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

   1 #include "cache.h"
   2 #include "sequencer.h"
   3 #include "dir.h"
   4 #include "object.h"
   5 #include "commit.h"
   6 #include "tag.h"
   7 #include "run-command.h"
   8 #include "exec_cmd.h"
   9 #include "utf8.h"
  10 #include "cache-tree.h"
  11 #include "diff.h"
  12 #include "revision.h"
  13 #include "rerere.h"
  14 #include "merge-recursive.h"
  15 #include "refs.h"
  16 #include "argv-array.h"
  17
  18 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
  19
  20 const char sign_off_header[] = "Signed-off-by: ";
  21 static const char cherry_picked_prefix[] = "(cherry picked from commit ";
  22
  23 static int is_rfc2822_line(const char *buf, int len)
  24 {
  25         int i;
  26
  27         for (i = 0; i < len; i++) {
  28                 int ch = buf[i];
  29                 if (ch == ':')
  30                         return 1;
  31                 if (!isalnum(ch) && ch != '-')
  32                         break;
  33         }
  34
  35         return 0;
  36 }
  37
  38 static int is_cherry_picked_from_line(const char *buf, int len)
  39 {
  40         /*
  41          * We only care that it looks roughly like (cherry picked from ...)
  42          */
  43         return len > strlen(cherry_picked_prefix) + 1 &&
  44                 starts_with(buf, cherry_picked_prefix) && buf[len - 1] == ')';
  45 }
  46
  47 /*
  48  * Returns 0 for non-conforming footer
  49  * Returns 1 for conforming footer
  50  * Returns 2 when sob exists within conforming footer
  51  * Returns 3 when sob exists within conforming footer as last entry
  52  */
  53 static int has_conforming_footer(struct strbuf *sb, struct strbuf *sob,
  54         int ignore_footer)
  55 {
  56         char prev;
  57         int i, k;
  58         int len = sb->len - ignore_footer;
  59         const char *buf = sb->buf;
  60         int found_sob = 0;
  61
  62         /* footer must end with newline */
  63         if (!len || buf[len - 1] != '\n')
  64                 return 0;
  65
  66         prev = '\0';
  67         for (i = len - 1; i > 0; i--) {
  68                 char ch = buf[i];
  69                 if (prev == '\n' && ch == '\n') /* paragraph break */
  70                         break;
  71                 prev = ch;
  72         }
  73
  74         /* require at least one blank line */
  75         if (prev != '\n' || buf[i] != '\n')
  76                 return 0;
  77
  78         /* advance to start of last paragraph */
  79         while (i < len - 1 && buf[i] == '\n')
  80                 i++;
  81
  82         for (; i < len; i = k) {
  83                 int found_rfc2822;
  84
  85                 for (k = i; k < len && buf[k] != '\n'; k++)
  86                         ; /* do nothing */
  87                 k++;
  88
  89                 found_rfc2822 = is_rfc2822_line(buf + i, k - i - 1);
  90                 if (found_rfc2822 && sob &&
  91                     !strncmp(buf + i, sob->buf, sob->len))
  92                         found_sob = k;
  93
  94                 if (!(found_rfc2822 ||
  95                       is_cherry_picked_from_line(buf + i, k - i - 1)))
  96                         return 0;
  97         }
  98         if (found_sob == i)
  99                 return 3;
 100         if (found_sob)
 101                 return 2;
 102         return 1;
 103 }
 104
 105 static void remove_sequencer_state(void)
 106 {
 107         struct strbuf seq_dir = STRBUF_INIT;
 108
 109         strbuf_addf(&seq_dir, "%s", git_path(SEQ_DIR));
 110         remove_dir_recursively(&seq_dir, 0);
 111         strbuf_release(&seq_dir);
 112 }
 113
 114 static const char *action_name(const struct replay_opts *opts)
 115 {
 116         return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
 117 }
 118
 119 static char *get_encoding(const char *message);
 120
 121 struct commit_message {
 122         char *parent_label;
 123         const char *label;
 124         const char *subject;
 125         char *reencoded_message;
 126         const char *message;
 127 };
 128
 129 static int get_message(struct commit *commit, struct commit_message *out)
 130 {
 131         const char *encoding;
 132         const char *abbrev, *subject;
 133         int abbrev_len, subject_len;
 134         char *q;
 135
 136         if (!commit->buffer)
 137                 return -1;
 138         encoding = get_encoding(commit->buffer);
 139         if (!encoding)
 140                 encoding = "UTF-8";
 141         if (!git_commit_encoding)
 142                 git_commit_encoding = "UTF-8";
 143
 144         out->reencoded_message = NULL;
 145         out->message = commit->buffer;
 146         if (same_encoding(encoding, git_commit_encoding))
 147                 out->reencoded_message = reencode_string(commit->buffer,
 148                                         git_commit_encoding, encoding);
 149         if (out->reencoded_message)
 150                 out->message = out->reencoded_message;
 151
 152         abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
 153         abbrev_len = strlen(abbrev);
 154
 155         subject_len = find_commit_subject(out->message, &subject);
 156
 157         out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
 158                               strlen("... ") + subject_len + 1);
 159         q = out->parent_label;
 160         q = mempcpy(q, "parent of ", strlen("parent of "));
 161         out->label = q;
 162         q = mempcpy(q, abbrev, abbrev_len);
 163         q = mempcpy(q, "... ", strlen("... "));
 164         out->subject = q;
 165         q = mempcpy(q, subject, subject_len);
 166         *q = '\0';
 167         return 0;
 168 }
 169
 170 static void free_message(struct commit_message *msg)
 171 {
 172         free(msg->parent_label);
 173         free(msg->reencoded_message);
 174 }
 175
 176 static char *get_encoding(const char *message)
 177 {
 178         const char *p = message, *eol;
 179
 180         while (*p && *p != '\n') {
 181                 for (eol = p + 1; *eol && *eol != '\n'; eol++)
 182                         ; /* do nothing */
 183                 if (starts_with(p, "encoding ")) {
 184                         char *result = xmalloc(eol - 8 - p);
 185                         strlcpy(result, p + 9, eol - 8 - p);
 186                         return result;
 187                 }
 188                 p = eol;
 189                 if (*p == '\n')
 190                         p++;
 191         }
 192         return NULL;
 193 }
 194
 195 static void write_cherry_pick_head(struct commit *commit, const char *pseudoref)
 196 {
 197         const char *filename;
 198         int fd;
 199         struct strbuf buf = STRBUF_INIT;
 200
 201         strbuf_addf(&buf, "%s\n", sha1_to_hex(commit->object.sha1));
 202
 203         filename = git_path("%s", pseudoref);
 204         fd = open(filename, O_WRONLY | O_CREAT, 0666);
 205         if (fd < 0)
 206                 die_errno(_("Could not open '%s' for writing"), filename);
 207         if (write_in_full(fd, buf.buf, buf.len) != buf.len || close(fd))
 208                 die_errno(_("Could not write to '%s'"), filename);
 209         strbuf_release(&buf);
 210 }
 211
 212 static void print_advice(int show_hint, struct replay_opts *opts)
 213 {
 214         char *msg = getenv("GIT_CHERRY_PICK_HELP");
 215
 216         if (msg) {
 217                 fprintf(stderr, "%s\n", msg);
 218                 /*
 219                  * A conflict has occurred but the porcelain
 220                  * (typically rebase --interactive) wants to take care
 221                  * of the commit itself so remove CHERRY_PICK_HEAD
 222                  */
 223                 unlink(git_path("CHERRY_PICK_HEAD"));
 224                 return;
 225         }
 226
 227         if (show_hint) {
 228                 if (opts->no_commit)
 229                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 230                                  "with 'git add <paths>' or 'git rm <paths>'"));
 231                 else
 232                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 233                                  "with 'git add <paths>' or 'git rm <paths>'\n"
 234                                  "and commit the result with 'git commit'"));
 235         }
 236 }
 237
 238 static void write_message(struct strbuf *msgbuf, const char *filename)
 239 {
 240         static struct lock_file msg_file;
 241
 242         int msg_fd = hold_lock_file_for_update(&msg_file, filename,
 243                                                LOCK_DIE_ON_ERROR);
 244         if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
 245                 die_errno(_("Could not write to %s"), filename);
 246         strbuf_release(msgbuf);
 247         if (commit_lock_file(&msg_file) < 0)
 248                 die(_("Error wrapping up %s"), filename);
 249 }
 250
 251 static struct tree *empty_tree(void)
 252 {
 253         return lookup_tree(EMPTY_TREE_SHA1_BIN);
 254 }
 255
 256 static int error_dirty_index(struct replay_opts *opts)
 257 {
 258         if (read_cache_unmerged())
 259                 return error_resolve_conflict(action_name(opts));
 260
 261         /* Different translation strings for cherry-pick and revert */
 262         if (opts->action == REPLAY_PICK)
 263                 error(_("Your local changes would be overwritten by cherry-pick."));
 264         else
 265                 error(_("Your local changes would be overwritten by revert."));
 266
 267         if (advice_commit_before_merge)
 268                 advise(_("Commit your changes or stash them to proceed."));
 269         return -1;
 270 }
 271
 272 static int fast_forward_to(const unsigned char *to, const unsigned char *from,
 273                         int unborn, struct replay_opts *opts)
 274 {
 275         struct ref_transaction *transaction;
 276         struct strbuf sb = STRBUF_INIT;
 277         struct strbuf err = STRBUF_INIT;
 278
 279         read_cache();
 280         if (checkout_fast_forward(from, to, 1))
 281                 exit(1); /* the callee should have complained already */
 282
 283         strbuf_addf(&sb, "%s: fast-forward", action_name(opts));
 284
 285         transaction = ref_transaction_begin(&err);
 286         if (!transaction ||
 287             ref_transaction_update(transaction, "HEAD",
 288                                    to, unborn ? null_sha1 : from,
 289                                    0, 1, &err) ||
 290             ref_transaction_commit(transaction, sb.buf, &err)) {
 291                 ref_transaction_free(transaction);
 292                 error("%s", err.buf);
 293                 strbuf_release(&sb);
 294                 strbuf_release(&err);
 295                 return -1;
 296         }
 297
 298         strbuf_release(&sb);
 299         strbuf_release(&err);
 300         ref_transaction_free(transaction);
 301         return 0;
 302 }
 303
 304 static int do_recursive_merge(struct commit *base, struct commit *next,
 305                               const char *base_label, const char *next_label,
 306                               unsigned char *head, struct strbuf *msgbuf,
 307                               struct replay_opts *opts)
 308 {
 309         struct merge_options o;
 310         struct tree *result, *next_tree, *base_tree, *head_tree;
 311         int clean, index_fd;
 312         const char **xopt;
 313         static struct lock_file index_lock;
 314
 315         index_fd = hold_locked_index(&index_lock, 1);
 316
 317         read_cache();
 318
 319         init_merge_options(&o);
 320         o.ancestor = base ? base_label : "(empty tree)";
 321         o.branch1 = "HEAD";
 322         o.branch2 = next ? next_label : "(empty tree)";
 323
 324         head_tree = parse_tree_indirect(head);
 325         next_tree = next ? next->tree : empty_tree();
 326         base_tree = base ? base->tree : empty_tree();
 327
 328         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 329                 parse_merge_opt(&o, *xopt);
 330
 331         clean = merge_trees(&o,
 332                             head_tree,
 333                             next_tree, base_tree, &result);
 334
 335         if (active_cache_changed &&
 336             (write_cache(index_fd, active_cache, active_nr) ||
 337              commit_locked_index(&index_lock)))
 338                 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 339                 die(_("%s: Unable to write new index file"), action_name(opts));
 340         rollback_lock_file(&index_lock);
 341
 342         if (opts->signoff)
 343                 append_signoff(msgbuf, 0, 0);
 344
 345         if (!clean) {
 346                 int i;
 347                 strbuf_addstr(msgbuf, "\nConflicts:\n");
 348                 for (i = 0; i < active_nr;) {
 349                         const struct cache_entry *ce = active_cache[i++];
 350                         if (ce_stage(ce)) {
 351                                 strbuf_addch(msgbuf, '\t');
 352                                 strbuf_addstr(msgbuf, ce->name);
 353                                 strbuf_addch(msgbuf, '\n');
 354                                 while (i < active_nr && !strcmp(ce->name,
 355                                                 active_cache[i]->name))
 356                                         i++;
 357                         }
 358                 }
 359         }
 360
 361         return !clean;
 362 }
 363
 364 static int is_index_unchanged(void)
 365 {
 366         unsigned char head_sha1[20];
 367         struct commit *head_commit;
 368
 369         if (!resolve_ref_unsafe("HEAD", head_sha1, 1, NULL))
 370                 return error(_("Could not resolve HEAD commit\n"));
 371
 372         head_commit = lookup_commit(head_sha1);
 373
 374         /*
 375          * If head_commit is NULL, check_commit, called from
 376          * lookup_commit, would have indicated that head_commit is not
 377          * a commit object already.  parse_commit() will return failure
 378          * without further complaints in such a case.  Otherwise, if
 379          * the commit is invalid, parse_commit() will complain.  So
 380          * there is nothing for us to say here.  Just return failure.
 381          */
 382         if (parse_commit(head_commit))
 383                 return -1;
 384
 385         if (!active_cache_tree)
 386                 active_cache_tree = cache_tree();
 387
 388         if (!cache_tree_fully_valid(active_cache_tree))
 389                 if (cache_tree_update(active_cache_tree,
 390                                       (const struct cache_entry * const *)active_cache,
 391                                       active_nr, 0))
 392                         return error(_("Unable to update cache tree\n"));
 393
 394         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.sha1);
 395 }
 396
 397 /*
 398  * If we are cherry-pick, and if the merge did not result in
 399  * hand-editing, we will hit this commit and inherit the original
 400  * author date and name.
 401  * If we are revert, or if our cherry-pick results in a hand merge,
 402  * we had better say that the current user is responsible for that.
 403  */
 404 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 405                           int allow_empty)
 406 {
 407         struct argv_array array;
 408         int rc;
 409         char *gpg_sign;
 410
 411         argv_array_init(&array);
 412         argv_array_push(&array, "commit");
 413         argv_array_push(&array, "-n");
 414
 415         if (opts->gpg_sign) {
 416                 gpg_sign = xmalloc(3 + strlen(opts->gpg_sign));
 417                 sprintf(gpg_sign, "-S%s", opts->gpg_sign);
 418                 argv_array_push(&array, gpg_sign);
 419                 free(gpg_sign);
 420         }
 421         if (opts->signoff)
 422                 argv_array_push(&array, "-s");
 423         if (!opts->edit) {
 424                 argv_array_push(&array, "-F");
 425                 argv_array_push(&array, defmsg);
 426         }
 427
 428         if (allow_empty)
 429                 argv_array_push(&array, "--allow-empty");
 430
 431         if (opts->allow_empty_message)
 432                 argv_array_push(&array, "--allow-empty-message");
 433
 434         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 435         argv_array_clear(&array);
 436         return rc;
 437 }
 438
 439 static int is_original_commit_empty(struct commit *commit)
 440 {
 441         const unsigned char *ptree_sha1;
 442
 443         if (parse_commit(commit))
 444                 return error(_("Could not parse commit %s\n"),
 445                              sha1_to_hex(commit->object.sha1));
 446         if (commit->parents) {
 447                 struct commit *parent = commit->parents->item;
 448                 if (parse_commit(parent))
 449                         return error(_("Could not parse parent commit %s\n"),
 450                                 sha1_to_hex(parent->object.sha1));
 451                 ptree_sha1 = parent->tree->object.sha1;
 452         } else {
 453                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 454         }
 455
 456         return !hashcmp(ptree_sha1, commit->tree->object.sha1);
 457 }
 458
 459 /*
 460  * Do we run "git commit" with "--allow-empty"?
 461  */
 462 static int allow_empty(struct replay_opts *opts, struct commit *commit)
 463 {
 464         int index_unchanged, empty_commit;
 465
 466         /*
 467          * Three cases:
 468          *
 469          * (1) we do not allow empty at all and error out.
 470          *
 471          * (2) we allow ones that were initially empty, but
 472          * forbid the ones that become empty;
 473          *
 474          * (3) we allow both.
 475          */
 476         if (!opts->allow_empty)
 477                 return 0; /* let "git commit" barf as necessary */
 478
 479         index_unchanged = is_index_unchanged();
 480         if (index_unchanged < 0)
 481                 return index_unchanged;
 482         if (!index_unchanged)
 483                 return 0; /* we do not have to say --allow-empty */
 484
 485         if (opts->keep_redundant_commits)
 486                 return 1;
 487
 488         empty_commit = is_original_commit_empty(commit);
 489         if (empty_commit < 0)
 490                 return empty_commit;
 491         if (!empty_commit)
 492                 return 0;
 493         else
 494                 return 1;
 495 }
 496
 497 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 498 {
 499         unsigned char head[20];
 500         struct commit *base, *next, *parent;
 501         const char *base_label, *next_label;
 502         struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
 503         char *defmsg = NULL;
 504         struct strbuf msgbuf = STRBUF_INIT;
 505         int res, unborn = 0, allow;
 506
 507         if (opts->no_commit) {
 508                 /*
 509                  * We do not intend to commit immediately.  We just want to
 510                  * merge the differences in, so let's compute the tree
 511                  * that represents the "current" state for merge-recursive
 512                  * to work on.
 513                  */
 514                 if (write_cache_as_tree(head, 0, NULL))
 515                         die (_("Your index file is unmerged."));
 516         } else {
 517                 unborn = get_sha1("HEAD", head);
 518                 if (unborn)
 519                         hashcpy(head, EMPTY_TREE_SHA1_BIN);
 520                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
 521                         return error_dirty_index(opts);
 522         }
 523         discard_cache();
 524
 525         if (!commit->parents) {
 526                 parent = NULL;
 527         }
 528         else if (commit->parents->next) {
 529                 /* Reverting or cherry-picking a merge commit */
 530                 int cnt;
 531                 struct commit_list *p;
 532
 533                 if (!opts->mainline)
 534                         return error(_("Commit %s is a merge but no -m option was given."),
 535                                 sha1_to_hex(commit->object.sha1));
 536
 537                 for (cnt = 1, p = commit->parents;
 538                      cnt != opts->mainline && p;
 539                      cnt++)
 540                         p = p->next;
 541                 if (cnt != opts->mainline || !p)
 542                         return error(_("Commit %s does not have parent %d"),
 543                                 sha1_to_hex(commit->object.sha1), opts->mainline);
 544                 parent = p->item;
 545         } else if (0 < opts->mainline)
 546                 return error(_("Mainline was specified but commit %s is not a merge."),
 547                         sha1_to_hex(commit->object.sha1));
 548         else
 549                 parent = commit->parents->item;
 550
 551         if (opts->allow_ff &&
 552             ((parent && !hashcmp(parent->object.sha1, head)) ||
 553              (!parent && unborn)))
 554                 return fast_forward_to(commit->object.sha1, head, unborn, opts);
 555
 556         if (parent && parse_commit(parent) < 0)
 557                 /* TRANSLATORS: The first %s will be "revert" or
 558                    "cherry-pick", the second %s a SHA1 */
 559                 return error(_("%s: cannot parse parent commit %s"),
 560                         action_name(opts), sha1_to_hex(parent->object.sha1));
 561
 562         if (get_message(commit, &msg) != 0)
 563                 return error(_("Cannot get commit message for %s"),
 564                         sha1_to_hex(commit->object.sha1));
 565
 566         /*
 567          * "commit" is an existing commit.  We would want to apply
 568          * the difference it introduces since its first parent "prev"
 569          * on top of the current HEAD if we are cherry-pick.  Or the
 570          * reverse of it if we are revert.
 571          */
 572
 573         defmsg = git_pathdup("MERGE_MSG");
 574
 575         if (opts->action == REPLAY_REVERT) {
 576                 base = commit;
 577                 base_label = msg.label;
 578                 next = parent;
 579                 next_label = msg.parent_label;
 580                 strbuf_addstr(&msgbuf, "Revert \"");
 581                 strbuf_addstr(&msgbuf, msg.subject);
 582                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 583                 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 584
 585                 if (commit->parents && commit->parents->next) {
 586                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 587                         strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
 588                 }
 589                 strbuf_addstr(&msgbuf, ".\n");
 590         } else {
 591                 const char *p;
 592
 593                 base = parent;
 594                 base_label = msg.parent_label;
 595                 next = commit;
 596                 next_label = msg.label;
 597
 598                 /*
 599                  * Append the commit log message to msgbuf; it starts
 600                  * after the tree, parent, author, committer
 601                  * information followed by "\n\n".
 602                  */
 603                 p = strstr(msg.message, "\n\n");
 604                 if (p) {
 605                         p += 2;
 606                         strbuf_addstr(&msgbuf, p);
 607                 }
 608
 609                 if (opts->record_origin) {
 610                         if (!has_conforming_footer(&msgbuf, NULL, 0))
 611                                 strbuf_addch(&msgbuf, '\n');
 612                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
 613                         strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 614                         strbuf_addstr(&msgbuf, ")\n");
 615                 }
 616         }
 617
 618         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 619                 res = do_recursive_merge(base, next, base_label, next_label,
 620                                          head, &msgbuf, opts);
 621                 write_message(&msgbuf, defmsg);
 622         } else {
 623                 struct commit_list *common = NULL;
 624                 struct commit_list *remotes = NULL;
 625
 626                 write_message(&msgbuf, defmsg);
 627
 628                 commit_list_insert(base, &common);
 629                 commit_list_insert(next, &remotes);
 630                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 631                                         common, sha1_to_hex(head), remotes);
 632                 free_commit_list(common);
 633                 free_commit_list(remotes);
 634         }
 635
 636         /*
 637          * If the merge was clean or if it failed due to conflict, we write
 638          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 639          * However, if the merge did not even start, then we don't want to
 640          * write it at all.
 641          */
 642         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 643                 write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
 644         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 645                 write_cherry_pick_head(commit, "REVERT_HEAD");
 646
 647         if (res) {
 648                 error(opts->action == REPLAY_REVERT
 649                       ? _("could not revert %s... %s")
 650                       : _("could not apply %s... %s"),
 651                       find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
 652                       msg.subject);
 653                 print_advice(res == 1, opts);
 654                 rerere(opts->allow_rerere_auto);
 655                 goto leave;
 656         }
 657
 658         allow = allow_empty(opts, commit);
 659         if (allow < 0) {
 660                 res = allow;
 661                 goto leave;
 662         }
 663         if (!opts->no_commit)
 664                 res = run_git_commit(defmsg, opts, allow);
 665
 666 leave:
 667         free_message(&msg);
 668         free(defmsg);
 669
 670         return res;
 671 }
 672
 673 static void prepare_revs(struct replay_opts *opts)
 674 {
 675         /*
 676          * picking (but not reverting) ranges (but not individual revisions)
 677          * should be done in reverse
 678          */
 679         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 680                 opts->revs->reverse ^= 1;
 681
 682         if (prepare_revision_walk(opts->revs))
 683                 die(_("revision walk setup failed"));
 684
 685         if (!opts->revs->commits)
 686                 die(_("empty commit set passed"));
 687 }
 688
 689 static void read_and_refresh_cache(struct replay_opts *opts)
 690 {
 691         static struct lock_file index_lock;
 692         int index_fd = hold_locked_index(&index_lock, 0);
 693         if (read_index_preload(&the_index, NULL) < 0)
 694                 die(_("git %s: failed to read the index"), action_name(opts));
 695         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 696         if (the_index.cache_changed) {
 697                 if (write_index(&the_index, index_fd) ||
 698                     commit_locked_index(&index_lock))
 699                         die(_("git %s: failed to refresh the index"), action_name(opts));
 700         }
 701         rollback_lock_file(&index_lock);
 702 }
 703
 704 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 705                 struct replay_opts *opts)
 706 {
 707         struct commit_list *cur = NULL;
 708         const char *sha1_abbrev = NULL;
 709         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 710         const char *subject;
 711         int subject_len;
 712
 713         for (cur = todo_list; cur; cur = cur->next) {
 714                 sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
 715                 subject_len = find_commit_subject(cur->item->buffer, &subject);
 716                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 717                         subject_len, subject);
 718         }
 719         return 0;
 720 }
 721
 722 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 723 {
 724         unsigned char commit_sha1[20];
 725         enum replay_action action;
 726         char *end_of_object_name;
 727         int saved, status, padding;
 728
 729         if (starts_with(bol, "pick")) {
 730                 action = REPLAY_PICK;
 731                 bol += strlen("pick");
 732         } else if (starts_with(bol, "revert")) {
 733                 action = REPLAY_REVERT;
 734                 bol += strlen("revert");
 735         } else
 736                 return NULL;
 737
 738         /* Eat up extra spaces/ tabs before object name */
 739         padding = strspn(bol, " \t");
 740         if (!padding)
 741                 return NULL;
 742         bol += padding;
 743
 744         end_of_object_name = bol + strcspn(bol, " \t\n");
 745         saved = *end_of_object_name;
 746         *end_of_object_name = '\0';
 747         status = get_sha1(bol, commit_sha1);
 748         *end_of_object_name = saved;
 749
 750         /*
 751          * Verify that the action matches up with the one in
 752          * opts; we don't support arbitrary instructions
 753          */
 754         if (action != opts->action) {
 755                 const char *action_str;
 756                 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
 757                 error(_("Cannot %s during a %s"), action_str, action_name(opts));
 758                 return NULL;
 759         }
 760
 761         if (status < 0)
 762                 return NULL;
 763
 764         return lookup_commit_reference(commit_sha1);
 765 }
 766
 767 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
 768                         struct replay_opts *opts)
 769 {
 770         struct commit_list **next = todo_list;
 771         struct commit *commit;
 772         char *p = buf;
 773         int i;
 774
 775         for (i = 1; *p; i++) {
 776                 char *eol = strchrnul(p, '\n');
 777                 commit = parse_insn_line(p, eol, opts);
 778                 if (!commit)
 779                         return error(_("Could not parse line %d."), i);
 780                 next = commit_list_append(commit, next);
 781                 p = *eol ? eol + 1 : eol;
 782         }
 783         if (!*todo_list)
 784                 return error(_("No commits parsed."));
 785         return 0;
 786 }
 787
 788 static void read_populate_todo(struct commit_list **todo_list,
 789                         struct replay_opts *opts)
 790 {
 791         const char *todo_file = git_path(SEQ_TODO_FILE);
 792         struct strbuf buf = STRBUF_INIT;
 793         int fd, res;
 794
 795         fd = open(todo_file, O_RDONLY);
 796         if (fd < 0)
 797                 die_errno(_("Could not open %s"), todo_file);
 798         if (strbuf_read(&buf, fd, 0) < 0) {
 799                 close(fd);
 800                 strbuf_release(&buf);
 801                 die(_("Could not read %s."), todo_file);
 802         }
 803         close(fd);
 804
 805         res = parse_insn_buffer(buf.buf, todo_list, opts);
 806         strbuf_release(&buf);
 807         if (res)
 808                 die(_("Unusable instruction sheet: %s"), todo_file);
 809 }
 810
 811 static int populate_opts_cb(const char *key, const char *value, void *data)
 812 {
 813         struct replay_opts *opts = data;
 814         int error_flag = 1;
 815
 816         if (!value)
 817                 error_flag = 0;
 818         else if (!strcmp(key, "options.no-commit"))
 819                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 820         else if (!strcmp(key, "options.edit"))
 821                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
 822         else if (!strcmp(key, "options.signoff"))
 823                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 824         else if (!strcmp(key, "options.record-origin"))
 825                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 826         else if (!strcmp(key, "options.allow-ff"))
 827                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 828         else if (!strcmp(key, "options.mainline"))
 829                 opts->mainline = git_config_int(key, value);
 830         else if (!strcmp(key, "options.strategy"))
 831                 git_config_string(&opts->strategy, key, value);
 832         else if (!strcmp(key, "options.gpg-sign"))
 833                 git_config_string(&opts->gpg_sign, key, value);
 834         else if (!strcmp(key, "options.strategy-option")) {
 835                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 836                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
 837         } else
 838                 return error(_("Invalid key: %s"), key);
 839
 840         if (!error_flag)
 841                 return error(_("Invalid value for %s: %s"), key, value);
 842
 843         return 0;
 844 }
 845
 846 static void read_populate_opts(struct replay_opts **opts_ptr)
 847 {
 848         const char *opts_file = git_path(SEQ_OPTS_FILE);
 849
 850         if (!file_exists(opts_file))
 851                 return;
 852         if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
 853                 die(_("Malformed options sheet: %s"), opts_file);
 854 }
 855
 856 static void walk_revs_populate_todo(struct commit_list **todo_list,
 857                                 struct replay_opts *opts)
 858 {
 859         struct commit *commit;
 860         struct commit_list **next;
 861
 862         prepare_revs(opts);
 863
 864         next = todo_list;
 865         while ((commit = get_revision(opts->revs)))
 866                 next = commit_list_append(commit, next);
 867 }
 868
 869 static int create_seq_dir(void)
 870 {
 871         const char *seq_dir = git_path(SEQ_DIR);
 872
 873         if (file_exists(seq_dir)) {
 874                 error(_("a cherry-pick or revert is already in progress"));
 875                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 876                 return -1;
 877         }
 878         else if (mkdir(seq_dir, 0777) < 0)
 879                 die_errno(_("Could not create sequencer directory %s"), seq_dir);
 880         return 0;
 881 }
 882
 883 static void save_head(const char *head)
 884 {
 885         const char *head_file = git_path(SEQ_HEAD_FILE);
 886         static struct lock_file head_lock;
 887         struct strbuf buf = STRBUF_INIT;
 888         int fd;
 889
 890         fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
 891         strbuf_addf(&buf, "%s\n", head);
 892         if (write_in_full(fd, buf.buf, buf.len) < 0)
 893                 die_errno(_("Could not write to %s"), head_file);
 894         if (commit_lock_file(&head_lock) < 0)
 895                 die(_("Error wrapping up %s."), head_file);
 896 }
 897
 898 static int reset_for_rollback(const unsigned char *sha1)
 899 {
 900         const char *argv[4];    /* reset --merge <arg> + NULL */
 901         argv[0] = "reset";
 902         argv[1] = "--merge";
 903         argv[2] = sha1_to_hex(sha1);
 904         argv[3] = NULL;
 905         return run_command_v_opt(argv, RUN_GIT_CMD);
 906 }
 907
 908 static int rollback_single_pick(void)
 909 {
 910         unsigned char head_sha1[20];
 911
 912         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
 913             !file_exists(git_path("REVERT_HEAD")))
 914                 return error(_("no cherry-pick or revert in progress"));
 915         if (read_ref_full("HEAD", head_sha1, 0, NULL))
 916                 return error(_("cannot resolve HEAD"));
 917         if (is_null_sha1(head_sha1))
 918                 return error(_("cannot abort from a branch yet to be born"));
 919         return reset_for_rollback(head_sha1);
 920 }
 921
 922 static int sequencer_rollback(struct replay_opts *opts)
 923 {
 924         const char *filename;
 925         FILE *f;
 926         unsigned char sha1[20];
 927         struct strbuf buf = STRBUF_INIT;
 928
 929         filename = git_path(SEQ_HEAD_FILE);
 930         f = fopen(filename, "r");
 931         if (!f && errno == ENOENT) {
 932                 /*
 933                  * There is no multiple-cherry-pick in progress.
 934                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 935                  * a single-cherry-pick in progress, abort that.
 936                  */
 937                 return rollback_single_pick();
 938         }
 939         if (!f)
 940                 return error(_("cannot open %s: %s"), filename,
 941                                                 strerror(errno));
 942         if (strbuf_getline(&buf, f, '\n')) {
 943                 error(_("cannot read %s: %s"), filename, ferror(f) ?
 944                         strerror(errno) : _("unexpected end of file"));
 945                 fclose(f);
 946                 goto fail;
 947         }
 948         fclose(f);
 949         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 950                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 951                         filename);
 952                 goto fail;
 953         }
 954         if (reset_for_rollback(sha1))
 955                 goto fail;
 956         remove_sequencer_state();
 957         strbuf_release(&buf);
 958         return 0;
 959 fail:
 960         strbuf_release(&buf);
 961         return -1;
 962 }
 963
 964 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 965 {
 966         const char *todo_file = git_path(SEQ_TODO_FILE);
 967         static struct lock_file todo_lock;
 968         struct strbuf buf = STRBUF_INIT;
 969         int fd;
 970
 971         fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
 972         if (format_todo(&buf, todo_list, opts) < 0)
 973                 die(_("Could not format %s."), todo_file);
 974         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 975                 strbuf_release(&buf);
 976                 die_errno(_("Could not write to %s"), todo_file);
 977         }
 978         if (commit_lock_file(&todo_lock) < 0) {
 979                 strbuf_release(&buf);
 980                 die(_("Error wrapping up %s."), todo_file);
 981         }
 982         strbuf_release(&buf);
 983 }
 984
 985 static void save_opts(struct replay_opts *opts)
 986 {
 987         const char *opts_file = git_path(SEQ_OPTS_FILE);
 988
 989         if (opts->no_commit)
 990                 git_config_set_in_file(opts_file, "options.no-commit", "true");
 991         if (opts->edit)
 992                 git_config_set_in_file(opts_file, "options.edit", "true");
 993         if (opts->signoff)
 994                 git_config_set_in_file(opts_file, "options.signoff", "true");
 995         if (opts->record_origin)
 996                 git_config_set_in_file(opts_file, "options.record-origin", "true");
 997         if (opts->allow_ff)
 998                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
 999         if (opts->mainline) {
1000                 struct strbuf buf = STRBUF_INIT;
1001                 strbuf_addf(&buf, "%d", opts->mainline);
1002                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
1003                 strbuf_release(&buf);
1004         }
1005         if (opts->strategy)
1006                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
1007         if (opts->gpg_sign)
1008                 git_config_set_in_file(opts_file, "options.gpg-sign", opts->gpg_sign);
1009         if (opts->xopts) {
1010                 int i;
1011                 for (i = 0; i < opts->xopts_nr; i++)
1012                         git_config_set_multivar_in_file(opts_file,
1013                                                         "options.strategy-option",
1014                                                         opts->xopts[i], "^$", 0);
1015         }
1016 }
1017
1018 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
1019 {
1020         struct commit_list *cur;
1021         int res;
1022
1023         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1024         if (opts->allow_ff)
1025                 assert(!(opts->signoff || opts->no_commit ||
1026                                 opts->record_origin || opts->edit));
1027         read_and_refresh_cache(opts);
1028
1029         for (cur = todo_list; cur; cur = cur->next) {
1030                 save_todo(cur, opts);
1031                 res = do_pick_commit(cur->item, opts);
1032                 if (res)
1033                         return res;
1034         }
1035
1036         /*
1037          * Sequence of picks finished successfully; cleanup by
1038          * removing the .git/sequencer directory
1039          */
1040         remove_sequencer_state();
1041         return 0;
1042 }
1043
1044 static int continue_single_pick(void)
1045 {
1046         const char *argv[] = { "commit", NULL };
1047
1048         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
1049             !file_exists(git_path("REVERT_HEAD")))
1050                 return error(_("no cherry-pick or revert in progress"));
1051         return run_command_v_opt(argv, RUN_GIT_CMD);
1052 }
1053
1054 static int sequencer_continue(struct replay_opts *opts)
1055 {
1056         struct commit_list *todo_list = NULL;
1057
1058         if (!file_exists(git_path(SEQ_TODO_FILE)))
1059                 return continue_single_pick();
1060         read_populate_opts(&opts);
1061         read_populate_todo(&todo_list, opts);
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         todo_list = todo_list->next;
1073         return pick_commits(todo_list, opts);
1074 }
1075
1076 static int single_pick(struct commit *cmit, struct replay_opts *opts)
1077 {
1078         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1079         return do_pick_commit(cmit, opts);
1080 }
1081
1082 int sequencer_pick_revisions(struct replay_opts *opts)
1083 {
1084         struct commit_list *todo_list = NULL;
1085         unsigned char sha1[20];
1086         int i;
1087
1088         if (opts->subcommand == REPLAY_NONE)
1089                 assert(opts->revs);
1090
1091         read_and_refresh_cache(opts);
1092
1093         /*
1094          * Decide what to do depending on the arguments; a fresh
1095          * cherry-pick should be handled differently from an existing
1096          * one that is being continued
1097          */
1098         if (opts->subcommand == REPLAY_REMOVE_STATE) {
1099                 remove_sequencer_state();
1100                 return 0;
1101         }
1102         if (opts->subcommand == REPLAY_ROLLBACK)
1103                 return sequencer_rollback(opts);
1104         if (opts->subcommand == REPLAY_CONTINUE)
1105                 return sequencer_continue(opts);
1106
1107         for (i = 0; i < opts->revs->pending.nr; i++) {
1108                 unsigned char sha1[20];
1109                 const char *name = opts->revs->pending.objects[i].name;
1110
1111                 /* This happens when using --stdin. */
1112                 if (!strlen(name))
1113                         continue;
1114
1115                 if (!get_sha1(name, sha1)) {
1116                         if (!lookup_commit_reference_gently(sha1, 1)) {
1117                                 enum object_type type = sha1_object_info(sha1, NULL);
1118                                 die(_("%s: can't cherry-pick a %s"), name, typename(type));
1119                         }
1120                 } else
1121                         die(_("%s: bad revision"), name);
1122         }
1123
1124         /*
1125          * If we were called as "git cherry-pick <commit>", just
1126          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1127          * REVERT_HEAD, and don't touch the sequencer state.
1128          * This means it is possible to cherry-pick in the middle
1129          * of a cherry-pick sequence.
1130          */
1131         if (opts->revs->cmdline.nr == 1 &&
1132             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1133             opts->revs->no_walk &&
1134             !opts->revs->cmdline.rev->flags) {
1135                 struct commit *cmit;
1136                 if (prepare_revision_walk(opts->revs))
1137                         die(_("revision walk setup failed"));
1138                 cmit = get_revision(opts->revs);
1139                 if (!cmit || get_revision(opts->revs))
1140                         die("BUG: expected exactly one commit from walk");
1141                 return single_pick(cmit, opts);
1142         }
1143
1144         /*
1145          * Start a new cherry-pick/ revert sequence; but
1146          * first, make sure that an existing one isn't in
1147          * progress
1148          */
1149
1150         walk_revs_populate_todo(&todo_list, opts);
1151         if (create_seq_dir() < 0)
1152                 return -1;
1153         if (get_sha1("HEAD", sha1)) {
1154                 if (opts->action == REPLAY_REVERT)
1155                         return error(_("Can't revert as initial commit"));
1156                 return error(_("Can't cherry-pick into empty head"));
1157         }
1158         save_head(sha1_to_hex(sha1));
1159         save_opts(opts);
1160         return pick_commits(todo_list, opts);
1161 }
1162
1163 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1164 {
1165         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1166         struct strbuf sob = STRBUF_INIT;
1167         int has_footer;
1168
1169         strbuf_addstr(&sob, sign_off_header);
1170         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1171                                 getenv("GIT_COMMITTER_EMAIL")));
1172         strbuf_addch(&sob, '\n');
1173
1174         /*
1175          * If the whole message buffer is equal to the sob, pretend that we
1176          * found a conforming footer with a matching sob
1177          */
1178         if (msgbuf->len - ignore_footer == sob.len &&
1179             !strncmp(msgbuf->buf, sob.buf, sob.len))
1180                 has_footer = 3;
1181         else
1182                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1183
1184         if (!has_footer) {
1185                 const char *append_newlines = NULL;
1186                 size_t len = msgbuf->len - ignore_footer;
1187
1188                 if (!len) {
1189                         /*
1190                          * The buffer is completely empty.  Leave foom for
1191                          * the title and body to be filled in by the user.
1192                          */
1193                         append_newlines = "\n\n";
1194                 } else if (msgbuf->buf[len - 1] != '\n') {
1195                         /*
1196                          * Incomplete line.  Complete the line and add a
1197                          * blank one so that there is an empty line between
1198                          * the message body and the sob.
1199                          */
1200                         append_newlines = "\n\n";
1201                 } else if (len == 1) {
1202                         /*
1203                          * Buffer contains a single newline.  Add another
1204                          * so that we leave room for the title and body.
1205                          */
1206                         append_newlines = "\n";
1207                 } else if (msgbuf->buf[len - 2] != '\n') {
1208                         /*
1209                          * Buffer ends with a single newline.  Add another
1210                          * so that there is an empty line between the message
1211                          * body and the sob.
1212                          */
1213                         append_newlines = "\n";
1214                 } /* else, the buffer already ends with two newlines. */
1215
1216                 if (append_newlines)
1217                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1218                                 append_newlines, strlen(append_newlines));
1219         }
1220
1221         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1222                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1223                                 sob.buf, sob.len);
1224
1225         strbuf_release(&sob);
1226 }