commit.con commit Merge branch 'es/chain-lint-in-subshell' (cfec613)
   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(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(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(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, unsigned long);
 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        one->object.flags |= PARENT1;
 878        if (!n) {
 879                commit_list_append(one, &result);
 880                return result;
 881        }
 882        prio_queue_put(&queue, one);
 883
 884        for (i = 0; i < n; i++) {
 885                twos[i]->object.flags |= PARENT2;
 886                prio_queue_put(&queue, twos[i]);
 887        }
 888
 889        while (queue_has_nonstale(&queue)) {
 890                struct commit *commit = prio_queue_get(&queue);
 891                struct commit_list *parents;
 892                int flags;
 893
 894                if (commit->generation > last_gen)
 895                        BUG("bad generation skip %8x > %8x at %s",
 896                            commit->generation, last_gen,
 897                            oid_to_hex(&commit->object.oid));
 898                last_gen = commit->generation;
 899
 900                if (commit->generation < min_generation)
 901                        break;
 902
 903                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 904                if (flags == (PARENT1 | PARENT2)) {
 905                        if (!(commit->object.flags & RESULT)) {
 906                                commit->object.flags |= RESULT;
 907                                commit_list_insert_by_date(commit, &result);
 908                        }
 909                        /* Mark parents of a found merge stale */
 910                        flags |= STALE;
 911                }
 912                parents = commit->parents;
 913                while (parents) {
 914                        struct commit *p = parents->item;
 915                        parents = parents->next;
 916                        if ((p->object.flags & flags) == flags)
 917                                continue;
 918                        if (parse_commit(p))
 919                                return NULL;
 920                        p->object.flags |= flags;
 921                        prio_queue_put(&queue, p);
 922                }
 923        }
 924
 925        clear_prio_queue(&queue);
 926        return result;
 927}
 928
 929static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 930{
 931        struct commit_list *list = NULL;
 932        struct commit_list *result = NULL;
 933        int i;
 934
 935        for (i = 0; i < n; i++) {
 936                if (one == twos[i])
 937                        /*
 938                         * We do not mark this even with RESULT so we do not
 939                         * have to clean it up.
 940                         */
 941                        return commit_list_insert(one, &result);
 942        }
 943
 944        if (parse_commit(one))
 945                return NULL;
 946        for (i = 0; i < n; i++) {
 947                if (parse_commit(twos[i]))
 948                        return NULL;
 949        }
 950
 951        list = paint_down_to_common(one, n, twos, 0);
 952
 953        while (list) {
 954                struct commit *commit = pop_commit(&list);
 955                if (!(commit->object.flags & STALE))
 956                        commit_list_insert_by_date(commit, &result);
 957        }
 958        return result;
 959}
 960
 961struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 962{
 963        struct commit_list *i, *j, *k, *ret = NULL;
 964
 965        if (!in)
 966                return ret;
 967
 968        commit_list_insert(in->item, &ret);
 969
 970        for (i = in->next; i; i = i->next) {
 971                struct commit_list *new_commits = NULL, *end = NULL;
 972
 973                for (j = ret; j; j = j->next) {
 974                        struct commit_list *bases;
 975                        bases = get_merge_bases(i->item, j->item);
 976                        if (!new_commits)
 977                                new_commits = bases;
 978                        else
 979                                end->next = bases;
 980                        for (k = bases; k; k = k->next)
 981                                end = k;
 982                }
 983                ret = new_commits;
 984        }
 985        return ret;
 986}
 987
 988static int remove_redundant(struct commit **array, int cnt)
 989{
 990        /*
 991         * Some commit in the array may be an ancestor of
 992         * another commit.  Move such commit to the end of
 993         * the array, and return the number of commits that
 994         * are independent from each other.
 995         */
 996        struct commit **work;
 997        unsigned char *redundant;
 998        int *filled_index;
 999        int i, j, filled;
1000
1001        work = xcalloc(cnt, sizeof(*work));
1002        redundant = xcalloc(cnt, 1);
1003        ALLOC_ARRAY(filled_index, cnt - 1);
1004
1005        for (i = 0; i < cnt; i++)
1006                parse_commit(array[i]);
1007        for (i = 0; i < cnt; i++) {
1008                struct commit_list *common;
1009                uint32_t min_generation = array[i]->generation;
1010
1011                if (redundant[i])
1012                        continue;
1013                for (j = filled = 0; j < cnt; j++) {
1014                        if (i == j || redundant[j])
1015                                continue;
1016                        filled_index[filled] = j;
1017                        work[filled++] = array[j];
1018
1019                        if (array[j]->generation < min_generation)
1020                                min_generation = array[j]->generation;
1021                }
1022                common = paint_down_to_common(array[i], filled, work,
1023                                              min_generation);
1024                if (array[i]->object.flags & PARENT2)
1025                        redundant[i] = 1;
1026                for (j = 0; j < filled; j++)
1027                        if (work[j]->object.flags & PARENT1)
1028                                redundant[filled_index[j]] = 1;
1029                clear_commit_marks(array[i], all_flags);
1030                clear_commit_marks_many(filled, work, all_flags);
1031                free_commit_list(common);
1032        }
1033
1034        /* Now collect the result */
1035        COPY_ARRAY(work, array, cnt);
1036        for (i = filled = 0; i < cnt; i++)
1037                if (!redundant[i])
1038                        array[filled++] = work[i];
1039        for (j = filled, i = 0; i < cnt; i++)
1040                if (redundant[i])
1041                        array[j++] = work[i];
1042        free(work);
1043        free(redundant);
1044        free(filled_index);
1045        return filled;
1046}
1047
1048static struct commit_list *get_merge_bases_many_0(struct commit *one,
1049                                                  int n,
1050                                                  struct commit **twos,
1051                                                  int cleanup)
1052{
1053        struct commit_list *list;
1054        struct commit **rslt;
1055        struct commit_list *result;
1056        int cnt, i;
1057
1058        result = merge_bases_many(one, n, twos);
1059        for (i = 0; i < n; i++) {
1060                if (one == twos[i])
1061                        return result;
1062        }
1063        if (!result || !result->next) {
1064                if (cleanup) {
1065                        clear_commit_marks(one, all_flags);
1066                        clear_commit_marks_many(n, twos, all_flags);
1067                }
1068                return result;
1069        }
1070
1071        /* There are more than one */
1072        cnt = commit_list_count(result);
1073        rslt = xcalloc(cnt, sizeof(*rslt));
1074        for (list = result, i = 0; list; list = list->next)
1075                rslt[i++] = list->item;
1076        free_commit_list(result);
1077
1078        clear_commit_marks(one, all_flags);
1079        clear_commit_marks_many(n, twos, all_flags);
1080
1081        cnt = remove_redundant(rslt, cnt);
1082        result = NULL;
1083        for (i = 0; i < cnt; i++)
1084                commit_list_insert_by_date(rslt[i], &result);
1085        free(rslt);
1086        return result;
1087}
1088
1089struct commit_list *get_merge_bases_many(struct commit *one,
1090                                         int n,
1091                                         struct commit **twos)
1092{
1093        return get_merge_bases_many_0(one, n, twos, 1);
1094}
1095
1096struct commit_list *get_merge_bases_many_dirty(struct commit *one,
1097                                               int n,
1098                                               struct commit **twos)
1099{
1100        return get_merge_bases_many_0(one, n, twos, 0);
1101}
1102
1103struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
1104{
1105        return get_merge_bases_many_0(one, 1, &two, 1);
1106}
1107
1108/*
1109 * Is "commit" a descendant of one of the elements on the "with_commit" list?
1110 */
1111int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
1112{
1113        if (!with_commit)
1114                return 1;
1115        while (with_commit) {
1116                struct commit *other;
1117
1118                other = with_commit->item;
1119                with_commit = with_commit->next;
1120                if (in_merge_bases(other, commit))
1121                        return 1;
1122        }
1123        return 0;
1124}
1125
1126/*
1127 * Is "commit" an ancestor of one of the "references"?
1128 */
1129int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1130{
1131        struct commit_list *bases;
1132        int ret = 0, i;
1133        uint32_t min_generation = GENERATION_NUMBER_INFINITY;
1134
1135        if (parse_commit(commit))
1136                return ret;
1137        for (i = 0; i < nr_reference; i++) {
1138                if (parse_commit(reference[i]))
1139                        return ret;
1140                if (reference[i]->generation < min_generation)
1141                        min_generation = reference[i]->generation;
1142        }
1143
1144        if (commit->generation > min_generation)
1145                return ret;
1146
1147        bases = paint_down_to_common(commit, nr_reference, reference, commit->generation);
1148        if (commit->object.flags & PARENT2)
1149                ret = 1;
1150        clear_commit_marks(commit, all_flags);
1151        clear_commit_marks_many(nr_reference, reference, all_flags);
1152        free_commit_list(bases);
1153        return ret;
1154}
1155
1156/*
1157 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1158 */
1159int in_merge_bases(struct commit *commit, struct commit *reference)
1160{
1161        return in_merge_bases_many(commit, 1, &reference);
1162}
1163
1164struct commit_list *reduce_heads(struct commit_list *heads)
1165{
1166        struct commit_list *p;
1167        struct commit_list *result = NULL, **tail = &result;
1168        struct commit **array;
1169        int num_head, i;
1170
1171        if (!heads)
1172                return NULL;
1173
1174        /* Uniquify */
1175        for (p = heads; p; p = p->next)
1176                p->item->object.flags &= ~STALE;
1177        for (p = heads, num_head = 0; p; p = p->next) {
1178                if (p->item->object.flags & STALE)
1179                        continue;
1180                p->item->object.flags |= STALE;
1181                num_head++;
1182        }
1183        array = xcalloc(num_head, sizeof(*array));
1184        for (p = heads, i = 0; p; p = p->next) {
1185                if (p->item->object.flags & STALE) {
1186                        array[i++] = p->item;
1187                        p->item->object.flags &= ~STALE;
1188                }
1189        }
1190        num_head = remove_redundant(array, num_head);
1191        for (i = 0; i < num_head; i++)
1192                tail = &commit_list_insert(array[i], tail)->next;
1193        free(array);
1194        return result;
1195}
1196
1197void reduce_heads_replace(struct commit_list **heads)
1198{
1199        struct commit_list *result = reduce_heads(*heads);
1200        free_commit_list(*heads);
1201        *heads = result;
1202}
1203
1204static const char gpg_sig_header[] = "gpgsig";
1205static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1206
1207static int do_sign_commit(struct strbuf *buf, const char *keyid)
1208{
1209        struct strbuf sig = STRBUF_INIT;
1210        int inspos, copypos;
1211        const char *eoh;
1212
1213        /* find the end of the header */
1214        eoh = strstr(buf->buf, "\n\n");
1215        if (!eoh)
1216                inspos = buf->len;
1217        else
1218                inspos = eoh - buf->buf + 1;
1219
1220        if (!keyid || !*keyid)
1221                keyid = get_signing_key();
1222        if (sign_buffer(buf, &sig, keyid)) {
1223                strbuf_release(&sig);
1224                return -1;
1225        }
1226
1227        for (copypos = 0; sig.buf[copypos]; ) {
1228                const char *bol = sig.buf + copypos;
1229                const char *eol = strchrnul(bol, '\n');
1230                int len = (eol - bol) + !!*eol;
1231
1232                if (!copypos) {
1233                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1234                        inspos += gpg_sig_header_len;
1235                }
1236                strbuf_insert(buf, inspos++, " ", 1);
1237                strbuf_insert(buf, inspos, bol, len);
1238                inspos += len;
1239                copypos += len;
1240        }
1241        strbuf_release(&sig);
1242        return 0;
1243}
1244
1245int parse_signed_commit(const struct commit *commit,
1246                        struct strbuf *payload, struct strbuf *signature)
1247{
1248
1249        unsigned long size;
1250        const char *buffer = get_commit_buffer(commit, &size);
1251        int in_signature, saw_signature = -1;
1252        const char *line, *tail;
1253
1254        line = buffer;
1255        tail = buffer + size;
1256        in_signature = 0;
1257        saw_signature = 0;
1258        while (line < tail) {
1259                const char *sig = NULL;
1260                const char *next = memchr(line, '\n', tail - line);
1261
1262                next = next ? next + 1 : tail;
1263                if (in_signature && line[0] == ' ')
1264                        sig = line + 1;
1265                else if (starts_with(line, gpg_sig_header) &&
1266                         line[gpg_sig_header_len] == ' ')
1267                        sig = line + gpg_sig_header_len + 1;
1268                if (sig) {
1269                        strbuf_add(signature, sig, next - sig);
1270                        saw_signature = 1;
1271                        in_signature = 1;
1272                } else {
1273                        if (*line == '\n')
1274                                /* dump the whole remainder of the buffer */
1275                                next = tail;
1276                        strbuf_add(payload, line, next - line);
1277                        in_signature = 0;
1278                }
1279                line = next;
1280        }
1281        unuse_commit_buffer(commit, buffer);
1282        return saw_signature;
1283}
1284
1285int remove_signature(struct strbuf *buf)
1286{
1287        const char *line = buf->buf;
1288        const char *tail = buf->buf + buf->len;
1289        int in_signature = 0;
1290        const char *sig_start = NULL;
1291        const char *sig_end = NULL;
1292
1293        while (line < tail) {
1294                const char *next = memchr(line, '\n', tail - line);
1295                next = next ? next + 1 : tail;
1296
1297                if (in_signature && line[0] == ' ')
1298                        sig_end = next;
1299                else if (starts_with(line, gpg_sig_header) &&
1300                         line[gpg_sig_header_len] == ' ') {
1301                        sig_start = line;
1302                        sig_end = next;
1303                        in_signature = 1;
1304                } else {
1305                        if (*line == '\n')
1306                                /* dump the whole remainder of the buffer */
1307                                next = tail;
1308                        in_signature = 0;
1309                }
1310                line = next;
1311        }
1312
1313        if (sig_start)
1314                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1315
1316        return sig_start != NULL;
1317}
1318
1319static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1320{
1321        struct merge_remote_desc *desc;
1322        struct commit_extra_header *mergetag;
1323        char *buf;
1324        unsigned long size, len;
1325        enum object_type type;
1326
1327        desc = merge_remote_util(parent);
1328        if (!desc || !desc->obj)
1329                return;
1330        buf = read_object_file(&desc->obj->oid, &type, &size);
1331        if (!buf || type != OBJ_TAG)
1332                goto free_return;
1333        len = parse_signature(buf, size);
1334        if (size == len)
1335                goto free_return;
1336        /*
1337         * We could verify this signature and either omit the tag when
1338         * it does not validate, but the integrator may not have the
1339         * public key of the signer of the tag he is merging, while a
1340         * later auditor may have it while auditing, so let's not run
1341         * verify-signed-buffer here for now...
1342         *
1343         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1344         *      warn("warning: signed tag unverified.");
1345         */
1346        mergetag = xcalloc(1, sizeof(*mergetag));
1347        mergetag->key = xstrdup("mergetag");
1348        mergetag->value = buf;
1349        mergetag->len = size;
1350
1351        **tail = mergetag;
1352        *tail = &mergetag->next;
1353        return;
1354
1355free_return:
1356        free(buf);
1357}
1358
1359int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1360{
1361        struct strbuf payload = STRBUF_INIT;
1362        struct strbuf signature = STRBUF_INIT;
1363        int ret = 1;
1364
1365        sigc->result = 'N';
1366
1367        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1368                goto out;
1369        ret = check_signature(payload.buf, payload.len, signature.buf,
1370                signature.len, sigc);
1371
1372 out:
1373        strbuf_release(&payload);
1374        strbuf_release(&signature);
1375
1376        return ret;
1377}
1378
1379
1380
1381void append_merge_tag_headers(struct commit_list *parents,
1382                              struct commit_extra_header ***tail)
1383{
1384        while (parents) {
1385                struct commit *parent = parents->item;
1386                handle_signed_tag(parent, tail);
1387                parents = parents->next;
1388        }
1389}
1390
1391static void add_extra_header(struct strbuf *buffer,
1392                             struct commit_extra_header *extra)
1393{
1394        strbuf_addstr(buffer, extra->key);
1395        if (extra->len)
1396                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1397        else
1398                strbuf_addch(buffer, '\n');
1399}
1400
1401struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1402                                                      const char **exclude)
1403{
1404        struct commit_extra_header *extra = NULL;
1405        unsigned long size;
1406        const char *buffer = get_commit_buffer(commit, &size);
1407        extra = read_commit_extra_header_lines(buffer, size, exclude);
1408        unuse_commit_buffer(commit, buffer);
1409        return extra;
1410}
1411
1412int for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1413{
1414        struct commit_extra_header *extra, *to_free;
1415        int res = 0;
1416
1417        to_free = read_commit_extra_headers(commit, NULL);
1418        for (extra = to_free; !res && extra; extra = extra->next) {
1419                if (strcmp(extra->key, "mergetag"))
1420                        continue; /* not a merge tag */
1421                res = fn(commit, extra, data);
1422        }
1423        free_commit_extra_headers(to_free);
1424        return res;
1425}
1426
1427static inline int standard_header_field(const char *field, size_t len)
1428{
1429        return ((len == 4 && !memcmp(field, "tree", 4)) ||
1430                (len == 6 && !memcmp(field, "parent", 6)) ||
1431                (len == 6 && !memcmp(field, "author", 6)) ||
1432                (len == 9 && !memcmp(field, "committer", 9)) ||
1433                (len == 8 && !memcmp(field, "encoding", 8)));
1434}
1435
1436static int excluded_header_field(const char *field, size_t len, const char **exclude)
1437{
1438        if (!exclude)
1439                return 0;
1440
1441        while (*exclude) {
1442                size_t xlen = strlen(*exclude);
1443                if (len == xlen && !memcmp(field, *exclude, xlen))
1444                        return 1;
1445                exclude++;
1446        }
1447        return 0;
1448}
1449
1450static struct commit_extra_header *read_commit_extra_header_lines(
1451        const char *buffer, size_t size,
1452        const char **exclude)
1453{
1454        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1455        const char *line, *next, *eof, *eob;
1456        struct strbuf buf = STRBUF_INIT;
1457
1458        for (line = buffer, eob = line + size;
1459             line < eob && *line != '\n';
1460             line = next) {
1461                next = memchr(line, '\n', eob - line);
1462                next = next ? next + 1 : eob;
1463                if (*line == ' ') {
1464                        /* continuation */
1465                        if (it)
1466                                strbuf_add(&buf, line + 1, next - (line + 1));
1467                        continue;
1468                }
1469                if (it)
1470                        it->value = strbuf_detach(&buf, &it->len);
1471                strbuf_reset(&buf);
1472                it = NULL;
1473
1474                eof = memchr(line, ' ', next - line);
1475                if (!eof)
1476                        eof = next;
1477                else if (standard_header_field(line, eof - line) ||
1478                         excluded_header_field(line, eof - line, exclude))
1479                        continue;
1480
1481                it = xcalloc(1, sizeof(*it));
1482                it->key = xmemdupz(line, eof-line);
1483                *tail = it;
1484                tail = &it->next;
1485                if (eof + 1 < next)
1486                        strbuf_add(&buf, eof + 1, next - (eof + 1));
1487        }
1488        if (it)
1489                it->value = strbuf_detach(&buf, &it->len);
1490        return extra;
1491}
1492
1493void free_commit_extra_headers(struct commit_extra_header *extra)
1494{
1495        while (extra) {
1496                struct commit_extra_header *next = extra->next;
1497                free(extra->key);
1498                free(extra->value);
1499                free(extra);
1500                extra = next;
1501        }
1502}
1503
1504int commit_tree(const char *msg, size_t msg_len, const struct object_id *tree,
1505                struct commit_list *parents, struct object_id *ret,
1506                const char *author, const char *sign_commit)
1507{
1508        struct commit_extra_header *extra = NULL, **tail = &extra;
1509        int result;
1510
1511        append_merge_tag_headers(parents, &tail);
1512        result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1513                                      author, sign_commit, extra);
1514        free_commit_extra_headers(extra);
1515        return result;
1516}
1517
1518static int find_invalid_utf8(const char *buf, int len)
1519{
1520        int offset = 0;
1521        static const unsigned int max_codepoint[] = {
1522                0x7f, 0x7ff, 0xffff, 0x10ffff
1523        };
1524
1525        while (len) {
1526                unsigned char c = *buf++;
1527                int bytes, bad_offset;
1528                unsigned int codepoint;
1529                unsigned int min_val, max_val;
1530
1531                len--;
1532                offset++;
1533
1534                /* Simple US-ASCII? No worries. */
1535                if (c < 0x80)
1536                        continue;
1537
1538                bad_offset = offset-1;
1539
1540                /*
1541                 * Count how many more high bits set: that's how
1542                 * many more bytes this sequence should have.
1543                 */
1544                bytes = 0;
1545                while (c & 0x40) {
1546                        c <<= 1;
1547                        bytes++;
1548                }
1549
1550                /*
1551                 * Must be between 1 and 3 more bytes.  Longer sequences result in
1552                 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1553                 */
1554                if (bytes < 1 || 3 < bytes)
1555                        return bad_offset;
1556
1557                /* Do we *have* that many bytes? */
1558                if (len < bytes)
1559                        return bad_offset;
1560
1561                /*
1562                 * Place the encoded bits at the bottom of the value and compute the
1563                 * valid range.
1564                 */
1565                codepoint = (c & 0x7f) >> bytes;
1566                min_val = max_codepoint[bytes-1] + 1;
1567                max_val = max_codepoint[bytes];
1568
1569                offset += bytes;
1570                len -= bytes;
1571
1572                /* And verify that they are good continuation bytes */
1573                do {
1574                        codepoint <<= 6;
1575                        codepoint |= *buf & 0x3f;
1576                        if ((*buf++ & 0xc0) != 0x80)
1577                                return bad_offset;
1578                } while (--bytes);
1579
1580                /* Reject codepoints that are out of range for the sequence length. */
1581                if (codepoint < min_val || codepoint > max_val)
1582                        return bad_offset;
1583                /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1584                if ((codepoint & 0x1ff800) == 0xd800)
1585                        return bad_offset;
1586                /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1587                if ((codepoint & 0xfffe) == 0xfffe)
1588                        return bad_offset;
1589                /* So are anything in the range U+FDD0..U+FDEF. */
1590                if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1591                        return bad_offset;
1592        }
1593        return -1;
1594}
1595
1596/*
1597 * This verifies that the buffer is in proper utf8 format.
1598 *
1599 * If it isn't, it assumes any non-utf8 characters are Latin1,
1600 * and does the conversion.
1601 */
1602static int verify_utf8(struct strbuf *buf)
1603{
1604        int ok = 1;
1605        long pos = 0;
1606
1607        for (;;) {
1608                int bad;
1609                unsigned char c;
1610                unsigned char replace[2];
1611
1612                bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1613                if (bad < 0)
1614                        return ok;
1615                pos += bad;
1616                ok = 0;
1617                c = buf->buf[pos];
1618                strbuf_remove(buf, pos, 1);
1619
1620                /* We know 'c' must be in the range 128-255 */
1621                replace[0] = 0xc0 + (c >> 6);
1622                replace[1] = 0x80 + (c & 0x3f);
1623                strbuf_insert(buf, pos, replace, 2);
1624                pos += 2;
1625        }
1626}
1627
1628static const char commit_utf8_warn[] =
1629N_("Warning: commit message did not conform to UTF-8.\n"
1630   "You may want to amend it after fixing the message, or set the config\n"
1631   "variable i18n.commitencoding to the encoding your project uses.\n");
1632
1633int commit_tree_extended(const char *msg, size_t msg_len,
1634                         const struct object_id *tree,
1635                         struct commit_list *parents, struct object_id *ret,
1636                         const char *author, const char *sign_commit,
1637                         struct commit_extra_header *extra)
1638{
1639        int result;
1640        int encoding_is_utf8;
1641        struct strbuf buffer;
1642
1643        assert_oid_type(tree, OBJ_TREE);
1644
1645        if (memchr(msg, '\0', msg_len))
1646                return error("a NUL byte in commit log message not allowed.");
1647
1648        /* Not having i18n.commitencoding is the same as having utf-8 */
1649        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1650
1651        strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1652        strbuf_addf(&buffer, "tree %s\n", oid_to_hex(tree));
1653
1654        /*
1655         * NOTE! This ordering means that the same exact tree merged with a
1656         * different order of parents will be a _different_ changeset even
1657         * if everything else stays the same.
1658         */
1659        while (parents) {
1660                struct commit *parent = pop_commit(&parents);
1661                strbuf_addf(&buffer, "parent %s\n",
1662                            oid_to_hex(&parent->object.oid));
1663        }
1664
1665        /* Person/date information */
1666        if (!author)
1667                author = git_author_info(IDENT_STRICT);
1668        strbuf_addf(&buffer, "author %s\n", author);
1669        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1670        if (!encoding_is_utf8)
1671                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1672
1673        while (extra) {
1674                add_extra_header(&buffer, extra);
1675                extra = extra->next;
1676        }
1677        strbuf_addch(&buffer, '\n');
1678
1679        /* And add the comment */
1680        strbuf_add(&buffer, msg, msg_len);
1681
1682        /* And check the encoding */
1683        if (encoding_is_utf8 && !verify_utf8(&buffer))
1684                fprintf(stderr, _(commit_utf8_warn));
1685
1686        if (sign_commit && do_sign_commit(&buffer, sign_commit)) {
1687                result = -1;
1688                goto out;
1689        }
1690
1691        result = write_object_file(buffer.buf, buffer.len, commit_type, ret);
1692out:
1693        strbuf_release(&buffer);
1694        return result;
1695}
1696
1697define_commit_slab(merge_desc_slab, struct merge_remote_desc *);
1698static struct merge_desc_slab merge_desc_slab = COMMIT_SLAB_INIT(1, merge_desc_slab);
1699
1700struct merge_remote_desc *merge_remote_util(struct commit *commit)
1701{
1702        return *merge_desc_slab_at(&merge_desc_slab, commit);
1703}
1704
1705void set_merge_remote_desc(struct commit *commit,
1706                           const char *name, struct object *obj)
1707{
1708        struct merge_remote_desc *desc;
1709        FLEX_ALLOC_STR(desc, name, name);
1710        desc->obj = obj;
1711        *merge_desc_slab_at(&merge_desc_slab, commit) = desc;
1712}
1713
1714struct commit *get_merge_parent(const char *name)
1715{
1716        struct object *obj;
1717        struct commit *commit;
1718        struct object_id oid;
1719        if (get_oid(name, &oid))
1720                return NULL;
1721        obj = parse_object(the_repository, &oid);
1722        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1723        if (commit && !merge_remote_util(commit))
1724                set_merge_remote_desc(commit, name, obj);
1725        return commit;
1726}
1727
1728/*
1729 * Append a commit to the end of the commit_list.
1730 *
1731 * next starts by pointing to the variable that holds the head of an
1732 * empty commit_list, and is updated to point to the "next" field of
1733 * the last item on the list as new commits are appended.
1734 *
1735 * Usage example:
1736 *
1737 *     struct commit_list *list;
1738 *     struct commit_list **next = &list;
1739 *
1740 *     next = commit_list_append(c1, next);
1741 *     next = commit_list_append(c2, next);
1742 *     assert(commit_list_count(list) == 2);
1743 *     return list;
1744 */
1745struct commit_list **commit_list_append(struct commit *commit,
1746                                        struct commit_list **next)
1747{
1748        struct commit_list *new_commit = xmalloc(sizeof(struct commit_list));
1749        new_commit->item = commit;
1750        *next = new_commit;
1751        new_commit->next = NULL;
1752        return &new_commit->next;
1753}
1754
1755const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1756{
1757        int key_len = strlen(key);
1758        const char *line = msg;
1759
1760        while (line) {
1761                const char *eol = strchrnul(line, '\n');
1762
1763                if (line == eol)
1764                        return NULL;
1765
1766                if (eol - line > key_len &&
1767                    !strncmp(line, key, key_len) &&
1768                    line[key_len] == ' ') {
1769                        *out_len = eol - line - key_len - 1;
1770                        return line + key_len + 1;
1771                }
1772                line = *eol ? eol + 1 : NULL;
1773        }
1774        return NULL;
1775}
1776
1777/*
1778 * Inspect the given string and determine the true "end" of the log message, in
1779 * order to find where to put a new Signed-off-by: line.  Ignored are
1780 * trailing comment lines and blank lines.  To support "git commit -s
1781 * --amend" on an existing commit, we also ignore "Conflicts:".  To
1782 * support "git commit -v", we truncate at cut lines.
1783 *
1784 * Returns the number of bytes from the tail to ignore, to be fed as
1785 * the second parameter to append_signoff().
1786 */
1787int ignore_non_trailer(const char *buf, size_t len)
1788{
1789        int boc = 0;
1790        int bol = 0;
1791        int in_old_conflicts_block = 0;
1792        size_t cutoff = wt_status_locate_end(buf, len);
1793
1794        while (bol < cutoff) {
1795                const char *next_line = memchr(buf + bol, '\n', len - bol);
1796
1797                if (!next_line)
1798                        next_line = buf + len;
1799                else
1800                        next_line++;
1801
1802                if (buf[bol] == comment_line_char || buf[bol] == '\n') {
1803                        /* is this the first of the run of comments? */
1804                        if (!boc)
1805                                boc = bol;
1806                        /* otherwise, it is just continuing */
1807                } else if (starts_with(buf + bol, "Conflicts:\n")) {
1808                        in_old_conflicts_block = 1;
1809                        if (!boc)
1810                                boc = bol;
1811                } else if (in_old_conflicts_block && buf[bol] == '\t') {
1812                        ; /* a pathname in the conflicts block */
1813                } else if (boc) {
1814                        /* the previous was not trailing comment */
1815                        boc = 0;
1816                        in_old_conflicts_block = 0;
1817                }
1818                bol = next_line - buf;
1819        }
1820        return boc ? len - boc : len - cutoff;
1821}