commit.c

   1 #include "cache.h"
   2 #include "tag.h"
   3 #include "commit.h"
   4 #include "commit-graph.h"
   5 #include "repository.h"
   6 #include "object-store.h"
   7 #include "pkt-line.h"
   8 #include "utf8.h"
   9 #include "diff.h"
  10 #include "revision.h"
  11 #include "notes.h"
  12 #include "alloc.h"
  13 #include "gpg-interface.h"
  14 #include "mergesort.h"
  15 #include "commit-slab.h"
  16 #include "prio-queue.h"
  17 #include "sha1-lookup.h"
  18 #include "wt-status.h"
  19 #include "advice.h"
  20 #include "refs.h"
  21 #include "commit-reach.h"
  22 #include "run-command.h"
  23 #include "shallow.h"
  24
  25 static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
  26
  27 int save_commit_buffer = 1;
  28
  29 const char *commit_type = "commit";
  30
  31 struct commit *lookup_commit_reference_gently(struct repository *r,
  32                 const struct object_id *oid, int quiet)
  33 {
  34         struct object *obj = deref_tag(r,
  35                                        parse_object(r, oid),
  36                                        NULL, 0);
  37
  38         if (!obj)
  39                 return NULL;
  40         return object_as_type(r, obj, OBJ_COMMIT, quiet);
  41 }
  42
  43 struct commit *lookup_commit_reference(struct repository *r, const struct object_id *oid)
  44 {
  45         return lookup_commit_reference_gently(r, oid, 0);
  46 }
  47
  48 struct commit *lookup_commit_or_die(const struct object_id *oid, const char *ref_name)
  49 {
  50         struct commit *c = lookup_commit_reference(the_repository, oid);
  51         if (!c)
  52                 die(_("could not parse %s"), ref_name);
  53         if (!oideq(oid, &c->object.oid)) {
  54                 warning(_("%s %s is not a commit!"),
  55                         ref_name, oid_to_hex(oid));
  56         }
  57         return c;
  58 }
  59
  60 struct commit *lookup_commit(struct repository *r, const struct object_id *oid)
  61 {
  62         struct object *obj = lookup_object(r, oid);
  63         if (!obj)
  64                 return create_object(r, oid, alloc_commit_node(r));
  65         return object_as_type(r, obj, OBJ_COMMIT, 0);
  66 }
  67
  68 struct commit *lookup_commit_reference_by_name(const char *name)
  69 {
  70         struct object_id oid;
  71         struct commit *commit;
  72
  73         if (get_oid_committish(name, &oid))
  74                 return NULL;
  75         commit = lookup_commit_reference(the_repository, &oid);
  76         if (parse_commit(commit))
  77                 return NULL;
  78         return commit;
  79 }
  80
  81 static timestamp_t parse_commit_date(const char *buf, const char *tail)
  82 {
  83         const char *dateptr;
  84
  85         if (buf + 6 >= tail)
  86                 return 0;
  87         if (memcmp(buf, "author", 6))
  88                 return 0;
  89         while (buf < tail && *buf++ != '\n')
  90                 /* nada */;
  91         if (buf + 9 >= tail)
  92                 return 0;
  93         if (memcmp(buf, "committer", 9))
  94                 return 0;
  95         while (buf < tail && *buf++ != '>')
  96                 /* nada */;
  97         if (buf >= tail)
  98                 return 0;
  99         dateptr = buf;
 100         while (buf < tail && *buf++ != '\n')
 101                 /* nada */;
 102         if (buf >= tail)
 103                 return 0;
 104         /* dateptr < buf && buf[-1] == '\n', so parsing will stop at buf-1 */
 105         return parse_timestamp(dateptr, NULL, 10);
 106 }
 107
 108 static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
 109 {
 110         struct commit_graft **commit_graft_table = table;
 111         return commit_graft_table[index]->oid.hash;
 112 }
 113
 114 int commit_graft_pos(struct repository *r, const unsigned char *sha1)
 115 {
 116         return sha1_pos(sha1, r->parsed_objects->grafts,
 117                         r->parsed_objects->grafts_nr,
 118                         commit_graft_sha1_access);
 119 }
 120
 121 int register_commit_graft(struct repository *r, struct commit_graft *graft,
 122                           int ignore_dups)
 123 {
 124         int pos = commit_graft_pos(r, graft->oid.hash);
 125
 126         if (0 <= pos) {
 127                 if (ignore_dups)
 128                         free(graft);
 129                 else {
 130                         free(r->parsed_objects->grafts[pos]);
 131                         r->parsed_objects->grafts[pos] = graft;
 132                 }
 133                 return 1;
 134         }
 135         pos = -pos - 1;
 136         ALLOC_GROW(r->parsed_objects->grafts,
 137                    r->parsed_objects->grafts_nr + 1,
 138                    r->parsed_objects->grafts_alloc);
 139         r->parsed_objects->grafts_nr++;
 140         if (pos < r->parsed_objects->grafts_nr)
 141                 memmove(r->parsed_objects->grafts + pos + 1,
 142                         r->parsed_objects->grafts + pos,
 143                         (r->parsed_objects->grafts_nr - pos - 1) *
 144                         sizeof(*r->parsed_objects->grafts));
 145         r->parsed_objects->grafts[pos] = graft;
 146         return 0;
 147 }
 148
 149 struct commit_graft *read_graft_line(struct strbuf *line)
 150 {
 151         /* The format is just "Commit Parent1 Parent2 ...\n" */
 152         int i, phase;
 153         const char *tail = NULL;
 154         struct commit_graft *graft = NULL;
 155         struct object_id dummy_oid, *oid;
 156
 157         strbuf_rtrim(line);
 158         if (!line->len || line->buf[0] == '#')
 159                 return NULL;
 160         /*
 161          * phase 0 verifies line, counts hashes in line and allocates graft
 162          * phase 1 fills graft
 163          */
 164         for (phase = 0; phase < 2; phase++) {
 165                 oid = graft ? &graft->oid : &dummy_oid;
 166                 if (parse_oid_hex(line->buf, oid, &tail))
 167                         goto bad_graft_data;
 168                 for (i = 0; *tail != '\0'; i++) {
 169                         oid = graft ? &graft->parent[i] : &dummy_oid;
 170                         if (!isspace(*tail++) || parse_oid_hex(tail, oid, &tail))
 171                                 goto bad_graft_data;
 172                 }
 173                 if (!graft) {
 174                         graft = xmalloc(st_add(sizeof(*graft),
 175                                                st_mult(sizeof(struct object_id), i)));
 176                         graft->nr_parent = i;
 177                 }
 178         }
 179         return graft;
 180
 181 bad_graft_data:
 182         error("bad graft data: %s", line->buf);
 183         assert(!graft);
 184         return NULL;
 185 }
 186
 187 static int read_graft_file(struct repository *r, const char *graft_file)
 188 {
 189         FILE *fp = fopen_or_warn(graft_file, "r");
 190         struct strbuf buf = STRBUF_INIT;
 191         if (!fp)
 192                 return -1;
 193         if (advice_graft_file_deprecated)
 194                 advise(_("Support for <GIT_DIR>/info/grafts is deprecated\n"
 195                          "and will be removed in a future Git version.\n"
 196                          "\n"
 197                          "Please use \"git replace --convert-graft-file\"\n"
 198                          "to convert the grafts into replace refs.\n"
 199                          "\n"
 200                          "Turn this message off by running\n"
 201                          "\"git config advice.graftFileDeprecated false\""));
 202         while (!strbuf_getwholeline(&buf, fp, '\n')) {
 203                 /* The format is just "Commit Parent1 Parent2 ...\n" */
 204                 struct commit_graft *graft = read_graft_line(&buf);
 205                 if (!graft)
 206                         continue;
 207                 if (register_commit_graft(r, graft, 1))
 208                         error("duplicate graft data: %s", buf.buf);
 209         }
 210         fclose(fp);
 211         strbuf_release(&buf);
 212         return 0;
 213 }
 214
 215 void prepare_commit_graft(struct repository *r)
 216 {
 217         char *graft_file;
 218
 219         if (r->parsed_objects->commit_graft_prepared)
 220                 return;
 221         if (!startup_info->have_repository)
 222                 return;
 223
 224         graft_file = get_graft_file(r);
 225         read_graft_file(r, graft_file);
 226         /* make sure shallows are read */
 227         is_repository_shallow(r);
 228         r->parsed_objects->commit_graft_prepared = 1;
 229 }
 230
 231 struct commit_graft *lookup_commit_graft(struct repository *r, const struct object_id *oid)
 232 {
 233         int pos;
 234         prepare_commit_graft(r);
 235         pos = commit_graft_pos(r, oid->hash);
 236         if (pos < 0)
 237                 return NULL;
 238         return r->parsed_objects->grafts[pos];
 239 }
 240
 241 int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
 242 {
 243         int i, ret;
 244         for (i = ret = 0; i < the_repository->parsed_objects->grafts_nr && !ret; i++)
 245                 ret = fn(the_repository->parsed_objects->grafts[i], cb_data);
 246         return ret;
 247 }
 248
 249 struct commit_buffer {
 250         void *buffer;
 251         unsigned long size;
 252 };
 253 define_commit_slab(buffer_slab, struct commit_buffer);
 254
 255 struct buffer_slab *allocate_commit_buffer_slab(void)
 256 {
 257         struct buffer_slab *bs = xmalloc(sizeof(*bs));
 258         init_buffer_slab(bs);
 259         return bs;
 260 }
 261
 262 void free_commit_buffer_slab(struct buffer_slab *bs)
 263 {
 264         clear_buffer_slab(bs);
 265         free(bs);
 266 }
 267
 268 void set_commit_buffer(struct repository *r, struct commit *commit, void *buffer, unsigned long size)
 269 {
 270         struct commit_buffer *v = buffer_slab_at(
 271                 r->parsed_objects->buffer_slab, commit);
 272         v->buffer = buffer;
 273         v->size = size;
 274 }
 275
 276 const void *get_cached_commit_buffer(struct repository *r, const struct commit *commit, unsigned long *sizep)
 277 {
 278         struct commit_buffer *v = buffer_slab_peek(
 279                 r->parsed_objects->buffer_slab, commit);
 280         if (!v) {
 281                 if (sizep)
 282                         *sizep = 0;
 283                 return NULL;
 284         }
 285         if (sizep)
 286                 *sizep = v->size;
 287         return v->buffer;
 288 }
 289
 290 const void *repo_get_commit_buffer(struct repository *r,
 291                                    const struct commit *commit,
 292                                    unsigned long *sizep)
 293 {
 294         const void *ret = get_cached_commit_buffer(r, commit, sizep);
 295         if (!ret) {
 296                 enum object_type type;
 297                 unsigned long size;
 298                 ret = repo_read_object_file(r, &commit->object.oid, &type, &size);
 299                 if (!ret)
 300                         die("cannot read commit object %s",
 301                             oid_to_hex(&commit->object.oid));
 302                 if (type != OBJ_COMMIT)
 303                         die("expected commit for %s, got %s",
 304                             oid_to_hex(&commit->object.oid), type_name(type));
 305                 if (sizep)
 306                         *sizep = size;
 307         }
 308         return ret;
 309 }
 310
 311 void repo_unuse_commit_buffer(struct repository *r,
 312                               const struct commit *commit,
 313                               const void *buffer)
 314 {
 315         struct commit_buffer *v = buffer_slab_peek(
 316                 r->parsed_objects->buffer_slab, commit);
 317         if (!(v && v->buffer == buffer))
 318                 free((void *)buffer);
 319 }
 320
 321 void free_commit_buffer(struct parsed_object_pool *pool, struct commit *commit)
 322 {
 323         struct commit_buffer *v = buffer_slab_peek(
 324                 pool->buffer_slab, commit);
 325         if (v) {
 326                 FREE_AND_NULL(v->buffer);
 327                 v->size = 0;
 328         }
 329 }
 330
 331 static inline void set_commit_tree(struct commit *c, struct tree *t)
 332 {
 333         c->maybe_tree = t;
 334 }
 335
 336 struct tree *repo_get_commit_tree(struct repository *r,
 337                                   const struct commit *commit)
 338 {
 339         if (commit->maybe_tree || !commit->object.parsed)
 340                 return commit->maybe_tree;
 341
 342         if (commit->graph_pos != COMMIT_NOT_FROM_GRAPH)
 343                 return get_commit_tree_in_graph(r, commit);
 344
 345         return NULL;
 346 }
 347
 348 struct object_id *get_commit_tree_oid(const struct commit *commit)
 349 {
 350         struct tree *tree = get_commit_tree(commit);
 351         return tree ? &tree->object.oid : NULL;
 352 }
 353
 354 void release_commit_memory(struct parsed_object_pool *pool, struct commit *c)
 355 {
 356         set_commit_tree(c, NULL);
 357         free_commit_buffer(pool, c);
 358         c->index = 0;
 359         free_commit_list(c->parents);
 360
 361         c->object.parsed = 0;
 362 }
 363
 364 const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 365 {
 366         struct commit_buffer *v = buffer_slab_peek(
 367                 the_repository->parsed_objects->buffer_slab, commit);
 368         void *ret;
 369
 370         if (!v) {
 371                 if (sizep)
 372                         *sizep = 0;
 373                 return NULL;
 374         }
 375         ret = v->buffer;
 376         if (sizep)
 377                 *sizep = v->size;
 378
 379         v->buffer = NULL;
 380         v->size = 0;
 381         return ret;
 382 }
 383
 384 int parse_commit_buffer(struct repository *r, struct commit *item, const void *buffer, unsigned long size, int check_graph)
 385 {
 386         const char *tail = buffer;
 387         const char *bufptr = buffer;
 388         struct object_id parent;
 389         struct commit_list **pptr;
 390         struct commit_graft *graft;
 391         const int tree_entry_len = the_hash_algo->hexsz + 5;
 392         const int parent_entry_len = the_hash_algo->hexsz + 7;
 393         struct tree *tree;
 394
 395         if (item->object.parsed)
 396                 return 0;
 397
 398         if (item->parents) {
 399                 /*
 400                  * Presumably this is leftover from an earlier failed parse;
 401                  * clear it out in preparation for us re-parsing (we'll hit the
 402                  * same error, but that's good, since it lets our caller know
 403                  * the result cannot be trusted.
 404                  */
 405                 free_commit_list(item->parents);
 406                 item->parents = NULL;
 407         }
 408
 409         tail += size;
 410         if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
 411                         bufptr[tree_entry_len] != '\n')
 412                 return error("bogus commit object %s", oid_to_hex(&item->object.oid));
 413         if (get_oid_hex(bufptr + 5, &parent) < 0)
 414                 return error("bad tree pointer in commit %s",
 415                              oid_to_hex(&item->object.oid));
 416         tree = lookup_tree(r, &parent);
 417         if (!tree)
 418                 return error("bad tree pointer %s in commit %s",
 419                              oid_to_hex(&parent),
 420                              oid_to_hex(&item->object.oid));
 421         set_commit_tree(item, tree);
 422         bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
 423         pptr = &item->parents;
 424
 425         graft = lookup_commit_graft(r, &item->object.oid);
 426         while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
 427                 struct commit *new_parent;
 428
 429                 if (tail <= bufptr + parent_entry_len + 1 ||
 430                     get_oid_hex(bufptr + 7, &parent) ||
 431                     bufptr[parent_entry_len] != '\n')
 432                         return error("bad parents in commit %s", oid_to_hex(&item->object.oid));
 433                 bufptr += parent_entry_len + 1;
 434                 /*
 435                  * The clone is shallow if nr_parent < 0, and we must
 436                  * not traverse its real parents even when we unhide them.
 437                  */
 438                 if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
 439                         continue;
 440                 new_parent = lookup_commit(r, &parent);
 441                 if (!new_parent)
 442                         return error("bad parent %s in commit %s",
 443                                      oid_to_hex(&parent),
 444                                      oid_to_hex(&item->object.oid));
 445                 pptr = &commit_list_insert(new_parent, pptr)->next;
 446         }
 447         if (graft) {
 448                 int i;
 449                 struct commit *new_parent;
 450                 for (i = 0; i < graft->nr_parent; i++) {
 451                         new_parent = lookup_commit(r,
 452                                                    &graft->parent[i]);
 453                         if (!new_parent)
 454                                 return error("bad graft parent %s in commit %s",
 455                                              oid_to_hex(&graft->parent[i]),
 456                                              oid_to_hex(&item->object.oid));
 457                         pptr = &commit_list_insert(new_parent, pptr)->next;
 458                 }
 459         }
 460         item->date = parse_commit_date(bufptr, tail);
 461
 462         if (check_graph)
 463                 load_commit_graph_info(r, item);
 464
 465         item->object.parsed = 1;
 466         return 0;
 467 }
 468
 469 int repo_parse_commit_internal(struct repository *r,
 470                                struct commit *item,
 471                                int quiet_on_missing,
 472                                int use_commit_graph)
 473 {
 474         enum object_type type;
 475         void *buffer;
 476         unsigned long size;
 477         int ret;
 478
 479         if (!item)
 480                 return -1;
 481         if (item->object.parsed)
 482                 return 0;
 483         if (use_commit_graph && parse_commit_in_graph(r, item))
 484                 return 0;
 485         buffer = repo_read_object_file(r, &item->object.oid, &type, &size);
 486         if (!buffer)
 487                 return quiet_on_missing ? -1 :
 488                         error("Could not read %s",
 489                              oid_to_hex(&item->object.oid));
 490         if (type != OBJ_COMMIT) {
 491                 free(buffer);
 492                 return error("Object %s not a commit",
 493                              oid_to_hex(&item->object.oid));
 494         }
 495
 496         ret = parse_commit_buffer(r, item, buffer, size, 0);
 497         if (save_commit_buffer && !ret) {
 498                 set_commit_buffer(r, item, buffer, size);
 499                 return 0;
 500         }
 501         free(buffer);
 502         return ret;
 503 }
 504
 505 int repo_parse_commit_gently(struct repository *r,
 506                              struct commit *item, int quiet_on_missing)
 507 {
 508         return repo_parse_commit_internal(r, item, quiet_on_missing, 1);
 509 }
 510
 511 void parse_commit_or_die(struct commit *item)
 512 {
 513         if (parse_commit(item))
 514                 die("unable to parse commit %s",
 515                     item ? oid_to_hex(&item->object.oid) : "(null)");
 516 }
 517
 518 int find_commit_subject(const char *commit_buffer, const char **subject)
 519 {
 520         const char *eol;
 521         const char *p = commit_buffer;
 522
 523         while (*p && (*p != '\n' || p[1] != '\n'))
 524                 p++;
 525         if (*p) {
 526                 p = skip_blank_lines(p + 2);
 527                 eol = strchrnul(p, '\n');
 528         } else
 529                 eol = p;
 530
 531         *subject = p;
 532
 533         return eol - p;
 534 }
 535
 536 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 537 {
 538         struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 539         new_list->item = item;
 540         new_list->next = *list_p;
 541         *list_p = new_list;
 542         return new_list;
 543 }
 544
 545 unsigned commit_list_count(const struct commit_list *l)
 546 {
 547         unsigned c = 0;
 548         for (; l; l = l->next )
 549                 c++;
 550         return c;
 551 }
 552
 553 struct commit_list *copy_commit_list(struct commit_list *list)
 554 {
 555         struct commit_list *head = NULL;
 556         struct commit_list **pp = &head;
 557         while (list) {
 558                 pp = commit_list_append(list->item, pp);
 559                 list = list->next;
 560         }
 561         return head;
 562 }
 563
 564 void free_commit_list(struct commit_list *list)
 565 {
 566         while (list)
 567                 pop_commit(&list);
 568 }
 569
 570 struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 571 {
 572         struct commit_list **pp = list;
 573         struct commit_list *p;
 574         while ((p = *pp) != NULL) {
 575                 if (p->item->date < item->date) {
 576                         break;
 577                 }
 578                 pp = &p->next;
 579         }
 580         return commit_list_insert(item, pp);
 581 }
 582
 583 static int commit_list_compare_by_date(const void *a, const void *b)
 584 {
 585         timestamp_t a_date = ((const struct commit_list *)a)->item->date;
 586         timestamp_t b_date = ((const struct commit_list *)b)->item->date;
 587         if (a_date < b_date)
 588                 return 1;
 589         if (a_date > b_date)
 590                 return -1;
 591         return 0;
 592 }
 593
 594 static void *commit_list_get_next(const void *a)
 595 {
 596         return ((const struct commit_list *)a)->next;
 597 }
 598
 599 static void commit_list_set_next(void *a, void *next)
 600 {
 601         ((struct commit_list *)a)->next = next;
 602 }
 603
 604 void commit_list_sort_by_date(struct commit_list **list)
 605 {
 606         *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 607                                 commit_list_compare_by_date);
 608 }
 609
 610 struct commit *pop_most_recent_commit(struct commit_list **list,
 611                                       unsigned int mark)
 612 {
 613         struct commit *ret = pop_commit(list);
 614         struct commit_list *parents = ret->parents;
 615
 616         while (parents) {
 617                 struct commit *commit = parents->item;
 618                 if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 619                         commit->object.flags |= mark;
 620                         commit_list_insert_by_date(commit, list);
 621                 }
 622                 parents = parents->next;
 623         }
 624         return ret;
 625 }
 626
 627 static void clear_commit_marks_1(struct commit_list **plist,
 628                                  struct commit *commit, unsigned int mark)
 629 {
 630         while (commit) {
 631                 struct commit_list *parents;
 632
 633                 if (!(mark & commit->object.flags))
 634                         return;
 635
 636                 commit->object.flags &= ~mark;
 637
 638                 parents = commit->parents;
 639                 if (!parents)
 640                         return;
 641
 642                 while ((parents = parents->next))
 643                         commit_list_insert(parents->item, plist);
 644
 645                 commit = commit->parents->item;
 646         }
 647 }
 648
 649 void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 650 {
 651         struct commit_list *list = NULL;
 652
 653         while (nr--) {
 654                 clear_commit_marks_1(&list, *commit, mark);
 655                 commit++;
 656         }
 657         while (list)
 658                 clear_commit_marks_1(&list, pop_commit(&list), mark);
 659 }
 660
 661 void clear_commit_marks(struct commit *commit, unsigned int mark)
 662 {
 663         clear_commit_marks_many(1, &commit, mark);
 664 }
 665
 666 struct commit *pop_commit(struct commit_list **stack)
 667 {
 668         struct commit_list *top = *stack;
 669         struct commit *item = top ? top->item : NULL;
 670
 671         if (top) {
 672                 *stack = top->next;
 673                 free(top);
 674         }
 675         return item;
 676 }
 677
 678 /*
 679  * Topological sort support
 680  */
 681
 682 /* count number of children that have not been emitted */
 683 define_commit_slab(indegree_slab, int);
 684
 685 define_commit_slab(author_date_slab, timestamp_t);
 686
 687 void record_author_date(struct author_date_slab *author_date,
 688                         struct commit *commit)
 689 {
 690         const char *buffer = get_commit_buffer(commit, NULL);
 691         struct ident_split ident;
 692         const char *ident_line;
 693         size_t ident_len;
 694         char *date_end;
 695         timestamp_t date;
 696
 697         ident_line = find_commit_header(buffer, "author", &ident_len);
 698         if (!ident_line)
 699                 goto fail_exit; /* no author line */
 700         if (split_ident_line(&ident, ident_line, ident_len) ||
 701             !ident.date_begin || !ident.date_end)
 702                 goto fail_exit; /* malformed "author" line */
 703
 704         date = parse_timestamp(ident.date_begin, &date_end, 10);
 705         if (date_end != ident.date_end)
 706                 goto fail_exit; /* malformed date */
 707         *(author_date_slab_at(author_date, commit)) = date;
 708
 709 fail_exit:
 710         unuse_commit_buffer(commit, buffer);
 711 }
 712
 713 int compare_commits_by_author_date(const void *a_, const void *b_,
 714                                    void *cb_data)
 715 {
 716         const struct commit *a = a_, *b = b_;
 717         struct author_date_slab *author_date = cb_data;
 718         timestamp_t a_date = *(author_date_slab_at(author_date, a));
 719         timestamp_t b_date = *(author_date_slab_at(author_date, b));
 720
 721         /* newer commits with larger date first */
 722         if (a_date < b_date)
 723                 return 1;
 724         else if (a_date > b_date)
 725                 return -1;
 726         return 0;
 727 }
 728
 729 int compare_commits_by_gen_then_commit_date(const void *a_, const void *b_, void *unused)
 730 {
 731         const struct commit *a = a_, *b = b_;
 732
 733         /* newer commits first */
 734         if (a->generation < b->generation)
 735                 return 1;
 736         else if (a->generation > b->generation)
 737                 return -1;
 738
 739         /* use date as a heuristic when generations are equal */
 740         if (a->date < b->date)
 741                 return 1;
 742         else if (a->date > b->date)
 743                 return -1;
 744         return 0;
 745 }
 746
 747 int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 748 {
 749         const struct commit *a = a_, *b = b_;
 750         /* newer commits with larger date first */
 751         if (a->date < b->date)
 752                 return 1;
 753         else if (a->date > b->date)
 754                 return -1;
 755         return 0;
 756 }
 757
 758 /*
 759  * Performs an in-place topological sort on the list supplied.
 760  */
 761 void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 762 {
 763         struct commit_list *next, *orig = *list;
 764         struct commit_list **pptr;
 765         struct indegree_slab indegree;
 766         struct prio_queue queue;
 767         struct commit *commit;
 768         struct author_date_slab author_date;
 769
 770         if (!orig)
 771                 return;
 772         *list = NULL;
 773
 774         init_indegree_slab(&indegree);
 775         memset(&queue, '\0', sizeof(queue));
 776
 777         switch (sort_order) {
 778         default: /* REV_SORT_IN_GRAPH_ORDER */
 779                 queue.compare = NULL;
 780                 break;
 781         case REV_SORT_BY_COMMIT_DATE:
 782                 queue.compare = compare_commits_by_commit_date;
 783                 break;
 784         case REV_SORT_BY_AUTHOR_DATE:
 785                 init_author_date_slab(&author_date);
 786                 queue.compare = compare_commits_by_author_date;
 787                 queue.cb_data = &author_date;
 788                 break;
 789         }
 790
 791         /* Mark them and clear the indegree */
 792         for (next = orig; next; next = next->next) {
 793                 struct commit *commit = next->item;
 794                 *(indegree_slab_at(&indegree, commit)) = 1;
 795                 /* also record the author dates, if needed */
 796                 if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 797                         record_author_date(&author_date, commit);
 798         }
 799
 800         /* update the indegree */
 801         for (next = orig; next; next = next->next) {
 802                 struct commit_list *parents = next->item->parents;
 803                 while (parents) {
 804                         struct commit *parent = parents->item;
 805                         int *pi = indegree_slab_at(&indegree, parent);
 806
 807                         if (*pi)
 808                                 (*pi)++;
 809                         parents = parents->next;
 810                 }
 811         }
 812
 813         /*
 814          * find the tips
 815          *
 816          * tips are nodes not reachable from any other node in the list
 817          *
 818          * the tips serve as a starting set for the work queue.
 819          */
 820         for (next = orig; next; next = next->next) {
 821                 struct commit *commit = next->item;
 822
 823                 if (*(indegree_slab_at(&indegree, commit)) == 1)
 824                         prio_queue_put(&queue, commit);
 825         }
 826
 827         /*
 828          * This is unfortunate; the initial tips need to be shown
 829          * in the order given from the revision traversal machinery.
 830          */
 831         if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 832                 prio_queue_reverse(&queue);
 833
 834         /* We no longer need the commit list */
 835         free_commit_list(orig);
 836
 837         pptr = list;
 838         *list = NULL;
 839         while ((commit = prio_queue_get(&queue)) != NULL) {
 840                 struct commit_list *parents;
 841
 842                 for (parents = commit->parents; parents ; parents = parents->next) {
 843                         struct commit *parent = parents->item;
 844                         int *pi = indegree_slab_at(&indegree, parent);
 845
 846                         if (!*pi)
 847                                 continue;
 848
 849                         /*
 850                          * parents are only enqueued for emission
 851                          * when all their children have been emitted thereby
 852                          * guaranteeing topological order.
 853                          */
 854                         if (--(*pi) == 1)
 855                                 prio_queue_put(&queue, parent);
 856                 }
 857                 /*
 858                  * all children of commit have already been
 859                  * emitted. we can emit it now.
 860                  */
 861                 *(indegree_slab_at(&indegree, commit)) = 0;
 862
 863                 pptr = &commit_list_insert(commit, pptr)->next;
 864         }
 865
 866         clear_indegree_slab(&indegree);
 867         clear_prio_queue(&queue);
 868         if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 869                 clear_author_date_slab(&author_date);
 870 }
 871
 872 struct rev_collect {
 873         struct commit **commit;
 874         int nr;
 875         int alloc;
 876         unsigned int initial : 1;
 877 };
 878
 879 static void add_one_commit(struct object_id *oid, struct rev_collect *revs)
 880 {
 881         struct commit *commit;
 882
 883         if (is_null_oid(oid))
 884                 return;
 885
 886         commit = lookup_commit(the_repository, oid);
 887         if (!commit ||
 888             (commit->object.flags & TMP_MARK) ||
 889             parse_commit(commit))
 890                 return;
 891
 892         ALLOC_GROW(revs->commit, revs->nr + 1, revs->alloc);
 893         revs->commit[revs->nr++] = commit;
 894         commit->object.flags |= TMP_MARK;
 895 }
 896
 897 static int collect_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
 898                                   const char *ident, timestamp_t timestamp,
 899                                   int tz, const char *message, void *cbdata)
 900 {
 901         struct rev_collect *revs = cbdata;
 902
 903         if (revs->initial) {
 904                 revs->initial = 0;
 905                 add_one_commit(ooid, revs);
 906         }
 907         add_one_commit(noid, revs);
 908         return 0;
 909 }
 910
 911 struct commit *get_fork_point(const char *refname, struct commit *commit)
 912 {
 913         struct object_id oid;
 914         struct rev_collect revs;
 915         struct commit_list *bases;
 916         int i;
 917         struct commit *ret = NULL;
 918
 919         memset(&revs, 0, sizeof(revs));
 920         revs.initial = 1;
 921         for_each_reflog_ent(refname, collect_one_reflog_ent, &revs);
 922
 923         if (!revs.nr && !get_oid(refname, &oid))
 924                 add_one_commit(&oid, &revs);
 925
 926         for (i = 0; i < revs.nr; i++)
 927                 revs.commit[i]->object.flags &= ~TMP_MARK;
 928
 929         bases = get_merge_bases_many(commit, revs.nr, revs.commit);
 930
 931         /*
 932          * There should be one and only one merge base, when we found
 933          * a common ancestor among reflog entries.
 934          */
 935         if (!bases || bases->next)
 936                 goto cleanup_return;
 937
 938         /* And the found one must be one of the reflog entries */
 939         for (i = 0; i < revs.nr; i++)
 940                 if (&bases->item->object == &revs.commit[i]->object)
 941                         break; /* found */
 942         if (revs.nr <= i)
 943                 goto cleanup_return;
 944
 945         ret = bases->item;
 946
 947 cleanup_return:
 948         free_commit_list(bases);
 949         return ret;
 950 }
 951
 952 static const char gpg_sig_header[] = "gpgsig";
 953 static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
 954
 955 static int do_sign_commit(struct strbuf *buf, const char *keyid)
 956 {
 957         struct strbuf sig = STRBUF_INIT;
 958         int inspos, copypos;
 959         const char *eoh;
 960
 961         /* find the end of the header */
 962         eoh = strstr(buf->buf, "\n\n");
 963         if (!eoh)
 964                 inspos = buf->len;
 965         else
 966                 inspos = eoh - buf->buf + 1;
 967
 968         if (!keyid || !*keyid)
 969                 keyid = get_signing_key();
 970         if (sign_buffer(buf, &sig, keyid)) {
 971                 strbuf_release(&sig);
 972                 return -1;
 973         }
 974
 975         for (copypos = 0; sig.buf[copypos]; ) {
 976                 const char *bol = sig.buf + copypos;
 977                 const char *eol = strchrnul(bol, '\n');
 978                 int len = (eol - bol) + !!*eol;
 979
 980                 if (!copypos) {
 981                         strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
 982                         inspos += gpg_sig_header_len;
 983                 }
 984                 strbuf_insertstr(buf, inspos++, " ");
 985                 strbuf_insert(buf, inspos, bol, len);
 986                 inspos += len;
 987                 copypos += len;
 988         }
 989         strbuf_release(&sig);
 990         return 0;
 991 }
 992
 993 int parse_signed_commit(const struct commit *commit,
 994                         struct strbuf *payload, struct strbuf *signature)
 995 {
 996
 997         unsigned long size;
 998         const char *buffer = get_commit_buffer(commit, &size);
 999         int in_signature, saw_signature = -1;
1000         const char *line, *tail;
1001
1002         line = buffer;
1003         tail = buffer + size;
1004         in_signature = 0;
1005         saw_signature = 0;
1006         while (line < tail) {
1007                 const char *sig = NULL;
1008                 const char *next = memchr(line, '\n', tail - line);
1009
1010                 next = next ? next + 1 : tail;
1011                 if (in_signature && line[0] == ' ')
1012                         sig = line + 1;
1013                 else if (starts_with(line, gpg_sig_header) &&
1014                          line[gpg_sig_header_len] == ' ')
1015                         sig = line + gpg_sig_header_len + 1;
1016                 if (sig) {
1017                         strbuf_add(signature, sig, next - sig);
1018                         saw_signature = 1;
1019                         in_signature = 1;
1020                 } else {
1021                         if (*line == '\n')
1022                                 /* dump the whole remainder of the buffer */
1023                                 next = tail;
1024                         strbuf_add(payload, line, next - line);
1025                         in_signature = 0;
1026                 }
1027                 line = next;
1028         }
1029         unuse_commit_buffer(commit, buffer);
1030         return saw_signature;
1031 }
1032
1033 int remove_signature(struct strbuf *buf)
1034 {
1035         const char *line = buf->buf;
1036         const char *tail = buf->buf + buf->len;
1037         int in_signature = 0;
1038         const char *sig_start = NULL;
1039         const char *sig_end = NULL;
1040
1041         while (line < tail) {
1042                 const char *next = memchr(line, '\n', tail - line);
1043                 next = next ? next + 1 : tail;
1044
1045                 if (in_signature && line[0] == ' ')
1046                         sig_end = next;
1047                 else if (starts_with(line, gpg_sig_header) &&
1048                          line[gpg_sig_header_len] == ' ') {
1049                         sig_start = line;
1050                         sig_end = next;
1051                         in_signature = 1;
1052                 } else {
1053                         if (*line == '\n')
1054                                 /* dump the whole remainder of the buffer */
1055                                 next = tail;
1056                         in_signature = 0;
1057                 }
1058                 line = next;
1059         }
1060
1061         if (sig_start)
1062                 strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1063
1064         return sig_start != NULL;
1065 }
1066
1067 static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1068 {
1069         struct merge_remote_desc *desc;
1070         struct commit_extra_header *mergetag;
1071         char *buf;
1072         unsigned long size, len;
1073         enum object_type type;
1074
1075         desc = merge_remote_util(parent);
1076         if (!desc || !desc->obj)
1077                 return;
1078         buf = read_object_file(&desc->obj->oid, &type, &size);
1079         if (!buf || type != OBJ_TAG)
1080                 goto free_return;
1081         len = parse_signature(buf, size);
1082         if (size == len)
1083                 goto free_return;
1084         /*
1085          * We could verify this signature and either omit the tag when
1086          * it does not validate, but the integrator may not have the
1087          * public key of the signer of the tag he is merging, while a
1088          * later auditor may have it while auditing, so let's not run
1089          * verify-signed-buffer here for now...
1090          *
1091          * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1092          *      warn("warning: signed tag unverified.");
1093          */
1094         mergetag = xcalloc(1, sizeof(*mergetag));
1095         mergetag->key = xstrdup("mergetag");
1096         mergetag->value = buf;
1097         mergetag->len = size;
1098
1099         **tail = mergetag;
1100         *tail = &mergetag->next;
1101         return;
1102
1103 free_return:
1104         free(buf);
1105 }
1106
1107 int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1108 {
1109         struct strbuf payload = STRBUF_INIT;
1110         struct strbuf signature = STRBUF_INIT;
1111         int ret = 1;
1112
1113         sigc->result = 'N';
1114
1115         if (parse_signed_commit(commit, &payload, &signature) <= 0)
1116                 goto out;
1117         ret = check_signature(payload.buf, payload.len, signature.buf,
1118                 signature.len, sigc);
1119
1120  out:
1121         strbuf_release(&payload);
1122         strbuf_release(&signature);
1123
1124         return ret;
1125 }
1126
1127 void verify_merge_signature(struct commit *commit, int verbosity,
1128                             int check_trust)
1129 {
1130         char hex[GIT_MAX_HEXSZ + 1];
1131         struct signature_check signature_check;
1132         int ret;
1133         memset(&signature_check, 0, sizeof(signature_check));
1134
1135         ret = check_commit_signature(commit, &signature_check);
1136
1137         find_unique_abbrev_r(hex, &commit->object.oid, DEFAULT_ABBREV);
1138         switch (signature_check.result) {
1139         case 'G':
1140                 if (ret || (check_trust && signature_check.trust_level < TRUST_MARGINAL))
1141                         die(_("Commit %s has an untrusted GPG signature, "
1142                               "allegedly by %s."), hex, signature_check.signer);
1143                 break;
1144         case 'B':
1145                 die(_("Commit %s has a bad GPG signature "
1146                       "allegedly by %s."), hex, signature_check.signer);
1147         default: /* 'N' */
1148                 die(_("Commit %s does not have a GPG signature."), hex);
1149         }
1150         if (verbosity >= 0 && signature_check.result == 'G')
1151                 printf(_("Commit %s has a good GPG signature by %s\n"),
1152                        hex, signature_check.signer);
1153
1154         signature_check_clear(&signature_check);
1155 }
1156
1157 void append_merge_tag_headers(struct commit_list *parents,
1158                               struct commit_extra_header ***tail)
1159 {
1160         while (parents) {
1161                 struct commit *parent = parents->item;
1162                 handle_signed_tag(parent, tail);
1163                 parents = parents->next;
1164         }
1165 }
1166
1167 static void add_extra_header(struct strbuf *buffer,
1168                              struct commit_extra_header *extra)
1169 {
1170         strbuf_addstr(buffer, extra->key);
1171         if (extra->len)
1172                 strbuf_add_lines(buffer, " ", extra->value, extra->len);
1173         else
1174                 strbuf_addch(buffer, '\n');
1175 }
1176
1177 struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1178                                                       const char **exclude)
1179 {
1180         struct commit_extra_header *extra = NULL;
1181         unsigned long size;
1182         const char *buffer = get_commit_buffer(commit, &size);
1183         extra = read_commit_extra_header_lines(buffer, size, exclude);
1184         unuse_commit_buffer(commit, buffer);
1185         return extra;
1186 }
1187
1188 int for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1189 {
1190         struct commit_extra_header *extra, *to_free;
1191         int res = 0;
1192
1193         to_free = read_commit_extra_headers(commit, NULL);
1194         for (extra = to_free; !res && extra; extra = extra->next) {
1195                 if (strcmp(extra->key, "mergetag"))
1196                         continue; /* not a merge tag */
1197                 res = fn(commit, extra, data);
1198         }
1199         free_commit_extra_headers(to_free);
1200         return res;
1201 }
1202
1203 static inline int standard_header_field(const char *field, size_t len)
1204 {
1205         return ((len == 4 && !memcmp(field, "tree", 4)) ||
1206                 (len == 6 && !memcmp(field, "parent", 6)) ||
1207                 (len == 6 && !memcmp(field, "author", 6)) ||
1208                 (len == 9 && !memcmp(field, "committer", 9)) ||
1209                 (len == 8 && !memcmp(field, "encoding", 8)));
1210 }
1211
1212 static int excluded_header_field(const char *field, size_t len, const char **exclude)
1213 {
1214         if (!exclude)
1215                 return 0;
1216
1217         while (*exclude) {
1218                 size_t xlen = strlen(*exclude);
1219                 if (len == xlen && !memcmp(field, *exclude, xlen))
1220                         return 1;
1221                 exclude++;
1222         }
1223         return 0;
1224 }
1225
1226 static struct commit_extra_header *read_commit_extra_header_lines(
1227         const char *buffer, size_t size,
1228         const char **exclude)
1229 {
1230         struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1231         const char *line, *next, *eof, *eob;
1232         struct strbuf buf = STRBUF_INIT;
1233
1234         for (line = buffer, eob = line + size;
1235              line < eob && *line != '\n';
1236              line = next) {
1237                 next = memchr(line, '\n', eob - line);
1238                 next = next ? next + 1 : eob;
1239                 if (*line == ' ') {
1240                         /* continuation */
1241                         if (it)
1242                                 strbuf_add(&buf, line + 1, next - (line + 1));
1243                         continue;
1244                 }
1245                 if (it)
1246                         it->value = strbuf_detach(&buf, &it->len);
1247                 strbuf_reset(&buf);
1248                 it = NULL;
1249
1250                 eof = memchr(line, ' ', next - line);
1251                 if (!eof)
1252                         eof = next;
1253                 else if (standard_header_field(line, eof - line) ||
1254                          excluded_header_field(line, eof - line, exclude))
1255                         continue;
1256
1257                 it = xcalloc(1, sizeof(*it));
1258                 it->key = xmemdupz(line, eof-line);
1259                 *tail = it;
1260                 tail = &it->next;
1261                 if (eof + 1 < next)
1262                         strbuf_add(&buf, eof + 1, next - (eof + 1));
1263         }
1264         if (it)
1265                 it->value = strbuf_detach(&buf, &it->len);
1266         return extra;
1267 }
1268
1269 void free_commit_extra_headers(struct commit_extra_header *extra)
1270 {
1271         while (extra) {
1272                 struct commit_extra_header *next = extra->next;
1273                 free(extra->key);
1274                 free(extra->value);
1275                 free(extra);
1276                 extra = next;
1277         }
1278 }
1279
1280 int commit_tree(const char *msg, size_t msg_len, const struct object_id *tree,
1281                 struct commit_list *parents, struct object_id *ret,
1282                 const char *author, const char *sign_commit)
1283 {
1284         struct commit_extra_header *extra = NULL, **tail = &extra;
1285         int result;
1286
1287         append_merge_tag_headers(parents, &tail);
1288         result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1289                                       author, sign_commit, extra);
1290         free_commit_extra_headers(extra);
1291         return result;
1292 }
1293
1294 static int find_invalid_utf8(const char *buf, int len)
1295 {
1296         int offset = 0;
1297         static const unsigned int max_codepoint[] = {
1298                 0x7f, 0x7ff, 0xffff, 0x10ffff
1299         };
1300
1301         while (len) {
1302                 unsigned char c = *buf++;
1303                 int bytes, bad_offset;
1304                 unsigned int codepoint;
1305                 unsigned int min_val, max_val;
1306
1307                 len--;
1308                 offset++;
1309
1310                 /* Simple US-ASCII? No worries. */
1311                 if (c < 0x80)
1312                         continue;
1313
1314                 bad_offset = offset-1;
1315
1316                 /*
1317                  * Count how many more high bits set: that's how
1318                  * many more bytes this sequence should have.
1319                  */
1320                 bytes = 0;
1321                 while (c & 0x40) {
1322                         c <<= 1;
1323                         bytes++;
1324                 }
1325
1326                 /*
1327                  * Must be between 1 and 3 more bytes.  Longer sequences result in
1328                  * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1329                  */
1330                 if (bytes < 1 || 3 < bytes)
1331                         return bad_offset;
1332
1333                 /* Do we *have* that many bytes? */
1334                 if (len < bytes)
1335                         return bad_offset;
1336
1337                 /*
1338                  * Place the encoded bits at the bottom of the value and compute the
1339                  * valid range.
1340                  */
1341                 codepoint = (c & 0x7f) >> bytes;
1342                 min_val = max_codepoint[bytes-1] + 1;
1343                 max_val = max_codepoint[bytes];
1344
1345                 offset += bytes;
1346                 len -= bytes;
1347
1348                 /* And verify that they are good continuation bytes */
1349                 do {
1350                         codepoint <<= 6;
1351                         codepoint |= *buf & 0x3f;
1352                         if ((*buf++ & 0xc0) != 0x80)
1353                                 return bad_offset;
1354                 } while (--bytes);
1355
1356                 /* Reject codepoints that are out of range for the sequence length. */
1357                 if (codepoint < min_val || codepoint > max_val)
1358                         return bad_offset;
1359                 /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1360                 if ((codepoint & 0x1ff800) == 0xd800)
1361                         return bad_offset;
1362                 /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1363                 if ((codepoint & 0xfffe) == 0xfffe)
1364                         return bad_offset;
1365                 /* So are anything in the range U+FDD0..U+FDEF. */
1366                 if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1367                         return bad_offset;
1368         }
1369         return -1;
1370 }
1371
1372 /*
1373  * This verifies that the buffer is in proper utf8 format.
1374  *
1375  * If it isn't, it assumes any non-utf8 characters are Latin1,
1376  * and does the conversion.
1377  */
1378 static int verify_utf8(struct strbuf *buf)
1379 {
1380         int ok = 1;
1381         long pos = 0;
1382
1383         for (;;) {
1384                 int bad;
1385                 unsigned char c;
1386                 unsigned char replace[2];
1387
1388                 bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1389                 if (bad < 0)
1390                         return ok;
1391                 pos += bad;
1392                 ok = 0;
1393                 c = buf->buf[pos];
1394                 strbuf_remove(buf, pos, 1);
1395
1396                 /* We know 'c' must be in the range 128-255 */
1397                 replace[0] = 0xc0 + (c >> 6);
1398                 replace[1] = 0x80 + (c & 0x3f);
1399                 strbuf_insert(buf, pos, replace, 2);
1400                 pos += 2;
1401         }
1402 }
1403
1404 static const char commit_utf8_warn[] =
1405 N_("Warning: commit message did not conform to UTF-8.\n"
1406    "You may want to amend it after fixing the message, or set the config\n"
1407    "variable i18n.commitencoding to the encoding your project uses.\n");
1408
1409 int commit_tree_extended(const char *msg, size_t msg_len,
1410                          const struct object_id *tree,
1411                          struct commit_list *parents, struct object_id *ret,
1412                          const char *author, const char *sign_commit,
1413                          struct commit_extra_header *extra)
1414 {
1415         int result;
1416         int encoding_is_utf8;
1417         struct strbuf buffer;
1418
1419         assert_oid_type(tree, OBJ_TREE);
1420
1421         if (memchr(msg, '\0', msg_len))
1422                 return error("a NUL byte in commit log message not allowed.");
1423
1424         /* Not having i18n.commitencoding is the same as having utf-8 */
1425         encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1426
1427         strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1428         strbuf_addf(&buffer, "tree %s\n", oid_to_hex(tree));
1429
1430         /*
1431          * NOTE! This ordering means that the same exact tree merged with a
1432          * different order of parents will be a _different_ changeset even
1433          * if everything else stays the same.
1434          */
1435         while (parents) {
1436                 struct commit *parent = pop_commit(&parents);
1437                 strbuf_addf(&buffer, "parent %s\n",
1438                             oid_to_hex(&parent->object.oid));
1439         }
1440
1441         /* Person/date information */
1442         if (!author)
1443                 author = git_author_info(IDENT_STRICT);
1444         strbuf_addf(&buffer, "author %s\n", author);
1445         strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1446         if (!encoding_is_utf8)
1447                 strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1448
1449         while (extra) {
1450                 add_extra_header(&buffer, extra);
1451                 extra = extra->next;
1452         }
1453         strbuf_addch(&buffer, '\n');
1454
1455         /* And add the comment */
1456         strbuf_add(&buffer, msg, msg_len);
1457
1458         /* And check the encoding */
1459         if (encoding_is_utf8 && !verify_utf8(&buffer))
1460                 fprintf(stderr, _(commit_utf8_warn));
1461
1462         if (sign_commit && do_sign_commit(&buffer, sign_commit)) {
1463                 result = -1;
1464                 goto out;
1465         }
1466
1467         result = write_object_file(buffer.buf, buffer.len, commit_type, ret);
1468 out:
1469         strbuf_release(&buffer);
1470         return result;
1471 }
1472
1473 define_commit_slab(merge_desc_slab, struct merge_remote_desc *);
1474 static struct merge_desc_slab merge_desc_slab = COMMIT_SLAB_INIT(1, merge_desc_slab);
1475
1476 struct merge_remote_desc *merge_remote_util(struct commit *commit)
1477 {
1478         return *merge_desc_slab_at(&merge_desc_slab, commit);
1479 }
1480
1481 void set_merge_remote_desc(struct commit *commit,
1482                            const char *name, struct object *obj)
1483 {
1484         struct merge_remote_desc *desc;
1485         FLEX_ALLOC_STR(desc, name, name);
1486         desc->obj = obj;
1487         *merge_desc_slab_at(&merge_desc_slab, commit) = desc;
1488 }
1489
1490 struct commit *get_merge_parent(const char *name)
1491 {
1492         struct object *obj;
1493         struct commit *commit;
1494         struct object_id oid;
1495         if (get_oid(name, &oid))
1496                 return NULL;
1497         obj = parse_object(the_repository, &oid);
1498         commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1499         if (commit && !merge_remote_util(commit))
1500                 set_merge_remote_desc(commit, name, obj);
1501         return commit;
1502 }
1503
1504 /*
1505  * Append a commit to the end of the commit_list.
1506  *
1507  * next starts by pointing to the variable that holds the head of an
1508  * empty commit_list, and is updated to point to the "next" field of
1509  * the last item on the list as new commits are appended.
1510  *
1511  * Usage example:
1512  *
1513  *     struct commit_list *list;
1514  *     struct commit_list **next = &list;
1515  *
1516  *     next = commit_list_append(c1, next);
1517  *     next = commit_list_append(c2, next);
1518  *     assert(commit_list_count(list) == 2);
1519  *     return list;
1520  */
1521 struct commit_list **commit_list_append(struct commit *commit,
1522                                         struct commit_list **next)
1523 {
1524         struct commit_list *new_commit = xmalloc(sizeof(struct commit_list));
1525         new_commit->item = commit;
1526         *next = new_commit;
1527         new_commit->next = NULL;
1528         return &new_commit->next;
1529 }
1530
1531 const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1532 {
1533         int key_len = strlen(key);
1534         const char *line = msg;
1535
1536         while (line) {
1537                 const char *eol = strchrnul(line, '\n');
1538
1539                 if (line == eol)
1540                         return NULL;
1541
1542                 if (eol - line > key_len &&
1543                     !strncmp(line, key, key_len) &&
1544                     line[key_len] == ' ') {
1545                         *out_len = eol - line - key_len - 1;
1546                         return line + key_len + 1;
1547                 }
1548                 line = *eol ? eol + 1 : NULL;
1549         }
1550         return NULL;
1551 }
1552
1553 /*
1554  * Inspect the given string and determine the true "end" of the log message, in
1555  * order to find where to put a new Signed-off-by: line.  Ignored are
1556  * trailing comment lines and blank lines.  To support "git commit -s
1557  * --amend" on an existing commit, we also ignore "Conflicts:".  To
1558  * support "git commit -v", we truncate at cut lines.
1559  *
1560  * Returns the number of bytes from the tail to ignore, to be fed as
1561  * the second parameter to append_signoff().
1562  */
1563 size_t ignore_non_trailer(const char *buf, size_t len)
1564 {
1565         size_t boc = 0;
1566         size_t bol = 0;
1567         int in_old_conflicts_block = 0;
1568         size_t cutoff = wt_status_locate_end(buf, len);
1569
1570         while (bol < cutoff) {
1571                 const char *next_line = memchr(buf + bol, '\n', len - bol);
1572
1573                 if (!next_line)
1574                         next_line = buf + len;
1575                 else
1576                         next_line++;
1577
1578                 if (buf[bol] == comment_line_char || buf[bol] == '\n') {
1579                         /* is this the first of the run of comments? */
1580                         if (!boc)
1581                                 boc = bol;
1582                         /* otherwise, it is just continuing */
1583                 } else if (starts_with(buf + bol, "Conflicts:\n")) {
1584                         in_old_conflicts_block = 1;
1585                         if (!boc)
1586                                 boc = bol;
1587                 } else if (in_old_conflicts_block && buf[bol] == '\t') {
1588                         ; /* a pathname in the conflicts block */
1589                 } else if (boc) {
1590                         /* the previous was not trailing comment */
1591                         boc = 0;
1592                         in_old_conflicts_block = 0;
1593                 }
1594                 bol = next_line - buf;
1595         }
1596         return boc ? len - boc : len - cutoff;
1597 }
1598
1599 int run_commit_hook(int editor_is_used, const char *index_file,
1600                     const char *name, ...)
1601 {
1602         struct argv_array hook_env = ARGV_ARRAY_INIT;
1603         va_list args;
1604         int ret;
1605
1606         argv_array_pushf(&hook_env, "GIT_INDEX_FILE=%s", index_file);
1607
1608         /*
1609          * Let the hook know that no editor will be launched.
1610          */
1611         if (!editor_is_used)
1612                 argv_array_push(&hook_env, "GIT_EDITOR=:");
1613
1614         va_start(args, name);
1615         ret = run_hook_ve(hook_env.argv,name, args);
1616         va_end(args);
1617         argv_array_clear(&hook_env);
1618
1619         return ret;
1620 }