builtin / rebase.con commit get-tar-commit-id: parse comment record (3548726)
   1/*
   2 * "git rebase" builtin command
   3 *
   4 * Copyright (c) 2018 Pratik Karki
   5 */
   6
   7#define USE_THE_INDEX_COMPATIBILITY_MACROS
   8#include "builtin.h"
   9#include "run-command.h"
  10#include "exec-cmd.h"
  11#include "argv-array.h"
  12#include "dir.h"
  13#include "packfile.h"
  14#include "refs.h"
  15#include "quote.h"
  16#include "config.h"
  17#include "cache-tree.h"
  18#include "unpack-trees.h"
  19#include "lockfile.h"
  20#include "parse-options.h"
  21#include "commit.h"
  22#include "diff.h"
  23#include "wt-status.h"
  24#include "revision.h"
  25#include "commit-reach.h"
  26#include "rerere.h"
  27#include "branch.h"
  28
  29static char const * const builtin_rebase_usage[] = {
  30        N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  31                "[<upstream>] [<branch>]"),
  32        N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  33                "--root [<branch>]"),
  34        N_("git rebase --continue | --abort | --skip | --edit-todo"),
  35        NULL
  36};
  37
  38static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  39static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  40
  41enum rebase_type {
  42        REBASE_UNSPECIFIED = -1,
  43        REBASE_AM,
  44        REBASE_MERGE,
  45        REBASE_INTERACTIVE,
  46        REBASE_PRESERVE_MERGES
  47};
  48
  49static int use_builtin_rebase(void)
  50{
  51        struct child_process cp = CHILD_PROCESS_INIT;
  52        struct strbuf out = STRBUF_INIT;
  53        int ret, env = git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1);
  54
  55        if (env != -1)
  56                return env;
  57
  58        argv_array_pushl(&cp.args,
  59                         "config", "--bool", "rebase.usebuiltin", NULL);
  60        cp.git_cmd = 1;
  61        if (capture_command(&cp, &out, 6)) {
  62                strbuf_release(&out);
  63                return 1;
  64        }
  65
  66        strbuf_trim(&out);
  67        ret = !strcmp("true", out.buf);
  68        strbuf_release(&out);
  69        return ret;
  70}
  71
  72struct rebase_options {
  73        enum rebase_type type;
  74        const char *state_dir;
  75        struct commit *upstream;
  76        const char *upstream_name;
  77        const char *upstream_arg;
  78        char *head_name;
  79        struct object_id orig_head;
  80        struct commit *onto;
  81        const char *onto_name;
  82        const char *revisions;
  83        const char *switch_to;
  84        int root;
  85        struct object_id *squash_onto;
  86        struct commit *restrict_revision;
  87        int dont_finish_rebase;
  88        enum {
  89                REBASE_NO_QUIET = 1<<0,
  90                REBASE_VERBOSE = 1<<1,
  91                REBASE_DIFFSTAT = 1<<2,
  92                REBASE_FORCE = 1<<3,
  93                REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  94        } flags;
  95        struct argv_array git_am_opts;
  96        const char *action;
  97        int signoff;
  98        int allow_rerere_autoupdate;
  99        int keep_empty;
 100        int autosquash;
 101        char *gpg_sign_opt;
 102        int autostash;
 103        char *cmd;
 104        int allow_empty_message;
 105        int rebase_merges, rebase_cousins;
 106        char *strategy, *strategy_opts;
 107        struct strbuf git_format_patch_opt;
 108        int reschedule_failed_exec;
 109};
 110
 111static int is_interactive(struct rebase_options *opts)
 112{
 113        return opts->type == REBASE_INTERACTIVE ||
 114                opts->type == REBASE_PRESERVE_MERGES;
 115}
 116
 117static void imply_interactive(struct rebase_options *opts, const char *option)
 118{
 119        switch (opts->type) {
 120        case REBASE_AM:
 121                die(_("%s requires an interactive rebase"), option);
 122                break;
 123        case REBASE_INTERACTIVE:
 124        case REBASE_PRESERVE_MERGES:
 125                break;
 126        case REBASE_MERGE:
 127                /* we now implement --merge via --interactive */
 128        default:
 129                opts->type = REBASE_INTERACTIVE; /* implied */
 130                break;
 131        }
 132}
 133
 134/* Returns the filename prefixed by the state_dir */
 135static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 136{
 137        static struct strbuf path = STRBUF_INIT;
 138        static size_t prefix_len;
 139
 140        if (!prefix_len) {
 141                strbuf_addf(&path, "%s/", opts->state_dir);
 142                prefix_len = path.len;
 143        }
 144
 145        strbuf_setlen(&path, prefix_len);
 146        strbuf_addstr(&path, filename);
 147        return path.buf;
 148}
 149
 150/* Read one file, then strip line endings */
 151static int read_one(const char *path, struct strbuf *buf)
 152{
 153        if (strbuf_read_file(buf, path, 0) < 0)
 154                return error_errno(_("could not read '%s'"), path);
 155        strbuf_trim_trailing_newline(buf);
 156        return 0;
 157}
 158
 159/* Initialize the rebase options from the state directory. */
 160static int read_basic_state(struct rebase_options *opts)
 161{
 162        struct strbuf head_name = STRBUF_INIT;
 163        struct strbuf buf = STRBUF_INIT;
 164        struct object_id oid;
 165
 166        if (read_one(state_dir_path("head-name", opts), &head_name) ||
 167            read_one(state_dir_path("onto", opts), &buf))
 168                return -1;
 169        opts->head_name = starts_with(head_name.buf, "refs/") ?
 170                xstrdup(head_name.buf) : NULL;
 171        strbuf_release(&head_name);
 172        if (get_oid(buf.buf, &oid))
 173                return error(_("could not get 'onto': '%s'"), buf.buf);
 174        opts->onto = lookup_commit_or_die(&oid, buf.buf);
 175
 176        /*
 177         * We always write to orig-head, but interactive rebase used to write to
 178         * head. Fall back to reading from head to cover for the case that the
 179         * user upgraded git with an ongoing interactive rebase.
 180         */
 181        strbuf_reset(&buf);
 182        if (file_exists(state_dir_path("orig-head", opts))) {
 183                if (read_one(state_dir_path("orig-head", opts), &buf))
 184                        return -1;
 185        } else if (read_one(state_dir_path("head", opts), &buf))
 186                return -1;
 187        if (get_oid(buf.buf, &opts->orig_head))
 188                return error(_("invalid orig-head: '%s'"), buf.buf);
 189
 190        if (file_exists(state_dir_path("quiet", opts)))
 191                opts->flags &= ~REBASE_NO_QUIET;
 192        else
 193                opts->flags |= REBASE_NO_QUIET;
 194
 195        if (file_exists(state_dir_path("verbose", opts)))
 196                opts->flags |= REBASE_VERBOSE;
 197
 198        if (file_exists(state_dir_path("signoff", opts))) {
 199                opts->signoff = 1;
 200                opts->flags |= REBASE_FORCE;
 201        }
 202
 203        if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 204                strbuf_reset(&buf);
 205                if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 206                            &buf))
 207                        return -1;
 208                if (!strcmp(buf.buf, "--rerere-autoupdate"))
 209                        opts->allow_rerere_autoupdate = 1;
 210                else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 211                        opts->allow_rerere_autoupdate = 0;
 212                else
 213                        warning(_("ignoring invalid allow_rerere_autoupdate: "
 214                                  "'%s'"), buf.buf);
 215        } else
 216                opts->allow_rerere_autoupdate = -1;
 217
 218        if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 219                strbuf_reset(&buf);
 220                if (read_one(state_dir_path("gpg_sign_opt", opts),
 221                            &buf))
 222                        return -1;
 223                free(opts->gpg_sign_opt);
 224                opts->gpg_sign_opt = xstrdup(buf.buf);
 225        }
 226
 227        if (file_exists(state_dir_path("strategy", opts))) {
 228                strbuf_reset(&buf);
 229                if (read_one(state_dir_path("strategy", opts), &buf))
 230                        return -1;
 231                free(opts->strategy);
 232                opts->strategy = xstrdup(buf.buf);
 233        }
 234
 235        if (file_exists(state_dir_path("strategy_opts", opts))) {
 236                strbuf_reset(&buf);
 237                if (read_one(state_dir_path("strategy_opts", opts), &buf))
 238                        return -1;
 239                free(opts->strategy_opts);
 240                opts->strategy_opts = xstrdup(buf.buf);
 241        }
 242
 243        strbuf_release(&buf);
 244
 245        return 0;
 246}
 247
 248static int write_basic_state(struct rebase_options *opts)
 249{
 250        write_file(state_dir_path("head-name", opts), "%s",
 251                   opts->head_name ? opts->head_name : "detached HEAD");
 252        write_file(state_dir_path("onto", opts), "%s",
 253                   opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 254        write_file(state_dir_path("orig-head", opts), "%s",
 255                   oid_to_hex(&opts->orig_head));
 256        write_file(state_dir_path("quiet", opts), "%s",
 257                   opts->flags & REBASE_NO_QUIET ? "" : "t");
 258        if (opts->flags & REBASE_VERBOSE)
 259                write_file(state_dir_path("verbose", opts), "%s", "");
 260        if (opts->strategy)
 261                write_file(state_dir_path("strategy", opts), "%s",
 262                           opts->strategy);
 263        if (opts->strategy_opts)
 264                write_file(state_dir_path("strategy_opts", opts), "%s",
 265                           opts->strategy_opts);
 266        if (opts->allow_rerere_autoupdate >= 0)
 267                write_file(state_dir_path("allow_rerere_autoupdate", opts),
 268                           "-%s-rerere-autoupdate",
 269                           opts->allow_rerere_autoupdate ? "" : "-no");
 270        if (opts->gpg_sign_opt)
 271                write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 272                           opts->gpg_sign_opt);
 273        if (opts->signoff)
 274                write_file(state_dir_path("strategy", opts), "--signoff");
 275
 276        return 0;
 277}
 278
 279static int apply_autostash(struct rebase_options *opts)
 280{
 281        const char *path = state_dir_path("autostash", opts);
 282        struct strbuf autostash = STRBUF_INIT;
 283        struct child_process stash_apply = CHILD_PROCESS_INIT;
 284
 285        if (!file_exists(path))
 286                return 0;
 287
 288        if (read_one(path, &autostash))
 289                return error(_("Could not read '%s'"), path);
 290        /* Ensure that the hash is not mistaken for a number */
 291        strbuf_addstr(&autostash, "^0");
 292        argv_array_pushl(&stash_apply.args,
 293                         "stash", "apply", autostash.buf, NULL);
 294        stash_apply.git_cmd = 1;
 295        stash_apply.no_stderr = stash_apply.no_stdout =
 296                stash_apply.no_stdin = 1;
 297        if (!run_command(&stash_apply))
 298                printf(_("Applied autostash.\n"));
 299        else {
 300                struct argv_array args = ARGV_ARRAY_INIT;
 301                int res = 0;
 302
 303                argv_array_pushl(&args,
 304                                 "stash", "store", "-m", "autostash", "-q",
 305                                 autostash.buf, NULL);
 306                if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 307                        res = error(_("Cannot store %s"), autostash.buf);
 308                argv_array_clear(&args);
 309                strbuf_release(&autostash);
 310                if (res)
 311                        return res;
 312
 313                fprintf(stderr,
 314                        _("Applying autostash resulted in conflicts.\n"
 315                          "Your changes are safe in the stash.\n"
 316                          "You can run \"git stash pop\" or \"git stash drop\" "
 317                          "at any time.\n"));
 318        }
 319
 320        strbuf_release(&autostash);
 321        return 0;
 322}
 323
 324static int finish_rebase(struct rebase_options *opts)
 325{
 326        struct strbuf dir = STRBUF_INIT;
 327        const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 328
 329        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 330        apply_autostash(opts);
 331        close_all_packs(the_repository->objects);
 332        /*
 333         * We ignore errors in 'gc --auto', since the
 334         * user should see them.
 335         */
 336        run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 337        strbuf_addstr(&dir, opts->state_dir);
 338        remove_dir_recursively(&dir, 0);
 339        strbuf_release(&dir);
 340
 341        return 0;
 342}
 343
 344static struct commit *peel_committish(const char *name)
 345{
 346        struct object *obj;
 347        struct object_id oid;
 348
 349        if (get_oid(name, &oid))
 350                return NULL;
 351        obj = parse_object(the_repository, &oid);
 352        return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 353}
 354
 355static void add_var(struct strbuf *buf, const char *name, const char *value)
 356{
 357        if (!value)
 358                strbuf_addf(buf, "unset %s; ", name);
 359        else {
 360                strbuf_addf(buf, "%s=", name);
 361                sq_quote_buf(buf, value);
 362                strbuf_addstr(buf, "; ");
 363        }
 364}
 365
 366#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 367
 368#define RESET_HEAD_DETACH (1<<0)
 369#define RESET_HEAD_HARD (1<<1)
 370#define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 371#define RESET_HEAD_REFS_ONLY (1<<3)
 372#define RESET_ORIG_HEAD (1<<4)
 373
 374static int reset_head(struct object_id *oid, const char *action,
 375                      const char *switch_to_branch, unsigned flags,
 376                      const char *reflog_orig_head, const char *reflog_head)
 377{
 378        unsigned detach_head = flags & RESET_HEAD_DETACH;
 379        unsigned reset_hard = flags & RESET_HEAD_HARD;
 380        unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 381        unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
 382        unsigned update_orig_head = flags & RESET_ORIG_HEAD;
 383        struct object_id head_oid;
 384        struct tree_desc desc[2] = { { NULL }, { NULL } };
 385        struct lock_file lock = LOCK_INIT;
 386        struct unpack_trees_options unpack_tree_opts;
 387        struct tree *tree;
 388        const char *reflog_action;
 389        struct strbuf msg = STRBUF_INIT;
 390        size_t prefix_len;
 391        struct object_id *orig = NULL, oid_orig,
 392                *old_orig = NULL, oid_old_orig;
 393        int ret = 0, nr = 0;
 394
 395        if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 396                BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 397
 398        if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 399                ret = -1;
 400                goto leave_reset_head;
 401        }
 402
 403        if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 404                ret = error(_("could not determine HEAD revision"));
 405                goto leave_reset_head;
 406        }
 407
 408        if (!oid)
 409                oid = &head_oid;
 410
 411        if (refs_only)
 412                goto reset_head_refs;
 413
 414        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 415        setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 416        unpack_tree_opts.head_idx = 1;
 417        unpack_tree_opts.src_index = the_repository->index;
 418        unpack_tree_opts.dst_index = the_repository->index;
 419        unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 420        unpack_tree_opts.update = 1;
 421        unpack_tree_opts.merge = 1;
 422        if (!detach_head)
 423                unpack_tree_opts.reset = 1;
 424
 425        if (repo_read_index_unmerged(the_repository) < 0) {
 426                ret = error(_("could not read index"));
 427                goto leave_reset_head;
 428        }
 429
 430        if (!reset_hard && !fill_tree_descriptor(&desc[nr++], &head_oid)) {
 431                ret = error(_("failed to find tree of %s"),
 432                            oid_to_hex(&head_oid));
 433                goto leave_reset_head;
 434        }
 435
 436        if (!fill_tree_descriptor(&desc[nr++], oid)) {
 437                ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 438                goto leave_reset_head;
 439        }
 440
 441        if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 442                ret = -1;
 443                goto leave_reset_head;
 444        }
 445
 446        tree = parse_tree_indirect(oid);
 447        prime_cache_tree(the_repository, the_repository->index, tree);
 448
 449        if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 450                ret = error(_("could not write index"));
 451                goto leave_reset_head;
 452        }
 453
 454reset_head_refs:
 455        reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 456        strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 457        prefix_len = msg.len;
 458
 459        if (update_orig_head) {
 460                if (!get_oid("ORIG_HEAD", &oid_old_orig))
 461                        old_orig = &oid_old_orig;
 462                if (!get_oid("HEAD", &oid_orig)) {
 463                        orig = &oid_orig;
 464                        if (!reflog_orig_head) {
 465                                strbuf_addstr(&msg, "updating ORIG_HEAD");
 466                                reflog_orig_head = msg.buf;
 467                        }
 468                        update_ref(reflog_orig_head, "ORIG_HEAD", orig,
 469                                   old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
 470                } else if (old_orig)
 471                        delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 472        }
 473
 474        if (!reflog_head) {
 475                strbuf_setlen(&msg, prefix_len);
 476                strbuf_addstr(&msg, "updating HEAD");
 477                reflog_head = msg.buf;
 478        }
 479        if (!switch_to_branch)
 480                ret = update_ref(reflog_head, "HEAD", oid, orig,
 481                                 detach_head ? REF_NO_DEREF : 0,
 482                                 UPDATE_REFS_MSG_ON_ERR);
 483        else {
 484                ret = update_ref(reflog_head, switch_to_branch, oid,
 485                                 NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 486                if (!ret)
 487                        ret = create_symref("HEAD", switch_to_branch,
 488                                            reflog_head);
 489        }
 490        if (run_hook)
 491                run_hook_le(NULL, "post-checkout",
 492                            oid_to_hex(orig ? orig : &null_oid),
 493                            oid_to_hex(oid), "1", NULL);
 494
 495leave_reset_head:
 496        strbuf_release(&msg);
 497        rollback_lock_file(&lock);
 498        while (nr)
 499                free((void *)desc[--nr].buffer);
 500        return ret;
 501}
 502
 503static int move_to_original_branch(struct rebase_options *opts)
 504{
 505        struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 506        int ret;
 507
 508        if (!opts->head_name)
 509                return 0; /* nothing to move back to */
 510
 511        if (!opts->onto)
 512                BUG("move_to_original_branch without onto");
 513
 514        strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
 515                    opts->head_name, oid_to_hex(&opts->onto->object.oid));
 516        strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 517                    opts->head_name);
 518        ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
 519                         orig_head_reflog.buf, head_reflog.buf);
 520
 521        strbuf_release(&orig_head_reflog);
 522        strbuf_release(&head_reflog);
 523        return ret;
 524}
 525
 526static const char *resolvemsg =
 527N_("Resolve all conflicts manually, mark them as resolved with\n"
 528"\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 529"You can instead skip this commit: run \"git rebase --skip\".\n"
 530"To abort and get back to the state before \"git rebase\", run "
 531"\"git rebase --abort\".");
 532
 533static int run_am(struct rebase_options *opts)
 534{
 535        struct child_process am = CHILD_PROCESS_INIT;
 536        struct child_process format_patch = CHILD_PROCESS_INIT;
 537        struct strbuf revisions = STRBUF_INIT;
 538        int status;
 539        char *rebased_patches;
 540
 541        am.git_cmd = 1;
 542        argv_array_push(&am.args, "am");
 543
 544        if (opts->action && !strcmp("continue", opts->action)) {
 545                argv_array_push(&am.args, "--resolved");
 546                argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 547                if (opts->gpg_sign_opt)
 548                        argv_array_push(&am.args, opts->gpg_sign_opt);
 549                status = run_command(&am);
 550                if (status)
 551                        return status;
 552
 553                return move_to_original_branch(opts);
 554        }
 555        if (opts->action && !strcmp("skip", opts->action)) {
 556                argv_array_push(&am.args, "--skip");
 557                argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 558                status = run_command(&am);
 559                if (status)
 560                        return status;
 561
 562                return move_to_original_branch(opts);
 563        }
 564        if (opts->action && !strcmp("show-current-patch", opts->action)) {
 565                argv_array_push(&am.args, "--show-current-patch");
 566                return run_command(&am);
 567        }
 568
 569        strbuf_addf(&revisions, "%s...%s",
 570                    oid_to_hex(opts->root ?
 571                               /* this is now equivalent to !opts->upstream */
 572                               &opts->onto->object.oid :
 573                               &opts->upstream->object.oid),
 574                    oid_to_hex(&opts->orig_head));
 575
 576        rebased_patches = xstrdup(git_path("rebased-patches"));
 577        format_patch.out = open(rebased_patches,
 578                                O_WRONLY | O_CREAT | O_TRUNC, 0666);
 579        if (format_patch.out < 0) {
 580                status = error_errno(_("could not open '%s' for writing"),
 581                                     rebased_patches);
 582                free(rebased_patches);
 583                argv_array_clear(&am.args);
 584                return status;
 585        }
 586
 587        format_patch.git_cmd = 1;
 588        argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
 589                         "--full-index", "--cherry-pick", "--right-only",
 590                         "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
 591                         "--no-cover-letter", "--pretty=mboxrd", "--topo-order", NULL);
 592        if (opts->git_format_patch_opt.len)
 593                argv_array_split(&format_patch.args,
 594                                 opts->git_format_patch_opt.buf);
 595        argv_array_push(&format_patch.args, revisions.buf);
 596        if (opts->restrict_revision)
 597                argv_array_pushf(&format_patch.args, "^%s",
 598                                 oid_to_hex(&opts->restrict_revision->object.oid));
 599
 600        status = run_command(&format_patch);
 601        if (status) {
 602                unlink(rebased_patches);
 603                free(rebased_patches);
 604                argv_array_clear(&am.args);
 605
 606                reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
 607                           "HEAD", NULL);
 608                error(_("\ngit encountered an error while preparing the "
 609                        "patches to replay\n"
 610                        "these revisions:\n"
 611                        "\n    %s\n\n"
 612                        "As a result, git cannot rebase them."),
 613                      opts->revisions);
 614
 615                strbuf_release(&revisions);
 616                return status;
 617        }
 618        strbuf_release(&revisions);
 619
 620        am.in = open(rebased_patches, O_RDONLY);
 621        if (am.in < 0) {
 622                status = error_errno(_("could not open '%s' for reading"),
 623                                     rebased_patches);
 624                free(rebased_patches);
 625                argv_array_clear(&am.args);
 626                return status;
 627        }
 628
 629        argv_array_pushv(&am.args, opts->git_am_opts.argv);
 630        argv_array_push(&am.args, "--rebasing");
 631        argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 632        argv_array_push(&am.args, "--patch-format=mboxrd");
 633        if (opts->allow_rerere_autoupdate > 0)
 634                argv_array_push(&am.args, "--rerere-autoupdate");
 635        else if (opts->allow_rerere_autoupdate == 0)
 636                argv_array_push(&am.args, "--no-rerere-autoupdate");
 637        if (opts->gpg_sign_opt)
 638                argv_array_push(&am.args, opts->gpg_sign_opt);
 639        status = run_command(&am);
 640        unlink(rebased_patches);
 641        free(rebased_patches);
 642
 643        if (!status) {
 644                return move_to_original_branch(opts);
 645        }
 646
 647        if (is_directory(opts->state_dir))
 648                write_basic_state(opts);
 649
 650        return status;
 651}
 652
 653static int run_specific_rebase(struct rebase_options *opts)
 654{
 655        const char *argv[] = { NULL, NULL };
 656        struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
 657        int status;
 658        const char *backend, *backend_func;
 659
 660        if (opts->type == REBASE_INTERACTIVE) {
 661                /* Run builtin interactive rebase */
 662                struct child_process child = CHILD_PROCESS_INIT;
 663
 664                argv_array_pushf(&child.env_array, "GIT_CHERRY_PICK_HELP=%s",
 665                                 resolvemsg);
 666                if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 667                        argv_array_push(&child.env_array,
 668                                        "GIT_SEQUENCE_EDITOR=:");
 669                        opts->autosquash = 0;
 670                }
 671
 672                child.git_cmd = 1;
 673                argv_array_push(&child.args, "rebase--interactive");
 674
 675                if (opts->action)
 676                        argv_array_pushf(&child.args, "--%s", opts->action);
 677                if (opts->keep_empty)
 678                        argv_array_push(&child.args, "--keep-empty");
 679                if (opts->rebase_merges)
 680                        argv_array_push(&child.args, "--rebase-merges");
 681                if (opts->rebase_cousins)
 682                        argv_array_push(&child.args, "--rebase-cousins");
 683                if (opts->autosquash)
 684                        argv_array_push(&child.args, "--autosquash");
 685                if (opts->flags & REBASE_VERBOSE)
 686                        argv_array_push(&child.args, "--verbose");
 687                if (opts->flags & REBASE_FORCE)
 688                        argv_array_push(&child.args, "--no-ff");
 689                if (opts->restrict_revision)
 690                        argv_array_pushf(&child.args,
 691                                         "--restrict-revision=^%s",
 692                                         oid_to_hex(&opts->restrict_revision->object.oid));
 693                if (opts->upstream)
 694                        argv_array_pushf(&child.args, "--upstream=%s",
 695                                         oid_to_hex(&opts->upstream->object.oid));
 696                if (opts->onto)
 697                        argv_array_pushf(&child.args, "--onto=%s",
 698                                         oid_to_hex(&opts->onto->object.oid));
 699                if (opts->squash_onto)
 700                        argv_array_pushf(&child.args, "--squash-onto=%s",
 701                                         oid_to_hex(opts->squash_onto));
 702                if (opts->onto_name)
 703                        argv_array_pushf(&child.args, "--onto-name=%s",
 704                                         opts->onto_name);
 705                argv_array_pushf(&child.args, "--head-name=%s",
 706                                 opts->head_name ?
 707                                 opts->head_name : "detached HEAD");
 708                if (opts->strategy)
 709                        argv_array_pushf(&child.args, "--strategy=%s",
 710                                         opts->strategy);
 711                if (opts->strategy_opts)
 712                        argv_array_pushf(&child.args, "--strategy-opts=%s",
 713                                         opts->strategy_opts);
 714                if (opts->switch_to)
 715                        argv_array_pushf(&child.args, "--switch-to=%s",
 716                                         opts->switch_to);
 717                if (opts->cmd)
 718                        argv_array_pushf(&child.args, "--cmd=%s", opts->cmd);
 719                if (opts->allow_empty_message)
 720                        argv_array_push(&child.args, "--allow-empty-message");
 721                if (opts->allow_rerere_autoupdate > 0)
 722                        argv_array_push(&child.args, "--rerere-autoupdate");
 723                else if (opts->allow_rerere_autoupdate == 0)
 724                        argv_array_push(&child.args, "--no-rerere-autoupdate");
 725                if (opts->gpg_sign_opt)
 726                        argv_array_push(&child.args, opts->gpg_sign_opt);
 727                if (opts->signoff)
 728                        argv_array_push(&child.args, "--signoff");
 729                if (opts->reschedule_failed_exec)
 730                        argv_array_push(&child.args, "--reschedule-failed-exec");
 731
 732                status = run_command(&child);
 733                goto finished_rebase;
 734        }
 735
 736        if (opts->type == REBASE_AM) {
 737                status = run_am(opts);
 738                goto finished_rebase;
 739        }
 740
 741        add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 742        add_var(&script_snippet, "state_dir", opts->state_dir);
 743
 744        add_var(&script_snippet, "upstream_name", opts->upstream_name);
 745        add_var(&script_snippet, "upstream", opts->upstream ?
 746                oid_to_hex(&opts->upstream->object.oid) : NULL);
 747        add_var(&script_snippet, "head_name",
 748                opts->head_name ? opts->head_name : "detached HEAD");
 749        add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 750        add_var(&script_snippet, "onto", opts->onto ?
 751                oid_to_hex(&opts->onto->object.oid) : NULL);
 752        add_var(&script_snippet, "onto_name", opts->onto_name);
 753        add_var(&script_snippet, "revisions", opts->revisions);
 754        add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 755                oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 756        add_var(&script_snippet, "GIT_QUIET",
 757                opts->flags & REBASE_NO_QUIET ? "" : "t");
 758        sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
 759        add_var(&script_snippet, "git_am_opt", buf.buf);
 760        strbuf_release(&buf);
 761        add_var(&script_snippet, "verbose",
 762                opts->flags & REBASE_VERBOSE ? "t" : "");
 763        add_var(&script_snippet, "diffstat",
 764                opts->flags & REBASE_DIFFSTAT ? "t" : "");
 765        add_var(&script_snippet, "force_rebase",
 766                opts->flags & REBASE_FORCE ? "t" : "");
 767        if (opts->switch_to)
 768                add_var(&script_snippet, "switch_to", opts->switch_to);
 769        add_var(&script_snippet, "action", opts->action ? opts->action : "");
 770        add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
 771        add_var(&script_snippet, "allow_rerere_autoupdate",
 772                opts->allow_rerere_autoupdate < 0 ? "" :
 773                opts->allow_rerere_autoupdate ?
 774                "--rerere-autoupdate" : "--no-rerere-autoupdate");
 775        add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
 776        add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
 777        add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
 778        add_var(&script_snippet, "cmd", opts->cmd);
 779        add_var(&script_snippet, "allow_empty_message",
 780                opts->allow_empty_message ?  "--allow-empty-message" : "");
 781        add_var(&script_snippet, "rebase_merges",
 782                opts->rebase_merges ? "t" : "");
 783        add_var(&script_snippet, "rebase_cousins",
 784                opts->rebase_cousins ? "t" : "");
 785        add_var(&script_snippet, "strategy", opts->strategy);
 786        add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
 787        add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
 788        add_var(&script_snippet, "squash_onto",
 789                opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
 790        add_var(&script_snippet, "git_format_patch_opt",
 791                opts->git_format_patch_opt.buf);
 792
 793        if (is_interactive(opts) &&
 794            !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 795                strbuf_addstr(&script_snippet,
 796                              "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
 797                opts->autosquash = 0;
 798        }
 799
 800        switch (opts->type) {
 801        case REBASE_AM:
 802                backend = "git-rebase--am";
 803                backend_func = "git_rebase__am";
 804                break;
 805        case REBASE_PRESERVE_MERGES:
 806                backend = "git-rebase--preserve-merges";
 807                backend_func = "git_rebase__preserve_merges";
 808                break;
 809        default:
 810                BUG("Unhandled rebase type %d", opts->type);
 811                break;
 812        }
 813
 814        strbuf_addf(&script_snippet,
 815                    ". git-sh-setup && . git-rebase--common &&"
 816                    " . %s && %s", backend, backend_func);
 817        argv[0] = script_snippet.buf;
 818
 819        status = run_command_v_opt(argv, RUN_USING_SHELL);
 820finished_rebase:
 821        if (opts->dont_finish_rebase)
 822                ; /* do nothing */
 823        else if (opts->type == REBASE_INTERACTIVE)
 824                ; /* interactive rebase cleans up after itself */
 825        else if (status == 0) {
 826                if (!file_exists(state_dir_path("stopped-sha", opts)))
 827                        finish_rebase(opts);
 828        } else if (status == 2) {
 829                struct strbuf dir = STRBUF_INIT;
 830
 831                apply_autostash(opts);
 832                strbuf_addstr(&dir, opts->state_dir);
 833                remove_dir_recursively(&dir, 0);
 834                strbuf_release(&dir);
 835                die("Nothing to do");
 836        }
 837
 838        strbuf_release(&script_snippet);
 839
 840        return status ? -1 : 0;
 841}
 842
 843static int rebase_config(const char *var, const char *value, void *data)
 844{
 845        struct rebase_options *opts = data;
 846
 847        if (!strcmp(var, "rebase.stat")) {
 848                if (git_config_bool(var, value))
 849                        opts->flags |= REBASE_DIFFSTAT;
 850                else
 851                        opts->flags &= !REBASE_DIFFSTAT;
 852                return 0;
 853        }
 854
 855        if (!strcmp(var, "rebase.autosquash")) {
 856                opts->autosquash = git_config_bool(var, value);
 857                return 0;
 858        }
 859
 860        if (!strcmp(var, "commit.gpgsign")) {
 861                free(opts->gpg_sign_opt);
 862                opts->gpg_sign_opt = git_config_bool(var, value) ?
 863                        xstrdup("-S") : NULL;
 864                return 0;
 865        }
 866
 867        if (!strcmp(var, "rebase.autostash")) {
 868                opts->autostash = git_config_bool(var, value);
 869                return 0;
 870        }
 871
 872        if (!strcmp(var, "rebase.reschedulefailedexec")) {
 873                opts->reschedule_failed_exec = git_config_bool(var, value);
 874                return 0;
 875        }
 876
 877        return git_default_config(var, value, data);
 878}
 879
 880/*
 881 * Determines whether the commits in from..to are linear, i.e. contain
 882 * no merge commits. This function *expects* `from` to be an ancestor of
 883 * `to`.
 884 */
 885static int is_linear_history(struct commit *from, struct commit *to)
 886{
 887        while (to && to != from) {
 888                parse_commit(to);
 889                if (!to->parents)
 890                        return 1;
 891                if (to->parents->next)
 892                        return 0;
 893                to = to->parents->item;
 894        }
 895        return 1;
 896}
 897
 898static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
 899                            struct object_id *merge_base)
 900{
 901        struct commit *head = lookup_commit(the_repository, head_oid);
 902        struct commit_list *merge_bases;
 903        int res;
 904
 905        if (!head)
 906                return 0;
 907
 908        merge_bases = get_merge_bases(onto, head);
 909        if (merge_bases && !merge_bases->next) {
 910                oidcpy(merge_base, &merge_bases->item->object.oid);
 911                res = oideq(merge_base, &onto->object.oid);
 912        } else {
 913                oidcpy(merge_base, &null_oid);
 914                res = 0;
 915        }
 916        free_commit_list(merge_bases);
 917        return res && is_linear_history(onto, head);
 918}
 919
 920/* -i followed by -m is still -i */
 921static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 922{
 923        struct rebase_options *opts = opt->value;
 924
 925        BUG_ON_OPT_NEG(unset);
 926        BUG_ON_OPT_ARG(arg);
 927
 928        if (!is_interactive(opts))
 929                opts->type = REBASE_MERGE;
 930
 931        return 0;
 932}
 933
 934/* -i followed by -p is still explicitly interactive, but -p alone is not */
 935static int parse_opt_interactive(const struct option *opt, const char *arg,
 936                                 int unset)
 937{
 938        struct rebase_options *opts = opt->value;
 939
 940        BUG_ON_OPT_NEG(unset);
 941        BUG_ON_OPT_ARG(arg);
 942
 943        opts->type = REBASE_INTERACTIVE;
 944        opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 945
 946        return 0;
 947}
 948
 949static void NORETURN error_on_missing_default_upstream(void)
 950{
 951        struct branch *current_branch = branch_get(NULL);
 952
 953        printf(_("%s\n"
 954                 "Please specify which branch you want to rebase against.\n"
 955                 "See git-rebase(1) for details.\n"
 956                 "\n"
 957                 "    git rebase '<branch>'\n"
 958                 "\n"),
 959                current_branch ? _("There is no tracking information for "
 960                        "the current branch.") :
 961                        _("You are not currently on a branch."));
 962
 963        if (current_branch) {
 964                const char *remote = current_branch->remote_name;
 965
 966                if (!remote)
 967                        remote = _("<remote>");
 968
 969                printf(_("If you wish to set tracking information for this "
 970                         "branch you can do so with:\n"
 971                         "\n"
 972                         "    git branch --set-upstream-to=%s/<branch> %s\n"
 973                         "\n"),
 974                       remote, current_branch->name);
 975        }
 976        exit(1);
 977}
 978
 979static void set_reflog_action(struct rebase_options *options)
 980{
 981        const char *env;
 982        struct strbuf buf = STRBUF_INIT;
 983
 984        if (!is_interactive(options))
 985                return;
 986
 987        env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 988        if (env && strcmp("rebase", env))
 989                return; /* only override it if it is "rebase" */
 990
 991        strbuf_addf(&buf, "rebase -i (%s)", options->action);
 992        setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
 993        strbuf_release(&buf);
 994}
 995
 996static int check_exec_cmd(const char *cmd)
 997{
 998        if (strchr(cmd, '\n'))
 999                return error(_("exec commands cannot contain newlines"));
1000
1001        /* Does the command consist purely of whitespace? */
1002        if (!cmd[strspn(cmd, " \t\r\f\v")])
1003                return error(_("empty exec command"));
1004
1005        return 0;
1006}
1007
1008
1009int cmd_rebase(int argc, const char **argv, const char *prefix)
1010{
1011        struct rebase_options options = {
1012                .type = REBASE_UNSPECIFIED,
1013                .flags = REBASE_NO_QUIET,
1014                .git_am_opts = ARGV_ARRAY_INIT,
1015                .allow_rerere_autoupdate  = -1,
1016                .allow_empty_message = 1,
1017                .git_format_patch_opt = STRBUF_INIT,
1018        };
1019        const char *branch_name;
1020        int ret, flags, total_argc, in_progress = 0;
1021        int ok_to_skip_pre_rebase = 0;
1022        struct strbuf msg = STRBUF_INIT;
1023        struct strbuf revisions = STRBUF_INIT;
1024        struct strbuf buf = STRBUF_INIT;
1025        struct object_id merge_base;
1026        enum {
1027                NO_ACTION,
1028                ACTION_CONTINUE,
1029                ACTION_SKIP,
1030                ACTION_ABORT,
1031                ACTION_QUIT,
1032                ACTION_EDIT_TODO,
1033                ACTION_SHOW_CURRENT_PATCH,
1034        } action = NO_ACTION;
1035        static const char *action_names[] = { N_("undefined"),
1036                                              N_("continue"),
1037                                              N_("skip"),
1038                                              N_("abort"),
1039                                              N_("quit"),
1040                                              N_("edit_todo"),
1041                                              N_("show_current_patch"),
1042                                              NULL };
1043        const char *gpg_sign = NULL;
1044        struct string_list exec = STRING_LIST_INIT_NODUP;
1045        const char *rebase_merges = NULL;
1046        int fork_point = -1;
1047        struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1048        struct object_id squash_onto;
1049        char *squash_onto_name = NULL;
1050        struct option builtin_rebase_options[] = {
1051                OPT_STRING(0, "onto", &options.onto_name,
1052                           N_("revision"),
1053                           N_("rebase onto given branch instead of upstream")),
1054                OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1055                         N_("allow pre-rebase hook to run")),
1056                OPT_NEGBIT('q', "quiet", &options.flags,
1057                           N_("be quiet. implies --no-stat"),
1058                           REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
1059                OPT_BIT('v', "verbose", &options.flags,
1060                        N_("display a diffstat of what changed upstream"),
1061                        REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1062                {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1063                        N_("do not show diffstat of what changed upstream"),
1064                        PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1065                OPT_BOOL(0, "signoff", &options.signoff,
1066                         N_("add a Signed-off-by: line to each commit")),
1067                OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
1068                                  NULL, N_("passed to 'git am'"),
1069                                  PARSE_OPT_NOARG),
1070                OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
1071                                  &options.git_am_opts, NULL,
1072                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
1073                OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
1074                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
1075                OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1076                                  N_("passed to 'git apply'"), 0),
1077                OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1078                                  N_("action"), N_("passed to 'git apply'"), 0),
1079                OPT_BIT('f', "force-rebase", &options.flags,
1080                        N_("cherry-pick all commits, even if unchanged"),
1081                        REBASE_FORCE),
1082                OPT_BIT(0, "no-ff", &options.flags,
1083                        N_("cherry-pick all commits, even if unchanged"),
1084                        REBASE_FORCE),
1085                OPT_CMDMODE(0, "continue", &action, N_("continue"),
1086                            ACTION_CONTINUE),
1087                OPT_CMDMODE(0, "skip", &action,
1088                            N_("skip current patch and continue"), ACTION_SKIP),
1089                OPT_CMDMODE(0, "abort", &action,
1090                            N_("abort and check out the original branch"),
1091                            ACTION_ABORT),
1092                OPT_CMDMODE(0, "quit", &action,
1093                            N_("abort but keep HEAD where it is"), ACTION_QUIT),
1094                OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1095                            "during an interactive rebase"), ACTION_EDIT_TODO),
1096                OPT_CMDMODE(0, "show-current-patch", &action,
1097                            N_("show the patch file being applied or merged"),
1098                            ACTION_SHOW_CURRENT_PATCH),
1099                { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1100                        N_("use merging strategies to rebase"),
1101                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1102                        parse_opt_merge },
1103                { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1104                        N_("let the user edit the list of commits to rebase"),
1105                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1106                        parse_opt_interactive },
1107                OPT_SET_INT('p', "preserve-merges", &options.type,
1108                            N_("try to recreate merges instead of ignoring "
1109                               "them"), REBASE_PRESERVE_MERGES),
1110                OPT_BOOL(0, "rerere-autoupdate",
1111                         &options.allow_rerere_autoupdate,
1112                         N_("allow rerere to update index with resolved "
1113                            "conflict")),
1114                OPT_BOOL('k', "keep-empty", &options.keep_empty,
1115                         N_("preserve empty commits during rebase")),
1116                OPT_BOOL(0, "autosquash", &options.autosquash,
1117                         N_("move commits that begin with "
1118                            "squash!/fixup! under -i")),
1119                { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1120                        N_("GPG-sign commits"),
1121                        PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1122                OPT_BOOL(0, "autostash", &options.autostash,
1123                         N_("automatically stash/stash pop before and after")),
1124                OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1125                                N_("add exec lines after each commit of the "
1126                                   "editable list")),
1127                OPT_BOOL(0, "allow-empty-message",
1128                         &options.allow_empty_message,
1129                         N_("allow rebasing commits with empty messages")),
1130                {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1131                        N_("mode"),
1132                        N_("try to rebase merges instead of skipping them"),
1133                        PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1134                OPT_BOOL(0, "fork-point", &fork_point,
1135                         N_("use 'merge-base --fork-point' to refine upstream")),
1136                OPT_STRING('s', "strategy", &options.strategy,
1137                           N_("strategy"), N_("use the given merge strategy")),
1138                OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1139                                N_("option"),
1140                                N_("pass the argument through to the merge "
1141                                   "strategy")),
1142                OPT_BOOL(0, "root", &options.root,
1143                         N_("rebase all reachable commits up to the root(s)")),
1144                OPT_BOOL(0, "reschedule-failed-exec",
1145                         &options.reschedule_failed_exec,
1146                         N_("automatically re-schedule any `exec` that fails")),
1147                OPT_END(),
1148        };
1149        int i;
1150
1151        /*
1152         * NEEDSWORK: Once the builtin rebase has been tested enough
1153         * and git-legacy-rebase.sh is retired to contrib/, this preamble
1154         * can be removed.
1155         */
1156
1157        if (!use_builtin_rebase()) {
1158                const char *path = mkpath("%s/git-legacy-rebase",
1159                                          git_exec_path());
1160
1161                if (sane_execvp(path, (char **)argv) < 0)
1162                        die_errno(_("could not exec %s"), path);
1163                else
1164                        BUG("sane_execvp() returned???");
1165        }
1166
1167        if (argc == 2 && !strcmp(argv[1], "-h"))
1168                usage_with_options(builtin_rebase_usage,
1169                                   builtin_rebase_options);
1170
1171        prefix = setup_git_directory();
1172        trace_repo_setup(prefix);
1173        setup_work_tree();
1174
1175        git_config(rebase_config, &options);
1176
1177        strbuf_reset(&buf);
1178        strbuf_addf(&buf, "%s/applying", apply_dir());
1179        if(file_exists(buf.buf))
1180                die(_("It looks like 'git am' is in progress. Cannot rebase."));
1181
1182        if (is_directory(apply_dir())) {
1183                options.type = REBASE_AM;
1184                options.state_dir = apply_dir();
1185        } else if (is_directory(merge_dir())) {
1186                strbuf_reset(&buf);
1187                strbuf_addf(&buf, "%s/rewritten", merge_dir());
1188                if (is_directory(buf.buf)) {
1189                        options.type = REBASE_PRESERVE_MERGES;
1190                        options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1191                } else {
1192                        strbuf_reset(&buf);
1193                        strbuf_addf(&buf, "%s/interactive", merge_dir());
1194                        if(file_exists(buf.buf)) {
1195                                options.type = REBASE_INTERACTIVE;
1196                                options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1197                        } else
1198                                options.type = REBASE_MERGE;
1199                }
1200                options.state_dir = merge_dir();
1201        }
1202
1203        if (options.type != REBASE_UNSPECIFIED)
1204                in_progress = 1;
1205
1206        total_argc = argc;
1207        argc = parse_options(argc, argv, prefix,
1208                             builtin_rebase_options,
1209                             builtin_rebase_usage, 0);
1210
1211        if (action != NO_ACTION && total_argc != 2) {
1212                usage_with_options(builtin_rebase_usage,
1213                                   builtin_rebase_options);
1214        }
1215
1216        if (argc > 2)
1217                usage_with_options(builtin_rebase_usage,
1218                                   builtin_rebase_options);
1219
1220        if (action != NO_ACTION && !in_progress)
1221                die(_("No rebase in progress?"));
1222        setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1223
1224        if (action == ACTION_EDIT_TODO && !is_interactive(&options))
1225                die(_("The --edit-todo action can only be used during "
1226                      "interactive rebase."));
1227
1228        if (trace2_is_enabled()) {
1229                if (is_interactive(&options))
1230                        trace2_cmd_mode("interactive");
1231                else if (exec.nr)
1232                        trace2_cmd_mode("interactive-exec");
1233                else
1234                        trace2_cmd_mode(action_names[action]);
1235        }
1236
1237        switch (action) {
1238        case ACTION_CONTINUE: {
1239                struct object_id head;
1240                struct lock_file lock_file = LOCK_INIT;
1241                int fd;
1242
1243                options.action = "continue";
1244                set_reflog_action(&options);
1245
1246                /* Sanity check */
1247                if (get_oid("HEAD", &head))
1248                        die(_("Cannot read HEAD"));
1249
1250                fd = hold_locked_index(&lock_file, 0);
1251                if (repo_read_index(the_repository) < 0)
1252                        die(_("could not read index"));
1253                refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1254                              NULL);
1255                if (0 <= fd)
1256                        repo_update_index_if_able(the_repository, &lock_file);
1257                rollback_lock_file(&lock_file);
1258
1259                if (has_unstaged_changes(the_repository, 1)) {
1260                        puts(_("You must edit all merge conflicts and then\n"
1261                               "mark them as resolved using git add"));
1262                        exit(1);
1263                }
1264                if (read_basic_state(&options))
1265                        exit(1);
1266                goto run_rebase;
1267        }
1268        case ACTION_SKIP: {
1269                struct string_list merge_rr = STRING_LIST_INIT_DUP;
1270
1271                options.action = "skip";
1272                set_reflog_action(&options);
1273
1274                rerere_clear(the_repository, &merge_rr);
1275                string_list_clear(&merge_rr, 1);
1276
1277                if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1278                               NULL, NULL) < 0)
1279                        die(_("could not discard worktree changes"));
1280                remove_branch_state(the_repository);
1281                if (read_basic_state(&options))
1282                        exit(1);
1283                goto run_rebase;
1284        }
1285        case ACTION_ABORT: {
1286                struct string_list merge_rr = STRING_LIST_INIT_DUP;
1287                options.action = "abort";
1288                set_reflog_action(&options);
1289
1290                rerere_clear(the_repository, &merge_rr);
1291                string_list_clear(&merge_rr, 1);
1292
1293                if (read_basic_state(&options))
1294                        exit(1);
1295                if (reset_head(&options.orig_head, "reset",
1296                               options.head_name, RESET_HEAD_HARD,
1297                               NULL, NULL) < 0)
1298                        die(_("could not move back to %s"),
1299                            oid_to_hex(&options.orig_head));
1300                remove_branch_state(the_repository);
1301                ret = finish_rebase(&options);
1302                goto cleanup;
1303        }
1304        case ACTION_QUIT: {
1305                strbuf_reset(&buf);
1306                strbuf_addstr(&buf, options.state_dir);
1307                ret = !!remove_dir_recursively(&buf, 0);
1308                if (ret)
1309                        die(_("could not remove '%s'"), options.state_dir);
1310                goto cleanup;
1311        }
1312        case ACTION_EDIT_TODO:
1313                options.action = "edit-todo";
1314                options.dont_finish_rebase = 1;
1315                goto run_rebase;
1316        case ACTION_SHOW_CURRENT_PATCH:
1317                options.action = "show-current-patch";
1318                options.dont_finish_rebase = 1;
1319                goto run_rebase;
1320        case NO_ACTION:
1321                break;
1322        default:
1323                BUG("action: %d", action);
1324        }
1325
1326        /* Make sure no rebase is in progress */
1327        if (in_progress) {
1328                const char *last_slash = strrchr(options.state_dir, '/');
1329                const char *state_dir_base =
1330                        last_slash ? last_slash + 1 : options.state_dir;
1331                const char *cmd_live_rebase =
1332                        "git rebase (--continue | --abort | --skip)";
1333                strbuf_reset(&buf);
1334                strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1335                die(_("It seems that there is already a %s directory, and\n"
1336                      "I wonder if you are in the middle of another rebase.  "
1337                      "If that is the\n"
1338                      "case, please try\n\t%s\n"
1339                      "If that is not the case, please\n\t%s\n"
1340                      "and run me again.  I am stopping in case you still "
1341                      "have something\n"
1342                      "valuable there.\n"),
1343                    state_dir_base, cmd_live_rebase, buf.buf);
1344        }
1345
1346        for (i = 0; i < options.git_am_opts.argc; i++) {
1347                const char *option = options.git_am_opts.argv[i], *p;
1348                if (!strcmp(option, "--committer-date-is-author-date") ||
1349                    !strcmp(option, "--ignore-date") ||
1350                    !strcmp(option, "--whitespace=fix") ||
1351                    !strcmp(option, "--whitespace=strip"))
1352                        options.flags |= REBASE_FORCE;
1353                else if (skip_prefix(option, "-C", &p)) {
1354                        while (*p)
1355                                if (!isdigit(*(p++)))
1356                                        die(_("switch `C' expects a "
1357                                              "numerical value"));
1358                } else if (skip_prefix(option, "--whitespace=", &p)) {
1359                        if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1360                            strcmp(p, "error") && strcmp(p, "error-all"))
1361                                die("Invalid whitespace option: '%s'", p);
1362                }
1363        }
1364
1365        for (i = 0; i < exec.nr; i++)
1366                if (check_exec_cmd(exec.items[i].string))
1367                        exit(1);
1368
1369        if (!(options.flags & REBASE_NO_QUIET))
1370                argv_array_push(&options.git_am_opts, "-q");
1371
1372        if (options.keep_empty)
1373                imply_interactive(&options, "--keep-empty");
1374
1375        if (gpg_sign) {
1376                free(options.gpg_sign_opt);
1377                options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1378        }
1379
1380        if (exec.nr) {
1381                int i;
1382
1383                imply_interactive(&options, "--exec");
1384
1385                strbuf_reset(&buf);
1386                for (i = 0; i < exec.nr; i++)
1387                        strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1388                options.cmd = xstrdup(buf.buf);
1389        }
1390
1391        if (rebase_merges) {
1392                if (!*rebase_merges)
1393                        ; /* default mode; do nothing */
1394                else if (!strcmp("rebase-cousins", rebase_merges))
1395                        options.rebase_cousins = 1;
1396                else if (strcmp("no-rebase-cousins", rebase_merges))
1397                        die(_("Unknown mode: %s"), rebase_merges);
1398                options.rebase_merges = 1;
1399                imply_interactive(&options, "--rebase-merges");
1400        }
1401
1402        if (strategy_options.nr) {
1403                int i;
1404
1405                if (!options.strategy)
1406                        options.strategy = "recursive";
1407
1408                strbuf_reset(&buf);
1409                for (i = 0; i < strategy_options.nr; i++)
1410                        strbuf_addf(&buf, " --%s",
1411                                    strategy_options.items[i].string);
1412                options.strategy_opts = xstrdup(buf.buf);
1413        }
1414
1415        if (options.strategy) {
1416                options.strategy = xstrdup(options.strategy);
1417                switch (options.type) {
1418                case REBASE_AM:
1419                        die(_("--strategy requires --merge or --interactive"));
1420                case REBASE_MERGE:
1421                case REBASE_INTERACTIVE:
1422                case REBASE_PRESERVE_MERGES:
1423                        /* compatible */
1424                        break;
1425                case REBASE_UNSPECIFIED:
1426                        options.type = REBASE_MERGE;
1427                        break;
1428                default:
1429                        BUG("unhandled rebase type (%d)", options.type);
1430                }
1431        }
1432
1433        if (options.type == REBASE_MERGE)
1434                imply_interactive(&options, "--merge");
1435
1436        if (options.root && !options.onto_name)
1437                imply_interactive(&options, "--root without --onto");
1438
1439        if (isatty(2) && options.flags & REBASE_NO_QUIET)
1440                strbuf_addstr(&options.git_format_patch_opt, " --progress");
1441
1442        switch (options.type) {
1443        case REBASE_MERGE:
1444        case REBASE_INTERACTIVE:
1445        case REBASE_PRESERVE_MERGES:
1446                options.state_dir = merge_dir();
1447                break;
1448        case REBASE_AM:
1449                options.state_dir = apply_dir();
1450                break;
1451        default:
1452                /* the default rebase backend is `--am` */
1453                options.type = REBASE_AM;
1454                options.state_dir = apply_dir();
1455                break;
1456        }
1457
1458        if (options.reschedule_failed_exec && !is_interactive(&options))
1459                die(_("%s requires an interactive rebase"), "--reschedule-failed-exec");
1460
1461        if (options.git_am_opts.argc) {
1462                /* all am options except -q are compatible only with --am */
1463                for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1464                        if (strcmp(options.git_am_opts.argv[i], "-q"))
1465                                break;
1466
1467                if (is_interactive(&options) && i >= 0)
1468                        die(_("cannot combine am options with either "
1469                              "interactive or merge options"));
1470        }
1471
1472        if (options.signoff) {
1473                if (options.type == REBASE_PRESERVE_MERGES)
1474                        die("cannot combine '--signoff' with "
1475                            "'--preserve-merges'");
1476                argv_array_push(&options.git_am_opts, "--signoff");
1477                options.flags |= REBASE_FORCE;
1478        }
1479
1480        if (options.type == REBASE_PRESERVE_MERGES) {
1481                /*
1482                 * Note: incompatibility with --signoff handled in signoff block above
1483                 * Note: incompatibility with --interactive is just a strong warning;
1484                 *       git-rebase.txt caveats with "unless you know what you are doing"
1485                 */
1486                if (options.rebase_merges)
1487                        die(_("cannot combine '--preserve-merges' with "
1488                              "'--rebase-merges'"));
1489
1490                if (options.reschedule_failed_exec)
1491                        die(_("error: cannot combine '--preserve-merges' with "
1492                              "'--reschedule-failed-exec'"));
1493        }
1494
1495        if (options.rebase_merges) {
1496                if (strategy_options.nr)
1497                        die(_("cannot combine '--rebase-merges' with "
1498                              "'--strategy-option'"));
1499                if (options.strategy)
1500                        die(_("cannot combine '--rebase-merges' with "
1501                              "'--strategy'"));
1502        }
1503
1504        if (!options.root) {
1505                if (argc < 1) {
1506                        struct branch *branch;
1507
1508                        branch = branch_get(NULL);
1509                        options.upstream_name = branch_get_upstream(branch,
1510                                                                    NULL);
1511                        if (!options.upstream_name)
1512                                error_on_missing_default_upstream();
1513                        if (fork_point < 0)
1514                                fork_point = 1;
1515                } else {
1516                        options.upstream_name = argv[0];
1517                        argc--;
1518                        argv++;
1519                        if (!strcmp(options.upstream_name, "-"))
1520                                options.upstream_name = "@{-1}";
1521                }
1522                options.upstream = peel_committish(options.upstream_name);
1523                if (!options.upstream)
1524                        die(_("invalid upstream '%s'"), options.upstream_name);
1525                options.upstream_arg = options.upstream_name;
1526        } else {
1527                if (!options.onto_name) {
1528                        if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1529                                        &squash_onto, NULL, NULL) < 0)
1530                                die(_("Could not create new root commit"));
1531                        options.squash_onto = &squash_onto;
1532                        options.onto_name = squash_onto_name =
1533                                xstrdup(oid_to_hex(&squash_onto));
1534                }
1535                options.upstream_name = NULL;
1536                options.upstream = NULL;
1537                if (argc > 1)
1538                        usage_with_options(builtin_rebase_usage,
1539                                           builtin_rebase_options);
1540                options.upstream_arg = "--root";
1541        }
1542
1543        /* Make sure the branch to rebase onto is valid. */
1544        if (!options.onto_name)
1545                options.onto_name = options.upstream_name;
1546        if (strstr(options.onto_name, "...")) {
1547                if (get_oid_mb(options.onto_name, &merge_base) < 0)
1548                        die(_("'%s': need exactly one merge base"),
1549                            options.onto_name);
1550                options.onto = lookup_commit_or_die(&merge_base,
1551                                                    options.onto_name);
1552        } else {
1553                options.onto = peel_committish(options.onto_name);
1554                if (!options.onto)
1555                        die(_("Does not point to a valid commit '%s'"),
1556                                options.onto_name);
1557        }
1558
1559        /*
1560         * If the branch to rebase is given, that is the branch we will rebase
1561         * branch_name -- branch/commit being rebased, or
1562         *                HEAD (already detached)
1563         * orig_head -- commit object name of tip of the branch before rebasing
1564         * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1565         */
1566        if (argc == 1) {
1567                /* Is it "rebase other branchname" or "rebase other commit"? */
1568                branch_name = argv[0];
1569                options.switch_to = argv[0];
1570
1571                /* Is it a local branch? */
1572                strbuf_reset(&buf);
1573                strbuf_addf(&buf, "refs/heads/%s", branch_name);
1574                if (!read_ref(buf.buf, &options.orig_head))
1575                        options.head_name = xstrdup(buf.buf);
1576                /* If not is it a valid ref (branch or commit)? */
1577                else if (!get_oid(branch_name, &options.orig_head))
1578                        options.head_name = NULL;
1579                else
1580                        die(_("fatal: no such branch/commit '%s'"),
1581                            branch_name);
1582        } else if (argc == 0) {
1583                /* Do not need to switch branches, we are already on it. */
1584                options.head_name =
1585                        xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1586                                         &flags));
1587                if (!options.head_name)
1588                        die(_("No such ref: %s"), "HEAD");
1589                if (flags & REF_ISSYMREF) {
1590                        if (!skip_prefix(options.head_name,
1591                                         "refs/heads/", &branch_name))
1592                                branch_name = options.head_name;
1593
1594                } else {
1595                        free(options.head_name);
1596                        options.head_name = NULL;
1597                        branch_name = "HEAD";
1598                }
1599                if (get_oid("HEAD", &options.orig_head))
1600                        die(_("Could not resolve HEAD to a revision"));
1601        } else
1602                BUG("unexpected number of arguments left to parse");
1603
1604        if (fork_point > 0) {
1605                struct commit *head =
1606                        lookup_commit_reference(the_repository,
1607                                                &options.orig_head);
1608                options.restrict_revision =
1609                        get_fork_point(options.upstream_name, head);
1610        }
1611
1612        if (repo_read_index(the_repository) < 0)
1613                die(_("could not read index"));
1614
1615        if (options.autostash) {
1616                struct lock_file lock_file = LOCK_INIT;
1617                int fd;
1618
1619                fd = hold_locked_index(&lock_file, 0);
1620                refresh_cache(REFRESH_QUIET);
1621                if (0 <= fd)
1622                        repo_update_index_if_able(the_repository, &lock_file);
1623                rollback_lock_file(&lock_file);
1624
1625                if (has_unstaged_changes(the_repository, 1) ||
1626                    has_uncommitted_changes(the_repository, 1)) {
1627                        const char *autostash =
1628                                state_dir_path("autostash", &options);
1629                        struct child_process stash = CHILD_PROCESS_INIT;
1630                        struct object_id oid;
1631                        struct commit *head =
1632                                lookup_commit_reference(the_repository,
1633                                                        &options.orig_head);
1634
1635                        argv_array_pushl(&stash.args,
1636                                         "stash", "create", "autostash", NULL);
1637                        stash.git_cmd = 1;
1638                        stash.no_stdin = 1;
1639                        strbuf_reset(&buf);
1640                        if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1641                                die(_("Cannot autostash"));
1642                        strbuf_trim_trailing_newline(&buf);
1643                        if (get_oid(buf.buf, &oid))
1644                                die(_("Unexpected stash response: '%s'"),
1645                                    buf.buf);
1646                        strbuf_reset(&buf);
1647                        strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1648
1649                        if (safe_create_leading_directories_const(autostash))
1650                                die(_("Could not create directory for '%s'"),
1651                                    options.state_dir);
1652                        write_file(autostash, "%s", oid_to_hex(&oid));
1653                        printf(_("Created autostash: %s\n"), buf.buf);
1654                        if (reset_head(&head->object.oid, "reset --hard",
1655                                       NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
1656                                die(_("could not reset --hard"));
1657                        printf(_("HEAD is now at %s"),
1658                               find_unique_abbrev(&head->object.oid,
1659                                                  DEFAULT_ABBREV));
1660                        strbuf_reset(&buf);
1661                        pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
1662                        if (buf.len > 0)
1663                                printf(" %s", buf.buf);
1664                        putchar('\n');
1665
1666                        if (discard_index(the_repository->index) < 0 ||
1667                                repo_read_index(the_repository) < 0)
1668                                die(_("could not read index"));
1669                }
1670        }
1671
1672        if (require_clean_work_tree(the_repository, "rebase",
1673                                    _("Please commit or stash them."), 1, 1)) {
1674                ret = 1;
1675                goto cleanup;
1676        }
1677
1678        /*
1679         * Now we are rebasing commits upstream..orig_head (or with --root,
1680         * everything leading up to orig_head) on top of onto.
1681         */
1682
1683        /*
1684         * Check if we are already based on onto with linear history,
1685         * but this should be done only when upstream and onto are the same
1686         * and if this is not an interactive rebase.
1687         */
1688        if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
1689            !is_interactive(&options) && !options.restrict_revision &&
1690            options.upstream &&
1691            !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
1692                int flag;
1693
1694                if (!(options.flags & REBASE_FORCE)) {
1695                        /* Lazily switch to the target branch if needed... */
1696                        if (options.switch_to) {
1697                                struct object_id oid;
1698
1699                                if (get_oid(options.switch_to, &oid) < 0) {
1700                                        ret = !!error(_("could not parse '%s'"),
1701                                                      options.switch_to);
1702                                        goto cleanup;
1703                                }
1704
1705                                strbuf_reset(&buf);
1706                                strbuf_addf(&buf, "%s: checkout %s",
1707                                            getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
1708                                            options.switch_to);
1709                                if (reset_head(&oid, "checkout",
1710                                               options.head_name,
1711                                               RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
1712                                               NULL, buf.buf) < 0) {
1713                                        ret = !!error(_("could not switch to "
1714                                                        "%s"),
1715                                                      options.switch_to);
1716                                        goto cleanup;
1717                                }
1718                        }
1719
1720                        if (!(options.flags & REBASE_NO_QUIET))
1721                                ; /* be quiet */
1722                        else if (!strcmp(branch_name, "HEAD") &&
1723                                 resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1724                                puts(_("HEAD is up to date."));
1725                        else
1726                                printf(_("Current branch %s is up to date.\n"),
1727                                       branch_name);
1728                        ret = !!finish_rebase(&options);
1729                        goto cleanup;
1730                } else if (!(options.flags & REBASE_NO_QUIET))
1731                        ; /* be quiet */
1732                else if (!strcmp(branch_name, "HEAD") &&
1733                         resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1734                        puts(_("HEAD is up to date, rebase forced."));
1735                else
1736                        printf(_("Current branch %s is up to date, rebase "
1737                                 "forced.\n"), branch_name);
1738        }
1739
1740        /* If a hook exists, give it a chance to interrupt*/
1741        if (!ok_to_skip_pre_rebase &&
1742            run_hook_le(NULL, "pre-rebase", options.upstream_arg,
1743                        argc ? argv[0] : NULL, NULL))
1744                die(_("The pre-rebase hook refused to rebase."));
1745
1746        if (options.flags & REBASE_DIFFSTAT) {
1747                struct diff_options opts;
1748
1749                if (options.flags & REBASE_VERBOSE) {
1750                        if (is_null_oid(&merge_base))
1751                                printf(_("Changes to %s:\n"),
1752                                       oid_to_hex(&options.onto->object.oid));
1753                        else
1754                                printf(_("Changes from %s to %s:\n"),
1755                                       oid_to_hex(&merge_base),
1756                                       oid_to_hex(&options.onto->object.oid));
1757                }
1758
1759                /* We want color (if set), but no pager */
1760                diff_setup(&opts);
1761                opts.stat_width = -1; /* use full terminal width */
1762                opts.stat_graph_width = -1; /* respect statGraphWidth config */
1763                opts.output_format |=
1764                        DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1765                opts.detect_rename = DIFF_DETECT_RENAME;
1766                diff_setup_done(&opts);
1767                diff_tree_oid(is_null_oid(&merge_base) ?
1768                              the_hash_algo->empty_tree : &merge_base,
1769                              &options.onto->object.oid, "", &opts);
1770                diffcore_std(&opts);
1771                diff_flush(&opts);
1772        }
1773
1774        if (is_interactive(&options))
1775                goto run_rebase;
1776
1777        /* Detach HEAD and reset the tree */
1778        if (options.flags & REBASE_NO_QUIET)
1779                printf(_("First, rewinding head to replay your work on top of "
1780                         "it...\n"));
1781
1782        strbuf_addf(&msg, "%s: checkout %s",
1783                    getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
1784        if (reset_head(&options.onto->object.oid, "checkout", NULL,
1785                       RESET_HEAD_DETACH | RESET_ORIG_HEAD | 
1786                       RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
1787                       NULL, msg.buf))
1788                die(_("Could not detach HEAD"));
1789        strbuf_release(&msg);
1790
1791        /*
1792         * If the onto is a proper descendant of the tip of the branch, then
1793         * we just fast-forwarded.
1794         */
1795        strbuf_reset(&msg);
1796        if (!oidcmp(&merge_base, &options.orig_head)) {
1797                printf(_("Fast-forwarded %s to %s.\n"),
1798                        branch_name, options.onto_name);
1799                strbuf_addf(&msg, "rebase finished: %s onto %s",
1800                        options.head_name ? options.head_name : "detached HEAD",
1801                        oid_to_hex(&options.onto->object.oid));
1802                reset_head(NULL, "Fast-forwarded", options.head_name,
1803                           RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
1804                strbuf_release(&msg);
1805                ret = !!finish_rebase(&options);
1806                goto cleanup;
1807        }
1808
1809        strbuf_addf(&revisions, "%s..%s",
1810                    options.root ? oid_to_hex(&options.onto->object.oid) :
1811                    (options.restrict_revision ?
1812                     oid_to_hex(&options.restrict_revision->object.oid) :
1813                     oid_to_hex(&options.upstream->object.oid)),
1814                    oid_to_hex(&options.orig_head));
1815
1816        options.revisions = revisions.buf;
1817
1818run_rebase:
1819        ret = !!run_specific_rebase(&options);
1820
1821cleanup:
1822        strbuf_release(&revisions);
1823        free(options.head_name);
1824        free(options.gpg_sign_opt);
1825        free(options.cmd);
1826        free(squash_onto_name);
1827        return ret;
1828}