600788bf725ff523011e91b4fde1b89c76d94728
   1/*
   2 * "git rebase" builtin command
   3 *
   4 * Copyright (c) 2018 Pratik Karki
   5 */
   6
   7#include "builtin.h"
   8#include "run-command.h"
   9#include "exec-cmd.h"
  10#include "argv-array.h"
  11#include "dir.h"
  12#include "packfile.h"
  13#include "refs.h"
  14#include "quote.h"
  15#include "config.h"
  16#include "cache-tree.h"
  17#include "unpack-trees.h"
  18#include "lockfile.h"
  19#include "parse-options.h"
  20#include "commit.h"
  21#include "diff.h"
  22#include "wt-status.h"
  23#include "revision.h"
  24#include "rerere.h"
  25
  26static char const * const builtin_rebase_usage[] = {
  27        N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  28                "[<upstream>] [<branch>]"),
  29        N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  30                "--root [<branch>]"),
  31        N_("git rebase --continue | --abort | --skip | --edit-todo"),
  32        NULL
  33};
  34
  35static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  36static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  37
  38enum rebase_type {
  39        REBASE_UNSPECIFIED = -1,
  40        REBASE_AM,
  41        REBASE_MERGE,
  42        REBASE_INTERACTIVE,
  43        REBASE_PRESERVE_MERGES
  44};
  45
  46static int use_builtin_rebase(void)
  47{
  48        struct child_process cp = CHILD_PROCESS_INIT;
  49        struct strbuf out = STRBUF_INIT;
  50        int ret;
  51
  52        argv_array_pushl(&cp.args,
  53                         "config", "--bool", "rebase.usebuiltin", NULL);
  54        cp.git_cmd = 1;
  55        if (capture_command(&cp, &out, 6)) {
  56                strbuf_release(&out);
  57                return 0;
  58        }
  59
  60        strbuf_trim(&out);
  61        ret = !strcmp("true", out.buf);
  62        strbuf_release(&out);
  63        return ret;
  64}
  65
  66struct rebase_options {
  67        enum rebase_type type;
  68        const char *state_dir;
  69        struct commit *upstream;
  70        const char *upstream_name;
  71        const char *upstream_arg;
  72        char *head_name;
  73        struct object_id orig_head;
  74        struct commit *onto;
  75        const char *onto_name;
  76        const char *revisions;
  77        const char *switch_to;
  78        int root;
  79        struct object_id *squash_onto;
  80        struct commit *restrict_revision;
  81        int dont_finish_rebase;
  82        enum {
  83                REBASE_NO_QUIET = 1<<0,
  84                REBASE_VERBOSE = 1<<1,
  85                REBASE_DIFFSTAT = 1<<2,
  86                REBASE_FORCE = 1<<3,
  87                REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  88        } flags;
  89        struct strbuf git_am_opt;
  90        const char *action;
  91        int signoff;
  92        int allow_rerere_autoupdate;
  93        int keep_empty;
  94        int autosquash;
  95        char *gpg_sign_opt;
  96        int autostash;
  97        char *cmd;
  98        int allow_empty_message;
  99        int rebase_merges, rebase_cousins;
 100        char *strategy, *strategy_opts;
 101        struct strbuf git_format_patch_opt;
 102};
 103
 104static int is_interactive(struct rebase_options *opts)
 105{
 106        return opts->type == REBASE_INTERACTIVE ||
 107                opts->type == REBASE_PRESERVE_MERGES;
 108}
 109
 110static void imply_interactive(struct rebase_options *opts, const char *option)
 111{
 112        switch (opts->type) {
 113        case REBASE_AM:
 114                die(_("%s requires an interactive rebase"), option);
 115                break;
 116        case REBASE_INTERACTIVE:
 117        case REBASE_PRESERVE_MERGES:
 118                break;
 119        case REBASE_MERGE:
 120                /* we silently *upgrade* --merge to --interactive if needed */
 121        default:
 122                opts->type = REBASE_INTERACTIVE; /* implied */
 123                break;
 124        }
 125}
 126
 127/* Returns the filename prefixed by the state_dir */
 128static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 129{
 130        static struct strbuf path = STRBUF_INIT;
 131        static size_t prefix_len;
 132
 133        if (!prefix_len) {
 134                strbuf_addf(&path, "%s/", opts->state_dir);
 135                prefix_len = path.len;
 136        }
 137
 138        strbuf_setlen(&path, prefix_len);
 139        strbuf_addstr(&path, filename);
 140        return path.buf;
 141}
 142
 143/* Read one file, then strip line endings */
 144static int read_one(const char *path, struct strbuf *buf)
 145{
 146        if (strbuf_read_file(buf, path, 0) < 0)
 147                return error_errno(_("could not read '%s'"), path);
 148        strbuf_trim_trailing_newline(buf);
 149        return 0;
 150}
 151
 152/* Initialize the rebase options from the state directory. */
 153static int read_basic_state(struct rebase_options *opts)
 154{
 155        struct strbuf head_name = STRBUF_INIT;
 156        struct strbuf buf = STRBUF_INIT;
 157        struct object_id oid;
 158
 159        if (read_one(state_dir_path("head-name", opts), &head_name) ||
 160            read_one(state_dir_path("onto", opts), &buf))
 161                return -1;
 162        opts->head_name = starts_with(head_name.buf, "refs/") ?
 163                xstrdup(head_name.buf) : NULL;
 164        strbuf_release(&head_name);
 165        if (get_oid(buf.buf, &oid))
 166                return error(_("could not get 'onto': '%s'"), buf.buf);
 167        opts->onto = lookup_commit_or_die(&oid, buf.buf);
 168
 169        /*
 170         * We always write to orig-head, but interactive rebase used to write to
 171         * head. Fall back to reading from head to cover for the case that the
 172         * user upgraded git with an ongoing interactive rebase.
 173         */
 174        strbuf_reset(&buf);
 175        if (file_exists(state_dir_path("orig-head", opts))) {
 176                if (read_one(state_dir_path("orig-head", opts), &buf))
 177                        return -1;
 178        } else if (read_one(state_dir_path("head", opts), &buf))
 179                return -1;
 180        if (get_oid(buf.buf, &opts->orig_head))
 181                return error(_("invalid orig-head: '%s'"), buf.buf);
 182
 183        strbuf_reset(&buf);
 184        if (read_one(state_dir_path("quiet", opts), &buf))
 185                return -1;
 186        if (buf.len)
 187                opts->flags &= ~REBASE_NO_QUIET;
 188        else
 189                opts->flags |= REBASE_NO_QUIET;
 190
 191        if (file_exists(state_dir_path("verbose", opts)))
 192                opts->flags |= REBASE_VERBOSE;
 193
 194        if (file_exists(state_dir_path("signoff", opts))) {
 195                opts->signoff = 1;
 196                opts->flags |= REBASE_FORCE;
 197        }
 198
 199        if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 200                strbuf_reset(&buf);
 201                if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 202                            &buf))
 203                        return -1;
 204                if (!strcmp(buf.buf, "--rerere-autoupdate"))
 205                        opts->allow_rerere_autoupdate = 1;
 206                else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 207                        opts->allow_rerere_autoupdate = 0;
 208                else
 209                        warning(_("ignoring invalid allow_rerere_autoupdate: "
 210                                  "'%s'"), buf.buf);
 211        } else
 212                opts->allow_rerere_autoupdate = -1;
 213
 214        if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 215                strbuf_reset(&buf);
 216                if (read_one(state_dir_path("gpg_sign_opt", opts),
 217                            &buf))
 218                        return -1;
 219                free(opts->gpg_sign_opt);
 220                opts->gpg_sign_opt = xstrdup(buf.buf);
 221        }
 222
 223        if (file_exists(state_dir_path("strategy", opts))) {
 224                strbuf_reset(&buf);
 225                if (read_one(state_dir_path("strategy", opts), &buf))
 226                        return -1;
 227                free(opts->strategy);
 228                opts->strategy = xstrdup(buf.buf);
 229        }
 230
 231        if (file_exists(state_dir_path("strategy_opts", opts))) {
 232                strbuf_reset(&buf);
 233                if (read_one(state_dir_path("strategy_opts", opts), &buf))
 234                        return -1;
 235                free(opts->strategy_opts);
 236                opts->strategy_opts = xstrdup(buf.buf);
 237        }
 238
 239        strbuf_release(&buf);
 240
 241        return 0;
 242}
 243
 244static int apply_autostash(struct rebase_options *opts)
 245{
 246        const char *path = state_dir_path("autostash", opts);
 247        struct strbuf autostash = STRBUF_INIT;
 248        struct child_process stash_apply = CHILD_PROCESS_INIT;
 249
 250        if (!file_exists(path))
 251                return 0;
 252
 253        if (read_one(state_dir_path("autostash", opts), &autostash))
 254                return error(_("Could not read '%s'"), path);
 255        argv_array_pushl(&stash_apply.args,
 256                         "stash", "apply", autostash.buf, NULL);
 257        stash_apply.git_cmd = 1;
 258        stash_apply.no_stderr = stash_apply.no_stdout =
 259                stash_apply.no_stdin = 1;
 260        if (!run_command(&stash_apply))
 261                printf(_("Applied autostash.\n"));
 262        else {
 263                struct argv_array args = ARGV_ARRAY_INIT;
 264                int res = 0;
 265
 266                argv_array_pushl(&args,
 267                                 "stash", "store", "-m", "autostash", "-q",
 268                                 autostash.buf, NULL);
 269                if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 270                        res = error(_("Cannot store %s"), autostash.buf);
 271                argv_array_clear(&args);
 272                strbuf_release(&autostash);
 273                if (res)
 274                        return res;
 275
 276                fprintf(stderr,
 277                        _("Applying autostash resulted in conflicts.\n"
 278                          "Your changes are safe in the stash.\n"
 279                          "You can run \"git stash pop\" or \"git stash drop\" "
 280                          "at any time.\n"));
 281        }
 282
 283        strbuf_release(&autostash);
 284        return 0;
 285}
 286
 287static int finish_rebase(struct rebase_options *opts)
 288{
 289        struct strbuf dir = STRBUF_INIT;
 290        const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 291
 292        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 293        apply_autostash(opts);
 294        close_all_packs(the_repository->objects);
 295        /*
 296         * We ignore errors in 'gc --auto', since the
 297         * user should see them.
 298         */
 299        run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 300        strbuf_addstr(&dir, opts->state_dir);
 301        remove_dir_recursively(&dir, 0);
 302        strbuf_release(&dir);
 303
 304        return 0;
 305}
 306
 307static struct commit *peel_committish(const char *name)
 308{
 309        struct object *obj;
 310        struct object_id oid;
 311
 312        if (get_oid(name, &oid))
 313                return NULL;
 314        obj = parse_object(the_repository, &oid);
 315        return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 316}
 317
 318static void add_var(struct strbuf *buf, const char *name, const char *value)
 319{
 320        if (!value)
 321                strbuf_addf(buf, "unset %s; ", name);
 322        else {
 323                strbuf_addf(buf, "%s=", name);
 324                sq_quote_buf(buf, value);
 325                strbuf_addstr(buf, "; ");
 326        }
 327}
 328
 329static int run_specific_rebase(struct rebase_options *opts)
 330{
 331        const char *argv[] = { NULL, NULL };
 332        struct strbuf script_snippet = STRBUF_INIT;
 333        int status;
 334        const char *backend, *backend_func;
 335
 336        add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 337        add_var(&script_snippet, "state_dir", opts->state_dir);
 338
 339        add_var(&script_snippet, "upstream_name", opts->upstream_name);
 340        add_var(&script_snippet, "upstream", opts->upstream ?
 341                oid_to_hex(&opts->upstream->object.oid) : NULL);
 342        add_var(&script_snippet, "head_name",
 343                opts->head_name ? opts->head_name : "detached HEAD");
 344        add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 345        add_var(&script_snippet, "onto", opts->onto ?
 346                oid_to_hex(&opts->onto->object.oid) : NULL);
 347        add_var(&script_snippet, "onto_name", opts->onto_name);
 348        add_var(&script_snippet, "revisions", opts->revisions);
 349        add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 350                oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 351        add_var(&script_snippet, "GIT_QUIET",
 352                opts->flags & REBASE_NO_QUIET ? "" : "t");
 353        add_var(&script_snippet, "git_am_opt", opts->git_am_opt.buf);
 354        add_var(&script_snippet, "verbose",
 355                opts->flags & REBASE_VERBOSE ? "t" : "");
 356        add_var(&script_snippet, "diffstat",
 357                opts->flags & REBASE_DIFFSTAT ? "t" : "");
 358        add_var(&script_snippet, "force_rebase",
 359                opts->flags & REBASE_FORCE ? "t" : "");
 360        if (opts->switch_to)
 361                add_var(&script_snippet, "switch_to", opts->switch_to);
 362        add_var(&script_snippet, "action", opts->action ? opts->action : "");
 363        add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
 364        add_var(&script_snippet, "allow_rerere_autoupdate",
 365                opts->allow_rerere_autoupdate < 0 ? "" :
 366                opts->allow_rerere_autoupdate ?
 367                "--rerere-autoupdate" : "--no-rerere-autoupdate");
 368        add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
 369        add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
 370        add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
 371        add_var(&script_snippet, "cmd", opts->cmd);
 372        add_var(&script_snippet, "allow_empty_message",
 373                opts->allow_empty_message ?  "--allow-empty-message" : "");
 374        add_var(&script_snippet, "rebase_merges",
 375                opts->rebase_merges ? "t" : "");
 376        add_var(&script_snippet, "rebase_cousins",
 377                opts->rebase_cousins ? "t" : "");
 378        add_var(&script_snippet, "strategy", opts->strategy);
 379        add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
 380        add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
 381        add_var(&script_snippet, "squash_onto",
 382                opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
 383        add_var(&script_snippet, "git_format_patch_opt",
 384                opts->git_format_patch_opt.buf);
 385
 386        switch (opts->type) {
 387        case REBASE_AM:
 388                backend = "git-rebase--am";
 389                backend_func = "git_rebase__am";
 390                break;
 391        case REBASE_INTERACTIVE:
 392                backend = "git-rebase--interactive";
 393                backend_func = "git_rebase__interactive";
 394                break;
 395        case REBASE_MERGE:
 396                backend = "git-rebase--merge";
 397                backend_func = "git_rebase__merge";
 398                break;
 399        case REBASE_PRESERVE_MERGES:
 400                backend = "git-rebase--preserve-merges";
 401                backend_func = "git_rebase__preserve_merges";
 402                break;
 403        default:
 404                BUG("Unhandled rebase type %d", opts->type);
 405                break;
 406        }
 407
 408        strbuf_addf(&script_snippet,
 409                    ". git-sh-setup && . git-rebase--common &&"
 410                    " . %s && %s", backend, backend_func);
 411        argv[0] = script_snippet.buf;
 412
 413        status = run_command_v_opt(argv, RUN_USING_SHELL);
 414        if (opts->dont_finish_rebase)
 415                ; /* do nothing */
 416        else if (status == 0) {
 417                if (!file_exists(state_dir_path("stopped-sha", opts)))
 418                        finish_rebase(opts);
 419        } else if (status == 2) {
 420                struct strbuf dir = STRBUF_INIT;
 421
 422                apply_autostash(opts);
 423                strbuf_addstr(&dir, opts->state_dir);
 424                remove_dir_recursively(&dir, 0);
 425                strbuf_release(&dir);
 426                die("Nothing to do");
 427        }
 428
 429        strbuf_release(&script_snippet);
 430
 431        return status ? -1 : 0;
 432}
 433
 434#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 435
 436static int reset_head(struct object_id *oid, const char *action,
 437                      const char *switch_to_branch, int detach_head,
 438                      const char *reflog_orig_head, const char *reflog_head)
 439{
 440        struct object_id head_oid;
 441        struct tree_desc desc;
 442        struct lock_file lock = LOCK_INIT;
 443        struct unpack_trees_options unpack_tree_opts;
 444        struct tree *tree;
 445        const char *reflog_action;
 446        struct strbuf msg = STRBUF_INIT;
 447        size_t prefix_len;
 448        struct object_id *orig = NULL, oid_orig,
 449                *old_orig = NULL, oid_old_orig;
 450        int ret = 0;
 451
 452        if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 453                BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 454
 455        if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
 456                return -1;
 457
 458        if (!oid) {
 459                if (get_oid("HEAD", &head_oid)) {
 460                        rollback_lock_file(&lock);
 461                        return error(_("could not determine HEAD revision"));
 462                }
 463                oid = &head_oid;
 464        }
 465
 466        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 467        setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 468        unpack_tree_opts.head_idx = 1;
 469        unpack_tree_opts.src_index = the_repository->index;
 470        unpack_tree_opts.dst_index = the_repository->index;
 471        unpack_tree_opts.fn = oneway_merge;
 472        unpack_tree_opts.update = 1;
 473        unpack_tree_opts.merge = 1;
 474        if (!detach_head)
 475                unpack_tree_opts.reset = 1;
 476
 477        if (read_index_unmerged(the_repository->index) < 0) {
 478                rollback_lock_file(&lock);
 479                return error(_("could not read index"));
 480        }
 481
 482        if (!fill_tree_descriptor(&desc, oid)) {
 483                error(_("failed to find tree of %s"), oid_to_hex(oid));
 484                rollback_lock_file(&lock);
 485                free((void *)desc.buffer);
 486                return -1;
 487        }
 488
 489        if (unpack_trees(1, &desc, &unpack_tree_opts)) {
 490                rollback_lock_file(&lock);
 491                free((void *)desc.buffer);
 492                return -1;
 493        }
 494
 495        tree = parse_tree_indirect(oid);
 496        prime_cache_tree(the_repository->index, tree);
 497
 498        if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
 499                ret = error(_("could not write index"));
 500        free((void *)desc.buffer);
 501
 502        if (ret)
 503                return ret;
 504
 505        reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 506        strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 507        prefix_len = msg.len;
 508
 509        if (!get_oid("ORIG_HEAD", &oid_old_orig))
 510                old_orig = &oid_old_orig;
 511        if (!get_oid("HEAD", &oid_orig)) {
 512                orig = &oid_orig;
 513                if (!reflog_orig_head) {
 514                        strbuf_addstr(&msg, "updating ORIG_HEAD");
 515                        reflog_orig_head = msg.buf;
 516                }
 517                update_ref(reflog_orig_head, "ORIG_HEAD", orig, old_orig, 0,
 518                           UPDATE_REFS_MSG_ON_ERR);
 519        } else if (old_orig)
 520                delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 521        if (!reflog_head) {
 522                strbuf_setlen(&msg, prefix_len);
 523                strbuf_addstr(&msg, "updating HEAD");
 524                reflog_head = msg.buf;
 525        }
 526        if (!switch_to_branch)
 527                ret = update_ref(reflog_head, "HEAD", oid, orig, REF_NO_DEREF,
 528                                 UPDATE_REFS_MSG_ON_ERR);
 529        else {
 530                ret = create_symref("HEAD", switch_to_branch, msg.buf);
 531                if (!ret)
 532                        ret = update_ref(reflog_head, "HEAD", oid, NULL, 0,
 533                                         UPDATE_REFS_MSG_ON_ERR);
 534        }
 535
 536        strbuf_release(&msg);
 537        return ret;
 538}
 539
 540static int rebase_config(const char *var, const char *value, void *data)
 541{
 542        struct rebase_options *opts = data;
 543
 544        if (!strcmp(var, "rebase.stat")) {
 545                if (git_config_bool(var, value))
 546                        opts->flags |= REBASE_DIFFSTAT;
 547                else
 548                        opts->flags &= !REBASE_DIFFSTAT;
 549                return 0;
 550        }
 551
 552        if (!strcmp(var, "rebase.autosquash")) {
 553                opts->autosquash = git_config_bool(var, value);
 554                return 0;
 555        }
 556
 557        if (!strcmp(var, "commit.gpgsign")) {
 558                free(opts->gpg_sign_opt);
 559                opts->gpg_sign_opt = git_config_bool(var, value) ?
 560                        xstrdup("-S") : NULL;
 561                return 0;
 562        }
 563
 564        if (!strcmp(var, "rebase.autostash")) {
 565                opts->autostash = git_config_bool(var, value);
 566                return 0;
 567        }
 568
 569        return git_default_config(var, value, data);
 570}
 571
 572/*
 573 * Determines whether the commits in from..to are linear, i.e. contain
 574 * no merge commits. This function *expects* `from` to be an ancestor of
 575 * `to`.
 576 */
 577static int is_linear_history(struct commit *from, struct commit *to)
 578{
 579        while (to && to != from) {
 580                parse_commit(to);
 581                if (!to->parents)
 582                        return 1;
 583                if (to->parents->next)
 584                        return 0;
 585                to = to->parents->item;
 586        }
 587        return 1;
 588}
 589
 590static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
 591                            struct object_id *merge_base)
 592{
 593        struct commit *head = lookup_commit(the_repository, head_oid);
 594        struct commit_list *merge_bases;
 595        int res;
 596
 597        if (!head)
 598                return 0;
 599
 600        merge_bases = get_merge_bases(onto, head);
 601        if (merge_bases && !merge_bases->next) {
 602                oidcpy(merge_base, &merge_bases->item->object.oid);
 603                res = !oidcmp(merge_base, &onto->object.oid);
 604        } else {
 605                oidcpy(merge_base, &null_oid);
 606                res = 0;
 607        }
 608        free_commit_list(merge_bases);
 609        return res && is_linear_history(onto, head);
 610}
 611
 612/* -i followed by -m is still -i */
 613static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 614{
 615        struct rebase_options *opts = opt->value;
 616
 617        if (!is_interactive(opts))
 618                opts->type = REBASE_MERGE;
 619
 620        return 0;
 621}
 622
 623/* -i followed by -p is still explicitly interactive, but -p alone is not */
 624static int parse_opt_interactive(const struct option *opt, const char *arg,
 625                                 int unset)
 626{
 627        struct rebase_options *opts = opt->value;
 628
 629        opts->type = REBASE_INTERACTIVE;
 630        opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 631
 632        return 0;
 633}
 634
 635static void NORETURN error_on_missing_default_upstream(void)
 636{
 637        struct branch *current_branch = branch_get(NULL);
 638
 639        printf(_("%s\n"
 640                 "Please specify which branch you want to rebase against.\n"
 641                 "See git-rebase(1) for details.\n"
 642                 "\n"
 643                 "    git rebase '<branch>'\n"
 644                 "\n"),
 645                current_branch ? _("There is no tracking information for "
 646                        "the current branch.") :
 647                        _("You are not currently on a branch."));
 648
 649        if (current_branch) {
 650                const char *remote = current_branch->remote_name;
 651
 652                if (!remote)
 653                        remote = _("<remote>");
 654
 655                printf(_("If you wish to set tracking information for this "
 656                         "branch you can do so with:\n"
 657                         "\n"
 658                         "    git branch --set-upstream-to=%s/<branch> %s\n"
 659                         "\n"),
 660                       remote, current_branch->name);
 661        }
 662        exit(1);
 663}
 664
 665int cmd_rebase(int argc, const char **argv, const char *prefix)
 666{
 667        struct rebase_options options = {
 668                .type = REBASE_UNSPECIFIED,
 669                .flags = REBASE_NO_QUIET,
 670                .git_am_opt = STRBUF_INIT,
 671                .allow_rerere_autoupdate  = -1,
 672                .allow_empty_message = 1,
 673                .git_format_patch_opt = STRBUF_INIT,
 674        };
 675        const char *branch_name;
 676        int ret, flags, total_argc, in_progress = 0;
 677        int ok_to_skip_pre_rebase = 0;
 678        struct strbuf msg = STRBUF_INIT;
 679        struct strbuf revisions = STRBUF_INIT;
 680        struct strbuf buf = STRBUF_INIT;
 681        struct object_id merge_base;
 682        enum {
 683                NO_ACTION,
 684                ACTION_CONTINUE,
 685                ACTION_SKIP,
 686                ACTION_ABORT,
 687                ACTION_QUIT,
 688                ACTION_EDIT_TODO,
 689                ACTION_SHOW_CURRENT_PATCH,
 690        } action = NO_ACTION;
 691        int committer_date_is_author_date = 0;
 692        int ignore_date = 0;
 693        int ignore_whitespace = 0;
 694        const char *gpg_sign = NULL;
 695        int opt_c = -1;
 696        struct string_list whitespace = STRING_LIST_INIT_NODUP;
 697        struct string_list exec = STRING_LIST_INIT_NODUP;
 698        const char *rebase_merges = NULL;
 699        int fork_point = -1;
 700        struct string_list strategy_options = STRING_LIST_INIT_NODUP;
 701        struct object_id squash_onto;
 702        char *squash_onto_name = NULL;
 703        struct option builtin_rebase_options[] = {
 704                OPT_STRING(0, "onto", &options.onto_name,
 705                           N_("revision"),
 706                           N_("rebase onto given branch instead of upstream")),
 707                OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
 708                         N_("allow pre-rebase hook to run")),
 709                OPT_NEGBIT('q', "quiet", &options.flags,
 710                           N_("be quiet. implies --no-stat"),
 711                           REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
 712                OPT_BIT('v', "verbose", &options.flags,
 713                        N_("display a diffstat of what changed upstream"),
 714                        REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 715                {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
 716                        N_("do not show diffstat of what changed upstream"),
 717                        PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 718                OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
 719                         N_("passed to 'git apply'")),
 720                OPT_BOOL(0, "signoff", &options.signoff,
 721                         N_("add a Signed-off-by: line to each commit")),
 722                OPT_BOOL(0, "committer-date-is-author-date",
 723                         &committer_date_is_author_date,
 724                         N_("passed to 'git am'")),
 725                OPT_BOOL(0, "ignore-date", &ignore_date,
 726                         N_("passed to 'git am'")),
 727                OPT_BIT('f', "force-rebase", &options.flags,
 728                        N_("cherry-pick all commits, even if unchanged"),
 729                        REBASE_FORCE),
 730                OPT_BIT(0, "no-ff", &options.flags,
 731                        N_("cherry-pick all commits, even if unchanged"),
 732                        REBASE_FORCE),
 733                OPT_CMDMODE(0, "continue", &action, N_("continue"),
 734                            ACTION_CONTINUE),
 735                OPT_CMDMODE(0, "skip", &action,
 736                            N_("skip current patch and continue"), ACTION_SKIP),
 737                OPT_CMDMODE(0, "abort", &action,
 738                            N_("abort and check out the original branch"),
 739                            ACTION_ABORT),
 740                OPT_CMDMODE(0, "quit", &action,
 741                            N_("abort but keep HEAD where it is"), ACTION_QUIT),
 742                OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
 743                            "during an interactive rebase"), ACTION_EDIT_TODO),
 744                OPT_CMDMODE(0, "show-current-patch", &action,
 745                            N_("show the patch file being applied or merged"),
 746                            ACTION_SHOW_CURRENT_PATCH),
 747                { OPTION_CALLBACK, 'm', "merge", &options, NULL,
 748                        N_("use merging strategies to rebase"),
 749                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 750                        parse_opt_merge },
 751                { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
 752                        N_("let the user edit the list of commits to rebase"),
 753                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 754                        parse_opt_interactive },
 755                OPT_SET_INT('p', "preserve-merges", &options.type,
 756                            N_("try to recreate merges instead of ignoring "
 757                               "them"), REBASE_PRESERVE_MERGES),
 758                OPT_BOOL(0, "rerere-autoupdate",
 759                         &options.allow_rerere_autoupdate,
 760                         N_("allow rerere to update index  with resolved "
 761                            "conflict")),
 762                OPT_BOOL('k', "keep-empty", &options.keep_empty,
 763                         N_("preserve empty commits during rebase")),
 764                OPT_BOOL(0, "autosquash", &options.autosquash,
 765                         N_("move commits that begin with "
 766                            "squash!/fixup! under -i")),
 767                { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
 768                        N_("GPG-sign commits"),
 769                        PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 770                OPT_STRING_LIST(0, "whitespace", &whitespace,
 771                                N_("whitespace"), N_("passed to 'git apply'")),
 772                OPT_SET_INT('C', NULL, &opt_c, N_("passed to 'git apply'"),
 773                            REBASE_AM),
 774                OPT_BOOL(0, "autostash", &options.autostash,
 775                         N_("automatically stash/stash pop before and after")),
 776                OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
 777                                N_("add exec lines after each commit of the "
 778                                   "editable list")),
 779                OPT_BOOL(0, "allow-empty-message",
 780                         &options.allow_empty_message,
 781                         N_("allow rebasing commits with empty messages")),
 782                {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
 783                        N_("mode"),
 784                        N_("try to rebase merges instead of skipping them"),
 785                        PARSE_OPT_OPTARG, NULL, (intptr_t)""},
 786                OPT_BOOL(0, "fork-point", &fork_point,
 787                         N_("use 'merge-base --fork-point' to refine upstream")),
 788                OPT_STRING('s', "strategy", &options.strategy,
 789                           N_("strategy"), N_("use the given merge strategy")),
 790                OPT_STRING_LIST('X', "strategy-option", &strategy_options,
 791                                N_("option"),
 792                                N_("pass the argument through to the merge "
 793                                   "strategy")),
 794                OPT_BOOL(0, "root", &options.root,
 795                         N_("rebase all reachable commits up to the root(s)")),
 796                OPT_END(),
 797        };
 798
 799        /*
 800         * NEEDSWORK: Once the builtin rebase has been tested enough
 801         * and git-legacy-rebase.sh is retired to contrib/, this preamble
 802         * can be removed.
 803         */
 804
 805        if (!use_builtin_rebase()) {
 806                const char *path = mkpath("%s/git-legacy-rebase",
 807                                          git_exec_path());
 808
 809                if (sane_execvp(path, (char **)argv) < 0)
 810                        die_errno(_("could not exec %s"), path);
 811                else
 812                        BUG("sane_execvp() returned???");
 813        }
 814
 815        if (argc == 2 && !strcmp(argv[1], "-h"))
 816                usage_with_options(builtin_rebase_usage,
 817                                   builtin_rebase_options);
 818
 819        prefix = setup_git_directory();
 820        trace_repo_setup(prefix);
 821        setup_work_tree();
 822
 823        git_config(rebase_config, &options);
 824
 825        strbuf_reset(&buf);
 826        strbuf_addf(&buf, "%s/applying", apply_dir());
 827        if(file_exists(buf.buf))
 828                die(_("It looks like 'git am' is in progress. Cannot rebase."));
 829
 830        if (is_directory(apply_dir())) {
 831                options.type = REBASE_AM;
 832                options.state_dir = apply_dir();
 833        } else if (is_directory(merge_dir())) {
 834                strbuf_reset(&buf);
 835                strbuf_addf(&buf, "%s/rewritten", merge_dir());
 836                if (is_directory(buf.buf)) {
 837                        options.type = REBASE_PRESERVE_MERGES;
 838                        options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 839                } else {
 840                        strbuf_reset(&buf);
 841                        strbuf_addf(&buf, "%s/interactive", merge_dir());
 842                        if(file_exists(buf.buf)) {
 843                                options.type = REBASE_INTERACTIVE;
 844                                options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 845                        } else
 846                                options.type = REBASE_MERGE;
 847                }
 848                options.state_dir = merge_dir();
 849        }
 850
 851        if (options.type != REBASE_UNSPECIFIED)
 852                in_progress = 1;
 853
 854        total_argc = argc;
 855        argc = parse_options(argc, argv, prefix,
 856                             builtin_rebase_options,
 857                             builtin_rebase_usage, 0);
 858
 859        if (action != NO_ACTION && total_argc != 2) {
 860                usage_with_options(builtin_rebase_usage,
 861                                   builtin_rebase_options);
 862        }
 863
 864        if (argc > 2)
 865                usage_with_options(builtin_rebase_usage,
 866                                   builtin_rebase_options);
 867
 868        if (action != NO_ACTION && !in_progress)
 869                die(_("No rebase in progress?"));
 870
 871        if (action == ACTION_EDIT_TODO && !is_interactive(&options))
 872                die(_("The --edit-todo action can only be used during "
 873                      "interactive rebase."));
 874
 875        switch (action) {
 876        case ACTION_CONTINUE: {
 877                struct object_id head;
 878                struct lock_file lock_file = LOCK_INIT;
 879                int fd;
 880
 881                options.action = "continue";
 882
 883                /* Sanity check */
 884                if (get_oid("HEAD", &head))
 885                        die(_("Cannot read HEAD"));
 886
 887                fd = hold_locked_index(&lock_file, 0);
 888                if (read_index(the_repository->index) < 0)
 889                        die(_("could not read index"));
 890                refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
 891                              NULL);
 892                if (0 <= fd)
 893                        update_index_if_able(the_repository->index,
 894                                             &lock_file);
 895                rollback_lock_file(&lock_file);
 896
 897                if (has_unstaged_changes(1)) {
 898                        puts(_("You must edit all merge conflicts and then\n"
 899                               "mark them as resolved using git add"));
 900                        exit(1);
 901                }
 902                if (read_basic_state(&options))
 903                        exit(1);
 904                goto run_rebase;
 905        }
 906        case ACTION_SKIP: {
 907                struct string_list merge_rr = STRING_LIST_INIT_DUP;
 908
 909                options.action = "skip";
 910
 911                rerere_clear(&merge_rr);
 912                string_list_clear(&merge_rr, 1);
 913
 914                if (reset_head(NULL, "reset", NULL, 0, NULL, NULL) < 0)
 915                        die(_("could not discard worktree changes"));
 916                if (read_basic_state(&options))
 917                        exit(1);
 918                goto run_rebase;
 919        }
 920        case ACTION_ABORT: {
 921                struct string_list merge_rr = STRING_LIST_INIT_DUP;
 922                options.action = "abort";
 923
 924                rerere_clear(&merge_rr);
 925                string_list_clear(&merge_rr, 1);
 926
 927                if (read_basic_state(&options))
 928                        exit(1);
 929                if (reset_head(&options.orig_head, "reset",
 930                               options.head_name, 0, NULL, NULL) < 0)
 931                        die(_("could not move back to %s"),
 932                            oid_to_hex(&options.orig_head));
 933                ret = finish_rebase(&options);
 934                goto cleanup;
 935        }
 936        case ACTION_QUIT: {
 937                strbuf_reset(&buf);
 938                strbuf_addstr(&buf, options.state_dir);
 939                ret = !!remove_dir_recursively(&buf, 0);
 940                if (ret)
 941                        die(_("could not remove '%s'"), options.state_dir);
 942                goto cleanup;
 943        }
 944        case ACTION_EDIT_TODO:
 945                options.action = "edit-todo";
 946                options.dont_finish_rebase = 1;
 947                goto run_rebase;
 948        case ACTION_SHOW_CURRENT_PATCH:
 949                options.action = "show-current-patch";
 950                options.dont_finish_rebase = 1;
 951                goto run_rebase;
 952        case NO_ACTION:
 953                break;
 954        default:
 955                BUG("action: %d", action);
 956        }
 957
 958        /* Make sure no rebase is in progress */
 959        if (in_progress) {
 960                const char *last_slash = strrchr(options.state_dir, '/');
 961                const char *state_dir_base =
 962                        last_slash ? last_slash + 1 : options.state_dir;
 963                const char *cmd_live_rebase =
 964                        "git rebase (--continue | --abort | --skip)";
 965                strbuf_reset(&buf);
 966                strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
 967                die(_("It seems that there is already a %s directory, and\n"
 968                      "I wonder if you are in the middle of another rebase.  "
 969                      "If that is the\n"
 970                      "case, please try\n\t%s\n"
 971                      "If that is not the case, please\n\t%s\n"
 972                      "and run me again.  I am stopping in case you still "
 973                      "have something\n"
 974                      "valuable there.\n"),
 975                    state_dir_base, cmd_live_rebase, buf.buf);
 976        }
 977
 978        if (!(options.flags & REBASE_NO_QUIET))
 979                strbuf_addstr(&options.git_am_opt, " -q");
 980
 981        if (committer_date_is_author_date) {
 982                strbuf_addstr(&options.git_am_opt,
 983                              " --committer-date-is-author-date");
 984                options.flags |= REBASE_FORCE;
 985        }
 986
 987        if (ignore_whitespace)
 988                strbuf_addstr(&options.git_am_opt, " --ignore-whitespace");
 989
 990        if (ignore_date) {
 991                strbuf_addstr(&options.git_am_opt, " --ignore-date");
 992                options.flags |= REBASE_FORCE;
 993        }
 994
 995        if (options.keep_empty)
 996                imply_interactive(&options, "--keep-empty");
 997
 998        if (gpg_sign) {
 999                free(options.gpg_sign_opt);
1000                options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1001        }
1002
1003        if (opt_c >= 0)
1004                strbuf_addf(&options.git_am_opt, " -C%d", opt_c);
1005
1006        if (whitespace.nr) {
1007                int i;
1008
1009                for (i = 0; i < whitespace.nr; i++) {
1010                        const char *item = whitespace.items[i].string;
1011
1012                        strbuf_addf(&options.git_am_opt, " --whitespace=%s",
1013                                    item);
1014
1015                        if ((!strcmp(item, "fix")) || (!strcmp(item, "strip")))
1016                                options.flags |= REBASE_FORCE;
1017                }
1018        }
1019
1020        if (exec.nr) {
1021                int i;
1022
1023                imply_interactive(&options, "--exec");
1024
1025                strbuf_reset(&buf);
1026                for (i = 0; i < exec.nr; i++)
1027                        strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1028                options.cmd = xstrdup(buf.buf);
1029        }
1030
1031        if (rebase_merges) {
1032                if (!*rebase_merges)
1033                        ; /* default mode; do nothing */
1034                else if (!strcmp("rebase-cousins", rebase_merges))
1035                        options.rebase_cousins = 1;
1036                else if (strcmp("no-rebase-cousins", rebase_merges))
1037                        die(_("Unknown mode: %s"), rebase_merges);
1038                options.rebase_merges = 1;
1039                imply_interactive(&options, "--rebase-merges");
1040        }
1041
1042        if (strategy_options.nr) {
1043                int i;
1044
1045                if (!options.strategy)
1046                        options.strategy = "recursive";
1047
1048                strbuf_reset(&buf);
1049                for (i = 0; i < strategy_options.nr; i++)
1050                        strbuf_addf(&buf, " --%s",
1051                                    strategy_options.items[i].string);
1052                options.strategy_opts = xstrdup(buf.buf);
1053        }
1054
1055        if (options.strategy) {
1056                options.strategy = xstrdup(options.strategy);
1057                switch (options.type) {
1058                case REBASE_AM:
1059                        die(_("--strategy requires --merge or --interactive"));
1060                case REBASE_MERGE:
1061                case REBASE_INTERACTIVE:
1062                case REBASE_PRESERVE_MERGES:
1063                        /* compatible */
1064                        break;
1065                case REBASE_UNSPECIFIED:
1066                        options.type = REBASE_MERGE;
1067                        break;
1068                default:
1069                        BUG("unhandled rebase type (%d)", options.type);
1070                }
1071        }
1072
1073        if (options.root && !options.onto_name)
1074                imply_interactive(&options, "--root without --onto");
1075
1076        if (isatty(2) && options.flags & REBASE_NO_QUIET)
1077                strbuf_addstr(&options.git_format_patch_opt, " --progress");
1078
1079        switch (options.type) {
1080        case REBASE_MERGE:
1081        case REBASE_INTERACTIVE:
1082        case REBASE_PRESERVE_MERGES:
1083                options.state_dir = merge_dir();
1084                break;
1085        case REBASE_AM:
1086                options.state_dir = apply_dir();
1087                break;
1088        default:
1089                /* the default rebase backend is `--am` */
1090                options.type = REBASE_AM;
1091                options.state_dir = apply_dir();
1092                break;
1093        }
1094
1095        if (options.signoff) {
1096                if (options.type == REBASE_PRESERVE_MERGES)
1097                        die("cannot combine '--signoff' with "
1098                            "'--preserve-merges'");
1099                strbuf_addstr(&options.git_am_opt, " --signoff");
1100                options.flags |= REBASE_FORCE;
1101        }
1102
1103        if (!options.root) {
1104                if (argc < 1) {
1105                        struct branch *branch;
1106
1107                        branch = branch_get(NULL);
1108                        options.upstream_name = branch_get_upstream(branch,
1109                                                                    NULL);
1110                        if (!options.upstream_name)
1111                                error_on_missing_default_upstream();
1112                        if (fork_point < 0)
1113                                fork_point = 1;
1114                } else {
1115                        options.upstream_name = argv[0];
1116                        argc--;
1117                        argv++;
1118                        if (!strcmp(options.upstream_name, "-"))
1119                                options.upstream_name = "@{-1}";
1120                }
1121                options.upstream = peel_committish(options.upstream_name);
1122                if (!options.upstream)
1123                        die(_("invalid upstream '%s'"), options.upstream_name);
1124                options.upstream_arg = options.upstream_name;
1125        } else {
1126                if (!options.onto_name) {
1127                        if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1128                                        &squash_onto, NULL, NULL) < 0)
1129                                die(_("Could not create new root commit"));
1130                        options.squash_onto = &squash_onto;
1131                        options.onto_name = squash_onto_name =
1132                                xstrdup(oid_to_hex(&squash_onto));
1133                }
1134                options.upstream_name = NULL;
1135                options.upstream = NULL;
1136                if (argc > 1)
1137                        usage_with_options(builtin_rebase_usage,
1138                                           builtin_rebase_options);
1139                options.upstream_arg = "--root";
1140        }
1141
1142        /* Make sure the branch to rebase onto is valid. */
1143        if (!options.onto_name)
1144                options.onto_name = options.upstream_name;
1145        if (strstr(options.onto_name, "...")) {
1146                if (get_oid_mb(options.onto_name, &merge_base) < 0)
1147                        die(_("'%s': need exactly one merge base"),
1148                            options.onto_name);
1149                options.onto = lookup_commit_or_die(&merge_base,
1150                                                    options.onto_name);
1151        } else {
1152                options.onto = peel_committish(options.onto_name);
1153                if (!options.onto)
1154                        die(_("Does not point to a valid commit '%s'"),
1155                                options.onto_name);
1156        }
1157
1158        /*
1159         * If the branch to rebase is given, that is the branch we will rebase
1160         * branch_name -- branch/commit being rebased, or
1161         *                HEAD (already detached)
1162         * orig_head -- commit object name of tip of the branch before rebasing
1163         * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1164         */
1165        if (argc == 1) {
1166                /* Is it "rebase other branchname" or "rebase other commit"? */
1167                branch_name = argv[0];
1168                options.switch_to = argv[0];
1169
1170                /* Is it a local branch? */
1171                strbuf_reset(&buf);
1172                strbuf_addf(&buf, "refs/heads/%s", branch_name);
1173                if (!read_ref(buf.buf, &options.orig_head))
1174                        options.head_name = xstrdup(buf.buf);
1175                /* If not is it a valid ref (branch or commit)? */
1176                else if (!get_oid(branch_name, &options.orig_head))
1177                        options.head_name = NULL;
1178                else
1179                        die(_("fatal: no such branch/commit '%s'"),
1180                            branch_name);
1181        } else if (argc == 0) {
1182                /* Do not need to switch branches, we are already on it. */
1183                options.head_name =
1184                        xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1185                                         &flags));
1186                if (!options.head_name)
1187                        die(_("No such ref: %s"), "HEAD");
1188                if (flags & REF_ISSYMREF) {
1189                        if (!skip_prefix(options.head_name,
1190                                         "refs/heads/", &branch_name))
1191                                branch_name = options.head_name;
1192
1193                } else {
1194                        free(options.head_name);
1195                        options.head_name = NULL;
1196                        branch_name = "HEAD";
1197                }
1198                if (get_oid("HEAD", &options.orig_head))
1199                        die(_("Could not resolve HEAD to a revision"));
1200        } else
1201                BUG("unexpected number of arguments left to parse");
1202
1203        if (fork_point > 0) {
1204                struct commit *head =
1205                        lookup_commit_reference(the_repository,
1206                                                &options.orig_head);
1207                options.restrict_revision =
1208                        get_fork_point(options.upstream_name, head);
1209        }
1210
1211        if (read_index(the_repository->index) < 0)
1212                die(_("could not read index"));
1213
1214        if (options.autostash) {
1215                struct lock_file lock_file = LOCK_INIT;
1216                int fd;
1217
1218                fd = hold_locked_index(&lock_file, 0);
1219                refresh_cache(REFRESH_QUIET);
1220                if (0 <= fd)
1221                        update_index_if_able(&the_index, &lock_file);
1222                rollback_lock_file(&lock_file);
1223
1224                if (has_unstaged_changes(0) || has_uncommitted_changes(0)) {
1225                        const char *autostash =
1226                                state_dir_path("autostash", &options);
1227                        struct child_process stash = CHILD_PROCESS_INIT;
1228                        struct object_id oid;
1229                        struct commit *head =
1230                                lookup_commit_reference(the_repository,
1231                                                        &options.orig_head);
1232
1233                        argv_array_pushl(&stash.args,
1234                                         "stash", "create", "autostash", NULL);
1235                        stash.git_cmd = 1;
1236                        stash.no_stdin = 1;
1237                        strbuf_reset(&buf);
1238                        if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1239                                die(_("Cannot autostash"));
1240                        strbuf_trim_trailing_newline(&buf);
1241                        if (get_oid(buf.buf, &oid))
1242                                die(_("Unexpected stash response: '%s'"),
1243                                    buf.buf);
1244                        strbuf_reset(&buf);
1245                        strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1246
1247                        if (safe_create_leading_directories_const(autostash))
1248                                die(_("Could not create directory for '%s'"),
1249                                    options.state_dir);
1250                        write_file(autostash, "%s", buf.buf);
1251                        printf(_("Created autostash: %s\n"), buf.buf);
1252                        if (reset_head(&head->object.oid, "reset --hard",
1253                                       NULL, 0, NULL, NULL) < 0)
1254                                die(_("could not reset --hard"));
1255                        printf(_("HEAD is now at %s"),
1256                               find_unique_abbrev(&head->object.oid,
1257                                                  DEFAULT_ABBREV));
1258                        strbuf_reset(&buf);
1259                        pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
1260                        if (buf.len > 0)
1261                                printf(" %s", buf.buf);
1262                        putchar('\n');
1263
1264                        if (discard_index(the_repository->index) < 0 ||
1265                                read_index(the_repository->index) < 0)
1266                                die(_("could not read index"));
1267                }
1268        }
1269
1270        if (require_clean_work_tree("rebase",
1271                                    _("Please commit or stash them."), 1, 1)) {
1272                ret = 1;
1273                goto cleanup;
1274        }
1275
1276        /*
1277         * Now we are rebasing commits upstream..orig_head (or with --root,
1278         * everything leading up to orig_head) on top of onto.
1279         */
1280
1281        /*
1282         * Check if we are already based on onto with linear history,
1283         * but this should be done only when upstream and onto are the same
1284         * and if this is not an interactive rebase.
1285         */
1286        if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
1287            !is_interactive(&options) && !options.restrict_revision &&
1288            options.upstream &&
1289            !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
1290                int flag;
1291
1292                if (!(options.flags & REBASE_FORCE)) {
1293                        /* Lazily switch to the target branch if needed... */
1294                        if (options.switch_to) {
1295                                struct object_id oid;
1296
1297                                if (get_oid(options.switch_to, &oid) < 0) {
1298                                        ret = !!error(_("could not parse '%s'"),
1299                                                      options.switch_to);
1300                                        goto cleanup;
1301                                }
1302
1303                                strbuf_reset(&buf);
1304                                strbuf_addf(&buf, "rebase: checkout %s",
1305                                            options.switch_to);
1306                                if (reset_head(&oid, "checkout",
1307                                               options.head_name, 0,
1308                                               NULL, NULL) < 0) {
1309                                        ret = !!error(_("could not switch to "
1310                                                        "%s"),
1311                                                      options.switch_to);
1312                                        goto cleanup;
1313                                }
1314                        }
1315
1316                        if (!(options.flags & REBASE_NO_QUIET))
1317                                ; /* be quiet */
1318                        else if (!strcmp(branch_name, "HEAD") &&
1319                                 resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1320                                puts(_("HEAD is up to date."));
1321                        else
1322                                printf(_("Current branch %s is up to date.\n"),
1323                                       branch_name);
1324                        ret = !!finish_rebase(&options);
1325                        goto cleanup;
1326                } else if (!(options.flags & REBASE_NO_QUIET))
1327                        ; /* be quiet */
1328                else if (!strcmp(branch_name, "HEAD") &&
1329                         resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1330                        puts(_("HEAD is up to date, rebase forced."));
1331                else
1332                        printf(_("Current branch %s is up to date, rebase "
1333                                 "forced.\n"), branch_name);
1334        }
1335
1336        /* If a hook exists, give it a chance to interrupt*/
1337        if (!ok_to_skip_pre_rebase &&
1338            run_hook_le(NULL, "pre-rebase", options.upstream_arg,
1339                        argc ? argv[0] : NULL, NULL))
1340                die(_("The pre-rebase hook refused to rebase."));
1341
1342        if (options.flags & REBASE_DIFFSTAT) {
1343                struct diff_options opts;
1344
1345                if (options.flags & REBASE_VERBOSE)
1346                        printf(_("Changes from %s to %s:\n"),
1347                                oid_to_hex(&merge_base),
1348                                oid_to_hex(&options.onto->object.oid));
1349
1350                /* We want color (if set), but no pager */
1351                diff_setup(&opts);
1352                opts.stat_width = -1; /* use full terminal width */
1353                opts.stat_graph_width = -1; /* respect statGraphWidth config */
1354                opts.output_format |=
1355                        DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1356                opts.detect_rename = DIFF_DETECT_RENAME;
1357                diff_setup_done(&opts);
1358                diff_tree_oid(&merge_base, &options.onto->object.oid,
1359                              "", &opts);
1360                diffcore_std(&opts);
1361                diff_flush(&opts);
1362        }
1363
1364        if (is_interactive(&options))
1365                goto run_rebase;
1366
1367        /* Detach HEAD and reset the tree */
1368        if (options.flags & REBASE_NO_QUIET)
1369                printf(_("First, rewinding head to replay your work on top of "
1370                         "it...\n"));
1371
1372        strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
1373        if (reset_head(&options.onto->object.oid, "checkout", NULL, 1,
1374            NULL, msg.buf))
1375                die(_("Could not detach HEAD"));
1376        strbuf_release(&msg);
1377
1378        /*
1379         * If the onto is a proper descendant of the tip of the branch, then
1380         * we just fast-forwarded.
1381         */
1382        strbuf_reset(&msg);
1383        if (!oidcmp(&merge_base, &options.orig_head)) {
1384                printf(_("Fast-forwarded %s to %s. \n"),
1385                        branch_name, options.onto_name);
1386                strbuf_addf(&msg, "rebase finished: %s onto %s",
1387                        options.head_name ? options.head_name : "detached HEAD",
1388                        oid_to_hex(&options.onto->object.oid));
1389                reset_head(NULL, "Fast-forwarded", options.head_name, 0,
1390                           "HEAD", msg.buf);
1391                strbuf_release(&msg);
1392                ret = !!finish_rebase(&options);
1393                goto cleanup;
1394        }
1395
1396        strbuf_addf(&revisions, "%s..%s",
1397                    options.root ? oid_to_hex(&options.onto->object.oid) :
1398                    (options.restrict_revision ?
1399                     oid_to_hex(&options.restrict_revision->object.oid) :
1400                     oid_to_hex(&options.upstream->object.oid)),
1401                    oid_to_hex(&options.orig_head));
1402
1403        options.revisions = revisions.buf;
1404
1405run_rebase:
1406        ret = !!run_specific_rebase(&options);
1407
1408cleanup:
1409        strbuf_release(&revisions);
1410        free(options.head_name);
1411        free(options.gpg_sign_opt);
1412        free(options.cmd);
1413        free(squash_onto_name);
1414        return ret;
1415}