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         strbuf_addf(&sb, "%s: fast-forward", action_name(opts));
 285         ret = write_ref_sha1(ref_lock, to, sb.buf);
 286         strbuf_release(&sb);
 287         return ret;
 288 }
 289
 290 static int do_recursive_merge(struct commit *base, struct commit *next,
 291                               const char *base_label, const char *next_label,
 292                               unsigned char *head, struct strbuf *msgbuf,
 293                               struct replay_opts *opts)
 294 {
 295         struct merge_options o;
 296         struct tree *result, *next_tree, *base_tree, *head_tree;
 297         int clean, index_fd;
 298         const char **xopt;
 299         static struct lock_file index_lock;
 300
 301         index_fd = hold_locked_index(&index_lock, 1);
 302
 303         read_cache();
 304
 305         init_merge_options(&o);
 306         o.ancestor = base ? base_label : "(empty tree)";
 307         o.branch1 = "HEAD";
 308         o.branch2 = next ? next_label : "(empty tree)";
 309
 310         head_tree = parse_tree_indirect(head);
 311         next_tree = next ? next->tree : empty_tree();
 312         base_tree = base ? base->tree : empty_tree();
 313
 314         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 315                 parse_merge_opt(&o, *xopt);
 316
 317         clean = merge_trees(&o,
 318                             head_tree,
 319                             next_tree, base_tree, &result);
 320
 321         if (active_cache_changed &&
 322             (write_cache(index_fd, active_cache, active_nr) ||
 323              commit_locked_index(&index_lock)))
 324                 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 325                 die(_("%s: Unable to write new index file"), action_name(opts));
 326         rollback_lock_file(&index_lock);
 327
 328         if (opts->signoff)
 329                 append_signoff(msgbuf, 0, 0);
 330
 331         if (!clean) {
 332                 int i;
 333                 strbuf_addstr(msgbuf, "\nConflicts:\n");
 334                 for (i = 0; i < active_nr;) {
 335                         const struct cache_entry *ce = active_cache[i++];
 336                         if (ce_stage(ce)) {
 337                                 strbuf_addch(msgbuf, '\t');
 338                                 strbuf_addstr(msgbuf, ce->name);
 339                                 strbuf_addch(msgbuf, '\n');
 340                                 while (i < active_nr && !strcmp(ce->name,
 341                                                 active_cache[i]->name))
 342                                         i++;
 343                         }
 344                 }
 345         }
 346
 347         return !clean;
 348 }
 349
 350 static int is_index_unchanged(void)
 351 {
 352         unsigned char head_sha1[20];
 353         struct commit *head_commit;
 354
 355         if (!resolve_ref_unsafe("HEAD", head_sha1, 1, NULL))
 356                 return error(_("Could not resolve HEAD commit\n"));
 357
 358         head_commit = lookup_commit(head_sha1);
 359
 360         /*
 361          * If head_commit is NULL, check_commit, called from
 362          * lookup_commit, would have indicated that head_commit is not
 363          * a commit object already.  parse_commit() will return failure
 364          * without further complaints in such a case.  Otherwise, if
 365          * the commit is invalid, parse_commit() will complain.  So
 366          * there is nothing for us to say here.  Just return failure.
 367          */
 368         if (parse_commit(head_commit))
 369                 return -1;
 370
 371         if (!active_cache_tree)
 372                 active_cache_tree = cache_tree();
 373
 374         if (!cache_tree_fully_valid(active_cache_tree))
 375                 if (cache_tree_update(active_cache_tree,
 376                                       (const struct cache_entry * const *)active_cache,
 377                                       active_nr, 0))
 378                         return error(_("Unable to update cache tree\n"));
 379
 380         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.sha1);
 381 }
 382
 383 /*
 384  * If we are cherry-pick, and if the merge did not result in
 385  * hand-editing, we will hit this commit and inherit the original
 386  * author date and name.
 387  * If we are revert, or if our cherry-pick results in a hand merge,
 388  * we had better say that the current user is responsible for that.
 389  */
 390 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 391                           int allow_empty)
 392 {
 393         struct argv_array array;
 394         int rc;
 395         char *gpg_sign;
 396
 397         argv_array_init(&array);
 398         argv_array_push(&array, "commit");
 399         argv_array_push(&array, "-n");
 400
 401         if (opts->gpg_sign) {
 402                 gpg_sign = xmalloc(3 + strlen(opts->gpg_sign));
 403                 sprintf(gpg_sign, "-S%s", opts->gpg_sign);
 404                 argv_array_push(&array, gpg_sign);
 405                 free(gpg_sign);
 406         }
 407         if (opts->signoff)
 408                 argv_array_push(&array, "-s");
 409         if (!opts->edit) {
 410                 argv_array_push(&array, "-F");
 411                 argv_array_push(&array, defmsg);
 412         }
 413
 414         if (allow_empty)
 415                 argv_array_push(&array, "--allow-empty");
 416
 417         if (opts->allow_empty_message)
 418                 argv_array_push(&array, "--allow-empty-message");
 419
 420         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 421         argv_array_clear(&array);
 422         return rc;
 423 }
 424
 425 static int is_original_commit_empty(struct commit *commit)
 426 {
 427         const unsigned char *ptree_sha1;
 428
 429         if (parse_commit(commit))
 430                 return error(_("Could not parse commit %s\n"),
 431                              sha1_to_hex(commit->object.sha1));
 432         if (commit->parents) {
 433                 struct commit *parent = commit->parents->item;
 434                 if (parse_commit(parent))
 435                         return error(_("Could not parse parent commit %s\n"),
 436                                 sha1_to_hex(parent->object.sha1));
 437                 ptree_sha1 = parent->tree->object.sha1;
 438         } else {
 439                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 440         }
 441
 442         return !hashcmp(ptree_sha1, commit->tree->object.sha1);
 443 }
 444
 445 /*
 446  * Do we run "git commit" with "--allow-empty"?
 447  */
 448 static int allow_empty(struct replay_opts *opts, struct commit *commit)
 449 {
 450         int index_unchanged, empty_commit;
 451
 452         /*
 453          * Three cases:
 454          *
 455          * (1) we do not allow empty at all and error out.
 456          *
 457          * (2) we allow ones that were initially empty, but
 458          * forbid the ones that become empty;
 459          *
 460          * (3) we allow both.
 461          */
 462         if (!opts->allow_empty)
 463                 return 0; /* let "git commit" barf as necessary */
 464
 465         index_unchanged = is_index_unchanged();
 466         if (index_unchanged < 0)
 467                 return index_unchanged;
 468         if (!index_unchanged)
 469                 return 0; /* we do not have to say --allow-empty */
 470
 471         if (opts->keep_redundant_commits)
 472                 return 1;
 473
 474         empty_commit = is_original_commit_empty(commit);
 475         if (empty_commit < 0)
 476                 return empty_commit;
 477         if (!empty_commit)
 478                 return 0;
 479         else
 480                 return 1;
 481 }
 482
 483 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 484 {
 485         unsigned char head[20];
 486         struct commit *base, *next, *parent;
 487         const char *base_label, *next_label;
 488         struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
 489         char *defmsg = NULL;
 490         struct strbuf msgbuf = STRBUF_INIT;
 491         int res, unborn = 0, allow;
 492
 493         if (opts->no_commit) {
 494                 /*
 495                  * We do not intend to commit immediately.  We just want to
 496                  * merge the differences in, so let's compute the tree
 497                  * that represents the "current" state for merge-recursive
 498                  * to work on.
 499                  */
 500                 if (write_cache_as_tree(head, 0, NULL))
 501                         die (_("Your index file is unmerged."));
 502         } else {
 503                 unborn = get_sha1("HEAD", head);
 504                 if (unborn)
 505                         hashcpy(head, EMPTY_TREE_SHA1_BIN);
 506                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
 507                         return error_dirty_index(opts);
 508         }
 509         discard_cache();
 510
 511         if (!commit->parents) {
 512                 parent = NULL;
 513         }
 514         else if (commit->parents->next) {
 515                 /* Reverting or cherry-picking a merge commit */
 516                 int cnt;
 517                 struct commit_list *p;
 518
 519                 if (!opts->mainline)
 520                         return error(_("Commit %s is a merge but no -m option was given."),
 521                                 sha1_to_hex(commit->object.sha1));
 522
 523                 for (cnt = 1, p = commit->parents;
 524                      cnt != opts->mainline && p;
 525                      cnt++)
 526                         p = p->next;
 527                 if (cnt != opts->mainline || !p)
 528                         return error(_("Commit %s does not have parent %d"),
 529                                 sha1_to_hex(commit->object.sha1), opts->mainline);
 530                 parent = p->item;
 531         } else if (0 < opts->mainline)
 532                 return error(_("Mainline was specified but commit %s is not a merge."),
 533                         sha1_to_hex(commit->object.sha1));
 534         else
 535                 parent = commit->parents->item;
 536
 537         if (opts->allow_ff &&
 538             ((parent && !hashcmp(parent->object.sha1, head)) ||
 539              (!parent && unborn)))
 540                 return fast_forward_to(commit->object.sha1, head, unborn, opts);
 541
 542         if (parent && parse_commit(parent) < 0)
 543                 /* TRANSLATORS: The first %s will be "revert" or
 544                    "cherry-pick", the second %s a SHA1 */
 545                 return error(_("%s: cannot parse parent commit %s"),
 546                         action_name(opts), sha1_to_hex(parent->object.sha1));
 547
 548         if (get_message(commit, &msg) != 0)
 549                 return error(_("Cannot get commit message for %s"),
 550                         sha1_to_hex(commit->object.sha1));
 551
 552         /*
 553          * "commit" is an existing commit.  We would want to apply
 554          * the difference it introduces since its first parent "prev"
 555          * on top of the current HEAD if we are cherry-pick.  Or the
 556          * reverse of it if we are revert.
 557          */
 558
 559         defmsg = git_pathdup("MERGE_MSG");
 560
 561         if (opts->action == REPLAY_REVERT) {
 562                 base = commit;
 563                 base_label = msg.label;
 564                 next = parent;
 565                 next_label = msg.parent_label;
 566                 strbuf_addstr(&msgbuf, "Revert \"");
 567                 strbuf_addstr(&msgbuf, msg.subject);
 568                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 569                 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 570
 571                 if (commit->parents && commit->parents->next) {
 572                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 573                         strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
 574                 }
 575                 strbuf_addstr(&msgbuf, ".\n");
 576         } else {
 577                 const char *p;
 578
 579                 base = parent;
 580                 base_label = msg.parent_label;
 581                 next = commit;
 582                 next_label = msg.label;
 583
 584                 /*
 585                  * Append the commit log message to msgbuf; it starts
 586                  * after the tree, parent, author, committer
 587                  * information followed by "\n\n".
 588                  */
 589                 p = strstr(msg.message, "\n\n");
 590                 if (p) {
 591                         p += 2;
 592                         strbuf_addstr(&msgbuf, p);
 593                 }
 594
 595                 if (opts->record_origin) {
 596                         if (!has_conforming_footer(&msgbuf, NULL, 0))
 597                                 strbuf_addch(&msgbuf, '\n');
 598                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
 599                         strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 600                         strbuf_addstr(&msgbuf, ")\n");
 601                 }
 602         }
 603
 604         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 605                 res = do_recursive_merge(base, next, base_label, next_label,
 606                                          head, &msgbuf, opts);
 607                 write_message(&msgbuf, defmsg);
 608         } else {
 609                 struct commit_list *common = NULL;
 610                 struct commit_list *remotes = NULL;
 611
 612                 write_message(&msgbuf, defmsg);
 613
 614                 commit_list_insert(base, &common);
 615                 commit_list_insert(next, &remotes);
 616                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 617                                         common, sha1_to_hex(head), remotes);
 618                 free_commit_list(common);
 619                 free_commit_list(remotes);
 620         }
 621
 622         /*
 623          * If the merge was clean or if it failed due to conflict, we write
 624          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 625          * However, if the merge did not even start, then we don't want to
 626          * write it at all.
 627          */
 628         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 629                 write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
 630         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 631                 write_cherry_pick_head(commit, "REVERT_HEAD");
 632
 633         if (res) {
 634                 error(opts->action == REPLAY_REVERT
 635                       ? _("could not revert %s... %s")
 636                       : _("could not apply %s... %s"),
 637                       find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
 638                       msg.subject);
 639                 print_advice(res == 1, opts);
 640                 rerere(opts->allow_rerere_auto);
 641                 goto leave;
 642         }
 643
 644         allow = allow_empty(opts, commit);
 645         if (allow < 0) {
 646                 res = allow;
 647                 goto leave;
 648         }
 649         if (!opts->no_commit)
 650                 res = run_git_commit(defmsg, opts, allow);
 651
 652 leave:
 653         free_message(&msg);
 654         free(defmsg);
 655
 656         return res;
 657 }
 658
 659 static void prepare_revs(struct replay_opts *opts)
 660 {
 661         /*
 662          * picking (but not reverting) ranges (but not individual revisions)
 663          * should be done in reverse
 664          */
 665         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 666                 opts->revs->reverse ^= 1;
 667
 668         if (prepare_revision_walk(opts->revs))
 669                 die(_("revision walk setup failed"));
 670
 671         if (!opts->revs->commits)
 672                 die(_("empty commit set passed"));
 673 }
 674
 675 static void read_and_refresh_cache(struct replay_opts *opts)
 676 {
 677         static struct lock_file index_lock;
 678         int index_fd = hold_locked_index(&index_lock, 0);
 679         if (read_index_preload(&the_index, NULL) < 0)
 680                 die(_("git %s: failed to read the index"), action_name(opts));
 681         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 682         if (the_index.cache_changed) {
 683                 if (write_index(&the_index, index_fd) ||
 684                     commit_locked_index(&index_lock))
 685                         die(_("git %s: failed to refresh the index"), action_name(opts));
 686         }
 687         rollback_lock_file(&index_lock);
 688 }
 689
 690 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 691                 struct replay_opts *opts)
 692 {
 693         struct commit_list *cur = NULL;
 694         const char *sha1_abbrev = NULL;
 695         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 696         const char *subject;
 697         int subject_len;
 698
 699         for (cur = todo_list; cur; cur = cur->next) {
 700                 sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
 701                 subject_len = find_commit_subject(cur->item->buffer, &subject);
 702                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 703                         subject_len, subject);
 704         }
 705         return 0;
 706 }
 707
 708 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 709 {
 710         unsigned char commit_sha1[20];
 711         enum replay_action action;
 712         char *end_of_object_name;
 713         int saved, status, padding;
 714
 715         if (starts_with(bol, "pick")) {
 716                 action = REPLAY_PICK;
 717                 bol += strlen("pick");
 718         } else if (starts_with(bol, "revert")) {
 719                 action = REPLAY_REVERT;
 720                 bol += strlen("revert");
 721         } else
 722                 return NULL;
 723
 724         /* Eat up extra spaces/ tabs before object name */
 725         padding = strspn(bol, " \t");
 726         if (!padding)
 727                 return NULL;
 728         bol += padding;
 729
 730         end_of_object_name = bol + strcspn(bol, " \t\n");
 731         saved = *end_of_object_name;
 732         *end_of_object_name = '\0';
 733         status = get_sha1(bol, commit_sha1);
 734         *end_of_object_name = saved;
 735
 736         /*
 737          * Verify that the action matches up with the one in
 738          * opts; we don't support arbitrary instructions
 739          */
 740         if (action != opts->action) {
 741                 const char *action_str;
 742                 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
 743                 error(_("Cannot %s during a %s"), action_str, action_name(opts));
 744                 return NULL;
 745         }
 746
 747         if (status < 0)
 748                 return NULL;
 749
 750         return lookup_commit_reference(commit_sha1);
 751 }
 752
 753 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
 754                         struct replay_opts *opts)
 755 {
 756         struct commit_list **next = todo_list;
 757         struct commit *commit;
 758         char *p = buf;
 759         int i;
 760
 761         for (i = 1; *p; i++) {
 762                 char *eol = strchrnul(p, '\n');
 763                 commit = parse_insn_line(p, eol, opts);
 764                 if (!commit)
 765                         return error(_("Could not parse line %d."), i);
 766                 next = commit_list_append(commit, next);
 767                 p = *eol ? eol + 1 : eol;
 768         }
 769         if (!*todo_list)
 770                 return error(_("No commits parsed."));
 771         return 0;
 772 }
 773
 774 static void read_populate_todo(struct commit_list **todo_list,
 775                         struct replay_opts *opts)
 776 {
 777         const char *todo_file = git_path(SEQ_TODO_FILE);
 778         struct strbuf buf = STRBUF_INIT;
 779         int fd, res;
 780
 781         fd = open(todo_file, O_RDONLY);
 782         if (fd < 0)
 783                 die_errno(_("Could not open %s"), todo_file);
 784         if (strbuf_read(&buf, fd, 0) < 0) {
 785                 close(fd);
 786                 strbuf_release(&buf);
 787                 die(_("Could not read %s."), todo_file);
 788         }
 789         close(fd);
 790
 791         res = parse_insn_buffer(buf.buf, todo_list, opts);
 792         strbuf_release(&buf);
 793         if (res)
 794                 die(_("Unusable instruction sheet: %s"), todo_file);
 795 }
 796
 797 static int populate_opts_cb(const char *key, const char *value, void *data)
 798 {
 799         struct replay_opts *opts = data;
 800         int error_flag = 1;
 801
 802         if (!value)
 803                 error_flag = 0;
 804         else if (!strcmp(key, "options.no-commit"))
 805                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 806         else if (!strcmp(key, "options.edit"))
 807                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
 808         else if (!strcmp(key, "options.signoff"))
 809                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 810         else if (!strcmp(key, "options.record-origin"))
 811                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 812         else if (!strcmp(key, "options.allow-ff"))
 813                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 814         else if (!strcmp(key, "options.mainline"))
 815                 opts->mainline = git_config_int(key, value);
 816         else if (!strcmp(key, "options.strategy"))
 817                 git_config_string(&opts->strategy, key, value);
 818         else if (!strcmp(key, "options.gpg-sign"))
 819                 git_config_string(&opts->gpg_sign, key, value);
 820         else if (!strcmp(key, "options.strategy-option")) {
 821                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 822                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
 823         } else
 824                 return error(_("Invalid key: %s"), key);
 825
 826         if (!error_flag)
 827                 return error(_("Invalid value for %s: %s"), key, value);
 828
 829         return 0;
 830 }
 831
 832 static void read_populate_opts(struct replay_opts **opts_ptr)
 833 {
 834         const char *opts_file = git_path(SEQ_OPTS_FILE);
 835
 836         if (!file_exists(opts_file))
 837                 return;
 838         if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
 839                 die(_("Malformed options sheet: %s"), opts_file);
 840 }
 841
 842 static void walk_revs_populate_todo(struct commit_list **todo_list,
 843                                 struct replay_opts *opts)
 844 {
 845         struct commit *commit;
 846         struct commit_list **next;
 847
 848         prepare_revs(opts);
 849
 850         next = todo_list;
 851         while ((commit = get_revision(opts->revs)))
 852                 next = commit_list_append(commit, next);
 853 }
 854
 855 static int create_seq_dir(void)
 856 {
 857         const char *seq_dir = git_path(SEQ_DIR);
 858
 859         if (file_exists(seq_dir)) {
 860                 error(_("a cherry-pick or revert is already in progress"));
 861                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 862                 return -1;
 863         }
 864         else if (mkdir(seq_dir, 0777) < 0)
 865                 die_errno(_("Could not create sequencer directory %s"), seq_dir);
 866         return 0;
 867 }
 868
 869 static void save_head(const char *head)
 870 {
 871         const char *head_file = git_path(SEQ_HEAD_FILE);
 872         static struct lock_file head_lock;
 873         struct strbuf buf = STRBUF_INIT;
 874         int fd;
 875
 876         fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
 877         strbuf_addf(&buf, "%s\n", head);
 878         if (write_in_full(fd, buf.buf, buf.len) < 0)
 879                 die_errno(_("Could not write to %s"), head_file);
 880         if (commit_lock_file(&head_lock) < 0)
 881                 die(_("Error wrapping up %s."), head_file);
 882 }
 883
 884 static int reset_for_rollback(const unsigned char *sha1)
 885 {
 886         const char *argv[4];    /* reset --merge <arg> + NULL */
 887         argv[0] = "reset";
 888         argv[1] = "--merge";
 889         argv[2] = sha1_to_hex(sha1);
 890         argv[3] = NULL;
 891         return run_command_v_opt(argv, RUN_GIT_CMD);
 892 }
 893
 894 static int rollback_single_pick(void)
 895 {
 896         unsigned char head_sha1[20];
 897
 898         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
 899             !file_exists(git_path("REVERT_HEAD")))
 900                 return error(_("no cherry-pick or revert in progress"));
 901         if (read_ref_full("HEAD", head_sha1, 0, NULL))
 902                 return error(_("cannot resolve HEAD"));
 903         if (is_null_sha1(head_sha1))
 904                 return error(_("cannot abort from a branch yet to be born"));
 905         return reset_for_rollback(head_sha1);
 906 }
 907
 908 static int sequencer_rollback(struct replay_opts *opts)
 909 {
 910         const char *filename;
 911         FILE *f;
 912         unsigned char sha1[20];
 913         struct strbuf buf = STRBUF_INIT;
 914
 915         filename = git_path(SEQ_HEAD_FILE);
 916         f = fopen(filename, "r");
 917         if (!f && errno == ENOENT) {
 918                 /*
 919                  * There is no multiple-cherry-pick in progress.
 920                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 921                  * a single-cherry-pick in progress, abort that.
 922                  */
 923                 return rollback_single_pick();
 924         }
 925         if (!f)
 926                 return error(_("cannot open %s: %s"), filename,
 927                                                 strerror(errno));
 928         if (strbuf_getline(&buf, f, '\n')) {
 929                 error(_("cannot read %s: %s"), filename, ferror(f) ?
 930                         strerror(errno) : _("unexpected end of file"));
 931                 fclose(f);
 932                 goto fail;
 933         }
 934         fclose(f);
 935         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 936                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 937                         filename);
 938                 goto fail;
 939         }
 940         if (reset_for_rollback(sha1))
 941                 goto fail;
 942         remove_sequencer_state();
 943         strbuf_release(&buf);
 944         return 0;
 945 fail:
 946         strbuf_release(&buf);
 947         return -1;
 948 }
 949
 950 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 951 {
 952         const char *todo_file = git_path(SEQ_TODO_FILE);
 953         static struct lock_file todo_lock;
 954         struct strbuf buf = STRBUF_INIT;
 955         int fd;
 956
 957         fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
 958         if (format_todo(&buf, todo_list, opts) < 0)
 959                 die(_("Could not format %s."), todo_file);
 960         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 961                 strbuf_release(&buf);
 962                 die_errno(_("Could not write to %s"), todo_file);
 963         }
 964         if (commit_lock_file(&todo_lock) < 0) {
 965                 strbuf_release(&buf);
 966                 die(_("Error wrapping up %s."), todo_file);
 967         }
 968         strbuf_release(&buf);
 969 }
 970
 971 static void save_opts(struct replay_opts *opts)
 972 {
 973         const char *opts_file = git_path(SEQ_OPTS_FILE);
 974
 975         if (opts->no_commit)
 976                 git_config_set_in_file(opts_file, "options.no-commit", "true");
 977         if (opts->edit)
 978                 git_config_set_in_file(opts_file, "options.edit", "true");
 979         if (opts->signoff)
 980                 git_config_set_in_file(opts_file, "options.signoff", "true");
 981         if (opts->record_origin)
 982                 git_config_set_in_file(opts_file, "options.record-origin", "true");
 983         if (opts->allow_ff)
 984                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
 985         if (opts->mainline) {
 986                 struct strbuf buf = STRBUF_INIT;
 987                 strbuf_addf(&buf, "%d", opts->mainline);
 988                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
 989                 strbuf_release(&buf);
 990         }
 991         if (opts->strategy)
 992                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
 993         if (opts->gpg_sign)
 994                 git_config_set_in_file(opts_file, "options.gpg-sign", opts->gpg_sign);
 995         if (opts->xopts) {
 996                 int i;
 997                 for (i = 0; i < opts->xopts_nr; i++)
 998                         git_config_set_multivar_in_file(opts_file,
 999                                                         "options.strategy-option",
1000                                                         opts->xopts[i], "^$", 0);
1001         }
1002 }
1003
1004 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
1005 {
1006         struct commit_list *cur;
1007         int res;
1008
1009         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1010         if (opts->allow_ff)
1011                 assert(!(opts->signoff || opts->no_commit ||
1012                                 opts->record_origin || opts->edit));
1013         read_and_refresh_cache(opts);
1014
1015         for (cur = todo_list; cur; cur = cur->next) {
1016                 save_todo(cur, opts);
1017                 res = do_pick_commit(cur->item, opts);
1018                 if (res)
1019                         return res;
1020         }
1021
1022         /*
1023          * Sequence of picks finished successfully; cleanup by
1024          * removing the .git/sequencer directory
1025          */
1026         remove_sequencer_state();
1027         return 0;
1028 }
1029
1030 static int continue_single_pick(void)
1031 {
1032         const char *argv[] = { "commit", NULL };
1033
1034         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
1035             !file_exists(git_path("REVERT_HEAD")))
1036                 return error(_("no cherry-pick or revert in progress"));
1037         return run_command_v_opt(argv, RUN_GIT_CMD);
1038 }
1039
1040 static int sequencer_continue(struct replay_opts *opts)
1041 {
1042         struct commit_list *todo_list = NULL;
1043
1044         if (!file_exists(git_path(SEQ_TODO_FILE)))
1045                 return continue_single_pick();
1046         read_populate_opts(&opts);
1047         read_populate_todo(&todo_list, opts);
1048
1049         /* Verify that the conflict has been resolved */
1050         if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
1051             file_exists(git_path("REVERT_HEAD"))) {
1052                 int ret = continue_single_pick();
1053                 if (ret)
1054                         return ret;
1055         }
1056         if (index_differs_from("HEAD", 0))
1057                 return error_dirty_index(opts);
1058         todo_list = todo_list->next;
1059         return pick_commits(todo_list, opts);
1060 }
1061
1062 static int single_pick(struct commit *cmit, struct replay_opts *opts)
1063 {
1064         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1065         return do_pick_commit(cmit, opts);
1066 }
1067
1068 int sequencer_pick_revisions(struct replay_opts *opts)
1069 {
1070         struct commit_list *todo_list = NULL;
1071         unsigned char sha1[20];
1072         int i;
1073
1074         if (opts->subcommand == REPLAY_NONE)
1075                 assert(opts->revs);
1076
1077         read_and_refresh_cache(opts);
1078
1079         /*
1080          * Decide what to do depending on the arguments; a fresh
1081          * cherry-pick should be handled differently from an existing
1082          * one that is being continued
1083          */
1084         if (opts->subcommand == REPLAY_REMOVE_STATE) {
1085                 remove_sequencer_state();
1086                 return 0;
1087         }
1088         if (opts->subcommand == REPLAY_ROLLBACK)
1089                 return sequencer_rollback(opts);
1090         if (opts->subcommand == REPLAY_CONTINUE)
1091                 return sequencer_continue(opts);
1092
1093         for (i = 0; i < opts->revs->pending.nr; i++) {
1094                 unsigned char sha1[20];
1095                 const char *name = opts->revs->pending.objects[i].name;
1096
1097                 /* This happens when using --stdin. */
1098                 if (!strlen(name))
1099                         continue;
1100
1101                 if (!get_sha1(name, sha1)) {
1102                         if (!lookup_commit_reference_gently(sha1, 1)) {
1103                                 enum object_type type = sha1_object_info(sha1, NULL);
1104                                 die(_("%s: can't cherry-pick a %s"), name, typename(type));
1105                         }
1106                 } else
1107                         die(_("%s: bad revision"), name);
1108         }
1109
1110         /*
1111          * If we were called as "git cherry-pick <commit>", just
1112          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1113          * REVERT_HEAD, and don't touch the sequencer state.
1114          * This means it is possible to cherry-pick in the middle
1115          * of a cherry-pick sequence.
1116          */
1117         if (opts->revs->cmdline.nr == 1 &&
1118             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1119             opts->revs->no_walk &&
1120             !opts->revs->cmdline.rev->flags) {
1121                 struct commit *cmit;
1122                 if (prepare_revision_walk(opts->revs))
1123                         die(_("revision walk setup failed"));
1124                 cmit = get_revision(opts->revs);
1125                 if (!cmit || get_revision(opts->revs))
1126                         die("BUG: expected exactly one commit from walk");
1127                 return single_pick(cmit, opts);
1128         }
1129
1130         /*
1131          * Start a new cherry-pick/ revert sequence; but
1132          * first, make sure that an existing one isn't in
1133          * progress
1134          */
1135
1136         walk_revs_populate_todo(&todo_list, opts);
1137         if (create_seq_dir() < 0)
1138                 return -1;
1139         if (get_sha1("HEAD", sha1)) {
1140                 if (opts->action == REPLAY_REVERT)
1141                         return error(_("Can't revert as initial commit"));
1142                 return error(_("Can't cherry-pick into empty head"));
1143         }
1144         save_head(sha1_to_hex(sha1));
1145         save_opts(opts);
1146         return pick_commits(todo_list, opts);
1147 }
1148
1149 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1150 {
1151         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1152         struct strbuf sob = STRBUF_INIT;
1153         int has_footer;
1154
1155         strbuf_addstr(&sob, sign_off_header);
1156         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1157                                 getenv("GIT_COMMITTER_EMAIL")));
1158         strbuf_addch(&sob, '\n');
1159
1160         /*
1161          * If the whole message buffer is equal to the sob, pretend that we
1162          * found a conforming footer with a matching sob
1163          */
1164         if (msgbuf->len - ignore_footer == sob.len &&
1165             !strncmp(msgbuf->buf, sob.buf, sob.len))
1166                 has_footer = 3;
1167         else
1168                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1169
1170         if (!has_footer) {
1171                 const char *append_newlines = NULL;
1172                 size_t len = msgbuf->len - ignore_footer;
1173
1174                 if (!len) {
1175                         /*
1176                          * The buffer is completely empty.  Leave foom for
1177                          * the title and body to be filled in by the user.
1178                          */
1179                         append_newlines = "\n\n";
1180                 } else if (msgbuf->buf[len - 1] != '\n') {
1181                         /*
1182                          * Incomplete line.  Complete the line and add a
1183                          * blank one so that there is an empty line between
1184                          * the message body and the sob.
1185                          */
1186                         append_newlines = "\n\n";
1187                 } else if (len == 1) {
1188                         /*
1189                          * Buffer contains a single newline.  Add another
1190                          * so that we leave room for the title and body.
1191                          */
1192                         append_newlines = "\n";
1193                 } else if (msgbuf->buf[len - 2] != '\n') {
1194                         /*
1195                          * Buffer ends with a single newline.  Add another
1196                          * so that there is an empty line between the message
1197                          * body and the sob.
1198                          */
1199                         append_newlines = "\n";
1200                 } /* else, the buffer already ends with two newlines. */
1201
1202                 if (append_newlines)
1203                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1204                                 append_newlines, strlen(append_newlines));
1205         }
1206
1207         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1208                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1209                                 sob.buf, sob.len);
1210
1211         strbuf_release(&sob);
1212 }