Andrew's git / gitweb.git / commit.c
?
commit.con commit fetch-pack.c: use oidset to check existence of loose object (024aa46)
   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), type_name(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                clear_commit_marks_1(&list, *commit, mark);
 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
 560struct commit *pop_commit(struct commit_list **stack)
 561{
 562        struct commit_list *top = *stack;
 563        struct commit *item = top ? top->item : NULL;
 564
 565        if (top) {
 566                *stack = top->next;
 567                free(top);
 568        }
 569        return item;
 570}
 571
 572/*
 573 * Topological sort support
 574 */
 575
 576/* count number of children that have not been emitted */
 577define_commit_slab(indegree_slab, int);
 578
 579/* record author-date for each commit object */
 580define_commit_slab(author_date_slab, unsigned long);
 581
 582static void record_author_date(struct author_date_slab *author_date,
 583                               struct commit *commit)
 584{
 585        const char *buffer = get_commit_buffer(commit, NULL);
 586        struct ident_split ident;
 587        const char *ident_line;
 588        size_t ident_len;
 589        char *date_end;
 590        timestamp_t date;
 591
 592        ident_line = find_commit_header(buffer, "author", &ident_len);
 593        if (!ident_line)
 594                goto fail_exit; /* no author line */
 595        if (split_ident_line(&ident, ident_line, ident_len) ||
 596            !ident.date_begin || !ident.date_end)
 597                goto fail_exit; /* malformed "author" line */
 598
 599        date = parse_timestamp(ident.date_begin, &date_end, 10);
 600        if (date_end != ident.date_end)
 601                goto fail_exit; /* malformed date */
 602        *(author_date_slab_at(author_date, commit)) = date;
 603
 604fail_exit:
 605        unuse_commit_buffer(commit, buffer);
 606}
 607
 608static int compare_commits_by_author_date(const void *a_, const void *b_,
 609                                          void *cb_data)
 610{
 611        const struct commit *a = a_, *b = b_;
 612        struct author_date_slab *author_date = cb_data;
 613        timestamp_t a_date = *(author_date_slab_at(author_date, a));
 614        timestamp_t b_date = *(author_date_slab_at(author_date, b));
 615
 616        /* newer commits with larger date first */
 617        if (a_date < b_date)
 618                return 1;
 619        else if (a_date > b_date)
 620                return -1;
 621        return 0;
 622}
 623
 624int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 625{
 626        const struct commit *a = a_, *b = b_;
 627        /* newer commits with larger date first */
 628        if (a->date < b->date)
 629                return 1;
 630        else if (a->date > b->date)
 631                return -1;
 632        return 0;
 633}
 634
 635/*
 636 * Performs an in-place topological sort on the list supplied.
 637 */
 638void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 639{
 640        struct commit_list *next, *orig = *list;
 641        struct commit_list **pptr;
 642        struct indegree_slab indegree;
 643        struct prio_queue queue;
 644        struct commit *commit;
 645        struct author_date_slab author_date;
 646
 647        if (!orig)
 648                return;
 649        *list = NULL;
 650
 651        init_indegree_slab(&indegree);
 652        memset(&queue, '\0', sizeof(queue));
 653
 654        switch (sort_order) {
 655        default: /* REV_SORT_IN_GRAPH_ORDER */
 656                queue.compare = NULL;
 657                break;
 658        case REV_SORT_BY_COMMIT_DATE:
 659                queue.compare = compare_commits_by_commit_date;
 660                break;
 661        case REV_SORT_BY_AUTHOR_DATE:
 662                init_author_date_slab(&author_date);
 663                queue.compare = compare_commits_by_author_date;
 664                queue.cb_data = &author_date;
 665                break;
 666        }
 667
 668        /* Mark them and clear the indegree */
 669        for (next = orig; next; next = next->next) {
 670                struct commit *commit = next->item;
 671                *(indegree_slab_at(&indegree, commit)) = 1;
 672                /* also record the author dates, if needed */
 673                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 674                        record_author_date(&author_date, commit);
 675        }
 676
 677        /* update the indegree */
 678        for (next = orig; next; next = next->next) {
 679                struct commit_list *parents = next->item->parents;
 680                while (parents) {
 681                        struct commit *parent = parents->item;
 682                        int *pi = indegree_slab_at(&indegree, parent);
 683
 684                        if (*pi)
 685                                (*pi)++;
 686                        parents = parents->next;
 687                }
 688        }
 689
 690        /*
 691         * find the tips
 692         *
 693         * tips are nodes not reachable from any other node in the list
 694         *
 695         * the tips serve as a starting set for the work queue.
 696         */
 697        for (next = orig; next; next = next->next) {
 698                struct commit *commit = next->item;
 699
 700                if (*(indegree_slab_at(&indegree, commit)) == 1)
 701                        prio_queue_put(&queue, commit);
 702        }
 703
 704        /*
 705         * This is unfortunate; the initial tips need to be shown
 706         * in the order given from the revision traversal machinery.
 707         */
 708        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 709                prio_queue_reverse(&queue);
 710
 711        /* We no longer need the commit list */
 712        free_commit_list(orig);
 713
 714        pptr = list;
 715        *list = NULL;
 716        while ((commit = prio_queue_get(&queue)) != NULL) {
 717                struct commit_list *parents;
 718
 719                for (parents = commit->parents; parents ; parents = parents->next) {
 720                        struct commit *parent = parents->item;
 721                        int *pi = indegree_slab_at(&indegree, parent);
 722
 723                        if (!*pi)
 724                                continue;
 725
 726                        /*
 727                         * parents are only enqueued for emission
 728                         * when all their children have been emitted thereby
 729                         * guaranteeing topological order.
 730                         */
 731                        if (--(*pi) == 1)
 732                                prio_queue_put(&queue, parent);
 733                }
 734                /*
 735                 * all children of commit have already been
 736                 * emitted. we can emit it now.
 737                 */
 738                *(indegree_slab_at(&indegree, commit)) = 0;
 739
 740                pptr = &commit_list_insert(commit, pptr)->next;
 741        }
 742
 743        clear_indegree_slab(&indegree);
 744        clear_prio_queue(&queue);
 745        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 746                clear_author_date_slab(&author_date);
 747}
 748
 749/* merge-base stuff */
 750
 751/* Remember to update object flag allocation in object.h */
 752#define PARENT1         (1u<<16)
 753#define PARENT2         (1u<<17)
 754#define STALE           (1u<<18)
 755#define RESULT          (1u<<19)
 756
 757static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 758
 759static int queue_has_nonstale(struct prio_queue *queue)
 760{
 761        int i;
 762        for (i = 0; i < queue->nr; i++) {
 763                struct commit *commit = queue->array[i].data;
 764                if (!(commit->object.flags & STALE))
 765                        return 1;
 766        }
 767        return 0;
 768}
 769
 770/* all input commits in one and twos[] must have been parsed! */
 771static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
 772{
 773        struct prio_queue queue = { compare_commits_by_commit_date };
 774        struct commit_list *result = NULL;
 775        int i;
 776
 777        one->object.flags |= PARENT1;
 778        if (!n) {
 779                commit_list_append(one, &result);
 780                return result;
 781        }
 782        prio_queue_put(&queue, one);
 783
 784        for (i = 0; i < n; i++) {
 785                twos[i]->object.flags |= PARENT2;
 786                prio_queue_put(&queue, twos[i]);
 787        }
 788
 789        while (queue_has_nonstale(&queue)) {
 790                struct commit *commit = prio_queue_get(&queue);
 791                struct commit_list *parents;
 792                int flags;
 793
 794                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 795                if (flags == (PARENT1 | PARENT2)) {
 796                        if (!(commit->object.flags & RESULT)) {
 797                                commit->object.flags |= RESULT;
 798                                commit_list_insert_by_date(commit, &result);
 799                        }
 800                        /* Mark parents of a found merge stale */
 801                        flags |= STALE;
 802                }
 803                parents = commit->parents;
 804                while (parents) {
 805                        struct commit *p = parents->item;
 806                        parents = parents->next;
 807                        if ((p->object.flags & flags) == flags)
 808                                continue;
 809                        if (parse_commit(p))
 810                                return NULL;
 811                        p->object.flags |= flags;
 812                        prio_queue_put(&queue, p);
 813                }
 814        }
 815
 816        clear_prio_queue(&queue);
 817        return result;
 818}
 819
 820static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 821{
 822        struct commit_list *list = NULL;
 823        struct commit_list *result = NULL;
 824        int i;
 825
 826        for (i = 0; i < n; i++) {
 827                if (one == twos[i])
 828                        /*
 829                         * We do not mark this even with RESULT so we do not
 830                         * have to clean it up.
 831                         */
 832                        return commit_list_insert(one, &result);
 833        }
 834
 835        if (parse_commit(one))
 836                return NULL;
 837        for (i = 0; i < n; i++) {
 838                if (parse_commit(twos[i]))
 839                        return NULL;
 840        }
 841
 842        list = paint_down_to_common(one, n, twos);
 843
 844        while (list) {
 845                struct commit *commit = pop_commit(&list);
 846                if (!(commit->object.flags & STALE))
 847                        commit_list_insert_by_date(commit, &result);
 848        }
 849        return result;
 850}
 851
 852struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 853{
 854        struct commit_list *i, *j, *k, *ret = NULL;
 855
 856        if (!in)
 857                return ret;
 858
 859        commit_list_insert(in->item, &ret);
 860
 861        for (i = in->next; i; i = i->next) {
 862                struct commit_list *new_commits = NULL, *end = NULL;
 863
 864                for (j = ret; j; j = j->next) {
 865                        struct commit_list *bases;
 866                        bases = get_merge_bases(i->item, j->item);
 867                        if (!new_commits)
 868                                new_commits = bases;
 869                        else
 870                                end->next = bases;
 871                        for (k = bases; k; k = k->next)
 872                                end = k;
 873                }
 874                ret = new_commits;
 875        }
 876        return ret;
 877}
 878
 879static int remove_redundant(struct commit **array, int cnt)
 880{
 881        /*
 882         * Some commit in the array may be an ancestor of
 883         * another commit.  Move such commit to the end of
 884         * the array, and return the number of commits that
 885         * are independent from each other.
 886         */
 887        struct commit **work;
 888        unsigned char *redundant;
 889        int *filled_index;
 890        int i, j, filled;
 891
 892        work = xcalloc(cnt, sizeof(*work));
 893        redundant = xcalloc(cnt, 1);
 894        ALLOC_ARRAY(filled_index, cnt - 1);
 895
 896        for (i = 0; i < cnt; i++)
 897                parse_commit(array[i]);
 898        for (i = 0; i < cnt; i++) {
 899                struct commit_list *common;
 900
 901                if (redundant[i])
 902                        continue;
 903                for (j = filled = 0; j < cnt; j++) {
 904                        if (i == j || redundant[j])
 905                                continue;
 906                        filled_index[filled] = j;
 907                        work[filled++] = array[j];
 908                }
 909                common = paint_down_to_common(array[i], filled, work);
 910                if (array[i]->object.flags & PARENT2)
 911                        redundant[i] = 1;
 912                for (j = 0; j < filled; j++)
 913                        if (work[j]->object.flags & PARENT1)
 914                                redundant[filled_index[j]] = 1;
 915                clear_commit_marks(array[i], all_flags);
 916                clear_commit_marks_many(filled, work, all_flags);
 917                free_commit_list(common);
 918        }
 919
 920        /* Now collect the result */
 921        COPY_ARRAY(work, array, cnt);
 922        for (i = filled = 0; i < cnt; i++)
 923                if (!redundant[i])
 924                        array[filled++] = work[i];
 925        for (j = filled, i = 0; i < cnt; i++)
 926                if (redundant[i])
 927                        array[j++] = work[i];
 928        free(work);
 929        free(redundant);
 930        free(filled_index);
 931        return filled;
 932}
 933
 934static struct commit_list *get_merge_bases_many_0(struct commit *one,
 935                                                  int n,
 936                                                  struct commit **twos,
 937                                                  int cleanup)
 938{
 939        struct commit_list *list;
 940        struct commit **rslt;
 941        struct commit_list *result;
 942        int cnt, i;
 943
 944        result = merge_bases_many(one, n, twos);
 945        for (i = 0; i < n; i++) {
 946                if (one == twos[i])
 947                        return result;
 948        }
 949        if (!result || !result->next) {
 950                if (cleanup) {
 951                        clear_commit_marks(one, all_flags);
 952                        clear_commit_marks_many(n, twos, all_flags);
 953                }
 954                return result;
 955        }
 956
 957        /* There are more than one */
 958        cnt = commit_list_count(result);
 959        rslt = xcalloc(cnt, sizeof(*rslt));
 960        for (list = result, i = 0; list; list = list->next)
 961                rslt[i++] = list->item;
 962        free_commit_list(result);
 963
 964        clear_commit_marks(one, all_flags);
 965        clear_commit_marks_many(n, twos, all_flags);
 966
 967        cnt = remove_redundant(rslt, cnt);
 968        result = NULL;
 969        for (i = 0; i < cnt; i++)
 970                commit_list_insert_by_date(rslt[i], &result);
 971        free(rslt);
 972        return result;
 973}
 974
 975struct commit_list *get_merge_bases_many(struct commit *one,
 976                                         int n,
 977                                         struct commit **twos)
 978{
 979        return get_merge_bases_many_0(one, n, twos, 1);
 980}
 981
 982struct commit_list *get_merge_bases_many_dirty(struct commit *one,
 983                                               int n,
 984                                               struct commit **twos)
 985{
 986        return get_merge_bases_many_0(one, n, twos, 0);
 987}
 988
 989struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
 990{
 991        return get_merge_bases_many_0(one, 1, &two, 1);
 992}
 993
 994/*
 995 * Is "commit" a descendant of one of the elements on the "with_commit" list?
 996 */
 997int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
 998{
 999        if (!with_commit)
1000                return 1;
1001        while (with_commit) {
1002                struct commit *other;
1003
1004                other = with_commit->item;
1005                with_commit = with_commit->next;
1006                if (in_merge_bases(other, commit))
1007                        return 1;
1008        }
1009        return 0;
1010}
1011
1012/*
1013 * Is "commit" an ancestor of one of the "references"?
1014 */
1015int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1016{
1017        struct commit_list *bases;
1018        int ret = 0, i;
1019
1020        if (parse_commit(commit))
1021                return ret;
1022        for (i = 0; i < nr_reference; i++)
1023                if (parse_commit(reference[i]))
1024                        return ret;
1025
1026        bases = paint_down_to_common(commit, nr_reference, reference);
1027        if (commit->object.flags & PARENT2)
1028                ret = 1;
1029        clear_commit_marks(commit, all_flags);
1030        clear_commit_marks_many(nr_reference, reference, all_flags);
1031        free_commit_list(bases);
1032        return ret;
1033}
1034
1035/*
1036 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1037 */
1038int in_merge_bases(struct commit *commit, struct commit *reference)
1039{
1040        return in_merge_bases_many(commit, 1, &reference);
1041}
1042
1043struct commit_list *reduce_heads(struct commit_list *heads)
1044{
1045        struct commit_list *p;
1046        struct commit_list *result = NULL, **tail = &result;
1047        struct commit **array;
1048        int num_head, i;
1049
1050        if (!heads)
1051                return NULL;
1052
1053        /* Uniquify */
1054        for (p = heads; p; p = p->next)
1055                p->item->object.flags &= ~STALE;
1056        for (p = heads, num_head = 0; p; p = p->next) {
1057                if (p->item->object.flags & STALE)
1058                        continue;
1059                p->item->object.flags |= STALE;
1060                num_head++;
1061        }
1062        array = xcalloc(num_head, sizeof(*array));
1063        for (p = heads, i = 0; p; p = p->next) {
1064                if (p->item->object.flags & STALE) {
1065                        array[i++] = p->item;
1066                        p->item->object.flags &= ~STALE;
1067                }
1068        }
1069        num_head = remove_redundant(array, num_head);
1070        for (i = 0; i < num_head; i++)
1071                tail = &commit_list_insert(array[i], tail)->next;
1072        free(array);
1073        return result;
1074}
1075
1076void reduce_heads_replace(struct commit_list **heads)
1077{
1078        struct commit_list *result = reduce_heads(*heads);
1079        free_commit_list(*heads);
1080        *heads = result;
1081}
1082
1083static const char gpg_sig_header[] = "gpgsig";
1084static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1085
1086static int do_sign_commit(struct strbuf *buf, const char *keyid)
1087{
1088        struct strbuf sig = STRBUF_INIT;
1089        int inspos, copypos;
1090        const char *eoh;
1091
1092        /* find the end of the header */
1093        eoh = strstr(buf->buf, "\n\n");
1094        if (!eoh)
1095                inspos = buf->len;
1096        else
1097                inspos = eoh - buf->buf + 1;
1098
1099        if (!keyid || !*keyid)
1100                keyid = get_signing_key();
1101        if (sign_buffer(buf, &sig, keyid)) {
1102                strbuf_release(&sig);
1103                return -1;
1104        }
1105
1106        for (copypos = 0; sig.buf[copypos]; ) {
1107                const char *bol = sig.buf + copypos;
1108                const char *eol = strchrnul(bol, '\n');
1109                int len = (eol - bol) + !!*eol;
1110
1111                if (!copypos) {
1112                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1113                        inspos += gpg_sig_header_len;
1114                }
1115                strbuf_insert(buf, inspos++, " ", 1);
1116                strbuf_insert(buf, inspos, bol, len);
1117                inspos += len;
1118                copypos += len;
1119        }
1120        strbuf_release(&sig);
1121        return 0;
1122}
1123
1124int parse_signed_commit(const struct commit *commit,
1125                        struct strbuf *payload, struct strbuf *signature)
1126{
1127
1128        unsigned long size;
1129        const char *buffer = get_commit_buffer(commit, &size);
1130        int in_signature, saw_signature = -1;
1131        const char *line, *tail;
1132
1133        line = buffer;
1134        tail = buffer + size;
1135        in_signature = 0;
1136        saw_signature = 0;
1137        while (line < tail) {
1138                const char *sig = NULL;
1139                const char *next = memchr(line, '\n', tail - line);
1140
1141                next = next ? next + 1 : tail;
1142                if (in_signature && line[0] == ' ')
1143                        sig = line + 1;
1144                else if (starts_with(line, gpg_sig_header) &&
1145                         line[gpg_sig_header_len] == ' ')
1146                        sig = line + gpg_sig_header_len + 1;
1147                if (sig) {
1148                        strbuf_add(signature, sig, next - sig);
1149                        saw_signature = 1;
1150                        in_signature = 1;
1151                } else {
1152                        if (*line == '\n')
1153                                /* dump the whole remainder of the buffer */
1154                                next = tail;
1155                        strbuf_add(payload, line, next - line);
1156                        in_signature = 0;
1157                }
1158                line = next;
1159        }
1160        unuse_commit_buffer(commit, buffer);
1161        return saw_signature;
1162}
1163
1164int remove_signature(struct strbuf *buf)
1165{
1166        const char *line = buf->buf;
1167        const char *tail = buf->buf + buf->len;
1168        int in_signature = 0;
1169        const char *sig_start = NULL;
1170        const char *sig_end = NULL;
1171
1172        while (line < tail) {
1173                const char *next = memchr(line, '\n', tail - line);
1174                next = next ? next + 1 : tail;
1175
1176                if (in_signature && line[0] == ' ')
1177                        sig_end = next;
1178                else if (starts_with(line, gpg_sig_header) &&
1179                         line[gpg_sig_header_len] == ' ') {
1180                        sig_start = line;
1181                        sig_end = next;
1182                        in_signature = 1;
1183                } else {
1184                        if (*line == '\n')
1185                                /* dump the whole remainder of the buffer */
1186                                next = tail;
1187                        in_signature = 0;
1188                }
1189                line = next;
1190        }
1191
1192        if (sig_start)
1193                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1194
1195        return sig_start != NULL;
1196}
1197
1198static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1199{
1200        struct merge_remote_desc *desc;
1201        struct commit_extra_header *mergetag;
1202        char *buf;
1203        unsigned long size, len;
1204        enum object_type type;
1205
1206        desc = merge_remote_util(parent);
1207        if (!desc || !desc->obj)
1208                return;
1209        buf = read_sha1_file(desc->obj->oid.hash, &type, &size);
1210        if (!buf || type != OBJ_TAG)
1211                goto free_return;
1212        len = parse_signature(buf, size);
1213        if (size == len)
1214                goto free_return;
1215        /*
1216         * We could verify this signature and either omit the tag when
1217         * it does not validate, but the integrator may not have the
1218         * public key of the signer of the tag he is merging, while a
1219         * later auditor may have it while auditing, so let's not run
1220         * verify-signed-buffer here for now...
1221         *
1222         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1223         *      warn("warning: signed tag unverified.");
1224         */
1225        mergetag = xcalloc(1, sizeof(*mergetag));
1226        mergetag->key = xstrdup("mergetag");
1227        mergetag->value = buf;
1228        mergetag->len = size;
1229
1230        **tail = mergetag;
1231        *tail = &mergetag->next;
1232        return;
1233
1234free_return:
1235        free(buf);
1236}
1237
1238int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1239{
1240        struct strbuf payload = STRBUF_INIT;
1241        struct strbuf signature = STRBUF_INIT;
1242        int ret = 1;
1243
1244        sigc->result = 'N';
1245
1246        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1247                goto out;
1248        ret = check_signature(payload.buf, payload.len, signature.buf,
1249                signature.len, sigc);
1250
1251 out:
1252        strbuf_release(&payload);
1253        strbuf_release(&signature);
1254
1255        return ret;
1256}
1257
1258
1259
1260void append_merge_tag_headers(struct commit_list *parents,
1261                              struct commit_extra_header ***tail)
1262{
1263        while (parents) {
1264                struct commit *parent = parents->item;
1265                handle_signed_tag(parent, tail);
1266                parents = parents->next;
1267        }
1268}
1269
1270static void add_extra_header(struct strbuf *buffer,
1271                             struct commit_extra_header *extra)
1272{
1273        strbuf_addstr(buffer, extra->key);
1274        if (extra->len)
1275                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1276        else
1277                strbuf_addch(buffer, '\n');
1278}
1279
1280struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1281                                                      const char **exclude)
1282{
1283        struct commit_extra_header *extra = NULL;
1284        unsigned long size;
1285        const char *buffer = get_commit_buffer(commit, &size);
1286        extra = read_commit_extra_header_lines(buffer, size, exclude);
1287        unuse_commit_buffer(commit, buffer);
1288        return extra;
1289}
1290
1291void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1292{
1293        struct commit_extra_header *extra, *to_free;
1294
1295        to_free = read_commit_extra_headers(commit, NULL);
1296        for (extra = to_free; extra; extra = extra->next) {
1297                if (strcmp(extra->key, "mergetag"))
1298                        continue; /* not a merge tag */
1299                fn(commit, extra, data);
1300        }
1301        free_commit_extra_headers(to_free);
1302}
1303
1304static inline int standard_header_field(const char *field, size_t len)
1305{
1306        return ((len == 4 && !memcmp(field, "tree", 4)) ||
1307                (len == 6 && !memcmp(field, "parent", 6)) ||
1308                (len == 6 && !memcmp(field, "author", 6)) ||
1309                (len == 9 && !memcmp(field, "committer", 9)) ||
1310                (len == 8 && !memcmp(field, "encoding", 8)));
1311}
1312
1313static int excluded_header_field(const char *field, size_t len, const char **exclude)
1314{
1315        if (!exclude)
1316                return 0;
1317
1318        while (*exclude) {
1319                size_t xlen = strlen(*exclude);
1320                if (len == xlen && !memcmp(field, *exclude, xlen))
1321                        return 1;
1322                exclude++;
1323        }
1324        return 0;
1325}
1326
1327static struct commit_extra_header *read_commit_extra_header_lines(
1328        const char *buffer, size_t size,
1329        const char **exclude)
1330{
1331        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1332        const char *line, *next, *eof, *eob;
1333        struct strbuf buf = STRBUF_INIT;
1334
1335        for (line = buffer, eob = line + size;
1336             line < eob && *line != '\n';
1337             line = next) {
1338                next = memchr(line, '\n', eob - line);
1339                next = next ? next + 1 : eob;
1340                if (*line == ' ') {
1341                        /* continuation */
1342                        if (it)
1343                                strbuf_add(&buf, line + 1, next - (line + 1));
1344                        continue;
1345                }
1346                if (it)
1347                        it->value = strbuf_detach(&buf, &it->len);
1348                strbuf_reset(&buf);
1349                it = NULL;
1350
1351                eof = memchr(line, ' ', next - line);
1352                if (!eof)
1353                        eof = next;
1354                else if (standard_header_field(line, eof - line) ||
1355                         excluded_header_field(line, eof - line, exclude))
1356                        continue;
1357
1358                it = xcalloc(1, sizeof(*it));
1359                it->key = xmemdupz(line, eof-line);
1360                *tail = it;
1361                tail = &it->next;
1362                if (eof + 1 < next)
1363                        strbuf_add(&buf, eof + 1, next - (eof + 1));
1364        }
1365        if (it)
1366                it->value = strbuf_detach(&buf, &it->len);
1367        return extra;
1368}
1369
1370void free_commit_extra_headers(struct commit_extra_header *extra)
1371{
1372        while (extra) {
1373                struct commit_extra_header *next = extra->next;
1374                free(extra->key);
1375                free(extra->value);
1376                free(extra);
1377                extra = next;
1378        }
1379}
1380
1381int commit_tree(const char *msg, size_t msg_len, const struct object_id *tree,
1382                struct commit_list *parents, struct object_id *ret,
1383                const char *author, const char *sign_commit)
1384{
1385        struct commit_extra_header *extra = NULL, **tail = &extra;
1386        int result;
1387
1388        append_merge_tag_headers(parents, &tail);
1389        result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1390                                      author, sign_commit, extra);
1391        free_commit_extra_headers(extra);
1392        return result;
1393}
1394
1395static int find_invalid_utf8(const char *buf, int len)
1396{
1397        int offset = 0;
1398        static const unsigned int max_codepoint[] = {
1399                0x7f, 0x7ff, 0xffff, 0x10ffff
1400        };
1401
1402        while (len) {
1403                unsigned char c = *buf++;
1404                int bytes, bad_offset;
1405                unsigned int codepoint;
1406                unsigned int min_val, max_val;
1407
1408                len--;
1409                offset++;
1410
1411                /* Simple US-ASCII? No worries. */
1412                if (c < 0x80)
1413                        continue;
1414
1415                bad_offset = offset-1;
1416
1417                /*
1418                 * Count how many more high bits set: that's how
1419                 * many more bytes this sequence should have.
1420                 */
1421                bytes = 0;
1422                while (c & 0x40) {
1423                        c <<= 1;
1424                        bytes++;
1425                }
1426
1427                /*
1428                 * Must be between 1 and 3 more bytes.  Longer sequences result in
1429                 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1430                 */
1431                if (bytes < 1 || 3 < bytes)
1432                        return bad_offset;
1433
1434                /* Do we *have* that many bytes? */
1435                if (len < bytes)
1436                        return bad_offset;
1437
1438                /*
1439                 * Place the encoded bits at the bottom of the value and compute the
1440                 * valid range.
1441                 */
1442                codepoint = (c & 0x7f) >> bytes;
1443                min_val = max_codepoint[bytes-1] + 1;
1444                max_val = max_codepoint[bytes];
1445
1446                offset += bytes;
1447                len -= bytes;
1448
1449                /* And verify that they are good continuation bytes */
1450                do {
1451                        codepoint <<= 6;
1452                        codepoint |= *buf & 0x3f;
1453                        if ((*buf++ & 0xc0) != 0x80)
1454                                return bad_offset;
1455                } while (--bytes);
1456
1457                /* Reject codepoints that are out of range for the sequence length. */
1458                if (codepoint < min_val || codepoint > max_val)
1459                        return bad_offset;
1460                /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1461                if ((codepoint & 0x1ff800) == 0xd800)
1462                        return bad_offset;
1463                /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1464                if ((codepoint & 0xfffe) == 0xfffe)
1465                        return bad_offset;
1466                /* So are anything in the range U+FDD0..U+FDEF. */
1467                if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1468                        return bad_offset;
1469        }
1470        return -1;
1471}
1472
1473/*
1474 * This verifies that the buffer is in proper utf8 format.
1475 *
1476 * If it isn't, it assumes any non-utf8 characters are Latin1,
1477 * and does the conversion.
1478 */
1479static int verify_utf8(struct strbuf *buf)
1480{
1481        int ok = 1;
1482        long pos = 0;
1483
1484        for (;;) {
1485                int bad;
1486                unsigned char c;
1487                unsigned char replace[2];
1488
1489                bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1490                if (bad < 0)
1491                        return ok;
1492                pos += bad;
1493                ok = 0;
1494                c = buf->buf[pos];
1495                strbuf_remove(buf, pos, 1);
1496
1497                /* We know 'c' must be in the range 128-255 */
1498                replace[0] = 0xc0 + (c >> 6);
1499                replace[1] = 0x80 + (c & 0x3f);
1500                strbuf_insert(buf, pos, replace, 2);
1501                pos += 2;
1502        }
1503}
1504
1505static const char commit_utf8_warn[] =
1506N_("Warning: commit message did not conform to UTF-8.\n"
1507   "You may want to amend it after fixing the message, or set the config\n"
1508   "variable i18n.commitencoding to the encoding your project uses.\n");
1509
1510int commit_tree_extended(const char *msg, size_t msg_len,
1511                         const struct object_id *tree,
1512                         struct commit_list *parents, struct object_id *ret,
1513                         const char *author, const char *sign_commit,
1514                         struct commit_extra_header *extra)
1515{
1516        int result;
1517        int encoding_is_utf8;
1518        struct strbuf buffer;
1519
1520        assert_sha1_type(tree->hash, OBJ_TREE);
1521
1522        if (memchr(msg, '\0', msg_len))
1523                return error("a NUL byte in commit log message not allowed.");
1524
1525        /* Not having i18n.commitencoding is the same as having utf-8 */
1526        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1527
1528        strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1529        strbuf_addf(&buffer, "tree %s\n", oid_to_hex(tree));
1530
1531        /*
1532         * NOTE! This ordering means that the same exact tree merged with a
1533         * different order of parents will be a _different_ changeset even
1534         * if everything else stays the same.
1535         */
1536        while (parents) {
1537                struct commit *parent = pop_commit(&parents);
1538                strbuf_addf(&buffer, "parent %s\n",
1539                            oid_to_hex(&parent->object.oid));
1540        }
1541
1542        /* Person/date information */
1543        if (!author)
1544                author = git_author_info(IDENT_STRICT);
1545        strbuf_addf(&buffer, "author %s\n", author);
1546        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1547        if (!encoding_is_utf8)
1548                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1549
1550        while (extra) {
1551                add_extra_header(&buffer, extra);
1552                extra = extra->next;
1553        }
1554        strbuf_addch(&buffer, '\n');
1555
1556        /* And add the comment */
1557        strbuf_add(&buffer, msg, msg_len);
1558
1559        /* And check the encoding */
1560        if (encoding_is_utf8 && !verify_utf8(&buffer))
1561                fprintf(stderr, _(commit_utf8_warn));
1562
1563        if (sign_commit && do_sign_commit(&buffer, sign_commit)) {
1564                result = -1;
1565                goto out;
1566        }
1567
1568        result = write_object_file(buffer.buf, buffer.len, commit_type, ret);
1569out:
1570        strbuf_release(&buffer);
1571        return result;
1572}
1573
1574void set_merge_remote_desc(struct commit *commit,
1575                           const char *name, struct object *obj)
1576{
1577        struct merge_remote_desc *desc;
1578        FLEX_ALLOC_STR(desc, name, name);
1579        desc->obj = obj;
1580        commit->util = desc;
1581}
1582
1583struct commit *get_merge_parent(const char *name)
1584{
1585        struct object *obj;
1586        struct commit *commit;
1587        struct object_id oid;
1588        if (get_oid(name, &oid))
1589                return NULL;
1590        obj = parse_object(&oid);
1591        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1592        if (commit && !commit->util)
1593                set_merge_remote_desc(commit, name, obj);
1594        return commit;
1595}
1596
1597/*
1598 * Append a commit to the end of the commit_list.
1599 *
1600 * next starts by pointing to the variable that holds the head of an
1601 * empty commit_list, and is updated to point to the "next" field of
1602 * the last item on the list as new commits are appended.
1603 *
1604 * Usage example:
1605 *
1606 *     struct commit_list *list;
1607 *     struct commit_list **next = &list;
1608 *
1609 *     next = commit_list_append(c1, next);
1610 *     next = commit_list_append(c2, next);
1611 *     assert(commit_list_count(list) == 2);
1612 *     return list;
1613 */
1614struct commit_list **commit_list_append(struct commit *commit,
1615                                        struct commit_list **next)
1616{
1617        struct commit_list *new_commit = xmalloc(sizeof(struct commit_list));
1618        new_commit->item = commit;
1619        *next = new_commit;
1620        new_commit->next = NULL;
1621        return &new_commit->next;
1622}
1623
1624const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1625{
1626        int key_len = strlen(key);
1627        const char *line = msg;
1628
1629        while (line) {
1630                const char *eol = strchrnul(line, '\n');
1631
1632                if (line == eol)
1633                        return NULL;
1634
1635                if (eol - line > key_len &&
1636                    !strncmp(line, key, key_len) &&
1637                    line[key_len] == ' ') {
1638                        *out_len = eol - line - key_len - 1;
1639                        return line + key_len + 1;
1640                }
1641                line = *eol ? eol + 1 : NULL;
1642        }
1643        return NULL;
1644}
1645
1646/*
1647 * Inspect the given string and determine the true "end" of the log message, in
1648 * order to find where to put a new Signed-off-by: line.  Ignored are
1649 * trailing comment lines and blank lines.  To support "git commit -s
1650 * --amend" on an existing commit, we also ignore "Conflicts:".  To
1651 * support "git commit -v", we truncate at cut lines.
1652 *
1653 * Returns the number of bytes from the tail to ignore, to be fed as
1654 * the second parameter to append_signoff().
1655 */
1656int ignore_non_trailer(const char *buf, size_t len)
1657{
1658        int boc = 0;
1659        int bol = 0;
1660        int in_old_conflicts_block = 0;
1661        size_t cutoff = wt_status_locate_end(buf, len);
1662
1663        while (bol < cutoff) {
1664                const char *next_line = memchr(buf + bol, '\n', len - bol);
1665
1666                if (!next_line)
1667                        next_line = buf + len;
1668                else
1669                        next_line++;
1670
1671                if (buf[bol] == comment_line_char || buf[bol] == '\n') {
1672                        /* is this the first of the run of comments? */
1673                        if (!boc)
1674                                boc = bol;
1675                        /* otherwise, it is just continuing */
1676                } else if (starts_with(buf + bol, "Conflicts:\n")) {
1677                        in_old_conflicts_block = 1;
1678                        if (!boc)
1679                                boc = bol;
1680                } else if (in_old_conflicts_block && buf[bol] == '\t') {
1681                        ; /* a pathname in the conflicts block */
1682                } else if (boc) {
1683                        /* the previous was not trailing comment */
1684                        boc = 0;
1685                        in_old_conflicts_block = 0;
1686                }
1687                bol = next_line - buf;
1688        }
1689        return boc ? len - boc : len - cutoff;
1690}