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                 !prefixcmp(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 static char *get_encoding(const char *message);
 120
 121 struct commit_message {
 122         char *parent_label;
 123         const char *label;
 124         const char *subject;
 125         char *reencoded_message;
 126         const char *message;
 127 };
 128
 129 static int get_message(struct commit *commit, struct commit_message *out)
 130 {
 131         const char *encoding;
 132         const char *abbrev, *subject;
 133         int abbrev_len, subject_len;
 134         char *q;
 135
 136         if (!commit->buffer)
 137                 return -1;
 138         encoding = get_encoding(commit->buffer);
 139         if (!encoding)
 140                 encoding = "UTF-8";
 141         if (!git_commit_encoding)
 142                 git_commit_encoding = "UTF-8";
 143
 144         out->reencoded_message = NULL;
 145         out->message = commit->buffer;
 146         if (same_encoding(encoding, git_commit_encoding))
 147                 out->reencoded_message = reencode_string(commit->buffer,
 148                                         git_commit_encoding, encoding);
 149         if (out->reencoded_message)
 150                 out->message = out->reencoded_message;
 151
 152         abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
 153         abbrev_len = strlen(abbrev);
 154
 155         subject_len = find_commit_subject(out->message, &subject);
 156
 157         out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
 158                               strlen("... ") + subject_len + 1);
 159         q = out->parent_label;
 160         q = mempcpy(q, "parent of ", strlen("parent of "));
 161         out->label = q;
 162         q = mempcpy(q, abbrev, abbrev_len);
 163         q = mempcpy(q, "... ", strlen("... "));
 164         out->subject = q;
 165         q = mempcpy(q, subject, subject_len);
 166         *q = '\0';
 167         return 0;
 168 }
 169
 170 static void free_message(struct commit_message *msg)
 171 {
 172         free(msg->parent_label);
 173         free(msg->reencoded_message);
 174 }
 175
 176 static char *get_encoding(const char *message)
 177 {
 178         const char *p = message, *eol;
 179
 180         while (*p && *p != '\n') {
 181                 for (eol = p + 1; *eol && *eol != '\n'; eol++)
 182                         ; /* do nothing */
 183                 if (!prefixcmp(p, "encoding ")) {
 184                         char *result = xmalloc(eol - 8 - p);
 185                         strlcpy(result, p + 9, eol - 8 - p);
 186                         return result;
 187                 }
 188                 p = eol;
 189                 if (*p == '\n')
 190                         p++;
 191         }
 192         return NULL;
 193 }
 194
 195 static void write_cherry_pick_head(struct commit *commit, const char *pseudoref)
 196 {
 197         const char *filename;
 198         int fd;
 199         struct strbuf buf = STRBUF_INIT;
 200
 201         strbuf_addf(&buf, "%s\n", sha1_to_hex(commit->object.sha1));
 202
 203         filename = git_path("%s", pseudoref);
 204         fd = open(filename, O_WRONLY | O_CREAT, 0666);
 205         if (fd < 0)
 206                 die_errno(_("Could not open '%s' for writing"), filename);
 207         if (write_in_full(fd, buf.buf, buf.len) != buf.len || close(fd))
 208                 die_errno(_("Could not write to '%s'"), filename);
 209         strbuf_release(&buf);
 210 }
 211
 212 static void print_advice(int show_hint, struct replay_opts *opts)
 213 {
 214         char *msg = getenv("GIT_CHERRY_PICK_HELP");
 215
 216         if (msg) {
 217                 fprintf(stderr, "%s\n", msg);
 218                 /*
 219                  * A conflict has occurred but the porcelain
 220                  * (typically rebase --interactive) wants to take care
 221                  * of the commit itself so remove CHERRY_PICK_HEAD
 222                  */
 223                 unlink(git_path("CHERRY_PICK_HEAD"));
 224                 return;
 225         }
 226
 227         if (show_hint) {
 228                 if (opts->no_commit)
 229                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 230                                  "with 'git add <paths>' or 'git rm <paths>'"));
 231                 else
 232                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 233                                  "with 'git add <paths>' or 'git rm <paths>'\n"
 234                                  "and commit the result with 'git commit'"));
 235         }
 236 }
 237
 238 static void write_message(struct strbuf *msgbuf, const char *filename)
 239 {
 240         static struct lock_file msg_file;
 241
 242         int msg_fd = hold_lock_file_for_update(&msg_file, filename,
 243                                                LOCK_DIE_ON_ERROR);
 244         if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
 245                 die_errno(_("Could not write to %s"), filename);
 246         strbuf_release(msgbuf);
 247         if (commit_lock_file(&msg_file) < 0)
 248                 die(_("Error wrapping up %s"), filename);
 249 }
 250
 251 static struct tree *empty_tree(void)
 252 {
 253         return lookup_tree(EMPTY_TREE_SHA1_BIN);
 254 }
 255
 256 static int error_dirty_index(struct replay_opts *opts)
 257 {
 258         if (read_cache_unmerged())
 259                 return error_resolve_conflict(action_name(opts));
 260
 261         /* Different translation strings for cherry-pick and revert */
 262         if (opts->action == REPLAY_PICK)
 263                 error(_("Your local changes would be overwritten by cherry-pick."));
 264         else
 265                 error(_("Your local changes would be overwritten by revert."));
 266
 267         if (advice_commit_before_merge)
 268                 advise(_("Commit your changes or stash them to proceed."));
 269         return -1;
 270 }
 271
 272 static int fast_forward_to(const unsigned char *to, const unsigned char *from,
 273                            int unborn)
 274 {
 275         struct ref_lock *ref_lock;
 276
 277         read_cache();
 278         if (checkout_fast_forward(from, to, 1))
 279                 exit(1); /* the callee should have complained already */
 280         ref_lock = lock_any_ref_for_update("HEAD", unborn ? null_sha1 : from, 0);
 281         return write_ref_sha1(ref_lock, to, "cherry-pick");
 282 }
 283
 284 static int do_recursive_merge(struct commit *base, struct commit *next,
 285                               const char *base_label, const char *next_label,
 286                               unsigned char *head, struct strbuf *msgbuf,
 287                               struct replay_opts *opts)
 288 {
 289         struct merge_options o;
 290         struct tree *result, *next_tree, *base_tree, *head_tree;
 291         int clean, index_fd;
 292         const char **xopt;
 293         static struct lock_file index_lock;
 294
 295         index_fd = hold_locked_index(&index_lock, 1);
 296
 297         read_cache();
 298
 299         init_merge_options(&o);
 300         o.ancestor = base ? base_label : "(empty tree)";
 301         o.branch1 = "HEAD";
 302         o.branch2 = next ? next_label : "(empty tree)";
 303
 304         head_tree = parse_tree_indirect(head);
 305         next_tree = next ? next->tree : empty_tree();
 306         base_tree = base ? base->tree : empty_tree();
 307
 308         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 309                 parse_merge_opt(&o, *xopt);
 310
 311         clean = merge_trees(&o,
 312                             head_tree,
 313                             next_tree, base_tree, &result);
 314
 315         if (active_cache_changed &&
 316             (write_cache(index_fd, active_cache, active_nr) ||
 317              commit_locked_index(&index_lock)))
 318                 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 319                 die(_("%s: Unable to write new index file"), action_name(opts));
 320         rollback_lock_file(&index_lock);
 321
 322         if (opts->signoff)
 323                 append_signoff(msgbuf, 0, 0);
 324
 325         if (!clean) {
 326                 int i;
 327                 strbuf_addstr(msgbuf, "\nConflicts:\n");
 328                 for (i = 0; i < active_nr;) {
 329                         struct cache_entry *ce = active_cache[i++];
 330                         if (ce_stage(ce)) {
 331                                 strbuf_addch(msgbuf, '\t');
 332                                 strbuf_addstr(msgbuf, ce->name);
 333                                 strbuf_addch(msgbuf, '\n');
 334                                 while (i < active_nr && !strcmp(ce->name,
 335                                                 active_cache[i]->name))
 336                                         i++;
 337                         }
 338                 }
 339         }
 340
 341         return !clean;
 342 }
 343
 344 static int is_index_unchanged(void)
 345 {
 346         unsigned char head_sha1[20];
 347         struct commit *head_commit;
 348
 349         if (!resolve_ref_unsafe("HEAD", head_sha1, 1, NULL))
 350                 return error(_("Could not resolve HEAD commit\n"));
 351
 352         head_commit = lookup_commit(head_sha1);
 353
 354         /*
 355          * If head_commit is NULL, check_commit, called from
 356          * lookup_commit, would have indicated that head_commit is not
 357          * a commit object already.  parse_commit() will return failure
 358          * without further complaints in such a case.  Otherwise, if
 359          * the commit is invalid, parse_commit() will complain.  So
 360          * there is nothing for us to say here.  Just return failure.
 361          */
 362         if (parse_commit(head_commit))
 363                 return -1;
 364
 365         if (!active_cache_tree)
 366                 active_cache_tree = cache_tree();
 367
 368         if (!cache_tree_fully_valid(active_cache_tree))
 369                 if (cache_tree_update(active_cache_tree, active_cache,
 370                                   active_nr, 0))
 371                         return error(_("Unable to update cache tree\n"));
 372
 373         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.sha1);
 374 }
 375
 376 /*
 377  * If we are cherry-pick, and if the merge did not result in
 378  * hand-editing, we will hit this commit and inherit the original
 379  * author date and name.
 380  * If we are revert, or if our cherry-pick results in a hand merge,
 381  * we had better say that the current user is responsible for that.
 382  */
 383 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 384                           int allow_empty)
 385 {
 386         struct argv_array array;
 387         int rc;
 388
 389         argv_array_init(&array);
 390         argv_array_push(&array, "commit");
 391         argv_array_push(&array, "-n");
 392
 393         if (opts->signoff)
 394                 argv_array_push(&array, "-s");
 395         if (!opts->edit) {
 396                 argv_array_push(&array, "-F");
 397                 argv_array_push(&array, defmsg);
 398         }
 399
 400         if (allow_empty)
 401                 argv_array_push(&array, "--allow-empty");
 402
 403         if (opts->allow_empty_message)
 404                 argv_array_push(&array, "--allow-empty-message");
 405
 406         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 407         argv_array_clear(&array);
 408         return rc;
 409 }
 410
 411 static int is_original_commit_empty(struct commit *commit)
 412 {
 413         const unsigned char *ptree_sha1;
 414
 415         if (parse_commit(commit))
 416                 return error(_("Could not parse commit %s\n"),
 417                              sha1_to_hex(commit->object.sha1));
 418         if (commit->parents) {
 419                 struct commit *parent = commit->parents->item;
 420                 if (parse_commit(parent))
 421                         return error(_("Could not parse parent commit %s\n"),
 422                                 sha1_to_hex(parent->object.sha1));
 423                 ptree_sha1 = parent->tree->object.sha1;
 424         } else {
 425                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 426         }
 427
 428         return !hashcmp(ptree_sha1, commit->tree->object.sha1);
 429 }
 430
 431 /*
 432  * Do we run "git commit" with "--allow-empty"?
 433  */
 434 static int allow_empty(struct replay_opts *opts, struct commit *commit)
 435 {
 436         int index_unchanged, empty_commit;
 437
 438         /*
 439          * Three cases:
 440          *
 441          * (1) we do not allow empty at all and error out.
 442          *
 443          * (2) we allow ones that were initially empty, but
 444          * forbid the ones that become empty;
 445          *
 446          * (3) we allow both.
 447          */
 448         if (!opts->allow_empty)
 449                 return 0; /* let "git commit" barf as necessary */
 450
 451         index_unchanged = is_index_unchanged();
 452         if (index_unchanged < 0)
 453                 return index_unchanged;
 454         if (!index_unchanged)
 455                 return 0; /* we do not have to say --allow-empty */
 456
 457         if (opts->keep_redundant_commits)
 458                 return 1;
 459
 460         empty_commit = is_original_commit_empty(commit);
 461         if (empty_commit < 0)
 462                 return empty_commit;
 463         if (!empty_commit)
 464                 return 0;
 465         else
 466                 return 1;
 467 }
 468
 469 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 470 {
 471         unsigned char head[20];
 472         struct commit *base, *next, *parent;
 473         const char *base_label, *next_label;
 474         struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
 475         char *defmsg = NULL;
 476         struct strbuf msgbuf = STRBUF_INIT;
 477         int res, unborn = 0, allow;
 478
 479         if (opts->no_commit) {
 480                 /*
 481                  * We do not intend to commit immediately.  We just want to
 482                  * merge the differences in, so let's compute the tree
 483                  * that represents the "current" state for merge-recursive
 484                  * to work on.
 485                  */
 486                 if (write_cache_as_tree(head, 0, NULL))
 487                         die (_("Your index file is unmerged."));
 488         } else {
 489                 unborn = get_sha1("HEAD", head);
 490                 if (unborn)
 491                         hashcpy(head, EMPTY_TREE_SHA1_BIN);
 492                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
 493                         return error_dirty_index(opts);
 494         }
 495         discard_cache();
 496
 497         if (!commit->parents) {
 498                 parent = NULL;
 499         }
 500         else if (commit->parents->next) {
 501                 /* Reverting or cherry-picking a merge commit */
 502                 int cnt;
 503                 struct commit_list *p;
 504
 505                 if (!opts->mainline)
 506                         return error(_("Commit %s is a merge but no -m option was given."),
 507                                 sha1_to_hex(commit->object.sha1));
 508
 509                 for (cnt = 1, p = commit->parents;
 510                      cnt != opts->mainline && p;
 511                      cnt++)
 512                         p = p->next;
 513                 if (cnt != opts->mainline || !p)
 514                         return error(_("Commit %s does not have parent %d"),
 515                                 sha1_to_hex(commit->object.sha1), opts->mainline);
 516                 parent = p->item;
 517         } else if (0 < opts->mainline)
 518                 return error(_("Mainline was specified but commit %s is not a merge."),
 519                         sha1_to_hex(commit->object.sha1));
 520         else
 521                 parent = commit->parents->item;
 522
 523         if (opts->allow_ff &&
 524             ((parent && !hashcmp(parent->object.sha1, head)) ||
 525              (!parent && unborn)))
 526              return fast_forward_to(commit->object.sha1, head, unborn);
 527
 528         if (parent && parse_commit(parent) < 0)
 529                 /* TRANSLATORS: The first %s will be "revert" or
 530                    "cherry-pick", the second %s a SHA1 */
 531                 return error(_("%s: cannot parse parent commit %s"),
 532                         action_name(opts), sha1_to_hex(parent->object.sha1));
 533
 534         if (get_message(commit, &msg) != 0)
 535                 return error(_("Cannot get commit message for %s"),
 536                         sha1_to_hex(commit->object.sha1));
 537
 538         /*
 539          * "commit" is an existing commit.  We would want to apply
 540          * the difference it introduces since its first parent "prev"
 541          * on top of the current HEAD if we are cherry-pick.  Or the
 542          * reverse of it if we are revert.
 543          */
 544
 545         defmsg = git_pathdup("MERGE_MSG");
 546
 547         if (opts->action == REPLAY_REVERT) {
 548                 base = commit;
 549                 base_label = msg.label;
 550                 next = parent;
 551                 next_label = msg.parent_label;
 552                 strbuf_addstr(&msgbuf, "Revert \"");
 553                 strbuf_addstr(&msgbuf, msg.subject);
 554                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 555                 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 556
 557                 if (commit->parents && commit->parents->next) {
 558                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 559                         strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
 560                 }
 561                 strbuf_addstr(&msgbuf, ".\n");
 562         } else {
 563                 const char *p;
 564
 565                 base = parent;
 566                 base_label = msg.parent_label;
 567                 next = commit;
 568                 next_label = msg.label;
 569
 570                 /*
 571                  * Append the commit log message to msgbuf; it starts
 572                  * after the tree, parent, author, committer
 573                  * information followed by "\n\n".
 574                  */
 575                 p = strstr(msg.message, "\n\n");
 576                 if (p) {
 577                         p += 2;
 578                         strbuf_addstr(&msgbuf, p);
 579                 }
 580
 581                 if (opts->record_origin) {
 582                         if (!has_conforming_footer(&msgbuf, NULL, 0))
 583                                 strbuf_addch(&msgbuf, '\n');
 584                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
 585                         strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 586                         strbuf_addstr(&msgbuf, ")\n");
 587                 }
 588         }
 589
 590         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 591                 res = do_recursive_merge(base, next, base_label, next_label,
 592                                          head, &msgbuf, opts);
 593                 write_message(&msgbuf, defmsg);
 594         } else {
 595                 struct commit_list *common = NULL;
 596                 struct commit_list *remotes = NULL;
 597
 598                 write_message(&msgbuf, defmsg);
 599
 600                 commit_list_insert(base, &common);
 601                 commit_list_insert(next, &remotes);
 602                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 603                                         common, sha1_to_hex(head), remotes);
 604                 free_commit_list(common);
 605                 free_commit_list(remotes);
 606         }
 607
 608         /*
 609          * If the merge was clean or if it failed due to conflict, we write
 610          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 611          * However, if the merge did not even start, then we don't want to
 612          * write it at all.
 613          */
 614         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 615                 write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
 616         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 617                 write_cherry_pick_head(commit, "REVERT_HEAD");
 618
 619         if (res) {
 620                 error(opts->action == REPLAY_REVERT
 621                       ? _("could not revert %s... %s")
 622                       : _("could not apply %s... %s"),
 623                       find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
 624                       msg.subject);
 625                 print_advice(res == 1, opts);
 626                 rerere(opts->allow_rerere_auto);
 627                 goto leave;
 628         }
 629
 630         allow = allow_empty(opts, commit);
 631         if (allow < 0) {
 632                 res = allow;
 633                 goto leave;
 634         }
 635         if (!opts->no_commit)
 636                 res = run_git_commit(defmsg, opts, allow);
 637
 638 leave:
 639         free_message(&msg);
 640         free(defmsg);
 641
 642         return res;
 643 }
 644
 645 static void prepare_revs(struct replay_opts *opts)
 646 {
 647         /*
 648          * picking (but not reverting) ranges (but not individual revisions)
 649          * should be done in reverse
 650          */
 651         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 652                 opts->revs->reverse ^= 1;
 653
 654         if (prepare_revision_walk(opts->revs))
 655                 die(_("revision walk setup failed"));
 656
 657         if (!opts->revs->commits)
 658                 die(_("empty commit set passed"));
 659 }
 660
 661 static void read_and_refresh_cache(struct replay_opts *opts)
 662 {
 663         static struct lock_file index_lock;
 664         int index_fd = hold_locked_index(&index_lock, 0);
 665         if (read_index_preload(&the_index, NULL) < 0)
 666                 die(_("git %s: failed to read the index"), action_name(opts));
 667         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 668         if (the_index.cache_changed) {
 669                 if (write_index(&the_index, index_fd) ||
 670                     commit_locked_index(&index_lock))
 671                         die(_("git %s: failed to refresh the index"), action_name(opts));
 672         }
 673         rollback_lock_file(&index_lock);
 674 }
 675
 676 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 677                 struct replay_opts *opts)
 678 {
 679         struct commit_list *cur = NULL;
 680         const char *sha1_abbrev = NULL;
 681         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 682         const char *subject;
 683         int subject_len;
 684
 685         for (cur = todo_list; cur; cur = cur->next) {
 686                 sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
 687                 subject_len = find_commit_subject(cur->item->buffer, &subject);
 688                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 689                         subject_len, subject);
 690         }
 691         return 0;
 692 }
 693
 694 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 695 {
 696         unsigned char commit_sha1[20];
 697         enum replay_action action;
 698         char *end_of_object_name;
 699         int saved, status, padding;
 700
 701         if (!prefixcmp(bol, "pick")) {
 702                 action = REPLAY_PICK;
 703                 bol += strlen("pick");
 704         } else if (!prefixcmp(bol, "revert")) {
 705                 action = REPLAY_REVERT;
 706                 bol += strlen("revert");
 707         } else
 708                 return NULL;
 709
 710         /* Eat up extra spaces/ tabs before object name */
 711         padding = strspn(bol, " \t");
 712         if (!padding)
 713                 return NULL;
 714         bol += padding;
 715
 716         end_of_object_name = bol + strcspn(bol, " \t\n");
 717         saved = *end_of_object_name;
 718         *end_of_object_name = '\0';
 719         status = get_sha1(bol, commit_sha1);
 720         *end_of_object_name = saved;
 721
 722         /*
 723          * Verify that the action matches up with the one in
 724          * opts; we don't support arbitrary instructions
 725          */
 726         if (action != opts->action) {
 727                 const char *action_str;
 728                 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
 729                 error(_("Cannot %s during a %s"), action_str, action_name(opts));
 730                 return NULL;
 731         }
 732
 733         if (status < 0)
 734                 return NULL;
 735
 736         return lookup_commit_reference(commit_sha1);
 737 }
 738
 739 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
 740                         struct replay_opts *opts)
 741 {
 742         struct commit_list **next = todo_list;
 743         struct commit *commit;
 744         char *p = buf;
 745         int i;
 746
 747         for (i = 1; *p; i++) {
 748                 char *eol = strchrnul(p, '\n');
 749                 commit = parse_insn_line(p, eol, opts);
 750                 if (!commit)
 751                         return error(_("Could not parse line %d."), i);
 752                 next = commit_list_append(commit, next);
 753                 p = *eol ? eol + 1 : eol;
 754         }
 755         if (!*todo_list)
 756                 return error(_("No commits parsed."));
 757         return 0;
 758 }
 759
 760 static void read_populate_todo(struct commit_list **todo_list,
 761                         struct replay_opts *opts)
 762 {
 763         const char *todo_file = git_path(SEQ_TODO_FILE);
 764         struct strbuf buf = STRBUF_INIT;
 765         int fd, res;
 766
 767         fd = open(todo_file, O_RDONLY);
 768         if (fd < 0)
 769                 die_errno(_("Could not open %s"), todo_file);
 770         if (strbuf_read(&buf, fd, 0) < 0) {
 771                 close(fd);
 772                 strbuf_release(&buf);
 773                 die(_("Could not read %s."), todo_file);
 774         }
 775         close(fd);
 776
 777         res = parse_insn_buffer(buf.buf, todo_list, opts);
 778         strbuf_release(&buf);
 779         if (res)
 780                 die(_("Unusable instruction sheet: %s"), todo_file);
 781 }
 782
 783 static int populate_opts_cb(const char *key, const char *value, void *data)
 784 {
 785         struct replay_opts *opts = data;
 786         int error_flag = 1;
 787
 788         if (!value)
 789                 error_flag = 0;
 790         else if (!strcmp(key, "options.no-commit"))
 791                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 792         else if (!strcmp(key, "options.edit"))
 793                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
 794         else if (!strcmp(key, "options.signoff"))
 795                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 796         else if (!strcmp(key, "options.record-origin"))
 797                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 798         else if (!strcmp(key, "options.allow-ff"))
 799                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 800         else if (!strcmp(key, "options.mainline"))
 801                 opts->mainline = git_config_int(key, value);
 802         else if (!strcmp(key, "options.strategy"))
 803                 git_config_string(&opts->strategy, key, value);
 804         else if (!strcmp(key, "options.strategy-option")) {
 805                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 806                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
 807         } else
 808                 return error(_("Invalid key: %s"), key);
 809
 810         if (!error_flag)
 811                 return error(_("Invalid value for %s: %s"), key, value);
 812
 813         return 0;
 814 }
 815
 816 static void read_populate_opts(struct replay_opts **opts_ptr)
 817 {
 818         const char *opts_file = git_path(SEQ_OPTS_FILE);
 819
 820         if (!file_exists(opts_file))
 821                 return;
 822         if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
 823                 die(_("Malformed options sheet: %s"), opts_file);
 824 }
 825
 826 static void walk_revs_populate_todo(struct commit_list **todo_list,
 827                                 struct replay_opts *opts)
 828 {
 829         struct commit *commit;
 830         struct commit_list **next;
 831
 832         prepare_revs(opts);
 833
 834         next = todo_list;
 835         while ((commit = get_revision(opts->revs)))
 836                 next = commit_list_append(commit, next);
 837 }
 838
 839 static int create_seq_dir(void)
 840 {
 841         const char *seq_dir = git_path(SEQ_DIR);
 842
 843         if (file_exists(seq_dir)) {
 844                 error(_("a cherry-pick or revert is already in progress"));
 845                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 846                 return -1;
 847         }
 848         else if (mkdir(seq_dir, 0777) < 0)
 849                 die_errno(_("Could not create sequencer directory %s"), seq_dir);
 850         return 0;
 851 }
 852
 853 static void save_head(const char *head)
 854 {
 855         const char *head_file = git_path(SEQ_HEAD_FILE);
 856         static struct lock_file head_lock;
 857         struct strbuf buf = STRBUF_INIT;
 858         int fd;
 859
 860         fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
 861         strbuf_addf(&buf, "%s\n", head);
 862         if (write_in_full(fd, buf.buf, buf.len) < 0)
 863                 die_errno(_("Could not write to %s"), head_file);
 864         if (commit_lock_file(&head_lock) < 0)
 865                 die(_("Error wrapping up %s."), head_file);
 866 }
 867
 868 static int reset_for_rollback(const unsigned char *sha1)
 869 {
 870         const char *argv[4];    /* reset --merge <arg> + NULL */
 871         argv[0] = "reset";
 872         argv[1] = "--merge";
 873         argv[2] = sha1_to_hex(sha1);
 874         argv[3] = NULL;
 875         return run_command_v_opt(argv, RUN_GIT_CMD);
 876 }
 877
 878 static int rollback_single_pick(void)
 879 {
 880         unsigned char head_sha1[20];
 881
 882         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
 883             !file_exists(git_path("REVERT_HEAD")))
 884                 return error(_("no cherry-pick or revert in progress"));
 885         if (read_ref_full("HEAD", head_sha1, 0, NULL))
 886                 return error(_("cannot resolve HEAD"));
 887         if (is_null_sha1(head_sha1))
 888                 return error(_("cannot abort from a branch yet to be born"));
 889         return reset_for_rollback(head_sha1);
 890 }
 891
 892 static int sequencer_rollback(struct replay_opts *opts)
 893 {
 894         const char *filename;
 895         FILE *f;
 896         unsigned char sha1[20];
 897         struct strbuf buf = STRBUF_INIT;
 898
 899         filename = git_path(SEQ_HEAD_FILE);
 900         f = fopen(filename, "r");
 901         if (!f && errno == ENOENT) {
 902                 /*
 903                  * There is no multiple-cherry-pick in progress.
 904                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 905                  * a single-cherry-pick in progress, abort that.
 906                  */
 907                 return rollback_single_pick();
 908         }
 909         if (!f)
 910                 return error(_("cannot open %s: %s"), filename,
 911                                                 strerror(errno));
 912         if (strbuf_getline(&buf, f, '\n')) {
 913                 error(_("cannot read %s: %s"), filename, ferror(f) ?
 914                         strerror(errno) : _("unexpected end of file"));
 915                 fclose(f);
 916                 goto fail;
 917         }
 918         fclose(f);
 919         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 920                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 921                         filename);
 922                 goto fail;
 923         }
 924         if (reset_for_rollback(sha1))
 925                 goto fail;
 926         remove_sequencer_state();
 927         strbuf_release(&buf);
 928         return 0;
 929 fail:
 930         strbuf_release(&buf);
 931         return -1;
 932 }
 933
 934 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 935 {
 936         const char *todo_file = git_path(SEQ_TODO_FILE);
 937         static struct lock_file todo_lock;
 938         struct strbuf buf = STRBUF_INIT;
 939         int fd;
 940
 941         fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
 942         if (format_todo(&buf, todo_list, opts) < 0)
 943                 die(_("Could not format %s."), todo_file);
 944         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 945                 strbuf_release(&buf);
 946                 die_errno(_("Could not write to %s"), todo_file);
 947         }
 948         if (commit_lock_file(&todo_lock) < 0) {
 949                 strbuf_release(&buf);
 950                 die(_("Error wrapping up %s."), todo_file);
 951         }
 952         strbuf_release(&buf);
 953 }
 954
 955 static void save_opts(struct replay_opts *opts)
 956 {
 957         const char *opts_file = git_path(SEQ_OPTS_FILE);
 958
 959         if (opts->no_commit)
 960                 git_config_set_in_file(opts_file, "options.no-commit", "true");
 961         if (opts->edit)
 962                 git_config_set_in_file(opts_file, "options.edit", "true");
 963         if (opts->signoff)
 964                 git_config_set_in_file(opts_file, "options.signoff", "true");
 965         if (opts->record_origin)
 966                 git_config_set_in_file(opts_file, "options.record-origin", "true");
 967         if (opts->allow_ff)
 968                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
 969         if (opts->mainline) {
 970                 struct strbuf buf = STRBUF_INIT;
 971                 strbuf_addf(&buf, "%d", opts->mainline);
 972                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
 973                 strbuf_release(&buf);
 974         }
 975         if (opts->strategy)
 976                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
 977         if (opts->xopts) {
 978                 int i;
 979                 for (i = 0; i < opts->xopts_nr; i++)
 980                         git_config_set_multivar_in_file(opts_file,
 981                                                         "options.strategy-option",
 982                                                         opts->xopts[i], "^$", 0);
 983         }
 984 }
 985
 986 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
 987 {
 988         struct commit_list *cur;
 989         int res;
 990
 991         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
 992         if (opts->allow_ff)
 993                 assert(!(opts->signoff || opts->no_commit ||
 994                                 opts->record_origin || opts->edit));
 995         read_and_refresh_cache(opts);
 996
 997         for (cur = todo_list; cur; cur = cur->next) {
 998                 save_todo(cur, opts);
 999                 res = do_pick_commit(cur->item, opts);
1000                 if (res)
1001                         return res;
1002         }
1003
1004         /*
1005          * Sequence of picks finished successfully; cleanup by
1006          * removing the .git/sequencer directory
1007          */
1008         remove_sequencer_state();
1009         return 0;
1010 }
1011
1012 static int continue_single_pick(void)
1013 {
1014         const char *argv[] = { "commit", NULL };
1015
1016         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
1017             !file_exists(git_path("REVERT_HEAD")))
1018                 return error(_("no cherry-pick or revert in progress"));
1019         return run_command_v_opt(argv, RUN_GIT_CMD);
1020 }
1021
1022 static int sequencer_continue(struct replay_opts *opts)
1023 {
1024         struct commit_list *todo_list = NULL;
1025
1026         if (!file_exists(git_path(SEQ_TODO_FILE)))
1027                 return continue_single_pick();
1028         read_populate_opts(&opts);
1029         read_populate_todo(&todo_list, opts);
1030
1031         /* Verify that the conflict has been resolved */
1032         if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
1033             file_exists(git_path("REVERT_HEAD"))) {
1034                 int ret = continue_single_pick();
1035                 if (ret)
1036                         return ret;
1037         }
1038         if (index_differs_from("HEAD", 0))
1039                 return error_dirty_index(opts);
1040         todo_list = todo_list->next;
1041         return pick_commits(todo_list, opts);
1042 }
1043
1044 static int single_pick(struct commit *cmit, struct replay_opts *opts)
1045 {
1046         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1047         return do_pick_commit(cmit, opts);
1048 }
1049
1050 int sequencer_pick_revisions(struct replay_opts *opts)
1051 {
1052         struct commit_list *todo_list = NULL;
1053         unsigned char sha1[20];
1054         int i;
1055
1056         if (opts->subcommand == REPLAY_NONE)
1057                 assert(opts->revs);
1058
1059         read_and_refresh_cache(opts);
1060
1061         /*
1062          * Decide what to do depending on the arguments; a fresh
1063          * cherry-pick should be handled differently from an existing
1064          * one that is being continued
1065          */
1066         if (opts->subcommand == REPLAY_REMOVE_STATE) {
1067                 remove_sequencer_state();
1068                 return 0;
1069         }
1070         if (opts->subcommand == REPLAY_ROLLBACK)
1071                 return sequencer_rollback(opts);
1072         if (opts->subcommand == REPLAY_CONTINUE)
1073                 return sequencer_continue(opts);
1074
1075         for (i = 0; i < opts->revs->pending.nr; i++) {
1076                 unsigned char sha1[20];
1077                 const char *name = opts->revs->pending.objects[i].name;
1078
1079                 /* This happens when using --stdin. */
1080                 if (!strlen(name))
1081                         continue;
1082
1083                 if (!get_sha1(name, sha1)) {
1084                         if (!lookup_commit_reference_gently(sha1, 1)) {
1085                                 enum object_type type = sha1_object_info(sha1, NULL);
1086                                 die(_("%s: can't cherry-pick a %s"), name, typename(type));
1087                         }
1088                 } else
1089                         die(_("%s: bad revision"), name);
1090         }
1091
1092         /*
1093          * If we were called as "git cherry-pick <commit>", just
1094          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1095          * REVERT_HEAD, and don't touch the sequencer state.
1096          * This means it is possible to cherry-pick in the middle
1097          * of a cherry-pick sequence.
1098          */
1099         if (opts->revs->cmdline.nr == 1 &&
1100             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1101             opts->revs->no_walk &&
1102             !opts->revs->cmdline.rev->flags) {
1103                 struct commit *cmit;
1104                 if (prepare_revision_walk(opts->revs))
1105                         die(_("revision walk setup failed"));
1106                 cmit = get_revision(opts->revs);
1107                 if (!cmit || get_revision(opts->revs))
1108                         die("BUG: expected exactly one commit from walk");
1109                 return single_pick(cmit, opts);
1110         }
1111
1112         /*
1113          * Start a new cherry-pick/ revert sequence; but
1114          * first, make sure that an existing one isn't in
1115          * progress
1116          */
1117
1118         walk_revs_populate_todo(&todo_list, opts);
1119         if (create_seq_dir() < 0)
1120                 return -1;
1121         if (get_sha1("HEAD", sha1)) {
1122                 if (opts->action == REPLAY_REVERT)
1123                         return error(_("Can't revert as initial commit"));
1124                 return error(_("Can't cherry-pick into empty head"));
1125         }
1126         save_head(sha1_to_hex(sha1));
1127         save_opts(opts);
1128         return pick_commits(todo_list, opts);
1129 }
1130
1131 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1132 {
1133         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1134         struct strbuf sob = STRBUF_INIT;
1135         int has_footer;
1136
1137         strbuf_addstr(&sob, sign_off_header);
1138         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1139                                 getenv("GIT_COMMITTER_EMAIL")));
1140         strbuf_addch(&sob, '\n');
1141
1142         /*
1143          * If the whole message buffer is equal to the sob, pretend that we
1144          * found a conforming footer with a matching sob
1145          */
1146         if (msgbuf->len - ignore_footer == sob.len &&
1147             !strncmp(msgbuf->buf, sob.buf, sob.len))
1148                 has_footer = 3;
1149         else
1150                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1151
1152         if (!has_footer) {
1153                 const char *append_newlines = NULL;
1154                 size_t len = msgbuf->len - ignore_footer;
1155
1156                 if (!len) {
1157                         /*
1158                          * The buffer is completely empty.  Leave foom for
1159                          * the title and body to be filled in by the user.
1160                          */
1161                         append_newlines = "\n\n";
1162                 } else if (msgbuf->buf[len - 1] != '\n') {
1163                         /*
1164                          * Incomplete line.  Complete the line and add a
1165                          * blank one so that there is an empty line between
1166                          * the message body and the sob.
1167                          */
1168                         append_newlines = "\n\n";
1169                 } else if (len == 1) {
1170                         /*
1171                          * Buffer contains a single newline.  Add another
1172                          * so that we leave room for the title and body.
1173                          */
1174                         append_newlines = "\n";
1175                 } else if (msgbuf->buf[len - 2] != '\n') {
1176                         /*
1177                          * Buffer ends with a single newline.  Add another
1178                          * so that there is an empty line between the message
1179                          * body and the sob.
1180                          */
1181                         append_newlines = "\n";
1182                 } /* else, the buffer already ends with two newlines. */
1183
1184                 if (append_newlines)
1185                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1186                                 append_newlines, strlen(append_newlines));
1187         }
1188
1189         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1190                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1191                                 sob.buf, sob.len);
1192
1193         strbuf_release(&sob);
1194 }