Andrew's git / gitweb.git / commit.c
?
commit.con commit Merge branch 'bw/oidmap-autoinit' (d470b7a)
   1#include "cache.h"
   2#include "tag.h"
   3#include "commit.h"
   4#include "pkt-line.h"
   5#include "utf8.h"
   6#include "diff.h"
   7#include "revision.h"
   8#include "notes.h"
   9#include "gpg-interface.h"
  10#include "mergesort.h"
  11#include "commit-slab.h"
  12#include "prio-queue.h"
  13#include "sha1-lookup.h"
  14#include "wt-status.h"
  15
  16static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
  17
  18int save_commit_buffer = 1;
  19
  20const char *commit_type = "commit";
  21
  22struct commit *lookup_commit_reference_gently(const struct object_id *oid,
  23                                              int quiet)
  24{
  25        struct object *obj = deref_tag(parse_object(oid), NULL, 0);
  26
  27        if (!obj)
  28                return NULL;
  29        return object_as_type(obj, OBJ_COMMIT, quiet);
  30}
  31
  32struct commit *lookup_commit_reference(const struct object_id *oid)
  33{
  34        return lookup_commit_reference_gently(oid, 0);
  35}
  36
  37struct commit *lookup_commit_or_die(const struct object_id *oid, const char *ref_name)
  38{
  39        struct commit *c = lookup_commit_reference(oid);
  40        if (!c)
  41                die(_("could not parse %s"), ref_name);
  42        if (oidcmp(oid, &c->object.oid)) {
  43                warning(_("%s %s is not a commit!"),
  44                        ref_name, oid_to_hex(oid));
  45        }
  46        return c;
  47}
  48
  49struct commit *lookup_commit(const struct object_id *oid)
  50{
  51        struct object *obj = lookup_object(oid->hash);
  52        if (!obj)
  53                return create_object(oid->hash, alloc_commit_node());
  54        return object_as_type(obj, OBJ_COMMIT, 0);
  55}
  56
  57struct commit *lookup_commit_reference_by_name(const char *name)
  58{
  59        struct object_id oid;
  60        struct commit *commit;
  61
  62        if (get_oid_committish(name, &oid))
  63                return NULL;
  64        commit = lookup_commit_reference(&oid);
  65        if (parse_commit(commit))
  66                return NULL;
  67        return commit;
  68}
  69
  70static timestamp_t parse_commit_date(const char *buf, const char *tail)
  71{
  72        const char *dateptr;
  73
  74        if (buf + 6 >= tail)
  75                return 0;
  76        if (memcmp(buf, "author", 6))
  77                return 0;
  78        while (buf < tail && *buf++ != '\n')
  79                /* nada */;
  80        if (buf + 9 >= tail)
  81                return 0;
  82        if (memcmp(buf, "committer", 9))
  83                return 0;
  84        while (buf < tail && *buf++ != '>')
  85                /* nada */;
  86        if (buf >= tail)
  87                return 0;
  88        dateptr = buf;
  89        while (buf < tail && *buf++ != '\n')
  90                /* nada */;
  91        if (buf >= tail)
  92                return 0;
  93        /* dateptr < buf && buf[-1] == '\n', so parsing will stop at buf-1 */
  94        return parse_timestamp(dateptr, NULL, 10);
  95}
  96
  97static struct commit_graft **commit_graft;
  98static int commit_graft_alloc, commit_graft_nr;
  99
 100static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
 101{
 102        struct commit_graft **commit_graft_table = table;
 103        return commit_graft_table[index]->oid.hash;
 104}
 105
 106static int commit_graft_pos(const unsigned char *sha1)
 107{
 108        return sha1_pos(sha1, commit_graft, commit_graft_nr,
 109                        commit_graft_sha1_access);
 110}
 111
 112int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 113{
 114        int pos = commit_graft_pos(graft->oid.hash);
 115
 116        if (0 <= pos) {
 117                if (ignore_dups)
 118                        free(graft);
 119                else {
 120                        free(commit_graft[pos]);
 121                        commit_graft[pos] = graft;
 122                }
 123                return 1;
 124        }
 125        pos = -pos - 1;
 126        ALLOC_GROW(commit_graft, commit_graft_nr + 1, commit_graft_alloc);
 127        commit_graft_nr++;
 128        if (pos < commit_graft_nr)
 129                memmove(commit_graft + pos + 1,
 130                        commit_graft + pos,
 131                        (commit_graft_nr - pos - 1) *
 132                        sizeof(*commit_graft));
 133        commit_graft[pos] = graft;
 134        return 0;
 135}
 136
 137struct commit_graft *read_graft_line(struct strbuf *line)
 138{
 139        /* The format is just "Commit Parent1 Parent2 ...\n" */
 140        int i, phase;
 141        const char *tail = NULL;
 142        struct commit_graft *graft = NULL;
 143        struct object_id dummy_oid, *oid;
 144
 145        strbuf_rtrim(line);
 146        if (!line->len || line->buf[0] == '#')
 147                return NULL;
 148        /*
 149         * phase 0 verifies line, counts hashes in line and allocates graft
 150         * phase 1 fills graft
 151         */
 152        for (phase = 0; phase < 2; phase++) {
 153                oid = graft ? &graft->oid : &dummy_oid;
 154                if (parse_oid_hex(line->buf, oid, &tail))
 155                        goto bad_graft_data;
 156                for (i = 0; *tail != '\0'; i++) {
 157                        oid = graft ? &graft->parent[i] : &dummy_oid;
 158                        if (!isspace(*tail++) || parse_oid_hex(tail, oid, &tail))
 159                                goto bad_graft_data;
 160                }
 161                if (!graft) {
 162                        graft = xmalloc(st_add(sizeof(*graft),
 163                                               st_mult(sizeof(struct object_id), i)));
 164                        graft->nr_parent = i;
 165                }
 166        }
 167        return graft;
 168
 169bad_graft_data:
 170        error("bad graft data: %s", line->buf);
 171        assert(!graft);
 172        return NULL;
 173}
 174
 175static int read_graft_file(const char *graft_file)
 176{
 177        FILE *fp = fopen_or_warn(graft_file, "r");
 178        struct strbuf buf = STRBUF_INIT;
 179        if (!fp)
 180                return -1;
 181        while (!strbuf_getwholeline(&buf, fp, '\n')) {
 182                /* The format is just "Commit Parent1 Parent2 ...\n" */
 183                struct commit_graft *graft = read_graft_line(&buf);
 184                if (!graft)
 185                        continue;
 186                if (register_commit_graft(graft, 1))
 187                        error("duplicate graft data: %s", buf.buf);
 188        }
 189        fclose(fp);
 190        strbuf_release(&buf);
 191        return 0;
 192}
 193
 194static void prepare_commit_graft(void)
 195{
 196        static int commit_graft_prepared;
 197        char *graft_file;
 198
 199        if (commit_graft_prepared)
 200                return;
 201        graft_file = get_graft_file();
 202        read_graft_file(graft_file);
 203        /* make sure shallows are read */
 204        is_repository_shallow();
 205        commit_graft_prepared = 1;
 206}
 207
 208struct commit_graft *lookup_commit_graft(const struct object_id *oid)
 209{
 210        int pos;
 211        prepare_commit_graft();
 212        pos = commit_graft_pos(oid->hash);
 213        if (pos < 0)
 214                return NULL;
 215        return commit_graft[pos];
 216}
 217
 218int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
 219{
 220        int i, ret;
 221        for (i = ret = 0; i < commit_graft_nr && !ret; i++)
 222                ret = fn(commit_graft[i], cb_data);
 223        return ret;
 224}
 225
 226int unregister_shallow(const struct object_id *oid)
 227{
 228        int pos = commit_graft_pos(oid->hash);
 229        if (pos < 0)
 230                return -1;
 231        if (pos + 1 < commit_graft_nr)
 232                MOVE_ARRAY(commit_graft + pos, commit_graft + pos + 1,
 233                           commit_graft_nr - pos - 1);
 234        commit_graft_nr--;
 235        return 0;
 236}
 237
 238struct commit_buffer {
 239        void *buffer;
 240        unsigned long size;
 241};
 242define_commit_slab(buffer_slab, struct commit_buffer);
 243static struct buffer_slab buffer_slab = COMMIT_SLAB_INIT(1, buffer_slab);
 244
 245void set_commit_buffer(struct commit *commit, void *buffer, unsigned long size)
 246{
 247        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 248        v->buffer = buffer;
 249        v->size = size;
 250}
 251
 252const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
 253{
 254        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 255        if (!v) {
 256                if (sizep)
 257                        *sizep = 0;
 258                return NULL;
 259        }
 260        if (sizep)
 261                *sizep = v->size;
 262        return v->buffer;
 263}
 264
 265const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
 266{
 267        const void *ret = get_cached_commit_buffer(commit, sizep);
 268        if (!ret) {
 269                enum object_type type;
 270                unsigned long size;
 271                ret = read_sha1_file(commit->object.oid.hash, &type, &size);
 272                if (!ret)
 273                        die("cannot read commit object %s",
 274                            oid_to_hex(&commit->object.oid));
 275                if (type != OBJ_COMMIT)
 276                        die("expected commit for %s, got %s",
 277                            oid_to_hex(&commit->object.oid), typename(type));
 278                if (sizep)
 279                        *sizep = size;
 280        }
 281        return ret;
 282}
 283
 284void unuse_commit_buffer(const struct commit *commit, const void *buffer)
 285{
 286        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 287        if (!(v && v->buffer == buffer))
 288                free((void *)buffer);
 289}
 290
 291void free_commit_buffer(struct commit *commit)
 292{
 293        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 294        if (v) {
 295                FREE_AND_NULL(v->buffer);
 296                v->size = 0;
 297        }
 298}
 299
 300const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 301{
 302        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 303        void *ret;
 304
 305        if (!v) {
 306                if (sizep)
 307                        *sizep = 0;
 308                return NULL;
 309        }
 310        ret = v->buffer;
 311        if (sizep)
 312                *sizep = v->size;
 313
 314        v->buffer = NULL;
 315        v->size = 0;
 316        return ret;
 317}
 318
 319int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
 320{
 321        const char *tail = buffer;
 322        const char *bufptr = buffer;
 323        struct object_id parent;
 324        struct commit_list **pptr;
 325        struct commit_graft *graft;
 326        const int tree_entry_len = GIT_SHA1_HEXSZ + 5;
 327        const int parent_entry_len = GIT_SHA1_HEXSZ + 7;
 328
 329        if (item->object.parsed)
 330                return 0;
 331        item->object.parsed = 1;
 332        tail += size;
 333        if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
 334                        bufptr[tree_entry_len] != '\n')
 335                return error("bogus commit object %s", oid_to_hex(&item->object.oid));
 336        if (get_sha1_hex(bufptr + 5, parent.hash) < 0)
 337                return error("bad tree pointer in commit %s",
 338                             oid_to_hex(&item->object.oid));
 339        item->tree = lookup_tree(&parent);
 340        bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
 341        pptr = &item->parents;
 342
 343        graft = lookup_commit_graft(&item->object.oid);
 344        while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
 345                struct commit *new_parent;
 346
 347                if (tail <= bufptr + parent_entry_len + 1 ||
 348                    get_sha1_hex(bufptr + 7, parent.hash) ||
 349                    bufptr[parent_entry_len] != '\n')
 350                        return error("bad parents in commit %s", oid_to_hex(&item->object.oid));
 351                bufptr += parent_entry_len + 1;
 352                /*
 353                 * The clone is shallow if nr_parent < 0, and we must
 354                 * not traverse its real parents even when we unhide them.
 355                 */
 356                if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
 357                        continue;
 358                new_parent = lookup_commit(&parent);
 359                if (new_parent)
 360                        pptr = &commit_list_insert(new_parent, pptr)->next;
 361        }
 362        if (graft) {
 363                int i;
 364                struct commit *new_parent;
 365                for (i = 0; i < graft->nr_parent; i++) {
 366                        new_parent = lookup_commit(&graft->parent[i]);
 367                        if (!new_parent)
 368                                continue;
 369                        pptr = &commit_list_insert(new_parent, pptr)->next;
 370                }
 371        }
 372        item->date = parse_commit_date(bufptr, tail);
 373
 374        return 0;
 375}
 376
 377int parse_commit_gently(struct commit *item, int quiet_on_missing)
 378{
 379        enum object_type type;
 380        void *buffer;
 381        unsigned long size;
 382        int ret;
 383
 384        if (!item)
 385                return -1;
 386        if (item->object.parsed)
 387                return 0;
 388        buffer = read_sha1_file(item->object.oid.hash, &type, &size);
 389        if (!buffer)
 390                return quiet_on_missing ? -1 :
 391                        error("Could not read %s",
 392                             oid_to_hex(&item->object.oid));
 393        if (type != OBJ_COMMIT) {
 394                free(buffer);
 395                return error("Object %s not a commit",
 396                             oid_to_hex(&item->object.oid));
 397        }
 398        ret = parse_commit_buffer(item, buffer, size);
 399        if (save_commit_buffer && !ret) {
 400                set_commit_buffer(item, buffer, size);
 401                return 0;
 402        }
 403        free(buffer);
 404        return ret;
 405}
 406
 407void parse_commit_or_die(struct commit *item)
 408{
 409        if (parse_commit(item))
 410                die("unable to parse commit %s",
 411                    item ? oid_to_hex(&item->object.oid) : "(null)");
 412}
 413
 414int find_commit_subject(const char *commit_buffer, const char **subject)
 415{
 416        const char *eol;
 417        const char *p = commit_buffer;
 418
 419        while (*p && (*p != '\n' || p[1] != '\n'))
 420                p++;
 421        if (*p) {
 422                p = skip_blank_lines(p + 2);
 423                eol = strchrnul(p, '\n');
 424        } else
 425                eol = p;
 426
 427        *subject = p;
 428
 429        return eol - p;
 430}
 431
 432struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 433{
 434        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 435        new_list->item = item;
 436        new_list->next = *list_p;
 437        *list_p = new_list;
 438        return new_list;
 439}
 440
 441unsigned commit_list_count(const struct commit_list *l)
 442{
 443        unsigned c = 0;
 444        for (; l; l = l->next )
 445                c++;
 446        return c;
 447}
 448
 449struct commit_list *copy_commit_list(struct commit_list *list)
 450{
 451        struct commit_list *head = NULL;
 452        struct commit_list **pp = &head;
 453        while (list) {
 454                pp = commit_list_append(list->item, pp);
 455                list = list->next;
 456        }
 457        return head;
 458}
 459
 460void free_commit_list(struct commit_list *list)
 461{
 462        while (list)
 463                pop_commit(&list);
 464}
 465
 466struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 467{
 468        struct commit_list **pp = list;
 469        struct commit_list *p;
 470        while ((p = *pp) != NULL) {
 471                if (p->item->date < item->date) {
 472                        break;
 473                }
 474                pp = &p->next;
 475        }
 476        return commit_list_insert(item, pp);
 477}
 478
 479static int commit_list_compare_by_date(const void *a, const void *b)
 480{
 481        timestamp_t a_date = ((const struct commit_list *)a)->item->date;
 482        timestamp_t b_date = ((const struct commit_list *)b)->item->date;
 483        if (a_date < b_date)
 484                return 1;
 485        if (a_date > b_date)
 486                return -1;
 487        return 0;
 488}
 489
 490static void *commit_list_get_next(const void *a)
 491{
 492        return ((const struct commit_list *)a)->next;
 493}
 494
 495static void commit_list_set_next(void *a, void *next)
 496{
 497        ((struct commit_list *)a)->next = next;
 498}
 499
 500void commit_list_sort_by_date(struct commit_list **list)
 501{
 502        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 503                                commit_list_compare_by_date);
 504}
 505
 506struct commit *pop_most_recent_commit(struct commit_list **list,
 507                                      unsigned int mark)
 508{
 509        struct commit *ret = pop_commit(list);
 510        struct commit_list *parents = ret->parents;
 511
 512        while (parents) {
 513                struct commit *commit = parents->item;
 514                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 515                        commit->object.flags |= mark;
 516                        commit_list_insert_by_date(commit, list);
 517                }
 518                parents = parents->next;
 519        }
 520        return ret;
 521}
 522
 523static void clear_commit_marks_1(struct commit_list **plist,
 524                                 struct commit *commit, unsigned int mark)
 525{
 526        while (commit) {
 527                struct commit_list *parents;
 528
 529                if (!(mark & commit->object.flags))
 530                        return;
 531
 532                commit->object.flags &= ~mark;
 533
 534                parents = commit->parents;
 535                if (!parents)
 536                        return;
 537
 538                while ((parents = parents->next))
 539                        commit_list_insert(parents->item, plist);
 540
 541                commit = commit->parents->item;
 542        }
 543}
 544
 545void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 546{
 547        struct commit_list *list = NULL;
 548
 549        while (nr--) {
 550                clear_commit_marks_1(&list, *commit, mark);
 551                commit++;
 552        }
 553        while (list)
 554                clear_commit_marks_1(&list, pop_commit(&list), mark);
 555}
 556
 557void clear_commit_marks(struct commit *commit, unsigned int mark)
 558{
 559        clear_commit_marks_many(1, &commit, mark);
 560}
 561
 562struct commit *pop_commit(struct commit_list **stack)
 563{
 564        struct commit_list *top = *stack;
 565        struct commit *item = top ? top->item : NULL;
 566
 567        if (top) {
 568                *stack = top->next;
 569                free(top);
 570        }
 571        return item;
 572}
 573
 574/*
 575 * Topological sort support
 576 */
 577
 578/* count number of children that have not been emitted */
 579define_commit_slab(indegree_slab, int);
 580
 581/* record author-date for each commit object */
 582define_commit_slab(author_date_slab, unsigned long);
 583
 584static void record_author_date(struct author_date_slab *author_date,
 585                               struct commit *commit)
 586{
 587        const char *buffer = get_commit_buffer(commit, NULL);
 588        struct ident_split ident;
 589        const char *ident_line;
 590        size_t ident_len;
 591        char *date_end;
 592        timestamp_t date;
 593
 594        ident_line = find_commit_header(buffer, "author", &ident_len);
 595        if (!ident_line)
 596                goto fail_exit; /* no author line */
 597        if (split_ident_line(&ident, ident_line, ident_len) ||
 598            !ident.date_begin || !ident.date_end)
 599                goto fail_exit; /* malformed "author" line */
 600
 601        date = parse_timestamp(ident.date_begin, &date_end, 10);
 602        if (date_end != ident.date_end)
 603                goto fail_exit; /* malformed date */
 604        *(author_date_slab_at(author_date, commit)) = date;
 605
 606fail_exit:
 607        unuse_commit_buffer(commit, buffer);
 608}
 609
 610static int compare_commits_by_author_date(const void *a_, const void *b_,
 611                                          void *cb_data)
 612{
 613        const struct commit *a = a_, *b = b_;
 614        struct author_date_slab *author_date = cb_data;
 615        timestamp_t a_date = *(author_date_slab_at(author_date, a));
 616        timestamp_t b_date = *(author_date_slab_at(author_date, b));
 617
 618        /* newer commits with larger date first */
 619        if (a_date < b_date)
 620                return 1;
 621        else if (a_date > b_date)
 622                return -1;
 623        return 0;
 624}
 625
 626int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 627{
 628        const struct commit *a = a_, *b = b_;
 629        /* newer commits with larger date first */
 630        if (a->date < b->date)
 631                return 1;
 632        else if (a->date > b->date)
 633                return -1;
 634        return 0;
 635}
 636
 637/*
 638 * Performs an in-place topological sort on the list supplied.
 639 */
 640void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 641{
 642        struct commit_list *next, *orig = *list;
 643        struct commit_list **pptr;
 644        struct indegree_slab indegree;
 645        struct prio_queue queue;
 646        struct commit *commit;
 647        struct author_date_slab author_date;
 648
 649        if (!orig)
 650                return;
 651        *list = NULL;
 652
 653        init_indegree_slab(&indegree);
 654        memset(&queue, '\0', sizeof(queue));
 655
 656        switch (sort_order) {
 657        default: /* REV_SORT_IN_GRAPH_ORDER */
 658                queue.compare = NULL;
 659                break;
 660        case REV_SORT_BY_COMMIT_DATE:
 661                queue.compare = compare_commits_by_commit_date;
 662                break;
 663        case REV_SORT_BY_AUTHOR_DATE:
 664                init_author_date_slab(&author_date);
 665                queue.compare = compare_commits_by_author_date;
 666                queue.cb_data = &author_date;
 667                break;
 668        }
 669
 670        /* Mark them and clear the indegree */
 671        for (next = orig; next; next = next->next) {
 672                struct commit *commit = next->item;
 673                *(indegree_slab_at(&indegree, commit)) = 1;
 674                /* also record the author dates, if needed */
 675                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 676                        record_author_date(&author_date, commit);
 677        }
 678
 679        /* update the indegree */
 680        for (next = orig; next; next = next->next) {
 681                struct commit_list *parents = next->item->parents;
 682                while (parents) {
 683                        struct commit *parent = parents->item;
 684                        int *pi = indegree_slab_at(&indegree, parent);
 685
 686                        if (*pi)
 687                                (*pi)++;
 688                        parents = parents->next;
 689                }
 690        }
 691
 692        /*
 693         * find the tips
 694         *
 695         * tips are nodes not reachable from any other node in the list
 696         *
 697         * the tips serve as a starting set for the work queue.
 698         */
 699        for (next = orig; next; next = next->next) {
 700                struct commit *commit = next->item;
 701
 702                if (*(indegree_slab_at(&indegree, commit)) == 1)
 703                        prio_queue_put(&queue, commit);
 704        }
 705
 706        /*
 707         * This is unfortunate; the initial tips need to be shown
 708         * in the order given from the revision traversal machinery.
 709         */
 710        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 711                prio_queue_reverse(&queue);
 712
 713        /* We no longer need the commit list */
 714        free_commit_list(orig);
 715
 716        pptr = list;
 717        *list = NULL;
 718        while ((commit = prio_queue_get(&queue)) != NULL) {
 719                struct commit_list *parents;
 720
 721                for (parents = commit->parents; parents ; parents = parents->next) {
 722                        struct commit *parent = parents->item;
 723                        int *pi = indegree_slab_at(&indegree, parent);
 724
 725                        if (!*pi)
 726                                continue;
 727
 728                        /*
 729                         * parents are only enqueued for emission
 730                         * when all their children have been emitted thereby
 731                         * guaranteeing topological order.
 732                         */
 733                        if (--(*pi) == 1)
 734                                prio_queue_put(&queue, parent);
 735                }
 736                /*
 737                 * all children of commit have already been
 738                 * emitted. we can emit it now.
 739                 */
 740                *(indegree_slab_at(&indegree, commit)) = 0;
 741
 742                pptr = &commit_list_insert(commit, pptr)->next;
 743        }
 744
 745        clear_indegree_slab(&indegree);
 746        clear_prio_queue(&queue);
 747        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 748                clear_author_date_slab(&author_date);
 749}
 750
 751/* merge-base stuff */
 752
 753/* Remember to update object flag allocation in object.h */
 754#define PARENT1         (1u<<16)
 755#define PARENT2         (1u<<17)
 756#define STALE           (1u<<18)
 757#define RESULT          (1u<<19)
 758
 759static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 760
 761static int queue_has_nonstale(struct prio_queue *queue)
 762{
 763        int i;
 764        for (i = 0; i < queue->nr; i++) {
 765                struct commit *commit = queue->array[i].data;
 766                if (!(commit->object.flags & STALE))
 767                        return 1;
 768        }
 769        return 0;
 770}
 771
 772/* all input commits in one and twos[] must have been parsed! */
 773static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
 774{
 775        struct prio_queue queue = { compare_commits_by_commit_date };
 776        struct commit_list *result = NULL;
 777        int i;
 778
 779        one->object.flags |= PARENT1;
 780        if (!n) {
 781                commit_list_append(one, &result);
 782                return result;
 783        }
 784        prio_queue_put(&queue, one);
 785
 786        for (i = 0; i < n; i++) {
 787                twos[i]->object.flags |= PARENT2;
 788                prio_queue_put(&queue, twos[i]);
 789        }
 790
 791        while (queue_has_nonstale(&queue)) {
 792                struct commit *commit = prio_queue_get(&queue);
 793                struct commit_list *parents;
 794                int flags;
 795
 796                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 797                if (flags == (PARENT1 | PARENT2)) {
 798                        if (!(commit->object.flags & RESULT)) {
 799                                commit->object.flags |= RESULT;
 800                                commit_list_insert_by_date(commit, &result);
 801                        }
 802                        /* Mark parents of a found merge stale */
 803                        flags |= STALE;
 804                }
 805                parents = commit->parents;
 806                while (parents) {
 807                        struct commit *p = parents->item;
 808                        parents = parents->next;
 809                        if ((p->object.flags & flags) == flags)
 810                                continue;
 811                        if (parse_commit(p))
 812                                return NULL;
 813                        p->object.flags |= flags;
 814                        prio_queue_put(&queue, p);
 815                }
 816        }
 817
 818        clear_prio_queue(&queue);
 819        return result;
 820}
 821
 822static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 823{
 824        struct commit_list *list = NULL;
 825        struct commit_list *result = NULL;
 826        int i;
 827
 828        for (i = 0; i < n; i++) {
 829                if (one == twos[i])
 830                        /*
 831                         * We do not mark this even with RESULT so we do not
 832                         * have to clean it up.
 833                         */
 834                        return commit_list_insert(one, &result);
 835        }
 836
 837        if (parse_commit(one))
 838                return NULL;
 839        for (i = 0; i < n; i++) {
 840                if (parse_commit(twos[i]))
 841                        return NULL;
 842        }
 843
 844        list = paint_down_to_common(one, n, twos);
 845
 846        while (list) {
 847                struct commit *commit = pop_commit(&list);
 848                if (!(commit->object.flags & STALE))
 849                        commit_list_insert_by_date(commit, &result);
 850        }
 851        return result;
 852}
 853
 854struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 855{
 856        struct commit_list *i, *j, *k, *ret = NULL;
 857
 858        if (!in)
 859                return ret;
 860
 861        commit_list_insert(in->item, &ret);
 862
 863        for (i = in->next; i; i = i->next) {
 864                struct commit_list *new = NULL, *end = NULL;
 865
 866                for (j = ret; j; j = j->next) {
 867                        struct commit_list *bases;
 868                        bases = get_merge_bases(i->item, j->item);
 869                        if (!new)
 870                                new = bases;
 871                        else
 872                                end->next = bases;
 873                        for (k = bases; k; k = k->next)
 874                                end = k;
 875                }
 876                ret = new;
 877        }
 878        return ret;
 879}
 880
 881static int remove_redundant(struct commit **array, int cnt)
 882{
 883        /*
 884         * Some commit in the array may be an ancestor of
 885         * another commit.  Move such commit to the end of
 886         * the array, and return the number of commits that
 887         * are independent from each other.
 888         */
 889        struct commit **work;
 890        unsigned char *redundant;
 891        int *filled_index;
 892        int i, j, filled;
 893
 894        work = xcalloc(cnt, sizeof(*work));
 895        redundant = xcalloc(cnt, 1);
 896        ALLOC_ARRAY(filled_index, cnt - 1);
 897
 898        for (i = 0; i < cnt; i++)
 899                parse_commit(array[i]);
 900        for (i = 0; i < cnt; i++) {
 901                struct commit_list *common;
 902
 903                if (redundant[i])
 904                        continue;
 905                for (j = filled = 0; j < cnt; j++) {
 906                        if (i == j || redundant[j])
 907                                continue;
 908                        filled_index[filled] = j;
 909                        work[filled++] = array[j];
 910                }
 911                common = paint_down_to_common(array[i], filled, work);
 912                if (array[i]->object.flags & PARENT2)
 913                        redundant[i] = 1;
 914                for (j = 0; j < filled; j++)
 915                        if (work[j]->object.flags & PARENT1)
 916                                redundant[filled_index[j]] = 1;
 917                clear_commit_marks(array[i], all_flags);
 918                clear_commit_marks_many(filled, work, all_flags);
 919                free_commit_list(common);
 920        }
 921
 922        /* Now collect the result */
 923        COPY_ARRAY(work, array, cnt);
 924        for (i = filled = 0; i < cnt; i++)
 925                if (!redundant[i])
 926                        array[filled++] = work[i];
 927        for (j = filled, i = 0; i < cnt; i++)
 928                if (redundant[i])
 929                        array[j++] = work[i];
 930        free(work);
 931        free(redundant);
 932        free(filled_index);
 933        return filled;
 934}
 935
 936static struct commit_list *get_merge_bases_many_0(struct commit *one,
 937                                                  int n,
 938                                                  struct commit **twos,
 939                                                  int cleanup)
 940{
 941        struct commit_list *list;
 942        struct commit **rslt;
 943        struct commit_list *result;
 944        int cnt, i;
 945
 946        result = merge_bases_many(one, n, twos);
 947        for (i = 0; i < n; i++) {
 948                if (one == twos[i])
 949                        return result;
 950        }
 951        if (!result || !result->next) {
 952                if (cleanup) {
 953                        clear_commit_marks(one, all_flags);
 954                        clear_commit_marks_many(n, twos, all_flags);
 955                }
 956                return result;
 957        }
 958
 959        /* There are more than one */
 960        cnt = commit_list_count(result);
 961        rslt = xcalloc(cnt, sizeof(*rslt));
 962        for (list = result, i = 0; list; list = list->next)
 963                rslt[i++] = list->item;
 964        free_commit_list(result);
 965
 966        clear_commit_marks(one, all_flags);
 967        clear_commit_marks_many(n, twos, all_flags);
 968
 969        cnt = remove_redundant(rslt, cnt);
 970        result = NULL;
 971        for (i = 0; i < cnt; i++)
 972                commit_list_insert_by_date(rslt[i], &result);
 973        free(rslt);
 974        return result;
 975}
 976
 977struct commit_list *get_merge_bases_many(struct commit *one,
 978                                         int n,
 979                                         struct commit **twos)
 980{
 981        return get_merge_bases_many_0(one, n, twos, 1);
 982}
 983
 984struct commit_list *get_merge_bases_many_dirty(struct commit *one,
 985                                               int n,
 986                                               struct commit **twos)
 987{
 988        return get_merge_bases_many_0(one, n, twos, 0);
 989}
 990
 991struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
 992{
 993        return get_merge_bases_many_0(one, 1, &two, 1);
 994}
 995
 996/*
 997 * Is "commit" a descendant of one of the elements on the "with_commit" list?
 998 */
 999int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
1000{
1001        if (!with_commit)
1002                return 1;
1003        while (with_commit) {
1004                struct commit *other;
1005
1006                other = with_commit->item;
1007                with_commit = with_commit->next;
1008                if (in_merge_bases(other, commit))
1009                        return 1;
1010        }
1011        return 0;
1012}
1013
1014/*
1015 * Is "commit" an ancestor of one of the "references"?
1016 */
1017int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1018{
1019        struct commit_list *bases;
1020        int ret = 0, i;
1021
1022        if (parse_commit(commit))
1023                return ret;
1024        for (i = 0; i < nr_reference; i++)
1025                if (parse_commit(reference[i]))
1026                        return ret;
1027
1028        bases = paint_down_to_common(commit, nr_reference, reference);
1029        if (commit->object.flags & PARENT2)
1030                ret = 1;
1031        clear_commit_marks(commit, all_flags);
1032        clear_commit_marks_many(nr_reference, reference, all_flags);
1033        free_commit_list(bases);
1034        return ret;
1035}
1036
1037/*
1038 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1039 */
1040int in_merge_bases(struct commit *commit, struct commit *reference)
1041{
1042        return in_merge_bases_many(commit, 1, &reference);
1043}
1044
1045struct commit_list *reduce_heads(struct commit_list *heads)
1046{
1047        struct commit_list *p;
1048        struct commit_list *result = NULL, **tail = &result;
1049        struct commit **array;
1050        int num_head, i;
1051
1052        if (!heads)
1053                return NULL;
1054
1055        /* Uniquify */
1056        for (p = heads; p; p = p->next)
1057                p->item->object.flags &= ~STALE;
1058        for (p = heads, num_head = 0; p; p = p->next) {
1059                if (p->item->object.flags & STALE)
1060                        continue;
1061                p->item->object.flags |= STALE;
1062                num_head++;
1063        }
1064        array = xcalloc(num_head, sizeof(*array));
1065        for (p = heads, i = 0; p; p = p->next) {
1066                if (p->item->object.flags & STALE) {
1067                        array[i++] = p->item;
1068                        p->item->object.flags &= ~STALE;
1069                }
1070        }
1071        num_head = remove_redundant(array, num_head);
1072        for (i = 0; i < num_head; i++)
1073                tail = &commit_list_insert(array[i], tail)->next;
1074        free(array);
1075        return result;
1076}
1077
1078void reduce_heads_replace(struct commit_list **heads)
1079{
1080        struct commit_list *result = reduce_heads(*heads);
1081        free_commit_list(*heads);
1082        *heads = result;
1083}
1084
1085static const char gpg_sig_header[] = "gpgsig";
1086static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1087
1088static int do_sign_commit(struct strbuf *buf, const char *keyid)
1089{
1090        struct strbuf sig = STRBUF_INIT;
1091        int inspos, copypos;
1092        const char *eoh;
1093
1094        /* find the end of the header */
1095        eoh = strstr(buf->buf, "\n\n");
1096        if (!eoh)
1097                inspos = buf->len;
1098        else
1099                inspos = eoh - buf->buf + 1;
1100
1101        if (!keyid || !*keyid)
1102                keyid = get_signing_key();
1103        if (sign_buffer(buf, &sig, keyid)) {
1104                strbuf_release(&sig);
1105                return -1;
1106        }
1107
1108        for (copypos = 0; sig.buf[copypos]; ) {
1109                const char *bol = sig.buf + copypos;
1110                const char *eol = strchrnul(bol, '\n');
1111                int len = (eol - bol) + !!*eol;
1112
1113                if (!copypos) {
1114                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1115                        inspos += gpg_sig_header_len;
1116                }
1117                strbuf_insert(buf, inspos++, " ", 1);
1118                strbuf_insert(buf, inspos, bol, len);
1119                inspos += len;
1120                copypos += len;
1121        }
1122        strbuf_release(&sig);
1123        return 0;
1124}
1125
1126int parse_signed_commit(const struct commit *commit,
1127                        struct strbuf *payload, struct strbuf *signature)
1128{
1129
1130        unsigned long size;
1131        const char *buffer = get_commit_buffer(commit, &size);
1132        int in_signature, saw_signature = -1;
1133        const char *line, *tail;
1134
1135        line = buffer;
1136        tail = buffer + size;
1137        in_signature = 0;
1138        saw_signature = 0;
1139        while (line < tail) {
1140                const char *sig = NULL;
1141                const char *next = memchr(line, '\n', tail - line);
1142
1143                next = next ? next + 1 : tail;
1144                if (in_signature && line[0] == ' ')
1145                        sig = line + 1;
1146                else if (starts_with(line, gpg_sig_header) &&
1147                         line[gpg_sig_header_len] == ' ')
1148                        sig = line + gpg_sig_header_len + 1;
1149                if (sig) {
1150                        strbuf_add(signature, sig, next - sig);
1151                        saw_signature = 1;
1152                        in_signature = 1;
1153                } else {
1154                        if (*line == '\n')
1155                                /* dump the whole remainder of the buffer */
1156                                next = tail;
1157                        strbuf_add(payload, line, next - line);
1158                        in_signature = 0;
1159                }
1160                line = next;
1161        }
1162        unuse_commit_buffer(commit, buffer);
1163        return saw_signature;
1164}
1165
1166int remove_signature(struct strbuf *buf)
1167{
1168        const char *line = buf->buf;
1169        const char *tail = buf->buf + buf->len;
1170        int in_signature = 0;
1171        const char *sig_start = NULL;
1172        const char *sig_end = NULL;
1173
1174        while (line < tail) {
1175                const char *next = memchr(line, '\n', tail - line);
1176                next = next ? next + 1 : tail;
1177
1178                if (in_signature && line[0] == ' ')
1179                        sig_end = next;
1180                else if (starts_with(line, gpg_sig_header) &&
1181                         line[gpg_sig_header_len] == ' ') {
1182                        sig_start = line;
1183                        sig_end = next;
1184                        in_signature = 1;
1185                } else {
1186                        if (*line == '\n')
1187                                /* dump the whole remainder of the buffer */
1188                                next = tail;
1189                        in_signature = 0;
1190                }
1191                line = next;
1192        }
1193
1194        if (sig_start)
1195                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1196
1197        return sig_start != NULL;
1198}
1199
1200static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1201{
1202        struct merge_remote_desc *desc;
1203        struct commit_extra_header *mergetag;
1204        char *buf;
1205        unsigned long size, len;
1206        enum object_type type;
1207
1208        desc = merge_remote_util(parent);
1209        if (!desc || !desc->obj)
1210                return;
1211        buf = read_sha1_file(desc->obj->oid.hash, &type, &size);
1212        if (!buf || type != OBJ_TAG)
1213                goto free_return;
1214        len = parse_signature(buf, size);
1215        if (size == len)
1216                goto free_return;
1217        /*
1218         * We could verify this signature and either omit the tag when
1219         * it does not validate, but the integrator may not have the
1220         * public key of the signer of the tag he is merging, while a
1221         * later auditor may have it while auditing, so let's not run
1222         * verify-signed-buffer here for now...
1223         *
1224         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1225         *      warn("warning: signed tag unverified.");
1226         */
1227        mergetag = xcalloc(1, sizeof(*mergetag));
1228        mergetag->key = xstrdup("mergetag");
1229        mergetag->value = buf;
1230        mergetag->len = size;
1231
1232        **tail = mergetag;
1233        *tail = &mergetag->next;
1234        return;
1235
1236free_return:
1237        free(buf);
1238}
1239
1240int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1241{
1242        struct strbuf payload = STRBUF_INIT;
1243        struct strbuf signature = STRBUF_INIT;
1244        int ret = 1;
1245
1246        sigc->result = 'N';
1247
1248        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1249                goto out;
1250        ret = check_signature(payload.buf, payload.len, signature.buf,
1251                signature.len, sigc);
1252
1253 out:
1254        strbuf_release(&payload);
1255        strbuf_release(&signature);
1256
1257        return ret;
1258}
1259
1260
1261
1262void append_merge_tag_headers(struct commit_list *parents,
1263                              struct commit_extra_header ***tail)
1264{
1265        while (parents) {
1266                struct commit *parent = parents->item;
1267                handle_signed_tag(parent, tail);
1268                parents = parents->next;
1269        }
1270}
1271
1272static void add_extra_header(struct strbuf *buffer,
1273                             struct commit_extra_header *extra)
1274{
1275        strbuf_addstr(buffer, extra->key);
1276        if (extra->len)
1277                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1278        else
1279                strbuf_addch(buffer, '\n');
1280}
1281
1282struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1283                                                      const char **exclude)
1284{
1285        struct commit_extra_header *extra = NULL;
1286        unsigned long size;
1287        const char *buffer = get_commit_buffer(commit, &size);
1288        extra = read_commit_extra_header_lines(buffer, size, exclude);
1289        unuse_commit_buffer(commit, buffer);
1290        return extra;
1291}
1292
1293void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1294{
1295        struct commit_extra_header *extra, *to_free;
1296
1297        to_free = read_commit_extra_headers(commit, NULL);
1298        for (extra = to_free; extra; extra = extra->next) {
1299                if (strcmp(extra->key, "mergetag"))
1300                        continue; /* not a merge tag */
1301                fn(commit, extra, data);
1302        }
1303        free_commit_extra_headers(to_free);
1304}
1305
1306static inline int standard_header_field(const char *field, size_t len)
1307{
1308        return ((len == 4 && !memcmp(field, "tree", 4)) ||
1309                (len == 6 && !memcmp(field, "parent", 6)) ||
1310                (len == 6 && !memcmp(field, "author", 6)) ||
1311                (len == 9 && !memcmp(field, "committer", 9)) ||
1312                (len == 8 && !memcmp(field, "encoding", 8)));
1313}
1314
1315static int excluded_header_field(const char *field, size_t len, const char **exclude)
1316{
1317        if (!exclude)
1318                return 0;
1319
1320        while (*exclude) {
1321                size_t xlen = strlen(*exclude);
1322                if (len == xlen && !memcmp(field, *exclude, xlen))
1323                        return 1;
1324                exclude++;
1325        }
1326        return 0;
1327}
1328
1329static struct commit_extra_header *read_commit_extra_header_lines(
1330        const char *buffer, size_t size,
1331        const char **exclude)
1332{
1333        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1334        const char *line, *next, *eof, *eob;
1335        struct strbuf buf = STRBUF_INIT;
1336
1337        for (line = buffer, eob = line + size;
1338             line < eob && *line != '\n';
1339             line = next) {
1340                next = memchr(line, '\n', eob - line);
1341                next = next ? next + 1 : eob;
1342                if (*line == ' ') {
1343                        /* continuation */
1344                        if (it)
1345                                strbuf_add(&buf, line + 1, next - (line + 1));
1346                        continue;
1347                }
1348                if (it)
1349                        it->value = strbuf_detach(&buf, &it->len);
1350                strbuf_reset(&buf);
1351                it = NULL;
1352
1353                eof = memchr(line, ' ', next - line);
1354                if (!eof)
1355                        eof = next;
1356                else if (standard_header_field(line, eof - line) ||
1357                         excluded_header_field(line, eof - line, exclude))
1358                        continue;
1359
1360                it = xcalloc(1, sizeof(*it));
1361                it->key = xmemdupz(line, eof-line);
1362                *tail = it;
1363                tail = &it->next;
1364                if (eof + 1 < next)
1365                        strbuf_add(&buf, eof + 1, next - (eof + 1));
1366        }
1367        if (it)
1368                it->value = strbuf_detach(&buf, &it->len);
1369        return extra;
1370}
1371
1372void free_commit_extra_headers(struct commit_extra_header *extra)
1373{
1374        while (extra) {
1375                struct commit_extra_header *next = extra->next;
1376                free(extra->key);
1377                free(extra->value);
1378                free(extra);
1379                extra = next;
1380        }
1381}
1382
1383int commit_tree(const char *msg, size_t msg_len,
1384                const unsigned char *tree,
1385                struct commit_list *parents, unsigned char *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 unsigned char *tree,
1515                         struct commit_list *parents, unsigned char *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_sha1_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", sha1_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_sha1_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 = xmalloc(sizeof(struct commit_list));
1621        new->item = commit;
1622        *next = new;
1623        new->next = NULL;
1624        return &new->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}