Andrew's git / gitweb.git / commit.c
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commit.con commit t4014: abstract away SHA-1-specific constants (bdee9cd)
   1#include "cache.h"
   2#include "tag.h"
   3#include "commit.h"
   4#include "commit-graph.h"
   5#include "pkt-line.h"
   6#include "utf8.h"
   7#include "diff.h"
   8#include "revision.h"
   9#include "notes.h"
  10#include "gpg-interface.h"
  11#include "mergesort.h"
  12#include "commit-slab.h"
  13#include "prio-queue.h"
  14#include "sha1-lookup.h"
  15#include "wt-status.h"
  16
  17static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
  18
  19int save_commit_buffer = 1;
  20
  21const char *commit_type = "commit";
  22
  23struct commit *lookup_commit_reference_gently(const struct object_id *oid,
  24                                              int quiet)
  25{
  26        struct object *obj = deref_tag(parse_object(oid), NULL, 0);
  27
  28        if (!obj)
  29                return NULL;
  30        return object_as_type(obj, OBJ_COMMIT, quiet);
  31}
  32
  33struct commit *lookup_commit_reference(const struct object_id *oid)
  34{
  35        return lookup_commit_reference_gently(oid, 0);
  36}
  37
  38struct commit *lookup_commit_or_die(const struct object_id *oid, const char *ref_name)
  39{
  40        struct commit *c = lookup_commit_reference(oid);
  41        if (!c)
  42                die(_("could not parse %s"), ref_name);
  43        if (oidcmp(oid, &c->object.oid)) {
  44                warning(_("%s %s is not a commit!"),
  45                        ref_name, oid_to_hex(oid));
  46        }
  47        return c;
  48}
  49
  50struct commit *lookup_commit(const struct object_id *oid)
  51{
  52        struct object *obj = lookup_object(oid->hash);
  53        if (!obj)
  54                return create_object(oid->hash, 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        if (parse_commit_in_graph(item))
 388                return 0;
 389        buffer = read_object_file(&item->object.oid, &type, &size);
 390        if (!buffer)
 391                return quiet_on_missing ? -1 :
 392                        error("Could not read %s",
 393                             oid_to_hex(&item->object.oid));
 394        if (type != OBJ_COMMIT) {
 395                free(buffer);
 396                return error("Object %s not a commit",
 397                             oid_to_hex(&item->object.oid));
 398        }
 399        ret = parse_commit_buffer(item, buffer, size);
 400        if (save_commit_buffer && !ret) {
 401                set_commit_buffer(item, buffer, size);
 402                return 0;
 403        }
 404        free(buffer);
 405        return ret;
 406}
 407
 408void parse_commit_or_die(struct commit *item)
 409{
 410        if (parse_commit(item))
 411                die("unable to parse commit %s",
 412                    item ? oid_to_hex(&item->object.oid) : "(null)");
 413}
 414
 415int find_commit_subject(const char *commit_buffer, const char **subject)
 416{
 417        const char *eol;
 418        const char *p = commit_buffer;
 419
 420        while (*p && (*p != '\n' || p[1] != '\n'))
 421                p++;
 422        if (*p) {
 423                p = skip_blank_lines(p + 2);
 424                eol = strchrnul(p, '\n');
 425        } else
 426                eol = p;
 427
 428        *subject = p;
 429
 430        return eol - p;
 431}
 432
 433struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 434{
 435        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 436        new_list->item = item;
 437        new_list->next = *list_p;
 438        *list_p = new_list;
 439        return new_list;
 440}
 441
 442unsigned commit_list_count(const struct commit_list *l)
 443{
 444        unsigned c = 0;
 445        for (; l; l = l->next )
 446                c++;
 447        return c;
 448}
 449
 450struct commit_list *copy_commit_list(struct commit_list *list)
 451{
 452        struct commit_list *head = NULL;
 453        struct commit_list **pp = &head;
 454        while (list) {
 455                pp = commit_list_append(list->item, pp);
 456                list = list->next;
 457        }
 458        return head;
 459}
 460
 461void free_commit_list(struct commit_list *list)
 462{
 463        while (list)
 464                pop_commit(&list);
 465}
 466
 467struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 468{
 469        struct commit_list **pp = list;
 470        struct commit_list *p;
 471        while ((p = *pp) != NULL) {
 472                if (p->item->date < item->date) {
 473                        break;
 474                }
 475                pp = &p->next;
 476        }
 477        return commit_list_insert(item, pp);
 478}
 479
 480static int commit_list_compare_by_date(const void *a, const void *b)
 481{
 482        timestamp_t a_date = ((const struct commit_list *)a)->item->date;
 483        timestamp_t b_date = ((const struct commit_list *)b)->item->date;
 484        if (a_date < b_date)
 485                return 1;
 486        if (a_date > b_date)
 487                return -1;
 488        return 0;
 489}
 490
 491static void *commit_list_get_next(const void *a)
 492{
 493        return ((const struct commit_list *)a)->next;
 494}
 495
 496static void commit_list_set_next(void *a, void *next)
 497{
 498        ((struct commit_list *)a)->next = next;
 499}
 500
 501void commit_list_sort_by_date(struct commit_list **list)
 502{
 503        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 504                                commit_list_compare_by_date);
 505}
 506
 507struct commit *pop_most_recent_commit(struct commit_list **list,
 508                                      unsigned int mark)
 509{
 510        struct commit *ret = pop_commit(list);
 511        struct commit_list *parents = ret->parents;
 512
 513        while (parents) {
 514                struct commit *commit = parents->item;
 515                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 516                        commit->object.flags |= mark;
 517                        commit_list_insert_by_date(commit, list);
 518                }
 519                parents = parents->next;
 520        }
 521        return ret;
 522}
 523
 524static void clear_commit_marks_1(struct commit_list **plist,
 525                                 struct commit *commit, unsigned int mark)
 526{
 527        while (commit) {
 528                struct commit_list *parents;
 529
 530                if (!(mark & commit->object.flags))
 531                        return;
 532
 533                commit->object.flags &= ~mark;
 534
 535                parents = commit->parents;
 536                if (!parents)
 537                        return;
 538
 539                while ((parents = parents->next))
 540                        commit_list_insert(parents->item, plist);
 541
 542                commit = commit->parents->item;
 543        }
 544}
 545
 546void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 547{
 548        struct commit_list *list = NULL;
 549
 550        while (nr--) {
 551                clear_commit_marks_1(&list, *commit, mark);
 552                commit++;
 553        }
 554        while (list)
 555                clear_commit_marks_1(&list, pop_commit(&list), mark);
 556}
 557
 558void clear_commit_marks(struct commit *commit, unsigned int mark)
 559{
 560        clear_commit_marks_many(1, &commit, mark);
 561}
 562
 563struct commit *pop_commit(struct commit_list **stack)
 564{
 565        struct commit_list *top = *stack;
 566        struct commit *item = top ? top->item : NULL;
 567
 568        if (top) {
 569                *stack = top->next;
 570                free(top);
 571        }
 572        return item;
 573}
 574
 575/*
 576 * Topological sort support
 577 */
 578
 579/* count number of children that have not been emitted */
 580define_commit_slab(indegree_slab, int);
 581
 582/* record author-date for each commit object */
 583define_commit_slab(author_date_slab, unsigned long);
 584
 585static void record_author_date(struct author_date_slab *author_date,
 586                               struct commit *commit)
 587{
 588        const char *buffer = get_commit_buffer(commit, NULL);
 589        struct ident_split ident;
 590        const char *ident_line;
 591        size_t ident_len;
 592        char *date_end;
 593        timestamp_t date;
 594
 595        ident_line = find_commit_header(buffer, "author", &ident_len);
 596        if (!ident_line)
 597                goto fail_exit; /* no author line */
 598        if (split_ident_line(&ident, ident_line, ident_len) ||
 599            !ident.date_begin || !ident.date_end)
 600                goto fail_exit; /* malformed "author" line */
 601
 602        date = parse_timestamp(ident.date_begin, &date_end, 10);
 603        if (date_end != ident.date_end)
 604                goto fail_exit; /* malformed date */
 605        *(author_date_slab_at(author_date, commit)) = date;
 606
 607fail_exit:
 608        unuse_commit_buffer(commit, buffer);
 609}
 610
 611static int compare_commits_by_author_date(const void *a_, const void *b_,
 612                                          void *cb_data)
 613{
 614        const struct commit *a = a_, *b = b_;
 615        struct author_date_slab *author_date = cb_data;
 616        timestamp_t a_date = *(author_date_slab_at(author_date, a));
 617        timestamp_t b_date = *(author_date_slab_at(author_date, b));
 618
 619        /* newer commits with larger date first */
 620        if (a_date < b_date)
 621                return 1;
 622        else if (a_date > b_date)
 623                return -1;
 624        return 0;
 625}
 626
 627int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 628{
 629        const struct commit *a = a_, *b = b_;
 630        /* newer commits with larger date first */
 631        if (a->date < b->date)
 632                return 1;
 633        else if (a->date > b->date)
 634                return -1;
 635        return 0;
 636}
 637
 638/*
 639 * Performs an in-place topological sort on the list supplied.
 640 */
 641void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 642{
 643        struct commit_list *next, *orig = *list;
 644        struct commit_list **pptr;
 645        struct indegree_slab indegree;
 646        struct prio_queue queue;
 647        struct commit *commit;
 648        struct author_date_slab author_date;
 649
 650        if (!orig)
 651                return;
 652        *list = NULL;
 653
 654        init_indegree_slab(&indegree);
 655        memset(&queue, '\0', sizeof(queue));
 656
 657        switch (sort_order) {
 658        default: /* REV_SORT_IN_GRAPH_ORDER */
 659                queue.compare = NULL;
 660                break;
 661        case REV_SORT_BY_COMMIT_DATE:
 662                queue.compare = compare_commits_by_commit_date;
 663                break;
 664        case REV_SORT_BY_AUTHOR_DATE:
 665                init_author_date_slab(&author_date);
 666                queue.compare = compare_commits_by_author_date;
 667                queue.cb_data = &author_date;
 668                break;
 669        }
 670
 671        /* Mark them and clear the indegree */
 672        for (next = orig; next; next = next->next) {
 673                struct commit *commit = next->item;
 674                *(indegree_slab_at(&indegree, commit)) = 1;
 675                /* also record the author dates, if needed */
 676                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 677                        record_author_date(&author_date, commit);
 678        }
 679
 680        /* update the indegree */
 681        for (next = orig; next; next = next->next) {
 682                struct commit_list *parents = next->item->parents;
 683                while (parents) {
 684                        struct commit *parent = parents->item;
 685                        int *pi = indegree_slab_at(&indegree, parent);
 686
 687                        if (*pi)
 688                                (*pi)++;
 689                        parents = parents->next;
 690                }
 691        }
 692
 693        /*
 694         * find the tips
 695         *
 696         * tips are nodes not reachable from any other node in the list
 697         *
 698         * the tips serve as a starting set for the work queue.
 699         */
 700        for (next = orig; next; next = next->next) {
 701                struct commit *commit = next->item;
 702
 703                if (*(indegree_slab_at(&indegree, commit)) == 1)
 704                        prio_queue_put(&queue, commit);
 705        }
 706
 707        /*
 708         * This is unfortunate; the initial tips need to be shown
 709         * in the order given from the revision traversal machinery.
 710         */
 711        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 712                prio_queue_reverse(&queue);
 713
 714        /* We no longer need the commit list */
 715        free_commit_list(orig);
 716
 717        pptr = list;
 718        *list = NULL;
 719        while ((commit = prio_queue_get(&queue)) != NULL) {
 720                struct commit_list *parents;
 721
 722                for (parents = commit->parents; parents ; parents = parents->next) {
 723                        struct commit *parent = parents->item;
 724                        int *pi = indegree_slab_at(&indegree, parent);
 725
 726                        if (!*pi)
 727                                continue;
 728
 729                        /*
 730                         * parents are only enqueued for emission
 731                         * when all their children have been emitted thereby
 732                         * guaranteeing topological order.
 733                         */
 734                        if (--(*pi) == 1)
 735                                prio_queue_put(&queue, parent);
 736                }
 737                /*
 738                 * all children of commit have already been
 739                 * emitted. we can emit it now.
 740                 */
 741                *(indegree_slab_at(&indegree, commit)) = 0;
 742
 743                pptr = &commit_list_insert(commit, pptr)->next;
 744        }
 745
 746        clear_indegree_slab(&indegree);
 747        clear_prio_queue(&queue);
 748        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 749                clear_author_date_slab(&author_date);
 750}
 751
 752/* merge-base stuff */
 753
 754/* Remember to update object flag allocation in object.h */
 755#define PARENT1         (1u<<16)
 756#define PARENT2         (1u<<17)
 757#define STALE           (1u<<18)
 758#define RESULT          (1u<<19)
 759
 760static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 761
 762static int queue_has_nonstale(struct prio_queue *queue)
 763{
 764        int i;
 765        for (i = 0; i < queue->nr; i++) {
 766                struct commit *commit = queue->array[i].data;
 767                if (!(commit->object.flags & STALE))
 768                        return 1;
 769        }
 770        return 0;
 771}
 772
 773/* all input commits in one and twos[] must have been parsed! */
 774static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
 775{
 776        struct prio_queue queue = { compare_commits_by_commit_date };
 777        struct commit_list *result = NULL;
 778        int i;
 779
 780        one->object.flags |= PARENT1;
 781        if (!n) {
 782                commit_list_append(one, &result);
 783                return result;
 784        }
 785        prio_queue_put(&queue, one);
 786
 787        for (i = 0; i < n; i++) {
 788                twos[i]->object.flags |= PARENT2;
 789                prio_queue_put(&queue, twos[i]);
 790        }
 791
 792        while (queue_has_nonstale(&queue)) {
 793                struct commit *commit = prio_queue_get(&queue);
 794                struct commit_list *parents;
 795                int flags;
 796
 797                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 798                if (flags == (PARENT1 | PARENT2)) {
 799                        if (!(commit->object.flags & RESULT)) {
 800                                commit->object.flags |= RESULT;
 801                                commit_list_insert_by_date(commit, &result);
 802                        }
 803                        /* Mark parents of a found merge stale */
 804                        flags |= STALE;
 805                }
 806                parents = commit->parents;
 807                while (parents) {
 808                        struct commit *p = parents->item;
 809                        parents = parents->next;
 810                        if ((p->object.flags & flags) == flags)
 811                                continue;
 812                        if (parse_commit(p))
 813                                return NULL;
 814                        p->object.flags |= flags;
 815                        prio_queue_put(&queue, p);
 816                }
 817        }
 818
 819        clear_prio_queue(&queue);
 820        return result;
 821}
 822
 823static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 824{
 825        struct commit_list *list = NULL;
 826        struct commit_list *result = NULL;
 827        int i;
 828
 829        for (i = 0; i < n; i++) {
 830                if (one == twos[i])
 831                        /*
 832                         * We do not mark this even with RESULT so we do not
 833                         * have to clean it up.
 834                         */
 835                        return commit_list_insert(one, &result);
 836        }
 837
 838        if (parse_commit(one))
 839                return NULL;
 840        for (i = 0; i < n; i++) {
 841                if (parse_commit(twos[i]))
 842                        return NULL;
 843        }
 844
 845        list = paint_down_to_common(one, n, twos);
 846
 847        while (list) {
 848                struct commit *commit = pop_commit(&list);
 849                if (!(commit->object.flags & STALE))
 850                        commit_list_insert_by_date(commit, &result);
 851        }
 852        return result;
 853}
 854
 855struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 856{
 857        struct commit_list *i, *j, *k, *ret = NULL;
 858
 859        if (!in)
 860                return ret;
 861
 862        commit_list_insert(in->item, &ret);
 863
 864        for (i = in->next; i; i = i->next) {
 865                struct commit_list *new_commits = NULL, *end = NULL;
 866
 867                for (j = ret; j; j = j->next) {
 868                        struct commit_list *bases;
 869                        bases = get_merge_bases(i->item, j->item);
 870                        if (!new_commits)
 871                                new_commits = bases;
 872                        else
 873                                end->next = bases;
 874                        for (k = bases; k; k = k->next)
 875                                end = k;
 876                }
 877                ret = new_commits;
 878        }
 879        return ret;
 880}
 881
 882static int remove_redundant(struct commit **array, int cnt)
 883{
 884        /*
 885         * Some commit in the array may be an ancestor of
 886         * another commit.  Move such commit to the end of
 887         * the array, and return the number of commits that
 888         * are independent from each other.
 889         */
 890        struct commit **work;
 891        unsigned char *redundant;
 892        int *filled_index;
 893        int i, j, filled;
 894
 895        work = xcalloc(cnt, sizeof(*work));
 896        redundant = xcalloc(cnt, 1);
 897        ALLOC_ARRAY(filled_index, cnt - 1);
 898
 899        for (i = 0; i < cnt; i++)
 900                parse_commit(array[i]);
 901        for (i = 0; i < cnt; i++) {
 902                struct commit_list *common;
 903
 904                if (redundant[i])
 905                        continue;
 906                for (j = filled = 0; j < cnt; j++) {
 907                        if (i == j || redundant[j])
 908                                continue;
 909                        filled_index[filled] = j;
 910                        work[filled++] = array[j];
 911                }
 912                common = paint_down_to_common(array[i], filled, work);
 913                if (array[i]->object.flags & PARENT2)
 914                        redundant[i] = 1;
 915                for (j = 0; j < filled; j++)
 916                        if (work[j]->object.flags & PARENT1)
 917                                redundant[filled_index[j]] = 1;
 918                clear_commit_marks(array[i], all_flags);
 919                clear_commit_marks_many(filled, work, all_flags);
 920                free_commit_list(common);
 921        }
 922
 923        /* Now collect the result */
 924        COPY_ARRAY(work, array, cnt);
 925        for (i = filled = 0; i < cnt; i++)
 926                if (!redundant[i])
 927                        array[filled++] = work[i];
 928        for (j = filled, i = 0; i < cnt; i++)
 929                if (redundant[i])
 930                        array[j++] = work[i];
 931        free(work);
 932        free(redundant);
 933        free(filled_index);
 934        return filled;
 935}
 936
 937static struct commit_list *get_merge_bases_many_0(struct commit *one,
 938                                                  int n,
 939                                                  struct commit **twos,
 940                                                  int cleanup)
 941{
 942        struct commit_list *list;
 943        struct commit **rslt;
 944        struct commit_list *result;
 945        int cnt, i;
 946
 947        result = merge_bases_many(one, n, twos);
 948        for (i = 0; i < n; i++) {
 949                if (one == twos[i])
 950                        return result;
 951        }
 952        if (!result || !result->next) {
 953                if (cleanup) {
 954                        clear_commit_marks(one, all_flags);
 955                        clear_commit_marks_many(n, twos, all_flags);
 956                }
 957                return result;
 958        }
 959
 960        /* There are more than one */
 961        cnt = commit_list_count(result);
 962        rslt = xcalloc(cnt, sizeof(*rslt));
 963        for (list = result, i = 0; list; list = list->next)
 964                rslt[i++] = list->item;
 965        free_commit_list(result);
 966
 967        clear_commit_marks(one, all_flags);
 968        clear_commit_marks_many(n, twos, all_flags);
 969
 970        cnt = remove_redundant(rslt, cnt);
 971        result = NULL;
 972        for (i = 0; i < cnt; i++)
 973                commit_list_insert_by_date(rslt[i], &result);
 974        free(rslt);
 975        return result;
 976}
 977
 978struct commit_list *get_merge_bases_many(struct commit *one,
 979                                         int n,
 980                                         struct commit **twos)
 981{
 982        return get_merge_bases_many_0(one, n, twos, 1);
 983}
 984
 985struct commit_list *get_merge_bases_many_dirty(struct commit *one,
 986                                               int n,
 987                                               struct commit **twos)
 988{
 989        return get_merge_bases_many_0(one, n, twos, 0);
 990}
 991
 992struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
 993{
 994        return get_merge_bases_many_0(one, 1, &two, 1);
 995}
 996
 997/*
 998 * Is "commit" a descendant of one of the elements on the "with_commit" list?
 999 */
1000int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
1001{
1002        if (!with_commit)
1003                return 1;
1004        while (with_commit) {
1005                struct commit *other;
1006
1007                other = with_commit->item;
1008                with_commit = with_commit->next;
1009                if (in_merge_bases(other, commit))
1010                        return 1;
1011        }
1012        return 0;
1013}
1014
1015/*
1016 * Is "commit" an ancestor of one of the "references"?
1017 */
1018int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1019{
1020        struct commit_list *bases;
1021        int ret = 0, i;
1022
1023        if (parse_commit(commit))
1024                return ret;
1025        for (i = 0; i < nr_reference; i++)
1026                if (parse_commit(reference[i]))
1027                        return ret;
1028
1029        bases = paint_down_to_common(commit, nr_reference, reference);
1030        if (commit->object.flags & PARENT2)
1031                ret = 1;
1032        clear_commit_marks(commit, all_flags);
1033        clear_commit_marks_many(nr_reference, reference, all_flags);
1034        free_commit_list(bases);
1035        return ret;
1036}
1037
1038/*
1039 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1040 */
1041int in_merge_bases(struct commit *commit, struct commit *reference)
1042{
1043        return in_merge_bases_many(commit, 1, &reference);
1044}
1045
1046struct commit_list *reduce_heads(struct commit_list *heads)
1047{
1048        struct commit_list *p;
1049        struct commit_list *result = NULL, **tail = &result;
1050        struct commit **array;
1051        int num_head, i;
1052
1053        if (!heads)
1054                return NULL;
1055
1056        /* Uniquify */
1057        for (p = heads; p; p = p->next)
1058                p->item->object.flags &= ~STALE;
1059        for (p = heads, num_head = 0; p; p = p->next) {
1060                if (p->item->object.flags & STALE)
1061                        continue;
1062                p->item->object.flags |= STALE;
1063                num_head++;
1064        }
1065        array = xcalloc(num_head, sizeof(*array));
1066        for (p = heads, i = 0; p; p = p->next) {
1067                if (p->item->object.flags & STALE) {
1068                        array[i++] = p->item;
1069                        p->item->object.flags &= ~STALE;
1070                }
1071        }
1072        num_head = remove_redundant(array, num_head);
1073        for (i = 0; i < num_head; i++)
1074                tail = &commit_list_insert(array[i], tail)->next;
1075        free(array);
1076        return result;
1077}
1078
1079void reduce_heads_replace(struct commit_list **heads)
1080{
1081        struct commit_list *result = reduce_heads(*heads);
1082        free_commit_list(*heads);
1083        *heads = result;
1084}
1085
1086static const char gpg_sig_header[] = "gpgsig";
1087static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1088
1089static int do_sign_commit(struct strbuf *buf, const char *keyid)
1090{
1091        struct strbuf sig = STRBUF_INIT;
1092        int inspos, copypos;
1093        const char *eoh;
1094
1095        /* find the end of the header */
1096        eoh = strstr(buf->buf, "\n\n");
1097        if (!eoh)
1098                inspos = buf->len;
1099        else
1100                inspos = eoh - buf->buf + 1;
1101
1102        if (!keyid || !*keyid)
1103                keyid = get_signing_key();
1104        if (sign_buffer(buf, &sig, keyid)) {
1105                strbuf_release(&sig);
1106                return -1;
1107        }
1108
1109        for (copypos = 0; sig.buf[copypos]; ) {
1110                const char *bol = sig.buf + copypos;
1111                const char *eol = strchrnul(bol, '\n');
1112                int len = (eol - bol) + !!*eol;
1113
1114                if (!copypos) {
1115                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1116                        inspos += gpg_sig_header_len;
1117                }
1118                strbuf_insert(buf, inspos++, " ", 1);
1119                strbuf_insert(buf, inspos, bol, len);
1120                inspos += len;
1121                copypos += len;
1122        }
1123        strbuf_release(&sig);
1124        return 0;
1125}
1126
1127int parse_signed_commit(const struct commit *commit,
1128                        struct strbuf *payload, struct strbuf *signature)
1129{
1130
1131        unsigned long size;
1132        const char *buffer = get_commit_buffer(commit, &size);
1133        int in_signature, saw_signature = -1;
1134        const char *line, *tail;
1135
1136        line = buffer;
1137        tail = buffer + size;
1138        in_signature = 0;
1139        saw_signature = 0;
1140        while (line < tail) {
1141                const char *sig = NULL;
1142                const char *next = memchr(line, '\n', tail - line);
1143
1144                next = next ? next + 1 : tail;
1145                if (in_signature && line[0] == ' ')
1146                        sig = line + 1;
1147                else if (starts_with(line, gpg_sig_header) &&
1148                         line[gpg_sig_header_len] == ' ')
1149                        sig = line + gpg_sig_header_len + 1;
1150                if (sig) {
1151                        strbuf_add(signature, sig, next - sig);
1152                        saw_signature = 1;
1153                        in_signature = 1;
1154                } else {
1155                        if (*line == '\n')
1156                                /* dump the whole remainder of the buffer */
1157                                next = tail;
1158                        strbuf_add(payload, line, next - line);
1159                        in_signature = 0;
1160                }
1161                line = next;
1162        }
1163        unuse_commit_buffer(commit, buffer);
1164        return saw_signature;
1165}
1166
1167int remove_signature(struct strbuf *buf)
1168{
1169        const char *line = buf->buf;
1170        const char *tail = buf->buf + buf->len;
1171        int in_signature = 0;
1172        const char *sig_start = NULL;
1173        const char *sig_end = NULL;
1174
1175        while (line < tail) {
1176                const char *next = memchr(line, '\n', tail - line);
1177                next = next ? next + 1 : tail;
1178
1179                if (in_signature && line[0] == ' ')
1180                        sig_end = next;
1181                else if (starts_with(line, gpg_sig_header) &&
1182                         line[gpg_sig_header_len] == ' ') {
1183                        sig_start = line;
1184                        sig_end = next;
1185                        in_signature = 1;
1186                } else {
1187                        if (*line == '\n')
1188                                /* dump the whole remainder of the buffer */
1189                                next = tail;
1190                        in_signature = 0;
1191                }
1192                line = next;
1193        }
1194
1195        if (sig_start)
1196                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1197
1198        return sig_start != NULL;
1199}
1200
1201static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1202{
1203        struct merge_remote_desc *desc;
1204        struct commit_extra_header *mergetag;
1205        char *buf;
1206        unsigned long size, len;
1207        enum object_type type;
1208
1209        desc = merge_remote_util(parent);
1210        if (!desc || !desc->obj)
1211                return;
1212        buf = read_object_file(&desc->obj->oid, &type, &size);
1213        if (!buf || type != OBJ_TAG)
1214                goto free_return;
1215        len = parse_signature(buf, size);
1216        if (size == len)
1217                goto free_return;
1218        /*
1219         * We could verify this signature and either omit the tag when
1220         * it does not validate, but the integrator may not have the
1221         * public key of the signer of the tag he is merging, while a
1222         * later auditor may have it while auditing, so let's not run
1223         * verify-signed-buffer here for now...
1224         *
1225         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1226         *      warn("warning: signed tag unverified.");
1227         */
1228        mergetag = xcalloc(1, sizeof(*mergetag));
1229        mergetag->key = xstrdup("mergetag");
1230        mergetag->value = buf;
1231        mergetag->len = size;
1232
1233        **tail = mergetag;
1234        *tail = &mergetag->next;
1235        return;
1236
1237free_return:
1238        free(buf);
1239}
1240
1241int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1242{
1243        struct strbuf payload = STRBUF_INIT;
1244        struct strbuf signature = STRBUF_INIT;
1245        int ret = 1;
1246
1247        sigc->result = 'N';
1248
1249        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1250                goto out;
1251        ret = check_signature(payload.buf, payload.len, signature.buf,
1252                signature.len, sigc);
1253
1254 out:
1255        strbuf_release(&payload);
1256        strbuf_release(&signature);
1257
1258        return ret;
1259}
1260
1261
1262
1263void append_merge_tag_headers(struct commit_list *parents,
1264                              struct commit_extra_header ***tail)
1265{
1266        while (parents) {
1267                struct commit *parent = parents->item;
1268                handle_signed_tag(parent, tail);
1269                parents = parents->next;
1270        }
1271}
1272
1273static void add_extra_header(struct strbuf *buffer,
1274                             struct commit_extra_header *extra)
1275{
1276        strbuf_addstr(buffer, extra->key);
1277        if (extra->len)
1278                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1279        else
1280                strbuf_addch(buffer, '\n');
1281}
1282
1283struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1284                                                      const char **exclude)
1285{
1286        struct commit_extra_header *extra = NULL;
1287        unsigned long size;
1288        const char *buffer = get_commit_buffer(commit, &size);
1289        extra = read_commit_extra_header_lines(buffer, size, exclude);
1290        unuse_commit_buffer(commit, buffer);
1291        return extra;
1292}
1293
1294void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1295{
1296        struct commit_extra_header *extra, *to_free;
1297
1298        to_free = read_commit_extra_headers(commit, NULL);
1299        for (extra = to_free; extra; extra = extra->next) {
1300                if (strcmp(extra->key, "mergetag"))
1301                        continue; /* not a merge tag */
1302                fn(commit, extra, data);
1303        }
1304        free_commit_extra_headers(to_free);
1305}
1306
1307static inline int standard_header_field(const char *field, size_t len)
1308{
1309        return ((len == 4 && !memcmp(field, "tree", 4)) ||
1310                (len == 6 && !memcmp(field, "parent", 6)) ||
1311                (len == 6 && !memcmp(field, "author", 6)) ||
1312                (len == 9 && !memcmp(field, "committer", 9)) ||
1313                (len == 8 && !memcmp(field, "encoding", 8)));
1314}
1315
1316static int excluded_header_field(const char *field, size_t len, const char **exclude)
1317{
1318        if (!exclude)
1319                return 0;
1320
1321        while (*exclude) {
1322                size_t xlen = strlen(*exclude);
1323                if (len == xlen && !memcmp(field, *exclude, xlen))
1324                        return 1;
1325                exclude++;
1326        }
1327        return 0;
1328}
1329
1330static struct commit_extra_header *read_commit_extra_header_lines(
1331        const char *buffer, size_t size,
1332        const char **exclude)
1333{
1334        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1335        const char *line, *next, *eof, *eob;
1336        struct strbuf buf = STRBUF_INIT;
1337
1338        for (line = buffer, eob = line + size;
1339             line < eob && *line != '\n';
1340             line = next) {
1341                next = memchr(line, '\n', eob - line);
1342                next = next ? next + 1 : eob;
1343                if (*line == ' ') {
1344                        /* continuation */
1345                        if (it)
1346                                strbuf_add(&buf, line + 1, next - (line + 1));
1347                        continue;
1348                }
1349                if (it)
1350                        it->value = strbuf_detach(&buf, &it->len);
1351                strbuf_reset(&buf);
1352                it = NULL;
1353
1354                eof = memchr(line, ' ', next - line);
1355                if (!eof)
1356                        eof = next;
1357                else if (standard_header_field(line, eof - line) ||
1358                         excluded_header_field(line, eof - line, exclude))
1359                        continue;
1360
1361                it = xcalloc(1, sizeof(*it));
1362                it->key = xmemdupz(line, eof-line);
1363                *tail = it;
1364                tail = &it->next;
1365                if (eof + 1 < next)
1366                        strbuf_add(&buf, eof + 1, next - (eof + 1));
1367        }
1368        if (it)
1369                it->value = strbuf_detach(&buf, &it->len);
1370        return extra;
1371}
1372
1373void free_commit_extra_headers(struct commit_extra_header *extra)
1374{
1375        while (extra) {
1376                struct commit_extra_header *next = extra->next;
1377                free(extra->key);
1378                free(extra->value);
1379                free(extra);
1380                extra = next;
1381        }
1382}
1383
1384int commit_tree(const char *msg, size_t msg_len, const struct object_id *tree,
1385                struct commit_list *parents, struct object_id *ret,
1386                const char *author, const char *sign_commit)
1387{
1388        struct commit_extra_header *extra = NULL, **tail = &extra;
1389        int result;
1390
1391        append_merge_tag_headers(parents, &tail);
1392        result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1393                                      author, sign_commit, extra);
1394        free_commit_extra_headers(extra);
1395        return result;
1396}
1397
1398static int find_invalid_utf8(const char *buf, int len)
1399{
1400        int offset = 0;
1401        static const unsigned int max_codepoint[] = {
1402                0x7f, 0x7ff, 0xffff, 0x10ffff
1403        };
1404
1405        while (len) {
1406                unsigned char c = *buf++;
1407                int bytes, bad_offset;
1408                unsigned int codepoint;
1409                unsigned int min_val, max_val;
1410
1411                len--;
1412                offset++;
1413
1414                /* Simple US-ASCII? No worries. */
1415                if (c < 0x80)
1416                        continue;
1417
1418                bad_offset = offset-1;
1419
1420                /*
1421                 * Count how many more high bits set: that's how
1422                 * many more bytes this sequence should have.
1423                 */
1424                bytes = 0;
1425                while (c & 0x40) {
1426                        c <<= 1;
1427                        bytes++;
1428                }
1429
1430                /*
1431                 * Must be between 1 and 3 more bytes.  Longer sequences result in
1432                 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1433                 */
1434                if (bytes < 1 || 3 < bytes)
1435                        return bad_offset;
1436
1437                /* Do we *have* that many bytes? */
1438                if (len < bytes)
1439                        return bad_offset;
1440
1441                /*
1442                 * Place the encoded bits at the bottom of the value and compute the
1443                 * valid range.
1444                 */
1445                codepoint = (c & 0x7f) >> bytes;
1446                min_val = max_codepoint[bytes-1] + 1;
1447                max_val = max_codepoint[bytes];
1448
1449                offset += bytes;
1450                len -= bytes;
1451
1452                /* And verify that they are good continuation bytes */
1453                do {
1454                        codepoint <<= 6;
1455                        codepoint |= *buf & 0x3f;
1456                        if ((*buf++ & 0xc0) != 0x80)
1457                                return bad_offset;
1458                } while (--bytes);
1459
1460                /* Reject codepoints that are out of range for the sequence length. */
1461                if (codepoint < min_val || codepoint > max_val)
1462                        return bad_offset;
1463                /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1464                if ((codepoint & 0x1ff800) == 0xd800)
1465                        return bad_offset;
1466                /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1467                if ((codepoint & 0xfffe) == 0xfffe)
1468                        return bad_offset;
1469                /* So are anything in the range U+FDD0..U+FDEF. */
1470                if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1471                        return bad_offset;
1472        }
1473        return -1;
1474}
1475
1476/*
1477 * This verifies that the buffer is in proper utf8 format.
1478 *
1479 * If it isn't, it assumes any non-utf8 characters are Latin1,
1480 * and does the conversion.
1481 */
1482static int verify_utf8(struct strbuf *buf)
1483{
1484        int ok = 1;
1485        long pos = 0;
1486
1487        for (;;) {
1488                int bad;
1489                unsigned char c;
1490                unsigned char replace[2];
1491
1492                bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1493                if (bad < 0)
1494                        return ok;
1495                pos += bad;
1496                ok = 0;
1497                c = buf->buf[pos];
1498                strbuf_remove(buf, pos, 1);
1499
1500                /* We know 'c' must be in the range 128-255 */
1501                replace[0] = 0xc0 + (c >> 6);
1502                replace[1] = 0x80 + (c & 0x3f);
1503                strbuf_insert(buf, pos, replace, 2);
1504                pos += 2;
1505        }
1506}
1507
1508static const char commit_utf8_warn[] =
1509N_("Warning: commit message did not conform to UTF-8.\n"
1510   "You may want to amend it after fixing the message, or set the config\n"
1511   "variable i18n.commitencoding to the encoding your project uses.\n");
1512
1513int commit_tree_extended(const char *msg, size_t msg_len,
1514                         const struct object_id *tree,
1515                         struct commit_list *parents, struct object_id *ret,
1516                         const char *author, const char *sign_commit,
1517                         struct commit_extra_header *extra)
1518{
1519        int result;
1520        int encoding_is_utf8;
1521        struct strbuf buffer;
1522
1523        assert_oid_type(tree, OBJ_TREE);
1524
1525        if (memchr(msg, '\0', msg_len))
1526                return error("a NUL byte in commit log message not allowed.");
1527
1528        /* Not having i18n.commitencoding is the same as having utf-8 */
1529        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1530
1531        strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1532        strbuf_addf(&buffer, "tree %s\n", oid_to_hex(tree));
1533
1534        /*
1535         * NOTE! This ordering means that the same exact tree merged with a
1536         * different order of parents will be a _different_ changeset even
1537         * if everything else stays the same.
1538         */
1539        while (parents) {
1540                struct commit *parent = pop_commit(&parents);
1541                strbuf_addf(&buffer, "parent %s\n",
1542                            oid_to_hex(&parent->object.oid));
1543        }
1544
1545        /* Person/date information */
1546        if (!author)
1547                author = git_author_info(IDENT_STRICT);
1548        strbuf_addf(&buffer, "author %s\n", author);
1549        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1550        if (!encoding_is_utf8)
1551                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1552
1553        while (extra) {
1554                add_extra_header(&buffer, extra);
1555                extra = extra->next;
1556        }
1557        strbuf_addch(&buffer, '\n');
1558
1559        /* And add the comment */
1560        strbuf_add(&buffer, msg, msg_len);
1561
1562        /* And check the encoding */
1563        if (encoding_is_utf8 && !verify_utf8(&buffer))
1564                fprintf(stderr, _(commit_utf8_warn));
1565
1566        if (sign_commit && do_sign_commit(&buffer, sign_commit)) {
1567                result = -1;
1568                goto out;
1569        }
1570
1571        result = write_object_file(buffer.buf, buffer.len, commit_type, ret);
1572out:
1573        strbuf_release(&buffer);
1574        return result;
1575}
1576
1577void set_merge_remote_desc(struct commit *commit,
1578                           const char *name, struct object *obj)
1579{
1580        struct merge_remote_desc *desc;
1581        FLEX_ALLOC_STR(desc, name, name);
1582        desc->obj = obj;
1583        commit->util = desc;
1584}
1585
1586struct commit *get_merge_parent(const char *name)
1587{
1588        struct object *obj;
1589        struct commit *commit;
1590        struct object_id oid;
1591        if (get_oid(name, &oid))
1592                return NULL;
1593        obj = parse_object(&oid);
1594        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1595        if (commit && !commit->util)
1596                set_merge_remote_desc(commit, name, obj);
1597        return commit;
1598}
1599
1600/*
1601 * Append a commit to the end of the commit_list.
1602 *
1603 * next starts by pointing to the variable that holds the head of an
1604 * empty commit_list, and is updated to point to the "next" field of
1605 * the last item on the list as new commits are appended.
1606 *
1607 * Usage example:
1608 *
1609 *     struct commit_list *list;
1610 *     struct commit_list **next = &list;
1611 *
1612 *     next = commit_list_append(c1, next);
1613 *     next = commit_list_append(c2, next);
1614 *     assert(commit_list_count(list) == 2);
1615 *     return list;
1616 */
1617struct commit_list **commit_list_append(struct commit *commit,
1618                                        struct commit_list **next)
1619{
1620        struct commit_list *new_commit = xmalloc(sizeof(struct commit_list));
1621        new_commit->item = commit;
1622        *next = new_commit;
1623        new_commit->next = NULL;
1624        return &new_commit->next;
1625}
1626
1627const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1628{
1629        int key_len = strlen(key);
1630        const char *line = msg;
1631
1632        while (line) {
1633                const char *eol = strchrnul(line, '\n');
1634
1635                if (line == eol)
1636                        return NULL;
1637
1638                if (eol - line > key_len &&
1639                    !strncmp(line, key, key_len) &&
1640                    line[key_len] == ' ') {
1641                        *out_len = eol - line - key_len - 1;
1642                        return line + key_len + 1;
1643                }
1644                line = *eol ? eol + 1 : NULL;
1645        }
1646        return NULL;
1647}
1648
1649/*
1650 * Inspect the given string and determine the true "end" of the log message, in
1651 * order to find where to put a new Signed-off-by: line.  Ignored are
1652 * trailing comment lines and blank lines.  To support "git commit -s
1653 * --amend" on an existing commit, we also ignore "Conflicts:".  To
1654 * support "git commit -v", we truncate at cut lines.
1655 *
1656 * Returns the number of bytes from the tail to ignore, to be fed as
1657 * the second parameter to append_signoff().
1658 */
1659int ignore_non_trailer(const char *buf, size_t len)
1660{
1661        int boc = 0;
1662        int bol = 0;
1663        int in_old_conflicts_block = 0;
1664        size_t cutoff = wt_status_locate_end(buf, len);
1665
1666        while (bol < cutoff) {
1667                const char *next_line = memchr(buf + bol, '\n', len - bol);
1668
1669                if (!next_line)
1670                        next_line = buf + len;
1671                else
1672                        next_line++;
1673
1674                if (buf[bol] == comment_line_char || buf[bol] == '\n') {
1675                        /* is this the first of the run of comments? */
1676                        if (!boc)
1677                                boc = bol;
1678                        /* otherwise, it is just continuing */
1679                } else if (starts_with(buf + bol, "Conflicts:\n")) {
1680                        in_old_conflicts_block = 1;
1681                        if (!boc)
1682                                boc = bol;
1683                } else if (in_old_conflicts_block && buf[bol] == '\t') {
1684                        ; /* a pathname in the conflicts block */
1685                } else if (boc) {
1686                        /* the previous was not trailing comment */
1687                        boc = 0;
1688                        in_old_conflicts_block = 0;
1689                }
1690                bol = next_line - buf;
1691        }
1692        return boc ? len - boc : len - cutoff;
1693}