink(rebase_path_stopped_sha());
                        unlink(rebase_path_amend());
                        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
+
+                       if (item->command == TODO_BREAK)
+                               return stopped_at_head();
                }
                if (item->command <= TODO_SQUASH) {
                        if (is_rebase_i(opts))
@@ -4420,24 +4604,20 @@ int transform_todos(unsigned flags)
        return i;
 }
 
-enum check_level {
-       CHECK_IGNORE = 0, CHECK_WARN, CHECK_ERROR
-};
-
-static enum check_level get_missing_commit_check_level(void)
+enum missing_commit_check_level get_missing_commit_check_level(void)
 {
        const char *value;
 
        if (git_config_get_value("rebase.missingcommitscheck", &value) ||
                        !strcasecmp("ignore", value))
-               return CHECK_IGNORE;
+               return MISSING_COMMIT_CHECK_IGNORE;
        if (!strcasecmp("warn", value))
-               return CHECK_WARN;
+               return MISSING_COMMIT_CHECK_WARN;
        if (!strcasecmp("error", value))
-               return CHECK_ERROR;
+               return MISSING_COMMIT_CHECK_ERROR;
        warning(_("unrecognized setting %s for option "
                  "rebase.missingCommitsCheck. Ignoring."), value);
-       return CHECK_IGNORE;
+       return MISSING_COMMIT_CHECK_IGNORE;
 }
 
 define_commit_slab(commit_seen, unsigned char);
@@ -4449,7 +4629,7 @@ define_commit_slab(commit_seen, unsigned char);
  */
 int check_todo_list(void)
 {
-       enum check_level check_level = get_missing_commit_check_level();
+       enum missing_commit_check_level check_level = get_missing_commit_check_level();
        struct strbuf todo_file = STRBUF_INIT;
        struct todo_list todo_list = TODO_LIST_INIT;
        struct strbuf missing = STRBUF_INIT;
@@ -4466,7 +4646,7 @@ int check_todo_list(void)
        advise_to_edit_todo = res =
                parse_insn_buffer(todo_list.buf.buf, &todo_list);
 
-       if (res || check_level == CHECK_IGNORE)
+       if (res || check_level == MISSING_COMMIT_CHECK_IGNORE)
                goto leave_check;
 
        /* Mark the commits in git-rebase-todo as seen */
@@ -4501,7 +4681,7 @@ int check_todo_list(void)
        if (!missing.len)
                goto leave_check;
 
-       if (check_level == CHECK_ERROR)
+       if (check_level == MISSING_COMMIT_CHECK_ERROR)
                advise_to_edit_todo = res = 1;
 
        fprintf(stderr,
@@ -4547,17 +4727,17 @@ static int rewrite_file(const char *path, const char *buf, size_t len)
 }
 
 /* skip picking commits whose parents are unchanged */
-int skip_unnecessary_picks(void)
+static int skip_unnecessary_picks(struct object_id *output_oid)
 {
        const char *todo_file = rebase_path_todo();
        struct strbuf buf = STRBUF_INIT;
        struct todo_list todo_list = TODO_LIST_INIT;
-       struct object_id onto_oid, *oid = &onto_oid, *parent_oid;
+       struct object_id *parent_oid;
        int fd, i;
 
        if (!read_oneliner(&buf, rebase_path_onto(), 0))
                return error(_("could not read 'onto'"));
-       if (get_oid(buf.buf, &onto_oid)) {
+       if (get_oid(buf.buf, output_oid)) {
                strbuf_release(&buf);
                return error(_("need a HEAD to fixup"));
        }
@@ -4587,9 +4767,9 @@ int skip_unnecessary_picks(void)
                if (item->commit->parents->next)
                        break; /* merge commit */
                parent_oid = &item->commit->parents->item->object.oid;
-               if (!oideq(parent_oid, oid))
+               if (!oideq(parent_oid, output_oid))
                        break;
-               oid = &item->commit->object.oid;
+               oidcpy(output_oid, &item->commit->object.oid);
        }
        if (i > 0) {
                int offset = get_item_line_offset(&todo_list, i);
@@ -4618,15 +4798,114 @@ int skip_unnecessary_picks(void)
 
                todo_list.current = i;
                if (is_fixup(peek_command(&todo_list, 0)))
-                       record_in_rewritten(oid, peek_command(&todo_list, 0));
+                       record_in_rewritten(output_oid, peek_command(&todo_list, 0));
        }
 
        todo_list_release(&todo_list);
-       printf("%s\n", oid_to_hex(oid));
 
        return 0;
 }
 
+int complete_action(struct replay_opts *opts, unsigned flags,
+                   const char *shortrevisions, const char *onto_name,
+                   const char *onto, const char *orig_head, const char *cmd,
+                   unsigned autosquash)
+{
+       const char *shortonto, *todo_file = rebase_path_todo();
+       struct todo_list todo_list = TODO_LIST_INIT;
+       struct strbuf *buf = &(todo_list.buf);
+       struct object_id oid;
+       struct stat st;
+
+       get_oid(onto, &oid);
+       shortonto = find_unique_abbrev(&oid, DEFAULT_ABBREV);
+
+       if (!lstat(todo_file, &st) && st.st_size == 0 &&
+           write_message("noop\n", 5, todo_file, 0))
+               return -1;
+
+       if (autosquash && rearrange_squash())
+               return -1;
+
+       if (cmd && *cmd)
+               sequencer_add_exec_commands(cmd);
+
+       if (strbuf_read_file(buf, todo_file, 0) < 0)
+               return error_errno(_("could not read '%s'."), todo_file);
+
+       if (parse_insn_buffer(buf->buf, &todo_list)) {
+               todo_list_release(&todo_list);
+               return error(_("unusable todo list: '%s'"), todo_file);
+       }
+
+       if (count_commands(&todo_list) == 0) {
+               apply_autostash(opts);
+               sequencer_remove_state(opts);
+               todo_list_release(&todo_list);
+
+               return error(_("nothing to do"));
+       }
+
+       strbuf_addch(buf, '\n');
+       strbuf_commented_addf(buf, Q_("Rebase %s onto %s (%d command)",
+                                     "Rebase %s onto %s (%d commands)",
+                                     count_commands(&todo_list)),
+                             shortrevisions, shortonto, count_commands(&todo_list));
+       append_todo_help(0, flags & TODO_LIST_KEEP_EMPTY, buf);
+
+       if (write_message(buf->buf, buf->len, todo_file, 0)) {
+               todo_list_release(&todo_list);
+               return -1;
+       }
+
+       if (copy_file(rebase_path_todo_backup(), todo_file, 0666))
+               return error(_("could not copy '%s' to '%s'."), todo_file,
+                            rebase_path_todo_backup());
+
+       if (transform_todos(flags | TODO_LIST_SHORTEN_IDS))
+               return error(_("could not transform the todo list"));
+
+       strbuf_reset(buf);
+
+       if (launch_sequence_editor(todo_file, buf, NULL)) {
+               apply_autostash(opts);
+               sequencer_remove_state(opts);
+               todo_list_release(&todo_list);
+
+               return -1;
+       }
+
+       strbuf_stripspace(buf, 1);
+       if (buf->len == 0) {
+               apply_autostash(opts);
+               sequencer_remove_state(opts);
+               todo_list_release(&todo_list);
+
+               return error(_("nothing to do"));
+       }
+
+       todo_list_release(&todo_list);
+
+       if (check_todo_list()) {
+               checkout_onto(opts, onto_name, onto, orig_head);
+               return -1;
+       }
+
+       if (transform_todos(flags & ~(TODO_LIST_SHORTEN_IDS)))
+               return error(_("could not transform the todo list"));
+
+       if (opts->allow_ff && skip_unnecessary_picks(&oid))
+               return error(_("could not skip unnecessary pick commands"));
+
+       if (checkout_onto(opts, onto_name, oid_to_hex(&oid), orig_head))
+               return -1;
+
+       if (require_clean_work_tree("rebase", "", 1, 1))
+               return -1;
+
+       return sequencer_continue(opts);
+}
+
 struct subject2item_entry {
        struct hashmap_entry entry;
        int i;