Andrew's git / gitweb.git / commit.c
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commit.con commit paint_down_to_common: use prio_queue (73f43f2)
   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                struct commit *c = alloc_commit_node();
  66                return create_object(sha1, OBJ_COMMIT, c);
  67        }
  68        if (!obj->type)
  69                obj->type = OBJ_COMMIT;
  70        return check_commit(obj, sha1, 0);
  71}
  72
  73struct commit *lookup_commit_reference_by_name(const char *name)
  74{
  75        unsigned char sha1[20];
  76        struct commit *commit;
  77
  78        if (get_sha1_committish(name, sha1))
  79                return NULL;
  80        commit = lookup_commit_reference(sha1);
  81        if (parse_commit(commit))
  82                return NULL;
  83        return commit;
  84}
  85
  86static unsigned long parse_commit_date(const char *buf, const char *tail)
  87{
  88        const char *dateptr;
  89
  90        if (buf + 6 >= tail)
  91                return 0;
  92        if (memcmp(buf, "author", 6))
  93                return 0;
  94        while (buf < tail && *buf++ != '\n')
  95                /* nada */;
  96        if (buf + 9 >= tail)
  97                return 0;
  98        if (memcmp(buf, "committer", 9))
  99                return 0;
 100        while (buf < tail && *buf++ != '>')
 101                /* nada */;
 102        if (buf >= tail)
 103                return 0;
 104        dateptr = buf;
 105        while (buf < tail && *buf++ != '\n')
 106                /* nada */;
 107        if (buf >= tail)
 108                return 0;
 109        /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
 110        return strtoul(dateptr, NULL, 10);
 111}
 112
 113static struct commit_graft **commit_graft;
 114static int commit_graft_alloc, commit_graft_nr;
 115
 116static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
 117{
 118        struct commit_graft **commit_graft_table = table;
 119        return commit_graft_table[index]->sha1;
 120}
 121
 122static int commit_graft_pos(const unsigned char *sha1)
 123{
 124        return sha1_pos(sha1, commit_graft, commit_graft_nr,
 125                        commit_graft_sha1_access);
 126}
 127
 128int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 129{
 130        int pos = commit_graft_pos(graft->sha1);
 131
 132        if (0 <= pos) {
 133                if (ignore_dups)
 134                        free(graft);
 135                else {
 136                        free(commit_graft[pos]);
 137                        commit_graft[pos] = graft;
 138                }
 139                return 1;
 140        }
 141        pos = -pos - 1;
 142        ALLOC_GROW(commit_graft, commit_graft_nr + 1, commit_graft_alloc);
 143        commit_graft_nr++;
 144        if (pos < commit_graft_nr)
 145                memmove(commit_graft + pos + 1,
 146                        commit_graft + pos,
 147                        (commit_graft_nr - pos - 1) *
 148                        sizeof(*commit_graft));
 149        commit_graft[pos] = graft;
 150        return 0;
 151}
 152
 153struct commit_graft *read_graft_line(char *buf, int len)
 154{
 155        /* The format is just "Commit Parent1 Parent2 ...\n" */
 156        int i;
 157        struct commit_graft *graft = NULL;
 158
 159        while (len && isspace(buf[len-1]))
 160                buf[--len] = '\0';
 161        if (buf[0] == '#' || buf[0] == '\0')
 162                return NULL;
 163        if ((len + 1) % 41)
 164                goto bad_graft_data;
 165        i = (len + 1) / 41 - 1;
 166        graft = xmalloc(sizeof(*graft) + 20 * i);
 167        graft->nr_parent = i;
 168        if (get_sha1_hex(buf, graft->sha1))
 169                goto bad_graft_data;
 170        for (i = 40; i < len; i += 41) {
 171                if (buf[i] != ' ')
 172                        goto bad_graft_data;
 173                if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
 174                        goto bad_graft_data;
 175        }
 176        return graft;
 177
 178bad_graft_data:
 179        error("bad graft data: %s", buf);
 180        free(graft);
 181        return NULL;
 182}
 183
 184static int read_graft_file(const char *graft_file)
 185{
 186        FILE *fp = fopen(graft_file, "r");
 187        struct strbuf buf = STRBUF_INIT;
 188        if (!fp)
 189                return -1;
 190        while (!strbuf_getwholeline(&buf, fp, '\n')) {
 191                /* The format is just "Commit Parent1 Parent2 ...\n" */
 192                struct commit_graft *graft = read_graft_line(buf.buf, buf.len);
 193                if (!graft)
 194                        continue;
 195                if (register_commit_graft(graft, 1))
 196                        error("duplicate graft data: %s", buf.buf);
 197        }
 198        fclose(fp);
 199        strbuf_release(&buf);
 200        return 0;
 201}
 202
 203static void prepare_commit_graft(void)
 204{
 205        static int commit_graft_prepared;
 206        char *graft_file;
 207
 208        if (commit_graft_prepared)
 209                return;
 210        graft_file = get_graft_file();
 211        read_graft_file(graft_file);
 212        /* make sure shallows are read */
 213        is_repository_shallow();
 214        commit_graft_prepared = 1;
 215}
 216
 217struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 218{
 219        int pos;
 220        prepare_commit_graft();
 221        pos = commit_graft_pos(sha1);
 222        if (pos < 0)
 223                return NULL;
 224        return commit_graft[pos];
 225}
 226
 227int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
 228{
 229        int i, ret;
 230        for (i = ret = 0; i < commit_graft_nr && !ret; i++)
 231                ret = fn(commit_graft[i], cb_data);
 232        return ret;
 233}
 234
 235int unregister_shallow(const unsigned char *sha1)
 236{
 237        int pos = commit_graft_pos(sha1);
 238        if (pos < 0)
 239                return -1;
 240        if (pos + 1 < commit_graft_nr)
 241                memmove(commit_graft + pos, commit_graft + pos + 1,
 242                                sizeof(struct commit_graft *)
 243                                * (commit_graft_nr - pos - 1));
 244        commit_graft_nr--;
 245        return 0;
 246}
 247
 248struct commit_buffer {
 249        void *buffer;
 250        unsigned long size;
 251};
 252define_commit_slab(buffer_slab, struct commit_buffer);
 253static struct buffer_slab buffer_slab = COMMIT_SLAB_INIT(1, buffer_slab);
 254
 255void set_commit_buffer(struct commit *commit, void *buffer, unsigned long size)
 256{
 257        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 258        v->buffer = buffer;
 259        v->size = size;
 260}
 261
 262const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
 263{
 264        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 265        if (sizep)
 266                *sizep = v->size;
 267        return v->buffer;
 268}
 269
 270const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
 271{
 272        const void *ret = get_cached_commit_buffer(commit, sizep);
 273        if (!ret) {
 274                enum object_type type;
 275                unsigned long size;
 276                ret = read_sha1_file(commit->object.sha1, &type, &size);
 277                if (!ret)
 278                        die("cannot read commit object %s",
 279                            sha1_to_hex(commit->object.sha1));
 280                if (type != OBJ_COMMIT)
 281                        die("expected commit for %s, got %s",
 282                            sha1_to_hex(commit->object.sha1), typename(type));
 283                if (sizep)
 284                        *sizep = size;
 285        }
 286        return ret;
 287}
 288
 289void unuse_commit_buffer(const struct commit *commit, const void *buffer)
 290{
 291        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 292        if (v->buffer != buffer)
 293                free((void *)buffer);
 294}
 295
 296void free_commit_buffer(struct commit *commit)
 297{
 298        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 299        free(v->buffer);
 300        v->buffer = NULL;
 301        v->size = 0;
 302}
 303
 304const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 305{
 306        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 307        void *ret;
 308
 309        ret = v->buffer;
 310        if (sizep)
 311                *sizep = v->size;
 312
 313        v->buffer = NULL;
 314        v->size = 0;
 315        return ret;
 316}
 317
 318int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
 319{
 320        const char *tail = buffer;
 321        const char *bufptr = buffer;
 322        unsigned char parent[20];
 323        struct commit_list **pptr;
 324        struct commit_graft *graft;
 325
 326        if (item->object.parsed)
 327                return 0;
 328        item->object.parsed = 1;
 329        tail += size;
 330        if (tail <= bufptr + 46 || memcmp(bufptr, "tree ", 5) || bufptr[45] != '\n')
 331                return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 332        if (get_sha1_hex(bufptr + 5, parent) < 0)
 333                return error("bad tree pointer in commit %s",
 334                             sha1_to_hex(item->object.sha1));
 335        item->tree = lookup_tree(parent);
 336        bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 337        pptr = &item->parents;
 338
 339        graft = lookup_commit_graft(item->object.sha1);
 340        while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
 341                struct commit *new_parent;
 342
 343                if (tail <= bufptr + 48 ||
 344                    get_sha1_hex(bufptr + 7, parent) ||
 345                    bufptr[47] != '\n')
 346                        return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 347                bufptr += 48;
 348                /*
 349                 * The clone is shallow if nr_parent < 0, and we must
 350                 * not traverse its real parents even when we unhide them.
 351                 */
 352                if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
 353                        continue;
 354                new_parent = lookup_commit(parent);
 355                if (new_parent)
 356                        pptr = &commit_list_insert(new_parent, pptr)->next;
 357        }
 358        if (graft) {
 359                int i;
 360                struct commit *new_parent;
 361                for (i = 0; i < graft->nr_parent; i++) {
 362                        new_parent = lookup_commit(graft->parent[i]);
 363                        if (!new_parent)
 364                                continue;
 365                        pptr = &commit_list_insert(new_parent, pptr)->next;
 366                }
 367        }
 368        item->date = parse_commit_date(bufptr, tail);
 369
 370        return 0;
 371}
 372
 373int parse_commit(struct commit *item)
 374{
 375        enum object_type type;
 376        void *buffer;
 377        unsigned long size;
 378        int ret;
 379
 380        if (!item)
 381                return -1;
 382        if (item->object.parsed)
 383                return 0;
 384        buffer = read_sha1_file(item->object.sha1, &type, &size);
 385        if (!buffer)
 386                return error("Could not read %s",
 387                             sha1_to_hex(item->object.sha1));
 388        if (type != OBJ_COMMIT) {
 389                free(buffer);
 390                return error("Object %s not a commit",
 391                             sha1_to_hex(item->object.sha1));
 392        }
 393        ret = parse_commit_buffer(item, buffer, size);
 394        if (save_commit_buffer && !ret) {
 395                set_commit_buffer(item, buffer, size);
 396                return 0;
 397        }
 398        free(buffer);
 399        return ret;
 400}
 401
 402void parse_commit_or_die(struct commit *item)
 403{
 404        if (parse_commit(item))
 405                die("unable to parse commit %s",
 406                    item ? sha1_to_hex(item->object.sha1) : "(null)");
 407}
 408
 409int find_commit_subject(const char *commit_buffer, const char **subject)
 410{
 411        const char *eol;
 412        const char *p = commit_buffer;
 413
 414        while (*p && (*p != '\n' || p[1] != '\n'))
 415                p++;
 416        if (*p) {
 417                p += 2;
 418                for (eol = p; *eol && *eol != '\n'; eol++)
 419                        ; /* do nothing */
 420        } else
 421                eol = p;
 422
 423        *subject = p;
 424
 425        return eol - p;
 426}
 427
 428struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 429{
 430        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 431        new_list->item = item;
 432        new_list->next = *list_p;
 433        *list_p = new_list;
 434        return new_list;
 435}
 436
 437unsigned commit_list_count(const struct commit_list *l)
 438{
 439        unsigned c = 0;
 440        for (; l; l = l->next )
 441                c++;
 442        return c;
 443}
 444
 445struct commit_list *copy_commit_list(struct commit_list *list)
 446{
 447        struct commit_list *head = NULL;
 448        struct commit_list **pp = &head;
 449        while (list) {
 450                struct commit_list *new;
 451                new = xmalloc(sizeof(struct commit_list));
 452                new->item = list->item;
 453                new->next = NULL;
 454                *pp = new;
 455                pp = &new->next;
 456                list = list->next;
 457        }
 458        return head;
 459}
 460
 461void free_commit_list(struct commit_list *list)
 462{
 463        while (list) {
 464                struct commit_list *temp = list;
 465                list = temp->next;
 466                free(temp);
 467        }
 468}
 469
 470struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 471{
 472        struct commit_list **pp = list;
 473        struct commit_list *p;
 474        while ((p = *pp) != NULL) {
 475                if (p->item->date < item->date) {
 476                        break;
 477                }
 478                pp = &p->next;
 479        }
 480        return commit_list_insert(item, pp);
 481}
 482
 483static int commit_list_compare_by_date(const void *a, const void *b)
 484{
 485        unsigned long a_date = ((const struct commit_list *)a)->item->date;
 486        unsigned long b_date = ((const struct commit_list *)b)->item->date;
 487        if (a_date < b_date)
 488                return 1;
 489        if (a_date > b_date)
 490                return -1;
 491        return 0;
 492}
 493
 494static void *commit_list_get_next(const void *a)
 495{
 496        return ((const struct commit_list *)a)->next;
 497}
 498
 499static void commit_list_set_next(void *a, void *next)
 500{
 501        ((struct commit_list *)a)->next = next;
 502}
 503
 504void commit_list_sort_by_date(struct commit_list **list)
 505{
 506        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 507                                commit_list_compare_by_date);
 508}
 509
 510struct commit *pop_most_recent_commit(struct commit_list **list,
 511                                      unsigned int mark)
 512{
 513        struct commit *ret = (*list)->item;
 514        struct commit_list *parents = ret->parents;
 515        struct commit_list *old = *list;
 516
 517        *list = (*list)->next;
 518        free(old);
 519
 520        while (parents) {
 521                struct commit *commit = parents->item;
 522                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 523                        commit->object.flags |= mark;
 524                        commit_list_insert_by_date(commit, list);
 525                }
 526                parents = parents->next;
 527        }
 528        return ret;
 529}
 530
 531static void clear_commit_marks_1(struct commit_list **plist,
 532                                 struct commit *commit, unsigned int mark)
 533{
 534        while (commit) {
 535                struct commit_list *parents;
 536
 537                if (!(mark & commit->object.flags))
 538                        return;
 539
 540                commit->object.flags &= ~mark;
 541
 542                parents = commit->parents;
 543                if (!parents)
 544                        return;
 545
 546                while ((parents = parents->next))
 547                        commit_list_insert(parents->item, plist);
 548
 549                commit = commit->parents->item;
 550        }
 551}
 552
 553void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 554{
 555        struct commit_list *list = NULL;
 556
 557        while (nr--) {
 558                commit_list_insert(*commit, &list);
 559                commit++;
 560        }
 561        while (list)
 562                clear_commit_marks_1(&list, pop_commit(&list), mark);
 563}
 564
 565void clear_commit_marks(struct commit *commit, unsigned int mark)
 566{
 567        clear_commit_marks_many(1, &commit, mark);
 568}
 569
 570void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
 571{
 572        struct object *object;
 573        struct commit *commit;
 574        unsigned int i;
 575
 576        for (i = 0; i < a->nr; i++) {
 577                object = a->objects[i].item;
 578                commit = lookup_commit_reference_gently(object->sha1, 1);
 579                if (commit)
 580                        clear_commit_marks(commit, mark);
 581        }
 582}
 583
 584struct commit *pop_commit(struct commit_list **stack)
 585{
 586        struct commit_list *top = *stack;
 587        struct commit *item = top ? top->item : NULL;
 588
 589        if (top) {
 590                *stack = top->next;
 591                free(top);
 592        }
 593        return item;
 594}
 595
 596/*
 597 * Topological sort support
 598 */
 599
 600/* count number of children that have not been emitted */
 601define_commit_slab(indegree_slab, int);
 602
 603/* record author-date for each commit object */
 604define_commit_slab(author_date_slab, unsigned long);
 605
 606static void record_author_date(struct author_date_slab *author_date,
 607                               struct commit *commit)
 608{
 609        const char *buf, *line_end, *ident_line;
 610        const char *buffer = get_commit_buffer(commit, NULL);
 611        struct ident_split ident;
 612        char *date_end;
 613        unsigned long date;
 614
 615        for (buf = buffer; buf; buf = line_end + 1) {
 616                line_end = strchrnul(buf, '\n');
 617                if (!skip_prefix(buf, "author ", &ident_line)) {
 618                        if (!line_end[0] || line_end[1] == '\n')
 619                                return; /* end of header */
 620                        continue;
 621                }
 622                if (split_ident_line(&ident,
 623                                     ident_line, line_end - ident_line) ||
 624                    !ident.date_begin || !ident.date_end)
 625                        goto fail_exit; /* malformed "author" line */
 626                break;
 627        }
 628
 629        date = strtoul(ident.date_begin, &date_end, 10);
 630        if (date_end != ident.date_end)
 631                goto fail_exit; /* malformed date */
 632        *(author_date_slab_at(author_date, commit)) = date;
 633
 634fail_exit:
 635        unuse_commit_buffer(commit, buffer);
 636}
 637
 638static int compare_commits_by_author_date(const void *a_, const void *b_,
 639                                          void *cb_data)
 640{
 641        const struct commit *a = a_, *b = b_;
 642        struct author_date_slab *author_date = cb_data;
 643        unsigned long a_date = *(author_date_slab_at(author_date, a));
 644        unsigned long b_date = *(author_date_slab_at(author_date, b));
 645
 646        /* newer commits with larger date first */
 647        if (a_date < b_date)
 648                return 1;
 649        else if (a_date > b_date)
 650                return -1;
 651        return 0;
 652}
 653
 654int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 655{
 656        const struct commit *a = a_, *b = b_;
 657        /* newer commits with larger date first */
 658        if (a->date < b->date)
 659                return 1;
 660        else if (a->date > b->date)
 661                return -1;
 662        return 0;
 663}
 664
 665/*
 666 * Performs an in-place topological sort on the list supplied.
 667 */
 668void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 669{
 670        struct commit_list *next, *orig = *list;
 671        struct commit_list **pptr;
 672        struct indegree_slab indegree;
 673        struct prio_queue queue;
 674        struct commit *commit;
 675        struct author_date_slab author_date;
 676
 677        if (!orig)
 678                return;
 679        *list = NULL;
 680
 681        init_indegree_slab(&indegree);
 682        memset(&queue, '\0', sizeof(queue));
 683
 684        switch (sort_order) {
 685        default: /* REV_SORT_IN_GRAPH_ORDER */
 686                queue.compare = NULL;
 687                break;
 688        case REV_SORT_BY_COMMIT_DATE:
 689                queue.compare = compare_commits_by_commit_date;
 690                break;
 691        case REV_SORT_BY_AUTHOR_DATE:
 692                init_author_date_slab(&author_date);
 693                queue.compare = compare_commits_by_author_date;
 694                queue.cb_data = &author_date;
 695                break;
 696        }
 697
 698        /* Mark them and clear the indegree */
 699        for (next = orig; next; next = next->next) {
 700                struct commit *commit = next->item;
 701                *(indegree_slab_at(&indegree, commit)) = 1;
 702                /* also record the author dates, if needed */
 703                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 704                        record_author_date(&author_date, commit);
 705        }
 706
 707        /* update the indegree */
 708        for (next = orig; next; next = next->next) {
 709                struct commit_list *parents = next->item->parents;
 710                while (parents) {
 711                        struct commit *parent = parents->item;
 712                        int *pi = indegree_slab_at(&indegree, parent);
 713
 714                        if (*pi)
 715                                (*pi)++;
 716                        parents = parents->next;
 717                }
 718        }
 719
 720        /*
 721         * find the tips
 722         *
 723         * tips are nodes not reachable from any other node in the list
 724         *
 725         * the tips serve as a starting set for the work queue.
 726         */
 727        for (next = orig; next; next = next->next) {
 728                struct commit *commit = next->item;
 729
 730                if (*(indegree_slab_at(&indegree, commit)) == 1)
 731                        prio_queue_put(&queue, commit);
 732        }
 733
 734        /*
 735         * This is unfortunate; the initial tips need to be shown
 736         * in the order given from the revision traversal machinery.
 737         */
 738        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 739                prio_queue_reverse(&queue);
 740
 741        /* We no longer need the commit list */
 742        free_commit_list(orig);
 743
 744        pptr = list;
 745        *list = NULL;
 746        while ((commit = prio_queue_get(&queue)) != NULL) {
 747                struct commit_list *parents;
 748
 749                for (parents = commit->parents; parents ; parents = parents->next) {
 750                        struct commit *parent = parents->item;
 751                        int *pi = indegree_slab_at(&indegree, parent);
 752
 753                        if (!*pi)
 754                                continue;
 755
 756                        /*
 757                         * parents are only enqueued for emission
 758                         * when all their children have been emitted thereby
 759                         * guaranteeing topological order.
 760                         */
 761                        if (--(*pi) == 1)
 762                                prio_queue_put(&queue, parent);
 763                }
 764                /*
 765                 * all children of commit have already been
 766                 * emitted. we can emit it now.
 767                 */
 768                *(indegree_slab_at(&indegree, commit)) = 0;
 769
 770                pptr = &commit_list_insert(commit, pptr)->next;
 771        }
 772
 773        clear_indegree_slab(&indegree);
 774        clear_prio_queue(&queue);
 775        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 776                clear_author_date_slab(&author_date);
 777}
 778
 779/* merge-base stuff */
 780
 781/* Remember to update object flag allocation in object.h */
 782#define PARENT1         (1u<<16)
 783#define PARENT2         (1u<<17)
 784#define STALE           (1u<<18)
 785#define RESULT          (1u<<19)
 786
 787static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 788
 789static int queue_has_nonstale(struct prio_queue *queue)
 790{
 791        int i;
 792        for (i = 0; i < queue->nr; i++) {
 793                struct commit *commit = queue->array[i].data;
 794                if (!(commit->object.flags & STALE))
 795                        return 1;
 796        }
 797        return 0;
 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 prio_queue queue = { compare_commits_by_commit_date };
 804        struct commit_list *result = NULL;
 805        int i;
 806
 807        one->object.flags |= PARENT1;
 808        if (!n) {
 809                commit_list_append(one, &result);
 810                return result;
 811        }
 812        prio_queue_put(&queue, one);
 813
 814        for (i = 0; i < n; i++) {
 815                twos[i]->object.flags |= PARENT2;
 816                prio_queue_put(&queue, twos[i]);
 817        }
 818
 819        while (queue_has_nonstale(&queue)) {
 820                struct commit *commit = prio_queue_get(&queue);
 821                struct commit_list *parents;
 822                int flags;
 823
 824                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 825                if (flags == (PARENT1 | PARENT2)) {
 826                        if (!(commit->object.flags & RESULT)) {
 827                                commit->object.flags |= RESULT;
 828                                commit_list_insert_by_date(commit, &result);
 829                        }
 830                        /* Mark parents of a found merge stale */
 831                        flags |= STALE;
 832                }
 833                parents = commit->parents;
 834                while (parents) {
 835                        struct commit *p = parents->item;
 836                        parents = parents->next;
 837                        if ((p->object.flags & flags) == flags)
 838                                continue;
 839                        if (parse_commit(p))
 840                                return NULL;
 841                        p->object.flags |= flags;
 842                        prio_queue_put(&queue, p);
 843                }
 844        }
 845
 846        clear_prio_queue(&queue);
 847        return result;
 848}
 849
 850static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 851{
 852        struct commit_list *list = NULL;
 853        struct commit_list *result = NULL;
 854        int i;
 855
 856        for (i = 0; i < n; i++) {
 857                if (one == twos[i])
 858                        /*
 859                         * We do not mark this even with RESULT so we do not
 860                         * have to clean it up.
 861                         */
 862                        return commit_list_insert(one, &result);
 863        }
 864
 865        if (parse_commit(one))
 866                return NULL;
 867        for (i = 0; i < n; i++) {
 868                if (parse_commit(twos[i]))
 869                        return NULL;
 870        }
 871
 872        list = paint_down_to_common(one, n, twos);
 873
 874        while (list) {
 875                struct commit_list *next = list->next;
 876                if (!(list->item->object.flags & STALE))
 877                        commit_list_insert_by_date(list->item, &result);
 878                free(list);
 879                list = next;
 880        }
 881        return result;
 882}
 883
 884struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 885{
 886        struct commit_list *i, *j, *k, *ret = NULL;
 887
 888        if (!in)
 889                return ret;
 890
 891        commit_list_insert(in->item, &ret);
 892
 893        for (i = in->next; i; i = i->next) {
 894                struct commit_list *new = NULL, *end = NULL;
 895
 896                for (j = ret; j; j = j->next) {
 897                        struct commit_list *bases;
 898                        bases = get_merge_bases(i->item, j->item, 1);
 899                        if (!new)
 900                                new = bases;
 901                        else
 902                                end->next = bases;
 903                        for (k = bases; k; k = k->next)
 904                                end = k;
 905                }
 906                ret = new;
 907        }
 908        return ret;
 909}
 910
 911static int remove_redundant(struct commit **array, int cnt)
 912{
 913        /*
 914         * Some commit in the array may be an ancestor of
 915         * another commit.  Move such commit to the end of
 916         * the array, and return the number of commits that
 917         * are independent from each other.
 918         */
 919        struct commit **work;
 920        unsigned char *redundant;
 921        int *filled_index;
 922        int i, j, filled;
 923
 924        work = xcalloc(cnt, sizeof(*work));
 925        redundant = xcalloc(cnt, 1);
 926        filled_index = xmalloc(sizeof(*filled_index) * (cnt - 1));
 927
 928        for (i = 0; i < cnt; i++)
 929                parse_commit(array[i]);
 930        for (i = 0; i < cnt; i++) {
 931                struct commit_list *common;
 932
 933                if (redundant[i])
 934                        continue;
 935                for (j = filled = 0; j < cnt; j++) {
 936                        if (i == j || redundant[j])
 937                                continue;
 938                        filled_index[filled] = j;
 939                        work[filled++] = array[j];
 940                }
 941                common = paint_down_to_common(array[i], filled, work);
 942                if (array[i]->object.flags & PARENT2)
 943                        redundant[i] = 1;
 944                for (j = 0; j < filled; j++)
 945                        if (work[j]->object.flags & PARENT1)
 946                                redundant[filled_index[j]] = 1;
 947                clear_commit_marks(array[i], all_flags);
 948                for (j = 0; j < filled; j++)
 949                        clear_commit_marks(work[j], all_flags);
 950                free_commit_list(common);
 951        }
 952
 953        /* Now collect the result */
 954        memcpy(work, array, sizeof(*array) * cnt);
 955        for (i = filled = 0; i < cnt; i++)
 956                if (!redundant[i])
 957                        array[filled++] = work[i];
 958        for (j = filled, i = 0; i < cnt; i++)
 959                if (redundant[i])
 960                        array[j++] = work[i];
 961        free(work);
 962        free(redundant);
 963        free(filled_index);
 964        return filled;
 965}
 966
 967struct commit_list *get_merge_bases_many(struct commit *one,
 968                                         int n,
 969                                         struct commit **twos,
 970                                         int cleanup)
 971{
 972        struct commit_list *list;
 973        struct commit **rslt;
 974        struct commit_list *result;
 975        int cnt, i;
 976
 977        result = merge_bases_many(one, n, twos);
 978        for (i = 0; i < n; i++) {
 979                if (one == twos[i])
 980                        return result;
 981        }
 982        if (!result || !result->next) {
 983                if (cleanup) {
 984                        clear_commit_marks(one, all_flags);
 985                        clear_commit_marks_many(n, twos, all_flags);
 986                }
 987                return result;
 988        }
 989
 990        /* There are more than one */
 991        cnt = 0;
 992        list = result;
 993        while (list) {
 994                list = list->next;
 995                cnt++;
 996        }
 997        rslt = xcalloc(cnt, sizeof(*rslt));
 998        for (list = result, i = 0; list; list = list->next)
 999                rslt[i++] = list->item;
1000        free_commit_list(result);
1001
1002        clear_commit_marks(one, all_flags);
1003        clear_commit_marks_many(n, twos, all_flags);
1004
1005        cnt = remove_redundant(rslt, cnt);
1006        result = NULL;
1007        for (i = 0; i < cnt; i++)
1008                commit_list_insert_by_date(rslt[i], &result);
1009        free(rslt);
1010        return result;
1011}
1012
1013struct commit_list *get_merge_bases(struct commit *one, struct commit *two,
1014                                    int cleanup)
1015{
1016        return get_merge_bases_many(one, 1, &two, cleanup);
1017}
1018
1019/*
1020 * Is "commit" a descendant of one of the elements on the "with_commit" list?
1021 */
1022int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
1023{
1024        if (!with_commit)
1025                return 1;
1026        while (with_commit) {
1027                struct commit *other;
1028
1029                other = with_commit->item;
1030                with_commit = with_commit->next;
1031                if (in_merge_bases(other, commit))
1032                        return 1;
1033        }
1034        return 0;
1035}
1036
1037/*
1038 * Is "commit" an ancestor of one of the "references"?
1039 */
1040int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1041{
1042        struct commit_list *bases;
1043        int ret = 0, i;
1044
1045        if (parse_commit(commit))
1046                return ret;
1047        for (i = 0; i < nr_reference; i++)
1048                if (parse_commit(reference[i]))
1049                        return ret;
1050
1051        bases = paint_down_to_common(commit, nr_reference, reference);
1052        if (commit->object.flags & PARENT2)
1053                ret = 1;
1054        clear_commit_marks(commit, all_flags);
1055        clear_commit_marks_many(nr_reference, reference, all_flags);
1056        free_commit_list(bases);
1057        return ret;
1058}
1059
1060/*
1061 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1062 */
1063int in_merge_bases(struct commit *commit, struct commit *reference)
1064{
1065        return in_merge_bases_many(commit, 1, &reference);
1066}
1067
1068struct commit_list *reduce_heads(struct commit_list *heads)
1069{
1070        struct commit_list *p;
1071        struct commit_list *result = NULL, **tail = &result;
1072        struct commit **array;
1073        int num_head, i;
1074
1075        if (!heads)
1076                return NULL;
1077
1078        /* Uniquify */
1079        for (p = heads; p; p = p->next)
1080                p->item->object.flags &= ~STALE;
1081        for (p = heads, num_head = 0; p; p = p->next) {
1082                if (p->item->object.flags & STALE)
1083                        continue;
1084                p->item->object.flags |= STALE;
1085                num_head++;
1086        }
1087        array = xcalloc(num_head, sizeof(*array));
1088        for (p = heads, i = 0; p; p = p->next) {
1089                if (p->item->object.flags & STALE) {
1090                        array[i++] = p->item;
1091                        p->item->object.flags &= ~STALE;
1092                }
1093        }
1094        num_head = remove_redundant(array, num_head);
1095        for (i = 0; i < num_head; i++)
1096                tail = &commit_list_insert(array[i], tail)->next;
1097        return result;
1098}
1099
1100static const char gpg_sig_header[] = "gpgsig";
1101static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1102
1103static int do_sign_commit(struct strbuf *buf, const char *keyid)
1104{
1105        struct strbuf sig = STRBUF_INIT;
1106        int inspos, copypos;
1107
1108        /* find the end of the header */
1109        inspos = strstr(buf->buf, "\n\n") - buf->buf + 1;
1110
1111        if (!keyid || !*keyid)
1112                keyid = get_signing_key();
1113        if (sign_buffer(buf, &sig, keyid)) {
1114                strbuf_release(&sig);
1115                return -1;
1116        }
1117
1118        for (copypos = 0; sig.buf[copypos]; ) {
1119                const char *bol = sig.buf + copypos;
1120                const char *eol = strchrnul(bol, '\n');
1121                int len = (eol - bol) + !!*eol;
1122
1123                if (!copypos) {
1124                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1125                        inspos += gpg_sig_header_len;
1126                }
1127                strbuf_insert(buf, inspos++, " ", 1);
1128                strbuf_insert(buf, inspos, bol, len);
1129                inspos += len;
1130                copypos += len;
1131        }
1132        strbuf_release(&sig);
1133        return 0;
1134}
1135
1136int parse_signed_commit(const struct commit *commit,
1137                        struct strbuf *payload, struct strbuf *signature)
1138{
1139
1140        unsigned long size;
1141        const char *buffer = get_commit_buffer(commit, &size);
1142        int in_signature, saw_signature = -1;
1143        const char *line, *tail;
1144
1145        line = buffer;
1146        tail = buffer + size;
1147        in_signature = 0;
1148        saw_signature = 0;
1149        while (line < tail) {
1150                const char *sig = NULL;
1151                const char *next = memchr(line, '\n', tail - line);
1152
1153                next = next ? next + 1 : tail;
1154                if (in_signature && line[0] == ' ')
1155                        sig = line + 1;
1156                else if (starts_with(line, gpg_sig_header) &&
1157                         line[gpg_sig_header_len] == ' ')
1158                        sig = line + gpg_sig_header_len + 1;
1159                if (sig) {
1160                        strbuf_add(signature, sig, next - sig);
1161                        saw_signature = 1;
1162                        in_signature = 1;
1163                } else {
1164                        if (*line == '\n')
1165                                /* dump the whole remainder of the buffer */
1166                                next = tail;
1167                        strbuf_add(payload, line, next - line);
1168                        in_signature = 0;
1169                }
1170                line = next;
1171        }
1172        unuse_commit_buffer(commit, buffer);
1173        return saw_signature;
1174}
1175
1176static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1177{
1178        struct merge_remote_desc *desc;
1179        struct commit_extra_header *mergetag;
1180        char *buf;
1181        unsigned long size, len;
1182        enum object_type type;
1183
1184        desc = merge_remote_util(parent);
1185        if (!desc || !desc->obj)
1186                return;
1187        buf = read_sha1_file(desc->obj->sha1, &type, &size);
1188        if (!buf || type != OBJ_TAG)
1189                goto free_return;
1190        len = parse_signature(buf, size);
1191        if (size == len)
1192                goto free_return;
1193        /*
1194         * We could verify this signature and either omit the tag when
1195         * it does not validate, but the integrator may not have the
1196         * public key of the signer of the tag he is merging, while a
1197         * later auditor may have it while auditing, so let's not run
1198         * verify-signed-buffer here for now...
1199         *
1200         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1201         *      warn("warning: signed tag unverified.");
1202         */
1203        mergetag = xcalloc(1, sizeof(*mergetag));
1204        mergetag->key = xstrdup("mergetag");
1205        mergetag->value = buf;
1206        mergetag->len = size;
1207
1208        **tail = mergetag;
1209        *tail = &mergetag->next;
1210        return;
1211
1212free_return:
1213        free(buf);
1214}
1215
1216static struct {
1217        char result;
1218        const char *check;
1219} sigcheck_gpg_status[] = {
1220        { 'G', "\n[GNUPG:] GOODSIG " },
1221        { 'B', "\n[GNUPG:] BADSIG " },
1222        { 'U', "\n[GNUPG:] TRUST_NEVER" },
1223        { 'U', "\n[GNUPG:] TRUST_UNDEFINED" },
1224};
1225
1226static void parse_gpg_output(struct signature_check *sigc)
1227{
1228        const char *buf = sigc->gpg_status;
1229        int i;
1230
1231        /* Iterate over all search strings */
1232        for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_status); i++) {
1233                const char *found, *next;
1234
1235                if (!skip_prefix(buf, sigcheck_gpg_status[i].check + 1, &found)) {
1236                        found = strstr(buf, sigcheck_gpg_status[i].check);
1237                        if (!found)
1238                                continue;
1239                        found += strlen(sigcheck_gpg_status[i].check);
1240                }
1241                sigc->result = sigcheck_gpg_status[i].result;
1242                /* The trust messages are not followed by key/signer information */
1243                if (sigc->result != 'U') {
1244                        sigc->key = xmemdupz(found, 16);
1245                        found += 17;
1246                        next = strchrnul(found, '\n');
1247                        sigc->signer = xmemdupz(found, next - found);
1248                }
1249        }
1250}
1251
1252void check_commit_signature(const struct commit* commit, struct signature_check *sigc)
1253{
1254        struct strbuf payload = STRBUF_INIT;
1255        struct strbuf signature = STRBUF_INIT;
1256        struct strbuf gpg_output = STRBUF_INIT;
1257        struct strbuf gpg_status = STRBUF_INIT;
1258        int status;
1259
1260        sigc->result = 'N';
1261
1262        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1263                goto out;
1264        status = verify_signed_buffer(payload.buf, payload.len,
1265                                      signature.buf, signature.len,
1266                                      &gpg_output, &gpg_status);
1267        if (status && !gpg_output.len)
1268                goto out;
1269        sigc->payload = strbuf_detach(&payload, NULL);
1270        sigc->gpg_output = strbuf_detach(&gpg_output, NULL);
1271        sigc->gpg_status = strbuf_detach(&gpg_status, NULL);
1272        parse_gpg_output(sigc);
1273
1274 out:
1275        strbuf_release(&gpg_status);
1276        strbuf_release(&gpg_output);
1277        strbuf_release(&payload);
1278        strbuf_release(&signature);
1279}
1280
1281
1282
1283void append_merge_tag_headers(struct commit_list *parents,
1284                              struct commit_extra_header ***tail)
1285{
1286        while (parents) {
1287                struct commit *parent = parents->item;
1288                handle_signed_tag(parent, tail);
1289                parents = parents->next;
1290        }
1291}
1292
1293static void add_extra_header(struct strbuf *buffer,
1294                             struct commit_extra_header *extra)
1295{
1296        strbuf_addstr(buffer, extra->key);
1297        if (extra->len)
1298                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1299        else
1300                strbuf_addch(buffer, '\n');
1301}
1302
1303struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1304                                                      const char **exclude)
1305{
1306        struct commit_extra_header *extra = NULL;
1307        unsigned long size;
1308        const char *buffer = get_commit_buffer(commit, &size);
1309        extra = read_commit_extra_header_lines(buffer, size, exclude);
1310        unuse_commit_buffer(commit, buffer);
1311        return extra;
1312}
1313
1314static inline int standard_header_field(const char *field, size_t len)
1315{
1316        return ((len == 4 && !memcmp(field, "tree ", 5)) ||
1317                (len == 6 && !memcmp(field, "parent ", 7)) ||
1318                (len == 6 && !memcmp(field, "author ", 7)) ||
1319                (len == 9 && !memcmp(field, "committer ", 10)) ||
1320                (len == 8 && !memcmp(field, "encoding ", 9)));
1321}
1322
1323static int excluded_header_field(const char *field, size_t len, const char **exclude)
1324{
1325        if (!exclude)
1326                return 0;
1327
1328        while (*exclude) {
1329                size_t xlen = strlen(*exclude);
1330                if (len == xlen &&
1331                    !memcmp(field, *exclude, xlen) && field[xlen] == ' ')
1332                        return 1;
1333                exclude++;
1334        }
1335        return 0;
1336}
1337
1338static struct commit_extra_header *read_commit_extra_header_lines(
1339        const char *buffer, size_t size,
1340        const char **exclude)
1341{
1342        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1343        const char *line, *next, *eof, *eob;
1344        struct strbuf buf = STRBUF_INIT;
1345
1346        for (line = buffer, eob = line + size;
1347             line < eob && *line != '\n';
1348             line = next) {
1349                next = memchr(line, '\n', eob - line);
1350                next = next ? next + 1 : eob;
1351                if (*line == ' ') {
1352                        /* continuation */
1353                        if (it)
1354                                strbuf_add(&buf, line + 1, next - (line + 1));
1355                        continue;
1356                }
1357                if (it)
1358                        it->value = strbuf_detach(&buf, &it->len);
1359                strbuf_reset(&buf);
1360                it = NULL;
1361
1362                eof = strchr(line, ' ');
1363                if (next <= eof)
1364                        eof = next;
1365
1366                if (standard_header_field(line, eof - line) ||
1367                    excluded_header_field(line, eof - line, exclude))
1368                        continue;
1369
1370                it = xcalloc(1, sizeof(*it));
1371                it->key = xmemdupz(line, eof-line);
1372                *tail = it;
1373                tail = &it->next;
1374                if (eof + 1 < next)
1375                        strbuf_add(&buf, eof + 1, next - (eof + 1));
1376        }
1377        if (it)
1378                it->value = strbuf_detach(&buf, &it->len);
1379        return extra;
1380}
1381
1382void free_commit_extra_headers(struct commit_extra_header *extra)
1383{
1384        while (extra) {
1385                struct commit_extra_header *next = extra->next;
1386                free(extra->key);
1387                free(extra->value);
1388                free(extra);
1389                extra = next;
1390        }
1391}
1392
1393int commit_tree(const char *msg, size_t msg_len,
1394                const unsigned char *tree,
1395                struct commit_list *parents, unsigned char *ret,
1396                const char *author, const char *sign_commit)
1397{
1398        struct commit_extra_header *extra = NULL, **tail = &extra;
1399        int result;
1400
1401        append_merge_tag_headers(parents, &tail);
1402        result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1403                                      author, sign_commit, extra);
1404        free_commit_extra_headers(extra);
1405        return result;
1406}
1407
1408static int find_invalid_utf8(const char *buf, int len)
1409{
1410        int offset = 0;
1411        static const unsigned int max_codepoint[] = {
1412                0x7f, 0x7ff, 0xffff, 0x10ffff
1413        };
1414
1415        while (len) {
1416                unsigned char c = *buf++;
1417                int bytes, bad_offset;
1418                unsigned int codepoint;
1419                unsigned int min_val, max_val;
1420
1421                len--;
1422                offset++;
1423
1424                /* Simple US-ASCII? No worries. */
1425                if (c < 0x80)
1426                        continue;
1427
1428                bad_offset = offset-1;
1429
1430                /*
1431                 * Count how many more high bits set: that's how
1432                 * many more bytes this sequence should have.
1433                 */
1434                bytes = 0;
1435                while (c & 0x40) {
1436                        c <<= 1;
1437                        bytes++;
1438                }
1439
1440                /*
1441                 * Must be between 1 and 3 more bytes.  Longer sequences result in
1442                 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1443                 */
1444                if (bytes < 1 || 3 < bytes)
1445                        return bad_offset;
1446
1447                /* Do we *have* that many bytes? */
1448                if (len < bytes)
1449                        return bad_offset;
1450
1451                /*
1452                 * Place the encoded bits at the bottom of the value and compute the
1453                 * valid range.
1454                 */
1455                codepoint = (c & 0x7f) >> bytes;
1456                min_val = max_codepoint[bytes-1] + 1;
1457                max_val = max_codepoint[bytes];
1458
1459                offset += bytes;
1460                len -= bytes;
1461
1462                /* And verify that they are good continuation bytes */
1463                do {
1464                        codepoint <<= 6;
1465                        codepoint |= *buf & 0x3f;
1466                        if ((*buf++ & 0xc0) != 0x80)
1467                                return bad_offset;
1468                } while (--bytes);
1469
1470                /* Reject codepoints that are out of range for the sequence length. */
1471                if (codepoint < min_val || codepoint > max_val)
1472                        return bad_offset;
1473                /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1474                if ((codepoint & 0x1ff800) == 0xd800)
1475                        return bad_offset;
1476                /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1477                if ((codepoint & 0xfffe) == 0xfffe)
1478                        return bad_offset;
1479                /* So are anything in the range U+FDD0..U+FDEF. */
1480                if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1481                        return bad_offset;
1482        }
1483        return -1;
1484}
1485
1486/*
1487 * This verifies that the buffer is in proper utf8 format.
1488 *
1489 * If it isn't, it assumes any non-utf8 characters are Latin1,
1490 * and does the conversion.
1491 */
1492static int verify_utf8(struct strbuf *buf)
1493{
1494        int ok = 1;
1495        long pos = 0;
1496
1497        for (;;) {
1498                int bad;
1499                unsigned char c;
1500                unsigned char replace[2];
1501
1502                bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1503                if (bad < 0)
1504                        return ok;
1505                pos += bad;
1506                ok = 0;
1507                c = buf->buf[pos];
1508                strbuf_remove(buf, pos, 1);
1509
1510                /* We know 'c' must be in the range 128-255 */
1511                replace[0] = 0xc0 + (c >> 6);
1512                replace[1] = 0x80 + (c & 0x3f);
1513                strbuf_insert(buf, pos, replace, 2);
1514                pos += 2;
1515        }
1516}
1517
1518static const char commit_utf8_warn[] =
1519"Warning: commit message did not conform to UTF-8.\n"
1520"You may want to amend it after fixing the message, or set the config\n"
1521"variable i18n.commitencoding to the encoding your project uses.\n";
1522
1523int commit_tree_extended(const char *msg, size_t msg_len,
1524                         const unsigned char *tree,
1525                         struct commit_list *parents, unsigned char *ret,
1526                         const char *author, const char *sign_commit,
1527                         struct commit_extra_header *extra)
1528{
1529        int result;
1530        int encoding_is_utf8;
1531        struct strbuf buffer;
1532
1533        assert_sha1_type(tree, OBJ_TREE);
1534
1535        if (memchr(msg, '\0', msg_len))
1536                return error("a NUL byte in commit log message not allowed.");
1537
1538        /* Not having i18n.commitencoding is the same as having utf-8 */
1539        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1540
1541        strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1542        strbuf_addf(&buffer, "tree %s\n", sha1_to_hex(tree));
1543
1544        /*
1545         * NOTE! This ordering means that the same exact tree merged with a
1546         * different order of parents will be a _different_ changeset even
1547         * if everything else stays the same.
1548         */
1549        while (parents) {
1550                struct commit_list *next = parents->next;
1551                struct commit *parent = parents->item;
1552
1553                strbuf_addf(&buffer, "parent %s\n",
1554                            sha1_to_hex(parent->object.sha1));
1555                free(parents);
1556                parents = next;
1557        }
1558
1559        /* Person/date information */
1560        if (!author)
1561                author = git_author_info(IDENT_STRICT);
1562        strbuf_addf(&buffer, "author %s\n", author);
1563        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1564        if (!encoding_is_utf8)
1565                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1566
1567        while (extra) {
1568                add_extra_header(&buffer, extra);
1569                extra = extra->next;
1570        }
1571        strbuf_addch(&buffer, '\n');
1572
1573        /* And add the comment */
1574        strbuf_add(&buffer, msg, msg_len);
1575
1576        /* And check the encoding */
1577        if (encoding_is_utf8 && !verify_utf8(&buffer))
1578                fprintf(stderr, commit_utf8_warn);
1579
1580        if (sign_commit && do_sign_commit(&buffer, sign_commit))
1581                return -1;
1582
1583        result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
1584        strbuf_release(&buffer);
1585        return result;
1586}
1587
1588struct commit *get_merge_parent(const char *name)
1589{
1590        struct object *obj;
1591        struct commit *commit;
1592        unsigned char sha1[20];
1593        if (get_sha1(name, sha1))
1594                return NULL;
1595        obj = parse_object(sha1);
1596        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1597        if (commit && !commit->util) {
1598                struct merge_remote_desc *desc;
1599                desc = xmalloc(sizeof(*desc));
1600                desc->obj = obj;
1601                desc->name = strdup(name);
1602                commit->util = desc;
1603        }
1604        return commit;
1605}
1606
1607/*
1608 * Append a commit to the end of the commit_list.
1609 *
1610 * next starts by pointing to the variable that holds the head of an
1611 * empty commit_list, and is updated to point to the "next" field of
1612 * the last item on the list as new commits are appended.
1613 *
1614 * Usage example:
1615 *
1616 *     struct commit_list *list;
1617 *     struct commit_list **next = &list;
1618 *
1619 *     next = commit_list_append(c1, next);
1620 *     next = commit_list_append(c2, next);
1621 *     assert(commit_list_count(list) == 2);
1622 *     return list;
1623 */
1624struct commit_list **commit_list_append(struct commit *commit,
1625                                        struct commit_list **next)
1626{
1627        struct commit_list *new = xmalloc(sizeof(struct commit_list));
1628        new->item = commit;
1629        *next = new;
1630        new->next = NULL;
1631        return &new->next;
1632}
1633
1634void print_commit_list(struct commit_list *list,
1635                       const char *format_cur,
1636                       const char *format_last)
1637{
1638        for ( ; list; list = list->next) {
1639                const char *format = list->next ? format_cur : format_last;
1640                printf(format, sha1_to_hex(list->item->object.sha1));
1641        }
1642}