builtin / rebase.con commit Merge branch 'pw/prompt-cherry-pick-revert-fix' (8a4acc5)
   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;
  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 |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
 378
 379        switch (command) {
 380        case ACTION_NONE: {
 381                if (!opts->onto && !opts->upstream)
 382                        die(_("a base commit must be provided with --upstream or --onto"));
 383
 384                ret = do_interactive_rebase(opts, flags);
 385                break;
 386        }
 387        case ACTION_SKIP: {
 388                struct string_list merge_rr = STRING_LIST_INIT_DUP;
 389
 390                rerere_clear(the_repository, &merge_rr);
 391        }
 392                /* fallthrough */
 393        case ACTION_CONTINUE: {
 394                struct replay_opts replay_opts = get_replay_opts(opts);
 395
 396                ret = sequencer_continue(the_repository, &replay_opts);
 397                break;
 398        }
 399        case ACTION_EDIT_TODO:
 400                ret = edit_todo_file(flags);
 401                break;
 402        case ACTION_SHOW_CURRENT_PATCH: {
 403                struct child_process cmd = CHILD_PROCESS_INIT;
 404
 405                cmd.git_cmd = 1;
 406                argv_array_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
 407                ret = run_command(&cmd);
 408
 409                break;
 410        }
 411        case ACTION_SHORTEN_OIDS:
 412        case ACTION_EXPAND_OIDS:
 413                ret = transform_todo_file(flags);
 414                break;
 415        case ACTION_CHECK_TODO_LIST:
 416                ret = check_todo_list_from_file(the_repository);
 417                break;
 418        case ACTION_REARRANGE_SQUASH:
 419                ret = rearrange_squash_in_todo_file();
 420                break;
 421        case ACTION_ADD_EXEC: {
 422                struct string_list commands = STRING_LIST_INIT_DUP;
 423
 424                split_exec_commands(opts->cmd, &commands);
 425                ret = add_exec_commands(&commands);
 426                string_list_clear(&commands, 0);
 427                break;
 428        }
 429        default:
 430                BUG("invalid command '%d'", command);
 431        }
 432
 433        return ret;
 434}
 435
 436static const char * const builtin_rebase_interactive_usage[] = {
 437        N_("git rebase--interactive [<options>]"),
 438        NULL
 439};
 440
 441int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 442{
 443        struct rebase_options opts = REBASE_OPTIONS_INIT;
 444        struct object_id squash_onto = null_oid;
 445        enum action command = ACTION_NONE;
 446        struct option options[] = {
 447                OPT_NEGBIT(0, "ff", &opts.flags, N_("allow fast-forward"),
 448                           REBASE_FORCE),
 449                OPT_BOOL(0, "keep-empty", &opts.keep_empty, N_("keep empty commits")),
 450                OPT_BOOL(0, "allow-empty-message", &opts.allow_empty_message,
 451                         N_("allow commits with empty messages")),
 452                OPT_BOOL(0, "rebase-merges", &opts.rebase_merges, N_("rebase merge commits")),
 453                OPT_BOOL(0, "rebase-cousins", &opts.rebase_cousins,
 454                         N_("keep original branch points of cousins")),
 455                OPT_BOOL(0, "autosquash", &opts.autosquash,
 456                         N_("move commits that begin with squash!/fixup!")),
 457                OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
 458                OPT_BIT('v', "verbose", &opts.flags,
 459                        N_("display a diffstat of what changed upstream"),
 460                        REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 461                OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
 462                            ACTION_CONTINUE),
 463                OPT_CMDMODE(0, "skip", &command, N_("skip commit"), ACTION_SKIP),
 464                OPT_CMDMODE(0, "edit-todo", &command, N_("edit the todo list"),
 465                            ACTION_EDIT_TODO),
 466                OPT_CMDMODE(0, "show-current-patch", &command, N_("show the current patch"),
 467                            ACTION_SHOW_CURRENT_PATCH),
 468                OPT_CMDMODE(0, "shorten-ids", &command,
 469                        N_("shorten commit ids in the todo list"), ACTION_SHORTEN_OIDS),
 470                OPT_CMDMODE(0, "expand-ids", &command,
 471                        N_("expand commit ids in the todo list"), ACTION_EXPAND_OIDS),
 472                OPT_CMDMODE(0, "check-todo-list", &command,
 473                        N_("check the todo list"), ACTION_CHECK_TODO_LIST),
 474                OPT_CMDMODE(0, "rearrange-squash", &command,
 475                        N_("rearrange fixup/squash lines"), ACTION_REARRANGE_SQUASH),
 476                OPT_CMDMODE(0, "add-exec-commands", &command,
 477                        N_("insert exec commands in todo list"), ACTION_ADD_EXEC),
 478                { OPTION_CALLBACK, 0, "onto", &opts.onto, N_("onto"), N_("onto"),
 479                  PARSE_OPT_NONEG, parse_opt_commit, 0 },
 480                { OPTION_CALLBACK, 0, "restrict-revision", &opts.restrict_revision,
 481                  N_("restrict-revision"), N_("restrict revision"),
 482                  PARSE_OPT_NONEG, parse_opt_commit, 0 },
 483                { OPTION_CALLBACK, 0, "squash-onto", &squash_onto, N_("squash-onto"),
 484                  N_("squash onto"), PARSE_OPT_NONEG, parse_opt_object_id, 0 },
 485                { OPTION_CALLBACK, 0, "upstream", &opts.upstream, N_("upstream"),
 486                  N_("the upstream commit"), PARSE_OPT_NONEG, parse_opt_commit,
 487                  0 },
 488                OPT_STRING(0, "head-name", &opts.head_name, N_("head-name"), N_("head name")),
 489                { OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign_opt, N_("key-id"),
 490                        N_("GPG-sign commits"),
 491                        PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 492                OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
 493                           N_("rebase strategy")),
 494                OPT_STRING(0, "strategy-opts", &opts.strategy_opts, N_("strategy-opts"),
 495                           N_("strategy options")),
 496                OPT_STRING(0, "switch-to", &opts.switch_to, N_("switch-to"),
 497                           N_("the branch or commit to checkout")),
 498                OPT_STRING(0, "onto-name", &opts.onto_name, N_("onto-name"), N_("onto name")),
 499                OPT_STRING(0, "cmd", &opts.cmd, N_("cmd"), N_("the command to run")),
 500                OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_autoupdate),
 501                OPT_BOOL(0, "reschedule-failed-exec", &opts.reschedule_failed_exec,
 502                         N_("automatically re-schedule any `exec` that fails")),
 503                OPT_END()
 504        };
 505
 506        opts.rebase_cousins = -1;
 507
 508        if (argc == 1)
 509                usage_with_options(builtin_rebase_interactive_usage, options);
 510
 511        argc = parse_options(argc, argv, prefix, options,
 512                        builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
 513
 514        if (!is_null_oid(&squash_onto))
 515                opts.squash_onto = &squash_onto;
 516
 517        if (opts.rebase_cousins >= 0 && !opts.rebase_merges)
 518                warning(_("--[no-]rebase-cousins has no effect without "
 519                          "--rebase-merges"));
 520
 521        return !!run_rebase_interactive(&opts, command);
 522}
 523
 524static int is_interactive(struct rebase_options *opts)
 525{
 526        return opts->type == REBASE_INTERACTIVE ||
 527                opts->type == REBASE_PRESERVE_MERGES;
 528}
 529
 530static void imply_interactive(struct rebase_options *opts, const char *option)
 531{
 532        switch (opts->type) {
 533        case REBASE_AM:
 534                die(_("%s requires an interactive rebase"), option);
 535                break;
 536        case REBASE_INTERACTIVE:
 537        case REBASE_PRESERVE_MERGES:
 538                break;
 539        case REBASE_MERGE:
 540                /* we now implement --merge via --interactive */
 541        default:
 542                opts->type = REBASE_INTERACTIVE; /* implied */
 543                break;
 544        }
 545}
 546
 547/* Returns the filename prefixed by the state_dir */
 548static const char *state_dir_path(const char *filename, struct rebase_options *opts)
 549{
 550        static struct strbuf path = STRBUF_INIT;
 551        static size_t prefix_len;
 552
 553        if (!prefix_len) {
 554                strbuf_addf(&path, "%s/", opts->state_dir);
 555                prefix_len = path.len;
 556        }
 557
 558        strbuf_setlen(&path, prefix_len);
 559        strbuf_addstr(&path, filename);
 560        return path.buf;
 561}
 562
 563/* Read one file, then strip line endings */
 564static int read_one(const char *path, struct strbuf *buf)
 565{
 566        if (strbuf_read_file(buf, path, 0) < 0)
 567                return error_errno(_("could not read '%s'"), path);
 568        strbuf_trim_trailing_newline(buf);
 569        return 0;
 570}
 571
 572/* Initialize the rebase options from the state directory. */
 573static int read_basic_state(struct rebase_options *opts)
 574{
 575        struct strbuf head_name = STRBUF_INIT;
 576        struct strbuf buf = STRBUF_INIT;
 577        struct object_id oid;
 578
 579        if (read_one(state_dir_path("head-name", opts), &head_name) ||
 580            read_one(state_dir_path("onto", opts), &buf))
 581                return -1;
 582        opts->head_name = starts_with(head_name.buf, "refs/") ?
 583                xstrdup(head_name.buf) : NULL;
 584        strbuf_release(&head_name);
 585        if (get_oid(buf.buf, &oid))
 586                return error(_("could not get 'onto': '%s'"), buf.buf);
 587        opts->onto = lookup_commit_or_die(&oid, buf.buf);
 588
 589        /*
 590         * We always write to orig-head, but interactive rebase used to write to
 591         * head. Fall back to reading from head to cover for the case that the
 592         * user upgraded git with an ongoing interactive rebase.
 593         */
 594        strbuf_reset(&buf);
 595        if (file_exists(state_dir_path("orig-head", opts))) {
 596                if (read_one(state_dir_path("orig-head", opts), &buf))
 597                        return -1;
 598        } else if (read_one(state_dir_path("head", opts), &buf))
 599                return -1;
 600        if (get_oid(buf.buf, &opts->orig_head))
 601                return error(_("invalid orig-head: '%s'"), buf.buf);
 602
 603        if (file_exists(state_dir_path("quiet", opts)))
 604                opts->flags &= ~REBASE_NO_QUIET;
 605        else
 606                opts->flags |= REBASE_NO_QUIET;
 607
 608        if (file_exists(state_dir_path("verbose", opts)))
 609                opts->flags |= REBASE_VERBOSE;
 610
 611        if (file_exists(state_dir_path("signoff", opts))) {
 612                opts->signoff = 1;
 613                opts->flags |= REBASE_FORCE;
 614        }
 615
 616        if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 617                strbuf_reset(&buf);
 618                if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
 619                            &buf))
 620                        return -1;
 621                if (!strcmp(buf.buf, "--rerere-autoupdate"))
 622                        opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
 623                else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
 624                        opts->allow_rerere_autoupdate = RERERE_NOAUTOUPDATE;
 625                else
 626                        warning(_("ignoring invalid allow_rerere_autoupdate: "
 627                                  "'%s'"), buf.buf);
 628        }
 629
 630        if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 631                strbuf_reset(&buf);
 632                if (read_one(state_dir_path("gpg_sign_opt", opts),
 633                            &buf))
 634                        return -1;
 635                free(opts->gpg_sign_opt);
 636                opts->gpg_sign_opt = xstrdup(buf.buf);
 637        }
 638
 639        if (file_exists(state_dir_path("strategy", opts))) {
 640                strbuf_reset(&buf);
 641                if (read_one(state_dir_path("strategy", opts), &buf))
 642                        return -1;
 643                free(opts->strategy);
 644                opts->strategy = xstrdup(buf.buf);
 645        }
 646
 647        if (file_exists(state_dir_path("strategy_opts", opts))) {
 648                strbuf_reset(&buf);
 649                if (read_one(state_dir_path("strategy_opts", opts), &buf))
 650                        return -1;
 651                free(opts->strategy_opts);
 652                opts->strategy_opts = xstrdup(buf.buf);
 653        }
 654
 655        strbuf_release(&buf);
 656
 657        return 0;
 658}
 659
 660static int rebase_write_basic_state(struct rebase_options *opts)
 661{
 662        write_file(state_dir_path("head-name", opts), "%s",
 663                   opts->head_name ? opts->head_name : "detached HEAD");
 664        write_file(state_dir_path("onto", opts), "%s",
 665                   opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
 666        write_file(state_dir_path("orig-head", opts), "%s",
 667                   oid_to_hex(&opts->orig_head));
 668        write_file(state_dir_path("quiet", opts), "%s",
 669                   opts->flags & REBASE_NO_QUIET ? "" : "t");
 670        if (opts->flags & REBASE_VERBOSE)
 671                write_file(state_dir_path("verbose", opts), "%s", "");
 672        if (opts->strategy)
 673                write_file(state_dir_path("strategy", opts), "%s",
 674                           opts->strategy);
 675        if (opts->strategy_opts)
 676                write_file(state_dir_path("strategy_opts", opts), "%s",
 677                           opts->strategy_opts);
 678        if (opts->allow_rerere_autoupdate > 0)
 679                write_file(state_dir_path("allow_rerere_autoupdate", opts),
 680                           "-%s-rerere-autoupdate",
 681                           opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
 682                                "" : "-no");
 683        if (opts->gpg_sign_opt)
 684                write_file(state_dir_path("gpg_sign_opt", opts), "%s",
 685                           opts->gpg_sign_opt);
 686        if (opts->signoff)
 687                write_file(state_dir_path("strategy", opts), "--signoff");
 688
 689        return 0;
 690}
 691
 692static int apply_autostash(struct rebase_options *opts)
 693{
 694        const char *path = state_dir_path("autostash", opts);
 695        struct strbuf autostash = STRBUF_INIT;
 696        struct child_process stash_apply = CHILD_PROCESS_INIT;
 697
 698        if (!file_exists(path))
 699                return 0;
 700
 701        if (read_one(path, &autostash))
 702                return error(_("Could not read '%s'"), path);
 703        /* Ensure that the hash is not mistaken for a number */
 704        strbuf_addstr(&autostash, "^0");
 705        argv_array_pushl(&stash_apply.args,
 706                         "stash", "apply", autostash.buf, NULL);
 707        stash_apply.git_cmd = 1;
 708        stash_apply.no_stderr = stash_apply.no_stdout =
 709                stash_apply.no_stdin = 1;
 710        if (!run_command(&stash_apply))
 711                printf(_("Applied autostash.\n"));
 712        else {
 713                struct argv_array args = ARGV_ARRAY_INIT;
 714                int res = 0;
 715
 716                argv_array_pushl(&args,
 717                                 "stash", "store", "-m", "autostash", "-q",
 718                                 autostash.buf, NULL);
 719                if (run_command_v_opt(args.argv, RUN_GIT_CMD))
 720                        res = error(_("Cannot store %s"), autostash.buf);
 721                argv_array_clear(&args);
 722                strbuf_release(&autostash);
 723                if (res)
 724                        return res;
 725
 726                fprintf(stderr,
 727                        _("Applying autostash resulted in conflicts.\n"
 728                          "Your changes are safe in the stash.\n"
 729                          "You can run \"git stash pop\" or \"git stash drop\" "
 730                          "at any time.\n"));
 731        }
 732
 733        strbuf_release(&autostash);
 734        return 0;
 735}
 736
 737static int finish_rebase(struct rebase_options *opts)
 738{
 739        struct strbuf dir = STRBUF_INIT;
 740        const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 741        int ret = 0;
 742
 743        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 744        apply_autostash(opts);
 745        close_object_store(the_repository->objects);
 746        /*
 747         * We ignore errors in 'gc --auto', since the
 748         * user should see them.
 749         */
 750        run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 751        if (opts->type == REBASE_INTERACTIVE) {
 752                struct replay_opts replay = REPLAY_OPTS_INIT;
 753
 754                replay.action = REPLAY_INTERACTIVE_REBASE;
 755                ret = sequencer_remove_state(&replay);
 756        } else {
 757                strbuf_addstr(&dir, opts->state_dir);
 758                if (remove_dir_recursively(&dir, 0))
 759                        ret = error(_("could not remove '%s'"),
 760                                    opts->state_dir);
 761                strbuf_release(&dir);
 762        }
 763
 764        return ret;
 765}
 766
 767static struct commit *peel_committish(const char *name)
 768{
 769        struct object *obj;
 770        struct object_id oid;
 771
 772        if (get_oid(name, &oid))
 773                return NULL;
 774        obj = parse_object(the_repository, &oid);
 775        return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 776}
 777
 778static void add_var(struct strbuf *buf, const char *name, const char *value)
 779{
 780        if (!value)
 781                strbuf_addf(buf, "unset %s; ", name);
 782        else {
 783                strbuf_addf(buf, "%s=", name);
 784                sq_quote_buf(buf, value);
 785                strbuf_addstr(buf, "; ");
 786        }
 787}
 788
 789#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 790
 791#define RESET_HEAD_DETACH (1<<0)
 792#define RESET_HEAD_HARD (1<<1)
 793#define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 794#define RESET_HEAD_REFS_ONLY (1<<3)
 795#define RESET_ORIG_HEAD (1<<4)
 796
 797static int reset_head(struct object_id *oid, const char *action,
 798                      const char *switch_to_branch, unsigned flags,
 799                      const char *reflog_orig_head, const char *reflog_head)
 800{
 801        unsigned detach_head = flags & RESET_HEAD_DETACH;
 802        unsigned reset_hard = flags & RESET_HEAD_HARD;
 803        unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 804        unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
 805        unsigned update_orig_head = flags & RESET_ORIG_HEAD;
 806        struct object_id head_oid;
 807        struct tree_desc desc[2] = { { NULL }, { NULL } };
 808        struct lock_file lock = LOCK_INIT;
 809        struct unpack_trees_options unpack_tree_opts;
 810        struct tree *tree;
 811        const char *reflog_action;
 812        struct strbuf msg = STRBUF_INIT;
 813        size_t prefix_len;
 814        struct object_id *orig = NULL, oid_orig,
 815                *old_orig = NULL, oid_old_orig;
 816        int ret = 0, nr = 0;
 817
 818        if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 819                BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 820
 821        if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
 822                ret = -1;
 823                goto leave_reset_head;
 824        }
 825
 826        if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
 827                ret = error(_("could not determine HEAD revision"));
 828                goto leave_reset_head;
 829        }
 830
 831        if (!oid)
 832                oid = &head_oid;
 833
 834        if (refs_only)
 835                goto reset_head_refs;
 836
 837        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 838        setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 839        unpack_tree_opts.head_idx = 1;
 840        unpack_tree_opts.src_index = the_repository->index;
 841        unpack_tree_opts.dst_index = the_repository->index;
 842        unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 843        unpack_tree_opts.update = 1;
 844        unpack_tree_opts.merge = 1;
 845        if (!detach_head)
 846                unpack_tree_opts.reset = 1;
 847
 848        if (repo_read_index_unmerged(the_repository) < 0) {
 849                ret = error(_("could not read index"));
 850                goto leave_reset_head;
 851        }
 852
 853        if (!reset_hard && !fill_tree_descriptor(the_repository, &desc[nr++], &head_oid)) {
 854                ret = error(_("failed to find tree of %s"),
 855                            oid_to_hex(&head_oid));
 856                goto leave_reset_head;
 857        }
 858
 859        if (!fill_tree_descriptor(the_repository, &desc[nr++], oid)) {
 860                ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 861                goto leave_reset_head;
 862        }
 863
 864        if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 865                ret = -1;
 866                goto leave_reset_head;
 867        }
 868
 869        tree = parse_tree_indirect(oid);
 870        prime_cache_tree(the_repository, the_repository->index, tree);
 871
 872        if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 873                ret = error(_("could not write index"));
 874                goto leave_reset_head;
 875        }
 876
 877reset_head_refs:
 878        reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 879        strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 880        prefix_len = msg.len;
 881
 882        if (update_orig_head) {
 883                if (!get_oid("ORIG_HEAD", &oid_old_orig))
 884                        old_orig = &oid_old_orig;
 885                if (!get_oid("HEAD", &oid_orig)) {
 886                        orig = &oid_orig;
 887                        if (!reflog_orig_head) {
 888                                strbuf_addstr(&msg, "updating ORIG_HEAD");
 889                                reflog_orig_head = msg.buf;
 890                        }
 891                        update_ref(reflog_orig_head, "ORIG_HEAD", orig,
 892                                   old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
 893                } else if (old_orig)
 894                        delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 895        }
 896
 897        if (!reflog_head) {
 898                strbuf_setlen(&msg, prefix_len);
 899                strbuf_addstr(&msg, "updating HEAD");
 900                reflog_head = msg.buf;
 901        }
 902        if (!switch_to_branch)
 903                ret = update_ref(reflog_head, "HEAD", oid, orig,
 904                                 detach_head ? REF_NO_DEREF : 0,
 905                                 UPDATE_REFS_MSG_ON_ERR);
 906        else {
 907                ret = update_ref(reflog_head, switch_to_branch, oid,
 908                                 NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 909                if (!ret)
 910                        ret = create_symref("HEAD", switch_to_branch,
 911                                            reflog_head);
 912        }
 913        if (run_hook)
 914                run_hook_le(NULL, "post-checkout",
 915                            oid_to_hex(orig ? orig : &null_oid),
 916                            oid_to_hex(oid), "1", NULL);
 917
 918leave_reset_head:
 919        strbuf_release(&msg);
 920        rollback_lock_file(&lock);
 921        while (nr)
 922                free((void *)desc[--nr].buffer);
 923        return ret;
 924}
 925
 926static int move_to_original_branch(struct rebase_options *opts)
 927{
 928        struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
 929        int ret;
 930
 931        if (!opts->head_name)
 932                return 0; /* nothing to move back to */
 933
 934        if (!opts->onto)
 935                BUG("move_to_original_branch without onto");
 936
 937        strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
 938                    opts->head_name, oid_to_hex(&opts->onto->object.oid));
 939        strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 940                    opts->head_name);
 941        ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
 942                         orig_head_reflog.buf, head_reflog.buf);
 943
 944        strbuf_release(&orig_head_reflog);
 945        strbuf_release(&head_reflog);
 946        return ret;
 947}
 948
 949static const char *resolvemsg =
 950N_("Resolve all conflicts manually, mark them as resolved with\n"
 951"\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
 952"You can instead skip this commit: run \"git rebase --skip\".\n"
 953"To abort and get back to the state before \"git rebase\", run "
 954"\"git rebase --abort\".");
 955
 956static int run_am(struct rebase_options *opts)
 957{
 958        struct child_process am = CHILD_PROCESS_INIT;
 959        struct child_process format_patch = CHILD_PROCESS_INIT;
 960        struct strbuf revisions = STRBUF_INIT;
 961        int status;
 962        char *rebased_patches;
 963
 964        am.git_cmd = 1;
 965        argv_array_push(&am.args, "am");
 966
 967        if (opts->action && !strcmp("continue", opts->action)) {
 968                argv_array_push(&am.args, "--resolved");
 969                argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 970                if (opts->gpg_sign_opt)
 971                        argv_array_push(&am.args, opts->gpg_sign_opt);
 972                status = run_command(&am);
 973                if (status)
 974                        return status;
 975
 976                return move_to_original_branch(opts);
 977        }
 978        if (opts->action && !strcmp("skip", opts->action)) {
 979                argv_array_push(&am.args, "--skip");
 980                argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
 981                status = run_command(&am);
 982                if (status)
 983                        return status;
 984
 985                return move_to_original_branch(opts);
 986        }
 987        if (opts->action && !strcmp("show-current-patch", opts->action)) {
 988                argv_array_push(&am.args, "--show-current-patch");
 989                return run_command(&am);
 990        }
 991
 992        strbuf_addf(&revisions, "%s...%s",
 993                    oid_to_hex(opts->root ?
 994                               /* this is now equivalent to !opts->upstream */
 995                               &opts->onto->object.oid :
 996                               &opts->upstream->object.oid),
 997                    oid_to_hex(&opts->orig_head));
 998
 999        rebased_patches = xstrdup(git_path("rebased-patches"));
1000        format_patch.out = open(rebased_patches,
1001                                O_WRONLY | O_CREAT | O_TRUNC, 0666);
1002        if (format_patch.out < 0) {
1003                status = error_errno(_("could not open '%s' for writing"),
1004                                     rebased_patches);
1005                free(rebased_patches);
1006                argv_array_clear(&am.args);
1007                return status;
1008        }
1009
1010        format_patch.git_cmd = 1;
1011        argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
1012                         "--full-index", "--cherry-pick", "--right-only",
1013                         "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
1014                         "--no-cover-letter", "--pretty=mboxrd", "--topo-order", NULL);
1015        if (opts->git_format_patch_opt.len)
1016                argv_array_split(&format_patch.args,
1017                                 opts->git_format_patch_opt.buf);
1018        argv_array_push(&format_patch.args, revisions.buf);
1019        if (opts->restrict_revision)
1020                argv_array_pushf(&format_patch.args, "^%s",
1021                                 oid_to_hex(&opts->restrict_revision->object.oid));
1022
1023        status = run_command(&format_patch);
1024        if (status) {
1025                unlink(rebased_patches);
1026                free(rebased_patches);
1027                argv_array_clear(&am.args);
1028
1029                reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
1030                           "HEAD", NULL);
1031                error(_("\ngit encountered an error while preparing the "
1032                        "patches to replay\n"
1033                        "these revisions:\n"
1034                        "\n    %s\n\n"
1035                        "As a result, git cannot rebase them."),
1036                      opts->revisions);
1037
1038                strbuf_release(&revisions);
1039                return status;
1040        }
1041        strbuf_release(&revisions);
1042
1043        am.in = open(rebased_patches, O_RDONLY);
1044        if (am.in < 0) {
1045                status = error_errno(_("could not open '%s' for reading"),
1046                                     rebased_patches);
1047                free(rebased_patches);
1048                argv_array_clear(&am.args);
1049                return status;
1050        }
1051
1052        argv_array_pushv(&am.args, opts->git_am_opts.argv);
1053        argv_array_push(&am.args, "--rebasing");
1054        argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
1055        argv_array_push(&am.args, "--patch-format=mboxrd");
1056        if (opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE)
1057                argv_array_push(&am.args, "--rerere-autoupdate");
1058        else if (opts->allow_rerere_autoupdate == RERERE_NOAUTOUPDATE)
1059                argv_array_push(&am.args, "--no-rerere-autoupdate");
1060        if (opts->gpg_sign_opt)
1061                argv_array_push(&am.args, opts->gpg_sign_opt);
1062        status = run_command(&am);
1063        unlink(rebased_patches);
1064        free(rebased_patches);
1065
1066        if (!status) {
1067                return move_to_original_branch(opts);
1068        }
1069
1070        if (is_directory(opts->state_dir))
1071                rebase_write_basic_state(opts);
1072
1073        return status;
1074}
1075
1076static int run_specific_rebase(struct rebase_options *opts, enum action action)
1077{
1078        const char *argv[] = { NULL, NULL };
1079        struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
1080        int status;
1081        const char *backend, *backend_func;
1082
1083        if (opts->type == REBASE_INTERACTIVE) {
1084                /* Run builtin interactive rebase */
1085                setenv("GIT_CHERRY_PICK_HELP", resolvemsg, 1);
1086                if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1087                        setenv("GIT_SEQUENCE_EDITOR", ":", 1);
1088                        opts->autosquash = 0;
1089                }
1090                if (opts->gpg_sign_opt) {
1091                        /* remove the leading "-S" */
1092                        char *tmp = xstrdup(opts->gpg_sign_opt + 2);
1093                        free(opts->gpg_sign_opt);
1094                        opts->gpg_sign_opt = tmp;
1095                }
1096
1097                status = run_rebase_interactive(opts, action);
1098                goto finished_rebase;
1099        }
1100
1101        if (opts->type == REBASE_AM) {
1102                status = run_am(opts);
1103                goto finished_rebase;
1104        }
1105
1106        add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
1107        add_var(&script_snippet, "state_dir", opts->state_dir);
1108
1109        add_var(&script_snippet, "upstream_name", opts->upstream_name);
1110        add_var(&script_snippet, "upstream", opts->upstream ?
1111                oid_to_hex(&opts->upstream->object.oid) : NULL);
1112        add_var(&script_snippet, "head_name",
1113                opts->head_name ? opts->head_name : "detached HEAD");
1114        add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
1115        add_var(&script_snippet, "onto", opts->onto ?
1116                oid_to_hex(&opts->onto->object.oid) : NULL);
1117        add_var(&script_snippet, "onto_name", opts->onto_name);
1118        add_var(&script_snippet, "revisions", opts->revisions);
1119        add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
1120                oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
1121        add_var(&script_snippet, "GIT_QUIET",
1122                opts->flags & REBASE_NO_QUIET ? "" : "t");
1123        sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
1124        add_var(&script_snippet, "git_am_opt", buf.buf);
1125        strbuf_release(&buf);
1126        add_var(&script_snippet, "verbose",
1127                opts->flags & REBASE_VERBOSE ? "t" : "");
1128        add_var(&script_snippet, "diffstat",
1129                opts->flags & REBASE_DIFFSTAT ? "t" : "");
1130        add_var(&script_snippet, "force_rebase",
1131                opts->flags & REBASE_FORCE ? "t" : "");
1132        if (opts->switch_to)
1133                add_var(&script_snippet, "switch_to", opts->switch_to);
1134        add_var(&script_snippet, "action", opts->action ? opts->action : "");
1135        add_var(&script_snippet, "signoff", opts->signoff ? "--signoff" : "");
1136        add_var(&script_snippet, "allow_rerere_autoupdate",
1137                opts->allow_rerere_autoupdate ?
1138                        opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
1139                        "--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
1140        add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
1141        add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
1142        add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
1143        add_var(&script_snippet, "cmd", opts->cmd);
1144        add_var(&script_snippet, "allow_empty_message",
1145                opts->allow_empty_message ?  "--allow-empty-message" : "");
1146        add_var(&script_snippet, "rebase_merges",
1147                opts->rebase_merges ? "t" : "");
1148        add_var(&script_snippet, "rebase_cousins",
1149                opts->rebase_cousins ? "t" : "");
1150        add_var(&script_snippet, "strategy", opts->strategy);
1151        add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
1152        add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
1153        add_var(&script_snippet, "squash_onto",
1154                opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
1155        add_var(&script_snippet, "git_format_patch_opt",
1156                opts->git_format_patch_opt.buf);
1157
1158        if (is_interactive(opts) &&
1159            !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
1160                strbuf_addstr(&script_snippet,
1161                              "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
1162                opts->autosquash = 0;
1163        }
1164
1165        switch (opts->type) {
1166        case REBASE_PRESERVE_MERGES:
1167                backend = "git-rebase--preserve-merges";
1168                backend_func = "git_rebase__preserve_merges";
1169                break;
1170        default:
1171                BUG("Unhandled rebase type %d", opts->type);
1172                break;
1173        }
1174
1175        strbuf_addf(&script_snippet,
1176                    ". git-sh-setup && . %s && %s", backend, backend_func);
1177        argv[0] = script_snippet.buf;
1178
1179        status = run_command_v_opt(argv, RUN_USING_SHELL);
1180finished_rebase:
1181        if (opts->dont_finish_rebase)
1182                ; /* do nothing */
1183        else if (opts->type == REBASE_INTERACTIVE)
1184                ; /* interactive rebase cleans up after itself */
1185        else if (status == 0) {
1186                if (!file_exists(state_dir_path("stopped-sha", opts)))
1187                        finish_rebase(opts);
1188        } else if (status == 2) {
1189                struct strbuf dir = STRBUF_INIT;
1190
1191                apply_autostash(opts);
1192                strbuf_addstr(&dir, opts->state_dir);
1193                remove_dir_recursively(&dir, 0);
1194                strbuf_release(&dir);
1195                die("Nothing to do");
1196        }
1197
1198        strbuf_release(&script_snippet);
1199
1200        return status ? -1 : 0;
1201}
1202
1203static int rebase_config(const char *var, const char *value, void *data)
1204{
1205        struct rebase_options *opts = data;
1206
1207        if (!strcmp(var, "rebase.stat")) {
1208                if (git_config_bool(var, value))
1209                        opts->flags |= REBASE_DIFFSTAT;
1210                else
1211                        opts->flags &= ~REBASE_DIFFSTAT;
1212                return 0;
1213        }
1214
1215        if (!strcmp(var, "rebase.autosquash")) {
1216                opts->autosquash = git_config_bool(var, value);
1217                return 0;
1218        }
1219
1220        if (!strcmp(var, "commit.gpgsign")) {
1221                free(opts->gpg_sign_opt);
1222                opts->gpg_sign_opt = git_config_bool(var, value) ?
1223                        xstrdup("-S") : NULL;
1224                return 0;
1225        }
1226
1227        if (!strcmp(var, "rebase.autostash")) {
1228                opts->autostash = git_config_bool(var, value);
1229                return 0;
1230        }
1231
1232        if (!strcmp(var, "rebase.reschedulefailedexec")) {
1233                opts->reschedule_failed_exec = git_config_bool(var, value);
1234                return 0;
1235        }
1236
1237        if (!strcmp(var, "rebase.usebuiltin")) {
1238                opts->use_legacy_rebase = !git_config_bool(var, value);
1239                return 0;
1240        }
1241
1242        return git_default_config(var, value, data);
1243}
1244
1245/*
1246 * Determines whether the commits in from..to are linear, i.e. contain
1247 * no merge commits. This function *expects* `from` to be an ancestor of
1248 * `to`.
1249 */
1250static int is_linear_history(struct commit *from, struct commit *to)
1251{
1252        while (to && to != from) {
1253                parse_commit(to);
1254                if (!to->parents)
1255                        return 1;
1256                if (to->parents->next)
1257                        return 0;
1258                to = to->parents->item;
1259        }
1260        return 1;
1261}
1262
1263static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
1264                            struct object_id *merge_base)
1265{
1266        struct commit *head = lookup_commit(the_repository, head_oid);
1267        struct commit_list *merge_bases;
1268        int res;
1269
1270        if (!head)
1271                return 0;
1272
1273        merge_bases = get_merge_bases(onto, head);
1274        if (merge_bases && !merge_bases->next) {
1275                oidcpy(merge_base, &merge_bases->item->object.oid);
1276                res = oideq(merge_base, &onto->object.oid);
1277        } else {
1278                oidcpy(merge_base, &null_oid);
1279                res = 0;
1280        }
1281        free_commit_list(merge_bases);
1282        return res && is_linear_history(onto, head);
1283}
1284
1285/* -i followed by -m is still -i */
1286static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
1287{
1288        struct rebase_options *opts = opt->value;
1289
1290        BUG_ON_OPT_NEG(unset);
1291        BUG_ON_OPT_ARG(arg);
1292
1293        if (!is_interactive(opts))
1294                opts->type = REBASE_MERGE;
1295
1296        return 0;
1297}
1298
1299/* -i followed by -p is still explicitly interactive, but -p alone is not */
1300static int parse_opt_interactive(const struct option *opt, const char *arg,
1301                                 int unset)
1302{
1303        struct rebase_options *opts = opt->value;
1304
1305        BUG_ON_OPT_NEG(unset);
1306        BUG_ON_OPT_ARG(arg);
1307
1308        opts->type = REBASE_INTERACTIVE;
1309        opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
1310
1311        return 0;
1312}
1313
1314static void NORETURN error_on_missing_default_upstream(void)
1315{
1316        struct branch *current_branch = branch_get(NULL);
1317
1318        printf(_("%s\n"
1319                 "Please specify which branch you want to rebase against.\n"
1320                 "See git-rebase(1) for details.\n"
1321                 "\n"
1322                 "    git rebase '<branch>'\n"
1323                 "\n"),
1324                current_branch ? _("There is no tracking information for "
1325                        "the current branch.") :
1326                        _("You are not currently on a branch."));
1327
1328        if (current_branch) {
1329                const char *remote = current_branch->remote_name;
1330
1331                if (!remote)
1332                        remote = _("<remote>");
1333
1334                printf(_("If you wish to set tracking information for this "
1335                         "branch you can do so with:\n"
1336                         "\n"
1337                         "    git branch --set-upstream-to=%s/<branch> %s\n"
1338                         "\n"),
1339                       remote, current_branch->name);
1340        }
1341        exit(1);
1342}
1343
1344static void set_reflog_action(struct rebase_options *options)
1345{
1346        const char *env;
1347        struct strbuf buf = STRBUF_INIT;
1348
1349        if (!is_interactive(options))
1350                return;
1351
1352        env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
1353        if (env && strcmp("rebase", env))
1354                return; /* only override it if it is "rebase" */
1355
1356        strbuf_addf(&buf, "rebase -i (%s)", options->action);
1357        setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
1358        strbuf_release(&buf);
1359}
1360
1361static int check_exec_cmd(const char *cmd)
1362{
1363        if (strchr(cmd, '\n'))
1364                return error(_("exec commands cannot contain newlines"));
1365
1366        /* Does the command consist purely of whitespace? */
1367        if (!cmd[strspn(cmd, " \t\r\f\v")])
1368                return error(_("empty exec command"));
1369
1370        return 0;
1371}
1372
1373
1374int cmd_rebase(int argc, const char **argv, const char *prefix)
1375{
1376        struct rebase_options options = REBASE_OPTIONS_INIT;
1377        const char *branch_name;
1378        int ret, flags, total_argc, in_progress = 0;
1379        int ok_to_skip_pre_rebase = 0;
1380        struct strbuf msg = STRBUF_INIT;
1381        struct strbuf revisions = STRBUF_INIT;
1382        struct strbuf buf = STRBUF_INIT;
1383        struct object_id merge_base;
1384        enum action action = ACTION_NONE;
1385        const char *gpg_sign = NULL;
1386        struct string_list exec = STRING_LIST_INIT_NODUP;
1387        const char *rebase_merges = NULL;
1388        int fork_point = -1;
1389        struct string_list strategy_options = STRING_LIST_INIT_NODUP;
1390        struct object_id squash_onto;
1391        char *squash_onto_name = NULL;
1392        int reschedule_failed_exec = -1;
1393        struct option builtin_rebase_options[] = {
1394                OPT_STRING(0, "onto", &options.onto_name,
1395                           N_("revision"),
1396                           N_("rebase onto given branch instead of upstream")),
1397                OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
1398                         N_("allow pre-rebase hook to run")),
1399                OPT_NEGBIT('q', "quiet", &options.flags,
1400                           N_("be quiet. implies --no-stat"),
1401                           REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
1402                OPT_BIT('v', "verbose", &options.flags,
1403                        N_("display a diffstat of what changed upstream"),
1404                        REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
1405                {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
1406                        N_("do not show diffstat of what changed upstream"),
1407                        PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
1408                OPT_BOOL(0, "signoff", &options.signoff,
1409                         N_("add a Signed-off-by: line to each commit")),
1410                OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
1411                                  NULL, N_("passed to 'git am'"),
1412                                  PARSE_OPT_NOARG),
1413                OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
1414                                  &options.git_am_opts, NULL,
1415                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
1416                OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
1417                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
1418                OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
1419                                  N_("passed to 'git apply'"), 0),
1420                OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
1421                                  N_("action"), N_("passed to 'git apply'"), 0),
1422                OPT_BIT('f', "force-rebase", &options.flags,
1423                        N_("cherry-pick all commits, even if unchanged"),
1424                        REBASE_FORCE),
1425                OPT_BIT(0, "no-ff", &options.flags,
1426                        N_("cherry-pick all commits, even if unchanged"),
1427                        REBASE_FORCE),
1428                OPT_CMDMODE(0, "continue", &action, N_("continue"),
1429                            ACTION_CONTINUE),
1430                OPT_CMDMODE(0, "skip", &action,
1431                            N_("skip current patch and continue"), ACTION_SKIP),
1432                OPT_CMDMODE(0, "abort", &action,
1433                            N_("abort and check out the original branch"),
1434                            ACTION_ABORT),
1435                OPT_CMDMODE(0, "quit", &action,
1436                            N_("abort but keep HEAD where it is"), ACTION_QUIT),
1437                OPT_CMDMODE(0, "edit-todo", &action, N_("edit the todo list "
1438                            "during an interactive rebase"), ACTION_EDIT_TODO),
1439                OPT_CMDMODE(0, "show-current-patch", &action,
1440                            N_("show the patch file being applied or merged"),
1441                            ACTION_SHOW_CURRENT_PATCH),
1442                { OPTION_CALLBACK, 'm', "merge", &options, NULL,
1443                        N_("use merging strategies to rebase"),
1444                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1445                        parse_opt_merge },
1446                { OPTION_CALLBACK, 'i', "interactive", &options, NULL,
1447                        N_("let the user edit the list of commits to rebase"),
1448                        PARSE_OPT_NOARG | PARSE_OPT_NONEG,
1449                        parse_opt_interactive },
1450                OPT_SET_INT('p', "preserve-merges", &options.type,
1451                            N_("(DEPRECATED) try to recreate merges instead of "
1452                               "ignoring them"), REBASE_PRESERVE_MERGES),
1453                OPT_RERERE_AUTOUPDATE(&options.allow_rerere_autoupdate),
1454                OPT_BOOL('k', "keep-empty", &options.keep_empty,
1455                         N_("preserve empty commits during rebase")),
1456                OPT_BOOL(0, "autosquash", &options.autosquash,
1457                         N_("move commits that begin with "
1458                            "squash!/fixup! under -i")),
1459                { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
1460                        N_("GPG-sign commits"),
1461                        PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
1462                OPT_BOOL(0, "autostash", &options.autostash,
1463                         N_("automatically stash/stash pop before and after")),
1464                OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
1465                                N_("add exec lines after each commit of the "
1466                                   "editable list")),
1467                OPT_BOOL(0, "allow-empty-message",
1468                         &options.allow_empty_message,
1469                         N_("allow rebasing commits with empty messages")),
1470                {OPTION_STRING, 'r', "rebase-merges", &rebase_merges,
1471                        N_("mode"),
1472                        N_("try to rebase merges instead of skipping them"),
1473                        PARSE_OPT_OPTARG, NULL, (intptr_t)""},
1474                OPT_BOOL(0, "fork-point", &fork_point,
1475                         N_("use 'merge-base --fork-point' to refine upstream")),
1476                OPT_STRING('s', "strategy", &options.strategy,
1477                           N_("strategy"), N_("use the given merge strategy")),
1478                OPT_STRING_LIST('X', "strategy-option", &strategy_options,
1479                                N_("option"),
1480                                N_("pass the argument through to the merge "
1481                                   "strategy")),
1482                OPT_BOOL(0, "root", &options.root,
1483                         N_("rebase all reachable commits up to the root(s)")),
1484                OPT_BOOL(0, "reschedule-failed-exec",
1485                         &reschedule_failed_exec,
1486                         N_("automatically re-schedule any `exec` that fails")),
1487                OPT_END(),
1488        };
1489        int i;
1490
1491        if (argc == 2 && !strcmp(argv[1], "-h"))
1492                usage_with_options(builtin_rebase_usage,
1493                                   builtin_rebase_options);
1494
1495        prefix = setup_git_directory();
1496        trace_repo_setup(prefix);
1497        setup_work_tree();
1498
1499        options.allow_empty_message = 1;
1500        git_config(rebase_config, &options);
1501
1502        if (options.use_legacy_rebase ||
1503            !git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1))
1504                warning(_("the rebase.useBuiltin support has been removed!\n"
1505                          "See its entry in 'git help config' for details."));
1506
1507        strbuf_reset(&buf);
1508        strbuf_addf(&buf, "%s/applying", apply_dir());
1509        if(file_exists(buf.buf))
1510                die(_("It looks like 'git am' is in progress. Cannot rebase."));
1511
1512        if (is_directory(apply_dir())) {
1513                options.type = REBASE_AM;
1514                options.state_dir = apply_dir();
1515        } else if (is_directory(merge_dir())) {
1516                strbuf_reset(&buf);
1517                strbuf_addf(&buf, "%s/rewritten", merge_dir());
1518                if (is_directory(buf.buf)) {
1519                        options.type = REBASE_PRESERVE_MERGES;
1520                        options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1521                } else {
1522                        strbuf_reset(&buf);
1523                        strbuf_addf(&buf, "%s/interactive", merge_dir());
1524                        if(file_exists(buf.buf)) {
1525                                options.type = REBASE_INTERACTIVE;
1526                                options.flags |= REBASE_INTERACTIVE_EXPLICIT;
1527                        } else
1528                                options.type = REBASE_MERGE;
1529                }
1530                options.state_dir = merge_dir();
1531        }
1532
1533        if (options.type != REBASE_UNSPECIFIED)
1534                in_progress = 1;
1535
1536        total_argc = argc;
1537        argc = parse_options(argc, argv, prefix,
1538                             builtin_rebase_options,
1539                             builtin_rebase_usage, 0);
1540
1541        if (action != ACTION_NONE && total_argc != 2) {
1542                usage_with_options(builtin_rebase_usage,
1543                                   builtin_rebase_options);
1544        }
1545
1546        if (argc > 2)
1547                usage_with_options(builtin_rebase_usage,
1548                                   builtin_rebase_options);
1549
1550        if (options.type == REBASE_PRESERVE_MERGES)
1551                warning(_("git rebase --preserve-merges is deprecated. "
1552                          "Use --rebase-merges instead."));
1553
1554        if (action != ACTION_NONE && !in_progress)
1555                die(_("No rebase in progress?"));
1556        setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
1557
1558        if (action == ACTION_EDIT_TODO && !is_interactive(&options))
1559                die(_("The --edit-todo action can only be used during "
1560                      "interactive rebase."));
1561
1562        if (trace2_is_enabled()) {
1563                if (is_interactive(&options))
1564                        trace2_cmd_mode("interactive");
1565                else if (exec.nr)
1566                        trace2_cmd_mode("interactive-exec");
1567                else
1568                        trace2_cmd_mode(action_names[action]);
1569        }
1570
1571        switch (action) {
1572        case ACTION_CONTINUE: {
1573                struct object_id head;
1574                struct lock_file lock_file = LOCK_INIT;
1575                int fd;
1576
1577                options.action = "continue";
1578                set_reflog_action(&options);
1579
1580                /* Sanity check */
1581                if (get_oid("HEAD", &head))
1582                        die(_("Cannot read HEAD"));
1583
1584                fd = hold_locked_index(&lock_file, 0);
1585                if (repo_read_index(the_repository) < 0)
1586                        die(_("could not read index"));
1587                refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
1588                              NULL);
1589                if (0 <= fd)
1590                        repo_update_index_if_able(the_repository, &lock_file);
1591                rollback_lock_file(&lock_file);
1592
1593                if (has_unstaged_changes(the_repository, 1)) {
1594                        puts(_("You must edit all merge conflicts and then\n"
1595                               "mark them as resolved using git add"));
1596                        exit(1);
1597                }
1598                if (read_basic_state(&options))
1599                        exit(1);
1600                goto run_rebase;
1601        }
1602        case ACTION_SKIP: {
1603                struct string_list merge_rr = STRING_LIST_INIT_DUP;
1604
1605                options.action = "skip";
1606                set_reflog_action(&options);
1607
1608                rerere_clear(the_repository, &merge_rr);
1609                string_list_clear(&merge_rr, 1);
1610
1611                if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
1612                               NULL, NULL) < 0)
1613                        die(_("could not discard worktree changes"));
1614                remove_branch_state(the_repository, 0);
1615                if (read_basic_state(&options))
1616                        exit(1);
1617                goto run_rebase;
1618        }
1619        case ACTION_ABORT: {
1620                struct string_list merge_rr = STRING_LIST_INIT_DUP;
1621                options.action = "abort";
1622                set_reflog_action(&options);
1623
1624                rerere_clear(the_repository, &merge_rr);
1625                string_list_clear(&merge_rr, 1);
1626
1627                if (read_basic_state(&options))
1628                        exit(1);
1629                if (reset_head(&options.orig_head, "reset",
1630                               options.head_name, RESET_HEAD_HARD,
1631                               NULL, NULL) < 0)
1632                        die(_("could not move back to %s"),
1633                            oid_to_hex(&options.orig_head));
1634                remove_branch_state(the_repository, 0);
1635                ret = !!finish_rebase(&options);
1636                goto cleanup;
1637        }
1638        case ACTION_QUIT: {
1639                if (options.type == REBASE_INTERACTIVE) {
1640                        struct replay_opts replay = REPLAY_OPTS_INIT;
1641
1642                        replay.action = REPLAY_INTERACTIVE_REBASE;
1643                        ret = !!sequencer_remove_state(&replay);
1644                } else {
1645                        strbuf_reset(&buf);
1646                        strbuf_addstr(&buf, options.state_dir);
1647                        ret = !!remove_dir_recursively(&buf, 0);
1648                        if (ret)
1649                                error(_("could not remove '%s'"),
1650                                       options.state_dir);
1651                }
1652                goto cleanup;
1653        }
1654        case ACTION_EDIT_TODO:
1655                options.action = "edit-todo";
1656                options.dont_finish_rebase = 1;
1657                goto run_rebase;
1658        case ACTION_SHOW_CURRENT_PATCH:
1659                options.action = "show-current-patch";
1660                options.dont_finish_rebase = 1;
1661                goto run_rebase;
1662        case ACTION_NONE:
1663                break;
1664        default:
1665                BUG("action: %d", action);
1666        }
1667
1668        /* Make sure no rebase is in progress */
1669        if (in_progress) {
1670                const char *last_slash = strrchr(options.state_dir, '/');
1671                const char *state_dir_base =
1672                        last_slash ? last_slash + 1 : options.state_dir;
1673                const char *cmd_live_rebase =
1674                        "git rebase (--continue | --abort | --skip)";
1675                strbuf_reset(&buf);
1676                strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
1677                die(_("It seems that there is already a %s directory, and\n"
1678                      "I wonder if you are in the middle of another rebase.  "
1679                      "If that is the\n"
1680                      "case, please try\n\t%s\n"
1681                      "If that is not the case, please\n\t%s\n"
1682                      "and run me again.  I am stopping in case you still "
1683                      "have something\n"
1684                      "valuable there.\n"),
1685                    state_dir_base, cmd_live_rebase, buf.buf);
1686        }
1687
1688        for (i = 0; i < options.git_am_opts.argc; i++) {
1689                const char *option = options.git_am_opts.argv[i], *p;
1690                if (!strcmp(option, "--committer-date-is-author-date") ||
1691                    !strcmp(option, "--ignore-date") ||
1692                    !strcmp(option, "--whitespace=fix") ||
1693                    !strcmp(option, "--whitespace=strip"))
1694                        options.flags |= REBASE_FORCE;
1695                else if (skip_prefix(option, "-C", &p)) {
1696                        while (*p)
1697                                if (!isdigit(*(p++)))
1698                                        die(_("switch `C' expects a "
1699                                              "numerical value"));
1700                } else if (skip_prefix(option, "--whitespace=", &p)) {
1701                        if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
1702                            strcmp(p, "error") && strcmp(p, "error-all"))
1703                                die("Invalid whitespace option: '%s'", p);
1704                }
1705        }
1706
1707        for (i = 0; i < exec.nr; i++)
1708                if (check_exec_cmd(exec.items[i].string))
1709                        exit(1);
1710
1711        if (!(options.flags & REBASE_NO_QUIET))
1712                argv_array_push(&options.git_am_opts, "-q");
1713
1714        if (options.keep_empty)
1715                imply_interactive(&options, "--keep-empty");
1716
1717        if (gpg_sign) {
1718                free(options.gpg_sign_opt);
1719                options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
1720        }
1721
1722        if (exec.nr) {
1723                int i;
1724
1725                imply_interactive(&options, "--exec");
1726
1727                strbuf_reset(&buf);
1728                for (i = 0; i < exec.nr; i++)
1729                        strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
1730                options.cmd = xstrdup(buf.buf);
1731        }
1732
1733        if (rebase_merges) {
1734                if (!*rebase_merges)
1735                        ; /* default mode; do nothing */
1736                else if (!strcmp("rebase-cousins", rebase_merges))
1737                        options.rebase_cousins = 1;
1738                else if (strcmp("no-rebase-cousins", rebase_merges))
1739                        die(_("Unknown mode: %s"), rebase_merges);
1740                options.rebase_merges = 1;
1741                imply_interactive(&options, "--rebase-merges");
1742        }
1743
1744        if (strategy_options.nr) {
1745                int i;
1746
1747                if (!options.strategy)
1748                        options.strategy = "recursive";
1749
1750                strbuf_reset(&buf);
1751                for (i = 0; i < strategy_options.nr; i++)
1752                        strbuf_addf(&buf, " --%s",
1753                                    strategy_options.items[i].string);
1754                options.strategy_opts = xstrdup(buf.buf);
1755        }
1756
1757        if (options.strategy) {
1758                options.strategy = xstrdup(options.strategy);
1759                switch (options.type) {
1760                case REBASE_AM:
1761                        die(_("--strategy requires --merge or --interactive"));
1762                case REBASE_MERGE:
1763                case REBASE_INTERACTIVE:
1764                case REBASE_PRESERVE_MERGES:
1765                        /* compatible */
1766                        break;
1767                case REBASE_UNSPECIFIED:
1768                        options.type = REBASE_MERGE;
1769                        break;
1770                default:
1771                        BUG("unhandled rebase type (%d)", options.type);
1772                }
1773        }
1774
1775        if (options.type == REBASE_MERGE)
1776                imply_interactive(&options, "--merge");
1777
1778        if (options.root && !options.onto_name)
1779                imply_interactive(&options, "--root without --onto");
1780
1781        if (isatty(2) && options.flags & REBASE_NO_QUIET)
1782                strbuf_addstr(&options.git_format_patch_opt, " --progress");
1783
1784        switch (options.type) {
1785        case REBASE_MERGE:
1786        case REBASE_INTERACTIVE:
1787        case REBASE_PRESERVE_MERGES:
1788                options.state_dir = merge_dir();
1789                break;
1790        case REBASE_AM:
1791                options.state_dir = apply_dir();
1792                break;
1793        default:
1794                /* the default rebase backend is `--am` */
1795                options.type = REBASE_AM;
1796                options.state_dir = apply_dir();
1797                break;
1798        }
1799
1800        if (reschedule_failed_exec > 0 && !is_interactive(&options))
1801                die(_("--reschedule-failed-exec requires "
1802                      "--exec or --interactive"));
1803        if (reschedule_failed_exec >= 0)
1804                options.reschedule_failed_exec = reschedule_failed_exec;
1805
1806        if (options.git_am_opts.argc) {
1807                /* all am options except -q are compatible only with --am */
1808                for (i = options.git_am_opts.argc - 1; i >= 0; i--)
1809                        if (strcmp(options.git_am_opts.argv[i], "-q"))
1810                                break;
1811
1812                if (is_interactive(&options) && i >= 0)
1813                        die(_("cannot combine am options with either "
1814                              "interactive or merge options"));
1815        }
1816
1817        if (options.signoff) {
1818                if (options.type == REBASE_PRESERVE_MERGES)
1819                        die("cannot combine '--signoff' with "
1820                            "'--preserve-merges'");
1821                argv_array_push(&options.git_am_opts, "--signoff");
1822                options.flags |= REBASE_FORCE;
1823        }
1824
1825        if (options.type == REBASE_PRESERVE_MERGES) {
1826                /*
1827                 * Note: incompatibility with --signoff handled in signoff block above
1828                 * Note: incompatibility with --interactive is just a strong warning;
1829                 *       git-rebase.txt caveats with "unless you know what you are doing"
1830                 */
1831                if (options.rebase_merges)
1832                        die(_("cannot combine '--preserve-merges' with "
1833                              "'--rebase-merges'"));
1834
1835                if (options.reschedule_failed_exec)
1836                        die(_("error: cannot combine '--preserve-merges' with "
1837                              "'--reschedule-failed-exec'"));
1838        }
1839
1840        if (options.rebase_merges) {
1841                if (strategy_options.nr)
1842                        die(_("cannot combine '--rebase-merges' with "
1843                              "'--strategy-option'"));
1844                if (options.strategy)
1845                        die(_("cannot combine '--rebase-merges' with "
1846                              "'--strategy'"));
1847        }
1848
1849        if (!options.root) {
1850                if (argc < 1) {
1851                        struct branch *branch;
1852
1853                        branch = branch_get(NULL);
1854                        options.upstream_name = branch_get_upstream(branch,
1855                                                                    NULL);
1856                        if (!options.upstream_name)
1857                                error_on_missing_default_upstream();
1858                        if (fork_point < 0)
1859                                fork_point = 1;
1860                } else {
1861                        options.upstream_name = argv[0];
1862                        argc--;
1863                        argv++;
1864                        if (!strcmp(options.upstream_name, "-"))
1865                                options.upstream_name = "@{-1}";
1866                }
1867                options.upstream = peel_committish(options.upstream_name);
1868                if (!options.upstream)
1869                        die(_("invalid upstream '%s'"), options.upstream_name);
1870                options.upstream_arg = options.upstream_name;
1871        } else {
1872                if (!options.onto_name) {
1873                        if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
1874                                        &squash_onto, NULL, NULL) < 0)
1875                                die(_("Could not create new root commit"));
1876                        options.squash_onto = &squash_onto;
1877                        options.onto_name = squash_onto_name =
1878                                xstrdup(oid_to_hex(&squash_onto));
1879                }
1880                options.upstream_name = NULL;
1881                options.upstream = NULL;
1882                if (argc > 1)
1883                        usage_with_options(builtin_rebase_usage,
1884                                           builtin_rebase_options);
1885                options.upstream_arg = "--root";
1886        }
1887
1888        /* Make sure the branch to rebase onto is valid. */
1889        if (!options.onto_name)
1890                options.onto_name = options.upstream_name;
1891        if (strstr(options.onto_name, "...")) {
1892                if (get_oid_mb(options.onto_name, &merge_base) < 0)
1893                        die(_("'%s': need exactly one merge base"),
1894                            options.onto_name);
1895                options.onto = lookup_commit_or_die(&merge_base,
1896                                                    options.onto_name);
1897        } else {
1898                options.onto = peel_committish(options.onto_name);
1899                if (!options.onto)
1900                        die(_("Does not point to a valid commit '%s'"),
1901                                options.onto_name);
1902        }
1903
1904        /*
1905         * If the branch to rebase is given, that is the branch we will rebase
1906         * branch_name -- branch/commit being rebased, or
1907         *                HEAD (already detached)
1908         * orig_head -- commit object name of tip of the branch before rebasing
1909         * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
1910         */
1911        if (argc == 1) {
1912                /* Is it "rebase other branchname" or "rebase other commit"? */
1913                branch_name = argv[0];
1914                options.switch_to = argv[0];
1915
1916                /* Is it a local branch? */
1917                strbuf_reset(&buf);
1918                strbuf_addf(&buf, "refs/heads/%s", branch_name);
1919                if (!read_ref(buf.buf, &options.orig_head))
1920                        options.head_name = xstrdup(buf.buf);
1921                /* If not is it a valid ref (branch or commit)? */
1922                else if (!get_oid(branch_name, &options.orig_head))
1923                        options.head_name = NULL;
1924                else
1925                        die(_("fatal: no such branch/commit '%s'"),
1926                            branch_name);
1927        } else if (argc == 0) {
1928                /* Do not need to switch branches, we are already on it. */
1929                options.head_name =
1930                        xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
1931                                         &flags));
1932                if (!options.head_name)
1933                        die(_("No such ref: %s"), "HEAD");
1934                if (flags & REF_ISSYMREF) {
1935                        if (!skip_prefix(options.head_name,
1936                                         "refs/heads/", &branch_name))
1937                                branch_name = options.head_name;
1938
1939                } else {
1940                        FREE_AND_NULL(options.head_name);
1941                        branch_name = "HEAD";
1942                }
1943                if (get_oid("HEAD", &options.orig_head))
1944                        die(_("Could not resolve HEAD to a revision"));
1945        } else
1946                BUG("unexpected number of arguments left to parse");
1947
1948        if (fork_point > 0) {
1949                struct commit *head =
1950                        lookup_commit_reference(the_repository,
1951                                                &options.orig_head);
1952                options.restrict_revision =
1953                        get_fork_point(options.upstream_name, head);
1954        }
1955
1956        if (repo_read_index(the_repository) < 0)
1957                die(_("could not read index"));
1958
1959        if (options.autostash) {
1960                struct lock_file lock_file = LOCK_INIT;
1961                int fd;
1962
1963                fd = hold_locked_index(&lock_file, 0);
1964                refresh_cache(REFRESH_QUIET);
1965                if (0 <= fd)
1966                        repo_update_index_if_able(the_repository, &lock_file);
1967                rollback_lock_file(&lock_file);
1968
1969                if (has_unstaged_changes(the_repository, 1) ||
1970                    has_uncommitted_changes(the_repository, 1)) {
1971                        const char *autostash =
1972                                state_dir_path("autostash", &options);
1973                        struct child_process stash = CHILD_PROCESS_INIT;
1974                        struct object_id oid;
1975                        struct commit *head =
1976                                lookup_commit_reference(the_repository,
1977                                                        &options.orig_head);
1978
1979                        argv_array_pushl(&stash.args,
1980                                         "stash", "create", "autostash", NULL);
1981                        stash.git_cmd = 1;
1982                        stash.no_stdin = 1;
1983                        strbuf_reset(&buf);
1984                        if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
1985                                die(_("Cannot autostash"));
1986                        strbuf_trim_trailing_newline(&buf);
1987                        if (get_oid(buf.buf, &oid))
1988                                die(_("Unexpected stash response: '%s'"),
1989                                    buf.buf);
1990                        strbuf_reset(&buf);
1991                        strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
1992
1993                        if (safe_create_leading_directories_const(autostash))
1994                                die(_("Could not create directory for '%s'"),
1995                                    options.state_dir);
1996                        write_file(autostash, "%s", oid_to_hex(&oid));
1997                        printf(_("Created autostash: %s\n"), buf.buf);
1998                        if (reset_head(&head->object.oid, "reset --hard",
1999                                       NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
2000                                die(_("could not reset --hard"));
2001                        printf(_("HEAD is now at %s"),
2002                               find_unique_abbrev(&head->object.oid,
2003                                                  DEFAULT_ABBREV));
2004                        strbuf_reset(&buf);
2005                        pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
2006                        if (buf.len > 0)
2007                                printf(" %s", buf.buf);
2008                        putchar('\n');
2009
2010                        if (discard_index(the_repository->index) < 0 ||
2011                                repo_read_index(the_repository) < 0)
2012                                die(_("could not read index"));
2013                }
2014        }
2015
2016        if (require_clean_work_tree(the_repository, "rebase",
2017                                    _("Please commit or stash them."), 1, 1)) {
2018                ret = 1;
2019                goto cleanup;
2020        }
2021
2022        /*
2023         * Now we are rebasing commits upstream..orig_head (or with --root,
2024         * everything leading up to orig_head) on top of onto.
2025         */
2026
2027        /*
2028         * Check if we are already based on onto with linear history,
2029         * but this should be done only when upstream and onto are the same
2030         * and if this is not an interactive rebase.
2031         */
2032        if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
2033            !is_interactive(&options) && !options.restrict_revision &&
2034            options.upstream &&
2035            !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
2036                int flag;
2037
2038                if (!(options.flags & REBASE_FORCE)) {
2039                        /* Lazily switch to the target branch if needed... */
2040                        if (options.switch_to) {
2041                                struct object_id oid;
2042
2043                                if (get_oid(options.switch_to, &oid) < 0) {
2044                                        ret = !!error(_("could not parse '%s'"),
2045                                                      options.switch_to);
2046                                        goto cleanup;
2047                                }
2048
2049                                strbuf_reset(&buf);
2050                                strbuf_addf(&buf, "%s: checkout %s",
2051                                            getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
2052                                            options.switch_to);
2053                                if (reset_head(&oid, "checkout",
2054                                               options.head_name,
2055                                               RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2056                                               NULL, buf.buf) < 0) {
2057                                        ret = !!error(_("could not switch to "
2058                                                        "%s"),
2059                                                      options.switch_to);
2060                                        goto cleanup;
2061                                }
2062                        }
2063
2064                        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."));
2069                        else
2070                                printf(_("Current branch %s is up to date.\n"),
2071                                       branch_name);
2072                        ret = !!finish_rebase(&options);
2073                        goto cleanup;
2074                } else if (!(options.flags & REBASE_NO_QUIET))
2075                        ; /* be quiet */
2076                else if (!strcmp(branch_name, "HEAD") &&
2077                         resolve_ref_unsafe("HEAD", 0, NULL, &flag))
2078                        puts(_("HEAD is up to date, rebase forced."));
2079                else
2080                        printf(_("Current branch %s is up to date, rebase "
2081                                 "forced.\n"), branch_name);
2082        }
2083
2084        /* If a hook exists, give it a chance to interrupt*/
2085        if (!ok_to_skip_pre_rebase &&
2086            run_hook_le(NULL, "pre-rebase", options.upstream_arg,
2087                        argc ? argv[0] : NULL, NULL))
2088                die(_("The pre-rebase hook refused to rebase."));
2089
2090        if (options.flags & REBASE_DIFFSTAT) {
2091                struct diff_options opts;
2092
2093                if (options.flags & REBASE_VERBOSE) {
2094                        if (is_null_oid(&merge_base))
2095                                printf(_("Changes to %s:\n"),
2096                                       oid_to_hex(&options.onto->object.oid));
2097                        else
2098                                printf(_("Changes from %s to %s:\n"),
2099                                       oid_to_hex(&merge_base),
2100                                       oid_to_hex(&options.onto->object.oid));
2101                }
2102
2103                /* We want color (if set), but no pager */
2104                diff_setup(&opts);
2105                opts.stat_width = -1; /* use full terminal width */
2106                opts.stat_graph_width = -1; /* respect statGraphWidth config */
2107                opts.output_format |=
2108                        DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
2109                opts.detect_rename = DIFF_DETECT_RENAME;
2110                diff_setup_done(&opts);
2111                diff_tree_oid(is_null_oid(&merge_base) ?
2112                              the_hash_algo->empty_tree : &merge_base,
2113                              &options.onto->object.oid, "", &opts);
2114                diffcore_std(&opts);
2115                diff_flush(&opts);
2116        }
2117
2118        if (is_interactive(&options))
2119                goto run_rebase;
2120
2121        /* Detach HEAD and reset the tree */
2122        if (options.flags & REBASE_NO_QUIET)
2123                printf(_("First, rewinding head to replay your work on top of "
2124                         "it...\n"));
2125
2126        strbuf_addf(&msg, "%s: checkout %s",
2127                    getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
2128        if (reset_head(&options.onto->object.oid, "checkout", NULL,
2129                       RESET_HEAD_DETACH | RESET_ORIG_HEAD | 
2130                       RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
2131                       NULL, msg.buf))
2132                die(_("Could not detach HEAD"));
2133        strbuf_release(&msg);
2134
2135        /*
2136         * If the onto is a proper descendant of the tip of the branch, then
2137         * we just fast-forwarded.
2138         */
2139        strbuf_reset(&msg);
2140        if (oideq(&merge_base, &options.orig_head)) {
2141                printf(_("Fast-forwarded %s to %s.\n"),
2142                        branch_name, options.onto_name);
2143                strbuf_addf(&msg, "rebase finished: %s onto %s",
2144                        options.head_name ? options.head_name : "detached HEAD",
2145                        oid_to_hex(&options.onto->object.oid));
2146                reset_head(NULL, "Fast-forwarded", options.head_name,
2147                           RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
2148                strbuf_release(&msg);
2149                ret = !!finish_rebase(&options);
2150                goto cleanup;
2151        }
2152
2153        strbuf_addf(&revisions, "%s..%s",
2154                    options.root ? oid_to_hex(&options.onto->object.oid) :
2155                    (options.restrict_revision ?
2156                     oid_to_hex(&options.restrict_revision->object.oid) :
2157                     oid_to_hex(&options.upstream->object.oid)),
2158                    oid_to_hex(&options.orig_head));
2159
2160        options.revisions = revisions.buf;
2161
2162run_rebase:
2163        ret = !!run_specific_rebase(&options, action);
2164
2165cleanup:
2166        strbuf_release(&buf);
2167        strbuf_release(&revisions);
2168        free(options.head_name);
2169        free(options.gpg_sign_opt);
2170        free(options.cmd);
2171        free(squash_onto_name);
2172        return ret;
2173}