commit.con commit Sync with 2.18.1 (1958ad5)
   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
  21static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
  22
  23int save_commit_buffer = 1;
  24
  25const char *commit_type = "commit";
  26
  27struct 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
  39struct commit *lookup_commit_reference(struct repository *r, const struct object_id *oid)
  40{
  41        return lookup_commit_reference_gently(r, oid, 0);
  42}
  43
  44struct 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 (oidcmp(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
  56struct 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
  65struct 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
  78static 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
 105static 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
 111static 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
 118int 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
 146struct 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
 178bad_graft_data:
 179        error("bad graft data: %s", line->buf);
 180        assert(!graft);
 181        return NULL;
 182}
 183
 184static 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
 212static 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
 228struct 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
 238int 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
 246int 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
 259struct commit_buffer {
 260        void *buffer;
 261        unsigned long size;
 262};
 263define_commit_slab(buffer_slab, struct commit_buffer);
 264
 265struct 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
 272void free_commit_buffer_slab(struct buffer_slab *bs)
 273{
 274        clear_buffer_slab(bs);
 275        free(bs);
 276}
 277
 278void 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
 286const 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
 300const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
 301{
 302        const void *ret = get_cached_commit_buffer(the_repository, commit, sizep);
 303        if (!ret) {
 304                enum object_type type;
 305                unsigned long size;
 306                ret = read_object_file(&commit->object.oid, &type, &size);
 307                if (!ret)
 308                        die("cannot read commit object %s",
 309                            oid_to_hex(&commit->object.oid));
 310                if (type != OBJ_COMMIT)
 311                        die("expected commit for %s, got %s",
 312                            oid_to_hex(&commit->object.oid), type_name(type));
 313                if (sizep)
 314                        *sizep = size;
 315        }
 316        return ret;
 317}
 318
 319void unuse_commit_buffer(const struct commit *commit, const void *buffer)
 320{
 321        struct commit_buffer *v = buffer_slab_peek(
 322                the_repository->parsed_objects->buffer_slab, commit);
 323        if (!(v && v->buffer == buffer))
 324                free((void *)buffer);
 325}
 326
 327void free_commit_buffer(struct commit *commit)
 328{
 329        struct commit_buffer *v = buffer_slab_peek(
 330                the_repository->parsed_objects->buffer_slab, commit);
 331        if (v) {
 332                FREE_AND_NULL(v->buffer);
 333                v->size = 0;
 334        }
 335}
 336
 337struct tree *get_commit_tree(const struct commit *commit)
 338{
 339        if (commit->maybe_tree || !commit->object.parsed)
 340                return commit->maybe_tree;
 341
 342        if (commit->graph_pos == COMMIT_NOT_FROM_GRAPH)
 343                BUG("commit has NULL tree, but was not loaded from commit-graph");
 344
 345        return get_commit_tree_in_graph(the_repository, commit);
 346}
 347
 348struct object_id *get_commit_tree_oid(const struct commit *commit)
 349{
 350        return &get_commit_tree(commit)->object.oid;
 351}
 352
 353void release_commit_memory(struct commit *c)
 354{
 355        c->maybe_tree = NULL;
 356        c->index = 0;
 357        free_commit_buffer(c);
 358        free_commit_list(c->parents);
 359        /* TODO: what about commit->util? */
 360
 361        c->object.parsed = 0;
 362}
 363
 364const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 365{
 366        struct commit_buffer *v = buffer_slab_peek(
 367                the_repository->parsed_objects->buffer_slab, commit);
 368        void *ret;
 369
 370        if (!v) {
 371                if (sizep)
 372                        *sizep = 0;
 373                return NULL;
 374        }
 375        ret = v->buffer;
 376        if (sizep)
 377                *sizep = v->size;
 378
 379        v->buffer = NULL;
 380        v->size = 0;
 381        return ret;
 382}
 383
 384int parse_commit_buffer(struct repository *r, struct commit *item, const void *buffer, unsigned long size, int check_graph)
 385{
 386        const char *tail = buffer;
 387        const char *bufptr = buffer;
 388        struct object_id parent;
 389        struct commit_list **pptr;
 390        struct commit_graft *graft;
 391        const int tree_entry_len = the_hash_algo->hexsz + 5;
 392        const int parent_entry_len = the_hash_algo->hexsz + 7;
 393
 394        if (item->object.parsed)
 395                return 0;
 396        item->object.parsed = 1;
 397        tail += size;
 398        if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
 399                        bufptr[tree_entry_len] != '\n')
 400                return error("bogus commit object %s", oid_to_hex(&item->object.oid));
 401        if (get_oid_hex(bufptr + 5, &parent) < 0)
 402                return error("bad tree pointer in commit %s",
 403                             oid_to_hex(&item->object.oid));
 404        item->maybe_tree = lookup_tree(r, &parent);
 405        bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
 406        pptr = &item->parents;
 407
 408        graft = lookup_commit_graft(r, &item->object.oid);
 409        while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
 410                struct commit *new_parent;
 411
 412                if (tail <= bufptr + parent_entry_len + 1 ||
 413                    get_oid_hex(bufptr + 7, &parent) ||
 414                    bufptr[parent_entry_len] != '\n')
 415                        return error("bad parents in commit %s", oid_to_hex(&item->object.oid));
 416                bufptr += parent_entry_len + 1;
 417                /*
 418                 * The clone is shallow if nr_parent < 0, and we must
 419                 * not traverse its real parents even when we unhide them.
 420                 */
 421                if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
 422                        continue;
 423                new_parent = lookup_commit(r, &parent);
 424                if (new_parent)
 425                        pptr = &commit_list_insert(new_parent, pptr)->next;
 426        }
 427        if (graft) {
 428                int i;
 429                struct commit *new_parent;
 430                for (i = 0; i < graft->nr_parent; i++) {
 431                        new_parent = lookup_commit(r,
 432                                                   &graft->parent[i]);
 433                        if (!new_parent)
 434                                continue;
 435                        pptr = &commit_list_insert(new_parent, pptr)->next;
 436                }
 437        }
 438        item->date = parse_commit_date(bufptr, tail);
 439
 440        if (check_graph)
 441                load_commit_graph_info(the_repository, item);
 442
 443        return 0;
 444}
 445
 446int parse_commit_internal(struct commit *item, int quiet_on_missing, int use_commit_graph)
 447{
 448        enum object_type type;
 449        void *buffer;
 450        unsigned long size;
 451        int ret;
 452
 453        if (!item)
 454                return -1;
 455        if (item->object.parsed)
 456                return 0;
 457        if (use_commit_graph && parse_commit_in_graph(the_repository, item))
 458                return 0;
 459        buffer = read_object_file(&item->object.oid, &type, &size);
 460        if (!buffer)
 461                return quiet_on_missing ? -1 :
 462                        error("Could not read %s",
 463                             oid_to_hex(&item->object.oid));
 464        if (type != OBJ_COMMIT) {
 465                free(buffer);
 466                return error("Object %s not a commit",
 467                             oid_to_hex(&item->object.oid));
 468        }
 469
 470        ret = parse_commit_buffer(the_repository, item, buffer, size, 0);
 471        if (save_commit_buffer && !ret) {
 472                set_commit_buffer(the_repository, item, buffer, size);
 473                return 0;
 474        }
 475        free(buffer);
 476        return ret;
 477}
 478
 479int parse_commit_gently(struct commit *item, int quiet_on_missing)
 480{
 481        return parse_commit_internal(item, quiet_on_missing, 1);
 482}
 483
 484void parse_commit_or_die(struct commit *item)
 485{
 486        if (parse_commit(item))
 487                die("unable to parse commit %s",
 488                    item ? oid_to_hex(&item->object.oid) : "(null)");
 489}
 490
 491int find_commit_subject(const char *commit_buffer, const char **subject)
 492{
 493        const char *eol;
 494        const char *p = commit_buffer;
 495
 496        while (*p && (*p != '\n' || p[1] != '\n'))
 497                p++;
 498        if (*p) {
 499                p = skip_blank_lines(p + 2);
 500                eol = strchrnul(p, '\n');
 501        } else
 502                eol = p;
 503
 504        *subject = p;
 505
 506        return eol - p;
 507}
 508
 509struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 510{
 511        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 512        new_list->item = item;
 513        new_list->next = *list_p;
 514        *list_p = new_list;
 515        return new_list;
 516}
 517
 518unsigned commit_list_count(const struct commit_list *l)
 519{
 520        unsigned c = 0;
 521        for (; l; l = l->next )
 522                c++;
 523        return c;
 524}
 525
 526struct commit_list *copy_commit_list(struct commit_list *list)
 527{
 528        struct commit_list *head = NULL;
 529        struct commit_list **pp = &head;
 530        while (list) {
 531                pp = commit_list_append(list->item, pp);
 532                list = list->next;
 533        }
 534        return head;
 535}
 536
 537void free_commit_list(struct commit_list *list)
 538{
 539        while (list)
 540                pop_commit(&list);
 541}
 542
 543struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 544{
 545        struct commit_list **pp = list;
 546        struct commit_list *p;
 547        while ((p = *pp) != NULL) {
 548                if (p->item->date < item->date) {
 549                        break;
 550                }
 551                pp = &p->next;
 552        }
 553        return commit_list_insert(item, pp);
 554}
 555
 556static int commit_list_compare_by_date(const void *a, const void *b)
 557{
 558        timestamp_t a_date = ((const struct commit_list *)a)->item->date;
 559        timestamp_t b_date = ((const struct commit_list *)b)->item->date;
 560        if (a_date < b_date)
 561                return 1;
 562        if (a_date > b_date)
 563                return -1;
 564        return 0;
 565}
 566
 567static void *commit_list_get_next(const void *a)
 568{
 569        return ((const struct commit_list *)a)->next;
 570}
 571
 572static void commit_list_set_next(void *a, void *next)
 573{
 574        ((struct commit_list *)a)->next = next;
 575}
 576
 577void commit_list_sort_by_date(struct commit_list **list)
 578{
 579        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 580                                commit_list_compare_by_date);
 581}
 582
 583struct commit *pop_most_recent_commit(struct commit_list **list,
 584                                      unsigned int mark)
 585{
 586        struct commit *ret = pop_commit(list);
 587        struct commit_list *parents = ret->parents;
 588
 589        while (parents) {
 590                struct commit *commit = parents->item;
 591                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 592                        commit->object.flags |= mark;
 593                        commit_list_insert_by_date(commit, list);
 594                }
 595                parents = parents->next;
 596        }
 597        return ret;
 598}
 599
 600static void clear_commit_marks_1(struct commit_list **plist,
 601                                 struct commit *commit, unsigned int mark)
 602{
 603        while (commit) {
 604                struct commit_list *parents;
 605
 606                if (!(mark & commit->object.flags))
 607                        return;
 608
 609                commit->object.flags &= ~mark;
 610
 611                parents = commit->parents;
 612                if (!parents)
 613                        return;
 614
 615                while ((parents = parents->next))
 616                        commit_list_insert(parents->item, plist);
 617
 618                commit = commit->parents->item;
 619        }
 620}
 621
 622void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 623{
 624        struct commit_list *list = NULL;
 625
 626        while (nr--) {
 627                clear_commit_marks_1(&list, *commit, mark);
 628                commit++;
 629        }
 630        while (list)
 631                clear_commit_marks_1(&list, pop_commit(&list), mark);
 632}
 633
 634void clear_commit_marks(struct commit *commit, unsigned int mark)
 635{
 636        clear_commit_marks_many(1, &commit, mark);
 637}
 638
 639struct commit *pop_commit(struct commit_list **stack)
 640{
 641        struct commit_list *top = *stack;
 642        struct commit *item = top ? top->item : NULL;
 643
 644        if (top) {
 645                *stack = top->next;
 646                free(top);
 647        }
 648        return item;
 649}
 650
 651/*
 652 * Topological sort support
 653 */
 654
 655/* count number of children that have not been emitted */
 656define_commit_slab(indegree_slab, int);
 657
 658/* record author-date for each commit object */
 659define_commit_slab(author_date_slab, timestamp_t);
 660
 661static void record_author_date(struct author_date_slab *author_date,
 662                               struct commit *commit)
 663{
 664        const char *buffer = get_commit_buffer(commit, NULL);
 665        struct ident_split ident;
 666        const char *ident_line;
 667        size_t ident_len;
 668        char *date_end;
 669        timestamp_t date;
 670
 671        ident_line = find_commit_header(buffer, "author", &ident_len);
 672        if (!ident_line)
 673                goto fail_exit; /* no author line */
 674        if (split_ident_line(&ident, ident_line, ident_len) ||
 675            !ident.date_begin || !ident.date_end)
 676                goto fail_exit; /* malformed "author" line */
 677
 678        date = parse_timestamp(ident.date_begin, &date_end, 10);
 679        if (date_end != ident.date_end)
 680                goto fail_exit; /* malformed date */
 681        *(author_date_slab_at(author_date, commit)) = date;
 682
 683fail_exit:
 684        unuse_commit_buffer(commit, buffer);
 685}
 686
 687static int compare_commits_by_author_date(const void *a_, const void *b_,
 688                                          void *cb_data)
 689{
 690        const struct commit *a = a_, *b = b_;
 691        struct author_date_slab *author_date = cb_data;
 692        timestamp_t a_date = *(author_date_slab_at(author_date, a));
 693        timestamp_t b_date = *(author_date_slab_at(author_date, b));
 694
 695        /* newer commits with larger date first */
 696        if (a_date < b_date)
 697                return 1;
 698        else if (a_date > b_date)
 699                return -1;
 700        return 0;
 701}
 702
 703int compare_commits_by_gen_then_commit_date(const void *a_, const void *b_, void *unused)
 704{
 705        const struct commit *a = a_, *b = b_;
 706
 707        /* newer commits first */
 708        if (a->generation < b->generation)
 709                return 1;
 710        else if (a->generation > b->generation)
 711                return -1;
 712
 713        /* use date as a heuristic when generations are equal */
 714        if (a->date < b->date)
 715                return 1;
 716        else if (a->date > b->date)
 717                return -1;
 718        return 0;
 719}
 720
 721int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 722{
 723        const struct commit *a = a_, *b = b_;
 724        /* newer commits with larger date first */
 725        if (a->date < b->date)
 726                return 1;
 727        else if (a->date > b->date)
 728                return -1;
 729        return 0;
 730}
 731
 732/*
 733 * Performs an in-place topological sort on the list supplied.
 734 */
 735void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 736{
 737        struct commit_list *next, *orig = *list;
 738        struct commit_list **pptr;
 739        struct indegree_slab indegree;
 740        struct prio_queue queue;
 741        struct commit *commit;
 742        struct author_date_slab author_date;
 743
 744        if (!orig)
 745                return;
 746        *list = NULL;
 747
 748        init_indegree_slab(&indegree);
 749        memset(&queue, '\0', sizeof(queue));
 750
 751        switch (sort_order) {
 752        default: /* REV_SORT_IN_GRAPH_ORDER */
 753                queue.compare = NULL;
 754                break;
 755        case REV_SORT_BY_COMMIT_DATE:
 756                queue.compare = compare_commits_by_commit_date;
 757                break;
 758        case REV_SORT_BY_AUTHOR_DATE:
 759                init_author_date_slab(&author_date);
 760                queue.compare = compare_commits_by_author_date;
 761                queue.cb_data = &author_date;
 762                break;
 763        }
 764
 765        /* Mark them and clear the indegree */
 766        for (next = orig; next; next = next->next) {
 767                struct commit *commit = next->item;
 768                *(indegree_slab_at(&indegree, commit)) = 1;
 769                /* also record the author dates, if needed */
 770                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 771                        record_author_date(&author_date, commit);
 772        }
 773
 774        /* update the indegree */
 775        for (next = orig; next; next = next->next) {
 776                struct commit_list *parents = next->item->parents;
 777                while (parents) {
 778                        struct commit *parent = parents->item;
 779                        int *pi = indegree_slab_at(&indegree, parent);
 780
 781                        if (*pi)
 782                                (*pi)++;
 783                        parents = parents->next;
 784                }
 785        }
 786
 787        /*
 788         * find the tips
 789         *
 790         * tips are nodes not reachable from any other node in the list
 791         *
 792         * the tips serve as a starting set for the work queue.
 793         */
 794        for (next = orig; next; next = next->next) {
 795                struct commit *commit = next->item;
 796
 797                if (*(indegree_slab_at(&indegree, commit)) == 1)
 798                        prio_queue_put(&queue, commit);
 799        }
 800
 801        /*
 802         * This is unfortunate; the initial tips need to be shown
 803         * in the order given from the revision traversal machinery.
 804         */
 805        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 806                prio_queue_reverse(&queue);
 807
 808        /* We no longer need the commit list */
 809        free_commit_list(orig);
 810
 811        pptr = list;
 812        *list = NULL;
 813        while ((commit = prio_queue_get(&queue)) != NULL) {
 814                struct commit_list *parents;
 815
 816                for (parents = commit->parents; parents ; parents = parents->next) {
 817                        struct commit *parent = parents->item;
 818                        int *pi = indegree_slab_at(&indegree, parent);
 819
 820                        if (!*pi)
 821                                continue;
 822
 823                        /*
 824                         * parents are only enqueued for emission
 825                         * when all their children have been emitted thereby
 826                         * guaranteeing topological order.
 827                         */
 828                        if (--(*pi) == 1)
 829                                prio_queue_put(&queue, parent);
 830                }
 831                /*
 832                 * all children of commit have already been
 833                 * emitted. we can emit it now.
 834                 */
 835                *(indegree_slab_at(&indegree, commit)) = 0;
 836
 837                pptr = &commit_list_insert(commit, pptr)->next;
 838        }
 839
 840        clear_indegree_slab(&indegree);
 841        clear_prio_queue(&queue);
 842        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 843                clear_author_date_slab(&author_date);
 844}
 845
 846/* merge-base stuff */
 847
 848/* Remember to update object flag allocation in object.h */
 849#define PARENT1         (1u<<16)
 850#define PARENT2         (1u<<17)
 851#define STALE           (1u<<18)
 852#define RESULT          (1u<<19)
 853
 854static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 855
 856static int queue_has_nonstale(struct prio_queue *queue)
 857{
 858        int i;
 859        for (i = 0; i < queue->nr; i++) {
 860                struct commit *commit = queue->array[i].data;
 861                if (!(commit->object.flags & STALE))
 862                        return 1;
 863        }
 864        return 0;
 865}
 866
 867/* all input commits in one and twos[] must have been parsed! */
 868static struct commit_list *paint_down_to_common(struct commit *one, int n,
 869                                                struct commit **twos,
 870                                                int min_generation)
 871{
 872        struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
 873        struct commit_list *result = NULL;
 874        int i;
 875        uint32_t last_gen = GENERATION_NUMBER_INFINITY;
 876
 877        if (!min_generation)
 878                queue.compare = compare_commits_by_commit_date;
 879
 880        one->object.flags |= PARENT1;
 881        if (!n) {
 882                commit_list_append(one, &result);
 883                return result;
 884        }
 885        prio_queue_put(&queue, one);
 886
 887        for (i = 0; i < n; i++) {
 888                twos[i]->object.flags |= PARENT2;
 889                prio_queue_put(&queue, twos[i]);
 890        }
 891
 892        while (queue_has_nonstale(&queue)) {
 893                struct commit *commit = prio_queue_get(&queue);
 894                struct commit_list *parents;
 895                int flags;
 896
 897                if (min_generation && commit->generation > last_gen)
 898                        BUG("bad generation skip %8x > %8x at %s",
 899                            commit->generation, last_gen,
 900                            oid_to_hex(&commit->object.oid));
 901                last_gen = commit->generation;
 902
 903                if (commit->generation < min_generation)
 904                        break;
 905
 906                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 907                if (flags == (PARENT1 | PARENT2)) {
 908                        if (!(commit->object.flags & RESULT)) {
 909                                commit->object.flags |= RESULT;
 910                                commit_list_insert_by_date(commit, &result);
 911                        }
 912                        /* Mark parents of a found merge stale */
 913                        flags |= STALE;
 914                }
 915                parents = commit->parents;
 916                while (parents) {
 917                        struct commit *p = parents->item;
 918                        parents = parents->next;
 919                        if ((p->object.flags & flags) == flags)
 920                                continue;
 921                        if (parse_commit(p))
 922                                return NULL;
 923                        p->object.flags |= flags;
 924                        prio_queue_put(&queue, p);
 925                }
 926        }
 927
 928        clear_prio_queue(&queue);
 929        return result;
 930}
 931
 932static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 933{
 934        struct commit_list *list = NULL;
 935        struct commit_list *result = NULL;
 936        int i;
 937
 938        for (i = 0; i < n; i++) {
 939                if (one == twos[i])
 940                        /*
 941                         * We do not mark this even with RESULT so we do not
 942                         * have to clean it up.
 943                         */
 944                        return commit_list_insert(one, &result);
 945        }
 946
 947        if (parse_commit(one))
 948                return NULL;
 949        for (i = 0; i < n; i++) {
 950                if (parse_commit(twos[i]))
 951                        return NULL;
 952        }
 953
 954        list = paint_down_to_common(one, n, twos, 0);
 955
 956        while (list) {
 957                struct commit *commit = pop_commit(&list);
 958                if (!(commit->object.flags & STALE))
 959                        commit_list_insert_by_date(commit, &result);
 960        }
 961        return result;
 962}
 963
 964struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 965{
 966        struct commit_list *i, *j, *k, *ret = NULL;
 967
 968        if (!in)
 969                return ret;
 970
 971        commit_list_insert(in->item, &ret);
 972
 973        for (i = in->next; i; i = i->next) {
 974                struct commit_list *new_commits = NULL, *end = NULL;
 975
 976                for (j = ret; j; j = j->next) {
 977                        struct commit_list *bases;
 978                        bases = get_merge_bases(i->item, j->item);
 979                        if (!new_commits)
 980                                new_commits = bases;
 981                        else
 982                                end->next = bases;
 983                        for (k = bases; k; k = k->next)
 984                                end = k;
 985                }
 986                ret = new_commits;
 987        }
 988        return ret;
 989}
 990
 991static int remove_redundant(struct commit **array, int cnt)
 992{
 993        /*
 994         * Some commit in the array may be an ancestor of
 995         * another commit.  Move such commit to the end of
 996         * the array, and return the number of commits that
 997         * are independent from each other.
 998         */
 999        struct commit **work;
1000        unsigned char *redundant;
1001        int *filled_index;
1002        int i, j, filled;
1003
1004        work = xcalloc(cnt, sizeof(*work));
1005        redundant = xcalloc(cnt, 1);
1006        ALLOC_ARRAY(filled_index, cnt - 1);
1007
1008        for (i = 0; i < cnt; i++)
1009                parse_commit(array[i]);
1010        for (i = 0; i < cnt; i++) {
1011                struct commit_list *common;
1012                uint32_t min_generation = array[i]->generation;
1013
1014                if (redundant[i])
1015                        continue;
1016                for (j = filled = 0; j < cnt; j++) {
1017                        if (i == j || redundant[j])
1018                                continue;
1019                        filled_index[filled] = j;
1020                        work[filled++] = array[j];
1021
1022                        if (array[j]->generation < min_generation)
1023                                min_generation = array[j]->generation;
1024                }
1025                common = paint_down_to_common(array[i], filled, work,
1026                                              min_generation);
1027                if (array[i]->object.flags & PARENT2)
1028                        redundant[i] = 1;
1029                for (j = 0; j < filled; j++)
1030                        if (work[j]->object.flags & PARENT1)
1031                                redundant[filled_index[j]] = 1;
1032                clear_commit_marks(array[i], all_flags);
1033                clear_commit_marks_many(filled, work, all_flags);
1034                free_commit_list(common);
1035        }
1036
1037        /* Now collect the result */
1038        COPY_ARRAY(work, array, cnt);
1039        for (i = filled = 0; i < cnt; i++)
1040                if (!redundant[i])
1041                        array[filled++] = work[i];
1042        for (j = filled, i = 0; i < cnt; i++)
1043                if (redundant[i])
1044                        array[j++] = work[i];
1045        free(work);
1046        free(redundant);
1047        free(filled_index);
1048        return filled;
1049}
1050
1051static struct commit_list *get_merge_bases_many_0(struct commit *one,
1052                                                  int n,
1053                                                  struct commit **twos,
1054                                                  int cleanup)
1055{
1056        struct commit_list *list;
1057        struct commit **rslt;
1058        struct commit_list *result;
1059        int cnt, i;
1060
1061        result = merge_bases_many(one, n, twos);
1062        for (i = 0; i < n; i++) {
1063                if (one == twos[i])
1064                        return result;
1065        }
1066        if (!result || !result->next) {
1067                if (cleanup) {
1068                        clear_commit_marks(one, all_flags);
1069                        clear_commit_marks_many(n, twos, all_flags);
1070                }
1071                return result;
1072        }
1073
1074        /* There are more than one */
1075        cnt = commit_list_count(result);
1076        rslt = xcalloc(cnt, sizeof(*rslt));
1077        for (list = result, i = 0; list; list = list->next)
1078                rslt[i++] = list->item;
1079        free_commit_list(result);
1080
1081        clear_commit_marks(one, all_flags);
1082        clear_commit_marks_many(n, twos, all_flags);
1083
1084        cnt = remove_redundant(rslt, cnt);
1085        result = NULL;
1086        for (i = 0; i < cnt; i++)
1087                commit_list_insert_by_date(rslt[i], &result);
1088        free(rslt);
1089        return result;
1090}
1091
1092struct commit_list *get_merge_bases_many(struct commit *one,
1093                                         int n,
1094                                         struct commit **twos)
1095{
1096        return get_merge_bases_many_0(one, n, twos, 1);
1097}
1098
1099struct commit_list *get_merge_bases_many_dirty(struct commit *one,
1100                                               int n,
1101                                               struct commit **twos)
1102{
1103        return get_merge_bases_many_0(one, n, twos, 0);
1104}
1105
1106struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
1107{
1108        return get_merge_bases_many_0(one, 1, &two, 1);
1109}
1110
1111/*
1112 * Is "commit" a descendant of one of the elements on the "with_commit" list?
1113 */
1114int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
1115{
1116        if (!with_commit)
1117                return 1;
1118        while (with_commit) {
1119                struct commit *other;
1120
1121                other = with_commit->item;
1122                with_commit = with_commit->next;
1123                if (in_merge_bases(other, commit))
1124                        return 1;
1125        }
1126        return 0;
1127}
1128
1129/*
1130 * Is "commit" an ancestor of one of the "references"?
1131 */
1132int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1133{
1134        struct commit_list *bases;
1135        int ret = 0, i;
1136        uint32_t min_generation = GENERATION_NUMBER_INFINITY;
1137
1138        if (parse_commit(commit))
1139                return ret;
1140        for (i = 0; i < nr_reference; i++) {
1141                if (parse_commit(reference[i]))
1142                        return ret;
1143                if (reference[i]->generation < min_generation)
1144                        min_generation = reference[i]->generation;
1145        }
1146
1147        if (commit->generation > min_generation)
1148                return ret;
1149
1150        bases = paint_down_to_common(commit, nr_reference, reference, commit->generation);
1151        if (commit->object.flags & PARENT2)
1152                ret = 1;
1153        clear_commit_marks(commit, all_flags);
1154        clear_commit_marks_many(nr_reference, reference, all_flags);
1155        free_commit_list(bases);
1156        return ret;
1157}
1158
1159/*
1160 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1161 */
1162int in_merge_bases(struct commit *commit, struct commit *reference)
1163{
1164        return in_merge_bases_many(commit, 1, &reference);
1165}
1166
1167struct commit_list *reduce_heads(struct commit_list *heads)
1168{
1169        struct commit_list *p;
1170        struct commit_list *result = NULL, **tail = &result;
1171        struct commit **array;
1172        int num_head, i;
1173
1174        if (!heads)
1175                return NULL;
1176
1177        /* Uniquify */
1178        for (p = heads; p; p = p->next)
1179                p->item->object.flags &= ~STALE;
1180        for (p = heads, num_head = 0; p; p = p->next) {
1181                if (p->item->object.flags & STALE)
1182                        continue;
1183                p->item->object.flags |= STALE;
1184                num_head++;
1185        }
1186        array = xcalloc(num_head, sizeof(*array));
1187        for (p = heads, i = 0; p; p = p->next) {
1188                if (p->item->object.flags & STALE) {
1189                        array[i++] = p->item;
1190                        p->item->object.flags &= ~STALE;
1191                }
1192        }
1193        num_head = remove_redundant(array, num_head);
1194        for (i = 0; i < num_head; i++)
1195                tail = &commit_list_insert(array[i], tail)->next;
1196        free(array);
1197        return result;
1198}
1199
1200void reduce_heads_replace(struct commit_list **heads)
1201{
1202        struct commit_list *result = reduce_heads(*heads);
1203        free_commit_list(*heads);
1204        *heads = result;
1205}
1206
1207static const char gpg_sig_header[] = "gpgsig";
1208static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1209
1210static int do_sign_commit(struct strbuf *buf, const char *keyid)
1211{
1212        struct strbuf sig = STRBUF_INIT;
1213        int inspos, copypos;
1214        const char *eoh;
1215
1216        /* find the end of the header */
1217        eoh = strstr(buf->buf, "\n\n");
1218        if (!eoh)
1219                inspos = buf->len;
1220        else
1221                inspos = eoh - buf->buf + 1;
1222
1223        if (!keyid || !*keyid)
1224                keyid = get_signing_key();
1225        if (sign_buffer(buf, &sig, keyid)) {
1226                strbuf_release(&sig);
1227                return -1;
1228        }
1229
1230        for (copypos = 0; sig.buf[copypos]; ) {
1231                const char *bol = sig.buf + copypos;
1232                const char *eol = strchrnul(bol, '\n');
1233                int len = (eol - bol) + !!*eol;
1234
1235                if (!copypos) {
1236                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1237                        inspos += gpg_sig_header_len;
1238                }
1239                strbuf_insert(buf, inspos++, " ", 1);
1240                strbuf_insert(buf, inspos, bol, len);
1241                inspos += len;
1242                copypos += len;
1243        }
1244        strbuf_release(&sig);
1245        return 0;
1246}
1247
1248int parse_signed_commit(const struct commit *commit,
1249                        struct strbuf *payload, struct strbuf *signature)
1250{
1251
1252        unsigned long size;
1253        const char *buffer = get_commit_buffer(commit, &size);
1254        int in_signature, saw_signature = -1;
1255        const char *line, *tail;
1256
1257        line = buffer;
1258        tail = buffer + size;
1259        in_signature = 0;
1260        saw_signature = 0;
1261        while (line < tail) {
1262                const char *sig = NULL;
1263                const char *next = memchr(line, '\n', tail - line);
1264
1265                next = next ? next + 1 : tail;
1266                if (in_signature && line[0] == ' ')
1267                        sig = line + 1;
1268                else if (starts_with(line, gpg_sig_header) &&
1269                         line[gpg_sig_header_len] == ' ')
1270                        sig = line + gpg_sig_header_len + 1;
1271                if (sig) {
1272                        strbuf_add(signature, sig, next - sig);
1273                        saw_signature = 1;
1274                        in_signature = 1;
1275                } else {
1276                        if (*line == '\n')
1277                                /* dump the whole remainder of the buffer */
1278                                next = tail;
1279                        strbuf_add(payload, line, next - line);
1280                        in_signature = 0;
1281                }
1282                line = next;
1283        }
1284        unuse_commit_buffer(commit, buffer);
1285        return saw_signature;
1286}
1287
1288int remove_signature(struct strbuf *buf)
1289{
1290        const char *line = buf->buf;
1291        const char *tail = buf->buf + buf->len;
1292        int in_signature = 0;
1293        const char *sig_start = NULL;
1294        const char *sig_end = NULL;
1295
1296        while (line < tail) {
1297                const char *next = memchr(line, '\n', tail - line);
1298                next = next ? next + 1 : tail;
1299
1300                if (in_signature && line[0] == ' ')
1301                        sig_end = next;
1302                else if (starts_with(line, gpg_sig_header) &&
1303                         line[gpg_sig_header_len] == ' ') {
1304                        sig_start = line;
1305                        sig_end = next;
1306                        in_signature = 1;
1307                } else {
1308                        if (*line == '\n')
1309                                /* dump the whole remainder of the buffer */
1310                                next = tail;
1311                        in_signature = 0;
1312                }
1313                line = next;
1314        }
1315
1316        if (sig_start)
1317                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1318
1319        return sig_start != NULL;
1320}
1321
1322static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1323{
1324        struct merge_remote_desc *desc;
1325        struct commit_extra_header *mergetag;
1326        char *buf;
1327        unsigned long size, len;
1328        enum object_type type;
1329
1330        desc = merge_remote_util(parent);
1331        if (!desc || !desc->obj)
1332                return;
1333        buf = read_object_file(&desc->obj->oid, &type, &size);
1334        if (!buf || type != OBJ_TAG)
1335                goto free_return;
1336        len = parse_signature(buf, size);
1337        if (size == len)
1338                goto free_return;
1339        /*
1340         * We could verify this signature and either omit the tag when
1341         * it does not validate, but the integrator may not have the
1342         * public key of the signer of the tag he is merging, while a
1343         * later auditor may have it while auditing, so let's not run
1344         * verify-signed-buffer here for now...
1345         *
1346         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1347         *      warn("warning: signed tag unverified.");
1348         */
1349        mergetag = xcalloc(1, sizeof(*mergetag));
1350        mergetag->key = xstrdup("mergetag");
1351        mergetag->value = buf;
1352        mergetag->len = size;
1353
1354        **tail = mergetag;
1355        *tail = &mergetag->next;
1356        return;
1357
1358free_return:
1359        free(buf);
1360}
1361
1362int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1363{
1364        struct strbuf payload = STRBUF_INIT;
1365        struct strbuf signature = STRBUF_INIT;
1366        int ret = 1;
1367
1368        sigc->result = 'N';
1369
1370        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1371                goto out;
1372        ret = check_signature(payload.buf, payload.len, signature.buf,
1373                signature.len, sigc);
1374
1375 out:
1376        strbuf_release(&payload);
1377        strbuf_release(&signature);
1378
1379        return ret;
1380}
1381
1382
1383
1384void append_merge_tag_headers(struct commit_list *parents,
1385                              struct commit_extra_header ***tail)
1386{
1387        while (parents) {
1388                struct commit *parent = parents->item;
1389                handle_signed_tag(parent, tail);
1390                parents = parents->next;
1391        }
1392}
1393
1394static void add_extra_header(struct strbuf *buffer,
1395                             struct commit_extra_header *extra)
1396{
1397        strbuf_addstr(buffer, extra->key);
1398        if (extra->len)
1399                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1400        else
1401                strbuf_addch(buffer, '\n');
1402}
1403
1404struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1405                                                      const char **exclude)
1406{
1407        struct commit_extra_header *extra = NULL;
1408        unsigned long size;
1409        const char *buffer = get_commit_buffer(commit, &size);
1410        extra = read_commit_extra_header_lines(buffer, size, exclude);
1411        unuse_commit_buffer(commit, buffer);
1412        return extra;
1413}
1414
1415int for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1416{
1417        struct commit_extra_header *extra, *to_free;
1418        int res = 0;
1419
1420        to_free = read_commit_extra_headers(commit, NULL);
1421        for (extra = to_free; !res && extra; extra = extra->next) {
1422                if (strcmp(extra->key, "mergetag"))
1423                        continue; /* not a merge tag */
1424                res = fn(commit, extra, data);
1425        }
1426        free_commit_extra_headers(to_free);
1427        return res;
1428}
1429
1430static inline int standard_header_field(const char *field, size_t len)
1431{
1432        return ((len == 4 && !memcmp(field, "tree", 4)) ||
1433                (len == 6 && !memcmp(field, "parent", 6)) ||
1434                (len == 6 && !memcmp(field, "author", 6)) ||
1435                (len == 9 && !memcmp(field, "committer", 9)) ||
1436                (len == 8 && !memcmp(field, "encoding", 8)));
1437}
1438
1439static int excluded_header_field(const char *field, size_t len, const char **exclude)
1440{
1441        if (!exclude)
1442                return 0;
1443
1444        while (*exclude) {
1445                size_t xlen = strlen(*exclude);
1446                if (len == xlen && !memcmp(field, *exclude, xlen))
1447                        return 1;
1448                exclude++;
1449        }
1450        return 0;
1451}
1452
1453static struct commit_extra_header *read_commit_extra_header_lines(
1454        const char *buffer, size_t size,
1455        const char **exclude)
1456{
1457        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1458        const char *line, *next, *eof, *eob;
1459        struct strbuf buf = STRBUF_INIT;
1460
1461        for (line = buffer, eob = line + size;
1462             line < eob && *line != '\n';
1463             line = next) {
1464                next = memchr(line, '\n', eob - line);
1465                next = next ? next + 1 : eob;
1466                if (*line == ' ') {
1467                        /* continuation */
1468                        if (it)
1469                                strbuf_add(&buf, line + 1, next - (line + 1));
1470                        continue;
1471                }
1472                if (it)
1473                        it->value = strbuf_detach(&buf, &it->len);
1474                strbuf_reset(&buf);
1475                it = NULL;
1476
1477                eof = memchr(line, ' ', next - line);
1478                if (!eof)
1479                        eof = next;
1480                else if (standard_header_field(line, eof - line) ||
1481                         excluded_header_field(line, eof - line, exclude))
1482                        continue;
1483
1484                it = xcalloc(1, sizeof(*it));
1485                it->key = xmemdupz(line, eof-line);
1486                *tail = it;
1487                tail = &it->next;
1488                if (eof + 1 < next)
1489                        strbuf_add(&buf, eof + 1, next - (eof + 1));
1490        }
1491        if (it)
1492                it->value = strbuf_detach(&buf, &it->len);
1493        return extra;
1494}
1495
1496void free_commit_extra_headers(struct commit_extra_header *extra)
1497{
1498        while (extra) {
1499                struct commit_extra_header *next = extra->next;
1500                free(extra->key);
1501                free(extra->value);
1502                free(extra);
1503                extra = next;
1504        }
1505}
1506
1507int commit_tree(const char *msg, size_t msg_len, const struct object_id *tree,
1508                struct commit_list *parents, struct object_id *ret,
1509                const char *author, const char *sign_commit)
1510{
1511        struct commit_extra_header *extra = NULL, **tail = &extra;
1512        int result;
1513
1514        append_merge_tag_headers(parents, &tail);
1515        result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1516                                      author, sign_commit, extra);
1517        free_commit_extra_headers(extra);
1518        return result;
1519}
1520
1521static int find_invalid_utf8(const char *buf, int len)
1522{
1523        int offset = 0;
1524        static const unsigned int max_codepoint[] = {
1525                0x7f, 0x7ff, 0xffff, 0x10ffff
1526        };
1527
1528        while (len) {
1529                unsigned char c = *buf++;
1530                int bytes, bad_offset;
1531                unsigned int codepoint;
1532                unsigned int min_val, max_val;
1533
1534                len--;
1535                offset++;
1536
1537                /* Simple US-ASCII? No worries. */
1538                if (c < 0x80)
1539                        continue;
1540
1541                bad_offset = offset-1;
1542
1543                /*
1544                 * Count how many more high bits set: that's how
1545                 * many more bytes this sequence should have.
1546                 */
1547                bytes = 0;
1548                while (c & 0x40) {
1549                        c <<= 1;
1550                        bytes++;
1551                }
1552
1553                /*
1554                 * Must be between 1 and 3 more bytes.  Longer sequences result in
1555                 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1556                 */
1557                if (bytes < 1 || 3 < bytes)
1558                        return bad_offset;
1559
1560                /* Do we *have* that many bytes? */
1561                if (len < bytes)
1562                        return bad_offset;
1563
1564                /*
1565                 * Place the encoded bits at the bottom of the value and compute the
1566                 * valid range.
1567                 */
1568                codepoint = (c & 0x7f) >> bytes;
1569                min_val = max_codepoint[bytes-1] + 1;
1570                max_val = max_codepoint[bytes];
1571
1572                offset += bytes;
1573                len -= bytes;
1574
1575                /* And verify that they are good continuation bytes */
1576                do {
1577                        codepoint <<= 6;
1578                        codepoint |= *buf & 0x3f;
1579                        if ((*buf++ & 0xc0) != 0x80)
1580                                return bad_offset;
1581                } while (--bytes);
1582
1583                /* Reject codepoints that are out of range for the sequence length. */
1584                if (codepoint < min_val || codepoint > max_val)
1585                        return bad_offset;
1586                /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1587                if ((codepoint & 0x1ff800) == 0xd800)
1588                        return bad_offset;
1589                /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1590                if ((codepoint & 0xfffe) == 0xfffe)
1591                        return bad_offset;
1592                /* So are anything in the range U+FDD0..U+FDEF. */
1593                if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1594                        return bad_offset;
1595        }
1596        return -1;
1597}
1598
1599/*
1600 * This verifies that the buffer is in proper utf8 format.
1601 *
1602 * If it isn't, it assumes any non-utf8 characters are Latin1,
1603 * and does the conversion.
1604 */
1605static int verify_utf8(struct strbuf *buf)
1606{
1607        int ok = 1;
1608        long pos = 0;
1609
1610        for (;;) {
1611                int bad;
1612                unsigned char c;
1613                unsigned char replace[2];
1614
1615                bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1616                if (bad < 0)
1617                        return ok;
1618                pos += bad;
1619                ok = 0;
1620                c = buf->buf[pos];
1621                strbuf_remove(buf, pos, 1);
1622
1623                /* We know 'c' must be in the range 128-255 */
1624                replace[0] = 0xc0 + (c >> 6);
1625                replace[1] = 0x80 + (c & 0x3f);
1626                strbuf_insert(buf, pos, replace, 2);
1627                pos += 2;
1628        }
1629}
1630
1631static const char commit_utf8_warn[] =
1632N_("Warning: commit message did not conform to UTF-8.\n"
1633   "You may want to amend it after fixing the message, or set the config\n"
1634   "variable i18n.commitencoding to the encoding your project uses.\n");
1635
1636int commit_tree_extended(const char *msg, size_t msg_len,
1637                         const struct object_id *tree,
1638                         struct commit_list *parents, struct object_id *ret,
1639                         const char *author, const char *sign_commit,
1640                         struct commit_extra_header *extra)
1641{
1642        int result;
1643        int encoding_is_utf8;
1644        struct strbuf buffer;
1645
1646        assert_oid_type(tree, OBJ_TREE);
1647
1648        if (memchr(msg, '\0', msg_len))
1649                return error("a NUL byte in commit log message not allowed.");
1650
1651        /* Not having i18n.commitencoding is the same as having utf-8 */
1652        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1653
1654        strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1655        strbuf_addf(&buffer, "tree %s\n", oid_to_hex(tree));
1656
1657        /*
1658         * NOTE! This ordering means that the same exact tree merged with a
1659         * different order of parents will be a _different_ changeset even
1660         * if everything else stays the same.
1661         */
1662        while (parents) {
1663                struct commit *parent = pop_commit(&parents);
1664                strbuf_addf(&buffer, "parent %s\n",
1665                            oid_to_hex(&parent->object.oid));
1666        }
1667
1668        /* Person/date information */
1669        if (!author)
1670                author = git_author_info(IDENT_STRICT);
1671        strbuf_addf(&buffer, "author %s\n", author);
1672        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1673        if (!encoding_is_utf8)
1674                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1675
1676        while (extra) {
1677                add_extra_header(&buffer, extra);
1678                extra = extra->next;
1679        }
1680        strbuf_addch(&buffer, '\n');
1681
1682        /* And add the comment */
1683        strbuf_add(&buffer, msg, msg_len);
1684
1685        /* And check the encoding */
1686        if (encoding_is_utf8 && !verify_utf8(&buffer))
1687                fprintf(stderr, _(commit_utf8_warn));
1688
1689        if (sign_commit && do_sign_commit(&buffer, sign_commit)) {
1690                result = -1;
1691                goto out;
1692        }
1693
1694        result = write_object_file(buffer.buf, buffer.len, commit_type, ret);
1695out:
1696        strbuf_release(&buffer);
1697        return result;
1698}
1699
1700define_commit_slab(merge_desc_slab, struct merge_remote_desc *);
1701static struct merge_desc_slab merge_desc_slab = COMMIT_SLAB_INIT(1, merge_desc_slab);
1702
1703struct merge_remote_desc *merge_remote_util(struct commit *commit)
1704{
1705        return *merge_desc_slab_at(&merge_desc_slab, commit);
1706}
1707
1708void set_merge_remote_desc(struct commit *commit,
1709                           const char *name, struct object *obj)
1710{
1711        struct merge_remote_desc *desc;
1712        FLEX_ALLOC_STR(desc, name, name);
1713        desc->obj = obj;
1714        *merge_desc_slab_at(&merge_desc_slab, commit) = desc;
1715}
1716
1717struct commit *get_merge_parent(const char *name)
1718{
1719        struct object *obj;
1720        struct commit *commit;
1721        struct object_id oid;
1722        if (get_oid(name, &oid))
1723                return NULL;
1724        obj = parse_object(the_repository, &oid);
1725        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1726        if (commit && !merge_remote_util(commit))
1727                set_merge_remote_desc(commit, name, obj);
1728        return commit;
1729}
1730
1731/*
1732 * Append a commit to the end of the commit_list.
1733 *
1734 * next starts by pointing to the variable that holds the head of an
1735 * empty commit_list, and is updated to point to the "next" field of
1736 * the last item on the list as new commits are appended.
1737 *
1738 * Usage example:
1739 *
1740 *     struct commit_list *list;
1741 *     struct commit_list **next = &list;
1742 *
1743 *     next = commit_list_append(c1, next);
1744 *     next = commit_list_append(c2, next);
1745 *     assert(commit_list_count(list) == 2);
1746 *     return list;
1747 */
1748struct commit_list **commit_list_append(struct commit *commit,
1749                                        struct commit_list **next)
1750{
1751        struct commit_list *new_commit = xmalloc(sizeof(struct commit_list));
1752        new_commit->item = commit;
1753        *next = new_commit;
1754        new_commit->next = NULL;
1755        return &new_commit->next;
1756}
1757
1758const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1759{
1760        int key_len = strlen(key);
1761        const char *line = msg;
1762
1763        while (line) {
1764                const char *eol = strchrnul(line, '\n');
1765
1766                if (line == eol)
1767                        return NULL;
1768
1769                if (eol - line > key_len &&
1770                    !strncmp(line, key, key_len) &&
1771                    line[key_len] == ' ') {
1772                        *out_len = eol - line - key_len - 1;
1773                        return line + key_len + 1;
1774                }
1775                line = *eol ? eol + 1 : NULL;
1776        }
1777        return NULL;
1778}
1779
1780/*
1781 * Inspect the given string and determine the true "end" of the log message, in
1782 * order to find where to put a new Signed-off-by: line.  Ignored are
1783 * trailing comment lines and blank lines.  To support "git commit -s
1784 * --amend" on an existing commit, we also ignore "Conflicts:".  To
1785 * support "git commit -v", we truncate at cut lines.
1786 *
1787 * Returns the number of bytes from the tail to ignore, to be fed as
1788 * the second parameter to append_signoff().
1789 */
1790int ignore_non_trailer(const char *buf, size_t len)
1791{
1792        int boc = 0;
1793        int bol = 0;
1794        int in_old_conflicts_block = 0;
1795        size_t cutoff = wt_status_locate_end(buf, len);
1796
1797        while (bol < cutoff) {
1798                const char *next_line = memchr(buf + bol, '\n', len - bol);
1799
1800                if (!next_line)
1801                        next_line = buf + len;
1802                else
1803                        next_line++;
1804
1805                if (buf[bol] == comment_line_char || buf[bol] == '\n') {
1806                        /* is this the first of the run of comments? */
1807                        if (!boc)
1808                                boc = bol;
1809                        /* otherwise, it is just continuing */
1810                } else if (starts_with(buf + bol, "Conflicts:\n")) {
1811                        in_old_conflicts_block = 1;
1812                        if (!boc)
1813                                boc = bol;
1814                } else if (in_old_conflicts_block && buf[bol] == '\t') {
1815                        ; /* a pathname in the conflicts block */
1816                } else if (boc) {
1817                        /* the previous was not trailing comment */
1818                        boc = 0;
1819                        in_old_conflicts_block = 0;
1820                }
1821                bol = next_line - buf;
1822        }
1823        return boc ? len - boc : len - cutoff;
1824}