Andrew's git / gitweb.git / commit.c
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commit.con commit git-p4: add tests for non-numeric revision range (eceafff)
   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
  15static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
  16
  17int save_commit_buffer = 1;
  18
  19const char *commit_type = "commit";
  20
  21struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
  22                                              int quiet)
  23{
  24        struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
  25
  26        if (!obj)
  27                return NULL;
  28        return object_as_type(obj, OBJ_COMMIT, quiet);
  29}
  30
  31struct commit *lookup_commit_reference(const unsigned char *sha1)
  32{
  33        return lookup_commit_reference_gently(sha1, 0);
  34}
  35
  36struct commit *lookup_commit_or_die(const unsigned char *sha1, const char *ref_name)
  37{
  38        struct commit *c = lookup_commit_reference(sha1);
  39        if (!c)
  40                die(_("could not parse %s"), ref_name);
  41        if (hashcmp(sha1, c->object.sha1)) {
  42                warning(_("%s %s is not a commit!"),
  43                        ref_name, sha1_to_hex(sha1));
  44        }
  45        return c;
  46}
  47
  48struct commit *lookup_commit(const unsigned char *sha1)
  49{
  50        struct object *obj = lookup_object(sha1);
  51        if (!obj)
  52                return create_object(sha1, alloc_commit_node());
  53        return object_as_type(obj, OBJ_COMMIT, 0);
  54}
  55
  56struct commit *lookup_commit_reference_by_name(const char *name)
  57{
  58        struct object_id oid;
  59        struct commit *commit;
  60
  61        if (get_sha1_committish(name, oid.hash))
  62                return NULL;
  63        commit = lookup_commit_reference(oid.hash);
  64        if (parse_commit(commit))
  65                return NULL;
  66        return commit;
  67}
  68
  69static unsigned long parse_commit_date(const char *buf, const char *tail)
  70{
  71        const char *dateptr;
  72
  73        if (buf + 6 >= tail)
  74                return 0;
  75        if (memcmp(buf, "author", 6))
  76                return 0;
  77        while (buf < tail && *buf++ != '\n')
  78                /* nada */;
  79        if (buf + 9 >= tail)
  80                return 0;
  81        if (memcmp(buf, "committer", 9))
  82                return 0;
  83        while (buf < tail && *buf++ != '>')
  84                /* nada */;
  85        if (buf >= tail)
  86                return 0;
  87        dateptr = buf;
  88        while (buf < tail && *buf++ != '\n')
  89                /* nada */;
  90        if (buf >= tail)
  91                return 0;
  92        /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
  93        return strtoul(dateptr, NULL, 10);
  94}
  95
  96static struct commit_graft **commit_graft;
  97static int commit_graft_alloc, commit_graft_nr;
  98
  99static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
 100{
 101        struct commit_graft **commit_graft_table = table;
 102        return commit_graft_table[index]->oid.hash;
 103}
 104
 105static int commit_graft_pos(const unsigned char *sha1)
 106{
 107        return sha1_pos(sha1, commit_graft, commit_graft_nr,
 108                        commit_graft_sha1_access);
 109}
 110
 111int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 112{
 113        int pos = commit_graft_pos(graft->oid.hash);
 114
 115        if (0 <= pos) {
 116                if (ignore_dups)
 117                        free(graft);
 118                else {
 119                        free(commit_graft[pos]);
 120                        commit_graft[pos] = graft;
 121                }
 122                return 1;
 123        }
 124        pos = -pos - 1;
 125        ALLOC_GROW(commit_graft, commit_graft_nr + 1, commit_graft_alloc);
 126        commit_graft_nr++;
 127        if (pos < commit_graft_nr)
 128                memmove(commit_graft + pos + 1,
 129                        commit_graft + pos,
 130                        (commit_graft_nr - pos - 1) *
 131                        sizeof(*commit_graft));
 132        commit_graft[pos] = graft;
 133        return 0;
 134}
 135
 136struct commit_graft *read_graft_line(char *buf, int len)
 137{
 138        /* The format is just "Commit Parent1 Parent2 ...\n" */
 139        int i;
 140        struct commit_graft *graft = NULL;
 141        const int entry_size = GIT_SHA1_HEXSZ + 1;
 142
 143        while (len && isspace(buf[len-1]))
 144                buf[--len] = '\0';
 145        if (buf[0] == '#' || buf[0] == '\0')
 146                return NULL;
 147        if ((len + 1) % entry_size)
 148                goto bad_graft_data;
 149        i = (len + 1) / entry_size - 1;
 150        graft = xmalloc(sizeof(*graft) + GIT_SHA1_RAWSZ * i);
 151        graft->nr_parent = i;
 152        if (get_oid_hex(buf, &graft->oid))
 153                goto bad_graft_data;
 154        for (i = GIT_SHA1_HEXSZ; i < len; i += entry_size) {
 155                if (buf[i] != ' ')
 156                        goto bad_graft_data;
 157                if (get_sha1_hex(buf + i + 1, graft->parent[i/entry_size].hash))
 158                        goto bad_graft_data;
 159        }
 160        return graft;
 161
 162bad_graft_data:
 163        error("bad graft data: %s", buf);
 164        free(graft);
 165        return NULL;
 166}
 167
 168static int read_graft_file(const char *graft_file)
 169{
 170        FILE *fp = fopen(graft_file, "r");
 171        struct strbuf buf = STRBUF_INIT;
 172        if (!fp)
 173                return -1;
 174        while (!strbuf_getwholeline(&buf, fp, '\n')) {
 175                /* The format is just "Commit Parent1 Parent2 ...\n" */
 176                struct commit_graft *graft = read_graft_line(buf.buf, buf.len);
 177                if (!graft)
 178                        continue;
 179                if (register_commit_graft(graft, 1))
 180                        error("duplicate graft data: %s", buf.buf);
 181        }
 182        fclose(fp);
 183        strbuf_release(&buf);
 184        return 0;
 185}
 186
 187static void prepare_commit_graft(void)
 188{
 189        static int commit_graft_prepared;
 190        char *graft_file;
 191
 192        if (commit_graft_prepared)
 193                return;
 194        graft_file = get_graft_file();
 195        read_graft_file(graft_file);
 196        /* make sure shallows are read */
 197        is_repository_shallow();
 198        commit_graft_prepared = 1;
 199}
 200
 201struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 202{
 203        int pos;
 204        prepare_commit_graft();
 205        pos = commit_graft_pos(sha1);
 206        if (pos < 0)
 207                return NULL;
 208        return commit_graft[pos];
 209}
 210
 211int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
 212{
 213        int i, ret;
 214        for (i = ret = 0; i < commit_graft_nr && !ret; i++)
 215                ret = fn(commit_graft[i], cb_data);
 216        return ret;
 217}
 218
 219int unregister_shallow(const unsigned char *sha1)
 220{
 221        int pos = commit_graft_pos(sha1);
 222        if (pos < 0)
 223                return -1;
 224        if (pos + 1 < commit_graft_nr)
 225                memmove(commit_graft + pos, commit_graft + pos + 1,
 226                                sizeof(struct commit_graft *)
 227                                * (commit_graft_nr - pos - 1));
 228        commit_graft_nr--;
 229        return 0;
 230}
 231
 232struct commit_buffer {
 233        void *buffer;
 234        unsigned long size;
 235};
 236define_commit_slab(buffer_slab, struct commit_buffer);
 237static struct buffer_slab buffer_slab = COMMIT_SLAB_INIT(1, buffer_slab);
 238
 239void set_commit_buffer(struct commit *commit, void *buffer, unsigned long size)
 240{
 241        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 242        v->buffer = buffer;
 243        v->size = size;
 244}
 245
 246const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
 247{
 248        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 249        if (sizep)
 250                *sizep = v->size;
 251        return v->buffer;
 252}
 253
 254const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
 255{
 256        const void *ret = get_cached_commit_buffer(commit, sizep);
 257        if (!ret) {
 258                enum object_type type;
 259                unsigned long size;
 260                ret = read_sha1_file(commit->object.sha1, &type, &size);
 261                if (!ret)
 262                        die("cannot read commit object %s",
 263                            sha1_to_hex(commit->object.sha1));
 264                if (type != OBJ_COMMIT)
 265                        die("expected commit for %s, got %s",
 266                            sha1_to_hex(commit->object.sha1), typename(type));
 267                if (sizep)
 268                        *sizep = size;
 269        }
 270        return ret;
 271}
 272
 273void unuse_commit_buffer(const struct commit *commit, const void *buffer)
 274{
 275        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 276        if (v->buffer != buffer)
 277                free((void *)buffer);
 278}
 279
 280void free_commit_buffer(struct commit *commit)
 281{
 282        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 283        free(v->buffer);
 284        v->buffer = NULL;
 285        v->size = 0;
 286}
 287
 288const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 289{
 290        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 291        void *ret;
 292
 293        ret = v->buffer;
 294        if (sizep)
 295                *sizep = v->size;
 296
 297        v->buffer = NULL;
 298        v->size = 0;
 299        return ret;
 300}
 301
 302int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
 303{
 304        const char *tail = buffer;
 305        const char *bufptr = buffer;
 306        struct object_id parent;
 307        struct commit_list **pptr;
 308        struct commit_graft *graft;
 309        const int tree_entry_len = GIT_SHA1_HEXSZ + 5;
 310        const int parent_entry_len = GIT_SHA1_HEXSZ + 7;
 311
 312        if (item->object.parsed)
 313                return 0;
 314        item->object.parsed = 1;
 315        tail += size;
 316        if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
 317                        bufptr[tree_entry_len] != '\n')
 318                return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 319        if (get_sha1_hex(bufptr + 5, parent.hash) < 0)
 320                return error("bad tree pointer in commit %s",
 321                             sha1_to_hex(item->object.sha1));
 322        item->tree = lookup_tree(parent.hash);
 323        bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
 324        pptr = &item->parents;
 325
 326        graft = lookup_commit_graft(item->object.sha1);
 327        while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
 328                struct commit *new_parent;
 329
 330                if (tail <= bufptr + parent_entry_len + 1 ||
 331                    get_sha1_hex(bufptr + 7, parent.hash) ||
 332                    bufptr[parent_entry_len] != '\n')
 333                        return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 334                bufptr += parent_entry_len + 1;
 335                /*
 336                 * The clone is shallow if nr_parent < 0, and we must
 337                 * not traverse its real parents even when we unhide them.
 338                 */
 339                if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
 340                        continue;
 341                new_parent = lookup_commit(parent.hash);
 342                if (new_parent)
 343                        pptr = &commit_list_insert(new_parent, pptr)->next;
 344        }
 345        if (graft) {
 346                int i;
 347                struct commit *new_parent;
 348                for (i = 0; i < graft->nr_parent; i++) {
 349                        new_parent = lookup_commit(graft->parent[i].hash);
 350                        if (!new_parent)
 351                                continue;
 352                        pptr = &commit_list_insert(new_parent, pptr)->next;
 353                }
 354        }
 355        item->date = parse_commit_date(bufptr, tail);
 356
 357        return 0;
 358}
 359
 360int parse_commit(struct commit *item)
 361{
 362        enum object_type type;
 363        void *buffer;
 364        unsigned long size;
 365        int ret;
 366
 367        if (!item)
 368                return -1;
 369        if (item->object.parsed)
 370                return 0;
 371        buffer = read_sha1_file(item->object.sha1, &type, &size);
 372        if (!buffer)
 373                return error("Could not read %s",
 374                             sha1_to_hex(item->object.sha1));
 375        if (type != OBJ_COMMIT) {
 376                free(buffer);
 377                return error("Object %s not a commit",
 378                             sha1_to_hex(item->object.sha1));
 379        }
 380        ret = parse_commit_buffer(item, buffer, size);
 381        if (save_commit_buffer && !ret) {
 382                set_commit_buffer(item, buffer, size);
 383                return 0;
 384        }
 385        free(buffer);
 386        return ret;
 387}
 388
 389void parse_commit_or_die(struct commit *item)
 390{
 391        if (parse_commit(item))
 392                die("unable to parse commit %s",
 393                    item ? sha1_to_hex(item->object.sha1) : "(null)");
 394}
 395
 396int find_commit_subject(const char *commit_buffer, const char **subject)
 397{
 398        const char *eol;
 399        const char *p = commit_buffer;
 400
 401        while (*p && (*p != '\n' || p[1] != '\n'))
 402                p++;
 403        if (*p) {
 404                p += 2;
 405                for (eol = p; *eol && *eol != '\n'; eol++)
 406                        ; /* do nothing */
 407        } else
 408                eol = p;
 409
 410        *subject = p;
 411
 412        return eol - p;
 413}
 414
 415struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 416{
 417        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 418        new_list->item = item;
 419        new_list->next = *list_p;
 420        *list_p = new_list;
 421        return new_list;
 422}
 423
 424unsigned commit_list_count(const struct commit_list *l)
 425{
 426        unsigned c = 0;
 427        for (; l; l = l->next )
 428                c++;
 429        return c;
 430}
 431
 432struct commit_list *copy_commit_list(struct commit_list *list)
 433{
 434        struct commit_list *head = NULL;
 435        struct commit_list **pp = &head;
 436        while (list) {
 437                pp = commit_list_append(list->item, pp);
 438                list = list->next;
 439        }
 440        return head;
 441}
 442
 443void free_commit_list(struct commit_list *list)
 444{
 445        while (list) {
 446                struct commit_list *temp = list;
 447                list = temp->next;
 448                free(temp);
 449        }
 450}
 451
 452struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 453{
 454        struct commit_list **pp = list;
 455        struct commit_list *p;
 456        while ((p = *pp) != NULL) {
 457                if (p->item->date < item->date) {
 458                        break;
 459                }
 460                pp = &p->next;
 461        }
 462        return commit_list_insert(item, pp);
 463}
 464
 465static int commit_list_compare_by_date(const void *a, const void *b)
 466{
 467        unsigned long a_date = ((const struct commit_list *)a)->item->date;
 468        unsigned long b_date = ((const struct commit_list *)b)->item->date;
 469        if (a_date < b_date)
 470                return 1;
 471        if (a_date > b_date)
 472                return -1;
 473        return 0;
 474}
 475
 476static void *commit_list_get_next(const void *a)
 477{
 478        return ((const struct commit_list *)a)->next;
 479}
 480
 481static void commit_list_set_next(void *a, void *next)
 482{
 483        ((struct commit_list *)a)->next = next;
 484}
 485
 486void commit_list_sort_by_date(struct commit_list **list)
 487{
 488        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 489                                commit_list_compare_by_date);
 490}
 491
 492struct commit *pop_most_recent_commit(struct commit_list **list,
 493                                      unsigned int mark)
 494{
 495        struct commit *ret = (*list)->item;
 496        struct commit_list *parents = ret->parents;
 497        struct commit_list *old = *list;
 498
 499        *list = (*list)->next;
 500        free(old);
 501
 502        while (parents) {
 503                struct commit *commit = parents->item;
 504                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 505                        commit->object.flags |= mark;
 506                        commit_list_insert_by_date(commit, list);
 507                }
 508                parents = parents->next;
 509        }
 510        return ret;
 511}
 512
 513static void clear_commit_marks_1(struct commit_list **plist,
 514                                 struct commit *commit, unsigned int mark)
 515{
 516        while (commit) {
 517                struct commit_list *parents;
 518
 519                if (!(mark & commit->object.flags))
 520                        return;
 521
 522                commit->object.flags &= ~mark;
 523
 524                parents = commit->parents;
 525                if (!parents)
 526                        return;
 527
 528                while ((parents = parents->next))
 529                        commit_list_insert(parents->item, plist);
 530
 531                commit = commit->parents->item;
 532        }
 533}
 534
 535void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 536{
 537        struct commit_list *list = NULL;
 538
 539        while (nr--) {
 540                commit_list_insert(*commit, &list);
 541                commit++;
 542        }
 543        while (list)
 544                clear_commit_marks_1(&list, pop_commit(&list), mark);
 545}
 546
 547void clear_commit_marks(struct commit *commit, unsigned int mark)
 548{
 549        clear_commit_marks_many(1, &commit, mark);
 550}
 551
 552void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
 553{
 554        struct object *object;
 555        struct commit *commit;
 556        unsigned int i;
 557
 558        for (i = 0; i < a->nr; i++) {
 559                object = a->objects[i].item;
 560                commit = lookup_commit_reference_gently(object->sha1, 1);
 561                if (commit)
 562                        clear_commit_marks(commit, mark);
 563        }
 564}
 565
 566struct commit *pop_commit(struct commit_list **stack)
 567{
 568        struct commit_list *top = *stack;
 569        struct commit *item = top ? top->item : NULL;
 570
 571        if (top) {
 572                *stack = top->next;
 573                free(top);
 574        }
 575        return item;
 576}
 577
 578/*
 579 * Topological sort support
 580 */
 581
 582/* count number of children that have not been emitted */
 583define_commit_slab(indegree_slab, int);
 584
 585/* record author-date for each commit object */
 586define_commit_slab(author_date_slab, unsigned long);
 587
 588static void record_author_date(struct author_date_slab *author_date,
 589                               struct commit *commit)
 590{
 591        const char *buffer = get_commit_buffer(commit, NULL);
 592        struct ident_split ident;
 593        const char *ident_line;
 594        size_t ident_len;
 595        char *date_end;
 596        unsigned long date;
 597
 598        ident_line = find_commit_header(buffer, "author", &ident_len);
 599        if (!ident_line)
 600                goto fail_exit; /* no author line */
 601        if (split_ident_line(&ident, ident_line, ident_len) ||
 602            !ident.date_begin || !ident.date_end)
 603                goto fail_exit; /* malformed "author" line */
 604
 605        date = strtoul(ident.date_begin, &date_end, 10);
 606        if (date_end != ident.date_end)
 607                goto fail_exit; /* malformed date */
 608        *(author_date_slab_at(author_date, commit)) = date;
 609
 610fail_exit:
 611        unuse_commit_buffer(commit, buffer);
 612}
 613
 614static int compare_commits_by_author_date(const void *a_, const void *b_,
 615                                          void *cb_data)
 616{
 617        const struct commit *a = a_, *b = b_;
 618        struct author_date_slab *author_date = cb_data;
 619        unsigned long a_date = *(author_date_slab_at(author_date, a));
 620        unsigned long b_date = *(author_date_slab_at(author_date, b));
 621
 622        /* newer commits with larger date first */
 623        if (a_date < b_date)
 624                return 1;
 625        else if (a_date > b_date)
 626                return -1;
 627        return 0;
 628}
 629
 630int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 631{
 632        const struct commit *a = a_, *b = b_;
 633        /* newer commits with larger date first */
 634        if (a->date < b->date)
 635                return 1;
 636        else if (a->date > b->date)
 637                return -1;
 638        return 0;
 639}
 640
 641/*
 642 * Performs an in-place topological sort on the list supplied.
 643 */
 644void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 645{
 646        struct commit_list *next, *orig = *list;
 647        struct commit_list **pptr;
 648        struct indegree_slab indegree;
 649        struct prio_queue queue;
 650        struct commit *commit;
 651        struct author_date_slab author_date;
 652
 653        if (!orig)
 654                return;
 655        *list = NULL;
 656
 657        init_indegree_slab(&indegree);
 658        memset(&queue, '\0', sizeof(queue));
 659
 660        switch (sort_order) {
 661        default: /* REV_SORT_IN_GRAPH_ORDER */
 662                queue.compare = NULL;
 663                break;
 664        case REV_SORT_BY_COMMIT_DATE:
 665                queue.compare = compare_commits_by_commit_date;
 666                break;
 667        case REV_SORT_BY_AUTHOR_DATE:
 668                init_author_date_slab(&author_date);
 669                queue.compare = compare_commits_by_author_date;
 670                queue.cb_data = &author_date;
 671                break;
 672        }
 673
 674        /* Mark them and clear the indegree */
 675        for (next = orig; next; next = next->next) {
 676                struct commit *commit = next->item;
 677                *(indegree_slab_at(&indegree, commit)) = 1;
 678                /* also record the author dates, if needed */
 679                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 680                        record_author_date(&author_date, commit);
 681        }
 682
 683        /* update the indegree */
 684        for (next = orig; next; next = next->next) {
 685                struct commit_list *parents = next->item->parents;
 686                while (parents) {
 687                        struct commit *parent = parents->item;
 688                        int *pi = indegree_slab_at(&indegree, parent);
 689
 690                        if (*pi)
 691                                (*pi)++;
 692                        parents = parents->next;
 693                }
 694        }
 695
 696        /*
 697         * find the tips
 698         *
 699         * tips are nodes not reachable from any other node in the list
 700         *
 701         * the tips serve as a starting set for the work queue.
 702         */
 703        for (next = orig; next; next = next->next) {
 704                struct commit *commit = next->item;
 705
 706                if (*(indegree_slab_at(&indegree, commit)) == 1)
 707                        prio_queue_put(&queue, commit);
 708        }
 709
 710        /*
 711         * This is unfortunate; the initial tips need to be shown
 712         * in the order given from the revision traversal machinery.
 713         */
 714        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 715                prio_queue_reverse(&queue);
 716
 717        /* We no longer need the commit list */
 718        free_commit_list(orig);
 719
 720        pptr = list;
 721        *list = NULL;
 722        while ((commit = prio_queue_get(&queue)) != NULL) {
 723                struct commit_list *parents;
 724
 725                for (parents = commit->parents; parents ; parents = parents->next) {
 726                        struct commit *parent = parents->item;
 727                        int *pi = indegree_slab_at(&indegree, parent);
 728
 729                        if (!*pi)
 730                                continue;
 731
 732                        /*
 733                         * parents are only enqueued for emission
 734                         * when all their children have been emitted thereby
 735                         * guaranteeing topological order.
 736                         */
 737                        if (--(*pi) == 1)
 738                                prio_queue_put(&queue, parent);
 739                }
 740                /*
 741                 * all children of commit have already been
 742                 * emitted. we can emit it now.
 743                 */
 744                *(indegree_slab_at(&indegree, commit)) = 0;
 745
 746                pptr = &commit_list_insert(commit, pptr)->next;
 747        }
 748
 749        clear_indegree_slab(&indegree);
 750        clear_prio_queue(&queue);
 751        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 752                clear_author_date_slab(&author_date);
 753}
 754
 755/* merge-base stuff */
 756
 757/* Remember to update object flag allocation in object.h */
 758#define PARENT1         (1u<<16)
 759#define PARENT2         (1u<<17)
 760#define STALE           (1u<<18)
 761#define RESULT          (1u<<19)
 762
 763static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 764
 765static int queue_has_nonstale(struct prio_queue *queue)
 766{
 767        int i;
 768        for (i = 0; i < queue->nr; i++) {
 769                struct commit *commit = queue->array[i].data;
 770                if (!(commit->object.flags & STALE))
 771                        return 1;
 772        }
 773        return 0;
 774}
 775
 776/* all input commits in one and twos[] must have been parsed! */
 777static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
 778{
 779        struct prio_queue queue = { compare_commits_by_commit_date };
 780        struct commit_list *result = NULL;
 781        int i;
 782
 783        one->object.flags |= PARENT1;
 784        if (!n) {
 785                commit_list_append(one, &result);
 786                return result;
 787        }
 788        prio_queue_put(&queue, one);
 789
 790        for (i = 0; i < n; i++) {
 791                twos[i]->object.flags |= PARENT2;
 792                prio_queue_put(&queue, twos[i]);
 793        }
 794
 795        while (queue_has_nonstale(&queue)) {
 796                struct commit *commit = prio_queue_get(&queue);
 797                struct commit_list *parents;
 798                int flags;
 799
 800                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 801                if (flags == (PARENT1 | PARENT2)) {
 802                        if (!(commit->object.flags & RESULT)) {
 803                                commit->object.flags |= RESULT;
 804                                commit_list_insert_by_date(commit, &result);
 805                        }
 806                        /* Mark parents of a found merge stale */
 807                        flags |= STALE;
 808                }
 809                parents = commit->parents;
 810                while (parents) {
 811                        struct commit *p = parents->item;
 812                        parents = parents->next;
 813                        if ((p->object.flags & flags) == flags)
 814                                continue;
 815                        if (parse_commit(p))
 816                                return NULL;
 817                        p->object.flags |= flags;
 818                        prio_queue_put(&queue, p);
 819                }
 820        }
 821
 822        clear_prio_queue(&queue);
 823        return result;
 824}
 825
 826static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 827{
 828        struct commit_list *list = NULL;
 829        struct commit_list *result = NULL;
 830        int i;
 831
 832        for (i = 0; i < n; i++) {
 833                if (one == twos[i])
 834                        /*
 835                         * We do not mark this even with RESULT so we do not
 836                         * have to clean it up.
 837                         */
 838                        return commit_list_insert(one, &result);
 839        }
 840
 841        if (parse_commit(one))
 842                return NULL;
 843        for (i = 0; i < n; i++) {
 844                if (parse_commit(twos[i]))
 845                        return NULL;
 846        }
 847
 848        list = paint_down_to_common(one, n, twos);
 849
 850        while (list) {
 851                struct commit_list *next = list->next;
 852                if (!(list->item->object.flags & STALE))
 853                        commit_list_insert_by_date(list->item, &result);
 854                free(list);
 855                list = next;
 856        }
 857        return result;
 858}
 859
 860struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 861{
 862        struct commit_list *i, *j, *k, *ret = NULL;
 863
 864        if (!in)
 865                return ret;
 866
 867        commit_list_insert(in->item, &ret);
 868
 869        for (i = in->next; i; i = i->next) {
 870                struct commit_list *new = NULL, *end = NULL;
 871
 872                for (j = ret; j; j = j->next) {
 873                        struct commit_list *bases;
 874                        bases = get_merge_bases(i->item, j->item);
 875                        if (!new)
 876                                new = bases;
 877                        else
 878                                end->next = bases;
 879                        for (k = bases; k; k = k->next)
 880                                end = k;
 881                }
 882                ret = new;
 883        }
 884        return ret;
 885}
 886
 887static int remove_redundant(struct commit **array, int cnt)
 888{
 889        /*
 890         * Some commit in the array may be an ancestor of
 891         * another commit.  Move such commit to the end of
 892         * the array, and return the number of commits that
 893         * are independent from each other.
 894         */
 895        struct commit **work;
 896        unsigned char *redundant;
 897        int *filled_index;
 898        int i, j, filled;
 899
 900        work = xcalloc(cnt, sizeof(*work));
 901        redundant = xcalloc(cnt, 1);
 902        filled_index = xmalloc(sizeof(*filled_index) * (cnt - 1));
 903
 904        for (i = 0; i < cnt; i++)
 905                parse_commit(array[i]);
 906        for (i = 0; i < cnt; i++) {
 907                struct commit_list *common;
 908
 909                if (redundant[i])
 910                        continue;
 911                for (j = filled = 0; j < cnt; j++) {
 912                        if (i == j || redundant[j])
 913                                continue;
 914                        filled_index[filled] = j;
 915                        work[filled++] = array[j];
 916                }
 917                common = paint_down_to_common(array[i], filled, work);
 918                if (array[i]->object.flags & PARENT2)
 919                        redundant[i] = 1;
 920                for (j = 0; j < filled; j++)
 921                        if (work[j]->object.flags & PARENT1)
 922                                redundant[filled_index[j]] = 1;
 923                clear_commit_marks(array[i], all_flags);
 924                for (j = 0; j < filled; j++)
 925                        clear_commit_marks(work[j], all_flags);
 926                free_commit_list(common);
 927        }
 928
 929        /* Now collect the result */
 930        memcpy(work, array, sizeof(*array) * cnt);
 931        for (i = filled = 0; i < cnt; i++)
 932                if (!redundant[i])
 933                        array[filled++] = work[i];
 934        for (j = filled, i = 0; i < cnt; i++)
 935                if (redundant[i])
 936                        array[j++] = work[i];
 937        free(work);
 938        free(redundant);
 939        free(filled_index);
 940        return filled;
 941}
 942
 943static struct commit_list *get_merge_bases_many_0(struct commit *one,
 944                                                  int n,
 945                                                  struct commit **twos,
 946                                                  int cleanup)
 947{
 948        struct commit_list *list;
 949        struct commit **rslt;
 950        struct commit_list *result;
 951        int cnt, i;
 952
 953        result = merge_bases_many(one, n, twos);
 954        for (i = 0; i < n; i++) {
 955                if (one == twos[i])
 956                        return result;
 957        }
 958        if (!result || !result->next) {
 959                if (cleanup) {
 960                        clear_commit_marks(one, all_flags);
 961                        clear_commit_marks_many(n, twos, all_flags);
 962                }
 963                return result;
 964        }
 965
 966        /* There are more than one */
 967        cnt = commit_list_count(result);
 968        rslt = xcalloc(cnt, sizeof(*rslt));
 969        for (list = result, i = 0; list; list = list->next)
 970                rslt[i++] = list->item;
 971        free_commit_list(result);
 972
 973        clear_commit_marks(one, all_flags);
 974        clear_commit_marks_many(n, twos, all_flags);
 975
 976        cnt = remove_redundant(rslt, cnt);
 977        result = NULL;
 978        for (i = 0; i < cnt; i++)
 979                commit_list_insert_by_date(rslt[i], &result);
 980        free(rslt);
 981        return result;
 982}
 983
 984struct commit_list *get_merge_bases_many(struct commit *one,
 985                                         int n,
 986                                         struct commit **twos)
 987{
 988        return get_merge_bases_many_0(one, n, twos, 1);
 989}
 990
 991struct commit_list *get_merge_bases_many_dirty(struct commit *one,
 992                                               int n,
 993                                               struct commit **twos)
 994{
 995        return get_merge_bases_many_0(one, n, twos, 0);
 996}
 997
 998struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
 999{
1000        return get_merge_bases_many_0(one, 1, &two, 1);
1001}
1002
1003/*
1004 * Is "commit" a descendant of one of the elements on the "with_commit" list?
1005 */
1006int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
1007{
1008        if (!with_commit)
1009                return 1;
1010        while (with_commit) {
1011                struct commit *other;
1012
1013                other = with_commit->item;
1014                with_commit = with_commit->next;
1015                if (in_merge_bases(other, commit))
1016                        return 1;
1017        }
1018        return 0;
1019}
1020
1021/*
1022 * Is "commit" an ancestor of one of the "references"?
1023 */
1024int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1025{
1026        struct commit_list *bases;
1027        int ret = 0, i;
1028
1029        if (parse_commit(commit))
1030                return ret;
1031        for (i = 0; i < nr_reference; i++)
1032                if (parse_commit(reference[i]))
1033                        return ret;
1034
1035        bases = paint_down_to_common(commit, nr_reference, reference);
1036        if (commit->object.flags & PARENT2)
1037                ret = 1;
1038        clear_commit_marks(commit, all_flags);
1039        clear_commit_marks_many(nr_reference, reference, all_flags);
1040        free_commit_list(bases);
1041        return ret;
1042}
1043
1044/*
1045 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1046 */
1047int in_merge_bases(struct commit *commit, struct commit *reference)
1048{
1049        return in_merge_bases_many(commit, 1, &reference);
1050}
1051
1052struct commit_list *reduce_heads(struct commit_list *heads)
1053{
1054        struct commit_list *p;
1055        struct commit_list *result = NULL, **tail = &result;
1056        struct commit **array;
1057        int num_head, i;
1058
1059        if (!heads)
1060                return NULL;
1061
1062        /* Uniquify */
1063        for (p = heads; p; p = p->next)
1064                p->item->object.flags &= ~STALE;
1065        for (p = heads, num_head = 0; p; p = p->next) {
1066                if (p->item->object.flags & STALE)
1067                        continue;
1068                p->item->object.flags |= STALE;
1069                num_head++;
1070        }
1071        array = xcalloc(num_head, sizeof(*array));
1072        for (p = heads, i = 0; p; p = p->next) {
1073                if (p->item->object.flags & STALE) {
1074                        array[i++] = p->item;
1075                        p->item->object.flags &= ~STALE;
1076                }
1077        }
1078        num_head = remove_redundant(array, num_head);
1079        for (i = 0; i < num_head; i++)
1080                tail = &commit_list_insert(array[i], tail)->next;
1081        return result;
1082}
1083
1084static const char gpg_sig_header[] = "gpgsig";
1085static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1086
1087static int do_sign_commit(struct strbuf *buf, const char *keyid)
1088{
1089        struct strbuf sig = STRBUF_INIT;
1090        int inspos, copypos;
1091
1092        /* find the end of the header */
1093        inspos = strstr(buf->buf, "\n\n") - buf->buf + 1;
1094
1095        if (!keyid || !*keyid)
1096                keyid = get_signing_key();
1097        if (sign_buffer(buf, &sig, keyid)) {
1098                strbuf_release(&sig);
1099                return -1;
1100        }
1101
1102        for (copypos = 0; sig.buf[copypos]; ) {
1103                const char *bol = sig.buf + copypos;
1104                const char *eol = strchrnul(bol, '\n');
1105                int len = (eol - bol) + !!*eol;
1106
1107                if (!copypos) {
1108                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1109                        inspos += gpg_sig_header_len;
1110                }
1111                strbuf_insert(buf, inspos++, " ", 1);
1112                strbuf_insert(buf, inspos, bol, len);
1113                inspos += len;
1114                copypos += len;
1115        }
1116        strbuf_release(&sig);
1117        return 0;
1118}
1119
1120int parse_signed_commit(const struct commit *commit,
1121                        struct strbuf *payload, struct strbuf *signature)
1122{
1123
1124        unsigned long size;
1125        const char *buffer = get_commit_buffer(commit, &size);
1126        int in_signature, saw_signature = -1;
1127        const char *line, *tail;
1128
1129        line = buffer;
1130        tail = buffer + size;
1131        in_signature = 0;
1132        saw_signature = 0;
1133        while (line < tail) {
1134                const char *sig = NULL;
1135                const char *next = memchr(line, '\n', tail - line);
1136
1137                next = next ? next + 1 : tail;
1138                if (in_signature && line[0] == ' ')
1139                        sig = line + 1;
1140                else if (starts_with(line, gpg_sig_header) &&
1141                         line[gpg_sig_header_len] == ' ')
1142                        sig = line + gpg_sig_header_len + 1;
1143                if (sig) {
1144                        strbuf_add(signature, sig, next - sig);
1145                        saw_signature = 1;
1146                        in_signature = 1;
1147                } else {
1148                        if (*line == '\n')
1149                                /* dump the whole remainder of the buffer */
1150                                next = tail;
1151                        strbuf_add(payload, line, next - line);
1152                        in_signature = 0;
1153                }
1154                line = next;
1155        }
1156        unuse_commit_buffer(commit, buffer);
1157        return saw_signature;
1158}
1159
1160int remove_signature(struct strbuf *buf)
1161{
1162        const char *line = buf->buf;
1163        const char *tail = buf->buf + buf->len;
1164        int in_signature = 0;
1165        const char *sig_start = NULL;
1166        const char *sig_end = NULL;
1167
1168        while (line < tail) {
1169                const char *next = memchr(line, '\n', tail - line);
1170                next = next ? next + 1 : tail;
1171
1172                if (in_signature && line[0] == ' ')
1173                        sig_end = next;
1174                else if (starts_with(line, gpg_sig_header) &&
1175                         line[gpg_sig_header_len] == ' ') {
1176                        sig_start = line;
1177                        sig_end = next;
1178                        in_signature = 1;
1179                } else {
1180                        if (*line == '\n')
1181                                /* dump the whole remainder of the buffer */
1182                                next = tail;
1183                        in_signature = 0;
1184                }
1185                line = next;
1186        }
1187
1188        if (sig_start)
1189                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1190
1191        return sig_start != NULL;
1192}
1193
1194static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1195{
1196        struct merge_remote_desc *desc;
1197        struct commit_extra_header *mergetag;
1198        char *buf;
1199        unsigned long size, len;
1200        enum object_type type;
1201
1202        desc = merge_remote_util(parent);
1203        if (!desc || !desc->obj)
1204                return;
1205        buf = read_sha1_file(desc->obj->sha1, &type, &size);
1206        if (!buf || type != OBJ_TAG)
1207                goto free_return;
1208        len = parse_signature(buf, size);
1209        if (size == len)
1210                goto free_return;
1211        /*
1212         * We could verify this signature and either omit the tag when
1213         * it does not validate, but the integrator may not have the
1214         * public key of the signer of the tag he is merging, while a
1215         * later auditor may have it while auditing, so let's not run
1216         * verify-signed-buffer here for now...
1217         *
1218         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1219         *      warn("warning: signed tag unverified.");
1220         */
1221        mergetag = xcalloc(1, sizeof(*mergetag));
1222        mergetag->key = xstrdup("mergetag");
1223        mergetag->value = buf;
1224        mergetag->len = size;
1225
1226        **tail = mergetag;
1227        *tail = &mergetag->next;
1228        return;
1229
1230free_return:
1231        free(buf);
1232}
1233
1234void check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1235{
1236        struct strbuf payload = STRBUF_INIT;
1237        struct strbuf signature = STRBUF_INIT;
1238        struct strbuf gpg_output = STRBUF_INIT;
1239        struct strbuf gpg_status = STRBUF_INIT;
1240        int status;
1241
1242        sigc->result = 'N';
1243
1244        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1245                goto out;
1246        status = verify_signed_buffer(payload.buf, payload.len,
1247                                      signature.buf, signature.len,
1248                                      &gpg_output, &gpg_status);
1249        if (status && !gpg_output.len)
1250                goto out;
1251        sigc->payload = strbuf_detach(&payload, NULL);
1252        sigc->gpg_output = strbuf_detach(&gpg_output, NULL);
1253        sigc->gpg_status = strbuf_detach(&gpg_status, NULL);
1254        parse_gpg_output(sigc);
1255
1256 out:
1257        strbuf_release(&gpg_status);
1258        strbuf_release(&gpg_output);
1259        strbuf_release(&payload);
1260        strbuf_release(&signature);
1261}
1262
1263
1264
1265void append_merge_tag_headers(struct commit_list *parents,
1266                              struct commit_extra_header ***tail)
1267{
1268        while (parents) {
1269                struct commit *parent = parents->item;
1270                handle_signed_tag(parent, tail);
1271                parents = parents->next;
1272        }
1273}
1274
1275static void add_extra_header(struct strbuf *buffer,
1276                             struct commit_extra_header *extra)
1277{
1278        strbuf_addstr(buffer, extra->key);
1279        if (extra->len)
1280                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1281        else
1282                strbuf_addch(buffer, '\n');
1283}
1284
1285struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1286                                                      const char **exclude)
1287{
1288        struct commit_extra_header *extra = NULL;
1289        unsigned long size;
1290        const char *buffer = get_commit_buffer(commit, &size);
1291        extra = read_commit_extra_header_lines(buffer, size, exclude);
1292        unuse_commit_buffer(commit, buffer);
1293        return extra;
1294}
1295
1296void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1297{
1298        struct commit_extra_header *extra, *to_free;
1299
1300        to_free = read_commit_extra_headers(commit, NULL);
1301        for (extra = to_free; extra; extra = extra->next) {
1302                if (strcmp(extra->key, "mergetag"))
1303                        continue; /* not a merge tag */
1304                fn(commit, extra, data);
1305        }
1306        free_commit_extra_headers(to_free);
1307}
1308
1309static inline int standard_header_field(const char *field, size_t len)
1310{
1311        return ((len == 4 && !memcmp(field, "tree ", 5)) ||
1312                (len == 6 && !memcmp(field, "parent ", 7)) ||
1313                (len == 6 && !memcmp(field, "author ", 7)) ||
1314                (len == 9 && !memcmp(field, "committer ", 10)) ||
1315                (len == 8 && !memcmp(field, "encoding ", 9)));
1316}
1317
1318static int excluded_header_field(const char *field, size_t len, const char **exclude)
1319{
1320        if (!exclude)
1321                return 0;
1322
1323        while (*exclude) {
1324                size_t xlen = strlen(*exclude);
1325                if (len == xlen &&
1326                    !memcmp(field, *exclude, xlen) && field[xlen] == ' ')
1327                        return 1;
1328                exclude++;
1329        }
1330        return 0;
1331}
1332
1333static struct commit_extra_header *read_commit_extra_header_lines(
1334        const char *buffer, size_t size,
1335        const char **exclude)
1336{
1337        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1338        const char *line, *next, *eof, *eob;
1339        struct strbuf buf = STRBUF_INIT;
1340
1341        for (line = buffer, eob = line + size;
1342             line < eob && *line != '\n';
1343             line = next) {
1344                next = memchr(line, '\n', eob - line);
1345                next = next ? next + 1 : eob;
1346                if (*line == ' ') {
1347                        /* continuation */
1348                        if (it)
1349                                strbuf_add(&buf, line + 1, next - (line + 1));
1350                        continue;
1351                }
1352                if (it)
1353                        it->value = strbuf_detach(&buf, &it->len);
1354                strbuf_reset(&buf);
1355                it = NULL;
1356
1357                eof = strchr(line, ' ');
1358                if (next <= eof)
1359                        eof = next;
1360
1361                if (standard_header_field(line, eof - line) ||
1362                    excluded_header_field(line, eof - line, exclude))
1363                        continue;
1364
1365                it = xcalloc(1, sizeof(*it));
1366                it->key = xmemdupz(line, eof-line);
1367                *tail = it;
1368                tail = &it->next;
1369                if (eof + 1 < next)
1370                        strbuf_add(&buf, eof + 1, next - (eof + 1));
1371        }
1372        if (it)
1373                it->value = strbuf_detach(&buf, &it->len);
1374        return extra;
1375}
1376
1377void free_commit_extra_headers(struct commit_extra_header *extra)
1378{
1379        while (extra) {
1380                struct commit_extra_header *next = extra->next;
1381                free(extra->key);
1382                free(extra->value);
1383                free(extra);
1384                extra = next;
1385        }
1386}
1387
1388int commit_tree(const char *msg, size_t msg_len,
1389                const unsigned char *tree,
1390                struct commit_list *parents, unsigned char *ret,
1391                const char *author, const char *sign_commit)
1392{
1393        struct commit_extra_header *extra = NULL, **tail = &extra;
1394        int result;
1395
1396        append_merge_tag_headers(parents, &tail);
1397        result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1398                                      author, sign_commit, extra);
1399        free_commit_extra_headers(extra);
1400        return result;
1401}
1402
1403static int find_invalid_utf8(const char *buf, int len)
1404{
1405        int offset = 0;
1406        static const unsigned int max_codepoint[] = {
1407                0x7f, 0x7ff, 0xffff, 0x10ffff
1408        };
1409
1410        while (len) {
1411                unsigned char c = *buf++;
1412                int bytes, bad_offset;
1413                unsigned int codepoint;
1414                unsigned int min_val, max_val;
1415
1416                len--;
1417                offset++;
1418
1419                /* Simple US-ASCII? No worries. */
1420                if (c < 0x80)
1421                        continue;
1422
1423                bad_offset = offset-1;
1424
1425                /*
1426                 * Count how many more high bits set: that's how
1427                 * many more bytes this sequence should have.
1428                 */
1429                bytes = 0;
1430                while (c & 0x40) {
1431                        c <<= 1;
1432                        bytes++;
1433                }
1434
1435                /*
1436                 * Must be between 1 and 3 more bytes.  Longer sequences result in
1437                 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1438                 */
1439                if (bytes < 1 || 3 < bytes)
1440                        return bad_offset;
1441
1442                /* Do we *have* that many bytes? */
1443                if (len < bytes)
1444                        return bad_offset;
1445
1446                /*
1447                 * Place the encoded bits at the bottom of the value and compute the
1448                 * valid range.
1449                 */
1450                codepoint = (c & 0x7f) >> bytes;
1451                min_val = max_codepoint[bytes-1] + 1;
1452                max_val = max_codepoint[bytes];
1453
1454                offset += bytes;
1455                len -= bytes;
1456
1457                /* And verify that they are good continuation bytes */
1458                do {
1459                        codepoint <<= 6;
1460                        codepoint |= *buf & 0x3f;
1461                        if ((*buf++ & 0xc0) != 0x80)
1462                                return bad_offset;
1463                } while (--bytes);
1464
1465                /* Reject codepoints that are out of range for the sequence length. */
1466                if (codepoint < min_val || codepoint > max_val)
1467                        return bad_offset;
1468                /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1469                if ((codepoint & 0x1ff800) == 0xd800)
1470                        return bad_offset;
1471                /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1472                if ((codepoint & 0xfffe) == 0xfffe)
1473                        return bad_offset;
1474                /* So are anything in the range U+FDD0..U+FDEF. */
1475                if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1476                        return bad_offset;
1477        }
1478        return -1;
1479}
1480
1481/*
1482 * This verifies that the buffer is in proper utf8 format.
1483 *
1484 * If it isn't, it assumes any non-utf8 characters are Latin1,
1485 * and does the conversion.
1486 */
1487static int verify_utf8(struct strbuf *buf)
1488{
1489        int ok = 1;
1490        long pos = 0;
1491
1492        for (;;) {
1493                int bad;
1494                unsigned char c;
1495                unsigned char replace[2];
1496
1497                bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1498                if (bad < 0)
1499                        return ok;
1500                pos += bad;
1501                ok = 0;
1502                c = buf->buf[pos];
1503                strbuf_remove(buf, pos, 1);
1504
1505                /* We know 'c' must be in the range 128-255 */
1506                replace[0] = 0xc0 + (c >> 6);
1507                replace[1] = 0x80 + (c & 0x3f);
1508                strbuf_insert(buf, pos, replace, 2);
1509                pos += 2;
1510        }
1511}
1512
1513static const char commit_utf8_warn[] =
1514"Warning: commit message did not conform to UTF-8.\n"
1515"You may want to amend it after fixing the message, or set the config\n"
1516"variable i18n.commitencoding to the encoding your project uses.\n";
1517
1518int commit_tree_extended(const char *msg, size_t msg_len,
1519                         const unsigned char *tree,
1520                         struct commit_list *parents, unsigned char *ret,
1521                         const char *author, const char *sign_commit,
1522                         struct commit_extra_header *extra)
1523{
1524        int result;
1525        int encoding_is_utf8;
1526        struct strbuf buffer;
1527
1528        assert_sha1_type(tree, OBJ_TREE);
1529
1530        if (memchr(msg, '\0', msg_len))
1531                return error("a NUL byte in commit log message not allowed.");
1532
1533        /* Not having i18n.commitencoding is the same as having utf-8 */
1534        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1535
1536        strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1537        strbuf_addf(&buffer, "tree %s\n", sha1_to_hex(tree));
1538
1539        /*
1540         * NOTE! This ordering means that the same exact tree merged with a
1541         * different order of parents will be a _different_ changeset even
1542         * if everything else stays the same.
1543         */
1544        while (parents) {
1545                struct commit_list *next = parents->next;
1546                struct commit *parent = parents->item;
1547
1548                strbuf_addf(&buffer, "parent %s\n",
1549                            sha1_to_hex(parent->object.sha1));
1550                free(parents);
1551                parents = next;
1552        }
1553
1554        /* Person/date information */
1555        if (!author)
1556                author = git_author_info(IDENT_STRICT);
1557        strbuf_addf(&buffer, "author %s\n", author);
1558        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1559        if (!encoding_is_utf8)
1560                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1561
1562        while (extra) {
1563                add_extra_header(&buffer, extra);
1564                extra = extra->next;
1565        }
1566        strbuf_addch(&buffer, '\n');
1567
1568        /* And add the comment */
1569        strbuf_add(&buffer, msg, msg_len);
1570
1571        /* And check the encoding */
1572        if (encoding_is_utf8 && !verify_utf8(&buffer))
1573                fprintf(stderr, commit_utf8_warn);
1574
1575        if (sign_commit && do_sign_commit(&buffer, sign_commit))
1576                return -1;
1577
1578        result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
1579        strbuf_release(&buffer);
1580        return result;
1581}
1582
1583struct commit *get_merge_parent(const char *name)
1584{
1585        struct object *obj;
1586        struct commit *commit;
1587        struct object_id oid;
1588        if (get_sha1(name, oid.hash))
1589                return NULL;
1590        obj = parse_object(oid.hash);
1591        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1592        if (commit && !commit->util) {
1593                struct merge_remote_desc *desc;
1594                desc = xmalloc(sizeof(*desc));
1595                desc->obj = obj;
1596                desc->name = strdup(name);
1597                commit->util = desc;
1598        }
1599        return commit;
1600}
1601
1602/*
1603 * Append a commit to the end of the commit_list.
1604 *
1605 * next starts by pointing to the variable that holds the head of an
1606 * empty commit_list, and is updated to point to the "next" field of
1607 * the last item on the list as new commits are appended.
1608 *
1609 * Usage example:
1610 *
1611 *     struct commit_list *list;
1612 *     struct commit_list **next = &list;
1613 *
1614 *     next = commit_list_append(c1, next);
1615 *     next = commit_list_append(c2, next);
1616 *     assert(commit_list_count(list) == 2);
1617 *     return list;
1618 */
1619struct commit_list **commit_list_append(struct commit *commit,
1620                                        struct commit_list **next)
1621{
1622        struct commit_list *new = xmalloc(sizeof(struct commit_list));
1623        new->item = commit;
1624        *next = new;
1625        new->next = NULL;
1626        return &new->next;
1627}
1628
1629void print_commit_list(struct commit_list *list,
1630                       const char *format_cur,
1631                       const char *format_last)
1632{
1633        for ( ; list; list = list->next) {
1634                const char *format = list->next ? format_cur : format_last;
1635                printf(format, sha1_to_hex(list->item->object.sha1));
1636        }
1637}
1638
1639const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1640{
1641        int key_len = strlen(key);
1642        const char *line = msg;
1643
1644        while (line) {
1645                const char *eol = strchrnul(line, '\n');
1646
1647                if (line == eol)
1648                        return NULL;
1649
1650                if (eol - line > key_len &&
1651                    !strncmp(line, key, key_len) &&
1652                    line[key_len] == ' ') {
1653                        *out_len = eol - line - key_len - 1;
1654                        return line + key_len + 1;
1655                }
1656                line = *eol ? eol + 1 : NULL;
1657        }
1658        return NULL;
1659}
1660
1661/*
1662 * Inspect sb and determine the true "end" of the log message, in
1663 * order to find where to put a new Signed-off-by: line.  Ignored are
1664 * trailing comment lines and blank lines, and also the traditional
1665 * "Conflicts:" block that is not commented out, so that we can use
1666 * "git commit -s --amend" on an existing commit that forgot to remove
1667 * it.
1668 *
1669 * Returns the number of bytes from the tail to ignore, to be fed as
1670 * the second parameter to append_signoff().
1671 */
1672int ignore_non_trailer(struct strbuf *sb)
1673{
1674        int boc = 0;
1675        int bol = 0;
1676        int in_old_conflicts_block = 0;
1677
1678        while (bol < sb->len) {
1679                char *next_line;
1680
1681                if (!(next_line = memchr(sb->buf + bol, '\n', sb->len - bol)))
1682                        next_line = sb->buf + sb->len;
1683                else
1684                        next_line++;
1685
1686                if (sb->buf[bol] == comment_line_char || sb->buf[bol] == '\n') {
1687                        /* is this the first of the run of comments? */
1688                        if (!boc)
1689                                boc = bol;
1690                        /* otherwise, it is just continuing */
1691                } else if (starts_with(sb->buf + bol, "Conflicts:\n")) {
1692                        in_old_conflicts_block = 1;
1693                        if (!boc)
1694                                boc = bol;
1695                } else if (in_old_conflicts_block && sb->buf[bol] == '\t') {
1696                        ; /* a pathname in the conflicts block */
1697                } else if (boc) {
1698                        /* the previous was not trailing comment */
1699                        boc = 0;
1700                        in_old_conflicts_block = 0;
1701                }
1702                bol = next_line - sb->buf;
1703        }
1704        return boc ? sb->len - boc : 0;
1705}