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