sequencer.con commit Merge branch 'po/range-doc' (d0b61dc)
   1#include "cache.h"
   2#include "lockfile.h"
   3#include "sequencer.h"
   4#include "dir.h"
   5#include "object.h"
   6#include "commit.h"
   7#include "tag.h"
   8#include "run-command.h"
   9#include "exec_cmd.h"
  10#include "utf8.h"
  11#include "cache-tree.h"
  12#include "diff.h"
  13#include "revision.h"
  14#include "rerere.h"
  15#include "merge-recursive.h"
  16#include "refs.h"
  17#include "argv-array.h"
  18
  19#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
  20
  21const char sign_off_header[] = "Signed-off-by: ";
  22static const char cherry_picked_prefix[] = "(cherry picked from commit ";
  23
  24static GIT_PATH_FUNC(git_path_todo_file, SEQ_TODO_FILE)
  25static GIT_PATH_FUNC(git_path_opts_file, SEQ_OPTS_FILE)
  26static GIT_PATH_FUNC(git_path_seq_dir, SEQ_DIR)
  27static GIT_PATH_FUNC(git_path_head_file, SEQ_HEAD_FILE)
  28
  29static int is_rfc2822_line(const char *buf, int len)
  30{
  31        int i;
  32
  33        for (i = 0; i < len; i++) {
  34                int ch = buf[i];
  35                if (ch == ':')
  36                        return 1;
  37                if (!isalnum(ch) && ch != '-')
  38                        break;
  39        }
  40
  41        return 0;
  42}
  43
  44static int is_cherry_picked_from_line(const char *buf, int len)
  45{
  46        /*
  47         * We only care that it looks roughly like (cherry picked from ...)
  48         */
  49        return len > strlen(cherry_picked_prefix) + 1 &&
  50                starts_with(buf, cherry_picked_prefix) && buf[len - 1] == ')';
  51}
  52
  53/*
  54 * Returns 0 for non-conforming footer
  55 * Returns 1 for conforming footer
  56 * Returns 2 when sob exists within conforming footer
  57 * Returns 3 when sob exists within conforming footer as last entry
  58 */
  59static int has_conforming_footer(struct strbuf *sb, struct strbuf *sob,
  60        int ignore_footer)
  61{
  62        char prev;
  63        int i, k;
  64        int len = sb->len - ignore_footer;
  65        const char *buf = sb->buf;
  66        int found_sob = 0;
  67
  68        /* footer must end with newline */
  69        if (!len || buf[len - 1] != '\n')
  70                return 0;
  71
  72        prev = '\0';
  73        for (i = len - 1; i > 0; i--) {
  74                char ch = buf[i];
  75                if (prev == '\n' && ch == '\n') /* paragraph break */
  76                        break;
  77                prev = ch;
  78        }
  79
  80        /* require at least one blank line */
  81        if (prev != '\n' || buf[i] != '\n')
  82                return 0;
  83
  84        /* advance to start of last paragraph */
  85        while (i < len - 1 && buf[i] == '\n')
  86                i++;
  87
  88        for (; i < len; i = k) {
  89                int found_rfc2822;
  90
  91                for (k = i; k < len && buf[k] != '\n'; k++)
  92                        ; /* do nothing */
  93                k++;
  94
  95                found_rfc2822 = is_rfc2822_line(buf + i, k - i - 1);
  96                if (found_rfc2822 && sob &&
  97                    !strncmp(buf + i, sob->buf, sob->len))
  98                        found_sob = k;
  99
 100                if (!(found_rfc2822 ||
 101                      is_cherry_picked_from_line(buf + i, k - i - 1)))
 102                        return 0;
 103        }
 104        if (found_sob == i)
 105                return 3;
 106        if (found_sob)
 107                return 2;
 108        return 1;
 109}
 110
 111static void remove_sequencer_state(void)
 112{
 113        struct strbuf seq_dir = STRBUF_INIT;
 114
 115        strbuf_addstr(&seq_dir, git_path(SEQ_DIR));
 116        remove_dir_recursively(&seq_dir, 0);
 117        strbuf_release(&seq_dir);
 118}
 119
 120static const char *action_name(const struct replay_opts *opts)
 121{
 122        return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
 123}
 124
 125struct commit_message {
 126        char *parent_label;
 127        char *label;
 128        char *subject;
 129        const char *message;
 130};
 131
 132static int get_message(struct commit *commit, struct commit_message *out)
 133{
 134        const char *abbrev, *subject;
 135        int subject_len;
 136
 137        out->message = logmsg_reencode(commit, NULL, get_commit_output_encoding());
 138        abbrev = find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV);
 139
 140        subject_len = find_commit_subject(out->message, &subject);
 141
 142        out->subject = xmemdupz(subject, subject_len);
 143        out->label = xstrfmt("%s... %s", abbrev, out->subject);
 144        out->parent_label = xstrfmt("parent of %s", out->label);
 145
 146        return 0;
 147}
 148
 149static void free_message(struct commit *commit, struct commit_message *msg)
 150{
 151        free(msg->parent_label);
 152        free(msg->label);
 153        free(msg->subject);
 154        unuse_commit_buffer(commit, msg->message);
 155}
 156
 157static void print_advice(int show_hint, struct replay_opts *opts)
 158{
 159        char *msg = getenv("GIT_CHERRY_PICK_HELP");
 160
 161        if (msg) {
 162                fprintf(stderr, "%s\n", msg);
 163                /*
 164                 * A conflict has occurred but the porcelain
 165                 * (typically rebase --interactive) wants to take care
 166                 * of the commit itself so remove CHERRY_PICK_HEAD
 167                 */
 168                unlink(git_path_cherry_pick_head());
 169                return;
 170        }
 171
 172        if (show_hint) {
 173                if (opts->no_commit)
 174                        advise(_("after resolving the conflicts, mark the corrected paths\n"
 175                                 "with 'git add <paths>' or 'git rm <paths>'"));
 176                else
 177                        advise(_("after resolving the conflicts, mark the corrected paths\n"
 178                                 "with 'git add <paths>' or 'git rm <paths>'\n"
 179                                 "and commit the result with 'git commit'"));
 180        }
 181}
 182
 183static void write_message(struct strbuf *msgbuf, const char *filename)
 184{
 185        static struct lock_file msg_file;
 186
 187        int msg_fd = hold_lock_file_for_update(&msg_file, filename,
 188                                               LOCK_DIE_ON_ERROR);
 189        if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
 190                die_errno(_("Could not write to %s"), filename);
 191        strbuf_release(msgbuf);
 192        if (commit_lock_file(&msg_file) < 0)
 193                die(_("Error wrapping up %s."), filename);
 194}
 195
 196static struct tree *empty_tree(void)
 197{
 198        return lookup_tree(EMPTY_TREE_SHA1_BIN);
 199}
 200
 201static int error_dirty_index(struct replay_opts *opts)
 202{
 203        if (read_cache_unmerged())
 204                return error_resolve_conflict(action_name(opts));
 205
 206        /* Different translation strings for cherry-pick and revert */
 207        if (opts->action == REPLAY_PICK)
 208                error(_("Your local changes would be overwritten by cherry-pick."));
 209        else
 210                error(_("Your local changes would be overwritten by revert."));
 211
 212        if (advice_commit_before_merge)
 213                advise(_("Commit your changes or stash them to proceed."));
 214        return -1;
 215}
 216
 217static int fast_forward_to(const unsigned char *to, const unsigned char *from,
 218                        int unborn, struct replay_opts *opts)
 219{
 220        struct ref_transaction *transaction;
 221        struct strbuf sb = STRBUF_INIT;
 222        struct strbuf err = STRBUF_INIT;
 223
 224        read_cache();
 225        if (checkout_fast_forward(from, to, 1))
 226                exit(128); /* the callee should have complained already */
 227
 228        strbuf_addf(&sb, _("%s: fast-forward"), action_name(opts));
 229
 230        transaction = ref_transaction_begin(&err);
 231        if (!transaction ||
 232            ref_transaction_update(transaction, "HEAD",
 233                                   to, unborn ? null_sha1 : from,
 234                                   0, sb.buf, &err) ||
 235            ref_transaction_commit(transaction, &err)) {
 236                ref_transaction_free(transaction);
 237                error("%s", err.buf);
 238                strbuf_release(&sb);
 239                strbuf_release(&err);
 240                return -1;
 241        }
 242
 243        strbuf_release(&sb);
 244        strbuf_release(&err);
 245        ref_transaction_free(transaction);
 246        return 0;
 247}
 248
 249void append_conflicts_hint(struct strbuf *msgbuf)
 250{
 251        int i;
 252
 253        strbuf_addch(msgbuf, '\n');
 254        strbuf_commented_addf(msgbuf, "Conflicts:\n");
 255        for (i = 0; i < active_nr;) {
 256                const struct cache_entry *ce = active_cache[i++];
 257                if (ce_stage(ce)) {
 258                        strbuf_commented_addf(msgbuf, "\t%s\n", ce->name);
 259                        while (i < active_nr && !strcmp(ce->name,
 260                                                        active_cache[i]->name))
 261                                i++;
 262                }
 263        }
 264}
 265
 266static int do_recursive_merge(struct commit *base, struct commit *next,
 267                              const char *base_label, const char *next_label,
 268                              unsigned char *head, struct strbuf *msgbuf,
 269                              struct replay_opts *opts)
 270{
 271        struct merge_options o;
 272        struct tree *result, *next_tree, *base_tree, *head_tree;
 273        int clean;
 274        const char **xopt;
 275        static struct lock_file index_lock;
 276
 277        hold_locked_index(&index_lock, 1);
 278
 279        read_cache();
 280
 281        init_merge_options(&o);
 282        o.ancestor = base ? base_label : "(empty tree)";
 283        o.branch1 = "HEAD";
 284        o.branch2 = next ? next_label : "(empty tree)";
 285
 286        head_tree = parse_tree_indirect(head);
 287        next_tree = next ? next->tree : empty_tree();
 288        base_tree = base ? base->tree : empty_tree();
 289
 290        for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 291                parse_merge_opt(&o, *xopt);
 292
 293        clean = merge_trees(&o,
 294                            head_tree,
 295                            next_tree, base_tree, &result);
 296        strbuf_release(&o.obuf);
 297        if (clean < 0)
 298                return clean;
 299
 300        if (active_cache_changed &&
 301            write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
 302                /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 303                die(_("%s: Unable to write new index file"), action_name(opts));
 304        rollback_lock_file(&index_lock);
 305
 306        if (opts->signoff)
 307                append_signoff(msgbuf, 0, 0);
 308
 309        if (!clean)
 310                append_conflicts_hint(msgbuf);
 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", RESOLVE_REF_READING, head_sha1, 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(&the_index, 0))
 341                        return error(_("Unable to update cache tree\n"));
 342
 343        return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.oid.hash);
 344}
 345
 346/*
 347 * If we are cherry-pick, and if the merge did not result in
 348 * hand-editing, we will hit this commit and inherit the original
 349 * author date and name.
 350 * If we are revert, or if our cherry-pick results in a hand merge,
 351 * we had better say that the current user is responsible for that.
 352 */
 353static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 354                          int allow_empty)
 355{
 356        struct argv_array array;
 357        int rc;
 358        const char *value;
 359
 360        argv_array_init(&array);
 361        argv_array_push(&array, "commit");
 362        argv_array_push(&array, "-n");
 363
 364        if (opts->gpg_sign)
 365                argv_array_pushf(&array, "-S%s", opts->gpg_sign);
 366        if (opts->signoff)
 367                argv_array_push(&array, "-s");
 368        if (!opts->edit) {
 369                argv_array_push(&array, "-F");
 370                argv_array_push(&array, defmsg);
 371                if (!opts->signoff &&
 372                    !opts->record_origin &&
 373                    git_config_get_value("commit.cleanup", &value))
 374                        argv_array_push(&array, "--cleanup=verbatim");
 375        }
 376
 377        if (allow_empty)
 378                argv_array_push(&array, "--allow-empty");
 379
 380        if (opts->allow_empty_message)
 381                argv_array_push(&array, "--allow-empty-message");
 382
 383        rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 384        argv_array_clear(&array);
 385        return rc;
 386}
 387
 388static int is_original_commit_empty(struct commit *commit)
 389{
 390        const unsigned char *ptree_sha1;
 391
 392        if (parse_commit(commit))
 393                return error(_("Could not parse commit %s\n"),
 394                             oid_to_hex(&commit->object.oid));
 395        if (commit->parents) {
 396                struct commit *parent = commit->parents->item;
 397                if (parse_commit(parent))
 398                        return error(_("Could not parse parent commit %s\n"),
 399                                oid_to_hex(&parent->object.oid));
 400                ptree_sha1 = parent->tree->object.oid.hash;
 401        } else {
 402                ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 403        }
 404
 405        return !hashcmp(ptree_sha1, commit->tree->object.oid.hash);
 406}
 407
 408/*
 409 * Do we run "git commit" with "--allow-empty"?
 410 */
 411static int allow_empty(struct replay_opts *opts, struct commit *commit)
 412{
 413        int index_unchanged, empty_commit;
 414
 415        /*
 416         * Three cases:
 417         *
 418         * (1) we do not allow empty at all and error out.
 419         *
 420         * (2) we allow ones that were initially empty, but
 421         * forbid the ones that become empty;
 422         *
 423         * (3) we allow both.
 424         */
 425        if (!opts->allow_empty)
 426                return 0; /* let "git commit" barf as necessary */
 427
 428        index_unchanged = is_index_unchanged();
 429        if (index_unchanged < 0)
 430                return index_unchanged;
 431        if (!index_unchanged)
 432                return 0; /* we do not have to say --allow-empty */
 433
 434        if (opts->keep_redundant_commits)
 435                return 1;
 436
 437        empty_commit = is_original_commit_empty(commit);
 438        if (empty_commit < 0)
 439                return empty_commit;
 440        if (!empty_commit)
 441                return 0;
 442        else
 443                return 1;
 444}
 445
 446static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 447{
 448        unsigned char head[20];
 449        struct commit *base, *next, *parent;
 450        const char *base_label, *next_label;
 451        struct commit_message msg = { NULL, NULL, NULL, NULL };
 452        struct strbuf msgbuf = STRBUF_INIT;
 453        int res, unborn = 0, allow;
 454
 455        if (opts->no_commit) {
 456                /*
 457                 * We do not intend to commit immediately.  We just want to
 458                 * merge the differences in, so let's compute the tree
 459                 * that represents the "current" state for merge-recursive
 460                 * to work on.
 461                 */
 462                if (write_cache_as_tree(head, 0, NULL))
 463                        die (_("Your index file is unmerged."));
 464        } else {
 465                unborn = get_sha1("HEAD", head);
 466                if (unborn)
 467                        hashcpy(head, EMPTY_TREE_SHA1_BIN);
 468                if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
 469                        return error_dirty_index(opts);
 470        }
 471        discard_cache();
 472
 473        if (!commit->parents) {
 474                parent = NULL;
 475        }
 476        else if (commit->parents->next) {
 477                /* Reverting or cherry-picking a merge commit */
 478                int cnt;
 479                struct commit_list *p;
 480
 481                if (!opts->mainline)
 482                        return error(_("Commit %s is a merge but no -m option was given."),
 483                                oid_to_hex(&commit->object.oid));
 484
 485                for (cnt = 1, p = commit->parents;
 486                     cnt != opts->mainline && p;
 487                     cnt++)
 488                        p = p->next;
 489                if (cnt != opts->mainline || !p)
 490                        return error(_("Commit %s does not have parent %d"),
 491                                oid_to_hex(&commit->object.oid), opts->mainline);
 492                parent = p->item;
 493        } else if (0 < opts->mainline)
 494                return error(_("Mainline was specified but commit %s is not a merge."),
 495                        oid_to_hex(&commit->object.oid));
 496        else
 497                parent = commit->parents->item;
 498
 499        if (opts->allow_ff &&
 500            ((parent && !hashcmp(parent->object.oid.hash, head)) ||
 501             (!parent && unborn)))
 502                return fast_forward_to(commit->object.oid.hash, head, unborn, opts);
 503
 504        if (parent && parse_commit(parent) < 0)
 505                /* TRANSLATORS: The first %s will be "revert" or
 506                   "cherry-pick", the second %s a SHA1 */
 507                return error(_("%s: cannot parse parent commit %s"),
 508                        action_name(opts), oid_to_hex(&parent->object.oid));
 509
 510        if (get_message(commit, &msg) != 0)
 511                return error(_("Cannot get commit message for %s"),
 512                        oid_to_hex(&commit->object.oid));
 513
 514        /*
 515         * "commit" is an existing commit.  We would want to apply
 516         * the difference it introduces since its first parent "prev"
 517         * on top of the current HEAD if we are cherry-pick.  Or the
 518         * reverse of it if we are revert.
 519         */
 520
 521        if (opts->action == REPLAY_REVERT) {
 522                base = commit;
 523                base_label = msg.label;
 524                next = parent;
 525                next_label = msg.parent_label;
 526                strbuf_addstr(&msgbuf, "Revert \"");
 527                strbuf_addstr(&msgbuf, msg.subject);
 528                strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 529                strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
 530
 531                if (commit->parents && commit->parents->next) {
 532                        strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 533                        strbuf_addstr(&msgbuf, oid_to_hex(&parent->object.oid));
 534                }
 535                strbuf_addstr(&msgbuf, ".\n");
 536        } else {
 537                const char *p;
 538
 539                base = parent;
 540                base_label = msg.parent_label;
 541                next = commit;
 542                next_label = msg.label;
 543
 544                /*
 545                 * Append the commit log message to msgbuf; it starts
 546                 * after the tree, parent, author, committer
 547                 * information followed by "\n\n".
 548                 */
 549                p = strstr(msg.message, "\n\n");
 550                if (p)
 551                        strbuf_addstr(&msgbuf, skip_blank_lines(p + 2));
 552
 553                if (opts->record_origin) {
 554                        if (!has_conforming_footer(&msgbuf, NULL, 0))
 555                                strbuf_addch(&msgbuf, '\n');
 556                        strbuf_addstr(&msgbuf, cherry_picked_prefix);
 557                        strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
 558                        strbuf_addstr(&msgbuf, ")\n");
 559                }
 560        }
 561
 562        if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 563                res = do_recursive_merge(base, next, base_label, next_label,
 564                                         head, &msgbuf, opts);
 565                if (res < 0)
 566                        return res;
 567                write_message(&msgbuf, git_path_merge_msg());
 568        } else {
 569                struct commit_list *common = NULL;
 570                struct commit_list *remotes = NULL;
 571
 572                write_message(&msgbuf, git_path_merge_msg());
 573
 574                commit_list_insert(base, &common);
 575                commit_list_insert(next, &remotes);
 576                res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 577                                        common, sha1_to_hex(head), remotes);
 578                free_commit_list(common);
 579                free_commit_list(remotes);
 580        }
 581
 582        /*
 583         * If the merge was clean or if it failed due to conflict, we write
 584         * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 585         * However, if the merge did not even start, then we don't want to
 586         * write it at all.
 587         */
 588        if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 589                update_ref(NULL, "CHERRY_PICK_HEAD", commit->object.oid.hash, NULL,
 590                           REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
 591        if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 592                update_ref(NULL, "REVERT_HEAD", commit->object.oid.hash, NULL,
 593                           REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
 594
 595        if (res) {
 596                error(opts->action == REPLAY_REVERT
 597                      ? _("could not revert %s... %s")
 598                      : _("could not apply %s... %s"),
 599                      find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV),
 600                      msg.subject);
 601                print_advice(res == 1, opts);
 602                rerere(opts->allow_rerere_auto);
 603                goto leave;
 604        }
 605
 606        allow = allow_empty(opts, commit);
 607        if (allow < 0) {
 608                res = allow;
 609                goto leave;
 610        }
 611        if (!opts->no_commit)
 612                res = run_git_commit(git_path_merge_msg(), opts, allow);
 613
 614leave:
 615        free_message(commit, &msg);
 616
 617        return res;
 618}
 619
 620static void prepare_revs(struct replay_opts *opts)
 621{
 622        /*
 623         * picking (but not reverting) ranges (but not individual revisions)
 624         * should be done in reverse
 625         */
 626        if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 627                opts->revs->reverse ^= 1;
 628
 629        if (prepare_revision_walk(opts->revs))
 630                die(_("revision walk setup failed"));
 631
 632        if (!opts->revs->commits)
 633                die(_("empty commit set passed"));
 634}
 635
 636static void read_and_refresh_cache(struct replay_opts *opts)
 637{
 638        static struct lock_file index_lock;
 639        int index_fd = hold_locked_index(&index_lock, 0);
 640        if (read_index_preload(&the_index, NULL) < 0)
 641                die(_("git %s: failed to read the index"), action_name(opts));
 642        refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 643        if (the_index.cache_changed && index_fd >= 0) {
 644                if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
 645                        die(_("git %s: failed to refresh the index"), action_name(opts));
 646        }
 647        rollback_lock_file(&index_lock);
 648}
 649
 650static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 651                struct replay_opts *opts)
 652{
 653        struct commit_list *cur = NULL;
 654        const char *sha1_abbrev = NULL;
 655        const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 656        const char *subject;
 657        int subject_len;
 658
 659        for (cur = todo_list; cur; cur = cur->next) {
 660                const char *commit_buffer = get_commit_buffer(cur->item, NULL);
 661                sha1_abbrev = find_unique_abbrev(cur->item->object.oid.hash, DEFAULT_ABBREV);
 662                subject_len = find_commit_subject(commit_buffer, &subject);
 663                strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 664                        subject_len, subject);
 665                unuse_commit_buffer(cur->item, commit_buffer);
 666        }
 667        return 0;
 668}
 669
 670static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 671{
 672        unsigned char commit_sha1[20];
 673        enum replay_action action;
 674        char *end_of_object_name;
 675        int saved, status, padding;
 676
 677        if (starts_with(bol, "pick")) {
 678                action = REPLAY_PICK;
 679                bol += strlen("pick");
 680        } else if (starts_with(bol, "revert")) {
 681                action = REPLAY_REVERT;
 682                bol += strlen("revert");
 683        } else
 684                return NULL;
 685
 686        /* Eat up extra spaces/ tabs before object name */
 687        padding = strspn(bol, " \t");
 688        if (!padding)
 689                return NULL;
 690        bol += padding;
 691
 692        end_of_object_name = bol + strcspn(bol, " \t\n");
 693        saved = *end_of_object_name;
 694        *end_of_object_name = '\0';
 695        status = get_sha1(bol, commit_sha1);
 696        *end_of_object_name = saved;
 697
 698        /*
 699         * Verify that the action matches up with the one in
 700         * opts; we don't support arbitrary instructions
 701         */
 702        if (action != opts->action) {
 703                if (action == REPLAY_REVERT)
 704                      error((opts->action == REPLAY_REVERT)
 705                            ? _("Cannot revert during another revert.")
 706                            : _("Cannot revert during a cherry-pick."));
 707                else
 708                      error((opts->action == REPLAY_REVERT)
 709                            ? _("Cannot cherry-pick during a revert.")
 710                            : _("Cannot cherry-pick during another cherry-pick."));
 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        struct strbuf buf = STRBUF_INIT;
 745        int fd, res;
 746
 747        fd = open(git_path_todo_file(), O_RDONLY);
 748        if (fd < 0)
 749                die_errno(_("Could not open %s"), git_path_todo_file());
 750        if (strbuf_read(&buf, fd, 0) < 0) {
 751                close(fd);
 752                strbuf_release(&buf);
 753                die(_("Could not read %s."), git_path_todo_file());
 754        }
 755        close(fd);
 756
 757        res = parse_insn_buffer(buf.buf, todo_list, opts);
 758        strbuf_release(&buf);
 759        if (res)
 760                die(_("Unusable instruction sheet: %s"), git_path_todo_file());
 761}
 762
 763static int populate_opts_cb(const char *key, const char *value, void *data)
 764{
 765        struct replay_opts *opts = data;
 766        int error_flag = 1;
 767
 768        if (!value)
 769                error_flag = 0;
 770        else if (!strcmp(key, "options.no-commit"))
 771                opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 772        else if (!strcmp(key, "options.edit"))
 773                opts->edit = git_config_bool_or_int(key, value, &error_flag);
 774        else if (!strcmp(key, "options.signoff"))
 775                opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 776        else if (!strcmp(key, "options.record-origin"))
 777                opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 778        else if (!strcmp(key, "options.allow-ff"))
 779                opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 780        else if (!strcmp(key, "options.mainline"))
 781                opts->mainline = git_config_int(key, value);
 782        else if (!strcmp(key, "options.strategy"))
 783                git_config_string(&opts->strategy, key, value);
 784        else if (!strcmp(key, "options.gpg-sign"))
 785                git_config_string(&opts->gpg_sign, key, value);
 786        else if (!strcmp(key, "options.strategy-option")) {
 787                ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 788                opts->xopts[opts->xopts_nr++] = xstrdup(value);
 789        } else
 790                return error(_("Invalid key: %s"), key);
 791
 792        if (!error_flag)
 793                return error(_("Invalid value for %s: %s"), key, value);
 794
 795        return 0;
 796}
 797
 798static void read_populate_opts(struct replay_opts **opts_ptr)
 799{
 800        if (!file_exists(git_path_opts_file()))
 801                return;
 802        if (git_config_from_file(populate_opts_cb, git_path_opts_file(), *opts_ptr) < 0)
 803                die(_("Malformed options sheet: %s"), git_path_opts_file());
 804}
 805
 806static void walk_revs_populate_todo(struct commit_list **todo_list,
 807                                struct replay_opts *opts)
 808{
 809        struct commit *commit;
 810        struct commit_list **next;
 811
 812        prepare_revs(opts);
 813
 814        next = todo_list;
 815        while ((commit = get_revision(opts->revs)))
 816                next = commit_list_append(commit, next);
 817}
 818
 819static int create_seq_dir(void)
 820{
 821        if (file_exists(git_path_seq_dir())) {
 822                error(_("a cherry-pick or revert is already in progress"));
 823                advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 824                return -1;
 825        }
 826        else if (mkdir(git_path_seq_dir(), 0777) < 0)
 827                die_errno(_("Could not create sequencer directory %s"),
 828                          git_path_seq_dir());
 829        return 0;
 830}
 831
 832static void save_head(const char *head)
 833{
 834        static struct lock_file head_lock;
 835        struct strbuf buf = STRBUF_INIT;
 836        int fd;
 837
 838        fd = hold_lock_file_for_update(&head_lock, git_path_head_file(), LOCK_DIE_ON_ERROR);
 839        strbuf_addf(&buf, "%s\n", head);
 840        if (write_in_full(fd, buf.buf, buf.len) < 0)
 841                die_errno(_("Could not write to %s"), git_path_head_file());
 842        if (commit_lock_file(&head_lock) < 0)
 843                die(_("Error wrapping up %s."), git_path_head_file());
 844}
 845
 846static int reset_for_rollback(const unsigned char *sha1)
 847{
 848        const char *argv[4];    /* reset --merge <arg> + NULL */
 849        argv[0] = "reset";
 850        argv[1] = "--merge";
 851        argv[2] = sha1_to_hex(sha1);
 852        argv[3] = NULL;
 853        return run_command_v_opt(argv, RUN_GIT_CMD);
 854}
 855
 856static int rollback_single_pick(void)
 857{
 858        unsigned char head_sha1[20];
 859
 860        if (!file_exists(git_path_cherry_pick_head()) &&
 861            !file_exists(git_path_revert_head()))
 862                return error(_("no cherry-pick or revert in progress"));
 863        if (read_ref_full("HEAD", 0, head_sha1, NULL))
 864                return error(_("cannot resolve HEAD"));
 865        if (is_null_sha1(head_sha1))
 866                return error(_("cannot abort from a branch yet to be born"));
 867        return reset_for_rollback(head_sha1);
 868}
 869
 870static int sequencer_rollback(struct replay_opts *opts)
 871{
 872        FILE *f;
 873        unsigned char sha1[20];
 874        struct strbuf buf = STRBUF_INIT;
 875
 876        f = fopen(git_path_head_file(), "r");
 877        if (!f && errno == ENOENT) {
 878                /*
 879                 * There is no multiple-cherry-pick in progress.
 880                 * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 881                 * a single-cherry-pick in progress, abort that.
 882                 */
 883                return rollback_single_pick();
 884        }
 885        if (!f)
 886                return error_errno(_("cannot open %s"), git_path_head_file());
 887        if (strbuf_getline_lf(&buf, f)) {
 888                error(_("cannot read %s: %s"), git_path_head_file(),
 889                      ferror(f) ?  strerror(errno) : _("unexpected end of file"));
 890                fclose(f);
 891                goto fail;
 892        }
 893        fclose(f);
 894        if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 895                error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 896                        git_path_head_file());
 897                goto fail;
 898        }
 899        if (is_null_sha1(sha1)) {
 900                error(_("cannot abort from a branch yet to be born"));
 901                goto fail;
 902        }
 903        if (reset_for_rollback(sha1))
 904                goto fail;
 905        remove_sequencer_state();
 906        strbuf_release(&buf);
 907        return 0;
 908fail:
 909        strbuf_release(&buf);
 910        return -1;
 911}
 912
 913static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 914{
 915        static struct lock_file todo_lock;
 916        struct strbuf buf = STRBUF_INIT;
 917        int fd;
 918
 919        fd = hold_lock_file_for_update(&todo_lock, git_path_todo_file(), LOCK_DIE_ON_ERROR);
 920        if (format_todo(&buf, todo_list, opts) < 0)
 921                die(_("Could not format %s."), git_path_todo_file());
 922        if (write_in_full(fd, buf.buf, buf.len) < 0) {
 923                strbuf_release(&buf);
 924                die_errno(_("Could not write to %s"), git_path_todo_file());
 925        }
 926        if (commit_lock_file(&todo_lock) < 0) {
 927                strbuf_release(&buf);
 928                die(_("Error wrapping up %s."), git_path_todo_file());
 929        }
 930        strbuf_release(&buf);
 931}
 932
 933static void save_opts(struct replay_opts *opts)
 934{
 935        const char *opts_file = git_path_opts_file();
 936
 937        if (opts->no_commit)
 938                git_config_set_in_file(opts_file, "options.no-commit", "true");
 939        if (opts->edit)
 940                git_config_set_in_file(opts_file, "options.edit", "true");
 941        if (opts->signoff)
 942                git_config_set_in_file(opts_file, "options.signoff", "true");
 943        if (opts->record_origin)
 944                git_config_set_in_file(opts_file, "options.record-origin", "true");
 945        if (opts->allow_ff)
 946                git_config_set_in_file(opts_file, "options.allow-ff", "true");
 947        if (opts->mainline) {
 948                struct strbuf buf = STRBUF_INIT;
 949                strbuf_addf(&buf, "%d", opts->mainline);
 950                git_config_set_in_file(opts_file, "options.mainline", buf.buf);
 951                strbuf_release(&buf);
 952        }
 953        if (opts->strategy)
 954                git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
 955        if (opts->gpg_sign)
 956                git_config_set_in_file(opts_file, "options.gpg-sign", opts->gpg_sign);
 957        if (opts->xopts) {
 958                int i;
 959                for (i = 0; i < opts->xopts_nr; i++)
 960                        git_config_set_multivar_in_file(opts_file,
 961                                                        "options.strategy-option",
 962                                                        opts->xopts[i], "^$", 0);
 963        }
 964}
 965
 966static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
 967{
 968        struct commit_list *cur;
 969        int res;
 970
 971        setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
 972        if (opts->allow_ff)
 973                assert(!(opts->signoff || opts->no_commit ||
 974                                opts->record_origin || opts->edit));
 975        read_and_refresh_cache(opts);
 976
 977        for (cur = todo_list; cur; cur = cur->next) {
 978                save_todo(cur, opts);
 979                res = do_pick_commit(cur->item, opts);
 980                if (res)
 981                        return res;
 982        }
 983
 984        /*
 985         * Sequence of picks finished successfully; cleanup by
 986         * removing the .git/sequencer directory
 987         */
 988        remove_sequencer_state();
 989        return 0;
 990}
 991
 992static int continue_single_pick(void)
 993{
 994        const char *argv[] = { "commit", NULL };
 995
 996        if (!file_exists(git_path_cherry_pick_head()) &&
 997            !file_exists(git_path_revert_head()))
 998                return error(_("no cherry-pick or revert in progress"));
 999        return run_command_v_opt(argv, RUN_GIT_CMD);
1000}
1001
1002static int sequencer_continue(struct replay_opts *opts)
1003{
1004        struct commit_list *todo_list = NULL;
1005
1006        if (!file_exists(git_path_todo_file()))
1007                return continue_single_pick();
1008        read_populate_opts(&opts);
1009        read_populate_todo(&todo_list, opts);
1010
1011        /* Verify that the conflict has been resolved */
1012        if (file_exists(git_path_cherry_pick_head()) ||
1013            file_exists(git_path_revert_head())) {
1014                int ret = continue_single_pick();
1015                if (ret)
1016                        return ret;
1017        }
1018        if (index_differs_from("HEAD", 0))
1019                return error_dirty_index(opts);
1020        todo_list = todo_list->next;
1021        return pick_commits(todo_list, opts);
1022}
1023
1024static int single_pick(struct commit *cmit, struct replay_opts *opts)
1025{
1026        setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1027        return do_pick_commit(cmit, opts);
1028}
1029
1030int sequencer_pick_revisions(struct replay_opts *opts)
1031{
1032        struct commit_list *todo_list = NULL;
1033        unsigned char sha1[20];
1034        int i;
1035
1036        if (opts->subcommand == REPLAY_NONE)
1037                assert(opts->revs);
1038
1039        read_and_refresh_cache(opts);
1040
1041        /*
1042         * Decide what to do depending on the arguments; a fresh
1043         * cherry-pick should be handled differently from an existing
1044         * one that is being continued
1045         */
1046        if (opts->subcommand == REPLAY_REMOVE_STATE) {
1047                remove_sequencer_state();
1048                return 0;
1049        }
1050        if (opts->subcommand == REPLAY_ROLLBACK)
1051                return sequencer_rollback(opts);
1052        if (opts->subcommand == REPLAY_CONTINUE)
1053                return sequencer_continue(opts);
1054
1055        for (i = 0; i < opts->revs->pending.nr; i++) {
1056                unsigned char sha1[20];
1057                const char *name = opts->revs->pending.objects[i].name;
1058
1059                /* This happens when using --stdin. */
1060                if (!strlen(name))
1061                        continue;
1062
1063                if (!get_sha1(name, sha1)) {
1064                        if (!lookup_commit_reference_gently(sha1, 1)) {
1065                                enum object_type type = sha1_object_info(sha1, NULL);
1066                                die(_("%s: can't cherry-pick a %s"), name, typename(type));
1067                        }
1068                } else
1069                        die(_("%s: bad revision"), name);
1070        }
1071
1072        /*
1073         * If we were called as "git cherry-pick <commit>", just
1074         * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1075         * REVERT_HEAD, and don't touch the sequencer state.
1076         * This means it is possible to cherry-pick in the middle
1077         * of a cherry-pick sequence.
1078         */
1079        if (opts->revs->cmdline.nr == 1 &&
1080            opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1081            opts->revs->no_walk &&
1082            !opts->revs->cmdline.rev->flags) {
1083                struct commit *cmit;
1084                if (prepare_revision_walk(opts->revs))
1085                        die(_("revision walk setup failed"));
1086                cmit = get_revision(opts->revs);
1087                if (!cmit || get_revision(opts->revs))
1088                        die("BUG: expected exactly one commit from walk");
1089                return single_pick(cmit, opts);
1090        }
1091
1092        /*
1093         * Start a new cherry-pick/ revert sequence; but
1094         * first, make sure that an existing one isn't in
1095         * progress
1096         */
1097
1098        walk_revs_populate_todo(&todo_list, opts);
1099        if (create_seq_dir() < 0)
1100                return -1;
1101        if (get_sha1("HEAD", sha1) && (opts->action == REPLAY_REVERT))
1102                return error(_("Can't revert as initial commit"));
1103        save_head(sha1_to_hex(sha1));
1104        save_opts(opts);
1105        return pick_commits(todo_list, opts);
1106}
1107
1108void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1109{
1110        unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1111        struct strbuf sob = STRBUF_INIT;
1112        int has_footer;
1113
1114        strbuf_addstr(&sob, sign_off_header);
1115        strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1116                                getenv("GIT_COMMITTER_EMAIL")));
1117        strbuf_addch(&sob, '\n');
1118
1119        /*
1120         * If the whole message buffer is equal to the sob, pretend that we
1121         * found a conforming footer with a matching sob
1122         */
1123        if (msgbuf->len - ignore_footer == sob.len &&
1124            !strncmp(msgbuf->buf, sob.buf, sob.len))
1125                has_footer = 3;
1126        else
1127                has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1128
1129        if (!has_footer) {
1130                const char *append_newlines = NULL;
1131                size_t len = msgbuf->len - ignore_footer;
1132
1133                if (!len) {
1134                        /*
1135                         * The buffer is completely empty.  Leave foom for
1136                         * the title and body to be filled in by the user.
1137                         */
1138                        append_newlines = "\n\n";
1139                } else if (msgbuf->buf[len - 1] != '\n') {
1140                        /*
1141                         * Incomplete line.  Complete the line and add a
1142                         * blank one so that there is an empty line between
1143                         * the message body and the sob.
1144                         */
1145                        append_newlines = "\n\n";
1146                } else if (len == 1) {
1147                        /*
1148                         * Buffer contains a single newline.  Add another
1149                         * so that we leave room for the title and body.
1150                         */
1151                        append_newlines = "\n";
1152                } else if (msgbuf->buf[len - 2] != '\n') {
1153                        /*
1154                         * Buffer ends with a single newline.  Add another
1155                         * so that there is an empty line between the message
1156                         * body and the sob.
1157                         */
1158                        append_newlines = "\n";
1159                } /* else, the buffer already ends with two newlines. */
1160
1161                if (append_newlines)
1162                        strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1163                                append_newlines, strlen(append_newlines));
1164        }
1165
1166        if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1167                strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1168                                sob.buf, sob.len);
1169
1170        strbuf_release(&sob);
1171}