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 void remove_sequencer_state(void)
  24 {
  25         struct strbuf seq_dir = STRBUF_INIT;
  26
  27         strbuf_addf(&seq_dir, "%s", git_path(SEQ_DIR));
  28         remove_dir_recursively(&seq_dir, 0);
  29         strbuf_release(&seq_dir);
  30 }
  31
  32 static const char *action_name(const struct replay_opts *opts)
  33 {
  34         return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
  35 }
  36
  37 static char *get_encoding(const char *message);
  38
  39 struct commit_message {
  40         char *parent_label;
  41         const char *label;
  42         const char *subject;
  43         char *reencoded_message;
  44         const char *message;
  45 };
  46
  47 static int get_message(struct commit *commit, struct commit_message *out)
  48 {
  49         const char *encoding;
  50         const char *abbrev, *subject;
  51         int abbrev_len, subject_len;
  52         char *q;
  53
  54         if (!commit->buffer)
  55                 return -1;
  56         encoding = get_encoding(commit->buffer);
  57         if (!encoding)
  58                 encoding = "UTF-8";
  59         if (!git_commit_encoding)
  60                 git_commit_encoding = "UTF-8";
  61
  62         out->reencoded_message = NULL;
  63         out->message = commit->buffer;
  64         if (same_encoding(encoding, git_commit_encoding))
  65                 out->reencoded_message = reencode_string(commit->buffer,
  66                                         git_commit_encoding, encoding);
  67         if (out->reencoded_message)
  68                 out->message = out->reencoded_message;
  69
  70         abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
  71         abbrev_len = strlen(abbrev);
  72
  73         subject_len = find_commit_subject(out->message, &subject);
  74
  75         out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
  76                               strlen("... ") + subject_len + 1);
  77         q = out->parent_label;
  78         q = mempcpy(q, "parent of ", strlen("parent of "));
  79         out->label = q;
  80         q = mempcpy(q, abbrev, abbrev_len);
  81         q = mempcpy(q, "... ", strlen("... "));
  82         out->subject = q;
  83         q = mempcpy(q, subject, subject_len);
  84         *q = '\0';
  85         return 0;
  86 }
  87
  88 static void free_message(struct commit_message *msg)
  89 {
  90         free(msg->parent_label);
  91         free(msg->reencoded_message);
  92 }
  93
  94 static char *get_encoding(const char *message)
  95 {
  96         const char *p = message, *eol;
  97
  98         while (*p && *p != '\n') {
  99                 for (eol = p + 1; *eol && *eol != '\n'; eol++)
 100                         ; /* do nothing */
 101                 if (!prefixcmp(p, "encoding ")) {
 102                         char *result = xmalloc(eol - 8 - p);
 103                         strlcpy(result, p + 9, eol - 8 - p);
 104                         return result;
 105                 }
 106                 p = eol;
 107                 if (*p == '\n')
 108                         p++;
 109         }
 110         return NULL;
 111 }
 112
 113 static void write_cherry_pick_head(struct commit *commit, const char *pseudoref)
 114 {
 115         const char *filename;
 116         int fd;
 117         struct strbuf buf = STRBUF_INIT;
 118
 119         strbuf_addf(&buf, "%s\n", sha1_to_hex(commit->object.sha1));
 120
 121         filename = git_path("%s", pseudoref);
 122         fd = open(filename, O_WRONLY | O_CREAT, 0666);
 123         if (fd < 0)
 124                 die_errno(_("Could not open '%s' for writing"), filename);
 125         if (write_in_full(fd, buf.buf, buf.len) != buf.len || close(fd))
 126                 die_errno(_("Could not write to '%s'"), filename);
 127         strbuf_release(&buf);
 128 }
 129
 130 static void print_advice(int show_hint, struct replay_opts *opts)
 131 {
 132         char *msg = getenv("GIT_CHERRY_PICK_HELP");
 133
 134         if (msg) {
 135                 fprintf(stderr, "%s\n", msg);
 136                 /*
 137                  * A conflict has occured but the porcelain
 138                  * (typically rebase --interactive) wants to take care
 139                  * of the commit itself so remove CHERRY_PICK_HEAD
 140                  */
 141                 unlink(git_path("CHERRY_PICK_HEAD"));
 142                 return;
 143         }
 144
 145         if (show_hint) {
 146                 if (opts->no_commit)
 147                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 148                                  "with 'git add <paths>' or 'git rm <paths>'"));
 149                 else
 150                         advise(_("after resolving the conflicts, mark the corrected paths\n"
 151                                  "with 'git add <paths>' or 'git rm <paths>'\n"
 152                                  "and commit the result with 'git commit'"));
 153         }
 154 }
 155
 156 static void write_message(struct strbuf *msgbuf, const char *filename)
 157 {
 158         static struct lock_file msg_file;
 159
 160         int msg_fd = hold_lock_file_for_update(&msg_file, filename,
 161                                                LOCK_DIE_ON_ERROR);
 162         if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
 163                 die_errno(_("Could not write to %s"), filename);
 164         strbuf_release(msgbuf);
 165         if (commit_lock_file(&msg_file) < 0)
 166                 die(_("Error wrapping up %s"), filename);
 167 }
 168
 169 static struct tree *empty_tree(void)
 170 {
 171         return lookup_tree(EMPTY_TREE_SHA1_BIN);
 172 }
 173
 174 static int error_dirty_index(struct replay_opts *opts)
 175 {
 176         if (read_cache_unmerged())
 177                 return error_resolve_conflict(action_name(opts));
 178
 179         /* Different translation strings for cherry-pick and revert */
 180         if (opts->action == REPLAY_PICK)
 181                 error(_("Your local changes would be overwritten by cherry-pick."));
 182         else
 183                 error(_("Your local changes would be overwritten by revert."));
 184
 185         if (advice_commit_before_merge)
 186                 advise(_("Commit your changes or stash them to proceed."));
 187         return -1;
 188 }
 189
 190 static int fast_forward_to(const unsigned char *to, const unsigned char *from)
 191 {
 192         struct ref_lock *ref_lock;
 193
 194         read_cache();
 195         if (checkout_fast_forward(from, to, 1))
 196                 exit(1); /* the callee should have complained already */
 197         ref_lock = lock_any_ref_for_update("HEAD", from, 0);
 198         return write_ref_sha1(ref_lock, to, "cherry-pick");
 199 }
 200
 201 static int do_recursive_merge(struct commit *base, struct commit *next,
 202                               const char *base_label, const char *next_label,
 203                               unsigned char *head, struct strbuf *msgbuf,
 204                               struct replay_opts *opts)
 205 {
 206         struct merge_options o;
 207         struct tree *result, *next_tree, *base_tree, *head_tree;
 208         int clean, index_fd;
 209         const char **xopt;
 210         static struct lock_file index_lock;
 211
 212         index_fd = hold_locked_index(&index_lock, 1);
 213
 214         read_cache();
 215
 216         init_merge_options(&o);
 217         o.ancestor = base ? base_label : "(empty tree)";
 218         o.branch1 = "HEAD";
 219         o.branch2 = next ? next_label : "(empty tree)";
 220
 221         head_tree = parse_tree_indirect(head);
 222         next_tree = next ? next->tree : empty_tree();
 223         base_tree = base ? base->tree : empty_tree();
 224
 225         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
 226                 parse_merge_opt(&o, *xopt);
 227
 228         clean = merge_trees(&o,
 229                             head_tree,
 230                             next_tree, base_tree, &result);
 231
 232         if (active_cache_changed &&
 233             (write_cache(index_fd, active_cache, active_nr) ||
 234              commit_locked_index(&index_lock)))
 235                 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
 236                 die(_("%s: Unable to write new index file"), action_name(opts));
 237         rollback_lock_file(&index_lock);
 238
 239         if (opts->signoff)
 240                 append_signoff(msgbuf, 0);
 241
 242         if (!clean) {
 243                 int i;
 244                 strbuf_addstr(msgbuf, "\nConflicts:\n");
 245                 for (i = 0; i < active_nr;) {
 246                         struct cache_entry *ce = active_cache[i++];
 247                         if (ce_stage(ce)) {
 248                                 strbuf_addch(msgbuf, '\t');
 249                                 strbuf_addstr(msgbuf, ce->name);
 250                                 strbuf_addch(msgbuf, '\n');
 251                                 while (i < active_nr && !strcmp(ce->name,
 252                                                 active_cache[i]->name))
 253                                         i++;
 254                         }
 255                 }
 256         }
 257
 258         return !clean;
 259 }
 260
 261 static int is_index_unchanged(void)
 262 {
 263         unsigned char head_sha1[20];
 264         struct commit *head_commit;
 265
 266         if (!resolve_ref_unsafe("HEAD", head_sha1, 1, NULL))
 267                 return error(_("Could not resolve HEAD commit\n"));
 268
 269         head_commit = lookup_commit(head_sha1);
 270
 271         /*
 272          * If head_commit is NULL, check_commit, called from
 273          * lookup_commit, would have indicated that head_commit is not
 274          * a commit object already.  parse_commit() will return failure
 275          * without further complaints in such a case.  Otherwise, if
 276          * the commit is invalid, parse_commit() will complain.  So
 277          * there is nothing for us to say here.  Just return failure.
 278          */
 279         if (parse_commit(head_commit))
 280                 return -1;
 281
 282         if (!active_cache_tree)
 283                 active_cache_tree = cache_tree();
 284
 285         if (!cache_tree_fully_valid(active_cache_tree))
 286                 if (cache_tree_update(active_cache_tree, active_cache,
 287                                   active_nr, 0))
 288                         return error(_("Unable to update cache tree\n"));
 289
 290         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.sha1);
 291 }
 292
 293 /*
 294  * If we are cherry-pick, and if the merge did not result in
 295  * hand-editing, we will hit this commit and inherit the original
 296  * author date and name.
 297  * If we are revert, or if our cherry-pick results in a hand merge,
 298  * we had better say that the current user is responsible for that.
 299  */
 300 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 301                           int allow_empty)
 302 {
 303         struct argv_array array;
 304         int rc;
 305
 306         argv_array_init(&array);
 307         argv_array_push(&array, "commit");
 308         argv_array_push(&array, "-n");
 309
 310         if (opts->signoff)
 311                 argv_array_push(&array, "-s");
 312         if (!opts->edit) {
 313                 argv_array_push(&array, "-F");
 314                 argv_array_push(&array, defmsg);
 315         }
 316
 317         if (allow_empty)
 318                 argv_array_push(&array, "--allow-empty");
 319
 320         if (opts->allow_empty_message)
 321                 argv_array_push(&array, "--allow-empty-message");
 322
 323         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
 324         argv_array_clear(&array);
 325         return rc;
 326 }
 327
 328 static int is_original_commit_empty(struct commit *commit)
 329 {
 330         const unsigned char *ptree_sha1;
 331
 332         if (parse_commit(commit))
 333                 return error(_("Could not parse commit %s\n"),
 334                              sha1_to_hex(commit->object.sha1));
 335         if (commit->parents) {
 336                 struct commit *parent = commit->parents->item;
 337                 if (parse_commit(parent))
 338                         return error(_("Could not parse parent commit %s\n"),
 339                                 sha1_to_hex(parent->object.sha1));
 340                 ptree_sha1 = parent->tree->object.sha1;
 341         } else {
 342                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
 343         }
 344
 345         return !hashcmp(ptree_sha1, commit->tree->object.sha1);
 346 }
 347
 348 /*
 349  * Do we run "git commit" with "--allow-empty"?
 350  */
 351 static int allow_empty(struct replay_opts *opts, struct commit *commit)
 352 {
 353         int index_unchanged, empty_commit;
 354
 355         /*
 356          * Three cases:
 357          *
 358          * (1) we do not allow empty at all and error out.
 359          *
 360          * (2) we allow ones that were initially empty, but
 361          * forbid the ones that become empty;
 362          *
 363          * (3) we allow both.
 364          */
 365         if (!opts->allow_empty)
 366                 return 0; /* let "git commit" barf as necessary */
 367
 368         index_unchanged = is_index_unchanged();
 369         if (index_unchanged < 0)
 370                 return index_unchanged;
 371         if (!index_unchanged)
 372                 return 0; /* we do not have to say --allow-empty */
 373
 374         if (opts->keep_redundant_commits)
 375                 return 1;
 376
 377         empty_commit = is_original_commit_empty(commit);
 378         if (empty_commit < 0)
 379                 return empty_commit;
 380         if (!empty_commit)
 381                 return 0;
 382         else
 383                 return 1;
 384 }
 385
 386 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 387 {
 388         unsigned char head[20];
 389         struct commit *base, *next, *parent;
 390         const char *base_label, *next_label;
 391         struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
 392         char *defmsg = NULL;
 393         struct strbuf msgbuf = STRBUF_INIT;
 394         int res;
 395
 396         if (opts->no_commit) {
 397                 /*
 398                  * We do not intend to commit immediately.  We just want to
 399                  * merge the differences in, so let's compute the tree
 400                  * that represents the "current" state for merge-recursive
 401                  * to work on.
 402                  */
 403                 if (write_cache_as_tree(head, 0, NULL))
 404                         die (_("Your index file is unmerged."));
 405         } else {
 406                 if (get_sha1("HEAD", head))
 407                         return error(_("You do not have a valid HEAD"));
 408                 if (index_differs_from("HEAD", 0))
 409                         return error_dirty_index(opts);
 410         }
 411         discard_cache();
 412
 413         if (!commit->parents) {
 414                 parent = NULL;
 415         }
 416         else if (commit->parents->next) {
 417                 /* Reverting or cherry-picking a merge commit */
 418                 int cnt;
 419                 struct commit_list *p;
 420
 421                 if (!opts->mainline)
 422                         return error(_("Commit %s is a merge but no -m option was given."),
 423                                 sha1_to_hex(commit->object.sha1));
 424
 425                 for (cnt = 1, p = commit->parents;
 426                      cnt != opts->mainline && p;
 427                      cnt++)
 428                         p = p->next;
 429                 if (cnt != opts->mainline || !p)
 430                         return error(_("Commit %s does not have parent %d"),
 431                                 sha1_to_hex(commit->object.sha1), opts->mainline);
 432                 parent = p->item;
 433         } else if (0 < opts->mainline)
 434                 return error(_("Mainline was specified but commit %s is not a merge."),
 435                         sha1_to_hex(commit->object.sha1));
 436         else
 437                 parent = commit->parents->item;
 438
 439         if (opts->allow_ff && parent && !hashcmp(parent->object.sha1, head))
 440                 return fast_forward_to(commit->object.sha1, head);
 441
 442         if (parent && parse_commit(parent) < 0)
 443                 /* TRANSLATORS: The first %s will be "revert" or
 444                    "cherry-pick", the second %s a SHA1 */
 445                 return error(_("%s: cannot parse parent commit %s"),
 446                         action_name(opts), sha1_to_hex(parent->object.sha1));
 447
 448         if (get_message(commit, &msg) != 0)
 449                 return error(_("Cannot get commit message for %s"),
 450                         sha1_to_hex(commit->object.sha1));
 451
 452         /*
 453          * "commit" is an existing commit.  We would want to apply
 454          * the difference it introduces since its first parent "prev"
 455          * on top of the current HEAD if we are cherry-pick.  Or the
 456          * reverse of it if we are revert.
 457          */
 458
 459         defmsg = git_pathdup("MERGE_MSG");
 460
 461         if (opts->action == REPLAY_REVERT) {
 462                 base = commit;
 463                 base_label = msg.label;
 464                 next = parent;
 465                 next_label = msg.parent_label;
 466                 strbuf_addstr(&msgbuf, "Revert \"");
 467                 strbuf_addstr(&msgbuf, msg.subject);
 468                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
 469                 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 470
 471                 if (commit->parents && commit->parents->next) {
 472                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
 473                         strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
 474                 }
 475                 strbuf_addstr(&msgbuf, ".\n");
 476         } else {
 477                 const char *p;
 478
 479                 base = parent;
 480                 base_label = msg.parent_label;
 481                 next = commit;
 482                 next_label = msg.label;
 483
 484                 /*
 485                  * Append the commit log message to msgbuf; it starts
 486                  * after the tree, parent, author, committer
 487                  * information followed by "\n\n".
 488                  */
 489                 p = strstr(msg.message, "\n\n");
 490                 if (p) {
 491                         p += 2;
 492                         strbuf_addstr(&msgbuf, p);
 493                 }
 494
 495                 if (opts->record_origin) {
 496                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
 497                         strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 498                         strbuf_addstr(&msgbuf, ")\n");
 499                 }
 500         }
 501
 502         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
 503                 res = do_recursive_merge(base, next, base_label, next_label,
 504                                          head, &msgbuf, opts);
 505                 write_message(&msgbuf, defmsg);
 506         } else {
 507                 struct commit_list *common = NULL;
 508                 struct commit_list *remotes = NULL;
 509
 510                 write_message(&msgbuf, defmsg);
 511
 512                 commit_list_insert(base, &common);
 513                 commit_list_insert(next, &remotes);
 514                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 515                                         common, sha1_to_hex(head), remotes);
 516                 free_commit_list(common);
 517                 free_commit_list(remotes);
 518         }
 519
 520         /*
 521          * If the merge was clean or if it failed due to conflict, we write
 522          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
 523          * However, if the merge did not even start, then we don't want to
 524          * write it at all.
 525          */
 526         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
 527                 write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
 528         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
 529                 write_cherry_pick_head(commit, "REVERT_HEAD");
 530
 531         if (res) {
 532                 error(opts->action == REPLAY_REVERT
 533                       ? _("could not revert %s... %s")
 534                       : _("could not apply %s... %s"),
 535                       find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
 536                       msg.subject);
 537                 print_advice(res == 1, opts);
 538                 rerere(opts->allow_rerere_auto);
 539         } else {
 540                 int allow = allow_empty(opts, commit);
 541                 if (allow < 0)
 542                         return allow;
 543                 if (!opts->no_commit)
 544                         res = run_git_commit(defmsg, opts, allow);
 545         }
 546
 547         free_message(&msg);
 548         free(defmsg);
 549
 550         return res;
 551 }
 552
 553 static void prepare_revs(struct replay_opts *opts)
 554 {
 555         /*
 556          * picking (but not reverting) ranges (but not individual revisions)
 557          * should be done in reverse
 558          */
 559         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
 560                 opts->revs->reverse ^= 1;
 561
 562         if (prepare_revision_walk(opts->revs))
 563                 die(_("revision walk setup failed"));
 564
 565         if (!opts->revs->commits)
 566                 die(_("empty commit set passed"));
 567 }
 568
 569 static void read_and_refresh_cache(struct replay_opts *opts)
 570 {
 571         static struct lock_file index_lock;
 572         int index_fd = hold_locked_index(&index_lock, 0);
 573         if (read_index_preload(&the_index, NULL) < 0)
 574                 die(_("git %s: failed to read the index"), action_name(opts));
 575         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
 576         if (the_index.cache_changed) {
 577                 if (write_index(&the_index, index_fd) ||
 578                     commit_locked_index(&index_lock))
 579                         die(_("git %s: failed to refresh the index"), action_name(opts));
 580         }
 581         rollback_lock_file(&index_lock);
 582 }
 583
 584 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
 585                 struct replay_opts *opts)
 586 {
 587         struct commit_list *cur = NULL;
 588         const char *sha1_abbrev = NULL;
 589         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
 590         const char *subject;
 591         int subject_len;
 592
 593         for (cur = todo_list; cur; cur = cur->next) {
 594                 sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
 595                 subject_len = find_commit_subject(cur->item->buffer, &subject);
 596                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
 597                         subject_len, subject);
 598         }
 599         return 0;
 600 }
 601
 602 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
 603 {
 604         unsigned char commit_sha1[20];
 605         enum replay_action action;
 606         char *end_of_object_name;
 607         int saved, status, padding;
 608
 609         if (!prefixcmp(bol, "pick")) {
 610                 action = REPLAY_PICK;
 611                 bol += strlen("pick");
 612         } else if (!prefixcmp(bol, "revert")) {
 613                 action = REPLAY_REVERT;
 614                 bol += strlen("revert");
 615         } else
 616                 return NULL;
 617
 618         /* Eat up extra spaces/ tabs before object name */
 619         padding = strspn(bol, " \t");
 620         if (!padding)
 621                 return NULL;
 622         bol += padding;
 623
 624         end_of_object_name = bol + strcspn(bol, " \t\n");
 625         saved = *end_of_object_name;
 626         *end_of_object_name = '\0';
 627         status = get_sha1(bol, commit_sha1);
 628         *end_of_object_name = saved;
 629
 630         /*
 631          * Verify that the action matches up with the one in
 632          * opts; we don't support arbitrary instructions
 633          */
 634         if (action != opts->action) {
 635                 const char *action_str;
 636                 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
 637                 error(_("Cannot %s during a %s"), action_str, action_name(opts));
 638                 return NULL;
 639         }
 640
 641         if (status < 0)
 642                 return NULL;
 643
 644         return lookup_commit_reference(commit_sha1);
 645 }
 646
 647 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
 648                         struct replay_opts *opts)
 649 {
 650         struct commit_list **next = todo_list;
 651         struct commit *commit;
 652         char *p = buf;
 653         int i;
 654
 655         for (i = 1; *p; i++) {
 656                 char *eol = strchrnul(p, '\n');
 657                 commit = parse_insn_line(p, eol, opts);
 658                 if (!commit)
 659                         return error(_("Could not parse line %d."), i);
 660                 next = commit_list_append(commit, next);
 661                 p = *eol ? eol + 1 : eol;
 662         }
 663         if (!*todo_list)
 664                 return error(_("No commits parsed."));
 665         return 0;
 666 }
 667
 668 static void read_populate_todo(struct commit_list **todo_list,
 669                         struct replay_opts *opts)
 670 {
 671         const char *todo_file = git_path(SEQ_TODO_FILE);
 672         struct strbuf buf = STRBUF_INIT;
 673         int fd, res;
 674
 675         fd = open(todo_file, O_RDONLY);
 676         if (fd < 0)
 677                 die_errno(_("Could not open %s"), todo_file);
 678         if (strbuf_read(&buf, fd, 0) < 0) {
 679                 close(fd);
 680                 strbuf_release(&buf);
 681                 die(_("Could not read %s."), todo_file);
 682         }
 683         close(fd);
 684
 685         res = parse_insn_buffer(buf.buf, todo_list, opts);
 686         strbuf_release(&buf);
 687         if (res)
 688                 die(_("Unusable instruction sheet: %s"), todo_file);
 689 }
 690
 691 static int populate_opts_cb(const char *key, const char *value, void *data)
 692 {
 693         struct replay_opts *opts = data;
 694         int error_flag = 1;
 695
 696         if (!value)
 697                 error_flag = 0;
 698         else if (!strcmp(key, "options.no-commit"))
 699                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
 700         else if (!strcmp(key, "options.edit"))
 701                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
 702         else if (!strcmp(key, "options.signoff"))
 703                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 704         else if (!strcmp(key, "options.record-origin"))
 705                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
 706         else if (!strcmp(key, "options.allow-ff"))
 707                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 708         else if (!strcmp(key, "options.mainline"))
 709                 opts->mainline = git_config_int(key, value);
 710         else if (!strcmp(key, "options.strategy"))
 711                 git_config_string(&opts->strategy, key, value);
 712         else if (!strcmp(key, "options.strategy-option")) {
 713                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
 714                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
 715         } else
 716                 return error(_("Invalid key: %s"), key);
 717
 718         if (!error_flag)
 719                 return error(_("Invalid value for %s: %s"), key, value);
 720
 721         return 0;
 722 }
 723
 724 static void read_populate_opts(struct replay_opts **opts_ptr)
 725 {
 726         const char *opts_file = git_path(SEQ_OPTS_FILE);
 727
 728         if (!file_exists(opts_file))
 729                 return;
 730         if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
 731                 die(_("Malformed options sheet: %s"), opts_file);
 732 }
 733
 734 static void walk_revs_populate_todo(struct commit_list **todo_list,
 735                                 struct replay_opts *opts)
 736 {
 737         struct commit *commit;
 738         struct commit_list **next;
 739
 740         prepare_revs(opts);
 741
 742         next = todo_list;
 743         while ((commit = get_revision(opts->revs)))
 744                 next = commit_list_append(commit, next);
 745 }
 746
 747 static int create_seq_dir(void)
 748 {
 749         const char *seq_dir = git_path(SEQ_DIR);
 750
 751         if (file_exists(seq_dir)) {
 752                 error(_("a cherry-pick or revert is already in progress"));
 753                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
 754                 return -1;
 755         }
 756         else if (mkdir(seq_dir, 0777) < 0)
 757                 die_errno(_("Could not create sequencer directory %s"), seq_dir);
 758         return 0;
 759 }
 760
 761 static void save_head(const char *head)
 762 {
 763         const char *head_file = git_path(SEQ_HEAD_FILE);
 764         static struct lock_file head_lock;
 765         struct strbuf buf = STRBUF_INIT;
 766         int fd;
 767
 768         fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
 769         strbuf_addf(&buf, "%s\n", head);
 770         if (write_in_full(fd, buf.buf, buf.len) < 0)
 771                 die_errno(_("Could not write to %s"), head_file);
 772         if (commit_lock_file(&head_lock) < 0)
 773                 die(_("Error wrapping up %s."), head_file);
 774 }
 775
 776 static int reset_for_rollback(const unsigned char *sha1)
 777 {
 778         const char *argv[4];    /* reset --merge <arg> + NULL */
 779         argv[0] = "reset";
 780         argv[1] = "--merge";
 781         argv[2] = sha1_to_hex(sha1);
 782         argv[3] = NULL;
 783         return run_command_v_opt(argv, RUN_GIT_CMD);
 784 }
 785
 786 static int rollback_single_pick(void)
 787 {
 788         unsigned char head_sha1[20];
 789
 790         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
 791             !file_exists(git_path("REVERT_HEAD")))
 792                 return error(_("no cherry-pick or revert in progress"));
 793         if (read_ref_full("HEAD", head_sha1, 0, NULL))
 794                 return error(_("cannot resolve HEAD"));
 795         if (is_null_sha1(head_sha1))
 796                 return error(_("cannot abort from a branch yet to be born"));
 797         return reset_for_rollback(head_sha1);
 798 }
 799
 800 static int sequencer_rollback(struct replay_opts *opts)
 801 {
 802         const char *filename;
 803         FILE *f;
 804         unsigned char sha1[20];
 805         struct strbuf buf = STRBUF_INIT;
 806
 807         filename = git_path(SEQ_HEAD_FILE);
 808         f = fopen(filename, "r");
 809         if (!f && errno == ENOENT) {
 810                 /*
 811                  * There is no multiple-cherry-pick in progress.
 812                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
 813                  * a single-cherry-pick in progress, abort that.
 814                  */
 815                 return rollback_single_pick();
 816         }
 817         if (!f)
 818                 return error(_("cannot open %s: %s"), filename,
 819                                                 strerror(errno));
 820         if (strbuf_getline(&buf, f, '\n')) {
 821                 error(_("cannot read %s: %s"), filename, ferror(f) ?
 822                         strerror(errno) : _("unexpected end of file"));
 823                 fclose(f);
 824                 goto fail;
 825         }
 826         fclose(f);
 827         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
 828                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
 829                         filename);
 830                 goto fail;
 831         }
 832         if (reset_for_rollback(sha1))
 833                 goto fail;
 834         remove_sequencer_state();
 835         strbuf_release(&buf);
 836         return 0;
 837 fail:
 838         strbuf_release(&buf);
 839         return -1;
 840 }
 841
 842 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 843 {
 844         const char *todo_file = git_path(SEQ_TODO_FILE);
 845         static struct lock_file todo_lock;
 846         struct strbuf buf = STRBUF_INIT;
 847         int fd;
 848
 849         fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
 850         if (format_todo(&buf, todo_list, opts) < 0)
 851                 die(_("Could not format %s."), todo_file);
 852         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 853                 strbuf_release(&buf);
 854                 die_errno(_("Could not write to %s"), todo_file);
 855         }
 856         if (commit_lock_file(&todo_lock) < 0) {
 857                 strbuf_release(&buf);
 858                 die(_("Error wrapping up %s."), todo_file);
 859         }
 860         strbuf_release(&buf);
 861 }
 862
 863 static void save_opts(struct replay_opts *opts)
 864 {
 865         const char *opts_file = git_path(SEQ_OPTS_FILE);
 866
 867         if (opts->no_commit)
 868                 git_config_set_in_file(opts_file, "options.no-commit", "true");
 869         if (opts->edit)
 870                 git_config_set_in_file(opts_file, "options.edit", "true");
 871         if (opts->signoff)
 872                 git_config_set_in_file(opts_file, "options.signoff", "true");
 873         if (opts->record_origin)
 874                 git_config_set_in_file(opts_file, "options.record-origin", "true");
 875         if (opts->allow_ff)
 876                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
 877         if (opts->mainline) {
 878                 struct strbuf buf = STRBUF_INIT;
 879                 strbuf_addf(&buf, "%d", opts->mainline);
 880                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
 881                 strbuf_release(&buf);
 882         }
 883         if (opts->strategy)
 884                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
 885         if (opts->xopts) {
 886                 int i;
 887                 for (i = 0; i < opts->xopts_nr; i++)
 888                         git_config_set_multivar_in_file(opts_file,
 889                                                         "options.strategy-option",
 890                                                         opts->xopts[i], "^$", 0);
 891         }
 892 }
 893
 894 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
 895 {
 896         struct commit_list *cur;
 897         int res;
 898
 899         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
 900         if (opts->allow_ff)
 901                 assert(!(opts->signoff || opts->no_commit ||
 902                                 opts->record_origin || opts->edit));
 903         read_and_refresh_cache(opts);
 904
 905         for (cur = todo_list; cur; cur = cur->next) {
 906                 save_todo(cur, opts);
 907                 res = do_pick_commit(cur->item, opts);
 908                 if (res)
 909                         return res;
 910         }
 911
 912         /*
 913          * Sequence of picks finished successfully; cleanup by
 914          * removing the .git/sequencer directory
 915          */
 916         remove_sequencer_state();
 917         return 0;
 918 }
 919
 920 static int continue_single_pick(void)
 921 {
 922         const char *argv[] = { "commit", NULL };
 923
 924         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
 925             !file_exists(git_path("REVERT_HEAD")))
 926                 return error(_("no cherry-pick or revert in progress"));
 927         return run_command_v_opt(argv, RUN_GIT_CMD);
 928 }
 929
 930 static int sequencer_continue(struct replay_opts *opts)
 931 {
 932         struct commit_list *todo_list = NULL;
 933
 934         if (!file_exists(git_path(SEQ_TODO_FILE)))
 935                 return continue_single_pick();
 936         read_populate_opts(&opts);
 937         read_populate_todo(&todo_list, opts);
 938
 939         /* Verify that the conflict has been resolved */
 940         if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
 941             file_exists(git_path("REVERT_HEAD"))) {
 942                 int ret = continue_single_pick();
 943                 if (ret)
 944                         return ret;
 945         }
 946         if (index_differs_from("HEAD", 0))
 947                 return error_dirty_index(opts);
 948         todo_list = todo_list->next;
 949         return pick_commits(todo_list, opts);
 950 }
 951
 952 static int single_pick(struct commit *cmit, struct replay_opts *opts)
 953 {
 954         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
 955         return do_pick_commit(cmit, opts);
 956 }
 957
 958 int sequencer_pick_revisions(struct replay_opts *opts)
 959 {
 960         struct commit_list *todo_list = NULL;
 961         unsigned char sha1[20];
 962
 963         if (opts->subcommand == REPLAY_NONE)
 964                 assert(opts->revs);
 965
 966         read_and_refresh_cache(opts);
 967
 968         /*
 969          * Decide what to do depending on the arguments; a fresh
 970          * cherry-pick should be handled differently from an existing
 971          * one that is being continued
 972          */
 973         if (opts->subcommand == REPLAY_REMOVE_STATE) {
 974                 remove_sequencer_state();
 975                 return 0;
 976         }
 977         if (opts->subcommand == REPLAY_ROLLBACK)
 978                 return sequencer_rollback(opts);
 979         if (opts->subcommand == REPLAY_CONTINUE)
 980                 return sequencer_continue(opts);
 981
 982         /*
 983          * If we were called as "git cherry-pick <commit>", just
 984          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
 985          * REVERT_HEAD, and don't touch the sequencer state.
 986          * This means it is possible to cherry-pick in the middle
 987          * of a cherry-pick sequence.
 988          */
 989         if (opts->revs->cmdline.nr == 1 &&
 990             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
 991             opts->revs->no_walk &&
 992             !opts->revs->cmdline.rev->flags) {
 993                 struct commit *cmit;
 994                 if (prepare_revision_walk(opts->revs))
 995                         die(_("revision walk setup failed"));
 996                 cmit = get_revision(opts->revs);
 997                 if (!cmit || get_revision(opts->revs))
 998                         die("BUG: expected exactly one commit from walk");
 999                 return single_pick(cmit, opts);
1000         }
1001
1002         /*
1003          * Start a new cherry-pick/ revert sequence; but
1004          * first, make sure that an existing one isn't in
1005          * progress
1006          */
1007
1008         walk_revs_populate_todo(&todo_list, opts);
1009         if (create_seq_dir() < 0)
1010                 return -1;
1011         if (get_sha1("HEAD", sha1)) {
1012                 if (opts->action == REPLAY_REVERT)
1013                         return error(_("Can't revert as initial commit"));
1014                 return error(_("Can't cherry-pick into empty head"));
1015         }
1016         save_head(sha1_to_hex(sha1));
1017         save_opts(opts);
1018         return pick_commits(todo_list, opts);
1019 }
1020
1021 static int is_rfc2822_line(const char *buf, int len)
1022 {
1023         int i;
1024
1025         for (i = 0; i < len; i++) {
1026                 int ch = buf[i];
1027                 if (ch == ':')
1028                         return 1;
1029                 if (!isalnum(ch) && ch != '-')
1030                         break;
1031         }
1032
1033         return 0;
1034 }
1035
1036 static int is_cherry_picked_from_line(const char *buf, int len)
1037 {
1038         /*
1039          * We only care that it looks roughly like (cherry picked from ...)
1040          */
1041         return len > strlen(cherry_picked_prefix) + 1 &&
1042                 !prefixcmp(buf, cherry_picked_prefix) && buf[len - 1] == ')';
1043 }
1044
1045 static int has_conforming_footer(struct strbuf *sb, int ignore_footer)
1046 {
1047         char prev;
1048         int i, k;
1049         int len = sb->len - ignore_footer;
1050         const char *buf = sb->buf;
1051
1052         /* footer must end with newline */
1053         if (!len || buf[len - 1] != '\n')
1054                 return 0;
1055
1056         prev = '\0';
1057         for (i = len - 1; i > 0; i--) {
1058                 char ch = buf[i];
1059                 if (prev == '\n' && ch == '\n') /* paragraph break */
1060                         break;
1061                 prev = ch;
1062         }
1063
1064         /* require at least one blank line */
1065         if (prev != '\n' || buf[i] != '\n')
1066                 return 0;
1067
1068         /* advance to start of last paragraph */
1069         while (i < len - 1 && buf[i] == '\n')
1070                 i++;
1071
1072         for (; i < len; i = k) {
1073                 for (k = i; k < len && buf[k] != '\n'; k++)
1074                         ; /* do nothing */
1075                 k++;
1076
1077                 if (!is_rfc2822_line(buf + i, k - i - 1) &&
1078                     !is_cherry_picked_from_line(buf + i, k - i - 1))
1079                         return 0;
1080         }
1081         return 1;
1082 }
1083
1084 void append_signoff(struct strbuf *msgbuf, int ignore_footer)
1085 {
1086         struct strbuf sob = STRBUF_INIT;
1087         int i;
1088
1089         strbuf_addstr(&sob, sign_off_header);
1090         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1091                                 getenv("GIT_COMMITTER_EMAIL")));
1092         strbuf_addch(&sob, '\n');
1093         for (i = msgbuf->len - 1 - ignore_footer; i > 0 && msgbuf->buf[i - 1] != '\n'; i--)
1094                 ; /* do nothing */
1095         if (prefixcmp(msgbuf->buf + i, sob.buf)) {
1096                 if (!has_conforming_footer(msgbuf, ignore_footer))
1097                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0, "\n", 1);
1098                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0, sob.buf, sob.len);
1099         }
1100         strbuf_release(&sob);
1101 }