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

   1 #include "cache.h"
   2 #include "sequencer.h"
   3 #include "dir.h"
   4 #include "object.h"
   5 #include "commit.h"
   6 #include "tag.h"
   7 #include "run-command.h"
   8 #include "exec_cmd.h"
   9 #include "utf8.h"
  10 #include "cache-tree.h"
  11 #include "diff.h"
  12 #include "revision.h"
  13 #include "rerere.h"
  14 #include "merge-recursive.h"
  15 #include "refs.h"
  16 #include "argv-array.h"
  17
  18 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
  19
  20 const char sign_off_header[] = "Signed-off-by: ";
  21 static const char cherry_picked_prefix[] = "(cherry picked from commit ";
  22
  23 static int is_rfc2822_line(const char *buf, int len)
  24 {
  25         int i;
  26
  27         for (i = 0; i < len; i++) {
  28                 int ch = buf[i];
  29                 if (ch == ':')
  30                         return 1;
  31                 if (!isalnum(ch) && ch != '-')
  32                         break;
  33         }
  34
  35         return 0;
  36 }
  37
  38 static int is_cherry_picked_from_line(const char *buf, int len)
  39 {
  40         /*
  41          * We only care that it looks roughly like (cherry picked from ...)
  42          */
  43         return len > strlen(cherry_picked_prefix) + 1 &&
  44                 starts_with(buf, cherry_picked_prefix) && buf[len - 1] == ')';
  45 }
  46
  47 /*
  48  * Returns 0 for non-conforming footer
  49  * Returns 1 for conforming footer
  50  * Returns 2 when sob exists within conforming footer
  51  * Returns 3 when sob exists within conforming footer as last entry
  52  */
  53 static int has_conforming_footer(struct strbuf *sb, struct strbuf *sob,
  54         int ignore_footer)
  55 {
  56         char prev;
  57         int i, k;
  58         int len = sb->len - ignore_footer;
  59         const char *buf = sb->buf;
  60         int found_sob = 0;
  61
  62         /* footer must end with newline */
  63         if (!len || buf[len - 1] != '\n')
  64                 return 0;
  65
  66         prev = '\0';
  67         for (i = len - 1; i > 0; i--) {
  68                 char ch = buf[i];
  69                 if (prev == '\n' && ch == '\n') /* paragraph break */
  70                         break;
  71                 prev = ch;
  72         }
  73
  74         /* require at least one blank line */
  75         if (prev != '\n' || buf[i] != '\n')
  76                 return 0;
  77
  78         /* advance to start of last paragraph */
  79         while (i < len - 1 && buf[i] == '\n')
  80                 i++;
  81
  82         for (; i < len; i = k) {
  83                 int found_rfc2822;
  84
  85                 for (k = i; k < len && buf[k] != '\n'; k++)
  86                         ; /* do nothing */
  87                 k++;
  88
  89                 found_rfc2822 = is_rfc2822_line(buf + i, k - i - 1);
  90                 if (found_rfc2822 && sob &&
  91                     !strncmp(buf + i, sob->buf, sob->len))
  92                         found_sob = k;
  93
  94                 if (!(found_rfc2822 ||
  95                       is_cherry_picked_from_line(buf + i, k - i - 1)))
  96                         return 0;
  97         }
  98         if (found_sob == i)
  99                 return 3;
 100         if (found_sob)
 101                 return 2;
 102         return 1;
 103 }
 104
 105 static void remove_sequencer_state(void)
 106 {
 107         struct strbuf seq_dir = STRBUF_INIT;
 108
 109         strbuf_addf(&seq_dir, "%s", git_path(SEQ_DIR));
 110         remove_dir_recursively(&seq_dir, 0);
 111         strbuf_release(&seq_dir);
 112 }
 113
 114 static const char *action_name(const struct replay_opts *opts)
 115 {
 116         return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
 117 }
 118
 119 struct commit_message {
 120         char *parent_label;
 121         const char *label;
 122         const char *subject;
 123         const char *message;
 124 };
 125
 126 static int get_message(struct commit *commit, struct commit_message *out)
 127 {
 128         const char *abbrev, *subject;
 129         int abbrev_len, subject_len;
 130         char *q;
 131
 132         if (!git_commit_encoding)
 133                 git_commit_encoding = "UTF-8";
 134
 135         out->message = logmsg_reencode(commit, NULL, git_commit_encoding);
 136         abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
 137         abbrev_len = strlen(abbrev);
 138
 139         subject_len = find_commit_subject(out->message, &subject);
 140
 141         out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
 142                               strlen("... ") + subject_len + 1);
 143         q = out->parent_label;
 144         q = mempcpy(q, "parent of ", strlen("parent of "));
 145         out->label = q;
 146         q = mempcpy(q, abbrev, abbrev_len);
 147         q = mempcpy(q, "... ", strlen("... "));
 148         out->subject = q;
 149         q = mempcpy(q, subject, subject_len);
 150         *q = '\0';
 151         return 0;
 152 }
 153
 154 static void free_message(struct commit *commit, struct commit_message *msg)
 155 {
 156         free(msg->parent_label);
 157         unuse_commit_buffer(commit, msg->message);
 158 }
 159
 160 static void write_cherry_pick_head(struct commit *commit, const char *pseudoref)
 161 {
 162         const char *filename;
 163         int fd;
 164         struct strbuf buf = STRBUF_INIT;
 165
 166         strbuf_addf(&buf, "%s\n", sha1_to_hex(commit->object.sha1));
 167
 168         filename = git_path("%s", pseudoref);
 169         fd = open(filename, O_WRONLY | O_CREAT, 0666);
 170         if (fd < 0)
 171                 die_errno(_("Could not open '%s' for writing"), filename);
 172         if (write_in_full(fd, buf.buf, buf.len) != buf.len || close(fd))
 173                 die_errno(_("Could not write to '%s'"), filename);
 174         strbuf_release(&buf);
 175 }
 176
 177 static void print_advice(int show_hint, struct replay_opts *opts)
 178 {
 179         char *msg = getenv("GIT_CHERRY_PICK_HELP");
 180
 181         if (msg) {
 182                 fprintf(stderr, "%s\n", msg);
 183                 /*
 184                  * A conflict has occurred but the porcelain
 185                  * (typically rebase --interactive) wants to take care
 186                  * of the commit itself so remove CHERRY_PICK_HEAD
 187                  */
 188                 unlink(git_path("CHERRY_PICK_HEAD"));
 189                 return;
 190         }
 191
 192         if (show_hint) {
 193                 if (opts->no_commit)
 194                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 195                                  "with 'git add <paths>' or 'git rm <paths>'"));
 196                 else
 197                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 198                                  "with 'git add <paths>' or 'git rm <paths>'\n"
 199                                  "and commit the result with 'git commit'"));
 200         }
 201 }
 202
 203 static void write_message(struct strbuf *msgbuf, const char *filename)
 204 {
 205         static struct lock_file msg_file;
 206
 207         int msg_fd = hold_lock_file_for_update(&msg_file, filename,
 208                                                LOCK_DIE_ON_ERROR);
 209         if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
 210                 die_errno(_("Could not write to %s"), filename);
 211         strbuf_release(msgbuf);
 212         if (commit_lock_file(&msg_file) < 0)
 213                 die(_("Error wrapping up %s"), filename);
 214 }
 215
 216 static struct tree *empty_tree(void)
 217 {
 218         return lookup_tree(EMPTY_TREE_SHA1_BIN);
 219 }
 220
 221 static int error_dirty_index(struct replay_opts *opts)
 222 {
 223         if (read_cache_unmerged())
 224                 return error_resolve_conflict(action_name(opts));
 225
 226         /* Different translation strings for cherry-pick and revert */
 227         if (opts->action == REPLAY_PICK)
 228                 error(_("Your local changes would be overwritten by cherry-pick."));
 229         else
 230                 error(_("Your local changes would be overwritten by revert."));
 231
 232         if (advice_commit_before_merge)
 233                 advise(_("Commit your changes or stash them to proceed."));
 234         return -1;
 235 }
 236
 237 static int fast_forward_to(const unsigned char *to, const unsigned char *from,
 238                         int unborn, struct replay_opts *opts)
 239 {
 240         struct ref_transaction *transaction;
 241         struct strbuf sb = STRBUF_INIT;
 242         struct strbuf err = STRBUF_INIT;
 243
 244         read_cache();
 245         if (checkout_fast_forward(from, to, 1))
 246                 exit(128); /* the callee should have complained already */
 247
 248         strbuf_addf(&sb, "%s: fast-forward", action_name(opts));
 249
 250         transaction = ref_transaction_begin(&err);
 251         if (!transaction ||
 252             ref_transaction_update(transaction, "HEAD",
 253                                    to, unborn ? null_sha1 : from,
 254                                    0, 1, &err) ||
 255             ref_transaction_commit(transaction, sb.buf, &err)) {
 256                 ref_transaction_free(transaction);
 257                 error("%s", err.buf);
 258                 strbuf_release(&sb);
 259                 strbuf_release(&err);
 260                 return -1;
 261         }
 262
 263         strbuf_release(&sb);
 264         strbuf_release(&err);
 265         ref_transaction_free(transaction);
 266         return 0;
 267 }
 268
 269 static int do_recursive_merge(struct commit *base, struct commit *next,
 270                               const char *base_label, const char *next_label,
 271                               unsigned char *head, struct strbuf *msgbuf,
 272                               struct replay_opts *opts)
 273 {
 274         struct merge_options o;
 275         struct tree *result, *next_tree, *base_tree, *head_tree;
 276         int clean;
 277         const char **xopt;
 278         static struct lock_file index_lock;
 279
 280         hold_locked_index(&index_lock, 1);
 281
 282         read_cache();
 283
 284         init_merge_options(&o);
 285         o.ancestor = base ? base_label : "(empty tree)";
 286         o.branch1 = "HEAD";
 287         o.branch2 = next ? next_label : "(empty tree)";
 288
 289         head_tree = parse_tree_indirect(head);
 290         next_tree = next ? next->tree : empty_tree();
 291         base_tree = base ? base->tree : empty_tree();
 292
 293         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 294                 parse_merge_opt(&o, *xopt);
 295
 296         clean = merge_trees(&o,
 297                             head_tree,
 298                             next_tree, base_tree, &result);
 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                 int i;
 311                 strbuf_addstr(msgbuf, "\nConflicts:\n");
 312                 for (i = 0; i < active_nr;) {
 313                         const struct cache_entry *ce = active_cache[i++];
 314                         if (ce_stage(ce)) {
 315                                 strbuf_addch(msgbuf, '\t');
 316                                 strbuf_addstr(msgbuf, ce->name);
 317                                 strbuf_addch(msgbuf, '\n');
 318                                 while (i < active_nr && !strcmp(ce->name,
 319                                                 active_cache[i]->name))
 320                                         i++;
 321                         }
 322                 }
 323         }
 324
 325         return !clean;
 326 }
 327
 328 static int is_index_unchanged(void)
 329 {
 330         unsigned char head_sha1[20];
 331         struct commit *head_commit;
 332
 333         if (!resolve_ref_unsafe("HEAD", head_sha1, 1, NULL))
 334                 return error(_("Could not resolve HEAD commit\n"));
 335
 336         head_commit = lookup_commit(head_sha1);
 337
 338         /*
 339          * If head_commit is NULL, check_commit, called from
 340          * lookup_commit, would have indicated that head_commit is not
 341          * a commit object already.  parse_commit() will return failure
 342          * without further complaints in such a case.  Otherwise, if
 343          * the commit is invalid, parse_commit() will complain.  So
 344          * there is nothing for us to say here.  Just return failure.
 345          */
 346         if (parse_commit(head_commit))
 347                 return -1;
 348
 349         if (!active_cache_tree)
 350                 active_cache_tree = cache_tree();
 351
 352         if (!cache_tree_fully_valid(active_cache_tree))
 353                 if (cache_tree_update(&the_index, 0))
 354                         return error(_("Unable to update cache tree\n"));
 355
 356         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.sha1);
 357 }
 358
 359 /*
 360  * If we are cherry-pick, and if the merge did not result in
 361  * hand-editing, we will hit this commit and inherit the original
 362  * author date and name.
 363  * If we are revert, or if our cherry-pick results in a hand merge,
 364  * we had better say that the current user is responsible for that.
 365  */
 366 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 367                           int allow_empty)
 368 {
 369         struct argv_array array;
 370         int rc;
 371
 372         argv_array_init(&array);
 373         argv_array_push(&array, "commit");
 374         argv_array_push(&array, "-n");
 375
 376         if (opts->gpg_sign)
 377                 argv_array_pushf(&array, "-S%s", opts->gpg_sign);
 378         if (opts->signoff)
 379                 argv_array_push(&array, "-s");
 380         if (!opts->edit) {
 381                 argv_array_push(&array, "-F");
 382                 argv_array_push(&array, defmsg);
 383         }
 384
 385         if (allow_empty)
 386                 argv_array_push(&array, "--allow-empty");
 387
 388         if (opts->allow_empty_message)
 389                 argv_array_push(&array, "--allow-empty-message");
 390
 391         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 392         argv_array_clear(&array);
 393         return rc;
 394 }
 395
 396 static int is_original_commit_empty(struct commit *commit)
 397 {
 398         const unsigned char *ptree_sha1;
 399
 400         if (parse_commit(commit))
 401                 return error(_("Could not parse commit %s\n"),
 402                              sha1_to_hex(commit->object.sha1));
 403         if (commit->parents) {
 404                 struct commit *parent = commit->parents->item;
 405                 if (parse_commit(parent))
 406                         return error(_("Could not parse parent commit %s\n"),
 407                                 sha1_to_hex(parent->object.sha1));
 408                 ptree_sha1 = parent->tree->object.sha1;
 409         } else {
 410                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 411         }
 412
 413         return !hashcmp(ptree_sha1, commit->tree->object.sha1);
 414 }
 415
 416 /*
 417  * Do we run "git commit" with "--allow-empty"?
 418  */
 419 static int allow_empty(struct replay_opts *opts, struct commit *commit)
 420 {
 421         int index_unchanged, empty_commit;
 422
 423         /*
 424          * Three cases:
 425          *
 426          * (1) we do not allow empty at all and error out.
 427          *
 428          * (2) we allow ones that were initially empty, but
 429          * forbid the ones that become empty;
 430          *
 431          * (3) we allow both.
 432          */
 433         if (!opts->allow_empty)
 434                 return 0; /* let "git commit" barf as necessary */
 435
 436         index_unchanged = is_index_unchanged();
 437         if (index_unchanged < 0)
 438                 return index_unchanged;
 439         if (!index_unchanged)
 440                 return 0; /* we do not have to say --allow-empty */
 441
 442         if (opts->keep_redundant_commits)
 443                 return 1;
 444
 445         empty_commit = is_original_commit_empty(commit);
 446         if (empty_commit < 0)
 447                 return empty_commit;
 448         if (!empty_commit)
 449                 return 0;
 450         else
 451                 return 1;
 452 }
 453
 454 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 455 {
 456         unsigned char head[20];
 457         struct commit *base, *next, *parent;
 458         const char *base_label, *next_label;
 459         struct commit_message msg = { NULL, NULL, NULL, NULL };
 460         char *defmsg = NULL;
 461         struct strbuf msgbuf = STRBUF_INIT;
 462         int res, unborn = 0, allow;
 463
 464         if (opts->no_commit) {
 465                 /*
 466                  * We do not intend to commit immediately.  We just want to
 467                  * merge the differences in, so let's compute the tree
 468                  * that represents the "current" state for merge-recursive
 469                  * to work on.
 470                  */
 471                 if (write_cache_as_tree(head, 0, NULL))
 472                         die (_("Your index file is unmerged."));
 473         } else {
 474                 unborn = get_sha1("HEAD", head);
 475                 if (unborn)
 476                         hashcpy(head, EMPTY_TREE_SHA1_BIN);
 477                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
 478                         return error_dirty_index(opts);
 479         }
 480         discard_cache();
 481
 482         if (!commit->parents) {
 483                 parent = NULL;
 484         }
 485         else if (commit->parents->next) {
 486                 /* Reverting or cherry-picking a merge commit */
 487                 int cnt;
 488                 struct commit_list *p;
 489
 490                 if (!opts->mainline)
 491                         return error(_("Commit %s is a merge but no -m option was given."),
 492                                 sha1_to_hex(commit->object.sha1));
 493
 494                 for (cnt = 1, p = commit->parents;
 495                      cnt != opts->mainline && p;
 496                      cnt++)
 497                         p = p->next;
 498                 if (cnt != opts->mainline || !p)
 499                         return error(_("Commit %s does not have parent %d"),
 500                                 sha1_to_hex(commit->object.sha1), opts->mainline);
 501                 parent = p->item;
 502         } else if (0 < opts->mainline)
 503                 return error(_("Mainline was specified but commit %s is not a merge."),
 504                         sha1_to_hex(commit->object.sha1));
 505         else
 506                 parent = commit->parents->item;
 507
 508         if (opts->allow_ff &&
 509             ((parent && !hashcmp(parent->object.sha1, head)) ||
 510              (!parent && unborn)))
 511                 return fast_forward_to(commit->object.sha1, head, unborn, opts);
 512
 513         if (parent && parse_commit(parent) < 0)
 514                 /* TRANSLATORS: The first %s will be "revert" or
 515                    "cherry-pick", the second %s a SHA1 */
 516                 return error(_("%s: cannot parse parent commit %s"),
 517                         action_name(opts), sha1_to_hex(parent->object.sha1));
 518
 519         if (get_message(commit, &msg) != 0)
 520                 return error(_("Cannot get commit message for %s"),
 521                         sha1_to_hex(commit->object.sha1));
 522
 523         /*
 524          * "commit" is an existing commit.  We would want to apply
 525          * the difference it introduces since its first parent "prev"
 526          * on top of the current HEAD if we are cherry-pick.  Or the
 527          * reverse of it if we are revert.
 528          */
 529
 530         defmsg = git_pathdup("MERGE_MSG");
 531
 532         if (opts->action == REPLAY_REVERT) {
 533                 base = commit;
 534                 base_label = msg.label;
 535                 next = parent;
 536                 next_label = msg.parent_label;
 537                 strbuf_addstr(&msgbuf, "Revert \"");
 538                 strbuf_addstr(&msgbuf, msg.subject);
 539                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 540                 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 541
 542                 if (commit->parents && commit->parents->next) {
 543                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 544                         strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
 545                 }
 546                 strbuf_addstr(&msgbuf, ".\n");
 547         } else {
 548                 const char *p;
 549
 550                 base = parent;
 551                 base_label = msg.parent_label;
 552                 next = commit;
 553                 next_label = msg.label;
 554
 555                 /*
 556                  * Append the commit log message to msgbuf; it starts
 557                  * after the tree, parent, author, committer
 558                  * information followed by "\n\n".
 559                  */
 560                 p = strstr(msg.message, "\n\n");
 561                 if (p) {
 562                         p += 2;
 563                         strbuf_addstr(&msgbuf, p);
 564                 }
 565
 566                 if (opts->record_origin) {
 567                         if (!has_conforming_footer(&msgbuf, NULL, 0))
 568                                 strbuf_addch(&msgbuf, '\n');
 569                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
 570                         strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 571                         strbuf_addstr(&msgbuf, ")\n");
 572                 }
 573         }
 574
 575         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 576                 res = do_recursive_merge(base, next, base_label, next_label,
 577                                          head, &msgbuf, opts);
 578                 write_message(&msgbuf, defmsg);
 579         } else {
 580                 struct commit_list *common = NULL;
 581                 struct commit_list *remotes = NULL;
 582
 583                 write_message(&msgbuf, defmsg);
 584
 585                 commit_list_insert(base, &common);
 586                 commit_list_insert(next, &remotes);
 587                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 588                                         common, sha1_to_hex(head), remotes);
 589                 free_commit_list(common);
 590                 free_commit_list(remotes);
 591         }
 592
 593         /*
 594          * If the merge was clean or if it failed due to conflict, we write
 595          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 596          * However, if the merge did not even start, then we don't want to
 597          * write it at all.
 598          */
 599         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 600                 write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
 601         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 602                 write_cherry_pick_head(commit, "REVERT_HEAD");
 603
 604         if (res) {
 605                 error(opts->action == REPLAY_REVERT
 606                       ? _("could not revert %s... %s")
 607                       : _("could not apply %s... %s"),
 608                       find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
 609                       msg.subject);
 610                 print_advice(res == 1, opts);
 611                 rerere(opts->allow_rerere_auto);
 612                 goto leave;
 613         }
 614
 615         allow = allow_empty(opts, commit);
 616         if (allow < 0) {
 617                 res = allow;
 618                 goto leave;
 619         }
 620         if (!opts->no_commit)
 621                 res = run_git_commit(defmsg, opts, allow);
 622
 623 leave:
 624         free_message(commit, &msg);
 625         free(defmsg);
 626
 627         return res;
 628 }
 629
 630 static void prepare_revs(struct replay_opts *opts)
 631 {
 632         /*
 633          * picking (but not reverting) ranges (but not individual revisions)
 634          * should be done in reverse
 635          */
 636         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 637                 opts->revs->reverse ^= 1;
 638
 639         if (prepare_revision_walk(opts->revs))
 640                 die(_("revision walk setup failed"));
 641
 642         if (!opts->revs->commits)
 643                 die(_("empty commit set passed"));
 644 }
 645
 646 static void read_and_refresh_cache(struct replay_opts *opts)
 647 {
 648         static struct lock_file index_lock;
 649         int index_fd = hold_locked_index(&index_lock, 0);
 650         if (read_index_preload(&the_index, NULL) < 0)
 651                 die(_("git %s: failed to read the index"), action_name(opts));
 652         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 653         if (the_index.cache_changed && index_fd >= 0) {
 654                 if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
 655                         die(_("git %s: failed to refresh the index"), action_name(opts));
 656         }
 657         rollback_lock_file(&index_lock);
 658 }
 659
 660 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 661                 struct replay_opts *opts)
 662 {
 663         struct commit_list *cur = NULL;
 664         const char *sha1_abbrev = NULL;
 665         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 666         const char *subject;
 667         int subject_len;
 668
 669         for (cur = todo_list; cur; cur = cur->next) {
 670                 const char *commit_buffer = get_commit_buffer(cur->item, NULL);
 671                 sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
 672                 subject_len = find_commit_subject(commit_buffer, &subject);
 673                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 674                         subject_len, subject);
 675                 unuse_commit_buffer(cur->item, commit_buffer);
 676         }
 677         return 0;
 678 }
 679
 680 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 681 {
 682         unsigned char commit_sha1[20];
 683         enum replay_action action;
 684         char *end_of_object_name;
 685         int saved, status, padding;
 686
 687         if (starts_with(bol, "pick")) {
 688                 action = REPLAY_PICK;
 689                 bol += strlen("pick");
 690         } else if (starts_with(bol, "revert")) {
 691                 action = REPLAY_REVERT;
 692                 bol += strlen("revert");
 693         } else
 694                 return NULL;
 695
 696         /* Eat up extra spaces/ tabs before object name */
 697         padding = strspn(bol, " \t");
 698         if (!padding)
 699                 return NULL;
 700         bol += padding;
 701
 702         end_of_object_name = bol + strcspn(bol, " \t\n");
 703         saved = *end_of_object_name;
 704         *end_of_object_name = '\0';
 705         status = get_sha1(bol, commit_sha1);
 706         *end_of_object_name = saved;
 707
 708         /*
 709          * Verify that the action matches up with the one in
 710          * opts; we don't support arbitrary instructions
 711          */
 712         if (action != opts->action) {
 713                 const char *action_str;
 714                 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
 715                 error(_("Cannot %s during a %s"), action_str, action_name(opts));
 716                 return NULL;
 717         }
 718
 719         if (status < 0)
 720                 return NULL;
 721
 722         return lookup_commit_reference(commit_sha1);
 723 }
 724
 725 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
 726                         struct replay_opts *opts)
 727 {
 728         struct commit_list **next = todo_list;
 729         struct commit *commit;
 730         char *p = buf;
 731         int i;
 732
 733         for (i = 1; *p; i++) {
 734                 char *eol = strchrnul(p, '\n');
 735                 commit = parse_insn_line(p, eol, opts);
 736                 if (!commit)
 737                         return error(_("Could not parse line %d."), i);
 738                 next = commit_list_append(commit, next);
 739                 p = *eol ? eol + 1 : eol;
 740         }
 741         if (!*todo_list)
 742                 return error(_("No commits parsed."));
 743         return 0;
 744 }
 745
 746 static void read_populate_todo(struct commit_list **todo_list,
 747                         struct replay_opts *opts)
 748 {
 749         const char *todo_file = git_path(SEQ_TODO_FILE);
 750         struct strbuf buf = STRBUF_INIT;
 751         int fd, res;
 752
 753         fd = open(todo_file, O_RDONLY);
 754         if (fd < 0)
 755                 die_errno(_("Could not open %s"), todo_file);
 756         if (strbuf_read(&buf, fd, 0) < 0) {
 757                 close(fd);
 758                 strbuf_release(&buf);
 759                 die(_("Could not read %s."), todo_file);
 760         }
 761         close(fd);
 762
 763         res = parse_insn_buffer(buf.buf, todo_list, opts);
 764         strbuf_release(&buf);
 765         if (res)
 766                 die(_("Unusable instruction sheet: %s"), todo_file);
 767 }
 768
 769 static int populate_opts_cb(const char *key, const char *value, void *data)
 770 {
 771         struct replay_opts *opts = data;
 772         int error_flag = 1;
 773
 774         if (!value)
 775                 error_flag = 0;
 776         else if (!strcmp(key, "options.no-commit"))
 777                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 778         else if (!strcmp(key, "options.edit"))
 779                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
 780         else if (!strcmp(key, "options.signoff"))
 781                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 782         else if (!strcmp(key, "options.record-origin"))
 783                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 784         else if (!strcmp(key, "options.allow-ff"))
 785                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 786         else if (!strcmp(key, "options.mainline"))
 787                 opts->mainline = git_config_int(key, value);
 788         else if (!strcmp(key, "options.strategy"))
 789                 git_config_string(&opts->strategy, key, value);
 790         else if (!strcmp(key, "options.gpg-sign"))
 791                 git_config_string(&opts->gpg_sign, key, value);
 792         else if (!strcmp(key, "options.strategy-option")) {
 793                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 794                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
 795         } else
 796                 return error(_("Invalid key: %s"), key);
 797
 798         if (!error_flag)
 799                 return error(_("Invalid value for %s: %s"), key, value);
 800
 801         return 0;
 802 }
 803
 804 static void read_populate_opts(struct replay_opts **opts_ptr)
 805 {
 806         const char *opts_file = git_path(SEQ_OPTS_FILE);
 807
 808         if (!file_exists(opts_file))
 809                 return;
 810         if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
 811                 die(_("Malformed options sheet: %s"), opts_file);
 812 }
 813
 814 static void walk_revs_populate_todo(struct commit_list **todo_list,
 815                                 struct replay_opts *opts)
 816 {
 817         struct commit *commit;
 818         struct commit_list **next;
 819
 820         prepare_revs(opts);
 821
 822         next = todo_list;
 823         while ((commit = get_revision(opts->revs)))
 824                 next = commit_list_append(commit, next);
 825 }
 826
 827 static int create_seq_dir(void)
 828 {
 829         const char *seq_dir = git_path(SEQ_DIR);
 830
 831         if (file_exists(seq_dir)) {
 832                 error(_("a cherry-pick or revert is already in progress"));
 833                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 834                 return -1;
 835         }
 836         else if (mkdir(seq_dir, 0777) < 0)
 837                 die_errno(_("Could not create sequencer directory %s"), seq_dir);
 838         return 0;
 839 }
 840
 841 static void save_head(const char *head)
 842 {
 843         const char *head_file = git_path(SEQ_HEAD_FILE);
 844         static struct lock_file head_lock;
 845         struct strbuf buf = STRBUF_INIT;
 846         int fd;
 847
 848         fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
 849         strbuf_addf(&buf, "%s\n", head);
 850         if (write_in_full(fd, buf.buf, buf.len) < 0)
 851                 die_errno(_("Could not write to %s"), head_file);
 852         if (commit_lock_file(&head_lock) < 0)
 853                 die(_("Error wrapping up %s."), head_file);
 854 }
 855
 856 static int reset_for_rollback(const unsigned char *sha1)
 857 {
 858         const char *argv[4];    /* reset --merge <arg> + NULL */
 859         argv[0] = "reset";
 860         argv[1] = "--merge";
 861         argv[2] = sha1_to_hex(sha1);
 862         argv[3] = NULL;
 863         return run_command_v_opt(argv, RUN_GIT_CMD);
 864 }
 865
 866 static int rollback_single_pick(void)
 867 {
 868         unsigned char head_sha1[20];
 869
 870         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
 871             !file_exists(git_path("REVERT_HEAD")))
 872                 return error(_("no cherry-pick or revert in progress"));
 873         if (read_ref_full("HEAD", head_sha1, 0, NULL))
 874                 return error(_("cannot resolve HEAD"));
 875         if (is_null_sha1(head_sha1))
 876                 return error(_("cannot abort from a branch yet to be born"));
 877         return reset_for_rollback(head_sha1);
 878 }
 879
 880 static int sequencer_rollback(struct replay_opts *opts)
 881 {
 882         const char *filename;
 883         FILE *f;
 884         unsigned char sha1[20];
 885         struct strbuf buf = STRBUF_INIT;
 886
 887         filename = git_path(SEQ_HEAD_FILE);
 888         f = fopen(filename, "r");
 889         if (!f && errno == ENOENT) {
 890                 /*
 891                  * There is no multiple-cherry-pick in progress.
 892                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 893                  * a single-cherry-pick in progress, abort that.
 894                  */
 895                 return rollback_single_pick();
 896         }
 897         if (!f)
 898                 return error(_("cannot open %s: %s"), filename,
 899                                                 strerror(errno));
 900         if (strbuf_getline(&buf, f, '\n')) {
 901                 error(_("cannot read %s: %s"), filename, ferror(f) ?
 902                         strerror(errno) : _("unexpected end of file"));
 903                 fclose(f);
 904                 goto fail;
 905         }
 906         fclose(f);
 907         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 908                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 909                         filename);
 910                 goto fail;
 911         }
 912         if (reset_for_rollback(sha1))
 913                 goto fail;
 914         remove_sequencer_state();
 915         strbuf_release(&buf);
 916         return 0;
 917 fail:
 918         strbuf_release(&buf);
 919         return -1;
 920 }
 921
 922 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 923 {
 924         const char *todo_file = git_path(SEQ_TODO_FILE);
 925         static struct lock_file todo_lock;
 926         struct strbuf buf = STRBUF_INIT;
 927         int fd;
 928
 929         fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
 930         if (format_todo(&buf, todo_list, opts) < 0)
 931                 die(_("Could not format %s."), todo_file);
 932         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 933                 strbuf_release(&buf);
 934                 die_errno(_("Could not write to %s"), todo_file);
 935         }
 936         if (commit_lock_file(&todo_lock) < 0) {
 937                 strbuf_release(&buf);
 938                 die(_("Error wrapping up %s."), todo_file);
 939         }
 940         strbuf_release(&buf);
 941 }
 942
 943 static void save_opts(struct replay_opts *opts)
 944 {
 945         const char *opts_file = git_path(SEQ_OPTS_FILE);
 946
 947         if (opts->no_commit)
 948                 git_config_set_in_file(opts_file, "options.no-commit", "true");
 949         if (opts->edit)
 950                 git_config_set_in_file(opts_file, "options.edit", "true");
 951         if (opts->signoff)
 952                 git_config_set_in_file(opts_file, "options.signoff", "true");
 953         if (opts->record_origin)
 954                 git_config_set_in_file(opts_file, "options.record-origin", "true");
 955         if (opts->allow_ff)
 956                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
 957         if (opts->mainline) {
 958                 struct strbuf buf = STRBUF_INIT;
 959                 strbuf_addf(&buf, "%d", opts->mainline);
 960                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
 961                 strbuf_release(&buf);
 962         }
 963         if (opts->strategy)
 964                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
 965         if (opts->gpg_sign)
 966                 git_config_set_in_file(opts_file, "options.gpg-sign", opts->gpg_sign);
 967         if (opts->xopts) {
 968                 int i;
 969                 for (i = 0; i < opts->xopts_nr; i++)
 970                         git_config_set_multivar_in_file(opts_file,
 971                                                         "options.strategy-option",
 972                                                         opts->xopts[i], "^$", 0);
 973         }
 974 }
 975
 976 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
 977 {
 978         struct commit_list *cur;
 979         int res;
 980
 981         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
 982         if (opts->allow_ff)
 983                 assert(!(opts->signoff || opts->no_commit ||
 984                                 opts->record_origin || opts->edit));
 985         read_and_refresh_cache(opts);
 986
 987         for (cur = todo_list; cur; cur = cur->next) {
 988                 save_todo(cur, opts);
 989                 res = do_pick_commit(cur->item, opts);
 990                 if (res)
 991                         return res;
 992         }
 993
 994         /*
 995          * Sequence of picks finished successfully; cleanup by
 996          * removing the .git/sequencer directory
 997          */
 998         remove_sequencer_state();
 999         return 0;
1000 }
1001
1002 static int continue_single_pick(void)
1003 {
1004         const char *argv[] = { "commit", NULL };
1005
1006         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
1007             !file_exists(git_path("REVERT_HEAD")))
1008                 return error(_("no cherry-pick or revert in progress"));
1009         return run_command_v_opt(argv, RUN_GIT_CMD);
1010 }
1011
1012 static int sequencer_continue(struct replay_opts *opts)
1013 {
1014         struct commit_list *todo_list = NULL;
1015
1016         if (!file_exists(git_path(SEQ_TODO_FILE)))
1017                 return continue_single_pick();
1018         read_populate_opts(&opts);
1019         read_populate_todo(&todo_list, opts);
1020
1021         /* Verify that the conflict has been resolved */
1022         if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
1023             file_exists(git_path("REVERT_HEAD"))) {
1024                 int ret = continue_single_pick();
1025                 if (ret)
1026                         return ret;
1027         }
1028         if (index_differs_from("HEAD", 0))
1029                 return error_dirty_index(opts);
1030         todo_list = todo_list->next;
1031         return pick_commits(todo_list, opts);
1032 }
1033
1034 static int single_pick(struct commit *cmit, struct replay_opts *opts)
1035 {
1036         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1037         return do_pick_commit(cmit, opts);
1038 }
1039
1040 int sequencer_pick_revisions(struct replay_opts *opts)
1041 {
1042         struct commit_list *todo_list = NULL;
1043         unsigned char sha1[20];
1044         int i;
1045
1046         if (opts->subcommand == REPLAY_NONE)
1047                 assert(opts->revs);
1048
1049         read_and_refresh_cache(opts);
1050
1051         /*
1052          * Decide what to do depending on the arguments; a fresh
1053          * cherry-pick should be handled differently from an existing
1054          * one that is being continued
1055          */
1056         if (opts->subcommand == REPLAY_REMOVE_STATE) {
1057                 remove_sequencer_state();
1058                 return 0;
1059         }
1060         if (opts->subcommand == REPLAY_ROLLBACK)
1061                 return sequencer_rollback(opts);
1062         if (opts->subcommand == REPLAY_CONTINUE)
1063                 return sequencer_continue(opts);
1064
1065         for (i = 0; i < opts->revs->pending.nr; i++) {
1066                 unsigned char sha1[20];
1067                 const char *name = opts->revs->pending.objects[i].name;
1068
1069                 /* This happens when using --stdin. */
1070                 if (!strlen(name))
1071                         continue;
1072
1073                 if (!get_sha1(name, sha1)) {
1074                         if (!lookup_commit_reference_gently(sha1, 1)) {
1075                                 enum object_type type = sha1_object_info(sha1, NULL);
1076                                 die(_("%s: can't cherry-pick a %s"), name, typename(type));
1077                         }
1078                 } else
1079                         die(_("%s: bad revision"), name);
1080         }
1081
1082         /*
1083          * If we were called as "git cherry-pick <commit>", just
1084          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1085          * REVERT_HEAD, and don't touch the sequencer state.
1086          * This means it is possible to cherry-pick in the middle
1087          * of a cherry-pick sequence.
1088          */
1089         if (opts->revs->cmdline.nr == 1 &&
1090             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1091             opts->revs->no_walk &&
1092             !opts->revs->cmdline.rev->flags) {
1093                 struct commit *cmit;
1094                 if (prepare_revision_walk(opts->revs))
1095                         die(_("revision walk setup failed"));
1096                 cmit = get_revision(opts->revs);
1097                 if (!cmit || get_revision(opts->revs))
1098                         die("BUG: expected exactly one commit from walk");
1099                 return single_pick(cmit, opts);
1100         }
1101
1102         /*
1103          * Start a new cherry-pick/ revert sequence; but
1104          * first, make sure that an existing one isn't in
1105          * progress
1106          */
1107
1108         walk_revs_populate_todo(&todo_list, opts);
1109         if (create_seq_dir() < 0)
1110                 return -1;
1111         if (get_sha1("HEAD", sha1)) {
1112                 if (opts->action == REPLAY_REVERT)
1113                         return error(_("Can't revert as initial commit"));
1114                 return error(_("Can't cherry-pick into empty head"));
1115         }
1116         save_head(sha1_to_hex(sha1));
1117         save_opts(opts);
1118         return pick_commits(todo_list, opts);
1119 }
1120
1121 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1122 {
1123         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1124         struct strbuf sob = STRBUF_INIT;
1125         int has_footer;
1126
1127         strbuf_addstr(&sob, sign_off_header);
1128         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1129                                 getenv("GIT_COMMITTER_EMAIL")));
1130         strbuf_addch(&sob, '\n');
1131
1132         /*
1133          * If the whole message buffer is equal to the sob, pretend that we
1134          * found a conforming footer with a matching sob
1135          */
1136         if (msgbuf->len - ignore_footer == sob.len &&
1137             !strncmp(msgbuf->buf, sob.buf, sob.len))
1138                 has_footer = 3;
1139         else
1140                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1141
1142         if (!has_footer) {
1143                 const char *append_newlines = NULL;
1144                 size_t len = msgbuf->len - ignore_footer;
1145
1146                 if (!len) {
1147                         /*
1148                          * The buffer is completely empty.  Leave foom for
1149                          * the title and body to be filled in by the user.
1150                          */
1151                         append_newlines = "\n\n";
1152                 } else if (msgbuf->buf[len - 1] != '\n') {
1153                         /*
1154                          * Incomplete line.  Complete the line and add a
1155                          * blank one so that there is an empty line between
1156                          * the message body and the sob.
1157                          */
1158                         append_newlines = "\n\n";
1159                 } else if (len == 1) {
1160                         /*
1161                          * Buffer contains a single newline.  Add another
1162                          * so that we leave room for the title and body.
1163                          */
1164                         append_newlines = "\n";
1165                 } else if (msgbuf->buf[len - 2] != '\n') {
1166                         /*
1167                          * Buffer ends with a single newline.  Add another
1168                          * so that there is an empty line between the message
1169                          * body and the sob.
1170                          */
1171                         append_newlines = "\n";
1172                 } /* else, the buffer already ends with two newlines. */
1173
1174                 if (append_newlines)
1175                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1176                                 append_newlines, strlen(append_newlines));
1177         }
1178
1179         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1180                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1181                                 sob.buf, sob.len);
1182
1183         strbuf_release(&sob);
1184 }