git.oblomov.eu Git - git/blob - sequencer.c

   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
  21 const char sign_off_header[] = "Signed-off-by: ";
  22 static const char cherry_picked_prefix[] = "(cherry picked from commit ";
  23
  24 static GIT_PATH_FUNC(git_path_todo_file, SEQ_TODO_FILE)
  25 static GIT_PATH_FUNC(git_path_opts_file, SEQ_OPTS_FILE)
  26 static GIT_PATH_FUNC(git_path_seq_dir, SEQ_DIR)
  27 static GIT_PATH_FUNC(git_path_head_file, SEQ_HEAD_FILE)
  28
  29 static 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
  44 static 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  */
  59 static 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
 111 static 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
 120 static const char *action_name(const struct replay_opts *opts)
 121 {
 122         return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
 123 }
 124
 125 struct commit_message {
 126         char *parent_label;
 127         char *label;
 128         char *subject;
 129         const char *message;
 130 };
 131
 132 static 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
 149 static 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
 157 static 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
 183 static 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
 196 static struct tree *empty_tree(void)
 197 {
 198         return lookup_tree(EMPTY_TREE_SHA1_BIN);
 199 }
 200
 201 static 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
 217 static 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
 249 void 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
 266 static 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
 315 static 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  */
 353 static 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
 388 static 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  */
 411 static 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
 446 static 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
 614 leave:
 615         free_message(commit, &msg);
 616
 617         return res;
 618 }
 619
 620 static 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
 636 static 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
 650 static 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
 670 static 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
 720 static 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
 741 static 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
 763 static 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
 798 static 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
 806 static 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
 819 static 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
 832 static 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
 846 static 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
 856 static 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
 870 static 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;
 908 fail:
 909         strbuf_release(&buf);
 910         return -1;
 911 }
 912
 913 static 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
 933 static 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
 966 static 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
 992 static 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
1002 static 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
1024 static 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
1030 int 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
1108 void 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 }