f9f9f8a77268cadde74e36c70821e25a1842ec01
   1#include "cache.h"
   2#include "sequencer.h"
   3#include "dir.h"
   4#include "object.h"
   5#include "commit.h"
   6#include "tag.h"
   7#include "run-command.h"
   8#include "exec_cmd.h"
   9#include "utf8.h"
  10#include "cache-tree.h"
  11#include "diff.h"
  12#include "revision.h"
  13#include "rerere.h"
  14#include "merge-recursive.h"
  15#include "refs.h"
  16#include "argv-array.h"
  17
  18#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
  19
  20const char sign_off_header[] = "Signed-off-by: ";
  21static const char cherry_picked_prefix[] = "(cherry picked from commit ";
  22
  23static int is_rfc2822_line(const char *buf, int len)
  24{
  25        int i;
  26
  27        for (i = 0; i < len; i++) {
  28                int ch = buf[i];
  29                if (ch == ':')
  30                        return 1;
  31                if (!isalnum(ch) && ch != '-')
  32                        break;
  33        }
  34
  35        return 0;
  36}
  37
  38static int is_cherry_picked_from_line(const char *buf, int len)
  39{
  40        /*
  41         * We only care that it looks roughly like (cherry picked from ...)
  42         */
  43        return len > strlen(cherry_picked_prefix) + 1 &&
  44                !prefixcmp(buf, cherry_picked_prefix) && buf[len - 1] == ')';
  45}
  46
  47static int has_conforming_footer(struct strbuf *sb, int ignore_footer)
  48{
  49        char prev;
  50        int i, k;
  51        int len = sb->len - ignore_footer;
  52        const char *buf = sb->buf;
  53
  54        /* footer must end with newline */
  55        if (!len || buf[len - 1] != '\n')
  56                return 0;
  57
  58        prev = '\0';
  59        for (i = len - 1; i > 0; i--) {
  60                char ch = buf[i];
  61                if (prev == '\n' && ch == '\n') /* paragraph break */
  62                        break;
  63                prev = ch;
  64        }
  65
  66        /* require at least one blank line */
  67        if (prev != '\n' || buf[i] != '\n')
  68                return 0;
  69
  70        /* advance to start of last paragraph */
  71        while (i < len - 1 && buf[i] == '\n')
  72                i++;
  73
  74        for (; i < len; i = k) {
  75                for (k = i; k < len && buf[k] != '\n'; k++)
  76                        ; /* do nothing */
  77                k++;
  78
  79                if (!is_rfc2822_line(buf + i, k - i - 1) &&
  80                    !is_cherry_picked_from_line(buf + i, k - i - 1))
  81                        return 0;
  82        }
  83        return 1;
  84}
  85
  86static void remove_sequencer_state(void)
  87{
  88        struct strbuf seq_dir = STRBUF_INIT;
  89
  90        strbuf_addf(&seq_dir, "%s", git_path(SEQ_DIR));
  91        remove_dir_recursively(&seq_dir, 0);
  92        strbuf_release(&seq_dir);
  93}
  94
  95static const char *action_name(const struct replay_opts *opts)
  96{
  97        return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
  98}
  99
 100static char *get_encoding(const char *message);
 101
 102struct commit_message {
 103        char *parent_label;
 104        const char *label;
 105        const char *subject;
 106        char *reencoded_message;
 107        const char *message;
 108};
 109
 110static int get_message(struct commit *commit, struct commit_message *out)
 111{
 112        const char *encoding;
 113        const char *abbrev, *subject;
 114        int abbrev_len, subject_len;
 115        char *q;
 116
 117        if (!commit->buffer)
 118                return -1;
 119        encoding = get_encoding(commit->buffer);
 120        if (!encoding)
 121                encoding = "UTF-8";
 122        if (!git_commit_encoding)
 123                git_commit_encoding = "UTF-8";
 124
 125        out->reencoded_message = NULL;
 126        out->message = commit->buffer;
 127        if (same_encoding(encoding, git_commit_encoding))
 128                out->reencoded_message = reencode_string(commit->buffer,
 129                                        git_commit_encoding, encoding);
 130        if (out->reencoded_message)
 131                out->message = out->reencoded_message;
 132
 133        abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
 134        abbrev_len = strlen(abbrev);
 135
 136        subject_len = find_commit_subject(out->message, &subject);
 137
 138        out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
 139                              strlen("... ") + subject_len + 1);
 140        q = out->parent_label;
 141        q = mempcpy(q, "parent of ", strlen("parent of "));
 142        out->label = q;
 143        q = mempcpy(q, abbrev, abbrev_len);
 144        q = mempcpy(q, "... ", strlen("... "));
 145        out->subject = q;
 146        q = mempcpy(q, subject, subject_len);
 147        *q = '\0';
 148        return 0;
 149}
 150
 151static void free_message(struct commit_message *msg)
 152{
 153        free(msg->parent_label);
 154        free(msg->reencoded_message);
 155}
 156
 157static char *get_encoding(const char *message)
 158{
 159        const char *p = message, *eol;
 160
 161        while (*p && *p != '\n') {
 162                for (eol = p + 1; *eol && *eol != '\n'; eol++)
 163                        ; /* do nothing */
 164                if (!prefixcmp(p, "encoding ")) {
 165                        char *result = xmalloc(eol - 8 - p);
 166                        strlcpy(result, p + 9, eol - 8 - p);
 167                        return result;
 168                }
 169                p = eol;
 170                if (*p == '\n')
 171                        p++;
 172        }
 173        return NULL;
 174}
 175
 176static void write_cherry_pick_head(struct commit *commit, const char *pseudoref)
 177{
 178        const char *filename;
 179        int fd;
 180        struct strbuf buf = STRBUF_INIT;
 181
 182        strbuf_addf(&buf, "%s\n", sha1_to_hex(commit->object.sha1));
 183
 184        filename = git_path("%s", pseudoref);
 185        fd = open(filename, O_WRONLY | O_CREAT, 0666);
 186        if (fd < 0)
 187                die_errno(_("Could not open '%s' for writing"), filename);
 188        if (write_in_full(fd, buf.buf, buf.len) != buf.len || close(fd))
 189                die_errno(_("Could not write to '%s'"), filename);
 190        strbuf_release(&buf);
 191}
 192
 193static void print_advice(int show_hint, struct replay_opts *opts)
 194{
 195        char *msg = getenv("GIT_CHERRY_PICK_HELP");
 196
 197        if (msg) {
 198                fprintf(stderr, "%s\n", msg);
 199                /*
 200                 * A conflict has occured but the porcelain
 201                 * (typically rebase --interactive) wants to take care
 202                 * of the commit itself so remove CHERRY_PICK_HEAD
 203                 */
 204                unlink(git_path("CHERRY_PICK_HEAD"));
 205                return;
 206        }
 207
 208        if (show_hint) {
 209                if (opts->no_commit)
 210                        advise(_("after resolving the conflicts, mark the corrected paths\n"
 211                                 "with 'git add <paths>' or 'git rm <paths>'"));
 212                else
 213                        advise(_("after resolving the conflicts, mark the corrected paths\n"
 214                                 "with 'git add <paths>' or 'git rm <paths>'\n"
 215                                 "and commit the result with 'git commit'"));
 216        }
 217}
 218
 219static void write_message(struct strbuf *msgbuf, const char *filename)
 220{
 221        static struct lock_file msg_file;
 222
 223        int msg_fd = hold_lock_file_for_update(&msg_file, filename,
 224                                               LOCK_DIE_ON_ERROR);
 225        if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
 226                die_errno(_("Could not write to %s"), filename);
 227        strbuf_release(msgbuf);
 228        if (commit_lock_file(&msg_file) < 0)
 229                die(_("Error wrapping up %s"), filename);
 230}
 231
 232static struct tree *empty_tree(void)
 233{
 234        return lookup_tree(EMPTY_TREE_SHA1_BIN);
 235}
 236
 237static int error_dirty_index(struct replay_opts *opts)
 238{
 239        if (read_cache_unmerged())
 240                return error_resolve_conflict(action_name(opts));
 241
 242        /* Different translation strings for cherry-pick and revert */
 243        if (opts->action == REPLAY_PICK)
 244                error(_("Your local changes would be overwritten by cherry-pick."));
 245        else
 246                error(_("Your local changes would be overwritten by revert."));
 247
 248        if (advice_commit_before_merge)
 249                advise(_("Commit your changes or stash them to proceed."));
 250        return -1;
 251}
 252
 253static int fast_forward_to(const unsigned char *to, const unsigned char *from)
 254{
 255        struct ref_lock *ref_lock;
 256
 257        read_cache();
 258        if (checkout_fast_forward(from, to, 1))
 259                exit(1); /* the callee should have complained already */
 260        ref_lock = lock_any_ref_for_update("HEAD", from, 0);
 261        return write_ref_sha1(ref_lock, to, "cherry-pick");
 262}
 263
 264static int do_recursive_merge(struct commit *base, struct commit *next,
 265                              const char *base_label, const char *next_label,
 266                              unsigned char *head, struct strbuf *msgbuf,
 267                              struct replay_opts *opts)
 268{
 269        struct merge_options o;
 270        struct tree *result, *next_tree, *base_tree, *head_tree;
 271        int clean, index_fd;
 272        const char **xopt;
 273        static struct lock_file index_lock;
 274
 275        index_fd = hold_locked_index(&index_lock, 1);
 276
 277        read_cache();
 278
 279        init_merge_options(&o);
 280        o.ancestor = base ? base_label : "(empty tree)";
 281        o.branch1 = "HEAD";
 282        o.branch2 = next ? next_label : "(empty tree)";
 283
 284        head_tree = parse_tree_indirect(head);
 285        next_tree = next ? next->tree : empty_tree();
 286        base_tree = base ? base->tree : empty_tree();
 287
 288        for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 289                parse_merge_opt(&o, *xopt);
 290
 291        clean = merge_trees(&o,
 292                            head_tree,
 293                            next_tree, base_tree, &result);
 294
 295        if (active_cache_changed &&
 296            (write_cache(index_fd, active_cache, active_nr) ||
 297             commit_locked_index(&index_lock)))
 298                /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 299                die(_("%s: Unable to write new index file"), action_name(opts));
 300        rollback_lock_file(&index_lock);
 301
 302        if (opts->signoff)
 303                append_signoff(msgbuf, 0);
 304
 305        if (!clean) {
 306                int i;
 307                strbuf_addstr(msgbuf, "\nConflicts:\n");
 308                for (i = 0; i < active_nr;) {
 309                        struct cache_entry *ce = active_cache[i++];
 310                        if (ce_stage(ce)) {
 311                                strbuf_addch(msgbuf, '\t');
 312                                strbuf_addstr(msgbuf, ce->name);
 313                                strbuf_addch(msgbuf, '\n');
 314                                while (i < active_nr && !strcmp(ce->name,
 315                                                active_cache[i]->name))
 316                                        i++;
 317                        }
 318                }
 319        }
 320
 321        return !clean;
 322}
 323
 324static int is_index_unchanged(void)
 325{
 326        unsigned char head_sha1[20];
 327        struct commit *head_commit;
 328
 329        if (!resolve_ref_unsafe("HEAD", head_sha1, 1, NULL))
 330                return error(_("Could not resolve HEAD commit\n"));
 331
 332        head_commit = lookup_commit(head_sha1);
 333
 334        /*
 335         * If head_commit is NULL, check_commit, called from
 336         * lookup_commit, would have indicated that head_commit is not
 337         * a commit object already.  parse_commit() will return failure
 338         * without further complaints in such a case.  Otherwise, if
 339         * the commit is invalid, parse_commit() will complain.  So
 340         * there is nothing for us to say here.  Just return failure.
 341         */
 342        if (parse_commit(head_commit))
 343                return -1;
 344
 345        if (!active_cache_tree)
 346                active_cache_tree = cache_tree();
 347
 348        if (!cache_tree_fully_valid(active_cache_tree))
 349                if (cache_tree_update(active_cache_tree, active_cache,
 350                                  active_nr, 0))
 351                        return error(_("Unable to update cache tree\n"));
 352
 353        return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.sha1);
 354}
 355
 356/*
 357 * If we are cherry-pick, and if the merge did not result in
 358 * hand-editing, we will hit this commit and inherit the original
 359 * author date and name.
 360 * If we are revert, or if our cherry-pick results in a hand merge,
 361 * we had better say that the current user is responsible for that.
 362 */
 363static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 364                          int allow_empty)
 365{
 366        struct argv_array array;
 367        int rc;
 368
 369        argv_array_init(&array);
 370        argv_array_push(&array, "commit");
 371        argv_array_push(&array, "-n");
 372
 373        if (opts->signoff)
 374                argv_array_push(&array, "-s");
 375        if (!opts->edit) {
 376                argv_array_push(&array, "-F");
 377                argv_array_push(&array, defmsg);
 378        }
 379
 380        if (allow_empty)
 381                argv_array_push(&array, "--allow-empty");
 382
 383        if (opts->allow_empty_message)
 384                argv_array_push(&array, "--allow-empty-message");
 385
 386        rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 387        argv_array_clear(&array);
 388        return rc;
 389}
 390
 391static int is_original_commit_empty(struct commit *commit)
 392{
 393        const unsigned char *ptree_sha1;
 394
 395        if (parse_commit(commit))
 396                return error(_("Could not parse commit %s\n"),
 397                             sha1_to_hex(commit->object.sha1));
 398        if (commit->parents) {
 399                struct commit *parent = commit->parents->item;
 400                if (parse_commit(parent))
 401                        return error(_("Could not parse parent commit %s\n"),
 402                                sha1_to_hex(parent->object.sha1));
 403                ptree_sha1 = parent->tree->object.sha1;
 404        } else {
 405                ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 406        }
 407
 408        return !hashcmp(ptree_sha1, commit->tree->object.sha1);
 409}
 410
 411/*
 412 * Do we run "git commit" with "--allow-empty"?
 413 */
 414static int allow_empty(struct replay_opts *opts, struct commit *commit)
 415{
 416        int index_unchanged, empty_commit;
 417
 418        /*
 419         * Three cases:
 420         *
 421         * (1) we do not allow empty at all and error out.
 422         *
 423         * (2) we allow ones that were initially empty, but
 424         * forbid the ones that become empty;
 425         *
 426         * (3) we allow both.
 427         */
 428        if (!opts->allow_empty)
 429                return 0; /* let "git commit" barf as necessary */
 430
 431        index_unchanged = is_index_unchanged();
 432        if (index_unchanged < 0)
 433                return index_unchanged;
 434        if (!index_unchanged)
 435                return 0; /* we do not have to say --allow-empty */
 436
 437        if (opts->keep_redundant_commits)
 438                return 1;
 439
 440        empty_commit = is_original_commit_empty(commit);
 441        if (empty_commit < 0)
 442                return empty_commit;
 443        if (!empty_commit)
 444                return 0;
 445        else
 446                return 1;
 447}
 448
 449static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 450{
 451        unsigned char head[20];
 452        struct commit *base, *next, *parent;
 453        const char *base_label, *next_label;
 454        struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
 455        char *defmsg = NULL;
 456        struct strbuf msgbuf = STRBUF_INIT;
 457        int res;
 458
 459        if (opts->no_commit) {
 460                /*
 461                 * We do not intend to commit immediately.  We just want to
 462                 * merge the differences in, so let's compute the tree
 463                 * that represents the "current" state for merge-recursive
 464                 * to work on.
 465                 */
 466                if (write_cache_as_tree(head, 0, NULL))
 467                        die (_("Your index file is unmerged."));
 468        } else {
 469                if (get_sha1("HEAD", head))
 470                        return error(_("You do not have a valid HEAD"));
 471                if (index_differs_from("HEAD", 0))
 472                        return error_dirty_index(opts);
 473        }
 474        discard_cache();
 475
 476        if (!commit->parents) {
 477                parent = NULL;
 478        }
 479        else if (commit->parents->next) {
 480                /* Reverting or cherry-picking a merge commit */
 481                int cnt;
 482                struct commit_list *p;
 483
 484                if (!opts->mainline)
 485                        return error(_("Commit %s is a merge but no -m option was given."),
 486                                sha1_to_hex(commit->object.sha1));
 487
 488                for (cnt = 1, p = commit->parents;
 489                     cnt != opts->mainline && p;
 490                     cnt++)
 491                        p = p->next;
 492                if (cnt != opts->mainline || !p)
 493                        return error(_("Commit %s does not have parent %d"),
 494                                sha1_to_hex(commit->object.sha1), opts->mainline);
 495                parent = p->item;
 496        } else if (0 < opts->mainline)
 497                return error(_("Mainline was specified but commit %s is not a merge."),
 498                        sha1_to_hex(commit->object.sha1));
 499        else
 500                parent = commit->parents->item;
 501
 502        if (opts->allow_ff && parent && !hashcmp(parent->object.sha1, head))
 503                return fast_forward_to(commit->object.sha1, head);
 504
 505        if (parent && parse_commit(parent) < 0)
 506                /* TRANSLATORS: The first %s will be "revert" or
 507                   "cherry-pick", the second %s a SHA1 */
 508                return error(_("%s: cannot parse parent commit %s"),
 509                        action_name(opts), sha1_to_hex(parent->object.sha1));
 510
 511        if (get_message(commit, &msg) != 0)
 512                return error(_("Cannot get commit message for %s"),
 513                        sha1_to_hex(commit->object.sha1));
 514
 515        /*
 516         * "commit" is an existing commit.  We would want to apply
 517         * the difference it introduces since its first parent "prev"
 518         * on top of the current HEAD if we are cherry-pick.  Or the
 519         * reverse of it if we are revert.
 520         */
 521
 522        defmsg = git_pathdup("MERGE_MSG");
 523
 524        if (opts->action == REPLAY_REVERT) {
 525                base = commit;
 526                base_label = msg.label;
 527                next = parent;
 528                next_label = msg.parent_label;
 529                strbuf_addstr(&msgbuf, "Revert \"");
 530                strbuf_addstr(&msgbuf, msg.subject);
 531                strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 532                strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 533
 534                if (commit->parents && commit->parents->next) {
 535                        strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 536                        strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
 537                }
 538                strbuf_addstr(&msgbuf, ".\n");
 539        } else {
 540                const char *p;
 541
 542                base = parent;
 543                base_label = msg.parent_label;
 544                next = commit;
 545                next_label = msg.label;
 546
 547                /*
 548                 * Append the commit log message to msgbuf; it starts
 549                 * after the tree, parent, author, committer
 550                 * information followed by "\n\n".
 551                 */
 552                p = strstr(msg.message, "\n\n");
 553                if (p) {
 554                        p += 2;
 555                        strbuf_addstr(&msgbuf, p);
 556                }
 557
 558                if (opts->record_origin) {
 559                        if (!has_conforming_footer(&msgbuf, 0))
 560                                strbuf_addch(&msgbuf, '\n');
 561                        strbuf_addstr(&msgbuf, cherry_picked_prefix);
 562                        strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 563                        strbuf_addstr(&msgbuf, ")\n");
 564                }
 565        }
 566
 567        if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 568                res = do_recursive_merge(base, next, base_label, next_label,
 569                                         head, &msgbuf, opts);
 570                write_message(&msgbuf, defmsg);
 571        } else {
 572                struct commit_list *common = NULL;
 573                struct commit_list *remotes = NULL;
 574
 575                write_message(&msgbuf, defmsg);
 576
 577                commit_list_insert(base, &common);
 578                commit_list_insert(next, &remotes);
 579                res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 580                                        common, sha1_to_hex(head), remotes);
 581                free_commit_list(common);
 582                free_commit_list(remotes);
 583        }
 584
 585        /*
 586         * If the merge was clean or if it failed due to conflict, we write
 587         * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 588         * However, if the merge did not even start, then we don't want to
 589         * write it at all.
 590         */
 591        if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 592                write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
 593        if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 594                write_cherry_pick_head(commit, "REVERT_HEAD");
 595
 596        if (res) {
 597                error(opts->action == REPLAY_REVERT
 598                      ? _("could not revert %s... %s")
 599                      : _("could not apply %s... %s"),
 600                      find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
 601                      msg.subject);
 602                print_advice(res == 1, opts);
 603                rerere(opts->allow_rerere_auto);
 604        } else {
 605                int allow = allow_empty(opts, commit);
 606                if (allow < 0)
 607                        return allow;
 608                if (!opts->no_commit)
 609                        res = run_git_commit(defmsg, opts, allow);
 610        }
 611
 612        free_message(&msg);
 613        free(defmsg);
 614
 615        return res;
 616}
 617
 618static void prepare_revs(struct replay_opts *opts)
 619{
 620        /*
 621         * picking (but not reverting) ranges (but not individual revisions)
 622         * should be done in reverse
 623         */
 624        if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 625                opts->revs->reverse ^= 1;
 626
 627        if (prepare_revision_walk(opts->revs))
 628                die(_("revision walk setup failed"));
 629
 630        if (!opts->revs->commits)
 631                die(_("empty commit set passed"));
 632}
 633
 634static void read_and_refresh_cache(struct replay_opts *opts)
 635{
 636        static struct lock_file index_lock;
 637        int index_fd = hold_locked_index(&index_lock, 0);
 638        if (read_index_preload(&the_index, NULL) < 0)
 639                die(_("git %s: failed to read the index"), action_name(opts));
 640        refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 641        if (the_index.cache_changed) {
 642                if (write_index(&the_index, index_fd) ||
 643                    commit_locked_index(&index_lock))
 644                        die(_("git %s: failed to refresh the index"), action_name(opts));
 645        }
 646        rollback_lock_file(&index_lock);
 647}
 648
 649static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 650                struct replay_opts *opts)
 651{
 652        struct commit_list *cur = NULL;
 653        const char *sha1_abbrev = NULL;
 654        const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 655        const char *subject;
 656        int subject_len;
 657
 658        for (cur = todo_list; cur; cur = cur->next) {
 659                sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
 660                subject_len = find_commit_subject(cur->item->buffer, &subject);
 661                strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 662                        subject_len, subject);
 663        }
 664        return 0;
 665}
 666
 667static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 668{
 669        unsigned char commit_sha1[20];
 670        enum replay_action action;
 671        char *end_of_object_name;
 672        int saved, status, padding;
 673
 674        if (!prefixcmp(bol, "pick")) {
 675                action = REPLAY_PICK;
 676                bol += strlen("pick");
 677        } else if (!prefixcmp(bol, "revert")) {
 678                action = REPLAY_REVERT;
 679                bol += strlen("revert");
 680        } else
 681                return NULL;
 682
 683        /* Eat up extra spaces/ tabs before object name */
 684        padding = strspn(bol, " \t");
 685        if (!padding)
 686                return NULL;
 687        bol += padding;
 688
 689        end_of_object_name = bol + strcspn(bol, " \t\n");
 690        saved = *end_of_object_name;
 691        *end_of_object_name = '\0';
 692        status = get_sha1(bol, commit_sha1);
 693        *end_of_object_name = saved;
 694
 695        /*
 696         * Verify that the action matches up with the one in
 697         * opts; we don't support arbitrary instructions
 698         */
 699        if (action != opts->action) {
 700                const char *action_str;
 701                action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
 702                error(_("Cannot %s during a %s"), action_str, action_name(opts));
 703                return NULL;
 704        }
 705
 706        if (status < 0)
 707                return NULL;
 708
 709        return lookup_commit_reference(commit_sha1);
 710}
 711
 712static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
 713                        struct replay_opts *opts)
 714{
 715        struct commit_list **next = todo_list;
 716        struct commit *commit;
 717        char *p = buf;
 718        int i;
 719
 720        for (i = 1; *p; i++) {
 721                char *eol = strchrnul(p, '\n');
 722                commit = parse_insn_line(p, eol, opts);
 723                if (!commit)
 724                        return error(_("Could not parse line %d."), i);
 725                next = commit_list_append(commit, next);
 726                p = *eol ? eol + 1 : eol;
 727        }
 728        if (!*todo_list)
 729                return error(_("No commits parsed."));
 730        return 0;
 731}
 732
 733static void read_populate_todo(struct commit_list **todo_list,
 734                        struct replay_opts *opts)
 735{
 736        const char *todo_file = git_path(SEQ_TODO_FILE);
 737        struct strbuf buf = STRBUF_INIT;
 738        int fd, res;
 739
 740        fd = open(todo_file, O_RDONLY);
 741        if (fd < 0)
 742                die_errno(_("Could not open %s"), todo_file);
 743        if (strbuf_read(&buf, fd, 0) < 0) {
 744                close(fd);
 745                strbuf_release(&buf);
 746                die(_("Could not read %s."), todo_file);
 747        }
 748        close(fd);
 749
 750        res = parse_insn_buffer(buf.buf, todo_list, opts);
 751        strbuf_release(&buf);
 752        if (res)
 753                die(_("Unusable instruction sheet: %s"), todo_file);
 754}
 755
 756static int populate_opts_cb(const char *key, const char *value, void *data)
 757{
 758        struct replay_opts *opts = data;
 759        int error_flag = 1;
 760
 761        if (!value)
 762                error_flag = 0;
 763        else if (!strcmp(key, "options.no-commit"))
 764                opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 765        else if (!strcmp(key, "options.edit"))
 766                opts->edit = git_config_bool_or_int(key, value, &error_flag);
 767        else if (!strcmp(key, "options.signoff"))
 768                opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 769        else if (!strcmp(key, "options.record-origin"))
 770                opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 771        else if (!strcmp(key, "options.allow-ff"))
 772                opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 773        else if (!strcmp(key, "options.mainline"))
 774                opts->mainline = git_config_int(key, value);
 775        else if (!strcmp(key, "options.strategy"))
 776                git_config_string(&opts->strategy, key, value);
 777        else if (!strcmp(key, "options.strategy-option")) {
 778                ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 779                opts->xopts[opts->xopts_nr++] = xstrdup(value);
 780        } else
 781                return error(_("Invalid key: %s"), key);
 782
 783        if (!error_flag)
 784                return error(_("Invalid value for %s: %s"), key, value);
 785
 786        return 0;
 787}
 788
 789static void read_populate_opts(struct replay_opts **opts_ptr)
 790{
 791        const char *opts_file = git_path(SEQ_OPTS_FILE);
 792
 793        if (!file_exists(opts_file))
 794                return;
 795        if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
 796                die(_("Malformed options sheet: %s"), opts_file);
 797}
 798
 799static void walk_revs_populate_todo(struct commit_list **todo_list,
 800                                struct replay_opts *opts)
 801{
 802        struct commit *commit;
 803        struct commit_list **next;
 804
 805        prepare_revs(opts);
 806
 807        next = todo_list;
 808        while ((commit = get_revision(opts->revs)))
 809                next = commit_list_append(commit, next);
 810}
 811
 812static int create_seq_dir(void)
 813{
 814        const char *seq_dir = git_path(SEQ_DIR);
 815
 816        if (file_exists(seq_dir)) {
 817                error(_("a cherry-pick or revert is already in progress"));
 818                advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 819                return -1;
 820        }
 821        else if (mkdir(seq_dir, 0777) < 0)
 822                die_errno(_("Could not create sequencer directory %s"), seq_dir);
 823        return 0;
 824}
 825
 826static void save_head(const char *head)
 827{
 828        const char *head_file = git_path(SEQ_HEAD_FILE);
 829        static struct lock_file head_lock;
 830        struct strbuf buf = STRBUF_INIT;
 831        int fd;
 832
 833        fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
 834        strbuf_addf(&buf, "%s\n", head);
 835        if (write_in_full(fd, buf.buf, buf.len) < 0)
 836                die_errno(_("Could not write to %s"), head_file);
 837        if (commit_lock_file(&head_lock) < 0)
 838                die(_("Error wrapping up %s."), head_file);
 839}
 840
 841static int reset_for_rollback(const unsigned char *sha1)
 842{
 843        const char *argv[4];    /* reset --merge <arg> + NULL */
 844        argv[0] = "reset";
 845        argv[1] = "--merge";
 846        argv[2] = sha1_to_hex(sha1);
 847        argv[3] = NULL;
 848        return run_command_v_opt(argv, RUN_GIT_CMD);
 849}
 850
 851static int rollback_single_pick(void)
 852{
 853        unsigned char head_sha1[20];
 854
 855        if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
 856            !file_exists(git_path("REVERT_HEAD")))
 857                return error(_("no cherry-pick or revert in progress"));
 858        if (read_ref_full("HEAD", head_sha1, 0, NULL))
 859                return error(_("cannot resolve HEAD"));
 860        if (is_null_sha1(head_sha1))
 861                return error(_("cannot abort from a branch yet to be born"));
 862        return reset_for_rollback(head_sha1);
 863}
 864
 865static int sequencer_rollback(struct replay_opts *opts)
 866{
 867        const char *filename;
 868        FILE *f;
 869        unsigned char sha1[20];
 870        struct strbuf buf = STRBUF_INIT;
 871
 872        filename = git_path(SEQ_HEAD_FILE);
 873        f = fopen(filename, "r");
 874        if (!f && errno == ENOENT) {
 875                /*
 876                 * There is no multiple-cherry-pick in progress.
 877                 * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 878                 * a single-cherry-pick in progress, abort that.
 879                 */
 880                return rollback_single_pick();
 881        }
 882        if (!f)
 883                return error(_("cannot open %s: %s"), filename,
 884                                                strerror(errno));
 885        if (strbuf_getline(&buf, f, '\n')) {
 886                error(_("cannot read %s: %s"), filename, ferror(f) ?
 887                        strerror(errno) : _("unexpected end of file"));
 888                fclose(f);
 889                goto fail;
 890        }
 891        fclose(f);
 892        if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 893                error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 894                        filename);
 895                goto fail;
 896        }
 897        if (reset_for_rollback(sha1))
 898                goto fail;
 899        remove_sequencer_state();
 900        strbuf_release(&buf);
 901        return 0;
 902fail:
 903        strbuf_release(&buf);
 904        return -1;
 905}
 906
 907static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 908{
 909        const char *todo_file = git_path(SEQ_TODO_FILE);
 910        static struct lock_file todo_lock;
 911        struct strbuf buf = STRBUF_INIT;
 912        int fd;
 913
 914        fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
 915        if (format_todo(&buf, todo_list, opts) < 0)
 916                die(_("Could not format %s."), todo_file);
 917        if (write_in_full(fd, buf.buf, buf.len) < 0) {
 918                strbuf_release(&buf);
 919                die_errno(_("Could not write to %s"), todo_file);
 920        }
 921        if (commit_lock_file(&todo_lock) < 0) {
 922                strbuf_release(&buf);
 923                die(_("Error wrapping up %s."), todo_file);
 924        }
 925        strbuf_release(&buf);
 926}
 927
 928static void save_opts(struct replay_opts *opts)
 929{
 930        const char *opts_file = git_path(SEQ_OPTS_FILE);
 931
 932        if (opts->no_commit)
 933                git_config_set_in_file(opts_file, "options.no-commit", "true");
 934        if (opts->edit)
 935                git_config_set_in_file(opts_file, "options.edit", "true");
 936        if (opts->signoff)
 937                git_config_set_in_file(opts_file, "options.signoff", "true");
 938        if (opts->record_origin)
 939                git_config_set_in_file(opts_file, "options.record-origin", "true");
 940        if (opts->allow_ff)
 941                git_config_set_in_file(opts_file, "options.allow-ff", "true");
 942        if (opts->mainline) {
 943                struct strbuf buf = STRBUF_INIT;
 944                strbuf_addf(&buf, "%d", opts->mainline);
 945                git_config_set_in_file(opts_file, "options.mainline", buf.buf);
 946                strbuf_release(&buf);
 947        }
 948        if (opts->strategy)
 949                git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
 950        if (opts->xopts) {
 951                int i;
 952                for (i = 0; i < opts->xopts_nr; i++)
 953                        git_config_set_multivar_in_file(opts_file,
 954                                                        "options.strategy-option",
 955                                                        opts->xopts[i], "^$", 0);
 956        }
 957}
 958
 959static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
 960{
 961        struct commit_list *cur;
 962        int res;
 963
 964        setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
 965        if (opts->allow_ff)
 966                assert(!(opts->signoff || opts->no_commit ||
 967                                opts->record_origin || opts->edit));
 968        read_and_refresh_cache(opts);
 969
 970        for (cur = todo_list; cur; cur = cur->next) {
 971                save_todo(cur, opts);
 972                res = do_pick_commit(cur->item, opts);
 973                if (res)
 974                        return res;
 975        }
 976
 977        /*
 978         * Sequence of picks finished successfully; cleanup by
 979         * removing the .git/sequencer directory
 980         */
 981        remove_sequencer_state();
 982        return 0;
 983}
 984
 985static int continue_single_pick(void)
 986{
 987        const char *argv[] = { "commit", NULL };
 988
 989        if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
 990            !file_exists(git_path("REVERT_HEAD")))
 991                return error(_("no cherry-pick or revert in progress"));
 992        return run_command_v_opt(argv, RUN_GIT_CMD);
 993}
 994
 995static int sequencer_continue(struct replay_opts *opts)
 996{
 997        struct commit_list *todo_list = NULL;
 998
 999        if (!file_exists(git_path(SEQ_TODO_FILE)))
1000                return continue_single_pick();
1001        read_populate_opts(&opts);
1002        read_populate_todo(&todo_list, opts);
1003
1004        /* Verify that the conflict has been resolved */
1005        if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
1006            file_exists(git_path("REVERT_HEAD"))) {
1007                int ret = continue_single_pick();
1008                if (ret)
1009                        return ret;
1010        }
1011        if (index_differs_from("HEAD", 0))
1012                return error_dirty_index(opts);
1013        todo_list = todo_list->next;
1014        return pick_commits(todo_list, opts);
1015}
1016
1017static int single_pick(struct commit *cmit, struct replay_opts *opts)
1018{
1019        setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1020        return do_pick_commit(cmit, opts);
1021}
1022
1023int sequencer_pick_revisions(struct replay_opts *opts)
1024{
1025        struct commit_list *todo_list = NULL;
1026        unsigned char sha1[20];
1027
1028        if (opts->subcommand == REPLAY_NONE)
1029                assert(opts->revs);
1030
1031        read_and_refresh_cache(opts);
1032
1033        /*
1034         * Decide what to do depending on the arguments; a fresh
1035         * cherry-pick should be handled differently from an existing
1036         * one that is being continued
1037         */
1038        if (opts->subcommand == REPLAY_REMOVE_STATE) {
1039                remove_sequencer_state();
1040                return 0;
1041        }
1042        if (opts->subcommand == REPLAY_ROLLBACK)
1043                return sequencer_rollback(opts);
1044        if (opts->subcommand == REPLAY_CONTINUE)
1045                return sequencer_continue(opts);
1046
1047        /*
1048         * If we were called as "git cherry-pick <commit>", just
1049         * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1050         * REVERT_HEAD, and don't touch the sequencer state.
1051         * This means it is possible to cherry-pick in the middle
1052         * of a cherry-pick sequence.
1053         */
1054        if (opts->revs->cmdline.nr == 1 &&
1055            opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1056            opts->revs->no_walk &&
1057            !opts->revs->cmdline.rev->flags) {
1058                struct commit *cmit;
1059                if (prepare_revision_walk(opts->revs))
1060                        die(_("revision walk setup failed"));
1061                cmit = get_revision(opts->revs);
1062                if (!cmit || get_revision(opts->revs))
1063                        die("BUG: expected exactly one commit from walk");
1064                return single_pick(cmit, opts);
1065        }
1066
1067        /*
1068         * Start a new cherry-pick/ revert sequence; but
1069         * first, make sure that an existing one isn't in
1070         * progress
1071         */
1072
1073        walk_revs_populate_todo(&todo_list, opts);
1074        if (create_seq_dir() < 0)
1075                return -1;
1076        if (get_sha1("HEAD", sha1)) {
1077                if (opts->action == REPLAY_REVERT)
1078                        return error(_("Can't revert as initial commit"));
1079                return error(_("Can't cherry-pick into empty head"));
1080        }
1081        save_head(sha1_to_hex(sha1));
1082        save_opts(opts);
1083        return pick_commits(todo_list, opts);
1084}
1085
1086void append_signoff(struct strbuf *msgbuf, int ignore_footer)
1087{
1088        struct strbuf sob = STRBUF_INIT;
1089        int i;
1090
1091        strbuf_addstr(&sob, sign_off_header);
1092        strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1093                                getenv("GIT_COMMITTER_EMAIL")));
1094        strbuf_addch(&sob, '\n');
1095        for (i = msgbuf->len - 1 - ignore_footer; i > 0 && msgbuf->buf[i - 1] != '\n'; i--)
1096                ; /* do nothing */
1097        if (prefixcmp(msgbuf->buf + i, sob.buf)) {
1098                if (!has_conforming_footer(msgbuf, ignore_footer))
1099                        strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0, "\n", 1);
1100                strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0, sob.buf, sob.len);
1101        }
1102        strbuf_release(&sob);
1103}