builtin / rebase.con commit rebase: introduce a shortcut for --reschedule-failed-exec (81ef8ee)
   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
 537static int reset_head(struct object_id *oid, const char *action,
 538                      const char *switch_to_branch, unsigned flags,
 539                      const char *reflog_orig_head, const char *reflog_head)
 540{
 541        unsigned detach_head = flags & RESET_HEAD_DETACH;
 542        unsigned reset_hard = flags & RESET_HEAD_HARD;
 543        struct object_id head_oid;
 544        struct tree_desc desc[2] = { { NULL }, { NULL } };
 545        struct lock_file lock = LOCK_INIT;
 546        struct unpack_trees_options unpack_tree_opts;
 547        struct tree *tree;
 548        const char *reflog_action;
 549        struct strbuf msg = STRBUF_INIT;
 550        size_t prefix_len;
 551        struct object_id *orig = NULL, oid_orig,
 552                *old_orig = NULL, oid_old_orig;
 553        int ret = 0, nr = 0;
 554
 555        if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 556                BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 557
 558        if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 559                ret = -1;
 560                goto leave_reset_head;
 561        }
 562
 563        if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 564                ret = error(_("could not determine HEAD revision"));
 565                goto leave_reset_head;
 566        }
 567
 568        if (!oid)
 569                oid = &head_oid;
 570
 571        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 572        setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 573        unpack_tree_opts.head_idx = 1;
 574        unpack_tree_opts.src_index = the_repository->index;
 575        unpack_tree_opts.dst_index = the_repository->index;
 576        unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 577        unpack_tree_opts.update = 1;
 578        unpack_tree_opts.merge = 1;
 579        if (!detach_head)
 580                unpack_tree_opts.reset = 1;
 581
 582        if (read_index_unmerged(the_repository->index) < 0) {
 583                ret = error(_("could not read index"));
 584                goto leave_reset_head;
 585        }
 586
 587        if (!reset_hard && !fill_tree_descriptor(&desc[nr++], &head_oid)) {
 588                ret = error(_("failed to find tree of %s"),
 589                            oid_to_hex(&head_oid));
 590                goto leave_reset_head;
 591        }
 592
 593        if (!fill_tree_descriptor(&desc[nr++], oid)) {
 594                ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 595                goto leave_reset_head;
 596        }
 597
 598        if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 599                ret = -1;
 600                goto leave_reset_head;
 601        }
 602
 603        tree = parse_tree_indirect(oid);
 604        prime_cache_tree(the_repository->index, tree);
 605
 606        if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 607                ret = error(_("could not write index"));
 608                goto leave_reset_head;
 609        }
 610
 611        reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 612        strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 613        prefix_len = msg.len;
 614
 615        if (!get_oid("ORIG_HEAD", &oid_old_orig))
 616                old_orig = &oid_old_orig;
 617        if (!get_oid("HEAD", &oid_orig)) {
 618                orig = &oid_orig;
 619                if (!reflog_orig_head) {
 620                        strbuf_addstr(&msg, "updating ORIG_HEAD");
 621                        reflog_orig_head = msg.buf;
 622                }
 623                update_ref(reflog_orig_head, "ORIG_HEAD", orig, old_orig, 0,
 624                           UPDATE_REFS_MSG_ON_ERR);
 625        } else if (old_orig)
 626                delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 627        if (!reflog_head) {
 628                strbuf_setlen(&msg, prefix_len);
 629                strbuf_addstr(&msg, "updating HEAD");
 630                reflog_head = msg.buf;
 631        }
 632        if (!switch_to_branch)
 633                ret = update_ref(reflog_head, "HEAD", oid, orig,
 634                                 detach_head ? REF_NO_DEREF : 0,
 635                                 UPDATE_REFS_MSG_ON_ERR);
 636        else {
 637                ret = create_symref("HEAD", switch_to_branch, msg.buf);
 638                if (!ret)
 639                        ret = update_ref(reflog_head, "HEAD", oid, NULL, 0,
 640                                         UPDATE_REFS_MSG_ON_ERR);
 641        }
 642
 643leave_reset_head:
 644        strbuf_release(&msg);
 645        rollback_lock_file(&lock);
 646        while (nr)
 647                free((void *)desc[--nr].buffer);
 648        return ret;
 649}
 650
 651static int rebase_config(const char *var, const char *value, void *data)
 652{
 653        struct rebase_options *opts = data;
 654
 655        if (!strcmp(var, "rebase.stat")) {
 656                if (git_config_bool(var, value))
 657                        opts->flags |= REBASE_DIFFSTAT;
 658                else
 659                        opts->flags &= !REBASE_DIFFSTAT;
 660                return 0;
 661        }
 662
 663        if (!strcmp(var, "rebase.autosquash")) {
 664                opts->autosquash = git_config_bool(var, value);
 665                return 0;
 666        }
 667
 668        if (!strcmp(var, "commit.gpgsign")) {
 669                free(opts->gpg_sign_opt);
 670                opts->gpg_sign_opt = git_config_bool(var, value) ?
 671                        xstrdup("-S") : NULL;
 672                return 0;
 673        }
 674
 675        if (!strcmp(var, "rebase.autostash")) {
 676                opts->autostash = git_config_bool(var, value);
 677                return 0;
 678        }
 679
 680        if (!strcmp(var, "rebase.reschedulefailedexec")) {
 681                opts->reschedule_failed_exec = git_config_bool(var, value);
 682                return 0;
 683        }
 684
 685        return git_default_config(var, value, data);
 686}
 687
 688/*
 689 * Determines whether the commits in from..to are linear, i.e. contain
 690 * no merge commits. This function *expects* `from` to be an ancestor of
 691 * `to`.
 692 */
 693static int is_linear_history(struct commit *from, struct commit *to)
 694{
 695        while (to && to != from) {
 696                parse_commit(to);
 697                if (!to->parents)
 698                        return 1;
 699                if (to->parents->next)
 700                        return 0;
 701                to = to->parents->item;
 702        }
 703        return 1;
 704}
 705
 706static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
 707                            struct object_id *merge_base)
 708{
 709        struct commit *head = lookup_commit(the_repository, head_oid);
 710        struct commit_list *merge_bases;
 711        int res;
 712
 713        if (!head)
 714                return 0;
 715
 716        merge_bases = get_merge_bases(onto, head);
 717        if (merge_bases && !merge_bases->next) {
 718                oidcpy(merge_base, &merge_bases->item->object.oid);
 719                res = oideq(merge_base, &onto->object.oid);
 720        } else {
 721                oidcpy(merge_base, &null_oid);
 722                res = 0;
 723        }
 724        free_commit_list(merge_bases);
 725        return res && is_linear_history(onto, head);
 726}
 727
 728/* -i followed by -m is still -i */
 729static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 730{
 731        struct rebase_options *opts = opt->value;
 732
 733        BUG_ON_OPT_NEG(unset);
 734        BUG_ON_OPT_ARG(arg);
 735
 736        if (!is_interactive(opts))
 737                opts->type = REBASE_MERGE;
 738
 739        return 0;
 740}
 741
 742/* -i followed by -p is still explicitly interactive, but -p alone is not */
 743static int parse_opt_interactive(const struct option *opt, const char *arg,
 744                                 int unset)
 745{
 746        struct rebase_options *opts = opt->value;
 747
 748        BUG_ON_OPT_NEG(unset);
 749        BUG_ON_OPT_ARG(arg);
 750
 751        opts->type = REBASE_INTERACTIVE;
 752        opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 753
 754        return 0;
 755}
 756
 757struct opt_y {
 758        struct string_list *list;
 759        struct rebase_options *options;
 760};
 761
 762static int parse_opt_y(const struct option *opt, const char *arg, int unset)
 763{
 764        struct opt_y *o = opt->value;
 765
 766        if (unset || !arg)
 767                return -1;
 768
 769        o->options->reschedule_failed_exec = 1;
 770        string_list_append(o->list, arg);
 771        return 0;
 772}
 773
 774static void NORETURN error_on_missing_default_upstream(void)
 775{
 776        struct branch *current_branch = branch_get(NULL);
 777
 778        printf(_("%s\n"
 779                 "Please specify which branch you want to rebase against.\n"
 780                 "See git-rebase(1) for details.\n"
 781                 "\n"
 782                 "    git rebase '<branch>'\n"
 783                 "\n"),
 784                current_branch ? _("There is no tracking information for "
 785                        "the current branch.") :
 786                        _("You are not currently on a branch."));
 787
 788        if (current_branch) {
 789                const char *remote = current_branch->remote_name;
 790
 791                if (!remote)
 792                        remote = _("<remote>");
 793
 794                printf(_("If you wish to set tracking information for this "
 795                         "branch you can do so with:\n"
 796                         "\n"
 797                         "    git branch --set-upstream-to=%s/<branch> %s\n"
 798                         "\n"),
 799                       remote, current_branch->name);
 800        }
 801        exit(1);
 802}
 803
 804static void set_reflog_action(struct rebase_options *options)
 805{
 806        const char *env;
 807        struct strbuf buf = STRBUF_INIT;
 808
 809        if (!is_interactive(options))
 810                return;
 811
 812        env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 813        if (env && strcmp("rebase", env))
 814                return; /* only override it if it is "rebase" */
 815
 816        strbuf_addf(&buf, "rebase -i (%s)", options->action);
 817        setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
 818        strbuf_release(&buf);
 819}
 820
 821int cmd_rebase(int argc, const char **argv, const char *prefix)
 822{
 823        struct rebase_options options = {
 824                .type = REBASE_UNSPECIFIED,
 825                .flags = REBASE_NO_QUIET,
 826                .git_am_opts = ARGV_ARRAY_INIT,
 827                .allow_rerere_autoupdate  = -1,
 828                .allow_empty_message = 1,
 829                .git_format_patch_opt = STRBUF_INIT,
 830        };
 831        const char *branch_name;
 832        int ret, flags, total_argc, in_progress = 0;
 833        int ok_to_skip_pre_rebase = 0;
 834        struct strbuf msg = STRBUF_INIT;
 835        struct strbuf revisions = STRBUF_INIT;
 836        struct strbuf buf = STRBUF_INIT;
 837        struct object_id merge_base;
 838        enum {
 839                NO_ACTION,
 840                ACTION_CONTINUE,
 841                ACTION_SKIP,
 842                ACTION_ABORT,
 843                ACTION_QUIT,
 844                ACTION_EDIT_TODO,
 845                ACTION_SHOW_CURRENT_PATCH,
 846        } action = NO_ACTION;
 847        const char *gpg_sign = NULL;
 848        struct string_list exec = STRING_LIST_INIT_NODUP;
 849        const char *rebase_merges = NULL;
 850        int fork_point = -1;
 851        struct string_list strategy_options = STRING_LIST_INIT_NODUP;
 852        struct object_id squash_onto;
 853        char *squash_onto_name = NULL;
 854        struct opt_y opt_y = { .list = &exec, .options = &options };
 855        struct option builtin_rebase_options[] = {
 856                OPT_STRING(0, "onto", &options.onto_name,
 857                           N_("revision"),
 858                           N_("rebase onto given branch instead of upstream")),
 859                OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
 860                         N_("allow pre-rebase hook to run")),
 861                OPT_NEGBIT('q', "quiet", &options.flags,
 862                           N_("be quiet. implies --no-stat"),
 863                           REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
 864                OPT_BIT('v', "verbose", &options.flags,
 865                        N_("display a diffstat of what changed upstream"),
 866                        REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 867                {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
 868                        N_("do not show diffstat of what changed upstream"),
 869                        PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 870                OPT_BOOL(0, "signoff", &options.signoff,
 871                         N_("add a Signed-off-by: line to each commit")),
 872                OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
 873                                  NULL, N_("passed to 'git am'"),
 874                                  PARSE_OPT_NOARG),
 875                OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
 876                                  &options.git_am_opts, NULL,
 877                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
 878                OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
 879                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
 880                OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
 881                                  N_("passed to 'git apply'"), 0),
 882                OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
 883                                  N_("action"), N_("passed to 'git apply'"), 0),
 884                OPT_BIT('f', "force-rebase", &options.flags,
 885                        N_("cherry-pick all commits, even if unchanged"),
 886                        REBASE_FORCE),
 887                OPT_BIT(0, "no-ff", &options.flags,
 888                        N_("cherry-pick all commits, even if unchanged"),
 889                        REBASE_FORCE),
 890                OPT_CMDMODE(0, "continue", &action, N_("continue"),
 891                            ACTION_CONTINUE),
 892                OPT_CMDMODE(0, "skip", &action,
 893                            N_("skip current patch and continue"), ACTION_SKIP),
 894                OPT_CMDMODE(0, "abort", &action,
 895                            N_("abort and check out the original branch"),
 896                            ACTION_ABORT),
 897                OPT_CMDMODE(0, "quit", &action,
 898                            N_("abort but keep HEAD where it is"), ACTION_QUIT),
 899                OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
 900                            "during an interactive rebase"), ACTION_EDIT_TODO),
 901                OPT_CMDMODE(0, "show-current-patch", &action,
 902                            N_("show the patch file being applied or merged"),
 903                            ACTION_SHOW_CURRENT_PATCH),
 904                { OPTION_CALLBACK, 'm', "merge", &options, NULL,
 905                        N_("use merging strategies to rebase"),
 906                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 907                        parse_opt_merge },
 908                { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
 909                        N_("let the user edit the list of commits to rebase"),
 910                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 911                        parse_opt_interactive },
 912                OPT_SET_INT('p', "preserve-merges", &options.type,
 913                            N_("try to recreate merges instead of ignoring "
 914                               "them"), REBASE_PRESERVE_MERGES),
 915                OPT_BOOL(0, "rerere-autoupdate",
 916                         &options.allow_rerere_autoupdate,
 917                         N_("allow rerere to update index with resolved "
 918                            "conflict")),
 919                OPT_BOOL('k', "keep-empty", &options.keep_empty,
 920                         N_("preserve empty commits during rebase")),
 921                OPT_BOOL(0, "autosquash", &options.autosquash,
 922                         N_("move commits that begin with "
 923                            "squash!/fixup! under -i")),
 924                { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
 925                        N_("GPG-sign commits"),
 926                        PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 927                OPT_BOOL(0, "autostash", &options.autostash,
 928                         N_("automatically stash/stash pop before and after")),
 929                OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
 930                                N_("add exec lines after each commit of the "
 931                                   "editable list")),
 932                { OPTION_CALLBACK, 'y', NULL, &opt_y, N_("<cmd>"),
 933                        N_("same as --reschedule-failed-exec -x <cmd>"),
 934                        PARSE_OPT_NONEG, parse_opt_y },
 935                OPT_BOOL(0, "allow-empty-message",
 936                         &options.allow_empty_message,
 937                         N_("allow rebasing commits with empty messages")),
 938                {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
 939                        N_("mode"),
 940                        N_("try to rebase merges instead of skipping them"),
 941                        PARSE_OPT_OPTARG, NULL, (intptr_t)""},
 942                OPT_BOOL(0, "fork-point", &fork_point,
 943                         N_("use 'merge-base --fork-point' to refine upstream")),
 944                OPT_STRING('s', "strategy", &options.strategy,
 945                           N_("strategy"), N_("use the given merge strategy")),
 946                OPT_STRING_LIST('X', "strategy-option", &strategy_options,
 947                                N_("option"),
 948                                N_("pass the argument through to the merge "
 949                                   "strategy")),
 950                OPT_BOOL(0, "root", &options.root,
 951                         N_("rebase all reachable commits up to the root(s)")),
 952                OPT_BOOL(0, "reschedule-failed-exec",
 953                         &options.reschedule_failed_exec,
 954                         N_("automatically re-schedule any `exec` that fails")),
 955                OPT_END(),
 956        };
 957        int i;
 958
 959        /*
 960         * NEEDSWORK: Once the builtin rebase has been tested enough
 961         * and git-legacy-rebase.sh is retired to contrib/, this preamble
 962         * can be removed.
 963         */
 964
 965        if (!use_builtin_rebase()) {
 966                const char *path = mkpath("%s/git-legacy-rebase",
 967                                          git_exec_path());
 968
 969                if (sane_execvp(path, (char **)argv) < 0)
 970                        die_errno(_("could not exec %s"), path);
 971                else
 972                        BUG("sane_execvp() returned???");
 973        }
 974
 975        if (argc == 2 && !strcmp(argv[1], "-h"))
 976                usage_with_options(builtin_rebase_usage,
 977                                   builtin_rebase_options);
 978
 979        prefix = setup_git_directory();
 980        trace_repo_setup(prefix);
 981        setup_work_tree();
 982
 983        git_config(rebase_config, &options);
 984
 985        strbuf_reset(&buf);
 986        strbuf_addf(&buf, "%s/applying", apply_dir());
 987        if(file_exists(buf.buf))
 988                die(_("It looks like 'git am' is in progress. Cannot rebase."));
 989
 990        if (is_directory(apply_dir())) {
 991                options.type = REBASE_AM;
 992                options.state_dir = apply_dir();
 993        } else if (is_directory(merge_dir())) {
 994                strbuf_reset(&buf);
 995                strbuf_addf(&buf, "%s/rewritten", merge_dir());
 996                if (is_directory(buf.buf)) {
 997                        options.type = REBASE_PRESERVE_MERGES;
 998                        options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 999                } else {
1000                        strbuf_reset(&buf);
1001                        strbuf_addf(&buf, "%s/interactive", merge_dir());
1002                        if(file_exists(buf.buf)) {
1003                                options.type = REBASE_INTERACTIVE;
1004                                options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1005                        } else
1006                                options.type = REBASE_MERGE;
1007                }
1008                options.state_dir = merge_dir();
1009        }
1010
1011        if (options.type != REBASE_UNSPECIFIED)
1012                in_progress = 1;
1013
1014        total_argc = argc;
1015        argc = parse_options(argc, argv, prefix,
1016                             builtin_rebase_options,
1017                             builtin_rebase_usage, 0);
1018
1019        if (action != NO_ACTION && total_argc != 2) {
1020                usage_with_options(builtin_rebase_usage,
1021                                   builtin_rebase_options);
1022        }
1023
1024        if (argc > 2)
1025                usage_with_options(builtin_rebase_usage,
1026                                   builtin_rebase_options);
1027
1028        if (action != NO_ACTION && !in_progress)
1029                die(_("No rebase in progress?"));
1030        setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1031
1032        if (action == ACTION_EDIT_TODO && !is_interactive(&options))
1033                die(_("The --edit-todo action can only be used during "
1034                      "interactive rebase."));
1035
1036        switch (action) {
1037        case ACTION_CONTINUE: {
1038                struct object_id head;
1039                struct lock_file lock_file = LOCK_INIT;
1040                int fd;
1041
1042                options.action = "continue";
1043                set_reflog_action(&options);
1044
1045                /* Sanity check */
1046                if (get_oid("HEAD", &head))
1047                        die(_("Cannot read HEAD"));
1048
1049                fd = hold_locked_index(&lock_file, 0);
1050                if (read_index(the_repository->index) < 0)
1051                        die(_("could not read index"));
1052                refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1053                              NULL);
1054                if (0 <= fd)
1055                        update_index_if_able(the_repository->index,
1056                                             &lock_file);
1057                rollback_lock_file(&lock_file);
1058
1059                if (has_unstaged_changes(1)) {
1060                        puts(_("You must edit all merge conflicts and then\n"
1061                               "mark them as resolved using git add"));
1062                        exit(1);
1063                }
1064                if (read_basic_state(&options))
1065                        exit(1);
1066                goto run_rebase;
1067        }
1068        case ACTION_SKIP: {
1069                struct string_list merge_rr = STRING_LIST_INIT_DUP;
1070
1071                options.action = "skip";
1072                set_reflog_action(&options);
1073
1074                rerere_clear(&merge_rr);
1075                string_list_clear(&merge_rr, 1);
1076
1077                if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1078                               NULL, NULL) < 0)
1079                        die(_("could not discard worktree changes"));
1080                remove_branch_state();
1081                if (read_basic_state(&options))
1082                        exit(1);
1083                goto run_rebase;
1084        }
1085        case ACTION_ABORT: {
1086                struct string_list merge_rr = STRING_LIST_INIT_DUP;
1087                options.action = "abort";
1088                set_reflog_action(&options);
1089
1090                rerere_clear(&merge_rr);
1091                string_list_clear(&merge_rr, 1);
1092
1093                if (read_basic_state(&options))
1094                        exit(1);
1095                if (reset_head(&options.orig_head, "reset",
1096                               options.head_name, RESET_HEAD_HARD,
1097                               NULL, NULL) < 0)
1098                        die(_("could not move back to %s"),
1099                            oid_to_hex(&options.orig_head));
1100                remove_branch_state();
1101                ret = finish_rebase(&options);
1102                goto cleanup;
1103        }
1104        case ACTION_QUIT: {
1105                strbuf_reset(&buf);
1106                strbuf_addstr(&buf, options.state_dir);
1107                ret = !!remove_dir_recursively(&buf, 0);
1108                if (ret)
1109                        die(_("could not remove '%s'"), options.state_dir);
1110                goto cleanup;
1111        }
1112        case ACTION_EDIT_TODO:
1113                options.action = "edit-todo";
1114                options.dont_finish_rebase = 1;
1115                goto run_rebase;
1116        case ACTION_SHOW_CURRENT_PATCH:
1117                options.action = "show-current-patch";
1118                options.dont_finish_rebase = 1;
1119                goto run_rebase;
1120        case NO_ACTION:
1121                break;
1122        default:
1123                BUG("action: %d", action);
1124        }
1125
1126        /* Make sure no rebase is in progress */
1127        if (in_progress) {
1128                const char *last_slash = strrchr(options.state_dir, '/');
1129                const char *state_dir_base =
1130                        last_slash ? last_slash + 1 : options.state_dir;
1131                const char *cmd_live_rebase =
1132                        "git rebase (--continue | --abort | --skip)";
1133                strbuf_reset(&buf);
1134                strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1135                die(_("It seems that there is already a %s directory, and\n"
1136                      "I wonder if you are in the middle of another rebase.  "
1137                      "If that is the\n"
1138                      "case, please try\n\t%s\n"
1139                      "If that is not the case, please\n\t%s\n"
1140                      "and run me again.  I am stopping in case you still "
1141                      "have something\n"
1142                      "valuable there.\n"),
1143                    state_dir_base, cmd_live_rebase, buf.buf);
1144        }
1145
1146        for (i = 0; i < options.git_am_opts.argc; i++) {
1147                const char *option = options.git_am_opts.argv[i], *p;
1148                if (!strcmp(option, "--committer-date-is-author-date") ||
1149                    !strcmp(option, "--ignore-date") ||
1150                    !strcmp(option, "--whitespace=fix") ||
1151                    !strcmp(option, "--whitespace=strip"))
1152                        options.flags |= REBASE_FORCE;
1153                else if (skip_prefix(option, "-C", &p)) {
1154                        while (*p)
1155                                if (!isdigit(*(p++)))
1156                                        die(_("switch `C' expects a "
1157                                              "numerical value"));
1158                } else if (skip_prefix(option, "--whitespace=", &p)) {
1159                        if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1160                            strcmp(p, "error") && strcmp(p, "error-all"))
1161                                die("Invalid whitespace option: '%s'", p);
1162                }
1163        }
1164
1165        if (!(options.flags & REBASE_NO_QUIET))
1166                argv_array_push(&options.git_am_opts, "-q");
1167
1168        if (options.keep_empty)
1169                imply_interactive(&options, "--keep-empty");
1170
1171        if (gpg_sign) {
1172                free(options.gpg_sign_opt);
1173                options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1174        }
1175
1176        if (exec.nr) {
1177                int i;
1178
1179                imply_interactive(&options, "--exec");
1180
1181                strbuf_reset(&buf);
1182                for (i = 0; i < exec.nr; i++)
1183                        strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1184                options.cmd = xstrdup(buf.buf);
1185        }
1186
1187        if (rebase_merges) {
1188                if (!*rebase_merges)
1189                        ; /* default mode; do nothing */
1190                else if (!strcmp("rebase-cousins", rebase_merges))
1191                        options.rebase_cousins = 1;
1192                else if (strcmp("no-rebase-cousins", rebase_merges))
1193                        die(_("Unknown mode: %s"), rebase_merges);
1194                options.rebase_merges = 1;
1195                imply_interactive(&options, "--rebase-merges");
1196        }
1197
1198        if (strategy_options.nr) {
1199                int i;
1200
1201                if (!options.strategy)
1202                        options.strategy = "recursive";
1203
1204                strbuf_reset(&buf);
1205                for (i = 0; i < strategy_options.nr; i++)
1206                        strbuf_addf(&buf, " --%s",
1207                                    strategy_options.items[i].string);
1208                options.strategy_opts = xstrdup(buf.buf);
1209        }
1210
1211        if (options.strategy) {
1212                options.strategy = xstrdup(options.strategy);
1213                switch (options.type) {
1214                case REBASE_AM:
1215                        die(_("--strategy requires --merge or --interactive"));
1216                case REBASE_MERGE:
1217                case REBASE_INTERACTIVE:
1218                case REBASE_PRESERVE_MERGES:
1219                        /* compatible */
1220                        break;
1221                case REBASE_UNSPECIFIED:
1222                        options.type = REBASE_MERGE;
1223                        break;
1224                default:
1225                        BUG("unhandled rebase type (%d)", options.type);
1226                }
1227        }
1228
1229        if (options.root && !options.onto_name)
1230                imply_interactive(&options, "--root without --onto");
1231
1232        if (isatty(2) && options.flags & REBASE_NO_QUIET)
1233                strbuf_addstr(&options.git_format_patch_opt, " --progress");
1234
1235        switch (options.type) {
1236        case REBASE_MERGE:
1237        case REBASE_INTERACTIVE:
1238        case REBASE_PRESERVE_MERGES:
1239                options.state_dir = merge_dir();
1240                break;
1241        case REBASE_AM:
1242                options.state_dir = apply_dir();
1243                break;
1244        default:
1245                /* the default rebase backend is `--am` */
1246                options.type = REBASE_AM;
1247                options.state_dir = apply_dir();
1248                break;
1249        }
1250
1251        if (options.reschedule_failed_exec && !is_interactive(&options))
1252                die(_("--reschedule-failed-exec requires an interactive rebase"));
1253
1254        if (options.git_am_opts.argc) {
1255                /* all am options except -q are compatible only with --am */
1256                for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1257                        if (strcmp(options.git_am_opts.argv[i], "-q"))
1258                                break;
1259
1260                if (is_interactive(&options) && i >= 0)
1261                        die(_("error: cannot combine interactive options "
1262                              "(--interactive, --exec, --rebase-merges, "
1263                              "--preserve-merges, --keep-empty, --root + "
1264                              "--onto) with am options (%s)"), buf.buf);
1265                if (options.type == REBASE_MERGE && i >= 0)
1266                        die(_("error: cannot combine merge options (--merge, "
1267                              "--strategy, --strategy-option) with am options "
1268                              "(%s)"), buf.buf);
1269        }
1270
1271        if (options.signoff) {
1272                if (options.type == REBASE_PRESERVE_MERGES)
1273                        die("cannot combine '--signoff' with "
1274                            "'--preserve-merges'");
1275                argv_array_push(&options.git_am_opts, "--signoff");
1276                options.flags |= REBASE_FORCE;
1277        }
1278
1279        if (options.type == REBASE_PRESERVE_MERGES) {
1280                /*
1281                 * Note: incompatibility with --signoff handled in signoff block above
1282                 * Note: incompatibility with --interactive is just a strong warning;
1283                 *       git-rebase.txt caveats with "unless you know what you are doing"
1284                 */
1285                if (options.rebase_merges)
1286                        die(_("error: cannot combine '--preserve-merges' with "
1287                              "'--rebase-merges'"));
1288
1289                if (options.reschedule_failed_exec)
1290                        die(_("error: cannot combine '--preserve-merges' with "
1291                              "'--reschedule-failed-exec'"));
1292        }
1293
1294        if (options.rebase_merges) {
1295                if (strategy_options.nr)
1296                        die(_("error: cannot combine '--rebase-merges' with "
1297                              "'--strategy-option'"));
1298                if (options.strategy)
1299                        die(_("error: cannot combine '--rebase-merges' with "
1300                              "'--strategy'"));
1301        }
1302
1303        if (!options.root) {
1304                if (argc < 1) {
1305                        struct branch *branch;
1306
1307                        branch = branch_get(NULL);
1308                        options.upstream_name = branch_get_upstream(branch,
1309                                                                    NULL);
1310                        if (!options.upstream_name)
1311                                error_on_missing_default_upstream();
1312                        if (fork_point < 0)
1313                                fork_point = 1;
1314                } else {
1315                        options.upstream_name = argv[0];
1316                        argc--;
1317                        argv++;
1318                        if (!strcmp(options.upstream_name, "-"))
1319                                options.upstream_name = "@{-1}";
1320                }
1321                options.upstream = peel_committish(options.upstream_name);
1322                if (!options.upstream)
1323                        die(_("invalid upstream '%s'"), options.upstream_name);
1324                options.upstream_arg = options.upstream_name;
1325        } else {
1326                if (!options.onto_name) {
1327                        if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1328                                        &squash_onto, NULL, NULL) < 0)
1329                                die(_("Could not create new root commit"));
1330                        options.squash_onto = &squash_onto;
1331                        options.onto_name = squash_onto_name =
1332                                xstrdup(oid_to_hex(&squash_onto));
1333                }
1334                options.upstream_name = NULL;
1335                options.upstream = NULL;
1336                if (argc > 1)
1337                        usage_with_options(builtin_rebase_usage,
1338                                           builtin_rebase_options);
1339                options.upstream_arg = "--root";
1340        }
1341
1342        /* Make sure the branch to rebase onto is valid. */
1343        if (!options.onto_name)
1344                options.onto_name = options.upstream_name;
1345        if (strstr(options.onto_name, "...")) {
1346                if (get_oid_mb(options.onto_name, &merge_base) < 0)
1347                        die(_("'%s': need exactly one merge base"),
1348                            options.onto_name);
1349                options.onto = lookup_commit_or_die(&merge_base,
1350                                                    options.onto_name);
1351        } else {
1352                options.onto = peel_committish(options.onto_name);
1353                if (!options.onto)
1354                        die(_("Does not point to a valid commit '%s'"),
1355                                options.onto_name);
1356        }
1357
1358        /*
1359         * If the branch to rebase is given, that is the branch we will rebase
1360         * branch_name -- branch/commit being rebased, or
1361         *                HEAD (already detached)
1362         * orig_head -- commit object name of tip of the branch before rebasing
1363         * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1364         */
1365        if (argc == 1) {
1366                /* Is it "rebase other branchname" or "rebase other commit"? */
1367                branch_name = argv[0];
1368                options.switch_to = argv[0];
1369
1370                /* Is it a local branch? */
1371                strbuf_reset(&buf);
1372                strbuf_addf(&buf, "refs/heads/%s", branch_name);
1373                if (!read_ref(buf.buf, &options.orig_head))
1374                        options.head_name = xstrdup(buf.buf);
1375                /* If not is it a valid ref (branch or commit)? */
1376                else if (!get_oid(branch_name, &options.orig_head))
1377                        options.head_name = NULL;
1378                else
1379                        die(_("fatal: no such branch/commit '%s'"),
1380                            branch_name);
1381        } else if (argc == 0) {
1382                /* Do not need to switch branches, we are already on it. */
1383                options.head_name =
1384                        xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1385                                         &flags));
1386                if (!options.head_name)
1387                        die(_("No such ref: %s"), "HEAD");
1388                if (flags & REF_ISSYMREF) {
1389                        if (!skip_prefix(options.head_name,
1390                                         "refs/heads/", &branch_name))
1391                                branch_name = options.head_name;
1392
1393                } else {
1394                        free(options.head_name);
1395                        options.head_name = NULL;
1396                        branch_name = "HEAD";
1397                }
1398                if (get_oid("HEAD", &options.orig_head))
1399                        die(_("Could not resolve HEAD to a revision"));
1400        } else
1401                BUG("unexpected number of arguments left to parse");
1402
1403        if (fork_point > 0) {
1404                struct commit *head =
1405                        lookup_commit_reference(the_repository,
1406                                                &options.orig_head);
1407                options.restrict_revision =
1408                        get_fork_point(options.upstream_name, head);
1409        }
1410
1411        if (read_index(the_repository->index) < 0)
1412                die(_("could not read index"));
1413
1414        if (options.autostash) {
1415                struct lock_file lock_file = LOCK_INIT;
1416                int fd;
1417
1418                fd = hold_locked_index(&lock_file, 0);
1419                refresh_cache(REFRESH_QUIET);
1420                if (0 <= fd)
1421                        update_index_if_able(&the_index, &lock_file);
1422                rollback_lock_file(&lock_file);
1423
1424                if (has_unstaged_changes(1) || has_uncommitted_changes(1)) {
1425                        const char *autostash =
1426                                state_dir_path("autostash", &options);
1427                        struct child_process stash = CHILD_PROCESS_INIT;
1428                        struct object_id oid;
1429                        struct commit *head =
1430                                lookup_commit_reference(the_repository,
1431                                                        &options.orig_head);
1432
1433                        argv_array_pushl(&stash.args,
1434                                         "stash", "create", "autostash", NULL);
1435                        stash.git_cmd = 1;
1436                        stash.no_stdin = 1;
1437                        strbuf_reset(&buf);
1438                        if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1439                                die(_("Cannot autostash"));
1440                        strbuf_trim_trailing_newline(&buf);
1441                        if (get_oid(buf.buf, &oid))
1442                                die(_("Unexpected stash response: '%s'"),
1443                                    buf.buf);
1444                        strbuf_reset(&buf);
1445                        strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1446
1447                        if (safe_create_leading_directories_const(autostash))
1448                                die(_("Could not create directory for '%s'"),
1449                                    options.state_dir);
1450                        write_file(autostash, "%s", oid_to_hex(&oid));
1451                        printf(_("Created autostash: %s\n"), buf.buf);
1452                        if (reset_head(&head->object.oid, "reset --hard",
1453                                       NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
1454                                die(_("could not reset --hard"));
1455                        printf(_("HEAD is now at %s"),
1456                               find_unique_abbrev(&head->object.oid,
1457                                                  DEFAULT_ABBREV));
1458                        strbuf_reset(&buf);
1459                        pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
1460                        if (buf.len > 0)
1461                                printf(" %s", buf.buf);
1462                        putchar('\n');
1463
1464                        if (discard_index(the_repository->index) < 0 ||
1465                                read_index(the_repository->index) < 0)
1466                                die(_("could not read index"));
1467                }
1468        }
1469
1470        if (require_clean_work_tree("rebase",
1471                                    _("Please commit or stash them."), 1, 1)) {
1472                ret = 1;
1473                goto cleanup;
1474        }
1475
1476        /*
1477         * Now we are rebasing commits upstream..orig_head (or with --root,
1478         * everything leading up to orig_head) on top of onto.
1479         */
1480
1481        /*
1482         * Check if we are already based on onto with linear history,
1483         * but this should be done only when upstream and onto are the same
1484         * and if this is not an interactive rebase.
1485         */
1486        if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
1487            !is_interactive(&options) && !options.restrict_revision &&
1488            options.upstream &&
1489            !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
1490                int flag;
1491
1492                if (!(options.flags & REBASE_FORCE)) {
1493                        /* Lazily switch to the target branch if needed... */
1494                        if (options.switch_to) {
1495                                struct object_id oid;
1496
1497                                if (get_oid(options.switch_to, &oid) < 0) {
1498                                        ret = !!error(_("could not parse '%s'"),
1499                                                      options.switch_to);
1500                                        goto cleanup;
1501                                }
1502
1503                                strbuf_reset(&buf);
1504                                strbuf_addf(&buf, "%s: checkout %s",
1505                                            getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
1506                                            options.switch_to);
1507                                if (reset_head(&oid, "checkout",
1508                                               options.head_name, 0,
1509                                               NULL, buf.buf) < 0) {
1510                                        ret = !!error(_("could not switch to "
1511                                                        "%s"),
1512                                                      options.switch_to);
1513                                        goto cleanup;
1514                                }
1515                        }
1516
1517                        if (!(options.flags & REBASE_NO_QUIET))
1518                                ; /* be quiet */
1519                        else if (!strcmp(branch_name, "HEAD") &&
1520                                 resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1521                                puts(_("HEAD is up to date."));
1522                        else
1523                                printf(_("Current branch %s is up to date.\n"),
1524                                       branch_name);
1525                        ret = !!finish_rebase(&options);
1526                        goto cleanup;
1527                } else if (!(options.flags & REBASE_NO_QUIET))
1528                        ; /* be quiet */
1529                else if (!strcmp(branch_name, "HEAD") &&
1530                         resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1531                        puts(_("HEAD is up to date, rebase forced."));
1532                else
1533                        printf(_("Current branch %s is up to date, rebase "
1534                                 "forced.\n"), branch_name);
1535        }
1536
1537        /* If a hook exists, give it a chance to interrupt*/
1538        if (!ok_to_skip_pre_rebase &&
1539            run_hook_le(NULL, "pre-rebase", options.upstream_arg,
1540                        argc ? argv[0] : NULL, NULL))
1541                die(_("The pre-rebase hook refused to rebase."));
1542
1543        if (options.flags & REBASE_DIFFSTAT) {
1544                struct diff_options opts;
1545
1546                if (options.flags & REBASE_VERBOSE) {
1547                        if (is_null_oid(&merge_base))
1548                                printf(_("Changes to %s:\n"),
1549                                       oid_to_hex(&options.onto->object.oid));
1550                        else
1551                                printf(_("Changes from %s to %s:\n"),
1552                                       oid_to_hex(&merge_base),
1553                                       oid_to_hex(&options.onto->object.oid));
1554                }
1555
1556                /* We want color (if set), but no pager */
1557                diff_setup(&opts);
1558                opts.stat_width = -1; /* use full terminal width */
1559                opts.stat_graph_width = -1; /* respect statGraphWidth config */
1560                opts.output_format |=
1561                        DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1562                opts.detect_rename = DIFF_DETECT_RENAME;
1563                diff_setup_done(&opts);
1564                diff_tree_oid(is_null_oid(&merge_base) ?
1565                              the_hash_algo->empty_tree : &merge_base,
1566                              &options.onto->object.oid, "", &opts);
1567                diffcore_std(&opts);
1568                diff_flush(&opts);
1569        }
1570
1571        if (is_interactive(&options))
1572                goto run_rebase;
1573
1574        /* Detach HEAD and reset the tree */
1575        if (options.flags & REBASE_NO_QUIET)
1576                printf(_("First, rewinding head to replay your work on top of "
1577                         "it...\n"));
1578
1579        strbuf_addf(&msg, "%s: checkout %s",
1580                    getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
1581        if (reset_head(&options.onto->object.oid, "checkout", NULL,
1582                       RESET_HEAD_DETACH, NULL, msg.buf))
1583                die(_("Could not detach HEAD"));
1584        strbuf_release(&msg);
1585
1586        /*
1587         * If the onto is a proper descendant of the tip of the branch, then
1588         * we just fast-forwarded.
1589         */
1590        strbuf_reset(&msg);
1591        if (!oidcmp(&merge_base, &options.orig_head)) {
1592                printf(_("Fast-forwarded %s to %s.\n"),
1593                        branch_name, options.onto_name);
1594                strbuf_addf(&msg, "rebase finished: %s onto %s",
1595                        options.head_name ? options.head_name : "detached HEAD",
1596                        oid_to_hex(&options.onto->object.oid));
1597                reset_head(NULL, "Fast-forwarded", options.head_name, 0,
1598                           "HEAD", msg.buf);
1599                strbuf_release(&msg);
1600                ret = !!finish_rebase(&options);
1601                goto cleanup;
1602        }
1603
1604        strbuf_addf(&revisions, "%s..%s",
1605                    options.root ? oid_to_hex(&options.onto->object.oid) :
1606                    (options.restrict_revision ?
1607                     oid_to_hex(&options.restrict_revision->object.oid) :
1608                     oid_to_hex(&options.upstream->object.oid)),
1609                    oid_to_hex(&options.orig_head));
1610
1611        options.revisions = revisions.buf;
1612
1613run_rebase:
1614        ret = !!run_specific_rebase(&options);
1615
1616cleanup:
1617        strbuf_release(&revisions);
1618        free(options.head_name);
1619        free(options.gpg_sign_opt);
1620        free(options.cmd);
1621        free(squash_onto_name);
1622        return ret;
1623}