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_lock *ref_lock;
 276         struct strbuf sb = STRBUF_INIT;
 277         int ret;
 278
 279         read_cache();
 280         if (checkout_fast_forward(from, to, 1))
 281                 exit(1); /* the callee should have complained already */
 282         ref_lock = lock_any_ref_for_update("HEAD", unborn ? null_sha1 : from,
 283                                            0, NULL);
 284         if (!ref_lock)
 285                 return error(_("Failed to lock HEAD during fast_forward_to"));
 286
 287         strbuf_addf(&sb, "%s: fast-forward", action_name(opts));
 288         ret = write_ref_sha1(ref_lock, to, sb.buf);
 289
 290         strbuf_release(&sb);
 291         return ret;
 292 }
 293
 294 static int do_recursive_merge(struct commit *base, struct commit *next,
 295                               const char *base_label, const char *next_label,
 296                               unsigned char *head, struct strbuf *msgbuf,
 297                               struct replay_opts *opts)
 298 {
 299         struct merge_options o;
 300         struct tree *result, *next_tree, *base_tree, *head_tree;
 301         int clean, index_fd;
 302         const char **xopt;
 303         static struct lock_file index_lock;
 304
 305         index_fd = hold_locked_index(&index_lock, 1);
 306
 307         read_cache();
 308
 309         init_merge_options(&o);
 310         o.ancestor = base ? base_label : "(empty tree)";
 311         o.branch1 = "HEAD";
 312         o.branch2 = next ? next_label : "(empty tree)";
 313
 314         head_tree = parse_tree_indirect(head);
 315         next_tree = next ? next->tree : empty_tree();
 316         base_tree = base ? base->tree : empty_tree();
 317
 318         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 319                 parse_merge_opt(&o, *xopt);
 320
 321         clean = merge_trees(&o,
 322                             head_tree,
 323                             next_tree, base_tree, &result);
 324
 325         if (active_cache_changed &&
 326             (write_cache(index_fd, active_cache, active_nr) ||
 327              commit_locked_index(&index_lock)))
 328                 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 329                 die(_("%s: Unable to write new index file"), action_name(opts));
 330         rollback_lock_file(&index_lock);
 331
 332         if (opts->signoff)
 333                 append_signoff(msgbuf, 0, 0);
 334
 335         if (!clean) {
 336                 int i;
 337                 strbuf_addstr(msgbuf, "\nConflicts:\n");
 338                 for (i = 0; i < active_nr;) {
 339                         const struct cache_entry *ce = active_cache[i++];
 340                         if (ce_stage(ce)) {
 341                                 strbuf_addch(msgbuf, '\t');
 342                                 strbuf_addstr(msgbuf, ce->name);
 343                                 strbuf_addch(msgbuf, '\n');
 344                                 while (i < active_nr && !strcmp(ce->name,
 345                                                 active_cache[i]->name))
 346                                         i++;
 347                         }
 348                 }
 349         }
 350
 351         return !clean;
 352 }
 353
 354 static int is_index_unchanged(void)
 355 {
 356         unsigned char head_sha1[20];
 357         struct commit *head_commit;
 358
 359         if (!resolve_ref_unsafe("HEAD", head_sha1, 1, NULL))
 360                 return error(_("Could not resolve HEAD commit\n"));
 361
 362         head_commit = lookup_commit(head_sha1);
 363
 364         /*
 365          * If head_commit is NULL, check_commit, called from
 366          * lookup_commit, would have indicated that head_commit is not
 367          * a commit object already.  parse_commit() will return failure
 368          * without further complaints in such a case.  Otherwise, if
 369          * the commit is invalid, parse_commit() will complain.  So
 370          * there is nothing for us to say here.  Just return failure.
 371          */
 372         if (parse_commit(head_commit))
 373                 return -1;
 374
 375         if (!active_cache_tree)
 376                 active_cache_tree = cache_tree();
 377
 378         if (!cache_tree_fully_valid(active_cache_tree))
 379                 if (cache_tree_update(active_cache_tree,
 380                                       (const struct cache_entry * const *)active_cache,
 381                                       active_nr, 0))
 382                         return error(_("Unable to update cache tree\n"));
 383
 384         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.sha1);
 385 }
 386
 387 /*
 388  * If we are cherry-pick, and if the merge did not result in
 389  * hand-editing, we will hit this commit and inherit the original
 390  * author date and name.
 391  * If we are revert, or if our cherry-pick results in a hand merge,
 392  * we had better say that the current user is responsible for that.
 393  */
 394 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 395                           int allow_empty)
 396 {
 397         struct argv_array array;
 398         int rc;
 399
 400         argv_array_init(&array);
 401         argv_array_push(&array, "commit");
 402         argv_array_push(&array, "-n");
 403
 404         if (opts->gpg_sign)
 405                 argv_array_pushf(&array, "-S%s", opts->gpg_sign);
 406         if (opts->signoff)
 407                 argv_array_push(&array, "-s");
 408         if (!opts->edit) {
 409                 argv_array_push(&array, "-F");
 410                 argv_array_push(&array, defmsg);
 411         }
 412
 413         if (allow_empty)
 414                 argv_array_push(&array, "--allow-empty");
 415
 416         if (opts->allow_empty_message)
 417                 argv_array_push(&array, "--allow-empty-message");
 418
 419         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 420         argv_array_clear(&array);
 421         return rc;
 422 }
 423
 424 static int is_original_commit_empty(struct commit *commit)
 425 {
 426         const unsigned char *ptree_sha1;
 427
 428         if (parse_commit(commit))
 429                 return error(_("Could not parse commit %s\n"),
 430                              sha1_to_hex(commit->object.sha1));
 431         if (commit->parents) {
 432                 struct commit *parent = commit->parents->item;
 433                 if (parse_commit(parent))
 434                         return error(_("Could not parse parent commit %s\n"),
 435                                 sha1_to_hex(parent->object.sha1));
 436                 ptree_sha1 = parent->tree->object.sha1;
 437         } else {
 438                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 439         }
 440
 441         return !hashcmp(ptree_sha1, commit->tree->object.sha1);
 442 }
 443
 444 /*
 445  * Do we run "git commit" with "--allow-empty"?
 446  */
 447 static int allow_empty(struct replay_opts *opts, struct commit *commit)
 448 {
 449         int index_unchanged, empty_commit;
 450
 451         /*
 452          * Three cases:
 453          *
 454          * (1) we do not allow empty at all and error out.
 455          *
 456          * (2) we allow ones that were initially empty, but
 457          * forbid the ones that become empty;
 458          *
 459          * (3) we allow both.
 460          */
 461         if (!opts->allow_empty)
 462                 return 0; /* let "git commit" barf as necessary */
 463
 464         index_unchanged = is_index_unchanged();
 465         if (index_unchanged < 0)
 466                 return index_unchanged;
 467         if (!index_unchanged)
 468                 return 0; /* we do not have to say --allow-empty */
 469
 470         if (opts->keep_redundant_commits)
 471                 return 1;
 472
 473         empty_commit = is_original_commit_empty(commit);
 474         if (empty_commit < 0)
 475                 return empty_commit;
 476         if (!empty_commit)
 477                 return 0;
 478         else
 479                 return 1;
 480 }
 481
 482 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 483 {
 484         unsigned char head[20];
 485         struct commit *base, *next, *parent;
 486         const char *base_label, *next_label;
 487         struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
 488         char *defmsg = NULL;
 489         struct strbuf msgbuf = STRBUF_INIT;
 490         int res, unborn = 0, allow;
 491
 492         if (opts->no_commit) {
 493                 /*
 494                  * We do not intend to commit immediately.  We just want to
 495                  * merge the differences in, so let's compute the tree
 496                  * that represents the "current" state for merge-recursive
 497                  * to work on.
 498                  */
 499                 if (write_cache_as_tree(head, 0, NULL))
 500                         die (_("Your index file is unmerged."));
 501         } else {
 502                 unborn = get_sha1("HEAD", head);
 503                 if (unborn)
 504                         hashcpy(head, EMPTY_TREE_SHA1_BIN);
 505                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
 506                         return error_dirty_index(opts);
 507         }
 508         discard_cache();
 509
 510         if (!commit->parents) {
 511                 parent = NULL;
 512         }
 513         else if (commit->parents->next) {
 514                 /* Reverting or cherry-picking a merge commit */
 515                 int cnt;
 516                 struct commit_list *p;
 517
 518                 if (!opts->mainline)
 519                         return error(_("Commit %s is a merge but no -m option was given."),
 520                                 sha1_to_hex(commit->object.sha1));
 521
 522                 for (cnt = 1, p = commit->parents;
 523                      cnt != opts->mainline && p;
 524                      cnt++)
 525                         p = p->next;
 526                 if (cnt != opts->mainline || !p)
 527                         return error(_("Commit %s does not have parent %d"),
 528                                 sha1_to_hex(commit->object.sha1), opts->mainline);
 529                 parent = p->item;
 530         } else if (0 < opts->mainline)
 531                 return error(_("Mainline was specified but commit %s is not a merge."),
 532                         sha1_to_hex(commit->object.sha1));
 533         else
 534                 parent = commit->parents->item;
 535
 536         if (opts->allow_ff &&
 537             ((parent && !hashcmp(parent->object.sha1, head)) ||
 538              (!parent && unborn)))
 539                 return fast_forward_to(commit->object.sha1, head, unborn, opts);
 540
 541         if (parent && parse_commit(parent) < 0)
 542                 /* TRANSLATORS: The first %s will be "revert" or
 543                    "cherry-pick", the second %s a SHA1 */
 544                 return error(_("%s: cannot parse parent commit %s"),
 545                         action_name(opts), sha1_to_hex(parent->object.sha1));
 546
 547         if (get_message(commit, &msg) != 0)
 548                 return error(_("Cannot get commit message for %s"),
 549                         sha1_to_hex(commit->object.sha1));
 550
 551         /*
 552          * "commit" is an existing commit.  We would want to apply
 553          * the difference it introduces since its first parent "prev"
 554          * on top of the current HEAD if we are cherry-pick.  Or the
 555          * reverse of it if we are revert.
 556          */
 557
 558         defmsg = git_pathdup("MERGE_MSG");
 559
 560         if (opts->action == REPLAY_REVERT) {
 561                 base = commit;
 562                 base_label = msg.label;
 563                 next = parent;
 564                 next_label = msg.parent_label;
 565                 strbuf_addstr(&msgbuf, "Revert \"");
 566                 strbuf_addstr(&msgbuf, msg.subject);
 567                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 568                 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 569
 570                 if (commit->parents && commit->parents->next) {
 571                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 572                         strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
 573                 }
 574                 strbuf_addstr(&msgbuf, ".\n");
 575         } else {
 576                 const char *p;
 577
 578                 base = parent;
 579                 base_label = msg.parent_label;
 580                 next = commit;
 581                 next_label = msg.label;
 582
 583                 /*
 584                  * Append the commit log message to msgbuf; it starts
 585                  * after the tree, parent, author, committer
 586                  * information followed by "\n\n".
 587                  */
 588                 p = strstr(msg.message, "\n\n");
 589                 if (p) {
 590                         p += 2;
 591                         strbuf_addstr(&msgbuf, p);
 592                 }
 593
 594                 if (opts->record_origin) {
 595                         if (!has_conforming_footer(&msgbuf, NULL, 0))
 596                                 strbuf_addch(&msgbuf, '\n');
 597                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
 598                         strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 599                         strbuf_addstr(&msgbuf, ")\n");
 600                 }
 601         }
 602
 603         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 604                 res = do_recursive_merge(base, next, base_label, next_label,
 605                                          head, &msgbuf, opts);
 606                 write_message(&msgbuf, defmsg);
 607         } else {
 608                 struct commit_list *common = NULL;
 609                 struct commit_list *remotes = NULL;
 610
 611                 write_message(&msgbuf, defmsg);
 612
 613                 commit_list_insert(base, &common);
 614                 commit_list_insert(next, &remotes);
 615                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 616                                         common, sha1_to_hex(head), remotes);
 617                 free_commit_list(common);
 618                 free_commit_list(remotes);
 619         }
 620
 621         /*
 622          * If the merge was clean or if it failed due to conflict, we write
 623          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 624          * However, if the merge did not even start, then we don't want to
 625          * write it at all.
 626          */
 627         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 628                 write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
 629         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 630                 write_cherry_pick_head(commit, "REVERT_HEAD");
 631
 632         if (res) {
 633                 error(opts->action == REPLAY_REVERT
 634                       ? _("could not revert %s... %s")
 635                       : _("could not apply %s... %s"),
 636                       find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
 637                       msg.subject);
 638                 print_advice(res == 1, opts);
 639                 rerere(opts->allow_rerere_auto);
 640                 goto leave;
 641         }
 642
 643         allow = allow_empty(opts, commit);
 644         if (allow < 0) {
 645                 res = allow;
 646                 goto leave;
 647         }
 648         if (!opts->no_commit)
 649                 res = run_git_commit(defmsg, opts, allow);
 650
 651 leave:
 652         free_message(&msg);
 653         free(defmsg);
 654
 655         return res;
 656 }
 657
 658 static void prepare_revs(struct replay_opts *opts)
 659 {
 660         /*
 661          * picking (but not reverting) ranges (but not individual revisions)
 662          * should be done in reverse
 663          */
 664         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 665                 opts->revs->reverse ^= 1;
 666
 667         if (prepare_revision_walk(opts->revs))
 668                 die(_("revision walk setup failed"));
 669
 670         if (!opts->revs->commits)
 671                 die(_("empty commit set passed"));
 672 }
 673
 674 static void read_and_refresh_cache(struct replay_opts *opts)
 675 {
 676         static struct lock_file index_lock;
 677         int index_fd = hold_locked_index(&index_lock, 0);
 678         if (read_index_preload(&the_index, NULL) < 0)
 679                 die(_("git %s: failed to read the index"), action_name(opts));
 680         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 681         if (the_index.cache_changed) {
 682                 if (write_index(&the_index, index_fd) ||
 683                     commit_locked_index(&index_lock))
 684                         die(_("git %s: failed to refresh the index"), action_name(opts));
 685         }
 686         rollback_lock_file(&index_lock);
 687 }
 688
 689 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 690                 struct replay_opts *opts)
 691 {
 692         struct commit_list *cur = NULL;
 693         const char *sha1_abbrev = NULL;
 694         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 695         const char *subject;
 696         int subject_len;
 697
 698         for (cur = todo_list; cur; cur = cur->next) {
 699                 sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
 700                 subject_len = find_commit_subject(cur->item->buffer, &subject);
 701                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 702                         subject_len, subject);
 703         }
 704         return 0;
 705 }
 706
 707 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 708 {
 709         unsigned char commit_sha1[20];
 710         enum replay_action action;
 711         char *end_of_object_name;
 712         int saved, status, padding;
 713
 714         if (starts_with(bol, "pick")) {
 715                 action = REPLAY_PICK;
 716                 bol += strlen("pick");
 717         } else if (starts_with(bol, "revert")) {
 718                 action = REPLAY_REVERT;
 719                 bol += strlen("revert");
 720         } else
 721                 return NULL;
 722
 723         /* Eat up extra spaces/ tabs before object name */
 724         padding = strspn(bol, " \t");
 725         if (!padding)
 726                 return NULL;
 727         bol += padding;
 728
 729         end_of_object_name = bol + strcspn(bol, " \t\n");
 730         saved = *end_of_object_name;
 731         *end_of_object_name = '\0';
 732         status = get_sha1(bol, commit_sha1);
 733         *end_of_object_name = saved;
 734
 735         /*
 736          * Verify that the action matches up with the one in
 737          * opts; we don't support arbitrary instructions
 738          */
 739         if (action != opts->action) {
 740                 const char *action_str;
 741                 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
 742                 error(_("Cannot %s during a %s"), action_str, action_name(opts));
 743                 return NULL;
 744         }
 745
 746         if (status < 0)
 747                 return NULL;
 748
 749         return lookup_commit_reference(commit_sha1);
 750 }
 751
 752 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
 753                         struct replay_opts *opts)
 754 {
 755         struct commit_list **next = todo_list;
 756         struct commit *commit;
 757         char *p = buf;
 758         int i;
 759
 760         for (i = 1; *p; i++) {
 761                 char *eol = strchrnul(p, '\n');
 762                 commit = parse_insn_line(p, eol, opts);
 763                 if (!commit)
 764                         return error(_("Could not parse line %d."), i);
 765                 next = commit_list_append(commit, next);
 766                 p = *eol ? eol + 1 : eol;
 767         }
 768         if (!*todo_list)
 769                 return error(_("No commits parsed."));
 770         return 0;
 771 }
 772
 773 static void read_populate_todo(struct commit_list **todo_list,
 774                         struct replay_opts *opts)
 775 {
 776         const char *todo_file = git_path(SEQ_TODO_FILE);
 777         struct strbuf buf = STRBUF_INIT;
 778         int fd, res;
 779
 780         fd = open(todo_file, O_RDONLY);
 781         if (fd < 0)
 782                 die_errno(_("Could not open %s"), todo_file);
 783         if (strbuf_read(&buf, fd, 0) < 0) {
 784                 close(fd);
 785                 strbuf_release(&buf);
 786                 die(_("Could not read %s."), todo_file);
 787         }
 788         close(fd);
 789
 790         res = parse_insn_buffer(buf.buf, todo_list, opts);
 791         strbuf_release(&buf);
 792         if (res)
 793                 die(_("Unusable instruction sheet: %s"), todo_file);
 794 }
 795
 796 static int populate_opts_cb(const char *key, const char *value, void *data)
 797 {
 798         struct replay_opts *opts = data;
 799         int error_flag = 1;
 800
 801         if (!value)
 802                 error_flag = 0;
 803         else if (!strcmp(key, "options.no-commit"))
 804                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 805         else if (!strcmp(key, "options.edit"))
 806                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
 807         else if (!strcmp(key, "options.signoff"))
 808                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 809         else if (!strcmp(key, "options.record-origin"))
 810                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 811         else if (!strcmp(key, "options.allow-ff"))
 812                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 813         else if (!strcmp(key, "options.mainline"))
 814                 opts->mainline = git_config_int(key, value);
 815         else if (!strcmp(key, "options.strategy"))
 816                 git_config_string(&opts->strategy, key, value);
 817         else if (!strcmp(key, "options.gpg-sign"))
 818                 git_config_string(&opts->gpg_sign, key, value);
 819         else if (!strcmp(key, "options.strategy-option")) {
 820                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 821                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
 822         } else
 823                 return error(_("Invalid key: %s"), key);
 824
 825         if (!error_flag)
 826                 return error(_("Invalid value for %s: %s"), key, value);
 827
 828         return 0;
 829 }
 830
 831 static void read_populate_opts(struct replay_opts **opts_ptr)
 832 {
 833         const char *opts_file = git_path(SEQ_OPTS_FILE);
 834
 835         if (!file_exists(opts_file))
 836                 return;
 837         if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
 838                 die(_("Malformed options sheet: %s"), opts_file);
 839 }
 840
 841 static void walk_revs_populate_todo(struct commit_list **todo_list,
 842                                 struct replay_opts *opts)
 843 {
 844         struct commit *commit;
 845         struct commit_list **next;
 846
 847         prepare_revs(opts);
 848
 849         next = todo_list;
 850         while ((commit = get_revision(opts->revs)))
 851                 next = commit_list_append(commit, next);
 852 }
 853
 854 static int create_seq_dir(void)
 855 {
 856         const char *seq_dir = git_path(SEQ_DIR);
 857
 858         if (file_exists(seq_dir)) {
 859                 error(_("a cherry-pick or revert is already in progress"));
 860                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 861                 return -1;
 862         }
 863         else if (mkdir(seq_dir, 0777) < 0)
 864                 die_errno(_("Could not create sequencer directory %s"), seq_dir);
 865         return 0;
 866 }
 867
 868 static void save_head(const char *head)
 869 {
 870         const char *head_file = git_path(SEQ_HEAD_FILE);
 871         static struct lock_file head_lock;
 872         struct strbuf buf = STRBUF_INIT;
 873         int fd;
 874
 875         fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
 876         strbuf_addf(&buf, "%s\n", head);
 877         if (write_in_full(fd, buf.buf, buf.len) < 0)
 878                 die_errno(_("Could not write to %s"), head_file);
 879         if (commit_lock_file(&head_lock) < 0)
 880                 die(_("Error wrapping up %s."), head_file);
 881 }
 882
 883 static int reset_for_rollback(const unsigned char *sha1)
 884 {
 885         const char *argv[4];    /* reset --merge <arg> + NULL */
 886         argv[0] = "reset";
 887         argv[1] = "--merge";
 888         argv[2] = sha1_to_hex(sha1);
 889         argv[3] = NULL;
 890         return run_command_v_opt(argv, RUN_GIT_CMD);
 891 }
 892
 893 static int rollback_single_pick(void)
 894 {
 895         unsigned char head_sha1[20];
 896
 897         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
 898             !file_exists(git_path("REVERT_HEAD")))
 899                 return error(_("no cherry-pick or revert in progress"));
 900         if (read_ref_full("HEAD", head_sha1, 0, NULL))
 901                 return error(_("cannot resolve HEAD"));
 902         if (is_null_sha1(head_sha1))
 903                 return error(_("cannot abort from a branch yet to be born"));
 904         return reset_for_rollback(head_sha1);
 905 }
 906
 907 static int sequencer_rollback(struct replay_opts *opts)
 908 {
 909         const char *filename;
 910         FILE *f;
 911         unsigned char sha1[20];
 912         struct strbuf buf = STRBUF_INIT;
 913
 914         filename = git_path(SEQ_HEAD_FILE);
 915         f = fopen(filename, "r");
 916         if (!f && errno == ENOENT) {
 917                 /*
 918                  * There is no multiple-cherry-pick in progress.
 919                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 920                  * a single-cherry-pick in progress, abort that.
 921                  */
 922                 return rollback_single_pick();
 923         }
 924         if (!f)
 925                 return error(_("cannot open %s: %s"), filename,
 926                                                 strerror(errno));
 927         if (strbuf_getline(&buf, f, '\n')) {
 928                 error(_("cannot read %s: %s"), filename, ferror(f) ?
 929                         strerror(errno) : _("unexpected end of file"));
 930                 fclose(f);
 931                 goto fail;
 932         }
 933         fclose(f);
 934         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 935                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 936                         filename);
 937                 goto fail;
 938         }
 939         if (reset_for_rollback(sha1))
 940                 goto fail;
 941         remove_sequencer_state();
 942         strbuf_release(&buf);
 943         return 0;
 944 fail:
 945         strbuf_release(&buf);
 946         return -1;
 947 }
 948
 949 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 950 {
 951         const char *todo_file = git_path(SEQ_TODO_FILE);
 952         static struct lock_file todo_lock;
 953         struct strbuf buf = STRBUF_INIT;
 954         int fd;
 955
 956         fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
 957         if (format_todo(&buf, todo_list, opts) < 0)
 958                 die(_("Could not format %s."), todo_file);
 959         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 960                 strbuf_release(&buf);
 961                 die_errno(_("Could not write to %s"), todo_file);
 962         }
 963         if (commit_lock_file(&todo_lock) < 0) {
 964                 strbuf_release(&buf);
 965                 die(_("Error wrapping up %s."), todo_file);
 966         }
 967         strbuf_release(&buf);
 968 }
 969
 970 static void save_opts(struct replay_opts *opts)
 971 {
 972         const char *opts_file = git_path(SEQ_OPTS_FILE);
 973
 974         if (opts->no_commit)
 975                 git_config_set_in_file(opts_file, "options.no-commit", "true");
 976         if (opts->edit)
 977                 git_config_set_in_file(opts_file, "options.edit", "true");
 978         if (opts->signoff)
 979                 git_config_set_in_file(opts_file, "options.signoff", "true");
 980         if (opts->record_origin)
 981                 git_config_set_in_file(opts_file, "options.record-origin", "true");
 982         if (opts->allow_ff)
 983                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
 984         if (opts->mainline) {
 985                 struct strbuf buf = STRBUF_INIT;
 986                 strbuf_addf(&buf, "%d", opts->mainline);
 987                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
 988                 strbuf_release(&buf);
 989         }
 990         if (opts->strategy)
 991                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
 992         if (opts->gpg_sign)
 993                 git_config_set_in_file(opts_file, "options.gpg-sign", opts->gpg_sign);
 994         if (opts->xopts) {
 995                 int i;
 996                 for (i = 0; i < opts->xopts_nr; i++)
 997                         git_config_set_multivar_in_file(opts_file,
 998                                                         "options.strategy-option",
 999                                                         opts->xopts[i], "^$", 0);
1000         }
1001 }
1002
1003 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
1004 {
1005         struct commit_list *cur;
1006         int res;
1007
1008         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1009         if (opts->allow_ff)
1010                 assert(!(opts->signoff || opts->no_commit ||
1011                                 opts->record_origin || opts->edit));
1012         read_and_refresh_cache(opts);
1013
1014         for (cur = todo_list; cur; cur = cur->next) {
1015                 save_todo(cur, opts);
1016                 res = do_pick_commit(cur->item, opts);
1017                 if (res)
1018                         return res;
1019         }
1020
1021         /*
1022          * Sequence of picks finished successfully; cleanup by
1023          * removing the .git/sequencer directory
1024          */
1025         remove_sequencer_state();
1026         return 0;
1027 }
1028
1029 static int continue_single_pick(void)
1030 {
1031         const char *argv[] = { "commit", NULL };
1032
1033         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
1034             !file_exists(git_path("REVERT_HEAD")))
1035                 return error(_("no cherry-pick or revert in progress"));
1036         return run_command_v_opt(argv, RUN_GIT_CMD);
1037 }
1038
1039 static int sequencer_continue(struct replay_opts *opts)
1040 {
1041         struct commit_list *todo_list = NULL;
1042
1043         if (!file_exists(git_path(SEQ_TODO_FILE)))
1044                 return continue_single_pick();
1045         read_populate_opts(&opts);
1046         read_populate_todo(&todo_list, opts);
1047
1048         /* Verify that the conflict has been resolved */
1049         if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
1050             file_exists(git_path("REVERT_HEAD"))) {
1051                 int ret = continue_single_pick();
1052                 if (ret)
1053                         return ret;
1054         }
1055         if (index_differs_from("HEAD", 0))
1056                 return error_dirty_index(opts);
1057         todo_list = todo_list->next;
1058         return pick_commits(todo_list, opts);
1059 }
1060
1061 static int single_pick(struct commit *cmit, struct replay_opts *opts)
1062 {
1063         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1064         return do_pick_commit(cmit, opts);
1065 }
1066
1067 int sequencer_pick_revisions(struct replay_opts *opts)
1068 {
1069         struct commit_list *todo_list = NULL;
1070         unsigned char sha1[20];
1071         int i;
1072
1073         if (opts->subcommand == REPLAY_NONE)
1074                 assert(opts->revs);
1075
1076         read_and_refresh_cache(opts);
1077
1078         /*
1079          * Decide what to do depending on the arguments; a fresh
1080          * cherry-pick should be handled differently from an existing
1081          * one that is being continued
1082          */
1083         if (opts->subcommand == REPLAY_REMOVE_STATE) {
1084                 remove_sequencer_state();
1085                 return 0;
1086         }
1087         if (opts->subcommand == REPLAY_ROLLBACK)
1088                 return sequencer_rollback(opts);
1089         if (opts->subcommand == REPLAY_CONTINUE)
1090                 return sequencer_continue(opts);
1091
1092         for (i = 0; i < opts->revs->pending.nr; i++) {
1093                 unsigned char sha1[20];
1094                 const char *name = opts->revs->pending.objects[i].name;
1095
1096                 /* This happens when using --stdin. */
1097                 if (!strlen(name))
1098                         continue;
1099
1100                 if (!get_sha1(name, sha1)) {
1101                         if (!lookup_commit_reference_gently(sha1, 1)) {
1102                                 enum object_type type = sha1_object_info(sha1, NULL);
1103                                 die(_("%s: can't cherry-pick a %s"), name, typename(type));
1104                         }
1105                 } else
1106                         die(_("%s: bad revision"), name);
1107         }
1108
1109         /*
1110          * If we were called as "git cherry-pick <commit>", just
1111          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1112          * REVERT_HEAD, and don't touch the sequencer state.
1113          * This means it is possible to cherry-pick in the middle
1114          * of a cherry-pick sequence.
1115          */
1116         if (opts->revs->cmdline.nr == 1 &&
1117             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1118             opts->revs->no_walk &&
1119             !opts->revs->cmdline.rev->flags) {
1120                 struct commit *cmit;
1121                 if (prepare_revision_walk(opts->revs))
1122                         die(_("revision walk setup failed"));
1123                 cmit = get_revision(opts->revs);
1124                 if (!cmit || get_revision(opts->revs))
1125                         die("BUG: expected exactly one commit from walk");
1126                 return single_pick(cmit, opts);
1127         }
1128
1129         /*
1130          * Start a new cherry-pick/ revert sequence; but
1131          * first, make sure that an existing one isn't in
1132          * progress
1133          */
1134
1135         walk_revs_populate_todo(&todo_list, opts);
1136         if (create_seq_dir() < 0)
1137                 return -1;
1138         if (get_sha1("HEAD", sha1)) {
1139                 if (opts->action == REPLAY_REVERT)
1140                         return error(_("Can't revert as initial commit"));
1141                 return error(_("Can't cherry-pick into empty head"));
1142         }
1143         save_head(sha1_to_hex(sha1));
1144         save_opts(opts);
1145         return pick_commits(todo_list, opts);
1146 }
1147
1148 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1149 {
1150         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1151         struct strbuf sob = STRBUF_INIT;
1152         int has_footer;
1153
1154         strbuf_addstr(&sob, sign_off_header);
1155         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1156                                 getenv("GIT_COMMITTER_EMAIL")));
1157         strbuf_addch(&sob, '\n');
1158
1159         /*
1160          * If the whole message buffer is equal to the sob, pretend that we
1161          * found a conforming footer with a matching sob
1162          */
1163         if (msgbuf->len - ignore_footer == sob.len &&
1164             !strncmp(msgbuf->buf, sob.buf, sob.len))
1165                 has_footer = 3;
1166         else
1167                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1168
1169         if (!has_footer) {
1170                 const char *append_newlines = NULL;
1171                 size_t len = msgbuf->len - ignore_footer;
1172
1173                 if (!len) {
1174                         /*
1175                          * The buffer is completely empty.  Leave foom for
1176                          * the title and body to be filled in by the user.
1177                          */
1178                         append_newlines = "\n\n";
1179                 } else if (msgbuf->buf[len - 1] != '\n') {
1180                         /*
1181                          * Incomplete line.  Complete the line and add a
1182                          * blank one so that there is an empty line between
1183                          * the message body and the sob.
1184                          */
1185                         append_newlines = "\n\n";
1186                 } else if (len == 1) {
1187                         /*
1188                          * Buffer contains a single newline.  Add another
1189                          * so that we leave room for the title and body.
1190                          */
1191                         append_newlines = "\n";
1192                 } else if (msgbuf->buf[len - 2] != '\n') {
1193                         /*
1194                          * Buffer ends with a single newline.  Add another
1195                          * so that there is an empty line between the message
1196                          * body and the sob.
1197                          */
1198                         append_newlines = "\n";
1199                 } /* else, the buffer already ends with two newlines. */
1200
1201                 if (append_newlines)
1202                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1203                                 append_newlines, strlen(append_newlines));
1204         }
1205
1206         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1207                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1208                                 sob.buf, sob.len);
1209
1210         strbuf_release(&sob);
1211 }