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, struct replay_opts *opts)
 274 {
 275         struct ref_lock *ref_lock;
 276         struct strbuf sb = STRBUF_INIT;
 277         int ret;
 278
 279         read_cache();
 280         if (checkout_fast_forward(from, to, 1))
 281                 exit(1); /* the callee should have complained already */
 282         ref_lock = lock_any_ref_for_update("HEAD", unborn ? null_sha1 : from, 0);
 283         strbuf_addf(&sb, "%s: fast-forward", action_name(opts));
 284         ret = write_ref_sha1(ref_lock, to, sb.buf);
 285         strbuf_release(&sb);
 286         return ret;
 287 }
 288
 289 static int do_recursive_merge(struct commit *base, struct commit *next,
 290                               const char *base_label, const char *next_label,
 291                               unsigned char *head, struct strbuf *msgbuf,
 292                               struct replay_opts *opts)
 293 {
 294         struct merge_options o;
 295         struct tree *result, *next_tree, *base_tree, *head_tree;
 296         int clean, index_fd;
 297         const char **xopt;
 298         static struct lock_file index_lock;
 299
 300         index_fd = hold_locked_index(&index_lock, 1);
 301
 302         read_cache();
 303
 304         init_merge_options(&o);
 305         o.ancestor = base ? base_label : "(empty tree)";
 306         o.branch1 = "HEAD";
 307         o.branch2 = next ? next_label : "(empty tree)";
 308
 309         head_tree = parse_tree_indirect(head);
 310         next_tree = next ? next->tree : empty_tree();
 311         base_tree = base ? base->tree : empty_tree();
 312
 313         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 314                 parse_merge_opt(&o, *xopt);
 315
 316         clean = merge_trees(&o,
 317                             head_tree,
 318                             next_tree, base_tree, &result);
 319
 320         if (active_cache_changed &&
 321             (write_cache(index_fd, active_cache, active_nr) ||
 322              commit_locked_index(&index_lock)))
 323                 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 324                 die(_("%s: Unable to write new index file"), action_name(opts));
 325         rollback_lock_file(&index_lock);
 326
 327         if (opts->signoff)
 328                 append_signoff(msgbuf, 0, 0);
 329
 330         if (!clean) {
 331                 int i;
 332                 strbuf_addstr(msgbuf, "\nConflicts:\n");
 333                 for (i = 0; i < active_nr;) {
 334                         struct cache_entry *ce = active_cache[i++];
 335                         if (ce_stage(ce)) {
 336                                 strbuf_addch(msgbuf, '\t');
 337                                 strbuf_addstr(msgbuf, ce->name);
 338                                 strbuf_addch(msgbuf, '\n');
 339                                 while (i < active_nr && !strcmp(ce->name,
 340                                                 active_cache[i]->name))
 341                                         i++;
 342                         }
 343                 }
 344         }
 345
 346         return !clean;
 347 }
 348
 349 static int is_index_unchanged(void)
 350 {
 351         unsigned char head_sha1[20];
 352         struct commit *head_commit;
 353
 354         if (!resolve_ref_unsafe("HEAD", head_sha1, 1, NULL))
 355                 return error(_("Could not resolve HEAD commit\n"));
 356
 357         head_commit = lookup_commit(head_sha1);
 358
 359         /*
 360          * If head_commit is NULL, check_commit, called from
 361          * lookup_commit, would have indicated that head_commit is not
 362          * a commit object already.  parse_commit() will return failure
 363          * without further complaints in such a case.  Otherwise, if
 364          * the commit is invalid, parse_commit() will complain.  So
 365          * there is nothing for us to say here.  Just return failure.
 366          */
 367         if (parse_commit(head_commit))
 368                 return -1;
 369
 370         if (!active_cache_tree)
 371                 active_cache_tree = cache_tree();
 372
 373         if (!cache_tree_fully_valid(active_cache_tree))
 374                 if (cache_tree_update(active_cache_tree, active_cache,
 375                                   active_nr, 0))
 376                         return error(_("Unable to update cache tree\n"));
 377
 378         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.sha1);
 379 }
 380
 381 /*
 382  * If we are cherry-pick, and if the merge did not result in
 383  * hand-editing, we will hit this commit and inherit the original
 384  * author date and name.
 385  * If we are revert, or if our cherry-pick results in a hand merge,
 386  * we had better say that the current user is responsible for that.
 387  */
 388 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 389                           int allow_empty)
 390 {
 391         struct argv_array array;
 392         int rc;
 393
 394         argv_array_init(&array);
 395         argv_array_push(&array, "commit");
 396         argv_array_push(&array, "-n");
 397
 398         if (opts->signoff)
 399                 argv_array_push(&array, "-s");
 400         if (!opts->edit) {
 401                 argv_array_push(&array, "-F");
 402                 argv_array_push(&array, defmsg);
 403         }
 404
 405         if (allow_empty)
 406                 argv_array_push(&array, "--allow-empty");
 407
 408         if (opts->allow_empty_message)
 409                 argv_array_push(&array, "--allow-empty-message");
 410
 411         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 412         argv_array_clear(&array);
 413         return rc;
 414 }
 415
 416 static int is_original_commit_empty(struct commit *commit)
 417 {
 418         const unsigned char *ptree_sha1;
 419
 420         if (parse_commit(commit))
 421                 return error(_("Could not parse commit %s\n"),
 422                              sha1_to_hex(commit->object.sha1));
 423         if (commit->parents) {
 424                 struct commit *parent = commit->parents->item;
 425                 if (parse_commit(parent))
 426                         return error(_("Could not parse parent commit %s\n"),
 427                                 sha1_to_hex(parent->object.sha1));
 428                 ptree_sha1 = parent->tree->object.sha1;
 429         } else {
 430                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 431         }
 432
 433         return !hashcmp(ptree_sha1, commit->tree->object.sha1);
 434 }
 435
 436 /*
 437  * Do we run "git commit" with "--allow-empty"?
 438  */
 439 static int allow_empty(struct replay_opts *opts, struct commit *commit)
 440 {
 441         int index_unchanged, empty_commit;
 442
 443         /*
 444          * Three cases:
 445          *
 446          * (1) we do not allow empty at all and error out.
 447          *
 448          * (2) we allow ones that were initially empty, but
 449          * forbid the ones that become empty;
 450          *
 451          * (3) we allow both.
 452          */
 453         if (!opts->allow_empty)
 454                 return 0; /* let "git commit" barf as necessary */
 455
 456         index_unchanged = is_index_unchanged();
 457         if (index_unchanged < 0)
 458                 return index_unchanged;
 459         if (!index_unchanged)
 460                 return 0; /* we do not have to say --allow-empty */
 461
 462         if (opts->keep_redundant_commits)
 463                 return 1;
 464
 465         empty_commit = is_original_commit_empty(commit);
 466         if (empty_commit < 0)
 467                 return empty_commit;
 468         if (!empty_commit)
 469                 return 0;
 470         else
 471                 return 1;
 472 }
 473
 474 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 475 {
 476         unsigned char head[20];
 477         struct commit *base, *next, *parent;
 478         const char *base_label, *next_label;
 479         struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
 480         char *defmsg = NULL;
 481         struct strbuf msgbuf = STRBUF_INIT;
 482         int res, unborn = 0;
 483
 484         if (opts->no_commit) {
 485                 /*
 486                  * We do not intend to commit immediately.  We just want to
 487                  * merge the differences in, so let's compute the tree
 488                  * that represents the "current" state for merge-recursive
 489                  * to work on.
 490                  */
 491                 if (write_cache_as_tree(head, 0, NULL))
 492                         die (_("Your index file is unmerged."));
 493         } else {
 494                 unborn = get_sha1("HEAD", head);
 495                 if (unborn)
 496                         hashcpy(head, EMPTY_TREE_SHA1_BIN);
 497                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
 498                         return error_dirty_index(opts);
 499         }
 500         discard_cache();
 501
 502         if (!commit->parents) {
 503                 parent = NULL;
 504         }
 505         else if (commit->parents->next) {
 506                 /* Reverting or cherry-picking a merge commit */
 507                 int cnt;
 508                 struct commit_list *p;
 509
 510                 if (!opts->mainline)
 511                         return error(_("Commit %s is a merge but no -m option was given."),
 512                                 sha1_to_hex(commit->object.sha1));
 513
 514                 for (cnt = 1, p = commit->parents;
 515                      cnt != opts->mainline && p;
 516                      cnt++)
 517                         p = p->next;
 518                 if (cnt != opts->mainline || !p)
 519                         return error(_("Commit %s does not have parent %d"),
 520                                 sha1_to_hex(commit->object.sha1), opts->mainline);
 521                 parent = p->item;
 522         } else if (0 < opts->mainline)
 523                 return error(_("Mainline was specified but commit %s is not a merge."),
 524                         sha1_to_hex(commit->object.sha1));
 525         else
 526                 parent = commit->parents->item;
 527
 528         if (opts->allow_ff &&
 529             ((parent && !hashcmp(parent->object.sha1, head)) ||
 530              (!parent && unborn)))
 531                 return fast_forward_to(commit->object.sha1, head, unborn, opts);
 532
 533         if (parent && parse_commit(parent) < 0)
 534                 /* TRANSLATORS: The first %s will be "revert" or
 535                    "cherry-pick", the second %s a SHA1 */
 536                 return error(_("%s: cannot parse parent commit %s"),
 537                         action_name(opts), sha1_to_hex(parent->object.sha1));
 538
 539         if (get_message(commit, &msg) != 0)
 540                 return error(_("Cannot get commit message for %s"),
 541                         sha1_to_hex(commit->object.sha1));
 542
 543         /*
 544          * "commit" is an existing commit.  We would want to apply
 545          * the difference it introduces since its first parent "prev"
 546          * on top of the current HEAD if we are cherry-pick.  Or the
 547          * reverse of it if we are revert.
 548          */
 549
 550         defmsg = git_pathdup("MERGE_MSG");
 551
 552         if (opts->action == REPLAY_REVERT) {
 553                 base = commit;
 554                 base_label = msg.label;
 555                 next = parent;
 556                 next_label = msg.parent_label;
 557                 strbuf_addstr(&msgbuf, "Revert \"");
 558                 strbuf_addstr(&msgbuf, msg.subject);
 559                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 560                 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 561
 562                 if (commit->parents && commit->parents->next) {
 563                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 564                         strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
 565                 }
 566                 strbuf_addstr(&msgbuf, ".\n");
 567         } else {
 568                 const char *p;
 569
 570                 base = parent;
 571                 base_label = msg.parent_label;
 572                 next = commit;
 573                 next_label = msg.label;
 574
 575                 /*
 576                  * Append the commit log message to msgbuf; it starts
 577                  * after the tree, parent, author, committer
 578                  * information followed by "\n\n".
 579                  */
 580                 p = strstr(msg.message, "\n\n");
 581                 if (p) {
 582                         p += 2;
 583                         strbuf_addstr(&msgbuf, p);
 584                 }
 585
 586                 if (opts->record_origin) {
 587                         if (!has_conforming_footer(&msgbuf, NULL, 0))
 588                                 strbuf_addch(&msgbuf, '\n');
 589                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
 590                         strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 591                         strbuf_addstr(&msgbuf, ")\n");
 592                 }
 593         }
 594
 595         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 596                 res = do_recursive_merge(base, next, base_label, next_label,
 597                                          head, &msgbuf, opts);
 598                 write_message(&msgbuf, defmsg);
 599         } else {
 600                 struct commit_list *common = NULL;
 601                 struct commit_list *remotes = NULL;
 602
 603                 write_message(&msgbuf, defmsg);
 604
 605                 commit_list_insert(base, &common);
 606                 commit_list_insert(next, &remotes);
 607                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 608                                         common, sha1_to_hex(head), remotes);
 609                 free_commit_list(common);
 610                 free_commit_list(remotes);
 611         }
 612
 613         /*
 614          * If the merge was clean or if it failed due to conflict, we write
 615          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 616          * However, if the merge did not even start, then we don't want to
 617          * write it at all.
 618          */
 619         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 620                 write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
 621         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 622                 write_cherry_pick_head(commit, "REVERT_HEAD");
 623
 624         if (res) {
 625                 error(opts->action == REPLAY_REVERT
 626                       ? _("could not revert %s... %s")
 627                       : _("could not apply %s... %s"),
 628                       find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
 629                       msg.subject);
 630                 print_advice(res == 1, opts);
 631                 rerere(opts->allow_rerere_auto);
 632         } else {
 633                 int allow = allow_empty(opts, commit);
 634                 if (allow < 0)
 635                         return allow;
 636                 if (!opts->no_commit)
 637                         res = run_git_commit(defmsg, opts, allow);
 638         }
 639
 640         free_message(&msg);
 641         free(defmsg);
 642
 643         return res;
 644 }
 645
 646 static void prepare_revs(struct replay_opts *opts)
 647 {
 648         /*
 649          * picking (but not reverting) ranges (but not individual revisions)
 650          * should be done in reverse
 651          */
 652         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 653                 opts->revs->reverse ^= 1;
 654
 655         if (prepare_revision_walk(opts->revs))
 656                 die(_("revision walk setup failed"));
 657
 658         if (!opts->revs->commits)
 659                 die(_("empty commit set passed"));
 660 }
 661
 662 static void read_and_refresh_cache(struct replay_opts *opts)
 663 {
 664         static struct lock_file index_lock;
 665         int index_fd = hold_locked_index(&index_lock, 0);
 666         if (read_index_preload(&the_index, NULL) < 0)
 667                 die(_("git %s: failed to read the index"), action_name(opts));
 668         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 669         if (the_index.cache_changed) {
 670                 if (write_index(&the_index, index_fd) ||
 671                     commit_locked_index(&index_lock))
 672                         die(_("git %s: failed to refresh the index"), action_name(opts));
 673         }
 674         rollback_lock_file(&index_lock);
 675 }
 676
 677 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 678                 struct replay_opts *opts)
 679 {
 680         struct commit_list *cur = NULL;
 681         const char *sha1_abbrev = NULL;
 682         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 683         const char *subject;
 684         int subject_len;
 685
 686         for (cur = todo_list; cur; cur = cur->next) {
 687                 sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
 688                 subject_len = find_commit_subject(cur->item->buffer, &subject);
 689                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 690                         subject_len, subject);
 691         }
 692         return 0;
 693 }
 694
 695 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 696 {
 697         unsigned char commit_sha1[20];
 698         enum replay_action action;
 699         char *end_of_object_name;
 700         int saved, status, padding;
 701
 702         if (!prefixcmp(bol, "pick")) {
 703                 action = REPLAY_PICK;
 704                 bol += strlen("pick");
 705         } else if (!prefixcmp(bol, "revert")) {
 706                 action = REPLAY_REVERT;
 707                 bol += strlen("revert");
 708         } else
 709                 return NULL;
 710
 711         /* Eat up extra spaces/ tabs before object name */
 712         padding = strspn(bol, " \t");
 713         if (!padding)
 714                 return NULL;
 715         bol += padding;
 716
 717         end_of_object_name = bol + strcspn(bol, " \t\n");
 718         saved = *end_of_object_name;
 719         *end_of_object_name = '\0';
 720         status = get_sha1(bol, commit_sha1);
 721         *end_of_object_name = saved;
 722
 723         /*
 724          * Verify that the action matches up with the one in
 725          * opts; we don't support arbitrary instructions
 726          */
 727         if (action != opts->action) {
 728                 const char *action_str;
 729                 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
 730                 error(_("Cannot %s during a %s"), action_str, action_name(opts));
 731                 return NULL;
 732         }
 733
 734         if (status < 0)
 735                 return NULL;
 736
 737         return lookup_commit_reference(commit_sha1);
 738 }
 739
 740 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
 741                         struct replay_opts *opts)
 742 {
 743         struct commit_list **next = todo_list;
 744         struct commit *commit;
 745         char *p = buf;
 746         int i;
 747
 748         for (i = 1; *p; i++) {
 749                 char *eol = strchrnul(p, '\n');
 750                 commit = parse_insn_line(p, eol, opts);
 751                 if (!commit)
 752                         return error(_("Could not parse line %d."), i);
 753                 next = commit_list_append(commit, next);
 754                 p = *eol ? eol + 1 : eol;
 755         }
 756         if (!*todo_list)
 757                 return error(_("No commits parsed."));
 758         return 0;
 759 }
 760
 761 static void read_populate_todo(struct commit_list **todo_list,
 762                         struct replay_opts *opts)
 763 {
 764         const char *todo_file = git_path(SEQ_TODO_FILE);
 765         struct strbuf buf = STRBUF_INIT;
 766         int fd, res;
 767
 768         fd = open(todo_file, O_RDONLY);
 769         if (fd < 0)
 770                 die_errno(_("Could not open %s"), todo_file);
 771         if (strbuf_read(&buf, fd, 0) < 0) {
 772                 close(fd);
 773                 strbuf_release(&buf);
 774                 die(_("Could not read %s."), todo_file);
 775         }
 776         close(fd);
 777
 778         res = parse_insn_buffer(buf.buf, todo_list, opts);
 779         strbuf_release(&buf);
 780         if (res)
 781                 die(_("Unusable instruction sheet: %s"), todo_file);
 782 }
 783
 784 static int populate_opts_cb(const char *key, const char *value, void *data)
 785 {
 786         struct replay_opts *opts = data;
 787         int error_flag = 1;
 788
 789         if (!value)
 790                 error_flag = 0;
 791         else if (!strcmp(key, "options.no-commit"))
 792                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 793         else if (!strcmp(key, "options.edit"))
 794                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
 795         else if (!strcmp(key, "options.signoff"))
 796                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 797         else if (!strcmp(key, "options.record-origin"))
 798                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 799         else if (!strcmp(key, "options.allow-ff"))
 800                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 801         else if (!strcmp(key, "options.mainline"))
 802                 opts->mainline = git_config_int(key, value);
 803         else if (!strcmp(key, "options.strategy"))
 804                 git_config_string(&opts->strategy, key, value);
 805         else if (!strcmp(key, "options.strategy-option")) {
 806                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 807                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
 808         } else
 809                 return error(_("Invalid key: %s"), key);
 810
 811         if (!error_flag)
 812                 return error(_("Invalid value for %s: %s"), key, value);
 813
 814         return 0;
 815 }
 816
 817 static void read_populate_opts(struct replay_opts **opts_ptr)
 818 {
 819         const char *opts_file = git_path(SEQ_OPTS_FILE);
 820
 821         if (!file_exists(opts_file))
 822                 return;
 823         if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
 824                 die(_("Malformed options sheet: %s"), opts_file);
 825 }
 826
 827 static void walk_revs_populate_todo(struct commit_list **todo_list,
 828                                 struct replay_opts *opts)
 829 {
 830         struct commit *commit;
 831         struct commit_list **next;
 832
 833         prepare_revs(opts);
 834
 835         next = todo_list;
 836         while ((commit = get_revision(opts->revs)))
 837                 next = commit_list_append(commit, next);
 838 }
 839
 840 static int create_seq_dir(void)
 841 {
 842         const char *seq_dir = git_path(SEQ_DIR);
 843
 844         if (file_exists(seq_dir)) {
 845                 error(_("a cherry-pick or revert is already in progress"));
 846                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 847                 return -1;
 848         }
 849         else if (mkdir(seq_dir, 0777) < 0)
 850                 die_errno(_("Could not create sequencer directory %s"), seq_dir);
 851         return 0;
 852 }
 853
 854 static void save_head(const char *head)
 855 {
 856         const char *head_file = git_path(SEQ_HEAD_FILE);
 857         static struct lock_file head_lock;
 858         struct strbuf buf = STRBUF_INIT;
 859         int fd;
 860
 861         fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
 862         strbuf_addf(&buf, "%s\n", head);
 863         if (write_in_full(fd, buf.buf, buf.len) < 0)
 864                 die_errno(_("Could not write to %s"), head_file);
 865         if (commit_lock_file(&head_lock) < 0)
 866                 die(_("Error wrapping up %s."), head_file);
 867 }
 868
 869 static int reset_for_rollback(const unsigned char *sha1)
 870 {
 871         const char *argv[4];    /* reset --merge <arg> + NULL */
 872         argv[0] = "reset";
 873         argv[1] = "--merge";
 874         argv[2] = sha1_to_hex(sha1);
 875         argv[3] = NULL;
 876         return run_command_v_opt(argv, RUN_GIT_CMD);
 877 }
 878
 879 static int rollback_single_pick(void)
 880 {
 881         unsigned char head_sha1[20];
 882
 883         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
 884             !file_exists(git_path("REVERT_HEAD")))
 885                 return error(_("no cherry-pick or revert in progress"));
 886         if (read_ref_full("HEAD", head_sha1, 0, NULL))
 887                 return error(_("cannot resolve HEAD"));
 888         if (is_null_sha1(head_sha1))
 889                 return error(_("cannot abort from a branch yet to be born"));
 890         return reset_for_rollback(head_sha1);
 891 }
 892
 893 static int sequencer_rollback(struct replay_opts *opts)
 894 {
 895         const char *filename;
 896         FILE *f;
 897         unsigned char sha1[20];
 898         struct strbuf buf = STRBUF_INIT;
 899
 900         filename = git_path(SEQ_HEAD_FILE);
 901         f = fopen(filename, "r");
 902         if (!f && errno == ENOENT) {
 903                 /*
 904                  * There is no multiple-cherry-pick in progress.
 905                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 906                  * a single-cherry-pick in progress, abort that.
 907                  */
 908                 return rollback_single_pick();
 909         }
 910         if (!f)
 911                 return error(_("cannot open %s: %s"), filename,
 912                                                 strerror(errno));
 913         if (strbuf_getline(&buf, f, '\n')) {
 914                 error(_("cannot read %s: %s"), filename, ferror(f) ?
 915                         strerror(errno) : _("unexpected end of file"));
 916                 fclose(f);
 917                 goto fail;
 918         }
 919         fclose(f);
 920         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 921                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 922                         filename);
 923                 goto fail;
 924         }
 925         if (reset_for_rollback(sha1))
 926                 goto fail;
 927         remove_sequencer_state();
 928         strbuf_release(&buf);
 929         return 0;
 930 fail:
 931         strbuf_release(&buf);
 932         return -1;
 933 }
 934
 935 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 936 {
 937         const char *todo_file = git_path(SEQ_TODO_FILE);
 938         static struct lock_file todo_lock;
 939         struct strbuf buf = STRBUF_INIT;
 940         int fd;
 941
 942         fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
 943         if (format_todo(&buf, todo_list, opts) < 0)
 944                 die(_("Could not format %s."), todo_file);
 945         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 946                 strbuf_release(&buf);
 947                 die_errno(_("Could not write to %s"), todo_file);
 948         }
 949         if (commit_lock_file(&todo_lock) < 0) {
 950                 strbuf_release(&buf);
 951                 die(_("Error wrapping up %s."), todo_file);
 952         }
 953         strbuf_release(&buf);
 954 }
 955
 956 static void save_opts(struct replay_opts *opts)
 957 {
 958         const char *opts_file = git_path(SEQ_OPTS_FILE);
 959
 960         if (opts->no_commit)
 961                 git_config_set_in_file(opts_file, "options.no-commit", "true");
 962         if (opts->edit)
 963                 git_config_set_in_file(opts_file, "options.edit", "true");
 964         if (opts->signoff)
 965                 git_config_set_in_file(opts_file, "options.signoff", "true");
 966         if (opts->record_origin)
 967                 git_config_set_in_file(opts_file, "options.record-origin", "true");
 968         if (opts->allow_ff)
 969                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
 970         if (opts->mainline) {
 971                 struct strbuf buf = STRBUF_INIT;
 972                 strbuf_addf(&buf, "%d", opts->mainline);
 973                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
 974                 strbuf_release(&buf);
 975         }
 976         if (opts->strategy)
 977                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
 978         if (opts->xopts) {
 979                 int i;
 980                 for (i = 0; i < opts->xopts_nr; i++)
 981                         git_config_set_multivar_in_file(opts_file,
 982                                                         "options.strategy-option",
 983                                                         opts->xopts[i], "^$", 0);
 984         }
 985 }
 986
 987 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
 988 {
 989         struct commit_list *cur;
 990         int res;
 991
 992         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
 993         if (opts->allow_ff)
 994                 assert(!(opts->signoff || opts->no_commit ||
 995                                 opts->record_origin || opts->edit));
 996         read_and_refresh_cache(opts);
 997
 998         for (cur = todo_list; cur; cur = cur->next) {
 999                 save_todo(cur, opts);
1000                 res = do_pick_commit(cur->item, opts);
1001                 if (res)
1002                         return res;
1003         }
1004
1005         /*
1006          * Sequence of picks finished successfully; cleanup by
1007          * removing the .git/sequencer directory
1008          */
1009         remove_sequencer_state();
1010         return 0;
1011 }
1012
1013 static int continue_single_pick(void)
1014 {
1015         const char *argv[] = { "commit", NULL };
1016
1017         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
1018             !file_exists(git_path("REVERT_HEAD")))
1019                 return error(_("no cherry-pick or revert in progress"));
1020         return run_command_v_opt(argv, RUN_GIT_CMD);
1021 }
1022
1023 static int sequencer_continue(struct replay_opts *opts)
1024 {
1025         struct commit_list *todo_list = NULL;
1026
1027         if (!file_exists(git_path(SEQ_TODO_FILE)))
1028                 return continue_single_pick();
1029         read_populate_opts(&opts);
1030         read_populate_todo(&todo_list, opts);
1031
1032         /* Verify that the conflict has been resolved */
1033         if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
1034             file_exists(git_path("REVERT_HEAD"))) {
1035                 int ret = continue_single_pick();
1036                 if (ret)
1037                         return ret;
1038         }
1039         if (index_differs_from("HEAD", 0))
1040                 return error_dirty_index(opts);
1041         todo_list = todo_list->next;
1042         return pick_commits(todo_list, opts);
1043 }
1044
1045 static int single_pick(struct commit *cmit, struct replay_opts *opts)
1046 {
1047         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1048         return do_pick_commit(cmit, opts);
1049 }
1050
1051 int sequencer_pick_revisions(struct replay_opts *opts)
1052 {
1053         struct commit_list *todo_list = NULL;
1054         unsigned char sha1[20];
1055         int i;
1056
1057         if (opts->subcommand == REPLAY_NONE)
1058                 assert(opts->revs);
1059
1060         read_and_refresh_cache(opts);
1061
1062         /*
1063          * Decide what to do depending on the arguments; a fresh
1064          * cherry-pick should be handled differently from an existing
1065          * one that is being continued
1066          */
1067         if (opts->subcommand == REPLAY_REMOVE_STATE) {
1068                 remove_sequencer_state();
1069                 return 0;
1070         }
1071         if (opts->subcommand == REPLAY_ROLLBACK)
1072                 return sequencer_rollback(opts);
1073         if (opts->subcommand == REPLAY_CONTINUE)
1074                 return sequencer_continue(opts);
1075
1076         for (i = 0; i < opts->revs->pending.nr; i++) {
1077                 unsigned char sha1[20];
1078                 const char *name = opts->revs->pending.objects[i].name;
1079
1080                 /* This happens when using --stdin. */
1081                 if (!strlen(name))
1082                         continue;
1083
1084                 if (!get_sha1(name, sha1)) {
1085                         if (!lookup_commit_reference_gently(sha1, 1)) {
1086                                 enum object_type type = sha1_object_info(sha1, NULL);
1087                                 die(_("%s: can't cherry-pick a %s"), name, typename(type));
1088                         }
1089                 } else
1090                         die(_("%s: bad revision"), name);
1091         }
1092
1093         /*
1094          * If we were called as "git cherry-pick <commit>", just
1095          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1096          * REVERT_HEAD, and don't touch the sequencer state.
1097          * This means it is possible to cherry-pick in the middle
1098          * of a cherry-pick sequence.
1099          */
1100         if (opts->revs->cmdline.nr == 1 &&
1101             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1102             opts->revs->no_walk &&
1103             !opts->revs->cmdline.rev->flags) {
1104                 struct commit *cmit;
1105                 if (prepare_revision_walk(opts->revs))
1106                         die(_("revision walk setup failed"));
1107                 cmit = get_revision(opts->revs);
1108                 if (!cmit || get_revision(opts->revs))
1109                         die("BUG: expected exactly one commit from walk");
1110                 return single_pick(cmit, opts);
1111         }
1112
1113         /*
1114          * Start a new cherry-pick/ revert sequence; but
1115          * first, make sure that an existing one isn't in
1116          * progress
1117          */
1118
1119         walk_revs_populate_todo(&todo_list, opts);
1120         if (create_seq_dir() < 0)
1121                 return -1;
1122         if (get_sha1("HEAD", sha1)) {
1123                 if (opts->action == REPLAY_REVERT)
1124                         return error(_("Can't revert as initial commit"));
1125                 return error(_("Can't cherry-pick into empty head"));
1126         }
1127         save_head(sha1_to_hex(sha1));
1128         save_opts(opts);
1129         return pick_commits(todo_list, opts);
1130 }
1131
1132 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1133 {
1134         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1135         struct strbuf sob = STRBUF_INIT;
1136         int has_footer;
1137
1138         strbuf_addstr(&sob, sign_off_header);
1139         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1140                                 getenv("GIT_COMMITTER_EMAIL")));
1141         strbuf_addch(&sob, '\n');
1142
1143         /*
1144          * If the whole message buffer is equal to the sob, pretend that we
1145          * found a conforming footer with a matching sob
1146          */
1147         if (msgbuf->len - ignore_footer == sob.len &&
1148             !strncmp(msgbuf->buf, sob.buf, sob.len))
1149                 has_footer = 3;
1150         else
1151                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1152
1153         if (!has_footer) {
1154                 const char *append_newlines = NULL;
1155                 size_t len = msgbuf->len - ignore_footer;
1156
1157                 if (!len) {
1158                         /*
1159                          * The buffer is completely empty.  Leave foom for
1160                          * the title and body to be filled in by the user.
1161                          */
1162                         append_newlines = "\n\n";
1163                 } else if (msgbuf->buf[len - 1] != '\n') {
1164                         /*
1165                          * Incomplete line.  Complete the line and add a
1166                          * blank one so that there is an empty line between
1167                          * the message body and the sob.
1168                          */
1169                         append_newlines = "\n\n";
1170                 } else if (len == 1) {
1171                         /*
1172                          * Buffer contains a single newline.  Add another
1173                          * so that we leave room for the title and body.
1174                          */
1175                         append_newlines = "\n";
1176                 } else if (msgbuf->buf[len - 2] != '\n') {
1177                         /*
1178                          * Buffer ends with a single newline.  Add another
1179                          * so that there is an empty line between the message
1180                          * body and the sob.
1181                          */
1182                         append_newlines = "\n";
1183                 } /* else, the buffer already ends with two newlines. */
1184
1185                 if (append_newlines)
1186                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1187                                 append_newlines, strlen(append_newlines));
1188         }
1189
1190         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1191                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1192                                 sob.buf, sob.len);
1193
1194         strbuf_release(&sob);
1195 }