commit.c

   1 #include "cache.h"
   2 #include "tag.h"
   3 #include "commit.h"
   4 #include "commit-graph.h"
   5 #include "environment.h"
   6 #include "gettext.h"
   7 #include "hex.h"
   8 #include "repository.h"
   9 #include "object-name.h"
  10 #include "object-store.h"
  11 #include "pkt-line.h"
  12 #include "utf8.h"
  13 #include "diff.h"
  14 #include "revision.h"
  15 #include "notes.h"
  16 #include "alloc.h"
  17 #include "gpg-interface.h"
  18 #include "mergesort.h"
  19 #include "commit-slab.h"
  20 #include "prio-queue.h"
  21 #include "hash-lookup.h"
  22 #include "wt-status.h"
  23 #include "advice.h"
  24 #include "refs.h"
  25 #include "commit-reach.h"
  26 #include "run-command.h"
  27 #include "setup.h"
  28 #include "shallow.h"
  29 #include "hook.h"
  30
  31 static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
  32
  33 int save_commit_buffer = 1;
  34 int no_graft_file_deprecated_advice;
  35
  36 const char *commit_type = "commit";
  37
  38 struct commit *lookup_commit_reference_gently(struct repository *r,
  39                 const struct object_id *oid, int quiet)
  40 {
  41         struct object *obj = deref_tag(r,
  42                                        parse_object(r, oid),
  43                                        NULL, 0);
  44
  45         if (!obj)
  46                 return NULL;
  47         return object_as_type(obj, OBJ_COMMIT, quiet);
  48 }
  49
  50 struct commit *lookup_commit_reference(struct repository *r, const struct object_id *oid)
  51 {
  52         return lookup_commit_reference_gently(r, oid, 0);
  53 }
  54
  55 struct commit *lookup_commit_or_die(const struct object_id *oid, const char *ref_name)
  56 {
  57         struct commit *c = lookup_commit_reference(the_repository, oid);
  58         if (!c)
  59                 die(_("could not parse %s"), ref_name);
  60         if (!oideq(oid, &c->object.oid)) {
  61                 warning(_("%s %s is not a commit!"),
  62                         ref_name, oid_to_hex(oid));
  63         }
  64         return c;
  65 }
  66
  67 struct commit *lookup_commit_object(struct repository *r,
  68                                     const struct object_id *oid)
  69 {
  70         struct object *obj = parse_object(r, oid);
  71         return obj ? object_as_type(obj, OBJ_COMMIT, 0) : NULL;
  72
  73 }
  74
  75 struct commit *lookup_commit(struct repository *r, const struct object_id *oid)
  76 {
  77         struct object *obj = lookup_object(r, oid);
  78         if (!obj)
  79                 return create_object(r, oid, alloc_commit_node(r));
  80         return object_as_type(obj, OBJ_COMMIT, 0);
  81 }
  82
  83 struct commit *lookup_commit_reference_by_name(const char *name)
  84 {
  85         struct object_id oid;
  86         struct commit *commit;
  87
  88         if (repo_get_oid_committish(the_repository, name, &oid))
  89                 return NULL;
  90         commit = lookup_commit_reference(the_repository, &oid);
  91         if (repo_parse_commit(the_repository, commit))
  92                 return NULL;
  93         return commit;
  94 }
  95
  96 static timestamp_t parse_commit_date(const char *buf, const char *tail)
  97 {
  98         const char *dateptr;
  99
 100         if (buf + 6 >= tail)
 101                 return 0;
 102         if (memcmp(buf, "author", 6))
 103                 return 0;
 104         while (buf < tail && *buf++ != '\n')
 105                 /* nada */;
 106         if (buf + 9 >= tail)
 107                 return 0;
 108         if (memcmp(buf, "committer", 9))
 109                 return 0;
 110         while (buf < tail && *buf++ != '>')
 111                 /* nada */;
 112         if (buf >= tail)
 113                 return 0;
 114         dateptr = buf;
 115         while (buf < tail && *buf++ != '\n')
 116                 /* nada */;
 117         if (buf >= tail)
 118                 return 0;
 119         /* dateptr < buf && buf[-1] == '\n', so parsing will stop at buf-1 */
 120         return parse_timestamp(dateptr, NULL, 10);
 121 }
 122
 123 static const struct object_id *commit_graft_oid_access(size_t index, const void *table)
 124 {
 125         const struct commit_graft * const *commit_graft_table = table;
 126         return &commit_graft_table[index]->oid;
 127 }
 128
 129 int commit_graft_pos(struct repository *r, const struct object_id *oid)
 130 {
 131         return oid_pos(oid, r->parsed_objects->grafts,
 132                        r->parsed_objects->grafts_nr,
 133                        commit_graft_oid_access);
 134 }
 135
 136 static void unparse_commit(struct repository *r, const struct object_id *oid)
 137 {
 138         struct commit *c = lookup_commit(r, oid);
 139
 140         if (!c->object.parsed)
 141                 return;
 142         free_commit_list(c->parents);
 143         c->parents = NULL;
 144         c->object.parsed = 0;
 145 }
 146
 147 int register_commit_graft(struct repository *r, struct commit_graft *graft,
 148                           int ignore_dups)
 149 {
 150         int pos = commit_graft_pos(r, &graft->oid);
 151
 152         if (0 <= pos) {
 153                 if (ignore_dups)
 154                         free(graft);
 155                 else {
 156                         free(r->parsed_objects->grafts[pos]);
 157                         r->parsed_objects->grafts[pos] = graft;
 158                 }
 159                 return 1;
 160         }
 161         pos = -pos - 1;
 162         ALLOC_GROW(r->parsed_objects->grafts,
 163                    r->parsed_objects->grafts_nr + 1,
 164                    r->parsed_objects->grafts_alloc);
 165         r->parsed_objects->grafts_nr++;
 166         if (pos < r->parsed_objects->grafts_nr)
 167                 memmove(r->parsed_objects->grafts + pos + 1,
 168                         r->parsed_objects->grafts + pos,
 169                         (r->parsed_objects->grafts_nr - pos - 1) *
 170                         sizeof(*r->parsed_objects->grafts));
 171         r->parsed_objects->grafts[pos] = graft;
 172         unparse_commit(r, &graft->oid);
 173         return 0;
 174 }
 175
 176 struct commit_graft *read_graft_line(struct strbuf *line)
 177 {
 178         /* The format is just "Commit Parent1 Parent2 ...\n" */
 179         int i, phase;
 180         const char *tail = NULL;
 181         struct commit_graft *graft = NULL;
 182         struct object_id dummy_oid, *oid;
 183
 184         strbuf_rtrim(line);
 185         if (!line->len || line->buf[0] == '#')
 186                 return NULL;
 187         /*
 188          * phase 0 verifies line, counts hashes in line and allocates graft
 189          * phase 1 fills graft
 190          */
 191         for (phase = 0; phase < 2; phase++) {
 192                 oid = graft ? &graft->oid : &dummy_oid;
 193                 if (parse_oid_hex(line->buf, oid, &tail))
 194                         goto bad_graft_data;
 195                 for (i = 0; *tail != '\0'; i++) {
 196                         oid = graft ? &graft->parent[i] : &dummy_oid;
 197                         if (!isspace(*tail++) || parse_oid_hex(tail, oid, &tail))
 198                                 goto bad_graft_data;
 199                 }
 200                 if (!graft) {
 201                         graft = xmalloc(st_add(sizeof(*graft),
 202                                                st_mult(sizeof(struct object_id), i)));
 203                         graft->nr_parent = i;
 204                 }
 205         }
 206         return graft;
 207
 208 bad_graft_data:
 209         error("bad graft data: %s", line->buf);
 210         assert(!graft);
 211         return NULL;
 212 }
 213
 214 static int read_graft_file(struct repository *r, const char *graft_file)
 215 {
 216         FILE *fp = fopen_or_warn(graft_file, "r");
 217         struct strbuf buf = STRBUF_INIT;
 218         if (!fp)
 219                 return -1;
 220         if (!no_graft_file_deprecated_advice &&
 221             advice_enabled(ADVICE_GRAFT_FILE_DEPRECATED))
 222                 advise(_("Support for <GIT_DIR>/info/grafts is deprecated\n"
 223                          "and will be removed in a future Git version.\n"
 224                          "\n"
 225                          "Please use \"git replace --convert-graft-file\"\n"
 226                          "to convert the grafts into replace refs.\n"
 227                          "\n"
 228                          "Turn this message off by running\n"
 229                          "\"git config advice.graftFileDeprecated false\""));
 230         while (!strbuf_getwholeline(&buf, fp, '\n')) {
 231                 /* The format is just "Commit Parent1 Parent2 ...\n" */
 232                 struct commit_graft *graft = read_graft_line(&buf);
 233                 if (!graft)
 234                         continue;
 235                 if (register_commit_graft(r, graft, 1))
 236                         error("duplicate graft data: %s", buf.buf);
 237         }
 238         fclose(fp);
 239         strbuf_release(&buf);
 240         return 0;
 241 }
 242
 243 void prepare_commit_graft(struct repository *r)
 244 {
 245         char *graft_file;
 246
 247         if (r->parsed_objects->commit_graft_prepared)
 248                 return;
 249         if (!startup_info->have_repository)
 250                 return;
 251
 252         graft_file = get_graft_file(r);
 253         read_graft_file(r, graft_file);
 254         /* make sure shallows are read */
 255         is_repository_shallow(r);
 256         r->parsed_objects->commit_graft_prepared = 1;
 257 }
 258
 259 struct commit_graft *lookup_commit_graft(struct repository *r, const struct object_id *oid)
 260 {
 261         int pos;
 262         prepare_commit_graft(r);
 263         pos = commit_graft_pos(r, oid);
 264         if (pos < 0)
 265                 return NULL;
 266         return r->parsed_objects->grafts[pos];
 267 }
 268
 269 int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
 270 {
 271         int i, ret;
 272         for (i = ret = 0; i < the_repository->parsed_objects->grafts_nr && !ret; i++)
 273                 ret = fn(the_repository->parsed_objects->grafts[i], cb_data);
 274         return ret;
 275 }
 276
 277 void reset_commit_grafts(struct repository *r)
 278 {
 279         int i;
 280
 281         for (i = 0; i < r->parsed_objects->grafts_nr; i++) {
 282                 unparse_commit(r, &r->parsed_objects->grafts[i]->oid);
 283                 free(r->parsed_objects->grafts[i]);
 284         }
 285         r->parsed_objects->grafts_nr = 0;
 286         r->parsed_objects->commit_graft_prepared = 0;
 287 }
 288
 289 struct commit_buffer {
 290         void *buffer;
 291         unsigned long size;
 292 };
 293 define_commit_slab(buffer_slab, struct commit_buffer);
 294
 295 struct buffer_slab *allocate_commit_buffer_slab(void)
 296 {
 297         struct buffer_slab *bs = xmalloc(sizeof(*bs));
 298         init_buffer_slab(bs);
 299         return bs;
 300 }
 301
 302 void free_commit_buffer_slab(struct buffer_slab *bs)
 303 {
 304         clear_buffer_slab(bs);
 305         free(bs);
 306 }
 307
 308 void set_commit_buffer(struct repository *r, struct commit *commit, void *buffer, unsigned long size)
 309 {
 310         struct commit_buffer *v = buffer_slab_at(
 311                 r->parsed_objects->buffer_slab, commit);
 312         v->buffer = buffer;
 313         v->size = size;
 314 }
 315
 316 const void *get_cached_commit_buffer(struct repository *r, const struct commit *commit, unsigned long *sizep)
 317 {
 318         struct commit_buffer *v = buffer_slab_peek(
 319                 r->parsed_objects->buffer_slab, commit);
 320         if (!v) {
 321                 if (sizep)
 322                         *sizep = 0;
 323                 return NULL;
 324         }
 325         if (sizep)
 326                 *sizep = v->size;
 327         return v->buffer;
 328 }
 329
 330 const void *repo_get_commit_buffer(struct repository *r,
 331                                    const struct commit *commit,
 332                                    unsigned long *sizep)
 333 {
 334         const void *ret = get_cached_commit_buffer(r, commit, sizep);
 335         if (!ret) {
 336                 enum object_type type;
 337                 unsigned long size;
 338                 ret = repo_read_object_file(r, &commit->object.oid, &type, &size);
 339                 if (!ret)
 340                         die("cannot read commit object %s",
 341                             oid_to_hex(&commit->object.oid));
 342                 if (type != OBJ_COMMIT)
 343                         die("expected commit for %s, got %s",
 344                             oid_to_hex(&commit->object.oid), type_name(type));
 345                 if (sizep)
 346                         *sizep = size;
 347         }
 348         return ret;
 349 }
 350
 351 void repo_unuse_commit_buffer(struct repository *r,
 352                               const struct commit *commit,
 353                               const void *buffer)
 354 {
 355         struct commit_buffer *v = buffer_slab_peek(
 356                 r->parsed_objects->buffer_slab, commit);
 357         if (!(v && v->buffer == buffer))
 358                 free((void *)buffer);
 359 }
 360
 361 void free_commit_buffer(struct parsed_object_pool *pool, struct commit *commit)
 362 {
 363         struct commit_buffer *v = buffer_slab_peek(
 364                 pool->buffer_slab, commit);
 365         if (v) {
 366                 FREE_AND_NULL(v->buffer);
 367                 v->size = 0;
 368         }
 369 }
 370
 371 static inline void set_commit_tree(struct commit *c, struct tree *t)
 372 {
 373         c->maybe_tree = t;
 374 }
 375
 376 struct tree *repo_get_commit_tree(struct repository *r,
 377                                   const struct commit *commit)
 378 {
 379         if (commit->maybe_tree || !commit->object.parsed)
 380                 return commit->maybe_tree;
 381
 382         if (commit_graph_position(commit) != COMMIT_NOT_FROM_GRAPH)
 383                 return get_commit_tree_in_graph(r, commit);
 384
 385         return NULL;
 386 }
 387
 388 struct object_id *get_commit_tree_oid(const struct commit *commit)
 389 {
 390         struct tree *tree = repo_get_commit_tree(the_repository, commit);
 391         return tree ? &tree->object.oid : NULL;
 392 }
 393
 394 void release_commit_memory(struct parsed_object_pool *pool, struct commit *c)
 395 {
 396         set_commit_tree(c, NULL);
 397         free_commit_buffer(pool, c);
 398         c->index = 0;
 399         free_commit_list(c->parents);
 400
 401         c->object.parsed = 0;
 402 }
 403
 404 const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 405 {
 406         struct commit_buffer *v = buffer_slab_peek(
 407                 the_repository->parsed_objects->buffer_slab, commit);
 408         void *ret;
 409
 410         if (!v) {
 411                 if (sizep)
 412                         *sizep = 0;
 413                 return NULL;
 414         }
 415         ret = v->buffer;
 416         if (sizep)
 417                 *sizep = v->size;
 418
 419         v->buffer = NULL;
 420         v->size = 0;
 421         return ret;
 422 }
 423
 424 int parse_commit_buffer(struct repository *r, struct commit *item, const void *buffer, unsigned long size, int check_graph)
 425 {
 426         const char *tail = buffer;
 427         const char *bufptr = buffer;
 428         struct object_id parent;
 429         struct commit_list **pptr;
 430         struct commit_graft *graft;
 431         const int tree_entry_len = the_hash_algo->hexsz + 5;
 432         const int parent_entry_len = the_hash_algo->hexsz + 7;
 433         struct tree *tree;
 434
 435         if (item->object.parsed)
 436                 return 0;
 437         /*
 438          * Presumably this is leftover from an earlier failed parse;
 439          * clear it out in preparation for us re-parsing (we'll hit the
 440          * same error, but that's good, since it lets our caller know
 441          * the result cannot be trusted.
 442          */
 443         free_commit_list(item->parents);
 444         item->parents = NULL;
 445
 446         tail += size;
 447         if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
 448                         bufptr[tree_entry_len] != '\n')
 449                 return error("bogus commit object %s", oid_to_hex(&item->object.oid));
 450         if (get_oid_hex(bufptr + 5, &parent) < 0)
 451                 return error("bad tree pointer in commit %s",
 452                              oid_to_hex(&item->object.oid));
 453         tree = lookup_tree(r, &parent);
 454         if (!tree)
 455                 return error("bad tree pointer %s in commit %s",
 456                              oid_to_hex(&parent),
 457                              oid_to_hex(&item->object.oid));
 458         set_commit_tree(item, tree);
 459         bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
 460         pptr = &item->parents;
 461
 462         graft = lookup_commit_graft(r, &item->object.oid);
 463         if (graft)
 464                 r->parsed_objects->substituted_parent = 1;
 465         while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
 466                 struct commit *new_parent;
 467
 468                 if (tail <= bufptr + parent_entry_len + 1 ||
 469                     get_oid_hex(bufptr + 7, &parent) ||
 470                     bufptr[parent_entry_len] != '\n')
 471                         return error("bad parents in commit %s", oid_to_hex(&item->object.oid));
 472                 bufptr += parent_entry_len + 1;
 473                 /*
 474                  * The clone is shallow if nr_parent < 0, and we must
 475                  * not traverse its real parents even when we unhide them.
 476                  */
 477                 if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
 478                         continue;
 479                 new_parent = lookup_commit(r, &parent);
 480                 if (!new_parent)
 481                         return error("bad parent %s in commit %s",
 482                                      oid_to_hex(&parent),
 483                                      oid_to_hex(&item->object.oid));
 484                 pptr = &commit_list_insert(new_parent, pptr)->next;
 485         }
 486         if (graft) {
 487                 int i;
 488                 struct commit *new_parent;
 489                 for (i = 0; i < graft->nr_parent; i++) {
 490                         new_parent = lookup_commit(r,
 491                                                    &graft->parent[i]);
 492                         if (!new_parent)
 493                                 return error("bad graft parent %s in commit %s",
 494                                              oid_to_hex(&graft->parent[i]),
 495                                              oid_to_hex(&item->object.oid));
 496                         pptr = &commit_list_insert(new_parent, pptr)->next;
 497                 }
 498         }
 499         item->date = parse_commit_date(bufptr, tail);
 500
 501         if (check_graph)
 502                 load_commit_graph_info(r, item);
 503
 504         item->object.parsed = 1;
 505         return 0;
 506 }
 507
 508 int repo_parse_commit_internal(struct repository *r,
 509                                struct commit *item,
 510                                int quiet_on_missing,
 511                                int use_commit_graph)
 512 {
 513         enum object_type type;
 514         void *buffer;
 515         unsigned long size;
 516         struct object_info oi = {
 517                 .typep = &type,
 518                 .sizep = &size,
 519                 .contentp = &buffer,
 520         };
 521         /*
 522          * Git does not support partial clones that exclude commits, so set
 523          * OBJECT_INFO_SKIP_FETCH_OBJECT to fail fast when an object is missing.
 524          */
 525         int flags = OBJECT_INFO_LOOKUP_REPLACE | OBJECT_INFO_SKIP_FETCH_OBJECT |
 526                 OBJECT_INFO_DIE_IF_CORRUPT;
 527         int ret;
 528
 529         if (!item)
 530                 return -1;
 531         if (item->object.parsed)
 532                 return 0;
 533         if (use_commit_graph && parse_commit_in_graph(r, item))
 534                 return 0;
 535
 536         if (oid_object_info_extended(r, &item->object.oid, &oi, flags) < 0)
 537                 return quiet_on_missing ? -1 :
 538                         error("Could not read %s",
 539                              oid_to_hex(&item->object.oid));
 540         if (type != OBJ_COMMIT) {
 541                 free(buffer);
 542                 return error("Object %s not a commit",
 543                              oid_to_hex(&item->object.oid));
 544         }
 545
 546         ret = parse_commit_buffer(r, item, buffer, size, 0);
 547         if (save_commit_buffer && !ret) {
 548                 set_commit_buffer(r, item, buffer, size);
 549                 return 0;
 550         }
 551         free(buffer);
 552         return ret;
 553 }
 554
 555 int repo_parse_commit_gently(struct repository *r,
 556                              struct commit *item, int quiet_on_missing)
 557 {
 558         return repo_parse_commit_internal(r, item, quiet_on_missing, 1);
 559 }
 560
 561 void parse_commit_or_die(struct commit *item)
 562 {
 563         if (repo_parse_commit(the_repository, item))
 564                 die("unable to parse commit %s",
 565                     item ? oid_to_hex(&item->object.oid) : "(null)");
 566 }
 567
 568 int find_commit_subject(const char *commit_buffer, const char **subject)
 569 {
 570         const char *eol;
 571         const char *p = commit_buffer;
 572
 573         while (*p && (*p != '\n' || p[1] != '\n'))
 574                 p++;
 575         if (*p) {
 576                 p = skip_blank_lines(p + 2);
 577                 eol = strchrnul(p, '\n');
 578         } else
 579                 eol = p;
 580
 581         *subject = p;
 582
 583         return eol - p;
 584 }
 585
 586 size_t commit_subject_length(const char *body)
 587 {
 588         const char *p = body;
 589         while (*p) {
 590                 const char *next = skip_blank_lines(p);
 591                 if (next != p)
 592                         break;
 593                 p = strchrnul(p, '\n');
 594                 if (*p)
 595                         p++;
 596         }
 597         return p - body;
 598 }
 599
 600 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 601 {
 602         struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 603         new_list->item = item;
 604         new_list->next = *list_p;
 605         *list_p = new_list;
 606         return new_list;
 607 }
 608
 609 int commit_list_contains(struct commit *item, struct commit_list *list)
 610 {
 611         while (list) {
 612                 if (list->item == item)
 613                         return 1;
 614                 list = list->next;
 615         }
 616
 617         return 0;
 618 }
 619
 620 unsigned commit_list_count(const struct commit_list *l)
 621 {
 622         unsigned c = 0;
 623         for (; l; l = l->next )
 624                 c++;
 625         return c;
 626 }
 627
 628 struct commit_list *copy_commit_list(struct commit_list *list)
 629 {
 630         struct commit_list *head = NULL;
 631         struct commit_list **pp = &head;
 632         while (list) {
 633                 pp = commit_list_append(list->item, pp);
 634                 list = list->next;
 635         }
 636         return head;
 637 }
 638
 639 struct commit_list *reverse_commit_list(struct commit_list *list)
 640 {
 641         struct commit_list *next = NULL, *current, *backup;
 642         for (current = list; current; current = backup) {
 643                 backup = current->next;
 644                 current->next = next;
 645                 next = current;
 646         }
 647         return next;
 648 }
 649
 650 void free_commit_list(struct commit_list *list)
 651 {
 652         while (list)
 653                 pop_commit(&list);
 654 }
 655
 656 struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 657 {
 658         struct commit_list **pp = list;
 659         struct commit_list *p;
 660         while ((p = *pp) != NULL) {
 661                 if (p->item->date < item->date) {
 662                         break;
 663                 }
 664                 pp = &p->next;
 665         }
 666         return commit_list_insert(item, pp);
 667 }
 668
 669 static int commit_list_compare_by_date(const struct commit_list *a,
 670                                        const struct commit_list *b)
 671 {
 672         timestamp_t a_date = a->item->date;
 673         timestamp_t b_date = b->item->date;
 674         if (a_date < b_date)
 675                 return 1;
 676         if (a_date > b_date)
 677                 return -1;
 678         return 0;
 679 }
 680
 681 DEFINE_LIST_SORT(static, commit_list_sort, struct commit_list, next);
 682
 683 void commit_list_sort_by_date(struct commit_list **list)
 684 {
 685         commit_list_sort(list, commit_list_compare_by_date);
 686 }
 687
 688 struct commit *pop_most_recent_commit(struct commit_list **list,
 689                                       unsigned int mark)
 690 {
 691         struct commit *ret = pop_commit(list);
 692         struct commit_list *parents = ret->parents;
 693
 694         while (parents) {
 695                 struct commit *commit = parents->item;
 696                 if (!repo_parse_commit(the_repository, commit) && !(commit->object.flags & mark)) {
 697                         commit->object.flags |= mark;
 698                         commit_list_insert_by_date(commit, list);
 699                 }
 700                 parents = parents->next;
 701         }
 702         return ret;
 703 }
 704
 705 static void clear_commit_marks_1(struct commit_list **plist,
 706                                  struct commit *commit, unsigned int mark)
 707 {
 708         while (commit) {
 709                 struct commit_list *parents;
 710
 711                 if (!(mark & commit->object.flags))
 712                         return;
 713
 714                 commit->object.flags &= ~mark;
 715
 716                 parents = commit->parents;
 717                 if (!parents)
 718                         return;
 719
 720                 while ((parents = parents->next)) {
 721                         if (parents->item->object.flags & mark)
 722                                 commit_list_insert(parents->item, plist);
 723                 }
 724
 725                 commit = commit->parents->item;
 726         }
 727 }
 728
 729 void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 730 {
 731         struct commit_list *list = NULL;
 732
 733         while (nr--) {
 734                 clear_commit_marks_1(&list, *commit, mark);
 735                 commit++;
 736         }
 737         while (list)
 738                 clear_commit_marks_1(&list, pop_commit(&list), mark);
 739 }
 740
 741 void clear_commit_marks(struct commit *commit, unsigned int mark)
 742 {
 743         clear_commit_marks_many(1, &commit, mark);
 744 }
 745
 746 struct commit *pop_commit(struct commit_list **stack)
 747 {
 748         struct commit_list *top = *stack;
 749         struct commit *item = top ? top->item : NULL;
 750
 751         if (top) {
 752                 *stack = top->next;
 753                 free(top);
 754         }
 755         return item;
 756 }
 757
 758 /*
 759  * Topological sort support
 760  */
 761
 762 /* count number of children that have not been emitted */
 763 define_commit_slab(indegree_slab, int);
 764
 765 define_commit_slab(author_date_slab, timestamp_t);
 766
 767 void record_author_date(struct author_date_slab *author_date,
 768                         struct commit *commit)
 769 {
 770         const char *buffer = repo_get_commit_buffer(the_repository, commit,
 771                                                     NULL);
 772         struct ident_split ident;
 773         const char *ident_line;
 774         size_t ident_len;
 775         char *date_end;
 776         timestamp_t date;
 777
 778         ident_line = find_commit_header(buffer, "author", &ident_len);
 779         if (!ident_line)
 780                 goto fail_exit; /* no author line */
 781         if (split_ident_line(&ident, ident_line, ident_len) ||
 782             !ident.date_begin || !ident.date_end)
 783                 goto fail_exit; /* malformed "author" line */
 784
 785         date = parse_timestamp(ident.date_begin, &date_end, 10);
 786         if (date_end != ident.date_end)
 787                 goto fail_exit; /* malformed date */
 788         *(author_date_slab_at(author_date, commit)) = date;
 789
 790 fail_exit:
 791         repo_unuse_commit_buffer(the_repository, commit, buffer);
 792 }
 793
 794 int compare_commits_by_author_date(const void *a_, const void *b_,
 795                                    void *cb_data)
 796 {
 797         const struct commit *a = a_, *b = b_;
 798         struct author_date_slab *author_date = cb_data;
 799         timestamp_t a_date = *(author_date_slab_at(author_date, a));
 800         timestamp_t b_date = *(author_date_slab_at(author_date, b));
 801
 802         /* newer commits with larger date first */
 803         if (a_date < b_date)
 804                 return 1;
 805         else if (a_date > b_date)
 806                 return -1;
 807         return 0;
 808 }
 809
 810 int compare_commits_by_gen_then_commit_date(const void *a_, const void *b_,
 811                                             void *unused UNUSED)
 812 {
 813         const struct commit *a = a_, *b = b_;
 814         const timestamp_t generation_a = commit_graph_generation(a),
 815                           generation_b = commit_graph_generation(b);
 816
 817         /* newer commits first */
 818         if (generation_a < generation_b)
 819                 return 1;
 820         else if (generation_a > generation_b)
 821                 return -1;
 822
 823         /* use date as a heuristic when generations are equal */
 824         if (a->date < b->date)
 825                 return 1;
 826         else if (a->date > b->date)
 827                 return -1;
 828         return 0;
 829 }
 830
 831 int compare_commits_by_commit_date(const void *a_, const void *b_,
 832                                    void *unused UNUSED)
 833 {
 834         const struct commit *a = a_, *b = b_;
 835         /* newer commits with larger date first */
 836         if (a->date < b->date)
 837                 return 1;
 838         else if (a->date > b->date)
 839                 return -1;
 840         return 0;
 841 }
 842
 843 /*
 844  * Performs an in-place topological sort on the list supplied.
 845  */
 846 void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 847 {
 848         struct commit_list *next, *orig = *list;
 849         struct commit_list **pptr;
 850         struct indegree_slab indegree;
 851         struct prio_queue queue;
 852         struct commit *commit;
 853         struct author_date_slab author_date;
 854
 855         if (!orig)
 856                 return;
 857         *list = NULL;
 858
 859         init_indegree_slab(&indegree);
 860         memset(&queue, '\0', sizeof(queue));
 861
 862         switch (sort_order) {
 863         default: /* REV_SORT_IN_GRAPH_ORDER */
 864                 queue.compare = NULL;
 865                 break;
 866         case REV_SORT_BY_COMMIT_DATE:
 867                 queue.compare = compare_commits_by_commit_date;
 868                 break;
 869         case REV_SORT_BY_AUTHOR_DATE:
 870                 init_author_date_slab(&author_date);
 871                 queue.compare = compare_commits_by_author_date;
 872                 queue.cb_data = &author_date;
 873                 break;
 874         }
 875
 876         /* Mark them and clear the indegree */
 877         for (next = orig; next; next = next->next) {
 878                 struct commit *commit = next->item;
 879                 *(indegree_slab_at(&indegree, commit)) = 1;
 880                 /* also record the author dates, if needed */
 881                 if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 882                         record_author_date(&author_date, commit);
 883         }
 884
 885         /* update the indegree */
 886         for (next = orig; next; next = next->next) {
 887                 struct commit_list *parents = next->item->parents;
 888                 while (parents) {
 889                         struct commit *parent = parents->item;
 890                         int *pi = indegree_slab_at(&indegree, parent);
 891
 892                         if (*pi)
 893                                 (*pi)++;
 894                         parents = parents->next;
 895                 }
 896         }
 897
 898         /*
 899          * find the tips
 900          *
 901          * tips are nodes not reachable from any other node in the list
 902          *
 903          * the tips serve as a starting set for the work queue.
 904          */
 905         for (next = orig; next; next = next->next) {
 906                 struct commit *commit = next->item;
 907
 908                 if (*(indegree_slab_at(&indegree, commit)) == 1)
 909                         prio_queue_put(&queue, commit);
 910         }
 911
 912         /*
 913          * This is unfortunate; the initial tips need to be shown
 914          * in the order given from the revision traversal machinery.
 915          */
 916         if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 917                 prio_queue_reverse(&queue);
 918
 919         /* We no longer need the commit list */
 920         free_commit_list(orig);
 921
 922         pptr = list;
 923         *list = NULL;
 924         while ((commit = prio_queue_get(&queue)) != NULL) {
 925                 struct commit_list *parents;
 926
 927                 for (parents = commit->parents; parents ; parents = parents->next) {
 928                         struct commit *parent = parents->item;
 929                         int *pi = indegree_slab_at(&indegree, parent);
 930
 931                         if (!*pi)
 932                                 continue;
 933
 934                         /*
 935                          * parents are only enqueued for emission
 936                          * when all their children have been emitted thereby
 937                          * guaranteeing topological order.
 938                          */
 939                         if (--(*pi) == 1)
 940                                 prio_queue_put(&queue, parent);
 941                 }
 942                 /*
 943                  * all children of commit have already been
 944                  * emitted. we can emit it now.
 945                  */
 946                 *(indegree_slab_at(&indegree, commit)) = 0;
 947
 948                 pptr = &commit_list_insert(commit, pptr)->next;
 949         }
 950
 951         clear_indegree_slab(&indegree);
 952         clear_prio_queue(&queue);
 953         if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 954                 clear_author_date_slab(&author_date);
 955 }
 956
 957 struct rev_collect {
 958         struct commit **commit;
 959         int nr;
 960         int alloc;
 961         unsigned int initial : 1;
 962 };
 963
 964 static void add_one_commit(struct object_id *oid, struct rev_collect *revs)
 965 {
 966         struct commit *commit;
 967
 968         if (is_null_oid(oid))
 969                 return;
 970
 971         commit = lookup_commit(the_repository, oid);
 972         if (!commit ||
 973             (commit->object.flags & TMP_MARK) ||
 974             repo_parse_commit(the_repository, commit))
 975                 return;
 976
 977         ALLOC_GROW(revs->commit, revs->nr + 1, revs->alloc);
 978         revs->commit[revs->nr++] = commit;
 979         commit->object.flags |= TMP_MARK;
 980 }
 981
 982 static int collect_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
 983                                   const char *ident UNUSED,
 984                                   timestamp_t timestamp UNUSED, int tz UNUSED,
 985                                   const char *message UNUSED, void *cbdata)
 986 {
 987         struct rev_collect *revs = cbdata;
 988
 989         if (revs->initial) {
 990                 revs->initial = 0;
 991                 add_one_commit(ooid, revs);
 992         }
 993         add_one_commit(noid, revs);
 994         return 0;
 995 }
 996
 997 struct commit *get_fork_point(const char *refname, struct commit *commit)
 998 {
 999         struct object_id oid;
1000         struct rev_collect revs;
1001         struct commit_list *bases;
1002         int i;
1003         struct commit *ret = NULL;
1004         char *full_refname;
1005
1006         switch (repo_dwim_ref(the_repository, refname, strlen(refname), &oid,
1007                               &full_refname, 0)) {
1008         case 0:
1009                 die("No such ref: '%s'", refname);
1010         case 1:
1011                 break; /* good */
1012         default:
1013                 die("Ambiguous refname: '%s'", refname);
1014         }
1015
1016         memset(&revs, 0, sizeof(revs));
1017         revs.initial = 1;
1018         for_each_reflog_ent(full_refname, collect_one_reflog_ent, &revs);
1019
1020         if (!revs.nr)
1021                 add_one_commit(&oid, &revs);
1022
1023         for (i = 0; i < revs.nr; i++)
1024                 revs.commit[i]->object.flags &= ~TMP_MARK;
1025
1026         bases = repo_get_merge_bases_many(the_repository, commit, revs.nr,
1027                                           revs.commit);
1028
1029         /*
1030          * There should be one and only one merge base, when we found
1031          * a common ancestor among reflog entries.
1032          */
1033         if (!bases || bases->next)
1034                 goto cleanup_return;
1035
1036         /* And the found one must be one of the reflog entries */
1037         for (i = 0; i < revs.nr; i++)
1038                 if (&bases->item->object == &revs.commit[i]->object)
1039                         break; /* found */
1040         if (revs.nr <= i)
1041                 goto cleanup_return;
1042
1043         ret = bases->item;
1044
1045 cleanup_return:
1046         free(revs.commit);
1047         free_commit_list(bases);
1048         free(full_refname);
1049         return ret;
1050 }
1051
1052 /*
1053  * Indexed by hash algorithm identifier.
1054  */
1055 static const char *gpg_sig_headers[] = {
1056         NULL,
1057         "gpgsig",
1058         "gpgsig-sha256",
1059 };
1060
1061 int sign_with_header(struct strbuf *buf, const char *keyid)
1062 {
1063         struct strbuf sig = STRBUF_INIT;
1064         int inspos, copypos;
1065         const char *eoh;
1066         const char *gpg_sig_header = gpg_sig_headers[hash_algo_by_ptr(the_hash_algo)];
1067         int gpg_sig_header_len = strlen(gpg_sig_header);
1068
1069         /* find the end of the header */
1070         eoh = strstr(buf->buf, "\n\n");
1071         if (!eoh)
1072                 inspos = buf->len;
1073         else
1074                 inspos = eoh - buf->buf + 1;
1075
1076         if (!keyid || !*keyid)
1077                 keyid = get_signing_key();
1078         if (sign_buffer(buf, &sig, keyid)) {
1079                 strbuf_release(&sig);
1080                 return -1;
1081         }
1082
1083         for (copypos = 0; sig.buf[copypos]; ) {
1084                 const char *bol = sig.buf + copypos;
1085                 const char *eol = strchrnul(bol, '\n');
1086                 int len = (eol - bol) + !!*eol;
1087
1088                 if (!copypos) {
1089                         strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1090                         inspos += gpg_sig_header_len;
1091                 }
1092                 strbuf_insertstr(buf, inspos++, " ");
1093                 strbuf_insert(buf, inspos, bol, len);
1094                 inspos += len;
1095                 copypos += len;
1096         }
1097         strbuf_release(&sig);
1098         return 0;
1099 }
1100
1101
1102
1103 int parse_signed_commit(const struct commit *commit,
1104                         struct strbuf *payload, struct strbuf *signature,
1105                         const struct git_hash_algo *algop)
1106 {
1107         unsigned long size;
1108         const char *buffer = repo_get_commit_buffer(the_repository, commit,
1109                                                     &size);
1110         int ret = parse_buffer_signed_by_header(buffer, size, payload, signature, algop);
1111
1112         repo_unuse_commit_buffer(the_repository, commit, buffer);
1113         return ret;
1114 }
1115
1116 int parse_buffer_signed_by_header(const char *buffer,
1117                                   unsigned long size,
1118                                   struct strbuf *payload,
1119                                   struct strbuf *signature,
1120                                   const struct git_hash_algo *algop)
1121 {
1122         int in_signature = 0, saw_signature = 0, other_signature = 0;
1123         const char *line, *tail, *p;
1124         const char *gpg_sig_header = gpg_sig_headers[hash_algo_by_ptr(algop)];
1125
1126         line = buffer;
1127         tail = buffer + size;
1128         while (line < tail) {
1129                 const char *sig = NULL;
1130                 const char *next = memchr(line, '\n', tail - line);
1131
1132                 next = next ? next + 1 : tail;
1133                 if (in_signature && line[0] == ' ')
1134                         sig = line + 1;
1135                 else if (skip_prefix(line, gpg_sig_header, &p) &&
1136                          *p == ' ') {
1137                         sig = line + strlen(gpg_sig_header) + 1;
1138                         other_signature = 0;
1139                 }
1140                 else if (starts_with(line, "gpgsig"))
1141                         other_signature = 1;
1142                 else if (other_signature && line[0] != ' ')
1143                         other_signature = 0;
1144                 if (sig) {
1145                         strbuf_add(signature, sig, next - sig);
1146                         saw_signature = 1;
1147                         in_signature = 1;
1148                 } else {
1149                         if (*line == '\n')
1150                                 /* dump the whole remainder of the buffer */
1151                                 next = tail;
1152                         if (!other_signature)
1153                                 strbuf_add(payload, line, next - line);
1154                         in_signature = 0;
1155                 }
1156                 line = next;
1157         }
1158         return saw_signature;
1159 }
1160
1161 int remove_signature(struct strbuf *buf)
1162 {
1163         const char *line = buf->buf;
1164         const char *tail = buf->buf + buf->len;
1165         int in_signature = 0;
1166         struct sigbuf {
1167                 const char *start;
1168                 const char *end;
1169         } sigs[2], *sigp = &sigs[0];
1170         int i;
1171         const char *orig_buf = buf->buf;
1172
1173         memset(sigs, 0, sizeof(sigs));
1174
1175         while (line < tail) {
1176                 const char *next = memchr(line, '\n', tail - line);
1177                 next = next ? next + 1 : tail;
1178
1179                 if (in_signature && line[0] == ' ')
1180                         sigp->end = next;
1181                 else if (starts_with(line, "gpgsig")) {
1182                         int i;
1183                         for (i = 1; i < GIT_HASH_NALGOS; i++) {
1184                                 const char *p;
1185                                 if (skip_prefix(line, gpg_sig_headers[i], &p) &&
1186                                     *p == ' ') {
1187                                         sigp->start = line;
1188                                         sigp->end = next;
1189                                         in_signature = 1;
1190                                 }
1191                         }
1192                 } else {
1193                         if (*line == '\n')
1194                                 /* dump the whole remainder of the buffer */
1195                                 next = tail;
1196                         if (in_signature && sigp - sigs != ARRAY_SIZE(sigs))
1197                                 sigp++;
1198                         in_signature = 0;
1199                 }
1200                 line = next;
1201         }
1202
1203         for (i = ARRAY_SIZE(sigs) - 1; i >= 0; i--)
1204                 if (sigs[i].start)
1205                         strbuf_remove(buf, sigs[i].start - orig_buf, sigs[i].end - sigs[i].start);
1206
1207         return sigs[0].start != NULL;
1208 }
1209
1210 static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1211 {
1212         struct merge_remote_desc *desc;
1213         struct commit_extra_header *mergetag;
1214         char *buf;
1215         unsigned long size;
1216         enum object_type type;
1217         struct strbuf payload = STRBUF_INIT;
1218         struct strbuf signature = STRBUF_INIT;
1219
1220         desc = merge_remote_util(parent);
1221         if (!desc || !desc->obj)
1222                 return;
1223         buf = repo_read_object_file(the_repository, &desc->obj->oid, &type,
1224                                     &size);
1225         if (!buf || type != OBJ_TAG)
1226                 goto free_return;
1227         if (!parse_signature(buf, size, &payload, &signature))
1228                 goto free_return;
1229         /*
1230          * We could verify this signature and either omit the tag when
1231          * it does not validate, but the integrator may not have the
1232          * public key of the signer of the tag being merged, while a
1233          * later auditor may have it while auditing, so let's not run
1234          * verify-signed-buffer here for now...
1235          *
1236          * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1237          *      warn("warning: signed tag unverified.");
1238          */
1239         CALLOC_ARRAY(mergetag, 1);
1240         mergetag->key = xstrdup("mergetag");
1241         mergetag->value = buf;
1242         mergetag->len = size;
1243
1244         **tail = mergetag;
1245         *tail = &mergetag->next;
1246         strbuf_release(&payload);
1247         strbuf_release(&signature);
1248         return;
1249
1250 free_return:
1251         free(buf);
1252 }
1253
1254 int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1255 {
1256         struct strbuf payload = STRBUF_INIT;
1257         struct strbuf signature = STRBUF_INIT;
1258         int ret = 1;
1259
1260         sigc->result = 'N';
1261
1262         if (parse_signed_commit(commit, &payload, &signature, the_hash_algo) <= 0)
1263                 goto out;
1264
1265         sigc->payload_type = SIGNATURE_PAYLOAD_COMMIT;
1266         sigc->payload = strbuf_detach(&payload, &sigc->payload_len);
1267         ret = check_signature(sigc, signature.buf, signature.len);
1268
1269  out:
1270         strbuf_release(&payload);
1271         strbuf_release(&signature);
1272
1273         return ret;
1274 }
1275
1276 void verify_merge_signature(struct commit *commit, int verbosity,
1277                             int check_trust)
1278 {
1279         char hex[GIT_MAX_HEXSZ + 1];
1280         struct signature_check signature_check;
1281         int ret;
1282         memset(&signature_check, 0, sizeof(signature_check));
1283
1284         ret = check_commit_signature(commit, &signature_check);
1285
1286         repo_find_unique_abbrev_r(the_repository, hex, &commit->object.oid,
1287                                   DEFAULT_ABBREV);
1288         switch (signature_check.result) {
1289         case 'G':
1290                 if (ret || (check_trust && signature_check.trust_level < TRUST_MARGINAL))
1291                         die(_("Commit %s has an untrusted GPG signature, "
1292                               "allegedly by %s."), hex, signature_check.signer);
1293                 break;
1294         case 'B':
1295                 die(_("Commit %s has a bad GPG signature "
1296                       "allegedly by %s."), hex, signature_check.signer);
1297         default: /* 'N' */
1298                 die(_("Commit %s does not have a GPG signature."), hex);
1299         }
1300         if (verbosity >= 0 && signature_check.result == 'G')
1301                 printf(_("Commit %s has a good GPG signature by %s\n"),
1302                        hex, signature_check.signer);
1303
1304         signature_check_clear(&signature_check);
1305 }
1306
1307 void append_merge_tag_headers(struct commit_list *parents,
1308                               struct commit_extra_header ***tail)
1309 {
1310         while (parents) {
1311                 struct commit *parent = parents->item;
1312                 handle_signed_tag(parent, tail);
1313                 parents = parents->next;
1314         }
1315 }
1316
1317 static void add_extra_header(struct strbuf *buffer,
1318                              struct commit_extra_header *extra)
1319 {
1320         strbuf_addstr(buffer, extra->key);
1321         if (extra->len)
1322                 strbuf_add_lines(buffer, " ", extra->value, extra->len);
1323         else
1324                 strbuf_addch(buffer, '\n');
1325 }
1326
1327 struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1328                                                       const char **exclude)
1329 {
1330         struct commit_extra_header *extra = NULL;
1331         unsigned long size;
1332         const char *buffer = repo_get_commit_buffer(the_repository, commit,
1333                                                     &size);
1334         extra = read_commit_extra_header_lines(buffer, size, exclude);
1335         repo_unuse_commit_buffer(the_repository, commit, buffer);
1336         return extra;
1337 }
1338
1339 int for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1340 {
1341         struct commit_extra_header *extra, *to_free;
1342         int res = 0;
1343
1344         to_free = read_commit_extra_headers(commit, NULL);
1345         for (extra = to_free; !res && extra; extra = extra->next) {
1346                 if (strcmp(extra->key, "mergetag"))
1347                         continue; /* not a merge tag */
1348                 res = fn(commit, extra, data);
1349         }
1350         free_commit_extra_headers(to_free);
1351         return res;
1352 }
1353
1354 static inline int standard_header_field(const char *field, size_t len)
1355 {
1356         return ((len == 4 && !memcmp(field, "tree", 4)) ||
1357                 (len == 6 && !memcmp(field, "parent", 6)) ||
1358                 (len == 6 && !memcmp(field, "author", 6)) ||
1359                 (len == 9 && !memcmp(field, "committer", 9)) ||
1360                 (len == 8 && !memcmp(field, "encoding", 8)));
1361 }
1362
1363 static int excluded_header_field(const char *field, size_t len, const char **exclude)
1364 {
1365         if (!exclude)
1366                 return 0;
1367
1368         while (*exclude) {
1369                 size_t xlen = strlen(*exclude);
1370                 if (len == xlen && !memcmp(field, *exclude, xlen))
1371                         return 1;
1372                 exclude++;
1373         }
1374         return 0;
1375 }
1376
1377 static struct commit_extra_header *read_commit_extra_header_lines(
1378         const char *buffer, size_t size,
1379         const char **exclude)
1380 {
1381         struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1382         const char *line, *next, *eof, *eob;
1383         struct strbuf buf = STRBUF_INIT;
1384
1385         for (line = buffer, eob = line + size;
1386              line < eob && *line != '\n';
1387              line = next) {
1388                 next = memchr(line, '\n', eob - line);
1389                 next = next ? next + 1 : eob;
1390                 if (*line == ' ') {
1391                         /* continuation */
1392                         if (it)
1393                                 strbuf_add(&buf, line + 1, next - (line + 1));
1394                         continue;
1395                 }
1396                 if (it)
1397                         it->value = strbuf_detach(&buf, &it->len);
1398                 strbuf_reset(&buf);
1399                 it = NULL;
1400
1401                 eof = memchr(line, ' ', next - line);
1402                 if (!eof)
1403                         eof = next;
1404                 else if (standard_header_field(line, eof - line) ||
1405                          excluded_header_field(line, eof - line, exclude))
1406                         continue;
1407
1408                 CALLOC_ARRAY(it, 1);
1409                 it->key = xmemdupz(line, eof-line);
1410                 *tail = it;
1411                 tail = &it->next;
1412                 if (eof + 1 < next)
1413                         strbuf_add(&buf, eof + 1, next - (eof + 1));
1414         }
1415         if (it)
1416                 it->value = strbuf_detach(&buf, &it->len);
1417         return extra;
1418 }
1419
1420 void free_commit_extra_headers(struct commit_extra_header *extra)
1421 {
1422         while (extra) {
1423                 struct commit_extra_header *next = extra->next;
1424                 free(extra->key);
1425                 free(extra->value);
1426                 free(extra);
1427                 extra = next;
1428         }
1429 }
1430
1431 int commit_tree(const char *msg, size_t msg_len, const struct object_id *tree,
1432                 struct commit_list *parents, struct object_id *ret,
1433                 const char *author, const char *sign_commit)
1434 {
1435         struct commit_extra_header *extra = NULL, **tail = &extra;
1436         int result;
1437
1438         append_merge_tag_headers(parents, &tail);
1439         result = commit_tree_extended(msg, msg_len, tree, parents, ret, author,
1440                                       NULL, sign_commit, extra);
1441         free_commit_extra_headers(extra);
1442         return result;
1443 }
1444
1445 static int find_invalid_utf8(const char *buf, int len)
1446 {
1447         int offset = 0;
1448         static const unsigned int max_codepoint[] = {
1449                 0x7f, 0x7ff, 0xffff, 0x10ffff
1450         };
1451
1452         while (len) {
1453                 unsigned char c = *buf++;
1454                 int bytes, bad_offset;
1455                 unsigned int codepoint;
1456                 unsigned int min_val, max_val;
1457
1458                 len--;
1459                 offset++;
1460
1461                 /* Simple US-ASCII? No worries. */
1462                 if (c < 0x80)
1463                         continue;
1464
1465                 bad_offset = offset-1;
1466
1467                 /*
1468                  * Count how many more high bits set: that's how
1469                  * many more bytes this sequence should have.
1470                  */
1471                 bytes = 0;
1472                 while (c & 0x40) {
1473                         c <<= 1;
1474                         bytes++;
1475                 }
1476
1477                 /*
1478                  * Must be between 1 and 3 more bytes.  Longer sequences result in
1479                  * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1480                  */
1481                 if (bytes < 1 || 3 < bytes)
1482                         return bad_offset;
1483
1484                 /* Do we *have* that many bytes? */
1485                 if (len < bytes)
1486                         return bad_offset;
1487
1488                 /*
1489                  * Place the encoded bits at the bottom of the value and compute the
1490                  * valid range.
1491                  */
1492                 codepoint = (c & 0x7f) >> bytes;
1493                 min_val = max_codepoint[bytes-1] + 1;
1494                 max_val = max_codepoint[bytes];
1495
1496                 offset += bytes;
1497                 len -= bytes;
1498
1499                 /* And verify that they are good continuation bytes */
1500                 do {
1501                         codepoint <<= 6;
1502                         codepoint |= *buf & 0x3f;
1503                         if ((*buf++ & 0xc0) != 0x80)
1504                                 return bad_offset;
1505                 } while (--bytes);
1506
1507                 /* Reject codepoints that are out of range for the sequence length. */
1508                 if (codepoint < min_val || codepoint > max_val)
1509                         return bad_offset;
1510                 /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1511                 if ((codepoint & 0x1ff800) == 0xd800)
1512                         return bad_offset;
1513                 /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1514                 if ((codepoint & 0xfffe) == 0xfffe)
1515                         return bad_offset;
1516                 /* So are anything in the range U+FDD0..U+FDEF. */
1517                 if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1518                         return bad_offset;
1519         }
1520         return -1;
1521 }
1522
1523 /*
1524  * This verifies that the buffer is in proper utf8 format.
1525  *
1526  * If it isn't, it assumes any non-utf8 characters are Latin1,
1527  * and does the conversion.
1528  */
1529 static int verify_utf8(struct strbuf *buf)
1530 {
1531         int ok = 1;
1532         long pos = 0;
1533
1534         for (;;) {
1535                 int bad;
1536                 unsigned char c;
1537                 unsigned char replace[2];
1538
1539                 bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1540                 if (bad < 0)
1541                         return ok;
1542                 pos += bad;
1543                 ok = 0;
1544                 c = buf->buf[pos];
1545                 strbuf_remove(buf, pos, 1);
1546
1547                 /* We know 'c' must be in the range 128-255 */
1548                 replace[0] = 0xc0 + (c >> 6);
1549                 replace[1] = 0x80 + (c & 0x3f);
1550                 strbuf_insert(buf, pos, replace, 2);
1551                 pos += 2;
1552         }
1553 }
1554
1555 static const char commit_utf8_warn[] =
1556 N_("Warning: commit message did not conform to UTF-8.\n"
1557    "You may want to amend it after fixing the message, or set the config\n"
1558    "variable i18n.commitEncoding to the encoding your project uses.\n");
1559
1560 int commit_tree_extended(const char *msg, size_t msg_len,
1561                          const struct object_id *tree,
1562                          struct commit_list *parents, struct object_id *ret,
1563                          const char *author, const char *committer,
1564                          const char *sign_commit,
1565                          struct commit_extra_header *extra)
1566 {
1567         int result;
1568         int encoding_is_utf8;
1569         struct strbuf buffer;
1570
1571         assert_oid_type(tree, OBJ_TREE);
1572
1573         if (memchr(msg, '\0', msg_len))
1574                 return error("a NUL byte in commit log message not allowed.");
1575
1576         /* Not having i18n.commitencoding is the same as having utf-8 */
1577         encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1578
1579         strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1580         strbuf_addf(&buffer, "tree %s\n", oid_to_hex(tree));
1581
1582         /*
1583          * NOTE! This ordering means that the same exact tree merged with a
1584          * different order of parents will be a _different_ changeset even
1585          * if everything else stays the same.
1586          */
1587         while (parents) {
1588                 struct commit *parent = pop_commit(&parents);
1589                 strbuf_addf(&buffer, "parent %s\n",
1590                             oid_to_hex(&parent->object.oid));
1591         }
1592
1593         /* Person/date information */
1594         if (!author)
1595                 author = git_author_info(IDENT_STRICT);
1596         strbuf_addf(&buffer, "author %s\n", author);
1597         if (!committer)
1598                 committer = git_committer_info(IDENT_STRICT);
1599         strbuf_addf(&buffer, "committer %s\n", committer);
1600         if (!encoding_is_utf8)
1601                 strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1602
1603         while (extra) {
1604                 add_extra_header(&buffer, extra);
1605                 extra = extra->next;
1606         }
1607         strbuf_addch(&buffer, '\n');
1608
1609         /* And add the comment */
1610         strbuf_add(&buffer, msg, msg_len);
1611
1612         /* And check the encoding */
1613         if (encoding_is_utf8 && !verify_utf8(&buffer))
1614                 fprintf(stderr, _(commit_utf8_warn));
1615
1616         if (sign_commit && sign_with_header(&buffer, sign_commit)) {
1617                 result = -1;
1618                 goto out;
1619         }
1620
1621         result = write_object_file(buffer.buf, buffer.len, OBJ_COMMIT, ret);
1622 out:
1623         strbuf_release(&buffer);
1624         return result;
1625 }
1626
1627 define_commit_slab(merge_desc_slab, struct merge_remote_desc *);
1628 static struct merge_desc_slab merge_desc_slab = COMMIT_SLAB_INIT(1, merge_desc_slab);
1629
1630 struct merge_remote_desc *merge_remote_util(struct commit *commit)
1631 {
1632         return *merge_desc_slab_at(&merge_desc_slab, commit);
1633 }
1634
1635 void set_merge_remote_desc(struct commit *commit,
1636                            const char *name, struct object *obj)
1637 {
1638         struct merge_remote_desc *desc;
1639         FLEX_ALLOC_STR(desc, name, name);
1640         desc->obj = obj;
1641         *merge_desc_slab_at(&merge_desc_slab, commit) = desc;
1642 }
1643
1644 struct commit *get_merge_parent(const char *name)
1645 {
1646         struct object *obj;
1647         struct commit *commit;
1648         struct object_id oid;
1649         if (repo_get_oid(the_repository, name, &oid))
1650                 return NULL;
1651         obj = parse_object(the_repository, &oid);
1652         commit = (struct commit *)repo_peel_to_type(the_repository, name, 0,
1653                                                     obj, OBJ_COMMIT);
1654         if (commit && !merge_remote_util(commit))
1655                 set_merge_remote_desc(commit, name, obj);
1656         return commit;
1657 }
1658
1659 /*
1660  * Append a commit to the end of the commit_list.
1661  *
1662  * next starts by pointing to the variable that holds the head of an
1663  * empty commit_list, and is updated to point to the "next" field of
1664  * the last item on the list as new commits are appended.
1665  *
1666  * Usage example:
1667  *
1668  *     struct commit_list *list;
1669  *     struct commit_list **next = &list;
1670  *
1671  *     next = commit_list_append(c1, next);
1672  *     next = commit_list_append(c2, next);
1673  *     assert(commit_list_count(list) == 2);
1674  *     return list;
1675  */
1676 struct commit_list **commit_list_append(struct commit *commit,
1677                                         struct commit_list **next)
1678 {
1679         struct commit_list *new_commit = xmalloc(sizeof(struct commit_list));
1680         new_commit->item = commit;
1681         *next = new_commit;
1682         new_commit->next = NULL;
1683         return &new_commit->next;
1684 }
1685
1686 const char *find_header_mem(const char *msg, size_t len,
1687                         const char *key, size_t *out_len)
1688 {
1689         int key_len = strlen(key);
1690         const char *line = msg;
1691
1692         /*
1693          * NEEDSWORK: It's possible for strchrnul() to scan beyond the range
1694          * given by len. However, current callers are safe because they compute
1695          * len by scanning a NUL-terminated block of memory starting at msg.
1696          * Nonetheless, it would be better to ensure the function does not look
1697          * at msg beyond the len provided by the caller.
1698          */
1699         while (line && line < msg + len) {
1700                 const char *eol = strchrnul(line, '\n');
1701
1702                 if (line == eol)
1703                         return NULL;
1704
1705                 if (eol - line > key_len &&
1706                     !strncmp(line, key, key_len) &&
1707                     line[key_len] == ' ') {
1708                         *out_len = eol - line - key_len - 1;
1709                         return line + key_len + 1;
1710                 }
1711                 line = *eol ? eol + 1 : NULL;
1712         }
1713         return NULL;
1714 }
1715
1716 const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1717 {
1718         return find_header_mem(msg, strlen(msg), key, out_len);
1719 }
1720 /*
1721  * Inspect the given string and determine the true "end" of the log message, in
1722  * order to find where to put a new Signed-off-by trailer.  Ignored are
1723  * trailing comment lines and blank lines.  To support "git commit -s
1724  * --amend" on an existing commit, we also ignore "Conflicts:".  To
1725  * support "git commit -v", we truncate at cut lines.
1726  *
1727  * Returns the number of bytes from the tail to ignore, to be fed as
1728  * the second parameter to append_signoff().
1729  */
1730 size_t ignore_non_trailer(const char *buf, size_t len)
1731 {
1732         size_t boc = 0;
1733         size_t bol = 0;
1734         int in_old_conflicts_block = 0;
1735         size_t cutoff = wt_status_locate_end(buf, len);
1736
1737         while (bol < cutoff) {
1738                 const char *next_line = memchr(buf + bol, '\n', len - bol);
1739
1740                 if (!next_line)
1741                         next_line = buf + len;
1742                 else
1743                         next_line++;
1744
1745                 if (buf[bol] == comment_line_char || buf[bol] == '\n') {
1746                         /* is this the first of the run of comments? */
1747                         if (!boc)
1748                                 boc = bol;
1749                         /* otherwise, it is just continuing */
1750                 } else if (starts_with(buf + bol, "Conflicts:\n")) {
1751                         in_old_conflicts_block = 1;
1752                         if (!boc)
1753                                 boc = bol;
1754                 } else if (in_old_conflicts_block && buf[bol] == '\t') {
1755                         ; /* a pathname in the conflicts block */
1756                 } else if (boc) {
1757                         /* the previous was not trailing comment */
1758                         boc = 0;
1759                         in_old_conflicts_block = 0;
1760                 }
1761                 bol = next_line - buf;
1762         }
1763         return boc ? len - boc : len - cutoff;
1764 }
1765
1766 int run_commit_hook(int editor_is_used, const char *index_file,
1767                     int *invoked_hook, const char *name, ...)
1768 {
1769         struct run_hooks_opt opt = RUN_HOOKS_OPT_INIT;
1770         va_list args;
1771         const char *arg;
1772
1773         strvec_pushf(&opt.env, "GIT_INDEX_FILE=%s", index_file);
1774
1775         /*
1776          * Let the hook know that no editor will be launched.
1777          */
1778         if (!editor_is_used)
1779                 strvec_push(&opt.env, "GIT_EDITOR=:");
1780
1781         va_start(args, name);
1782         while ((arg = va_arg(args, const char *)))
1783                 strvec_push(&opt.args, arg);
1784         va_end(args);
1785
1786         opt.invoked_hook = invoked_hook;
1787         return run_hooks_opt(name, &opt);
1788 }