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,
 283                                            0, NULL);
 284         strbuf_addf(&sb, "%s: fast-forward", action_name(opts));
 285         ret = write_ref_sha1(ref_lock, to, sb.buf);
 286         strbuf_release(&sb);
 287         return ret;
 288 }
 289
 290 void append_conflicts_hint(struct strbuf *msgbuf)
 291 {
 292         int i;
 293
 294         strbuf_addch(msgbuf, '\n');
 295         strbuf_commented_addf(msgbuf, "Conflicts:\n");
 296         for (i = 0; i < active_nr;) {
 297                 const struct cache_entry *ce = active_cache[i++];
 298                 if (ce_stage(ce)) {
 299                         strbuf_commented_addf(msgbuf, "\t%s\n", ce->name);
 300                         while (i < active_nr && !strcmp(ce->name,
 301                                                         active_cache[i]->name))
 302                                 i++;
 303                 }
 304         }
 305 }
 306
 307 static int do_recursive_merge(struct commit *base, struct commit *next,
 308                               const char *base_label, const char *next_label,
 309                               unsigned char *head, struct strbuf *msgbuf,
 310                               struct replay_opts *opts)
 311 {
 312         struct merge_options o;
 313         struct tree *result, *next_tree, *base_tree, *head_tree;
 314         int clean, index_fd;
 315         const char **xopt;
 316         static struct lock_file index_lock;
 317
 318         index_fd = hold_locked_index(&index_lock, 1);
 319
 320         read_cache();
 321
 322         init_merge_options(&o);
 323         o.ancestor = base ? base_label : "(empty tree)";
 324         o.branch1 = "HEAD";
 325         o.branch2 = next ? next_label : "(empty tree)";
 326
 327         head_tree = parse_tree_indirect(head);
 328         next_tree = next ? next->tree : empty_tree();
 329         base_tree = base ? base->tree : empty_tree();
 330
 331         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 332                 parse_merge_opt(&o, *xopt);
 333
 334         clean = merge_trees(&o,
 335                             head_tree,
 336                             next_tree, base_tree, &result);
 337
 338         if (active_cache_changed &&
 339             (write_cache(index_fd, active_cache, active_nr) ||
 340              commit_locked_index(&index_lock)))
 341                 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 342                 die(_("%s: Unable to write new index file"), action_name(opts));
 343         rollback_lock_file(&index_lock);
 344
 345         if (opts->signoff)
 346                 append_signoff(msgbuf, 0, 0);
 347
 348         if (!clean)
 349                 append_conflicts_hint(msgbuf);
 350
 351         return !clean;
 352 }
 353
 354 static int is_index_unchanged(void)
 355 {
 356         unsigned char head_sha1[20];
 357         struct commit *head_commit;
 358
 359         if (!resolve_ref_unsafe("HEAD", head_sha1, 1, NULL))
 360                 return error(_("Could not resolve HEAD commit\n"));
 361
 362         head_commit = lookup_commit(head_sha1);
 363
 364         /*
 365          * If head_commit is NULL, check_commit, called from
 366          * lookup_commit, would have indicated that head_commit is not
 367          * a commit object already.  parse_commit() will return failure
 368          * without further complaints in such a case.  Otherwise, if
 369          * the commit is invalid, parse_commit() will complain.  So
 370          * there is nothing for us to say here.  Just return failure.
 371          */
 372         if (parse_commit(head_commit))
 373                 return -1;
 374
 375         if (!active_cache_tree)
 376                 active_cache_tree = cache_tree();
 377
 378         if (!cache_tree_fully_valid(active_cache_tree))
 379                 if (cache_tree_update(active_cache_tree,
 380                                       (const struct cache_entry * const *)active_cache,
 381                                       active_nr, 0))
 382                         return error(_("Unable to update cache tree\n"));
 383
 384         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.sha1);
 385 }
 386
 387 /*
 388  * If we are cherry-pick, and if the merge did not result in
 389  * hand-editing, we will hit this commit and inherit the original
 390  * author date and name.
 391  * If we are revert, or if our cherry-pick results in a hand merge,
 392  * we had better say that the current user is responsible for that.
 393  */
 394 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 395                           int allow_empty)
 396 {
 397         struct argv_array array;
 398         int rc;
 399
 400         argv_array_init(&array);
 401         argv_array_push(&array, "commit");
 402         argv_array_push(&array, "-n");
 403
 404         if (opts->signoff)
 405                 argv_array_push(&array, "-s");
 406         if (!opts->edit) {
 407                 argv_array_push(&array, "-F");
 408                 argv_array_push(&array, defmsg);
 409         }
 410
 411         if (allow_empty)
 412                 argv_array_push(&array, "--allow-empty");
 413
 414         if (opts->allow_empty_message)
 415                 argv_array_push(&array, "--allow-empty-message");
 416
 417         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 418         argv_array_clear(&array);
 419         return rc;
 420 }
 421
 422 static int is_original_commit_empty(struct commit *commit)
 423 {
 424         const unsigned char *ptree_sha1;
 425
 426         if (parse_commit(commit))
 427                 return error(_("Could not parse commit %s\n"),
 428                              sha1_to_hex(commit->object.sha1));
 429         if (commit->parents) {
 430                 struct commit *parent = commit->parents->item;
 431                 if (parse_commit(parent))
 432                         return error(_("Could not parse parent commit %s\n"),
 433                                 sha1_to_hex(parent->object.sha1));
 434                 ptree_sha1 = parent->tree->object.sha1;
 435         } else {
 436                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 437         }
 438
 439         return !hashcmp(ptree_sha1, commit->tree->object.sha1);
 440 }
 441
 442 /*
 443  * Do we run "git commit" with "--allow-empty"?
 444  */
 445 static int allow_empty(struct replay_opts *opts, struct commit *commit)
 446 {
 447         int index_unchanged, empty_commit;
 448
 449         /*
 450          * Three cases:
 451          *
 452          * (1) we do not allow empty at all and error out.
 453          *
 454          * (2) we allow ones that were initially empty, but
 455          * forbid the ones that become empty;
 456          *
 457          * (3) we allow both.
 458          */
 459         if (!opts->allow_empty)
 460                 return 0; /* let "git commit" barf as necessary */
 461
 462         index_unchanged = is_index_unchanged();
 463         if (index_unchanged < 0)
 464                 return index_unchanged;
 465         if (!index_unchanged)
 466                 return 0; /* we do not have to say --allow-empty */
 467
 468         if (opts->keep_redundant_commits)
 469                 return 1;
 470
 471         empty_commit = is_original_commit_empty(commit);
 472         if (empty_commit < 0)
 473                 return empty_commit;
 474         if (!empty_commit)
 475                 return 0;
 476         else
 477                 return 1;
 478 }
 479
 480 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 481 {
 482         unsigned char head[20];
 483         struct commit *base, *next, *parent;
 484         const char *base_label, *next_label;
 485         struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
 486         char *defmsg = NULL;
 487         struct strbuf msgbuf = STRBUF_INIT;
 488         int res, unborn = 0, allow;
 489
 490         if (opts->no_commit) {
 491                 /*
 492                  * We do not intend to commit immediately.  We just want to
 493                  * merge the differences in, so let's compute the tree
 494                  * that represents the "current" state for merge-recursive
 495                  * to work on.
 496                  */
 497                 if (write_cache_as_tree(head, 0, NULL))
 498                         die (_("Your index file is unmerged."));
 499         } else {
 500                 unborn = get_sha1("HEAD", head);
 501                 if (unborn)
 502                         hashcpy(head, EMPTY_TREE_SHA1_BIN);
 503                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
 504                         return error_dirty_index(opts);
 505         }
 506         discard_cache();
 507
 508         if (!commit->parents) {
 509                 parent = NULL;
 510         }
 511         else if (commit->parents->next) {
 512                 /* Reverting or cherry-picking a merge commit */
 513                 int cnt;
 514                 struct commit_list *p;
 515
 516                 if (!opts->mainline)
 517                         return error(_("Commit %s is a merge but no -m option was given."),
 518                                 sha1_to_hex(commit->object.sha1));
 519
 520                 for (cnt = 1, p = commit->parents;
 521                      cnt != opts->mainline && p;
 522                      cnt++)
 523                         p = p->next;
 524                 if (cnt != opts->mainline || !p)
 525                         return error(_("Commit %s does not have parent %d"),
 526                                 sha1_to_hex(commit->object.sha1), opts->mainline);
 527                 parent = p->item;
 528         } else if (0 < opts->mainline)
 529                 return error(_("Mainline was specified but commit %s is not a merge."),
 530                         sha1_to_hex(commit->object.sha1));
 531         else
 532                 parent = commit->parents->item;
 533
 534         if (opts->allow_ff &&
 535             ((parent && !hashcmp(parent->object.sha1, head)) ||
 536              (!parent && unborn)))
 537                 return fast_forward_to(commit->object.sha1, head, unborn, opts);
 538
 539         if (parent && parse_commit(parent) < 0)
 540                 /* TRANSLATORS: The first %s will be "revert" or
 541                    "cherry-pick", the second %s a SHA1 */
 542                 return error(_("%s: cannot parse parent commit %s"),
 543                         action_name(opts), sha1_to_hex(parent->object.sha1));
 544
 545         if (get_message(commit, &msg) != 0)
 546                 return error(_("Cannot get commit message for %s"),
 547                         sha1_to_hex(commit->object.sha1));
 548
 549         /*
 550          * "commit" is an existing commit.  We would want to apply
 551          * the difference it introduces since its first parent "prev"
 552          * on top of the current HEAD if we are cherry-pick.  Or the
 553          * reverse of it if we are revert.
 554          */
 555
 556         defmsg = git_pathdup("MERGE_MSG");
 557
 558         if (opts->action == REPLAY_REVERT) {
 559                 base = commit;
 560                 base_label = msg.label;
 561                 next = parent;
 562                 next_label = msg.parent_label;
 563                 strbuf_addstr(&msgbuf, "Revert \"");
 564                 strbuf_addstr(&msgbuf, msg.subject);
 565                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 566                 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 567
 568                 if (commit->parents && commit->parents->next) {
 569                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 570                         strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
 571                 }
 572                 strbuf_addstr(&msgbuf, ".\n");
 573         } else {
 574                 const char *p;
 575
 576                 base = parent;
 577                 base_label = msg.parent_label;
 578                 next = commit;
 579                 next_label = msg.label;
 580
 581                 /*
 582                  * Append the commit log message to msgbuf; it starts
 583                  * after the tree, parent, author, committer
 584                  * information followed by "\n\n".
 585                  */
 586                 p = strstr(msg.message, "\n\n");
 587                 if (p) {
 588                         p += 2;
 589                         strbuf_addstr(&msgbuf, p);
 590                 }
 591
 592                 if (opts->record_origin) {
 593                         if (!has_conforming_footer(&msgbuf, NULL, 0))
 594                                 strbuf_addch(&msgbuf, '\n');
 595                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
 596                         strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 597                         strbuf_addstr(&msgbuf, ")\n");
 598                 }
 599         }
 600
 601         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 602                 res = do_recursive_merge(base, next, base_label, next_label,
 603                                          head, &msgbuf, opts);
 604                 write_message(&msgbuf, defmsg);
 605         } else {
 606                 struct commit_list *common = NULL;
 607                 struct commit_list *remotes = NULL;
 608
 609                 write_message(&msgbuf, defmsg);
 610
 611                 commit_list_insert(base, &common);
 612                 commit_list_insert(next, &remotes);
 613                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 614                                         common, sha1_to_hex(head), remotes);
 615                 free_commit_list(common);
 616                 free_commit_list(remotes);
 617         }
 618
 619         /*
 620          * If the merge was clean or if it failed due to conflict, we write
 621          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 622          * However, if the merge did not even start, then we don't want to
 623          * write it at all.
 624          */
 625         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 626                 write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
 627         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 628                 write_cherry_pick_head(commit, "REVERT_HEAD");
 629
 630         if (res) {
 631                 error(opts->action == REPLAY_REVERT
 632                       ? _("could not revert %s... %s")
 633                       : _("could not apply %s... %s"),
 634                       find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
 635                       msg.subject);
 636                 print_advice(res == 1, opts);
 637                 rerere(opts->allow_rerere_auto);
 638                 goto leave;
 639         }
 640
 641         allow = allow_empty(opts, commit);
 642         if (allow < 0) {
 643                 res = allow;
 644                 goto leave;
 645         }
 646         if (!opts->no_commit)
 647                 res = run_git_commit(defmsg, opts, allow);
 648
 649 leave:
 650         free_message(&msg);
 651         free(defmsg);
 652
 653         return res;
 654 }
 655
 656 static void prepare_revs(struct replay_opts *opts)
 657 {
 658         /*
 659          * picking (but not reverting) ranges (but not individual revisions)
 660          * should be done in reverse
 661          */
 662         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 663                 opts->revs->reverse ^= 1;
 664
 665         if (prepare_revision_walk(opts->revs))
 666                 die(_("revision walk setup failed"));
 667
 668         if (!opts->revs->commits)
 669                 die(_("empty commit set passed"));
 670 }
 671
 672 static void read_and_refresh_cache(struct replay_opts *opts)
 673 {
 674         static struct lock_file index_lock;
 675         int index_fd = hold_locked_index(&index_lock, 0);
 676         if (read_index_preload(&the_index, NULL) < 0)
 677                 die(_("git %s: failed to read the index"), action_name(opts));
 678         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 679         if (the_index.cache_changed) {
 680                 if (write_index(&the_index, index_fd) ||
 681                     commit_locked_index(&index_lock))
 682                         die(_("git %s: failed to refresh the index"), action_name(opts));
 683         }
 684         rollback_lock_file(&index_lock);
 685 }
 686
 687 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 688                 struct replay_opts *opts)
 689 {
 690         struct commit_list *cur = NULL;
 691         const char *sha1_abbrev = NULL;
 692         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 693         const char *subject;
 694         int subject_len;
 695
 696         for (cur = todo_list; cur; cur = cur->next) {
 697                 sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
 698                 subject_len = find_commit_subject(cur->item->buffer, &subject);
 699                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 700                         subject_len, subject);
 701         }
 702         return 0;
 703 }
 704
 705 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 706 {
 707         unsigned char commit_sha1[20];
 708         enum replay_action action;
 709         char *end_of_object_name;
 710         int saved, status, padding;
 711
 712         if (!prefixcmp(bol, "pick")) {
 713                 action = REPLAY_PICK;
 714                 bol += strlen("pick");
 715         } else if (!prefixcmp(bol, "revert")) {
 716                 action = REPLAY_REVERT;
 717                 bol += strlen("revert");
 718         } else
 719                 return NULL;
 720
 721         /* Eat up extra spaces/ tabs before object name */
 722         padding = strspn(bol, " \t");
 723         if (!padding)
 724                 return NULL;
 725         bol += padding;
 726
 727         end_of_object_name = bol + strcspn(bol, " \t\n");
 728         saved = *end_of_object_name;
 729         *end_of_object_name = '\0';
 730         status = get_sha1(bol, commit_sha1);
 731         *end_of_object_name = saved;
 732
 733         /*
 734          * Verify that the action matches up with the one in
 735          * opts; we don't support arbitrary instructions
 736          */
 737         if (action != opts->action) {
 738                 const char *action_str;
 739                 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
 740                 error(_("Cannot %s during a %s"), action_str, action_name(opts));
 741                 return NULL;
 742         }
 743
 744         if (status < 0)
 745                 return NULL;
 746
 747         return lookup_commit_reference(commit_sha1);
 748 }
 749
 750 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
 751                         struct replay_opts *opts)
 752 {
 753         struct commit_list **next = todo_list;
 754         struct commit *commit;
 755         char *p = buf;
 756         int i;
 757
 758         for (i = 1; *p; i++) {
 759                 char *eol = strchrnul(p, '\n');
 760                 commit = parse_insn_line(p, eol, opts);
 761                 if (!commit)
 762                         return error(_("Could not parse line %d."), i);
 763                 next = commit_list_append(commit, next);
 764                 p = *eol ? eol + 1 : eol;
 765         }
 766         if (!*todo_list)
 767                 return error(_("No commits parsed."));
 768         return 0;
 769 }
 770
 771 static void read_populate_todo(struct commit_list **todo_list,
 772                         struct replay_opts *opts)
 773 {
 774         const char *todo_file = git_path(SEQ_TODO_FILE);
 775         struct strbuf buf = STRBUF_INIT;
 776         int fd, res;
 777
 778         fd = open(todo_file, O_RDONLY);
 779         if (fd < 0)
 780                 die_errno(_("Could not open %s"), todo_file);
 781         if (strbuf_read(&buf, fd, 0) < 0) {
 782                 close(fd);
 783                 strbuf_release(&buf);
 784                 die(_("Could not read %s."), todo_file);
 785         }
 786         close(fd);
 787
 788         res = parse_insn_buffer(buf.buf, todo_list, opts);
 789         strbuf_release(&buf);
 790         if (res)
 791                 die(_("Unusable instruction sheet: %s"), todo_file);
 792 }
 793
 794 static int populate_opts_cb(const char *key, const char *value, void *data)
 795 {
 796         struct replay_opts *opts = data;
 797         int error_flag = 1;
 798
 799         if (!value)
 800                 error_flag = 0;
 801         else if (!strcmp(key, "options.no-commit"))
 802                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 803         else if (!strcmp(key, "options.edit"))
 804                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
 805         else if (!strcmp(key, "options.signoff"))
 806                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 807         else if (!strcmp(key, "options.record-origin"))
 808                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 809         else if (!strcmp(key, "options.allow-ff"))
 810                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 811         else if (!strcmp(key, "options.mainline"))
 812                 opts->mainline = git_config_int(key, value);
 813         else if (!strcmp(key, "options.strategy"))
 814                 git_config_string(&opts->strategy, key, value);
 815         else if (!strcmp(key, "options.strategy-option")) {
 816                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 817                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
 818         } else
 819                 return error(_("Invalid key: %s"), key);
 820
 821         if (!error_flag)
 822                 return error(_("Invalid value for %s: %s"), key, value);
 823
 824         return 0;
 825 }
 826
 827 static void read_populate_opts(struct replay_opts **opts_ptr)
 828 {
 829         const char *opts_file = git_path(SEQ_OPTS_FILE);
 830
 831         if (!file_exists(opts_file))
 832                 return;
 833         if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
 834                 die(_("Malformed options sheet: %s"), opts_file);
 835 }
 836
 837 static void walk_revs_populate_todo(struct commit_list **todo_list,
 838                                 struct replay_opts *opts)
 839 {
 840         struct commit *commit;
 841         struct commit_list **next;
 842
 843         prepare_revs(opts);
 844
 845         next = todo_list;
 846         while ((commit = get_revision(opts->revs)))
 847                 next = commit_list_append(commit, next);
 848 }
 849
 850 static int create_seq_dir(void)
 851 {
 852         const char *seq_dir = git_path(SEQ_DIR);
 853
 854         if (file_exists(seq_dir)) {
 855                 error(_("a cherry-pick or revert is already in progress"));
 856                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 857                 return -1;
 858         }
 859         else if (mkdir(seq_dir, 0777) < 0)
 860                 die_errno(_("Could not create sequencer directory %s"), seq_dir);
 861         return 0;
 862 }
 863
 864 static void save_head(const char *head)
 865 {
 866         const char *head_file = git_path(SEQ_HEAD_FILE);
 867         static struct lock_file head_lock;
 868         struct strbuf buf = STRBUF_INIT;
 869         int fd;
 870
 871         fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
 872         strbuf_addf(&buf, "%s\n", head);
 873         if (write_in_full(fd, buf.buf, buf.len) < 0)
 874                 die_errno(_("Could not write to %s"), head_file);
 875         if (commit_lock_file(&head_lock) < 0)
 876                 die(_("Error wrapping up %s."), head_file);
 877 }
 878
 879 static int reset_for_rollback(const unsigned char *sha1)
 880 {
 881         const char *argv[4];    /* reset --merge <arg> + NULL */
 882         argv[0] = "reset";
 883         argv[1] = "--merge";
 884         argv[2] = sha1_to_hex(sha1);
 885         argv[3] = NULL;
 886         return run_command_v_opt(argv, RUN_GIT_CMD);
 887 }
 888
 889 static int rollback_single_pick(void)
 890 {
 891         unsigned char head_sha1[20];
 892
 893         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
 894             !file_exists(git_path("REVERT_HEAD")))
 895                 return error(_("no cherry-pick or revert in progress"));
 896         if (read_ref_full("HEAD", head_sha1, 0, NULL))
 897                 return error(_("cannot resolve HEAD"));
 898         if (is_null_sha1(head_sha1))
 899                 return error(_("cannot abort from a branch yet to be born"));
 900         return reset_for_rollback(head_sha1);
 901 }
 902
 903 static int sequencer_rollback(struct replay_opts *opts)
 904 {
 905         const char *filename;
 906         FILE *f;
 907         unsigned char sha1[20];
 908         struct strbuf buf = STRBUF_INIT;
 909
 910         filename = git_path(SEQ_HEAD_FILE);
 911         f = fopen(filename, "r");
 912         if (!f && errno == ENOENT) {
 913                 /*
 914                  * There is no multiple-cherry-pick in progress.
 915                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 916                  * a single-cherry-pick in progress, abort that.
 917                  */
 918                 return rollback_single_pick();
 919         }
 920         if (!f)
 921                 return error(_("cannot open %s: %s"), filename,
 922                                                 strerror(errno));
 923         if (strbuf_getline(&buf, f, '\n')) {
 924                 error(_("cannot read %s: %s"), filename, ferror(f) ?
 925                         strerror(errno) : _("unexpected end of file"));
 926                 fclose(f);
 927                 goto fail;
 928         }
 929         fclose(f);
 930         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 931                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 932                         filename);
 933                 goto fail;
 934         }
 935         if (reset_for_rollback(sha1))
 936                 goto fail;
 937         remove_sequencer_state();
 938         strbuf_release(&buf);
 939         return 0;
 940 fail:
 941         strbuf_release(&buf);
 942         return -1;
 943 }
 944
 945 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 946 {
 947         const char *todo_file = git_path(SEQ_TODO_FILE);
 948         static struct lock_file todo_lock;
 949         struct strbuf buf = STRBUF_INIT;
 950         int fd;
 951
 952         fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
 953         if (format_todo(&buf, todo_list, opts) < 0)
 954                 die(_("Could not format %s."), todo_file);
 955         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 956                 strbuf_release(&buf);
 957                 die_errno(_("Could not write to %s"), todo_file);
 958         }
 959         if (commit_lock_file(&todo_lock) < 0) {
 960                 strbuf_release(&buf);
 961                 die(_("Error wrapping up %s."), todo_file);
 962         }
 963         strbuf_release(&buf);
 964 }
 965
 966 static void save_opts(struct replay_opts *opts)
 967 {
 968         const char *opts_file = git_path(SEQ_OPTS_FILE);
 969
 970         if (opts->no_commit)
 971                 git_config_set_in_file(opts_file, "options.no-commit", "true");
 972         if (opts->edit)
 973                 git_config_set_in_file(opts_file, "options.edit", "true");
 974         if (opts->signoff)
 975                 git_config_set_in_file(opts_file, "options.signoff", "true");
 976         if (opts->record_origin)
 977                 git_config_set_in_file(opts_file, "options.record-origin", "true");
 978         if (opts->allow_ff)
 979                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
 980         if (opts->mainline) {
 981                 struct strbuf buf = STRBUF_INIT;
 982                 strbuf_addf(&buf, "%d", opts->mainline);
 983                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
 984                 strbuf_release(&buf);
 985         }
 986         if (opts->strategy)
 987                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
 988         if (opts->xopts) {
 989                 int i;
 990                 for (i = 0; i < opts->xopts_nr; i++)
 991                         git_config_set_multivar_in_file(opts_file,
 992                                                         "options.strategy-option",
 993                                                         opts->xopts[i], "^$", 0);
 994         }
 995 }
 996
 997 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
 998 {
 999         struct commit_list *cur;
1000         int res;
1001
1002         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1003         if (opts->allow_ff)
1004                 assert(!(opts->signoff || opts->no_commit ||
1005                                 opts->record_origin || opts->edit));
1006         read_and_refresh_cache(opts);
1007
1008         for (cur = todo_list; cur; cur = cur->next) {
1009                 save_todo(cur, opts);
1010                 res = do_pick_commit(cur->item, opts);
1011                 if (res)
1012                         return res;
1013         }
1014
1015         /*
1016          * Sequence of picks finished successfully; cleanup by
1017          * removing the .git/sequencer directory
1018          */
1019         remove_sequencer_state();
1020         return 0;
1021 }
1022
1023 static int continue_single_pick(void)
1024 {
1025         const char *argv[] = { "commit", NULL };
1026
1027         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
1028             !file_exists(git_path("REVERT_HEAD")))
1029                 return error(_("no cherry-pick or revert in progress"));
1030         return run_command_v_opt(argv, RUN_GIT_CMD);
1031 }
1032
1033 static int sequencer_continue(struct replay_opts *opts)
1034 {
1035         struct commit_list *todo_list = NULL;
1036
1037         if (!file_exists(git_path(SEQ_TODO_FILE)))
1038                 return continue_single_pick();
1039         read_populate_opts(&opts);
1040         read_populate_todo(&todo_list, opts);
1041
1042         /* Verify that the conflict has been resolved */
1043         if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
1044             file_exists(git_path("REVERT_HEAD"))) {
1045                 int ret = continue_single_pick();
1046                 if (ret)
1047                         return ret;
1048         }
1049         if (index_differs_from("HEAD", 0))
1050                 return error_dirty_index(opts);
1051         todo_list = todo_list->next;
1052         return pick_commits(todo_list, opts);
1053 }
1054
1055 static int single_pick(struct commit *cmit, struct replay_opts *opts)
1056 {
1057         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1058         return do_pick_commit(cmit, opts);
1059 }
1060
1061 int sequencer_pick_revisions(struct replay_opts *opts)
1062 {
1063         struct commit_list *todo_list = NULL;
1064         unsigned char sha1[20];
1065         int i;
1066
1067         if (opts->subcommand == REPLAY_NONE)
1068                 assert(opts->revs);
1069
1070         read_and_refresh_cache(opts);
1071
1072         /*
1073          * Decide what to do depending on the arguments; a fresh
1074          * cherry-pick should be handled differently from an existing
1075          * one that is being continued
1076          */
1077         if (opts->subcommand == REPLAY_REMOVE_STATE) {
1078                 remove_sequencer_state();
1079                 return 0;
1080         }
1081         if (opts->subcommand == REPLAY_ROLLBACK)
1082                 return sequencer_rollback(opts);
1083         if (opts->subcommand == REPLAY_CONTINUE)
1084                 return sequencer_continue(opts);
1085
1086         for (i = 0; i < opts->revs->pending.nr; i++) {
1087                 unsigned char sha1[20];
1088                 const char *name = opts->revs->pending.objects[i].name;
1089
1090                 /* This happens when using --stdin. */
1091                 if (!strlen(name))
1092                         continue;
1093
1094                 if (!get_sha1(name, sha1)) {
1095                         if (!lookup_commit_reference_gently(sha1, 1)) {
1096                                 enum object_type type = sha1_object_info(sha1, NULL);
1097                                 die(_("%s: can't cherry-pick a %s"), name, typename(type));
1098                         }
1099                 } else
1100                         die(_("%s: bad revision"), name);
1101         }
1102
1103         /*
1104          * If we were called as "git cherry-pick <commit>", just
1105          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1106          * REVERT_HEAD, and don't touch the sequencer state.
1107          * This means it is possible to cherry-pick in the middle
1108          * of a cherry-pick sequence.
1109          */
1110         if (opts->revs->cmdline.nr == 1 &&
1111             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1112             opts->revs->no_walk &&
1113             !opts->revs->cmdline.rev->flags) {
1114                 struct commit *cmit;
1115                 if (prepare_revision_walk(opts->revs))
1116                         die(_("revision walk setup failed"));
1117                 cmit = get_revision(opts->revs);
1118                 if (!cmit || get_revision(opts->revs))
1119                         die("BUG: expected exactly one commit from walk");
1120                 return single_pick(cmit, opts);
1121         }
1122
1123         /*
1124          * Start a new cherry-pick/ revert sequence; but
1125          * first, make sure that an existing one isn't in
1126          * progress
1127          */
1128
1129         walk_revs_populate_todo(&todo_list, opts);
1130         if (create_seq_dir() < 0)
1131                 return -1;
1132         if (get_sha1("HEAD", sha1)) {
1133                 if (opts->action == REPLAY_REVERT)
1134                         return error(_("Can't revert as initial commit"));
1135                 return error(_("Can't cherry-pick into empty head"));
1136         }
1137         save_head(sha1_to_hex(sha1));
1138         save_opts(opts);
1139         return pick_commits(todo_list, opts);
1140 }
1141
1142 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1143 {
1144         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1145         struct strbuf sob = STRBUF_INIT;
1146         int has_footer;
1147
1148         strbuf_addstr(&sob, sign_off_header);
1149         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1150                                 getenv("GIT_COMMITTER_EMAIL")));
1151         strbuf_addch(&sob, '\n');
1152
1153         /*
1154          * If the whole message buffer is equal to the sob, pretend that we
1155          * found a conforming footer with a matching sob
1156          */
1157         if (msgbuf->len - ignore_footer == sob.len &&
1158             !strncmp(msgbuf->buf, sob.buf, sob.len))
1159                 has_footer = 3;
1160         else
1161                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1162
1163         if (!has_footer) {
1164                 const char *append_newlines = NULL;
1165                 size_t len = msgbuf->len - ignore_footer;
1166
1167                 if (!len) {
1168                         /*
1169                          * The buffer is completely empty.  Leave foom for
1170                          * the title and body to be filled in by the user.
1171                          */
1172                         append_newlines = "\n\n";
1173                 } else if (msgbuf->buf[len - 1] != '\n') {
1174                         /*
1175                          * Incomplete line.  Complete the line and add a
1176                          * blank one so that there is an empty line between
1177                          * the message body and the sob.
1178                          */
1179                         append_newlines = "\n\n";
1180                 } else if (len == 1) {
1181                         /*
1182                          * Buffer contains a single newline.  Add another
1183                          * so that we leave room for the title and body.
1184                          */
1185                         append_newlines = "\n";
1186                 } else if (msgbuf->buf[len - 2] != '\n') {
1187                         /*
1188                          * Buffer ends with a single newline.  Add another
1189                          * so that there is an empty line between the message
1190                          * body and the sob.
1191                          */
1192                         append_newlines = "\n";
1193                 } /* else, the buffer already ends with two newlines. */
1194
1195                 if (append_newlines)
1196                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1197                                 append_newlines, strlen(append_newlines));
1198         }
1199
1200         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1201                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1202                                 sob.buf, sob.len);
1203
1204         strbuf_release(&sob);
1205 }