git.oblomov.eu Git - git/blob - sequencer.c

   1 #include "cache.h"
   2 #include "lockfile.h"
   3 #include "sequencer.h"
   4 #include "dir.h"
   5 #include "object.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "run-command.h"
   9 #include "exec_cmd.h"
  10 #include "utf8.h"
  11 #include "cache-tree.h"
  12 #include "diff.h"
  13 #include "revision.h"
  14 #include "rerere.h"
  15 #include "merge-recursive.h"
  16 #include "refs.h"
  17 #include "argv-array.h"
  18 #include "rewrite.h"
  19
  20 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
  21
  22 const char sign_off_header[] = "Signed-off-by: ";
  23 static const char cherry_picked_prefix[] = "(cherry picked from commit ";
  24 static struct rewritten rewritten;
  25
  26 static GIT_PATH_FUNC(git_path_todo_file, SEQ_TODO_FILE)
  27 static GIT_PATH_FUNC(git_path_opts_file, SEQ_OPTS_FILE)
  28 static GIT_PATH_FUNC(git_path_seq_dir, SEQ_DIR)
  29 static GIT_PATH_FUNC(git_path_head_file, SEQ_HEAD_FILE)
  30
  31 static void finish(struct replay_opts *opts)
  32 {
  33         const char *name;
  34         struct strbuf msg = STRBUF_INIT;
  35
  36         if (opts->action != REPLAY_PICK)
  37                 return;
  38
  39         name = opts->action_name ? opts->action_name : "cherry-pick";
  40
  41         if (!*name)
  42                 return;
  43
  44         strbuf_addf(&msg, "Notes added by 'git %s'", name);
  45         copy_rewrite_notes(&rewritten, name, msg.buf);
  46         run_rewrite_hook(&rewritten, name);
  47         strbuf_release(&msg);
  48 }
  49
  50 static int is_rfc2822_line(const char *buf, int len)
  51 {
  52         int i;
  53
  54         for (i = 0; i < len; i++) {
  55                 int ch = buf[i];
  56                 if (ch == ':')
  57                         return 1;
  58                 if (!isalnum(ch) && ch != '-')
  59                         break;
  60         }
  61
  62         return 0;
  63 }
  64
  65 static int is_cherry_picked_from_line(const char *buf, int len)
  66 {
  67         /*
  68          * We only care that it looks roughly like (cherry picked from ...)
  69          */
  70         return len > strlen(cherry_picked_prefix) + 1 &&
  71                 starts_with(buf, cherry_picked_prefix) && buf[len - 1] == ')';
  72 }
  73
  74 /*
  75  * Returns 0 for non-conforming footer
  76  * Returns 1 for conforming footer
  77  * Returns 2 when sob exists within conforming footer
  78  * Returns 3 when sob exists within conforming footer as last entry
  79  */
  80 static int has_conforming_footer(struct strbuf *sb, struct strbuf *sob,
  81         int ignore_footer)
  82 {
  83         char prev;
  84         int i, k;
  85         int len = sb->len - ignore_footer;
  86         const char *buf = sb->buf;
  87         int found_sob = 0;
  88
  89         /* footer must end with newline */
  90         if (!len || buf[len - 1] != '\n')
  91                 return 0;
  92
  93         prev = '\0';
  94         for (i = len - 1; i > 0; i--) {
  95                 char ch = buf[i];
  96                 if (prev == '\n' && ch == '\n') /* paragraph break */
  97                         break;
  98                 prev = ch;
  99         }
 100
 101         /* require at least one blank line */
 102         if (prev != '\n' || buf[i] != '\n')
 103                 return 0;
 104
 105         /* advance to start of last paragraph */
 106         while (i < len - 1 && buf[i] == '\n')
 107                 i++;
 108
 109         for (; i < len; i = k) {
 110                 int found_rfc2822;
 111
 112                 for (k = i; k < len && buf[k] != '\n'; k++)
 113                         ; /* do nothing */
 114                 k++;
 115
 116                 found_rfc2822 = is_rfc2822_line(buf + i, k - i - 1);
 117                 if (found_rfc2822 && sob &&
 118                     !strncmp(buf + i, sob->buf, sob->len))
 119                         found_sob = k;
 120
 121                 if (!(found_rfc2822 ||
 122                       is_cherry_picked_from_line(buf + i, k - i - 1)))
 123                         return 0;
 124         }
 125         if (found_sob == i)
 126                 return 3;
 127         if (found_sob)
 128                 return 2;
 129         return 1;
 130 }
 131
 132 static void remove_sequencer_state(void)
 133 {
 134         struct strbuf seq_dir = STRBUF_INIT;
 135
 136         strbuf_addf(&seq_dir, "%s", git_path(SEQ_DIR));
 137         remove_dir_recursively(&seq_dir, 0);
 138         strbuf_release(&seq_dir);
 139 }
 140
 141 static const char *action_name(const struct replay_opts *opts)
 142 {
 143         return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
 144 }
 145
 146 struct commit_message {
 147         char *parent_label;
 148         char *label;
 149         char *subject;
 150         const char *message;
 151 };
 152
 153 static int get_message(struct commit *commit, struct commit_message *out)
 154 {
 155         const char *abbrev, *subject;
 156         int subject_len;
 157
 158         out->message = logmsg_reencode(commit, NULL, get_commit_output_encoding());
 159         abbrev = find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV);
 160
 161         subject_len = find_commit_subject(out->message, &subject);
 162
 163         out->subject = xmemdupz(subject, subject_len);
 164         out->label = xstrfmt("%s... %s", abbrev, out->subject);
 165         out->parent_label = xstrfmt("parent of %s", out->label);
 166
 167         return 0;
 168 }
 169
 170 static void free_message(struct commit *commit, struct commit_message *msg)
 171 {
 172         free(msg->parent_label);
 173         free(msg->label);
 174         free(msg->subject);
 175         unuse_commit_buffer(commit, msg->message);
 176 }
 177
 178 static void print_advice(int show_hint, struct replay_opts *opts)
 179 {
 180         char *msg = getenv("GIT_CHERRY_PICK_HELP");
 181
 182         if (msg) {
 183                 fprintf(stderr, "%s\n", msg);
 184                 /*
 185                  * A conflict has occurred but the porcelain
 186                  * (typically rebase --interactive) wants to take care
 187                  * of the commit itself so remove CHERRY_PICK_HEAD
 188                  */
 189                 unlink(git_path_cherry_pick_head());
 190                 return;
 191         }
 192
 193         if (show_hint) {
 194                 if (opts->no_commit)
 195                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 196                                  "with 'git add <paths>' or 'git rm <paths>'"));
 197                 else
 198                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 199                                  "with 'git add <paths>' or 'git rm <paths>'\n"
 200                                  "and commit the result with 'git commit'"));
 201         }
 202 }
 203
 204 static void write_message(struct strbuf *msgbuf, const char *filename)
 205 {
 206         static struct lock_file msg_file;
 207
 208         int msg_fd = hold_lock_file_for_update(&msg_file, filename,
 209                                                LOCK_DIE_ON_ERROR);
 210         if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
 211                 die_errno(_("Could not write to %s"), filename);
 212         strbuf_release(msgbuf);
 213         if (commit_lock_file(&msg_file) < 0)
 214                 die(_("Error wrapping up %s"), filename);
 215 }
 216
 217 static struct tree *empty_tree(void)
 218 {
 219         return lookup_tree(EMPTY_TREE_SHA1_BIN);
 220 }
 221
 222 static int error_dirty_index(struct replay_opts *opts)
 223 {
 224         if (read_cache_unmerged())
 225                 return error_resolve_conflict(action_name(opts));
 226
 227         /* Different translation strings for cherry-pick and revert */
 228         if (opts->action == REPLAY_PICK)
 229                 error(_("Your local changes would be overwritten by cherry-pick."));
 230         else
 231                 error(_("Your local changes would be overwritten by revert."));
 232
 233         if (advice_commit_before_merge)
 234                 advise(_("Commit your changes or stash them to proceed."));
 235         return -1;
 236 }
 237
 238 static int fast_forward_to(const unsigned char *to, const unsigned char *from,
 239                         int unborn, struct replay_opts *opts)
 240 {
 241         struct ref_transaction *transaction;
 242         struct strbuf sb = STRBUF_INIT;
 243         struct strbuf err = STRBUF_INIT;
 244
 245         read_cache();
 246         if (checkout_fast_forward(from, to, 1))
 247                 exit(128); /* the callee should have complained already */
 248
 249         strbuf_addf(&sb, "%s: fast-forward", action_name(opts));
 250
 251         transaction = ref_transaction_begin(&err);
 252         if (!transaction ||
 253             ref_transaction_update(transaction, "HEAD",
 254                                    to, unborn ? null_sha1 : from,
 255                                    0, sb.buf, &err) ||
 256             ref_transaction_commit(transaction, &err)) {
 257                 ref_transaction_free(transaction);
 258                 error("%s", err.buf);
 259                 strbuf_release(&sb);
 260                 strbuf_release(&err);
 261                 return -1;
 262         }
 263
 264         strbuf_release(&sb);
 265         strbuf_release(&err);
 266         ref_transaction_free(transaction);
 267         return 0;
 268 }
 269
 270 void append_conflicts_hint(struct strbuf *msgbuf)
 271 {
 272         int i;
 273
 274         strbuf_addch(msgbuf, '\n');
 275         strbuf_commented_addf(msgbuf, "Conflicts:\n");
 276         for (i = 0; i < active_nr;) {
 277                 const struct cache_entry *ce = active_cache[i++];
 278                 if (ce_stage(ce)) {
 279                         strbuf_commented_addf(msgbuf, "\t%s\n", ce->name);
 280                         while (i < active_nr && !strcmp(ce->name,
 281                                                         active_cache[i]->name))
 282                                 i++;
 283                 }
 284         }
 285 }
 286
 287 static int do_recursive_merge(struct commit *base, struct commit *next,
 288                               const char *base_label, const char *next_label,
 289                               unsigned char *head, struct strbuf *msgbuf,
 290                               struct replay_opts *opts)
 291 {
 292         struct merge_options o;
 293         struct tree *result, *next_tree, *base_tree, *head_tree;
 294         int clean;
 295         const char **xopt;
 296         static struct lock_file index_lock;
 297
 298         hold_locked_index(&index_lock, 1);
 299
 300         read_cache();
 301
 302         init_merge_options(&o);
 303         o.ancestor = base ? base_label : "(empty tree)";
 304         o.branch1 = "HEAD";
 305         o.branch2 = next ? next_label : "(empty tree)";
 306
 307         head_tree = parse_tree_indirect(head);
 308         next_tree = next ? next->tree : empty_tree();
 309         base_tree = base ? base->tree : empty_tree();
 310
 311         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 312                 parse_merge_opt(&o, *xopt);
 313
 314         clean = merge_trees(&o,
 315                             head_tree,
 316                             next_tree, base_tree, &result);
 317
 318         if (active_cache_changed &&
 319             write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
 320                 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 321                 die(_("%s: Unable to write new index file"), action_name(opts));
 322         rollback_lock_file(&index_lock);
 323
 324         if (opts->signoff)
 325                 append_signoff(msgbuf, 0, 0);
 326
 327         if (!clean)
 328                 append_conflicts_hint(msgbuf);
 329
 330         return !clean;
 331 }
 332
 333 static int is_index_unchanged(void)
 334 {
 335         unsigned char head_sha1[20];
 336         struct commit *head_commit;
 337
 338         if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_sha1, NULL))
 339                 return error(_("Could not resolve HEAD commit\n"));
 340
 341         head_commit = lookup_commit(head_sha1);
 342
 343         /*
 344          * If head_commit is NULL, check_commit, called from
 345          * lookup_commit, would have indicated that head_commit is not
 346          * a commit object already.  parse_commit() will return failure
 347          * without further complaints in such a case.  Otherwise, if
 348          * the commit is invalid, parse_commit() will complain.  So
 349          * there is nothing for us to say here.  Just return failure.
 350          */
 351         if (parse_commit(head_commit))
 352                 return -1;
 353
 354         if (!active_cache_tree)
 355                 active_cache_tree = cache_tree();
 356
 357         if (!cache_tree_fully_valid(active_cache_tree))
 358                 if (cache_tree_update(&the_index, 0))
 359                         return error(_("Unable to update cache tree\n"));
 360
 361         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.oid.hash);
 362 }
 363
 364 /*
 365  * If we are cherry-pick, and if the merge did not result in
 366  * hand-editing, we will hit this commit and inherit the original
 367  * author date and name.
 368  * If we are revert, or if our cherry-pick results in a hand merge,
 369  * we had better say that the current user is responsible for that.
 370  */
 371 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 372                           int allow_empty)
 373 {
 374         struct argv_array array;
 375         int rc;
 376         const char *value;
 377
 378         argv_array_init(&array);
 379         argv_array_push(&array, "commit");
 380         argv_array_push(&array, "-n");
 381         if (opts->quiet)
 382                 argv_array_push(&array, "-q");
 383
 384         if (opts->gpg_sign)
 385                 argv_array_pushf(&array, "-S%s", opts->gpg_sign);
 386         if (opts->signoff)
 387                 argv_array_push(&array, "-s");
 388         if (!opts->edit) {
 389                 argv_array_push(&array, "-F");
 390                 argv_array_push(&array, defmsg);
 391                 if (!opts->signoff &&
 392                     !opts->record_origin &&
 393                     git_config_get_value("commit.cleanup", &value))
 394                         argv_array_push(&array, "--cleanup=verbatim");
 395         }
 396
 397         if (allow_empty)
 398                 argv_array_push(&array, "--allow-empty");
 399
 400         if (opts->allow_empty_message)
 401                 argv_array_push(&array, "--allow-empty-message");
 402
 403         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 404         argv_array_clear(&array);
 405         return rc;
 406 }
 407
 408 static int is_original_commit_empty(struct commit *commit)
 409 {
 410         const unsigned char *ptree_sha1;
 411
 412         if (parse_commit(commit))
 413                 return error(_("Could not parse commit %s\n"),
 414                              oid_to_hex(&commit->object.oid));
 415         if (commit->parents) {
 416                 struct commit *parent = commit->parents->item;
 417                 if (parse_commit(parent))
 418                         return error(_("Could not parse parent commit %s\n"),
 419                                 oid_to_hex(&parent->object.oid));
 420                 ptree_sha1 = parent->tree->object.oid.hash;
 421         } else {
 422                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 423         }
 424
 425         return !hashcmp(ptree_sha1, commit->tree->object.oid.hash);
 426 }
 427
 428 /*
 429  * Do we run "git commit" with "--allow-empty"?
 430  */
 431 static int allow_empty(struct replay_opts *opts, struct commit *commit)
 432 {
 433         int index_unchanged, empty_commit;
 434
 435         /*
 436          * Three cases:
 437          *
 438          * (1) we do not allow empty at all and error out.
 439          *
 440          * (2) we allow ones that were initially empty, but
 441          * forbid the ones that become empty;
 442          *
 443          * (3) we allow both.
 444          */
 445         if (!opts->allow_empty)
 446                 return 0; /* let "git commit" barf as necessary */
 447
 448         index_unchanged = is_index_unchanged();
 449         if (index_unchanged < 0)
 450                 return index_unchanged;
 451         if (!index_unchanged)
 452                 return 0; /* we do not have to say --allow-empty */
 453
 454         if (opts->keep_redundant_commits)
 455                 return 1;
 456
 457         empty_commit = is_original_commit_empty(commit);
 458         if (empty_commit < 0)
 459                 return empty_commit;
 460         if (!empty_commit)
 461                 return 0;
 462         else
 463                 return 1;
 464 }
 465
 466 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 467 {
 468         unsigned char head[20];
 469         struct commit *base, *next, *parent;
 470         const char *base_label, *next_label;
 471         struct commit_message msg = { NULL, NULL, NULL, NULL };
 472         struct strbuf msgbuf = STRBUF_INIT;
 473         int res, unborn = 0, allow;
 474
 475         if (opts->no_commit) {
 476                 /*
 477                  * We do not intend to commit immediately.  We just want to
 478                  * merge the differences in, so let's compute the tree
 479                  * that represents the "current" state for merge-recursive
 480                  * to work on.
 481                  */
 482                 if (write_cache_as_tree(head, 0, NULL))
 483                         die (_("Your index file is unmerged."));
 484         } else {
 485                 unborn = get_sha1("HEAD", head);
 486                 if (unborn)
 487                         hashcpy(head, EMPTY_TREE_SHA1_BIN);
 488                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
 489                         return error_dirty_index(opts);
 490         }
 491         discard_cache();
 492
 493         if (!commit->parents) {
 494                 parent = NULL;
 495         }
 496         else if (commit->parents->next) {
 497                 /* Reverting or cherry-picking a merge commit */
 498                 int cnt;
 499                 struct commit_list *p;
 500
 501                 if (!opts->mainline)
 502                         return error(_("Commit %s is a merge but no -m option was given."),
 503                                 oid_to_hex(&commit->object.oid));
 504
 505                 for (cnt = 1, p = commit->parents;
 506                      cnt != opts->mainline && p;
 507                      cnt++)
 508                         p = p->next;
 509                 if (cnt != opts->mainline || !p)
 510                         return error(_("Commit %s does not have parent %d"),
 511                                 oid_to_hex(&commit->object.oid), opts->mainline);
 512                 parent = p->item;
 513         } else if (0 < opts->mainline)
 514                 return error(_("Mainline was specified but commit %s is not a merge."),
 515                         oid_to_hex(&commit->object.oid));
 516         else
 517                 parent = commit->parents->item;
 518
 519         if (opts->allow_ff &&
 520             ((parent && !hashcmp(parent->object.oid.hash, head)) ||
 521              (!parent && unborn)))
 522                 return fast_forward_to(commit->object.oid.hash, head, unborn, opts);
 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), oid_to_hex(&parent->object.oid));
 529
 530         if (get_message(commit, &msg) != 0)
 531                 return error(_("Cannot get commit message for %s"),
 532                         oid_to_hex(&commit->object.oid));
 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         if (opts->action == REPLAY_REVERT) {
 542                 base = commit;
 543                 base_label = msg.label;
 544                 next = parent;
 545                 next_label = msg.parent_label;
 546                 strbuf_addstr(&msgbuf, "Revert \"");
 547                 strbuf_addstr(&msgbuf, msg.subject);
 548                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 549                 strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
 550
 551                 if (commit->parents && commit->parents->next) {
 552                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 553                         strbuf_addstr(&msgbuf, oid_to_hex(&parent->object.oid));
 554                 }
 555                 strbuf_addstr(&msgbuf, ".\n");
 556         } else {
 557                 const char *p;
 558
 559                 base = parent;
 560                 base_label = msg.parent_label;
 561                 next = commit;
 562                 next_label = msg.label;
 563
 564                 /*
 565                  * Append the commit log message to msgbuf; it starts
 566                  * after the tree, parent, author, committer
 567                  * information followed by "\n\n".
 568                  */
 569                 p = strstr(msg.message, "\n\n");
 570                 if (p) {
 571                         p += 2;
 572                         strbuf_addstr(&msgbuf, p);
 573                 }
 574
 575                 if (opts->record_origin) {
 576                         if (!has_conforming_footer(&msgbuf, NULL, 0))
 577                                 strbuf_addch(&msgbuf, '\n');
 578                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
 579                         strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
 580                         strbuf_addstr(&msgbuf, ")\n");
 581                 }
 582         }
 583
 584         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 585                 res = do_recursive_merge(base, next, base_label, next_label,
 586                                          head, &msgbuf, opts);
 587                 write_message(&msgbuf, git_path_merge_msg());
 588         } else {
 589                 struct commit_list *common = NULL;
 590                 struct commit_list *remotes = NULL;
 591
 592                 write_message(&msgbuf, git_path_merge_msg());
 593
 594                 commit_list_insert(base, &common);
 595                 commit_list_insert(next, &remotes);
 596                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 597                                         common, sha1_to_hex(head), remotes);
 598                 free_commit_list(common);
 599                 free_commit_list(remotes);
 600         }
 601
 602         /*
 603          * If the merge was clean or if it failed due to conflict, we write
 604          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 605          * However, if the merge did not even start, then we don't want to
 606          * write it at all.
 607          */
 608         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 609                 update_ref(NULL, "CHERRY_PICK_HEAD", commit->object.oid.hash, NULL,
 610                            REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
 611         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 612                 update_ref(NULL, "REVERT_HEAD", commit->object.oid.hash, NULL,
 613                            REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
 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.oid.hash, DEFAULT_ABBREV),
 620                       msg.subject);
 621                 print_advice(res == 1, opts);
 622                 rerere(opts->allow_rerere_auto);
 623                 goto leave;
 624         }
 625
 626         if (opts->skip_empty && is_index_unchanged() == 1) {
 627                 if (!opts->quiet)
 628                         warning(_("skipping %s... %s"),
 629                                 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV),
 630                                 msg.subject);
 631                 goto leave;
 632         }
 633         allow = allow_empty(opts, commit);
 634         if (allow < 0) {
 635                 res = allow;
 636                 goto leave;
 637         }
 638         if (!opts->no_commit)
 639                 res = run_git_commit(git_path_merge_msg(), opts, allow);
 640
 641         if (!res && opts->action == REPLAY_PICK) {
 642                 unsigned char to[20];
 643
 644                 if (read_ref("HEAD", to))
 645                         goto leave;
 646
 647                 add_rewritten(&rewritten, commit->object.oid.hash, to);
 648         }
 649 leave:
 650         free_message(commit, &msg);
 651
 652         return res;
 653 }
 654
 655 static void prepare_revs(struct replay_opts *opts)
 656 {
 657         /*
 658          * picking (but not reverting) ranges (but not individual revisions)
 659          * should be done in reverse
 660          */
 661         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 662                 opts->revs->reverse ^= 1;
 663
 664         if (prepare_revision_walk(opts->revs))
 665                 die(_("revision walk setup failed"));
 666
 667         if (!opts->revs->commits && !opts->quiet)
 668                 error(_("empty commit set passed"));
 669 }
 670
 671 static void read_and_refresh_cache(struct replay_opts *opts)
 672 {
 673         static struct lock_file index_lock;
 674         int index_fd = hold_locked_index(&index_lock, 0);
 675         if (read_index_preload(&the_index, NULL) < 0)
 676                 die(_("git %s: failed to read the index"), action_name(opts));
 677         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 678         if (the_index.cache_changed && index_fd >= 0) {
 679                 if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
 680                         die(_("git %s: failed to refresh the index"), action_name(opts));
 681         }
 682         rollback_lock_file(&index_lock);
 683 }
 684
 685 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 686                 struct replay_opts *opts)
 687 {
 688         struct commit_list *cur = NULL;
 689         const char *sha1_abbrev = NULL;
 690         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 691         const char *subject;
 692         int subject_len;
 693
 694         for (cur = todo_list; cur; cur = cur->next) {
 695                 const char *commit_buffer = get_commit_buffer(cur->item, NULL);
 696                 sha1_abbrev = find_unique_abbrev(cur->item->object.oid.hash, DEFAULT_ABBREV);
 697                 subject_len = find_commit_subject(commit_buffer, &subject);
 698                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 699                         subject_len, subject);
 700                 unuse_commit_buffer(cur->item, commit_buffer);
 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 (starts_with(bol, "pick")) {
 713                 action = REPLAY_PICK;
 714                 bol += strlen("pick");
 715         } else if (starts_with(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         struct strbuf buf = STRBUF_INIT;
 775         int fd, res;
 776
 777         fd = open(git_path_todo_file(), O_RDONLY);
 778         if (fd < 0)
 779                 die_errno(_("Could not open %s"), git_path_todo_file());
 780         if (strbuf_read(&buf, fd, 0) < 0) {
 781                 close(fd);
 782                 strbuf_release(&buf);
 783                 die(_("Could not read %s."), git_path_todo_file());
 784         }
 785         close(fd);
 786
 787         res = parse_insn_buffer(buf.buf, todo_list, opts);
 788         strbuf_release(&buf);
 789         if (res)
 790                 die(_("Unusable instruction sheet: %s"), git_path_todo_file());
 791 }
 792
 793 static int populate_opts_cb(const char *key, const char *value, void *data)
 794 {
 795         struct replay_opts *opts = data;
 796         int error_flag = 1;
 797
 798         if (!value)
 799                 error_flag = 0;
 800         else if (!strcmp(key, "options.no-commit"))
 801                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 802         else if (!strcmp(key, "options.edit"))
 803                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
 804         else if (!strcmp(key, "options.signoff"))
 805                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 806         else if (!strcmp(key, "options.record-origin"))
 807                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 808         else if (!strcmp(key, "options.allow-ff"))
 809                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 810         else if (!strcmp(key, "options.mainline"))
 811                 opts->mainline = git_config_int(key, value);
 812         else if (!strcmp(key, "options.strategy"))
 813                 git_config_string(&opts->strategy, key, value);
 814         else if (!strcmp(key, "options.gpg-sign"))
 815                 git_config_string(&opts->gpg_sign, key, value);
 816         else if (!strcmp(key, "options.strategy-option")) {
 817                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 818                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
 819         } else if (!strcmp(key, "options.allow-rerere-auto"))
 820                 opts->allow_rerere_auto = git_config_int(key, value);
 821         else if (!strcmp(key, "options.action-name"))
 822                 git_config_string(&opts->action_name, key, value);
 823         else
 824                 return error(_("Invalid key: %s"), key);
 825
 826         if (!error_flag)
 827                 return error(_("Invalid value for %s: %s"), key, value);
 828
 829         return 0;
 830 }
 831
 832 static void read_populate_opts(struct replay_opts **opts_ptr)
 833 {
 834         if (!file_exists(git_path_opts_file()))
 835                 return;
 836         if (git_config_from_file(populate_opts_cb, git_path_opts_file(), *opts_ptr) < 0)
 837                 die(_("Malformed options sheet: %s"), git_path_opts_file());
 838 }
 839
 840 static void walk_revs_populate_todo(struct commit_list **todo_list,
 841                                 struct replay_opts *opts)
 842 {
 843         struct commit *commit;
 844         struct commit_list **next;
 845
 846         prepare_revs(opts);
 847
 848         next = todo_list;
 849         while ((commit = get_revision(opts->revs)))
 850                 next = commit_list_append(commit, next);
 851 }
 852
 853 static int create_seq_dir(void)
 854 {
 855         if (file_exists(git_path_seq_dir())) {
 856                 error(_("a cherry-pick or revert is already in progress"));
 857                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 858                 return -1;
 859         }
 860         else if (mkdir(git_path_seq_dir(), 0777) < 0)
 861                 die_errno(_("Could not create sequencer directory %s"),
 862                           git_path_seq_dir());
 863         return 0;
 864 }
 865
 866 static void save_head(const char *head)
 867 {
 868         static struct lock_file head_lock;
 869         struct strbuf buf = STRBUF_INIT;
 870         int fd;
 871
 872         fd = hold_lock_file_for_update(&head_lock, git_path_head_file(), LOCK_DIE_ON_ERROR);
 873         strbuf_addf(&buf, "%s\n", head);
 874         if (write_in_full(fd, buf.buf, buf.len) < 0)
 875                 die_errno(_("Could not write to %s"), git_path_head_file());
 876         if (commit_lock_file(&head_lock) < 0)
 877                 die(_("Error wrapping up %s."), git_path_head_file());
 878 }
 879
 880 static int reset_for_rollback(const unsigned char *sha1)
 881 {
 882         const char *argv[4];    /* reset --merge <arg> + NULL */
 883         argv[0] = "reset";
 884         argv[1] = "--merge";
 885         argv[2] = sha1_to_hex(sha1);
 886         argv[3] = NULL;
 887         return run_command_v_opt(argv, RUN_GIT_CMD);
 888 }
 889
 890 static int rollback_single_pick(void)
 891 {
 892         unsigned char head_sha1[20];
 893
 894         if (!file_exists(git_path_cherry_pick_head()) &&
 895             !file_exists(git_path_revert_head()))
 896                 return error(_("no cherry-pick or revert in progress"));
 897         if (read_ref_full("HEAD", 0, head_sha1, NULL))
 898                 return error(_("cannot resolve HEAD"));
 899         if (is_null_sha1(head_sha1))
 900                 return error(_("cannot abort from a branch yet to be born"));
 901         return reset_for_rollback(head_sha1);
 902 }
 903
 904 static int sequencer_rollback(struct replay_opts *opts)
 905 {
 906         FILE *f;
 907         unsigned char sha1[20];
 908         struct strbuf buf = STRBUF_INIT;
 909         struct string_list merge_rr = STRING_LIST_INIT_DUP;
 910
 911         if (setup_rerere(&merge_rr, 0) >= 0) {
 912                 rerere_clear(&merge_rr);
 913                 string_list_clear(&merge_rr, 1);
 914         }
 915
 916         f = fopen(git_path_head_file(), "r");
 917         if (!f && errno == ENOENT) {
 918                 /*
 919                  * There is no multiple-cherry-pick in progress.
 920                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 921                  * a single-cherry-pick in progress, abort that.
 922                  */
 923                 return rollback_single_pick();
 924         }
 925         if (!f)
 926                 return error(_("cannot open %s: %s"), git_path_head_file(),
 927                                                 strerror(errno));
 928         if (strbuf_getline_lf(&buf, f)) {
 929                 error(_("cannot read %s: %s"), git_path_head_file(),
 930                       ferror(f) ?  strerror(errno) : _("unexpected end of file"));
 931                 fclose(f);
 932                 goto fail;
 933         }
 934         fclose(f);
 935         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 936                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 937                         git_path_head_file());
 938                 goto fail;
 939         }
 940         if (reset_for_rollback(sha1))
 941                 goto fail;
 942         remove_sequencer_state();
 943         strbuf_release(&buf);
 944         return 0;
 945 fail:
 946         strbuf_release(&buf);
 947         return -1;
 948 }
 949
 950 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 951 {
 952         static struct lock_file todo_lock;
 953         struct strbuf buf = STRBUF_INIT;
 954         int fd;
 955
 956         fd = hold_lock_file_for_update(&todo_lock, git_path_todo_file(), LOCK_DIE_ON_ERROR);
 957         if (format_todo(&buf, todo_list, opts) < 0)
 958                 die(_("Could not format %s."), git_path_todo_file());
 959         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 960                 strbuf_release(&buf);
 961                 die_errno(_("Could not write to %s"), git_path_todo_file());
 962         }
 963         if (commit_lock_file(&todo_lock) < 0) {
 964                 strbuf_release(&buf);
 965                 die(_("Error wrapping up %s."), git_path_todo_file());
 966         }
 967         strbuf_release(&buf);
 968 }
 969
 970 static void save_opts(struct replay_opts *opts)
 971 {
 972         const char *opts_file = git_path_opts_file();
 973
 974         if (opts->no_commit)
 975                 git_config_set_in_file(opts_file, "options.no-commit", "true");
 976         if (opts->edit)
 977                 git_config_set_in_file(opts_file, "options.edit", "true");
 978         if (opts->signoff)
 979                 git_config_set_in_file(opts_file, "options.signoff", "true");
 980         if (opts->record_origin)
 981                 git_config_set_in_file(opts_file, "options.record-origin", "true");
 982         if (opts->allow_ff)
 983                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
 984         if (opts->mainline) {
 985                 struct strbuf buf = STRBUF_INIT;
 986                 strbuf_addf(&buf, "%d", opts->mainline);
 987                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
 988                 strbuf_release(&buf);
 989         }
 990         if (opts->strategy)
 991                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
 992         if (opts->gpg_sign)
 993                 git_config_set_in_file(opts_file, "options.gpg-sign", opts->gpg_sign);
 994         if (opts->xopts) {
 995                 int i;
 996                 for (i = 0; i < opts->xopts_nr; i++)
 997                         git_config_set_multivar_in_file(opts_file,
 998                                                         "options.strategy-option",
 999                                                         opts->xopts[i], "^$", 0);
1000         }
1001         if (opts->allow_rerere_auto) {
1002                 struct strbuf buf = STRBUF_INIT;
1003                 strbuf_addf(&buf, "%d", opts->allow_rerere_auto);
1004                 git_config_set_in_file(opts_file, "options.allow-rerere-auto", buf.buf);
1005                 strbuf_release(&buf);
1006         }
1007         if (opts->action_name)
1008                 git_config_set_in_file(opts_file, "options.action-name", opts->action_name);
1009 }
1010
1011 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
1012 {
1013         struct commit_list *cur;
1014         int res;
1015
1016         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1017         if (opts->allow_ff)
1018                 assert(!(opts->signoff || opts->no_commit ||
1019                                 opts->record_origin || opts->edit));
1020         read_and_refresh_cache(opts);
1021
1022         for (cur = todo_list; cur; cur = cur->next) {
1023                 save_todo(cur, opts);
1024                 res = do_pick_commit(cur->item, opts);
1025                 if (res) {
1026                         if (opts->action == REPLAY_PICK)
1027                                 store_rewritten(&rewritten, git_path(SEQ_REWR_FILE));
1028                         return res;
1029                 }
1030         }
1031
1032         finish(opts);
1033
1034         /*
1035          * Sequence of picks finished successfully; cleanup by
1036          * removing the .git/sequencer directory
1037          */
1038         remove_sequencer_state();
1039         return 0;
1040 }
1041
1042 static int continue_single_pick(void)
1043 {
1044         const char *argv[] = { "commit", NULL };
1045
1046         if (!file_exists(git_path_cherry_pick_head()) &&
1047             !file_exists(git_path_revert_head()))
1048                 return error(_("no cherry-pick or revert in progress"));
1049         return run_command_v_opt(argv, RUN_GIT_CMD);
1050 }
1051
1052 static int sequencer_continue(struct replay_opts *opts, int skip)
1053 {
1054         struct commit_list *todo_list = NULL;
1055
1056         if (!file_exists(git_path_todo_file()))
1057                 return continue_single_pick();
1058         read_populate_opts(&opts);
1059         read_populate_todo(&todo_list, opts);
1060         if (opts->action == REPLAY_PICK)
1061                 load_rewritten(&rewritten, git_path(SEQ_REWR_FILE));
1062
1063         /* Verify that the conflict has been resolved */
1064         if (file_exists(git_path_cherry_pick_head()) ||
1065             file_exists(git_path_revert_head())) {
1066                 int ret = continue_single_pick();
1067                 if (ret)
1068                         return ret;
1069         }
1070         if (index_differs_from("HEAD", 0))
1071                 return error_dirty_index(opts);
1072         if (opts->action == REPLAY_PICK && !skip) {
1073                 unsigned char to[20];
1074                 if (!read_ref("HEAD", to))
1075                         add_rewritten(&rewritten, todo_list->item->object.oid.hash, to);
1076         }
1077         todo_list = todo_list->next;
1078         return pick_commits(todo_list, opts);
1079 }
1080
1081 static int sequencer_skip(struct replay_opts *opts)
1082 {
1083         const char *argv[3]; /* reset --hard + NULL */
1084         struct string_list merge_rr = STRING_LIST_INIT_DUP;
1085         int ret;
1086
1087         if (setup_rerere(&merge_rr, 0) >= 0) {
1088                 rerere_clear(&merge_rr);
1089                 string_list_clear(&merge_rr, 1);
1090         }
1091
1092         argv[0] = "reset";
1093         argv[1] = "--hard";
1094         argv[2] = NULL;
1095         ret = run_command_v_opt(argv, RUN_GIT_CMD);
1096         if (ret)
1097                 return ret;
1098
1099         discard_cache();
1100         read_cache();
1101
1102         return sequencer_continue(opts, 1);
1103 }
1104
1105 static int single_pick(struct commit *cmit, struct replay_opts *opts)
1106 {
1107         int ret;
1108         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1109         ret = do_pick_commit(cmit, opts);
1110         if (ret)
1111                 return ret;
1112         finish(opts);
1113         return 0;
1114 }
1115
1116 int sequencer_pick_revisions(struct replay_opts *opts)
1117 {
1118         struct commit_list *todo_list = NULL;
1119         unsigned char sha1[20];
1120         int i;
1121
1122         if (opts->subcommand == REPLAY_NONE)
1123                 assert(opts->revs);
1124
1125         read_and_refresh_cache(opts);
1126
1127         /*
1128          * Decide what to do depending on the arguments; a fresh
1129          * cherry-pick should be handled differently from an existing
1130          * one that is being continued
1131          */
1132         if (opts->subcommand == REPLAY_REMOVE_STATE) {
1133                 remove_sequencer_state();
1134                 return 0;
1135         }
1136         if (opts->subcommand == REPLAY_ROLLBACK)
1137                 return sequencer_rollback(opts);
1138         if (opts->subcommand == REPLAY_CONTINUE)
1139                 return sequencer_continue(opts, 0);
1140         if (opts->subcommand == REPLAY_SKIP)
1141                 return sequencer_skip(opts);
1142
1143         for (i = 0; i < opts->revs->pending.nr; i++) {
1144                 unsigned char sha1[20];
1145                 const char *name = opts->revs->pending.objects[i].name;
1146
1147                 /* This happens when using --stdin. */
1148                 if (!strlen(name))
1149                         continue;
1150
1151                 if (!get_sha1(name, sha1)) {
1152                         if (!lookup_commit_reference_gently(sha1, 1)) {
1153                                 enum object_type type = sha1_object_info(sha1, NULL);
1154                                 die(_("%s: can't cherry-pick a %s"), name, typename(type));
1155                         }
1156                 } else
1157                         die(_("%s: bad revision"), name);
1158         }
1159
1160         /*
1161          * If we were called as "git cherry-pick <commit>", just
1162          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1163          * REVERT_HEAD, and don't touch the sequencer state.
1164          * This means it is possible to cherry-pick in the middle
1165          * of a cherry-pick sequence.
1166          */
1167         if (opts->revs->cmdline.nr == 1 &&
1168             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1169             opts->revs->no_walk &&
1170             !opts->revs->cmdline.rev->flags) {
1171                 struct commit *cmit;
1172                 if (prepare_revision_walk(opts->revs))
1173                         die(_("revision walk setup failed"));
1174                 cmit = get_revision(opts->revs);
1175                 if (!cmit || get_revision(opts->revs))
1176                         die("BUG: expected exactly one commit from walk");
1177                 return single_pick(cmit, opts);
1178         }
1179
1180         /*
1181          * Start a new cherry-pick/ revert sequence; but
1182          * first, make sure that an existing one isn't in
1183          * progress
1184          */
1185
1186         walk_revs_populate_todo(&todo_list, opts);
1187         if (create_seq_dir() < 0)
1188                 return -1;
1189         if (get_sha1("HEAD", sha1)) {
1190                 if (opts->action == REPLAY_REVERT)
1191                         return error(_("Can't revert as initial commit"));
1192                 return error(_("Can't cherry-pick into empty head"));
1193         }
1194         save_head(sha1_to_hex(sha1));
1195         save_opts(opts);
1196         return pick_commits(todo_list, opts);
1197 }
1198
1199 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1200 {
1201         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1202         struct strbuf sob = STRBUF_INIT;
1203         int has_footer;
1204
1205         strbuf_addstr(&sob, sign_off_header);
1206         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1207                                 getenv("GIT_COMMITTER_EMAIL")));
1208         strbuf_addch(&sob, '\n');
1209
1210         /*
1211          * If the whole message buffer is equal to the sob, pretend that we
1212          * found a conforming footer with a matching sob
1213          */
1214         if (msgbuf->len - ignore_footer == sob.len &&
1215             !strncmp(msgbuf->buf, sob.buf, sob.len))
1216                 has_footer = 3;
1217         else
1218                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1219
1220         if (!has_footer) {
1221                 const char *append_newlines = NULL;
1222                 size_t len = msgbuf->len - ignore_footer;
1223
1224                 if (!len) {
1225                         /*
1226                          * The buffer is completely empty.  Leave foom for
1227                          * the title and body to be filled in by the user.
1228                          */
1229                         append_newlines = "\n\n";
1230                 } else if (msgbuf->buf[len - 1] != '\n') {
1231                         /*
1232                          * Incomplete line.  Complete the line and add a
1233                          * blank one so that there is an empty line between
1234                          * the message body and the sob.
1235                          */
1236                         append_newlines = "\n\n";
1237                 } else if (len == 1) {
1238                         /*
1239                          * Buffer contains a single newline.  Add another
1240                          * so that we leave room for the title and body.
1241                          */
1242                         append_newlines = "\n";
1243                 } else if (msgbuf->buf[len - 2] != '\n') {
1244                         /*
1245                          * Buffer ends with a single newline.  Add another
1246                          * so that there is an empty line between the message
1247                          * body and the sob.
1248                          */
1249                         append_newlines = "\n";
1250                 } /* else, the buffer already ends with two newlines. */
1251
1252                 if (append_newlines)
1253                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1254                                 append_newlines, strlen(append_newlines));
1255         }
1256
1257         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1258                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1259                                 sob.buf, sob.len);
1260
1261         strbuf_release(&sob);
1262 }