sequencer.con commit commit: record buffer length in cache (8597ea3)
   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                starts_with(buf, cherry_picked_prefix) && buf[len - 1] == ')';
  45}
  46
  47/*
  48 * Returns 0 for non-conforming footer
  49 * Returns 1 for conforming footer
  50 * Returns 2 when sob exists within conforming footer
  51 * Returns 3 when sob exists within conforming footer as last entry
  52 */
  53static int has_conforming_footer(struct strbuf *sb, struct strbuf *sob,
  54        int ignore_footer)
  55{
  56        char prev;
  57        int i, k;
  58        int len = sb->len - ignore_footer;
  59        const char *buf = sb->buf;
  60        int found_sob = 0;
  61
  62        /* footer must end with newline */
  63        if (!len || buf[len - 1] != '\n')
  64                return 0;
  65
  66        prev = '\0';
  67        for (i = len - 1; i > 0; i--) {
  68                char ch = buf[i];
  69                if (prev == '\n' && ch == '\n') /* paragraph break */
  70                        break;
  71                prev = ch;
  72        }
  73
  74        /* require at least one blank line */
  75        if (prev != '\n' || buf[i] != '\n')
  76                return 0;
  77
  78        /* advance to start of last paragraph */
  79        while (i < len - 1 && buf[i] == '\n')
  80                i++;
  81
  82        for (; i < len; i = k) {
  83                int found_rfc2822;
  84
  85                for (k = i; k < len && buf[k] != '\n'; k++)
  86                        ; /* do nothing */
  87                k++;
  88
  89                found_rfc2822 = is_rfc2822_line(buf + i, k - i - 1);
  90                if (found_rfc2822 && sob &&
  91                    !strncmp(buf + i, sob->buf, sob->len))
  92                        found_sob = k;
  93
  94                if (!(found_rfc2822 ||
  95                      is_cherry_picked_from_line(buf + i, k - i - 1)))
  96                        return 0;
  97        }
  98        if (found_sob == i)
  99                return 3;
 100        if (found_sob)
 101                return 2;
 102        return 1;
 103}
 104
 105static void remove_sequencer_state(void)
 106{
 107        struct strbuf seq_dir = STRBUF_INIT;
 108
 109        strbuf_addf(&seq_dir, "%s", git_path(SEQ_DIR));
 110        remove_dir_recursively(&seq_dir, 0);
 111        strbuf_release(&seq_dir);
 112}
 113
 114static const char *action_name(const struct replay_opts *opts)
 115{
 116        return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
 117}
 118
 119struct commit_message {
 120        char *parent_label;
 121        const char *label;
 122        const char *subject;
 123        const char *message;
 124};
 125
 126static int get_message(struct commit *commit, struct commit_message *out)
 127{
 128        const char *abbrev, *subject;
 129        int abbrev_len, subject_len;
 130        char *q;
 131
 132        if (!git_commit_encoding)
 133                git_commit_encoding = "UTF-8";
 134
 135        out->message = logmsg_reencode(commit, NULL, git_commit_encoding);
 136        abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
 137        abbrev_len = strlen(abbrev);
 138
 139        subject_len = find_commit_subject(out->message, &subject);
 140
 141        out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
 142                              strlen("... ") + subject_len + 1);
 143        q = out->parent_label;
 144        q = mempcpy(q, "parent of ", strlen("parent of "));
 145        out->label = q;
 146        q = mempcpy(q, abbrev, abbrev_len);
 147        q = mempcpy(q, "... ", strlen("... "));
 148        out->subject = q;
 149        q = mempcpy(q, subject, subject_len);
 150        *q = '\0';
 151        return 0;
 152}
 153
 154static void free_message(struct commit *commit, struct commit_message *msg)
 155{
 156        free(msg->parent_label);
 157        unuse_commit_buffer(commit, msg->message);
 158}
 159
 160static void write_cherry_pick_head(struct commit *commit, const char *pseudoref)
 161{
 162        const char *filename;
 163        int fd;
 164        struct strbuf buf = STRBUF_INIT;
 165
 166        strbuf_addf(&buf, "%s\n", sha1_to_hex(commit->object.sha1));
 167
 168        filename = git_path("%s", pseudoref);
 169        fd = open(filename, O_WRONLY | O_CREAT, 0666);
 170        if (fd < 0)
 171                die_errno(_("Could not open '%s' for writing"), filename);
 172        if (write_in_full(fd, buf.buf, buf.len) != buf.len || close(fd))
 173                die_errno(_("Could not write to '%s'"), filename);
 174        strbuf_release(&buf);
 175}
 176
 177static void print_advice(int show_hint, struct replay_opts *opts)
 178{
 179        char *msg = getenv("GIT_CHERRY_PICK_HELP");
 180
 181        if (msg) {
 182                fprintf(stderr, "%s\n", msg);
 183                /*
 184                 * A conflict has occurred but the porcelain
 185                 * (typically rebase --interactive) wants to take care
 186                 * of the commit itself so remove CHERRY_PICK_HEAD
 187                 */
 188                unlink(git_path("CHERRY_PICK_HEAD"));
 189                return;
 190        }
 191
 192        if (show_hint) {
 193                if (opts->no_commit)
 194                        advise(_("after resolving the conflicts, mark the corrected paths\n"
 195                                 "with 'git add <paths>' or 'git rm <paths>'"));
 196                else
 197                        advise(_("after resolving the conflicts, mark the corrected paths\n"
 198                                 "with 'git add <paths>' or 'git rm <paths>'\n"
 199                                 "and commit the result with 'git commit'"));
 200        }
 201}
 202
 203static void write_message(struct strbuf *msgbuf, const char *filename)
 204{
 205        static struct lock_file msg_file;
 206
 207        int msg_fd = hold_lock_file_for_update(&msg_file, filename,
 208                                               LOCK_DIE_ON_ERROR);
 209        if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
 210                die_errno(_("Could not write to %s"), filename);
 211        strbuf_release(msgbuf);
 212        if (commit_lock_file(&msg_file) < 0)
 213                die(_("Error wrapping up %s"), filename);
 214}
 215
 216static struct tree *empty_tree(void)
 217{
 218        return lookup_tree(EMPTY_TREE_SHA1_BIN);
 219}
 220
 221static int error_dirty_index(struct replay_opts *opts)
 222{
 223        if (read_cache_unmerged())
 224                return error_resolve_conflict(action_name(opts));
 225
 226        /* Different translation strings for cherry-pick and revert */
 227        if (opts->action == REPLAY_PICK)
 228                error(_("Your local changes would be overwritten by cherry-pick."));
 229        else
 230                error(_("Your local changes would be overwritten by revert."));
 231
 232        if (advice_commit_before_merge)
 233                advise(_("Commit your changes or stash them to proceed."));
 234        return -1;
 235}
 236
 237static int fast_forward_to(const unsigned char *to, const unsigned char *from,
 238                        int unborn, struct replay_opts *opts)
 239{
 240        struct ref_lock *ref_lock;
 241        struct strbuf sb = STRBUF_INIT;
 242        int ret;
 243
 244        read_cache();
 245        if (checkout_fast_forward(from, to, 1))
 246                exit(1); /* the callee should have complained already */
 247        ref_lock = lock_any_ref_for_update("HEAD", unborn ? null_sha1 : from,
 248                                           0, NULL);
 249        strbuf_addf(&sb, "%s: fast-forward", action_name(opts));
 250        ret = write_ref_sha1(ref_lock, to, sb.buf);
 251        strbuf_release(&sb);
 252        return ret;
 253}
 254
 255static int do_recursive_merge(struct commit *base, struct commit *next,
 256                              const char *base_label, const char *next_label,
 257                              unsigned char *head, struct strbuf *msgbuf,
 258                              struct replay_opts *opts)
 259{
 260        struct merge_options o;
 261        struct tree *result, *next_tree, *base_tree, *head_tree;
 262        int clean, index_fd;
 263        const char **xopt;
 264        static struct lock_file index_lock;
 265
 266        index_fd = hold_locked_index(&index_lock, 1);
 267
 268        read_cache();
 269
 270        init_merge_options(&o);
 271        o.ancestor = base ? base_label : "(empty tree)";
 272        o.branch1 = "HEAD";
 273        o.branch2 = next ? next_label : "(empty tree)";
 274
 275        head_tree = parse_tree_indirect(head);
 276        next_tree = next ? next->tree : empty_tree();
 277        base_tree = base ? base->tree : empty_tree();
 278
 279        for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 280                parse_merge_opt(&o, *xopt);
 281
 282        clean = merge_trees(&o,
 283                            head_tree,
 284                            next_tree, base_tree, &result);
 285
 286        if (active_cache_changed &&
 287            (write_cache(index_fd, active_cache, active_nr) ||
 288             commit_locked_index(&index_lock)))
 289                /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 290                die(_("%s: Unable to write new index file"), action_name(opts));
 291        rollback_lock_file(&index_lock);
 292
 293        if (opts->signoff)
 294                append_signoff(msgbuf, 0, 0);
 295
 296        if (!clean) {
 297                int i;
 298                strbuf_addstr(msgbuf, "\nConflicts:\n");
 299                for (i = 0; i < active_nr;) {
 300                        const struct cache_entry *ce = active_cache[i++];
 301                        if (ce_stage(ce)) {
 302                                strbuf_addch(msgbuf, '\t');
 303                                strbuf_addstr(msgbuf, ce->name);
 304                                strbuf_addch(msgbuf, '\n');
 305                                while (i < active_nr && !strcmp(ce->name,
 306                                                active_cache[i]->name))
 307                                        i++;
 308                        }
 309                }
 310        }
 311
 312        return !clean;
 313}
 314
 315static int is_index_unchanged(void)
 316{
 317        unsigned char head_sha1[20];
 318        struct commit *head_commit;
 319
 320        if (!resolve_ref_unsafe("HEAD", head_sha1, 1, NULL))
 321                return error(_("Could not resolve HEAD commit\n"));
 322
 323        head_commit = lookup_commit(head_sha1);
 324
 325        /*
 326         * If head_commit is NULL, check_commit, called from
 327         * lookup_commit, would have indicated that head_commit is not
 328         * a commit object already.  parse_commit() will return failure
 329         * without further complaints in such a case.  Otherwise, if
 330         * the commit is invalid, parse_commit() will complain.  So
 331         * there is nothing for us to say here.  Just return failure.
 332         */
 333        if (parse_commit(head_commit))
 334                return -1;
 335
 336        if (!active_cache_tree)
 337                active_cache_tree = cache_tree();
 338
 339        if (!cache_tree_fully_valid(active_cache_tree))
 340                if (cache_tree_update(active_cache_tree,
 341                                      (const struct cache_entry * const *)active_cache,
 342                                      active_nr, 0))
 343                        return error(_("Unable to update cache tree\n"));
 344
 345        return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.sha1);
 346}
 347
 348/*
 349 * If we are cherry-pick, and if the merge did not result in
 350 * hand-editing, we will hit this commit and inherit the original
 351 * author date and name.
 352 * If we are revert, or if our cherry-pick results in a hand merge,
 353 * we had better say that the current user is responsible for that.
 354 */
 355static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 356                          int allow_empty)
 357{
 358        struct argv_array array;
 359        int rc;
 360        char *gpg_sign;
 361
 362        argv_array_init(&array);
 363        argv_array_push(&array, "commit");
 364        argv_array_push(&array, "-n");
 365
 366        if (opts->gpg_sign) {
 367                gpg_sign = xmalloc(3 + strlen(opts->gpg_sign));
 368                sprintf(gpg_sign, "-S%s", opts->gpg_sign);
 369                argv_array_push(&array, gpg_sign);
 370                free(gpg_sign);
 371        }
 372        if (opts->signoff)
 373                argv_array_push(&array, "-s");
 374        if (!opts->edit) {
 375                argv_array_push(&array, "-F");
 376                argv_array_push(&array, defmsg);
 377        }
 378
 379        if (allow_empty)
 380                argv_array_push(&array, "--allow-empty");
 381
 382        if (opts->allow_empty_message)
 383                argv_array_push(&array, "--allow-empty-message");
 384
 385        rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 386        argv_array_clear(&array);
 387        return rc;
 388}
 389
 390static int is_original_commit_empty(struct commit *commit)
 391{
 392        const unsigned char *ptree_sha1;
 393
 394        if (parse_commit(commit))
 395                return error(_("Could not parse commit %s\n"),
 396                             sha1_to_hex(commit->object.sha1));
 397        if (commit->parents) {
 398                struct commit *parent = commit->parents->item;
 399                if (parse_commit(parent))
 400                        return error(_("Could not parse parent commit %s\n"),
 401                                sha1_to_hex(parent->object.sha1));
 402                ptree_sha1 = parent->tree->object.sha1;
 403        } else {
 404                ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 405        }
 406
 407        return !hashcmp(ptree_sha1, commit->tree->object.sha1);
 408}
 409
 410/*
 411 * Do we run "git commit" with "--allow-empty"?
 412 */
 413static int allow_empty(struct replay_opts *opts, struct commit *commit)
 414{
 415        int index_unchanged, empty_commit;
 416
 417        /*
 418         * Three cases:
 419         *
 420         * (1) we do not allow empty at all and error out.
 421         *
 422         * (2) we allow ones that were initially empty, but
 423         * forbid the ones that become empty;
 424         *
 425         * (3) we allow both.
 426         */
 427        if (!opts->allow_empty)
 428                return 0; /* let "git commit" barf as necessary */
 429
 430        index_unchanged = is_index_unchanged();
 431        if (index_unchanged < 0)
 432                return index_unchanged;
 433        if (!index_unchanged)
 434                return 0; /* we do not have to say --allow-empty */
 435
 436        if (opts->keep_redundant_commits)
 437                return 1;
 438
 439        empty_commit = is_original_commit_empty(commit);
 440        if (empty_commit < 0)
 441                return empty_commit;
 442        if (!empty_commit)
 443                return 0;
 444        else
 445                return 1;
 446}
 447
 448static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 449{
 450        unsigned char head[20];
 451        struct commit *base, *next, *parent;
 452        const char *base_label, *next_label;
 453        struct commit_message msg = { NULL, NULL, NULL, NULL };
 454        char *defmsg = NULL;
 455        struct strbuf msgbuf = STRBUF_INIT;
 456        int res, unborn = 0, allow;
 457
 458        if (opts->no_commit) {
 459                /*
 460                 * We do not intend to commit immediately.  We just want to
 461                 * merge the differences in, so let's compute the tree
 462                 * that represents the "current" state for merge-recursive
 463                 * to work on.
 464                 */
 465                if (write_cache_as_tree(head, 0, NULL))
 466                        die (_("Your index file is unmerged."));
 467        } else {
 468                unborn = get_sha1("HEAD", head);
 469                if (unborn)
 470                        hashcpy(head, EMPTY_TREE_SHA1_BIN);
 471                if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "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 &&
 503            ((parent && !hashcmp(parent->object.sha1, head)) ||
 504             (!parent && unborn)))
 505                return fast_forward_to(commit->object.sha1, head, unborn, opts);
 506
 507        if (parent && parse_commit(parent) < 0)
 508                /* TRANSLATORS: The first %s will be "revert" or
 509                   "cherry-pick", the second %s a SHA1 */
 510                return error(_("%s: cannot parse parent commit %s"),
 511                        action_name(opts), sha1_to_hex(parent->object.sha1));
 512
 513        if (get_message(commit, &msg) != 0)
 514                return error(_("Cannot get commit message for %s"),
 515                        sha1_to_hex(commit->object.sha1));
 516
 517        /*
 518         * "commit" is an existing commit.  We would want to apply
 519         * the difference it introduces since its first parent "prev"
 520         * on top of the current HEAD if we are cherry-pick.  Or the
 521         * reverse of it if we are revert.
 522         */
 523
 524        defmsg = git_pathdup("MERGE_MSG");
 525
 526        if (opts->action == REPLAY_REVERT) {
 527                base = commit;
 528                base_label = msg.label;
 529                next = parent;
 530                next_label = msg.parent_label;
 531                strbuf_addstr(&msgbuf, "Revert \"");
 532                strbuf_addstr(&msgbuf, msg.subject);
 533                strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 534                strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 535
 536                if (commit->parents && commit->parents->next) {
 537                        strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 538                        strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
 539                }
 540                strbuf_addstr(&msgbuf, ".\n");
 541        } else {
 542                const char *p;
 543
 544                base = parent;
 545                base_label = msg.parent_label;
 546                next = commit;
 547                next_label = msg.label;
 548
 549                /*
 550                 * Append the commit log message to msgbuf; it starts
 551                 * after the tree, parent, author, committer
 552                 * information followed by "\n\n".
 553                 */
 554                p = strstr(msg.message, "\n\n");
 555                if (p) {
 556                        p += 2;
 557                        strbuf_addstr(&msgbuf, p);
 558                }
 559
 560                if (opts->record_origin) {
 561                        if (!has_conforming_footer(&msgbuf, NULL, 0))
 562                                strbuf_addch(&msgbuf, '\n');
 563                        strbuf_addstr(&msgbuf, cherry_picked_prefix);
 564                        strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 565                        strbuf_addstr(&msgbuf, ")\n");
 566                }
 567        }
 568
 569        if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 570                res = do_recursive_merge(base, next, base_label, next_label,
 571                                         head, &msgbuf, opts);
 572                write_message(&msgbuf, defmsg);
 573        } else {
 574                struct commit_list *common = NULL;
 575                struct commit_list *remotes = NULL;
 576
 577                write_message(&msgbuf, defmsg);
 578
 579                commit_list_insert(base, &common);
 580                commit_list_insert(next, &remotes);
 581                res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 582                                        common, sha1_to_hex(head), remotes);
 583                free_commit_list(common);
 584                free_commit_list(remotes);
 585        }
 586
 587        /*
 588         * If the merge was clean or if it failed due to conflict, we write
 589         * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 590         * However, if the merge did not even start, then we don't want to
 591         * write it at all.
 592         */
 593        if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 594                write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
 595        if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 596                write_cherry_pick_head(commit, "REVERT_HEAD");
 597
 598        if (res) {
 599                error(opts->action == REPLAY_REVERT
 600                      ? _("could not revert %s... %s")
 601                      : _("could not apply %s... %s"),
 602                      find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
 603                      msg.subject);
 604                print_advice(res == 1, opts);
 605                rerere(opts->allow_rerere_auto);
 606                goto leave;
 607        }
 608
 609        allow = allow_empty(opts, commit);
 610        if (allow < 0) {
 611                res = allow;
 612                goto leave;
 613        }
 614        if (!opts->no_commit)
 615                res = run_git_commit(defmsg, opts, allow);
 616
 617leave:
 618        free_message(commit, &msg);
 619        free(defmsg);
 620
 621        return res;
 622}
 623
 624static void prepare_revs(struct replay_opts *opts)
 625{
 626        /*
 627         * picking (but not reverting) ranges (but not individual revisions)
 628         * should be done in reverse
 629         */
 630        if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 631                opts->revs->reverse ^= 1;
 632
 633        if (prepare_revision_walk(opts->revs))
 634                die(_("revision walk setup failed"));
 635
 636        if (!opts->revs->commits)
 637                die(_("empty commit set passed"));
 638}
 639
 640static void read_and_refresh_cache(struct replay_opts *opts)
 641{
 642        static struct lock_file index_lock;
 643        int index_fd = hold_locked_index(&index_lock, 0);
 644        if (read_index_preload(&the_index, NULL) < 0)
 645                die(_("git %s: failed to read the index"), action_name(opts));
 646        refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 647        if (the_index.cache_changed) {
 648                if (write_index(&the_index, index_fd) ||
 649                    commit_locked_index(&index_lock))
 650                        die(_("git %s: failed to refresh the index"), action_name(opts));
 651        }
 652        rollback_lock_file(&index_lock);
 653}
 654
 655static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 656                struct replay_opts *opts)
 657{
 658        struct commit_list *cur = NULL;
 659        const char *sha1_abbrev = NULL;
 660        const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 661        const char *subject;
 662        int subject_len;
 663
 664        for (cur = todo_list; cur; cur = cur->next) {
 665                const char *commit_buffer = get_commit_buffer(cur->item, NULL);
 666                sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
 667                subject_len = find_commit_subject(commit_buffer, &subject);
 668                strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 669                        subject_len, subject);
 670                unuse_commit_buffer(cur->item, commit_buffer);
 671        }
 672        return 0;
 673}
 674
 675static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 676{
 677        unsigned char commit_sha1[20];
 678        enum replay_action action;
 679        char *end_of_object_name;
 680        int saved, status, padding;
 681
 682        if (starts_with(bol, "pick")) {
 683                action = REPLAY_PICK;
 684                bol += strlen("pick");
 685        } else if (starts_with(bol, "revert")) {
 686                action = REPLAY_REVERT;
 687                bol += strlen("revert");
 688        } else
 689                return NULL;
 690
 691        /* Eat up extra spaces/ tabs before object name */
 692        padding = strspn(bol, " \t");
 693        if (!padding)
 694                return NULL;
 695        bol += padding;
 696
 697        end_of_object_name = bol + strcspn(bol, " \t\n");
 698        saved = *end_of_object_name;
 699        *end_of_object_name = '\0';
 700        status = get_sha1(bol, commit_sha1);
 701        *end_of_object_name = saved;
 702
 703        /*
 704         * Verify that the action matches up with the one in
 705         * opts; we don't support arbitrary instructions
 706         */
 707        if (action != opts->action) {
 708                const char *action_str;
 709                action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
 710                error(_("Cannot %s during a %s"), action_str, action_name(opts));
 711                return NULL;
 712        }
 713
 714        if (status < 0)
 715                return NULL;
 716
 717        return lookup_commit_reference(commit_sha1);
 718}
 719
 720static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
 721                        struct replay_opts *opts)
 722{
 723        struct commit_list **next = todo_list;
 724        struct commit *commit;
 725        char *p = buf;
 726        int i;
 727
 728        for (i = 1; *p; i++) {
 729                char *eol = strchrnul(p, '\n');
 730                commit = parse_insn_line(p, eol, opts);
 731                if (!commit)
 732                        return error(_("Could not parse line %d."), i);
 733                next = commit_list_append(commit, next);
 734                p = *eol ? eol + 1 : eol;
 735        }
 736        if (!*todo_list)
 737                return error(_("No commits parsed."));
 738        return 0;
 739}
 740
 741static void read_populate_todo(struct commit_list **todo_list,
 742                        struct replay_opts *opts)
 743{
 744        const char *todo_file = git_path(SEQ_TODO_FILE);
 745        struct strbuf buf = STRBUF_INIT;
 746        int fd, res;
 747
 748        fd = open(todo_file, O_RDONLY);
 749        if (fd < 0)
 750                die_errno(_("Could not open %s"), todo_file);
 751        if (strbuf_read(&buf, fd, 0) < 0) {
 752                close(fd);
 753                strbuf_release(&buf);
 754                die(_("Could not read %s."), todo_file);
 755        }
 756        close(fd);
 757
 758        res = parse_insn_buffer(buf.buf, todo_list, opts);
 759        strbuf_release(&buf);
 760        if (res)
 761                die(_("Unusable instruction sheet: %s"), todo_file);
 762}
 763
 764static int populate_opts_cb(const char *key, const char *value, void *data)
 765{
 766        struct replay_opts *opts = data;
 767        int error_flag = 1;
 768
 769        if (!value)
 770                error_flag = 0;
 771        else if (!strcmp(key, "options.no-commit"))
 772                opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 773        else if (!strcmp(key, "options.edit"))
 774                opts->edit = git_config_bool_or_int(key, value, &error_flag);
 775        else if (!strcmp(key, "options.signoff"))
 776                opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 777        else if (!strcmp(key, "options.record-origin"))
 778                opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 779        else if (!strcmp(key, "options.allow-ff"))
 780                opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 781        else if (!strcmp(key, "options.mainline"))
 782                opts->mainline = git_config_int(key, value);
 783        else if (!strcmp(key, "options.strategy"))
 784                git_config_string(&opts->strategy, key, value);
 785        else if (!strcmp(key, "options.gpg-sign"))
 786                git_config_string(&opts->gpg_sign, key, value);
 787        else if (!strcmp(key, "options.strategy-option")) {
 788                ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 789                opts->xopts[opts->xopts_nr++] = xstrdup(value);
 790        } else
 791                return error(_("Invalid key: %s"), key);
 792
 793        if (!error_flag)
 794                return error(_("Invalid value for %s: %s"), key, value);
 795
 796        return 0;
 797}
 798
 799static void read_populate_opts(struct replay_opts **opts_ptr)
 800{
 801        const char *opts_file = git_path(SEQ_OPTS_FILE);
 802
 803        if (!file_exists(opts_file))
 804                return;
 805        if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
 806                die(_("Malformed options sheet: %s"), opts_file);
 807}
 808
 809static void walk_revs_populate_todo(struct commit_list **todo_list,
 810                                struct replay_opts *opts)
 811{
 812        struct commit *commit;
 813        struct commit_list **next;
 814
 815        prepare_revs(opts);
 816
 817        next = todo_list;
 818        while ((commit = get_revision(opts->revs)))
 819                next = commit_list_append(commit, next);
 820}
 821
 822static int create_seq_dir(void)
 823{
 824        const char *seq_dir = git_path(SEQ_DIR);
 825
 826        if (file_exists(seq_dir)) {
 827                error(_("a cherry-pick or revert is already in progress"));
 828                advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 829                return -1;
 830        }
 831        else if (mkdir(seq_dir, 0777) < 0)
 832                die_errno(_("Could not create sequencer directory %s"), seq_dir);
 833        return 0;
 834}
 835
 836static void save_head(const char *head)
 837{
 838        const char *head_file = git_path(SEQ_HEAD_FILE);
 839        static struct lock_file head_lock;
 840        struct strbuf buf = STRBUF_INIT;
 841        int fd;
 842
 843        fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
 844        strbuf_addf(&buf, "%s\n", head);
 845        if (write_in_full(fd, buf.buf, buf.len) < 0)
 846                die_errno(_("Could not write to %s"), head_file);
 847        if (commit_lock_file(&head_lock) < 0)
 848                die(_("Error wrapping up %s."), head_file);
 849}
 850
 851static int reset_for_rollback(const unsigned char *sha1)
 852{
 853        const char *argv[4];    /* reset --merge <arg> + NULL */
 854        argv[0] = "reset";
 855        argv[1] = "--merge";
 856        argv[2] = sha1_to_hex(sha1);
 857        argv[3] = NULL;
 858        return run_command_v_opt(argv, RUN_GIT_CMD);
 859}
 860
 861static int rollback_single_pick(void)
 862{
 863        unsigned char head_sha1[20];
 864
 865        if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
 866            !file_exists(git_path("REVERT_HEAD")))
 867                return error(_("no cherry-pick or revert in progress"));
 868        if (read_ref_full("HEAD", head_sha1, 0, NULL))
 869                return error(_("cannot resolve HEAD"));
 870        if (is_null_sha1(head_sha1))
 871                return error(_("cannot abort from a branch yet to be born"));
 872        return reset_for_rollback(head_sha1);
 873}
 874
 875static int sequencer_rollback(struct replay_opts *opts)
 876{
 877        const char *filename;
 878        FILE *f;
 879        unsigned char sha1[20];
 880        struct strbuf buf = STRBUF_INIT;
 881
 882        filename = git_path(SEQ_HEAD_FILE);
 883        f = fopen(filename, "r");
 884        if (!f && errno == ENOENT) {
 885                /*
 886                 * There is no multiple-cherry-pick in progress.
 887                 * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 888                 * a single-cherry-pick in progress, abort that.
 889                 */
 890                return rollback_single_pick();
 891        }
 892        if (!f)
 893                return error(_("cannot open %s: %s"), filename,
 894                                                strerror(errno));
 895        if (strbuf_getline(&buf, f, '\n')) {
 896                error(_("cannot read %s: %s"), filename, ferror(f) ?
 897                        strerror(errno) : _("unexpected end of file"));
 898                fclose(f);
 899                goto fail;
 900        }
 901        fclose(f);
 902        if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 903                error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 904                        filename);
 905                goto fail;
 906        }
 907        if (reset_for_rollback(sha1))
 908                goto fail;
 909        remove_sequencer_state();
 910        strbuf_release(&buf);
 911        return 0;
 912fail:
 913        strbuf_release(&buf);
 914        return -1;
 915}
 916
 917static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 918{
 919        const char *todo_file = git_path(SEQ_TODO_FILE);
 920        static struct lock_file todo_lock;
 921        struct strbuf buf = STRBUF_INIT;
 922        int fd;
 923
 924        fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
 925        if (format_todo(&buf, todo_list, opts) < 0)
 926                die(_("Could not format %s."), todo_file);
 927        if (write_in_full(fd, buf.buf, buf.len) < 0) {
 928                strbuf_release(&buf);
 929                die_errno(_("Could not write to %s"), todo_file);
 930        }
 931        if (commit_lock_file(&todo_lock) < 0) {
 932                strbuf_release(&buf);
 933                die(_("Error wrapping up %s."), todo_file);
 934        }
 935        strbuf_release(&buf);
 936}
 937
 938static void save_opts(struct replay_opts *opts)
 939{
 940        const char *opts_file = git_path(SEQ_OPTS_FILE);
 941
 942        if (opts->no_commit)
 943                git_config_set_in_file(opts_file, "options.no-commit", "true");
 944        if (opts->edit)
 945                git_config_set_in_file(opts_file, "options.edit", "true");
 946        if (opts->signoff)
 947                git_config_set_in_file(opts_file, "options.signoff", "true");
 948        if (opts->record_origin)
 949                git_config_set_in_file(opts_file, "options.record-origin", "true");
 950        if (opts->allow_ff)
 951                git_config_set_in_file(opts_file, "options.allow-ff", "true");
 952        if (opts->mainline) {
 953                struct strbuf buf = STRBUF_INIT;
 954                strbuf_addf(&buf, "%d", opts->mainline);
 955                git_config_set_in_file(opts_file, "options.mainline", buf.buf);
 956                strbuf_release(&buf);
 957        }
 958        if (opts->strategy)
 959                git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
 960        if (opts->gpg_sign)
 961                git_config_set_in_file(opts_file, "options.gpg-sign", opts->gpg_sign);
 962        if (opts->xopts) {
 963                int i;
 964                for (i = 0; i < opts->xopts_nr; i++)
 965                        git_config_set_multivar_in_file(opts_file,
 966                                                        "options.strategy-option",
 967                                                        opts->xopts[i], "^$", 0);
 968        }
 969}
 970
 971static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
 972{
 973        struct commit_list *cur;
 974        int res;
 975
 976        setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
 977        if (opts->allow_ff)
 978                assert(!(opts->signoff || opts->no_commit ||
 979                                opts->record_origin || opts->edit));
 980        read_and_refresh_cache(opts);
 981
 982        for (cur = todo_list; cur; cur = cur->next) {
 983                save_todo(cur, opts);
 984                res = do_pick_commit(cur->item, opts);
 985                if (res)
 986                        return res;
 987        }
 988
 989        /*
 990         * Sequence of picks finished successfully; cleanup by
 991         * removing the .git/sequencer directory
 992         */
 993        remove_sequencer_state();
 994        return 0;
 995}
 996
 997static int continue_single_pick(void)
 998{
 999        const char *argv[] = { "commit", NULL };
1000
1001        if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
1002            !file_exists(git_path("REVERT_HEAD")))
1003                return error(_("no cherry-pick or revert in progress"));
1004        return run_command_v_opt(argv, RUN_GIT_CMD);
1005}
1006
1007static int sequencer_continue(struct replay_opts *opts)
1008{
1009        struct commit_list *todo_list = NULL;
1010
1011        if (!file_exists(git_path(SEQ_TODO_FILE)))
1012                return continue_single_pick();
1013        read_populate_opts(&opts);
1014        read_populate_todo(&todo_list, opts);
1015
1016        /* Verify that the conflict has been resolved */
1017        if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
1018            file_exists(git_path("REVERT_HEAD"))) {
1019                int ret = continue_single_pick();
1020                if (ret)
1021                        return ret;
1022        }
1023        if (index_differs_from("HEAD", 0))
1024                return error_dirty_index(opts);
1025        todo_list = todo_list->next;
1026        return pick_commits(todo_list, opts);
1027}
1028
1029static int single_pick(struct commit *cmit, struct replay_opts *opts)
1030{
1031        setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1032        return do_pick_commit(cmit, opts);
1033}
1034
1035int sequencer_pick_revisions(struct replay_opts *opts)
1036{
1037        struct commit_list *todo_list = NULL;
1038        unsigned char sha1[20];
1039        int i;
1040
1041        if (opts->subcommand == REPLAY_NONE)
1042                assert(opts->revs);
1043
1044        read_and_refresh_cache(opts);
1045
1046        /*
1047         * Decide what to do depending on the arguments; a fresh
1048         * cherry-pick should be handled differently from an existing
1049         * one that is being continued
1050         */
1051        if (opts->subcommand == REPLAY_REMOVE_STATE) {
1052                remove_sequencer_state();
1053                return 0;
1054        }
1055        if (opts->subcommand == REPLAY_ROLLBACK)
1056                return sequencer_rollback(opts);
1057        if (opts->subcommand == REPLAY_CONTINUE)
1058                return sequencer_continue(opts);
1059
1060        for (i = 0; i < opts->revs->pending.nr; i++) {
1061                unsigned char sha1[20];
1062                const char *name = opts->revs->pending.objects[i].name;
1063
1064                /* This happens when using --stdin. */
1065                if (!strlen(name))
1066                        continue;
1067
1068                if (!get_sha1(name, sha1)) {
1069                        if (!lookup_commit_reference_gently(sha1, 1)) {
1070                                enum object_type type = sha1_object_info(sha1, NULL);
1071                                die(_("%s: can't cherry-pick a %s"), name, typename(type));
1072                        }
1073                } else
1074                        die(_("%s: bad revision"), name);
1075        }
1076
1077        /*
1078         * If we were called as "git cherry-pick <commit>", just
1079         * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1080         * REVERT_HEAD, and don't touch the sequencer state.
1081         * This means it is possible to cherry-pick in the middle
1082         * of a cherry-pick sequence.
1083         */
1084        if (opts->revs->cmdline.nr == 1 &&
1085            opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1086            opts->revs->no_walk &&
1087            !opts->revs->cmdline.rev->flags) {
1088                struct commit *cmit;
1089                if (prepare_revision_walk(opts->revs))
1090                        die(_("revision walk setup failed"));
1091                cmit = get_revision(opts->revs);
1092                if (!cmit || get_revision(opts->revs))
1093                        die("BUG: expected exactly one commit from walk");
1094                return single_pick(cmit, opts);
1095        }
1096
1097        /*
1098         * Start a new cherry-pick/ revert sequence; but
1099         * first, make sure that an existing one isn't in
1100         * progress
1101         */
1102
1103        walk_revs_populate_todo(&todo_list, opts);
1104        if (create_seq_dir() < 0)
1105                return -1;
1106        if (get_sha1("HEAD", sha1)) {
1107                if (opts->action == REPLAY_REVERT)
1108                        return error(_("Can't revert as initial commit"));
1109                return error(_("Can't cherry-pick into empty head"));
1110        }
1111        save_head(sha1_to_hex(sha1));
1112        save_opts(opts);
1113        return pick_commits(todo_list, opts);
1114}
1115
1116void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1117{
1118        unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1119        struct strbuf sob = STRBUF_INIT;
1120        int has_footer;
1121
1122        strbuf_addstr(&sob, sign_off_header);
1123        strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1124                                getenv("GIT_COMMITTER_EMAIL")));
1125        strbuf_addch(&sob, '\n');
1126
1127        /*
1128         * If the whole message buffer is equal to the sob, pretend that we
1129         * found a conforming footer with a matching sob
1130         */
1131        if (msgbuf->len - ignore_footer == sob.len &&
1132            !strncmp(msgbuf->buf, sob.buf, sob.len))
1133                has_footer = 3;
1134        else
1135                has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1136
1137        if (!has_footer) {
1138                const char *append_newlines = NULL;
1139                size_t len = msgbuf->len - ignore_footer;
1140
1141                if (!len) {
1142                        /*
1143                         * The buffer is completely empty.  Leave foom for
1144                         * the title and body to be filled in by the user.
1145                         */
1146                        append_newlines = "\n\n";
1147                } else if (msgbuf->buf[len - 1] != '\n') {
1148                        /*
1149                         * Incomplete line.  Complete the line and add a
1150                         * blank one so that there is an empty line between
1151                         * the message body and the sob.
1152                         */
1153                        append_newlines = "\n\n";
1154                } else if (len == 1) {
1155                        /*
1156                         * Buffer contains a single newline.  Add another
1157                         * so that we leave room for the title and body.
1158                         */
1159                        append_newlines = "\n";
1160                } else if (msgbuf->buf[len - 2] != '\n') {
1161                        /*
1162                         * Buffer ends with a single newline.  Add another
1163                         * so that there is an empty line between the message
1164                         * body and the sob.
1165                         */
1166                        append_newlines = "\n";
1167                } /* else, the buffer already ends with two newlines. */
1168
1169                if (append_newlines)
1170                        strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1171                                append_newlines, strlen(append_newlines));
1172        }
1173
1174        if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1175                strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1176                                sob.buf, sob.len);
1177
1178        strbuf_release(&sob);
1179}