builtin / rebase.con commit git-rebase, sequencer: extend --quiet option for the interactive machinery (899b49c)
   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};
 108
 109static int is_interactive(struct rebase_options *opts)
 110{
 111        return opts->type == REBASE_INTERACTIVE ||
 112                opts->type == REBASE_PRESERVE_MERGES;
 113}
 114
 115static void imply_interactive(struct rebase_options *opts, const char *option)
 116{
 117        switch (opts->type) {
 118        case REBASE_AM:
 119                die(_("%s requires an interactive rebase"), option);
 120                break;
 121        case REBASE_INTERACTIVE:
 122        case REBASE_PRESERVE_MERGES:
 123                break;
 124        case REBASE_MERGE:
 125                /* we silently *upgrade* --merge to --interactive if needed */
 126        default:
 127                opts->type = REBASE_INTERACTIVE; /* implied */
 128                break;
 129        }
 130}
 131
 132/* Returns the filename prefixed by the state_dir */
 133static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 134{
 135        static struct strbuf path = STRBUF_INIT;
 136        static size_t prefix_len;
 137
 138        if (!prefix_len) {
 139                strbuf_addf(&path, "%s/", opts->state_dir);
 140                prefix_len = path.len;
 141        }
 142
 143        strbuf_setlen(&path, prefix_len);
 144        strbuf_addstr(&path, filename);
 145        return path.buf;
 146}
 147
 148/* Read one file, then strip line endings */
 149static int read_one(const char *path, struct strbuf *buf)
 150{
 151        if (strbuf_read_file(buf, path, 0) < 0)
 152                return error_errno(_("could not read '%s'"), path);
 153        strbuf_trim_trailing_newline(buf);
 154        return 0;
 155}
 156
 157/* Initialize the rebase options from the state directory. */
 158static int read_basic_state(struct rebase_options *opts)
 159{
 160        struct strbuf head_name = STRBUF_INIT;
 161        struct strbuf buf = STRBUF_INIT;
 162        struct object_id oid;
 163
 164        if (read_one(state_dir_path("head-name", opts), &head_name) ||
 165            read_one(state_dir_path("onto", opts), &buf))
 166                return -1;
 167        opts->head_name = starts_with(head_name.buf, "refs/") ?
 168                xstrdup(head_name.buf) : NULL;
 169        strbuf_release(&head_name);
 170        if (get_oid(buf.buf, &oid))
 171                return error(_("could not get 'onto': '%s'"), buf.buf);
 172        opts->onto = lookup_commit_or_die(&oid, buf.buf);
 173
 174        /*
 175         * We always write to orig-head, but interactive rebase used to write to
 176         * head. Fall back to reading from head to cover for the case that the
 177         * user upgraded git with an ongoing interactive rebase.
 178         */
 179        strbuf_reset(&buf);
 180        if (file_exists(state_dir_path("orig-head", opts))) {
 181                if (read_one(state_dir_path("orig-head", opts), &buf))
 182                        return -1;
 183        } else if (read_one(state_dir_path("head", opts), &buf))
 184                return -1;
 185        if (get_oid(buf.buf, &opts->orig_head))
 186                return error(_("invalid orig-head: '%s'"), buf.buf);
 187
 188        if (file_exists(state_dir_path("quiet", opts)))
 189                opts->flags &= ~REBASE_NO_QUIET;
 190        else
 191                opts->flags |= REBASE_NO_QUIET;
 192
 193        if (file_exists(state_dir_path("verbose", opts)))
 194                opts->flags |= REBASE_VERBOSE;
 195
 196        if (file_exists(state_dir_path("signoff", opts))) {
 197                opts->signoff = 1;
 198                opts->flags |= REBASE_FORCE;
 199        }
 200
 201        if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 202                strbuf_reset(&buf);
 203                if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 204                            &buf))
 205                        return -1;
 206                if (!strcmp(buf.buf, "--rerere-autoupdate"))
 207                        opts->allow_rerere_autoupdate = 1;
 208                else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 209                        opts->allow_rerere_autoupdate = 0;
 210                else
 211                        warning(_("ignoring invalid allow_rerere_autoupdate: "
 212                                  "'%s'"), buf.buf);
 213        } else
 214                opts->allow_rerere_autoupdate = -1;
 215
 216        if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 217                strbuf_reset(&buf);
 218                if (read_one(state_dir_path("gpg_sign_opt", opts),
 219                            &buf))
 220                        return -1;
 221                free(opts->gpg_sign_opt);
 222                opts->gpg_sign_opt = xstrdup(buf.buf);
 223        }
 224
 225        if (file_exists(state_dir_path("strategy", opts))) {
 226                strbuf_reset(&buf);
 227                if (read_one(state_dir_path("strategy", opts), &buf))
 228                        return -1;
 229                free(opts->strategy);
 230                opts->strategy = xstrdup(buf.buf);
 231        }
 232
 233        if (file_exists(state_dir_path("strategy_opts", opts))) {
 234                strbuf_reset(&buf);
 235                if (read_one(state_dir_path("strategy_opts", opts), &buf))
 236                        return -1;
 237                free(opts->strategy_opts);
 238                opts->strategy_opts = xstrdup(buf.buf);
 239        }
 240
 241        strbuf_release(&buf);
 242
 243        return 0;
 244}
 245
 246static int apply_autostash(struct rebase_options *opts)
 247{
 248        const char *path = state_dir_path("autostash", opts);
 249        struct strbuf autostash = STRBUF_INIT;
 250        struct child_process stash_apply = CHILD_PROCESS_INIT;
 251
 252        if (!file_exists(path))
 253                return 0;
 254
 255        if (read_one(path, &autostash))
 256                return error(_("Could not read '%s'"), path);
 257        /* Ensure that the hash is not mistaken for a number */
 258        strbuf_addstr(&autostash, "^0");
 259        argv_array_pushl(&stash_apply.args,
 260                         "stash", "apply", autostash.buf, NULL);
 261        stash_apply.git_cmd = 1;
 262        stash_apply.no_stderr = stash_apply.no_stdout =
 263                stash_apply.no_stdin = 1;
 264        if (!run_command(&stash_apply))
 265                printf(_("Applied autostash.\n"));
 266        else {
 267                struct argv_array args = ARGV_ARRAY_INIT;
 268                int res = 0;
 269
 270                argv_array_pushl(&args,
 271                                 "stash", "store", "-m", "autostash", "-q",
 272                                 autostash.buf, NULL);
 273                if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 274                        res = error(_("Cannot store %s"), autostash.buf);
 275                argv_array_clear(&args);
 276                strbuf_release(&autostash);
 277                if (res)
 278                        return res;
 279
 280                fprintf(stderr,
 281                        _("Applying autostash resulted in conflicts.\n"
 282                          "Your changes are safe in the stash.\n"
 283                          "You can run \"git stash pop\" or \"git stash drop\" "
 284                          "at any time.\n"));
 285        }
 286
 287        strbuf_release(&autostash);
 288        return 0;
 289}
 290
 291static int finish_rebase(struct rebase_options *opts)
 292{
 293        struct strbuf dir = STRBUF_INIT;
 294        const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 295
 296        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 297        apply_autostash(opts);
 298        close_all_packs(the_repository->objects);
 299        /*
 300         * We ignore errors in 'gc --auto', since the
 301         * user should see them.
 302         */
 303        run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 304        strbuf_addstr(&dir, opts->state_dir);
 305        remove_dir_recursively(&dir, 0);
 306        strbuf_release(&dir);
 307
 308        return 0;
 309}
 310
 311static struct commit *peel_committish(const char *name)
 312{
 313        struct object *obj;
 314        struct object_id oid;
 315
 316        if (get_oid(name, &oid))
 317                return NULL;
 318        obj = parse_object(the_repository, &oid);
 319        return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 320}
 321
 322static void add_var(struct strbuf *buf, const char *name, const char *value)
 323{
 324        if (!value)
 325                strbuf_addf(buf, "unset %s; ", name);
 326        else {
 327                strbuf_addf(buf, "%s=", name);
 328                sq_quote_buf(buf, value);
 329                strbuf_addstr(buf, "; ");
 330        }
 331}
 332
 333static const char *resolvemsg =
 334N_("Resolve all conflicts manually, mark them as resolved with\n"
 335"\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 336"You can instead skip this commit: run \"git rebase --skip\".\n"
 337"To abort and get back to the state before \"git rebase\", run "
 338"\"git rebase --abort\".");
 339
 340static int run_specific_rebase(struct rebase_options *opts)
 341{
 342        const char *argv[] = { NULL, NULL };
 343        struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
 344        int status;
 345        const char *backend, *backend_func;
 346
 347        if (opts->type == REBASE_INTERACTIVE) {
 348                /* Run builtin interactive rebase */
 349                struct child_process child = CHILD_PROCESS_INIT;
 350
 351                argv_array_pushf(&child.env_array, "GIT_CHERRY_PICK_HELP=%s",
 352                                 resolvemsg);
 353                if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 354                        argv_array_push(&child.env_array, "GIT_EDITOR=:");
 355                        opts->autosquash = 0;
 356                }
 357
 358                child.git_cmd = 1;
 359                argv_array_push(&child.args, "rebase--interactive");
 360
 361                if (opts->action)
 362                        argv_array_pushf(&child.args, "--%s", opts->action);
 363                if (opts->keep_empty)
 364                        argv_array_push(&child.args, "--keep-empty");
 365                if (opts->rebase_merges)
 366                        argv_array_push(&child.args, "--rebase-merges");
 367                if (opts->rebase_cousins)
 368                        argv_array_push(&child.args, "--rebase-cousins");
 369                if (opts->autosquash)
 370                        argv_array_push(&child.args, "--autosquash");
 371                if (opts->flags & REBASE_VERBOSE)
 372                        argv_array_push(&child.args, "--verbose");
 373                if (opts->flags & REBASE_FORCE)
 374                        argv_array_push(&child.args, "--no-ff");
 375                if (opts->restrict_revision)
 376                        argv_array_pushf(&child.args,
 377                                         "--restrict-revision=^%s",
 378                                         oid_to_hex(&opts->restrict_revision->object.oid));
 379                if (opts->upstream)
 380                        argv_array_pushf(&child.args, "--upstream=%s",
 381                                         oid_to_hex(&opts->upstream->object.oid));
 382                if (opts->onto)
 383                        argv_array_pushf(&child.args, "--onto=%s",
 384                                         oid_to_hex(&opts->onto->object.oid));
 385                if (opts->squash_onto)
 386                        argv_array_pushf(&child.args, "--squash-onto=%s",
 387                                         oid_to_hex(opts->squash_onto));
 388                if (opts->onto_name)
 389                        argv_array_pushf(&child.args, "--onto-name=%s",
 390                                         opts->onto_name);
 391                argv_array_pushf(&child.args, "--head-name=%s",
 392                                 opts->head_name ?
 393                                 opts->head_name : "detached HEAD");
 394                if (opts->strategy)
 395                        argv_array_pushf(&child.args, "--strategy=%s",
 396                                         opts->strategy);
 397                if (opts->strategy_opts)
 398                        argv_array_pushf(&child.args, "--strategy-opts=%s",
 399                                         opts->strategy_opts);
 400                if (opts->switch_to)
 401                        argv_array_pushf(&child.args, "--switch-to=%s",
 402                                         opts->switch_to);
 403                if (opts->cmd)
 404                        argv_array_pushf(&child.args, "--cmd=%s", opts->cmd);
 405                if (opts->allow_empty_message)
 406                        argv_array_push(&child.args, "--allow-empty-message");
 407                if (opts->allow_rerere_autoupdate > 0)
 408                        argv_array_push(&child.args, "--rerere-autoupdate");
 409                else if (opts->allow_rerere_autoupdate == 0)
 410                        argv_array_push(&child.args, "--no-rerere-autoupdate");
 411                if (opts->gpg_sign_opt)
 412                        argv_array_push(&child.args, opts->gpg_sign_opt);
 413                if (opts->signoff)
 414                        argv_array_push(&child.args, "--signoff");
 415
 416                status = run_command(&child);
 417                goto finished_rebase;
 418        }
 419
 420        add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 421        add_var(&script_snippet, "state_dir", opts->state_dir);
 422
 423        add_var(&script_snippet, "upstream_name", opts->upstream_name);
 424        add_var(&script_snippet, "upstream", opts->upstream ?
 425                oid_to_hex(&opts->upstream->object.oid) : NULL);
 426        add_var(&script_snippet, "head_name",
 427                opts->head_name ? opts->head_name : "detached HEAD");
 428        add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 429        add_var(&script_snippet, "onto", opts->onto ?
 430                oid_to_hex(&opts->onto->object.oid) : NULL);
 431        add_var(&script_snippet, "onto_name", opts->onto_name);
 432        add_var(&script_snippet, "revisions", opts->revisions);
 433        add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 434                oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 435        add_var(&script_snippet, "GIT_QUIET",
 436                opts->flags & REBASE_NO_QUIET ? "" : "t");
 437        sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
 438        add_var(&script_snippet, "git_am_opt", buf.buf);
 439        strbuf_release(&buf);
 440        add_var(&script_snippet, "verbose",
 441                opts->flags & REBASE_VERBOSE ? "t" : "");
 442        add_var(&script_snippet, "diffstat",
 443                opts->flags & REBASE_DIFFSTAT ? "t" : "");
 444        add_var(&script_snippet, "force_rebase",
 445                opts->flags & REBASE_FORCE ? "t" : "");
 446        if (opts->switch_to)
 447                add_var(&script_snippet, "switch_to", opts->switch_to);
 448        add_var(&script_snippet, "action", opts->action ? opts->action : "");
 449        add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
 450        add_var(&script_snippet, "allow_rerere_autoupdate",
 451                opts->allow_rerere_autoupdate < 0 ? "" :
 452                opts->allow_rerere_autoupdate ?
 453                "--rerere-autoupdate" : "--no-rerere-autoupdate");
 454        add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
 455        add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
 456        add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
 457        add_var(&script_snippet, "cmd", opts->cmd);
 458        add_var(&script_snippet, "allow_empty_message",
 459                opts->allow_empty_message ?  "--allow-empty-message" : "");
 460        add_var(&script_snippet, "rebase_merges",
 461                opts->rebase_merges ? "t" : "");
 462        add_var(&script_snippet, "rebase_cousins",
 463                opts->rebase_cousins ? "t" : "");
 464        add_var(&script_snippet, "strategy", opts->strategy);
 465        add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
 466        add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
 467        add_var(&script_snippet, "squash_onto",
 468                opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
 469        add_var(&script_snippet, "git_format_patch_opt",
 470                opts->git_format_patch_opt.buf);
 471
 472        if (is_interactive(opts) &&
 473            !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 474                strbuf_addstr(&script_snippet,
 475                              "GIT_EDITOR=:; export GIT_EDITOR; ");
 476                opts->autosquash = 0;
 477        }
 478
 479        switch (opts->type) {
 480        case REBASE_AM:
 481                backend = "git-rebase--am";
 482                backend_func = "git_rebase__am";
 483                break;
 484        case REBASE_MERGE:
 485                backend = "git-rebase--merge";
 486                backend_func = "git_rebase__merge";
 487                break;
 488        case REBASE_PRESERVE_MERGES:
 489                backend = "git-rebase--preserve-merges";
 490                backend_func = "git_rebase__preserve_merges";
 491                break;
 492        default:
 493                BUG("Unhandled rebase type %d", opts->type);
 494                break;
 495        }
 496
 497        strbuf_addf(&script_snippet,
 498                    ". git-sh-setup && . git-rebase--common &&"
 499                    " . %s && %s", backend, backend_func);
 500        argv[0] = script_snippet.buf;
 501
 502        status = run_command_v_opt(argv, RUN_USING_SHELL);
 503finished_rebase:
 504        if (opts->dont_finish_rebase)
 505                ; /* do nothing */
 506        else if (opts->type == REBASE_INTERACTIVE)
 507                ; /* interactive rebase cleans up after itself */
 508        else if (status == 0) {
 509                if (!file_exists(state_dir_path("stopped-sha", opts)))
 510                        finish_rebase(opts);
 511        } else if (status == 2) {
 512                struct strbuf dir = STRBUF_INIT;
 513
 514                apply_autostash(opts);
 515                strbuf_addstr(&dir, opts->state_dir);
 516                remove_dir_recursively(&dir, 0);
 517                strbuf_release(&dir);
 518                die("Nothing to do");
 519        }
 520
 521        strbuf_release(&script_snippet);
 522
 523        return status ? -1 : 0;
 524}
 525
 526#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 527
 528#define RESET_HEAD_DETACH (1<<0)
 529#define RESET_HEAD_HARD (1<<1)
 530
 531static int reset_head(struct object_id *oid, const char *action,
 532                      const char *switch_to_branch, unsigned flags,
 533                      const char *reflog_orig_head, const char *reflog_head)
 534{
 535        unsigned detach_head = flags & RESET_HEAD_DETACH;
 536        unsigned reset_hard = flags & RESET_HEAD_HARD;
 537        struct object_id head_oid;
 538        struct tree_desc desc[2] = { { NULL }, { NULL } };
 539        struct lock_file lock = LOCK_INIT;
 540        struct unpack_trees_options unpack_tree_opts;
 541        struct tree *tree;
 542        const char *reflog_action;
 543        struct strbuf msg = STRBUF_INIT;
 544        size_t prefix_len;
 545        struct object_id *orig = NULL, oid_orig,
 546                *old_orig = NULL, oid_old_orig;
 547        int ret = 0, nr = 0;
 548
 549        if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 550                BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 551
 552        if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 553                ret = -1;
 554                goto leave_reset_head;
 555        }
 556
 557        if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 558                ret = error(_("could not determine HEAD revision"));
 559                goto leave_reset_head;
 560        }
 561
 562        if (!oid)
 563                oid = &head_oid;
 564
 565        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 566        setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 567        unpack_tree_opts.head_idx = 1;
 568        unpack_tree_opts.src_index = the_repository->index;
 569        unpack_tree_opts.dst_index = the_repository->index;
 570        unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 571        unpack_tree_opts.update = 1;
 572        unpack_tree_opts.merge = 1;
 573        if (!detach_head)
 574                unpack_tree_opts.reset = 1;
 575
 576        if (read_index_unmerged(the_repository->index) < 0) {
 577                ret = error(_("could not read index"));
 578                goto leave_reset_head;
 579        }
 580
 581        if (!reset_hard && !fill_tree_descriptor(&desc[nr++], &head_oid)) {
 582                ret = error(_("failed to find tree of %s"),
 583                            oid_to_hex(&head_oid));
 584                goto leave_reset_head;
 585        }
 586
 587        if (!fill_tree_descriptor(&desc[nr++], oid)) {
 588                ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 589                goto leave_reset_head;
 590        }
 591
 592        if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 593                ret = -1;
 594                goto leave_reset_head;
 595        }
 596
 597        tree = parse_tree_indirect(oid);
 598        prime_cache_tree(the_repository->index, tree);
 599
 600        if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 601                ret = error(_("could not write index"));
 602                goto leave_reset_head;
 603        }
 604
 605        reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 606        strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 607        prefix_len = msg.len;
 608
 609        if (!get_oid("ORIG_HEAD", &oid_old_orig))
 610                old_orig = &oid_old_orig;
 611        if (!get_oid("HEAD", &oid_orig)) {
 612                orig = &oid_orig;
 613                if (!reflog_orig_head) {
 614                        strbuf_addstr(&msg, "updating ORIG_HEAD");
 615                        reflog_orig_head = msg.buf;
 616                }
 617                update_ref(reflog_orig_head, "ORIG_HEAD", orig, old_orig, 0,
 618                           UPDATE_REFS_MSG_ON_ERR);
 619        } else if (old_orig)
 620                delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 621        if (!reflog_head) {
 622                strbuf_setlen(&msg, prefix_len);
 623                strbuf_addstr(&msg, "updating HEAD");
 624                reflog_head = msg.buf;
 625        }
 626        if (!switch_to_branch)
 627                ret = update_ref(reflog_head, "HEAD", oid, orig,
 628                                 detach_head ? REF_NO_DEREF : 0,
 629                                 UPDATE_REFS_MSG_ON_ERR);
 630        else {
 631                ret = create_symref("HEAD", switch_to_branch, msg.buf);
 632                if (!ret)
 633                        ret = update_ref(reflog_head, "HEAD", oid, NULL, 0,
 634                                         UPDATE_REFS_MSG_ON_ERR);
 635        }
 636
 637leave_reset_head:
 638        strbuf_release(&msg);
 639        rollback_lock_file(&lock);
 640        while (nr)
 641                free((void *)desc[--nr].buffer);
 642        return ret;
 643}
 644
 645static int rebase_config(const char *var, const char *value, void *data)
 646{
 647        struct rebase_options *opts = data;
 648
 649        if (!strcmp(var, "rebase.stat")) {
 650                if (git_config_bool(var, value))
 651                        opts->flags |= REBASE_DIFFSTAT;
 652                else
 653                        opts->flags &= !REBASE_DIFFSTAT;
 654                return 0;
 655        }
 656
 657        if (!strcmp(var, "rebase.autosquash")) {
 658                opts->autosquash = git_config_bool(var, value);
 659                return 0;
 660        }
 661
 662        if (!strcmp(var, "commit.gpgsign")) {
 663                free(opts->gpg_sign_opt);
 664                opts->gpg_sign_opt = git_config_bool(var, value) ?
 665                        xstrdup("-S") : NULL;
 666                return 0;
 667        }
 668
 669        if (!strcmp(var, "rebase.autostash")) {
 670                opts->autostash = git_config_bool(var, value);
 671                return 0;
 672        }
 673
 674        return git_default_config(var, value, data);
 675}
 676
 677/*
 678 * Determines whether the commits in from..to are linear, i.e. contain
 679 * no merge commits. This function *expects* `from` to be an ancestor of
 680 * `to`.
 681 */
 682static int is_linear_history(struct commit *from, struct commit *to)
 683{
 684        while (to && to != from) {
 685                parse_commit(to);
 686                if (!to->parents)
 687                        return 1;
 688                if (to->parents->next)
 689                        return 0;
 690                to = to->parents->item;
 691        }
 692        return 1;
 693}
 694
 695static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
 696                            struct object_id *merge_base)
 697{
 698        struct commit *head = lookup_commit(the_repository, head_oid);
 699        struct commit_list *merge_bases;
 700        int res;
 701
 702        if (!head)
 703                return 0;
 704
 705        merge_bases = get_merge_bases(onto, head);
 706        if (merge_bases && !merge_bases->next) {
 707                oidcpy(merge_base, &merge_bases->item->object.oid);
 708                res = oideq(merge_base, &onto->object.oid);
 709        } else {
 710                oidcpy(merge_base, &null_oid);
 711                res = 0;
 712        }
 713        free_commit_list(merge_bases);
 714        return res && is_linear_history(onto, head);
 715}
 716
 717/* -i followed by -m is still -i */
 718static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 719{
 720        struct rebase_options *opts = opt->value;
 721
 722        BUG_ON_OPT_NEG(unset);
 723        BUG_ON_OPT_ARG(arg);
 724
 725        if (!is_interactive(opts))
 726                opts->type = REBASE_MERGE;
 727
 728        return 0;
 729}
 730
 731/* -i followed by -p is still explicitly interactive, but -p alone is not */
 732static int parse_opt_interactive(const struct option *opt, const char *arg,
 733                                 int unset)
 734{
 735        struct rebase_options *opts = opt->value;
 736
 737        BUG_ON_OPT_NEG(unset);
 738        BUG_ON_OPT_ARG(arg);
 739
 740        opts->type = REBASE_INTERACTIVE;
 741        opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 742
 743        return 0;
 744}
 745
 746static void NORETURN error_on_missing_default_upstream(void)
 747{
 748        struct branch *current_branch = branch_get(NULL);
 749
 750        printf(_("%s\n"
 751                 "Please specify which branch you want to rebase against.\n"
 752                 "See git-rebase(1) for details.\n"
 753                 "\n"
 754                 "    git rebase '<branch>'\n"
 755                 "\n"),
 756                current_branch ? _("There is no tracking information for "
 757                        "the current branch.") :
 758                        _("You are not currently on a branch."));
 759
 760        if (current_branch) {
 761                const char *remote = current_branch->remote_name;
 762
 763                if (!remote)
 764                        remote = _("<remote>");
 765
 766                printf(_("If you wish to set tracking information for this "
 767                         "branch you can do so with:\n"
 768                         "\n"
 769                         "    git branch --set-upstream-to=%s/<branch> %s\n"
 770                         "\n"),
 771                       remote, current_branch->name);
 772        }
 773        exit(1);
 774}
 775
 776static void set_reflog_action(struct rebase_options *options)
 777{
 778        const char *env;
 779        struct strbuf buf = STRBUF_INIT;
 780
 781        if (!is_interactive(options))
 782                return;
 783
 784        env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 785        if (env && strcmp("rebase", env))
 786                return; /* only override it if it is "rebase" */
 787
 788        strbuf_addf(&buf, "rebase -i (%s)", options->action);
 789        setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
 790        strbuf_release(&buf);
 791}
 792
 793int cmd_rebase(int argc, const char **argv, const char *prefix)
 794{
 795        struct rebase_options options = {
 796                .type = REBASE_UNSPECIFIED,
 797                .flags = REBASE_NO_QUIET,
 798                .git_am_opts = ARGV_ARRAY_INIT,
 799                .allow_rerere_autoupdate  = -1,
 800                .allow_empty_message = 1,
 801                .git_format_patch_opt = STRBUF_INIT,
 802        };
 803        const char *branch_name;
 804        int ret, flags, total_argc, in_progress = 0;
 805        int ok_to_skip_pre_rebase = 0;
 806        struct strbuf msg = STRBUF_INIT;
 807        struct strbuf revisions = STRBUF_INIT;
 808        struct strbuf buf = STRBUF_INIT;
 809        struct object_id merge_base;
 810        enum {
 811                NO_ACTION,
 812                ACTION_CONTINUE,
 813                ACTION_SKIP,
 814                ACTION_ABORT,
 815                ACTION_QUIT,
 816                ACTION_EDIT_TODO,
 817                ACTION_SHOW_CURRENT_PATCH,
 818        } action = NO_ACTION;
 819        const char *gpg_sign = NULL;
 820        struct string_list exec = STRING_LIST_INIT_NODUP;
 821        const char *rebase_merges = NULL;
 822        int fork_point = -1;
 823        struct string_list strategy_options = STRING_LIST_INIT_NODUP;
 824        struct object_id squash_onto;
 825        char *squash_onto_name = NULL;
 826        struct option builtin_rebase_options[] = {
 827                OPT_STRING(0, "onto", &options.onto_name,
 828                           N_("revision"),
 829                           N_("rebase onto given branch instead of upstream")),
 830                OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
 831                         N_("allow pre-rebase hook to run")),
 832                OPT_NEGBIT('q', "quiet", &options.flags,
 833                           N_("be quiet. implies --no-stat"),
 834                           REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
 835                OPT_BIT('v', "verbose", &options.flags,
 836                        N_("display a diffstat of what changed upstream"),
 837                        REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 838                {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
 839                        N_("do not show diffstat of what changed upstream"),
 840                        PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 841                OPT_BOOL(0, "signoff", &options.signoff,
 842                         N_("add a Signed-off-by: line to each commit")),
 843                OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
 844                                  NULL, N_("passed to 'git am'"),
 845                                  PARSE_OPT_NOARG),
 846                OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
 847                                  &options.git_am_opts, NULL,
 848                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
 849                OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
 850                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
 851                OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
 852                                  N_("passed to 'git apply'"), 0),
 853                OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
 854                                  N_("action"), N_("passed to 'git apply'"), 0),
 855                OPT_BIT('f', "force-rebase", &options.flags,
 856                        N_("cherry-pick all commits, even if unchanged"),
 857                        REBASE_FORCE),
 858                OPT_BIT(0, "no-ff", &options.flags,
 859                        N_("cherry-pick all commits, even if unchanged"),
 860                        REBASE_FORCE),
 861                OPT_CMDMODE(0, "continue", &action, N_("continue"),
 862                            ACTION_CONTINUE),
 863                OPT_CMDMODE(0, "skip", &action,
 864                            N_("skip current patch and continue"), ACTION_SKIP),
 865                OPT_CMDMODE(0, "abort", &action,
 866                            N_("abort and check out the original branch"),
 867                            ACTION_ABORT),
 868                OPT_CMDMODE(0, "quit", &action,
 869                            N_("abort but keep HEAD where it is"), ACTION_QUIT),
 870                OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
 871                            "during an interactive rebase"), ACTION_EDIT_TODO),
 872                OPT_CMDMODE(0, "show-current-patch", &action,
 873                            N_("show the patch file being applied or merged"),
 874                            ACTION_SHOW_CURRENT_PATCH),
 875                { OPTION_CALLBACK, 'm', "merge", &options, NULL,
 876                        N_("use merging strategies to rebase"),
 877                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 878                        parse_opt_merge },
 879                { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
 880                        N_("let the user edit the list of commits to rebase"),
 881                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 882                        parse_opt_interactive },
 883                OPT_SET_INT('p', "preserve-merges", &options.type,
 884                            N_("try to recreate merges instead of ignoring "
 885                               "them"), REBASE_PRESERVE_MERGES),
 886                OPT_BOOL(0, "rerere-autoupdate",
 887                         &options.allow_rerere_autoupdate,
 888                         N_("allow rerere to update index with resolved "
 889                            "conflict")),
 890                OPT_BOOL('k', "keep-empty", &options.keep_empty,
 891                         N_("preserve empty commits during rebase")),
 892                OPT_BOOL(0, "autosquash", &options.autosquash,
 893                         N_("move commits that begin with "
 894                            "squash!/fixup! under -i")),
 895                { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
 896                        N_("GPG-sign commits"),
 897                        PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 898                OPT_BOOL(0, "autostash", &options.autostash,
 899                         N_("automatically stash/stash pop before and after")),
 900                OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
 901                                N_("add exec lines after each commit of the "
 902                                   "editable list")),
 903                OPT_BOOL(0, "allow-empty-message",
 904                         &options.allow_empty_message,
 905                         N_("allow rebasing commits with empty messages")),
 906                {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
 907                        N_("mode"),
 908                        N_("try to rebase merges instead of skipping them"),
 909                        PARSE_OPT_OPTARG, NULL, (intptr_t)""},
 910                OPT_BOOL(0, "fork-point", &fork_point,
 911                         N_("use 'merge-base --fork-point' to refine upstream")),
 912                OPT_STRING('s', "strategy", &options.strategy,
 913                           N_("strategy"), N_("use the given merge strategy")),
 914                OPT_STRING_LIST('X', "strategy-option", &strategy_options,
 915                                N_("option"),
 916                                N_("pass the argument through to the merge "
 917                                   "strategy")),
 918                OPT_BOOL(0, "root", &options.root,
 919                         N_("rebase all reachable commits up to the root(s)")),
 920                OPT_END(),
 921        };
 922        int i;
 923
 924        /*
 925         * NEEDSWORK: Once the builtin rebase has been tested enough
 926         * and git-legacy-rebase.sh is retired to contrib/, this preamble
 927         * can be removed.
 928         */
 929
 930        if (!use_builtin_rebase()) {
 931                const char *path = mkpath("%s/git-legacy-rebase",
 932                                          git_exec_path());
 933
 934                if (sane_execvp(path, (char **)argv) < 0)
 935                        die_errno(_("could not exec %s"), path);
 936                else
 937                        BUG("sane_execvp() returned???");
 938        }
 939
 940        if (argc == 2 && !strcmp(argv[1], "-h"))
 941                usage_with_options(builtin_rebase_usage,
 942                                   builtin_rebase_options);
 943
 944        prefix = setup_git_directory();
 945        trace_repo_setup(prefix);
 946        setup_work_tree();
 947
 948        git_config(rebase_config, &options);
 949
 950        strbuf_reset(&buf);
 951        strbuf_addf(&buf, "%s/applying", apply_dir());
 952        if(file_exists(buf.buf))
 953                die(_("It looks like 'git am' is in progress. Cannot rebase."));
 954
 955        if (is_directory(apply_dir())) {
 956                options.type = REBASE_AM;
 957                options.state_dir = apply_dir();
 958        } else if (is_directory(merge_dir())) {
 959                strbuf_reset(&buf);
 960                strbuf_addf(&buf, "%s/rewritten", merge_dir());
 961                if (is_directory(buf.buf)) {
 962                        options.type = REBASE_PRESERVE_MERGES;
 963                        options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 964                } else {
 965                        strbuf_reset(&buf);
 966                        strbuf_addf(&buf, "%s/interactive", merge_dir());
 967                        if(file_exists(buf.buf)) {
 968                                options.type = REBASE_INTERACTIVE;
 969                                options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 970                        } else
 971                                options.type = REBASE_MERGE;
 972                }
 973                options.state_dir = merge_dir();
 974        }
 975
 976        if (options.type != REBASE_UNSPECIFIED)
 977                in_progress = 1;
 978
 979        total_argc = argc;
 980        argc = parse_options(argc, argv, prefix,
 981                             builtin_rebase_options,
 982                             builtin_rebase_usage, 0);
 983
 984        if (action != NO_ACTION && total_argc != 2) {
 985                usage_with_options(builtin_rebase_usage,
 986                                   builtin_rebase_options);
 987        }
 988
 989        if (argc > 2)
 990                usage_with_options(builtin_rebase_usage,
 991                                   builtin_rebase_options);
 992
 993        if (action != NO_ACTION && !in_progress)
 994                die(_("No rebase in progress?"));
 995        setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
 996
 997        if (action == ACTION_EDIT_TODO && !is_interactive(&options))
 998                die(_("The --edit-todo action can only be used during "
 999                      "interactive rebase."));
1000
1001        switch (action) {
1002        case ACTION_CONTINUE: {
1003                struct object_id head;
1004                struct lock_file lock_file = LOCK_INIT;
1005                int fd;
1006
1007                options.action = "continue";
1008                set_reflog_action(&options);
1009
1010                /* Sanity check */
1011                if (get_oid("HEAD", &head))
1012                        die(_("Cannot read HEAD"));
1013
1014                fd = hold_locked_index(&lock_file, 0);
1015                if (read_index(the_repository->index) < 0)
1016                        die(_("could not read index"));
1017                refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1018                              NULL);
1019                if (0 <= fd)
1020                        update_index_if_able(the_repository->index,
1021                                             &lock_file);
1022                rollback_lock_file(&lock_file);
1023
1024                if (has_unstaged_changes(1)) {
1025                        puts(_("You must edit all merge conflicts and then\n"
1026                               "mark them as resolved using git add"));
1027                        exit(1);
1028                }
1029                if (read_basic_state(&options))
1030                        exit(1);
1031                goto run_rebase;
1032        }
1033        case ACTION_SKIP: {
1034                struct string_list merge_rr = STRING_LIST_INIT_DUP;
1035
1036                options.action = "skip";
1037                set_reflog_action(&options);
1038
1039                rerere_clear(&merge_rr);
1040                string_list_clear(&merge_rr, 1);
1041
1042                if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1043                               NULL, NULL) < 0)
1044                        die(_("could not discard worktree changes"));
1045                remove_branch_state();
1046                if (read_basic_state(&options))
1047                        exit(1);
1048                goto run_rebase;
1049        }
1050        case ACTION_ABORT: {
1051                struct string_list merge_rr = STRING_LIST_INIT_DUP;
1052                options.action = "abort";
1053                set_reflog_action(&options);
1054
1055                rerere_clear(&merge_rr);
1056                string_list_clear(&merge_rr, 1);
1057
1058                if (read_basic_state(&options))
1059                        exit(1);
1060                if (reset_head(&options.orig_head, "reset",
1061                               options.head_name, RESET_HEAD_HARD,
1062                               NULL, NULL) < 0)
1063                        die(_("could not move back to %s"),
1064                            oid_to_hex(&options.orig_head));
1065                remove_branch_state();
1066                ret = finish_rebase(&options);
1067                goto cleanup;
1068        }
1069        case ACTION_QUIT: {
1070                strbuf_reset(&buf);
1071                strbuf_addstr(&buf, options.state_dir);
1072                ret = !!remove_dir_recursively(&buf, 0);
1073                if (ret)
1074                        die(_("could not remove '%s'"), options.state_dir);
1075                goto cleanup;
1076        }
1077        case ACTION_EDIT_TODO:
1078                options.action = "edit-todo";
1079                options.dont_finish_rebase = 1;
1080                goto run_rebase;
1081        case ACTION_SHOW_CURRENT_PATCH:
1082                options.action = "show-current-patch";
1083                options.dont_finish_rebase = 1;
1084                goto run_rebase;
1085        case NO_ACTION:
1086                break;
1087        default:
1088                BUG("action: %d", action);
1089        }
1090
1091        /* Make sure no rebase is in progress */
1092        if (in_progress) {
1093                const char *last_slash = strrchr(options.state_dir, '/');
1094                const char *state_dir_base =
1095                        last_slash ? last_slash + 1 : options.state_dir;
1096                const char *cmd_live_rebase =
1097                        "git rebase (--continue | --abort | --skip)";
1098                strbuf_reset(&buf);
1099                strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1100                die(_("It seems that there is already a %s directory, and\n"
1101                      "I wonder if you are in the middle of another rebase.  "
1102                      "If that is the\n"
1103                      "case, please try\n\t%s\n"
1104                      "If that is not the case, please\n\t%s\n"
1105                      "and run me again.  I am stopping in case you still "
1106                      "have something\n"
1107                      "valuable there.\n"),
1108                    state_dir_base, cmd_live_rebase, buf.buf);
1109        }
1110
1111        for (i = 0; i < options.git_am_opts.argc; i++) {
1112                const char *option = options.git_am_opts.argv[i], *p;
1113                if (!strcmp(option, "--committer-date-is-author-date") ||
1114                    !strcmp(option, "--ignore-date") ||
1115                    !strcmp(option, "--whitespace=fix") ||
1116                    !strcmp(option, "--whitespace=strip"))
1117                        options.flags |= REBASE_FORCE;
1118                else if (skip_prefix(option, "-C", &p)) {
1119                        while (*p)
1120                                if (!isdigit(*(p++)))
1121                                        die(_("switch `C' expects a "
1122                                              "numerical value"));
1123                } else if (skip_prefix(option, "--whitespace=", &p)) {
1124                        if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1125                            strcmp(p, "error") && strcmp(p, "error-all"))
1126                                die("Invalid whitespace option: '%s'", p);
1127                }
1128        }
1129
1130        if (!(options.flags & REBASE_NO_QUIET))
1131                argv_array_push(&options.git_am_opts, "-q");
1132
1133        if (options.keep_empty)
1134                imply_interactive(&options, "--keep-empty");
1135
1136        if (gpg_sign) {
1137                free(options.gpg_sign_opt);
1138                options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1139        }
1140
1141        if (exec.nr) {
1142                int i;
1143
1144                imply_interactive(&options, "--exec");
1145
1146                strbuf_reset(&buf);
1147                for (i = 0; i < exec.nr; i++)
1148                        strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1149                options.cmd = xstrdup(buf.buf);
1150        }
1151
1152        if (rebase_merges) {
1153                if (!*rebase_merges)
1154                        ; /* default mode; do nothing */
1155                else if (!strcmp("rebase-cousins", rebase_merges))
1156                        options.rebase_cousins = 1;
1157                else if (strcmp("no-rebase-cousins", rebase_merges))
1158                        die(_("Unknown mode: %s"), rebase_merges);
1159                options.rebase_merges = 1;
1160                imply_interactive(&options, "--rebase-merges");
1161        }
1162
1163        if (strategy_options.nr) {
1164                int i;
1165
1166                if (!options.strategy)
1167                        options.strategy = "recursive";
1168
1169                strbuf_reset(&buf);
1170                for (i = 0; i < strategy_options.nr; i++)
1171                        strbuf_addf(&buf, " --%s",
1172                                    strategy_options.items[i].string);
1173                options.strategy_opts = xstrdup(buf.buf);
1174        }
1175
1176        if (options.strategy) {
1177                options.strategy = xstrdup(options.strategy);
1178                switch (options.type) {
1179                case REBASE_AM:
1180                        die(_("--strategy requires --merge or --interactive"));
1181                case REBASE_MERGE:
1182                case REBASE_INTERACTIVE:
1183                case REBASE_PRESERVE_MERGES:
1184                        /* compatible */
1185                        break;
1186                case REBASE_UNSPECIFIED:
1187                        options.type = REBASE_MERGE;
1188                        break;
1189                default:
1190                        BUG("unhandled rebase type (%d)", options.type);
1191                }
1192        }
1193
1194        if (options.root && !options.onto_name)
1195                imply_interactive(&options, "--root without --onto");
1196
1197        if (isatty(2) && options.flags & REBASE_NO_QUIET)
1198                strbuf_addstr(&options.git_format_patch_opt, " --progress");
1199
1200        switch (options.type) {
1201        case REBASE_MERGE:
1202        case REBASE_INTERACTIVE:
1203        case REBASE_PRESERVE_MERGES:
1204                options.state_dir = merge_dir();
1205                break;
1206        case REBASE_AM:
1207                options.state_dir = apply_dir();
1208                break;
1209        default:
1210                /* the default rebase backend is `--am` */
1211                options.type = REBASE_AM;
1212                options.state_dir = apply_dir();
1213                break;
1214        }
1215
1216        if (options.git_am_opts.argc) {
1217                /* all am options except -q are compatible only with --am */
1218                for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1219                        if (strcmp(options.git_am_opts.argv[i], "-q"))
1220                                break;
1221
1222                if (is_interactive(&options) && i >= 0)
1223                        die(_("cannot combine am options "
1224                              "with interactive options"));
1225                if (options.type == REBASE_MERGE && i >= 0)
1226                        die(_("cannot combine am options with merge options "));
1227        }
1228
1229        if (options.signoff) {
1230                if (options.type == REBASE_PRESERVE_MERGES)
1231                        die("cannot combine '--signoff' with "
1232                            "'--preserve-merges'");
1233                argv_array_push(&options.git_am_opts, "--signoff");
1234                options.flags |= REBASE_FORCE;
1235        }
1236
1237        if (options.type == REBASE_PRESERVE_MERGES)
1238                /*
1239                 * Note: incompatibility with --signoff handled in signoff block above
1240                 * Note: incompatibility with --interactive is just a strong warning;
1241                 *       git-rebase.txt caveats with "unless you know what you are doing"
1242                 */
1243                if (options.rebase_merges)
1244                        die(_("cannot combine '--preserve-merges' with "
1245                              "'--rebase-merges'"));
1246
1247        if (options.rebase_merges) {
1248                if (strategy_options.nr)
1249                        die(_("cannot combine '--rebase-merges' with "
1250                              "'--strategy-option'"));
1251                if (options.strategy)
1252                        die(_("cannot combine '--rebase-merges' with "
1253                              "'--strategy'"));
1254        }
1255
1256        if (!options.root) {
1257                if (argc < 1) {
1258                        struct branch *branch;
1259
1260                        branch = branch_get(NULL);
1261                        options.upstream_name = branch_get_upstream(branch,
1262                                                                    NULL);
1263                        if (!options.upstream_name)
1264                                error_on_missing_default_upstream();
1265                        if (fork_point < 0)
1266                                fork_point = 1;
1267                } else {
1268                        options.upstream_name = argv[0];
1269                        argc--;
1270                        argv++;
1271                        if (!strcmp(options.upstream_name, "-"))
1272                                options.upstream_name = "@{-1}";
1273                }
1274                options.upstream = peel_committish(options.upstream_name);
1275                if (!options.upstream)
1276                        die(_("invalid upstream '%s'"), options.upstream_name);
1277                options.upstream_arg = options.upstream_name;
1278        } else {
1279                if (!options.onto_name) {
1280                        if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1281                                        &squash_onto, NULL, NULL) < 0)
1282                                die(_("Could not create new root commit"));
1283                        options.squash_onto = &squash_onto;
1284                        options.onto_name = squash_onto_name =
1285                                xstrdup(oid_to_hex(&squash_onto));
1286                }
1287                options.upstream_name = NULL;
1288                options.upstream = NULL;
1289                if (argc > 1)
1290                        usage_with_options(builtin_rebase_usage,
1291                                           builtin_rebase_options);
1292                options.upstream_arg = "--root";
1293        }
1294
1295        /* Make sure the branch to rebase onto is valid. */
1296        if (!options.onto_name)
1297                options.onto_name = options.upstream_name;
1298        if (strstr(options.onto_name, "...")) {
1299                if (get_oid_mb(options.onto_name, &merge_base) < 0)
1300                        die(_("'%s': need exactly one merge base"),
1301                            options.onto_name);
1302                options.onto = lookup_commit_or_die(&merge_base,
1303                                                    options.onto_name);
1304        } else {
1305                options.onto = peel_committish(options.onto_name);
1306                if (!options.onto)
1307                        die(_("Does not point to a valid commit '%s'"),
1308                                options.onto_name);
1309        }
1310
1311        /*
1312         * If the branch to rebase is given, that is the branch we will rebase
1313         * branch_name -- branch/commit being rebased, or
1314         *                HEAD (already detached)
1315         * orig_head -- commit object name of tip of the branch before rebasing
1316         * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1317         */
1318        if (argc == 1) {
1319                /* Is it "rebase other branchname" or "rebase other commit"? */
1320                branch_name = argv[0];
1321                options.switch_to = argv[0];
1322
1323                /* Is it a local branch? */
1324                strbuf_reset(&buf);
1325                strbuf_addf(&buf, "refs/heads/%s", branch_name);
1326                if (!read_ref(buf.buf, &options.orig_head))
1327                        options.head_name = xstrdup(buf.buf);
1328                /* If not is it a valid ref (branch or commit)? */
1329                else if (!get_oid(branch_name, &options.orig_head))
1330                        options.head_name = NULL;
1331                else
1332                        die(_("fatal: no such branch/commit '%s'"),
1333                            branch_name);
1334        } else if (argc == 0) {
1335                /* Do not need to switch branches, we are already on it. */
1336                options.head_name =
1337                        xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1338                                         &flags));
1339                if (!options.head_name)
1340                        die(_("No such ref: %s"), "HEAD");
1341                if (flags & REF_ISSYMREF) {
1342                        if (!skip_prefix(options.head_name,
1343                                         "refs/heads/", &branch_name))
1344                                branch_name = options.head_name;
1345
1346                } else {
1347                        free(options.head_name);
1348                        options.head_name = NULL;
1349                        branch_name = "HEAD";
1350                }
1351                if (get_oid("HEAD", &options.orig_head))
1352                        die(_("Could not resolve HEAD to a revision"));
1353        } else
1354                BUG("unexpected number of arguments left to parse");
1355
1356        if (fork_point > 0) {
1357                struct commit *head =
1358                        lookup_commit_reference(the_repository,
1359                                                &options.orig_head);
1360                options.restrict_revision =
1361                        get_fork_point(options.upstream_name, head);
1362        }
1363
1364        if (read_index(the_repository->index) < 0)
1365                die(_("could not read index"));
1366
1367        if (options.autostash) {
1368                struct lock_file lock_file = LOCK_INIT;
1369                int fd;
1370
1371                fd = hold_locked_index(&lock_file, 0);
1372                refresh_cache(REFRESH_QUIET);
1373                if (0 <= fd)
1374                        update_index_if_able(&the_index, &lock_file);
1375                rollback_lock_file(&lock_file);
1376
1377                if (has_unstaged_changes(1) || has_uncommitted_changes(1)) {
1378                        const char *autostash =
1379                                state_dir_path("autostash", &options);
1380                        struct child_process stash = CHILD_PROCESS_INIT;
1381                        struct object_id oid;
1382                        struct commit *head =
1383                                lookup_commit_reference(the_repository,
1384                                                        &options.orig_head);
1385
1386                        argv_array_pushl(&stash.args,
1387                                         "stash", "create", "autostash", NULL);
1388                        stash.git_cmd = 1;
1389                        stash.no_stdin = 1;
1390                        strbuf_reset(&buf);
1391                        if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1392                                die(_("Cannot autostash"));
1393                        strbuf_trim_trailing_newline(&buf);
1394                        if (get_oid(buf.buf, &oid))
1395                                die(_("Unexpected stash response: '%s'"),
1396                                    buf.buf);
1397                        strbuf_reset(&buf);
1398                        strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1399
1400                        if (safe_create_leading_directories_const(autostash))
1401                                die(_("Could not create directory for '%s'"),
1402                                    options.state_dir);
1403                        write_file(autostash, "%s", oid_to_hex(&oid));
1404                        printf(_("Created autostash: %s\n"), buf.buf);
1405                        if (reset_head(&head->object.oid, "reset --hard",
1406                                       NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
1407                                die(_("could not reset --hard"));
1408                        printf(_("HEAD is now at %s"),
1409                               find_unique_abbrev(&head->object.oid,
1410                                                  DEFAULT_ABBREV));
1411                        strbuf_reset(&buf);
1412                        pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
1413                        if (buf.len > 0)
1414                                printf(" %s", buf.buf);
1415                        putchar('\n');
1416
1417                        if (discard_index(the_repository->index) < 0 ||
1418                                read_index(the_repository->index) < 0)
1419                                die(_("could not read index"));
1420                }
1421        }
1422
1423        if (require_clean_work_tree("rebase",
1424                                    _("Please commit or stash them."), 1, 1)) {
1425                ret = 1;
1426                goto cleanup;
1427        }
1428
1429        /*
1430         * Now we are rebasing commits upstream..orig_head (or with --root,
1431         * everything leading up to orig_head) on top of onto.
1432         */
1433
1434        /*
1435         * Check if we are already based on onto with linear history,
1436         * but this should be done only when upstream and onto are the same
1437         * and if this is not an interactive rebase.
1438         */
1439        if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
1440            !is_interactive(&options) && !options.restrict_revision &&
1441            options.upstream &&
1442            !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
1443                int flag;
1444
1445                if (!(options.flags & REBASE_FORCE)) {
1446                        /* Lazily switch to the target branch if needed... */
1447                        if (options.switch_to) {
1448                                struct object_id oid;
1449
1450                                if (get_oid(options.switch_to, &oid) < 0) {
1451                                        ret = !!error(_("could not parse '%s'"),
1452                                                      options.switch_to);
1453                                        goto cleanup;
1454                                }
1455
1456                                strbuf_reset(&buf);
1457                                strbuf_addf(&buf, "%s: checkout %s",
1458                                            getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
1459                                            options.switch_to);
1460                                if (reset_head(&oid, "checkout",
1461                                               options.head_name, 0,
1462                                               NULL, buf.buf) < 0) {
1463                                        ret = !!error(_("could not switch to "
1464                                                        "%s"),
1465                                                      options.switch_to);
1466                                        goto cleanup;
1467                                }
1468                        }
1469
1470                        if (!(options.flags & REBASE_NO_QUIET))
1471                                ; /* be quiet */
1472                        else if (!strcmp(branch_name, "HEAD") &&
1473                                 resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1474                                puts(_("HEAD is up to date."));
1475                        else
1476                                printf(_("Current branch %s is up to date.\n"),
1477                                       branch_name);
1478                        ret = !!finish_rebase(&options);
1479                        goto cleanup;
1480                } else if (!(options.flags & REBASE_NO_QUIET))
1481                        ; /* be quiet */
1482                else if (!strcmp(branch_name, "HEAD") &&
1483                         resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1484                        puts(_("HEAD is up to date, rebase forced."));
1485                else
1486                        printf(_("Current branch %s is up to date, rebase "
1487                                 "forced.\n"), branch_name);
1488        }
1489
1490        /* If a hook exists, give it a chance to interrupt*/
1491        if (!ok_to_skip_pre_rebase &&
1492            run_hook_le(NULL, "pre-rebase", options.upstream_arg,
1493                        argc ? argv[0] : NULL, NULL))
1494                die(_("The pre-rebase hook refused to rebase."));
1495
1496        if (options.flags & REBASE_DIFFSTAT) {
1497                struct diff_options opts;
1498
1499                if (options.flags & REBASE_VERBOSE) {
1500                        if (is_null_oid(&merge_base))
1501                                printf(_("Changes to %s:\n"),
1502                                       oid_to_hex(&options.onto->object.oid));
1503                        else
1504                                printf(_("Changes from %s to %s:\n"),
1505                                       oid_to_hex(&merge_base),
1506                                       oid_to_hex(&options.onto->object.oid));
1507                }
1508
1509                /* We want color (if set), but no pager */
1510                diff_setup(&opts);
1511                opts.stat_width = -1; /* use full terminal width */
1512                opts.stat_graph_width = -1; /* respect statGraphWidth config */
1513                opts.output_format |=
1514                        DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1515                opts.detect_rename = DIFF_DETECT_RENAME;
1516                diff_setup_done(&opts);
1517                diff_tree_oid(is_null_oid(&merge_base) ?
1518                              the_hash_algo->empty_tree : &merge_base,
1519                              &options.onto->object.oid, "", &opts);
1520                diffcore_std(&opts);
1521                diff_flush(&opts);
1522        }
1523
1524        if (is_interactive(&options))
1525                goto run_rebase;
1526
1527        /* Detach HEAD and reset the tree */
1528        if (options.flags & REBASE_NO_QUIET)
1529                printf(_("First, rewinding head to replay your work on top of "
1530                         "it...\n"));
1531
1532        strbuf_addf(&msg, "%s: checkout %s",
1533                    getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
1534        if (reset_head(&options.onto->object.oid, "checkout", NULL,
1535                       RESET_HEAD_DETACH, NULL, msg.buf))
1536                die(_("Could not detach HEAD"));
1537        strbuf_release(&msg);
1538
1539        /*
1540         * If the onto is a proper descendant of the tip of the branch, then
1541         * we just fast-forwarded.
1542         */
1543        strbuf_reset(&msg);
1544        if (!oidcmp(&merge_base, &options.orig_head)) {
1545                printf(_("Fast-forwarded %s to %s.\n"),
1546                        branch_name, options.onto_name);
1547                strbuf_addf(&msg, "rebase finished: %s onto %s",
1548                        options.head_name ? options.head_name : "detached HEAD",
1549                        oid_to_hex(&options.onto->object.oid));
1550                reset_head(NULL, "Fast-forwarded", options.head_name, 0,
1551                           "HEAD", msg.buf);
1552                strbuf_release(&msg);
1553                ret = !!finish_rebase(&options);
1554                goto cleanup;
1555        }
1556
1557        strbuf_addf(&revisions, "%s..%s",
1558                    options.root ? oid_to_hex(&options.onto->object.oid) :
1559                    (options.restrict_revision ?
1560                     oid_to_hex(&options.restrict_revision->object.oid) :
1561                     oid_to_hex(&options.upstream->object.oid)),
1562                    oid_to_hex(&options.orig_head));
1563
1564        options.revisions = revisions.buf;
1565
1566run_rebase:
1567        ret = !!run_specific_rebase(&options);
1568
1569cleanup:
1570        strbuf_release(&revisions);
1571        free(options.head_name);
1572        free(options.gpg_sign_opt);
1573        free(options.cmd);
1574        free(squash_onto_name);
1575        return ret;
1576}