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