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 int is_rfc2822_line(const char *buf, int len)
  25 {
  26         int i;
  27
  28         for (i = 0; i < len; i++) {
  29                 int ch = buf[i];
  30                 if (ch == ':')
  31                         return 1;
  32                 if (!isalnum(ch) && ch != '-')
  33                         break;
  34         }
  35
  36         return 0;
  37 }
  38
  39 static int is_cherry_picked_from_line(const char *buf, int len)
  40 {
  41         /*
  42          * We only care that it looks roughly like (cherry picked from ...)
  43          */
  44         return len > strlen(cherry_picked_prefix) + 1 &&
  45                 starts_with(buf, cherry_picked_prefix) && buf[len - 1] == ')';
  46 }
  47
  48 /*
  49  * Returns 0 for non-conforming footer
  50  * Returns 1 for conforming footer
  51  * Returns 2 when sob exists within conforming footer
  52  * Returns 3 when sob exists within conforming footer as last entry
  53  */
  54 static int has_conforming_footer(struct strbuf *sb, struct strbuf *sob,
  55         int ignore_footer)
  56 {
  57         char prev;
  58         int i, k;
  59         int len = sb->len - ignore_footer;
  60         const char *buf = sb->buf;
  61         int found_sob = 0;
  62
  63         /* footer must end with newline */
  64         if (!len || buf[len - 1] != '\n')
  65                 return 0;
  66
  67         prev = '\0';
  68         for (i = len - 1; i > 0; i--) {
  69                 char ch = buf[i];
  70                 if (prev == '\n' && ch == '\n') /* paragraph break */
  71                         break;
  72                 prev = ch;
  73         }
  74
  75         /* require at least one blank line */
  76         if (prev != '\n' || buf[i] != '\n')
  77                 return 0;
  78
  79         /* advance to start of last paragraph */
  80         while (i < len - 1 && buf[i] == '\n')
  81                 i++;
  82
  83         for (; i < len; i = k) {
  84                 int found_rfc2822;
  85
  86                 for (k = i; k < len && buf[k] != '\n'; k++)
  87                         ; /* do nothing */
  88                 k++;
  89
  90                 found_rfc2822 = is_rfc2822_line(buf + i, k - i - 1);
  91                 if (found_rfc2822 && sob &&
  92                     !strncmp(buf + i, sob->buf, sob->len))
  93                         found_sob = k;
  94
  95                 if (!(found_rfc2822 ||
  96                       is_cherry_picked_from_line(buf + i, k - i - 1)))
  97                         return 0;
  98         }
  99         if (found_sob == i)
 100                 return 3;
 101         if (found_sob)
 102                 return 2;
 103         return 1;
 104 }
 105
 106 static void remove_sequencer_state(void)
 107 {
 108         struct strbuf seq_dir = STRBUF_INIT;
 109
 110         strbuf_addf(&seq_dir, "%s", git_path(SEQ_DIR));
 111         remove_dir_recursively(&seq_dir, 0);
 112         strbuf_release(&seq_dir);
 113 }
 114
 115 static const char *action_name(const struct replay_opts *opts)
 116 {
 117         return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
 118 }
 119
 120 struct commit_message {
 121         char *parent_label;
 122         const char *label;
 123         const char *subject;
 124         const char *message;
 125 };
 126
 127 static int get_message(struct commit *commit, struct commit_message *out)
 128 {
 129         const char *abbrev, *subject;
 130         int abbrev_len, subject_len;
 131         char *q;
 132
 133         if (!git_commit_encoding)
 134                 git_commit_encoding = "UTF-8";
 135
 136         out->message = logmsg_reencode(commit, NULL, git_commit_encoding);
 137         abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
 138         abbrev_len = strlen(abbrev);
 139
 140         subject_len = find_commit_subject(out->message, &subject);
 141
 142         out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
 143                               strlen("... ") + subject_len + 1);
 144         q = out->parent_label;
 145         q = mempcpy(q, "parent of ", strlen("parent of "));
 146         out->label = q;
 147         q = mempcpy(q, abbrev, abbrev_len);
 148         q = mempcpy(q, "... ", strlen("... "));
 149         out->subject = q;
 150         q = mempcpy(q, subject, subject_len);
 151         *q = '\0';
 152         return 0;
 153 }
 154
 155 static void free_message(struct commit *commit, struct commit_message *msg)
 156 {
 157         free(msg->parent_label);
 158         unuse_commit_buffer(commit, msg->message);
 159 }
 160
 161 static void print_advice(int show_hint, struct replay_opts *opts)
 162 {
 163         char *msg = getenv("GIT_CHERRY_PICK_HELP");
 164
 165         if (msg) {
 166                 fprintf(stderr, "%s\n", msg);
 167                 /*
 168                  * A conflict has occurred but the porcelain
 169                  * (typically rebase --interactive) wants to take care
 170                  * of the commit itself so remove CHERRY_PICK_HEAD
 171                  */
 172                 unlink(git_path("CHERRY_PICK_HEAD"));
 173                 return;
 174         }
 175
 176         if (show_hint) {
 177                 if (opts->no_commit)
 178                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 179                                  "with 'git add <paths>' or 'git rm <paths>'"));
 180                 else
 181                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 182                                  "with 'git add <paths>' or 'git rm <paths>'\n"
 183                                  "and commit the result with 'git commit'"));
 184         }
 185 }
 186
 187 static void write_message(struct strbuf *msgbuf, const char *filename)
 188 {
 189         static struct lock_file msg_file;
 190
 191         int msg_fd = hold_lock_file_for_update(&msg_file, filename,
 192                                                LOCK_DIE_ON_ERROR);
 193         if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
 194                 die_errno(_("Could not write to %s"), filename);
 195         strbuf_release(msgbuf);
 196         if (commit_lock_file(&msg_file) < 0)
 197                 die(_("Error wrapping up %s"), filename);
 198 }
 199
 200 static struct tree *empty_tree(void)
 201 {
 202         return lookup_tree(EMPTY_TREE_SHA1_BIN);
 203 }
 204
 205 static int error_dirty_index(struct replay_opts *opts)
 206 {
 207         if (read_cache_unmerged())
 208                 return error_resolve_conflict(action_name(opts));
 209
 210         /* Different translation strings for cherry-pick and revert */
 211         if (opts->action == REPLAY_PICK)
 212                 error(_("Your local changes would be overwritten by cherry-pick."));
 213         else
 214                 error(_("Your local changes would be overwritten by revert."));
 215
 216         if (advice_commit_before_merge)
 217                 advise(_("Commit your changes or stash them to proceed."));
 218         return -1;
 219 }
 220
 221 static int fast_forward_to(const unsigned char *to, const unsigned char *from,
 222                         int unborn, struct replay_opts *opts)
 223 {
 224         struct ref_transaction *transaction;
 225         struct strbuf sb = STRBUF_INIT;
 226         struct strbuf err = STRBUF_INIT;
 227
 228         read_cache();
 229         if (checkout_fast_forward(from, to, 1))
 230                 exit(128); /* the callee should have complained already */
 231
 232         strbuf_addf(&sb, "%s: fast-forward", action_name(opts));
 233
 234         transaction = ref_transaction_begin(&err);
 235         if (!transaction ||
 236             ref_transaction_update(transaction, "HEAD",
 237                                    to, unborn ? null_sha1 : from,
 238                                    0, sb.buf, &err) ||
 239             ref_transaction_commit(transaction, &err)) {
 240                 ref_transaction_free(transaction);
 241                 error("%s", err.buf);
 242                 strbuf_release(&sb);
 243                 strbuf_release(&err);
 244                 return -1;
 245         }
 246
 247         strbuf_release(&sb);
 248         strbuf_release(&err);
 249         ref_transaction_free(transaction);
 250         return 0;
 251 }
 252
 253 void append_conflicts_hint(struct strbuf *msgbuf)
 254 {
 255         int i;
 256
 257         strbuf_addch(msgbuf, '\n');
 258         strbuf_commented_addf(msgbuf, "Conflicts:\n");
 259         for (i = 0; i < active_nr;) {
 260                 const struct cache_entry *ce = active_cache[i++];
 261                 if (ce_stage(ce)) {
 262                         strbuf_commented_addf(msgbuf, "\t%s\n", ce->name);
 263                         while (i < active_nr && !strcmp(ce->name,
 264                                                         active_cache[i]->name))
 265                                 i++;
 266                 }
 267         }
 268 }
 269
 270 static int do_recursive_merge(struct commit *base, struct commit *next,
 271                               const char *base_label, const char *next_label,
 272                               unsigned char *head, struct strbuf *msgbuf,
 273                               struct replay_opts *opts)
 274 {
 275         struct merge_options o;
 276         struct tree *result, *next_tree, *base_tree, *head_tree;
 277         int clean;
 278         const char **xopt;
 279         static struct lock_file index_lock;
 280
 281         hold_locked_index(&index_lock, 1);
 282
 283         read_cache();
 284
 285         init_merge_options(&o);
 286         o.ancestor = base ? base_label : "(empty tree)";
 287         o.branch1 = "HEAD";
 288         o.branch2 = next ? next_label : "(empty tree)";
 289
 290         head_tree = parse_tree_indirect(head);
 291         next_tree = next ? next->tree : empty_tree();
 292         base_tree = base ? base->tree : empty_tree();
 293
 294         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 295                 parse_merge_opt(&o, *xopt);
 296
 297         clean = merge_trees(&o,
 298                             head_tree,
 299                             next_tree, base_tree, &result);
 300
 301         if (active_cache_changed &&
 302             write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
 303                 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 304                 die(_("%s: Unable to write new index file"), action_name(opts));
 305         rollback_lock_file(&index_lock);
 306
 307         if (opts->signoff)
 308                 append_signoff(msgbuf, 0, 0);
 309
 310         if (!clean)
 311                 append_conflicts_hint(msgbuf);
 312
 313         return !clean;
 314 }
 315
 316 static int is_index_unchanged(void)
 317 {
 318         unsigned char head_sha1[20];
 319         struct commit *head_commit;
 320
 321         if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_sha1, NULL))
 322                 return error(_("Could not resolve HEAD commit\n"));
 323
 324         head_commit = lookup_commit(head_sha1);
 325
 326         /*
 327          * If head_commit is NULL, check_commit, called from
 328          * lookup_commit, would have indicated that head_commit is not
 329          * a commit object already.  parse_commit() will return failure
 330          * without further complaints in such a case.  Otherwise, if
 331          * the commit is invalid, parse_commit() will complain.  So
 332          * there is nothing for us to say here.  Just return failure.
 333          */
 334         if (parse_commit(head_commit))
 335                 return -1;
 336
 337         if (!active_cache_tree)
 338                 active_cache_tree = cache_tree();
 339
 340         if (!cache_tree_fully_valid(active_cache_tree))
 341                 if (cache_tree_update(&the_index, 0))
 342                         return error(_("Unable to update cache tree\n"));
 343
 344         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.sha1);
 345 }
 346
 347 /*
 348  * If we are cherry-pick, and if the merge did not result in
 349  * hand-editing, we will hit this commit and inherit the original
 350  * author date and name.
 351  * If we are revert, or if our cherry-pick results in a hand merge,
 352  * we had better say that the current user is responsible for that.
 353  */
 354 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 355                           int allow_empty)
 356 {
 357         struct argv_array array;
 358         int rc;
 359         const char *value;
 360
 361         argv_array_init(&array);
 362         argv_array_push(&array, "commit");
 363         argv_array_push(&array, "-n");
 364
 365         if (opts->gpg_sign)
 366                 argv_array_pushf(&array, "-S%s", opts->gpg_sign);
 367         if (opts->signoff)
 368                 argv_array_push(&array, "-s");
 369         if (!opts->edit) {
 370                 argv_array_push(&array, "-F");
 371                 argv_array_push(&array, defmsg);
 372                 if (!opts->signoff &&
 373                     !opts->record_origin &&
 374                     git_config_get_value("commit.cleanup", &value))
 375                         argv_array_push(&array, "--cleanup=verbatim");
 376         }
 377
 378         if (allow_empty)
 379                 argv_array_push(&array, "--allow-empty");
 380
 381         if (opts->allow_empty_message)
 382                 argv_array_push(&array, "--allow-empty-message");
 383
 384         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 385         argv_array_clear(&array);
 386         return rc;
 387 }
 388
 389 static int is_original_commit_empty(struct commit *commit)
 390 {
 391         const unsigned char *ptree_sha1;
 392
 393         if (parse_commit(commit))
 394                 return error(_("Could not parse commit %s\n"),
 395                              sha1_to_hex(commit->object.sha1));
 396         if (commit->parents) {
 397                 struct commit *parent = commit->parents->item;
 398                 if (parse_commit(parent))
 399                         return error(_("Could not parse parent commit %s\n"),
 400                                 sha1_to_hex(parent->object.sha1));
 401                 ptree_sha1 = parent->tree->object.sha1;
 402         } else {
 403                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 404         }
 405
 406         return !hashcmp(ptree_sha1, commit->tree->object.sha1);
 407 }
 408
 409 /*
 410  * Do we run "git commit" with "--allow-empty"?
 411  */
 412 static int allow_empty(struct replay_opts *opts, struct commit *commit)
 413 {
 414         int index_unchanged, empty_commit;
 415
 416         /*
 417          * Three cases:
 418          *
 419          * (1) we do not allow empty at all and error out.
 420          *
 421          * (2) we allow ones that were initially empty, but
 422          * forbid the ones that become empty;
 423          *
 424          * (3) we allow both.
 425          */
 426         if (!opts->allow_empty)
 427                 return 0; /* let "git commit" barf as necessary */
 428
 429         index_unchanged = is_index_unchanged();
 430         if (index_unchanged < 0)
 431                 return index_unchanged;
 432         if (!index_unchanged)
 433                 return 0; /* we do not have to say --allow-empty */
 434
 435         if (opts->keep_redundant_commits)
 436                 return 1;
 437
 438         empty_commit = is_original_commit_empty(commit);
 439         if (empty_commit < 0)
 440                 return empty_commit;
 441         if (!empty_commit)
 442                 return 0;
 443         else
 444                 return 1;
 445 }
 446
 447 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 448 {
 449         unsigned char head[20];
 450         struct commit *base, *next, *parent;
 451         const char *base_label, *next_label;
 452         struct commit_message msg = { NULL, NULL, NULL, NULL };
 453         char *defmsg = NULL;
 454         struct strbuf msgbuf = STRBUF_INIT;
 455         int res, unborn = 0, allow;
 456
 457         if (opts->no_commit) {
 458                 /*
 459                  * We do not intend to commit immediately.  We just want to
 460                  * merge the differences in, so let's compute the tree
 461                  * that represents the "current" state for merge-recursive
 462                  * to work on.
 463                  */
 464                 if (write_cache_as_tree(head, 0, NULL))
 465                         die (_("Your index file is unmerged."));
 466         } else {
 467                 unborn = get_sha1("HEAD", head);
 468                 if (unborn)
 469                         hashcpy(head, EMPTY_TREE_SHA1_BIN);
 470                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
 471                         return error_dirty_index(opts);
 472         }
 473         discard_cache();
 474
 475         if (!commit->parents) {
 476                 parent = NULL;
 477         }
 478         else if (commit->parents->next) {
 479                 /* Reverting or cherry-picking a merge commit */
 480                 int cnt;
 481                 struct commit_list *p;
 482
 483                 if (!opts->mainline)
 484                         return error(_("Commit %s is a merge but no -m option was given."),
 485                                 sha1_to_hex(commit->object.sha1));
 486
 487                 for (cnt = 1, p = commit->parents;
 488                      cnt != opts->mainline && p;
 489                      cnt++)
 490                         p = p->next;
 491                 if (cnt != opts->mainline || !p)
 492                         return error(_("Commit %s does not have parent %d"),
 493                                 sha1_to_hex(commit->object.sha1), opts->mainline);
 494                 parent = p->item;
 495         } else if (0 < opts->mainline)
 496                 return error(_("Mainline was specified but commit %s is not a merge."),
 497                         sha1_to_hex(commit->object.sha1));
 498         else
 499                 parent = commit->parents->item;
 500
 501         if (opts->allow_ff &&
 502             ((parent && !hashcmp(parent->object.sha1, head)) ||
 503              (!parent && unborn)))
 504                 return fast_forward_to(commit->object.sha1, head, unborn, opts);
 505
 506         if (parent && parse_commit(parent) < 0)
 507                 /* TRANSLATORS: The first %s will be "revert" or
 508                    "cherry-pick", the second %s a SHA1 */
 509                 return error(_("%s: cannot parse parent commit %s"),
 510                         action_name(opts), sha1_to_hex(parent->object.sha1));
 511
 512         if (get_message(commit, &msg) != 0)
 513                 return error(_("Cannot get commit message for %s"),
 514                         sha1_to_hex(commit->object.sha1));
 515
 516         /*
 517          * "commit" is an existing commit.  We would want to apply
 518          * the difference it introduces since its first parent "prev"
 519          * on top of the current HEAD if we are cherry-pick.  Or the
 520          * reverse of it if we are revert.
 521          */
 522
 523         defmsg = git_pathdup("MERGE_MSG");
 524
 525         if (opts->action == REPLAY_REVERT) {
 526                 base = commit;
 527                 base_label = msg.label;
 528                 next = parent;
 529                 next_label = msg.parent_label;
 530                 strbuf_addstr(&msgbuf, "Revert \"");
 531                 strbuf_addstr(&msgbuf, msg.subject);
 532                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 533                 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 534
 535                 if (commit->parents && commit->parents->next) {
 536                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 537                         strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
 538                 }
 539                 strbuf_addstr(&msgbuf, ".\n");
 540         } else {
 541                 const char *p;
 542
 543                 base = parent;
 544                 base_label = msg.parent_label;
 545                 next = commit;
 546                 next_label = msg.label;
 547
 548                 /*
 549                  * Append the commit log message to msgbuf; it starts
 550                  * after the tree, parent, author, committer
 551                  * information followed by "\n\n".
 552                  */
 553                 p = strstr(msg.message, "\n\n");
 554                 if (p) {
 555                         p += 2;
 556                         strbuf_addstr(&msgbuf, p);
 557                 }
 558
 559                 if (opts->record_origin) {
 560                         if (!has_conforming_footer(&msgbuf, NULL, 0))
 561                                 strbuf_addch(&msgbuf, '\n');
 562                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
 563                         strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 564                         strbuf_addstr(&msgbuf, ")\n");
 565                 }
 566         }
 567
 568         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 569                 res = do_recursive_merge(base, next, base_label, next_label,
 570                                          head, &msgbuf, opts);
 571                 write_message(&msgbuf, defmsg);
 572         } else {
 573                 struct commit_list *common = NULL;
 574                 struct commit_list *remotes = NULL;
 575
 576                 write_message(&msgbuf, defmsg);
 577
 578                 commit_list_insert(base, &common);
 579                 commit_list_insert(next, &remotes);
 580                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 581                                         common, sha1_to_hex(head), remotes);
 582                 free_commit_list(common);
 583                 free_commit_list(remotes);
 584         }
 585
 586         /*
 587          * If the merge was clean or if it failed due to conflict, we write
 588          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 589          * However, if the merge did not even start, then we don't want to
 590          * write it at all.
 591          */
 592         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 593                 update_ref(NULL, "CHERRY_PICK_HEAD", commit->object.sha1, NULL,
 594                            REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
 595         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 596                 update_ref(NULL, "REVERT_HEAD", commit->object.sha1, NULL,
 597                            REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
 598
 599         if (res) {
 600                 error(opts->action == REPLAY_REVERT
 601                       ? _("could not revert %s... %s")
 602                       : _("could not apply %s... %s"),
 603                       find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
 604                       msg.subject);
 605                 print_advice(res == 1, opts);
 606                 rerere(opts->allow_rerere_auto);
 607                 goto leave;
 608         }
 609
 610         allow = allow_empty(opts, commit);
 611         if (allow < 0) {
 612                 res = allow;
 613                 goto leave;
 614         }
 615         if (!opts->no_commit)
 616                 res = run_git_commit(defmsg, opts, allow);
 617
 618 leave:
 619         free_message(commit, &msg);
 620         free(defmsg);
 621
 622         return res;
 623 }
 624
 625 static void prepare_revs(struct replay_opts *opts)
 626 {
 627         /*
 628          * picking (but not reverting) ranges (but not individual revisions)
 629          * should be done in reverse
 630          */
 631         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 632                 opts->revs->reverse ^= 1;
 633
 634         if (prepare_revision_walk(opts->revs))
 635                 die(_("revision walk setup failed"));
 636
 637         if (!opts->revs->commits)
 638                 die(_("empty commit set passed"));
 639 }
 640
 641 static void read_and_refresh_cache(struct replay_opts *opts)
 642 {
 643         static struct lock_file index_lock;
 644         int index_fd = hold_locked_index(&index_lock, 0);
 645         if (read_index_preload(&the_index, NULL) < 0)
 646                 die(_("git %s: failed to read the index"), action_name(opts));
 647         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 648         if (the_index.cache_changed && index_fd >= 0) {
 649                 if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
 650                         die(_("git %s: failed to refresh the index"), action_name(opts));
 651         }
 652         rollback_lock_file(&index_lock);
 653 }
 654
 655 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 656                 struct replay_opts *opts)
 657 {
 658         struct commit_list *cur = NULL;
 659         const char *sha1_abbrev = NULL;
 660         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 661         const char *subject;
 662         int subject_len;
 663
 664         for (cur = todo_list; cur; cur = cur->next) {
 665                 const char *commit_buffer = get_commit_buffer(cur->item, NULL);
 666                 sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
 667                 subject_len = find_commit_subject(commit_buffer, &subject);
 668                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 669                         subject_len, subject);
 670                 unuse_commit_buffer(cur->item, commit_buffer);
 671         }
 672         return 0;
 673 }
 674
 675 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 676 {
 677         unsigned char commit_sha1[20];
 678         enum replay_action action;
 679         char *end_of_object_name;
 680         int saved, status, padding;
 681
 682         if (starts_with(bol, "pick")) {
 683                 action = REPLAY_PICK;
 684                 bol += strlen("pick");
 685         } else if (starts_with(bol, "revert")) {
 686                 action = REPLAY_REVERT;
 687                 bol += strlen("revert");
 688         } else
 689                 return NULL;
 690
 691         /* Eat up extra spaces/ tabs before object name */
 692         padding = strspn(bol, " \t");
 693         if (!padding)
 694                 return NULL;
 695         bol += padding;
 696
 697         end_of_object_name = bol + strcspn(bol, " \t\n");
 698         saved = *end_of_object_name;
 699         *end_of_object_name = '\0';
 700         status = get_sha1(bol, commit_sha1);
 701         *end_of_object_name = saved;
 702
 703         /*
 704          * Verify that the action matches up with the one in
 705          * opts; we don't support arbitrary instructions
 706          */
 707         if (action != opts->action) {
 708                 const char *action_str;
 709                 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
 710                 error(_("Cannot %s during a %s"), action_str, action_name(opts));
 711                 return NULL;
 712         }
 713
 714         if (status < 0)
 715                 return NULL;
 716
 717         return lookup_commit_reference(commit_sha1);
 718 }
 719
 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         const char *todo_file = git_path(SEQ_TODO_FILE);
 745         struct strbuf buf = STRBUF_INIT;
 746         int fd, res;
 747
 748         fd = open(todo_file, O_RDONLY);
 749         if (fd < 0)
 750                 die_errno(_("Could not open %s"), todo_file);
 751         if (strbuf_read(&buf, fd, 0) < 0) {
 752                 close(fd);
 753                 strbuf_release(&buf);
 754                 die(_("Could not read %s."), todo_file);
 755         }
 756         close(fd);
 757
 758         res = parse_insn_buffer(buf.buf, todo_list, opts);
 759         strbuf_release(&buf);
 760         if (res)
 761                 die(_("Unusable instruction sheet: %s"), todo_file);
 762 }
 763
 764 static int populate_opts_cb(const char *key, const char *value, void *data)
 765 {
 766         struct replay_opts *opts = data;
 767         int error_flag = 1;
 768
 769         if (!value)
 770                 error_flag = 0;
 771         else if (!strcmp(key, "options.no-commit"))
 772                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 773         else if (!strcmp(key, "options.edit"))
 774                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
 775         else if (!strcmp(key, "options.signoff"))
 776                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 777         else if (!strcmp(key, "options.record-origin"))
 778                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 779         else if (!strcmp(key, "options.allow-ff"))
 780                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 781         else if (!strcmp(key, "options.mainline"))
 782                 opts->mainline = git_config_int(key, value);
 783         else if (!strcmp(key, "options.strategy"))
 784                 git_config_string(&opts->strategy, key, value);
 785         else if (!strcmp(key, "options.gpg-sign"))
 786                 git_config_string(&opts->gpg_sign, key, value);
 787         else if (!strcmp(key, "options.strategy-option")) {
 788                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 789                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
 790         } else
 791                 return error(_("Invalid key: %s"), key);
 792
 793         if (!error_flag)
 794                 return error(_("Invalid value for %s: %s"), key, value);
 795
 796         return 0;
 797 }
 798
 799 static void read_populate_opts(struct replay_opts **opts_ptr)
 800 {
 801         const char *opts_file = git_path(SEQ_OPTS_FILE);
 802
 803         if (!file_exists(opts_file))
 804                 return;
 805         if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
 806                 die(_("Malformed options sheet: %s"), opts_file);
 807 }
 808
 809 static void walk_revs_populate_todo(struct commit_list **todo_list,
 810                                 struct replay_opts *opts)
 811 {
 812         struct commit *commit;
 813         struct commit_list **next;
 814
 815         prepare_revs(opts);
 816
 817         next = todo_list;
 818         while ((commit = get_revision(opts->revs)))
 819                 next = commit_list_append(commit, next);
 820 }
 821
 822 static int create_seq_dir(void)
 823 {
 824         const char *seq_dir = git_path(SEQ_DIR);
 825
 826         if (file_exists(seq_dir)) {
 827                 error(_("a cherry-pick or revert is already in progress"));
 828                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 829                 return -1;
 830         }
 831         else if (mkdir(seq_dir, 0777) < 0)
 832                 die_errno(_("Could not create sequencer directory %s"), seq_dir);
 833         return 0;
 834 }
 835
 836 static void save_head(const char *head)
 837 {
 838         const char *head_file = git_path(SEQ_HEAD_FILE);
 839         static struct lock_file head_lock;
 840         struct strbuf buf = STRBUF_INIT;
 841         int fd;
 842
 843         fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
 844         strbuf_addf(&buf, "%s\n", head);
 845         if (write_in_full(fd, buf.buf, buf.len) < 0)
 846                 die_errno(_("Could not write to %s"), head_file);
 847         if (commit_lock_file(&head_lock) < 0)
 848                 die(_("Error wrapping up %s."), head_file);
 849 }
 850
 851 static int reset_for_rollback(const unsigned char *sha1)
 852 {
 853         const char *argv[4];    /* reset --merge <arg> + NULL */
 854         argv[0] = "reset";
 855         argv[1] = "--merge";
 856         argv[2] = sha1_to_hex(sha1);
 857         argv[3] = NULL;
 858         return run_command_v_opt(argv, RUN_GIT_CMD);
 859 }
 860
 861 static int rollback_single_pick(void)
 862 {
 863         unsigned char head_sha1[20];
 864
 865         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
 866             !file_exists(git_path("REVERT_HEAD")))
 867                 return error(_("no cherry-pick or revert in progress"));
 868         if (read_ref_full("HEAD", 0, head_sha1, NULL))
 869                 return error(_("cannot resolve HEAD"));
 870         if (is_null_sha1(head_sha1))
 871                 return error(_("cannot abort from a branch yet to be born"));
 872         return reset_for_rollback(head_sha1);
 873 }
 874
 875 static int sequencer_rollback(struct replay_opts *opts)
 876 {
 877         const char *filename;
 878         FILE *f;
 879         unsigned char sha1[20];
 880         struct strbuf buf = STRBUF_INIT;
 881
 882         filename = git_path(SEQ_HEAD_FILE);
 883         f = fopen(filename, "r");
 884         if (!f && errno == ENOENT) {
 885                 /*
 886                  * There is no multiple-cherry-pick in progress.
 887                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 888                  * a single-cherry-pick in progress, abort that.
 889                  */
 890                 return rollback_single_pick();
 891         }
 892         if (!f)
 893                 return error(_("cannot open %s: %s"), filename,
 894                                                 strerror(errno));
 895         if (strbuf_getline(&buf, f, '\n')) {
 896                 error(_("cannot read %s: %s"), filename, ferror(f) ?
 897                         strerror(errno) : _("unexpected end of file"));
 898                 fclose(f);
 899                 goto fail;
 900         }
 901         fclose(f);
 902         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 903                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 904                         filename);
 905                 goto fail;
 906         }
 907         if (reset_for_rollback(sha1))
 908                 goto fail;
 909         remove_sequencer_state();
 910         strbuf_release(&buf);
 911         return 0;
 912 fail:
 913         strbuf_release(&buf);
 914         return -1;
 915 }
 916
 917 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 918 {
 919         const char *todo_file = git_path(SEQ_TODO_FILE);
 920         static struct lock_file todo_lock;
 921         struct strbuf buf = STRBUF_INIT;
 922         int fd;
 923
 924         fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
 925         if (format_todo(&buf, todo_list, opts) < 0)
 926                 die(_("Could not format %s."), todo_file);
 927         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 928                 strbuf_release(&buf);
 929                 die_errno(_("Could not write to %s"), todo_file);
 930         }
 931         if (commit_lock_file(&todo_lock) < 0) {
 932                 strbuf_release(&buf);
 933                 die(_("Error wrapping up %s."), todo_file);
 934         }
 935         strbuf_release(&buf);
 936 }
 937
 938 static void save_opts(struct replay_opts *opts)
 939 {
 940         const char *opts_file = git_path(SEQ_OPTS_FILE);
 941
 942         if (opts->no_commit)
 943                 git_config_set_in_file(opts_file, "options.no-commit", "true");
 944         if (opts->edit)
 945                 git_config_set_in_file(opts_file, "options.edit", "true");
 946         if (opts->signoff)
 947                 git_config_set_in_file(opts_file, "options.signoff", "true");
 948         if (opts->record_origin)
 949                 git_config_set_in_file(opts_file, "options.record-origin", "true");
 950         if (opts->allow_ff)
 951                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
 952         if (opts->mainline) {
 953                 struct strbuf buf = STRBUF_INIT;
 954                 strbuf_addf(&buf, "%d", opts->mainline);
 955                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
 956                 strbuf_release(&buf);
 957         }
 958         if (opts->strategy)
 959                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
 960         if (opts->gpg_sign)
 961                 git_config_set_in_file(opts_file, "options.gpg-sign", opts->gpg_sign);
 962         if (opts->xopts) {
 963                 int i;
 964                 for (i = 0; i < opts->xopts_nr; i++)
 965                         git_config_set_multivar_in_file(opts_file,
 966                                                         "options.strategy-option",
 967                                                         opts->xopts[i], "^$", 0);
 968         }
 969 }
 970
 971 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
 972 {
 973         struct commit_list *cur;
 974         int res;
 975
 976         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
 977         if (opts->allow_ff)
 978                 assert(!(opts->signoff || opts->no_commit ||
 979                                 opts->record_origin || opts->edit));
 980         read_and_refresh_cache(opts);
 981
 982         for (cur = todo_list; cur; cur = cur->next) {
 983                 save_todo(cur, opts);
 984                 res = do_pick_commit(cur->item, opts);
 985                 if (res)
 986                         return res;
 987         }
 988
 989         /*
 990          * Sequence of picks finished successfully; cleanup by
 991          * removing the .git/sequencer directory
 992          */
 993         remove_sequencer_state();
 994         return 0;
 995 }
 996
 997 static int continue_single_pick(void)
 998 {
 999         const char *argv[] = { "commit", NULL };
1000
1001         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
1002             !file_exists(git_path("REVERT_HEAD")))
1003                 return error(_("no cherry-pick or revert in progress"));
1004         return run_command_v_opt(argv, RUN_GIT_CMD);
1005 }
1006
1007 static int sequencer_continue(struct replay_opts *opts)
1008 {
1009         struct commit_list *todo_list = NULL;
1010
1011         if (!file_exists(git_path(SEQ_TODO_FILE)))
1012                 return continue_single_pick();
1013         read_populate_opts(&opts);
1014         read_populate_todo(&todo_list, opts);
1015
1016         /* Verify that the conflict has been resolved */
1017         if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
1018             file_exists(git_path("REVERT_HEAD"))) {
1019                 int ret = continue_single_pick();
1020                 if (ret)
1021                         return ret;
1022         }
1023         if (index_differs_from("HEAD", 0))
1024                 return error_dirty_index(opts);
1025         todo_list = todo_list->next;
1026         return pick_commits(todo_list, opts);
1027 }
1028
1029 static int single_pick(struct commit *cmit, struct replay_opts *opts)
1030 {
1031         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1032         return do_pick_commit(cmit, opts);
1033 }
1034
1035 int sequencer_pick_revisions(struct replay_opts *opts)
1036 {
1037         struct commit_list *todo_list = NULL;
1038         unsigned char sha1[20];
1039         int i;
1040
1041         if (opts->subcommand == REPLAY_NONE)
1042                 assert(opts->revs);
1043
1044         read_and_refresh_cache(opts);
1045
1046         /*
1047          * Decide what to do depending on the arguments; a fresh
1048          * cherry-pick should be handled differently from an existing
1049          * one that is being continued
1050          */
1051         if (opts->subcommand == REPLAY_REMOVE_STATE) {
1052                 remove_sequencer_state();
1053                 return 0;
1054         }
1055         if (opts->subcommand == REPLAY_ROLLBACK)
1056                 return sequencer_rollback(opts);
1057         if (opts->subcommand == REPLAY_CONTINUE)
1058                 return sequencer_continue(opts);
1059
1060         for (i = 0; i < opts->revs->pending.nr; i++) {
1061                 unsigned char sha1[20];
1062                 const char *name = opts->revs->pending.objects[i].name;
1063
1064                 /* This happens when using --stdin. */
1065                 if (!strlen(name))
1066                         continue;
1067
1068                 if (!get_sha1(name, sha1)) {
1069                         if (!lookup_commit_reference_gently(sha1, 1)) {
1070                                 enum object_type type = sha1_object_info(sha1, NULL);
1071                                 die(_("%s: can't cherry-pick a %s"), name, typename(type));
1072                         }
1073                 } else
1074                         die(_("%s: bad revision"), name);
1075         }
1076
1077         /*
1078          * If we were called as "git cherry-pick <commit>", just
1079          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1080          * REVERT_HEAD, and don't touch the sequencer state.
1081          * This means it is possible to cherry-pick in the middle
1082          * of a cherry-pick sequence.
1083          */
1084         if (opts->revs->cmdline.nr == 1 &&
1085             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1086             opts->revs->no_walk &&
1087             !opts->revs->cmdline.rev->flags) {
1088                 struct commit *cmit;
1089                 if (prepare_revision_walk(opts->revs))
1090                         die(_("revision walk setup failed"));
1091                 cmit = get_revision(opts->revs);
1092                 if (!cmit || get_revision(opts->revs))
1093                         die("BUG: expected exactly one commit from walk");
1094                 return single_pick(cmit, opts);
1095         }
1096
1097         /*
1098          * Start a new cherry-pick/ revert sequence; but
1099          * first, make sure that an existing one isn't in
1100          * progress
1101          */
1102
1103         walk_revs_populate_todo(&todo_list, opts);
1104         if (create_seq_dir() < 0)
1105                 return -1;
1106         if (get_sha1("HEAD", sha1)) {
1107                 if (opts->action == REPLAY_REVERT)
1108                         return error(_("Can't revert as initial commit"));
1109                 return error(_("Can't cherry-pick into empty head"));
1110         }
1111         save_head(sha1_to_hex(sha1));
1112         save_opts(opts);
1113         return pick_commits(todo_list, opts);
1114 }
1115
1116 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1117 {
1118         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1119         struct strbuf sob = STRBUF_INIT;
1120         int has_footer;
1121
1122         strbuf_addstr(&sob, sign_off_header);
1123         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1124                                 getenv("GIT_COMMITTER_EMAIL")));
1125         strbuf_addch(&sob, '\n');
1126
1127         /*
1128          * If the whole message buffer is equal to the sob, pretend that we
1129          * found a conforming footer with a matching sob
1130          */
1131         if (msgbuf->len - ignore_footer == sob.len &&
1132             !strncmp(msgbuf->buf, sob.buf, sob.len))
1133                 has_footer = 3;
1134         else
1135                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1136
1137         if (!has_footer) {
1138                 const char *append_newlines = NULL;
1139                 size_t len = msgbuf->len - ignore_footer;
1140
1141                 if (!len) {
1142                         /*
1143                          * The buffer is completely empty.  Leave foom for
1144                          * the title and body to be filled in by the user.
1145                          */
1146                         append_newlines = "\n\n";
1147                 } else if (msgbuf->buf[len - 1] != '\n') {
1148                         /*
1149                          * Incomplete line.  Complete the line and add a
1150                          * blank one so that there is an empty line between
1151                          * the message body and the sob.
1152                          */
1153                         append_newlines = "\n\n";
1154                 } else if (len == 1) {
1155                         /*
1156                          * Buffer contains a single newline.  Add another
1157                          * so that we leave room for the title and body.
1158                          */
1159                         append_newlines = "\n";
1160                 } else if (msgbuf->buf[len - 2] != '\n') {
1161                         /*
1162                          * Buffer ends with a single newline.  Add another
1163                          * so that there is an empty line between the message
1164                          * body and the sob.
1165                          */
1166                         append_newlines = "\n";
1167                 } /* else, the buffer already ends with two newlines. */
1168
1169                 if (append_newlines)
1170                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1171                                 append_newlines, strlen(append_newlines));
1172         }
1173
1174         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1175                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1176                                 sob.buf, sob.len);
1177
1178         strbuf_release(&sob);
1179 }