Andrew's git / gitweb.git / commit.c
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commit.con commit Merge branch 'jc/doc-checkout' into maint (4e4a0c6)
   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 "gpg-interface.h"
  10#include "mergesort.h"
  11#include "commit-slab.h"
  12#include "prio-queue.h"
  13#include "sha1-lookup.h"
  14#include "wt-status.h"
  15
  16static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
  17
  18int save_commit_buffer = 1;
  19
  20const char *commit_type = "commit";
  21
  22struct commit *lookup_commit_reference_gently(const struct object_id *oid,
  23                                              int quiet)
  24{
  25        struct object *obj = deref_tag(parse_object(oid), NULL, 0);
  26
  27        if (!obj)
  28                return NULL;
  29        return object_as_type(obj, OBJ_COMMIT, quiet);
  30}
  31
  32struct commit *lookup_commit_reference(const struct object_id *oid)
  33{
  34        return lookup_commit_reference_gently(oid, 0);
  35}
  36
  37struct commit *lookup_commit_or_die(const struct object_id *oid, const char *ref_name)
  38{
  39        struct commit *c = lookup_commit_reference(oid);
  40        if (!c)
  41                die(_("could not parse %s"), ref_name);
  42        if (oidcmp(oid, &c->object.oid)) {
  43                warning(_("%s %s is not a commit!"),
  44                        ref_name, oid_to_hex(oid));
  45        }
  46        return c;
  47}
  48
  49struct commit *lookup_commit(const struct object_id *oid)
  50{
  51        struct object *obj = lookup_object(oid->hash);
  52        if (!obj)
  53                return create_object(oid->hash, alloc_commit_node());
  54        return object_as_type(obj, OBJ_COMMIT, 0);
  55}
  56
  57struct commit *lookup_commit_reference_by_name(const char *name)
  58{
  59        struct object_id oid;
  60        struct commit *commit;
  61
  62        if (get_sha1_committish(name, oid.hash))
  63                return NULL;
  64        commit = lookup_commit_reference(&oid);
  65        if (parse_commit(commit))
  66                return NULL;
  67        return commit;
  68}
  69
  70static timestamp_t parse_commit_date(const char *buf, const char *tail)
  71{
  72        const char *dateptr;
  73
  74        if (buf + 6 >= tail)
  75                return 0;
  76        if (memcmp(buf, "author", 6))
  77                return 0;
  78        while (buf < tail && *buf++ != '\n')
  79                /* nada */;
  80        if (buf + 9 >= tail)
  81                return 0;
  82        if (memcmp(buf, "committer", 9))
  83                return 0;
  84        while (buf < tail && *buf++ != '>')
  85                /* nada */;
  86        if (buf >= tail)
  87                return 0;
  88        dateptr = buf;
  89        while (buf < tail && *buf++ != '\n')
  90                /* nada */;
  91        if (buf >= tail)
  92                return 0;
  93        /* dateptr < buf && buf[-1] == '\n', so parsing will stop at buf-1 */
  94        return parse_timestamp(dateptr, NULL, 10);
  95}
  96
  97static struct commit_graft **commit_graft;
  98static int commit_graft_alloc, commit_graft_nr;
  99
 100static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
 101{
 102        struct commit_graft **commit_graft_table = table;
 103        return commit_graft_table[index]->oid.hash;
 104}
 105
 106static int commit_graft_pos(const unsigned char *sha1)
 107{
 108        return sha1_pos(sha1, commit_graft, commit_graft_nr,
 109                        commit_graft_sha1_access);
 110}
 111
 112int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 113{
 114        int pos = commit_graft_pos(graft->oid.hash);
 115
 116        if (0 <= pos) {
 117                if (ignore_dups)
 118                        free(graft);
 119                else {
 120                        free(commit_graft[pos]);
 121                        commit_graft[pos] = graft;
 122                }
 123                return 1;
 124        }
 125        pos = -pos - 1;
 126        ALLOC_GROW(commit_graft, commit_graft_nr + 1, commit_graft_alloc);
 127        commit_graft_nr++;
 128        if (pos < commit_graft_nr)
 129                memmove(commit_graft + pos + 1,
 130                        commit_graft + pos,
 131                        (commit_graft_nr - pos - 1) *
 132                        sizeof(*commit_graft));
 133        commit_graft[pos] = graft;
 134        return 0;
 135}
 136
 137struct commit_graft *read_graft_line(char *buf, int len)
 138{
 139        /* The format is just "Commit Parent1 Parent2 ...\n" */
 140        int i;
 141        struct commit_graft *graft = NULL;
 142        const int entry_size = GIT_SHA1_HEXSZ + 1;
 143
 144        while (len && isspace(buf[len-1]))
 145                buf[--len] = '\0';
 146        if (buf[0] == '#' || buf[0] == '\0')
 147                return NULL;
 148        if ((len + 1) % entry_size)
 149                goto bad_graft_data;
 150        i = (len + 1) / entry_size - 1;
 151        graft = xmalloc(st_add(sizeof(*graft), st_mult(GIT_SHA1_RAWSZ, i)));
 152        graft->nr_parent = i;
 153        if (get_oid_hex(buf, &graft->oid))
 154                goto bad_graft_data;
 155        for (i = GIT_SHA1_HEXSZ; i < len; i += entry_size) {
 156                if (buf[i] != ' ')
 157                        goto bad_graft_data;
 158                if (get_sha1_hex(buf + i + 1, graft->parent[i/entry_size].hash))
 159                        goto bad_graft_data;
 160        }
 161        return graft;
 162
 163bad_graft_data:
 164        error("bad graft data: %s", buf);
 165        free(graft);
 166        return NULL;
 167}
 168
 169static int read_graft_file(const char *graft_file)
 170{
 171        FILE *fp = fopen_or_warn(graft_file, "r");
 172        struct strbuf buf = STRBUF_INIT;
 173        if (!fp)
 174                return -1;
 175        while (!strbuf_getwholeline(&buf, fp, '\n')) {
 176                /* The format is just "Commit Parent1 Parent2 ...\n" */
 177                struct commit_graft *graft = read_graft_line(buf.buf, buf.len);
 178                if (!graft)
 179                        continue;
 180                if (register_commit_graft(graft, 1))
 181                        error("duplicate graft data: %s", buf.buf);
 182        }
 183        fclose(fp);
 184        strbuf_release(&buf);
 185        return 0;
 186}
 187
 188static void prepare_commit_graft(void)
 189{
 190        static int commit_graft_prepared;
 191        char *graft_file;
 192
 193        if (commit_graft_prepared)
 194                return;
 195        graft_file = get_graft_file();
 196        read_graft_file(graft_file);
 197        /* make sure shallows are read */
 198        is_repository_shallow();
 199        commit_graft_prepared = 1;
 200}
 201
 202struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 203{
 204        int pos;
 205        prepare_commit_graft();
 206        pos = commit_graft_pos(sha1);
 207        if (pos < 0)
 208                return NULL;
 209        return commit_graft[pos];
 210}
 211
 212int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
 213{
 214        int i, ret;
 215        for (i = ret = 0; i < commit_graft_nr && !ret; i++)
 216                ret = fn(commit_graft[i], cb_data);
 217        return ret;
 218}
 219
 220int unregister_shallow(const struct object_id *oid)
 221{
 222        int pos = commit_graft_pos(oid->hash);
 223        if (pos < 0)
 224                return -1;
 225        if (pos + 1 < commit_graft_nr)
 226                MOVE_ARRAY(commit_graft + pos, commit_graft + pos + 1,
 227                           commit_graft_nr - pos - 1);
 228        commit_graft_nr--;
 229        return 0;
 230}
 231
 232struct commit_buffer {
 233        void *buffer;
 234        unsigned long size;
 235};
 236define_commit_slab(buffer_slab, struct commit_buffer);
 237static struct buffer_slab buffer_slab = COMMIT_SLAB_INIT(1, buffer_slab);
 238
 239void set_commit_buffer(struct commit *commit, void *buffer, unsigned long size)
 240{
 241        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 242        v->buffer = buffer;
 243        v->size = size;
 244}
 245
 246const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
 247{
 248        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 249        if (!v) {
 250                if (sizep)
 251                        *sizep = 0;
 252                return NULL;
 253        }
 254        if (sizep)
 255                *sizep = v->size;
 256        return v->buffer;
 257}
 258
 259const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
 260{
 261        const void *ret = get_cached_commit_buffer(commit, sizep);
 262        if (!ret) {
 263                enum object_type type;
 264                unsigned long size;
 265                ret = read_sha1_file(commit->object.oid.hash, &type, &size);
 266                if (!ret)
 267                        die("cannot read commit object %s",
 268                            oid_to_hex(&commit->object.oid));
 269                if (type != OBJ_COMMIT)
 270                        die("expected commit for %s, got %s",
 271                            oid_to_hex(&commit->object.oid), typename(type));
 272                if (sizep)
 273                        *sizep = size;
 274        }
 275        return ret;
 276}
 277
 278void unuse_commit_buffer(const struct commit *commit, const void *buffer)
 279{
 280        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 281        if (!(v && v->buffer == buffer))
 282                free((void *)buffer);
 283}
 284
 285void free_commit_buffer(struct commit *commit)
 286{
 287        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 288        if (v) {
 289                FREE_AND_NULL(v->buffer);
 290                v->size = 0;
 291        }
 292}
 293
 294const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 295{
 296        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 297        void *ret;
 298
 299        if (!v) {
 300                if (sizep)
 301                        *sizep = 0;
 302                return NULL;
 303        }
 304        ret = v->buffer;
 305        if (sizep)
 306                *sizep = v->size;
 307
 308        v->buffer = NULL;
 309        v->size = 0;
 310        return ret;
 311}
 312
 313int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
 314{
 315        const char *tail = buffer;
 316        const char *bufptr = buffer;
 317        struct object_id parent;
 318        struct commit_list **pptr;
 319        struct commit_graft *graft;
 320        const int tree_entry_len = GIT_SHA1_HEXSZ + 5;
 321        const int parent_entry_len = GIT_SHA1_HEXSZ + 7;
 322
 323        if (item->object.parsed)
 324                return 0;
 325        item->object.parsed = 1;
 326        tail += size;
 327        if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
 328                        bufptr[tree_entry_len] != '\n')
 329                return error("bogus commit object %s", oid_to_hex(&item->object.oid));
 330        if (get_sha1_hex(bufptr + 5, parent.hash) < 0)
 331                return error("bad tree pointer in commit %s",
 332                             oid_to_hex(&item->object.oid));
 333        item->tree = lookup_tree(&parent);
 334        bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
 335        pptr = &item->parents;
 336
 337        graft = lookup_commit_graft(item->object.oid.hash);
 338        while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
 339                struct commit *new_parent;
 340
 341                if (tail <= bufptr + parent_entry_len + 1 ||
 342                    get_sha1_hex(bufptr + 7, parent.hash) ||
 343                    bufptr[parent_entry_len] != '\n')
 344                        return error("bad parents in commit %s", oid_to_hex(&item->object.oid));
 345                bufptr += parent_entry_len + 1;
 346                /*
 347                 * The clone is shallow if nr_parent < 0, and we must
 348                 * not traverse its real parents even when we unhide them.
 349                 */
 350                if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
 351                        continue;
 352                new_parent = lookup_commit(&parent);
 353                if (new_parent)
 354                        pptr = &commit_list_insert(new_parent, pptr)->next;
 355        }
 356        if (graft) {
 357                int i;
 358                struct commit *new_parent;
 359                for (i = 0; i < graft->nr_parent; i++) {
 360                        new_parent = lookup_commit(&graft->parent[i]);
 361                        if (!new_parent)
 362                                continue;
 363                        pptr = &commit_list_insert(new_parent, pptr)->next;
 364                }
 365        }
 366        item->date = parse_commit_date(bufptr, tail);
 367
 368        return 0;
 369}
 370
 371int parse_commit_gently(struct commit *item, int quiet_on_missing)
 372{
 373        enum object_type type;
 374        void *buffer;
 375        unsigned long size;
 376        int ret;
 377
 378        if (!item)
 379                return -1;
 380        if (item->object.parsed)
 381                return 0;
 382        buffer = read_sha1_file(item->object.oid.hash, &type, &size);
 383        if (!buffer)
 384                return quiet_on_missing ? -1 :
 385                        error("Could not read %s",
 386                             oid_to_hex(&item->object.oid));
 387        if (type != OBJ_COMMIT) {
 388                free(buffer);
 389                return error("Object %s not a commit",
 390                             oid_to_hex(&item->object.oid));
 391        }
 392        ret = parse_commit_buffer(item, buffer, size);
 393        if (save_commit_buffer && !ret) {
 394                set_commit_buffer(item, buffer, size);
 395                return 0;
 396        }
 397        free(buffer);
 398        return ret;
 399}
 400
 401void parse_commit_or_die(struct commit *item)
 402{
 403        if (parse_commit(item))
 404                die("unable to parse commit %s",
 405                    item ? oid_to_hex(&item->object.oid) : "(null)");
 406}
 407
 408int find_commit_subject(const char *commit_buffer, const char **subject)
 409{
 410        const char *eol;
 411        const char *p = commit_buffer;
 412
 413        while (*p && (*p != '\n' || p[1] != '\n'))
 414                p++;
 415        if (*p) {
 416                p = skip_blank_lines(p + 2);
 417                eol = strchrnul(p, '\n');
 418        } else
 419                eol = p;
 420
 421        *subject = p;
 422
 423        return eol - p;
 424}
 425
 426struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 427{
 428        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 429        new_list->item = item;
 430        new_list->next = *list_p;
 431        *list_p = new_list;
 432        return new_list;
 433}
 434
 435unsigned commit_list_count(const struct commit_list *l)
 436{
 437        unsigned c = 0;
 438        for (; l; l = l->next )
 439                c++;
 440        return c;
 441}
 442
 443struct commit_list *copy_commit_list(struct commit_list *list)
 444{
 445        struct commit_list *head = NULL;
 446        struct commit_list **pp = &head;
 447        while (list) {
 448                pp = commit_list_append(list->item, pp);
 449                list = list->next;
 450        }
 451        return head;
 452}
 453
 454void free_commit_list(struct commit_list *list)
 455{
 456        while (list)
 457                pop_commit(&list);
 458}
 459
 460struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 461{
 462        struct commit_list **pp = list;
 463        struct commit_list *p;
 464        while ((p = *pp) != NULL) {
 465                if (p->item->date < item->date) {
 466                        break;
 467                }
 468                pp = &p->next;
 469        }
 470        return commit_list_insert(item, pp);
 471}
 472
 473static int commit_list_compare_by_date(const void *a, const void *b)
 474{
 475        timestamp_t a_date = ((const struct commit_list *)a)->item->date;
 476        timestamp_t b_date = ((const struct commit_list *)b)->item->date;
 477        if (a_date < b_date)
 478                return 1;
 479        if (a_date > b_date)
 480                return -1;
 481        return 0;
 482}
 483
 484static void *commit_list_get_next(const void *a)
 485{
 486        return ((const struct commit_list *)a)->next;
 487}
 488
 489static void commit_list_set_next(void *a, void *next)
 490{
 491        ((struct commit_list *)a)->next = next;
 492}
 493
 494void commit_list_sort_by_date(struct commit_list **list)
 495{
 496        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 497                                commit_list_compare_by_date);
 498}
 499
 500struct commit *pop_most_recent_commit(struct commit_list **list,
 501                                      unsigned int mark)
 502{
 503        struct commit *ret = pop_commit(list);
 504        struct commit_list *parents = ret->parents;
 505
 506        while (parents) {
 507                struct commit *commit = parents->item;
 508                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 509                        commit->object.flags |= mark;
 510                        commit_list_insert_by_date(commit, list);
 511                }
 512                parents = parents->next;
 513        }
 514        return ret;
 515}
 516
 517static void clear_commit_marks_1(struct commit_list **plist,
 518                                 struct commit *commit, unsigned int mark)
 519{
 520        while (commit) {
 521                struct commit_list *parents;
 522
 523                if (!(mark & commit->object.flags))
 524                        return;
 525
 526                commit->object.flags &= ~mark;
 527
 528                parents = commit->parents;
 529                if (!parents)
 530                        return;
 531
 532                while ((parents = parents->next))
 533                        commit_list_insert(parents->item, plist);
 534
 535                commit = commit->parents->item;
 536        }
 537}
 538
 539void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 540{
 541        struct commit_list *list = NULL;
 542
 543        while (nr--) {
 544                commit_list_insert(*commit, &list);
 545                commit++;
 546        }
 547        while (list)
 548                clear_commit_marks_1(&list, pop_commit(&list), mark);
 549}
 550
 551void clear_commit_marks(struct commit *commit, unsigned int mark)
 552{
 553        clear_commit_marks_many(1, &commit, mark);
 554}
 555
 556void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
 557{
 558        struct object *object;
 559        struct commit *commit;
 560        unsigned int i;
 561
 562        for (i = 0; i < a->nr; i++) {
 563                object = a->objects[i].item;
 564                commit = lookup_commit_reference_gently(&object->oid, 1);
 565                if (commit)
 566                        clear_commit_marks(commit, mark);
 567        }
 568}
 569
 570struct commit *pop_commit(struct commit_list **stack)
 571{
 572        struct commit_list *top = *stack;
 573        struct commit *item = top ? top->item : NULL;
 574
 575        if (top) {
 576                *stack = top->next;
 577                free(top);
 578        }
 579        return item;
 580}
 581
 582/*
 583 * Topological sort support
 584 */
 585
 586/* count number of children that have not been emitted */
 587define_commit_slab(indegree_slab, int);
 588
 589/* record author-date for each commit object */
 590define_commit_slab(author_date_slab, unsigned long);
 591
 592static void record_author_date(struct author_date_slab *author_date,
 593                               struct commit *commit)
 594{
 595        const char *buffer = get_commit_buffer(commit, NULL);
 596        struct ident_split ident;
 597        const char *ident_line;
 598        size_t ident_len;
 599        char *date_end;
 600        timestamp_t date;
 601
 602        ident_line = find_commit_header(buffer, "author", &ident_len);
 603        if (!ident_line)
 604                goto fail_exit; /* no author line */
 605        if (split_ident_line(&ident, ident_line, ident_len) ||
 606            !ident.date_begin || !ident.date_end)
 607                goto fail_exit; /* malformed "author" line */
 608
 609        date = parse_timestamp(ident.date_begin, &date_end, 10);
 610        if (date_end != ident.date_end)
 611                goto fail_exit; /* malformed date */
 612        *(author_date_slab_at(author_date, commit)) = date;
 613
 614fail_exit:
 615        unuse_commit_buffer(commit, buffer);
 616}
 617
 618static int compare_commits_by_author_date(const void *a_, const void *b_,
 619                                          void *cb_data)
 620{
 621        const struct commit *a = a_, *b = b_;
 622        struct author_date_slab *author_date = cb_data;
 623        timestamp_t a_date = *(author_date_slab_at(author_date, a));
 624        timestamp_t b_date = *(author_date_slab_at(author_date, b));
 625
 626        /* newer commits with larger date first */
 627        if (a_date < b_date)
 628                return 1;
 629        else if (a_date > b_date)
 630                return -1;
 631        return 0;
 632}
 633
 634int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 635{
 636        const struct commit *a = a_, *b = b_;
 637        /* newer commits with larger date first */
 638        if (a->date < b->date)
 639                return 1;
 640        else if (a->date > b->date)
 641                return -1;
 642        return 0;
 643}
 644
 645/*
 646 * Performs an in-place topological sort on the list supplied.
 647 */
 648void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 649{
 650        struct commit_list *next, *orig = *list;
 651        struct commit_list **pptr;
 652        struct indegree_slab indegree;
 653        struct prio_queue queue;
 654        struct commit *commit;
 655        struct author_date_slab author_date;
 656
 657        if (!orig)
 658                return;
 659        *list = NULL;
 660
 661        init_indegree_slab(&indegree);
 662        memset(&queue, '\0', sizeof(queue));
 663
 664        switch (sort_order) {
 665        default: /* REV_SORT_IN_GRAPH_ORDER */
 666                queue.compare = NULL;
 667                break;
 668        case REV_SORT_BY_COMMIT_DATE:
 669                queue.compare = compare_commits_by_commit_date;
 670                break;
 671        case REV_SORT_BY_AUTHOR_DATE:
 672                init_author_date_slab(&author_date);
 673                queue.compare = compare_commits_by_author_date;
 674                queue.cb_data = &author_date;
 675                break;
 676        }
 677
 678        /* Mark them and clear the indegree */
 679        for (next = orig; next; next = next->next) {
 680                struct commit *commit = next->item;
 681                *(indegree_slab_at(&indegree, commit)) = 1;
 682                /* also record the author dates, if needed */
 683                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 684                        record_author_date(&author_date, commit);
 685        }
 686
 687        /* update the indegree */
 688        for (next = orig; next; next = next->next) {
 689                struct commit_list *parents = next->item->parents;
 690                while (parents) {
 691                        struct commit *parent = parents->item;
 692                        int *pi = indegree_slab_at(&indegree, parent);
 693
 694                        if (*pi)
 695                                (*pi)++;
 696                        parents = parents->next;
 697                }
 698        }
 699
 700        /*
 701         * find the tips
 702         *
 703         * tips are nodes not reachable from any other node in the list
 704         *
 705         * the tips serve as a starting set for the work queue.
 706         */
 707        for (next = orig; next; next = next->next) {
 708                struct commit *commit = next->item;
 709
 710                if (*(indegree_slab_at(&indegree, commit)) == 1)
 711                        prio_queue_put(&queue, commit);
 712        }
 713
 714        /*
 715         * This is unfortunate; the initial tips need to be shown
 716         * in the order given from the revision traversal machinery.
 717         */
 718        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 719                prio_queue_reverse(&queue);
 720
 721        /* We no longer need the commit list */
 722        free_commit_list(orig);
 723
 724        pptr = list;
 725        *list = NULL;
 726        while ((commit = prio_queue_get(&queue)) != NULL) {
 727                struct commit_list *parents;
 728
 729                for (parents = commit->parents; parents ; parents = parents->next) {
 730                        struct commit *parent = parents->item;
 731                        int *pi = indegree_slab_at(&indegree, parent);
 732
 733                        if (!*pi)
 734                                continue;
 735
 736                        /*
 737                         * parents are only enqueued for emission
 738                         * when all their children have been emitted thereby
 739                         * guaranteeing topological order.
 740                         */
 741                        if (--(*pi) == 1)
 742                                prio_queue_put(&queue, parent);
 743                }
 744                /*
 745                 * all children of commit have already been
 746                 * emitted. we can emit it now.
 747                 */
 748                *(indegree_slab_at(&indegree, commit)) = 0;
 749
 750                pptr = &commit_list_insert(commit, pptr)->next;
 751        }
 752
 753        clear_indegree_slab(&indegree);
 754        clear_prio_queue(&queue);
 755        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 756                clear_author_date_slab(&author_date);
 757}
 758
 759/* merge-base stuff */
 760
 761/* Remember to update object flag allocation in object.h */
 762#define PARENT1         (1u<<16)
 763#define PARENT2         (1u<<17)
 764#define STALE           (1u<<18)
 765#define RESULT          (1u<<19)
 766
 767static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 768
 769static int queue_has_nonstale(struct prio_queue *queue)
 770{
 771        int i;
 772        for (i = 0; i < queue->nr; i++) {
 773                struct commit *commit = queue->array[i].data;
 774                if (!(commit->object.flags & STALE))
 775                        return 1;
 776        }
 777        return 0;
 778}
 779
 780/* all input commits in one and twos[] must have been parsed! */
 781static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
 782{
 783        struct prio_queue queue = { compare_commits_by_commit_date };
 784        struct commit_list *result = NULL;
 785        int i;
 786
 787        one->object.flags |= PARENT1;
 788        if (!n) {
 789                commit_list_append(one, &result);
 790                return result;
 791        }
 792        prio_queue_put(&queue, one);
 793
 794        for (i = 0; i < n; i++) {
 795                twos[i]->object.flags |= PARENT2;
 796                prio_queue_put(&queue, twos[i]);
 797        }
 798
 799        while (queue_has_nonstale(&queue)) {
 800                struct commit *commit = prio_queue_get(&queue);
 801                struct commit_list *parents;
 802                int flags;
 803
 804                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 805                if (flags == (PARENT1 | PARENT2)) {
 806                        if (!(commit->object.flags & RESULT)) {
 807                                commit->object.flags |= RESULT;
 808                                commit_list_insert_by_date(commit, &result);
 809                        }
 810                        /* Mark parents of a found merge stale */
 811                        flags |= STALE;
 812                }
 813                parents = commit->parents;
 814                while (parents) {
 815                        struct commit *p = parents->item;
 816                        parents = parents->next;
 817                        if ((p->object.flags & flags) == flags)
 818                                continue;
 819                        if (parse_commit(p))
 820                                return NULL;
 821                        p->object.flags |= flags;
 822                        prio_queue_put(&queue, p);
 823                }
 824        }
 825
 826        clear_prio_queue(&queue);
 827        return result;
 828}
 829
 830static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 831{
 832        struct commit_list *list = NULL;
 833        struct commit_list *result = NULL;
 834        int i;
 835
 836        for (i = 0; i < n; i++) {
 837                if (one == twos[i])
 838                        /*
 839                         * We do not mark this even with RESULT so we do not
 840                         * have to clean it up.
 841                         */
 842                        return commit_list_insert(one, &result);
 843        }
 844
 845        if (parse_commit(one))
 846                return NULL;
 847        for (i = 0; i < n; i++) {
 848                if (parse_commit(twos[i]))
 849                        return NULL;
 850        }
 851
 852        list = paint_down_to_common(one, n, twos);
 853
 854        while (list) {
 855                struct commit *commit = pop_commit(&list);
 856                if (!(commit->object.flags & STALE))
 857                        commit_list_insert_by_date(commit, &result);
 858        }
 859        return result;
 860}
 861
 862struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 863{
 864        struct commit_list *i, *j, *k, *ret = NULL;
 865
 866        if (!in)
 867                return ret;
 868
 869        commit_list_insert(in->item, &ret);
 870
 871        for (i = in->next; i; i = i->next) {
 872                struct commit_list *new = NULL, *end = NULL;
 873
 874                for (j = ret; j; j = j->next) {
 875                        struct commit_list *bases;
 876                        bases = get_merge_bases(i->item, j->item);
 877                        if (!new)
 878                                new = bases;
 879                        else
 880                                end->next = bases;
 881                        for (k = bases; k; k = k->next)
 882                                end = k;
 883                }
 884                ret = new;
 885        }
 886        return ret;
 887}
 888
 889static int remove_redundant(struct commit **array, int cnt)
 890{
 891        /*
 892         * Some commit in the array may be an ancestor of
 893         * another commit.  Move such commit to the end of
 894         * the array, and return the number of commits that
 895         * are independent from each other.
 896         */
 897        struct commit **work;
 898        unsigned char *redundant;
 899        int *filled_index;
 900        int i, j, filled;
 901
 902        work = xcalloc(cnt, sizeof(*work));
 903        redundant = xcalloc(cnt, 1);
 904        ALLOC_ARRAY(filled_index, cnt - 1);
 905
 906        for (i = 0; i < cnt; i++)
 907                parse_commit(array[i]);
 908        for (i = 0; i < cnt; i++) {
 909                struct commit_list *common;
 910
 911                if (redundant[i])
 912                        continue;
 913                for (j = filled = 0; j < cnt; j++) {
 914                        if (i == j || redundant[j])
 915                                continue;
 916                        filled_index[filled] = j;
 917                        work[filled++] = array[j];
 918                }
 919                common = paint_down_to_common(array[i], filled, work);
 920                if (array[i]->object.flags & PARENT2)
 921                        redundant[i] = 1;
 922                for (j = 0; j < filled; j++)
 923                        if (work[j]->object.flags & PARENT1)
 924                                redundant[filled_index[j]] = 1;
 925                clear_commit_marks(array[i], all_flags);
 926                for (j = 0; j < filled; j++)
 927                        clear_commit_marks(work[j], all_flags);
 928                free_commit_list(common);
 929        }
 930
 931        /* Now collect the result */
 932        COPY_ARRAY(work, array, cnt);
 933        for (i = filled = 0; i < cnt; i++)
 934                if (!redundant[i])
 935                        array[filled++] = work[i];
 936        for (j = filled, i = 0; i < cnt; i++)
 937                if (redundant[i])
 938                        array[j++] = work[i];
 939        free(work);
 940        free(redundant);
 941        free(filled_index);
 942        return filled;
 943}
 944
 945static struct commit_list *get_merge_bases_many_0(struct commit *one,
 946                                                  int n,
 947                                                  struct commit **twos,
 948                                                  int cleanup)
 949{
 950        struct commit_list *list;
 951        struct commit **rslt;
 952        struct commit_list *result;
 953        int cnt, i;
 954
 955        result = merge_bases_many(one, n, twos);
 956        for (i = 0; i < n; i++) {
 957                if (one == twos[i])
 958                        return result;
 959        }
 960        if (!result || !result->next) {
 961                if (cleanup) {
 962                        clear_commit_marks(one, all_flags);
 963                        clear_commit_marks_many(n, twos, all_flags);
 964                }
 965                return result;
 966        }
 967
 968        /* There are more than one */
 969        cnt = commit_list_count(result);
 970        rslt = xcalloc(cnt, sizeof(*rslt));
 971        for (list = result, i = 0; list; list = list->next)
 972                rslt[i++] = list->item;
 973        free_commit_list(result);
 974
 975        clear_commit_marks(one, all_flags);
 976        clear_commit_marks_many(n, twos, all_flags);
 977
 978        cnt = remove_redundant(rslt, cnt);
 979        result = NULL;
 980        for (i = 0; i < cnt; i++)
 981                commit_list_insert_by_date(rslt[i], &result);
 982        free(rslt);
 983        return result;
 984}
 985
 986struct commit_list *get_merge_bases_many(struct commit *one,
 987                                         int n,
 988                                         struct commit **twos)
 989{
 990        return get_merge_bases_many_0(one, n, twos, 1);
 991}
 992
 993struct commit_list *get_merge_bases_many_dirty(struct commit *one,
 994                                               int n,
 995                                               struct commit **twos)
 996{
 997        return get_merge_bases_many_0(one, n, twos, 0);
 998}
 999
1000struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
1001{
1002        return get_merge_bases_many_0(one, 1, &two, 1);
1003}
1004
1005/*
1006 * Is "commit" a descendant of one of the elements on the "with_commit" list?
1007 */
1008int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
1009{
1010        if (!with_commit)
1011                return 1;
1012        while (with_commit) {
1013                struct commit *other;
1014
1015                other = with_commit->item;
1016                with_commit = with_commit->next;
1017                if (in_merge_bases(other, commit))
1018                        return 1;
1019        }
1020        return 0;
1021}
1022
1023/*
1024 * Is "commit" an ancestor of one of the "references"?
1025 */
1026int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1027{
1028        struct commit_list *bases;
1029        int ret = 0, i;
1030
1031        if (parse_commit(commit))
1032                return ret;
1033        for (i = 0; i < nr_reference; i++)
1034                if (parse_commit(reference[i]))
1035                        return ret;
1036
1037        bases = paint_down_to_common(commit, nr_reference, reference);
1038        if (commit->object.flags & PARENT2)
1039                ret = 1;
1040        clear_commit_marks(commit, all_flags);
1041        clear_commit_marks_many(nr_reference, reference, all_flags);
1042        free_commit_list(bases);
1043        return ret;
1044}
1045
1046/*
1047 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1048 */
1049int in_merge_bases(struct commit *commit, struct commit *reference)
1050{
1051        return in_merge_bases_many(commit, 1, &reference);
1052}
1053
1054struct commit_list *reduce_heads(struct commit_list *heads)
1055{
1056        struct commit_list *p;
1057        struct commit_list *result = NULL, **tail = &result;
1058        struct commit **array;
1059        int num_head, i;
1060
1061        if (!heads)
1062                return NULL;
1063
1064        /* Uniquify */
1065        for (p = heads; p; p = p->next)
1066                p->item->object.flags &= ~STALE;
1067        for (p = heads, num_head = 0; p; p = p->next) {
1068                if (p->item->object.flags & STALE)
1069                        continue;
1070                p->item->object.flags |= STALE;
1071                num_head++;
1072        }
1073        array = xcalloc(num_head, sizeof(*array));
1074        for (p = heads, i = 0; p; p = p->next) {
1075                if (p->item->object.flags & STALE) {
1076                        array[i++] = p->item;
1077                        p->item->object.flags &= ~STALE;
1078                }
1079        }
1080        num_head = remove_redundant(array, num_head);
1081        for (i = 0; i < num_head; i++)
1082                tail = &commit_list_insert(array[i], tail)->next;
1083        return result;
1084}
1085
1086static const char gpg_sig_header[] = "gpgsig";
1087static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1088
1089static int do_sign_commit(struct strbuf *buf, const char *keyid)
1090{
1091        struct strbuf sig = STRBUF_INIT;
1092        int inspos, copypos;
1093        const char *eoh;
1094
1095        /* find the end of the header */
1096        eoh = strstr(buf->buf, "\n\n");
1097        if (!eoh)
1098                inspos = buf->len;
1099        else
1100                inspos = eoh - buf->buf + 1;
1101
1102        if (!keyid || !*keyid)
1103                keyid = get_signing_key();
1104        if (sign_buffer(buf, &sig, keyid)) {
1105                strbuf_release(&sig);
1106                return -1;
1107        }
1108
1109        for (copypos = 0; sig.buf[copypos]; ) {
1110                const char *bol = sig.buf + copypos;
1111                const char *eol = strchrnul(bol, '\n');
1112                int len = (eol - bol) + !!*eol;
1113
1114                if (!copypos) {
1115                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1116                        inspos += gpg_sig_header_len;
1117                }
1118                strbuf_insert(buf, inspos++, " ", 1);
1119                strbuf_insert(buf, inspos, bol, len);
1120                inspos += len;
1121                copypos += len;
1122        }
1123        strbuf_release(&sig);
1124        return 0;
1125}
1126
1127int parse_signed_commit(const struct commit *commit,
1128                        struct strbuf *payload, struct strbuf *signature)
1129{
1130
1131        unsigned long size;
1132        const char *buffer = get_commit_buffer(commit, &size);
1133        int in_signature, saw_signature = -1;
1134        const char *line, *tail;
1135
1136        line = buffer;
1137        tail = buffer + size;
1138        in_signature = 0;
1139        saw_signature = 0;
1140        while (line < tail) {
1141                const char *sig = NULL;
1142                const char *next = memchr(line, '\n', tail - line);
1143
1144                next = next ? next + 1 : tail;
1145                if (in_signature && line[0] == ' ')
1146                        sig = line + 1;
1147                else if (starts_with(line, gpg_sig_header) &&
1148                         line[gpg_sig_header_len] == ' ')
1149                        sig = line + gpg_sig_header_len + 1;
1150                if (sig) {
1151                        strbuf_add(signature, sig, next - sig);
1152                        saw_signature = 1;
1153                        in_signature = 1;
1154                } else {
1155                        if (*line == '\n')
1156                                /* dump the whole remainder of the buffer */
1157                                next = tail;
1158                        strbuf_add(payload, line, next - line);
1159                        in_signature = 0;
1160                }
1161                line = next;
1162        }
1163        unuse_commit_buffer(commit, buffer);
1164        return saw_signature;
1165}
1166
1167int remove_signature(struct strbuf *buf)
1168{
1169        const char *line = buf->buf;
1170        const char *tail = buf->buf + buf->len;
1171        int in_signature = 0;
1172        const char *sig_start = NULL;
1173        const char *sig_end = NULL;
1174
1175        while (line < tail) {
1176                const char *next = memchr(line, '\n', tail - line);
1177                next = next ? next + 1 : tail;
1178
1179                if (in_signature && line[0] == ' ')
1180                        sig_end = next;
1181                else if (starts_with(line, gpg_sig_header) &&
1182                         line[gpg_sig_header_len] == ' ') {
1183                        sig_start = line;
1184                        sig_end = next;
1185                        in_signature = 1;
1186                } else {
1187                        if (*line == '\n')
1188                                /* dump the whole remainder of the buffer */
1189                                next = tail;
1190                        in_signature = 0;
1191                }
1192                line = next;
1193        }
1194
1195        if (sig_start)
1196                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1197
1198        return sig_start != NULL;
1199}
1200
1201static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1202{
1203        struct merge_remote_desc *desc;
1204        struct commit_extra_header *mergetag;
1205        char *buf;
1206        unsigned long size, len;
1207        enum object_type type;
1208
1209        desc = merge_remote_util(parent);
1210        if (!desc || !desc->obj)
1211                return;
1212        buf = read_sha1_file(desc->obj->oid.hash, &type, &size);
1213        if (!buf || type != OBJ_TAG)
1214                goto free_return;
1215        len = parse_signature(buf, size);
1216        if (size == len)
1217                goto free_return;
1218        /*
1219         * We could verify this signature and either omit the tag when
1220         * it does not validate, but the integrator may not have the
1221         * public key of the signer of the tag he is merging, while a
1222         * later auditor may have it while auditing, so let's not run
1223         * verify-signed-buffer here for now...
1224         *
1225         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1226         *      warn("warning: signed tag unverified.");
1227         */
1228        mergetag = xcalloc(1, sizeof(*mergetag));
1229        mergetag->key = xstrdup("mergetag");
1230        mergetag->value = buf;
1231        mergetag->len = size;
1232
1233        **tail = mergetag;
1234        *tail = &mergetag->next;
1235        return;
1236
1237free_return:
1238        free(buf);
1239}
1240
1241int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1242{
1243        struct strbuf payload = STRBUF_INIT;
1244        struct strbuf signature = STRBUF_INIT;
1245        int ret = 1;
1246
1247        sigc->result = 'N';
1248
1249        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1250                goto out;
1251        ret = check_signature(payload.buf, payload.len, signature.buf,
1252                signature.len, sigc);
1253
1254 out:
1255        strbuf_release(&payload);
1256        strbuf_release(&signature);
1257
1258        return ret;
1259}
1260
1261
1262
1263void append_merge_tag_headers(struct commit_list *parents,
1264                              struct commit_extra_header ***tail)
1265{
1266        while (parents) {
1267                struct commit *parent = parents->item;
1268                handle_signed_tag(parent, tail);
1269                parents = parents->next;
1270        }
1271}
1272
1273static void add_extra_header(struct strbuf *buffer,
1274                             struct commit_extra_header *extra)
1275{
1276        strbuf_addstr(buffer, extra->key);
1277        if (extra->len)
1278                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1279        else
1280                strbuf_addch(buffer, '\n');
1281}
1282
1283struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1284                                                      const char **exclude)
1285{
1286        struct commit_extra_header *extra = NULL;
1287        unsigned long size;
1288        const char *buffer = get_commit_buffer(commit, &size);
1289        extra = read_commit_extra_header_lines(buffer, size, exclude);
1290        unuse_commit_buffer(commit, buffer);
1291        return extra;
1292}
1293
1294void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1295{
1296        struct commit_extra_header *extra, *to_free;
1297
1298        to_free = read_commit_extra_headers(commit, NULL);
1299        for (extra = to_free; extra; extra = extra->next) {
1300                if (strcmp(extra->key, "mergetag"))
1301                        continue; /* not a merge tag */
1302                fn(commit, extra, data);
1303        }
1304        free_commit_extra_headers(to_free);
1305}
1306
1307static inline int standard_header_field(const char *field, size_t len)
1308{
1309        return ((len == 4 && !memcmp(field, "tree", 4)) ||
1310                (len == 6 && !memcmp(field, "parent", 6)) ||
1311                (len == 6 && !memcmp(field, "author", 6)) ||
1312                (len == 9 && !memcmp(field, "committer", 9)) ||
1313                (len == 8 && !memcmp(field, "encoding", 8)));
1314}
1315
1316static int excluded_header_field(const char *field, size_t len, const char **exclude)
1317{
1318        if (!exclude)
1319                return 0;
1320
1321        while (*exclude) {
1322                size_t xlen = strlen(*exclude);
1323                if (len == xlen && !memcmp(field, *exclude, xlen))
1324                        return 1;
1325                exclude++;
1326        }
1327        return 0;
1328}
1329
1330static struct commit_extra_header *read_commit_extra_header_lines(
1331        const char *buffer, size_t size,
1332        const char **exclude)
1333{
1334        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1335        const char *line, *next, *eof, *eob;
1336        struct strbuf buf = STRBUF_INIT;
1337
1338        for (line = buffer, eob = line + size;
1339             line < eob && *line != '\n';
1340             line = next) {
1341                next = memchr(line, '\n', eob - line);
1342                next = next ? next + 1 : eob;
1343                if (*line == ' ') {
1344                        /* continuation */
1345                        if (it)
1346                                strbuf_add(&buf, line + 1, next - (line + 1));
1347                        continue;
1348                }
1349                if (it)
1350                        it->value = strbuf_detach(&buf, &it->len);
1351                strbuf_reset(&buf);
1352                it = NULL;
1353
1354                eof = memchr(line, ' ', next - line);
1355                if (!eof)
1356                        eof = next;
1357                else if (standard_header_field(line, eof - line) ||
1358                         excluded_header_field(line, eof - line, exclude))
1359                        continue;
1360
1361                it = xcalloc(1, sizeof(*it));
1362                it->key = xmemdupz(line, eof-line);
1363                *tail = it;
1364                tail = &it->next;
1365                if (eof + 1 < next)
1366                        strbuf_add(&buf, eof + 1, next - (eof + 1));
1367        }
1368        if (it)
1369                it->value = strbuf_detach(&buf, &it->len);
1370        return extra;
1371}
1372
1373void free_commit_extra_headers(struct commit_extra_header *extra)
1374{
1375        while (extra) {
1376                struct commit_extra_header *next = extra->next;
1377                free(extra->key);
1378                free(extra->value);
1379                free(extra);
1380                extra = next;
1381        }
1382}
1383
1384int commit_tree(const char *msg, size_t msg_len,
1385                const unsigned char *tree,
1386                struct commit_list *parents, unsigned char *ret,
1387                const char *author, const char *sign_commit)
1388{
1389        struct commit_extra_header *extra = NULL, **tail = &extra;
1390        int result;
1391
1392        append_merge_tag_headers(parents, &tail);
1393        result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1394                                      author, sign_commit, extra);
1395        free_commit_extra_headers(extra);
1396        return result;
1397}
1398
1399static int find_invalid_utf8(const char *buf, int len)
1400{
1401        int offset = 0;
1402        static const unsigned int max_codepoint[] = {
1403                0x7f, 0x7ff, 0xffff, 0x10ffff
1404        };
1405
1406        while (len) {
1407                unsigned char c = *buf++;
1408                int bytes, bad_offset;
1409                unsigned int codepoint;
1410                unsigned int min_val, max_val;
1411
1412                len--;
1413                offset++;
1414
1415                /* Simple US-ASCII? No worries. */
1416                if (c < 0x80)
1417                        continue;
1418
1419                bad_offset = offset-1;
1420
1421                /*
1422                 * Count how many more high bits set: that's how
1423                 * many more bytes this sequence should have.
1424                 */
1425                bytes = 0;
1426                while (c & 0x40) {
1427                        c <<= 1;
1428                        bytes++;
1429                }
1430
1431                /*
1432                 * Must be between 1 and 3 more bytes.  Longer sequences result in
1433                 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1434                 */
1435                if (bytes < 1 || 3 < bytes)
1436                        return bad_offset;
1437
1438                /* Do we *have* that many bytes? */
1439                if (len < bytes)
1440                        return bad_offset;
1441
1442                /*
1443                 * Place the encoded bits at the bottom of the value and compute the
1444                 * valid range.
1445                 */
1446                codepoint = (c & 0x7f) >> bytes;
1447                min_val = max_codepoint[bytes-1] + 1;
1448                max_val = max_codepoint[bytes];
1449
1450                offset += bytes;
1451                len -= bytes;
1452
1453                /* And verify that they are good continuation bytes */
1454                do {
1455                        codepoint <<= 6;
1456                        codepoint |= *buf & 0x3f;
1457                        if ((*buf++ & 0xc0) != 0x80)
1458                                return bad_offset;
1459                } while (--bytes);
1460
1461                /* Reject codepoints that are out of range for the sequence length. */
1462                if (codepoint < min_val || codepoint > max_val)
1463                        return bad_offset;
1464                /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1465                if ((codepoint & 0x1ff800) == 0xd800)
1466                        return bad_offset;
1467                /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1468                if ((codepoint & 0xfffe) == 0xfffe)
1469                        return bad_offset;
1470                /* So are anything in the range U+FDD0..U+FDEF. */
1471                if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1472                        return bad_offset;
1473        }
1474        return -1;
1475}
1476
1477/*
1478 * This verifies that the buffer is in proper utf8 format.
1479 *
1480 * If it isn't, it assumes any non-utf8 characters are Latin1,
1481 * and does the conversion.
1482 */
1483static int verify_utf8(struct strbuf *buf)
1484{
1485        int ok = 1;
1486        long pos = 0;
1487
1488        for (;;) {
1489                int bad;
1490                unsigned char c;
1491                unsigned char replace[2];
1492
1493                bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1494                if (bad < 0)
1495                        return ok;
1496                pos += bad;
1497                ok = 0;
1498                c = buf->buf[pos];
1499                strbuf_remove(buf, pos, 1);
1500
1501                /* We know 'c' must be in the range 128-255 */
1502                replace[0] = 0xc0 + (c >> 6);
1503                replace[1] = 0x80 + (c & 0x3f);
1504                strbuf_insert(buf, pos, replace, 2);
1505                pos += 2;
1506        }
1507}
1508
1509static const char commit_utf8_warn[] =
1510N_("Warning: commit message did not conform to UTF-8.\n"
1511   "You may want to amend it after fixing the message, or set the config\n"
1512   "variable i18n.commitencoding to the encoding your project uses.\n");
1513
1514int commit_tree_extended(const char *msg, size_t msg_len,
1515                         const unsigned char *tree,
1516                         struct commit_list *parents, unsigned char *ret,
1517                         const char *author, const char *sign_commit,
1518                         struct commit_extra_header *extra)
1519{
1520        int result;
1521        int encoding_is_utf8;
1522        struct strbuf buffer;
1523
1524        assert_sha1_type(tree, OBJ_TREE);
1525
1526        if (memchr(msg, '\0', msg_len))
1527                return error("a NUL byte in commit log message not allowed.");
1528
1529        /* Not having i18n.commitencoding is the same as having utf-8 */
1530        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1531
1532        strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1533        strbuf_addf(&buffer, "tree %s\n", sha1_to_hex(tree));
1534
1535        /*
1536         * NOTE! This ordering means that the same exact tree merged with a
1537         * different order of parents will be a _different_ changeset even
1538         * if everything else stays the same.
1539         */
1540        while (parents) {
1541                struct commit *parent = pop_commit(&parents);
1542                strbuf_addf(&buffer, "parent %s\n",
1543                            oid_to_hex(&parent->object.oid));
1544        }
1545
1546        /* Person/date information */
1547        if (!author)
1548                author = git_author_info(IDENT_STRICT);
1549        strbuf_addf(&buffer, "author %s\n", author);
1550        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1551        if (!encoding_is_utf8)
1552                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1553
1554        while (extra) {
1555                add_extra_header(&buffer, extra);
1556                extra = extra->next;
1557        }
1558        strbuf_addch(&buffer, '\n');
1559
1560        /* And add the comment */
1561        strbuf_add(&buffer, msg, msg_len);
1562
1563        /* And check the encoding */
1564        if (encoding_is_utf8 && !verify_utf8(&buffer))
1565                fprintf(stderr, _(commit_utf8_warn));
1566
1567        if (sign_commit && do_sign_commit(&buffer, sign_commit))
1568                return -1;
1569
1570        result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
1571        strbuf_release(&buffer);
1572        return result;
1573}
1574
1575void set_merge_remote_desc(struct commit *commit,
1576                           const char *name, struct object *obj)
1577{
1578        struct merge_remote_desc *desc;
1579        FLEX_ALLOC_STR(desc, name, name);
1580        desc->obj = obj;
1581        commit->util = desc;
1582}
1583
1584struct commit *get_merge_parent(const char *name)
1585{
1586        struct object *obj;
1587        struct commit *commit;
1588        struct object_id oid;
1589        if (get_sha1(name, oid.hash))
1590                return NULL;
1591        obj = parse_object(&oid);
1592        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1593        if (commit && !commit->util)
1594                set_merge_remote_desc(commit, name, obj);
1595        return commit;
1596}
1597
1598/*
1599 * Append a commit to the end of the commit_list.
1600 *
1601 * next starts by pointing to the variable that holds the head of an
1602 * empty commit_list, and is updated to point to the "next" field of
1603 * the last item on the list as new commits are appended.
1604 *
1605 * Usage example:
1606 *
1607 *     struct commit_list *list;
1608 *     struct commit_list **next = &list;
1609 *
1610 *     next = commit_list_append(c1, next);
1611 *     next = commit_list_append(c2, next);
1612 *     assert(commit_list_count(list) == 2);
1613 *     return list;
1614 */
1615struct commit_list **commit_list_append(struct commit *commit,
1616                                        struct commit_list **next)
1617{
1618        struct commit_list *new = xmalloc(sizeof(struct commit_list));
1619        new->item = commit;
1620        *next = new;
1621        new->next = NULL;
1622        return &new->next;
1623}
1624
1625const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1626{
1627        int key_len = strlen(key);
1628        const char *line = msg;
1629
1630        while (line) {
1631                const char *eol = strchrnul(line, '\n');
1632
1633                if (line == eol)
1634                        return NULL;
1635
1636                if (eol - line > key_len &&
1637                    !strncmp(line, key, key_len) &&
1638                    line[key_len] == ' ') {
1639                        *out_len = eol - line - key_len - 1;
1640                        return line + key_len + 1;
1641                }
1642                line = *eol ? eol + 1 : NULL;
1643        }
1644        return NULL;
1645}
1646
1647/*
1648 * Inspect the given string and determine the true "end" of the log message, in
1649 * order to find where to put a new Signed-off-by: line.  Ignored are
1650 * trailing comment lines and blank lines.  To support "git commit -s
1651 * --amend" on an existing commit, we also ignore "Conflicts:".  To
1652 * support "git commit -v", we truncate at cut lines.
1653 *
1654 * Returns the number of bytes from the tail to ignore, to be fed as
1655 * the second parameter to append_signoff().
1656 */
1657int ignore_non_trailer(const char *buf, size_t len)
1658{
1659        int boc = 0;
1660        int bol = 0;
1661        int in_old_conflicts_block = 0;
1662        size_t cutoff = wt_status_locate_end(buf, len);
1663
1664        while (bol < cutoff) {
1665                const char *next_line = memchr(buf + bol, '\n', len - bol);
1666
1667                if (!next_line)
1668                        next_line = buf + len;
1669                else
1670                        next_line++;
1671
1672                if (buf[bol] == comment_line_char || buf[bol] == '\n') {
1673                        /* is this the first of the run of comments? */
1674                        if (!boc)
1675                                boc = bol;
1676                        /* otherwise, it is just continuing */
1677                } else if (starts_with(buf + bol, "Conflicts:\n")) {
1678                        in_old_conflicts_block = 1;
1679                        if (!boc)
1680                                boc = bol;
1681                } else if (in_old_conflicts_block && buf[bol] == '\t') {
1682                        ; /* a pathname in the conflicts block */
1683                } else if (boc) {
1684                        /* the previous was not trailing comment */
1685                        boc = 0;
1686                        in_old_conflicts_block = 0;
1687                }
1688                bol = next_line - buf;
1689        }
1690        return boc ? len - boc : len - cutoff;
1691}