Andrew's git / gitweb.git / commit.c
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commit.con commit alloc: add repository argument to alloc_tree_node (cf7203b)
   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(the_repository, oid->hash,
  54                                     alloc_commit_node());
  55        return object_as_type(obj, OBJ_COMMIT, 0);
  56}
  57
  58struct commit *lookup_commit_reference_by_name(const char *name)
  59{
  60        struct object_id oid;
  61        struct commit *commit;
  62
  63        if (get_oid_committish(name, &oid))
  64                return NULL;
  65        commit = lookup_commit_reference(&oid);
  66        if (parse_commit(commit))
  67                return NULL;
  68        return commit;
  69}
  70
  71static timestamp_t parse_commit_date(const char *buf, const char *tail)
  72{
  73        const char *dateptr;
  74
  75        if (buf + 6 >= tail)
  76                return 0;
  77        if (memcmp(buf, "author", 6))
  78                return 0;
  79        while (buf < tail && *buf++ != '\n')
  80                /* nada */;
  81        if (buf + 9 >= tail)
  82                return 0;
  83        if (memcmp(buf, "committer", 9))
  84                return 0;
  85        while (buf < tail && *buf++ != '>')
  86                /* nada */;
  87        if (buf >= tail)
  88                return 0;
  89        dateptr = buf;
  90        while (buf < tail && *buf++ != '\n')
  91                /* nada */;
  92        if (buf >= tail)
  93                return 0;
  94        /* dateptr < buf && buf[-1] == '\n', so parsing will stop at buf-1 */
  95        return parse_timestamp(dateptr, NULL, 10);
  96}
  97
  98static struct commit_graft **commit_graft;
  99static int commit_graft_alloc, commit_graft_nr;
 100
 101static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
 102{
 103        struct commit_graft **commit_graft_table = table;
 104        return commit_graft_table[index]->oid.hash;
 105}
 106
 107static int commit_graft_pos(const unsigned char *sha1)
 108{
 109        return sha1_pos(sha1, commit_graft, commit_graft_nr,
 110                        commit_graft_sha1_access);
 111}
 112
 113int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 114{
 115        int pos = commit_graft_pos(graft->oid.hash);
 116
 117        if (0 <= pos) {
 118                if (ignore_dups)
 119                        free(graft);
 120                else {
 121                        free(commit_graft[pos]);
 122                        commit_graft[pos] = graft;
 123                }
 124                return 1;
 125        }
 126        pos = -pos - 1;
 127        ALLOC_GROW(commit_graft, commit_graft_nr + 1, commit_graft_alloc);
 128        commit_graft_nr++;
 129        if (pos < commit_graft_nr)
 130                MOVE_ARRAY(commit_graft + pos + 1, commit_graft + pos,
 131                           commit_graft_nr - pos - 1);
 132        commit_graft[pos] = graft;
 133        return 0;
 134}
 135
 136struct commit_graft *read_graft_line(struct strbuf *line)
 137{
 138        /* The format is just "Commit Parent1 Parent2 ...\n" */
 139        int i, phase;
 140        const char *tail = NULL;
 141        struct commit_graft *graft = NULL;
 142        struct object_id dummy_oid, *oid;
 143
 144        strbuf_rtrim(line);
 145        if (!line->len || line->buf[0] == '#')
 146                return NULL;
 147        /*
 148         * phase 0 verifies line, counts hashes in line and allocates graft
 149         * phase 1 fills graft
 150         */
 151        for (phase = 0; phase < 2; phase++) {
 152                oid = graft ? &graft->oid : &dummy_oid;
 153                if (parse_oid_hex(line->buf, oid, &tail))
 154                        goto bad_graft_data;
 155                for (i = 0; *tail != '\0'; i++) {
 156                        oid = graft ? &graft->parent[i] : &dummy_oid;
 157                        if (!isspace(*tail++) || parse_oid_hex(tail, oid, &tail))
 158                                goto bad_graft_data;
 159                }
 160                if (!graft) {
 161                        graft = xmalloc(st_add(sizeof(*graft),
 162                                               st_mult(sizeof(struct object_id), i)));
 163                        graft->nr_parent = i;
 164                }
 165        }
 166        return graft;
 167
 168bad_graft_data:
 169        error("bad graft data: %s", line->buf);
 170        assert(!graft);
 171        return NULL;
 172}
 173
 174static int read_graft_file(const char *graft_file)
 175{
 176        FILE *fp = fopen_or_warn(graft_file, "r");
 177        struct strbuf buf = STRBUF_INIT;
 178        if (!fp)
 179                return -1;
 180        while (!strbuf_getwholeline(&buf, fp, '\n')) {
 181                /* The format is just "Commit Parent1 Parent2 ...\n" */
 182                struct commit_graft *graft = read_graft_line(&buf);
 183                if (!graft)
 184                        continue;
 185                if (register_commit_graft(graft, 1))
 186                        error("duplicate graft data: %s", buf.buf);
 187        }
 188        fclose(fp);
 189        strbuf_release(&buf);
 190        return 0;
 191}
 192
 193static void prepare_commit_graft(void)
 194{
 195        static int commit_graft_prepared;
 196        char *graft_file;
 197
 198        if (commit_graft_prepared)
 199                return;
 200        graft_file = get_graft_file();
 201        read_graft_file(graft_file);
 202        /* make sure shallows are read */
 203        is_repository_shallow();
 204        commit_graft_prepared = 1;
 205}
 206
 207struct commit_graft *lookup_commit_graft(const struct object_id *oid)
 208{
 209        int pos;
 210        prepare_commit_graft();
 211        pos = commit_graft_pos(oid->hash);
 212        if (pos < 0)
 213                return NULL;
 214        return commit_graft[pos];
 215}
 216
 217int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
 218{
 219        int i, ret;
 220        for (i = ret = 0; i < commit_graft_nr && !ret; i++)
 221                ret = fn(commit_graft[i], cb_data);
 222        return ret;
 223}
 224
 225int unregister_shallow(const struct object_id *oid)
 226{
 227        int pos = commit_graft_pos(oid->hash);
 228        if (pos < 0)
 229                return -1;
 230        if (pos + 1 < commit_graft_nr)
 231                MOVE_ARRAY(commit_graft + pos, commit_graft + pos + 1,
 232                           commit_graft_nr - pos - 1);
 233        commit_graft_nr--;
 234        return 0;
 235}
 236
 237struct commit_buffer {
 238        void *buffer;
 239        unsigned long size;
 240};
 241define_commit_slab(buffer_slab, struct commit_buffer);
 242static struct buffer_slab buffer_slab = COMMIT_SLAB_INIT(1, buffer_slab);
 243
 244void set_commit_buffer(struct commit *commit, void *buffer, unsigned long size)
 245{
 246        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 247        v->buffer = buffer;
 248        v->size = size;
 249}
 250
 251const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
 252{
 253        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 254        if (!v) {
 255                if (sizep)
 256                        *sizep = 0;
 257                return NULL;
 258        }
 259        if (sizep)
 260                *sizep = v->size;
 261        return v->buffer;
 262}
 263
 264const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
 265{
 266        const void *ret = get_cached_commit_buffer(commit, sizep);
 267        if (!ret) {
 268                enum object_type type;
 269                unsigned long size;
 270                ret = read_object_file(&commit->object.oid, &type, &size);
 271                if (!ret)
 272                        die("cannot read commit object %s",
 273                            oid_to_hex(&commit->object.oid));
 274                if (type != OBJ_COMMIT)
 275                        die("expected commit for %s, got %s",
 276                            oid_to_hex(&commit->object.oid), type_name(type));
 277                if (sizep)
 278                        *sizep = size;
 279        }
 280        return ret;
 281}
 282
 283void unuse_commit_buffer(const struct commit *commit, const void *buffer)
 284{
 285        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 286        if (!(v && v->buffer == buffer))
 287                free((void *)buffer);
 288}
 289
 290void free_commit_buffer(struct commit *commit)
 291{
 292        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 293        if (v) {
 294                FREE_AND_NULL(v->buffer);
 295                v->size = 0;
 296        }
 297}
 298
 299const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 300{
 301        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 302        void *ret;
 303
 304        if (!v) {
 305                if (sizep)
 306                        *sizep = 0;
 307                return NULL;
 308        }
 309        ret = v->buffer;
 310        if (sizep)
 311                *sizep = v->size;
 312
 313        v->buffer = NULL;
 314        v->size = 0;
 315        return ret;
 316}
 317
 318int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
 319{
 320        const char *tail = buffer;
 321        const char *bufptr = buffer;
 322        struct object_id parent;
 323        struct commit_list **pptr;
 324        struct commit_graft *graft;
 325        const int tree_entry_len = GIT_SHA1_HEXSZ + 5;
 326        const int parent_entry_len = GIT_SHA1_HEXSZ + 7;
 327
 328        if (item->object.parsed)
 329                return 0;
 330        item->object.parsed = 1;
 331        tail += size;
 332        if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
 333                        bufptr[tree_entry_len] != '\n')
 334                return error("bogus commit object %s", oid_to_hex(&item->object.oid));
 335        if (get_sha1_hex(bufptr + 5, parent.hash) < 0)
 336                return error("bad tree pointer in commit %s",
 337                             oid_to_hex(&item->object.oid));
 338        item->tree = lookup_tree(&parent);
 339        bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
 340        pptr = &item->parents;
 341
 342        graft = lookup_commit_graft(&item->object.oid);
 343        while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
 344                struct commit *new_parent;
 345
 346                if (tail <= bufptr + parent_entry_len + 1 ||
 347                    get_sha1_hex(bufptr + 7, parent.hash) ||
 348                    bufptr[parent_entry_len] != '\n')
 349                        return error("bad parents in commit %s", oid_to_hex(&item->object.oid));
 350                bufptr += parent_entry_len + 1;
 351                /*
 352                 * The clone is shallow if nr_parent < 0, and we must
 353                 * not traverse its real parents even when we unhide them.
 354                 */
 355                if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
 356                        continue;
 357                new_parent = lookup_commit(&parent);
 358                if (new_parent)
 359                        pptr = &commit_list_insert(new_parent, pptr)->next;
 360        }
 361        if (graft) {
 362                int i;
 363                struct commit *new_parent;
 364                for (i = 0; i < graft->nr_parent; i++) {
 365                        new_parent = lookup_commit(&graft->parent[i]);
 366                        if (!new_parent)
 367                                continue;
 368                        pptr = &commit_list_insert(new_parent, pptr)->next;
 369                }
 370        }
 371        item->date = parse_commit_date(bufptr, tail);
 372
 373        return 0;
 374}
 375
 376int parse_commit_gently(struct commit *item, int quiet_on_missing)
 377{
 378        enum object_type type;
 379        void *buffer;
 380        unsigned long size;
 381        int ret;
 382
 383        if (!item)
 384                return -1;
 385        if (item->object.parsed)
 386                return 0;
 387        buffer = read_object_file(&item->object.oid, &type, &size);
 388        if (!buffer)
 389                return quiet_on_missing ? -1 :
 390                        error("Could not read %s",
 391                             oid_to_hex(&item->object.oid));
 392        if (type != OBJ_COMMIT) {
 393                free(buffer);
 394                return error("Object %s not a commit",
 395                             oid_to_hex(&item->object.oid));
 396        }
 397        ret = parse_commit_buffer(item, buffer, size);
 398        if (save_commit_buffer && !ret) {
 399                set_commit_buffer(item, buffer, size);
 400                return 0;
 401        }
 402        free(buffer);
 403        return ret;
 404}
 405
 406void parse_commit_or_die(struct commit *item)
 407{
 408        if (parse_commit(item))
 409                die("unable to parse commit %s",
 410                    item ? oid_to_hex(&item->object.oid) : "(null)");
 411}
 412
 413int find_commit_subject(const char *commit_buffer, const char **subject)
 414{
 415        const char *eol;
 416        const char *p = commit_buffer;
 417
 418        while (*p && (*p != '\n' || p[1] != '\n'))
 419                p++;
 420        if (*p) {
 421                p = skip_blank_lines(p + 2);
 422                eol = strchrnul(p, '\n');
 423        } else
 424                eol = p;
 425
 426        *subject = p;
 427
 428        return eol - p;
 429}
 430
 431struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 432{
 433        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 434        new_list->item = item;
 435        new_list->next = *list_p;
 436        *list_p = new_list;
 437        return new_list;
 438}
 439
 440unsigned commit_list_count(const struct commit_list *l)
 441{
 442        unsigned c = 0;
 443        for (; l; l = l->next )
 444                c++;
 445        return c;
 446}
 447
 448struct commit_list *copy_commit_list(struct commit_list *list)
 449{
 450        struct commit_list *head = NULL;
 451        struct commit_list **pp = &head;
 452        while (list) {
 453                pp = commit_list_append(list->item, pp);
 454                list = list->next;
 455        }
 456        return head;
 457}
 458
 459void free_commit_list(struct commit_list *list)
 460{
 461        while (list)
 462                pop_commit(&list);
 463}
 464
 465struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 466{
 467        struct commit_list **pp = list;
 468        struct commit_list *p;
 469        while ((p = *pp) != NULL) {
 470                if (p->item->date < item->date) {
 471                        break;
 472                }
 473                pp = &p->next;
 474        }
 475        return commit_list_insert(item, pp);
 476}
 477
 478static int commit_list_compare_by_date(const void *a, const void *b)
 479{
 480        timestamp_t a_date = ((const struct commit_list *)a)->item->date;
 481        timestamp_t b_date = ((const struct commit_list *)b)->item->date;
 482        if (a_date < b_date)
 483                return 1;
 484        if (a_date > b_date)
 485                return -1;
 486        return 0;
 487}
 488
 489static void *commit_list_get_next(const void *a)
 490{
 491        return ((const struct commit_list *)a)->next;
 492}
 493
 494static void commit_list_set_next(void *a, void *next)
 495{
 496        ((struct commit_list *)a)->next = next;
 497}
 498
 499void commit_list_sort_by_date(struct commit_list **list)
 500{
 501        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 502                                commit_list_compare_by_date);
 503}
 504
 505struct commit *pop_most_recent_commit(struct commit_list **list,
 506                                      unsigned int mark)
 507{
 508        struct commit *ret = pop_commit(list);
 509        struct commit_list *parents = ret->parents;
 510
 511        while (parents) {
 512                struct commit *commit = parents->item;
 513                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 514                        commit->object.flags |= mark;
 515                        commit_list_insert_by_date(commit, list);
 516                }
 517                parents = parents->next;
 518        }
 519        return ret;
 520}
 521
 522static void clear_commit_marks_1(struct commit_list **plist,
 523                                 struct commit *commit, unsigned int mark)
 524{
 525        while (commit) {
 526                struct commit_list *parents;
 527
 528                if (!(mark & commit->object.flags))
 529                        return;
 530
 531                commit->object.flags &= ~mark;
 532
 533                parents = commit->parents;
 534                if (!parents)
 535                        return;
 536
 537                while ((parents = parents->next))
 538                        commit_list_insert(parents->item, plist);
 539
 540                commit = commit->parents->item;
 541        }
 542}
 543
 544void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 545{
 546        struct commit_list *list = NULL;
 547
 548        while (nr--) {
 549                clear_commit_marks_1(&list, *commit, mark);
 550                commit++;
 551        }
 552        while (list)
 553                clear_commit_marks_1(&list, pop_commit(&list), mark);
 554}
 555
 556void clear_commit_marks(struct commit *commit, unsigned int mark)
 557{
 558        clear_commit_marks_many(1, &commit, mark);
 559}
 560
 561struct commit *pop_commit(struct commit_list **stack)
 562{
 563        struct commit_list *top = *stack;
 564        struct commit *item = top ? top->item : NULL;
 565
 566        if (top) {
 567                *stack = top->next;
 568                free(top);
 569        }
 570        return item;
 571}
 572
 573/*
 574 * Topological sort support
 575 */
 576
 577/* count number of children that have not been emitted */
 578define_commit_slab(indegree_slab, int);
 579
 580/* record author-date for each commit object */
 581define_commit_slab(author_date_slab, unsigned long);
 582
 583static void record_author_date(struct author_date_slab *author_date,
 584                               struct commit *commit)
 585{
 586        const char *buffer = get_commit_buffer(commit, NULL);
 587        struct ident_split ident;
 588        const char *ident_line;
 589        size_t ident_len;
 590        char *date_end;
 591        timestamp_t date;
 592
 593        ident_line = find_commit_header(buffer, "author", &ident_len);
 594        if (!ident_line)
 595                goto fail_exit; /* no author line */
 596        if (split_ident_line(&ident, ident_line, ident_len) ||
 597            !ident.date_begin || !ident.date_end)
 598                goto fail_exit; /* malformed "author" line */
 599
 600        date = parse_timestamp(ident.date_begin, &date_end, 10);
 601        if (date_end != ident.date_end)
 602                goto fail_exit; /* malformed date */
 603        *(author_date_slab_at(author_date, commit)) = date;
 604
 605fail_exit:
 606        unuse_commit_buffer(commit, buffer);
 607}
 608
 609static int compare_commits_by_author_date(const void *a_, const void *b_,
 610                                          void *cb_data)
 611{
 612        const struct commit *a = a_, *b = b_;
 613        struct author_date_slab *author_date = cb_data;
 614        timestamp_t a_date = *(author_date_slab_at(author_date, a));
 615        timestamp_t b_date = *(author_date_slab_at(author_date, b));
 616
 617        /* newer commits with larger date first */
 618        if (a_date < b_date)
 619                return 1;
 620        else if (a_date > b_date)
 621                return -1;
 622        return 0;
 623}
 624
 625int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 626{
 627        const struct commit *a = a_, *b = b_;
 628        /* newer commits with larger date first */
 629        if (a->date < b->date)
 630                return 1;
 631        else if (a->date > b->date)
 632                return -1;
 633        return 0;
 634}
 635
 636/*
 637 * Performs an in-place topological sort on the list supplied.
 638 */
 639void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 640{
 641        struct commit_list *next, *orig = *list;
 642        struct commit_list **pptr;
 643        struct indegree_slab indegree;
 644        struct prio_queue queue;
 645        struct commit *commit;
 646        struct author_date_slab author_date;
 647
 648        if (!orig)
 649                return;
 650        *list = NULL;
 651
 652        init_indegree_slab(&indegree);
 653        memset(&queue, '\0', sizeof(queue));
 654
 655        switch (sort_order) {
 656        default: /* REV_SORT_IN_GRAPH_ORDER */
 657                queue.compare = NULL;
 658                break;
 659        case REV_SORT_BY_COMMIT_DATE:
 660                queue.compare = compare_commits_by_commit_date;
 661                break;
 662        case REV_SORT_BY_AUTHOR_DATE:
 663                init_author_date_slab(&author_date);
 664                queue.compare = compare_commits_by_author_date;
 665                queue.cb_data = &author_date;
 666                break;
 667        }
 668
 669        /* Mark them and clear the indegree */
 670        for (next = orig; next; next = next->next) {
 671                struct commit *commit = next->item;
 672                *(indegree_slab_at(&indegree, commit)) = 1;
 673                /* also record the author dates, if needed */
 674                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 675                        record_author_date(&author_date, commit);
 676        }
 677
 678        /* update the indegree */
 679        for (next = orig; next; next = next->next) {
 680                struct commit_list *parents = next->item->parents;
 681                while (parents) {
 682                        struct commit *parent = parents->item;
 683                        int *pi = indegree_slab_at(&indegree, parent);
 684
 685                        if (*pi)
 686                                (*pi)++;
 687                        parents = parents->next;
 688                }
 689        }
 690
 691        /*
 692         * find the tips
 693         *
 694         * tips are nodes not reachable from any other node in the list
 695         *
 696         * the tips serve as a starting set for the work queue.
 697         */
 698        for (next = orig; next; next = next->next) {
 699                struct commit *commit = next->item;
 700
 701                if (*(indegree_slab_at(&indegree, commit)) == 1)
 702                        prio_queue_put(&queue, commit);
 703        }
 704
 705        /*
 706         * This is unfortunate; the initial tips need to be shown
 707         * in the order given from the revision traversal machinery.
 708         */
 709        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 710                prio_queue_reverse(&queue);
 711
 712        /* We no longer need the commit list */
 713        free_commit_list(orig);
 714
 715        pptr = list;
 716        *list = NULL;
 717        while ((commit = prio_queue_get(&queue)) != NULL) {
 718                struct commit_list *parents;
 719
 720                for (parents = commit->parents; parents ; parents = parents->next) {
 721                        struct commit *parent = parents->item;
 722                        int *pi = indegree_slab_at(&indegree, parent);
 723
 724                        if (!*pi)
 725                                continue;
 726
 727                        /*
 728                         * parents are only enqueued for emission
 729                         * when all their children have been emitted thereby
 730                         * guaranteeing topological order.
 731                         */
 732                        if (--(*pi) == 1)
 733                                prio_queue_put(&queue, parent);
 734                }
 735                /*
 736                 * all children of commit have already been
 737                 * emitted. we can emit it now.
 738                 */
 739                *(indegree_slab_at(&indegree, commit)) = 0;
 740
 741                pptr = &commit_list_insert(commit, pptr)->next;
 742        }
 743
 744        clear_indegree_slab(&indegree);
 745        clear_prio_queue(&queue);
 746        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 747                clear_author_date_slab(&author_date);
 748}
 749
 750/* merge-base stuff */
 751
 752/* Remember to update object flag allocation in object.h */
 753#define PARENT1         (1u<<16)
 754#define PARENT2         (1u<<17)
 755#define STALE           (1u<<18)
 756#define RESULT          (1u<<19)
 757
 758static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 759
 760static int queue_has_nonstale(struct prio_queue *queue)
 761{
 762        int i;
 763        for (i = 0; i < queue->nr; i++) {
 764                struct commit *commit = queue->array[i].data;
 765                if (!(commit->object.flags & STALE))
 766                        return 1;
 767        }
 768        return 0;
 769}
 770
 771/* all input commits in one and twos[] must have been parsed! */
 772static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
 773{
 774        struct prio_queue queue = { compare_commits_by_commit_date };
 775        struct commit_list *result = NULL;
 776        int i;
 777
 778        one->object.flags |= PARENT1;
 779        if (!n) {
 780                commit_list_append(one, &result);
 781                return result;
 782        }
 783        prio_queue_put(&queue, one);
 784
 785        for (i = 0; i < n; i++) {
 786                twos[i]->object.flags |= PARENT2;
 787                prio_queue_put(&queue, twos[i]);
 788        }
 789
 790        while (queue_has_nonstale(&queue)) {
 791                struct commit *commit = prio_queue_get(&queue);
 792                struct commit_list *parents;
 793                int flags;
 794
 795                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 796                if (flags == (PARENT1 | PARENT2)) {
 797                        if (!(commit->object.flags & RESULT)) {
 798                                commit->object.flags |= RESULT;
 799                                commit_list_insert_by_date(commit, &result);
 800                        }
 801                        /* Mark parents of a found merge stale */
 802                        flags |= STALE;
 803                }
 804                parents = commit->parents;
 805                while (parents) {
 806                        struct commit *p = parents->item;
 807                        parents = parents->next;
 808                        if ((p->object.flags & flags) == flags)
 809                                continue;
 810                        if (parse_commit(p))
 811                                return NULL;
 812                        p->object.flags |= flags;
 813                        prio_queue_put(&queue, p);
 814                }
 815        }
 816
 817        clear_prio_queue(&queue);
 818        return result;
 819}
 820
 821static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 822{
 823        struct commit_list *list = NULL;
 824        struct commit_list *result = NULL;
 825        int i;
 826
 827        for (i = 0; i < n; i++) {
 828                if (one == twos[i])
 829                        /*
 830                         * We do not mark this even with RESULT so we do not
 831                         * have to clean it up.
 832                         */
 833                        return commit_list_insert(one, &result);
 834        }
 835
 836        if (parse_commit(one))
 837                return NULL;
 838        for (i = 0; i < n; i++) {
 839                if (parse_commit(twos[i]))
 840                        return NULL;
 841        }
 842
 843        list = paint_down_to_common(one, n, twos);
 844
 845        while (list) {
 846                struct commit *commit = pop_commit(&list);
 847                if (!(commit->object.flags & STALE))
 848                        commit_list_insert_by_date(commit, &result);
 849        }
 850        return result;
 851}
 852
 853struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 854{
 855        struct commit_list *i, *j, *k, *ret = NULL;
 856
 857        if (!in)
 858                return ret;
 859
 860        commit_list_insert(in->item, &ret);
 861
 862        for (i = in->next; i; i = i->next) {
 863                struct commit_list *new_commits = NULL, *end = NULL;
 864
 865                for (j = ret; j; j = j->next) {
 866                        struct commit_list *bases;
 867                        bases = get_merge_bases(i->item, j->item);
 868                        if (!new_commits)
 869                                new_commits = bases;
 870                        else
 871                                end->next = bases;
 872                        for (k = bases; k; k = k->next)
 873                                end = k;
 874                }
 875                ret = new_commits;
 876        }
 877        return ret;
 878}
 879
 880static int remove_redundant(struct commit **array, int cnt)
 881{
 882        /*
 883         * Some commit in the array may be an ancestor of
 884         * another commit.  Move such commit to the end of
 885         * the array, and return the number of commits that
 886         * are independent from each other.
 887         */
 888        struct commit **work;
 889        unsigned char *redundant;
 890        int *filled_index;
 891        int i, j, filled;
 892
 893        work = xcalloc(cnt, sizeof(*work));
 894        redundant = xcalloc(cnt, 1);
 895        ALLOC_ARRAY(filled_index, cnt - 1);
 896
 897        for (i = 0; i < cnt; i++)
 898                parse_commit(array[i]);
 899        for (i = 0; i < cnt; i++) {
 900                struct commit_list *common;
 901
 902                if (redundant[i])
 903                        continue;
 904                for (j = filled = 0; j < cnt; j++) {
 905                        if (i == j || redundant[j])
 906                                continue;
 907                        filled_index[filled] = j;
 908                        work[filled++] = array[j];
 909                }
 910                common = paint_down_to_common(array[i], filled, work);
 911                if (array[i]->object.flags & PARENT2)
 912                        redundant[i] = 1;
 913                for (j = 0; j < filled; j++)
 914                        if (work[j]->object.flags & PARENT1)
 915                                redundant[filled_index[j]] = 1;
 916                clear_commit_marks(array[i], all_flags);
 917                clear_commit_marks_many(filled, work, all_flags);
 918                free_commit_list(common);
 919        }
 920
 921        /* Now collect the result */
 922        COPY_ARRAY(work, array, cnt);
 923        for (i = filled = 0; i < cnt; i++)
 924                if (!redundant[i])
 925                        array[filled++] = work[i];
 926        for (j = filled, i = 0; i < cnt; i++)
 927                if (redundant[i])
 928                        array[j++] = work[i];
 929        free(work);
 930        free(redundant);
 931        free(filled_index);
 932        return filled;
 933}
 934
 935static struct commit_list *get_merge_bases_many_0(struct commit *one,
 936                                                  int n,
 937                                                  struct commit **twos,
 938                                                  int cleanup)
 939{
 940        struct commit_list *list;
 941        struct commit **rslt;
 942        struct commit_list *result;
 943        int cnt, i;
 944
 945        result = merge_bases_many(one, n, twos);
 946        for (i = 0; i < n; i++) {
 947                if (one == twos[i])
 948                        return result;
 949        }
 950        if (!result || !result->next) {
 951                if (cleanup) {
 952                        clear_commit_marks(one, all_flags);
 953                        clear_commit_marks_many(n, twos, all_flags);
 954                }
 955                return result;
 956        }
 957
 958        /* There are more than one */
 959        cnt = commit_list_count(result);
 960        rslt = xcalloc(cnt, sizeof(*rslt));
 961        for (list = result, i = 0; list; list = list->next)
 962                rslt[i++] = list->item;
 963        free_commit_list(result);
 964
 965        clear_commit_marks(one, all_flags);
 966        clear_commit_marks_many(n, twos, all_flags);
 967
 968        cnt = remove_redundant(rslt, cnt);
 969        result = NULL;
 970        for (i = 0; i < cnt; i++)
 971                commit_list_insert_by_date(rslt[i], &result);
 972        free(rslt);
 973        return result;
 974}
 975
 976struct commit_list *get_merge_bases_many(struct commit *one,
 977                                         int n,
 978                                         struct commit **twos)
 979{
 980        return get_merge_bases_many_0(one, n, twos, 1);
 981}
 982
 983struct commit_list *get_merge_bases_many_dirty(struct commit *one,
 984                                               int n,
 985                                               struct commit **twos)
 986{
 987        return get_merge_bases_many_0(one, n, twos, 0);
 988}
 989
 990struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
 991{
 992        return get_merge_bases_many_0(one, 1, &two, 1);
 993}
 994
 995/*
 996 * Is "commit" a descendant of one of the elements on the "with_commit" list?
 997 */
 998int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
 999{
1000        if (!with_commit)
1001                return 1;
1002        while (with_commit) {
1003                struct commit *other;
1004
1005                other = with_commit->item;
1006                with_commit = with_commit->next;
1007                if (in_merge_bases(other, commit))
1008                        return 1;
1009        }
1010        return 0;
1011}
1012
1013/*
1014 * Is "commit" an ancestor of one of the "references"?
1015 */
1016int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1017{
1018        struct commit_list *bases;
1019        int ret = 0, i;
1020
1021        if (parse_commit(commit))
1022                return ret;
1023        for (i = 0; i < nr_reference; i++)
1024                if (parse_commit(reference[i]))
1025                        return ret;
1026
1027        bases = paint_down_to_common(commit, nr_reference, reference);
1028        if (commit->object.flags & PARENT2)
1029                ret = 1;
1030        clear_commit_marks(commit, all_flags);
1031        clear_commit_marks_many(nr_reference, reference, all_flags);
1032        free_commit_list(bases);
1033        return ret;
1034}
1035
1036/*
1037 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1038 */
1039int in_merge_bases(struct commit *commit, struct commit *reference)
1040{
1041        return in_merge_bases_many(commit, 1, &reference);
1042}
1043
1044struct commit_list *reduce_heads(struct commit_list *heads)
1045{
1046        struct commit_list *p;
1047        struct commit_list *result = NULL, **tail = &result;
1048        struct commit **array;
1049        int num_head, i;
1050
1051        if (!heads)
1052                return NULL;
1053
1054        /* Uniquify */
1055        for (p = heads; p; p = p->next)
1056                p->item->object.flags &= ~STALE;
1057        for (p = heads, num_head = 0; p; p = p->next) {
1058                if (p->item->object.flags & STALE)
1059                        continue;
1060                p->item->object.flags |= STALE;
1061                num_head++;
1062        }
1063        array = xcalloc(num_head, sizeof(*array));
1064        for (p = heads, i = 0; p; p = p->next) {
1065                if (p->item->object.flags & STALE) {
1066                        array[i++] = p->item;
1067                        p->item->object.flags &= ~STALE;
1068                }
1069        }
1070        num_head = remove_redundant(array, num_head);
1071        for (i = 0; i < num_head; i++)
1072                tail = &commit_list_insert(array[i], tail)->next;
1073        free(array);
1074        return result;
1075}
1076
1077void reduce_heads_replace(struct commit_list **heads)
1078{
1079        struct commit_list *result = reduce_heads(*heads);
1080        free_commit_list(*heads);
1081        *heads = result;
1082}
1083
1084static const char gpg_sig_header[] = "gpgsig";
1085static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1086
1087static int do_sign_commit(struct strbuf *buf, const char *keyid)
1088{
1089        struct strbuf sig = STRBUF_INIT;
1090        int inspos, copypos;
1091        const char *eoh;
1092
1093        /* find the end of the header */
1094        eoh = strstr(buf->buf, "\n\n");
1095        if (!eoh)
1096                inspos = buf->len;
1097        else
1098                inspos = eoh - buf->buf + 1;
1099
1100        if (!keyid || !*keyid)
1101                keyid = get_signing_key();
1102        if (sign_buffer(buf, &sig, keyid)) {
1103                strbuf_release(&sig);
1104                return -1;
1105        }
1106
1107        for (copypos = 0; sig.buf[copypos]; ) {
1108                const char *bol = sig.buf + copypos;
1109                const char *eol = strchrnul(bol, '\n');
1110                int len = (eol - bol) + !!*eol;
1111
1112                if (!copypos) {
1113                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1114                        inspos += gpg_sig_header_len;
1115                }
1116                strbuf_insert(buf, inspos++, " ", 1);
1117                strbuf_insert(buf, inspos, bol, len);
1118                inspos += len;
1119                copypos += len;
1120        }
1121        strbuf_release(&sig);
1122        return 0;
1123}
1124
1125int parse_signed_commit(const struct commit *commit,
1126                        struct strbuf *payload, struct strbuf *signature)
1127{
1128
1129        unsigned long size;
1130        const char *buffer = get_commit_buffer(commit, &size);
1131        int in_signature, saw_signature = -1;
1132        const char *line, *tail;
1133
1134        line = buffer;
1135        tail = buffer + size;
1136        in_signature = 0;
1137        saw_signature = 0;
1138        while (line < tail) {
1139                const char *sig = NULL;
1140                const char *next = memchr(line, '\n', tail - line);
1141
1142                next = next ? next + 1 : tail;
1143                if (in_signature && line[0] == ' ')
1144                        sig = line + 1;
1145                else if (starts_with(line, gpg_sig_header) &&
1146                         line[gpg_sig_header_len] == ' ')
1147                        sig = line + gpg_sig_header_len + 1;
1148                if (sig) {
1149                        strbuf_add(signature, sig, next - sig);
1150                        saw_signature = 1;
1151                        in_signature = 1;
1152                } else {
1153                        if (*line == '\n')
1154                                /* dump the whole remainder of the buffer */
1155                                next = tail;
1156                        strbuf_add(payload, line, next - line);
1157                        in_signature = 0;
1158                }
1159                line = next;
1160        }
1161        unuse_commit_buffer(commit, buffer);
1162        return saw_signature;
1163}
1164
1165int remove_signature(struct strbuf *buf)
1166{
1167        const char *line = buf->buf;
1168        const char *tail = buf->buf + buf->len;
1169        int in_signature = 0;
1170        const char *sig_start = NULL;
1171        const char *sig_end = NULL;
1172
1173        while (line < tail) {
1174                const char *next = memchr(line, '\n', tail - line);
1175                next = next ? next + 1 : tail;
1176
1177                if (in_signature && line[0] == ' ')
1178                        sig_end = next;
1179                else if (starts_with(line, gpg_sig_header) &&
1180                         line[gpg_sig_header_len] == ' ') {
1181                        sig_start = line;
1182                        sig_end = next;
1183                        in_signature = 1;
1184                } else {
1185                        if (*line == '\n')
1186                                /* dump the whole remainder of the buffer */
1187                                next = tail;
1188                        in_signature = 0;
1189                }
1190                line = next;
1191        }
1192
1193        if (sig_start)
1194                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1195
1196        return sig_start != NULL;
1197}
1198
1199static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1200{
1201        struct merge_remote_desc *desc;
1202        struct commit_extra_header *mergetag;
1203        char *buf;
1204        unsigned long size, len;
1205        enum object_type type;
1206
1207        desc = merge_remote_util(parent);
1208        if (!desc || !desc->obj)
1209                return;
1210        buf = read_object_file(&desc->obj->oid, &type, &size);
1211        if (!buf || type != OBJ_TAG)
1212                goto free_return;
1213        len = parse_signature(buf, size);
1214        if (size == len)
1215                goto free_return;
1216        /*
1217         * We could verify this signature and either omit the tag when
1218         * it does not validate, but the integrator may not have the
1219         * public key of the signer of the tag he is merging, while a
1220         * later auditor may have it while auditing, so let's not run
1221         * verify-signed-buffer here for now...
1222         *
1223         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1224         *      warn("warning: signed tag unverified.");
1225         */
1226        mergetag = xcalloc(1, sizeof(*mergetag));
1227        mergetag->key = xstrdup("mergetag");
1228        mergetag->value = buf;
1229        mergetag->len = size;
1230
1231        **tail = mergetag;
1232        *tail = &mergetag->next;
1233        return;
1234
1235free_return:
1236        free(buf);
1237}
1238
1239int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1240{
1241        struct strbuf payload = STRBUF_INIT;
1242        struct strbuf signature = STRBUF_INIT;
1243        int ret = 1;
1244
1245        sigc->result = 'N';
1246
1247        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1248                goto out;
1249        ret = check_signature(payload.buf, payload.len, signature.buf,
1250                signature.len, sigc);
1251
1252 out:
1253        strbuf_release(&payload);
1254        strbuf_release(&signature);
1255
1256        return ret;
1257}
1258
1259
1260
1261void append_merge_tag_headers(struct commit_list *parents,
1262                              struct commit_extra_header ***tail)
1263{
1264        while (parents) {
1265                struct commit *parent = parents->item;
1266                handle_signed_tag(parent, tail);
1267                parents = parents->next;
1268        }
1269}
1270
1271static void add_extra_header(struct strbuf *buffer,
1272                             struct commit_extra_header *extra)
1273{
1274        strbuf_addstr(buffer, extra->key);
1275        if (extra->len)
1276                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1277        else
1278                strbuf_addch(buffer, '\n');
1279}
1280
1281struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1282                                                      const char **exclude)
1283{
1284        struct commit_extra_header *extra = NULL;
1285        unsigned long size;
1286        const char *buffer = get_commit_buffer(commit, &size);
1287        extra = read_commit_extra_header_lines(buffer, size, exclude);
1288        unuse_commit_buffer(commit, buffer);
1289        return extra;
1290}
1291
1292void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1293{
1294        struct commit_extra_header *extra, *to_free;
1295
1296        to_free = read_commit_extra_headers(commit, NULL);
1297        for (extra = to_free; extra; extra = extra->next) {
1298                if (strcmp(extra->key, "mergetag"))
1299                        continue; /* not a merge tag */
1300                fn(commit, extra, data);
1301        }
1302        free_commit_extra_headers(to_free);
1303}
1304
1305static inline int standard_header_field(const char *field, size_t len)
1306{
1307        return ((len == 4 && !memcmp(field, "tree", 4)) ||
1308                (len == 6 && !memcmp(field, "parent", 6)) ||
1309                (len == 6 && !memcmp(field, "author", 6)) ||
1310                (len == 9 && !memcmp(field, "committer", 9)) ||
1311                (len == 8 && !memcmp(field, "encoding", 8)));
1312}
1313
1314static int excluded_header_field(const char *field, size_t len, const char **exclude)
1315{
1316        if (!exclude)
1317                return 0;
1318
1319        while (*exclude) {
1320                size_t xlen = strlen(*exclude);
1321                if (len == xlen && !memcmp(field, *exclude, xlen))
1322                        return 1;
1323                exclude++;
1324        }
1325        return 0;
1326}
1327
1328static struct commit_extra_header *read_commit_extra_header_lines(
1329        const char *buffer, size_t size,
1330        const char **exclude)
1331{
1332        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1333        const char *line, *next, *eof, *eob;
1334        struct strbuf buf = STRBUF_INIT;
1335
1336        for (line = buffer, eob = line + size;
1337             line < eob && *line != '\n';
1338             line = next) {
1339                next = memchr(line, '\n', eob - line);
1340                next = next ? next + 1 : eob;
1341                if (*line == ' ') {
1342                        /* continuation */
1343                        if (it)
1344                                strbuf_add(&buf, line + 1, next - (line + 1));
1345                        continue;
1346                }
1347                if (it)
1348                        it->value = strbuf_detach(&buf, &it->len);
1349                strbuf_reset(&buf);
1350                it = NULL;
1351
1352                eof = memchr(line, ' ', next - line);
1353                if (!eof)
1354                        eof = next;
1355                else if (standard_header_field(line, eof - line) ||
1356                         excluded_header_field(line, eof - line, exclude))
1357                        continue;
1358
1359                it = xcalloc(1, sizeof(*it));
1360                it->key = xmemdupz(line, eof-line);
1361                *tail = it;
1362                tail = &it->next;
1363                if (eof + 1 < next)
1364                        strbuf_add(&buf, eof + 1, next - (eof + 1));
1365        }
1366        if (it)
1367                it->value = strbuf_detach(&buf, &it->len);
1368        return extra;
1369}
1370
1371void free_commit_extra_headers(struct commit_extra_header *extra)
1372{
1373        while (extra) {
1374                struct commit_extra_header *next = extra->next;
1375                free(extra->key);
1376                free(extra->value);
1377                free(extra);
1378                extra = next;
1379        }
1380}
1381
1382int commit_tree(const char *msg, size_t msg_len, const struct object_id *tree,
1383                struct commit_list *parents, struct object_id *ret,
1384                const char *author, const char *sign_commit)
1385{
1386        struct commit_extra_header *extra = NULL, **tail = &extra;
1387        int result;
1388
1389        append_merge_tag_headers(parents, &tail);
1390        result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1391                                      author, sign_commit, extra);
1392        free_commit_extra_headers(extra);
1393        return result;
1394}
1395
1396static int find_invalid_utf8(const char *buf, int len)
1397{
1398        int offset = 0;
1399        static const unsigned int max_codepoint[] = {
1400                0x7f, 0x7ff, 0xffff, 0x10ffff
1401        };
1402
1403        while (len) {
1404                unsigned char c = *buf++;
1405                int bytes, bad_offset;
1406                unsigned int codepoint;
1407                unsigned int min_val, max_val;
1408
1409                len--;
1410                offset++;
1411
1412                /* Simple US-ASCII? No worries. */
1413                if (c < 0x80)
1414                        continue;
1415
1416                bad_offset = offset-1;
1417
1418                /*
1419                 * Count how many more high bits set: that's how
1420                 * many more bytes this sequence should have.
1421                 */
1422                bytes = 0;
1423                while (c & 0x40) {
1424                        c <<= 1;
1425                        bytes++;
1426                }
1427
1428                /*
1429                 * Must be between 1 and 3 more bytes.  Longer sequences result in
1430                 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1431                 */
1432                if (bytes < 1 || 3 < bytes)
1433                        return bad_offset;
1434
1435                /* Do we *have* that many bytes? */
1436                if (len < bytes)
1437                        return bad_offset;
1438
1439                /*
1440                 * Place the encoded bits at the bottom of the value and compute the
1441                 * valid range.
1442                 */
1443                codepoint = (c & 0x7f) >> bytes;
1444                min_val = max_codepoint[bytes-1] + 1;
1445                max_val = max_codepoint[bytes];
1446
1447                offset += bytes;
1448                len -= bytes;
1449
1450                /* And verify that they are good continuation bytes */
1451                do {
1452                        codepoint <<= 6;
1453                        codepoint |= *buf & 0x3f;
1454                        if ((*buf++ & 0xc0) != 0x80)
1455                                return bad_offset;
1456                } while (--bytes);
1457
1458                /* Reject codepoints that are out of range for the sequence length. */
1459                if (codepoint < min_val || codepoint > max_val)
1460                        return bad_offset;
1461                /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1462                if ((codepoint & 0x1ff800) == 0xd800)
1463                        return bad_offset;
1464                /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1465                if ((codepoint & 0xfffe) == 0xfffe)
1466                        return bad_offset;
1467                /* So are anything in the range U+FDD0..U+FDEF. */
1468                if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1469                        return bad_offset;
1470        }
1471        return -1;
1472}
1473
1474/*
1475 * This verifies that the buffer is in proper utf8 format.
1476 *
1477 * If it isn't, it assumes any non-utf8 characters are Latin1,
1478 * and does the conversion.
1479 */
1480static int verify_utf8(struct strbuf *buf)
1481{
1482        int ok = 1;
1483        long pos = 0;
1484
1485        for (;;) {
1486                int bad;
1487                unsigned char c;
1488                unsigned char replace[2];
1489
1490                bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1491                if (bad < 0)
1492                        return ok;
1493                pos += bad;
1494                ok = 0;
1495                c = buf->buf[pos];
1496                strbuf_remove(buf, pos, 1);
1497
1498                /* We know 'c' must be in the range 128-255 */
1499                replace[0] = 0xc0 + (c >> 6);
1500                replace[1] = 0x80 + (c & 0x3f);
1501                strbuf_insert(buf, pos, replace, 2);
1502                pos += 2;
1503        }
1504}
1505
1506static const char commit_utf8_warn[] =
1507N_("Warning: commit message did not conform to UTF-8.\n"
1508   "You may want to amend it after fixing the message, or set the config\n"
1509   "variable i18n.commitencoding to the encoding your project uses.\n");
1510
1511int commit_tree_extended(const char *msg, size_t msg_len,
1512                         const struct object_id *tree,
1513                         struct commit_list *parents, struct object_id *ret,
1514                         const char *author, const char *sign_commit,
1515                         struct commit_extra_header *extra)
1516{
1517        int result;
1518        int encoding_is_utf8;
1519        struct strbuf buffer;
1520
1521        assert_oid_type(tree, OBJ_TREE);
1522
1523        if (memchr(msg, '\0', msg_len))
1524                return error("a NUL byte in commit log message not allowed.");
1525
1526        /* Not having i18n.commitencoding is the same as having utf-8 */
1527        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1528
1529        strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1530        strbuf_addf(&buffer, "tree %s\n", oid_to_hex(tree));
1531
1532        /*
1533         * NOTE! This ordering means that the same exact tree merged with a
1534         * different order of parents will be a _different_ changeset even
1535         * if everything else stays the same.
1536         */
1537        while (parents) {
1538                struct commit *parent = pop_commit(&parents);
1539                strbuf_addf(&buffer, "parent %s\n",
1540                            oid_to_hex(&parent->object.oid));
1541        }
1542
1543        /* Person/date information */
1544        if (!author)
1545                author = git_author_info(IDENT_STRICT);
1546        strbuf_addf(&buffer, "author %s\n", author);
1547        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1548        if (!encoding_is_utf8)
1549                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1550
1551        while (extra) {
1552                add_extra_header(&buffer, extra);
1553                extra = extra->next;
1554        }
1555        strbuf_addch(&buffer, '\n');
1556
1557        /* And add the comment */
1558        strbuf_add(&buffer, msg, msg_len);
1559
1560        /* And check the encoding */
1561        if (encoding_is_utf8 && !verify_utf8(&buffer))
1562                fprintf(stderr, _(commit_utf8_warn));
1563
1564        if (sign_commit && do_sign_commit(&buffer, sign_commit)) {
1565                result = -1;
1566                goto out;
1567        }
1568
1569        result = write_object_file(buffer.buf, buffer.len, commit_type, ret);
1570out:
1571        strbuf_release(&buffer);
1572        return result;
1573}
1574
1575void set_merge_remote_desc(struct commit *commit,
1576                           const char *name, struct object *obj)
1577{
1578        struct merge_remote_desc *desc;
1579        FLEX_ALLOC_STR(desc, name, name);
1580        desc->obj = obj;
1581        commit->util = desc;
1582}
1583
1584struct commit *get_merge_parent(const char *name)
1585{
1586        struct object *obj;
1587        struct commit *commit;
1588        struct object_id oid;
1589        if (get_oid(name, &oid))
1590                return NULL;
1591        obj = parse_object(&oid);
1592        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1593        if (commit && !commit->util)
1594                set_merge_remote_desc(commit, name, obj);
1595        return commit;
1596}
1597
1598/*
1599 * Append a commit to the end of the commit_list.
1600 *
1601 * next starts by pointing to the variable that holds the head of an
1602 * empty commit_list, and is updated to point to the "next" field of
1603 * the last item on the list as new commits are appended.
1604 *
1605 * Usage example:
1606 *
1607 *     struct commit_list *list;
1608 *     struct commit_list **next = &list;
1609 *
1610 *     next = commit_list_append(c1, next);
1611 *     next = commit_list_append(c2, next);
1612 *     assert(commit_list_count(list) == 2);
1613 *     return list;
1614 */
1615struct commit_list **commit_list_append(struct commit *commit,
1616                                        struct commit_list **next)
1617{
1618        struct commit_list *new_commit = xmalloc(sizeof(struct commit_list));
1619        new_commit->item = commit;
1620        *next = new_commit;
1621        new_commit->next = NULL;
1622        return &new_commit->next;
1623}
1624
1625const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1626{
1627        int key_len = strlen(key);
1628        const char *line = msg;
1629
1630        while (line) {
1631                const char *eol = strchrnul(line, '\n');
1632
1633                if (line == eol)
1634                        return NULL;
1635
1636                if (eol - line > key_len &&
1637                    !strncmp(line, key, key_len) &&
1638                    line[key_len] == ' ') {
1639                        *out_len = eol - line - key_len - 1;
1640                        return line + key_len + 1;
1641                }
1642                line = *eol ? eol + 1 : NULL;
1643        }
1644        return NULL;
1645}
1646
1647/*
1648 * Inspect the given string and determine the true "end" of the log message, in
1649 * order to find where to put a new Signed-off-by: line.  Ignored are
1650 * trailing comment lines and blank lines.  To support "git commit -s
1651 * --amend" on an existing commit, we also ignore "Conflicts:".  To
1652 * support "git commit -v", we truncate at cut lines.
1653 *
1654 * Returns the number of bytes from the tail to ignore, to be fed as
1655 * the second parameter to append_signoff().
1656 */
1657int ignore_non_trailer(const char *buf, size_t len)
1658{
1659        int boc = 0;
1660        int bol = 0;
1661        int in_old_conflicts_block = 0;
1662        size_t cutoff = wt_status_locate_end(buf, len);
1663
1664        while (bol < cutoff) {
1665                const char *next_line = memchr(buf + bol, '\n', len - bol);
1666
1667                if (!next_line)
1668                        next_line = buf + len;
1669                else
1670                        next_line++;
1671
1672                if (buf[bol] == comment_line_char || buf[bol] == '\n') {
1673                        /* is this the first of the run of comments? */
1674                        if (!boc)
1675                                boc = bol;
1676                        /* otherwise, it is just continuing */
1677                } else if (starts_with(buf + bol, "Conflicts:\n")) {
1678                        in_old_conflicts_block = 1;
1679                        if (!boc)
1680                                boc = bol;
1681                } else if (in_old_conflicts_block && buf[bol] == '\t') {
1682                        ; /* a pathname in the conflicts block */
1683                } else if (boc) {
1684                        /* the previous was not trailing comment */
1685                        boc = 0;
1686                        in_old_conflicts_block = 0;
1687                }
1688                bol = next_line - buf;
1689        }
1690        return boc ? len - boc : len - cutoff;
1691}