Andrew's git / gitweb.git / builtin/rebase.c
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builtin / rebase.con commit builtin rebase: support --abort (5e5d961)
   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
  66static int apply_autostash(void)
  67{
  68        warning("TODO");
  69        return 0;
  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 commit *restrict_revision;
  86        int dont_finish_rebase;
  87        enum {
  88                REBASE_NO_QUIET = 1<<0,
  89                REBASE_VERBOSE = 1<<1,
  90                REBASE_DIFFSTAT = 1<<2,
  91                REBASE_FORCE = 1<<3,
  92                REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  93        } flags;
  94        struct strbuf git_am_opt;
  95        const char *action;
  96};
  97
  98static int is_interactive(struct rebase_options *opts)
  99{
 100        return opts->type == REBASE_INTERACTIVE ||
 101                opts->type == REBASE_PRESERVE_MERGES;
 102}
 103
 104/* Returns the filename prefixed by the state_dir */
 105static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 106{
 107        static struct strbuf path = STRBUF_INIT;
 108        static size_t prefix_len;
 109
 110        if (!prefix_len) {
 111                strbuf_addf(&path, "%s/", opts->state_dir);
 112                prefix_len = path.len;
 113        }
 114
 115        strbuf_setlen(&path, prefix_len);
 116        strbuf_addstr(&path, filename);
 117        return path.buf;
 118}
 119
 120/* Read one file, then strip line endings */
 121static int read_one(const char *path, struct strbuf *buf)
 122{
 123        if (strbuf_read_file(buf, path, 0) < 0)
 124                return error_errno(_("could not read '%s'"), path);
 125        strbuf_trim_trailing_newline(buf);
 126        return 0;
 127}
 128
 129/* Initialize the rebase options from the state directory. */
 130static int read_basic_state(struct rebase_options *opts)
 131{
 132        struct strbuf head_name = STRBUF_INIT;
 133        struct strbuf buf = STRBUF_INIT;
 134        struct object_id oid;
 135
 136        if (read_one(state_dir_path("head-name", opts), &head_name) ||
 137            read_one(state_dir_path("onto", opts), &buf))
 138                return -1;
 139        opts->head_name = starts_with(head_name.buf, "refs/") ?
 140                xstrdup(head_name.buf) : NULL;
 141        strbuf_release(&head_name);
 142        if (get_oid(buf.buf, &oid))
 143                return error(_("could not get 'onto': '%s'"), buf.buf);
 144        opts->onto = lookup_commit_or_die(&oid, buf.buf);
 145
 146        /*
 147         * We always write to orig-head, but interactive rebase used to write to
 148         * head. Fall back to reading from head to cover for the case that the
 149         * user upgraded git with an ongoing interactive rebase.
 150         */
 151        strbuf_reset(&buf);
 152        if (file_exists(state_dir_path("orig-head", opts))) {
 153                if (read_one(state_dir_path("orig-head", opts), &buf))
 154                        return -1;
 155        } else if (read_one(state_dir_path("head", opts), &buf))
 156                return -1;
 157        if (get_oid(buf.buf, &opts->orig_head))
 158                return error(_("invalid orig-head: '%s'"), buf.buf);
 159
 160        strbuf_reset(&buf);
 161        if (read_one(state_dir_path("quiet", opts), &buf))
 162                return -1;
 163        if (buf.len)
 164                opts->flags &= ~REBASE_NO_QUIET;
 165        else
 166                opts->flags |= REBASE_NO_QUIET;
 167
 168        if (file_exists(state_dir_path("verbose", opts)))
 169                opts->flags |= REBASE_VERBOSE;
 170
 171        strbuf_release(&buf);
 172
 173        return 0;
 174}
 175
 176static int finish_rebase(struct rebase_options *opts)
 177{
 178        struct strbuf dir = STRBUF_INIT;
 179        const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 180
 181        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 182        apply_autostash();
 183        close_all_packs(the_repository->objects);
 184        /*
 185         * We ignore errors in 'gc --auto', since the
 186         * user should see them.
 187         */
 188        run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 189        strbuf_addstr(&dir, opts->state_dir);
 190        remove_dir_recursively(&dir, 0);
 191        strbuf_release(&dir);
 192
 193        return 0;
 194}
 195
 196static struct commit *peel_committish(const char *name)
 197{
 198        struct object *obj;
 199        struct object_id oid;
 200
 201        if (get_oid(name, &oid))
 202                return NULL;
 203        obj = parse_object(the_repository, &oid);
 204        return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 205}
 206
 207static void add_var(struct strbuf *buf, const char *name, const char *value)
 208{
 209        if (!value)
 210                strbuf_addf(buf, "unset %s; ", name);
 211        else {
 212                strbuf_addf(buf, "%s=", name);
 213                sq_quote_buf(buf, value);
 214                strbuf_addstr(buf, "; ");
 215        }
 216}
 217
 218static int run_specific_rebase(struct rebase_options *opts)
 219{
 220        const char *argv[] = { NULL, NULL };
 221        struct strbuf script_snippet = STRBUF_INIT;
 222        int status;
 223        const char *backend, *backend_func;
 224
 225        add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 226        add_var(&script_snippet, "state_dir", opts->state_dir);
 227
 228        add_var(&script_snippet, "upstream_name", opts->upstream_name);
 229        add_var(&script_snippet, "upstream", opts->upstream ?
 230                oid_to_hex(&opts->upstream->object.oid) : NULL);
 231        add_var(&script_snippet, "head_name",
 232                opts->head_name ? opts->head_name : "detached HEAD");
 233        add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 234        add_var(&script_snippet, "onto", opts->onto ?
 235                oid_to_hex(&opts->onto->object.oid) : NULL);
 236        add_var(&script_snippet, "onto_name", opts->onto_name);
 237        add_var(&script_snippet, "revisions", opts->revisions);
 238        add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 239                oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 240        add_var(&script_snippet, "GIT_QUIET",
 241                opts->flags & REBASE_NO_QUIET ? "" : "t");
 242        add_var(&script_snippet, "git_am_opt", opts->git_am_opt.buf);
 243        add_var(&script_snippet, "verbose",
 244                opts->flags & REBASE_VERBOSE ? "t" : "");
 245        add_var(&script_snippet, "diffstat",
 246                opts->flags & REBASE_DIFFSTAT ? "t" : "");
 247        add_var(&script_snippet, "force_rebase",
 248                opts->flags & REBASE_FORCE ? "t" : "");
 249        if (opts->switch_to)
 250                add_var(&script_snippet, "switch_to", opts->switch_to);
 251        add_var(&script_snippet, "action", opts->action ? opts->action : "");
 252
 253        switch (opts->type) {
 254        case REBASE_AM:
 255                backend = "git-rebase--am";
 256                backend_func = "git_rebase__am";
 257                break;
 258        case REBASE_INTERACTIVE:
 259                backend = "git-rebase--interactive";
 260                backend_func = "git_rebase__interactive";
 261                break;
 262        case REBASE_MERGE:
 263                backend = "git-rebase--merge";
 264                backend_func = "git_rebase__merge";
 265                break;
 266        case REBASE_PRESERVE_MERGES:
 267                backend = "git-rebase--preserve-merges";
 268                backend_func = "git_rebase__preserve_merges";
 269                break;
 270        default:
 271                BUG("Unhandled rebase type %d", opts->type);
 272                break;
 273        }
 274
 275        strbuf_addf(&script_snippet,
 276                    ". git-sh-setup && . git-rebase--common &&"
 277                    " . %s && %s", backend, backend_func);
 278        argv[0] = script_snippet.buf;
 279
 280        status = run_command_v_opt(argv, RUN_USING_SHELL);
 281        if (opts->dont_finish_rebase)
 282                ; /* do nothing */
 283        else if (status == 0) {
 284                if (!file_exists(state_dir_path("stopped-sha", opts)))
 285                        finish_rebase(opts);
 286        } else if (status == 2) {
 287                struct strbuf dir = STRBUF_INIT;
 288
 289                apply_autostash();
 290                strbuf_addstr(&dir, opts->state_dir);
 291                remove_dir_recursively(&dir, 0);
 292                strbuf_release(&dir);
 293                die("Nothing to do");
 294        }
 295
 296        strbuf_release(&script_snippet);
 297
 298        return status ? -1 : 0;
 299}
 300
 301#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 302
 303static int reset_head(struct object_id *oid, const char *action,
 304                      const char *switch_to_branch, int detach_head)
 305{
 306        struct object_id head_oid;
 307        struct tree_desc desc;
 308        struct lock_file lock = LOCK_INIT;
 309        struct unpack_trees_options unpack_tree_opts;
 310        struct tree *tree;
 311        const char *reflog_action;
 312        struct strbuf msg = STRBUF_INIT;
 313        size_t prefix_len;
 314        struct object_id *orig = NULL, oid_orig,
 315                *old_orig = NULL, oid_old_orig;
 316        int ret = 0;
 317
 318        if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 319                BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 320
 321        if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
 322                return -1;
 323
 324        if (!oid) {
 325                if (get_oid("HEAD", &head_oid)) {
 326                        rollback_lock_file(&lock);
 327                        return error(_("could not determine HEAD revision"));
 328                }
 329                oid = &head_oid;
 330        }
 331
 332        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 333        setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 334        unpack_tree_opts.head_idx = 1;
 335        unpack_tree_opts.src_index = the_repository->index;
 336        unpack_tree_opts.dst_index = the_repository->index;
 337        unpack_tree_opts.fn = oneway_merge;
 338        unpack_tree_opts.update = 1;
 339        unpack_tree_opts.merge = 1;
 340        if (!detach_head)
 341                unpack_tree_opts.reset = 1;
 342
 343        if (read_index_unmerged(the_repository->index) < 0) {
 344                rollback_lock_file(&lock);
 345                return error(_("could not read index"));
 346        }
 347
 348        if (!fill_tree_descriptor(&desc, oid)) {
 349                error(_("failed to find tree of %s"), oid_to_hex(oid));
 350                rollback_lock_file(&lock);
 351                free((void *)desc.buffer);
 352                return -1;
 353        }
 354
 355        if (unpack_trees(1, &desc, &unpack_tree_opts)) {
 356                rollback_lock_file(&lock);
 357                free((void *)desc.buffer);
 358                return -1;
 359        }
 360
 361        tree = parse_tree_indirect(oid);
 362        prime_cache_tree(the_repository->index, tree);
 363
 364        if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
 365                ret = error(_("could not write index"));
 366        free((void *)desc.buffer);
 367
 368        if (ret)
 369                return ret;
 370
 371        reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 372        strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 373        prefix_len = msg.len;
 374
 375        if (!get_oid("ORIG_HEAD", &oid_old_orig))
 376                old_orig = &oid_old_orig;
 377        if (!get_oid("HEAD", &oid_orig)) {
 378                orig = &oid_orig;
 379                strbuf_addstr(&msg, "updating ORIG_HEAD");
 380                update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 381                           UPDATE_REFS_MSG_ON_ERR);
 382        } else if (old_orig)
 383                delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 384        strbuf_setlen(&msg, prefix_len);
 385        strbuf_addstr(&msg, "updating HEAD");
 386        if (!switch_to_branch)
 387                ret = update_ref(msg.buf, "HEAD", oid, orig, REF_NO_DEREF,
 388                                 UPDATE_REFS_MSG_ON_ERR);
 389        else {
 390                ret = create_symref("HEAD", switch_to_branch, msg.buf);
 391                if (!ret)
 392                        ret = update_ref(msg.buf, "HEAD", oid, NULL, 0,
 393                                         UPDATE_REFS_MSG_ON_ERR);
 394        }
 395
 396        strbuf_release(&msg);
 397        return ret;
 398}
 399
 400static int rebase_config(const char *var, const char *value, void *data)
 401{
 402        struct rebase_options *opts = data;
 403
 404        if (!strcmp(var, "rebase.stat")) {
 405                if (git_config_bool(var, value))
 406                        opts->flags |= REBASE_DIFFSTAT;
 407                else
 408                        opts->flags &= !REBASE_DIFFSTAT;
 409                return 0;
 410        }
 411
 412        return git_default_config(var, value, data);
 413}
 414
 415/*
 416 * Determines whether the commits in from..to are linear, i.e. contain
 417 * no merge commits. This function *expects* `from` to be an ancestor of
 418 * `to`.
 419 */
 420static int is_linear_history(struct commit *from, struct commit *to)
 421{
 422        while (to && to != from) {
 423                parse_commit(to);
 424                if (!to->parents)
 425                        return 1;
 426                if (to->parents->next)
 427                        return 0;
 428                to = to->parents->item;
 429        }
 430        return 1;
 431}
 432
 433static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
 434                            struct object_id *merge_base)
 435{
 436        struct commit *head = lookup_commit(the_repository, head_oid);
 437        struct commit_list *merge_bases;
 438        int res;
 439
 440        if (!head)
 441                return 0;
 442
 443        merge_bases = get_merge_bases(onto, head);
 444        if (merge_bases && !merge_bases->next) {
 445                oidcpy(merge_base, &merge_bases->item->object.oid);
 446                res = !oidcmp(merge_base, &onto->object.oid);
 447        } else {
 448                oidcpy(merge_base, &null_oid);
 449                res = 0;
 450        }
 451        free_commit_list(merge_bases);
 452        return res && is_linear_history(onto, head);
 453}
 454
 455int cmd_rebase(int argc, const char **argv, const char *prefix)
 456{
 457        struct rebase_options options = {
 458                .type = REBASE_UNSPECIFIED,
 459                .flags = REBASE_NO_QUIET,
 460                .git_am_opt = STRBUF_INIT,
 461        };
 462        const char *branch_name;
 463        int ret, flags, total_argc, in_progress = 0;
 464        int ok_to_skip_pre_rebase = 0;
 465        struct strbuf msg = STRBUF_INIT;
 466        struct strbuf revisions = STRBUF_INIT;
 467        struct strbuf buf = STRBUF_INIT;
 468        struct object_id merge_base;
 469        enum {
 470                NO_ACTION,
 471                ACTION_CONTINUE,
 472                ACTION_SKIP,
 473                ACTION_ABORT,
 474        } action = NO_ACTION;
 475        struct option builtin_rebase_options[] = {
 476                OPT_STRING(0, "onto", &options.onto_name,
 477                           N_("revision"),
 478                           N_("rebase onto given branch instead of upstream")),
 479                OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
 480                         N_("allow pre-rebase hook to run")),
 481                OPT_NEGBIT('q', "quiet", &options.flags,
 482                           N_("be quiet. implies --no-stat"),
 483                           REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
 484                OPT_BIT('v', "verbose", &options.flags,
 485                        N_("display a diffstat of what changed upstream"),
 486                        REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 487                {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
 488                        N_("do not show diffstat of what changed upstream"),
 489                        PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 490                OPT_BIT('f', "force-rebase", &options.flags,
 491                        N_("cherry-pick all commits, even if unchanged"),
 492                        REBASE_FORCE),
 493                OPT_BIT(0, "no-ff", &options.flags,
 494                        N_("cherry-pick all commits, even if unchanged"),
 495                        REBASE_FORCE),
 496                OPT_CMDMODE(0, "continue", &action, N_("continue"),
 497                            ACTION_CONTINUE),
 498                OPT_CMDMODE(0, "skip", &action,
 499                            N_("skip current patch and continue"), ACTION_SKIP),
 500                OPT_CMDMODE(0, "abort", &action,
 501                            N_("abort and check out the original branch"),
 502                            ACTION_ABORT),
 503                OPT_END(),
 504        };
 505
 506        /*
 507         * NEEDSWORK: Once the builtin rebase has been tested enough
 508         * and git-legacy-rebase.sh is retired to contrib/, this preamble
 509         * can be removed.
 510         */
 511
 512        if (!use_builtin_rebase()) {
 513                const char *path = mkpath("%s/git-legacy-rebase",
 514                                          git_exec_path());
 515
 516                if (sane_execvp(path, (char **)argv) < 0)
 517                        die_errno(_("could not exec %s"), path);
 518                else
 519                        BUG("sane_execvp() returned???");
 520        }
 521
 522        if (argc == 2 && !strcmp(argv[1], "-h"))
 523                usage_with_options(builtin_rebase_usage,
 524                                   builtin_rebase_options);
 525
 526        prefix = setup_git_directory();
 527        trace_repo_setup(prefix);
 528        setup_work_tree();
 529
 530        git_config(rebase_config, &options);
 531
 532        if (is_directory(apply_dir())) {
 533                options.type = REBASE_AM;
 534                options.state_dir = apply_dir();
 535        } else if (is_directory(merge_dir())) {
 536                strbuf_reset(&buf);
 537                strbuf_addf(&buf, "%s/rewritten", merge_dir());
 538                if (is_directory(buf.buf)) {
 539                        options.type = REBASE_PRESERVE_MERGES;
 540                        options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 541                } else {
 542                        strbuf_reset(&buf);
 543                        strbuf_addf(&buf, "%s/interactive", merge_dir());
 544                        if(file_exists(buf.buf)) {
 545                                options.type = REBASE_INTERACTIVE;
 546                                options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 547                        } else
 548                                options.type = REBASE_MERGE;
 549                }
 550                options.state_dir = merge_dir();
 551        }
 552
 553        if (options.type != REBASE_UNSPECIFIED)
 554                in_progress = 1;
 555
 556        total_argc = argc;
 557        argc = parse_options(argc, argv, prefix,
 558                             builtin_rebase_options,
 559                             builtin_rebase_usage, 0);
 560
 561        if (action != NO_ACTION && total_argc != 2) {
 562                usage_with_options(builtin_rebase_usage,
 563                                   builtin_rebase_options);
 564        }
 565
 566        if (argc > 2)
 567                usage_with_options(builtin_rebase_usage,
 568                                   builtin_rebase_options);
 569
 570        switch (action) {
 571        case ACTION_CONTINUE: {
 572                struct object_id head;
 573                struct lock_file lock_file = LOCK_INIT;
 574                int fd;
 575
 576                options.action = "continue";
 577
 578                /* Sanity check */
 579                if (get_oid("HEAD", &head))
 580                        die(_("Cannot read HEAD"));
 581
 582                fd = hold_locked_index(&lock_file, 0);
 583                if (read_index(the_repository->index) < 0)
 584                        die(_("could not read index"));
 585                refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
 586                              NULL);
 587                if (0 <= fd)
 588                        update_index_if_able(the_repository->index,
 589                                             &lock_file);
 590                rollback_lock_file(&lock_file);
 591
 592                if (has_unstaged_changes(1)) {
 593                        puts(_("You must edit all merge conflicts and then\n"
 594                               "mark them as resolved using git add"));
 595                        exit(1);
 596                }
 597                if (read_basic_state(&options))
 598                        exit(1);
 599                goto run_rebase;
 600        }
 601        case ACTION_SKIP: {
 602                struct string_list merge_rr = STRING_LIST_INIT_DUP;
 603
 604                options.action = "skip";
 605
 606                rerere_clear(&merge_rr);
 607                string_list_clear(&merge_rr, 1);
 608
 609                if (reset_head(NULL, "reset", NULL, 0) < 0)
 610                        die(_("could not discard worktree changes"));
 611                if (read_basic_state(&options))
 612                        exit(1);
 613                goto run_rebase;
 614        }
 615        case ACTION_ABORT: {
 616                struct string_list merge_rr = STRING_LIST_INIT_DUP;
 617                options.action = "abort";
 618
 619                rerere_clear(&merge_rr);
 620                string_list_clear(&merge_rr, 1);
 621
 622                if (read_basic_state(&options))
 623                        exit(1);
 624                if (reset_head(&options.orig_head, "reset",
 625                               options.head_name, 0) < 0)
 626                        die(_("could not move back to %s"),
 627                            oid_to_hex(&options.orig_head));
 628                ret = finish_rebase(&options);
 629                goto cleanup;
 630        }
 631        default:
 632                die("TODO");
 633        }
 634
 635        /* Make sure no rebase is in progress */
 636        if (in_progress) {
 637                const char *last_slash = strrchr(options.state_dir, '/');
 638                const char *state_dir_base =
 639                        last_slash ? last_slash + 1 : options.state_dir;
 640                const char *cmd_live_rebase =
 641                        "git rebase (--continue | --abort | --skip)";
 642                strbuf_reset(&buf);
 643                strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
 644                die(_("It seems that there is already a %s directory, and\n"
 645                      "I wonder if you are in the middle of another rebase.  "
 646                      "If that is the\n"
 647                      "case, please try\n\t%s\n"
 648                      "If that is not the case, please\n\t%s\n"
 649                      "and run me again.  I am stopping in case you still "
 650                      "have something\n"
 651                      "valuable there.\n"),
 652                    state_dir_base, cmd_live_rebase, buf.buf);
 653        }
 654
 655        if (!(options.flags & REBASE_NO_QUIET))
 656                strbuf_addstr(&options.git_am_opt, " -q");
 657
 658        switch (options.type) {
 659        case REBASE_MERGE:
 660        case REBASE_INTERACTIVE:
 661        case REBASE_PRESERVE_MERGES:
 662                options.state_dir = merge_dir();
 663                break;
 664        case REBASE_AM:
 665                options.state_dir = apply_dir();
 666                break;
 667        default:
 668                /* the default rebase backend is `--am` */
 669                options.type = REBASE_AM;
 670                options.state_dir = apply_dir();
 671                break;
 672        }
 673
 674        if (!options.root) {
 675                if (argc < 1)
 676                        die("TODO: handle @{upstream}");
 677                else {
 678                        options.upstream_name = argv[0];
 679                        argc--;
 680                        argv++;
 681                        if (!strcmp(options.upstream_name, "-"))
 682                                options.upstream_name = "@{-1}";
 683                }
 684                options.upstream = peel_committish(options.upstream_name);
 685                if (!options.upstream)
 686                        die(_("invalid upstream '%s'"), options.upstream_name);
 687                options.upstream_arg = options.upstream_name;
 688        } else
 689                die("TODO: upstream for --root");
 690
 691        /* Make sure the branch to rebase onto is valid. */
 692        if (!options.onto_name)
 693                options.onto_name = options.upstream_name;
 694        if (strstr(options.onto_name, "...")) {
 695                if (get_oid_mb(options.onto_name, &merge_base) < 0)
 696                        die(_("'%s': need exactly one merge base"),
 697                            options.onto_name);
 698                options.onto = lookup_commit_or_die(&merge_base,
 699                                                    options.onto_name);
 700        } else {
 701                options.onto = peel_committish(options.onto_name);
 702                if (!options.onto)
 703                        die(_("Does not point to a valid commit '%s'"),
 704                                options.onto_name);
 705        }
 706
 707        /*
 708         * If the branch to rebase is given, that is the branch we will rebase
 709         * branch_name -- branch/commit being rebased, or
 710         *                HEAD (already detached)
 711         * orig_head -- commit object name of tip of the branch before rebasing
 712         * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
 713         */
 714        if (argc == 1) {
 715                /* Is it "rebase other branchname" or "rebase other commit"? */
 716                branch_name = argv[0];
 717                options.switch_to = argv[0];
 718
 719                /* Is it a local branch? */
 720                strbuf_reset(&buf);
 721                strbuf_addf(&buf, "refs/heads/%s", branch_name);
 722                if (!read_ref(buf.buf, &options.orig_head))
 723                        options.head_name = xstrdup(buf.buf);
 724                /* If not is it a valid ref (branch or commit)? */
 725                else if (!get_oid(branch_name, &options.orig_head))
 726                        options.head_name = NULL;
 727                else
 728                        die(_("fatal: no such branch/commit '%s'"),
 729                            branch_name);
 730        } else if (argc == 0) {
 731                /* Do not need to switch branches, we are already on it. */
 732                options.head_name =
 733                        xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
 734                                         &flags));
 735                if (!options.head_name)
 736                        die(_("No such ref: %s"), "HEAD");
 737                if (flags & REF_ISSYMREF) {
 738                        if (!skip_prefix(options.head_name,
 739                                         "refs/heads/", &branch_name))
 740                                branch_name = options.head_name;
 741
 742                } else {
 743                        free(options.head_name);
 744                        options.head_name = NULL;
 745                        branch_name = "HEAD";
 746                }
 747                if (get_oid("HEAD", &options.orig_head))
 748                        die(_("Could not resolve HEAD to a revision"));
 749        } else
 750                BUG("unexpected number of arguments left to parse");
 751
 752        if (read_index(the_repository->index) < 0)
 753                die(_("could not read index"));
 754
 755        if (require_clean_work_tree("rebase",
 756                                    _("Please commit or stash them."), 1, 1)) {
 757                ret = 1;
 758                goto cleanup;
 759        }
 760
 761        /*
 762         * Now we are rebasing commits upstream..orig_head (or with --root,
 763         * everything leading up to orig_head) on top of onto.
 764         */
 765
 766        /*
 767         * Check if we are already based on onto with linear history,
 768         * but this should be done only when upstream and onto are the same
 769         * and if this is not an interactive rebase.
 770         */
 771        if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
 772            !is_interactive(&options) && !options.restrict_revision &&
 773            !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
 774                int flag;
 775
 776                if (!(options.flags & REBASE_FORCE)) {
 777                        /* Lazily switch to the target branch if needed... */
 778                        if (options.switch_to) {
 779                                struct object_id oid;
 780
 781                                if (get_oid(options.switch_to, &oid) < 0) {
 782                                        ret = !!error(_("could not parse '%s'"),
 783                                                      options.switch_to);
 784                                        goto cleanup;
 785                                }
 786
 787                                strbuf_reset(&buf);
 788                                strbuf_addf(&buf, "rebase: checkout %s",
 789                                            options.switch_to);
 790                                if (reset_head(&oid, "checkout",
 791                                               options.head_name, 0) < 0) {
 792                                        ret = !!error(_("could not switch to "
 793                                                        "%s"),
 794                                                      options.switch_to);
 795                                        goto cleanup;
 796                                }
 797                        }
 798
 799                        if (!(options.flags & REBASE_NO_QUIET))
 800                                ; /* be quiet */
 801                        else if (!strcmp(branch_name, "HEAD") &&
 802                                 resolve_ref_unsafe("HEAD", 0, NULL, &flag))
 803                                puts(_("HEAD is up to date."));
 804                        else
 805                                printf(_("Current branch %s is up to date.\n"),
 806                                       branch_name);
 807                        ret = !!finish_rebase(&options);
 808                        goto cleanup;
 809                } else if (!(options.flags & REBASE_NO_QUIET))
 810                        ; /* be quiet */
 811                else if (!strcmp(branch_name, "HEAD") &&
 812                         resolve_ref_unsafe("HEAD", 0, NULL, &flag))
 813                        puts(_("HEAD is up to date, rebase forced."));
 814                else
 815                        printf(_("Current branch %s is up to date, rebase "
 816                                 "forced.\n"), branch_name);
 817        }
 818
 819        /* If a hook exists, give it a chance to interrupt*/
 820        if (!ok_to_skip_pre_rebase &&
 821            run_hook_le(NULL, "pre-rebase", options.upstream_arg,
 822                        argc ? argv[0] : NULL, NULL))
 823                die(_("The pre-rebase hook refused to rebase."));
 824
 825        if (options.flags & REBASE_DIFFSTAT) {
 826                struct diff_options opts;
 827
 828                if (options.flags & REBASE_VERBOSE)
 829                        printf(_("Changes from %s to %s:\n"),
 830                                oid_to_hex(&merge_base),
 831                                oid_to_hex(&options.onto->object.oid));
 832
 833                /* We want color (if set), but no pager */
 834                diff_setup(&opts);
 835                opts.stat_width = -1; /* use full terminal width */
 836                opts.stat_graph_width = -1; /* respect statGraphWidth config */
 837                opts.output_format |=
 838                        DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
 839                opts.detect_rename = DIFF_DETECT_RENAME;
 840                diff_setup_done(&opts);
 841                diff_tree_oid(&merge_base, &options.onto->object.oid,
 842                              "", &opts);
 843                diffcore_std(&opts);
 844                diff_flush(&opts);
 845        }
 846
 847        /* Detach HEAD and reset the tree */
 848        if (options.flags & REBASE_NO_QUIET)
 849                printf(_("First, rewinding head to replay your work on top of "
 850                         "it...\n"));
 851
 852        strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
 853        if (reset_head(&options.onto->object.oid, "checkout", NULL, 1))
 854                die(_("Could not detach HEAD"));
 855        strbuf_release(&msg);
 856
 857        strbuf_addf(&revisions, "%s..%s",
 858                    options.root ? oid_to_hex(&options.onto->object.oid) :
 859                    (options.restrict_revision ?
 860                     oid_to_hex(&options.restrict_revision->object.oid) :
 861                     oid_to_hex(&options.upstream->object.oid)),
 862                    oid_to_hex(&options.orig_head));
 863
 864        options.revisions = revisions.buf;
 865
 866run_rebase:
 867        ret = !!run_specific_rebase(&options);
 868
 869cleanup:
 870        strbuf_release(&revisions);
 871        free(options.head_name);
 872        return ret;
 873}