df151217dab16b27ca6d3392615991b333ec9f25
   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        strbuf_reset(&buf);
 189        if (read_one(state_dir_path("quiet", opts), &buf))
 190                return -1;
 191        if (buf.len)
 192                opts->flags &= ~REBASE_NO_QUIET;
 193        else
 194                opts->flags |= REBASE_NO_QUIET;
 195
 196        if (file_exists(state_dir_path("verbose", opts)))
 197                opts->flags |= REBASE_VERBOSE;
 198
 199        if (file_exists(state_dir_path("signoff", opts))) {
 200                opts->signoff = 1;
 201                opts->flags |= REBASE_FORCE;
 202        }
 203
 204        if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 205                strbuf_reset(&buf);
 206                if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 207                            &buf))
 208                        return -1;
 209                if (!strcmp(buf.buf, "--rerere-autoupdate"))
 210                        opts->allow_rerere_autoupdate = 1;
 211                else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 212                        opts->allow_rerere_autoupdate = 0;
 213                else
 214                        warning(_("ignoring invalid allow_rerere_autoupdate: "
 215                                  "'%s'"), buf.buf);
 216        } else
 217                opts->allow_rerere_autoupdate = -1;
 218
 219        if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 220                strbuf_reset(&buf);
 221                if (read_one(state_dir_path("gpg_sign_opt", opts),
 222                            &buf))
 223                        return -1;
 224                free(opts->gpg_sign_opt);
 225                opts->gpg_sign_opt = xstrdup(buf.buf);
 226        }
 227
 228        if (file_exists(state_dir_path("strategy", opts))) {
 229                strbuf_reset(&buf);
 230                if (read_one(state_dir_path("strategy", opts), &buf))
 231                        return -1;
 232                free(opts->strategy);
 233                opts->strategy = xstrdup(buf.buf);
 234        }
 235
 236        if (file_exists(state_dir_path("strategy_opts", opts))) {
 237                strbuf_reset(&buf);
 238                if (read_one(state_dir_path("strategy_opts", opts), &buf))
 239                        return -1;
 240                free(opts->strategy_opts);
 241                opts->strategy_opts = xstrdup(buf.buf);
 242        }
 243
 244        strbuf_release(&buf);
 245
 246        return 0;
 247}
 248
 249static int apply_autostash(struct rebase_options *opts)
 250{
 251        const char *path = state_dir_path("autostash", opts);
 252        struct strbuf autostash = STRBUF_INIT;
 253        struct child_process stash_apply = CHILD_PROCESS_INIT;
 254
 255        if (!file_exists(path))
 256                return 0;
 257
 258        if (read_one(path, &autostash))
 259                return error(_("Could not read '%s'"), path);
 260        /* Ensure that the hash is not mistaken for a number */
 261        strbuf_addstr(&autostash, "^0");
 262        argv_array_pushl(&stash_apply.args,
 263                         "stash", "apply", autostash.buf, NULL);
 264        stash_apply.git_cmd = 1;
 265        stash_apply.no_stderr = stash_apply.no_stdout =
 266                stash_apply.no_stdin = 1;
 267        if (!run_command(&stash_apply))
 268                printf(_("Applied autostash.\n"));
 269        else {
 270                struct argv_array args = ARGV_ARRAY_INIT;
 271                int res = 0;
 272
 273                argv_array_pushl(&args,
 274                                 "stash", "store", "-m", "autostash", "-q",
 275                                 autostash.buf, NULL);
 276                if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 277                        res = error(_("Cannot store %s"), autostash.buf);
 278                argv_array_clear(&args);
 279                strbuf_release(&autostash);
 280                if (res)
 281                        return res;
 282
 283                fprintf(stderr,
 284                        _("Applying autostash resulted in conflicts.\n"
 285                          "Your changes are safe in the stash.\n"
 286                          "You can run \"git stash pop\" or \"git stash drop\" "
 287                          "at any time.\n"));
 288        }
 289
 290        strbuf_release(&autostash);
 291        return 0;
 292}
 293
 294static int finish_rebase(struct rebase_options *opts)
 295{
 296        struct strbuf dir = STRBUF_INIT;
 297        const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 298
 299        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 300        apply_autostash(opts);
 301        close_all_packs(the_repository->objects);
 302        /*
 303         * We ignore errors in 'gc --auto', since the
 304         * user should see them.
 305         */
 306        run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 307        strbuf_addstr(&dir, opts->state_dir);
 308        remove_dir_recursively(&dir, 0);
 309        strbuf_release(&dir);
 310
 311        return 0;
 312}
 313
 314static struct commit *peel_committish(const char *name)
 315{
 316        struct object *obj;
 317        struct object_id oid;
 318
 319        if (get_oid(name, &oid))
 320                return NULL;
 321        obj = parse_object(the_repository, &oid);
 322        return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 323}
 324
 325static void add_var(struct strbuf *buf, const char *name, const char *value)
 326{
 327        if (!value)
 328                strbuf_addf(buf, "unset %s; ", name);
 329        else {
 330                strbuf_addf(buf, "%s=", name);
 331                sq_quote_buf(buf, value);
 332                strbuf_addstr(buf, "; ");
 333        }
 334}
 335
 336#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 337
 338#define RESET_HEAD_DETACH (1<<0)
 339#define RESET_HEAD_HARD (1<<1)
 340#define RESET_HEAD_REFS_ONLY (1<<2)
 341
 342static int reset_head(struct object_id *oid, const char *action,
 343                      const char *switch_to_branch, unsigned flags,
 344                      const char *reflog_orig_head, const char *reflog_head)
 345{
 346        unsigned detach_head = flags & RESET_HEAD_DETACH;
 347        unsigned reset_hard = flags & RESET_HEAD_HARD;
 348        unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
 349        struct object_id head_oid;
 350        struct tree_desc desc[2] = { { NULL }, { NULL } };
 351        struct lock_file lock = LOCK_INIT;
 352        struct unpack_trees_options unpack_tree_opts;
 353        struct tree *tree;
 354        const char *reflog_action;
 355        struct strbuf msg = STRBUF_INIT;
 356        size_t prefix_len;
 357        struct object_id *orig = NULL, oid_orig,
 358                *old_orig = NULL, oid_old_orig;
 359        int ret = 0, nr = 0;
 360
 361        if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 362                BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 363
 364        if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 365                ret = -1;
 366                goto leave_reset_head;
 367        }
 368
 369        if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 370                ret = error(_("could not determine HEAD revision"));
 371                goto leave_reset_head;
 372        }
 373
 374        if (!oid)
 375                oid = &head_oid;
 376
 377        if (refs_only)
 378                goto reset_head_refs;
 379
 380        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 381        setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 382        unpack_tree_opts.head_idx = 1;
 383        unpack_tree_opts.src_index = the_repository->index;
 384        unpack_tree_opts.dst_index = the_repository->index;
 385        unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 386        unpack_tree_opts.update = 1;
 387        unpack_tree_opts.merge = 1;
 388        if (!detach_head)
 389                unpack_tree_opts.reset = 1;
 390
 391        if (read_index_unmerged(the_repository->index) < 0) {
 392                ret = error(_("could not read index"));
 393                goto leave_reset_head;
 394        }
 395
 396        if (!reset_hard && !fill_tree_descriptor(&desc[nr++], &head_oid)) {
 397                ret = error(_("failed to find tree of %s"),
 398                            oid_to_hex(&head_oid));
 399                goto leave_reset_head;
 400        }
 401
 402        if (!fill_tree_descriptor(&desc[nr++], oid)) {
 403                ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 404                goto leave_reset_head;
 405        }
 406
 407        if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 408                ret = -1;
 409                goto leave_reset_head;
 410        }
 411
 412        tree = parse_tree_indirect(oid);
 413        prime_cache_tree(the_repository->index, tree);
 414
 415        if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 416                ret = error(_("could not write index"));
 417                goto leave_reset_head;
 418        }
 419
 420reset_head_refs:
 421        reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 422        strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 423        prefix_len = msg.len;
 424
 425        if (!get_oid("ORIG_HEAD", &oid_old_orig))
 426                old_orig = &oid_old_orig;
 427        if (!get_oid("HEAD", &oid_orig)) {
 428                orig = &oid_orig;
 429                if (!reflog_orig_head) {
 430                        strbuf_addstr(&msg, "updating ORIG_HEAD");
 431                        reflog_orig_head = msg.buf;
 432                }
 433                update_ref(reflog_orig_head, "ORIG_HEAD", orig, old_orig, 0,
 434                           UPDATE_REFS_MSG_ON_ERR);
 435        } else if (old_orig)
 436                delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 437        if (!reflog_head) {
 438                strbuf_setlen(&msg, prefix_len);
 439                strbuf_addstr(&msg, "updating HEAD");
 440                reflog_head = msg.buf;
 441        }
 442        if (!switch_to_branch)
 443                ret = update_ref(reflog_head, "HEAD", oid, orig,
 444                                 detach_head ? REF_NO_DEREF : 0,
 445                                 UPDATE_REFS_MSG_ON_ERR);
 446        else {
 447                ret = update_ref(reflog_orig_head, switch_to_branch, oid,
 448                                 NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 449                if (!ret)
 450                        ret = create_symref("HEAD", switch_to_branch,
 451                                            reflog_head);
 452        }
 453
 454leave_reset_head:
 455        strbuf_release(&msg);
 456        rollback_lock_file(&lock);
 457        while (nr)
 458                free((void *)desc[--nr].buffer);
 459        return ret;
 460}
 461
 462static const char *resolvemsg =
 463N_("Resolve all conflicts manually, mark them as resolved with\n"
 464"\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 465"You can instead skip this commit: run \"git rebase --skip\".\n"
 466"To abort and get back to the state before \"git rebase\", run "
 467"\"git rebase --abort\".");
 468
 469static int run_specific_rebase(struct rebase_options *opts)
 470{
 471        const char *argv[] = { NULL, NULL };
 472        struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
 473        int status;
 474        const char *backend, *backend_func;
 475
 476        if (opts->type == REBASE_INTERACTIVE) {
 477                /* Run builtin interactive rebase */
 478                struct child_process child = CHILD_PROCESS_INIT;
 479
 480                argv_array_pushf(&child.env_array, "GIT_CHERRY_PICK_HELP=%s",
 481                                 resolvemsg);
 482                if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 483                        argv_array_push(&child.env_array, "GIT_EDITOR=:");
 484                        opts->autosquash = 0;
 485                }
 486
 487                child.git_cmd = 1;
 488                argv_array_push(&child.args, "rebase--interactive");
 489
 490                if (opts->action)
 491                        argv_array_pushf(&child.args, "--%s", opts->action);
 492                if (opts->keep_empty)
 493                        argv_array_push(&child.args, "--keep-empty");
 494                if (opts->rebase_merges)
 495                        argv_array_push(&child.args, "--rebase-merges");
 496                if (opts->rebase_cousins)
 497                        argv_array_push(&child.args, "--rebase-cousins");
 498                if (opts->autosquash)
 499                        argv_array_push(&child.args, "--autosquash");
 500                if (opts->flags & REBASE_VERBOSE)
 501                        argv_array_push(&child.args, "--verbose");
 502                if (opts->flags & REBASE_FORCE)
 503                        argv_array_push(&child.args, "--no-ff");
 504                if (opts->restrict_revision)
 505                        argv_array_pushf(&child.args,
 506                                         "--restrict-revision=^%s",
 507                                         oid_to_hex(&opts->restrict_revision->object.oid));
 508                if (opts->upstream)
 509                        argv_array_pushf(&child.args, "--upstream=%s",
 510                                         oid_to_hex(&opts->upstream->object.oid));
 511                if (opts->onto)
 512                        argv_array_pushf(&child.args, "--onto=%s",
 513                                         oid_to_hex(&opts->onto->object.oid));
 514                if (opts->squash_onto)
 515                        argv_array_pushf(&child.args, "--squash-onto=%s",
 516                                         oid_to_hex(opts->squash_onto));
 517                if (opts->onto_name)
 518                        argv_array_pushf(&child.args, "--onto-name=%s",
 519                                         opts->onto_name);
 520                argv_array_pushf(&child.args, "--head-name=%s",
 521                                 opts->head_name ?
 522                                 opts->head_name : "detached HEAD");
 523                if (opts->strategy)
 524                        argv_array_pushf(&child.args, "--strategy=%s",
 525                                         opts->strategy);
 526                if (opts->strategy_opts)
 527                        argv_array_pushf(&child.args, "--strategy-opts=%s",
 528                                         opts->strategy_opts);
 529                if (opts->switch_to)
 530                        argv_array_pushf(&child.args, "--switch-to=%s",
 531                                         opts->switch_to);
 532                if (opts->cmd)
 533                        argv_array_pushf(&child.args, "--cmd=%s", opts->cmd);
 534                if (opts->allow_empty_message)
 535                        argv_array_push(&child.args, "--allow-empty-message");
 536                if (opts->allow_rerere_autoupdate > 0)
 537                        argv_array_push(&child.args, "--rerere-autoupdate");
 538                else if (opts->allow_rerere_autoupdate == 0)
 539                        argv_array_push(&child.args, "--no-rerere-autoupdate");
 540                if (opts->gpg_sign_opt)
 541                        argv_array_push(&child.args, opts->gpg_sign_opt);
 542                if (opts->signoff)
 543                        argv_array_push(&child.args, "--signoff");
 544
 545                status = run_command(&child);
 546                goto finished_rebase;
 547        }
 548
 549        add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 550        add_var(&script_snippet, "state_dir", opts->state_dir);
 551
 552        add_var(&script_snippet, "upstream_name", opts->upstream_name);
 553        add_var(&script_snippet, "upstream", opts->upstream ?
 554                oid_to_hex(&opts->upstream->object.oid) : NULL);
 555        add_var(&script_snippet, "head_name",
 556                opts->head_name ? opts->head_name : "detached HEAD");
 557        add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 558        add_var(&script_snippet, "onto", opts->onto ?
 559                oid_to_hex(&opts->onto->object.oid) : NULL);
 560        add_var(&script_snippet, "onto_name", opts->onto_name);
 561        add_var(&script_snippet, "revisions", opts->revisions);
 562        add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 563                oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 564        add_var(&script_snippet, "GIT_QUIET",
 565                opts->flags & REBASE_NO_QUIET ? "" : "t");
 566        sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
 567        add_var(&script_snippet, "git_am_opt", buf.buf);
 568        strbuf_release(&buf);
 569        add_var(&script_snippet, "verbose",
 570                opts->flags & REBASE_VERBOSE ? "t" : "");
 571        add_var(&script_snippet, "diffstat",
 572                opts->flags & REBASE_DIFFSTAT ? "t" : "");
 573        add_var(&script_snippet, "force_rebase",
 574                opts->flags & REBASE_FORCE ? "t" : "");
 575        if (opts->switch_to)
 576                add_var(&script_snippet, "switch_to", opts->switch_to);
 577        add_var(&script_snippet, "action", opts->action ? opts->action : "");
 578        add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
 579        add_var(&script_snippet, "allow_rerere_autoupdate",
 580                opts->allow_rerere_autoupdate < 0 ? "" :
 581                opts->allow_rerere_autoupdate ?
 582                "--rerere-autoupdate" : "--no-rerere-autoupdate");
 583        add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
 584        add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
 585        add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
 586        add_var(&script_snippet, "cmd", opts->cmd);
 587        add_var(&script_snippet, "allow_empty_message",
 588                opts->allow_empty_message ?  "--allow-empty-message" : "");
 589        add_var(&script_snippet, "rebase_merges",
 590                opts->rebase_merges ? "t" : "");
 591        add_var(&script_snippet, "rebase_cousins",
 592                opts->rebase_cousins ? "t" : "");
 593        add_var(&script_snippet, "strategy", opts->strategy);
 594        add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
 595        add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
 596        add_var(&script_snippet, "squash_onto",
 597                opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
 598        add_var(&script_snippet, "git_format_patch_opt",
 599                opts->git_format_patch_opt.buf);
 600
 601        if (is_interactive(opts) &&
 602            !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 603                strbuf_addstr(&script_snippet,
 604                              "GIT_EDITOR=:; export GIT_EDITOR; ");
 605                opts->autosquash = 0;
 606        }
 607
 608        switch (opts->type) {
 609        case REBASE_AM:
 610                backend = "git-rebase--am";
 611                backend_func = "git_rebase__am";
 612                break;
 613        case REBASE_MERGE:
 614                backend = "git-rebase--merge";
 615                backend_func = "git_rebase__merge";
 616                break;
 617        case REBASE_PRESERVE_MERGES:
 618                backend = "git-rebase--preserve-merges";
 619                backend_func = "git_rebase__preserve_merges";
 620                break;
 621        default:
 622                BUG("Unhandled rebase type %d", opts->type);
 623                break;
 624        }
 625
 626        strbuf_addf(&script_snippet,
 627                    ". git-sh-setup && . git-rebase--common &&"
 628                    " . %s && %s", backend, backend_func);
 629        argv[0] = script_snippet.buf;
 630
 631        status = run_command_v_opt(argv, RUN_USING_SHELL);
 632finished_rebase:
 633        if (opts->dont_finish_rebase)
 634                ; /* do nothing */
 635        else if (opts->type == REBASE_INTERACTIVE)
 636                ; /* interactive rebase cleans up after itself */
 637        else if (status == 0) {
 638                if (!file_exists(state_dir_path("stopped-sha", opts)))
 639                        finish_rebase(opts);
 640        } else if (status == 2) {
 641                struct strbuf dir = STRBUF_INIT;
 642
 643                apply_autostash(opts);
 644                strbuf_addstr(&dir, opts->state_dir);
 645                remove_dir_recursively(&dir, 0);
 646                strbuf_release(&dir);
 647                die("Nothing to do");
 648        }
 649
 650        strbuf_release(&script_snippet);
 651
 652        return status ? -1 : 0;
 653}
 654
 655static int rebase_config(const char *var, const char *value, void *data)
 656{
 657        struct rebase_options *opts = data;
 658
 659        if (!strcmp(var, "rebase.stat")) {
 660                if (git_config_bool(var, value))
 661                        opts->flags |= REBASE_DIFFSTAT;
 662                else
 663                        opts->flags &= !REBASE_DIFFSTAT;
 664                return 0;
 665        }
 666
 667        if (!strcmp(var, "rebase.autosquash")) {
 668                opts->autosquash = git_config_bool(var, value);
 669                return 0;
 670        }
 671
 672        if (!strcmp(var, "commit.gpgsign")) {
 673                free(opts->gpg_sign_opt);
 674                opts->gpg_sign_opt = git_config_bool(var, value) ?
 675                        xstrdup("-S") : NULL;
 676                return 0;
 677        }
 678
 679        if (!strcmp(var, "rebase.autostash")) {
 680                opts->autostash = git_config_bool(var, value);
 681                return 0;
 682        }
 683
 684        return git_default_config(var, value, data);
 685}
 686
 687/*
 688 * Determines whether the commits in from..to are linear, i.e. contain
 689 * no merge commits. This function *expects* `from` to be an ancestor of
 690 * `to`.
 691 */
 692static int is_linear_history(struct commit *from, struct commit *to)
 693{
 694        while (to && to != from) {
 695                parse_commit(to);
 696                if (!to->parents)
 697                        return 1;
 698                if (to->parents->next)
 699                        return 0;
 700                to = to->parents->item;
 701        }
 702        return 1;
 703}
 704
 705static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
 706                            struct object_id *merge_base)
 707{
 708        struct commit *head = lookup_commit(the_repository, head_oid);
 709        struct commit_list *merge_bases;
 710        int res;
 711
 712        if (!head)
 713                return 0;
 714
 715        merge_bases = get_merge_bases(onto, head);
 716        if (merge_bases && !merge_bases->next) {
 717                oidcpy(merge_base, &merge_bases->item->object.oid);
 718                res = oideq(merge_base, &onto->object.oid);
 719        } else {
 720                oidcpy(merge_base, &null_oid);
 721                res = 0;
 722        }
 723        free_commit_list(merge_bases);
 724        return res && is_linear_history(onto, head);
 725}
 726
 727/* -i followed by -m is still -i */
 728static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 729{
 730        struct rebase_options *opts = opt->value;
 731
 732        BUG_ON_OPT_NEG(unset);
 733        BUG_ON_OPT_ARG(arg);
 734
 735        if (!is_interactive(opts))
 736                opts->type = REBASE_MERGE;
 737
 738        return 0;
 739}
 740
 741/* -i followed by -p is still explicitly interactive, but -p alone is not */
 742static int parse_opt_interactive(const struct option *opt, const char *arg,
 743                                 int unset)
 744{
 745        struct rebase_options *opts = opt->value;
 746
 747        BUG_ON_OPT_NEG(unset);
 748        BUG_ON_OPT_ARG(arg);
 749
 750        opts->type = REBASE_INTERACTIVE;
 751        opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 752
 753        return 0;
 754}
 755
 756static void NORETURN error_on_missing_default_upstream(void)
 757{
 758        struct branch *current_branch = branch_get(NULL);
 759
 760        printf(_("%s\n"
 761                 "Please specify which branch you want to rebase against.\n"
 762                 "See git-rebase(1) for details.\n"
 763                 "\n"
 764                 "    git rebase '<branch>'\n"
 765                 "\n"),
 766                current_branch ? _("There is no tracking information for "
 767                        "the current branch.") :
 768                        _("You are not currently on a branch."));
 769
 770        if (current_branch) {
 771                const char *remote = current_branch->remote_name;
 772
 773                if (!remote)
 774                        remote = _("<remote>");
 775
 776                printf(_("If you wish to set tracking information for this "
 777                         "branch you can do so with:\n"
 778                         "\n"
 779                         "    git branch --set-upstream-to=%s/<branch> %s\n"
 780                         "\n"),
 781                       remote, current_branch->name);
 782        }
 783        exit(1);
 784}
 785
 786static void set_reflog_action(struct rebase_options *options)
 787{
 788        const char *env;
 789        struct strbuf buf = STRBUF_INIT;
 790
 791        if (!is_interactive(options))
 792                return;
 793
 794        env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 795        if (env && strcmp("rebase", env))
 796                return; /* only override it if it is "rebase" */
 797
 798        strbuf_addf(&buf, "rebase -i (%s)", options->action);
 799        setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
 800        strbuf_release(&buf);
 801}
 802
 803int cmd_rebase(int argc, const char **argv, const char *prefix)
 804{
 805        struct rebase_options options = {
 806                .type = REBASE_UNSPECIFIED,
 807                .flags = REBASE_NO_QUIET,
 808                .git_am_opts = ARGV_ARRAY_INIT,
 809                .allow_rerere_autoupdate  = -1,
 810                .allow_empty_message = 1,
 811                .git_format_patch_opt = STRBUF_INIT,
 812        };
 813        const char *branch_name;
 814        int ret, flags, total_argc, in_progress = 0;
 815        int ok_to_skip_pre_rebase = 0;
 816        struct strbuf msg = STRBUF_INIT;
 817        struct strbuf revisions = STRBUF_INIT;
 818        struct strbuf buf = STRBUF_INIT;
 819        struct object_id merge_base;
 820        enum {
 821                NO_ACTION,
 822                ACTION_CONTINUE,
 823                ACTION_SKIP,
 824                ACTION_ABORT,
 825                ACTION_QUIT,
 826                ACTION_EDIT_TODO,
 827                ACTION_SHOW_CURRENT_PATCH,
 828        } action = NO_ACTION;
 829        const char *gpg_sign = NULL;
 830        struct string_list exec = STRING_LIST_INIT_NODUP;
 831        const char *rebase_merges = NULL;
 832        int fork_point = -1;
 833        struct string_list strategy_options = STRING_LIST_INIT_NODUP;
 834        struct object_id squash_onto;
 835        char *squash_onto_name = NULL;
 836        struct option builtin_rebase_options[] = {
 837                OPT_STRING(0, "onto", &options.onto_name,
 838                           N_("revision"),
 839                           N_("rebase onto given branch instead of upstream")),
 840                OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
 841                         N_("allow pre-rebase hook to run")),
 842                OPT_NEGBIT('q', "quiet", &options.flags,
 843                           N_("be quiet. implies --no-stat"),
 844                           REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
 845                OPT_BIT('v', "verbose", &options.flags,
 846                        N_("display a diffstat of what changed upstream"),
 847                        REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 848                {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
 849                        N_("do not show diffstat of what changed upstream"),
 850                        PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 851                OPT_BOOL(0, "signoff", &options.signoff,
 852                         N_("add a Signed-off-by: line to each commit")),
 853                OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
 854                                  NULL, N_("passed to 'git am'"),
 855                                  PARSE_OPT_NOARG),
 856                OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
 857                                  &options.git_am_opts, NULL,
 858                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
 859                OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
 860                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
 861                OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
 862                                  N_("passed to 'git apply'"), 0),
 863                OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
 864                                  N_("action"), N_("passed to 'git apply'"), 0),
 865                OPT_BIT('f', "force-rebase", &options.flags,
 866                        N_("cherry-pick all commits, even if unchanged"),
 867                        REBASE_FORCE),
 868                OPT_BIT(0, "no-ff", &options.flags,
 869                        N_("cherry-pick all commits, even if unchanged"),
 870                        REBASE_FORCE),
 871                OPT_CMDMODE(0, "continue", &action, N_("continue"),
 872                            ACTION_CONTINUE),
 873                OPT_CMDMODE(0, "skip", &action,
 874                            N_("skip current patch and continue"), ACTION_SKIP),
 875                OPT_CMDMODE(0, "abort", &action,
 876                            N_("abort and check out the original branch"),
 877                            ACTION_ABORT),
 878                OPT_CMDMODE(0, "quit", &action,
 879                            N_("abort but keep HEAD where it is"), ACTION_QUIT),
 880                OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
 881                            "during an interactive rebase"), ACTION_EDIT_TODO),
 882                OPT_CMDMODE(0, "show-current-patch", &action,
 883                            N_("show the patch file being applied or merged"),
 884                            ACTION_SHOW_CURRENT_PATCH),
 885                { OPTION_CALLBACK, 'm', "merge", &options, NULL,
 886                        N_("use merging strategies to rebase"),
 887                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 888                        parse_opt_merge },
 889                { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
 890                        N_("let the user edit the list of commits to rebase"),
 891                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
 892                        parse_opt_interactive },
 893                OPT_SET_INT('p', "preserve-merges", &options.type,
 894                            N_("try to recreate merges instead of ignoring "
 895                               "them"), REBASE_PRESERVE_MERGES),
 896                OPT_BOOL(0, "rerere-autoupdate",
 897                         &options.allow_rerere_autoupdate,
 898                         N_("allow rerere to update index with resolved "
 899                            "conflict")),
 900                OPT_BOOL('k', "keep-empty", &options.keep_empty,
 901                         N_("preserve empty commits during rebase")),
 902                OPT_BOOL(0, "autosquash", &options.autosquash,
 903                         N_("move commits that begin with "
 904                            "squash!/fixup! under -i")),
 905                { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
 906                        N_("GPG-sign commits"),
 907                        PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 908                OPT_BOOL(0, "autostash", &options.autostash,
 909                         N_("automatically stash/stash pop before and after")),
 910                OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
 911                                N_("add exec lines after each commit of the "
 912                                   "editable list")),
 913                OPT_BOOL(0, "allow-empty-message",
 914                         &options.allow_empty_message,
 915                         N_("allow rebasing commits with empty messages")),
 916                {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
 917                        N_("mode"),
 918                        N_("try to rebase merges instead of skipping them"),
 919                        PARSE_OPT_OPTARG, NULL, (intptr_t)""},
 920                OPT_BOOL(0, "fork-point", &fork_point,
 921                         N_("use 'merge-base --fork-point' to refine upstream")),
 922                OPT_STRING('s', "strategy", &options.strategy,
 923                           N_("strategy"), N_("use the given merge strategy")),
 924                OPT_STRING_LIST('X', "strategy-option", &strategy_options,
 925                                N_("option"),
 926                                N_("pass the argument through to the merge "
 927                                   "strategy")),
 928                OPT_BOOL(0, "root", &options.root,
 929                         N_("rebase all reachable commits up to the root(s)")),
 930                OPT_END(),
 931        };
 932        int i;
 933
 934        /*
 935         * NEEDSWORK: Once the builtin rebase has been tested enough
 936         * and git-legacy-rebase.sh is retired to contrib/, this preamble
 937         * can be removed.
 938         */
 939
 940        if (!use_builtin_rebase()) {
 941                const char *path = mkpath("%s/git-legacy-rebase",
 942                                          git_exec_path());
 943
 944                if (sane_execvp(path, (char **)argv) < 0)
 945                        die_errno(_("could not exec %s"), path);
 946                else
 947                        BUG("sane_execvp() returned???");
 948        }
 949
 950        if (argc == 2 && !strcmp(argv[1], "-h"))
 951                usage_with_options(builtin_rebase_usage,
 952                                   builtin_rebase_options);
 953
 954        prefix = setup_git_directory();
 955        trace_repo_setup(prefix);
 956        setup_work_tree();
 957
 958        git_config(rebase_config, &options);
 959
 960        strbuf_reset(&buf);
 961        strbuf_addf(&buf, "%s/applying", apply_dir());
 962        if(file_exists(buf.buf))
 963                die(_("It looks like 'git am' is in progress. Cannot rebase."));
 964
 965        if (is_directory(apply_dir())) {
 966                options.type = REBASE_AM;
 967                options.state_dir = apply_dir();
 968        } else if (is_directory(merge_dir())) {
 969                strbuf_reset(&buf);
 970                strbuf_addf(&buf, "%s/rewritten", merge_dir());
 971                if (is_directory(buf.buf)) {
 972                        options.type = REBASE_PRESERVE_MERGES;
 973                        options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 974                } else {
 975                        strbuf_reset(&buf);
 976                        strbuf_addf(&buf, "%s/interactive", merge_dir());
 977                        if(file_exists(buf.buf)) {
 978                                options.type = REBASE_INTERACTIVE;
 979                                options.flags |= REBASE_INTERACTIVE_EXPLICIT;
 980                        } else
 981                                options.type = REBASE_MERGE;
 982                }
 983                options.state_dir = merge_dir();
 984        }
 985
 986        if (options.type != REBASE_UNSPECIFIED)
 987                in_progress = 1;
 988
 989        total_argc = argc;
 990        argc = parse_options(argc, argv, prefix,
 991                             builtin_rebase_options,
 992                             builtin_rebase_usage, 0);
 993
 994        if (action != NO_ACTION && total_argc != 2) {
 995                usage_with_options(builtin_rebase_usage,
 996                                   builtin_rebase_options);
 997        }
 998
 999        if (argc > 2)
1000                usage_with_options(builtin_rebase_usage,
1001                                   builtin_rebase_options);
1002
1003        if (action != NO_ACTION && !in_progress)
1004                die(_("No rebase in progress?"));
1005        setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1006
1007        if (action == ACTION_EDIT_TODO && !is_interactive(&options))
1008                die(_("The --edit-todo action can only be used during "
1009                      "interactive rebase."));
1010
1011        switch (action) {
1012        case ACTION_CONTINUE: {
1013                struct object_id head;
1014                struct lock_file lock_file = LOCK_INIT;
1015                int fd;
1016
1017                options.action = "continue";
1018                set_reflog_action(&options);
1019
1020                /* Sanity check */
1021                if (get_oid("HEAD", &head))
1022                        die(_("Cannot read HEAD"));
1023
1024                fd = hold_locked_index(&lock_file, 0);
1025                if (read_index(the_repository->index) < 0)
1026                        die(_("could not read index"));
1027                refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1028                              NULL);
1029                if (0 <= fd)
1030                        update_index_if_able(the_repository->index,
1031                                             &lock_file);
1032                rollback_lock_file(&lock_file);
1033
1034                if (has_unstaged_changes(1)) {
1035                        puts(_("You must edit all merge conflicts and then\n"
1036                               "mark them as resolved using git add"));
1037                        exit(1);
1038                }
1039                if (read_basic_state(&options))
1040                        exit(1);
1041                goto run_rebase;
1042        }
1043        case ACTION_SKIP: {
1044                struct string_list merge_rr = STRING_LIST_INIT_DUP;
1045
1046                options.action = "skip";
1047                set_reflog_action(&options);
1048
1049                rerere_clear(&merge_rr);
1050                string_list_clear(&merge_rr, 1);
1051
1052                if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1053                               NULL, NULL) < 0)
1054                        die(_("could not discard worktree changes"));
1055                remove_branch_state();
1056                if (read_basic_state(&options))
1057                        exit(1);
1058                goto run_rebase;
1059        }
1060        case ACTION_ABORT: {
1061                struct string_list merge_rr = STRING_LIST_INIT_DUP;
1062                options.action = "abort";
1063                set_reflog_action(&options);
1064
1065                rerere_clear(&merge_rr);
1066                string_list_clear(&merge_rr, 1);
1067
1068                if (read_basic_state(&options))
1069                        exit(1);
1070                if (reset_head(&options.orig_head, "reset",
1071                               options.head_name, RESET_HEAD_HARD,
1072                               NULL, NULL) < 0)
1073                        die(_("could not move back to %s"),
1074                            oid_to_hex(&options.orig_head));
1075                remove_branch_state();
1076                ret = finish_rebase(&options);
1077                goto cleanup;
1078        }
1079        case ACTION_QUIT: {
1080                strbuf_reset(&buf);
1081                strbuf_addstr(&buf, options.state_dir);
1082                ret = !!remove_dir_recursively(&buf, 0);
1083                if (ret)
1084                        die(_("could not remove '%s'"), options.state_dir);
1085                goto cleanup;
1086        }
1087        case ACTION_EDIT_TODO:
1088                options.action = "edit-todo";
1089                options.dont_finish_rebase = 1;
1090                goto run_rebase;
1091        case ACTION_SHOW_CURRENT_PATCH:
1092                options.action = "show-current-patch";
1093                options.dont_finish_rebase = 1;
1094                goto run_rebase;
1095        case NO_ACTION:
1096                break;
1097        default:
1098                BUG("action: %d", action);
1099        }
1100
1101        /* Make sure no rebase is in progress */
1102        if (in_progress) {
1103                const char *last_slash = strrchr(options.state_dir, '/');
1104                const char *state_dir_base =
1105                        last_slash ? last_slash + 1 : options.state_dir;
1106                const char *cmd_live_rebase =
1107                        "git rebase (--continue | --abort | --skip)";
1108                strbuf_reset(&buf);
1109                strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1110                die(_("It seems that there is already a %s directory, and\n"
1111                      "I wonder if you are in the middle of another rebase.  "
1112                      "If that is the\n"
1113                      "case, please try\n\t%s\n"
1114                      "If that is not the case, please\n\t%s\n"
1115                      "and run me again.  I am stopping in case you still "
1116                      "have something\n"
1117                      "valuable there.\n"),
1118                    state_dir_base, cmd_live_rebase, buf.buf);
1119        }
1120
1121        for (i = 0; i < options.git_am_opts.argc; i++) {
1122                const char *option = options.git_am_opts.argv[i], *p;
1123                if (!strcmp(option, "--committer-date-is-author-date") ||
1124                    !strcmp(option, "--ignore-date") ||
1125                    !strcmp(option, "--whitespace=fix") ||
1126                    !strcmp(option, "--whitespace=strip"))
1127                        options.flags |= REBASE_FORCE;
1128                else if (skip_prefix(option, "-C", &p)) {
1129                        while (*p)
1130                                if (!isdigit(*(p++)))
1131                                        die(_("switch `C' expects a "
1132                                              "numerical value"));
1133                } else if (skip_prefix(option, "--whitespace=", &p)) {
1134                        if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1135                            strcmp(p, "error") && strcmp(p, "error-all"))
1136                                die("Invalid whitespace option: '%s'", p);
1137                }
1138        }
1139
1140        if (!(options.flags & REBASE_NO_QUIET))
1141                argv_array_push(&options.git_am_opts, "-q");
1142
1143        if (options.keep_empty)
1144                imply_interactive(&options, "--keep-empty");
1145
1146        if (gpg_sign) {
1147                free(options.gpg_sign_opt);
1148                options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1149        }
1150
1151        if (exec.nr) {
1152                int i;
1153
1154                imply_interactive(&options, "--exec");
1155
1156                strbuf_reset(&buf);
1157                for (i = 0; i < exec.nr; i++)
1158                        strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1159                options.cmd = xstrdup(buf.buf);
1160        }
1161
1162        if (rebase_merges) {
1163                if (!*rebase_merges)
1164                        ; /* default mode; do nothing */
1165                else if (!strcmp("rebase-cousins", rebase_merges))
1166                        options.rebase_cousins = 1;
1167                else if (strcmp("no-rebase-cousins", rebase_merges))
1168                        die(_("Unknown mode: %s"), rebase_merges);
1169                options.rebase_merges = 1;
1170                imply_interactive(&options, "--rebase-merges");
1171        }
1172
1173        if (strategy_options.nr) {
1174                int i;
1175
1176                if (!options.strategy)
1177                        options.strategy = "recursive";
1178
1179                strbuf_reset(&buf);
1180                for (i = 0; i < strategy_options.nr; i++)
1181                        strbuf_addf(&buf, " --%s",
1182                                    strategy_options.items[i].string);
1183                options.strategy_opts = xstrdup(buf.buf);
1184        }
1185
1186        if (options.strategy) {
1187                options.strategy = xstrdup(options.strategy);
1188                switch (options.type) {
1189                case REBASE_AM:
1190                        die(_("--strategy requires --merge or --interactive"));
1191                case REBASE_MERGE:
1192                case REBASE_INTERACTIVE:
1193                case REBASE_PRESERVE_MERGES:
1194                        /* compatible */
1195                        break;
1196                case REBASE_UNSPECIFIED:
1197                        options.type = REBASE_MERGE;
1198                        break;
1199                default:
1200                        BUG("unhandled rebase type (%d)", options.type);
1201                }
1202        }
1203
1204        if (options.root && !options.onto_name)
1205                imply_interactive(&options, "--root without --onto");
1206
1207        if (isatty(2) && options.flags & REBASE_NO_QUIET)
1208                strbuf_addstr(&options.git_format_patch_opt, " --progress");
1209
1210        switch (options.type) {
1211        case REBASE_MERGE:
1212        case REBASE_INTERACTIVE:
1213        case REBASE_PRESERVE_MERGES:
1214                options.state_dir = merge_dir();
1215                break;
1216        case REBASE_AM:
1217                options.state_dir = apply_dir();
1218                break;
1219        default:
1220                /* the default rebase backend is `--am` */
1221                options.type = REBASE_AM;
1222                options.state_dir = apply_dir();
1223                break;
1224        }
1225
1226        if (options.git_am_opts.argc) {
1227                /* all am options except -q are compatible only with --am */
1228                for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1229                        if (strcmp(options.git_am_opts.argv[i], "-q"))
1230                                break;
1231
1232                if (is_interactive(&options) && i >= 0)
1233                        die(_("error: cannot combine interactive options "
1234                              "(--interactive, --exec, --rebase-merges, "
1235                              "--preserve-merges, --keep-empty, --root + "
1236                              "--onto) with am options (%s)"), buf.buf);
1237                if (options.type == REBASE_MERGE && i >= 0)
1238                        die(_("error: cannot combine merge options (--merge, "
1239                              "--strategy, --strategy-option) with am options "
1240                              "(%s)"), buf.buf);
1241        }
1242
1243        if (options.signoff) {
1244                if (options.type == REBASE_PRESERVE_MERGES)
1245                        die("cannot combine '--signoff' with "
1246                            "'--preserve-merges'");
1247                argv_array_push(&options.git_am_opts, "--signoff");
1248                options.flags |= REBASE_FORCE;
1249        }
1250
1251        if (options.type == REBASE_PRESERVE_MERGES)
1252                /*
1253                 * Note: incompatibility with --signoff handled in signoff block above
1254                 * Note: incompatibility with --interactive is just a strong warning;
1255                 *       git-rebase.txt caveats with "unless you know what you are doing"
1256                 */
1257                if (options.rebase_merges)
1258                        die(_("error: cannot combine '--preserve-merges' with "
1259                              "'--rebase-merges'"));
1260
1261        if (options.rebase_merges) {
1262                if (strategy_options.nr)
1263                        die(_("error: cannot combine '--rebase-merges' with "
1264                              "'--strategy-option'"));
1265                if (options.strategy)
1266                        die(_("error: cannot combine '--rebase-merges' with "
1267                              "'--strategy'"));
1268        }
1269
1270        if (!options.root) {
1271                if (argc < 1) {
1272                        struct branch *branch;
1273
1274                        branch = branch_get(NULL);
1275                        options.upstream_name = branch_get_upstream(branch,
1276                                                                    NULL);
1277                        if (!options.upstream_name)
1278                                error_on_missing_default_upstream();
1279                        if (fork_point < 0)
1280                                fork_point = 1;
1281                } else {
1282                        options.upstream_name = argv[0];
1283                        argc--;
1284                        argv++;
1285                        if (!strcmp(options.upstream_name, "-"))
1286                                options.upstream_name = "@{-1}";
1287                }
1288                options.upstream = peel_committish(options.upstream_name);
1289                if (!options.upstream)
1290                        die(_("invalid upstream '%s'"), options.upstream_name);
1291                options.upstream_arg = options.upstream_name;
1292        } else {
1293                if (!options.onto_name) {
1294                        if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1295                                        &squash_onto, NULL, NULL) < 0)
1296                                die(_("Could not create new root commit"));
1297                        options.squash_onto = &squash_onto;
1298                        options.onto_name = squash_onto_name =
1299                                xstrdup(oid_to_hex(&squash_onto));
1300                }
1301                options.upstream_name = NULL;
1302                options.upstream = NULL;
1303                if (argc > 1)
1304                        usage_with_options(builtin_rebase_usage,
1305                                           builtin_rebase_options);
1306                options.upstream_arg = "--root";
1307        }
1308
1309        /* Make sure the branch to rebase onto is valid. */
1310        if (!options.onto_name)
1311                options.onto_name = options.upstream_name;
1312        if (strstr(options.onto_name, "...")) {
1313                if (get_oid_mb(options.onto_name, &merge_base) < 0)
1314                        die(_("'%s': need exactly one merge base"),
1315                            options.onto_name);
1316                options.onto = lookup_commit_or_die(&merge_base,
1317                                                    options.onto_name);
1318        } else {
1319                options.onto = peel_committish(options.onto_name);
1320                if (!options.onto)
1321                        die(_("Does not point to a valid commit '%s'"),
1322                                options.onto_name);
1323        }
1324
1325        /*
1326         * If the branch to rebase is given, that is the branch we will rebase
1327         * branch_name -- branch/commit being rebased, or
1328         *                HEAD (already detached)
1329         * orig_head -- commit object name of tip of the branch before rebasing
1330         * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1331         */
1332        if (argc == 1) {
1333                /* Is it "rebase other branchname" or "rebase other commit"? */
1334                branch_name = argv[0];
1335                options.switch_to = argv[0];
1336
1337                /* Is it a local branch? */
1338                strbuf_reset(&buf);
1339                strbuf_addf(&buf, "refs/heads/%s", branch_name);
1340                if (!read_ref(buf.buf, &options.orig_head))
1341                        options.head_name = xstrdup(buf.buf);
1342                /* If not is it a valid ref (branch or commit)? */
1343                else if (!get_oid(branch_name, &options.orig_head))
1344                        options.head_name = NULL;
1345                else
1346                        die(_("fatal: no such branch/commit '%s'"),
1347                            branch_name);
1348        } else if (argc == 0) {
1349                /* Do not need to switch branches, we are already on it. */
1350                options.head_name =
1351                        xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1352                                         &flags));
1353                if (!options.head_name)
1354                        die(_("No such ref: %s"), "HEAD");
1355                if (flags & REF_ISSYMREF) {
1356                        if (!skip_prefix(options.head_name,
1357                                         "refs/heads/", &branch_name))
1358                                branch_name = options.head_name;
1359
1360                } else {
1361                        free(options.head_name);
1362                        options.head_name = NULL;
1363                        branch_name = "HEAD";
1364                }
1365                if (get_oid("HEAD", &options.orig_head))
1366                        die(_("Could not resolve HEAD to a revision"));
1367        } else
1368                BUG("unexpected number of arguments left to parse");
1369
1370        if (fork_point > 0) {
1371                struct commit *head =
1372                        lookup_commit_reference(the_repository,
1373                                                &options.orig_head);
1374                options.restrict_revision =
1375                        get_fork_point(options.upstream_name, head);
1376        }
1377
1378        if (read_index(the_repository->index) < 0)
1379                die(_("could not read index"));
1380
1381        if (options.autostash) {
1382                struct lock_file lock_file = LOCK_INIT;
1383                int fd;
1384
1385                fd = hold_locked_index(&lock_file, 0);
1386                refresh_cache(REFRESH_QUIET);
1387                if (0 <= fd)
1388                        update_index_if_able(&the_index, &lock_file);
1389                rollback_lock_file(&lock_file);
1390
1391                if (has_unstaged_changes(1) || has_uncommitted_changes(1)) {
1392                        const char *autostash =
1393                                state_dir_path("autostash", &options);
1394                        struct child_process stash = CHILD_PROCESS_INIT;
1395                        struct object_id oid;
1396                        struct commit *head =
1397                                lookup_commit_reference(the_repository,
1398                                                        &options.orig_head);
1399
1400                        argv_array_pushl(&stash.args,
1401                                         "stash", "create", "autostash", NULL);
1402                        stash.git_cmd = 1;
1403                        stash.no_stdin = 1;
1404                        strbuf_reset(&buf);
1405                        if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1406                                die(_("Cannot autostash"));
1407                        strbuf_trim_trailing_newline(&buf);
1408                        if (get_oid(buf.buf, &oid))
1409                                die(_("Unexpected stash response: '%s'"),
1410                                    buf.buf);
1411                        strbuf_reset(&buf);
1412                        strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1413
1414                        if (safe_create_leading_directories_const(autostash))
1415                                die(_("Could not create directory for '%s'"),
1416                                    options.state_dir);
1417                        write_file(autostash, "%s", oid_to_hex(&oid));
1418                        printf(_("Created autostash: %s\n"), buf.buf);
1419                        if (reset_head(&head->object.oid, "reset --hard",
1420                                       NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
1421                                die(_("could not reset --hard"));
1422                        printf(_("HEAD is now at %s"),
1423                               find_unique_abbrev(&head->object.oid,
1424                                                  DEFAULT_ABBREV));
1425                        strbuf_reset(&buf);
1426                        pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
1427                        if (buf.len > 0)
1428                                printf(" %s", buf.buf);
1429                        putchar('\n');
1430
1431                        if (discard_index(the_repository->index) < 0 ||
1432                                read_index(the_repository->index) < 0)
1433                                die(_("could not read index"));
1434                }
1435        }
1436
1437        if (require_clean_work_tree("rebase",
1438                                    _("Please commit or stash them."), 1, 1)) {
1439                ret = 1;
1440                goto cleanup;
1441        }
1442
1443        /*
1444         * Now we are rebasing commits upstream..orig_head (or with --root,
1445         * everything leading up to orig_head) on top of onto.
1446         */
1447
1448        /*
1449         * Check if we are already based on onto with linear history,
1450         * but this should be done only when upstream and onto are the same
1451         * and if this is not an interactive rebase.
1452         */
1453        if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
1454            !is_interactive(&options) && !options.restrict_revision &&
1455            options.upstream &&
1456            !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
1457                int flag;
1458
1459                if (!(options.flags & REBASE_FORCE)) {
1460                        /* Lazily switch to the target branch if needed... */
1461                        if (options.switch_to) {
1462                                struct object_id oid;
1463
1464                                if (get_oid(options.switch_to, &oid) < 0) {
1465                                        ret = !!error(_("could not parse '%s'"),
1466                                                      options.switch_to);
1467                                        goto cleanup;
1468                                }
1469
1470                                strbuf_reset(&buf);
1471                                strbuf_addf(&buf, "%s: checkout %s",
1472                                            getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
1473                                            options.switch_to);
1474                                if (reset_head(&oid, "checkout",
1475                                               options.head_name, 0,
1476                                               NULL, buf.buf) < 0) {
1477                                        ret = !!error(_("could not switch to "
1478                                                        "%s"),
1479                                                      options.switch_to);
1480                                        goto cleanup;
1481                                }
1482                        }
1483
1484                        if (!(options.flags & REBASE_NO_QUIET))
1485                                ; /* be quiet */
1486                        else if (!strcmp(branch_name, "HEAD") &&
1487                                 resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1488                                puts(_("HEAD is up to date."));
1489                        else
1490                                printf(_("Current branch %s is up to date.\n"),
1491                                       branch_name);
1492                        ret = !!finish_rebase(&options);
1493                        goto cleanup;
1494                } else if (!(options.flags & REBASE_NO_QUIET))
1495                        ; /* be quiet */
1496                else if (!strcmp(branch_name, "HEAD") &&
1497                         resolve_ref_unsafe("HEAD", 0, NULL, &flag))
1498                        puts(_("HEAD is up to date, rebase forced."));
1499                else
1500                        printf(_("Current branch %s is up to date, rebase "
1501                                 "forced.\n"), branch_name);
1502        }
1503
1504        /* If a hook exists, give it a chance to interrupt*/
1505        if (!ok_to_skip_pre_rebase &&
1506            run_hook_le(NULL, "pre-rebase", options.upstream_arg,
1507                        argc ? argv[0] : NULL, NULL))
1508                die(_("The pre-rebase hook refused to rebase."));
1509
1510        if (options.flags & REBASE_DIFFSTAT) {
1511                struct diff_options opts;
1512
1513                if (options.flags & REBASE_VERBOSE) {
1514                        if (is_null_oid(&merge_base))
1515                                printf(_("Changes to %s:\n"),
1516                                       oid_to_hex(&options.onto->object.oid));
1517                        else
1518                                printf(_("Changes from %s to %s:\n"),
1519                                       oid_to_hex(&merge_base),
1520                                       oid_to_hex(&options.onto->object.oid));
1521                }
1522
1523                /* We want color (if set), but no pager */
1524                diff_setup(&opts);
1525                opts.stat_width = -1; /* use full terminal width */
1526                opts.stat_graph_width = -1; /* respect statGraphWidth config */
1527                opts.output_format |=
1528                        DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
1529                opts.detect_rename = DIFF_DETECT_RENAME;
1530                diff_setup_done(&opts);
1531                diff_tree_oid(is_null_oid(&merge_base) ?
1532                              the_hash_algo->empty_tree : &merge_base,
1533                              &options.onto->object.oid, "", &opts);
1534                diffcore_std(&opts);
1535                diff_flush(&opts);
1536        }
1537
1538        if (is_interactive(&options))
1539                goto run_rebase;
1540
1541        /* Detach HEAD and reset the tree */
1542        if (options.flags & REBASE_NO_QUIET)
1543                printf(_("First, rewinding head to replay your work on top of "
1544                         "it...\n"));
1545
1546        strbuf_addf(&msg, "%s: checkout %s",
1547                    getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
1548        if (reset_head(&options.onto->object.oid, "checkout", NULL,
1549                       RESET_HEAD_DETACH, NULL, msg.buf))
1550                die(_("Could not detach HEAD"));
1551        strbuf_release(&msg);
1552
1553        /*
1554         * If the onto is a proper descendant of the tip of the branch, then
1555         * we just fast-forwarded.
1556         */
1557        strbuf_reset(&msg);
1558        if (!oidcmp(&merge_base, &options.orig_head)) {
1559                printf(_("Fast-forwarded %s to %s.\n"),
1560                        branch_name, options.onto_name);
1561                strbuf_addf(&msg, "rebase finished: %s onto %s",
1562                        options.head_name ? options.head_name : "detached HEAD",
1563                        oid_to_hex(&options.onto->object.oid));
1564                reset_head(NULL, "Fast-forwarded", options.head_name, 0,
1565                           "HEAD", msg.buf);
1566                strbuf_release(&msg);
1567                ret = !!finish_rebase(&options);
1568                goto cleanup;
1569        }
1570
1571        strbuf_addf(&revisions, "%s..%s",
1572                    options.root ? oid_to_hex(&options.onto->object.oid) :
1573                    (options.restrict_revision ?
1574                     oid_to_hex(&options.restrict_revision->object.oid) :
1575                     oid_to_hex(&options.upstream->object.oid)),
1576                    oid_to_hex(&options.orig_head));
1577
1578        options.revisions = revisions.buf;
1579
1580run_rebase:
1581        ret = !!run_specific_rebase(&options);
1582
1583cleanup:
1584        strbuf_release(&revisions);
1585        free(options.head_name);
1586        free(options.gpg_sign_opt);
1587        free(options.cmd);
1588        free(squash_onto_name);
1589        return ret;
1590}