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