builtin / rebase.con commit Merge branch 'bp/checkout-new-branch-optim' (5ad3550)
   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 "commit-reach.h"
  25#include "rerere.h"
  26#include "branch.h"
  27
  28static char const * const builtin_rebase_usage[] = {
  29        N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  30                "[<upstream>] [<branch>]"),
  31        N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  32                "--root [<branch>]"),
  33        N_("git rebase --continue | --abort | --skip | --edit-todo"),
  34        NULL
  35};
  36
  37static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  38static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  39
  40enum rebase_type {
  41        REBASE_UNSPECIFIED = -1,
  42        REBASE_AM,
  43        REBASE_MERGE,
  44        REBASE_INTERACTIVE,
  45        REBASE_PRESERVE_MERGES
  46};
  47
  48static int use_builtin_rebase(void)
  49{
  50        struct child_process cp = CHILD_PROCESS_INIT;
  51        struct strbuf out = STRBUF_INIT;
  52        int ret, env = git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1);
  53
  54        if (env != -1)
  55                return env;
  56
  57        argv_array_pushl(&cp.args,
  58                         "config", "--bool", "rebase.usebuiltin", NULL);
  59        cp.git_cmd = 1;
  60        if (capture_command(&cp, &out, 6)) {
  61                strbuf_release(&out);
  62                return 1;
  63        }
  64
  65        strbuf_trim(&out);
  66        ret = !strcmp("true", out.buf);
  67        strbuf_release(&out);
  68        return ret;
  69}
  70
  71struct rebase_options {
  72        enum rebase_type type;
  73        const char *state_dir;
  74        struct commit *upstream;
  75        const char *upstream_name;
  76        const char *upstream_arg;
  77        char *head_name;
  78        struct object_id orig_head;
  79        struct commit *onto;
  80        const char *onto_name;
  81        const char *revisions;
  82        const char *switch_to;
  83        int root;
  84        struct object_id *squash_onto;
  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 argv_array git_am_opts;
  95        const char *action;
  96        int signoff;
  97        int allow_rerere_autoupdate;
  98        int keep_empty;
  99        int autosquash;
 100        char *gpg_sign_opt;
 101        int autostash;
 102        char *cmd;
 103        int allow_empty_message;
 104        int rebase_merges, rebase_cousins;
 105        char *strategy, *strategy_opts;
 106        struct strbuf git_format_patch_opt;
 107        int reschedule_failed_exec;
 108};
 109
 110static int is_interactive(struct rebase_options *opts)
 111{
 112        return opts->type == REBASE_INTERACTIVE ||
 113                opts->type == REBASE_PRESERVE_MERGES;
 114}
 115
 116static void imply_interactive(struct rebase_options *opts, const char *option)
 117{
 118        switch (opts->type) {
 119        case REBASE_AM:
 120                die(_("%s requires an interactive rebase"), option);
 121                break;
 122        case REBASE_INTERACTIVE:
 123        case REBASE_PRESERVE_MERGES:
 124                break;
 125        case REBASE_MERGE:
 126                /* we silently *upgrade* --merge to --interactive if needed */
 127        default:
 128                opts->type = REBASE_INTERACTIVE; /* implied */
 129                break;
 130        }
 131}
 132
 133/* Returns the filename prefixed by the state_dir */
 134static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 135{
 136        static struct strbuf path = STRBUF_INIT;
 137        static size_t prefix_len;
 138
 139        if (!prefix_len) {
 140                strbuf_addf(&path, "%s/", opts->state_dir);
 141                prefix_len = path.len;
 142        }
 143
 144        strbuf_setlen(&path, prefix_len);
 145        strbuf_addstr(&path, filename);
 146        return path.buf;
 147}
 148
 149/* Read one file, then strip line endings */
 150static int read_one(const char *path, struct strbuf *buf)
 151{
 152        if (strbuf_read_file(buf, path, 0) < 0)
 153                return error_errno(_("could not read '%s'"), path);
 154        strbuf_trim_trailing_newline(buf);
 155        return 0;
 156}
 157
 158/* Initialize the rebase options from the state directory. */
 159static int read_basic_state(struct rebase_options *opts)
 160{
 161        struct strbuf head_name = STRBUF_INIT;
 162        struct strbuf buf = STRBUF_INIT;
 163        struct object_id oid;
 164
 165        if (read_one(state_dir_path("head-name", opts), &head_name) ||
 166            read_one(state_dir_path("onto", opts), &buf))
 167                return -1;
 168        opts->head_name = starts_with(head_name.buf, "refs/") ?
 169                xstrdup(head_name.buf) : NULL;
 170        strbuf_release(&head_name);
 171        if (get_oid(buf.buf, &oid))
 172                return error(_("could not get 'onto': '%s'"), buf.buf);
 173        opts->onto = lookup_commit_or_die(&oid, buf.buf);
 174
 175        /*
 176         * We always write to orig-head, but interactive rebase used to write to
 177         * head. Fall back to reading from head to cover for the case that the
 178         * user upgraded git with an ongoing interactive rebase.
 179         */
 180        strbuf_reset(&buf);
 181        if (file_exists(state_dir_path("orig-head", opts))) {
 182                if (read_one(state_dir_path("orig-head", opts), &buf))
 183                        return -1;
 184        } else if (read_one(state_dir_path("head", opts), &buf))
 185                return -1;
 186        if (get_oid(buf.buf, &opts->orig_head))
 187                return error(_("invalid orig-head: '%s'"), buf.buf);
 188
 189        strbuf_reset(&buf);
 190        if (read_one(state_dir_path("quiet", opts), &buf))
 191                return -1;
 192        if (buf.len)
 193                opts->flags &= ~REBASE_NO_QUIET;
 194        else
 195                opts->flags |= REBASE_NO_QUIET;
 196
 197        if (file_exists(state_dir_path("verbose", opts)))
 198                opts->flags |= REBASE_VERBOSE;
 199
 200        if (file_exists(state_dir_path("signoff", opts))) {
 201                opts->signoff = 1;
 202                opts->flags |= REBASE_FORCE;
 203        }
 204
 205        if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 206                strbuf_reset(&buf);
 207                if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 208                            &buf))
 209                        return -1;
 210                if (!strcmp(buf.buf, "--rerere-autoupdate"))
 211                        opts->allow_rerere_autoupdate = 1;
 212                else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 213                        opts->allow_rerere_autoupdate = 0;
 214                else
 215                        warning(_("ignoring invalid allow_rerere_autoupdate: "
 216                                  "'%s'"), buf.buf);
 217        } else
 218                opts->allow_rerere_autoupdate = -1;
 219
 220        if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 221                strbuf_reset(&buf);
 222                if (read_one(state_dir_path("gpg_sign_opt", opts),
 223                            &buf))
 224                        return -1;
 225                free(opts->gpg_sign_opt);
 226                opts->gpg_sign_opt = xstrdup(buf.buf);
 227        }
 228
 229        if (file_exists(state_dir_path("strategy", opts))) {
 230                strbuf_reset(&buf);
 231                if (read_one(state_dir_path("strategy", opts), &buf))
 232                        return -1;
 233                free(opts->strategy);
 234                opts->strategy = xstrdup(buf.buf);
 235        }
 236
 237        if (file_exists(state_dir_path("strategy_opts", opts))) {
 238                strbuf_reset(&buf);
 239                if (read_one(state_dir_path("strategy_opts", opts), &buf))
 240                        return -1;
 241                free(opts->strategy_opts);
 242                opts->strategy_opts = xstrdup(buf.buf);
 243        }
 244
 245        strbuf_release(&buf);
 246
 247        return 0;
 248}
 249
 250static int apply_autostash(struct rebase_options *opts)
 251{
 252        const char *path = state_dir_path("autostash", opts);
 253        struct strbuf autostash = STRBUF_INIT;
 254        struct child_process stash_apply = CHILD_PROCESS_INIT;
 255
 256        if (!file_exists(path))
 257                return 0;
 258
 259        if (read_one(path, &autostash))
 260                return error(_("Could not read '%s'"), path);
 261        /* Ensure that the hash is not mistaken for a number */
 262        strbuf_addstr(&autostash, "^0");
 263        argv_array_pushl(&stash_apply.args,
 264                         "stash", "apply", autostash.buf, NULL);
 265        stash_apply.git_cmd = 1;
 266        stash_apply.no_stderr = stash_apply.no_stdout =
 267                stash_apply.no_stdin = 1;
 268        if (!run_command(&stash_apply))
 269                printf(_("Applied autostash.\n"));
 270        else {
 271                struct argv_array args = ARGV_ARRAY_INIT;
 272                int res = 0;
 273
 274                argv_array_pushl(&args,
 275                                 "stash", "store", "-m", "autostash", "-q",
 276                                 autostash.buf, NULL);
 277                if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 278                        res = error(_("Cannot store %s"), autostash.buf);
 279                argv_array_clear(&args);
 280                strbuf_release(&autostash);
 281                if (res)
 282                        return res;
 283
 284                fprintf(stderr,
 285                        _("Applying autostash resulted in conflicts.\n"
 286                          "Your changes are safe in the stash.\n"
 287                          "You can run \"git stash pop\" or \"git stash drop\" "
 288                          "at any time.\n"));
 289        }
 290
 291        strbuf_release(&autostash);
 292        return 0;
 293}
 294
 295static int finish_rebase(struct rebase_options *opts)
 296{
 297        struct strbuf dir = STRBUF_INIT;
 298        const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 299
 300        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 301        apply_autostash(opts);
 302        close_all_packs(the_repository->objects);
 303        /*
 304         * We ignore errors in 'gc --auto', since the
 305         * user should see them.
 306         */
 307        run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 308        strbuf_addstr(&dir, opts->state_dir);
 309        remove_dir_recursively(&dir, 0);
 310        strbuf_release(&dir);
 311
 312        return 0;
 313}
 314
 315static struct commit *peel_committish(const char *name)
 316{
 317        struct object *obj;
 318        struct object_id oid;
 319
 320        if (get_oid(name, &oid))
 321                return NULL;
 322        obj = parse_object(the_repository, &oid);
 323        return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 324}
 325
 326static void add_var(struct strbuf *buf, const char *name, const char *value)
 327{
 328        if (!value)
 329                strbuf_addf(buf, "unset %s; ", name);
 330        else {
 331                strbuf_addf(buf, "%s=", name);
 332                sq_quote_buf(buf, value);
 333                strbuf_addstr(buf, "; ");
 334        }
 335}
 336
 337static const char *resolvemsg =
 338N_("Resolve all conflicts manually, mark them as resolved with\n"
 339"\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 340"You can instead skip this commit: run \"git rebase --skip\".\n"
 341"To abort and get back to the state before \"git rebase\", run "
 342"\"git rebase --abort\".");
 343
 344static int run_specific_rebase(struct rebase_options *opts)
 345{
 346        const char *argv[] = { NULL, NULL };
 347        struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
 348        int status;
 349        const char *backend, *backend_func;
 350
 351        if (opts->type == REBASE_INTERACTIVE) {
 352                /* Run builtin interactive rebase */
 353                struct child_process child = CHILD_PROCESS_INIT;
 354
 355                argv_array_pushf(&child.env_array, "GIT_CHERRY_PICK_HELP=%s",
 356                                 resolvemsg);
 357                if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 358                        argv_array_push(&child.env_array, "GIT_EDITOR=:");
 359                        opts->autosquash = 0;
 360                }
 361
 362                child.git_cmd = 1;
 363                argv_array_push(&child.args, "rebase--interactive");
 364
 365                if (opts->action)
 366                        argv_array_pushf(&child.args, "--%s", opts->action);
 367                if (opts->keep_empty)
 368                        argv_array_push(&child.args, "--keep-empty");
 369                if (opts->rebase_merges)
 370                        argv_array_push(&child.args, "--rebase-merges");
 371                if (opts->rebase_cousins)
 372                        argv_array_push(&child.args, "--rebase-cousins");
 373                if (opts->autosquash)
 374                        argv_array_push(&child.args, "--autosquash");
 375                if (opts->flags & REBASE_VERBOSE)
 376                        argv_array_push(&child.args, "--verbose");
 377                if (opts->flags & REBASE_FORCE)
 378                        argv_array_push(&child.args, "--no-ff");
 379                if (opts->restrict_revision)
 380                        argv_array_pushf(&child.args,
 381                                         "--restrict-revision=^%s",
 382                                         oid_to_hex(&opts->restrict_revision->object.oid));
 383                if (opts->upstream)
 384                        argv_array_pushf(&child.args, "--upstream=%s",
 385                                         oid_to_hex(&opts->upstream->object.oid));
 386                if (opts->onto)
 387                        argv_array_pushf(&child.args, "--onto=%s",
 388                                         oid_to_hex(&opts->onto->object.oid));
 389                if (opts->squash_onto)
 390                        argv_array_pushf(&child.args, "--squash-onto=%s",
 391                                         oid_to_hex(opts->squash_onto));
 392                if (opts->onto_name)
 393                        argv_array_pushf(&child.args, "--onto-name=%s",
 394                                         opts->onto_name);
 395                argv_array_pushf(&child.args, "--head-name=%s",
 396                                 opts->head_name ?
 397                                 opts->head_name : "detached HEAD");
 398                if (opts->strategy)
 399                        argv_array_pushf(&child.args, "--strategy=%s",
 400                                         opts->strategy);
 401                if (opts->strategy_opts)
 402                        argv_array_pushf(&child.args, "--strategy-opts=%s",
 403                                         opts->strategy_opts);
 404                if (opts->switch_to)
 405                        argv_array_pushf(&child.args, "--switch-to=%s",
 406                                         opts->switch_to);
 407                if (opts->cmd)
 408                        argv_array_pushf(&child.args, "--cmd=%s", opts->cmd);
 409                if (opts->allow_empty_message)
 410                        argv_array_push(&child.args, "--allow-empty-message");
 411                if (opts->allow_rerere_autoupdate > 0)
 412                        argv_array_push(&child.args, "--rerere-autoupdate");
 413                else if (opts->allow_rerere_autoupdate == 0)
 414                        argv_array_push(&child.args, "--no-rerere-autoupdate");
 415                if (opts->gpg_sign_opt)
 416                        argv_array_push(&child.args, opts->gpg_sign_opt);
 417                if (opts->signoff)
 418                        argv_array_push(&child.args, "--signoff");
 419                if (opts->reschedule_failed_exec)
 420                        argv_array_push(&child.args, "--reschedule-failed-exec");
 421
 422                status = run_command(&child);
 423                goto finished_rebase;
 424        }
 425
 426        add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 427        add_var(&script_snippet, "state_dir", opts->state_dir);
 428
 429        add_var(&script_snippet, "upstream_name", opts->upstream_name);
 430        add_var(&script_snippet, "upstream", opts->upstream ?
 431                oid_to_hex(&opts->upstream->object.oid) : NULL);
 432        add_var(&script_snippet, "head_name",
 433                opts->head_name ? opts->head_name : "detached HEAD");
 434        add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 435        add_var(&script_snippet, "onto", opts->onto ?
 436                oid_to_hex(&opts->onto->object.oid) : NULL);
 437        add_var(&script_snippet, "onto_name", opts->onto_name);
 438        add_var(&script_snippet, "revisions", opts->revisions);
 439        add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 440                oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 441        add_var(&script_snippet, "GIT_QUIET",
 442                opts->flags & REBASE_NO_QUIET ? "" : "t");
 443        sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
 444        add_var(&script_snippet, "git_am_opt", buf.buf);
 445        strbuf_release(&buf);
 446        add_var(&script_snippet, "verbose",
 447                opts->flags & REBASE_VERBOSE ? "t" : "");
 448        add_var(&script_snippet, "diffstat",
 449                opts->flags & REBASE_DIFFSTAT ? "t" : "");
 450        add_var(&script_snippet, "force_rebase",
 451                opts->flags & REBASE_FORCE ? "t" : "");
 452        if (opts->switch_to)
 453                add_var(&script_snippet, "switch_to", opts->switch_to);
 454        add_var(&script_snippet, "action", opts->action ? opts->action : "");
 455        add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
 456        add_var(&script_snippet, "allow_rerere_autoupdate",
 457                opts->allow_rerere_autoupdate < 0 ? "" :
 458                opts->allow_rerere_autoupdate ?
 459                "--rerere-autoupdate" : "--no-rerere-autoupdate");
 460        add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
 461        add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
 462        add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
 463        add_var(&script_snippet, "cmd", opts->cmd);
 464        add_var(&script_snippet, "allow_empty_message",
 465                opts->allow_empty_message ?  "--allow-empty-message" : "");
 466        add_var(&script_snippet, "rebase_merges",
 467                opts->rebase_merges ? "t" : "");
 468        add_var(&script_snippet, "rebase_cousins",
 469                opts->rebase_cousins ? "t" : "");
 470        add_var(&script_snippet, "strategy", opts->strategy);
 471        add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
 472        add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
 473        add_var(&script_snippet, "squash_onto",
 474                opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
 475        add_var(&script_snippet, "git_format_patch_opt",
 476                opts->git_format_patch_opt.buf);
 477
 478        if (is_interactive(opts) &&
 479            !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 480                strbuf_addstr(&script_snippet,
 481                              "GIT_EDITOR=:; export GIT_EDITOR; ");
 482                opts->autosquash = 0;
 483        }
 484
 485        switch (opts->type) {
 486        case REBASE_AM:
 487                backend = "git-rebase--am";
 488                backend_func = "git_rebase__am";
 489                break;
 490        case REBASE_MERGE:
 491                backend = "git-rebase--merge";
 492                backend_func = "git_rebase__merge";
 493                break;
 494        case REBASE_PRESERVE_MERGES:
 495                backend = "git-rebase--preserve-merges";
 496                backend_func = "git_rebase__preserve_merges";
 497                break;
 498        default:
 499                BUG("Unhandled rebase type %d", opts->type);
 500                break;
 501        }
 502
 503        strbuf_addf(&script_snippet,
 504                    ". git-sh-setup && . git-rebase--common &&"
 505                    " . %s && %s", backend, backend_func);
 506        argv[0] = script_snippet.buf;
 507
 508        status = run_command_v_opt(argv, RUN_USING_SHELL);
 509finished_rebase:
 510        if (opts->dont_finish_rebase)
 511                ; /* do nothing */
 512        else if (opts->type == REBASE_INTERACTIVE)
 513                ; /* interactive rebase cleans up after itself */
 514        else if (status == 0) {
 515                if (!file_exists(state_dir_path("stopped-sha", opts)))
 516                        finish_rebase(opts);
 517        } else if (status == 2) {
 518                struct strbuf dir = STRBUF_INIT;
 519
 520                apply_autostash(opts);
 521                strbuf_addstr(&dir, opts->state_dir);
 522                remove_dir_recursively(&dir, 0);
 523                strbuf_release(&dir);
 524                die("Nothing to do");
 525        }
 526
 527        strbuf_release(&script_snippet);
 528
 529        return status ? -1 : 0;
 530}
 531
 532#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 533
 534#define RESET_HEAD_DETACH (1<<0)
 535#define RESET_HEAD_HARD (1<<1)
 536#define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 537
 538static int reset_head(struct object_id *oid, const char *action,
 539                      const char *switch_to_branch, unsigned flags,
 540                      const char *reflog_orig_head, const char *reflog_head)
 541{
 542        unsigned detach_head = flags & RESET_HEAD_DETACH;
 543        unsigned reset_hard = flags & RESET_HEAD_HARD;
 544        unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 545        struct object_id head_oid;
 546        struct tree_desc desc[2] = { { NULL }, { NULL } };
 547        struct lock_file lock = LOCK_INIT;
 548        struct unpack_trees_options unpack_tree_opts;
 549        struct tree *tree;
 550        const char *reflog_action;
 551        struct strbuf msg = STRBUF_INIT;
 552        size_t prefix_len;
 553        struct object_id *orig = NULL, oid_orig,
 554                *old_orig = NULL, oid_old_orig;
 555        int ret = 0, nr = 0;
 556
 557        if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 558                BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 559
 560        if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 561                ret = -1;
 562                goto leave_reset_head;
 563        }
 564
 565        if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 566                ret = error(_("could not determine HEAD revision"));
 567                goto leave_reset_head;
 568        }
 569
 570        if (!oid)
 571                oid = &head_oid;
 572
 573        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 574        setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 575        unpack_tree_opts.head_idx = 1;
 576        unpack_tree_opts.src_index = the_repository->index;
 577        unpack_tree_opts.dst_index = the_repository->index;
 578        unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 579        unpack_tree_opts.update = 1;
 580        unpack_tree_opts.merge = 1;
 581        if (!detach_head)
 582                unpack_tree_opts.reset = 1;
 583
 584        if (read_index_unmerged(the_repository->index) < 0) {
 585                ret = error(_("could not read index"));
 586                goto leave_reset_head;
 587        }
 588
 589        if (!reset_hard && !fill_tree_descriptor(&desc[nr++], &head_oid)) {
 590                ret = error(_("failed to find tree of %s"),
 591                            oid_to_hex(&head_oid));
 592                goto leave_reset_head;
 593        }
 594
 595        if (!fill_tree_descriptor(&desc[nr++], oid)) {
 596                ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 597                goto leave_reset_head;
 598        }
 599
 600        if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 601                ret = -1;
 602                goto leave_reset_head;
 603        }
 604
 605        tree = parse_tree_indirect(oid);
 606        prime_cache_tree(the_repository, the_repository->index, tree);
 607
 608        if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 609                ret = error(_("could not write index"));
 610                goto leave_reset_head;
 611        }
 612
 613        reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 614        strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 615        prefix_len = msg.len;
 616
 617        if (!get_oid("ORIG_HEAD", &oid_old_orig))
 618                old_orig = &oid_old_orig;
 619        if (!get_oid("HEAD", &oid_orig)) {
 620                orig = &oid_orig;
 621                if (!reflog_orig_head) {
 622                        strbuf_addstr(&msg, "updating ORIG_HEAD");
 623                        reflog_orig_head = msg.buf;
 624                }
 625                update_ref(reflog_orig_head, "ORIG_HEAD", orig, old_orig, 0,
 626                           UPDATE_REFS_MSG_ON_ERR);
 627        } else if (old_orig)
 628                delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 629        if (!reflog_head) {
 630                strbuf_setlen(&msg, prefix_len);
 631                strbuf_addstr(&msg, "updating HEAD");
 632                reflog_head = msg.buf;
 633        }
 634        if (!switch_to_branch)
 635                ret = update_ref(reflog_head, "HEAD", oid, orig,
 636                                 detach_head ? REF_NO_DEREF : 0,
 637                                 UPDATE_REFS_MSG_ON_ERR);
 638        else {
 639                ret = create_symref("HEAD", switch_to_branch, msg.buf);
 640                if (!ret)
 641                        ret = update_ref(reflog_head, "HEAD", oid, NULL, 0,
 642                                         UPDATE_REFS_MSG_ON_ERR);
 643        }
 644        if (run_hook)
 645                run_hook_le(NULL, "post-checkout",
 646                            oid_to_hex(orig ? orig : &null_oid),
 647                            oid_to_hex(oid), "1", NULL);
 648
 649leave_reset_head:
 650        strbuf_release(&msg);
 651        rollback_lock_file(&lock);
 652        while (nr)
 653                free((void *)desc[--nr].buffer);
 654        return ret;
 655}
 656
 657static int rebase_config(const char *var, const char *value, void *data)
 658{
 659        struct rebase_options *opts = data;
 660
 661        if (!strcmp(var, "rebase.stat")) {
 662                if (git_config_bool(var, value))
 663                        opts->flags |= REBASE_DIFFSTAT;
 664                else
 665                        opts->flags &= !REBASE_DIFFSTAT;
 666                return 0;
 667        }
 668
 669        if (!strcmp(var, "rebase.autosquash")) {
 670                opts->autosquash = git_config_bool(var, value);
 671                return 0;
 672        }
 673
 674        if (!strcmp(var, "commit.gpgsign")) {
 675                free(opts->gpg_sign_opt);
 676                opts->gpg_sign_opt = git_config_bool(var, value) ?
 677                        xstrdup("-S") : NULL;
 678                return 0;
 679        }
 680
 681        if (!strcmp(var, "rebase.autostash")) {
 682                opts->autostash = git_config_bool(var, value);
 683                return 0;
 684        }
 685
 686        if (!strcmp(var, "rebase.reschedulefailedexec")) {
 687                opts->reschedule_failed_exec = git_config_bool(var, value);
 688                return 0;
 689        }
 690
 691        return git_default_config(var, value, data);
 692}
 693
 694/*
 695 * Determines whether the commits in from..to are linear, i.e. contain
 696 * no merge commits. This function *expects* `from` to be an ancestor of
 697 * `to`.
 698 */
 699static int is_linear_history(struct commit *from, struct commit *to)
 700{
 701        while (to && to != from) {
 702                parse_commit(to);
 703                if (!to->parents)
 704                        return 1;
 705                if (to->parents->next)
 706                        return 0;
 707                to = to->parents->item;
 708        }
 709        return 1;
 710}
 711
 712static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
 713                            struct object_id *merge_base)
 714{
 715        struct commit *head = lookup_commit(the_repository, head_oid);
 716        struct commit_list *merge_bases;
 717        int res;
 718
 719        if (!head)
 720                return 0;
 721
 722        merge_bases = get_merge_bases(onto, head);
 723        if (merge_bases && !merge_bases->next) {
 724                oidcpy(merge_base, &merge_bases->item->object.oid);
 725                res = oideq(merge_base, &onto->object.oid);
 726        } else {
 727                oidcpy(merge_base, &null_oid);
 728                res = 0;
 729        }
 730        free_commit_list(merge_bases);
 731        return res && is_linear_history(onto, head);
 732}
 733
 734/* -i followed by -m is still -i */
 735static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 736{
 737        struct rebase_options *opts = opt->value;
 738
 739        BUG_ON_OPT_NEG(unset);
 740        BUG_ON_OPT_ARG(arg);
 741
 742        if (!is_interactive(opts))
 743                opts->type = REBASE_MERGE;
 744
 745        return 0;
 746}
 747
 748/* -i followed by -p is still explicitly interactive, but -p alone is not */
 749static int parse_opt_interactive(const struct option *opt, const char *arg,
 750                                 int unset)
 751{
 752        struct rebase_options *opts = opt->value;
 753
 754        BUG_ON_OPT_NEG(unset);
 755        BUG_ON_OPT_ARG(arg);
 756
 757        opts->type = REBASE_INTERACTIVE;
 758        opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 759
 760        return 0;
 761}
 762
 763struct opt_y {
 764        struct string_list *list;
 765        struct rebase_options *options;
 766};
 767
 768static int parse_opt_y(const struct option *opt, const char *arg, int unset)
 769{
 770        struct opt_y *o = opt->value;
 771
 772        if (unset || !arg)
 773                return -1;
 774
 775        o->options->reschedule_failed_exec = 1;
 776        string_list_append(o->list, arg);
 777        return 0;
 778}
 779
 780static void NORETURN error_on_missing_default_upstream(void)
 781{
 782        struct branch *current_branch = branch_get(NULL);
 783
 784        printf(_("%s\n"
 785                 "Please specify which branch you want to rebase against.\n"
 786                 "See git-rebase(1) for details.\n"
 787                 "\n"
 788                 "    git rebase '<branch>'\n"
 789                 "\n"),
 790                current_branch ? _("There is no tracking information for "
 791                        "the current branch.") :
 792                        _("You are not currently on a branch."));
 793
 794        if (current_branch) {
 795                const char *remote = current_branch->remote_name;
 796
 797                if (!remote)
 798                        remote = _("<remote>");
 799
 800                printf(_("If you wish to set tracking information for this "
 801                         "branch you can do so with:\n"
 802                         "\n"
 803                         "    git branch --set-upstream-to=%s/<branch> %s\n"
 804                         "\n"),
 805                       remote, current_branch->name);
 806        }
 807        exit(1);
 808}
 809
 810static void set_reflog_action(struct rebase_options *options)
 811{
 812        const char *env;
 813        struct strbuf buf = STRBUF_INIT;
 814
 815        if (!is_interactive(options))
 816                return;
 817
 818        env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 819        if (env && strcmp("rebase", env))
 820                return; /* only override it if it is "rebase" */
 821
 822        strbuf_addf(&buf, "rebase -i (%s)", options->action);
 823        setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
 824        strbuf_release(&buf);
 825}
 826
 827int cmd_rebase(int argc, const char **argv, const char *prefix)
 828{
 829        struct rebase_options options = {
 830                .type = REBASE_UNSPECIFIED,
 831                .flags = REBASE_NO_QUIET,
 832                .git_am_opts = ARGV_ARRAY_INIT,
 833                .allow_rerere_autoupdate  = -1,
 834                .allow_empty_message = 1,
 835                .git_format_patch_opt = STRBUF_INIT,
 836        };
 837        const char *branch_name;
 838        int ret, flags, total_argc, in_progress = 0;
 839        int ok_to_skip_pre_rebase = 0;
 840        struct strbuf msg = STRBUF_INIT;
 841        struct strbuf revisions = STRBUF_INIT;
 842        struct strbuf buf = STRBUF_INIT;
 843        struct object_id merge_base;
 844        enum {
 845                NO_ACTION,
 846                ACTION_CONTINUE,
 847                ACTION_SKIP,
 848                ACTION_ABORT,
 849                ACTION_QUIT,
 850                ACTION_EDIT_TODO,
 851                ACTION_SHOW_CURRENT_PATCH,
 852        } action = NO_ACTION;
 853        const char *gpg_sign = NULL;
 854        struct string_list exec = STRING_LIST_INIT_NODUP;
 855        const char *rebase_merges = NULL;
 856        int fork_point = -1;
 857        struct string_list strategy_options = STRING_LIST_INIT_NODUP;
 858        struct object_id squash_onto;
 859        char *squash_onto_name = NULL;
 860        struct opt_y opt_y = { .list = &exec, .options = &options };
 861        struct option builtin_rebase_options[] = {
 862                OPT_STRING(0, "onto", &options.onto_name,
 863                           N_("revision"),
 864                           N_("rebase onto given branch instead of upstream")),
 865                OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
 866                         N_("allow pre-rebase hook to run")),
 867                OPT_NEGBIT('q', "quiet", &options.flags,
 868                           N_("be quiet. implies --no-stat"),
 869                           REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
 870                OPT_BIT('v', "verbose", &options.flags,
 871                        N_("display a diffstat of what changed upstream"),
 872                        REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 873                {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
 874                        N_("do not show diffstat of what changed upstream"),
 875                        PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 876                OPT_BOOL(0, "signoff", &options.signoff,
 877                         N_("add a Signed-off-by: line to each commit")),
 878                OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
 879                                  NULL, N_("passed to 'git am'"),
 880                                  PARSE_OPT_NOARG),
 881                OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
 882                                  &options.git_am_opts, NULL,
 883                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
 884                OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
 885                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
 886                OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
 887                                  N_("passed to 'git apply'"), 0),
 888                OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
 889                                  N_("action"), N_("passed to 'git apply'"), 0),
 890                OPT_BIT('f', "force-rebase", &options.flags,
 891                        N_("cherry-pick all commits, even if unchanged"),
 892                        REBASE_FORCE),
 893                OPT_BIT(0, "no-ff", &options.flags,
 894                        N_("cherry-pick all commits, even if unchanged"),
 895                        REBASE_FORCE),
 896                OPT_CMDMODE(0, "continue", &action, N_("continue"),
 897                            ACTION_CONTINUE),
 898                OPT_CMDMODE(0, "skip", &action,
 899                            N_("skip current patch and continue"), ACTION_SKIP),
 900                OPT_CMDMODE(0, "abort", &action,
 901                            N_("abort and check out the original branch"),
 902                            ACTION_ABORT),
 903                OPT_CMDMODE(0, "quit", &action,
 904                            N_("abort but keep HEAD where it is"), ACTION_QUIT),
 905                OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
 906                            "during an interactive rebase"), ACTION_EDIT_TODO),
 907                OPT_CMDMODE(0, "show-current-patch", &action,
 908                            N_("show the patch file being applied or merged"),
 909                            ACTION_SHOW_CURRENT_PATCH),
 910                { OPTION_CALLBACK, 'm', "merge", &options, NULL,
 911                        N_("use merging strategies to rebase"),
 912                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 913                        parse_opt_merge },
 914                { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
 915                        N_("let the user edit the list of commits to rebase"),
 916                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 917                        parse_opt_interactive },
 918                OPT_SET_INT('p', "preserve-merges", &options.type,
 919                            N_("try to recreate merges instead of ignoring "
 920                               "them"), REBASE_PRESERVE_MERGES),
 921                OPT_BOOL(0, "rerere-autoupdate",
 922                         &options.allow_rerere_autoupdate,
 923                         N_("allow rerere to update index with resolved "
 924                            "conflict")),
 925                OPT_BOOL('k', "keep-empty", &options.keep_empty,
 926                         N_("preserve empty commits during rebase")),
 927                OPT_BOOL(0, "autosquash", &options.autosquash,
 928                         N_("move commits that begin with "
 929                            "squash!/fixup! under -i")),
 930                { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
 931                        N_("GPG-sign commits"),
 932                        PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 933                OPT_BOOL(0, "autostash", &options.autostash,
 934                         N_("automatically stash/stash pop before and after")),
 935                OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
 936                                N_("add exec lines after each commit of the "
 937                                   "editable list")),
 938                { OPTION_CALLBACK, 'y', NULL, &opt_y, N_("<cmd>"),
 939                        N_("same as --reschedule-failed-exec -x <cmd>"),
 940                        PARSE_OPT_NONEG, parse_opt_y },
 941                OPT_BOOL(0, "allow-empty-message",
 942                         &options.allow_empty_message,
 943                         N_("allow rebasing commits with empty messages")),
 944                {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
 945                        N_("mode"),
 946                        N_("try to rebase merges instead of skipping them"),
 947                        PARSE_OPT_OPTARG, NULL, (intptr_t)""},
 948                OPT_BOOL(0, "fork-point", &fork_point,
 949                         N_("use 'merge-base --fork-point' to refine upstream")),
 950                OPT_STRING('s', "strategy", &options.strategy,
 951                           N_("strategy"), N_("use the given merge strategy")),
 952                OPT_STRING_LIST('X', "strategy-option", &strategy_options,
 953                                N_("option"),
 954                                N_("pass the argument through to the merge "
 955                                   "strategy")),
 956                OPT_BOOL(0, "root", &options.root,
 957                         N_("rebase all reachable commits up to the root(s)")),
 958                OPT_BOOL(0, "reschedule-failed-exec",
 959                         &options.reschedule_failed_exec,
 960                         N_("automatically re-schedule any `exec` that fails")),
 961                OPT_END(),
 962        };
 963        int i;
 964
 965        /*
 966         * NEEDSWORK: Once the builtin rebase has been tested enough
 967         * and git-legacy-rebase.sh is retired to contrib/, this preamble
 968         * can be removed.
 969         */
 970
 971        if (!use_builtin_rebase()) {
 972                const char *path = mkpath("%s/git-legacy-rebase",
 973                                          git_exec_path());
 974
 975                if (sane_execvp(path, (char **)argv) < 0)
 976                        die_errno(_("could not exec %s"), path);
 977                else
 978                        BUG("sane_execvp() returned???");
 979        }
 980
 981        if (argc == 2 && !strcmp(argv[1], "-h"))
 982                usage_with_options(builtin_rebase_usage,
 983                                   builtin_rebase_options);
 984
 985        prefix = setup_git_directory();
 986        trace_repo_setup(prefix);
 987        setup_work_tree();
 988
 989        git_config(rebase_config, &options);
 990
 991        strbuf_reset(&buf);
 992        strbuf_addf(&buf, "%s/applying", apply_dir());
 993        if(file_exists(buf.buf))
 994                die(_("It looks like 'git am' is in progress. Cannot rebase."));
 995
 996        if (is_directory(apply_dir())) {
 997                options.type = REBASE_AM;
 998                options.state_dir = apply_dir();
 999        } else if (is_directory(merge_dir())) {
1000                strbuf_reset(&buf);
1001                strbuf_addf(&buf, "%s/rewritten", merge_dir());
1002                if (is_directory(buf.buf)) {
1003                        options.type = REBASE_PRESERVE_MERGES;
1004                        options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1005                } else {
1006                        strbuf_reset(&buf);
1007                        strbuf_addf(&buf, "%s/interactive", merge_dir());
1008                        if(file_exists(buf.buf)) {
1009                                options.type = REBASE_INTERACTIVE;
1010                                options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1011                        } else
1012                                options.type = REBASE_MERGE;
1013                }
1014                options.state_dir = merge_dir();
1015        }
1016
1017        if (options.type != REBASE_UNSPECIFIED)
1018                in_progress = 1;
1019
1020        total_argc = argc;
1021        argc = parse_options(argc, argv, prefix,
1022                             builtin_rebase_options,
1023                             builtin_rebase_usage, 0);
1024
1025        if (action != NO_ACTION && total_argc != 2) {
1026                usage_with_options(builtin_rebase_usage,
1027                                   builtin_rebase_options);
1028        }
1029
1030        if (argc > 2)
1031                usage_with_options(builtin_rebase_usage,
1032                                   builtin_rebase_options);
1033
1034        if (action != NO_ACTION && !in_progress)
1035                die(_("No rebase in progress?"));
1036        setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1037
1038        if (action == ACTION_EDIT_TODO && !is_interactive(&options))
1039                die(_("The --edit-todo action can only be used during "
1040                      "interactive rebase."));
1041
1042        switch (action) {
1043        case ACTION_CONTINUE: {
1044                struct object_id head;
1045                struct lock_file lock_file = LOCK_INIT;
1046                int fd;
1047
1048                options.action = "continue";
1049                set_reflog_action(&options);
1050
1051                /* Sanity check */
1052                if (get_oid("HEAD", &head))
1053                        die(_("Cannot read HEAD"));
1054
1055                fd = hold_locked_index(&lock_file, 0);
1056                if (read_index(the_repository->index) < 0)
1057                        die(_("could not read index"));
1058                refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1059                              NULL);
1060                if (0 <= fd)
1061                        update_index_if_able(the_repository->index,
1062                                             &lock_file);
1063                rollback_lock_file(&lock_file);
1064
1065                if (has_unstaged_changes(the_repository, 1)) {
1066                        puts(_("You must edit all merge conflicts and then\n"
1067                               "mark them as resolved using git add"));
1068                        exit(1);
1069                }
1070                if (read_basic_state(&options))
1071                        exit(1);
1072                goto run_rebase;
1073        }
1074        case ACTION_SKIP: {
1075                struct string_list merge_rr = STRING_LIST_INIT_DUP;
1076
1077                options.action = "skip";
1078                set_reflog_action(&options);
1079
1080                rerere_clear(the_repository, &merge_rr);
1081                string_list_clear(&merge_rr, 1);
1082
1083                if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1084                               NULL, NULL) < 0)
1085                        die(_("could not discard worktree changes"));
1086                remove_branch_state(the_repository);
1087                if (read_basic_state(&options))
1088                        exit(1);
1089                goto run_rebase;
1090        }
1091        case ACTION_ABORT: {
1092                struct string_list merge_rr = STRING_LIST_INIT_DUP;
1093                options.action = "abort";
1094                set_reflog_action(&options);
1095
1096                rerere_clear(the_repository, &merge_rr);
1097                string_list_clear(&merge_rr, 1);
1098
1099                if (read_basic_state(&options))
1100                        exit(1);
1101                if (reset_head(&options.orig_head, "reset",
1102                               options.head_name, RESET_HEAD_HARD,
1103                               NULL, NULL) < 0)
1104                        die(_("could not move back to %s"),
1105                            oid_to_hex(&options.orig_head));
1106                remove_branch_state(the_repository);
1107                ret = finish_rebase(&options);
1108                goto cleanup;
1109        }
1110        case ACTION_QUIT: {
1111                strbuf_reset(&buf);
1112                strbuf_addstr(&buf, options.state_dir);
1113                ret = !!remove_dir_recursively(&buf, 0);
1114                if (ret)
1115                        die(_("could not remove '%s'"), options.state_dir);
1116                goto cleanup;
1117        }
1118        case ACTION_EDIT_TODO:
1119                options.action = "edit-todo";
1120                options.dont_finish_rebase = 1;
1121                goto run_rebase;
1122        case ACTION_SHOW_CURRENT_PATCH:
1123                options.action = "show-current-patch";
1124                options.dont_finish_rebase = 1;
1125                goto run_rebase;
1126        case NO_ACTION:
1127                break;
1128        default:
1129                BUG("action: %d", action);
1130        }
1131
1132        /* Make sure no rebase is in progress */
1133        if (in_progress) {
1134                const char *last_slash = strrchr(options.state_dir, '/');
1135                const char *state_dir_base =
1136                        last_slash ? last_slash + 1 : options.state_dir;
1137                const char *cmd_live_rebase =
1138                        "git rebase (--continue | --abort | --skip)";
1139                strbuf_reset(&buf);
1140                strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1141                die(_("It seems that there is already a %s directory, and\n"
1142                      "I wonder if you are in the middle of another rebase.  "
1143                      "If that is the\n"
1144                      "case, please try\n\t%s\n"
1145                      "If that is not the case, please\n\t%s\n"
1146                      "and run me again.  I am stopping in case you still "
1147                      "have something\n"
1148                      "valuable there.\n"),
1149                    state_dir_base, cmd_live_rebase, buf.buf);
1150        }
1151
1152        for (i = 0; i < options.git_am_opts.argc; i++) {
1153                const char *option = options.git_am_opts.argv[i], *p;
1154                if (!strcmp(option, "--committer-date-is-author-date") ||
1155                    !strcmp(option, "--ignore-date") ||
1156                    !strcmp(option, "--whitespace=fix") ||
1157                    !strcmp(option, "--whitespace=strip"))
1158                        options.flags |= REBASE_FORCE;
1159                else if (skip_prefix(option, "-C", &p)) {
1160                        while (*p)
1161                                if (!isdigit(*(p++)))
1162                                        die(_("switch `C' expects a "
1163                                              "numerical value"));
1164                } else if (skip_prefix(option, "--whitespace=", &p)) {
1165                        if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1166                            strcmp(p, "error") && strcmp(p, "error-all"))
1167                                die("Invalid whitespace option: '%s'", p);
1168                }
1169        }
1170
1171        if (!(options.flags & REBASE_NO_QUIET))
1172                argv_array_push(&options.git_am_opts, "-q");
1173
1174        if (options.keep_empty)
1175                imply_interactive(&options, "--keep-empty");
1176
1177        if (gpg_sign) {
1178                free(options.gpg_sign_opt);
1179                options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1180        }
1181
1182        if (exec.nr) {
1183                int i;
1184
1185                imply_interactive(&options, "--exec");
1186
1187                strbuf_reset(&buf);
1188                for (i = 0; i < exec.nr; i++)
1189                        strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1190                options.cmd = xstrdup(buf.buf);
1191        }
1192
1193        if (rebase_merges) {
1194                if (!*rebase_merges)
1195                        ; /* default mode; do nothing */
1196                else if (!strcmp("rebase-cousins", rebase_merges))
1197                        options.rebase_cousins = 1;
1198                else if (strcmp("no-rebase-cousins", rebase_merges))
1199                        die(_("Unknown mode: %s"), rebase_merges);
1200                options.rebase_merges = 1;
1201                imply_interactive(&options, "--rebase-merges");
1202        }
1203
1204        if (strategy_options.nr) {
1205                int i;
1206
1207                if (!options.strategy)
1208                        options.strategy = "recursive";
1209
1210                strbuf_reset(&buf);
1211                for (i = 0; i < strategy_options.nr; i++)
1212                        strbuf_addf(&buf, " --%s",
1213                                    strategy_options.items[i].string);
1214                options.strategy_opts = xstrdup(buf.buf);
1215        }
1216
1217        if (options.strategy) {
1218                options.strategy = xstrdup(options.strategy);
1219                switch (options.type) {
1220                case REBASE_AM:
1221                        die(_("--strategy requires --merge or --interactive"));
1222                case REBASE_MERGE:
1223                case REBASE_INTERACTIVE:
1224                case REBASE_PRESERVE_MERGES:
1225                        /* compatible */
1226                        break;
1227                case REBASE_UNSPECIFIED:
1228                        options.type = REBASE_MERGE;
1229                        break;
1230                default:
1231                        BUG("unhandled rebase type (%d)", options.type);
1232                }
1233        }
1234
1235        if (options.root && !options.onto_name)
1236                imply_interactive(&options, "--root without --onto");
1237
1238        if (isatty(2) && options.flags & REBASE_NO_QUIET)
1239                strbuf_addstr(&options.git_format_patch_opt, " --progress");
1240
1241        switch (options.type) {
1242        case REBASE_MERGE:
1243        case REBASE_INTERACTIVE:
1244        case REBASE_PRESERVE_MERGES:
1245                options.state_dir = merge_dir();
1246                break;
1247        case REBASE_AM:
1248                options.state_dir = apply_dir();
1249                break;
1250        default:
1251                /* the default rebase backend is `--am` */
1252                options.type = REBASE_AM;
1253                options.state_dir = apply_dir();
1254                break;
1255        }
1256
1257        if (options.reschedule_failed_exec && !is_interactive(&options))
1258                die(_("--reschedule-failed-exec requires an interactive rebase"));
1259
1260        if (options.git_am_opts.argc) {
1261                /* all am options except -q are compatible only with --am */
1262                for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1263                        if (strcmp(options.git_am_opts.argv[i], "-q"))
1264                                break;
1265
1266                if (is_interactive(&options) && i >= 0)
1267                        die(_("error: cannot combine interactive options "
1268                              "(--interactive, --exec, --rebase-merges, "
1269                              "--preserve-merges, --keep-empty, --root + "
1270                              "--onto) with am options (%s)"), buf.buf);
1271                if (options.type == REBASE_MERGE && i >= 0)
1272                        die(_("error: cannot combine merge options (--merge, "
1273                              "--strategy, --strategy-option) with am options "
1274                              "(%s)"), buf.buf);
1275        }
1276
1277        if (options.signoff) {
1278                if (options.type == REBASE_PRESERVE_MERGES)
1279                        die("cannot combine '--signoff' with "
1280                            "'--preserve-merges'");
1281                argv_array_push(&options.git_am_opts, "--signoff");
1282                options.flags |= REBASE_FORCE;
1283        }
1284
1285        if (options.type == REBASE_PRESERVE_MERGES) {
1286                /*
1287                 * Note: incompatibility with --signoff handled in signoff block above
1288                 * Note: incompatibility with --interactive is just a strong warning;
1289                 *       git-rebase.txt caveats with "unless you know what you are doing"
1290                 */
1291                if (options.rebase_merges)
1292                        die(_("error: cannot combine '--preserve-merges' with "
1293                              "'--rebase-merges'"));
1294
1295                if (options.reschedule_failed_exec)
1296                        die(_("error: cannot combine '--preserve-merges' with "
1297                              "'--reschedule-failed-exec'"));
1298        }
1299
1300        if (options.rebase_merges) {
1301                if (strategy_options.nr)
1302                        die(_("error: cannot combine '--rebase-merges' with "
1303                              "'--strategy-option'"));
1304                if (options.strategy)
1305                        die(_("error: cannot combine '--rebase-merges' with "
1306                              "'--strategy'"));
1307        }
1308
1309        if (!options.root) {
1310                if (argc < 1) {
1311                        struct branch *branch;
1312
1313                        branch = branch_get(NULL);
1314                        options.upstream_name = branch_get_upstream(branch,
1315                                                                    NULL);
1316                        if (!options.upstream_name)
1317                                error_on_missing_default_upstream();
1318                        if (fork_point < 0)
1319                                fork_point = 1;
1320                } else {
1321                        options.upstream_name = argv[0];
1322                        argc--;
1323                        argv++;
1324                        if (!strcmp(options.upstream_name, "-"))
1325                                options.upstream_name = "@{-1}";
1326                }
1327                options.upstream = peel_committish(options.upstream_name);
1328                if (!options.upstream)
1329                        die(_("invalid upstream '%s'"), options.upstream_name);
1330                options.upstream_arg = options.upstream_name;
1331        } else {
1332                if (!options.onto_name) {
1333                        if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1334                                        &squash_onto, NULL, NULL) < 0)
1335                                die(_("Could not create new root commit"));
1336                        options.squash_onto = &squash_onto;
1337                        options.onto_name = squash_onto_name =
1338                                xstrdup(oid_to_hex(&squash_onto));
1339                }
1340                options.upstream_name = NULL;
1341                options.upstream = NULL;
1342                if (argc > 1)
1343                        usage_with_options(builtin_rebase_usage,
1344                                           builtin_rebase_options);
1345                options.upstream_arg = "--root";
1346        }
1347
1348        /* Make sure the branch to rebase onto is valid. */
1349        if (!options.onto_name)
1350                options.onto_name = options.upstream_name;
1351        if (strstr(options.onto_name, "...")) {
1352                if (get_oid_mb(options.onto_name, &merge_base) < 0)
1353                        die(_("'%s': need exactly one merge base"),
1354                            options.onto_name);
1355                options.onto = lookup_commit_or_die(&merge_base,
1356                                                    options.onto_name);
1357        } else {
1358                options.onto = peel_committish(options.onto_name);
1359                if (!options.onto)
1360                        die(_("Does not point to a valid commit '%s'"),
1361                                options.onto_name);
1362        }
1363
1364        /*
1365         * If the branch to rebase is given, that is the branch we will rebase
1366         * branch_name -- branch/commit being rebased, or
1367         *                HEAD (already detached)
1368         * orig_head -- commit object name of tip of the branch before rebasing
1369         * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1370         */
1371        if (argc == 1) {
1372                /* Is it "rebase other branchname" or "rebase other commit"? */
1373                branch_name = argv[0];
1374                options.switch_to = argv[0];
1375
1376                /* Is it a local branch? */
1377                strbuf_reset(&buf);
1378                strbuf_addf(&buf, "refs/heads/%s", branch_name);
1379                if (!read_ref(buf.buf, &options.orig_head))
1380                        options.head_name = xstrdup(buf.buf);
1381                /* If not is it a valid ref (branch or commit)? */
1382                else if (!get_oid(branch_name, &options.orig_head))
1383                        options.head_name = NULL;
1384                else
1385                        die(_("fatal: no such branch/commit '%s'"),
1386                            branch_name);
1387        } else if (argc == 0) {
1388                /* Do not need to switch branches, we are already on it. */
1389                options.head_name =
1390                        xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1391                                         &flags));
1392                if (!options.head_name)
1393                        die(_("No such ref: %s"), "HEAD");
1394                if (flags & REF_ISSYMREF) {
1395                        if (!skip_prefix(options.head_name,
1396                                         "refs/heads/", &branch_name))
1397                                branch_name = options.head_name;
1398
1399                } else {
1400                        free(options.head_name);
1401                        options.head_name = NULL;
1402                        branch_name = "HEAD";
1403                }
1404                if (get_oid("HEAD", &options.orig_head))
1405                        die(_("Could not resolve HEAD to a revision"));
1406        } else
1407                BUG("unexpected number of arguments left to parse");
1408
1409        if (fork_point > 0) {
1410                struct commit *head =
1411                        lookup_commit_reference(the_repository,
1412                                                &options.orig_head);
1413                options.restrict_revision =
1414                        get_fork_point(options.upstream_name, head);
1415        }
1416
1417        if (read_index(the_repository->index) < 0)
1418                die(_("could not read index"));
1419
1420        if (options.autostash) {
1421                struct lock_file lock_file = LOCK_INIT;
1422                int fd;
1423
1424                fd = hold_locked_index(&lock_file, 0);
1425                refresh_cache(REFRESH_QUIET);
1426                if (0 <= fd)
1427                        update_index_if_able(&the_index, &lock_file);
1428                rollback_lock_file(&lock_file);
1429
1430                if (has_unstaged_changes(the_repository, 1) ||
1431                    has_uncommitted_changes(the_repository, 1)) {
1432                        const char *autostash =
1433                                state_dir_path("autostash", &options);
1434                        struct child_process stash = CHILD_PROCESS_INIT;
1435                        struct object_id oid;
1436                        struct commit *head =
1437                                lookup_commit_reference(the_repository,
1438                                                        &options.orig_head);
1439
1440                        argv_array_pushl(&stash.args,
1441                                         "stash", "create", "autostash", NULL);
1442                        stash.git_cmd = 1;
1443                        stash.no_stdin = 1;
1444                        strbuf_reset(&buf);
1445                        if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1446                                die(_("Cannot autostash"));
1447                        strbuf_trim_trailing_newline(&buf);
1448                        if (get_oid(buf.buf, &oid))
1449                                die(_("Unexpected stash response: '%s'"),
1450                                    buf.buf);
1451                        strbuf_reset(&buf);
1452                        strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1453
1454                        if (safe_create_leading_directories_const(autostash))
1455                                die(_("Could not create directory for '%s'"),
1456                                    options.state_dir);
1457                        write_file(autostash, "%s", oid_to_hex(&oid));
1458                        printf(_("Created autostash: %s\n"), buf.buf);
1459                        if (reset_head(&head->object.oid, "reset --hard",
1460                                       NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
1461                                die(_("could not reset --hard"));
1462                        printf(_("HEAD is now at %s"),
1463                               find_unique_abbrev(&head->object.oid,
1464                                                  DEFAULT_ABBREV));
1465                        strbuf_reset(&buf);
1466                        pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
1467                        if (buf.len > 0)
1468                                printf(" %s", buf.buf);
1469                        putchar('\n');
1470
1471                        if (discard_index(the_repository->index) < 0 ||
1472                                read_index(the_repository->index) < 0)
1473                                die(_("could not read index"));
1474                }
1475        }
1476
1477        if (require_clean_work_tree(the_repository, "rebase",
1478                                    _("Please commit or stash them."), 1, 1)) {
1479                ret = 1;
1480                goto cleanup;
1481        }
1482
1483        /*
1484         * Now we are rebasing commits upstream..orig_head (or with --root,
1485         * everything leading up to orig_head) on top of onto.
1486         */
1487
1488        /*
1489         * Check if we are already based on onto with linear history,
1490         * but this should be done only when upstream and onto are the same
1491         * and if this is not an interactive rebase.
1492         */
1493        if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
1494            !is_interactive(&options) && !options.restrict_revision &&
1495            options.upstream &&
1496            !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
1497                int flag;
1498
1499                if (!(options.flags & REBASE_FORCE)) {
1500                        /* Lazily switch to the target branch if needed... */
1501                        if (options.switch_to) {
1502                                struct object_id oid;
1503
1504                                if (get_oid(options.switch_to, &oid) < 0) {
1505                                        ret = !!error(_("could not parse '%s'"),
1506                                                      options.switch_to);
1507                                        goto cleanup;
1508                                }
1509
1510                                strbuf_reset(&buf);
1511                                strbuf_addf(&buf, "%s: checkout %s",
1512                                            getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
1513                                            options.switch_to);
1514                                if (reset_head(&oid, "checkout",
1515                                               options.head_name,
1516                                               RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
1517                                               NULL, buf.buf) < 0) {
1518                                        ret = !!error(_("could not switch to "
1519                                                        "%s"),
1520                                                      options.switch_to);
1521                                        goto cleanup;
1522                                }
1523                        }
1524
1525                        if (!(options.flags & REBASE_NO_QUIET))
1526                                ; /* be quiet */
1527                        else if (!strcmp(branch_name, "HEAD") &&
1528                                 resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1529                                puts(_("HEAD is up to date."));
1530                        else
1531                                printf(_("Current branch %s is up to date.\n"),
1532                                       branch_name);
1533                        ret = !!finish_rebase(&options);
1534                        goto cleanup;
1535                } else if (!(options.flags & REBASE_NO_QUIET))
1536                        ; /* be quiet */
1537                else if (!strcmp(branch_name, "HEAD") &&
1538                         resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1539                        puts(_("HEAD is up to date, rebase forced."));
1540                else
1541                        printf(_("Current branch %s is up to date, rebase "
1542                                 "forced.\n"), branch_name);
1543        }
1544
1545        /* If a hook exists, give it a chance to interrupt*/
1546        if (!ok_to_skip_pre_rebase &&
1547            run_hook_le(NULL, "pre-rebase", options.upstream_arg,
1548                        argc ? argv[0] : NULL, NULL))
1549                die(_("The pre-rebase hook refused to rebase."));
1550
1551        if (options.flags & REBASE_DIFFSTAT) {
1552                struct diff_options opts;
1553
1554                if (options.flags & REBASE_VERBOSE) {
1555                        if (is_null_oid(&merge_base))
1556                                printf(_("Changes to %s:\n"),
1557                                       oid_to_hex(&options.onto->object.oid));
1558                        else
1559                                printf(_("Changes from %s to %s:\n"),
1560                                       oid_to_hex(&merge_base),
1561                                       oid_to_hex(&options.onto->object.oid));
1562                }
1563
1564                /* We want color (if set), but no pager */
1565                diff_setup(&opts);
1566                opts.stat_width = -1; /* use full terminal width */
1567                opts.stat_graph_width = -1; /* respect statGraphWidth config */
1568                opts.output_format |=
1569                        DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1570                opts.detect_rename = DIFF_DETECT_RENAME;
1571                diff_setup_done(&opts);
1572                diff_tree_oid(is_null_oid(&merge_base) ?
1573                              the_hash_algo->empty_tree : &merge_base,
1574                              &options.onto->object.oid, "", &opts);
1575                diffcore_std(&opts);
1576                diff_flush(&opts);
1577        }
1578
1579        if (is_interactive(&options))
1580                goto run_rebase;
1581
1582        /* Detach HEAD and reset the tree */
1583        if (options.flags & REBASE_NO_QUIET)
1584                printf(_("First, rewinding head to replay your work on top of "
1585                         "it...\n"));
1586
1587        strbuf_addf(&msg, "%s: checkout %s",
1588                    getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
1589        if (reset_head(&options.onto->object.oid, "checkout", NULL,
1590                       RESET_HEAD_DETACH | RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
1591                       NULL, msg.buf))
1592                die(_("Could not detach HEAD"));
1593        strbuf_release(&msg);
1594
1595        /*
1596         * If the onto is a proper descendant of the tip of the branch, then
1597         * we just fast-forwarded.
1598         */
1599        strbuf_reset(&msg);
1600        if (!oidcmp(&merge_base, &options.orig_head)) {
1601                printf(_("Fast-forwarded %s to %s.\n"),
1602                        branch_name, options.onto_name);
1603                strbuf_addf(&msg, "rebase finished: %s onto %s",
1604                        options.head_name ? options.head_name : "detached HEAD",
1605                        oid_to_hex(&options.onto->object.oid));
1606                reset_head(NULL, "Fast-forwarded", options.head_name, 0,
1607                           "HEAD", msg.buf);
1608                strbuf_release(&msg);
1609                ret = !!finish_rebase(&options);
1610                goto cleanup;
1611        }
1612
1613        strbuf_addf(&revisions, "%s..%s",
1614                    options.root ? oid_to_hex(&options.onto->object.oid) :
1615                    (options.restrict_revision ?
1616                     oid_to_hex(&options.restrict_revision->object.oid) :
1617                     oid_to_hex(&options.upstream->object.oid)),
1618                    oid_to_hex(&options.orig_head));
1619
1620        options.revisions = revisions.buf;
1621
1622run_rebase:
1623        ret = !!run_specific_rebase(&options);
1624
1625cleanup:
1626        strbuf_release(&revisions);
1627        free(options.head_name);
1628        free(options.gpg_sign_opt);
1629        free(options.cmd);
1630        free(squash_onto_name);
1631        return ret;
1632}