Andrew's git / gitweb.git / commit.c
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commit.con commit Use MOVE_ARRAY (f919ffe)
   1#include "cache.h"
   2#include "tag.h"
   3#include "commit.h"
   4#include "pkt-line.h"
   5#include "utf8.h"
   6#include "diff.h"
   7#include "revision.h"
   8#include "notes.h"
   9#include "gpg-interface.h"
  10#include "mergesort.h"
  11#include "commit-slab.h"
  12#include "prio-queue.h"
  13#include "sha1-lookup.h"
  14#include "wt-status.h"
  15
  16static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
  17
  18int save_commit_buffer = 1;
  19
  20const char *commit_type = "commit";
  21
  22struct commit *lookup_commit_reference_gently(const struct object_id *oid,
  23                                              int quiet)
  24{
  25        struct object *obj = deref_tag(parse_object(oid), NULL, 0);
  26
  27        if (!obj)
  28                return NULL;
  29        return object_as_type(obj, OBJ_COMMIT, quiet);
  30}
  31
  32struct commit *lookup_commit_reference(const struct object_id *oid)
  33{
  34        return lookup_commit_reference_gently(oid, 0);
  35}
  36
  37struct commit *lookup_commit_or_die(const struct object_id *oid, const char *ref_name)
  38{
  39        struct commit *c = lookup_commit_reference(oid);
  40        if (!c)
  41                die(_("could not parse %s"), ref_name);
  42        if (oidcmp(oid, &c->object.oid)) {
  43                warning(_("%s %s is not a commit!"),
  44                        ref_name, oid_to_hex(oid));
  45        }
  46        return c;
  47}
  48
  49struct commit *lookup_commit(const struct object_id *oid)
  50{
  51        struct object *obj = lookup_object(oid->hash);
  52        if (!obj)
  53                return create_object(oid->hash, alloc_commit_node());
  54        return object_as_type(obj, OBJ_COMMIT, 0);
  55}
  56
  57struct commit *lookup_commit_reference_by_name(const char *name)
  58{
  59        struct object_id oid;
  60        struct commit *commit;
  61
  62        if (get_oid_committish(name, &oid))
  63                return NULL;
  64        commit = lookup_commit_reference(&oid);
  65        if (parse_commit(commit))
  66                return NULL;
  67        return commit;
  68}
  69
  70static timestamp_t parse_commit_date(const char *buf, const char *tail)
  71{
  72        const char *dateptr;
  73
  74        if (buf + 6 >= tail)
  75                return 0;
  76        if (memcmp(buf, "author", 6))
  77                return 0;
  78        while (buf < tail && *buf++ != '\n')
  79                /* nada */;
  80        if (buf + 9 >= tail)
  81                return 0;
  82        if (memcmp(buf, "committer", 9))
  83                return 0;
  84        while (buf < tail && *buf++ != '>')
  85                /* nada */;
  86        if (buf >= tail)
  87                return 0;
  88        dateptr = buf;
  89        while (buf < tail && *buf++ != '\n')
  90                /* nada */;
  91        if (buf >= tail)
  92                return 0;
  93        /* dateptr < buf && buf[-1] == '\n', so parsing will stop at buf-1 */
  94        return parse_timestamp(dateptr, NULL, 10);
  95}
  96
  97static struct commit_graft **commit_graft;
  98static int commit_graft_alloc, commit_graft_nr;
  99
 100static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
 101{
 102        struct commit_graft **commit_graft_table = table;
 103        return commit_graft_table[index]->oid.hash;
 104}
 105
 106static int commit_graft_pos(const unsigned char *sha1)
 107{
 108        return sha1_pos(sha1, commit_graft, commit_graft_nr,
 109                        commit_graft_sha1_access);
 110}
 111
 112int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 113{
 114        int pos = commit_graft_pos(graft->oid.hash);
 115
 116        if (0 <= pos) {
 117                if (ignore_dups)
 118                        free(graft);
 119                else {
 120                        free(commit_graft[pos]);
 121                        commit_graft[pos] = graft;
 122                }
 123                return 1;
 124        }
 125        pos = -pos - 1;
 126        ALLOC_GROW(commit_graft, commit_graft_nr + 1, commit_graft_alloc);
 127        commit_graft_nr++;
 128        if (pos < commit_graft_nr)
 129                MOVE_ARRAY(commit_graft + pos + 1, commit_graft + pos,
 130                           commit_graft_nr - pos - 1);
 131        commit_graft[pos] = graft;
 132        return 0;
 133}
 134
 135struct commit_graft *read_graft_line(struct strbuf *line)
 136{
 137        /* The format is just "Commit Parent1 Parent2 ...\n" */
 138        int i, phase;
 139        const char *tail = NULL;
 140        struct commit_graft *graft = NULL;
 141        struct object_id dummy_oid, *oid;
 142
 143        strbuf_rtrim(line);
 144        if (!line->len || line->buf[0] == '#')
 145                return NULL;
 146        /*
 147         * phase 0 verifies line, counts hashes in line and allocates graft
 148         * phase 1 fills graft
 149         */
 150        for (phase = 0; phase < 2; phase++) {
 151                oid = graft ? &graft->oid : &dummy_oid;
 152                if (parse_oid_hex(line->buf, oid, &tail))
 153                        goto bad_graft_data;
 154                for (i = 0; *tail != '\0'; i++) {
 155                        oid = graft ? &graft->parent[i] : &dummy_oid;
 156                        if (!isspace(*tail++) || parse_oid_hex(tail, oid, &tail))
 157                                goto bad_graft_data;
 158                }
 159                if (!graft) {
 160                        graft = xmalloc(st_add(sizeof(*graft),
 161                                               st_mult(sizeof(struct object_id), i)));
 162                        graft->nr_parent = i;
 163                }
 164        }
 165        return graft;
 166
 167bad_graft_data:
 168        error("bad graft data: %s", line->buf);
 169        assert(!graft);
 170        return NULL;
 171}
 172
 173static int read_graft_file(const char *graft_file)
 174{
 175        FILE *fp = fopen_or_warn(graft_file, "r");
 176        struct strbuf buf = STRBUF_INIT;
 177        if (!fp)
 178                return -1;
 179        while (!strbuf_getwholeline(&buf, fp, '\n')) {
 180                /* The format is just "Commit Parent1 Parent2 ...\n" */
 181                struct commit_graft *graft = read_graft_line(&buf);
 182                if (!graft)
 183                        continue;
 184                if (register_commit_graft(graft, 1))
 185                        error("duplicate graft data: %s", buf.buf);
 186        }
 187        fclose(fp);
 188        strbuf_release(&buf);
 189        return 0;
 190}
 191
 192static void prepare_commit_graft(void)
 193{
 194        static int commit_graft_prepared;
 195        char *graft_file;
 196
 197        if (commit_graft_prepared)
 198                return;
 199        graft_file = get_graft_file();
 200        read_graft_file(graft_file);
 201        /* make sure shallows are read */
 202        is_repository_shallow();
 203        commit_graft_prepared = 1;
 204}
 205
 206struct commit_graft *lookup_commit_graft(const struct object_id *oid)
 207{
 208        int pos;
 209        prepare_commit_graft();
 210        pos = commit_graft_pos(oid->hash);
 211        if (pos < 0)
 212                return NULL;
 213        return commit_graft[pos];
 214}
 215
 216int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
 217{
 218        int i, ret;
 219        for (i = ret = 0; i < commit_graft_nr && !ret; i++)
 220                ret = fn(commit_graft[i], cb_data);
 221        return ret;
 222}
 223
 224int unregister_shallow(const struct object_id *oid)
 225{
 226        int pos = commit_graft_pos(oid->hash);
 227        if (pos < 0)
 228                return -1;
 229        if (pos + 1 < commit_graft_nr)
 230                MOVE_ARRAY(commit_graft + pos, commit_graft + pos + 1,
 231                           commit_graft_nr - pos - 1);
 232        commit_graft_nr--;
 233        return 0;
 234}
 235
 236struct commit_buffer {
 237        void *buffer;
 238        unsigned long size;
 239};
 240define_commit_slab(buffer_slab, struct commit_buffer);
 241static struct buffer_slab buffer_slab = COMMIT_SLAB_INIT(1, buffer_slab);
 242
 243void set_commit_buffer(struct commit *commit, void *buffer, unsigned long size)
 244{
 245        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 246        v->buffer = buffer;
 247        v->size = size;
 248}
 249
 250const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
 251{
 252        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 253        if (!v) {
 254                if (sizep)
 255                        *sizep = 0;
 256                return NULL;
 257        }
 258        if (sizep)
 259                *sizep = v->size;
 260        return v->buffer;
 261}
 262
 263const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
 264{
 265        const void *ret = get_cached_commit_buffer(commit, sizep);
 266        if (!ret) {
 267                enum object_type type;
 268                unsigned long size;
 269                ret = read_sha1_file(commit->object.oid.hash, &type, &size);
 270                if (!ret)
 271                        die("cannot read commit object %s",
 272                            oid_to_hex(&commit->object.oid));
 273                if (type != OBJ_COMMIT)
 274                        die("expected commit for %s, got %s",
 275                            oid_to_hex(&commit->object.oid), typename(type));
 276                if (sizep)
 277                        *sizep = size;
 278        }
 279        return ret;
 280}
 281
 282void unuse_commit_buffer(const struct commit *commit, const void *buffer)
 283{
 284        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 285        if (!(v && v->buffer == buffer))
 286                free((void *)buffer);
 287}
 288
 289void free_commit_buffer(struct commit *commit)
 290{
 291        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 292        if (v) {
 293                FREE_AND_NULL(v->buffer);
 294                v->size = 0;
 295        }
 296}
 297
 298const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 299{
 300        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 301        void *ret;
 302
 303        if (!v) {
 304                if (sizep)
 305                        *sizep = 0;
 306                return NULL;
 307        }
 308        ret = v->buffer;
 309        if (sizep)
 310                *sizep = v->size;
 311
 312        v->buffer = NULL;
 313        v->size = 0;
 314        return ret;
 315}
 316
 317int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
 318{
 319        const char *tail = buffer;
 320        const char *bufptr = buffer;
 321        struct object_id parent;
 322        struct commit_list **pptr;
 323        struct commit_graft *graft;
 324        const int tree_entry_len = GIT_SHA1_HEXSZ + 5;
 325        const int parent_entry_len = GIT_SHA1_HEXSZ + 7;
 326
 327        if (item->object.parsed)
 328                return 0;
 329        item->object.parsed = 1;
 330        tail += size;
 331        if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
 332                        bufptr[tree_entry_len] != '\n')
 333                return error("bogus commit object %s", oid_to_hex(&item->object.oid));
 334        if (get_sha1_hex(bufptr + 5, parent.hash) < 0)
 335                return error("bad tree pointer in commit %s",
 336                             oid_to_hex(&item->object.oid));
 337        item->tree = lookup_tree(&parent);
 338        bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
 339        pptr = &item->parents;
 340
 341        graft = lookup_commit_graft(&item->object.oid);
 342        while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
 343                struct commit *new_parent;
 344
 345                if (tail <= bufptr + parent_entry_len + 1 ||
 346                    get_sha1_hex(bufptr + 7, parent.hash) ||
 347                    bufptr[parent_entry_len] != '\n')
 348                        return error("bad parents in commit %s", oid_to_hex(&item->object.oid));
 349                bufptr += parent_entry_len + 1;
 350                /*
 351                 * The clone is shallow if nr_parent < 0, and we must
 352                 * not traverse its real parents even when we unhide them.
 353                 */
 354                if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
 355                        continue;
 356                new_parent = lookup_commit(&parent);
 357                if (new_parent)
 358                        pptr = &commit_list_insert(new_parent, pptr)->next;
 359        }
 360        if (graft) {
 361                int i;
 362                struct commit *new_parent;
 363                for (i = 0; i < graft->nr_parent; i++) {
 364                        new_parent = lookup_commit(&graft->parent[i]);
 365                        if (!new_parent)
 366                                continue;
 367                        pptr = &commit_list_insert(new_parent, pptr)->next;
 368                }
 369        }
 370        item->date = parse_commit_date(bufptr, tail);
 371
 372        return 0;
 373}
 374
 375int parse_commit_gently(struct commit *item, int quiet_on_missing)
 376{
 377        enum object_type type;
 378        void *buffer;
 379        unsigned long size;
 380        int ret;
 381
 382        if (!item)
 383                return -1;
 384        if (item->object.parsed)
 385                return 0;
 386        buffer = read_sha1_file(item->object.oid.hash, &type, &size);
 387        if (!buffer)
 388                return quiet_on_missing ? -1 :
 389                        error("Could not read %s",
 390                             oid_to_hex(&item->object.oid));
 391        if (type != OBJ_COMMIT) {
 392                free(buffer);
 393                return error("Object %s not a commit",
 394                             oid_to_hex(&item->object.oid));
 395        }
 396        ret = parse_commit_buffer(item, buffer, size);
 397        if (save_commit_buffer && !ret) {
 398                set_commit_buffer(item, buffer, size);
 399                return 0;
 400        }
 401        free(buffer);
 402        return ret;
 403}
 404
 405void parse_commit_or_die(struct commit *item)
 406{
 407        if (parse_commit(item))
 408                die("unable to parse commit %s",
 409                    item ? oid_to_hex(&item->object.oid) : "(null)");
 410}
 411
 412int find_commit_subject(const char *commit_buffer, const char **subject)
 413{
 414        const char *eol;
 415        const char *p = commit_buffer;
 416
 417        while (*p && (*p != '\n' || p[1] != '\n'))
 418                p++;
 419        if (*p) {
 420                p = skip_blank_lines(p + 2);
 421                eol = strchrnul(p, '\n');
 422        } else
 423                eol = p;
 424
 425        *subject = p;
 426
 427        return eol - p;
 428}
 429
 430struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 431{
 432        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 433        new_list->item = item;
 434        new_list->next = *list_p;
 435        *list_p = new_list;
 436        return new_list;
 437}
 438
 439unsigned commit_list_count(const struct commit_list *l)
 440{
 441        unsigned c = 0;
 442        for (; l; l = l->next )
 443                c++;
 444        return c;
 445}
 446
 447struct commit_list *copy_commit_list(struct commit_list *list)
 448{
 449        struct commit_list *head = NULL;
 450        struct commit_list **pp = &head;
 451        while (list) {
 452                pp = commit_list_append(list->item, pp);
 453                list = list->next;
 454        }
 455        return head;
 456}
 457
 458void free_commit_list(struct commit_list *list)
 459{
 460        while (list)
 461                pop_commit(&list);
 462}
 463
 464struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 465{
 466        struct commit_list **pp = list;
 467        struct commit_list *p;
 468        while ((p = *pp) != NULL) {
 469                if (p->item->date < item->date) {
 470                        break;
 471                }
 472                pp = &p->next;
 473        }
 474        return commit_list_insert(item, pp);
 475}
 476
 477static int commit_list_compare_by_date(const void *a, const void *b)
 478{
 479        timestamp_t a_date = ((const struct commit_list *)a)->item->date;
 480        timestamp_t b_date = ((const struct commit_list *)b)->item->date;
 481        if (a_date < b_date)
 482                return 1;
 483        if (a_date > b_date)
 484                return -1;
 485        return 0;
 486}
 487
 488static void *commit_list_get_next(const void *a)
 489{
 490        return ((const struct commit_list *)a)->next;
 491}
 492
 493static void commit_list_set_next(void *a, void *next)
 494{
 495        ((struct commit_list *)a)->next = next;
 496}
 497
 498void commit_list_sort_by_date(struct commit_list **list)
 499{
 500        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 501                                commit_list_compare_by_date);
 502}
 503
 504struct commit *pop_most_recent_commit(struct commit_list **list,
 505                                      unsigned int mark)
 506{
 507        struct commit *ret = pop_commit(list);
 508        struct commit_list *parents = ret->parents;
 509
 510        while (parents) {
 511                struct commit *commit = parents->item;
 512                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 513                        commit->object.flags |= mark;
 514                        commit_list_insert_by_date(commit, list);
 515                }
 516                parents = parents->next;
 517        }
 518        return ret;
 519}
 520
 521static void clear_commit_marks_1(struct commit_list **plist,
 522                                 struct commit *commit, unsigned int mark)
 523{
 524        while (commit) {
 525                struct commit_list *parents;
 526
 527                if (!(mark & commit->object.flags))
 528                        return;
 529
 530                commit->object.flags &= ~mark;
 531
 532                parents = commit->parents;
 533                if (!parents)
 534                        return;
 535
 536                while ((parents = parents->next))
 537                        commit_list_insert(parents->item, plist);
 538
 539                commit = commit->parents->item;
 540        }
 541}
 542
 543void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 544{
 545        struct commit_list *list = NULL;
 546
 547        while (nr--) {
 548                commit_list_insert(*commit, &list);
 549                commit++;
 550        }
 551        while (list)
 552                clear_commit_marks_1(&list, pop_commit(&list), mark);
 553}
 554
 555void clear_commit_marks(struct commit *commit, unsigned int mark)
 556{
 557        clear_commit_marks_many(1, &commit, mark);
 558}
 559
 560void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
 561{
 562        struct object *object;
 563        struct commit *commit;
 564        unsigned int i;
 565
 566        for (i = 0; i < a->nr; i++) {
 567                object = a->objects[i].item;
 568                commit = lookup_commit_reference_gently(&object->oid, 1);
 569                if (commit)
 570                        clear_commit_marks(commit, mark);
 571        }
 572}
 573
 574struct commit *pop_commit(struct commit_list **stack)
 575{
 576        struct commit_list *top = *stack;
 577        struct commit *item = top ? top->item : NULL;
 578
 579        if (top) {
 580                *stack = top->next;
 581                free(top);
 582        }
 583        return item;
 584}
 585
 586/*
 587 * Topological sort support
 588 */
 589
 590/* count number of children that have not been emitted */
 591define_commit_slab(indegree_slab, int);
 592
 593/* record author-date for each commit object */
 594define_commit_slab(author_date_slab, unsigned long);
 595
 596static void record_author_date(struct author_date_slab *author_date,
 597                               struct commit *commit)
 598{
 599        const char *buffer = get_commit_buffer(commit, NULL);
 600        struct ident_split ident;
 601        const char *ident_line;
 602        size_t ident_len;
 603        char *date_end;
 604        timestamp_t date;
 605
 606        ident_line = find_commit_header(buffer, "author", &ident_len);
 607        if (!ident_line)
 608                goto fail_exit; /* no author line */
 609        if (split_ident_line(&ident, ident_line, ident_len) ||
 610            !ident.date_begin || !ident.date_end)
 611                goto fail_exit; /* malformed "author" line */
 612
 613        date = parse_timestamp(ident.date_begin, &date_end, 10);
 614        if (date_end != ident.date_end)
 615                goto fail_exit; /* malformed date */
 616        *(author_date_slab_at(author_date, commit)) = date;
 617
 618fail_exit:
 619        unuse_commit_buffer(commit, buffer);
 620}
 621
 622static int compare_commits_by_author_date(const void *a_, const void *b_,
 623                                          void *cb_data)
 624{
 625        const struct commit *a = a_, *b = b_;
 626        struct author_date_slab *author_date = cb_data;
 627        timestamp_t a_date = *(author_date_slab_at(author_date, a));
 628        timestamp_t b_date = *(author_date_slab_at(author_date, b));
 629
 630        /* newer commits with larger date first */
 631        if (a_date < b_date)
 632                return 1;
 633        else if (a_date > b_date)
 634                return -1;
 635        return 0;
 636}
 637
 638int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 639{
 640        const struct commit *a = a_, *b = b_;
 641        /* newer commits with larger date first */
 642        if (a->date < b->date)
 643                return 1;
 644        else if (a->date > b->date)
 645                return -1;
 646        return 0;
 647}
 648
 649/*
 650 * Performs an in-place topological sort on the list supplied.
 651 */
 652void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 653{
 654        struct commit_list *next, *orig = *list;
 655        struct commit_list **pptr;
 656        struct indegree_slab indegree;
 657        struct prio_queue queue;
 658        struct commit *commit;
 659        struct author_date_slab author_date;
 660
 661        if (!orig)
 662                return;
 663        *list = NULL;
 664
 665        init_indegree_slab(&indegree);
 666        memset(&queue, '\0', sizeof(queue));
 667
 668        switch (sort_order) {
 669        default: /* REV_SORT_IN_GRAPH_ORDER */
 670                queue.compare = NULL;
 671                break;
 672        case REV_SORT_BY_COMMIT_DATE:
 673                queue.compare = compare_commits_by_commit_date;
 674                break;
 675        case REV_SORT_BY_AUTHOR_DATE:
 676                init_author_date_slab(&author_date);
 677                queue.compare = compare_commits_by_author_date;
 678                queue.cb_data = &author_date;
 679                break;
 680        }
 681
 682        /* Mark them and clear the indegree */
 683        for (next = orig; next; next = next->next) {
 684                struct commit *commit = next->item;
 685                *(indegree_slab_at(&indegree, commit)) = 1;
 686                /* also record the author dates, if needed */
 687                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 688                        record_author_date(&author_date, commit);
 689        }
 690
 691        /* update the indegree */
 692        for (next = orig; next; next = next->next) {
 693                struct commit_list *parents = next->item->parents;
 694                while (parents) {
 695                        struct commit *parent = parents->item;
 696                        int *pi = indegree_slab_at(&indegree, parent);
 697
 698                        if (*pi)
 699                                (*pi)++;
 700                        parents = parents->next;
 701                }
 702        }
 703
 704        /*
 705         * find the tips
 706         *
 707         * tips are nodes not reachable from any other node in the list
 708         *
 709         * the tips serve as a starting set for the work queue.
 710         */
 711        for (next = orig; next; next = next->next) {
 712                struct commit *commit = next->item;
 713
 714                if (*(indegree_slab_at(&indegree, commit)) == 1)
 715                        prio_queue_put(&queue, commit);
 716        }
 717
 718        /*
 719         * This is unfortunate; the initial tips need to be shown
 720         * in the order given from the revision traversal machinery.
 721         */
 722        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 723                prio_queue_reverse(&queue);
 724
 725        /* We no longer need the commit list */
 726        free_commit_list(orig);
 727
 728        pptr = list;
 729        *list = NULL;
 730        while ((commit = prio_queue_get(&queue)) != NULL) {
 731                struct commit_list *parents;
 732
 733                for (parents = commit->parents; parents ; parents = parents->next) {
 734                        struct commit *parent = parents->item;
 735                        int *pi = indegree_slab_at(&indegree, parent);
 736
 737                        if (!*pi)
 738                                continue;
 739
 740                        /*
 741                         * parents are only enqueued for emission
 742                         * when all their children have been emitted thereby
 743                         * guaranteeing topological order.
 744                         */
 745                        if (--(*pi) == 1)
 746                                prio_queue_put(&queue, parent);
 747                }
 748                /*
 749                 * all children of commit have already been
 750                 * emitted. we can emit it now.
 751                 */
 752                *(indegree_slab_at(&indegree, commit)) = 0;
 753
 754                pptr = &commit_list_insert(commit, pptr)->next;
 755        }
 756
 757        clear_indegree_slab(&indegree);
 758        clear_prio_queue(&queue);
 759        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 760                clear_author_date_slab(&author_date);
 761}
 762
 763/* merge-base stuff */
 764
 765/* Remember to update object flag allocation in object.h */
 766#define PARENT1         (1u<<16)
 767#define PARENT2         (1u<<17)
 768#define STALE           (1u<<18)
 769#define RESULT          (1u<<19)
 770
 771static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 772
 773static int queue_has_nonstale(struct prio_queue *queue)
 774{
 775        int i;
 776        for (i = 0; i < queue->nr; i++) {
 777                struct commit *commit = queue->array[i].data;
 778                if (!(commit->object.flags & STALE))
 779                        return 1;
 780        }
 781        return 0;
 782}
 783
 784/* all input commits in one and twos[] must have been parsed! */
 785static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
 786{
 787        struct prio_queue queue = { compare_commits_by_commit_date };
 788        struct commit_list *result = NULL;
 789        int i;
 790
 791        one->object.flags |= PARENT1;
 792        if (!n) {
 793                commit_list_append(one, &result);
 794                return result;
 795        }
 796        prio_queue_put(&queue, one);
 797
 798        for (i = 0; i < n; i++) {
 799                twos[i]->object.flags |= PARENT2;
 800                prio_queue_put(&queue, twos[i]);
 801        }
 802
 803        while (queue_has_nonstale(&queue)) {
 804                struct commit *commit = prio_queue_get(&queue);
 805                struct commit_list *parents;
 806                int flags;
 807
 808                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 809                if (flags == (PARENT1 | PARENT2)) {
 810                        if (!(commit->object.flags & RESULT)) {
 811                                commit->object.flags |= RESULT;
 812                                commit_list_insert_by_date(commit, &result);
 813                        }
 814                        /* Mark parents of a found merge stale */
 815                        flags |= STALE;
 816                }
 817                parents = commit->parents;
 818                while (parents) {
 819                        struct commit *p = parents->item;
 820                        parents = parents->next;
 821                        if ((p->object.flags & flags) == flags)
 822                                continue;
 823                        if (parse_commit(p))
 824                                return NULL;
 825                        p->object.flags |= flags;
 826                        prio_queue_put(&queue, p);
 827                }
 828        }
 829
 830        clear_prio_queue(&queue);
 831        return result;
 832}
 833
 834static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 835{
 836        struct commit_list *list = NULL;
 837        struct commit_list *result = NULL;
 838        int i;
 839
 840        for (i = 0; i < n; i++) {
 841                if (one == twos[i])
 842                        /*
 843                         * We do not mark this even with RESULT so we do not
 844                         * have to clean it up.
 845                         */
 846                        return commit_list_insert(one, &result);
 847        }
 848
 849        if (parse_commit(one))
 850                return NULL;
 851        for (i = 0; i < n; i++) {
 852                if (parse_commit(twos[i]))
 853                        return NULL;
 854        }
 855
 856        list = paint_down_to_common(one, n, twos);
 857
 858        while (list) {
 859                struct commit *commit = pop_commit(&list);
 860                if (!(commit->object.flags & STALE))
 861                        commit_list_insert_by_date(commit, &result);
 862        }
 863        return result;
 864}
 865
 866struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 867{
 868        struct commit_list *i, *j, *k, *ret = NULL;
 869
 870        if (!in)
 871                return ret;
 872
 873        commit_list_insert(in->item, &ret);
 874
 875        for (i = in->next; i; i = i->next) {
 876                struct commit_list *new = NULL, *end = NULL;
 877
 878                for (j = ret; j; j = j->next) {
 879                        struct commit_list *bases;
 880                        bases = get_merge_bases(i->item, j->item);
 881                        if (!new)
 882                                new = bases;
 883                        else
 884                                end->next = bases;
 885                        for (k = bases; k; k = k->next)
 886                                end = k;
 887                }
 888                ret = new;
 889        }
 890        return ret;
 891}
 892
 893static int remove_redundant(struct commit **array, int cnt)
 894{
 895        /*
 896         * Some commit in the array may be an ancestor of
 897         * another commit.  Move such commit to the end of
 898         * the array, and return the number of commits that
 899         * are independent from each other.
 900         */
 901        struct commit **work;
 902        unsigned char *redundant;
 903        int *filled_index;
 904        int i, j, filled;
 905
 906        work = xcalloc(cnt, sizeof(*work));
 907        redundant = xcalloc(cnt, 1);
 908        ALLOC_ARRAY(filled_index, cnt - 1);
 909
 910        for (i = 0; i < cnt; i++)
 911                parse_commit(array[i]);
 912        for (i = 0; i < cnt; i++) {
 913                struct commit_list *common;
 914
 915                if (redundant[i])
 916                        continue;
 917                for (j = filled = 0; j < cnt; j++) {
 918                        if (i == j || redundant[j])
 919                                continue;
 920                        filled_index[filled] = j;
 921                        work[filled++] = array[j];
 922                }
 923                common = paint_down_to_common(array[i], filled, work);
 924                if (array[i]->object.flags & PARENT2)
 925                        redundant[i] = 1;
 926                for (j = 0; j < filled; j++)
 927                        if (work[j]->object.flags & PARENT1)
 928                                redundant[filled_index[j]] = 1;
 929                clear_commit_marks(array[i], all_flags);
 930                for (j = 0; j < filled; j++)
 931                        clear_commit_marks(work[j], all_flags);
 932                free_commit_list(common);
 933        }
 934
 935        /* Now collect the result */
 936        COPY_ARRAY(work, array, cnt);
 937        for (i = filled = 0; i < cnt; i++)
 938                if (!redundant[i])
 939                        array[filled++] = work[i];
 940        for (j = filled, i = 0; i < cnt; i++)
 941                if (redundant[i])
 942                        array[j++] = work[i];
 943        free(work);
 944        free(redundant);
 945        free(filled_index);
 946        return filled;
 947}
 948
 949static struct commit_list *get_merge_bases_many_0(struct commit *one,
 950                                                  int n,
 951                                                  struct commit **twos,
 952                                                  int cleanup)
 953{
 954        struct commit_list *list;
 955        struct commit **rslt;
 956        struct commit_list *result;
 957        int cnt, i;
 958
 959        result = merge_bases_many(one, n, twos);
 960        for (i = 0; i < n; i++) {
 961                if (one == twos[i])
 962                        return result;
 963        }
 964        if (!result || !result->next) {
 965                if (cleanup) {
 966                        clear_commit_marks(one, all_flags);
 967                        clear_commit_marks_many(n, twos, all_flags);
 968                }
 969                return result;
 970        }
 971
 972        /* There are more than one */
 973        cnt = commit_list_count(result);
 974        rslt = xcalloc(cnt, sizeof(*rslt));
 975        for (list = result, i = 0; list; list = list->next)
 976                rslt[i++] = list->item;
 977        free_commit_list(result);
 978
 979        clear_commit_marks(one, all_flags);
 980        clear_commit_marks_many(n, twos, all_flags);
 981
 982        cnt = remove_redundant(rslt, cnt);
 983        result = NULL;
 984        for (i = 0; i < cnt; i++)
 985                commit_list_insert_by_date(rslt[i], &result);
 986        free(rslt);
 987        return result;
 988}
 989
 990struct commit_list *get_merge_bases_many(struct commit *one,
 991                                         int n,
 992                                         struct commit **twos)
 993{
 994        return get_merge_bases_many_0(one, n, twos, 1);
 995}
 996
 997struct commit_list *get_merge_bases_many_dirty(struct commit *one,
 998                                               int n,
 999                                               struct commit **twos)
1000{
1001        return get_merge_bases_many_0(one, n, twos, 0);
1002}
1003
1004struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
1005{
1006        return get_merge_bases_many_0(one, 1, &two, 1);
1007}
1008
1009/*
1010 * Is "commit" a descendant of one of the elements on the "with_commit" list?
1011 */
1012int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
1013{
1014        if (!with_commit)
1015                return 1;
1016        while (with_commit) {
1017                struct commit *other;
1018
1019                other = with_commit->item;
1020                with_commit = with_commit->next;
1021                if (in_merge_bases(other, commit))
1022                        return 1;
1023        }
1024        return 0;
1025}
1026
1027/*
1028 * Is "commit" an ancestor of one of the "references"?
1029 */
1030int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1031{
1032        struct commit_list *bases;
1033        int ret = 0, i;
1034
1035        if (parse_commit(commit))
1036                return ret;
1037        for (i = 0; i < nr_reference; i++)
1038                if (parse_commit(reference[i]))
1039                        return ret;
1040
1041        bases = paint_down_to_common(commit, nr_reference, reference);
1042        if (commit->object.flags & PARENT2)
1043                ret = 1;
1044        clear_commit_marks(commit, all_flags);
1045        clear_commit_marks_many(nr_reference, reference, all_flags);
1046        free_commit_list(bases);
1047        return ret;
1048}
1049
1050/*
1051 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1052 */
1053int in_merge_bases(struct commit *commit, struct commit *reference)
1054{
1055        return in_merge_bases_many(commit, 1, &reference);
1056}
1057
1058struct commit_list *reduce_heads(struct commit_list *heads)
1059{
1060        struct commit_list *p;
1061        struct commit_list *result = NULL, **tail = &result;
1062        struct commit **array;
1063        int num_head, i;
1064
1065        if (!heads)
1066                return NULL;
1067
1068        /* Uniquify */
1069        for (p = heads; p; p = p->next)
1070                p->item->object.flags &= ~STALE;
1071        for (p = heads, num_head = 0; p; p = p->next) {
1072                if (p->item->object.flags & STALE)
1073                        continue;
1074                p->item->object.flags |= STALE;
1075                num_head++;
1076        }
1077        array = xcalloc(num_head, sizeof(*array));
1078        for (p = heads, i = 0; p; p = p->next) {
1079                if (p->item->object.flags & STALE) {
1080                        array[i++] = p->item;
1081                        p->item->object.flags &= ~STALE;
1082                }
1083        }
1084        num_head = remove_redundant(array, num_head);
1085        for (i = 0; i < num_head; i++)
1086                tail = &commit_list_insert(array[i], tail)->next;
1087        free(array);
1088        return result;
1089}
1090
1091void reduce_heads_replace(struct commit_list **heads)
1092{
1093        struct commit_list *result = reduce_heads(*heads);
1094        free_commit_list(*heads);
1095        *heads = result;
1096}
1097
1098static const char gpg_sig_header[] = "gpgsig";
1099static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1100
1101static int do_sign_commit(struct strbuf *buf, const char *keyid)
1102{
1103        struct strbuf sig = STRBUF_INIT;
1104        int inspos, copypos;
1105        const char *eoh;
1106
1107        /* find the end of the header */
1108        eoh = strstr(buf->buf, "\n\n");
1109        if (!eoh)
1110                inspos = buf->len;
1111        else
1112                inspos = eoh - 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
1179int remove_signature(struct strbuf *buf)
1180{
1181        const char *line = buf->buf;
1182        const char *tail = buf->buf + buf->len;
1183        int in_signature = 0;
1184        const char *sig_start = NULL;
1185        const char *sig_end = NULL;
1186
1187        while (line < tail) {
1188                const char *next = memchr(line, '\n', tail - line);
1189                next = next ? next + 1 : tail;
1190
1191                if (in_signature && line[0] == ' ')
1192                        sig_end = next;
1193                else if (starts_with(line, gpg_sig_header) &&
1194                         line[gpg_sig_header_len] == ' ') {
1195                        sig_start = line;
1196                        sig_end = next;
1197                        in_signature = 1;
1198                } else {
1199                        if (*line == '\n')
1200                                /* dump the whole remainder of the buffer */
1201                                next = tail;
1202                        in_signature = 0;
1203                }
1204                line = next;
1205        }
1206
1207        if (sig_start)
1208                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1209
1210        return sig_start != NULL;
1211}
1212
1213static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1214{
1215        struct merge_remote_desc *desc;
1216        struct commit_extra_header *mergetag;
1217        char *buf;
1218        unsigned long size, len;
1219        enum object_type type;
1220
1221        desc = merge_remote_util(parent);
1222        if (!desc || !desc->obj)
1223                return;
1224        buf = read_sha1_file(desc->obj->oid.hash, &type, &size);
1225        if (!buf || type != OBJ_TAG)
1226                goto free_return;
1227        len = parse_signature(buf, size);
1228        if (size == len)
1229                goto free_return;
1230        /*
1231         * We could verify this signature and either omit the tag when
1232         * it does not validate, but the integrator may not have the
1233         * public key of the signer of the tag he is merging, while a
1234         * later auditor may have it while auditing, so let's not run
1235         * verify-signed-buffer here for now...
1236         *
1237         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1238         *      warn("warning: signed tag unverified.");
1239         */
1240        mergetag = xcalloc(1, sizeof(*mergetag));
1241        mergetag->key = xstrdup("mergetag");
1242        mergetag->value = buf;
1243        mergetag->len = size;
1244
1245        **tail = mergetag;
1246        *tail = &mergetag->next;
1247        return;
1248
1249free_return:
1250        free(buf);
1251}
1252
1253int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1254{
1255        struct strbuf payload = STRBUF_INIT;
1256        struct strbuf signature = STRBUF_INIT;
1257        int ret = 1;
1258
1259        sigc->result = 'N';
1260
1261        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1262                goto out;
1263        ret = check_signature(payload.buf, payload.len, signature.buf,
1264                signature.len, sigc);
1265
1266 out:
1267        strbuf_release(&payload);
1268        strbuf_release(&signature);
1269
1270        return ret;
1271}
1272
1273
1274
1275void append_merge_tag_headers(struct commit_list *parents,
1276                              struct commit_extra_header ***tail)
1277{
1278        while (parents) {
1279                struct commit *parent = parents->item;
1280                handle_signed_tag(parent, tail);
1281                parents = parents->next;
1282        }
1283}
1284
1285static void add_extra_header(struct strbuf *buffer,
1286                             struct commit_extra_header *extra)
1287{
1288        strbuf_addstr(buffer, extra->key);
1289        if (extra->len)
1290                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1291        else
1292                strbuf_addch(buffer, '\n');
1293}
1294
1295struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1296                                                      const char **exclude)
1297{
1298        struct commit_extra_header *extra = NULL;
1299        unsigned long size;
1300        const char *buffer = get_commit_buffer(commit, &size);
1301        extra = read_commit_extra_header_lines(buffer, size, exclude);
1302        unuse_commit_buffer(commit, buffer);
1303        return extra;
1304}
1305
1306void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1307{
1308        struct commit_extra_header *extra, *to_free;
1309
1310        to_free = read_commit_extra_headers(commit, NULL);
1311        for (extra = to_free; extra; extra = extra->next) {
1312                if (strcmp(extra->key, "mergetag"))
1313                        continue; /* not a merge tag */
1314                fn(commit, extra, data);
1315        }
1316        free_commit_extra_headers(to_free);
1317}
1318
1319static inline int standard_header_field(const char *field, size_t len)
1320{
1321        return ((len == 4 && !memcmp(field, "tree", 4)) ||
1322                (len == 6 && !memcmp(field, "parent", 6)) ||
1323                (len == 6 && !memcmp(field, "author", 6)) ||
1324                (len == 9 && !memcmp(field, "committer", 9)) ||
1325                (len == 8 && !memcmp(field, "encoding", 8)));
1326}
1327
1328static int excluded_header_field(const char *field, size_t len, const char **exclude)
1329{
1330        if (!exclude)
1331                return 0;
1332
1333        while (*exclude) {
1334                size_t xlen = strlen(*exclude);
1335                if (len == xlen && !memcmp(field, *exclude, xlen))
1336                        return 1;
1337                exclude++;
1338        }
1339        return 0;
1340}
1341
1342static struct commit_extra_header *read_commit_extra_header_lines(
1343        const char *buffer, size_t size,
1344        const char **exclude)
1345{
1346        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1347        const char *line, *next, *eof, *eob;
1348        struct strbuf buf = STRBUF_INIT;
1349
1350        for (line = buffer, eob = line + size;
1351             line < eob && *line != '\n';
1352             line = next) {
1353                next = memchr(line, '\n', eob - line);
1354                next = next ? next + 1 : eob;
1355                if (*line == ' ') {
1356                        /* continuation */
1357                        if (it)
1358                                strbuf_add(&buf, line + 1, next - (line + 1));
1359                        continue;
1360                }
1361                if (it)
1362                        it->value = strbuf_detach(&buf, &it->len);
1363                strbuf_reset(&buf);
1364                it = NULL;
1365
1366                eof = memchr(line, ' ', next - line);
1367                if (!eof)
1368                        eof = next;
1369                else 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[] =
1522N_("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 *parent = pop_commit(&parents);
1554                strbuf_addf(&buffer, "parent %s\n",
1555                            oid_to_hex(&parent->object.oid));
1556        }
1557
1558        /* Person/date information */
1559        if (!author)
1560                author = git_author_info(IDENT_STRICT);
1561        strbuf_addf(&buffer, "author %s\n", author);
1562        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1563        if (!encoding_is_utf8)
1564                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1565
1566        while (extra) {
1567                add_extra_header(&buffer, extra);
1568                extra = extra->next;
1569        }
1570        strbuf_addch(&buffer, '\n');
1571
1572        /* And add the comment */
1573        strbuf_add(&buffer, msg, msg_len);
1574
1575        /* And check the encoding */
1576        if (encoding_is_utf8 && !verify_utf8(&buffer))
1577                fprintf(stderr, _(commit_utf8_warn));
1578
1579        if (sign_commit && do_sign_commit(&buffer, sign_commit)) {
1580                result = -1;
1581                goto out;
1582        }
1583
1584        result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
1585out:
1586        strbuf_release(&buffer);
1587        return result;
1588}
1589
1590void set_merge_remote_desc(struct commit *commit,
1591                           const char *name, struct object *obj)
1592{
1593        struct merge_remote_desc *desc;
1594        FLEX_ALLOC_STR(desc, name, name);
1595        desc->obj = obj;
1596        commit->util = desc;
1597}
1598
1599struct commit *get_merge_parent(const char *name)
1600{
1601        struct object *obj;
1602        struct commit *commit;
1603        struct object_id oid;
1604        if (get_oid(name, &oid))
1605                return NULL;
1606        obj = parse_object(&oid);
1607        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1608        if (commit && !commit->util)
1609                set_merge_remote_desc(commit, name, obj);
1610        return commit;
1611}
1612
1613/*
1614 * Append a commit to the end of the commit_list.
1615 *
1616 * next starts by pointing to the variable that holds the head of an
1617 * empty commit_list, and is updated to point to the "next" field of
1618 * the last item on the list as new commits are appended.
1619 *
1620 * Usage example:
1621 *
1622 *     struct commit_list *list;
1623 *     struct commit_list **next = &list;
1624 *
1625 *     next = commit_list_append(c1, next);
1626 *     next = commit_list_append(c2, next);
1627 *     assert(commit_list_count(list) == 2);
1628 *     return list;
1629 */
1630struct commit_list **commit_list_append(struct commit *commit,
1631                                        struct commit_list **next)
1632{
1633        struct commit_list *new = xmalloc(sizeof(struct commit_list));
1634        new->item = commit;
1635        *next = new;
1636        new->next = NULL;
1637        return &new->next;
1638}
1639
1640const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1641{
1642        int key_len = strlen(key);
1643        const char *line = msg;
1644
1645        while (line) {
1646                const char *eol = strchrnul(line, '\n');
1647
1648                if (line == eol)
1649                        return NULL;
1650
1651                if (eol - line > key_len &&
1652                    !strncmp(line, key, key_len) &&
1653                    line[key_len] == ' ') {
1654                        *out_len = eol - line - key_len - 1;
1655                        return line + key_len + 1;
1656                }
1657                line = *eol ? eol + 1 : NULL;
1658        }
1659        return NULL;
1660}
1661
1662/*
1663 * Inspect the given string and determine the true "end" of the log message, in
1664 * order to find where to put a new Signed-off-by: line.  Ignored are
1665 * trailing comment lines and blank lines.  To support "git commit -s
1666 * --amend" on an existing commit, we also ignore "Conflicts:".  To
1667 * support "git commit -v", we truncate at cut lines.
1668 *
1669 * Returns the number of bytes from the tail to ignore, to be fed as
1670 * the second parameter to append_signoff().
1671 */
1672int ignore_non_trailer(const char *buf, size_t len)
1673{
1674        int boc = 0;
1675        int bol = 0;
1676        int in_old_conflicts_block = 0;
1677        size_t cutoff = wt_status_locate_end(buf, len);
1678
1679        while (bol < cutoff) {
1680                const char *next_line = memchr(buf + bol, '\n', len - bol);
1681
1682                if (!next_line)
1683                        next_line = buf + len;
1684                else
1685                        next_line++;
1686
1687                if (buf[bol] == comment_line_char || buf[bol] == '\n') {
1688                        /* is this the first of the run of comments? */
1689                        if (!boc)
1690                                boc = bol;
1691                        /* otherwise, it is just continuing */
1692                } else if (starts_with(buf + bol, "Conflicts:\n")) {
1693                        in_old_conflicts_block = 1;
1694                        if (!boc)
1695                                boc = bol;
1696                } else if (in_old_conflicts_block && buf[bol] == '\t') {
1697                        ; /* a pathname in the conflicts block */
1698                } else if (boc) {
1699                        /* the previous was not trailing comment */
1700                        boc = 0;
1701                        in_old_conflicts_block = 0;
1702                }
1703                bol = next_line - buf;
1704        }
1705        return boc ? len - boc : len - cutoff;
1706}