Andrew's git / gitweb.git / commit.c
?
commit.con commit move setting of object->type to alloc_* functions (d36f51c)
   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
  15static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
  16
  17int save_commit_buffer = 1;
  18
  19const char *commit_type = "commit";
  20
  21static struct commit *check_commit(struct object *obj,
  22                                   const unsigned char *sha1,
  23                                   int quiet)
  24{
  25        if (obj->type != OBJ_COMMIT) {
  26                if (!quiet)
  27                        error("Object %s is a %s, not a commit",
  28                              sha1_to_hex(sha1), typename(obj->type));
  29                return NULL;
  30        }
  31        return (struct commit *) obj;
  32}
  33
  34struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
  35                                              int quiet)
  36{
  37        struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
  38
  39        if (!obj)
  40                return NULL;
  41        return check_commit(obj, sha1, quiet);
  42}
  43
  44struct commit *lookup_commit_reference(const unsigned char *sha1)
  45{
  46        return lookup_commit_reference_gently(sha1, 0);
  47}
  48
  49struct commit *lookup_commit_or_die(const unsigned char *sha1, const char *ref_name)
  50{
  51        struct commit *c = lookup_commit_reference(sha1);
  52        if (!c)
  53                die(_("could not parse %s"), ref_name);
  54        if (hashcmp(sha1, c->object.sha1)) {
  55                warning(_("%s %s is not a commit!"),
  56                        ref_name, sha1_to_hex(sha1));
  57        }
  58        return c;
  59}
  60
  61struct commit *lookup_commit(const unsigned char *sha1)
  62{
  63        struct object *obj = lookup_object(sha1);
  64        if (!obj)
  65                return create_object(sha1, alloc_commit_node());
  66        if (!obj->type)
  67                obj->type = OBJ_COMMIT;
  68        return check_commit(obj, sha1, 0);
  69}
  70
  71struct commit *lookup_commit_reference_by_name(const char *name)
  72{
  73        unsigned char sha1[20];
  74        struct commit *commit;
  75
  76        if (get_sha1_committish(name, sha1))
  77                return NULL;
  78        commit = lookup_commit_reference(sha1);
  79        if (parse_commit(commit))
  80                return NULL;
  81        return commit;
  82}
  83
  84static unsigned long parse_commit_date(const char *buf, const char *tail)
  85{
  86        const char *dateptr;
  87
  88        if (buf + 6 >= tail)
  89                return 0;
  90        if (memcmp(buf, "author", 6))
  91                return 0;
  92        while (buf < tail && *buf++ != '\n')
  93                /* nada */;
  94        if (buf + 9 >= tail)
  95                return 0;
  96        if (memcmp(buf, "committer", 9))
  97                return 0;
  98        while (buf < tail && *buf++ != '>')
  99                /* nada */;
 100        if (buf >= tail)
 101                return 0;
 102        dateptr = buf;
 103        while (buf < tail && *buf++ != '\n')
 104                /* nada */;
 105        if (buf >= tail)
 106                return 0;
 107        /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
 108        return strtoul(dateptr, NULL, 10);
 109}
 110
 111static struct commit_graft **commit_graft;
 112static int commit_graft_alloc, commit_graft_nr;
 113
 114static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
 115{
 116        struct commit_graft **commit_graft_table = table;
 117        return commit_graft_table[index]->sha1;
 118}
 119
 120static int commit_graft_pos(const unsigned char *sha1)
 121{
 122        return sha1_pos(sha1, commit_graft, commit_graft_nr,
 123                        commit_graft_sha1_access);
 124}
 125
 126int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 127{
 128        int pos = commit_graft_pos(graft->sha1);
 129
 130        if (0 <= pos) {
 131                if (ignore_dups)
 132                        free(graft);
 133                else {
 134                        free(commit_graft[pos]);
 135                        commit_graft[pos] = graft;
 136                }
 137                return 1;
 138        }
 139        pos = -pos - 1;
 140        ALLOC_GROW(commit_graft, commit_graft_nr + 1, commit_graft_alloc);
 141        commit_graft_nr++;
 142        if (pos < commit_graft_nr)
 143                memmove(commit_graft + pos + 1,
 144                        commit_graft + pos,
 145                        (commit_graft_nr - pos - 1) *
 146                        sizeof(*commit_graft));
 147        commit_graft[pos] = graft;
 148        return 0;
 149}
 150
 151struct commit_graft *read_graft_line(char *buf, int len)
 152{
 153        /* The format is just "Commit Parent1 Parent2 ...\n" */
 154        int i;
 155        struct commit_graft *graft = NULL;
 156
 157        while (len && isspace(buf[len-1]))
 158                buf[--len] = '\0';
 159        if (buf[0] == '#' || buf[0] == '\0')
 160                return NULL;
 161        if ((len + 1) % 41)
 162                goto bad_graft_data;
 163        i = (len + 1) / 41 - 1;
 164        graft = xmalloc(sizeof(*graft) + 20 * i);
 165        graft->nr_parent = i;
 166        if (get_sha1_hex(buf, graft->sha1))
 167                goto bad_graft_data;
 168        for (i = 40; i < len; i += 41) {
 169                if (buf[i] != ' ')
 170                        goto bad_graft_data;
 171                if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
 172                        goto bad_graft_data;
 173        }
 174        return graft;
 175
 176bad_graft_data:
 177        error("bad graft data: %s", buf);
 178        free(graft);
 179        return NULL;
 180}
 181
 182static int read_graft_file(const char *graft_file)
 183{
 184        FILE *fp = fopen(graft_file, "r");
 185        struct strbuf buf = STRBUF_INIT;
 186        if (!fp)
 187                return -1;
 188        while (!strbuf_getwholeline(&buf, fp, '\n')) {
 189                /* The format is just "Commit Parent1 Parent2 ...\n" */
 190                struct commit_graft *graft = read_graft_line(buf.buf, buf.len);
 191                if (!graft)
 192                        continue;
 193                if (register_commit_graft(graft, 1))
 194                        error("duplicate graft data: %s", buf.buf);
 195        }
 196        fclose(fp);
 197        strbuf_release(&buf);
 198        return 0;
 199}
 200
 201static void prepare_commit_graft(void)
 202{
 203        static int commit_graft_prepared;
 204        char *graft_file;
 205
 206        if (commit_graft_prepared)
 207                return;
 208        graft_file = get_graft_file();
 209        read_graft_file(graft_file);
 210        /* make sure shallows are read */
 211        is_repository_shallow();
 212        commit_graft_prepared = 1;
 213}
 214
 215struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 216{
 217        int pos;
 218        prepare_commit_graft();
 219        pos = commit_graft_pos(sha1);
 220        if (pos < 0)
 221                return NULL;
 222        return commit_graft[pos];
 223}
 224
 225int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
 226{
 227        int i, ret;
 228        for (i = ret = 0; i < commit_graft_nr && !ret; i++)
 229                ret = fn(commit_graft[i], cb_data);
 230        return ret;
 231}
 232
 233int unregister_shallow(const unsigned char *sha1)
 234{
 235        int pos = commit_graft_pos(sha1);
 236        if (pos < 0)
 237                return -1;
 238        if (pos + 1 < commit_graft_nr)
 239                memmove(commit_graft + pos, commit_graft + pos + 1,
 240                                sizeof(struct commit_graft *)
 241                                * (commit_graft_nr - pos - 1));
 242        commit_graft_nr--;
 243        return 0;
 244}
 245
 246struct commit_buffer {
 247        void *buffer;
 248        unsigned long size;
 249};
 250define_commit_slab(buffer_slab, struct commit_buffer);
 251static struct buffer_slab buffer_slab = COMMIT_SLAB_INIT(1, buffer_slab);
 252
 253void set_commit_buffer(struct commit *commit, void *buffer, unsigned long size)
 254{
 255        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 256        v->buffer = buffer;
 257        v->size = size;
 258}
 259
 260const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
 261{
 262        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 263        if (sizep)
 264                *sizep = v->size;
 265        return v->buffer;
 266}
 267
 268const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
 269{
 270        const void *ret = get_cached_commit_buffer(commit, sizep);
 271        if (!ret) {
 272                enum object_type type;
 273                unsigned long size;
 274                ret = read_sha1_file(commit->object.sha1, &type, &size);
 275                if (!ret)
 276                        die("cannot read commit object %s",
 277                            sha1_to_hex(commit->object.sha1));
 278                if (type != OBJ_COMMIT)
 279                        die("expected commit for %s, got %s",
 280                            sha1_to_hex(commit->object.sha1), typename(type));
 281                if (sizep)
 282                        *sizep = size;
 283        }
 284        return ret;
 285}
 286
 287void unuse_commit_buffer(const struct commit *commit, const void *buffer)
 288{
 289        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 290        if (v->buffer != buffer)
 291                free((void *)buffer);
 292}
 293
 294void free_commit_buffer(struct commit *commit)
 295{
 296        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 297        free(v->buffer);
 298        v->buffer = NULL;
 299        v->size = 0;
 300}
 301
 302const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 303{
 304        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 305        void *ret;
 306
 307        ret = v->buffer;
 308        if (sizep)
 309                *sizep = v->size;
 310
 311        v->buffer = NULL;
 312        v->size = 0;
 313        return ret;
 314}
 315
 316int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
 317{
 318        const char *tail = buffer;
 319        const char *bufptr = buffer;
 320        unsigned char parent[20];
 321        struct commit_list **pptr;
 322        struct commit_graft *graft;
 323
 324        if (item->object.parsed)
 325                return 0;
 326        item->object.parsed = 1;
 327        tail += size;
 328        if (tail <= bufptr + 46 || memcmp(bufptr, "tree ", 5) || bufptr[45] != '\n')
 329                return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 330        if (get_sha1_hex(bufptr + 5, parent) < 0)
 331                return error("bad tree pointer in commit %s",
 332                             sha1_to_hex(item->object.sha1));
 333        item->tree = lookup_tree(parent);
 334        bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 335        pptr = &item->parents;
 336
 337        graft = lookup_commit_graft(item->object.sha1);
 338        while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
 339                struct commit *new_parent;
 340
 341                if (tail <= bufptr + 48 ||
 342                    get_sha1_hex(bufptr + 7, parent) ||
 343                    bufptr[47] != '\n')
 344                        return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 345                bufptr += 48;
 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(struct commit *item)
 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.sha1, &type, &size);
 383        if (!buffer)
 384                return error("Could not read %s",
 385                             sha1_to_hex(item->object.sha1));
 386        if (type != OBJ_COMMIT) {
 387                free(buffer);
 388                return error("Object %s not a commit",
 389                             sha1_to_hex(item->object.sha1));
 390        }
 391        ret = parse_commit_buffer(item, buffer, size);
 392        if (save_commit_buffer && !ret) {
 393                set_commit_buffer(item, buffer, size);
 394                return 0;
 395        }
 396        free(buffer);
 397        return ret;
 398}
 399
 400void parse_commit_or_die(struct commit *item)
 401{
 402        if (parse_commit(item))
 403                die("unable to parse commit %s",
 404                    item ? sha1_to_hex(item->object.sha1) : "(null)");
 405}
 406
 407int find_commit_subject(const char *commit_buffer, const char **subject)
 408{
 409        const char *eol;
 410        const char *p = commit_buffer;
 411
 412        while (*p && (*p != '\n' || p[1] != '\n'))
 413                p++;
 414        if (*p) {
 415                p += 2;
 416                for (eol = p; *eol && *eol != '\n'; eol++)
 417                        ; /* do nothing */
 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                struct commit_list *new;
 449                new = xmalloc(sizeof(struct commit_list));
 450                new->item = list->item;
 451                new->next = NULL;
 452                *pp = new;
 453                pp = &new->next;
 454                list = list->next;
 455        }
 456        return head;
 457}
 458
 459void free_commit_list(struct commit_list *list)
 460{
 461        while (list) {
 462                struct commit_list *temp = list;
 463                list = temp->next;
 464                free(temp);
 465        }
 466}
 467
 468struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 469{
 470        struct commit_list **pp = list;
 471        struct commit_list *p;
 472        while ((p = *pp) != NULL) {
 473                if (p->item->date < item->date) {
 474                        break;
 475                }
 476                pp = &p->next;
 477        }
 478        return commit_list_insert(item, pp);
 479}
 480
 481static int commit_list_compare_by_date(const void *a, const void *b)
 482{
 483        unsigned long a_date = ((const struct commit_list *)a)->item->date;
 484        unsigned long b_date = ((const struct commit_list *)b)->item->date;
 485        if (a_date < b_date)
 486                return 1;
 487        if (a_date > b_date)
 488                return -1;
 489        return 0;
 490}
 491
 492static void *commit_list_get_next(const void *a)
 493{
 494        return ((const struct commit_list *)a)->next;
 495}
 496
 497static void commit_list_set_next(void *a, void *next)
 498{
 499        ((struct commit_list *)a)->next = next;
 500}
 501
 502void commit_list_sort_by_date(struct commit_list **list)
 503{
 504        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 505                                commit_list_compare_by_date);
 506}
 507
 508struct commit *pop_most_recent_commit(struct commit_list **list,
 509                                      unsigned int mark)
 510{
 511        struct commit *ret = (*list)->item;
 512        struct commit_list *parents = ret->parents;
 513        struct commit_list *old = *list;
 514
 515        *list = (*list)->next;
 516        free(old);
 517
 518        while (parents) {
 519                struct commit *commit = parents->item;
 520                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 521                        commit->object.flags |= mark;
 522                        commit_list_insert_by_date(commit, list);
 523                }
 524                parents = parents->next;
 525        }
 526        return ret;
 527}
 528
 529static void clear_commit_marks_1(struct commit_list **plist,
 530                                 struct commit *commit, unsigned int mark)
 531{
 532        while (commit) {
 533                struct commit_list *parents;
 534
 535                if (!(mark & commit->object.flags))
 536                        return;
 537
 538                commit->object.flags &= ~mark;
 539
 540                parents = commit->parents;
 541                if (!parents)
 542                        return;
 543
 544                while ((parents = parents->next))
 545                        commit_list_insert(parents->item, plist);
 546
 547                commit = commit->parents->item;
 548        }
 549}
 550
 551void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 552{
 553        struct commit_list *list = NULL;
 554
 555        while (nr--) {
 556                commit_list_insert(*commit, &list);
 557                commit++;
 558        }
 559        while (list)
 560                clear_commit_marks_1(&list, pop_commit(&list), mark);
 561}
 562
 563void clear_commit_marks(struct commit *commit, unsigned int mark)
 564{
 565        clear_commit_marks_many(1, &commit, mark);
 566}
 567
 568void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
 569{
 570        struct object *object;
 571        struct commit *commit;
 572        unsigned int i;
 573
 574        for (i = 0; i < a->nr; i++) {
 575                object = a->objects[i].item;
 576                commit = lookup_commit_reference_gently(object->sha1, 1);
 577                if (commit)
 578                        clear_commit_marks(commit, mark);
 579        }
 580}
 581
 582struct commit *pop_commit(struct commit_list **stack)
 583{
 584        struct commit_list *top = *stack;
 585        struct commit *item = top ? top->item : NULL;
 586
 587        if (top) {
 588                *stack = top->next;
 589                free(top);
 590        }
 591        return item;
 592}
 593
 594/*
 595 * Topological sort support
 596 */
 597
 598/* count number of children that have not been emitted */
 599define_commit_slab(indegree_slab, int);
 600
 601/* record author-date for each commit object */
 602define_commit_slab(author_date_slab, unsigned long);
 603
 604static void record_author_date(struct author_date_slab *author_date,
 605                               struct commit *commit)
 606{
 607        const char *buf, *line_end, *ident_line;
 608        const char *buffer = get_commit_buffer(commit, NULL);
 609        struct ident_split ident;
 610        char *date_end;
 611        unsigned long date;
 612
 613        for (buf = buffer; buf; buf = line_end + 1) {
 614                line_end = strchrnul(buf, '\n');
 615                ident_line = skip_prefix(buf, "author ");
 616                if (!ident_line) {
 617                        if (!line_end[0] || line_end[1] == '\n')
 618                                return; /* end of header */
 619                        continue;
 620                }
 621                if (split_ident_line(&ident,
 622                                     ident_line, line_end - ident_line) ||
 623                    !ident.date_begin || !ident.date_end)
 624                        goto fail_exit; /* malformed "author" line */
 625                break;
 626        }
 627
 628        date = strtoul(ident.date_begin, &date_end, 10);
 629        if (date_end != ident.date_end)
 630                goto fail_exit; /* malformed date */
 631        *(author_date_slab_at(author_date, commit)) = date;
 632
 633fail_exit:
 634        unuse_commit_buffer(commit, buffer);
 635}
 636
 637static int compare_commits_by_author_date(const void *a_, const void *b_,
 638                                          void *cb_data)
 639{
 640        const struct commit *a = a_, *b = b_;
 641        struct author_date_slab *author_date = cb_data;
 642        unsigned long a_date = *(author_date_slab_at(author_date, a));
 643        unsigned long b_date = *(author_date_slab_at(author_date, b));
 644
 645        /* newer commits with larger date first */
 646        if (a_date < b_date)
 647                return 1;
 648        else if (a_date > b_date)
 649                return -1;
 650        return 0;
 651}
 652
 653int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 654{
 655        const struct commit *a = a_, *b = b_;
 656        /* newer commits with larger date first */
 657        if (a->date < b->date)
 658                return 1;
 659        else if (a->date > b->date)
 660                return -1;
 661        return 0;
 662}
 663
 664/*
 665 * Performs an in-place topological sort on the list supplied.
 666 */
 667void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 668{
 669        struct commit_list *next, *orig = *list;
 670        struct commit_list **pptr;
 671        struct indegree_slab indegree;
 672        struct prio_queue queue;
 673        struct commit *commit;
 674        struct author_date_slab author_date;
 675
 676        if (!orig)
 677                return;
 678        *list = NULL;
 679
 680        init_indegree_slab(&indegree);
 681        memset(&queue, '\0', sizeof(queue));
 682
 683        switch (sort_order) {
 684        default: /* REV_SORT_IN_GRAPH_ORDER */
 685                queue.compare = NULL;
 686                break;
 687        case REV_SORT_BY_COMMIT_DATE:
 688                queue.compare = compare_commits_by_commit_date;
 689                break;
 690        case REV_SORT_BY_AUTHOR_DATE:
 691                init_author_date_slab(&author_date);
 692                queue.compare = compare_commits_by_author_date;
 693                queue.cb_data = &author_date;
 694                break;
 695        }
 696
 697        /* Mark them and clear the indegree */
 698        for (next = orig; next; next = next->next) {
 699                struct commit *commit = next->item;
 700                *(indegree_slab_at(&indegree, commit)) = 1;
 701                /* also record the author dates, if needed */
 702                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 703                        record_author_date(&author_date, commit);
 704        }
 705
 706        /* update the indegree */
 707        for (next = orig; next; next = next->next) {
 708                struct commit_list *parents = next->item->parents;
 709                while (parents) {
 710                        struct commit *parent = parents->item;
 711                        int *pi = indegree_slab_at(&indegree, parent);
 712
 713                        if (*pi)
 714                                (*pi)++;
 715                        parents = parents->next;
 716                }
 717        }
 718
 719        /*
 720         * find the tips
 721         *
 722         * tips are nodes not reachable from any other node in the list
 723         *
 724         * the tips serve as a starting set for the work queue.
 725         */
 726        for (next = orig; next; next = next->next) {
 727                struct commit *commit = next->item;
 728
 729                if (*(indegree_slab_at(&indegree, commit)) == 1)
 730                        prio_queue_put(&queue, commit);
 731        }
 732
 733        /*
 734         * This is unfortunate; the initial tips need to be shown
 735         * in the order given from the revision traversal machinery.
 736         */
 737        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 738                prio_queue_reverse(&queue);
 739
 740        /* We no longer need the commit list */
 741        free_commit_list(orig);
 742
 743        pptr = list;
 744        *list = NULL;
 745        while ((commit = prio_queue_get(&queue)) != NULL) {
 746                struct commit_list *parents;
 747
 748                for (parents = commit->parents; parents ; parents = parents->next) {
 749                        struct commit *parent = parents->item;
 750                        int *pi = indegree_slab_at(&indegree, parent);
 751
 752                        if (!*pi)
 753                                continue;
 754
 755                        /*
 756                         * parents are only enqueued for emission
 757                         * when all their children have been emitted thereby
 758                         * guaranteeing topological order.
 759                         */
 760                        if (--(*pi) == 1)
 761                                prio_queue_put(&queue, parent);
 762                }
 763                /*
 764                 * all children of commit have already been
 765                 * emitted. we can emit it now.
 766                 */
 767                *(indegree_slab_at(&indegree, commit)) = 0;
 768
 769                pptr = &commit_list_insert(commit, pptr)->next;
 770        }
 771
 772        clear_indegree_slab(&indegree);
 773        clear_prio_queue(&queue);
 774        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 775                clear_author_date_slab(&author_date);
 776}
 777
 778/* merge-base stuff */
 779
 780/* Remember to update object flag allocation in object.h */
 781#define PARENT1         (1u<<16)
 782#define PARENT2         (1u<<17)
 783#define STALE           (1u<<18)
 784#define RESULT          (1u<<19)
 785
 786static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 787
 788static struct commit *interesting(struct commit_list *list)
 789{
 790        while (list) {
 791                struct commit *commit = list->item;
 792                list = list->next;
 793                if (commit->object.flags & STALE)
 794                        continue;
 795                return commit;
 796        }
 797        return NULL;
 798}
 799
 800/* all input commits in one and twos[] must have been parsed! */
 801static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
 802{
 803        struct commit_list *list = NULL;
 804        struct commit_list *result = NULL;
 805        int i;
 806
 807        one->object.flags |= PARENT1;
 808        commit_list_insert_by_date(one, &list);
 809        if (!n)
 810                return list;
 811        for (i = 0; i < n; i++) {
 812                twos[i]->object.flags |= PARENT2;
 813                commit_list_insert_by_date(twos[i], &list);
 814        }
 815
 816        while (interesting(list)) {
 817                struct commit *commit;
 818                struct commit_list *parents;
 819                struct commit_list *next;
 820                int flags;
 821
 822                commit = list->item;
 823                next = list->next;
 824                free(list);
 825                list = next;
 826
 827                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 828                if (flags == (PARENT1 | PARENT2)) {
 829                        if (!(commit->object.flags & RESULT)) {
 830                                commit->object.flags |= RESULT;
 831                                commit_list_insert_by_date(commit, &result);
 832                        }
 833                        /* Mark parents of a found merge stale */
 834                        flags |= STALE;
 835                }
 836                parents = commit->parents;
 837                while (parents) {
 838                        struct commit *p = parents->item;
 839                        parents = parents->next;
 840                        if ((p->object.flags & flags) == flags)
 841                                continue;
 842                        if (parse_commit(p))
 843                                return NULL;
 844                        p->object.flags |= flags;
 845                        commit_list_insert_by_date(p, &list);
 846                }
 847        }
 848
 849        free_commit_list(list);
 850        return result;
 851}
 852
 853static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 854{
 855        struct commit_list *list = NULL;
 856        struct commit_list *result = NULL;
 857        int i;
 858
 859        for (i = 0; i < n; i++) {
 860                if (one == twos[i])
 861                        /*
 862                         * We do not mark this even with RESULT so we do not
 863                         * have to clean it up.
 864                         */
 865                        return commit_list_insert(one, &result);
 866        }
 867
 868        if (parse_commit(one))
 869                return NULL;
 870        for (i = 0; i < n; i++) {
 871                if (parse_commit(twos[i]))
 872                        return NULL;
 873        }
 874
 875        list = paint_down_to_common(one, n, twos);
 876
 877        while (list) {
 878                struct commit_list *next = list->next;
 879                if (!(list->item->object.flags & STALE))
 880                        commit_list_insert_by_date(list->item, &result);
 881                free(list);
 882                list = next;
 883        }
 884        return result;
 885}
 886
 887struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 888{
 889        struct commit_list *i, *j, *k, *ret = NULL;
 890
 891        if (!in)
 892                return ret;
 893
 894        commit_list_insert(in->item, &ret);
 895
 896        for (i = in->next; i; i = i->next) {
 897                struct commit_list *new = NULL, *end = NULL;
 898
 899                for (j = ret; j; j = j->next) {
 900                        struct commit_list *bases;
 901                        bases = get_merge_bases(i->item, j->item, 1);
 902                        if (!new)
 903                                new = bases;
 904                        else
 905                                end->next = bases;
 906                        for (k = bases; k; k = k->next)
 907                                end = k;
 908                }
 909                ret = new;
 910        }
 911        return ret;
 912}
 913
 914static int remove_redundant(struct commit **array, int cnt)
 915{
 916        /*
 917         * Some commit in the array may be an ancestor of
 918         * another commit.  Move such commit to the end of
 919         * the array, and return the number of commits that
 920         * are independent from each other.
 921         */
 922        struct commit **work;
 923        unsigned char *redundant;
 924        int *filled_index;
 925        int i, j, filled;
 926
 927        work = xcalloc(cnt, sizeof(*work));
 928        redundant = xcalloc(cnt, 1);
 929        filled_index = xmalloc(sizeof(*filled_index) * (cnt - 1));
 930
 931        for (i = 0; i < cnt; i++)
 932                parse_commit(array[i]);
 933        for (i = 0; i < cnt; i++) {
 934                struct commit_list *common;
 935
 936                if (redundant[i])
 937                        continue;
 938                for (j = filled = 0; j < cnt; j++) {
 939                        if (i == j || redundant[j])
 940                                continue;
 941                        filled_index[filled] = j;
 942                        work[filled++] = array[j];
 943                }
 944                common = paint_down_to_common(array[i], filled, work);
 945                if (array[i]->object.flags & PARENT2)
 946                        redundant[i] = 1;
 947                for (j = 0; j < filled; j++)
 948                        if (work[j]->object.flags & PARENT1)
 949                                redundant[filled_index[j]] = 1;
 950                clear_commit_marks(array[i], all_flags);
 951                for (j = 0; j < filled; j++)
 952                        clear_commit_marks(work[j], all_flags);
 953                free_commit_list(common);
 954        }
 955
 956        /* Now collect the result */
 957        memcpy(work, array, sizeof(*array) * cnt);
 958        for (i = filled = 0; i < cnt; i++)
 959                if (!redundant[i])
 960                        array[filled++] = work[i];
 961        for (j = filled, i = 0; i < cnt; i++)
 962                if (redundant[i])
 963                        array[j++] = work[i];
 964        free(work);
 965        free(redundant);
 966        free(filled_index);
 967        return filled;
 968}
 969
 970struct commit_list *get_merge_bases_many(struct commit *one,
 971                                         int n,
 972                                         struct commit **twos,
 973                                         int cleanup)
 974{
 975        struct commit_list *list;
 976        struct commit **rslt;
 977        struct commit_list *result;
 978        int cnt, i;
 979
 980        result = merge_bases_many(one, n, twos);
 981        for (i = 0; i < n; i++) {
 982                if (one == twos[i])
 983                        return result;
 984        }
 985        if (!result || !result->next) {
 986                if (cleanup) {
 987                        clear_commit_marks(one, all_flags);
 988                        clear_commit_marks_many(n, twos, all_flags);
 989                }
 990                return result;
 991        }
 992
 993        /* There are more than one */
 994        cnt = 0;
 995        list = result;
 996        while (list) {
 997                list = list->next;
 998                cnt++;
 999        }
1000        rslt = xcalloc(cnt, sizeof(*rslt));
1001        for (list = result, i = 0; list; list = list->next)
1002                rslt[i++] = list->item;
1003        free_commit_list(result);
1004
1005        clear_commit_marks(one, all_flags);
1006        clear_commit_marks_many(n, twos, all_flags);
1007
1008        cnt = remove_redundant(rslt, cnt);
1009        result = NULL;
1010        for (i = 0; i < cnt; i++)
1011                commit_list_insert_by_date(rslt[i], &result);
1012        free(rslt);
1013        return result;
1014}
1015
1016struct commit_list *get_merge_bases(struct commit *one, struct commit *two,
1017                                    int cleanup)
1018{
1019        return get_merge_bases_many(one, 1, &two, cleanup);
1020}
1021
1022/*
1023 * Is "commit" a descendant of one of the elements on the "with_commit" list?
1024 */
1025int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
1026{
1027        if (!with_commit)
1028                return 1;
1029        while (with_commit) {
1030                struct commit *other;
1031
1032                other = with_commit->item;
1033                with_commit = with_commit->next;
1034                if (in_merge_bases(other, commit))
1035                        return 1;
1036        }
1037        return 0;
1038}
1039
1040/*
1041 * Is "commit" an ancestor of one of the "references"?
1042 */
1043int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1044{
1045        struct commit_list *bases;
1046        int ret = 0, i;
1047
1048        if (parse_commit(commit))
1049                return ret;
1050        for (i = 0; i < nr_reference; i++)
1051                if (parse_commit(reference[i]))
1052                        return ret;
1053
1054        bases = paint_down_to_common(commit, nr_reference, reference);
1055        if (commit->object.flags & PARENT2)
1056                ret = 1;
1057        clear_commit_marks(commit, all_flags);
1058        clear_commit_marks_many(nr_reference, reference, all_flags);
1059        free_commit_list(bases);
1060        return ret;
1061}
1062
1063/*
1064 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1065 */
1066int in_merge_bases(struct commit *commit, struct commit *reference)
1067{
1068        return in_merge_bases_many(commit, 1, &reference);
1069}
1070
1071struct commit_list *reduce_heads(struct commit_list *heads)
1072{
1073        struct commit_list *p;
1074        struct commit_list *result = NULL, **tail = &result;
1075        struct commit **array;
1076        int num_head, i;
1077
1078        if (!heads)
1079                return NULL;
1080
1081        /* Uniquify */
1082        for (p = heads; p; p = p->next)
1083                p->item->object.flags &= ~STALE;
1084        for (p = heads, num_head = 0; p; p = p->next) {
1085                if (p->item->object.flags & STALE)
1086                        continue;
1087                p->item->object.flags |= STALE;
1088                num_head++;
1089        }
1090        array = xcalloc(num_head, sizeof(*array));
1091        for (p = heads, i = 0; p; p = p->next) {
1092                if (p->item->object.flags & STALE) {
1093                        array[i++] = p->item;
1094                        p->item->object.flags &= ~STALE;
1095                }
1096        }
1097        num_head = remove_redundant(array, num_head);
1098        for (i = 0; i < num_head; i++)
1099                tail = &commit_list_insert(array[i], tail)->next;
1100        return result;
1101}
1102
1103static const char gpg_sig_header[] = "gpgsig";
1104static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1105
1106static int do_sign_commit(struct strbuf *buf, const char *keyid)
1107{
1108        struct strbuf sig = STRBUF_INIT;
1109        int inspos, copypos;
1110
1111        /* find the end of the header */
1112        inspos = strstr(buf->buf, "\n\n") - buf->buf + 1;
1113
1114        if (!keyid || !*keyid)
1115                keyid = get_signing_key();
1116        if (sign_buffer(buf, &sig, keyid)) {
1117                strbuf_release(&sig);
1118                return -1;
1119        }
1120
1121        for (copypos = 0; sig.buf[copypos]; ) {
1122                const char *bol = sig.buf + copypos;
1123                const char *eol = strchrnul(bol, '\n');
1124                int len = (eol - bol) + !!*eol;
1125
1126                if (!copypos) {
1127                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1128                        inspos += gpg_sig_header_len;
1129                }
1130                strbuf_insert(buf, inspos++, " ", 1);
1131                strbuf_insert(buf, inspos, bol, len);
1132                inspos += len;
1133                copypos += len;
1134        }
1135        strbuf_release(&sig);
1136        return 0;
1137}
1138
1139int parse_signed_commit(const struct commit *commit,
1140                        struct strbuf *payload, struct strbuf *signature)
1141{
1142
1143        unsigned long size;
1144        const char *buffer = get_commit_buffer(commit, &size);
1145        int in_signature, saw_signature = -1;
1146        const char *line, *tail;
1147
1148        line = buffer;
1149        tail = buffer + size;
1150        in_signature = 0;
1151        saw_signature = 0;
1152        while (line < tail) {
1153                const char *sig = NULL;
1154                const char *next = memchr(line, '\n', tail - line);
1155
1156                next = next ? next + 1 : tail;
1157                if (in_signature && line[0] == ' ')
1158                        sig = line + 1;
1159                else if (starts_with(line, gpg_sig_header) &&
1160                         line[gpg_sig_header_len] == ' ')
1161                        sig = line + gpg_sig_header_len + 1;
1162                if (sig) {
1163                        strbuf_add(signature, sig, next - sig);
1164                        saw_signature = 1;
1165                        in_signature = 1;
1166                } else {
1167                        if (*line == '\n')
1168                                /* dump the whole remainder of the buffer */
1169                                next = tail;
1170                        strbuf_add(payload, line, next - line);
1171                        in_signature = 0;
1172                }
1173                line = next;
1174        }
1175        unuse_commit_buffer(commit, buffer);
1176        return saw_signature;
1177}
1178
1179static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1180{
1181        struct merge_remote_desc *desc;
1182        struct commit_extra_header *mergetag;
1183        char *buf;
1184        unsigned long size, len;
1185        enum object_type type;
1186
1187        desc = merge_remote_util(parent);
1188        if (!desc || !desc->obj)
1189                return;
1190        buf = read_sha1_file(desc->obj->sha1, &type, &size);
1191        if (!buf || type != OBJ_TAG)
1192                goto free_return;
1193        len = parse_signature(buf, size);
1194        if (size == len)
1195                goto free_return;
1196        /*
1197         * We could verify this signature and either omit the tag when
1198         * it does not validate, but the integrator may not have the
1199         * public key of the signer of the tag he is merging, while a
1200         * later auditor may have it while auditing, so let's not run
1201         * verify-signed-buffer here for now...
1202         *
1203         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1204         *      warn("warning: signed tag unverified.");
1205         */
1206        mergetag = xcalloc(1, sizeof(*mergetag));
1207        mergetag->key = xstrdup("mergetag");
1208        mergetag->value = buf;
1209        mergetag->len = size;
1210
1211        **tail = mergetag;
1212        *tail = &mergetag->next;
1213        return;
1214
1215free_return:
1216        free(buf);
1217}
1218
1219static struct {
1220        char result;
1221        const char *check;
1222} sigcheck_gpg_status[] = {
1223        { 'G', "\n[GNUPG:] GOODSIG " },
1224        { 'B', "\n[GNUPG:] BADSIG " },
1225        { 'U', "\n[GNUPG:] TRUST_NEVER" },
1226        { 'U', "\n[GNUPG:] TRUST_UNDEFINED" },
1227};
1228
1229static void parse_gpg_output(struct signature_check *sigc)
1230{
1231        const char *buf = sigc->gpg_status;
1232        int i;
1233
1234        /* Iterate over all search strings */
1235        for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_status); i++) {
1236                const char *found, *next;
1237
1238                found = skip_prefix(buf, sigcheck_gpg_status[i].check + 1);
1239                if (!found) {
1240                        found = strstr(buf, sigcheck_gpg_status[i].check);
1241                        if (!found)
1242                                continue;
1243                        found += strlen(sigcheck_gpg_status[i].check);
1244                }
1245                sigc->result = sigcheck_gpg_status[i].result;
1246                /* The trust messages are not followed by key/signer information */
1247                if (sigc->result != 'U') {
1248                        sigc->key = xmemdupz(found, 16);
1249                        found += 17;
1250                        next = strchrnul(found, '\n');
1251                        sigc->signer = xmemdupz(found, next - found);
1252                }
1253        }
1254}
1255
1256void check_commit_signature(const struct commit* commit, struct signature_check *sigc)
1257{
1258        struct strbuf payload = STRBUF_INIT;
1259        struct strbuf signature = STRBUF_INIT;
1260        struct strbuf gpg_output = STRBUF_INIT;
1261        struct strbuf gpg_status = STRBUF_INIT;
1262        int status;
1263
1264        sigc->result = 'N';
1265
1266        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1267                goto out;
1268        status = verify_signed_buffer(payload.buf, payload.len,
1269                                      signature.buf, signature.len,
1270                                      &gpg_output, &gpg_status);
1271        if (status && !gpg_output.len)
1272                goto out;
1273        sigc->gpg_output = strbuf_detach(&gpg_output, NULL);
1274        sigc->gpg_status = strbuf_detach(&gpg_status, NULL);
1275        parse_gpg_output(sigc);
1276
1277 out:
1278        strbuf_release(&gpg_status);
1279        strbuf_release(&gpg_output);
1280        strbuf_release(&payload);
1281        strbuf_release(&signature);
1282}
1283
1284
1285
1286void append_merge_tag_headers(struct commit_list *parents,
1287                              struct commit_extra_header ***tail)
1288{
1289        while (parents) {
1290                struct commit *parent = parents->item;
1291                handle_signed_tag(parent, tail);
1292                parents = parents->next;
1293        }
1294}
1295
1296static void add_extra_header(struct strbuf *buffer,
1297                             struct commit_extra_header *extra)
1298{
1299        strbuf_addstr(buffer, extra->key);
1300        if (extra->len)
1301                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1302        else
1303                strbuf_addch(buffer, '\n');
1304}
1305
1306struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1307                                                      const char **exclude)
1308{
1309        struct commit_extra_header *extra = NULL;
1310        unsigned long size;
1311        const char *buffer = get_commit_buffer(commit, &size);
1312        extra = read_commit_extra_header_lines(buffer, size, exclude);
1313        unuse_commit_buffer(commit, buffer);
1314        return extra;
1315}
1316
1317static inline int standard_header_field(const char *field, size_t len)
1318{
1319        return ((len == 4 && !memcmp(field, "tree ", 5)) ||
1320                (len == 6 && !memcmp(field, "parent ", 7)) ||
1321                (len == 6 && !memcmp(field, "author ", 7)) ||
1322                (len == 9 && !memcmp(field, "committer ", 10)) ||
1323                (len == 8 && !memcmp(field, "encoding ", 9)));
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 &&
1334                    !memcmp(field, *exclude, xlen) && field[xlen] == ' ')
1335                        return 1;
1336                exclude++;
1337        }
1338        return 0;
1339}
1340
1341static struct commit_extra_header *read_commit_extra_header_lines(
1342        const char *buffer, size_t size,
1343        const char **exclude)
1344{
1345        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1346        const char *line, *next, *eof, *eob;
1347        struct strbuf buf = STRBUF_INIT;
1348
1349        for (line = buffer, eob = line + size;
1350             line < eob && *line != '\n';
1351             line = next) {
1352                next = memchr(line, '\n', eob - line);
1353                next = next ? next + 1 : eob;
1354                if (*line == ' ') {
1355                        /* continuation */
1356                        if (it)
1357                                strbuf_add(&buf, line + 1, next - (line + 1));
1358                        continue;
1359                }
1360                if (it)
1361                        it->value = strbuf_detach(&buf, &it->len);
1362                strbuf_reset(&buf);
1363                it = NULL;
1364
1365                eof = strchr(line, ' ');
1366                if (next <= eof)
1367                        eof = next;
1368
1369                if (standard_header_field(line, eof - line) ||
1370                    excluded_header_field(line, eof - line, exclude))
1371                        continue;
1372
1373                it = xcalloc(1, sizeof(*it));
1374                it->key = xmemdupz(line, eof-line);
1375                *tail = it;
1376                tail = &it->next;
1377                if (eof + 1 < next)
1378                        strbuf_add(&buf, eof + 1, next - (eof + 1));
1379        }
1380        if (it)
1381                it->value = strbuf_detach(&buf, &it->len);
1382        return extra;
1383}
1384
1385void free_commit_extra_headers(struct commit_extra_header *extra)
1386{
1387        while (extra) {
1388                struct commit_extra_header *next = extra->next;
1389                free(extra->key);
1390                free(extra->value);
1391                free(extra);
1392                extra = next;
1393        }
1394}
1395
1396int commit_tree(const char *msg, size_t msg_len,
1397                const unsigned char *tree,
1398                struct commit_list *parents, unsigned char *ret,
1399                const char *author, const char *sign_commit)
1400{
1401        struct commit_extra_header *extra = NULL, **tail = &extra;
1402        int result;
1403
1404        append_merge_tag_headers(parents, &tail);
1405        result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1406                                      author, sign_commit, extra);
1407        free_commit_extra_headers(extra);
1408        return result;
1409}
1410
1411static int find_invalid_utf8(const char *buf, int len)
1412{
1413        int offset = 0;
1414        static const unsigned int max_codepoint[] = {
1415                0x7f, 0x7ff, 0xffff, 0x10ffff
1416        };
1417
1418        while (len) {
1419                unsigned char c = *buf++;
1420                int bytes, bad_offset;
1421                unsigned int codepoint;
1422                unsigned int min_val, max_val;
1423
1424                len--;
1425                offset++;
1426
1427                /* Simple US-ASCII? No worries. */
1428                if (c < 0x80)
1429                        continue;
1430
1431                bad_offset = offset-1;
1432
1433                /*
1434                 * Count how many more high bits set: that's how
1435                 * many more bytes this sequence should have.
1436                 */
1437                bytes = 0;
1438                while (c & 0x40) {
1439                        c <<= 1;
1440                        bytes++;
1441                }
1442
1443                /*
1444                 * Must be between 1 and 3 more bytes.  Longer sequences result in
1445                 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1446                 */
1447                if (bytes < 1 || 3 < bytes)
1448                        return bad_offset;
1449
1450                /* Do we *have* that many bytes? */
1451                if (len < bytes)
1452                        return bad_offset;
1453
1454                /*
1455                 * Place the encoded bits at the bottom of the value and compute the
1456                 * valid range.
1457                 */
1458                codepoint = (c & 0x7f) >> bytes;
1459                min_val = max_codepoint[bytes-1] + 1;
1460                max_val = max_codepoint[bytes];
1461
1462                offset += bytes;
1463                len -= bytes;
1464
1465                /* And verify that they are good continuation bytes */
1466                do {
1467                        codepoint <<= 6;
1468                        codepoint |= *buf & 0x3f;
1469                        if ((*buf++ & 0xc0) != 0x80)
1470                                return bad_offset;
1471                } while (--bytes);
1472
1473                /* Reject codepoints that are out of range for the sequence length. */
1474                if (codepoint < min_val || codepoint > max_val)
1475                        return bad_offset;
1476                /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1477                if ((codepoint & 0x1ff800) == 0xd800)
1478                        return bad_offset;
1479                /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1480                if ((codepoint & 0xfffe) == 0xfffe)
1481                        return bad_offset;
1482                /* So are anything in the range U+FDD0..U+FDEF. */
1483                if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1484                        return bad_offset;
1485        }
1486        return -1;
1487}
1488
1489/*
1490 * This verifies that the buffer is in proper utf8 format.
1491 *
1492 * If it isn't, it assumes any non-utf8 characters are Latin1,
1493 * and does the conversion.
1494 */
1495static int verify_utf8(struct strbuf *buf)
1496{
1497        int ok = 1;
1498        long pos = 0;
1499
1500        for (;;) {
1501                int bad;
1502                unsigned char c;
1503                unsigned char replace[2];
1504
1505                bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1506                if (bad < 0)
1507                        return ok;
1508                pos += bad;
1509                ok = 0;
1510                c = buf->buf[pos];
1511                strbuf_remove(buf, pos, 1);
1512
1513                /* We know 'c' must be in the range 128-255 */
1514                replace[0] = 0xc0 + (c >> 6);
1515                replace[1] = 0x80 + (c & 0x3f);
1516                strbuf_insert(buf, pos, replace, 2);
1517                pos += 2;
1518        }
1519}
1520
1521static const char commit_utf8_warn[] =
1522"Warning: commit message did not conform to UTF-8.\n"
1523"You may want to amend it after fixing the message, or set the config\n"
1524"variable i18n.commitencoding to the encoding your project uses.\n";
1525
1526int commit_tree_extended(const char *msg, size_t msg_len,
1527                         const unsigned char *tree,
1528                         struct commit_list *parents, unsigned char *ret,
1529                         const char *author, const char *sign_commit,
1530                         struct commit_extra_header *extra)
1531{
1532        int result;
1533        int encoding_is_utf8;
1534        struct strbuf buffer;
1535
1536        assert_sha1_type(tree, OBJ_TREE);
1537
1538        if (memchr(msg, '\0', msg_len))
1539                return error("a NUL byte in commit log message not allowed.");
1540
1541        /* Not having i18n.commitencoding is the same as having utf-8 */
1542        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1543
1544        strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1545        strbuf_addf(&buffer, "tree %s\n", sha1_to_hex(tree));
1546
1547        /*
1548         * NOTE! This ordering means that the same exact tree merged with a
1549         * different order of parents will be a _different_ changeset even
1550         * if everything else stays the same.
1551         */
1552        while (parents) {
1553                struct commit_list *next = parents->next;
1554                struct commit *parent = parents->item;
1555
1556                strbuf_addf(&buffer, "parent %s\n",
1557                            sha1_to_hex(parent->object.sha1));
1558                free(parents);
1559                parents = next;
1560        }
1561
1562        /* Person/date information */
1563        if (!author)
1564                author = git_author_info(IDENT_STRICT);
1565        strbuf_addf(&buffer, "author %s\n", author);
1566        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1567        if (!encoding_is_utf8)
1568                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1569
1570        while (extra) {
1571                add_extra_header(&buffer, extra);
1572                extra = extra->next;
1573        }
1574        strbuf_addch(&buffer, '\n');
1575
1576        /* And add the comment */
1577        strbuf_add(&buffer, msg, msg_len);
1578
1579        /* And check the encoding */
1580        if (encoding_is_utf8 && !verify_utf8(&buffer))
1581                fprintf(stderr, commit_utf8_warn);
1582
1583        if (sign_commit && do_sign_commit(&buffer, sign_commit))
1584                return -1;
1585
1586        result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
1587        strbuf_release(&buffer);
1588        return result;
1589}
1590
1591struct commit *get_merge_parent(const char *name)
1592{
1593        struct object *obj;
1594        struct commit *commit;
1595        unsigned char sha1[20];
1596        if (get_sha1(name, sha1))
1597                return NULL;
1598        obj = parse_object(sha1);
1599        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1600        if (commit && !commit->util) {
1601                struct merge_remote_desc *desc;
1602                desc = xmalloc(sizeof(*desc));
1603                desc->obj = obj;
1604                desc->name = strdup(name);
1605                commit->util = desc;
1606        }
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 = xmalloc(sizeof(struct commit_list));
1631        new->item = commit;
1632        *next = new;
1633        new->next = NULL;
1634        return &new->next;
1635}
1636
1637void print_commit_list(struct commit_list *list,
1638                       const char *format_cur,
1639                       const char *format_last)
1640{
1641        for ( ; list; list = list->next) {
1642                const char *format = list->next ? format_cur : format_last;
1643                printf(format, sha1_to_hex(list->item->object.sha1));
1644        }
1645}