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                 !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)
 274 {
 275         struct ref_lock *ref_lock;
 276
 277         read_cache();
 278         if (checkout_fast_forward(from, to, 1))
 279                 exit(1); /* the callee should have complained already */
 280         ref_lock = lock_any_ref_for_update("HEAD", unborn ? null_sha1 : from, 0);
 281         return write_ref_sha1(ref_lock, to, "cherry-pick");
 282 }
 283
 284 static int do_recursive_merge(struct commit *base, struct commit *next,
 285                               const char *base_label, const char *next_label,
 286                               unsigned char *head, struct strbuf *msgbuf,
 287                               struct replay_opts *opts)
 288 {
 289         struct merge_options o;
 290         struct tree *result, *next_tree, *base_tree, *head_tree;
 291         int clean, index_fd;
 292         const char **xopt;
 293         static struct lock_file index_lock;
 294
 295         index_fd = hold_locked_index(&index_lock, 1);
 296
 297         read_cache();
 298
 299         init_merge_options(&o);
 300         o.ancestor = base ? base_label : "(empty tree)";
 301         o.branch1 = "HEAD";
 302         o.branch2 = next ? next_label : "(empty tree)";
 303
 304         head_tree = parse_tree_indirect(head);
 305         next_tree = next ? next->tree : empty_tree();
 306         base_tree = base ? base->tree : empty_tree();
 307
 308         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 309                 parse_merge_opt(&o, *xopt);
 310
 311         clean = merge_trees(&o,
 312                             head_tree,
 313                             next_tree, base_tree, &result);
 314
 315         if (active_cache_changed &&
 316             (write_cache(index_fd, active_cache, active_nr) ||
 317              commit_locked_index(&index_lock)))
 318                 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 319                 die(_("%s: Unable to write new index file"), action_name(opts));
 320         rollback_lock_file(&index_lock);
 321
 322         if (opts->signoff)
 323                 append_signoff(msgbuf, 0, 0);
 324
 325         if (!clean) {
 326                 int i;
 327                 strbuf_addstr(msgbuf, "\nConflicts:\n");
 328                 for (i = 0; i < active_nr;) {
 329                         struct cache_entry *ce = active_cache[i++];
 330                         if (ce_stage(ce)) {
 331                                 strbuf_addch(msgbuf, '\t');
 332                                 strbuf_addstr(msgbuf, ce->name);
 333                                 strbuf_addch(msgbuf, '\n');
 334                                 while (i < active_nr && !strcmp(ce->name,
 335                                                 active_cache[i]->name))
 336                                         i++;
 337                         }
 338                 }
 339         }
 340
 341         return !clean;
 342 }
 343
 344 static int is_index_unchanged(void)
 345 {
 346         unsigned char head_sha1[20];
 347         struct commit *head_commit;
 348
 349         if (!resolve_ref_unsafe("HEAD", head_sha1, 1, NULL))
 350                 return error(_("Could not resolve HEAD commit\n"));
 351
 352         head_commit = lookup_commit(head_sha1);
 353
 354         /*
 355          * If head_commit is NULL, check_commit, called from
 356          * lookup_commit, would have indicated that head_commit is not
 357          * a commit object already.  parse_commit() will return failure
 358          * without further complaints in such a case.  Otherwise, if
 359          * the commit is invalid, parse_commit() will complain.  So
 360          * there is nothing for us to say here.  Just return failure.
 361          */
 362         if (parse_commit(head_commit))
 363                 return -1;
 364
 365         if (!active_cache_tree)
 366                 active_cache_tree = cache_tree();
 367
 368         if (!cache_tree_fully_valid(active_cache_tree))
 369                 if (cache_tree_update(active_cache_tree, active_cache,
 370                                   active_nr, 0))
 371                         return error(_("Unable to update cache tree\n"));
 372
 373         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.sha1);
 374 }
 375
 376 /*
 377  * If we are cherry-pick, and if the merge did not result in
 378  * hand-editing, we will hit this commit and inherit the original
 379  * author date and name.
 380  * If we are revert, or if our cherry-pick results in a hand merge,
 381  * we had better say that the current user is responsible for that.
 382  */
 383 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 384                           int allow_empty)
 385 {
 386         struct argv_array array;
 387         int rc;
 388
 389         argv_array_init(&array);
 390         argv_array_push(&array, "commit");
 391         argv_array_push(&array, "-n");
 392
 393         if (opts->signoff)
 394                 argv_array_push(&array, "-s");
 395         if (!opts->edit) {
 396                 argv_array_push(&array, "-F");
 397                 argv_array_push(&array, defmsg);
 398         }
 399
 400         if (allow_empty)
 401                 argv_array_push(&array, "--allow-empty");
 402
 403         if (opts->allow_empty_message)
 404                 argv_array_push(&array, "--allow-empty-message");
 405
 406         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 407         argv_array_clear(&array);
 408         return rc;
 409 }
 410
 411 static int is_original_commit_empty(struct commit *commit)
 412 {
 413         const unsigned char *ptree_sha1;
 414
 415         if (parse_commit(commit))
 416                 return error(_("Could not parse commit %s\n"),
 417                              sha1_to_hex(commit->object.sha1));
 418         if (commit->parents) {
 419                 struct commit *parent = commit->parents->item;
 420                 if (parse_commit(parent))
 421                         return error(_("Could not parse parent commit %s\n"),
 422                                 sha1_to_hex(parent->object.sha1));
 423                 ptree_sha1 = parent->tree->object.sha1;
 424         } else {
 425                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 426         }
 427
 428         return !hashcmp(ptree_sha1, commit->tree->object.sha1);
 429 }
 430
 431 /*
 432  * Do we run "git commit" with "--allow-empty"?
 433  */
 434 static int allow_empty(struct replay_opts *opts, struct commit *commit)
 435 {
 436         int index_unchanged, empty_commit;
 437
 438         /*
 439          * Three cases:
 440          *
 441          * (1) we do not allow empty at all and error out.
 442          *
 443          * (2) we allow ones that were initially empty, but
 444          * forbid the ones that become empty;
 445          *
 446          * (3) we allow both.
 447          */
 448         if (!opts->allow_empty)
 449                 return 0; /* let "git commit" barf as necessary */
 450
 451         index_unchanged = is_index_unchanged();
 452         if (index_unchanged < 0)
 453                 return index_unchanged;
 454         if (!index_unchanged)
 455                 return 0; /* we do not have to say --allow-empty */
 456
 457         if (opts->keep_redundant_commits)
 458                 return 1;
 459
 460         empty_commit = is_original_commit_empty(commit);
 461         if (empty_commit < 0)
 462                 return empty_commit;
 463         if (!empty_commit)
 464                 return 0;
 465         else
 466                 return 1;
 467 }
 468
 469 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 470 {
 471         unsigned char head[20];
 472         struct commit *base, *next, *parent;
 473         const char *base_label, *next_label;
 474         struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
 475         char *defmsg = NULL;
 476         struct strbuf msgbuf = STRBUF_INIT;
 477         int res, unborn = 0, allow;
 478
 479         if (opts->no_commit) {
 480                 /*
 481                  * We do not intend to commit immediately.  We just want to
 482                  * merge the differences in, so let's compute the tree
 483                  * that represents the "current" state for merge-recursive
 484                  * to work on.
 485                  */
 486                 if (write_cache_as_tree(head, 0, NULL))
 487                         die (_("Your index file is unmerged."));
 488         } else {
 489                 unborn = get_sha1("HEAD", head);
 490                 if (unborn)
 491                         hashcpy(head, EMPTY_TREE_SHA1_BIN);
 492                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
 493                         return error_dirty_index(opts);
 494         }
 495         discard_cache();
 496
 497         if (!commit->parents) {
 498                 parent = NULL;
 499         }
 500         else if (commit->parents->next) {
 501                 /* Reverting or cherry-picking a merge commit */
 502                 int cnt;
 503                 struct commit_list *p;
 504
 505                 if (!opts->mainline)
 506                         return error(_("Commit %s is a merge but no -m option was given."),
 507                                 sha1_to_hex(commit->object.sha1));
 508
 509                 for (cnt = 1, p = commit->parents;
 510                      cnt != opts->mainline && p;
 511                      cnt++)
 512                         p = p->next;
 513                 if (cnt != opts->mainline || !p)
 514                         return error(_("Commit %s does not have parent %d"),
 515                                 sha1_to_hex(commit->object.sha1), opts->mainline);
 516                 parent = p->item;
 517         } else if (0 < opts->mainline)
 518                 return error(_("Mainline was specified but commit %s is not a merge."),
 519                         sha1_to_hex(commit->object.sha1));
 520         else
 521                 parent = commit->parents->item;
 522
 523         if (opts->allow_ff &&
 524             ((parent && !hashcmp(parent->object.sha1, head)) ||
 525              (!parent && unborn)))
 526              return fast_forward_to(commit->object.sha1, head, unborn);
 527
 528         if (parent && parse_commit(parent) < 0)
 529                 /* TRANSLATORS: The first %s will be "revert" or
 530                    "cherry-pick", the second %s a SHA1 */
 531                 return error(_("%s: cannot parse parent commit %s"),
 532                         action_name(opts), sha1_to_hex(parent->object.sha1));
 533
 534         if (get_message(commit, &msg) != 0)
 535                 return error(_("Cannot get commit message for %s"),
 536                         sha1_to_hex(commit->object.sha1));
 537
 538         /*
 539          * "commit" is an existing commit.  We would want to apply
 540          * the difference it introduces since its first parent "prev"
 541          * on top of the current HEAD if we are cherry-pick.  Or the
 542          * reverse of it if we are revert.
 543          */
 544
 545         defmsg = git_pathdup("MERGE_MSG");
 546
 547         if (opts->action == REPLAY_REVERT) {
 548                 base = commit;
 549                 base_label = msg.label;
 550                 next = parent;
 551                 next_label = msg.parent_label;
 552                 strbuf_addstr(&msgbuf, "Revert \"");
 553                 strbuf_addstr(&msgbuf, msg.subject);
 554                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 555                 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 556
 557                 if (commit->parents && commit->parents->next) {
 558                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 559                         strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
 560                 }
 561                 strbuf_addstr(&msgbuf, ".\n");
 562         } else {
 563                 const char *p;
 564
 565                 base = parent;
 566                 base_label = msg.parent_label;
 567                 next = commit;
 568                 next_label = msg.label;
 569
 570                 /*
 571                  * Append the commit log message to msgbuf; it starts
 572                  * after the tree, parent, author, committer
 573                  * information followed by "\n\n".
 574                  */
 575                 p = strstr(msg.message, "\n\n");
 576                 if (p) {
 577                         p += 2;
 578                         strbuf_addstr(&msgbuf, p);
 579                 }
 580
 581                 if (opts->record_origin) {
 582                         if (!has_conforming_footer(&msgbuf, NULL, 0))
 583                                 strbuf_addch(&msgbuf, '\n');
 584                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
 585                         strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 586                         strbuf_addstr(&msgbuf, ")\n");
 587                 }
 588         }
 589
 590         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 591                 res = do_recursive_merge(base, next, base_label, next_label,
 592                                          head, &msgbuf, opts);
 593                 write_message(&msgbuf, defmsg);
 594         } else {
 595                 struct commit_list *common = NULL;
 596                 struct commit_list *remotes = NULL;
 597
 598                 write_message(&msgbuf, defmsg);
 599
 600                 commit_list_insert(base, &common);
 601                 commit_list_insert(next, &remotes);
 602                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 603                                         common, sha1_to_hex(head), remotes);
 604                 free_commit_list(common);
 605                 free_commit_list(remotes);
 606         }
 607
 608         /*
 609          * If the merge was clean or if it failed due to conflict, we write
 610          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 611          * However, if the merge did not even start, then we don't want to
 612          * write it at all.
 613          */
 614         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 615                 write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
 616         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 617                 write_cherry_pick_head(commit, "REVERT_HEAD");
 618
 619         if (res) {
 620                 error(opts->action == REPLAY_REVERT
 621                       ? _("could not revert %s... %s")
 622                       : _("could not apply %s... %s"),
 623                       find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
 624                       msg.subject);
 625                 print_advice(res == 1, opts);
 626                 rerere(opts->allow_rerere_auto);
 627                 goto leave;
 628         }
 629
 630         allow = allow_empty(opts, commit);
 631         if (allow < 0)
 632                 return allow;
 633         if (!opts->no_commit)
 634                 res = run_git_commit(defmsg, opts, allow);
 635
 636 leave:
 637         free_message(&msg);
 638         free(defmsg);
 639
 640         return res;
 641 }
 642
 643 static void prepare_revs(struct replay_opts *opts)
 644 {
 645         /*
 646          * picking (but not reverting) ranges (but not individual revisions)
 647          * should be done in reverse
 648          */
 649         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 650                 opts->revs->reverse ^= 1;
 651
 652         if (prepare_revision_walk(opts->revs))
 653                 die(_("revision walk setup failed"));
 654
 655         if (!opts->revs->commits)
 656                 die(_("empty commit set passed"));
 657 }
 658
 659 static void read_and_refresh_cache(struct replay_opts *opts)
 660 {
 661         static struct lock_file index_lock;
 662         int index_fd = hold_locked_index(&index_lock, 0);
 663         if (read_index_preload(&the_index, NULL) < 0)
 664                 die(_("git %s: failed to read the index"), action_name(opts));
 665         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 666         if (the_index.cache_changed) {
 667                 if (write_index(&the_index, index_fd) ||
 668                     commit_locked_index(&index_lock))
 669                         die(_("git %s: failed to refresh the index"), action_name(opts));
 670         }
 671         rollback_lock_file(&index_lock);
 672 }
 673
 674 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 675                 struct replay_opts *opts)
 676 {
 677         struct commit_list *cur = NULL;
 678         const char *sha1_abbrev = NULL;
 679         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 680         const char *subject;
 681         int subject_len;
 682
 683         for (cur = todo_list; cur; cur = cur->next) {
 684                 sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
 685                 subject_len = find_commit_subject(cur->item->buffer, &subject);
 686                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 687                         subject_len, subject);
 688         }
 689         return 0;
 690 }
 691
 692 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 693 {
 694         unsigned char commit_sha1[20];
 695         enum replay_action action;
 696         char *end_of_object_name;
 697         int saved, status, padding;
 698
 699         if (!prefixcmp(bol, "pick")) {
 700                 action = REPLAY_PICK;
 701                 bol += strlen("pick");
 702         } else if (!prefixcmp(bol, "revert")) {
 703                 action = REPLAY_REVERT;
 704                 bol += strlen("revert");
 705         } else
 706                 return NULL;
 707
 708         /* Eat up extra spaces/ tabs before object name */
 709         padding = strspn(bol, " \t");
 710         if (!padding)
 711                 return NULL;
 712         bol += padding;
 713
 714         end_of_object_name = bol + strcspn(bol, " \t\n");
 715         saved = *end_of_object_name;
 716         *end_of_object_name = '\0';
 717         status = get_sha1(bol, commit_sha1);
 718         *end_of_object_name = saved;
 719
 720         /*
 721          * Verify that the action matches up with the one in
 722          * opts; we don't support arbitrary instructions
 723          */
 724         if (action != opts->action) {
 725                 const char *action_str;
 726                 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
 727                 error(_("Cannot %s during a %s"), action_str, action_name(opts));
 728                 return NULL;
 729         }
 730
 731         if (status < 0)
 732                 return NULL;
 733
 734         return lookup_commit_reference(commit_sha1);
 735 }
 736
 737 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
 738                         struct replay_opts *opts)
 739 {
 740         struct commit_list **next = todo_list;
 741         struct commit *commit;
 742         char *p = buf;
 743         int i;
 744
 745         for (i = 1; *p; i++) {
 746                 char *eol = strchrnul(p, '\n');
 747                 commit = parse_insn_line(p, eol, opts);
 748                 if (!commit)
 749                         return error(_("Could not parse line %d."), i);
 750                 next = commit_list_append(commit, next);
 751                 p = *eol ? eol + 1 : eol;
 752         }
 753         if (!*todo_list)
 754                 return error(_("No commits parsed."));
 755         return 0;
 756 }
 757
 758 static void read_populate_todo(struct commit_list **todo_list,
 759                         struct replay_opts *opts)
 760 {
 761         const char *todo_file = git_path(SEQ_TODO_FILE);
 762         struct strbuf buf = STRBUF_INIT;
 763         int fd, res;
 764
 765         fd = open(todo_file, O_RDONLY);
 766         if (fd < 0)
 767                 die_errno(_("Could not open %s"), todo_file);
 768         if (strbuf_read(&buf, fd, 0) < 0) {
 769                 close(fd);
 770                 strbuf_release(&buf);
 771                 die(_("Could not read %s."), todo_file);
 772         }
 773         close(fd);
 774
 775         res = parse_insn_buffer(buf.buf, todo_list, opts);
 776         strbuf_release(&buf);
 777         if (res)
 778                 die(_("Unusable instruction sheet: %s"), todo_file);
 779 }
 780
 781 static int populate_opts_cb(const char *key, const char *value, void *data)
 782 {
 783         struct replay_opts *opts = data;
 784         int error_flag = 1;
 785
 786         if (!value)
 787                 error_flag = 0;
 788         else if (!strcmp(key, "options.no-commit"))
 789                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 790         else if (!strcmp(key, "options.edit"))
 791                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
 792         else if (!strcmp(key, "options.signoff"))
 793                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 794         else if (!strcmp(key, "options.record-origin"))
 795                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 796         else if (!strcmp(key, "options.allow-ff"))
 797                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 798         else if (!strcmp(key, "options.mainline"))
 799                 opts->mainline = git_config_int(key, value);
 800         else if (!strcmp(key, "options.strategy"))
 801                 git_config_string(&opts->strategy, key, value);
 802         else if (!strcmp(key, "options.strategy-option")) {
 803                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 804                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
 805         } else
 806                 return error(_("Invalid key: %s"), key);
 807
 808         if (!error_flag)
 809                 return error(_("Invalid value for %s: %s"), key, value);
 810
 811         return 0;
 812 }
 813
 814 static void read_populate_opts(struct replay_opts **opts_ptr)
 815 {
 816         const char *opts_file = git_path(SEQ_OPTS_FILE);
 817
 818         if (!file_exists(opts_file))
 819                 return;
 820         if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
 821                 die(_("Malformed options sheet: %s"), opts_file);
 822 }
 823
 824 static void walk_revs_populate_todo(struct commit_list **todo_list,
 825                                 struct replay_opts *opts)
 826 {
 827         struct commit *commit;
 828         struct commit_list **next;
 829
 830         prepare_revs(opts);
 831
 832         next = todo_list;
 833         while ((commit = get_revision(opts->revs)))
 834                 next = commit_list_append(commit, next);
 835 }
 836
 837 static int create_seq_dir(void)
 838 {
 839         const char *seq_dir = git_path(SEQ_DIR);
 840
 841         if (file_exists(seq_dir)) {
 842                 error(_("a cherry-pick or revert is already in progress"));
 843                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 844                 return -1;
 845         }
 846         else if (mkdir(seq_dir, 0777) < 0)
 847                 die_errno(_("Could not create sequencer directory %s"), seq_dir);
 848         return 0;
 849 }
 850
 851 static void save_head(const char *head)
 852 {
 853         const char *head_file = git_path(SEQ_HEAD_FILE);
 854         static struct lock_file head_lock;
 855         struct strbuf buf = STRBUF_INIT;
 856         int fd;
 857
 858         fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
 859         strbuf_addf(&buf, "%s\n", head);
 860         if (write_in_full(fd, buf.buf, buf.len) < 0)
 861                 die_errno(_("Could not write to %s"), head_file);
 862         if (commit_lock_file(&head_lock) < 0)
 863                 die(_("Error wrapping up %s."), head_file);
 864 }
 865
 866 static int reset_for_rollback(const unsigned char *sha1)
 867 {
 868         const char *argv[4];    /* reset --merge <arg> + NULL */
 869         argv[0] = "reset";
 870         argv[1] = "--merge";
 871         argv[2] = sha1_to_hex(sha1);
 872         argv[3] = NULL;
 873         return run_command_v_opt(argv, RUN_GIT_CMD);
 874 }
 875
 876 static int rollback_single_pick(void)
 877 {
 878         unsigned char head_sha1[20];
 879
 880         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
 881             !file_exists(git_path("REVERT_HEAD")))
 882                 return error(_("no cherry-pick or revert in progress"));
 883         if (read_ref_full("HEAD", head_sha1, 0, NULL))
 884                 return error(_("cannot resolve HEAD"));
 885         if (is_null_sha1(head_sha1))
 886                 return error(_("cannot abort from a branch yet to be born"));
 887         return reset_for_rollback(head_sha1);
 888 }
 889
 890 static int sequencer_rollback(struct replay_opts *opts)
 891 {
 892         const char *filename;
 893         FILE *f;
 894         unsigned char sha1[20];
 895         struct strbuf buf = STRBUF_INIT;
 896
 897         filename = git_path(SEQ_HEAD_FILE);
 898         f = fopen(filename, "r");
 899         if (!f && errno == ENOENT) {
 900                 /*
 901                  * There is no multiple-cherry-pick in progress.
 902                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 903                  * a single-cherry-pick in progress, abort that.
 904                  */
 905                 return rollback_single_pick();
 906         }
 907         if (!f)
 908                 return error(_("cannot open %s: %s"), filename,
 909                                                 strerror(errno));
 910         if (strbuf_getline(&buf, f, '\n')) {
 911                 error(_("cannot read %s: %s"), filename, ferror(f) ?
 912                         strerror(errno) : _("unexpected end of file"));
 913                 fclose(f);
 914                 goto fail;
 915         }
 916         fclose(f);
 917         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 918                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 919                         filename);
 920                 goto fail;
 921         }
 922         if (reset_for_rollback(sha1))
 923                 goto fail;
 924         remove_sequencer_state();
 925         strbuf_release(&buf);
 926         return 0;
 927 fail:
 928         strbuf_release(&buf);
 929         return -1;
 930 }
 931
 932 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 933 {
 934         const char *todo_file = git_path(SEQ_TODO_FILE);
 935         static struct lock_file todo_lock;
 936         struct strbuf buf = STRBUF_INIT;
 937         int fd;
 938
 939         fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
 940         if (format_todo(&buf, todo_list, opts) < 0)
 941                 die(_("Could not format %s."), todo_file);
 942         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 943                 strbuf_release(&buf);
 944                 die_errno(_("Could not write to %s"), todo_file);
 945         }
 946         if (commit_lock_file(&todo_lock) < 0) {
 947                 strbuf_release(&buf);
 948                 die(_("Error wrapping up %s."), todo_file);
 949         }
 950         strbuf_release(&buf);
 951 }
 952
 953 static void save_opts(struct replay_opts *opts)
 954 {
 955         const char *opts_file = git_path(SEQ_OPTS_FILE);
 956
 957         if (opts->no_commit)
 958                 git_config_set_in_file(opts_file, "options.no-commit", "true");
 959         if (opts->edit)
 960                 git_config_set_in_file(opts_file, "options.edit", "true");
 961         if (opts->signoff)
 962                 git_config_set_in_file(opts_file, "options.signoff", "true");
 963         if (opts->record_origin)
 964                 git_config_set_in_file(opts_file, "options.record-origin", "true");
 965         if (opts->allow_ff)
 966                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
 967         if (opts->mainline) {
 968                 struct strbuf buf = STRBUF_INIT;
 969                 strbuf_addf(&buf, "%d", opts->mainline);
 970                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
 971                 strbuf_release(&buf);
 972         }
 973         if (opts->strategy)
 974                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
 975         if (opts->xopts) {
 976                 int i;
 977                 for (i = 0; i < opts->xopts_nr; i++)
 978                         git_config_set_multivar_in_file(opts_file,
 979                                                         "options.strategy-option",
 980                                                         opts->xopts[i], "^$", 0);
 981         }
 982 }
 983
 984 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
 985 {
 986         struct commit_list *cur;
 987         int res;
 988
 989         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
 990         if (opts->allow_ff)
 991                 assert(!(opts->signoff || opts->no_commit ||
 992                                 opts->record_origin || opts->edit));
 993         read_and_refresh_cache(opts);
 994
 995         for (cur = todo_list; cur; cur = cur->next) {
 996                 save_todo(cur, opts);
 997                 res = do_pick_commit(cur->item, opts);
 998                 if (res)
 999                         return res;
1000         }
1001
1002         /*
1003          * Sequence of picks finished successfully; cleanup by
1004          * removing the .git/sequencer directory
1005          */
1006         remove_sequencer_state();
1007         return 0;
1008 }
1009
1010 static int continue_single_pick(void)
1011 {
1012         const char *argv[] = { "commit", NULL };
1013
1014         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
1015             !file_exists(git_path("REVERT_HEAD")))
1016                 return error(_("no cherry-pick or revert in progress"));
1017         return run_command_v_opt(argv, RUN_GIT_CMD);
1018 }
1019
1020 static int sequencer_continue(struct replay_opts *opts)
1021 {
1022         struct commit_list *todo_list = NULL;
1023
1024         if (!file_exists(git_path(SEQ_TODO_FILE)))
1025                 return continue_single_pick();
1026         read_populate_opts(&opts);
1027         read_populate_todo(&todo_list, opts);
1028
1029         /* Verify that the conflict has been resolved */
1030         if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
1031             file_exists(git_path("REVERT_HEAD"))) {
1032                 int ret = continue_single_pick();
1033                 if (ret)
1034                         return ret;
1035         }
1036         if (index_differs_from("HEAD", 0))
1037                 return error_dirty_index(opts);
1038         todo_list = todo_list->next;
1039         return pick_commits(todo_list, opts);
1040 }
1041
1042 static int single_pick(struct commit *cmit, struct replay_opts *opts)
1043 {
1044         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1045         return do_pick_commit(cmit, opts);
1046 }
1047
1048 int sequencer_pick_revisions(struct replay_opts *opts)
1049 {
1050         struct commit_list *todo_list = NULL;
1051         unsigned char sha1[20];
1052         int i;
1053
1054         if (opts->subcommand == REPLAY_NONE)
1055                 assert(opts->revs);
1056
1057         read_and_refresh_cache(opts);
1058
1059         /*
1060          * Decide what to do depending on the arguments; a fresh
1061          * cherry-pick should be handled differently from an existing
1062          * one that is being continued
1063          */
1064         if (opts->subcommand == REPLAY_REMOVE_STATE) {
1065                 remove_sequencer_state();
1066                 return 0;
1067         }
1068         if (opts->subcommand == REPLAY_ROLLBACK)
1069                 return sequencer_rollback(opts);
1070         if (opts->subcommand == REPLAY_CONTINUE)
1071                 return sequencer_continue(opts);
1072
1073         for (i = 0; i < opts->revs->pending.nr; i++) {
1074                 unsigned char sha1[20];
1075                 const char *name = opts->revs->pending.objects[i].name;
1076
1077                 /* This happens when using --stdin. */
1078                 if (!strlen(name))
1079                         continue;
1080
1081                 if (!get_sha1(name, sha1)) {
1082                         if (!lookup_commit_reference_gently(sha1, 1)) {
1083                                 enum object_type type = sha1_object_info(sha1, NULL);
1084                                 die(_("%s: can't cherry-pick a %s"), name, typename(type));
1085                         }
1086                 } else
1087                         die(_("%s: bad revision"), name);
1088         }
1089
1090         /*
1091          * If we were called as "git cherry-pick <commit>", just
1092          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1093          * REVERT_HEAD, and don't touch the sequencer state.
1094          * This means it is possible to cherry-pick in the middle
1095          * of a cherry-pick sequence.
1096          */
1097         if (opts->revs->cmdline.nr == 1 &&
1098             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1099             opts->revs->no_walk &&
1100             !opts->revs->cmdline.rev->flags) {
1101                 struct commit *cmit;
1102                 if (prepare_revision_walk(opts->revs))
1103                         die(_("revision walk setup failed"));
1104                 cmit = get_revision(opts->revs);
1105                 if (!cmit || get_revision(opts->revs))
1106                         die("BUG: expected exactly one commit from walk");
1107                 return single_pick(cmit, opts);
1108         }
1109
1110         /*
1111          * Start a new cherry-pick/ revert sequence; but
1112          * first, make sure that an existing one isn't in
1113          * progress
1114          */
1115
1116         walk_revs_populate_todo(&todo_list, opts);
1117         if (create_seq_dir() < 0)
1118                 return -1;
1119         if (get_sha1("HEAD", sha1)) {
1120                 if (opts->action == REPLAY_REVERT)
1121                         return error(_("Can't revert as initial commit"));
1122                 return error(_("Can't cherry-pick into empty head"));
1123         }
1124         save_head(sha1_to_hex(sha1));
1125         save_opts(opts);
1126         return pick_commits(todo_list, opts);
1127 }
1128
1129 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1130 {
1131         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1132         struct strbuf sob = STRBUF_INIT;
1133         int has_footer;
1134
1135         strbuf_addstr(&sob, sign_off_header);
1136         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1137                                 getenv("GIT_COMMITTER_EMAIL")));
1138         strbuf_addch(&sob, '\n');
1139
1140         /*
1141          * If the whole message buffer is equal to the sob, pretend that we
1142          * found a conforming footer with a matching sob
1143          */
1144         if (msgbuf->len - ignore_footer == sob.len &&
1145             !strncmp(msgbuf->buf, sob.buf, sob.len))
1146                 has_footer = 3;
1147         else
1148                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1149
1150         if (!has_footer) {
1151                 const char *append_newlines = NULL;
1152                 size_t len = msgbuf->len - ignore_footer;
1153
1154                 if (!len) {
1155                         /*
1156                          * The buffer is completely empty.  Leave foom for
1157                          * the title and body to be filled in by the user.
1158                          */
1159                         append_newlines = "\n\n";
1160                 } else if (msgbuf->buf[len - 1] != '\n') {
1161                         /*
1162                          * Incomplete line.  Complete the line and add a
1163                          * blank one so that there is an empty line between
1164                          * the message body and the sob.
1165                          */
1166                         append_newlines = "\n\n";
1167                 } else if (len == 1) {
1168                         /*
1169                          * Buffer contains a single newline.  Add another
1170                          * so that we leave room for the title and body.
1171                          */
1172                         append_newlines = "\n";
1173                 } else if (msgbuf->buf[len - 2] != '\n') {
1174                         /*
1175                          * Buffer ends with a single newline.  Add another
1176                          * so that there is an empty line between the message
1177                          * body and the sob.
1178                          */
1179                         append_newlines = "\n";
1180                 } /* else, the buffer already ends with two newlines. */
1181
1182                 if (append_newlines)
1183                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1184                                 append_newlines, strlen(append_newlines));
1185         }
1186
1187         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1188                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1189                                 sob.buf, sob.len);
1190
1191         strbuf_release(&sob);
1192 }