Andrew's git / gitweb.git / commit.c
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commit.con commit alloc: allow arbitrary repositories for alloc functions (14ba97f)
   1#include "cache.h"
   2#include "tag.h"
   3#include "commit.h"
   4#include "pkt-line.h"
   5#include "utf8.h"
   6#include "diff.h"
   7#include "revision.h"
   8#include "notes.h"
   9#include "alloc.h"
  10#include "gpg-interface.h"
  11#include "mergesort.h"
  12#include "commit-slab.h"
  13#include "prio-queue.h"
  14#include "sha1-lookup.h"
  15#include "wt-status.h"
  16
  17static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
  18
  19int save_commit_buffer = 1;
  20
  21const char *commit_type = "commit";
  22
  23struct commit *lookup_commit_reference_gently(const struct object_id *oid,
  24                                              int quiet)
  25{
  26        struct object *obj = deref_tag(parse_object(oid), NULL, 0);
  27
  28        if (!obj)
  29                return NULL;
  30        return object_as_type(obj, OBJ_COMMIT, quiet);
  31}
  32
  33struct commit *lookup_commit_reference(const struct object_id *oid)
  34{
  35        return lookup_commit_reference_gently(oid, 0);
  36}
  37
  38struct commit *lookup_commit_or_die(const struct object_id *oid, const char *ref_name)
  39{
  40        struct commit *c = lookup_commit_reference(oid);
  41        if (!c)
  42                die(_("could not parse %s"), ref_name);
  43        if (oidcmp(oid, &c->object.oid)) {
  44                warning(_("%s %s is not a commit!"),
  45                        ref_name, oid_to_hex(oid));
  46        }
  47        return c;
  48}
  49
  50struct commit *lookup_commit(const struct object_id *oid)
  51{
  52        struct object *obj = lookup_object(oid->hash);
  53        if (!obj)
  54                return create_object(the_repository, oid->hash,
  55                                     alloc_commit_node(the_repository));
  56        return object_as_type(obj, OBJ_COMMIT, 0);
  57}
  58
  59struct commit *lookup_commit_reference_by_name(const char *name)
  60{
  61        struct object_id oid;
  62        struct commit *commit;
  63
  64        if (get_oid_committish(name, &oid))
  65                return NULL;
  66        commit = lookup_commit_reference(&oid);
  67        if (parse_commit(commit))
  68                return NULL;
  69        return commit;
  70}
  71
  72static timestamp_t parse_commit_date(const char *buf, const char *tail)
  73{
  74        const char *dateptr;
  75
  76        if (buf + 6 >= tail)
  77                return 0;
  78        if (memcmp(buf, "author", 6))
  79                return 0;
  80        while (buf < tail && *buf++ != '\n')
  81                /* nada */;
  82        if (buf + 9 >= tail)
  83                return 0;
  84        if (memcmp(buf, "committer", 9))
  85                return 0;
  86        while (buf < tail && *buf++ != '>')
  87                /* nada */;
  88        if (buf >= tail)
  89                return 0;
  90        dateptr = buf;
  91        while (buf < tail && *buf++ != '\n')
  92                /* nada */;
  93        if (buf >= tail)
  94                return 0;
  95        /* dateptr < buf && buf[-1] == '\n', so parsing will stop at buf-1 */
  96        return parse_timestamp(dateptr, NULL, 10);
  97}
  98
  99static struct commit_graft **commit_graft;
 100static int commit_graft_alloc, commit_graft_nr;
 101
 102static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
 103{
 104        struct commit_graft **commit_graft_table = table;
 105        return commit_graft_table[index]->oid.hash;
 106}
 107
 108static int commit_graft_pos(const unsigned char *sha1)
 109{
 110        return sha1_pos(sha1, commit_graft, commit_graft_nr,
 111                        commit_graft_sha1_access);
 112}
 113
 114int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 115{
 116        int pos = commit_graft_pos(graft->oid.hash);
 117
 118        if (0 <= pos) {
 119                if (ignore_dups)
 120                        free(graft);
 121                else {
 122                        free(commit_graft[pos]);
 123                        commit_graft[pos] = graft;
 124                }
 125                return 1;
 126        }
 127        pos = -pos - 1;
 128        ALLOC_GROW(commit_graft, commit_graft_nr + 1, commit_graft_alloc);
 129        commit_graft_nr++;
 130        if (pos < commit_graft_nr)
 131                MOVE_ARRAY(commit_graft + pos + 1, commit_graft + pos,
 132                           commit_graft_nr - pos - 1);
 133        commit_graft[pos] = graft;
 134        return 0;
 135}
 136
 137struct commit_graft *read_graft_line(struct strbuf *line)
 138{
 139        /* The format is just "Commit Parent1 Parent2 ...\n" */
 140        int i, phase;
 141        const char *tail = NULL;
 142        struct commit_graft *graft = NULL;
 143        struct object_id dummy_oid, *oid;
 144
 145        strbuf_rtrim(line);
 146        if (!line->len || line->buf[0] == '#')
 147                return NULL;
 148        /*
 149         * phase 0 verifies line, counts hashes in line and allocates graft
 150         * phase 1 fills graft
 151         */
 152        for (phase = 0; phase < 2; phase++) {
 153                oid = graft ? &graft->oid : &dummy_oid;
 154                if (parse_oid_hex(line->buf, oid, &tail))
 155                        goto bad_graft_data;
 156                for (i = 0; *tail != '\0'; i++) {
 157                        oid = graft ? &graft->parent[i] : &dummy_oid;
 158                        if (!isspace(*tail++) || parse_oid_hex(tail, oid, &tail))
 159                                goto bad_graft_data;
 160                }
 161                if (!graft) {
 162                        graft = xmalloc(st_add(sizeof(*graft),
 163                                               st_mult(sizeof(struct object_id), i)));
 164                        graft->nr_parent = i;
 165                }
 166        }
 167        return graft;
 168
 169bad_graft_data:
 170        error("bad graft data: %s", line->buf);
 171        assert(!graft);
 172        return NULL;
 173}
 174
 175static int read_graft_file(const char *graft_file)
 176{
 177        FILE *fp = fopen_or_warn(graft_file, "r");
 178        struct strbuf buf = STRBUF_INIT;
 179        if (!fp)
 180                return -1;
 181        while (!strbuf_getwholeline(&buf, fp, '\n')) {
 182                /* The format is just "Commit Parent1 Parent2 ...\n" */
 183                struct commit_graft *graft = read_graft_line(&buf);
 184                if (!graft)
 185                        continue;
 186                if (register_commit_graft(graft, 1))
 187                        error("duplicate graft data: %s", buf.buf);
 188        }
 189        fclose(fp);
 190        strbuf_release(&buf);
 191        return 0;
 192}
 193
 194static void prepare_commit_graft(void)
 195{
 196        static int commit_graft_prepared;
 197        char *graft_file;
 198
 199        if (commit_graft_prepared)
 200                return;
 201        graft_file = get_graft_file();
 202        read_graft_file(graft_file);
 203        /* make sure shallows are read */
 204        is_repository_shallow();
 205        commit_graft_prepared = 1;
 206}
 207
 208struct commit_graft *lookup_commit_graft(const struct object_id *oid)
 209{
 210        int pos;
 211        prepare_commit_graft();
 212        pos = commit_graft_pos(oid->hash);
 213        if (pos < 0)
 214                return NULL;
 215        return commit_graft[pos];
 216}
 217
 218int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
 219{
 220        int i, ret;
 221        for (i = ret = 0; i < commit_graft_nr && !ret; i++)
 222                ret = fn(commit_graft[i], cb_data);
 223        return ret;
 224}
 225
 226int unregister_shallow(const struct object_id *oid)
 227{
 228        int pos = commit_graft_pos(oid->hash);
 229        if (pos < 0)
 230                return -1;
 231        if (pos + 1 < commit_graft_nr)
 232                MOVE_ARRAY(commit_graft + pos, commit_graft + pos + 1,
 233                           commit_graft_nr - pos - 1);
 234        commit_graft_nr--;
 235        return 0;
 236}
 237
 238struct commit_buffer {
 239        void *buffer;
 240        unsigned long size;
 241};
 242define_commit_slab(buffer_slab, struct commit_buffer);
 243static struct buffer_slab buffer_slab = COMMIT_SLAB_INIT(1, buffer_slab);
 244
 245void set_commit_buffer(struct commit *commit, void *buffer, unsigned long size)
 246{
 247        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 248        v->buffer = buffer;
 249        v->size = size;
 250}
 251
 252const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
 253{
 254        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 255        if (!v) {
 256                if (sizep)
 257                        *sizep = 0;
 258                return NULL;
 259        }
 260        if (sizep)
 261                *sizep = v->size;
 262        return v->buffer;
 263}
 264
 265const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
 266{
 267        const void *ret = get_cached_commit_buffer(commit, sizep);
 268        if (!ret) {
 269                enum object_type type;
 270                unsigned long size;
 271                ret = read_object_file(&commit->object.oid, &type, &size);
 272                if (!ret)
 273                        die("cannot read commit object %s",
 274                            oid_to_hex(&commit->object.oid));
 275                if (type != OBJ_COMMIT)
 276                        die("expected commit for %s, got %s",
 277                            oid_to_hex(&commit->object.oid), type_name(type));
 278                if (sizep)
 279                        *sizep = size;
 280        }
 281        return ret;
 282}
 283
 284void unuse_commit_buffer(const struct commit *commit, const void *buffer)
 285{
 286        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 287        if (!(v && v->buffer == buffer))
 288                free((void *)buffer);
 289}
 290
 291void free_commit_buffer(struct commit *commit)
 292{
 293        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 294        if (v) {
 295                FREE_AND_NULL(v->buffer);
 296                v->size = 0;
 297        }
 298}
 299
 300void release_commit_memory(struct commit *c)
 301{
 302        c->tree = NULL;
 303        c->index = 0;
 304        free_commit_buffer(c);
 305        free_commit_list(c->parents);
 306        /* TODO: what about commit->util? */
 307
 308        c->object.parsed = 0;
 309}
 310
 311const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 312{
 313        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 314        void *ret;
 315
 316        if (!v) {
 317                if (sizep)
 318                        *sizep = 0;
 319                return NULL;
 320        }
 321        ret = v->buffer;
 322        if (sizep)
 323                *sizep = v->size;
 324
 325        v->buffer = NULL;
 326        v->size = 0;
 327        return ret;
 328}
 329
 330int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
 331{
 332        const char *tail = buffer;
 333        const char *bufptr = buffer;
 334        struct object_id parent;
 335        struct commit_list **pptr;
 336        struct commit_graft *graft;
 337        const int tree_entry_len = GIT_SHA1_HEXSZ + 5;
 338        const int parent_entry_len = GIT_SHA1_HEXSZ + 7;
 339
 340        if (item->object.parsed)
 341                return 0;
 342        item->object.parsed = 1;
 343        tail += size;
 344        if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
 345                        bufptr[tree_entry_len] != '\n')
 346                return error("bogus commit object %s", oid_to_hex(&item->object.oid));
 347        if (get_sha1_hex(bufptr + 5, parent.hash) < 0)
 348                return error("bad tree pointer in commit %s",
 349                             oid_to_hex(&item->object.oid));
 350        item->tree = lookup_tree(&parent);
 351        bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
 352        pptr = &item->parents;
 353
 354        graft = lookup_commit_graft(&item->object.oid);
 355        while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
 356                struct commit *new_parent;
 357
 358                if (tail <= bufptr + parent_entry_len + 1 ||
 359                    get_sha1_hex(bufptr + 7, parent.hash) ||
 360                    bufptr[parent_entry_len] != '\n')
 361                        return error("bad parents in commit %s", oid_to_hex(&item->object.oid));
 362                bufptr += parent_entry_len + 1;
 363                /*
 364                 * The clone is shallow if nr_parent < 0, and we must
 365                 * not traverse its real parents even when we unhide them.
 366                 */
 367                if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
 368                        continue;
 369                new_parent = lookup_commit(&parent);
 370                if (new_parent)
 371                        pptr = &commit_list_insert(new_parent, pptr)->next;
 372        }
 373        if (graft) {
 374                int i;
 375                struct commit *new_parent;
 376                for (i = 0; i < graft->nr_parent; i++) {
 377                        new_parent = lookup_commit(&graft->parent[i]);
 378                        if (!new_parent)
 379                                continue;
 380                        pptr = &commit_list_insert(new_parent, pptr)->next;
 381                }
 382        }
 383        item->date = parse_commit_date(bufptr, tail);
 384
 385        return 0;
 386}
 387
 388int parse_commit_gently(struct commit *item, int quiet_on_missing)
 389{
 390        enum object_type type;
 391        void *buffer;
 392        unsigned long size;
 393        int ret;
 394
 395        if (!item)
 396                return -1;
 397        if (item->object.parsed)
 398                return 0;
 399        buffer = read_object_file(&item->object.oid, &type, &size);
 400        if (!buffer)
 401                return quiet_on_missing ? -1 :
 402                        error("Could not read %s",
 403                             oid_to_hex(&item->object.oid));
 404        if (type != OBJ_COMMIT) {
 405                free(buffer);
 406                return error("Object %s not a commit",
 407                             oid_to_hex(&item->object.oid));
 408        }
 409        ret = parse_commit_buffer(item, buffer, size);
 410        if (save_commit_buffer && !ret) {
 411                set_commit_buffer(item, buffer, size);
 412                return 0;
 413        }
 414        free(buffer);
 415        return ret;
 416}
 417
 418void parse_commit_or_die(struct commit *item)
 419{
 420        if (parse_commit(item))
 421                die("unable to parse commit %s",
 422                    item ? oid_to_hex(&item->object.oid) : "(null)");
 423}
 424
 425int find_commit_subject(const char *commit_buffer, const char **subject)
 426{
 427        const char *eol;
 428        const char *p = commit_buffer;
 429
 430        while (*p && (*p != '\n' || p[1] != '\n'))
 431                p++;
 432        if (*p) {
 433                p = skip_blank_lines(p + 2);
 434                eol = strchrnul(p, '\n');
 435        } else
 436                eol = p;
 437
 438        *subject = p;
 439
 440        return eol - p;
 441}
 442
 443struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 444{
 445        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 446        new_list->item = item;
 447        new_list->next = *list_p;
 448        *list_p = new_list;
 449        return new_list;
 450}
 451
 452unsigned commit_list_count(const struct commit_list *l)
 453{
 454        unsigned c = 0;
 455        for (; l; l = l->next )
 456                c++;
 457        return c;
 458}
 459
 460struct commit_list *copy_commit_list(struct commit_list *list)
 461{
 462        struct commit_list *head = NULL;
 463        struct commit_list **pp = &head;
 464        while (list) {
 465                pp = commit_list_append(list->item, pp);
 466                list = list->next;
 467        }
 468        return head;
 469}
 470
 471void free_commit_list(struct commit_list *list)
 472{
 473        while (list)
 474                pop_commit(&list);
 475}
 476
 477struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 478{
 479        struct commit_list **pp = list;
 480        struct commit_list *p;
 481        while ((p = *pp) != NULL) {
 482                if (p->item->date < item->date) {
 483                        break;
 484                }
 485                pp = &p->next;
 486        }
 487        return commit_list_insert(item, pp);
 488}
 489
 490static int commit_list_compare_by_date(const void *a, const void *b)
 491{
 492        timestamp_t a_date = ((const struct commit_list *)a)->item->date;
 493        timestamp_t b_date = ((const struct commit_list *)b)->item->date;
 494        if (a_date < b_date)
 495                return 1;
 496        if (a_date > b_date)
 497                return -1;
 498        return 0;
 499}
 500
 501static void *commit_list_get_next(const void *a)
 502{
 503        return ((const struct commit_list *)a)->next;
 504}
 505
 506static void commit_list_set_next(void *a, void *next)
 507{
 508        ((struct commit_list *)a)->next = next;
 509}
 510
 511void commit_list_sort_by_date(struct commit_list **list)
 512{
 513        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 514                                commit_list_compare_by_date);
 515}
 516
 517struct commit *pop_most_recent_commit(struct commit_list **list,
 518                                      unsigned int mark)
 519{
 520        struct commit *ret = pop_commit(list);
 521        struct commit_list *parents = ret->parents;
 522
 523        while (parents) {
 524                struct commit *commit = parents->item;
 525                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 526                        commit->object.flags |= mark;
 527                        commit_list_insert_by_date(commit, list);
 528                }
 529                parents = parents->next;
 530        }
 531        return ret;
 532}
 533
 534static void clear_commit_marks_1(struct commit_list **plist,
 535                                 struct commit *commit, unsigned int mark)
 536{
 537        while (commit) {
 538                struct commit_list *parents;
 539
 540                if (!(mark & commit->object.flags))
 541                        return;
 542
 543                commit->object.flags &= ~mark;
 544
 545                parents = commit->parents;
 546                if (!parents)
 547                        return;
 548
 549                while ((parents = parents->next))
 550                        commit_list_insert(parents->item, plist);
 551
 552                commit = commit->parents->item;
 553        }
 554}
 555
 556void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 557{
 558        struct commit_list *list = NULL;
 559
 560        while (nr--) {
 561                clear_commit_marks_1(&list, *commit, mark);
 562                commit++;
 563        }
 564        while (list)
 565                clear_commit_marks_1(&list, pop_commit(&list), mark);
 566}
 567
 568void clear_commit_marks(struct commit *commit, unsigned int mark)
 569{
 570        clear_commit_marks_many(1, &commit, mark);
 571}
 572
 573struct commit *pop_commit(struct commit_list **stack)
 574{
 575        struct commit_list *top = *stack;
 576        struct commit *item = top ? top->item : NULL;
 577
 578        if (top) {
 579                *stack = top->next;
 580                free(top);
 581        }
 582        return item;
 583}
 584
 585/*
 586 * Topological sort support
 587 */
 588
 589/* count number of children that have not been emitted */
 590define_commit_slab(indegree_slab, int);
 591
 592/* record author-date for each commit object */
 593define_commit_slab(author_date_slab, unsigned long);
 594
 595static void record_author_date(struct author_date_slab *author_date,
 596                               struct commit *commit)
 597{
 598        const char *buffer = get_commit_buffer(commit, NULL);
 599        struct ident_split ident;
 600        const char *ident_line;
 601        size_t ident_len;
 602        char *date_end;
 603        timestamp_t date;
 604
 605        ident_line = find_commit_header(buffer, "author", &ident_len);
 606        if (!ident_line)
 607                goto fail_exit; /* no author line */
 608        if (split_ident_line(&ident, ident_line, ident_len) ||
 609            !ident.date_begin || !ident.date_end)
 610                goto fail_exit; /* malformed "author" line */
 611
 612        date = parse_timestamp(ident.date_begin, &date_end, 10);
 613        if (date_end != ident.date_end)
 614                goto fail_exit; /* malformed date */
 615        *(author_date_slab_at(author_date, commit)) = date;
 616
 617fail_exit:
 618        unuse_commit_buffer(commit, buffer);
 619}
 620
 621static int compare_commits_by_author_date(const void *a_, const void *b_,
 622                                          void *cb_data)
 623{
 624        const struct commit *a = a_, *b = b_;
 625        struct author_date_slab *author_date = cb_data;
 626        timestamp_t a_date = *(author_date_slab_at(author_date, a));
 627        timestamp_t b_date = *(author_date_slab_at(author_date, b));
 628
 629        /* newer commits with larger date first */
 630        if (a_date < b_date)
 631                return 1;
 632        else if (a_date > b_date)
 633                return -1;
 634        return 0;
 635}
 636
 637int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 638{
 639        const struct commit *a = a_, *b = b_;
 640        /* newer commits with larger date first */
 641        if (a->date < b->date)
 642                return 1;
 643        else if (a->date > b->date)
 644                return -1;
 645        return 0;
 646}
 647
 648/*
 649 * Performs an in-place topological sort on the list supplied.
 650 */
 651void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 652{
 653        struct commit_list *next, *orig = *list;
 654        struct commit_list **pptr;
 655        struct indegree_slab indegree;
 656        struct prio_queue queue;
 657        struct commit *commit;
 658        struct author_date_slab author_date;
 659
 660        if (!orig)
 661                return;
 662        *list = NULL;
 663
 664        init_indegree_slab(&indegree);
 665        memset(&queue, '\0', sizeof(queue));
 666
 667        switch (sort_order) {
 668        default: /* REV_SORT_IN_GRAPH_ORDER */
 669                queue.compare = NULL;
 670                break;
 671        case REV_SORT_BY_COMMIT_DATE:
 672                queue.compare = compare_commits_by_commit_date;
 673                break;
 674        case REV_SORT_BY_AUTHOR_DATE:
 675                init_author_date_slab(&author_date);
 676                queue.compare = compare_commits_by_author_date;
 677                queue.cb_data = &author_date;
 678                break;
 679        }
 680
 681        /* Mark them and clear the indegree */
 682        for (next = orig; next; next = next->next) {
 683                struct commit *commit = next->item;
 684                *(indegree_slab_at(&indegree, commit)) = 1;
 685                /* also record the author dates, if needed */
 686                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 687                        record_author_date(&author_date, commit);
 688        }
 689
 690        /* update the indegree */
 691        for (next = orig; next; next = next->next) {
 692                struct commit_list *parents = next->item->parents;
 693                while (parents) {
 694                        struct commit *parent = parents->item;
 695                        int *pi = indegree_slab_at(&indegree, parent);
 696
 697                        if (*pi)
 698                                (*pi)++;
 699                        parents = parents->next;
 700                }
 701        }
 702
 703        /*
 704         * find the tips
 705         *
 706         * tips are nodes not reachable from any other node in the list
 707         *
 708         * the tips serve as a starting set for the work queue.
 709         */
 710        for (next = orig; next; next = next->next) {
 711                struct commit *commit = next->item;
 712
 713                if (*(indegree_slab_at(&indegree, commit)) == 1)
 714                        prio_queue_put(&queue, commit);
 715        }
 716
 717        /*
 718         * This is unfortunate; the initial tips need to be shown
 719         * in the order given from the revision traversal machinery.
 720         */
 721        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 722                prio_queue_reverse(&queue);
 723
 724        /* We no longer need the commit list */
 725        free_commit_list(orig);
 726
 727        pptr = list;
 728        *list = NULL;
 729        while ((commit = prio_queue_get(&queue)) != NULL) {
 730                struct commit_list *parents;
 731
 732                for (parents = commit->parents; parents ; parents = parents->next) {
 733                        struct commit *parent = parents->item;
 734                        int *pi = indegree_slab_at(&indegree, parent);
 735
 736                        if (!*pi)
 737                                continue;
 738
 739                        /*
 740                         * parents are only enqueued for emission
 741                         * when all their children have been emitted thereby
 742                         * guaranteeing topological order.
 743                         */
 744                        if (--(*pi) == 1)
 745                                prio_queue_put(&queue, parent);
 746                }
 747                /*
 748                 * all children of commit have already been
 749                 * emitted. we can emit it now.
 750                 */
 751                *(indegree_slab_at(&indegree, commit)) = 0;
 752
 753                pptr = &commit_list_insert(commit, pptr)->next;
 754        }
 755
 756        clear_indegree_slab(&indegree);
 757        clear_prio_queue(&queue);
 758        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 759                clear_author_date_slab(&author_date);
 760}
 761
 762/* merge-base stuff */
 763
 764/* Remember to update object flag allocation in object.h */
 765#define PARENT1         (1u<<16)
 766#define PARENT2         (1u<<17)
 767#define STALE           (1u<<18)
 768#define RESULT          (1u<<19)
 769
 770static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 771
 772static int queue_has_nonstale(struct prio_queue *queue)
 773{
 774        int i;
 775        for (i = 0; i < queue->nr; i++) {
 776                struct commit *commit = queue->array[i].data;
 777                if (!(commit->object.flags & STALE))
 778                        return 1;
 779        }
 780        return 0;
 781}
 782
 783/* all input commits in one and twos[] must have been parsed! */
 784static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
 785{
 786        struct prio_queue queue = { compare_commits_by_commit_date };
 787        struct commit_list *result = NULL;
 788        int i;
 789
 790        one->object.flags |= PARENT1;
 791        if (!n) {
 792                commit_list_append(one, &result);
 793                return result;
 794        }
 795        prio_queue_put(&queue, one);
 796
 797        for (i = 0; i < n; i++) {
 798                twos[i]->object.flags |= PARENT2;
 799                prio_queue_put(&queue, twos[i]);
 800        }
 801
 802        while (queue_has_nonstale(&queue)) {
 803                struct commit *commit = prio_queue_get(&queue);
 804                struct commit_list *parents;
 805                int flags;
 806
 807                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 808                if (flags == (PARENT1 | PARENT2)) {
 809                        if (!(commit->object.flags & RESULT)) {
 810                                commit->object.flags |= RESULT;
 811                                commit_list_insert_by_date(commit, &result);
 812                        }
 813                        /* Mark parents of a found merge stale */
 814                        flags |= STALE;
 815                }
 816                parents = commit->parents;
 817                while (parents) {
 818                        struct commit *p = parents->item;
 819                        parents = parents->next;
 820                        if ((p->object.flags & flags) == flags)
 821                                continue;
 822                        if (parse_commit(p))
 823                                return NULL;
 824                        p->object.flags |= flags;
 825                        prio_queue_put(&queue, p);
 826                }
 827        }
 828
 829        clear_prio_queue(&queue);
 830        return result;
 831}
 832
 833static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 834{
 835        struct commit_list *list = NULL;
 836        struct commit_list *result = NULL;
 837        int i;
 838
 839        for (i = 0; i < n; i++) {
 840                if (one == twos[i])
 841                        /*
 842                         * We do not mark this even with RESULT so we do not
 843                         * have to clean it up.
 844                         */
 845                        return commit_list_insert(one, &result);
 846        }
 847
 848        if (parse_commit(one))
 849                return NULL;
 850        for (i = 0; i < n; i++) {
 851                if (parse_commit(twos[i]))
 852                        return NULL;
 853        }
 854
 855        list = paint_down_to_common(one, n, twos);
 856
 857        while (list) {
 858                struct commit *commit = pop_commit(&list);
 859                if (!(commit->object.flags & STALE))
 860                        commit_list_insert_by_date(commit, &result);
 861        }
 862        return result;
 863}
 864
 865struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 866{
 867        struct commit_list *i, *j, *k, *ret = NULL;
 868
 869        if (!in)
 870                return ret;
 871
 872        commit_list_insert(in->item, &ret);
 873
 874        for (i = in->next; i; i = i->next) {
 875                struct commit_list *new_commits = NULL, *end = NULL;
 876
 877                for (j = ret; j; j = j->next) {
 878                        struct commit_list *bases;
 879                        bases = get_merge_bases(i->item, j->item);
 880                        if (!new_commits)
 881                                new_commits = bases;
 882                        else
 883                                end->next = bases;
 884                        for (k = bases; k; k = k->next)
 885                                end = k;
 886                }
 887                ret = new_commits;
 888        }
 889        return ret;
 890}
 891
 892static int remove_redundant(struct commit **array, int cnt)
 893{
 894        /*
 895         * Some commit in the array may be an ancestor of
 896         * another commit.  Move such commit to the end of
 897         * the array, and return the number of commits that
 898         * are independent from each other.
 899         */
 900        struct commit **work;
 901        unsigned char *redundant;
 902        int *filled_index;
 903        int i, j, filled;
 904
 905        work = xcalloc(cnt, sizeof(*work));
 906        redundant = xcalloc(cnt, 1);
 907        ALLOC_ARRAY(filled_index, cnt - 1);
 908
 909        for (i = 0; i < cnt; i++)
 910                parse_commit(array[i]);
 911        for (i = 0; i < cnt; i++) {
 912                struct commit_list *common;
 913
 914                if (redundant[i])
 915                        continue;
 916                for (j = filled = 0; j < cnt; j++) {
 917                        if (i == j || redundant[j])
 918                                continue;
 919                        filled_index[filled] = j;
 920                        work[filled++] = array[j];
 921                }
 922                common = paint_down_to_common(array[i], filled, work);
 923                if (array[i]->object.flags & PARENT2)
 924                        redundant[i] = 1;
 925                for (j = 0; j < filled; j++)
 926                        if (work[j]->object.flags & PARENT1)
 927                                redundant[filled_index[j]] = 1;
 928                clear_commit_marks(array[i], all_flags);
 929                clear_commit_marks_many(filled, work, all_flags);
 930                free_commit_list(common);
 931        }
 932
 933        /* Now collect the result */
 934        COPY_ARRAY(work, array, cnt);
 935        for (i = filled = 0; i < cnt; i++)
 936                if (!redundant[i])
 937                        array[filled++] = work[i];
 938        for (j = filled, i = 0; i < cnt; i++)
 939                if (redundant[i])
 940                        array[j++] = work[i];
 941        free(work);
 942        free(redundant);
 943        free(filled_index);
 944        return filled;
 945}
 946
 947static struct commit_list *get_merge_bases_many_0(struct commit *one,
 948                                                  int n,
 949                                                  struct commit **twos,
 950                                                  int cleanup)
 951{
 952        struct commit_list *list;
 953        struct commit **rslt;
 954        struct commit_list *result;
 955        int cnt, i;
 956
 957        result = merge_bases_many(one, n, twos);
 958        for (i = 0; i < n; i++) {
 959                if (one == twos[i])
 960                        return result;
 961        }
 962        if (!result || !result->next) {
 963                if (cleanup) {
 964                        clear_commit_marks(one, all_flags);
 965                        clear_commit_marks_many(n, twos, all_flags);
 966                }
 967                return result;
 968        }
 969
 970        /* There are more than one */
 971        cnt = commit_list_count(result);
 972        rslt = xcalloc(cnt, sizeof(*rslt));
 973        for (list = result, i = 0; list; list = list->next)
 974                rslt[i++] = list->item;
 975        free_commit_list(result);
 976
 977        clear_commit_marks(one, all_flags);
 978        clear_commit_marks_many(n, twos, all_flags);
 979
 980        cnt = remove_redundant(rslt, cnt);
 981        result = NULL;
 982        for (i = 0; i < cnt; i++)
 983                commit_list_insert_by_date(rslt[i], &result);
 984        free(rslt);
 985        return result;
 986}
 987
 988struct commit_list *get_merge_bases_many(struct commit *one,
 989                                         int n,
 990                                         struct commit **twos)
 991{
 992        return get_merge_bases_many_0(one, n, twos, 1);
 993}
 994
 995struct commit_list *get_merge_bases_many_dirty(struct commit *one,
 996                                               int n,
 997                                               struct commit **twos)
 998{
 999        return get_merge_bases_many_0(one, n, twos, 0);
1000}
1001
1002struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
1003{
1004        return get_merge_bases_many_0(one, 1, &two, 1);
1005}
1006
1007/*
1008 * Is "commit" a descendant of one of the elements on the "with_commit" list?
1009 */
1010int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
1011{
1012        if (!with_commit)
1013                return 1;
1014        while (with_commit) {
1015                struct commit *other;
1016
1017                other = with_commit->item;
1018                with_commit = with_commit->next;
1019                if (in_merge_bases(other, commit))
1020                        return 1;
1021        }
1022        return 0;
1023}
1024
1025/*
1026 * Is "commit" an ancestor of one of the "references"?
1027 */
1028int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1029{
1030        struct commit_list *bases;
1031        int ret = 0, i;
1032
1033        if (parse_commit(commit))
1034                return ret;
1035        for (i = 0; i < nr_reference; i++)
1036                if (parse_commit(reference[i]))
1037                        return ret;
1038
1039        bases = paint_down_to_common(commit, nr_reference, reference);
1040        if (commit->object.flags & PARENT2)
1041                ret = 1;
1042        clear_commit_marks(commit, all_flags);
1043        clear_commit_marks_many(nr_reference, reference, all_flags);
1044        free_commit_list(bases);
1045        return ret;
1046}
1047
1048/*
1049 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1050 */
1051int in_merge_bases(struct commit *commit, struct commit *reference)
1052{
1053        return in_merge_bases_many(commit, 1, &reference);
1054}
1055
1056struct commit_list *reduce_heads(struct commit_list *heads)
1057{
1058        struct commit_list *p;
1059        struct commit_list *result = NULL, **tail = &result;
1060        struct commit **array;
1061        int num_head, i;
1062
1063        if (!heads)
1064                return NULL;
1065
1066        /* Uniquify */
1067        for (p = heads; p; p = p->next)
1068                p->item->object.flags &= ~STALE;
1069        for (p = heads, num_head = 0; p; p = p->next) {
1070                if (p->item->object.flags & STALE)
1071                        continue;
1072                p->item->object.flags |= STALE;
1073                num_head++;
1074        }
1075        array = xcalloc(num_head, sizeof(*array));
1076        for (p = heads, i = 0; p; p = p->next) {
1077                if (p->item->object.flags & STALE) {
1078                        array[i++] = p->item;
1079                        p->item->object.flags &= ~STALE;
1080                }
1081        }
1082        num_head = remove_redundant(array, num_head);
1083        for (i = 0; i < num_head; i++)
1084                tail = &commit_list_insert(array[i], tail)->next;
1085        free(array);
1086        return result;
1087}
1088
1089void reduce_heads_replace(struct commit_list **heads)
1090{
1091        struct commit_list *result = reduce_heads(*heads);
1092        free_commit_list(*heads);
1093        *heads = result;
1094}
1095
1096static const char gpg_sig_header[] = "gpgsig";
1097static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1098
1099static int do_sign_commit(struct strbuf *buf, const char *keyid)
1100{
1101        struct strbuf sig = STRBUF_INIT;
1102        int inspos, copypos;
1103        const char *eoh;
1104
1105        /* find the end of the header */
1106        eoh = strstr(buf->buf, "\n\n");
1107        if (!eoh)
1108                inspos = buf->len;
1109        else
1110                inspos = eoh - buf->buf + 1;
1111
1112        if (!keyid || !*keyid)
1113                keyid = get_signing_key();
1114        if (sign_buffer(buf, &sig, keyid)) {
1115                strbuf_release(&sig);
1116                return -1;
1117        }
1118
1119        for (copypos = 0; sig.buf[copypos]; ) {
1120                const char *bol = sig.buf + copypos;
1121                const char *eol = strchrnul(bol, '\n');
1122                int len = (eol - bol) + !!*eol;
1123
1124                if (!copypos) {
1125                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1126                        inspos += gpg_sig_header_len;
1127                }
1128                strbuf_insert(buf, inspos++, " ", 1);
1129                strbuf_insert(buf, inspos, bol, len);
1130                inspos += len;
1131                copypos += len;
1132        }
1133        strbuf_release(&sig);
1134        return 0;
1135}
1136
1137int parse_signed_commit(const struct commit *commit,
1138                        struct strbuf *payload, struct strbuf *signature)
1139{
1140
1141        unsigned long size;
1142        const char *buffer = get_commit_buffer(commit, &size);
1143        int in_signature, saw_signature = -1;
1144        const char *line, *tail;
1145
1146        line = buffer;
1147        tail = buffer + size;
1148        in_signature = 0;
1149        saw_signature = 0;
1150        while (line < tail) {
1151                const char *sig = NULL;
1152                const char *next = memchr(line, '\n', tail - line);
1153
1154                next = next ? next + 1 : tail;
1155                if (in_signature && line[0] == ' ')
1156                        sig = line + 1;
1157                else if (starts_with(line, gpg_sig_header) &&
1158                         line[gpg_sig_header_len] == ' ')
1159                        sig = line + gpg_sig_header_len + 1;
1160                if (sig) {
1161                        strbuf_add(signature, sig, next - sig);
1162                        saw_signature = 1;
1163                        in_signature = 1;
1164                } else {
1165                        if (*line == '\n')
1166                                /* dump the whole remainder of the buffer */
1167                                next = tail;
1168                        strbuf_add(payload, line, next - line);
1169                        in_signature = 0;
1170                }
1171                line = next;
1172        }
1173        unuse_commit_buffer(commit, buffer);
1174        return saw_signature;
1175}
1176
1177int remove_signature(struct strbuf *buf)
1178{
1179        const char *line = buf->buf;
1180        const char *tail = buf->buf + buf->len;
1181        int in_signature = 0;
1182        const char *sig_start = NULL;
1183        const char *sig_end = NULL;
1184
1185        while (line < tail) {
1186                const char *next = memchr(line, '\n', tail - line);
1187                next = next ? next + 1 : tail;
1188
1189                if (in_signature && line[0] == ' ')
1190                        sig_end = next;
1191                else if (starts_with(line, gpg_sig_header) &&
1192                         line[gpg_sig_header_len] == ' ') {
1193                        sig_start = line;
1194                        sig_end = next;
1195                        in_signature = 1;
1196                } else {
1197                        if (*line == '\n')
1198                                /* dump the whole remainder of the buffer */
1199                                next = tail;
1200                        in_signature = 0;
1201                }
1202                line = next;
1203        }
1204
1205        if (sig_start)
1206                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1207
1208        return sig_start != NULL;
1209}
1210
1211static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1212{
1213        struct merge_remote_desc *desc;
1214        struct commit_extra_header *mergetag;
1215        char *buf;
1216        unsigned long size, len;
1217        enum object_type type;
1218
1219        desc = merge_remote_util(parent);
1220        if (!desc || !desc->obj)
1221                return;
1222        buf = read_object_file(&desc->obj->oid, &type, &size);
1223        if (!buf || type != OBJ_TAG)
1224                goto free_return;
1225        len = parse_signature(buf, size);
1226        if (size == len)
1227                goto free_return;
1228        /*
1229         * We could verify this signature and either omit the tag when
1230         * it does not validate, but the integrator may not have the
1231         * public key of the signer of the tag he is merging, while a
1232         * later auditor may have it while auditing, so let's not run
1233         * verify-signed-buffer here for now...
1234         *
1235         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1236         *      warn("warning: signed tag unverified.");
1237         */
1238        mergetag = xcalloc(1, sizeof(*mergetag));
1239        mergetag->key = xstrdup("mergetag");
1240        mergetag->value = buf;
1241        mergetag->len = size;
1242
1243        **tail = mergetag;
1244        *tail = &mergetag->next;
1245        return;
1246
1247free_return:
1248        free(buf);
1249}
1250
1251int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1252{
1253        struct strbuf payload = STRBUF_INIT;
1254        struct strbuf signature = STRBUF_INIT;
1255        int ret = 1;
1256
1257        sigc->result = 'N';
1258
1259        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1260                goto out;
1261        ret = check_signature(payload.buf, payload.len, signature.buf,
1262                signature.len, sigc);
1263
1264 out:
1265        strbuf_release(&payload);
1266        strbuf_release(&signature);
1267
1268        return ret;
1269}
1270
1271
1272
1273void append_merge_tag_headers(struct commit_list *parents,
1274                              struct commit_extra_header ***tail)
1275{
1276        while (parents) {
1277                struct commit *parent = parents->item;
1278                handle_signed_tag(parent, tail);
1279                parents = parents->next;
1280        }
1281}
1282
1283static void add_extra_header(struct strbuf *buffer,
1284                             struct commit_extra_header *extra)
1285{
1286        strbuf_addstr(buffer, extra->key);
1287        if (extra->len)
1288                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1289        else
1290                strbuf_addch(buffer, '\n');
1291}
1292
1293struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1294                                                      const char **exclude)
1295{
1296        struct commit_extra_header *extra = NULL;
1297        unsigned long size;
1298        const char *buffer = get_commit_buffer(commit, &size);
1299        extra = read_commit_extra_header_lines(buffer, size, exclude);
1300        unuse_commit_buffer(commit, buffer);
1301        return extra;
1302}
1303
1304void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1305{
1306        struct commit_extra_header *extra, *to_free;
1307
1308        to_free = read_commit_extra_headers(commit, NULL);
1309        for (extra = to_free; extra; extra = extra->next) {
1310                if (strcmp(extra->key, "mergetag"))
1311                        continue; /* not a merge tag */
1312                fn(commit, extra, data);
1313        }
1314        free_commit_extra_headers(to_free);
1315}
1316
1317static inline int standard_header_field(const char *field, size_t len)
1318{
1319        return ((len == 4 && !memcmp(field, "tree", 4)) ||
1320                (len == 6 && !memcmp(field, "parent", 6)) ||
1321                (len == 6 && !memcmp(field, "author", 6)) ||
1322                (len == 9 && !memcmp(field, "committer", 9)) ||
1323                (len == 8 && !memcmp(field, "encoding", 8)));
1324}
1325
1326static int excluded_header_field(const char *field, size_t len, const char **exclude)
1327{
1328        if (!exclude)
1329                return 0;
1330
1331        while (*exclude) {
1332                size_t xlen = strlen(*exclude);
1333                if (len == xlen && !memcmp(field, *exclude, xlen))
1334                        return 1;
1335                exclude++;
1336        }
1337        return 0;
1338}
1339
1340static struct commit_extra_header *read_commit_extra_header_lines(
1341        const char *buffer, size_t size,
1342        const char **exclude)
1343{
1344        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1345        const char *line, *next, *eof, *eob;
1346        struct strbuf buf = STRBUF_INIT;
1347
1348        for (line = buffer, eob = line + size;
1349             line < eob && *line != '\n';
1350             line = next) {
1351                next = memchr(line, '\n', eob - line);
1352                next = next ? next + 1 : eob;
1353                if (*line == ' ') {
1354                        /* continuation */
1355                        if (it)
1356                                strbuf_add(&buf, line + 1, next - (line + 1));
1357                        continue;
1358                }
1359                if (it)
1360                        it->value = strbuf_detach(&buf, &it->len);
1361                strbuf_reset(&buf);
1362                it = NULL;
1363
1364                eof = memchr(line, ' ', next - line);
1365                if (!eof)
1366                        eof = next;
1367                else if (standard_header_field(line, eof - line) ||
1368                         excluded_header_field(line, eof - line, exclude))
1369                        continue;
1370
1371                it = xcalloc(1, sizeof(*it));
1372                it->key = xmemdupz(line, eof-line);
1373                *tail = it;
1374                tail = &it->next;
1375                if (eof + 1 < next)
1376                        strbuf_add(&buf, eof + 1, next - (eof + 1));
1377        }
1378        if (it)
1379                it->value = strbuf_detach(&buf, &it->len);
1380        return extra;
1381}
1382
1383void free_commit_extra_headers(struct commit_extra_header *extra)
1384{
1385        while (extra) {
1386                struct commit_extra_header *next = extra->next;
1387                free(extra->key);
1388                free(extra->value);
1389                free(extra);
1390                extra = next;
1391        }
1392}
1393
1394int commit_tree(const char *msg, size_t msg_len, const struct object_id *tree,
1395                struct commit_list *parents, struct object_id *ret,
1396                const char *author, const char *sign_commit)
1397{
1398        struct commit_extra_header *extra = NULL, **tail = &extra;
1399        int result;
1400
1401        append_merge_tag_headers(parents, &tail);
1402        result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1403                                      author, sign_commit, extra);
1404        free_commit_extra_headers(extra);
1405        return result;
1406}
1407
1408static int find_invalid_utf8(const char *buf, int len)
1409{
1410        int offset = 0;
1411        static const unsigned int max_codepoint[] = {
1412                0x7f, 0x7ff, 0xffff, 0x10ffff
1413        };
1414
1415        while (len) {
1416                unsigned char c = *buf++;
1417                int bytes, bad_offset;
1418                unsigned int codepoint;
1419                unsigned int min_val, max_val;
1420
1421                len--;
1422                offset++;
1423
1424                /* Simple US-ASCII? No worries. */
1425                if (c < 0x80)
1426                        continue;
1427
1428                bad_offset = offset-1;
1429
1430                /*
1431                 * Count how many more high bits set: that's how
1432                 * many more bytes this sequence should have.
1433                 */
1434                bytes = 0;
1435                while (c & 0x40) {
1436                        c <<= 1;
1437                        bytes++;
1438                }
1439
1440                /*
1441                 * Must be between 1 and 3 more bytes.  Longer sequences result in
1442                 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1443                 */
1444                if (bytes < 1 || 3 < bytes)
1445                        return bad_offset;
1446
1447                /* Do we *have* that many bytes? */
1448                if (len < bytes)
1449                        return bad_offset;
1450
1451                /*
1452                 * Place the encoded bits at the bottom of the value and compute the
1453                 * valid range.
1454                 */
1455                codepoint = (c & 0x7f) >> bytes;
1456                min_val = max_codepoint[bytes-1] + 1;
1457                max_val = max_codepoint[bytes];
1458
1459                offset += bytes;
1460                len -= bytes;
1461
1462                /* And verify that they are good continuation bytes */
1463                do {
1464                        codepoint <<= 6;
1465                        codepoint |= *buf & 0x3f;
1466                        if ((*buf++ & 0xc0) != 0x80)
1467                                return bad_offset;
1468                } while (--bytes);
1469
1470                /* Reject codepoints that are out of range for the sequence length. */
1471                if (codepoint < min_val || codepoint > max_val)
1472                        return bad_offset;
1473                /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1474                if ((codepoint & 0x1ff800) == 0xd800)
1475                        return bad_offset;
1476                /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1477                if ((codepoint & 0xfffe) == 0xfffe)
1478                        return bad_offset;
1479                /* So are anything in the range U+FDD0..U+FDEF. */
1480                if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1481                        return bad_offset;
1482        }
1483        return -1;
1484}
1485
1486/*
1487 * This verifies that the buffer is in proper utf8 format.
1488 *
1489 * If it isn't, it assumes any non-utf8 characters are Latin1,
1490 * and does the conversion.
1491 */
1492static int verify_utf8(struct strbuf *buf)
1493{
1494        int ok = 1;
1495        long pos = 0;
1496
1497        for (;;) {
1498                int bad;
1499                unsigned char c;
1500                unsigned char replace[2];
1501
1502                bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1503                if (bad < 0)
1504                        return ok;
1505                pos += bad;
1506                ok = 0;
1507                c = buf->buf[pos];
1508                strbuf_remove(buf, pos, 1);
1509
1510                /* We know 'c' must be in the range 128-255 */
1511                replace[0] = 0xc0 + (c >> 6);
1512                replace[1] = 0x80 + (c & 0x3f);
1513                strbuf_insert(buf, pos, replace, 2);
1514                pos += 2;
1515        }
1516}
1517
1518static const char commit_utf8_warn[] =
1519N_("Warning: commit message did not conform to UTF-8.\n"
1520   "You may want to amend it after fixing the message, or set the config\n"
1521   "variable i18n.commitencoding to the encoding your project uses.\n");
1522
1523int commit_tree_extended(const char *msg, size_t msg_len,
1524                         const struct object_id *tree,
1525                         struct commit_list *parents, struct object_id *ret,
1526                         const char *author, const char *sign_commit,
1527                         struct commit_extra_header *extra)
1528{
1529        int result;
1530        int encoding_is_utf8;
1531        struct strbuf buffer;
1532
1533        assert_oid_type(tree, OBJ_TREE);
1534
1535        if (memchr(msg, '\0', msg_len))
1536                return error("a NUL byte in commit log message not allowed.");
1537
1538        /* Not having i18n.commitencoding is the same as having utf-8 */
1539        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1540
1541        strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1542        strbuf_addf(&buffer, "tree %s\n", oid_to_hex(tree));
1543
1544        /*
1545         * NOTE! This ordering means that the same exact tree merged with a
1546         * different order of parents will be a _different_ changeset even
1547         * if everything else stays the same.
1548         */
1549        while (parents) {
1550                struct commit *parent = pop_commit(&parents);
1551                strbuf_addf(&buffer, "parent %s\n",
1552                            oid_to_hex(&parent->object.oid));
1553        }
1554
1555        /* Person/date information */
1556        if (!author)
1557                author = git_author_info(IDENT_STRICT);
1558        strbuf_addf(&buffer, "author %s\n", author);
1559        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1560        if (!encoding_is_utf8)
1561                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1562
1563        while (extra) {
1564                add_extra_header(&buffer, extra);
1565                extra = extra->next;
1566        }
1567        strbuf_addch(&buffer, '\n');
1568
1569        /* And add the comment */
1570        strbuf_add(&buffer, msg, msg_len);
1571
1572        /* And check the encoding */
1573        if (encoding_is_utf8 && !verify_utf8(&buffer))
1574                fprintf(stderr, _(commit_utf8_warn));
1575
1576        if (sign_commit && do_sign_commit(&buffer, sign_commit)) {
1577                result = -1;
1578                goto out;
1579        }
1580
1581        result = write_object_file(buffer.buf, buffer.len, commit_type, ret);
1582out:
1583        strbuf_release(&buffer);
1584        return result;
1585}
1586
1587void set_merge_remote_desc(struct commit *commit,
1588                           const char *name, struct object *obj)
1589{
1590        struct merge_remote_desc *desc;
1591        FLEX_ALLOC_STR(desc, name, name);
1592        desc->obj = obj;
1593        commit->util = desc;
1594}
1595
1596struct commit *get_merge_parent(const char *name)
1597{
1598        struct object *obj;
1599        struct commit *commit;
1600        struct object_id oid;
1601        if (get_oid(name, &oid))
1602                return NULL;
1603        obj = parse_object(&oid);
1604        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1605        if (commit && !commit->util)
1606                set_merge_remote_desc(commit, name, obj);
1607        return commit;
1608}
1609
1610/*
1611 * Append a commit to the end of the commit_list.
1612 *
1613 * next starts by pointing to the variable that holds the head of an
1614 * empty commit_list, and is updated to point to the "next" field of
1615 * the last item on the list as new commits are appended.
1616 *
1617 * Usage example:
1618 *
1619 *     struct commit_list *list;
1620 *     struct commit_list **next = &list;
1621 *
1622 *     next = commit_list_append(c1, next);
1623 *     next = commit_list_append(c2, next);
1624 *     assert(commit_list_count(list) == 2);
1625 *     return list;
1626 */
1627struct commit_list **commit_list_append(struct commit *commit,
1628                                        struct commit_list **next)
1629{
1630        struct commit_list *new_commit = xmalloc(sizeof(struct commit_list));
1631        new_commit->item = commit;
1632        *next = new_commit;
1633        new_commit->next = NULL;
1634        return &new_commit->next;
1635}
1636
1637const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1638{
1639        int key_len = strlen(key);
1640        const char *line = msg;
1641
1642        while (line) {
1643                const char *eol = strchrnul(line, '\n');
1644
1645                if (line == eol)
1646                        return NULL;
1647
1648                if (eol - line > key_len &&
1649                    !strncmp(line, key, key_len) &&
1650                    line[key_len] == ' ') {
1651                        *out_len = eol - line - key_len - 1;
1652                        return line + key_len + 1;
1653                }
1654                line = *eol ? eol + 1 : NULL;
1655        }
1656        return NULL;
1657}
1658
1659/*
1660 * Inspect the given string and determine the true "end" of the log message, in
1661 * order to find where to put a new Signed-off-by: line.  Ignored are
1662 * trailing comment lines and blank lines.  To support "git commit -s
1663 * --amend" on an existing commit, we also ignore "Conflicts:".  To
1664 * support "git commit -v", we truncate at cut lines.
1665 *
1666 * Returns the number of bytes from the tail to ignore, to be fed as
1667 * the second parameter to append_signoff().
1668 */
1669int ignore_non_trailer(const char *buf, size_t len)
1670{
1671        int boc = 0;
1672        int bol = 0;
1673        int in_old_conflicts_block = 0;
1674        size_t cutoff = wt_status_locate_end(buf, len);
1675
1676        while (bol < cutoff) {
1677                const char *next_line = memchr(buf + bol, '\n', len - bol);
1678
1679                if (!next_line)
1680                        next_line = buf + len;
1681                else
1682                        next_line++;
1683
1684                if (buf[bol] == comment_line_char || buf[bol] == '\n') {
1685                        /* is this the first of the run of comments? */
1686                        if (!boc)
1687                                boc = bol;
1688                        /* otherwise, it is just continuing */
1689                } else if (starts_with(buf + bol, "Conflicts:\n")) {
1690                        in_old_conflicts_block = 1;
1691                        if (!boc)
1692                                boc = bol;
1693                } else if (in_old_conflicts_block && buf[bol] == '\t') {
1694                        ; /* a pathname in the conflicts block */
1695                } else if (boc) {
1696                        /* the previous was not trailing comment */
1697                        boc = 0;
1698                        in_old_conflicts_block = 0;
1699                }
1700                bol = next_line - buf;
1701        }
1702        return boc ? len - boc : len - cutoff;
1703}