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
  19 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
  20
  21 const char sign_off_header[] = "Signed-off-by: ";
  22 static const char cherry_picked_prefix[] = "(cherry picked from commit ";
  23
  24 static GIT_PATH_FUNC(git_path_todo_file, SEQ_TODO_FILE)
  25 static GIT_PATH_FUNC(git_path_opts_file, SEQ_OPTS_FILE)
  26 static GIT_PATH_FUNC(git_path_seq_dir, SEQ_DIR)
  27 static GIT_PATH_FUNC(git_path_head_file, SEQ_HEAD_FILE)
  28
  29 static int is_rfc2822_line(const char *buf, int len)
  30 {
  31         int i;
  32
  33         for (i = 0; i < len; i++) {
  34                 int ch = buf[i];
  35                 if (ch == ':')
  36                         return 1;
  37                 if (!isalnum(ch) && ch != '-')
  38                         break;
  39         }
  40
  41         return 0;
  42 }
  43
  44 static int is_cherry_picked_from_line(const char *buf, int len)
  45 {
  46         /*
  47          * We only care that it looks roughly like (cherry picked from ...)
  48          */
  49         return len > strlen(cherry_picked_prefix) + 1 &&
  50                 starts_with(buf, cherry_picked_prefix) && buf[len - 1] == ')';
  51 }
  52
  53 /*
  54  * Returns 0 for non-conforming footer
  55  * Returns 1 for conforming footer
  56  * Returns 2 when sob exists within conforming footer
  57  * Returns 3 when sob exists within conforming footer as last entry
  58  */
  59 static int has_conforming_footer(struct strbuf *sb, struct strbuf *sob,
  60         int ignore_footer)
  61 {
  62         char prev;
  63         int i, k;
  64         int len = sb->len - ignore_footer;
  65         const char *buf = sb->buf;
  66         int found_sob = 0;
  67
  68         /* footer must end with newline */
  69         if (!len || buf[len - 1] != '\n')
  70                 return 0;
  71
  72         prev = '\0';
  73         for (i = len - 1; i > 0; i--) {
  74                 char ch = buf[i];
  75                 if (prev == '\n' && ch == '\n') /* paragraph break */
  76                         break;
  77                 prev = ch;
  78         }
  79
  80         /* require at least one blank line */
  81         if (prev != '\n' || buf[i] != '\n')
  82                 return 0;
  83
  84         /* advance to start of last paragraph */
  85         while (i < len - 1 && buf[i] == '\n')
  86                 i++;
  87
  88         for (; i < len; i = k) {
  89                 int found_rfc2822;
  90
  91                 for (k = i; k < len && buf[k] != '\n'; k++)
  92                         ; /* do nothing */
  93                 k++;
  94
  95                 found_rfc2822 = is_rfc2822_line(buf + i, k - i - 1);
  96                 if (found_rfc2822 && sob &&
  97                     !strncmp(buf + i, sob->buf, sob->len))
  98                         found_sob = k;
  99
 100                 if (!(found_rfc2822 ||
 101                       is_cherry_picked_from_line(buf + i, k - i - 1)))
 102                         return 0;
 103         }
 104         if (found_sob == i)
 105                 return 3;
 106         if (found_sob)
 107                 return 2;
 108         return 1;
 109 }
 110
 111 static void remove_sequencer_state(void)
 112 {
 113         struct strbuf seq_dir = STRBUF_INIT;
 114
 115         strbuf_addf(&seq_dir, "%s", git_path(SEQ_DIR));
 116         remove_dir_recursively(&seq_dir, 0);
 117         strbuf_release(&seq_dir);
 118 }
 119
 120 static const char *action_name(const struct replay_opts *opts)
 121 {
 122         return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
 123 }
 124
 125 struct commit_message {
 126         char *parent_label;
 127         const char *label;
 128         const char *subject;
 129         const char *message;
 130 };
 131
 132 static int get_message(struct commit *commit, struct commit_message *out)
 133 {
 134         const char *abbrev, *subject;
 135         int abbrev_len, subject_len;
 136         char *q;
 137
 138         if (!git_commit_encoding)
 139                 git_commit_encoding = "UTF-8";
 140
 141         out->message = logmsg_reencode(commit, NULL, git_commit_encoding);
 142         abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
 143         abbrev_len = strlen(abbrev);
 144
 145         subject_len = find_commit_subject(out->message, &subject);
 146
 147         out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
 148                               strlen("... ") + subject_len + 1);
 149         q = out->parent_label;
 150         q = mempcpy(q, "parent of ", strlen("parent of "));
 151         out->label = q;
 152         q = mempcpy(q, abbrev, abbrev_len);
 153         q = mempcpy(q, "... ", strlen("... "));
 154         out->subject = q;
 155         q = mempcpy(q, subject, subject_len);
 156         *q = '\0';
 157         return 0;
 158 }
 159
 160 static void free_message(struct commit *commit, struct commit_message *msg)
 161 {
 162         free(msg->parent_label);
 163         unuse_commit_buffer(commit, msg->message);
 164 }
 165
 166 static void write_cherry_pick_head(struct commit *commit, const char *pseudoref)
 167 {
 168         const char *filename;
 169         int fd;
 170         struct strbuf buf = STRBUF_INIT;
 171
 172         strbuf_addf(&buf, "%s\n", sha1_to_hex(commit->object.sha1));
 173
 174         filename = git_path("%s", pseudoref);
 175         fd = open(filename, O_WRONLY | O_CREAT, 0666);
 176         if (fd < 0)
 177                 die_errno(_("Could not open '%s' for writing"), filename);
 178         if (write_in_full(fd, buf.buf, buf.len) != buf.len || close(fd))
 179                 die_errno(_("Could not write to '%s'"), filename);
 180         strbuf_release(&buf);
 181 }
 182
 183 static void print_advice(int show_hint, struct replay_opts *opts)
 184 {
 185         char *msg = getenv("GIT_CHERRY_PICK_HELP");
 186
 187         if (msg) {
 188                 fprintf(stderr, "%s\n", msg);
 189                 /*
 190                  * A conflict has occurred but the porcelain
 191                  * (typically rebase --interactive) wants to take care
 192                  * of the commit itself so remove CHERRY_PICK_HEAD
 193                  */
 194                 unlink(git_path_cherry_pick_head());
 195                 return;
 196         }
 197
 198         if (show_hint) {
 199                 if (opts->no_commit)
 200                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 201                                  "with 'git add <paths>' or 'git rm <paths>'"));
 202                 else
 203                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 204                                  "with 'git add <paths>' or 'git rm <paths>'\n"
 205                                  "and commit the result with 'git commit'"));
 206         }
 207 }
 208
 209 static void write_message(struct strbuf *msgbuf, const char *filename)
 210 {
 211         static struct lock_file msg_file;
 212
 213         int msg_fd = hold_lock_file_for_update(&msg_file, filename,
 214                                                LOCK_DIE_ON_ERROR);
 215         if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
 216                 die_errno(_("Could not write to %s"), filename);
 217         strbuf_release(msgbuf);
 218         if (commit_lock_file(&msg_file) < 0)
 219                 die(_("Error wrapping up %s"), filename);
 220 }
 221
 222 static struct tree *empty_tree(void)
 223 {
 224         return lookup_tree(EMPTY_TREE_SHA1_BIN);
 225 }
 226
 227 static int error_dirty_index(struct replay_opts *opts)
 228 {
 229         if (read_cache_unmerged())
 230                 return error_resolve_conflict(action_name(opts));
 231
 232         /* Different translation strings for cherry-pick and revert */
 233         if (opts->action == REPLAY_PICK)
 234                 error(_("Your local changes would be overwritten by cherry-pick."));
 235         else
 236                 error(_("Your local changes would be overwritten by revert."));
 237
 238         if (advice_commit_before_merge)
 239                 advise(_("Commit your changes or stash them to proceed."));
 240         return -1;
 241 }
 242
 243 static int fast_forward_to(const unsigned char *to, const unsigned char *from,
 244                         int unborn, struct replay_opts *opts)
 245 {
 246         struct ref_transaction *transaction;
 247         struct strbuf sb = STRBUF_INIT;
 248         struct strbuf err = STRBUF_INIT;
 249
 250         read_cache();
 251         if (checkout_fast_forward(from, to, 1))
 252                 exit(128); /* the callee should have complained already */
 253
 254         strbuf_addf(&sb, "%s: fast-forward", action_name(opts));
 255
 256         transaction = ref_transaction_begin(&err);
 257         if (!transaction ||
 258             ref_transaction_update(transaction, "HEAD",
 259                                    to, unborn ? null_sha1 : from,
 260                                    0, sb.buf, &err) ||
 261             ref_transaction_commit(transaction, &err)) {
 262                 ref_transaction_free(transaction);
 263                 error("%s", err.buf);
 264                 strbuf_release(&sb);
 265                 strbuf_release(&err);
 266                 return -1;
 267         }
 268
 269         strbuf_release(&sb);
 270         strbuf_release(&err);
 271         ref_transaction_free(transaction);
 272         return 0;
 273 }
 274
 275 void append_conflicts_hint(struct strbuf *msgbuf)
 276 {
 277         int i;
 278
 279         strbuf_addch(msgbuf, '\n');
 280         strbuf_commented_addf(msgbuf, "Conflicts:\n");
 281         for (i = 0; i < active_nr;) {
 282                 const struct cache_entry *ce = active_cache[i++];
 283                 if (ce_stage(ce)) {
 284                         strbuf_commented_addf(msgbuf, "\t%s\n", ce->name);
 285                         while (i < active_nr && !strcmp(ce->name,
 286                                                         active_cache[i]->name))
 287                                 i++;
 288                 }
 289         }
 290 }
 291
 292 static int do_recursive_merge(struct commit *base, struct commit *next,
 293                               const char *base_label, const char *next_label,
 294                               unsigned char *head, struct strbuf *msgbuf,
 295                               struct replay_opts *opts)
 296 {
 297         struct merge_options o;
 298         struct tree *result, *next_tree, *base_tree, *head_tree;
 299         int clean;
 300         const char **xopt;
 301         static struct lock_file index_lock;
 302
 303         hold_locked_index(&index_lock, 1);
 304
 305         read_cache();
 306
 307         init_merge_options(&o);
 308         o.ancestor = base ? base_label : "(empty tree)";
 309         o.branch1 = "HEAD";
 310         o.branch2 = next ? next_label : "(empty tree)";
 311
 312         head_tree = parse_tree_indirect(head);
 313         next_tree = next ? next->tree : empty_tree();
 314         base_tree = base ? base->tree : empty_tree();
 315
 316         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 317                 parse_merge_opt(&o, *xopt);
 318
 319         clean = merge_trees(&o,
 320                             head_tree,
 321                             next_tree, base_tree, &result);
 322
 323         if (active_cache_changed &&
 324             write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
 325                 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 326                 die(_("%s: Unable to write new index file"), action_name(opts));
 327         rollback_lock_file(&index_lock);
 328
 329         if (opts->signoff)
 330                 append_signoff(msgbuf, 0, 0);
 331
 332         if (!clean)
 333                 append_conflicts_hint(msgbuf);
 334
 335         return !clean;
 336 }
 337
 338 static int is_index_unchanged(void)
 339 {
 340         unsigned char head_sha1[20];
 341         struct commit *head_commit;
 342
 343         if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_sha1, NULL))
 344                 return error(_("Could not resolve HEAD commit\n"));
 345
 346         head_commit = lookup_commit(head_sha1);
 347
 348         /*
 349          * If head_commit is NULL, check_commit, called from
 350          * lookup_commit, would have indicated that head_commit is not
 351          * a commit object already.  parse_commit() will return failure
 352          * without further complaints in such a case.  Otherwise, if
 353          * the commit is invalid, parse_commit() will complain.  So
 354          * there is nothing for us to say here.  Just return failure.
 355          */
 356         if (parse_commit(head_commit))
 357                 return -1;
 358
 359         if (!active_cache_tree)
 360                 active_cache_tree = cache_tree();
 361
 362         if (!cache_tree_fully_valid(active_cache_tree))
 363                 if (cache_tree_update(&the_index, 0))
 364                         return error(_("Unable to update cache tree\n"));
 365
 366         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.sha1);
 367 }
 368
 369 /*
 370  * If we are cherry-pick, and if the merge did not result in
 371  * hand-editing, we will hit this commit and inherit the original
 372  * author date and name.
 373  * If we are revert, or if our cherry-pick results in a hand merge,
 374  * we had better say that the current user is responsible for that.
 375  */
 376 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 377                           int allow_empty)
 378 {
 379         struct argv_array array;
 380         int rc;
 381         const char *value;
 382
 383         argv_array_init(&array);
 384         argv_array_push(&array, "commit");
 385         argv_array_push(&array, "-n");
 386
 387         if (opts->gpg_sign)
 388                 argv_array_pushf(&array, "-S%s", opts->gpg_sign);
 389         if (opts->signoff)
 390                 argv_array_push(&array, "-s");
 391         if (!opts->edit) {
 392                 argv_array_push(&array, "-F");
 393                 argv_array_push(&array, defmsg);
 394                 if (!opts->signoff &&
 395                     !opts->record_origin &&
 396                     git_config_get_value("commit.cleanup", &value))
 397                         argv_array_push(&array, "--cleanup=verbatim");
 398         }
 399
 400         if (allow_empty)
 401                 argv_array_push(&array, "--allow-empty");
 402
 403         if (opts->allow_empty_message)
 404                 argv_array_push(&array, "--allow-empty-message");
 405
 406         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 407         argv_array_clear(&array);
 408         return rc;
 409 }
 410
 411 static int is_original_commit_empty(struct commit *commit)
 412 {
 413         const unsigned char *ptree_sha1;
 414
 415         if (parse_commit(commit))
 416                 return error(_("Could not parse commit %s\n"),
 417                              sha1_to_hex(commit->object.sha1));
 418         if (commit->parents) {
 419                 struct commit *parent = commit->parents->item;
 420                 if (parse_commit(parent))
 421                         return error(_("Could not parse parent commit %s\n"),
 422                                 sha1_to_hex(parent->object.sha1));
 423                 ptree_sha1 = parent->tree->object.sha1;
 424         } else {
 425                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 426         }
 427
 428         return !hashcmp(ptree_sha1, commit->tree->object.sha1);
 429 }
 430
 431 /*
 432  * Do we run "git commit" with "--allow-empty"?
 433  */
 434 static int allow_empty(struct replay_opts *opts, struct commit *commit)
 435 {
 436         int index_unchanged, empty_commit;
 437
 438         /*
 439          * Three cases:
 440          *
 441          * (1) we do not allow empty at all and error out.
 442          *
 443          * (2) we allow ones that were initially empty, but
 444          * forbid the ones that become empty;
 445          *
 446          * (3) we allow both.
 447          */
 448         if (!opts->allow_empty)
 449                 return 0; /* let "git commit" barf as necessary */
 450
 451         index_unchanged = is_index_unchanged();
 452         if (index_unchanged < 0)
 453                 return index_unchanged;
 454         if (!index_unchanged)
 455                 return 0; /* we do not have to say --allow-empty */
 456
 457         if (opts->keep_redundant_commits)
 458                 return 1;
 459
 460         empty_commit = is_original_commit_empty(commit);
 461         if (empty_commit < 0)
 462                 return empty_commit;
 463         if (!empty_commit)
 464                 return 0;
 465         else
 466                 return 1;
 467 }
 468
 469 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 470 {
 471         unsigned char head[20];
 472         struct commit *base, *next, *parent;
 473         const char *base_label, *next_label;
 474         struct commit_message msg = { NULL, NULL, NULL, NULL };
 475         struct strbuf msgbuf = STRBUF_INIT;
 476         int res, unborn = 0, allow;
 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                 unborn = get_sha1("HEAD", head);
 489                 if (unborn)
 490                         hashcpy(head, EMPTY_TREE_SHA1_BIN);
 491                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
 492                         return error_dirty_index(opts);
 493         }
 494         discard_cache();
 495
 496         if (!commit->parents) {
 497                 parent = NULL;
 498         }
 499         else if (commit->parents->next) {
 500                 /* Reverting or cherry-picking a merge commit */
 501                 int cnt;
 502                 struct commit_list *p;
 503
 504                 if (!opts->mainline)
 505                         return error(_("Commit %s is a merge but no -m option was given."),
 506                                 sha1_to_hex(commit->object.sha1));
 507
 508                 for (cnt = 1, p = commit->parents;
 509                      cnt != opts->mainline && p;
 510                      cnt++)
 511                         p = p->next;
 512                 if (cnt != opts->mainline || !p)
 513                         return error(_("Commit %s does not have parent %d"),
 514                                 sha1_to_hex(commit->object.sha1), opts->mainline);
 515                 parent = p->item;
 516         } else if (0 < opts->mainline)
 517                 return error(_("Mainline was specified but commit %s is not a merge."),
 518                         sha1_to_hex(commit->object.sha1));
 519         else
 520                 parent = commit->parents->item;
 521
 522         if (opts->allow_ff &&
 523             ((parent && !hashcmp(parent->object.sha1, head)) ||
 524              (!parent && unborn)))
 525                 return fast_forward_to(commit->object.sha1, head, unborn, opts);
 526
 527         if (parent && parse_commit(parent) < 0)
 528                 /* TRANSLATORS: The first %s will be "revert" or
 529                    "cherry-pick", the second %s a SHA1 */
 530                 return error(_("%s: cannot parse parent commit %s"),
 531                         action_name(opts), sha1_to_hex(parent->object.sha1));
 532
 533         if (get_message(commit, &msg) != 0)
 534                 return error(_("Cannot get commit message for %s"),
 535                         sha1_to_hex(commit->object.sha1));
 536
 537         /*
 538          * "commit" is an existing commit.  We would want to apply
 539          * the difference it introduces since its first parent "prev"
 540          * on top of the current HEAD if we are cherry-pick.  Or the
 541          * reverse of it if we are revert.
 542          */
 543
 544         if (opts->action == REPLAY_REVERT) {
 545                 base = commit;
 546                 base_label = msg.label;
 547                 next = parent;
 548                 next_label = msg.parent_label;
 549                 strbuf_addstr(&msgbuf, "Revert \"");
 550                 strbuf_addstr(&msgbuf, msg.subject);
 551                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 552                 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 553
 554                 if (commit->parents && commit->parents->next) {
 555                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 556                         strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
 557                 }
 558                 strbuf_addstr(&msgbuf, ".\n");
 559         } else {
 560                 const char *p;
 561
 562                 base = parent;
 563                 base_label = msg.parent_label;
 564                 next = commit;
 565                 next_label = msg.label;
 566
 567                 /*
 568                  * Append the commit log message to msgbuf; it starts
 569                  * after the tree, parent, author, committer
 570                  * information followed by "\n\n".
 571                  */
 572                 p = strstr(msg.message, "\n\n");
 573                 if (p) {
 574                         p += 2;
 575                         strbuf_addstr(&msgbuf, p);
 576                 }
 577
 578                 if (opts->record_origin) {
 579                         if (!has_conforming_footer(&msgbuf, NULL, 0))
 580                                 strbuf_addch(&msgbuf, '\n');
 581                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
 582                         strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 583                         strbuf_addstr(&msgbuf, ")\n");
 584                 }
 585         }
 586
 587         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 588                 res = do_recursive_merge(base, next, base_label, next_label,
 589                                          head, &msgbuf, opts);
 590                 write_message(&msgbuf, git_path_merge_msg());
 591         } else {
 592                 struct commit_list *common = NULL;
 593                 struct commit_list *remotes = NULL;
 594
 595                 write_message(&msgbuf, git_path_merge_msg());
 596
 597                 commit_list_insert(base, &common);
 598                 commit_list_insert(next, &remotes);
 599                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 600                                         common, sha1_to_hex(head), remotes);
 601                 free_commit_list(common);
 602                 free_commit_list(remotes);
 603         }
 604
 605         /*
 606          * If the merge was clean or if it failed due to conflict, we write
 607          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 608          * However, if the merge did not even start, then we don't want to
 609          * write it at all.
 610          */
 611         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 612                 write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
 613         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 614                 write_cherry_pick_head(commit, "REVERT_HEAD");
 615
 616         if (res) {
 617                 error(opts->action == REPLAY_REVERT
 618                       ? _("could not revert %s... %s")
 619                       : _("could not apply %s... %s"),
 620                       find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
 621                       msg.subject);
 622                 print_advice(res == 1, opts);
 623                 rerere(opts->allow_rerere_auto);
 624                 goto leave;
 625         }
 626
 627         allow = allow_empty(opts, commit);
 628         if (allow < 0) {
 629                 res = allow;
 630                 goto leave;
 631         }
 632         if (!opts->no_commit)
 633                 res = run_git_commit(git_path_merge_msg(), opts, allow);
 634
 635 leave:
 636         free_message(commit, &msg);
 637
 638         return res;
 639 }
 640
 641 static void prepare_revs(struct replay_opts *opts)
 642 {
 643         /*
 644          * picking (but not reverting) ranges (but not individual revisions)
 645          * should be done in reverse
 646          */
 647         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 648                 opts->revs->reverse ^= 1;
 649
 650         if (prepare_revision_walk(opts->revs))
 651                 die(_("revision walk setup failed"));
 652
 653         if (!opts->revs->commits)
 654                 die(_("empty commit set passed"));
 655 }
 656
 657 static void read_and_refresh_cache(struct replay_opts *opts)
 658 {
 659         static struct lock_file index_lock;
 660         int index_fd = hold_locked_index(&index_lock, 0);
 661         if (read_index_preload(&the_index, NULL) < 0)
 662                 die(_("git %s: failed to read the index"), action_name(opts));
 663         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 664         if (the_index.cache_changed && index_fd >= 0) {
 665                 if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
 666                         die(_("git %s: failed to refresh the index"), action_name(opts));
 667         }
 668         rollback_lock_file(&index_lock);
 669 }
 670
 671 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 672                 struct replay_opts *opts)
 673 {
 674         struct commit_list *cur = NULL;
 675         const char *sha1_abbrev = NULL;
 676         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 677         const char *subject;
 678         int subject_len;
 679
 680         for (cur = todo_list; cur; cur = cur->next) {
 681                 const char *commit_buffer = get_commit_buffer(cur->item, NULL);
 682                 sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
 683                 subject_len = find_commit_subject(commit_buffer, &subject);
 684                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 685                         subject_len, subject);
 686                 unuse_commit_buffer(cur->item, commit_buffer);
 687         }
 688         return 0;
 689 }
 690
 691 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 692 {
 693         unsigned char commit_sha1[20];
 694         enum replay_action action;
 695         char *end_of_object_name;
 696         int saved, status, padding;
 697
 698         if (starts_with(bol, "pick")) {
 699                 action = REPLAY_PICK;
 700                 bol += strlen("pick");
 701         } else if (starts_with(bol, "revert")) {
 702                 action = REPLAY_REVERT;
 703                 bol += strlen("revert");
 704         } else
 705                 return NULL;
 706
 707         /* Eat up extra spaces/ tabs before object name */
 708         padding = strspn(bol, " \t");
 709         if (!padding)
 710                 return NULL;
 711         bol += padding;
 712
 713         end_of_object_name = bol + strcspn(bol, " \t\n");
 714         saved = *end_of_object_name;
 715         *end_of_object_name = '\0';
 716         status = get_sha1(bol, commit_sha1);
 717         *end_of_object_name = saved;
 718
 719         /*
 720          * Verify that the action matches up with the one in
 721          * opts; we don't support arbitrary instructions
 722          */
 723         if (action != opts->action) {
 724                 const char *action_str;
 725                 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
 726                 error(_("Cannot %s during a %s"), action_str, action_name(opts));
 727                 return NULL;
 728         }
 729
 730         if (status < 0)
 731                 return NULL;
 732
 733         return lookup_commit_reference(commit_sha1);
 734 }
 735
 736 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
 737                         struct replay_opts *opts)
 738 {
 739         struct commit_list **next = todo_list;
 740         struct commit *commit;
 741         char *p = buf;
 742         int i;
 743
 744         for (i = 1; *p; i++) {
 745                 char *eol = strchrnul(p, '\n');
 746                 commit = parse_insn_line(p, eol, opts);
 747                 if (!commit)
 748                         return error(_("Could not parse line %d."), i);
 749                 next = commit_list_append(commit, next);
 750                 p = *eol ? eol + 1 : eol;
 751         }
 752         if (!*todo_list)
 753                 return error(_("No commits parsed."));
 754         return 0;
 755 }
 756
 757 static void read_populate_todo(struct commit_list **todo_list,
 758                         struct replay_opts *opts)
 759 {
 760         struct strbuf buf = STRBUF_INIT;
 761         int fd, res;
 762
 763         fd = open(git_path_todo_file(), O_RDONLY);
 764         if (fd < 0)
 765                 die_errno(_("Could not open %s"), git_path_todo_file());
 766         if (strbuf_read(&buf, fd, 0) < 0) {
 767                 close(fd);
 768                 strbuf_release(&buf);
 769                 die(_("Could not read %s."), git_path_todo_file());
 770         }
 771         close(fd);
 772
 773         res = parse_insn_buffer(buf.buf, todo_list, opts);
 774         strbuf_release(&buf);
 775         if (res)
 776                 die(_("Unusable instruction sheet: %s"), git_path_todo_file());
 777 }
 778
 779 static int populate_opts_cb(const char *key, const char *value, void *data)
 780 {
 781         struct replay_opts *opts = data;
 782         int error_flag = 1;
 783
 784         if (!value)
 785                 error_flag = 0;
 786         else if (!strcmp(key, "options.no-commit"))
 787                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 788         else if (!strcmp(key, "options.edit"))
 789                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
 790         else if (!strcmp(key, "options.signoff"))
 791                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 792         else if (!strcmp(key, "options.record-origin"))
 793                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 794         else if (!strcmp(key, "options.allow-ff"))
 795                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 796         else if (!strcmp(key, "options.mainline"))
 797                 opts->mainline = git_config_int(key, value);
 798         else if (!strcmp(key, "options.strategy"))
 799                 git_config_string(&opts->strategy, key, value);
 800         else if (!strcmp(key, "options.gpg-sign"))
 801                 git_config_string(&opts->gpg_sign, key, value);
 802         else if (!strcmp(key, "options.strategy-option")) {
 803                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 804                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
 805         } else
 806                 return error(_("Invalid key: %s"), key);
 807
 808         if (!error_flag)
 809                 return error(_("Invalid value for %s: %s"), key, value);
 810
 811         return 0;
 812 }
 813
 814 static void read_populate_opts(struct replay_opts **opts_ptr)
 815 {
 816         if (!file_exists(git_path_opts_file()))
 817                 return;
 818         if (git_config_from_file(populate_opts_cb, git_path_opts_file(), *opts_ptr) < 0)
 819                 die(_("Malformed options sheet: %s"), git_path_opts_file());
 820 }
 821
 822 static void walk_revs_populate_todo(struct commit_list **todo_list,
 823                                 struct replay_opts *opts)
 824 {
 825         struct commit *commit;
 826         struct commit_list **next;
 827
 828         prepare_revs(opts);
 829
 830         next = todo_list;
 831         while ((commit = get_revision(opts->revs)))
 832                 next = commit_list_append(commit, next);
 833 }
 834
 835 static int create_seq_dir(void)
 836 {
 837         if (file_exists(git_path_seq_dir())) {
 838                 error(_("a cherry-pick or revert is already in progress"));
 839                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 840                 return -1;
 841         }
 842         else if (mkdir(git_path_seq_dir(), 0777) < 0)
 843                 die_errno(_("Could not create sequencer directory %s"),
 844                           git_path_seq_dir());
 845         return 0;
 846 }
 847
 848 static void save_head(const char *head)
 849 {
 850         static struct lock_file head_lock;
 851         struct strbuf buf = STRBUF_INIT;
 852         int fd;
 853
 854         fd = hold_lock_file_for_update(&head_lock, git_path_head_file(), LOCK_DIE_ON_ERROR);
 855         strbuf_addf(&buf, "%s\n", head);
 856         if (write_in_full(fd, buf.buf, buf.len) < 0)
 857                 die_errno(_("Could not write to %s"), git_path_head_file());
 858         if (commit_lock_file(&head_lock) < 0)
 859                 die(_("Error wrapping up %s."), git_path_head_file());
 860 }
 861
 862 static int reset_for_rollback(const unsigned char *sha1)
 863 {
 864         const char *argv[4];    /* reset --merge <arg> + NULL */
 865         argv[0] = "reset";
 866         argv[1] = "--merge";
 867         argv[2] = sha1_to_hex(sha1);
 868         argv[3] = NULL;
 869         return run_command_v_opt(argv, RUN_GIT_CMD);
 870 }
 871
 872 static int rollback_single_pick(void)
 873 {
 874         unsigned char head_sha1[20];
 875
 876         if (!file_exists(git_path_cherry_pick_head()) &&
 877             !file_exists(git_path_revert_head()))
 878                 return error(_("no cherry-pick or revert in progress"));
 879         if (read_ref_full("HEAD", 0, head_sha1, NULL))
 880                 return error(_("cannot resolve HEAD"));
 881         if (is_null_sha1(head_sha1))
 882                 return error(_("cannot abort from a branch yet to be born"));
 883         return reset_for_rollback(head_sha1);
 884 }
 885
 886 static int sequencer_rollback(struct replay_opts *opts)
 887 {
 888         FILE *f;
 889         unsigned char sha1[20];
 890         struct strbuf buf = STRBUF_INIT;
 891
 892         f = fopen(git_path_head_file(), "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"), git_path_head_file(),
 903                                                 strerror(errno));
 904         if (strbuf_getline(&buf, f, '\n')) {
 905                 error(_("cannot read %s: %s"), git_path_head_file(),
 906                       ferror(f) ?  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                         git_path_head_file());
 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         static struct lock_file todo_lock;
 929         struct strbuf buf = STRBUF_INIT;
 930         int fd;
 931
 932         fd = hold_lock_file_for_update(&todo_lock, git_path_todo_file(), LOCK_DIE_ON_ERROR);
 933         if (format_todo(&buf, todo_list, opts) < 0)
 934                 die(_("Could not format %s."), git_path_todo_file());
 935         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 936                 strbuf_release(&buf);
 937                 die_errno(_("Could not write to %s"), git_path_todo_file());
 938         }
 939         if (commit_lock_file(&todo_lock) < 0) {
 940                 strbuf_release(&buf);
 941                 die(_("Error wrapping up %s."), git_path_todo_file());
 942         }
 943         strbuf_release(&buf);
 944 }
 945
 946 static void save_opts(struct replay_opts *opts)
 947 {
 948         const char *opts_file = git_path_opts_file();
 949
 950         if (opts->no_commit)
 951                 git_config_set_in_file(opts_file, "options.no-commit", "true");
 952         if (opts->edit)
 953                 git_config_set_in_file(opts_file, "options.edit", "true");
 954         if (opts->signoff)
 955                 git_config_set_in_file(opts_file, "options.signoff", "true");
 956         if (opts->record_origin)
 957                 git_config_set_in_file(opts_file, "options.record-origin", "true");
 958         if (opts->allow_ff)
 959                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
 960         if (opts->mainline) {
 961                 struct strbuf buf = STRBUF_INIT;
 962                 strbuf_addf(&buf, "%d", opts->mainline);
 963                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
 964                 strbuf_release(&buf);
 965         }
 966         if (opts->strategy)
 967                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
 968         if (opts->gpg_sign)
 969                 git_config_set_in_file(opts_file, "options.gpg-sign", opts->gpg_sign);
 970         if (opts->xopts) {
 971                 int i;
 972                 for (i = 0; i < opts->xopts_nr; i++)
 973                         git_config_set_multivar_in_file(opts_file,
 974                                                         "options.strategy-option",
 975                                                         opts->xopts[i], "^$", 0);
 976         }
 977 }
 978
 979 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
 980 {
 981         struct commit_list *cur;
 982         int res;
 983
 984         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
 985         if (opts->allow_ff)
 986                 assert(!(opts->signoff || opts->no_commit ||
 987                                 opts->record_origin || opts->edit));
 988         read_and_refresh_cache(opts);
 989
 990         for (cur = todo_list; cur; cur = cur->next) {
 991                 save_todo(cur, opts);
 992                 res = do_pick_commit(cur->item, opts);
 993                 if (res)
 994                         return res;
 995         }
 996
 997         /*
 998          * Sequence of picks finished successfully; cleanup by
 999          * removing the .git/sequencer directory
1000          */
1001         remove_sequencer_state();
1002         return 0;
1003 }
1004
1005 static int continue_single_pick(void)
1006 {
1007         const char *argv[] = { "commit", NULL };
1008
1009         if (!file_exists(git_path_cherry_pick_head()) &&
1010             !file_exists(git_path_revert_head()))
1011                 return error(_("no cherry-pick or revert in progress"));
1012         return run_command_v_opt(argv, RUN_GIT_CMD);
1013 }
1014
1015 static int sequencer_continue(struct replay_opts *opts)
1016 {
1017         struct commit_list *todo_list = NULL;
1018
1019         if (!file_exists(git_path_todo_file()))
1020                 return continue_single_pick();
1021         read_populate_opts(&opts);
1022         read_populate_todo(&todo_list, opts);
1023
1024         /* Verify that the conflict has been resolved */
1025         if (file_exists(git_path_cherry_pick_head()) ||
1026             file_exists(git_path_revert_head())) {
1027                 int ret = continue_single_pick();
1028                 if (ret)
1029                         return ret;
1030         }
1031         if (index_differs_from("HEAD", 0))
1032                 return error_dirty_index(opts);
1033         todo_list = todo_list->next;
1034         return pick_commits(todo_list, opts);
1035 }
1036
1037 static int single_pick(struct commit *cmit, struct replay_opts *opts)
1038 {
1039         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1040         return do_pick_commit(cmit, opts);
1041 }
1042
1043 int sequencer_pick_revisions(struct replay_opts *opts)
1044 {
1045         struct commit_list *todo_list = NULL;
1046         unsigned char sha1[20];
1047         int i;
1048
1049         if (opts->subcommand == REPLAY_NONE)
1050                 assert(opts->revs);
1051
1052         read_and_refresh_cache(opts);
1053
1054         /*
1055          * Decide what to do depending on the arguments; a fresh
1056          * cherry-pick should be handled differently from an existing
1057          * one that is being continued
1058          */
1059         if (opts->subcommand == REPLAY_REMOVE_STATE) {
1060                 remove_sequencer_state();
1061                 return 0;
1062         }
1063         if (opts->subcommand == REPLAY_ROLLBACK)
1064                 return sequencer_rollback(opts);
1065         if (opts->subcommand == REPLAY_CONTINUE)
1066                 return sequencer_continue(opts);
1067
1068         for (i = 0; i < opts->revs->pending.nr; i++) {
1069                 unsigned char sha1[20];
1070                 const char *name = opts->revs->pending.objects[i].name;
1071
1072                 /* This happens when using --stdin. */
1073                 if (!strlen(name))
1074                         continue;
1075
1076                 if (!get_sha1(name, sha1)) {
1077                         if (!lookup_commit_reference_gently(sha1, 1)) {
1078                                 enum object_type type = sha1_object_info(sha1, NULL);
1079                                 die(_("%s: can't cherry-pick a %s"), name, typename(type));
1080                         }
1081                 } else
1082                         die(_("%s: bad revision"), name);
1083         }
1084
1085         /*
1086          * If we were called as "git cherry-pick <commit>", just
1087          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1088          * REVERT_HEAD, and don't touch the sequencer state.
1089          * This means it is possible to cherry-pick in the middle
1090          * of a cherry-pick sequence.
1091          */
1092         if (opts->revs->cmdline.nr == 1 &&
1093             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1094             opts->revs->no_walk &&
1095             !opts->revs->cmdline.rev->flags) {
1096                 struct commit *cmit;
1097                 if (prepare_revision_walk(opts->revs))
1098                         die(_("revision walk setup failed"));
1099                 cmit = get_revision(opts->revs);
1100                 if (!cmit || get_revision(opts->revs))
1101                         die("BUG: expected exactly one commit from walk");
1102                 return single_pick(cmit, opts);
1103         }
1104
1105         /*
1106          * Start a new cherry-pick/ revert sequence; but
1107          * first, make sure that an existing one isn't in
1108          * progress
1109          */
1110
1111         walk_revs_populate_todo(&todo_list, opts);
1112         if (create_seq_dir() < 0)
1113                 return -1;
1114         if (get_sha1("HEAD", sha1)) {
1115                 if (opts->action == REPLAY_REVERT)
1116                         return error(_("Can't revert as initial commit"));
1117                 return error(_("Can't cherry-pick into empty head"));
1118         }
1119         save_head(sha1_to_hex(sha1));
1120         save_opts(opts);
1121         return pick_commits(todo_list, opts);
1122 }
1123
1124 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1125 {
1126         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1127         struct strbuf sob = STRBUF_INIT;
1128         int has_footer;
1129
1130         strbuf_addstr(&sob, sign_off_header);
1131         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1132                                 getenv("GIT_COMMITTER_EMAIL")));
1133         strbuf_addch(&sob, '\n');
1134
1135         /*
1136          * If the whole message buffer is equal to the sob, pretend that we
1137          * found a conforming footer with a matching sob
1138          */
1139         if (msgbuf->len - ignore_footer == sob.len &&
1140             !strncmp(msgbuf->buf, sob.buf, sob.len))
1141                 has_footer = 3;
1142         else
1143                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1144
1145         if (!has_footer) {
1146                 const char *append_newlines = NULL;
1147                 size_t len = msgbuf->len - ignore_footer;
1148
1149                 if (!len) {
1150                         /*
1151                          * The buffer is completely empty.  Leave foom for
1152                          * the title and body to be filled in by the user.
1153                          */
1154                         append_newlines = "\n\n";
1155                 } else if (msgbuf->buf[len - 1] != '\n') {
1156                         /*
1157                          * Incomplete line.  Complete the line and add a
1158                          * blank one so that there is an empty line between
1159                          * the message body and the sob.
1160                          */
1161                         append_newlines = "\n\n";
1162                 } else if (len == 1) {
1163                         /*
1164                          * Buffer contains a single newline.  Add another
1165                          * so that we leave room for the title and body.
1166                          */
1167                         append_newlines = "\n";
1168                 } else if (msgbuf->buf[len - 2] != '\n') {
1169                         /*
1170                          * Buffer ends with a single newline.  Add another
1171                          * so that there is an empty line between the message
1172                          * body and the sob.
1173                          */
1174                         append_newlines = "\n";
1175                 } /* else, the buffer already ends with two newlines. */
1176
1177                 if (append_newlines)
1178                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1179                                 append_newlines, strlen(append_newlines));
1180         }
1181
1182         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1183                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1184                                 sob.buf, sob.len);
1185
1186         strbuf_release(&sob);
1187 }