499f5ee89dcb9b5d42c573126552c0f64b91efc3
   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
  24GIT_PATH_FUNC(git_path_seq_dir, "sequencer")
  25
  26static GIT_PATH_FUNC(git_path_todo_file, "sequencer/todo")
  27static GIT_PATH_FUNC(git_path_opts_file, "sequencer/opts")
  28static GIT_PATH_FUNC(git_path_head_file, "sequencer/head")
  29
  30static const char *get_dir(const struct replay_opts *opts)
  31{
  32        return git_path_seq_dir();
  33}
  34
  35static const char *get_todo_path(const struct replay_opts *opts)
  36{
  37        return git_path_todo_file();
  38}
  39
  40static int is_rfc2822_line(const char *buf, int len)
  41{
  42        int i;
  43
  44        for (i = 0; i < len; i++) {
  45                int ch = buf[i];
  46                if (ch == ':')
  47                        return 1;
  48                if (!isalnum(ch) && ch != '-')
  49                        break;
  50        }
  51
  52        return 0;
  53}
  54
  55static int is_cherry_picked_from_line(const char *buf, int len)
  56{
  57        /*
  58         * We only care that it looks roughly like (cherry picked from ...)
  59         */
  60        return len > strlen(cherry_picked_prefix) + 1 &&
  61                starts_with(buf, cherry_picked_prefix) && buf[len - 1] == ')';
  62}
  63
  64/*
  65 * Returns 0 for non-conforming footer
  66 * Returns 1 for conforming footer
  67 * Returns 2 when sob exists within conforming footer
  68 * Returns 3 when sob exists within conforming footer as last entry
  69 */
  70static int has_conforming_footer(struct strbuf *sb, struct strbuf *sob,
  71        int ignore_footer)
  72{
  73        char prev;
  74        int i, k;
  75        int len = sb->len - ignore_footer;
  76        const char *buf = sb->buf;
  77        int found_sob = 0;
  78
  79        /* footer must end with newline */
  80        if (!len || buf[len - 1] != '\n')
  81                return 0;
  82
  83        prev = '\0';
  84        for (i = len - 1; i > 0; i--) {
  85                char ch = buf[i];
  86                if (prev == '\n' && ch == '\n') /* paragraph break */
  87                        break;
  88                prev = ch;
  89        }
  90
  91        /* require at least one blank line */
  92        if (prev != '\n' || buf[i] != '\n')
  93                return 0;
  94
  95        /* advance to start of last paragraph */
  96        while (i < len - 1 && buf[i] == '\n')
  97                i++;
  98
  99        for (; i < len; i = k) {
 100                int found_rfc2822;
 101
 102                for (k = i; k < len && buf[k] != '\n'; k++)
 103                        ; /* do nothing */
 104                k++;
 105
 106                found_rfc2822 = is_rfc2822_line(buf + i, k - i - 1);
 107                if (found_rfc2822 && sob &&
 108                    !strncmp(buf + i, sob->buf, sob->len))
 109                        found_sob = k;
 110
 111                if (!(found_rfc2822 ||
 112                      is_cherry_picked_from_line(buf + i, k - i - 1)))
 113                        return 0;
 114        }
 115        if (found_sob == i)
 116                return 3;
 117        if (found_sob)
 118                return 2;
 119        return 1;
 120}
 121
 122static void remove_sequencer_state(const struct replay_opts *opts)
 123{
 124        struct strbuf dir = STRBUF_INIT;
 125        int i;
 126
 127        free(opts->gpg_sign);
 128        free(opts->strategy);
 129        for (i = 0; i < opts->xopts_nr; i++)
 130                free(opts->xopts[i]);
 131        free(opts->xopts);
 132
 133        strbuf_addf(&dir, "%s", get_dir(opts));
 134        remove_dir_recursively(&dir, 0);
 135        strbuf_release(&dir);
 136}
 137
 138static const char *action_name(const struct replay_opts *opts)
 139{
 140        return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
 141}
 142
 143struct commit_message {
 144        char *parent_label;
 145        char *label;
 146        char *subject;
 147        const char *message;
 148};
 149
 150static const char *short_commit_name(struct commit *commit)
 151{
 152        return find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV);
 153}
 154
 155static int get_message(struct commit *commit, struct commit_message *out)
 156{
 157        const char *abbrev, *subject;
 158        int subject_len;
 159
 160        out->message = logmsg_reencode(commit, NULL, get_commit_output_encoding());
 161        abbrev = short_commit_name(commit);
 162
 163        subject_len = find_commit_subject(out->message, &subject);
 164
 165        out->subject = xmemdupz(subject, subject_len);
 166        out->label = xstrfmt("%s... %s", abbrev, out->subject);
 167        out->parent_label = xstrfmt("parent of %s", out->label);
 168
 169        return 0;
 170}
 171
 172static void free_message(struct commit *commit, struct commit_message *msg)
 173{
 174        free(msg->parent_label);
 175        free(msg->label);
 176        free(msg->subject);
 177        unuse_commit_buffer(commit, msg->message);
 178}
 179
 180static void print_advice(int show_hint, struct replay_opts *opts)
 181{
 182        char *msg = getenv("GIT_CHERRY_PICK_HELP");
 183
 184        if (msg) {
 185                fprintf(stderr, "%s\n", msg);
 186                /*
 187                 * A conflict has occurred but the porcelain
 188                 * (typically rebase --interactive) wants to take care
 189                 * of the commit itself so remove CHERRY_PICK_HEAD
 190                 */
 191                unlink(git_path_cherry_pick_head());
 192                return;
 193        }
 194
 195        if (show_hint) {
 196                if (opts->no_commit)
 197                        advise(_("after resolving the conflicts, mark the corrected paths\n"
 198                                 "with 'git add <paths>' or 'git rm <paths>'"));
 199                else
 200                        advise(_("after resolving the conflicts, mark the corrected paths\n"
 201                                 "with 'git add <paths>' or 'git rm <paths>'\n"
 202                                 "and commit the result with 'git commit'"));
 203        }
 204}
 205
 206static int write_message(struct strbuf *msgbuf, const char *filename)
 207{
 208        static struct lock_file msg_file;
 209
 210        int msg_fd = hold_lock_file_for_update(&msg_file, filename, 0);
 211        if (msg_fd < 0)
 212                return error_errno(_("Could not lock '%s'"), filename);
 213        if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
 214                return error_errno(_("Could not write to %s"), filename);
 215        strbuf_release(msgbuf);
 216        if (commit_lock_file(&msg_file) < 0)
 217                return error(_("Error wrapping up %s."), filename);
 218
 219        return 0;
 220}
 221
 222static struct tree *empty_tree(void)
 223{
 224        return lookup_tree(EMPTY_TREE_SHA1_BIN);
 225}
 226
 227static int error_dirty_index(struct replay_opts *opts)
 228{
 229        if (read_cache_unmerged())
 230                return error_resolve_conflict(action_name(opts));
 231
 232        /* Different translation strings for cherry-pick and revert */
 233        if (opts->action == REPLAY_PICK)
 234                error(_("Your local changes would be overwritten by cherry-pick."));
 235        else
 236                error(_("Your local changes would be overwritten by revert."));
 237
 238        if (advice_commit_before_merge)
 239                advise(_("Commit your changes or stash them to proceed."));
 240        return -1;
 241}
 242
 243static int fast_forward_to(const unsigned char *to, const unsigned char *from,
 244                        int unborn, struct replay_opts *opts)
 245{
 246        struct ref_transaction *transaction;
 247        struct strbuf sb = STRBUF_INIT;
 248        struct strbuf err = STRBUF_INIT;
 249
 250        read_cache();
 251        if (checkout_fast_forward(from, to, 1))
 252                return -1; /* the callee should have complained already */
 253
 254        strbuf_addf(&sb, _("%s: fast-forward"), action_name(opts));
 255
 256        transaction = ref_transaction_begin(&err);
 257        if (!transaction ||
 258            ref_transaction_update(transaction, "HEAD",
 259                                   to, unborn ? null_sha1 : from,
 260                                   0, sb.buf, &err) ||
 261            ref_transaction_commit(transaction, &err)) {
 262                ref_transaction_free(transaction);
 263                error("%s", err.buf);
 264                strbuf_release(&sb);
 265                strbuf_release(&err);
 266                return -1;
 267        }
 268
 269        strbuf_release(&sb);
 270        strbuf_release(&err);
 271        ref_transaction_free(transaction);
 272        return 0;
 273}
 274
 275void append_conflicts_hint(struct strbuf *msgbuf)
 276{
 277        int i;
 278
 279        strbuf_addch(msgbuf, '\n');
 280        strbuf_commented_addf(msgbuf, "Conflicts:\n");
 281        for (i = 0; i < active_nr;) {
 282                const struct cache_entry *ce = active_cache[i++];
 283                if (ce_stage(ce)) {
 284                        strbuf_commented_addf(msgbuf, "\t%s\n", ce->name);
 285                        while (i < active_nr && !strcmp(ce->name,
 286                                                        active_cache[i]->name))
 287                                i++;
 288                }
 289        }
 290}
 291
 292static int do_recursive_merge(struct commit *base, struct commit *next,
 293                              const char *base_label, const char *next_label,
 294                              unsigned char *head, struct strbuf *msgbuf,
 295                              struct replay_opts *opts)
 296{
 297        struct merge_options o;
 298        struct tree *result, *next_tree, *base_tree, *head_tree;
 299        int clean;
 300        char **xopt;
 301        static struct lock_file index_lock;
 302
 303        hold_locked_index(&index_lock, 1);
 304
 305        read_cache();
 306
 307        init_merge_options(&o);
 308        o.ancestor = base ? base_label : "(empty tree)";
 309        o.branch1 = "HEAD";
 310        o.branch2 = next ? next_label : "(empty tree)";
 311
 312        head_tree = parse_tree_indirect(head);
 313        next_tree = next ? next->tree : empty_tree();
 314        base_tree = base ? base->tree : empty_tree();
 315
 316        for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 317                parse_merge_opt(&o, *xopt);
 318
 319        clean = merge_trees(&o,
 320                            head_tree,
 321                            next_tree, base_tree, &result);
 322        strbuf_release(&o.obuf);
 323        if (clean < 0)
 324                return clean;
 325
 326        if (active_cache_changed &&
 327            write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
 328                /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 329                return error(_("%s: Unable to write new index file"),
 330                        action_name(opts));
 331        rollback_lock_file(&index_lock);
 332
 333        if (opts->signoff)
 334                append_signoff(msgbuf, 0, 0);
 335
 336        if (!clean)
 337                append_conflicts_hint(msgbuf);
 338
 339        return !clean;
 340}
 341
 342static int is_index_unchanged(void)
 343{
 344        unsigned char head_sha1[20];
 345        struct commit *head_commit;
 346
 347        if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_sha1, NULL))
 348                return error(_("Could not resolve HEAD commit\n"));
 349
 350        head_commit = lookup_commit(head_sha1);
 351
 352        /*
 353         * If head_commit is NULL, check_commit, called from
 354         * lookup_commit, would have indicated that head_commit is not
 355         * a commit object already.  parse_commit() will return failure
 356         * without further complaints in such a case.  Otherwise, if
 357         * the commit is invalid, parse_commit() will complain.  So
 358         * there is nothing for us to say here.  Just return failure.
 359         */
 360        if (parse_commit(head_commit))
 361                return -1;
 362
 363        if (!active_cache_tree)
 364                active_cache_tree = cache_tree();
 365
 366        if (!cache_tree_fully_valid(active_cache_tree))
 367                if (cache_tree_update(&the_index, 0))
 368                        return error(_("Unable to update cache tree\n"));
 369
 370        return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.oid.hash);
 371}
 372
 373/*
 374 * If we are cherry-pick, and if the merge did not result in
 375 * hand-editing, we will hit this commit and inherit the original
 376 * author date and name.
 377 * If we are revert, or if our cherry-pick results in a hand merge,
 378 * we had better say that the current user is responsible for that.
 379 */
 380static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 381                          int allow_empty)
 382{
 383        struct argv_array array;
 384        int rc;
 385        const char *value;
 386
 387        argv_array_init(&array);
 388        argv_array_push(&array, "commit");
 389        argv_array_push(&array, "-n");
 390
 391        if (opts->gpg_sign)
 392                argv_array_pushf(&array, "-S%s", opts->gpg_sign);
 393        if (opts->signoff)
 394                argv_array_push(&array, "-s");
 395        if (!opts->edit) {
 396                argv_array_push(&array, "-F");
 397                argv_array_push(&array, defmsg);
 398                if (!opts->signoff &&
 399                    !opts->record_origin &&
 400                    git_config_get_value("commit.cleanup", &value))
 401                        argv_array_push(&array, "--cleanup=verbatim");
 402        }
 403
 404        if (allow_empty)
 405                argv_array_push(&array, "--allow-empty");
 406
 407        if (opts->allow_empty_message)
 408                argv_array_push(&array, "--allow-empty-message");
 409
 410        rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 411        argv_array_clear(&array);
 412        return rc;
 413}
 414
 415static int is_original_commit_empty(struct commit *commit)
 416{
 417        const unsigned char *ptree_sha1;
 418
 419        if (parse_commit(commit))
 420                return error(_("Could not parse commit %s\n"),
 421                             oid_to_hex(&commit->object.oid));
 422        if (commit->parents) {
 423                struct commit *parent = commit->parents->item;
 424                if (parse_commit(parent))
 425                        return error(_("Could not parse parent commit %s\n"),
 426                                oid_to_hex(&parent->object.oid));
 427                ptree_sha1 = parent->tree->object.oid.hash;
 428        } else {
 429                ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 430        }
 431
 432        return !hashcmp(ptree_sha1, commit->tree->object.oid.hash);
 433}
 434
 435/*
 436 * Do we run "git commit" with "--allow-empty"?
 437 */
 438static int allow_empty(struct replay_opts *opts, struct commit *commit)
 439{
 440        int index_unchanged, empty_commit;
 441
 442        /*
 443         * Three cases:
 444         *
 445         * (1) we do not allow empty at all and error out.
 446         *
 447         * (2) we allow ones that were initially empty, but
 448         * forbid the ones that become empty;
 449         *
 450         * (3) we allow both.
 451         */
 452        if (!opts->allow_empty)
 453                return 0; /* let "git commit" barf as necessary */
 454
 455        index_unchanged = is_index_unchanged();
 456        if (index_unchanged < 0)
 457                return index_unchanged;
 458        if (!index_unchanged)
 459                return 0; /* we do not have to say --allow-empty */
 460
 461        if (opts->keep_redundant_commits)
 462                return 1;
 463
 464        empty_commit = is_original_commit_empty(commit);
 465        if (empty_commit < 0)
 466                return empty_commit;
 467        if (!empty_commit)
 468                return 0;
 469        else
 470                return 1;
 471}
 472
 473static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 474{
 475        unsigned char head[20];
 476        struct commit *base, *next, *parent;
 477        const char *base_label, *next_label;
 478        struct commit_message msg = { NULL, NULL, NULL, NULL };
 479        struct strbuf msgbuf = STRBUF_INIT;
 480        int res, unborn = 0, allow;
 481
 482        if (opts->no_commit) {
 483                /*
 484                 * We do not intend to commit immediately.  We just want to
 485                 * merge the differences in, so let's compute the tree
 486                 * that represents the "current" state for merge-recursive
 487                 * to work on.
 488                 */
 489                if (write_cache_as_tree(head, 0, NULL))
 490                        return error(_("Your index file is unmerged."));
 491        } else {
 492                unborn = get_sha1("HEAD", head);
 493                if (unborn)
 494                        hashcpy(head, EMPTY_TREE_SHA1_BIN);
 495                if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
 496                        return error_dirty_index(opts);
 497        }
 498        discard_cache();
 499
 500        if (!commit->parents) {
 501                parent = NULL;
 502        }
 503        else if (commit->parents->next) {
 504                /* Reverting or cherry-picking a merge commit */
 505                int cnt;
 506                struct commit_list *p;
 507
 508                if (!opts->mainline)
 509                        return error(_("Commit %s is a merge but no -m option was given."),
 510                                oid_to_hex(&commit->object.oid));
 511
 512                for (cnt = 1, p = commit->parents;
 513                     cnt != opts->mainline && p;
 514                     cnt++)
 515                        p = p->next;
 516                if (cnt != opts->mainline || !p)
 517                        return error(_("Commit %s does not have parent %d"),
 518                                oid_to_hex(&commit->object.oid), opts->mainline);
 519                parent = p->item;
 520        } else if (0 < opts->mainline)
 521                return error(_("Mainline was specified but commit %s is not a merge."),
 522                        oid_to_hex(&commit->object.oid));
 523        else
 524                parent = commit->parents->item;
 525
 526        if (opts->allow_ff &&
 527            ((parent && !hashcmp(parent->object.oid.hash, head)) ||
 528             (!parent && unborn)))
 529                return fast_forward_to(commit->object.oid.hash, head, unborn, opts);
 530
 531        if (parent && parse_commit(parent) < 0)
 532                /* TRANSLATORS: The first %s will be "revert" or
 533                   "cherry-pick", the second %s a SHA1 */
 534                return error(_("%s: cannot parse parent commit %s"),
 535                        action_name(opts), oid_to_hex(&parent->object.oid));
 536
 537        if (get_message(commit, &msg) != 0)
 538                return error(_("Cannot get commit message for %s"),
 539                        oid_to_hex(&commit->object.oid));
 540
 541        /*
 542         * "commit" is an existing commit.  We would want to apply
 543         * the difference it introduces since its first parent "prev"
 544         * on top of the current HEAD if we are cherry-pick.  Or the
 545         * reverse of it if we are revert.
 546         */
 547
 548        if (opts->action == REPLAY_REVERT) {
 549                base = commit;
 550                base_label = msg.label;
 551                next = parent;
 552                next_label = msg.parent_label;
 553                strbuf_addstr(&msgbuf, "Revert \"");
 554                strbuf_addstr(&msgbuf, msg.subject);
 555                strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 556                strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
 557
 558                if (commit->parents && commit->parents->next) {
 559                        strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 560                        strbuf_addstr(&msgbuf, oid_to_hex(&parent->object.oid));
 561                }
 562                strbuf_addstr(&msgbuf, ".\n");
 563        } else {
 564                const char *p;
 565
 566                base = parent;
 567                base_label = msg.parent_label;
 568                next = commit;
 569                next_label = msg.label;
 570
 571                /*
 572                 * Append the commit log message to msgbuf; it starts
 573                 * after the tree, parent, author, committer
 574                 * information followed by "\n\n".
 575                 */
 576                p = strstr(msg.message, "\n\n");
 577                if (p)
 578                        strbuf_addstr(&msgbuf, skip_blank_lines(p + 2));
 579
 580                if (opts->record_origin) {
 581                        if (!has_conforming_footer(&msgbuf, NULL, 0))
 582                                strbuf_addch(&msgbuf, '\n');
 583                        strbuf_addstr(&msgbuf, cherry_picked_prefix);
 584                        strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
 585                        strbuf_addstr(&msgbuf, ")\n");
 586                }
 587        }
 588
 589        if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 590                res = do_recursive_merge(base, next, base_label, next_label,
 591                                         head, &msgbuf, opts);
 592                if (res < 0)
 593                        return res;
 594                res |= write_message(&msgbuf, git_path_merge_msg());
 595        } else {
 596                struct commit_list *common = NULL;
 597                struct commit_list *remotes = NULL;
 598
 599                res = write_message(&msgbuf, git_path_merge_msg());
 600
 601                commit_list_insert(base, &common);
 602                commit_list_insert(next, &remotes);
 603                res |= try_merge_command(opts->strategy,
 604                                         opts->xopts_nr, (const char **)opts->xopts,
 605                                        common, sha1_to_hex(head), remotes);
 606                free_commit_list(common);
 607                free_commit_list(remotes);
 608        }
 609
 610        /*
 611         * If the merge was clean or if it failed due to conflict, we write
 612         * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 613         * However, if the merge did not even start, then we don't want to
 614         * write it at all.
 615         */
 616        if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1) &&
 617            update_ref(NULL, "CHERRY_PICK_HEAD", commit->object.oid.hash, NULL,
 618                       REF_NODEREF, UPDATE_REFS_MSG_ON_ERR))
 619                res = -1;
 620        if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1) &&
 621            update_ref(NULL, "REVERT_HEAD", commit->object.oid.hash, NULL,
 622                       REF_NODEREF, UPDATE_REFS_MSG_ON_ERR))
 623                res = -1;
 624
 625        if (res) {
 626                error(opts->action == REPLAY_REVERT
 627                      ? _("could not revert %s... %s")
 628                      : _("could not apply %s... %s"),
 629                      short_commit_name(commit), msg.subject);
 630                print_advice(res == 1, opts);
 631                rerere(opts->allow_rerere_auto);
 632                goto leave;
 633        }
 634
 635        allow = allow_empty(opts, commit);
 636        if (allow < 0) {
 637                res = allow;
 638                goto leave;
 639        }
 640        if (!opts->no_commit)
 641                res = run_git_commit(git_path_merge_msg(), opts, allow);
 642
 643leave:
 644        free_message(commit, &msg);
 645
 646        return res;
 647}
 648
 649static int prepare_revs(struct replay_opts *opts)
 650{
 651        /*
 652         * picking (but not reverting) ranges (but not individual revisions)
 653         * should be done in reverse
 654         */
 655        if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 656                opts->revs->reverse ^= 1;
 657
 658        if (prepare_revision_walk(opts->revs))
 659                return error(_("revision walk setup failed"));
 660
 661        if (!opts->revs->commits)
 662                return error(_("empty commit set passed"));
 663        return 0;
 664}
 665
 666static int read_and_refresh_cache(struct replay_opts *opts)
 667{
 668        static struct lock_file index_lock;
 669        int index_fd = hold_locked_index(&index_lock, 0);
 670        if (read_index_preload(&the_index, NULL) < 0) {
 671                rollback_lock_file(&index_lock);
 672                return error(_("git %s: failed to read the index"),
 673                        action_name(opts));
 674        }
 675        refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 676        if (the_index.cache_changed && index_fd >= 0) {
 677                if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK)) {
 678                        rollback_lock_file(&index_lock);
 679                        return error(_("git %s: failed to refresh the index"),
 680                                action_name(opts));
 681                }
 682        }
 683        rollback_lock_file(&index_lock);
 684        return 0;
 685}
 686
 687static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 688                struct replay_opts *opts)
 689{
 690        struct commit_list *cur = NULL;
 691        const char *sha1_abbrev = NULL;
 692        const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 693        const char *subject;
 694        int subject_len;
 695
 696        for (cur = todo_list; cur; cur = cur->next) {
 697                const char *commit_buffer = get_commit_buffer(cur->item, NULL);
 698                sha1_abbrev = find_unique_abbrev(cur->item->object.oid.hash, DEFAULT_ABBREV);
 699                subject_len = find_commit_subject(commit_buffer, &subject);
 700                strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 701                        subject_len, subject);
 702                unuse_commit_buffer(cur->item, commit_buffer);
 703        }
 704        return 0;
 705}
 706
 707static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 708{
 709        unsigned char commit_sha1[20];
 710        enum replay_action action;
 711        char *end_of_object_name;
 712        int saved, status, padding;
 713
 714        if (starts_with(bol, "pick")) {
 715                action = REPLAY_PICK;
 716                bol += strlen("pick");
 717        } else if (starts_with(bol, "revert")) {
 718                action = REPLAY_REVERT;
 719                bol += strlen("revert");
 720        } else
 721                return NULL;
 722
 723        /* Eat up extra spaces/ tabs before object name */
 724        padding = strspn(bol, " \t");
 725        if (!padding)
 726                return NULL;
 727        bol += padding;
 728
 729        end_of_object_name = bol + strcspn(bol, " \t\n");
 730        saved = *end_of_object_name;
 731        *end_of_object_name = '\0';
 732        status = get_sha1(bol, commit_sha1);
 733        *end_of_object_name = saved;
 734
 735        /*
 736         * Verify that the action matches up with the one in
 737         * opts; we don't support arbitrary instructions
 738         */
 739        if (action != opts->action) {
 740                if (action == REPLAY_REVERT)
 741                      error((opts->action == REPLAY_REVERT)
 742                            ? _("Cannot revert during another revert.")
 743                            : _("Cannot revert during a cherry-pick."));
 744                else
 745                      error((opts->action == REPLAY_REVERT)
 746                            ? _("Cannot cherry-pick during a revert.")
 747                            : _("Cannot cherry-pick during another cherry-pick."));
 748                return NULL;
 749        }
 750
 751        if (status < 0)
 752                return NULL;
 753
 754        return lookup_commit_reference(commit_sha1);
 755}
 756
 757static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
 758                        struct replay_opts *opts)
 759{
 760        struct commit_list **next = todo_list;
 761        struct commit *commit;
 762        char *p = buf;
 763        int i;
 764
 765        for (i = 1; *p; i++) {
 766                char *eol = strchrnul(p, '\n');
 767                commit = parse_insn_line(p, eol, opts);
 768                if (!commit)
 769                        return error(_("Could not parse line %d."), i);
 770                next = commit_list_append(commit, next);
 771                p = *eol ? eol + 1 : eol;
 772        }
 773        if (!*todo_list)
 774                return error(_("No commits parsed."));
 775        return 0;
 776}
 777
 778static int read_populate_todo(struct commit_list **todo_list,
 779                        struct replay_opts *opts)
 780{
 781        const char *todo_file = get_todo_path(opts);
 782        struct strbuf buf = STRBUF_INIT;
 783        int fd, res;
 784
 785        fd = open(todo_file, O_RDONLY);
 786        if (fd < 0)
 787                return error_errno(_("Could not open %s"), todo_file);
 788        if (strbuf_read(&buf, fd, 0) < 0) {
 789                close(fd);
 790                strbuf_release(&buf);
 791                return error(_("Could not read %s."), todo_file);
 792        }
 793        close(fd);
 794
 795        res = parse_insn_buffer(buf.buf, todo_list, opts);
 796        strbuf_release(&buf);
 797        if (res)
 798                return error(_("Unusable instruction sheet: %s"), todo_file);
 799        return 0;
 800}
 801
 802static int git_config_string_dup(char **dest,
 803                                 const char *var, const char *value)
 804{
 805        if (!value)
 806                return config_error_nonbool(var);
 807        free(*dest);
 808        *dest = xstrdup(value);
 809        return 0;
 810}
 811
 812static int populate_opts_cb(const char *key, const char *value, void *data)
 813{
 814        struct replay_opts *opts = data;
 815        int error_flag = 1;
 816
 817        if (!value)
 818                error_flag = 0;
 819        else if (!strcmp(key, "options.no-commit"))
 820                opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 821        else if (!strcmp(key, "options.edit"))
 822                opts->edit = git_config_bool_or_int(key, value, &error_flag);
 823        else if (!strcmp(key, "options.signoff"))
 824                opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 825        else if (!strcmp(key, "options.record-origin"))
 826                opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 827        else if (!strcmp(key, "options.allow-ff"))
 828                opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 829        else if (!strcmp(key, "options.mainline"))
 830                opts->mainline = git_config_int(key, value);
 831        else if (!strcmp(key, "options.strategy"))
 832                git_config_string_dup(&opts->strategy, key, value);
 833        else if (!strcmp(key, "options.gpg-sign"))
 834                git_config_string_dup(&opts->gpg_sign, key, value);
 835        else if (!strcmp(key, "options.strategy-option")) {
 836                ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 837                opts->xopts[opts->xopts_nr++] = xstrdup(value);
 838        } else
 839                return error(_("Invalid key: %s"), key);
 840
 841        if (!error_flag)
 842                return error(_("Invalid value for %s: %s"), key, value);
 843
 844        return 0;
 845}
 846
 847static int read_populate_opts(struct replay_opts *opts)
 848{
 849        if (!file_exists(git_path_opts_file()))
 850                return 0;
 851        /*
 852         * The function git_parse_source(), called from git_config_from_file(),
 853         * may die() in case of a syntactically incorrect file. We do not care
 854         * about this case, though, because we wrote that file ourselves, so we
 855         * are pretty certain that it is syntactically correct.
 856         */
 857        if (git_config_from_file(populate_opts_cb, git_path_opts_file(), opts) < 0)
 858                return error(_("Malformed options sheet: %s"),
 859                        git_path_opts_file());
 860        return 0;
 861}
 862
 863static int walk_revs_populate_todo(struct commit_list **todo_list,
 864                                struct replay_opts *opts)
 865{
 866        struct commit *commit;
 867        struct commit_list **next;
 868
 869        if (prepare_revs(opts))
 870                return -1;
 871
 872        next = todo_list;
 873        while ((commit = get_revision(opts->revs)))
 874                next = commit_list_append(commit, next);
 875        return 0;
 876}
 877
 878static int create_seq_dir(void)
 879{
 880        if (file_exists(git_path_seq_dir())) {
 881                error(_("a cherry-pick or revert is already in progress"));
 882                advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 883                return -1;
 884        }
 885        else if (mkdir(git_path_seq_dir(), 0777) < 0)
 886                return error_errno(_("Could not create sequencer directory %s"),
 887                                   git_path_seq_dir());
 888        return 0;
 889}
 890
 891static int save_head(const char *head)
 892{
 893        static struct lock_file head_lock;
 894        struct strbuf buf = STRBUF_INIT;
 895        int fd;
 896
 897        fd = hold_lock_file_for_update(&head_lock, git_path_head_file(), 0);
 898        if (fd < 0) {
 899                rollback_lock_file(&head_lock);
 900                return error_errno(_("Could not lock HEAD"));
 901        }
 902        strbuf_addf(&buf, "%s\n", head);
 903        if (write_in_full(fd, buf.buf, buf.len) < 0) {
 904                rollback_lock_file(&head_lock);
 905                return error_errno(_("Could not write to %s"),
 906                                   git_path_head_file());
 907        }
 908        if (commit_lock_file(&head_lock) < 0) {
 909                rollback_lock_file(&head_lock);
 910                return error(_("Error wrapping up %s."), git_path_head_file());
 911        }
 912        return 0;
 913}
 914
 915static int reset_for_rollback(const unsigned char *sha1)
 916{
 917        const char *argv[4];    /* reset --merge <arg> + NULL */
 918        argv[0] = "reset";
 919        argv[1] = "--merge";
 920        argv[2] = sha1_to_hex(sha1);
 921        argv[3] = NULL;
 922        return run_command_v_opt(argv, RUN_GIT_CMD);
 923}
 924
 925static int rollback_single_pick(void)
 926{
 927        unsigned char head_sha1[20];
 928
 929        if (!file_exists(git_path_cherry_pick_head()) &&
 930            !file_exists(git_path_revert_head()))
 931                return error(_("no cherry-pick or revert in progress"));
 932        if (read_ref_full("HEAD", 0, head_sha1, NULL))
 933                return error(_("cannot resolve HEAD"));
 934        if (is_null_sha1(head_sha1))
 935                return error(_("cannot abort from a branch yet to be born"));
 936        return reset_for_rollback(head_sha1);
 937}
 938
 939static int sequencer_rollback(struct replay_opts *opts)
 940{
 941        FILE *f;
 942        unsigned char sha1[20];
 943        struct strbuf buf = STRBUF_INIT;
 944
 945        f = fopen(git_path_head_file(), "r");
 946        if (!f && errno == ENOENT) {
 947                /*
 948                 * There is no multiple-cherry-pick in progress.
 949                 * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 950                 * a single-cherry-pick in progress, abort that.
 951                 */
 952                return rollback_single_pick();
 953        }
 954        if (!f)
 955                return error_errno(_("cannot open %s"), git_path_head_file());
 956        if (strbuf_getline_lf(&buf, f)) {
 957                error(_("cannot read %s: %s"), git_path_head_file(),
 958                      ferror(f) ?  strerror(errno) : _("unexpected end of file"));
 959                fclose(f);
 960                goto fail;
 961        }
 962        fclose(f);
 963        if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 964                error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 965                        git_path_head_file());
 966                goto fail;
 967        }
 968        if (is_null_sha1(sha1)) {
 969                error(_("cannot abort from a branch yet to be born"));
 970                goto fail;
 971        }
 972        if (reset_for_rollback(sha1))
 973                goto fail;
 974        remove_sequencer_state(opts);
 975        strbuf_release(&buf);
 976        return 0;
 977fail:
 978        strbuf_release(&buf);
 979        return -1;
 980}
 981
 982static int save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 983{
 984        static struct lock_file todo_lock;
 985        struct strbuf buf = STRBUF_INIT;
 986        int fd;
 987
 988        fd = hold_lock_file_for_update(&todo_lock, git_path_todo_file(), 0);
 989        if (fd < 0)
 990                return error_errno(_("Could not lock '%s'"),
 991                                   git_path_todo_file());
 992        if (format_todo(&buf, todo_list, opts) < 0) {
 993                strbuf_release(&buf);
 994                return error(_("Could not format %s."), git_path_todo_file());
 995        }
 996        if (write_in_full(fd, buf.buf, buf.len) < 0) {
 997                strbuf_release(&buf);
 998                return error_errno(_("Could not write to %s"),
 999                                   git_path_todo_file());
1000        }
1001        if (commit_lock_file(&todo_lock) < 0) {
1002                strbuf_release(&buf);
1003                return error(_("Error wrapping up %s."), git_path_todo_file());
1004        }
1005        strbuf_release(&buf);
1006        return 0;
1007}
1008
1009static int save_opts(struct replay_opts *opts)
1010{
1011        const char *opts_file = git_path_opts_file();
1012        int res = 0;
1013
1014        if (opts->no_commit)
1015                res |= git_config_set_in_file_gently(opts_file, "options.no-commit", "true");
1016        if (opts->edit)
1017                res |= git_config_set_in_file_gently(opts_file, "options.edit", "true");
1018        if (opts->signoff)
1019                res |= git_config_set_in_file_gently(opts_file, "options.signoff", "true");
1020        if (opts->record_origin)
1021                res |= git_config_set_in_file_gently(opts_file, "options.record-origin", "true");
1022        if (opts->allow_ff)
1023                res |= git_config_set_in_file_gently(opts_file, "options.allow-ff", "true");
1024        if (opts->mainline) {
1025                struct strbuf buf = STRBUF_INIT;
1026                strbuf_addf(&buf, "%d", opts->mainline);
1027                res |= git_config_set_in_file_gently(opts_file, "options.mainline", buf.buf);
1028                strbuf_release(&buf);
1029        }
1030        if (opts->strategy)
1031                res |= git_config_set_in_file_gently(opts_file, "options.strategy", opts->strategy);
1032        if (opts->gpg_sign)
1033                res |= git_config_set_in_file_gently(opts_file, "options.gpg-sign", opts->gpg_sign);
1034        if (opts->xopts) {
1035                int i;
1036                for (i = 0; i < opts->xopts_nr; i++)
1037                        res |= git_config_set_multivar_in_file_gently(opts_file,
1038                                                        "options.strategy-option",
1039                                                        opts->xopts[i], "^$", 0);
1040        }
1041        return res;
1042}
1043
1044static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
1045{
1046        struct commit_list *cur;
1047        int res;
1048
1049        setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1050        if (opts->allow_ff)
1051                assert(!(opts->signoff || opts->no_commit ||
1052                                opts->record_origin || opts->edit));
1053        if (read_and_refresh_cache(opts))
1054                return -1;
1055
1056        for (cur = todo_list; cur; cur = cur->next) {
1057                if (save_todo(cur, opts))
1058                        return -1;
1059                res = do_pick_commit(cur->item, opts);
1060                if (res)
1061                        return res;
1062        }
1063
1064        /*
1065         * Sequence of picks finished successfully; cleanup by
1066         * removing the .git/sequencer directory
1067         */
1068        remove_sequencer_state(opts);
1069        return 0;
1070}
1071
1072static int continue_single_pick(void)
1073{
1074        const char *argv[] = { "commit", NULL };
1075
1076        if (!file_exists(git_path_cherry_pick_head()) &&
1077            !file_exists(git_path_revert_head()))
1078                return error(_("no cherry-pick or revert in progress"));
1079        return run_command_v_opt(argv, RUN_GIT_CMD);
1080}
1081
1082static int sequencer_continue(struct replay_opts *opts)
1083{
1084        struct commit_list *todo_list = NULL;
1085
1086        if (!file_exists(get_todo_path(opts)))
1087                return continue_single_pick();
1088        if (read_populate_opts(opts) ||
1089                        read_populate_todo(&todo_list, opts))
1090                return -1;
1091
1092        /* Verify that the conflict has been resolved */
1093        if (file_exists(git_path_cherry_pick_head()) ||
1094            file_exists(git_path_revert_head())) {
1095                int ret = continue_single_pick();
1096                if (ret)
1097                        return ret;
1098        }
1099        if (index_differs_from("HEAD", 0))
1100                return error_dirty_index(opts);
1101        todo_list = todo_list->next;
1102        return pick_commits(todo_list, opts);
1103}
1104
1105static int single_pick(struct commit *cmit, struct replay_opts *opts)
1106{
1107        setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1108        return do_pick_commit(cmit, opts);
1109}
1110
1111int sequencer_pick_revisions(struct replay_opts *opts)
1112{
1113        struct commit_list *todo_list = NULL;
1114        unsigned char sha1[20];
1115        int i;
1116
1117        if (opts->subcommand == REPLAY_NONE)
1118                assert(opts->revs);
1119
1120        if (read_and_refresh_cache(opts))
1121                return -1;
1122
1123        /*
1124         * Decide what to do depending on the arguments; a fresh
1125         * cherry-pick should be handled differently from an existing
1126         * one that is being continued
1127         */
1128        if (opts->subcommand == REPLAY_REMOVE_STATE) {
1129                remove_sequencer_state(opts);
1130                return 0;
1131        }
1132        if (opts->subcommand == REPLAY_ROLLBACK)
1133                return sequencer_rollback(opts);
1134        if (opts->subcommand == REPLAY_CONTINUE)
1135                return sequencer_continue(opts);
1136
1137        for (i = 0; i < opts->revs->pending.nr; i++) {
1138                unsigned char sha1[20];
1139                const char *name = opts->revs->pending.objects[i].name;
1140
1141                /* This happens when using --stdin. */
1142                if (!strlen(name))
1143                        continue;
1144
1145                if (!get_sha1(name, sha1)) {
1146                        if (!lookup_commit_reference_gently(sha1, 1)) {
1147                                enum object_type type = sha1_object_info(sha1, NULL);
1148                                return error(_("%s: can't cherry-pick a %s"),
1149                                        name, typename(type));
1150                        }
1151                } else
1152                        return error(_("%s: bad revision"), name);
1153        }
1154
1155        /*
1156         * If we were called as "git cherry-pick <commit>", just
1157         * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1158         * REVERT_HEAD, and don't touch the sequencer state.
1159         * This means it is possible to cherry-pick in the middle
1160         * of a cherry-pick sequence.
1161         */
1162        if (opts->revs->cmdline.nr == 1 &&
1163            opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1164            opts->revs->no_walk &&
1165            !opts->revs->cmdline.rev->flags) {
1166                struct commit *cmit;
1167                if (prepare_revision_walk(opts->revs))
1168                        return error(_("revision walk setup failed"));
1169                cmit = get_revision(opts->revs);
1170                if (!cmit || get_revision(opts->revs))
1171                        return error("BUG: expected exactly one commit from walk");
1172                return single_pick(cmit, opts);
1173        }
1174
1175        /*
1176         * Start a new cherry-pick/ revert sequence; but
1177         * first, make sure that an existing one isn't in
1178         * progress
1179         */
1180
1181        if (walk_revs_populate_todo(&todo_list, opts) ||
1182                        create_seq_dir() < 0)
1183                return -1;
1184        if (get_sha1("HEAD", sha1) && (opts->action == REPLAY_REVERT))
1185                return error(_("Can't revert as initial commit"));
1186        if (save_head(sha1_to_hex(sha1)))
1187                return -1;
1188        if (save_opts(opts))
1189                return -1;
1190        return pick_commits(todo_list, opts);
1191}
1192
1193void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1194{
1195        unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1196        struct strbuf sob = STRBUF_INIT;
1197        int has_footer;
1198
1199        strbuf_addstr(&sob, sign_off_header);
1200        strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1201                                getenv("GIT_COMMITTER_EMAIL")));
1202        strbuf_addch(&sob, '\n');
1203
1204        /*
1205         * If the whole message buffer is equal to the sob, pretend that we
1206         * found a conforming footer with a matching sob
1207         */
1208        if (msgbuf->len - ignore_footer == sob.len &&
1209            !strncmp(msgbuf->buf, sob.buf, sob.len))
1210                has_footer = 3;
1211        else
1212                has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1213
1214        if (!has_footer) {
1215                const char *append_newlines = NULL;
1216                size_t len = msgbuf->len - ignore_footer;
1217
1218                if (!len) {
1219                        /*
1220                         * The buffer is completely empty.  Leave foom for
1221                         * the title and body to be filled in by the user.
1222                         */
1223                        append_newlines = "\n\n";
1224                } else if (msgbuf->buf[len - 1] != '\n') {
1225                        /*
1226                         * Incomplete line.  Complete the line and add a
1227                         * blank one so that there is an empty line between
1228                         * the message body and the sob.
1229                         */
1230                        append_newlines = "\n\n";
1231                } else if (len == 1) {
1232                        /*
1233                         * Buffer contains a single newline.  Add another
1234                         * so that we leave room for the title and body.
1235                         */
1236                        append_newlines = "\n";
1237                } else if (msgbuf->buf[len - 2] != '\n') {
1238                        /*
1239                         * Buffer ends with a single newline.  Add another
1240                         * so that there is an empty line between the message
1241                         * body and the sob.
1242                         */
1243                        append_newlines = "\n";
1244                } /* else, the buffer already ends with two newlines. */
1245
1246                if (append_newlines)
1247                        strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1248                                append_newlines, strlen(append_newlines));
1249        }
1250
1251        if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1252                strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1253                                sob.buf, sob.len);
1254
1255        strbuf_release(&sob);
1256}