builtin / rebase.con commit Merge branch 'tg/push-all-in-mirror-forbidden' (fe048e4)
   1/*
   2 * "git rebase" builtin command
   3 *
   4 * Copyright (c) 2018 Pratik Karki
   5 */
   6
   7#define USE_THE_INDEX_COMPATIBILITY_MACROS
   8#include "builtin.h"
   9#include "run-command.h"
  10#include "exec-cmd.h"
  11#include "argv-array.h"
  12#include "dir.h"
  13#include "packfile.h"
  14#include "refs.h"
  15#include "quote.h"
  16#include "config.h"
  17#include "cache-tree.h"
  18#include "unpack-trees.h"
  19#include "lockfile.h"
  20#include "parse-options.h"
  21#include "commit.h"
  22#include "diff.h"
  23#include "wt-status.h"
  24#include "revision.h"
  25#include "commit-reach.h"
  26#include "rerere.h"
  27#include "branch.h"
  28#include "sequencer.h"
  29#include "rebase-interactive.h"
  30
  31static char const * const builtin_rebase_usage[] = {
  32        N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  33                "[<upstream>] [<branch>]"),
  34        N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  35                "--root [<branch>]"),
  36        N_("git rebase --continue | --abort | --skip | --edit-todo"),
  37        NULL
  38};
  39
  40static GIT_PATH_FUNC(path_squash_onto, "rebase-merge/squash-onto")
  41static GIT_PATH_FUNC(path_interactive, "rebase-merge/interactive")
  42static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  43static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  44
  45enum rebase_type {
  46        REBASE_UNSPECIFIED = -1,
  47        REBASE_AM,
  48        REBASE_MERGE,
  49        REBASE_INTERACTIVE,
  50        REBASE_PRESERVE_MERGES
  51};
  52
  53struct rebase_options {
  54        enum rebase_type type;
  55        const char *state_dir;
  56        struct commit *upstream;
  57        const char *upstream_name;
  58        const char *upstream_arg;
  59        char *head_name;
  60        struct object_id orig_head;
  61        struct commit *onto;
  62        const char *onto_name;
  63        const char *revisions;
  64        const char *switch_to;
  65        int root, root_with_onto;
  66        struct object_id *squash_onto;
  67        struct commit *restrict_revision;
  68        int dont_finish_rebase;
  69        enum {
  70                REBASE_NO_QUIET = 1<<0,
  71                REBASE_VERBOSE = 1<<1,
  72                REBASE_DIFFSTAT = 1<<2,
  73                REBASE_FORCE = 1<<3,
  74                REBASE_INTERACTIVE_EXPLICIT = 1<<4,
  75        } flags;
  76        struct argv_array git_am_opts;
  77        const char *action;
  78        int signoff;
  79        int allow_rerere_autoupdate;
  80        int keep_empty;
  81        int autosquash;
  82        char *gpg_sign_opt;
  83        int autostash;
  84        char *cmd;
  85        int allow_empty_message;
  86        int rebase_merges, rebase_cousins;
  87        char *strategy, *strategy_opts;
  88        struct strbuf git_format_patch_opt;
  89        int reschedule_failed_exec;
  90        int use_legacy_rebase;
  91};
  92
  93#define REBASE_OPTIONS_INIT {                           \
  94                .type = REBASE_UNSPECIFIED,             \
  95                .flags = REBASE_NO_QUIET,               \
  96                .git_am_opts = ARGV_ARRAY_INIT,         \
  97                .git_format_patch_opt = STRBUF_INIT     \
  98        }
  99
 100static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 101{
 102        struct replay_opts replay = REPLAY_OPTS_INIT;
 103
 104        replay.action = REPLAY_INTERACTIVE_REBASE;
 105        sequencer_init_config(&replay);
 106
 107        replay.signoff = opts->signoff;
 108        replay.allow_ff = !(opts->flags & REBASE_FORCE);
 109        if (opts->allow_rerere_autoupdate)
 110                replay.allow_rerere_auto = opts->allow_rerere_autoupdate;
 111        replay.allow_empty = 1;
 112        replay.allow_empty_message = opts->allow_empty_message;
 113        replay.verbose = opts->flags & REBASE_VERBOSE;
 114        replay.reschedule_failed_exec = opts->reschedule_failed_exec;
 115        replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 116        replay.strategy = opts->strategy;
 117        if (opts->strategy_opts)
 118                parse_strategy_opts(&replay, opts->strategy_opts);
 119
 120        return replay;
 121}
 122
 123enum action {
 124        ACTION_NONE = 0,
 125        ACTION_CONTINUE,
 126        ACTION_SKIP,
 127        ACTION_ABORT,
 128        ACTION_QUIT,
 129        ACTION_EDIT_TODO,
 130        ACTION_SHOW_CURRENT_PATCH,
 131        ACTION_SHORTEN_OIDS,
 132        ACTION_EXPAND_OIDS,
 133        ACTION_CHECK_TODO_LIST,
 134        ACTION_REARRANGE_SQUASH,
 135        ACTION_ADD_EXEC
 136};
 137
 138static const char *action_names[] = { "undefined",
 139                                      "continue",
 140                                      "skip",
 141                                      "abort",
 142                                      "quit",
 143                                      "edit_todo",
 144                                      "show_current_patch" };
 145
 146static int add_exec_commands(struct string_list *commands)
 147{
 148        const char *todo_file = rebase_path_todo();
 149        struct todo_list todo_list = TODO_LIST_INIT;
 150        int res;
 151
 152        if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 153                return error_errno(_("could not read '%s'."), todo_file);
 154
 155        if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 156                                        &todo_list)) {
 157                todo_list_release(&todo_list);
 158                return error(_("unusable todo list: '%s'"), todo_file);
 159        }
 160
 161        todo_list_add_exec_commands(&todo_list, commands);
 162        res = todo_list_write_to_file(the_repository, &todo_list,
 163                                      todo_file, NULL, NULL, -1, 0);
 164        todo_list_release(&todo_list);
 165
 166        if (res)
 167                return error_errno(_("could not write '%s'."), todo_file);
 168        return 0;
 169}
 170
 171static int rearrange_squash_in_todo_file(void)
 172{
 173        const char *todo_file = rebase_path_todo();
 174        struct todo_list todo_list = TODO_LIST_INIT;
 175        int res = 0;
 176
 177        if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 178                return error_errno(_("could not read '%s'."), todo_file);
 179        if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 180                                        &todo_list)) {
 181                todo_list_release(&todo_list);
 182                return error(_("unusable todo list: '%s'"), todo_file);
 183        }
 184
 185        res = todo_list_rearrange_squash(&todo_list);
 186        if (!res)
 187                res = todo_list_write_to_file(the_repository, &todo_list,
 188                                              todo_file, NULL, NULL, -1, 0);
 189
 190        todo_list_release(&todo_list);
 191
 192        if (res)
 193                return error_errno(_("could not write '%s'."), todo_file);
 194        return 0;
 195}
 196
 197static int transform_todo_file(unsigned flags)
 198{
 199        const char *todo_file = rebase_path_todo();
 200        struct todo_list todo_list = TODO_LIST_INIT;
 201        int res;
 202
 203        if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 204                return error_errno(_("could not read '%s'."), todo_file);
 205
 206        if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 207                                        &todo_list)) {
 208                todo_list_release(&todo_list);
 209                return error(_("unusable todo list: '%s'"), todo_file);
 210        }
 211
 212        res = todo_list_write_to_file(the_repository, &todo_list, todo_file,
 213                                      NULL, NULL, -1, flags);
 214        todo_list_release(&todo_list);
 215
 216        if (res)
 217                return error_errno(_("could not write '%s'."), todo_file);
 218        return 0;
 219}
 220
 221static int edit_todo_file(unsigned flags)
 222{
 223        const char *todo_file = rebase_path_todo();
 224        struct todo_list todo_list = TODO_LIST_INIT,
 225                new_todo = TODO_LIST_INIT;
 226        int res = 0;
 227
 228        if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 229                return error_errno(_("could not read '%s'."), todo_file);
 230
 231        strbuf_stripspace(&todo_list.buf, 1);
 232        res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
 233        if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
 234                                            NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
 235                res = error_errno(_("could not write '%s'"), todo_file);
 236
 237        todo_list_release(&todo_list);
 238        todo_list_release(&new_todo);
 239
 240        return res;
 241}
 242
 243static int get_revision_ranges(struct commit *upstream, struct commit *onto,
 244                               const char **head_hash,
 245                               char **revisions, char **shortrevisions)
 246{
 247        struct commit *base_rev = upstream ? upstream : onto;
 248        const char *shorthead;
 249        struct object_id orig_head;
 250
 251        if (get_oid("HEAD", &orig_head))
 252                return error(_("no HEAD?"));
 253
 254        *head_hash = find_unique_abbrev(&orig_head, GIT_MAX_HEXSZ);
 255        *revisions = xstrfmt("%s...%s", oid_to_hex(&base_rev->object.oid),
 256                                                   *head_hash);
 257
 258        shorthead = find_unique_abbrev(&orig_head, DEFAULT_ABBREV);
 259
 260        if (upstream) {
 261                const char *shortrev;
 262
 263                shortrev = find_unique_abbrev(&base_rev->object.oid,
 264                                              DEFAULT_ABBREV);
 265
 266                *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
 267        } else
 268                *shortrevisions = xstrdup(shorthead);
 269
 270        return 0;
 271}
 272
 273static int init_basic_state(struct replay_opts *opts, const char *head_name,
 274                            struct commit *onto, const char *orig_head)
 275{
 276        FILE *interactive;
 277
 278        if (!is_directory(merge_dir()) && mkdir_in_gitdir(merge_dir()))
 279                return error_errno(_("could not create temporary %s"), merge_dir());
 280
 281        delete_reflog("REBASE_HEAD");
 282
 283        interactive = fopen(path_interactive(), "w");
 284        if (!interactive)
 285                return error_errno(_("could not mark as interactive"));
 286        fclose(interactive);
 287
 288        return write_basic_state(opts, head_name, onto, orig_head);
 289}
 290
 291static void split_exec_commands(const char *cmd, struct string_list *commands)
 292{
 293        if (cmd && *cmd) {
 294                string_list_split(commands, cmd, '\n', -1);
 295
 296                /* rebase.c adds a new line to cmd after every command,
 297                 * so here the last command is always empty */
 298                string_list_remove_empty_items(commands, 0);
 299        }
 300}
 301
 302static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 303{
 304        int ret;
 305        const char *head_hash = NULL;
 306        char *revisions = NULL, *shortrevisions = NULL;
 307        struct argv_array make_script_args = ARGV_ARRAY_INIT;
 308        struct todo_list todo_list = TODO_LIST_INIT;
 309        struct replay_opts replay = get_replay_opts(opts);
 310        struct string_list commands = STRING_LIST_INIT_DUP;
 311
 312        if (prepare_branch_to_be_rebased(the_repository, &replay,
 313                                         opts->switch_to))
 314                return -1;
 315
 316        if (get_revision_ranges(opts->upstream, opts->onto, &head_hash,
 317                                &revisions, &shortrevisions))
 318                return -1;
 319
 320        if (init_basic_state(&replay,
 321                             opts->head_name ? opts->head_name : "detached HEAD",
 322                             opts->onto, head_hash)) {
 323                free(revisions);
 324                free(shortrevisions);
 325
 326                return -1;
 327        }
 328
 329        if (!opts->upstream && opts->squash_onto)
 330                write_file(path_squash_onto(), "%s\n",
 331                           oid_to_hex(opts->squash_onto));
 332
 333        argv_array_pushl(&make_script_args, "", revisions, NULL);
 334        if (opts->restrict_revision)
 335                argv_array_push(&make_script_args,
 336                                oid_to_hex(&opts->restrict_revision->object.oid));
 337
 338        ret = sequencer_make_script(the_repository, &todo_list.buf,
 339                                    make_script_args.argc, make_script_args.argv,
 340                                    flags);
 341
 342        if (ret)
 343                error(_("could not generate todo list"));
 344        else {
 345                discard_cache();
 346                if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
 347                                                &todo_list))
 348                        BUG("unusable todo list");
 349
 350                split_exec_commands(opts->cmd, &commands);
 351                ret = complete_action(the_repository, &replay, flags,
 352                        shortrevisions, opts->onto_name, opts->onto, head_hash,
 353                        &commands, opts->autosquash, &todo_list);
 354        }
 355
 356        string_list_clear(&commands, 0);
 357        free(revisions);
 358        free(shortrevisions);
 359        todo_list_release(&todo_list);
 360        argv_array_clear(&make_script_args);
 361
 362        return ret;
 363}
 364
 365static int run_rebase_interactive(struct rebase_options *opts,
 366                                  enum action command)
 367{
 368        unsigned flags = 0;
 369        int abbreviate_commands = 0, ret = 0;
 370
 371        git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
 372
 373        flags |= opts->keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
 374        flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
 375        flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
 376        flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
 377        flags |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
 378        flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
 379
 380        switch (command) {
 381        case ACTION_NONE: {
 382                if (!opts->onto && !opts->upstream)
 383                        die(_("a base commit must be provided with --upstream or --onto"));
 384
 385                ret = do_interactive_rebase(opts, flags);
 386                break;
 387        }
 388        case ACTION_SKIP: {
 389                struct string_list merge_rr = STRING_LIST_INIT_DUP;
 390
 391                rerere_clear(the_repository, &merge_rr);
 392        }
 393                /* fallthrough */
 394        case ACTION_CONTINUE: {
 395                struct replay_opts replay_opts = get_replay_opts(opts);
 396
 397                ret = sequencer_continue(the_repository, &replay_opts);
 398                break;
 399        }
 400        case ACTION_EDIT_TODO:
 401                ret = edit_todo_file(flags);
 402                break;
 403        case ACTION_SHOW_CURRENT_PATCH: {
 404                struct child_process cmd = CHILD_PROCESS_INIT;
 405
 406                cmd.git_cmd = 1;
 407                argv_array_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
 408                ret = run_command(&cmd);
 409
 410                break;
 411        }
 412        case ACTION_SHORTEN_OIDS:
 413        case ACTION_EXPAND_OIDS:
 414                ret = transform_todo_file(flags);
 415                break;
 416        case ACTION_CHECK_TODO_LIST:
 417                ret = check_todo_list_from_file(the_repository);
 418                break;
 419        case ACTION_REARRANGE_SQUASH:
 420                ret = rearrange_squash_in_todo_file();
 421                break;
 422        case ACTION_ADD_EXEC: {
 423                struct string_list commands = STRING_LIST_INIT_DUP;
 424
 425                split_exec_commands(opts->cmd, &commands);
 426                ret = add_exec_commands(&commands);
 427                string_list_clear(&commands, 0);
 428                break;
 429        }
 430        default:
 431                BUG("invalid command '%d'", command);
 432        }
 433
 434        return ret;
 435}
 436
 437static const char * const builtin_rebase_interactive_usage[] = {
 438        N_("git rebase--interactive [<options>]"),
 439        NULL
 440};
 441
 442int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 443{
 444        struct rebase_options opts = REBASE_OPTIONS_INIT;
 445        struct object_id squash_onto = null_oid;
 446        enum action command = ACTION_NONE;
 447        struct option options[] = {
 448                OPT_NEGBIT(0, "ff", &opts.flags, N_("allow fast-forward"),
 449                           REBASE_FORCE),
 450                OPT_BOOL(0, "keep-empty", &opts.keep_empty, N_("keep empty commits")),
 451                OPT_BOOL(0, "allow-empty-message", &opts.allow_empty_message,
 452                         N_("allow commits with empty messages")),
 453                OPT_BOOL(0, "rebase-merges", &opts.rebase_merges, N_("rebase merge commits")),
 454                OPT_BOOL(0, "rebase-cousins", &opts.rebase_cousins,
 455                         N_("keep original branch points of cousins")),
 456                OPT_BOOL(0, "autosquash", &opts.autosquash,
 457                         N_("move commits that begin with squash!/fixup!")),
 458                OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
 459                OPT_BIT('v', "verbose", &opts.flags,
 460                        N_("display a diffstat of what changed upstream"),
 461                        REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 462                OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
 463                            ACTION_CONTINUE),
 464                OPT_CMDMODE(0, "skip", &command, N_("skip commit"), ACTION_SKIP),
 465                OPT_CMDMODE(0, "edit-todo", &command, N_("edit the todo list"),
 466                            ACTION_EDIT_TODO),
 467                OPT_CMDMODE(0, "show-current-patch", &command, N_("show the current patch"),
 468                            ACTION_SHOW_CURRENT_PATCH),
 469                OPT_CMDMODE(0, "shorten-ids", &command,
 470                        N_("shorten commit ids in the todo list"), ACTION_SHORTEN_OIDS),
 471                OPT_CMDMODE(0, "expand-ids", &command,
 472                        N_("expand commit ids in the todo list"), ACTION_EXPAND_OIDS),
 473                OPT_CMDMODE(0, "check-todo-list", &command,
 474                        N_("check the todo list"), ACTION_CHECK_TODO_LIST),
 475                OPT_CMDMODE(0, "rearrange-squash", &command,
 476                        N_("rearrange fixup/squash lines"), ACTION_REARRANGE_SQUASH),
 477                OPT_CMDMODE(0, "add-exec-commands", &command,
 478                        N_("insert exec commands in todo list"), ACTION_ADD_EXEC),
 479                { OPTION_CALLBACK, 0, "onto", &opts.onto, N_("onto"), N_("onto"),
 480                  PARSE_OPT_NONEG, parse_opt_commit, 0 },
 481                { OPTION_CALLBACK, 0, "restrict-revision", &opts.restrict_revision,
 482                  N_("restrict-revision"), N_("restrict revision"),
 483                  PARSE_OPT_NONEG, parse_opt_commit, 0 },
 484                { OPTION_CALLBACK, 0, "squash-onto", &squash_onto, N_("squash-onto"),
 485                  N_("squash onto"), PARSE_OPT_NONEG, parse_opt_object_id, 0 },
 486                { OPTION_CALLBACK, 0, "upstream", &opts.upstream, N_("upstream"),
 487                  N_("the upstream commit"), PARSE_OPT_NONEG, parse_opt_commit,
 488                  0 },
 489                OPT_STRING(0, "head-name", &opts.head_name, N_("head-name"), N_("head name")),
 490                { OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign_opt, N_("key-id"),
 491                        N_("GPG-sign commits"),
 492                        PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 493                OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
 494                           N_("rebase strategy")),
 495                OPT_STRING(0, "strategy-opts", &opts.strategy_opts, N_("strategy-opts"),
 496                           N_("strategy options")),
 497                OPT_STRING(0, "switch-to", &opts.switch_to, N_("switch-to"),
 498                           N_("the branch or commit to checkout")),
 499                OPT_STRING(0, "onto-name", &opts.onto_name, N_("onto-name"), N_("onto name")),
 500                OPT_STRING(0, "cmd", &opts.cmd, N_("cmd"), N_("the command to run")),
 501                OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_autoupdate),
 502                OPT_BOOL(0, "reschedule-failed-exec", &opts.reschedule_failed_exec,
 503                         N_("automatically re-schedule any `exec` that fails")),
 504                OPT_END()
 505        };
 506
 507        opts.rebase_cousins = -1;
 508
 509        if (argc == 1)
 510                usage_with_options(builtin_rebase_interactive_usage, options);
 511
 512        argc = parse_options(argc, argv, prefix, options,
 513                        builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
 514
 515        if (!is_null_oid(&squash_onto))
 516                opts.squash_onto = &squash_onto;
 517
 518        if (opts.rebase_cousins >= 0 && !opts.rebase_merges)
 519                warning(_("--[no-]rebase-cousins has no effect without "
 520                          "--rebase-merges"));
 521
 522        return !!run_rebase_interactive(&opts, command);
 523}
 524
 525static int is_interactive(struct rebase_options *opts)
 526{
 527        return opts->type == REBASE_INTERACTIVE ||
 528                opts->type == REBASE_PRESERVE_MERGES;
 529}
 530
 531static void imply_interactive(struct rebase_options *opts, const char *option)
 532{
 533        switch (opts->type) {
 534        case REBASE_AM:
 535                die(_("%s requires an interactive rebase"), option);
 536                break;
 537        case REBASE_INTERACTIVE:
 538        case REBASE_PRESERVE_MERGES:
 539                break;
 540        case REBASE_MERGE:
 541                /* we now implement --merge via --interactive */
 542        default:
 543                opts->type = REBASE_INTERACTIVE; /* implied */
 544                break;
 545        }
 546}
 547
 548/* Returns the filename prefixed by the state_dir */
 549static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 550{
 551        static struct strbuf path = STRBUF_INIT;
 552        static size_t prefix_len;
 553
 554        if (!prefix_len) {
 555                strbuf_addf(&path, "%s/", opts->state_dir);
 556                prefix_len = path.len;
 557        }
 558
 559        strbuf_setlen(&path, prefix_len);
 560        strbuf_addstr(&path, filename);
 561        return path.buf;
 562}
 563
 564/* Read one file, then strip line endings */
 565static int read_one(const char *path, struct strbuf *buf)
 566{
 567        if (strbuf_read_file(buf, path, 0) < 0)
 568                return error_errno(_("could not read '%s'"), path);
 569        strbuf_trim_trailing_newline(buf);
 570        return 0;
 571}
 572
 573/* Initialize the rebase options from the state directory. */
 574static int read_basic_state(struct rebase_options *opts)
 575{
 576        struct strbuf head_name = STRBUF_INIT;
 577        struct strbuf buf = STRBUF_INIT;
 578        struct object_id oid;
 579
 580        if (read_one(state_dir_path("head-name", opts), &head_name) ||
 581            read_one(state_dir_path("onto", opts), &buf))
 582                return -1;
 583        opts->head_name = starts_with(head_name.buf, "refs/") ?
 584                xstrdup(head_name.buf) : NULL;
 585        strbuf_release(&head_name);
 586        if (get_oid(buf.buf, &oid))
 587                return error(_("could not get 'onto': '%s'"), buf.buf);
 588        opts->onto = lookup_commit_or_die(&oid, buf.buf);
 589
 590        /*
 591         * We always write to orig-head, but interactive rebase used to write to
 592         * head. Fall back to reading from head to cover for the case that the
 593         * user upgraded git with an ongoing interactive rebase.
 594         */
 595        strbuf_reset(&buf);
 596        if (file_exists(state_dir_path("orig-head", opts))) {
 597                if (read_one(state_dir_path("orig-head", opts), &buf))
 598                        return -1;
 599        } else if (read_one(state_dir_path("head", opts), &buf))
 600                return -1;
 601        if (get_oid(buf.buf, &opts->orig_head))
 602                return error(_("invalid orig-head: '%s'"), buf.buf);
 603
 604        if (file_exists(state_dir_path("quiet", opts)))
 605                opts->flags &= ~REBASE_NO_QUIET;
 606        else
 607                opts->flags |= REBASE_NO_QUIET;
 608
 609        if (file_exists(state_dir_path("verbose", opts)))
 610                opts->flags |= REBASE_VERBOSE;
 611
 612        if (file_exists(state_dir_path("signoff", opts))) {
 613                opts->signoff = 1;
 614                opts->flags |= REBASE_FORCE;
 615        }
 616
 617        if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 618                strbuf_reset(&buf);
 619                if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 620                            &buf))
 621                        return -1;
 622                if (!strcmp(buf.buf, "--rerere-autoupdate"))
 623                        opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
 624                else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 625                        opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
 626                else
 627                        warning(_("ignoring invalid allow_rerere_autoupdate: "
 628                                  "'%s'"), buf.buf);
 629        }
 630
 631        if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 632                strbuf_reset(&buf);
 633                if (read_one(state_dir_path("gpg_sign_opt", opts),
 634                            &buf))
 635                        return -1;
 636                free(opts->gpg_sign_opt);
 637                opts->gpg_sign_opt = xstrdup(buf.buf);
 638        }
 639
 640        if (file_exists(state_dir_path("strategy", opts))) {
 641                strbuf_reset(&buf);
 642                if (read_one(state_dir_path("strategy", opts), &buf))
 643                        return -1;
 644                free(opts->strategy);
 645                opts->strategy = xstrdup(buf.buf);
 646        }
 647
 648        if (file_exists(state_dir_path("strategy_opts", opts))) {
 649                strbuf_reset(&buf);
 650                if (read_one(state_dir_path("strategy_opts", opts), &buf))
 651                        return -1;
 652                free(opts->strategy_opts);
 653                opts->strategy_opts = xstrdup(buf.buf);
 654        }
 655
 656        strbuf_release(&buf);
 657
 658        return 0;
 659}
 660
 661static int rebase_write_basic_state(struct rebase_options *opts)
 662{
 663        write_file(state_dir_path("head-name", opts), "%s",
 664                   opts->head_name ? opts->head_name : "detached HEAD");
 665        write_file(state_dir_path("onto", opts), "%s",
 666                   opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 667        write_file(state_dir_path("orig-head", opts), "%s",
 668                   oid_to_hex(&opts->orig_head));
 669        write_file(state_dir_path("quiet", opts), "%s",
 670                   opts->flags & REBASE_NO_QUIET ? "" : "t");
 671        if (opts->flags & REBASE_VERBOSE)
 672                write_file(state_dir_path("verbose", opts), "%s", "");
 673        if (opts->strategy)
 674                write_file(state_dir_path("strategy", opts), "%s",
 675                           opts->strategy);
 676        if (opts->strategy_opts)
 677                write_file(state_dir_path("strategy_opts", opts), "%s",
 678                           opts->strategy_opts);
 679        if (opts->allow_rerere_autoupdate > 0)
 680                write_file(state_dir_path("allow_rerere_autoupdate", opts),
 681                           "-%s-rerere-autoupdate",
 682                           opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
 683                                "" : "-no");
 684        if (opts->gpg_sign_opt)
 685                write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 686                           opts->gpg_sign_opt);
 687        if (opts->signoff)
 688                write_file(state_dir_path("strategy", opts), "--signoff");
 689
 690        return 0;
 691}
 692
 693static int apply_autostash(struct rebase_options *opts)
 694{
 695        const char *path = state_dir_path("autostash", opts);
 696        struct strbuf autostash = STRBUF_INIT;
 697        struct child_process stash_apply = CHILD_PROCESS_INIT;
 698
 699        if (!file_exists(path))
 700                return 0;
 701
 702        if (read_one(path, &autostash))
 703                return error(_("Could not read '%s'"), path);
 704        /* Ensure that the hash is not mistaken for a number */
 705        strbuf_addstr(&autostash, "^0");
 706        argv_array_pushl(&stash_apply.args,
 707                         "stash", "apply", autostash.buf, NULL);
 708        stash_apply.git_cmd = 1;
 709        stash_apply.no_stderr = stash_apply.no_stdout =
 710                stash_apply.no_stdin = 1;
 711        if (!run_command(&stash_apply))
 712                printf(_("Applied autostash.\n"));
 713        else {
 714                struct argv_array args = ARGV_ARRAY_INIT;
 715                int res = 0;
 716
 717                argv_array_pushl(&args,
 718                                 "stash", "store", "-m", "autostash", "-q",
 719                                 autostash.buf, NULL);
 720                if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 721                        res = error(_("Cannot store %s"), autostash.buf);
 722                argv_array_clear(&args);
 723                strbuf_release(&autostash);
 724                if (res)
 725                        return res;
 726
 727                fprintf(stderr,
 728                        _("Applying autostash resulted in conflicts.\n"
 729                          "Your changes are safe in the stash.\n"
 730                          "You can run \"git stash pop\" or \"git stash drop\" "
 731                          "at any time.\n"));
 732        }
 733
 734        strbuf_release(&autostash);
 735        return 0;
 736}
 737
 738static int finish_rebase(struct rebase_options *opts)
 739{
 740        struct strbuf dir = STRBUF_INIT;
 741        const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 742        int ret = 0;
 743
 744        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 745        apply_autostash(opts);
 746        close_object_store(the_repository->objects);
 747        /*
 748         * We ignore errors in 'gc --auto', since the
 749         * user should see them.
 750         */
 751        run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 752        if (opts->type == REBASE_INTERACTIVE) {
 753                struct replay_opts replay = REPLAY_OPTS_INIT;
 754
 755                replay.action = REPLAY_INTERACTIVE_REBASE;
 756                ret = sequencer_remove_state(&replay);
 757        } else {
 758                strbuf_addstr(&dir, opts->state_dir);
 759                if (remove_dir_recursively(&dir, 0))
 760                        ret = error(_("could not remove '%s'"),
 761                                    opts->state_dir);
 762                strbuf_release(&dir);
 763        }
 764
 765        return ret;
 766}
 767
 768static struct commit *peel_committish(const char *name)
 769{
 770        struct object *obj;
 771        struct object_id oid;
 772
 773        if (get_oid(name, &oid))
 774                return NULL;
 775        obj = parse_object(the_repository, &oid);
 776        return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 777}
 778
 779static void add_var(struct strbuf *buf, const char *name, const char *value)
 780{
 781        if (!value)
 782                strbuf_addf(buf, "unset %s; ", name);
 783        else {
 784                strbuf_addf(buf, "%s=", name);
 785                sq_quote_buf(buf, value);
 786                strbuf_addstr(buf, "; ");
 787        }
 788}
 789
 790#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 791
 792#define RESET_HEAD_DETACH (1<<0)
 793#define RESET_HEAD_HARD (1<<1)
 794#define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 795#define RESET_HEAD_REFS_ONLY (1<<3)
 796#define RESET_ORIG_HEAD (1<<4)
 797
 798static int reset_head(struct object_id *oid, const char *action,
 799                      const char *switch_to_branch, unsigned flags,
 800                      const char *reflog_orig_head, const char *reflog_head)
 801{
 802        unsigned detach_head = flags & RESET_HEAD_DETACH;
 803        unsigned reset_hard = flags & RESET_HEAD_HARD;
 804        unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 805        unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
 806        unsigned update_orig_head = flags & RESET_ORIG_HEAD;
 807        struct object_id head_oid;
 808        struct tree_desc desc[2] = { { NULL }, { NULL } };
 809        struct lock_file lock = LOCK_INIT;
 810        struct unpack_trees_options unpack_tree_opts;
 811        struct tree *tree;
 812        const char *reflog_action;
 813        struct strbuf msg = STRBUF_INIT;
 814        size_t prefix_len;
 815        struct object_id *orig = NULL, oid_orig,
 816                *old_orig = NULL, oid_old_orig;
 817        int ret = 0, nr = 0;
 818
 819        if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 820                BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 821
 822        if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 823                ret = -1;
 824                goto leave_reset_head;
 825        }
 826
 827        if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 828                ret = error(_("could not determine HEAD revision"));
 829                goto leave_reset_head;
 830        }
 831
 832        if (!oid)
 833                oid = &head_oid;
 834
 835        if (refs_only)
 836                goto reset_head_refs;
 837
 838        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 839        setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 840        unpack_tree_opts.head_idx = 1;
 841        unpack_tree_opts.src_index = the_repository->index;
 842        unpack_tree_opts.dst_index = the_repository->index;
 843        unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 844        unpack_tree_opts.update = 1;
 845        unpack_tree_opts.merge = 1;
 846        if (!detach_head)
 847                unpack_tree_opts.reset = 1;
 848
 849        if (repo_read_index_unmerged(the_repository) < 0) {
 850                ret = error(_("could not read index"));
 851                goto leave_reset_head;
 852        }
 853
 854        if (!reset_hard && !fill_tree_descriptor(the_repository, &desc[nr++], &head_oid)) {
 855                ret = error(_("failed to find tree of %s"),
 856                            oid_to_hex(&head_oid));
 857                goto leave_reset_head;
 858        }
 859
 860        if (!fill_tree_descriptor(the_repository, &desc[nr++], oid)) {
 861                ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 862                goto leave_reset_head;
 863        }
 864
 865        if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 866                ret = -1;
 867                goto leave_reset_head;
 868        }
 869
 870        tree = parse_tree_indirect(oid);
 871        prime_cache_tree(the_repository, the_repository->index, tree);
 872
 873        if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 874                ret = error(_("could not write index"));
 875                goto leave_reset_head;
 876        }
 877
 878reset_head_refs:
 879        reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 880        strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 881        prefix_len = msg.len;
 882
 883        if (update_orig_head) {
 884                if (!get_oid("ORIG_HEAD", &oid_old_orig))
 885                        old_orig = &oid_old_orig;
 886                if (!get_oid("HEAD", &oid_orig)) {
 887                        orig = &oid_orig;
 888                        if (!reflog_orig_head) {
 889                                strbuf_addstr(&msg, "updating ORIG_HEAD");
 890                                reflog_orig_head = msg.buf;
 891                        }
 892                        update_ref(reflog_orig_head, "ORIG_HEAD", orig,
 893                                   old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
 894                } else if (old_orig)
 895                        delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 896        }
 897
 898        if (!reflog_head) {
 899                strbuf_setlen(&msg, prefix_len);
 900                strbuf_addstr(&msg, "updating HEAD");
 901                reflog_head = msg.buf;
 902        }
 903        if (!switch_to_branch)
 904                ret = update_ref(reflog_head, "HEAD", oid, orig,
 905                                 detach_head ? REF_NO_DEREF : 0,
 906                                 UPDATE_REFS_MSG_ON_ERR);
 907        else {
 908                ret = update_ref(reflog_head, switch_to_branch, oid,
 909                                 NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 910                if (!ret)
 911                        ret = create_symref("HEAD", switch_to_branch,
 912                                            reflog_head);
 913        }
 914        if (run_hook)
 915                run_hook_le(NULL, "post-checkout",
 916                            oid_to_hex(orig ? orig : &null_oid),
 917                            oid_to_hex(oid), "1", NULL);
 918
 919leave_reset_head:
 920        strbuf_release(&msg);
 921        rollback_lock_file(&lock);
 922        while (nr)
 923                free((void *)desc[--nr].buffer);
 924        return ret;
 925}
 926
 927static int move_to_original_branch(struct rebase_options *opts)
 928{
 929        struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 930        int ret;
 931
 932        if (!opts->head_name)
 933                return 0; /* nothing to move back to */
 934
 935        if (!opts->onto)
 936                BUG("move_to_original_branch without onto");
 937
 938        strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
 939                    opts->head_name, oid_to_hex(&opts->onto->object.oid));
 940        strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 941                    opts->head_name);
 942        ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
 943                         orig_head_reflog.buf, head_reflog.buf);
 944
 945        strbuf_release(&orig_head_reflog);
 946        strbuf_release(&head_reflog);
 947        return ret;
 948}
 949
 950static const char *resolvemsg =
 951N_("Resolve all conflicts manually, mark them as resolved with\n"
 952"\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 953"You can instead skip this commit: run \"git rebase --skip\".\n"
 954"To abort and get back to the state before \"git rebase\", run "
 955"\"git rebase --abort\".");
 956
 957static int run_am(struct rebase_options *opts)
 958{
 959        struct child_process am = CHILD_PROCESS_INIT;
 960        struct child_process format_patch = CHILD_PROCESS_INIT;
 961        struct strbuf revisions = STRBUF_INIT;
 962        int status;
 963        char *rebased_patches;
 964
 965        am.git_cmd = 1;
 966        argv_array_push(&am.args, "am");
 967
 968        if (opts->action && !strcmp("continue", opts->action)) {
 969                argv_array_push(&am.args, "--resolved");
 970                argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 971                if (opts->gpg_sign_opt)
 972                        argv_array_push(&am.args, opts->gpg_sign_opt);
 973                status = run_command(&am);
 974                if (status)
 975                        return status;
 976
 977                return move_to_original_branch(opts);
 978        }
 979        if (opts->action && !strcmp("skip", opts->action)) {
 980                argv_array_push(&am.args, "--skip");
 981                argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 982                status = run_command(&am);
 983                if (status)
 984                        return status;
 985
 986                return move_to_original_branch(opts);
 987        }
 988        if (opts->action && !strcmp("show-current-patch", opts->action)) {
 989                argv_array_push(&am.args, "--show-current-patch");
 990                return run_command(&am);
 991        }
 992
 993        strbuf_addf(&revisions, "%s...%s",
 994                    oid_to_hex(opts->root ?
 995                               /* this is now equivalent to !opts->upstream */
 996                               &opts->onto->object.oid :
 997                               &opts->upstream->object.oid),
 998                    oid_to_hex(&opts->orig_head));
 999
1000        rebased_patches = xstrdup(git_path("rebased-patches"));
1001        format_patch.out = open(rebased_patches,
1002                                O_WRONLY | O_CREAT | O_TRUNC, 0666);
1003        if (format_patch.out < 0) {
1004                status = error_errno(_("could not open '%s' for writing"),
1005                                     rebased_patches);
1006                free(rebased_patches);
1007                argv_array_clear(&am.args);
1008                return status;
1009        }
1010
1011        format_patch.git_cmd = 1;
1012        argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
1013                         "--full-index", "--cherry-pick", "--right-only",
1014                         "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
1015                         "--no-cover-letter", "--pretty=mboxrd", "--topo-order", NULL);
1016        if (opts->git_format_patch_opt.len)
1017                argv_array_split(&format_patch.args,
1018                                 opts->git_format_patch_opt.buf);
1019        argv_array_push(&format_patch.args, revisions.buf);
1020        if (opts->restrict_revision)
1021                argv_array_pushf(&format_patch.args, "^%s",
1022                                 oid_to_hex(&opts->restrict_revision->object.oid));
1023
1024        status = run_command(&format_patch);
1025        if (status) {
1026                unlink(rebased_patches);
1027                free(rebased_patches);
1028                argv_array_clear(&am.args);
1029
1030                reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
1031                           "HEAD", NULL);
1032                error(_("\ngit encountered an error while preparing the "
1033                        "patches to replay\n"
1034                        "these revisions:\n"
1035                        "\n    %s\n\n"
1036                        "As a result, git cannot rebase them."),
1037                      opts->revisions);
1038
1039                strbuf_release(&revisions);
1040                return status;
1041        }
1042        strbuf_release(&revisions);
1043
1044        am.in = open(rebased_patches, O_RDONLY);
1045        if (am.in < 0) {
1046                status = error_errno(_("could not open '%s' for reading"),
1047                                     rebased_patches);
1048                free(rebased_patches);
1049                argv_array_clear(&am.args);
1050                return status;
1051        }
1052
1053        argv_array_pushv(&am.args, opts->git_am_opts.argv);
1054        argv_array_push(&am.args, "--rebasing");
1055        argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1056        argv_array_push(&am.args, "--patch-format=mboxrd");
1057        if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
1058                argv_array_push(&am.args, "--rerere-autoupdate");
1059        else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
1060                argv_array_push(&am.args, "--no-rerere-autoupdate");
1061        if (opts->gpg_sign_opt)
1062                argv_array_push(&am.args, opts->gpg_sign_opt);
1063        status = run_command(&am);
1064        unlink(rebased_patches);
1065        free(rebased_patches);
1066
1067        if (!status) {
1068                return move_to_original_branch(opts);
1069        }
1070
1071        if (is_directory(opts->state_dir))
1072                rebase_write_basic_state(opts);
1073
1074        return status;
1075}
1076
1077static int run_specific_rebase(struct rebase_options *opts, enum action action)
1078{
1079        const char *argv[] = { NULL, NULL };
1080        struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
1081        int status;
1082        const char *backend, *backend_func;
1083
1084        if (opts->type == REBASE_INTERACTIVE) {
1085                /* Run builtin interactive rebase */
1086                setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
1087                if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1088                        setenv("GIT_SEQUENCE_EDITOR", ":", 1);
1089                        opts->autosquash = 0;
1090                }
1091                if (opts->gpg_sign_opt) {
1092                        /* remove the leading "-S" */
1093                        char *tmp = xstrdup(opts->gpg_sign_opt + 2);
1094                        free(opts->gpg_sign_opt);
1095                        opts->gpg_sign_opt = tmp;
1096                }
1097
1098                status = run_rebase_interactive(opts, action);
1099                goto finished_rebase;
1100        }
1101
1102        if (opts->type == REBASE_AM) {
1103                status = run_am(opts);
1104                goto finished_rebase;
1105        }
1106
1107        add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
1108        add_var(&script_snippet, "state_dir", opts->state_dir);
1109
1110        add_var(&script_snippet, "upstream_name", opts->upstream_name);
1111        add_var(&script_snippet, "upstream", opts->upstream ?
1112                oid_to_hex(&opts->upstream->object.oid) : NULL);
1113        add_var(&script_snippet, "head_name",
1114                opts->head_name ? opts->head_name : "detached HEAD");
1115        add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
1116        add_var(&script_snippet, "onto", opts->onto ?
1117                oid_to_hex(&opts->onto->object.oid) : NULL);
1118        add_var(&script_snippet, "onto_name", opts->onto_name);
1119        add_var(&script_snippet, "revisions", opts->revisions);
1120        add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
1121                oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
1122        add_var(&script_snippet, "GIT_QUIET",
1123                opts->flags & REBASE_NO_QUIET ? "" : "t");
1124        sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
1125        add_var(&script_snippet, "git_am_opt", buf.buf);
1126        strbuf_release(&buf);
1127        add_var(&script_snippet, "verbose",
1128                opts->flags & REBASE_VERBOSE ? "t" : "");
1129        add_var(&script_snippet, "diffstat",
1130                opts->flags & REBASE_DIFFSTAT ? "t" : "");
1131        add_var(&script_snippet, "force_rebase",
1132                opts->flags & REBASE_FORCE ? "t" : "");
1133        if (opts->switch_to)
1134                add_var(&script_snippet, "switch_to", opts->switch_to);
1135        add_var(&script_snippet, "action", opts->action ? opts->action : "");
1136        add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
1137        add_var(&script_snippet, "allow_rerere_autoupdate",
1138                opts->allow_rerere_autoupdate ?
1139                        opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
1140                        "--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
1141        add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
1142        add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
1143        add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
1144        add_var(&script_snippet, "cmd", opts->cmd);
1145        add_var(&script_snippet, "allow_empty_message",
1146                opts->allow_empty_message ?  "--allow-empty-message" : "");
1147        add_var(&script_snippet, "rebase_merges",
1148                opts->rebase_merges ? "t" : "");
1149        add_var(&script_snippet, "rebase_cousins",
1150                opts->rebase_cousins ? "t" : "");
1151        add_var(&script_snippet, "strategy", opts->strategy);
1152        add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
1153        add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
1154        add_var(&script_snippet, "squash_onto",
1155                opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
1156        add_var(&script_snippet, "git_format_patch_opt",
1157                opts->git_format_patch_opt.buf);
1158
1159        if (is_interactive(opts) &&
1160            !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1161                strbuf_addstr(&script_snippet,
1162                              "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
1163                opts->autosquash = 0;
1164        }
1165
1166        switch (opts->type) {
1167        case REBASE_PRESERVE_MERGES:
1168                backend = "git-rebase--preserve-merges";
1169                backend_func = "git_rebase__preserve_merges";
1170                break;
1171        default:
1172                BUG("Unhandled rebase type %d", opts->type);
1173                break;
1174        }
1175
1176        strbuf_addf(&script_snippet,
1177                    ". git-sh-setup && . %s && %s", backend, backend_func);
1178        argv[0] = script_snippet.buf;
1179
1180        status = run_command_v_opt(argv, RUN_USING_SHELL);
1181finished_rebase:
1182        if (opts->dont_finish_rebase)
1183                ; /* do nothing */
1184        else if (opts->type == REBASE_INTERACTIVE)
1185                ; /* interactive rebase cleans up after itself */
1186        else if (status == 0) {
1187                if (!file_exists(state_dir_path("stopped-sha", opts)))
1188                        finish_rebase(opts);
1189        } else if (status == 2) {
1190                struct strbuf dir = STRBUF_INIT;
1191
1192                apply_autostash(opts);
1193                strbuf_addstr(&dir, opts->state_dir);
1194                remove_dir_recursively(&dir, 0);
1195                strbuf_release(&dir);
1196                die("Nothing to do");
1197        }
1198
1199        strbuf_release(&script_snippet);
1200
1201        return status ? -1 : 0;
1202}
1203
1204static int rebase_config(const char *var, const char *value, void *data)
1205{
1206        struct rebase_options *opts = data;
1207
1208        if (!strcmp(var, "rebase.stat")) {
1209                if (git_config_bool(var, value))
1210                        opts->flags |= REBASE_DIFFSTAT;
1211                else
1212                        opts->flags &= ~REBASE_DIFFSTAT;
1213                return 0;
1214        }
1215
1216        if (!strcmp(var, "rebase.autosquash")) {
1217                opts->autosquash = git_config_bool(var, value);
1218                return 0;
1219        }
1220
1221        if (!strcmp(var, "commit.gpgsign")) {
1222                free(opts->gpg_sign_opt);
1223                opts->gpg_sign_opt = git_config_bool(var, value) ?
1224                        xstrdup("-S") : NULL;
1225                return 0;
1226        }
1227
1228        if (!strcmp(var, "rebase.autostash")) {
1229                opts->autostash = git_config_bool(var, value);
1230                return 0;
1231        }
1232
1233        if (!strcmp(var, "rebase.reschedulefailedexec")) {
1234                opts->reschedule_failed_exec = git_config_bool(var, value);
1235                return 0;
1236        }
1237
1238        if (!strcmp(var, "rebase.usebuiltin")) {
1239                opts->use_legacy_rebase = !git_config_bool(var, value);
1240                return 0;
1241        }
1242
1243        return git_default_config(var, value, data);
1244}
1245
1246/*
1247 * Determines whether the commits in from..to are linear, i.e. contain
1248 * no merge commits. This function *expects* `from` to be an ancestor of
1249 * `to`.
1250 */
1251static int is_linear_history(struct commit *from, struct commit *to)
1252{
1253        while (to && to != from) {
1254                parse_commit(to);
1255                if (!to->parents)
1256                        return 1;
1257                if (to->parents->next)
1258                        return 0;
1259                to = to->parents->item;
1260        }
1261        return 1;
1262}
1263
1264static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
1265                            struct object_id *merge_base)
1266{
1267        struct commit *head = lookup_commit(the_repository, head_oid);
1268        struct commit_list *merge_bases;
1269        int res;
1270
1271        if (!head)
1272                return 0;
1273
1274        merge_bases = get_merge_bases(onto, head);
1275        if (merge_bases && !merge_bases->next) {
1276                oidcpy(merge_base, &merge_bases->item->object.oid);
1277                res = oideq(merge_base, &onto->object.oid);
1278        } else {
1279                oidcpy(merge_base, &null_oid);
1280                res = 0;
1281        }
1282        free_commit_list(merge_bases);
1283        return res && is_linear_history(onto, head);
1284}
1285
1286/* -i followed by -m is still -i */
1287static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
1288{
1289        struct rebase_options *opts = opt->value;
1290
1291        BUG_ON_OPT_NEG(unset);
1292        BUG_ON_OPT_ARG(arg);
1293
1294        if (!is_interactive(opts))
1295                opts->type = REBASE_MERGE;
1296
1297        return 0;
1298}
1299
1300/* -i followed by -p is still explicitly interactive, but -p alone is not */
1301static int parse_opt_interactive(const struct option *opt, const char *arg,
1302                                 int unset)
1303{
1304        struct rebase_options *opts = opt->value;
1305
1306        BUG_ON_OPT_NEG(unset);
1307        BUG_ON_OPT_ARG(arg);
1308
1309        opts->type = REBASE_INTERACTIVE;
1310        opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
1311
1312        return 0;
1313}
1314
1315static void NORETURN error_on_missing_default_upstream(void)
1316{
1317        struct branch *current_branch = branch_get(NULL);
1318
1319        printf(_("%s\n"
1320                 "Please specify which branch you want to rebase against.\n"
1321                 "See git-rebase(1) for details.\n"
1322                 "\n"
1323                 "    git rebase '<branch>'\n"
1324                 "\n"),
1325                current_branch ? _("There is no tracking information for "
1326                        "the current branch.") :
1327                        _("You are not currently on a branch."));
1328
1329        if (current_branch) {
1330                const char *remote = current_branch->remote_name;
1331
1332                if (!remote)
1333                        remote = _("<remote>");
1334
1335                printf(_("If you wish to set tracking information for this "
1336                         "branch you can do so with:\n"
1337                         "\n"
1338                         "    git branch --set-upstream-to=%s/<branch> %s\n"
1339                         "\n"),
1340                       remote, current_branch->name);
1341        }
1342        exit(1);
1343}
1344
1345static void set_reflog_action(struct rebase_options *options)
1346{
1347        const char *env;
1348        struct strbuf buf = STRBUF_INIT;
1349
1350        if (!is_interactive(options))
1351                return;
1352
1353        env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1354        if (env && strcmp("rebase", env))
1355                return; /* only override it if it is "rebase" */
1356
1357        strbuf_addf(&buf, "rebase -i (%s)", options->action);
1358        setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
1359        strbuf_release(&buf);
1360}
1361
1362static int check_exec_cmd(const char *cmd)
1363{
1364        if (strchr(cmd, '\n'))
1365                return error(_("exec commands cannot contain newlines"));
1366
1367        /* Does the command consist purely of whitespace? */
1368        if (!cmd[strspn(cmd, " \t\r\f\v")])
1369                return error(_("empty exec command"));
1370
1371        return 0;
1372}
1373
1374
1375int cmd_rebase(int argc, const char **argv, const char *prefix)
1376{
1377        struct rebase_options options = REBASE_OPTIONS_INIT;
1378        const char *branch_name;
1379        int ret, flags, total_argc, in_progress = 0;
1380        int ok_to_skip_pre_rebase = 0;
1381        struct strbuf msg = STRBUF_INIT;
1382        struct strbuf revisions = STRBUF_INIT;
1383        struct strbuf buf = STRBUF_INIT;
1384        struct object_id merge_base;
1385        enum action action = ACTION_NONE;
1386        const char *gpg_sign = NULL;
1387        struct string_list exec = STRING_LIST_INIT_NODUP;
1388        const char *rebase_merges = NULL;
1389        int fork_point = -1;
1390        struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1391        struct object_id squash_onto;
1392        char *squash_onto_name = NULL;
1393        int reschedule_failed_exec = -1;
1394        struct option builtin_rebase_options[] = {
1395                OPT_STRING(0, "onto", &options.onto_name,
1396                           N_("revision"),
1397                           N_("rebase onto given branch instead of upstream")),
1398                OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1399                         N_("allow pre-rebase hook to run")),
1400                OPT_NEGBIT('q', "quiet", &options.flags,
1401                           N_("be quiet. implies --no-stat"),
1402                           REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
1403                OPT_BIT('v', "verbose", &options.flags,
1404                        N_("display a diffstat of what changed upstream"),
1405                        REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1406                {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1407                        N_("do not show diffstat of what changed upstream"),
1408                        PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1409                OPT_BOOL(0, "signoff", &options.signoff,
1410                         N_("add a Signed-off-by: line to each commit")),
1411                OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
1412                                  NULL, N_("passed to 'git am'"),
1413                                  PARSE_OPT_NOARG),
1414                OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
1415                                  &options.git_am_opts, NULL,
1416                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
1417                OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
1418                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
1419                OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1420                                  N_("passed to 'git apply'"), 0),
1421                OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1422                                  N_("action"), N_("passed to 'git apply'"), 0),
1423                OPT_BIT('f', "force-rebase", &options.flags,
1424                        N_("cherry-pick all commits, even if unchanged"),
1425                        REBASE_FORCE),
1426                OPT_BIT(0, "no-ff", &options.flags,
1427                        N_("cherry-pick all commits, even if unchanged"),
1428                        REBASE_FORCE),
1429                OPT_CMDMODE(0, "continue", &action, N_("continue"),
1430                            ACTION_CONTINUE),
1431                OPT_CMDMODE(0, "skip", &action,
1432                            N_("skip current patch and continue"), ACTION_SKIP),
1433                OPT_CMDMODE(0, "abort", &action,
1434                            N_("abort and check out the original branch"),
1435                            ACTION_ABORT),
1436                OPT_CMDMODE(0, "quit", &action,
1437                            N_("abort but keep HEAD where it is"), ACTION_QUIT),
1438                OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1439                            "during an interactive rebase"), ACTION_EDIT_TODO),
1440                OPT_CMDMODE(0, "show-current-patch", &action,
1441                            N_("show the patch file being applied or merged"),
1442                            ACTION_SHOW_CURRENT_PATCH),
1443                { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1444                        N_("use merging strategies to rebase"),
1445                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1446                        parse_opt_merge },
1447                { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1448                        N_("let the user edit the list of commits to rebase"),
1449                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1450                        parse_opt_interactive },
1451                OPT_SET_INT('p', "preserve-merges", &options.type,
1452                            N_("(DEPRECATED) try to recreate merges instead of "
1453                               "ignoring them"), REBASE_PRESERVE_MERGES),
1454                OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1455                OPT_BOOL('k', "keep-empty", &options.keep_empty,
1456                         N_("preserve empty commits during rebase")),
1457                OPT_BOOL(0, "autosquash", &options.autosquash,
1458                         N_("move commits that begin with "
1459                            "squash!/fixup! under -i")),
1460                { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1461                        N_("GPG-sign commits"),
1462                        PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1463                OPT_BOOL(0, "autostash", &options.autostash,
1464                         N_("automatically stash/stash pop before and after")),
1465                OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1466                                N_("add exec lines after each commit of the "
1467                                   "editable list")),
1468                OPT_BOOL(0, "allow-empty-message",
1469                         &options.allow_empty_message,
1470                         N_("allow rebasing commits with empty messages")),
1471                {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1472                        N_("mode"),
1473                        N_("try to rebase merges instead of skipping them"),
1474                        PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1475                OPT_BOOL(0, "fork-point", &fork_point,
1476                         N_("use 'merge-base --fork-point' to refine upstream")),
1477                OPT_STRING('s', "strategy", &options.strategy,
1478                           N_("strategy"), N_("use the given merge strategy")),
1479                OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1480                                N_("option"),
1481                                N_("pass the argument through to the merge "
1482                                   "strategy")),
1483                OPT_BOOL(0, "root", &options.root,
1484                         N_("rebase all reachable commits up to the root(s)")),
1485                OPT_BOOL(0, "reschedule-failed-exec",
1486                         &reschedule_failed_exec,
1487                         N_("automatically re-schedule any `exec` that fails")),
1488                OPT_END(),
1489        };
1490        int i;
1491
1492        if (argc == 2 && !strcmp(argv[1], "-h"))
1493                usage_with_options(builtin_rebase_usage,
1494                                   builtin_rebase_options);
1495
1496        options.allow_empty_message = 1;
1497        git_config(rebase_config, &options);
1498
1499        if (options.use_legacy_rebase ||
1500            !git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1))
1501                warning(_("the rebase.useBuiltin support has been removed!\n"
1502                          "See its entry in 'git help config' for details."));
1503
1504        strbuf_reset(&buf);
1505        strbuf_addf(&buf, "%s/applying", apply_dir());
1506        if(file_exists(buf.buf))
1507                die(_("It looks like 'git am' is in progress. Cannot rebase."));
1508
1509        if (is_directory(apply_dir())) {
1510                options.type = REBASE_AM;
1511                options.state_dir = apply_dir();
1512        } else if (is_directory(merge_dir())) {
1513                strbuf_reset(&buf);
1514                strbuf_addf(&buf, "%s/rewritten", merge_dir());
1515                if (is_directory(buf.buf)) {
1516                        options.type = REBASE_PRESERVE_MERGES;
1517                        options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1518                } else {
1519                        strbuf_reset(&buf);
1520                        strbuf_addf(&buf, "%s/interactive", merge_dir());
1521                        if(file_exists(buf.buf)) {
1522                                options.type = REBASE_INTERACTIVE;
1523                                options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1524                        } else
1525                                options.type = REBASE_MERGE;
1526                }
1527                options.state_dir = merge_dir();
1528        }
1529
1530        if (options.type != REBASE_UNSPECIFIED)
1531                in_progress = 1;
1532
1533        total_argc = argc;
1534        argc = parse_options(argc, argv, prefix,
1535                             builtin_rebase_options,
1536                             builtin_rebase_usage, 0);
1537
1538        if (action != ACTION_NONE && total_argc != 2) {
1539                usage_with_options(builtin_rebase_usage,
1540                                   builtin_rebase_options);
1541        }
1542
1543        if (argc > 2)
1544                usage_with_options(builtin_rebase_usage,
1545                                   builtin_rebase_options);
1546
1547        if (options.type == REBASE_PRESERVE_MERGES)
1548                warning(_("git rebase --preserve-merges is deprecated. "
1549                          "Use --rebase-merges instead."));
1550
1551        if (action != ACTION_NONE && !in_progress)
1552                die(_("No rebase in progress?"));
1553        setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1554
1555        if (action == ACTION_EDIT_TODO && !is_interactive(&options))
1556                die(_("The --edit-todo action can only be used during "
1557                      "interactive rebase."));
1558
1559        if (trace2_is_enabled()) {
1560                if (is_interactive(&options))
1561                        trace2_cmd_mode("interactive");
1562                else if (exec.nr)
1563                        trace2_cmd_mode("interactive-exec");
1564                else
1565                        trace2_cmd_mode(action_names[action]);
1566        }
1567
1568        switch (action) {
1569        case ACTION_CONTINUE: {
1570                struct object_id head;
1571                struct lock_file lock_file = LOCK_INIT;
1572                int fd;
1573
1574                options.action = "continue";
1575                set_reflog_action(&options);
1576
1577                /* Sanity check */
1578                if (get_oid("HEAD", &head))
1579                        die(_("Cannot read HEAD"));
1580
1581                fd = hold_locked_index(&lock_file, 0);
1582                if (repo_read_index(the_repository) < 0)
1583                        die(_("could not read index"));
1584                refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1585                              NULL);
1586                if (0 <= fd)
1587                        repo_update_index_if_able(the_repository, &lock_file);
1588                rollback_lock_file(&lock_file);
1589
1590                if (has_unstaged_changes(the_repository, 1)) {
1591                        puts(_("You must edit all merge conflicts and then\n"
1592                               "mark them as resolved using git add"));
1593                        exit(1);
1594                }
1595                if (read_basic_state(&options))
1596                        exit(1);
1597                goto run_rebase;
1598        }
1599        case ACTION_SKIP: {
1600                struct string_list merge_rr = STRING_LIST_INIT_DUP;
1601
1602                options.action = "skip";
1603                set_reflog_action(&options);
1604
1605                rerere_clear(the_repository, &merge_rr);
1606                string_list_clear(&merge_rr, 1);
1607
1608                if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1609                               NULL, NULL) < 0)
1610                        die(_("could not discard worktree changes"));
1611                remove_branch_state(the_repository, 0);
1612                if (read_basic_state(&options))
1613                        exit(1);
1614                goto run_rebase;
1615        }
1616        case ACTION_ABORT: {
1617                struct string_list merge_rr = STRING_LIST_INIT_DUP;
1618                options.action = "abort";
1619                set_reflog_action(&options);
1620
1621                rerere_clear(the_repository, &merge_rr);
1622                string_list_clear(&merge_rr, 1);
1623
1624                if (read_basic_state(&options))
1625                        exit(1);
1626                if (reset_head(&options.orig_head, "reset",
1627                               options.head_name, RESET_HEAD_HARD,
1628                               NULL, NULL) < 0)
1629                        die(_("could not move back to %s"),
1630                            oid_to_hex(&options.orig_head));
1631                remove_branch_state(the_repository, 0);
1632                ret = !!finish_rebase(&options);
1633                goto cleanup;
1634        }
1635        case ACTION_QUIT: {
1636                if (options.type == REBASE_INTERACTIVE) {
1637                        struct replay_opts replay = REPLAY_OPTS_INIT;
1638
1639                        replay.action = REPLAY_INTERACTIVE_REBASE;
1640                        ret = !!sequencer_remove_state(&replay);
1641                } else {
1642                        strbuf_reset(&buf);
1643                        strbuf_addstr(&buf, options.state_dir);
1644                        ret = !!remove_dir_recursively(&buf, 0);
1645                        if (ret)
1646                                error(_("could not remove '%s'"),
1647                                       options.state_dir);
1648                }
1649                goto cleanup;
1650        }
1651        case ACTION_EDIT_TODO:
1652                options.action = "edit-todo";
1653                options.dont_finish_rebase = 1;
1654                goto run_rebase;
1655        case ACTION_SHOW_CURRENT_PATCH:
1656                options.action = "show-current-patch";
1657                options.dont_finish_rebase = 1;
1658                goto run_rebase;
1659        case ACTION_NONE:
1660                break;
1661        default:
1662                BUG("action: %d", action);
1663        }
1664
1665        /* Make sure no rebase is in progress */
1666        if (in_progress) {
1667                const char *last_slash = strrchr(options.state_dir, '/');
1668                const char *state_dir_base =
1669                        last_slash ? last_slash + 1 : options.state_dir;
1670                const char *cmd_live_rebase =
1671                        "git rebase (--continue | --abort | --skip)";
1672                strbuf_reset(&buf);
1673                strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1674                die(_("It seems that there is already a %s directory, and\n"
1675                      "I wonder if you are in the middle of another rebase.  "
1676                      "If that is the\n"
1677                      "case, please try\n\t%s\n"
1678                      "If that is not the case, please\n\t%s\n"
1679                      "and run me again.  I am stopping in case you still "
1680                      "have something\n"
1681                      "valuable there.\n"),
1682                    state_dir_base, cmd_live_rebase, buf.buf);
1683        }
1684
1685        for (i = 0; i < options.git_am_opts.argc; i++) {
1686                const char *option = options.git_am_opts.argv[i], *p;
1687                if (!strcmp(option, "--committer-date-is-author-date") ||
1688                    !strcmp(option, "--ignore-date") ||
1689                    !strcmp(option, "--whitespace=fix") ||
1690                    !strcmp(option, "--whitespace=strip"))
1691                        options.flags |= REBASE_FORCE;
1692                else if (skip_prefix(option, "-C", &p)) {
1693                        while (*p)
1694                                if (!isdigit(*(p++)))
1695                                        die(_("switch `C' expects a "
1696                                              "numerical value"));
1697                } else if (skip_prefix(option, "--whitespace=", &p)) {
1698                        if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1699                            strcmp(p, "error") && strcmp(p, "error-all"))
1700                                die("Invalid whitespace option: '%s'", p);
1701                }
1702        }
1703
1704        for (i = 0; i < exec.nr; i++)
1705                if (check_exec_cmd(exec.items[i].string))
1706                        exit(1);
1707
1708        if (!(options.flags & REBASE_NO_QUIET))
1709                argv_array_push(&options.git_am_opts, "-q");
1710
1711        if (options.keep_empty)
1712                imply_interactive(&options, "--keep-empty");
1713
1714        if (gpg_sign) {
1715                free(options.gpg_sign_opt);
1716                options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1717        }
1718
1719        if (exec.nr) {
1720                int i;
1721
1722                imply_interactive(&options, "--exec");
1723
1724                strbuf_reset(&buf);
1725                for (i = 0; i < exec.nr; i++)
1726                        strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1727                options.cmd = xstrdup(buf.buf);
1728        }
1729
1730        if (rebase_merges) {
1731                if (!*rebase_merges)
1732                        ; /* default mode; do nothing */
1733                else if (!strcmp("rebase-cousins", rebase_merges))
1734                        options.rebase_cousins = 1;
1735                else if (strcmp("no-rebase-cousins", rebase_merges))
1736                        die(_("Unknown mode: %s"), rebase_merges);
1737                options.rebase_merges = 1;
1738                imply_interactive(&options, "--rebase-merges");
1739        }
1740
1741        if (strategy_options.nr) {
1742                int i;
1743
1744                if (!options.strategy)
1745                        options.strategy = "recursive";
1746
1747                strbuf_reset(&buf);
1748                for (i = 0; i < strategy_options.nr; i++)
1749                        strbuf_addf(&buf, " --%s",
1750                                    strategy_options.items[i].string);
1751                options.strategy_opts = xstrdup(buf.buf);
1752        }
1753
1754        if (options.strategy) {
1755                options.strategy = xstrdup(options.strategy);
1756                switch (options.type) {
1757                case REBASE_AM:
1758                        die(_("--strategy requires --merge or --interactive"));
1759                case REBASE_MERGE:
1760                case REBASE_INTERACTIVE:
1761                case REBASE_PRESERVE_MERGES:
1762                        /* compatible */
1763                        break;
1764                case REBASE_UNSPECIFIED:
1765                        options.type = REBASE_MERGE;
1766                        break;
1767                default:
1768                        BUG("unhandled rebase type (%d)", options.type);
1769                }
1770        }
1771
1772        if (options.type == REBASE_MERGE)
1773                imply_interactive(&options, "--merge");
1774
1775        if (options.root && !options.onto_name)
1776                imply_interactive(&options, "--root without --onto");
1777
1778        if (isatty(2) && options.flags & REBASE_NO_QUIET)
1779                strbuf_addstr(&options.git_format_patch_opt, " --progress");
1780
1781        switch (options.type) {
1782        case REBASE_MERGE:
1783        case REBASE_INTERACTIVE:
1784        case REBASE_PRESERVE_MERGES:
1785                options.state_dir = merge_dir();
1786                break;
1787        case REBASE_AM:
1788                options.state_dir = apply_dir();
1789                break;
1790        default:
1791                /* the default rebase backend is `--am` */
1792                options.type = REBASE_AM;
1793                options.state_dir = apply_dir();
1794                break;
1795        }
1796
1797        if (reschedule_failed_exec > 0 && !is_interactive(&options))
1798                die(_("--reschedule-failed-exec requires "
1799                      "--exec or --interactive"));
1800        if (reschedule_failed_exec >= 0)
1801                options.reschedule_failed_exec = reschedule_failed_exec;
1802
1803        if (options.git_am_opts.argc) {
1804                /* all am options except -q are compatible only with --am */
1805                for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1806                        if (strcmp(options.git_am_opts.argv[i], "-q"))
1807                                break;
1808
1809                if (is_interactive(&options) && i >= 0)
1810                        die(_("cannot combine am options with either "
1811                              "interactive or merge options"));
1812        }
1813
1814        if (options.signoff) {
1815                if (options.type == REBASE_PRESERVE_MERGES)
1816                        die("cannot combine '--signoff' with "
1817                            "'--preserve-merges'");
1818                argv_array_push(&options.git_am_opts, "--signoff");
1819                options.flags |= REBASE_FORCE;
1820        }
1821
1822        if (options.type == REBASE_PRESERVE_MERGES) {
1823                /*
1824                 * Note: incompatibility with --signoff handled in signoff block above
1825                 * Note: incompatibility with --interactive is just a strong warning;
1826                 *       git-rebase.txt caveats with "unless you know what you are doing"
1827                 */
1828                if (options.rebase_merges)
1829                        die(_("cannot combine '--preserve-merges' with "
1830                              "'--rebase-merges'"));
1831
1832                if (options.reschedule_failed_exec)
1833                        die(_("error: cannot combine '--preserve-merges' with "
1834                              "'--reschedule-failed-exec'"));
1835        }
1836
1837        if (!options.root) {
1838                if (argc < 1) {
1839                        struct branch *branch;
1840
1841                        branch = branch_get(NULL);
1842                        options.upstream_name = branch_get_upstream(branch,
1843                                                                    NULL);
1844                        if (!options.upstream_name)
1845                                error_on_missing_default_upstream();
1846                        if (fork_point < 0)
1847                                fork_point = 1;
1848                } else {
1849                        options.upstream_name = argv[0];
1850                        argc--;
1851                        argv++;
1852                        if (!strcmp(options.upstream_name, "-"))
1853                                options.upstream_name = "@{-1}";
1854                }
1855                options.upstream = peel_committish(options.upstream_name);
1856                if (!options.upstream)
1857                        die(_("invalid upstream '%s'"), options.upstream_name);
1858                options.upstream_arg = options.upstream_name;
1859        } else {
1860                if (!options.onto_name) {
1861                        if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1862                                        &squash_onto, NULL, NULL) < 0)
1863                                die(_("Could not create new root commit"));
1864                        options.squash_onto = &squash_onto;
1865                        options.onto_name = squash_onto_name =
1866                                xstrdup(oid_to_hex(&squash_onto));
1867                } else
1868                        options.root_with_onto = 1;
1869
1870                options.upstream_name = NULL;
1871                options.upstream = NULL;
1872                if (argc > 1)
1873                        usage_with_options(builtin_rebase_usage,
1874                                           builtin_rebase_options);
1875                options.upstream_arg = "--root";
1876        }
1877
1878        /* Make sure the branch to rebase onto is valid. */
1879        if (!options.onto_name)
1880                options.onto_name = options.upstream_name;
1881        if (strstr(options.onto_name, "...")) {
1882                if (get_oid_mb(options.onto_name, &merge_base) < 0)
1883                        die(_("'%s': need exactly one merge base"),
1884                            options.onto_name);
1885                options.onto = lookup_commit_or_die(&merge_base,
1886                                                    options.onto_name);
1887        } else {
1888                options.onto = peel_committish(options.onto_name);
1889                if (!options.onto)
1890                        die(_("Does not point to a valid commit '%s'"),
1891                                options.onto_name);
1892        }
1893
1894        /*
1895         * If the branch to rebase is given, that is the branch we will rebase
1896         * branch_name -- branch/commit being rebased, or
1897         *                HEAD (already detached)
1898         * orig_head -- commit object name of tip of the branch before rebasing
1899         * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1900         */
1901        if (argc == 1) {
1902                /* Is it "rebase other branchname" or "rebase other commit"? */
1903                branch_name = argv[0];
1904                options.switch_to = argv[0];
1905
1906                /* Is it a local branch? */
1907                strbuf_reset(&buf);
1908                strbuf_addf(&buf, "refs/heads/%s", branch_name);
1909                if (!read_ref(buf.buf, &options.orig_head))
1910                        options.head_name = xstrdup(buf.buf);
1911                /* If not is it a valid ref (branch or commit)? */
1912                else if (!get_oid(branch_name, &options.orig_head))
1913                        options.head_name = NULL;
1914                else
1915                        die(_("fatal: no such branch/commit '%s'"),
1916                            branch_name);
1917        } else if (argc == 0) {
1918                /* Do not need to switch branches, we are already on it. */
1919                options.head_name =
1920                        xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1921                                         &flags));
1922                if (!options.head_name)
1923                        die(_("No such ref: %s"), "HEAD");
1924                if (flags & REF_ISSYMREF) {
1925                        if (!skip_prefix(options.head_name,
1926                                         "refs/heads/", &branch_name))
1927                                branch_name = options.head_name;
1928
1929                } else {
1930                        FREE_AND_NULL(options.head_name);
1931                        branch_name = "HEAD";
1932                }
1933                if (get_oid("HEAD", &options.orig_head))
1934                        die(_("Could not resolve HEAD to a revision"));
1935        } else
1936                BUG("unexpected number of arguments left to parse");
1937
1938        if (fork_point > 0) {
1939                struct commit *head =
1940                        lookup_commit_reference(the_repository,
1941                                                &options.orig_head);
1942                options.restrict_revision =
1943                        get_fork_point(options.upstream_name, head);
1944        }
1945
1946        if (repo_read_index(the_repository) < 0)
1947                die(_("could not read index"));
1948
1949        if (options.autostash) {
1950                struct lock_file lock_file = LOCK_INIT;
1951                int fd;
1952
1953                fd = hold_locked_index(&lock_file, 0);
1954                refresh_cache(REFRESH_QUIET);
1955                if (0 <= fd)
1956                        repo_update_index_if_able(the_repository, &lock_file);
1957                rollback_lock_file(&lock_file);
1958
1959                if (has_unstaged_changes(the_repository, 1) ||
1960                    has_uncommitted_changes(the_repository, 1)) {
1961                        const char *autostash =
1962                                state_dir_path("autostash", &options);
1963                        struct child_process stash = CHILD_PROCESS_INIT;
1964                        struct object_id oid;
1965                        struct commit *head =
1966                                lookup_commit_reference(the_repository,
1967                                                        &options.orig_head);
1968
1969                        argv_array_pushl(&stash.args,
1970                                         "stash", "create", "autostash", NULL);
1971                        stash.git_cmd = 1;
1972                        stash.no_stdin = 1;
1973                        strbuf_reset(&buf);
1974                        if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1975                                die(_("Cannot autostash"));
1976                        strbuf_trim_trailing_newline(&buf);
1977                        if (get_oid(buf.buf, &oid))
1978                                die(_("Unexpected stash response: '%s'"),
1979                                    buf.buf);
1980                        strbuf_reset(&buf);
1981                        strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1982
1983                        if (safe_create_leading_directories_const(autostash))
1984                                die(_("Could not create directory for '%s'"),
1985                                    options.state_dir);
1986                        write_file(autostash, "%s", oid_to_hex(&oid));
1987                        printf(_("Created autostash: %s\n"), buf.buf);
1988                        if (reset_head(&head->object.oid, "reset --hard",
1989                                       NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
1990                                die(_("could not reset --hard"));
1991                        printf(_("HEAD is now at %s"),
1992                               find_unique_abbrev(&head->object.oid,
1993                                                  DEFAULT_ABBREV));
1994                        strbuf_reset(&buf);
1995                        pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
1996                        if (buf.len > 0)
1997                                printf(" %s", buf.buf);
1998                        putchar('\n');
1999
2000                        if (discard_index(the_repository->index) < 0 ||
2001                                repo_read_index(the_repository) < 0)
2002                                die(_("could not read index"));
2003                }
2004        }
2005
2006        if (require_clean_work_tree(the_repository, "rebase",
2007                                    _("Please commit or stash them."), 1, 1)) {
2008                ret = 1;
2009                goto cleanup;
2010        }
2011
2012        /*
2013         * Now we are rebasing commits upstream..orig_head (or with --root,
2014         * everything leading up to orig_head) on top of onto.
2015         */
2016
2017        /*
2018         * Check if we are already based on onto with linear history,
2019         * but this should be done only when upstream and onto are the same
2020         * and if this is not an interactive rebase.
2021         */
2022        if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
2023            !is_interactive(&options) && !options.restrict_revision &&
2024            options.upstream &&
2025            !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
2026                int flag;
2027
2028                if (!(options.flags & REBASE_FORCE)) {
2029                        /* Lazily switch to the target branch if needed... */
2030                        if (options.switch_to) {
2031                                struct object_id oid;
2032
2033                                if (get_oid(options.switch_to, &oid) < 0) {
2034                                        ret = !!error(_("could not parse '%s'"),
2035                                                      options.switch_to);
2036                                        goto cleanup;
2037                                }
2038
2039                                strbuf_reset(&buf);
2040                                strbuf_addf(&buf, "%s: checkout %s",
2041                                            getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
2042                                            options.switch_to);
2043                                if (reset_head(&oid, "checkout",
2044                                               options.head_name,
2045                                               RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2046                                               NULL, buf.buf) < 0) {
2047                                        ret = !!error(_("could not switch to "
2048                                                        "%s"),
2049                                                      options.switch_to);
2050                                        goto cleanup;
2051                                }
2052                        }
2053
2054                        if (!(options.flags & REBASE_NO_QUIET))
2055                                ; /* be quiet */
2056                        else if (!strcmp(branch_name, "HEAD") &&
2057                                 resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2058                                puts(_("HEAD is up to date."));
2059                        else
2060                                printf(_("Current branch %s is up to date.\n"),
2061                                       branch_name);
2062                        ret = !!finish_rebase(&options);
2063                        goto cleanup;
2064                } else if (!(options.flags & REBASE_NO_QUIET))
2065                        ; /* be quiet */
2066                else if (!strcmp(branch_name, "HEAD") &&
2067                         resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2068                        puts(_("HEAD is up to date, rebase forced."));
2069                else
2070                        printf(_("Current branch %s is up to date, rebase "
2071                                 "forced.\n"), branch_name);
2072        }
2073
2074        /* If a hook exists, give it a chance to interrupt*/
2075        if (!ok_to_skip_pre_rebase &&
2076            run_hook_le(NULL, "pre-rebase", options.upstream_arg,
2077                        argc ? argv[0] : NULL, NULL))
2078                die(_("The pre-rebase hook refused to rebase."));
2079
2080        if (options.flags & REBASE_DIFFSTAT) {
2081                struct diff_options opts;
2082
2083                if (options.flags & REBASE_VERBOSE) {
2084                        if (is_null_oid(&merge_base))
2085                                printf(_("Changes to %s:\n"),
2086                                       oid_to_hex(&options.onto->object.oid));
2087                        else
2088                                printf(_("Changes from %s to %s:\n"),
2089                                       oid_to_hex(&merge_base),
2090                                       oid_to_hex(&options.onto->object.oid));
2091                }
2092
2093                /* We want color (if set), but no pager */
2094                diff_setup(&opts);
2095                opts.stat_width = -1; /* use full terminal width */
2096                opts.stat_graph_width = -1; /* respect statGraphWidth config */
2097                opts.output_format |=
2098                        DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
2099                opts.detect_rename = DIFF_DETECT_RENAME;
2100                diff_setup_done(&opts);
2101                diff_tree_oid(is_null_oid(&merge_base) ?
2102                              the_hash_algo->empty_tree : &merge_base,
2103                              &options.onto->object.oid, "", &opts);
2104                diffcore_std(&opts);
2105                diff_flush(&opts);
2106        }
2107
2108        if (is_interactive(&options))
2109                goto run_rebase;
2110
2111        /* Detach HEAD and reset the tree */
2112        if (options.flags & REBASE_NO_QUIET)
2113                printf(_("First, rewinding head to replay your work on top of "
2114                         "it...\n"));
2115
2116        strbuf_addf(&msg, "%s: checkout %s",
2117                    getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
2118        if (reset_head(&options.onto->object.oid, "checkout", NULL,
2119                       RESET_HEAD_DETACH | RESET_ORIG_HEAD |
2120                       RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2121                       NULL, msg.buf))
2122                die(_("Could not detach HEAD"));
2123        strbuf_release(&msg);
2124
2125        /*
2126         * If the onto is a proper descendant of the tip of the branch, then
2127         * we just fast-forwarded.
2128         */
2129        strbuf_reset(&msg);
2130        if (oideq(&merge_base, &options.orig_head)) {
2131                printf(_("Fast-forwarded %s to %s.\n"),
2132                        branch_name, options.onto_name);
2133                strbuf_addf(&msg, "rebase finished: %s onto %s",
2134                        options.head_name ? options.head_name : "detached HEAD",
2135                        oid_to_hex(&options.onto->object.oid));
2136                reset_head(NULL, "Fast-forwarded", options.head_name,
2137                           RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
2138                strbuf_release(&msg);
2139                ret = !!finish_rebase(&options);
2140                goto cleanup;
2141        }
2142
2143        strbuf_addf(&revisions, "%s..%s",
2144                    options.root ? oid_to_hex(&options.onto->object.oid) :
2145                    (options.restrict_revision ?
2146                     oid_to_hex(&options.restrict_revision->object.oid) :
2147                     oid_to_hex(&options.upstream->object.oid)),
2148                    oid_to_hex(&options.orig_head));
2149
2150        options.revisions = revisions.buf;
2151
2152run_rebase:
2153        ret = !!run_specific_rebase(&options, action);
2154
2155cleanup:
2156        strbuf_release(&buf);
2157        strbuf_release(&revisions);
2158        free(options.head_name);
2159        free(options.gpg_sign_opt);
2160        free(options.cmd);
2161        free(squash_onto_name);
2162        return ret;
2163}