Andrew's git / gitweb.git / commit.c
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commit.con commit print errno when reporting a system call error (5118d7f)
   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.oid.hash)) {
  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(st_add(sizeof(*graft), st_mult(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_or_warn(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_peek(&buffer_slab, commit);
 249        if (!v) {
 250                if (sizep)
 251                        *sizep = 0;
 252                return NULL;
 253        }
 254        if (sizep)
 255                *sizep = v->size;
 256        return v->buffer;
 257}
 258
 259const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
 260{
 261        const void *ret = get_cached_commit_buffer(commit, sizep);
 262        if (!ret) {
 263                enum object_type type;
 264                unsigned long size;
 265                ret = read_sha1_file(commit->object.oid.hash, &type, &size);
 266                if (!ret)
 267                        die("cannot read commit object %s",
 268                            oid_to_hex(&commit->object.oid));
 269                if (type != OBJ_COMMIT)
 270                        die("expected commit for %s, got %s",
 271                            oid_to_hex(&commit->object.oid), typename(type));
 272                if (sizep)
 273                        *sizep = size;
 274        }
 275        return ret;
 276}
 277
 278void unuse_commit_buffer(const struct commit *commit, const void *buffer)
 279{
 280        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 281        if (!(v && v->buffer == buffer))
 282                free((void *)buffer);
 283}
 284
 285void free_commit_buffer(struct commit *commit)
 286{
 287        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 288        if (v) {
 289                free(v->buffer);
 290                v->buffer = NULL;
 291                v->size = 0;
 292        }
 293}
 294
 295const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 296{
 297        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 298        void *ret;
 299
 300        if (!v) {
 301                if (sizep)
 302                        *sizep = 0;
 303                return NULL;
 304        }
 305        ret = v->buffer;
 306        if (sizep)
 307                *sizep = v->size;
 308
 309        v->buffer = NULL;
 310        v->size = 0;
 311        return ret;
 312}
 313
 314int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
 315{
 316        const char *tail = buffer;
 317        const char *bufptr = buffer;
 318        struct object_id parent;
 319        struct commit_list **pptr;
 320        struct commit_graft *graft;
 321        const int tree_entry_len = GIT_SHA1_HEXSZ + 5;
 322        const int parent_entry_len = GIT_SHA1_HEXSZ + 7;
 323
 324        if (item->object.parsed)
 325                return 0;
 326        item->object.parsed = 1;
 327        tail += size;
 328        if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
 329                        bufptr[tree_entry_len] != '\n')
 330                return error("bogus commit object %s", oid_to_hex(&item->object.oid));
 331        if (get_sha1_hex(bufptr + 5, parent.hash) < 0)
 332                return error("bad tree pointer in commit %s",
 333                             oid_to_hex(&item->object.oid));
 334        item->tree = lookup_tree(parent.hash);
 335        bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
 336        pptr = &item->parents;
 337
 338        graft = lookup_commit_graft(item->object.oid.hash);
 339        while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
 340                struct commit *new_parent;
 341
 342                if (tail <= bufptr + parent_entry_len + 1 ||
 343                    get_sha1_hex(bufptr + 7, parent.hash) ||
 344                    bufptr[parent_entry_len] != '\n')
 345                        return error("bad parents in commit %s", oid_to_hex(&item->object.oid));
 346                bufptr += parent_entry_len + 1;
 347                /*
 348                 * The clone is shallow if nr_parent < 0, and we must
 349                 * not traverse its real parents even when we unhide them.
 350                 */
 351                if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
 352                        continue;
 353                new_parent = lookup_commit(parent.hash);
 354                if (new_parent)
 355                        pptr = &commit_list_insert(new_parent, pptr)->next;
 356        }
 357        if (graft) {
 358                int i;
 359                struct commit *new_parent;
 360                for (i = 0; i < graft->nr_parent; i++) {
 361                        new_parent = lookup_commit(graft->parent[i].hash);
 362                        if (!new_parent)
 363                                continue;
 364                        pptr = &commit_list_insert(new_parent, pptr)->next;
 365                }
 366        }
 367        item->date = parse_commit_date(bufptr, tail);
 368
 369        return 0;
 370}
 371
 372int parse_commit_gently(struct commit *item, int quiet_on_missing)
 373{
 374        enum object_type type;
 375        void *buffer;
 376        unsigned long size;
 377        int ret;
 378
 379        if (!item)
 380                return -1;
 381        if (item->object.parsed)
 382                return 0;
 383        buffer = read_sha1_file(item->object.oid.hash, &type, &size);
 384        if (!buffer)
 385                return quiet_on_missing ? -1 :
 386                        error("Could not read %s",
 387                             oid_to_hex(&item->object.oid));
 388        if (type != OBJ_COMMIT) {
 389                free(buffer);
 390                return error("Object %s not a commit",
 391                             oid_to_hex(&item->object.oid));
 392        }
 393        ret = parse_commit_buffer(item, buffer, size);
 394        if (save_commit_buffer && !ret) {
 395                set_commit_buffer(item, buffer, size);
 396                return 0;
 397        }
 398        free(buffer);
 399        return ret;
 400}
 401
 402void parse_commit_or_die(struct commit *item)
 403{
 404        if (parse_commit(item))
 405                die("unable to parse commit %s",
 406                    item ? oid_to_hex(&item->object.oid) : "(null)");
 407}
 408
 409int find_commit_subject(const char *commit_buffer, const char **subject)
 410{
 411        const char *eol;
 412        const char *p = commit_buffer;
 413
 414        while (*p && (*p != '\n' || p[1] != '\n'))
 415                p++;
 416        if (*p) {
 417                p = skip_blank_lines(p + 2);
 418                eol = strchrnul(p, '\n');
 419        } else
 420                eol = p;
 421
 422        *subject = p;
 423
 424        return eol - p;
 425}
 426
 427struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 428{
 429        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 430        new_list->item = item;
 431        new_list->next = *list_p;
 432        *list_p = new_list;
 433        return new_list;
 434}
 435
 436unsigned commit_list_count(const struct commit_list *l)
 437{
 438        unsigned c = 0;
 439        for (; l; l = l->next )
 440                c++;
 441        return c;
 442}
 443
 444struct commit_list *copy_commit_list(struct commit_list *list)
 445{
 446        struct commit_list *head = NULL;
 447        struct commit_list **pp = &head;
 448        while (list) {
 449                pp = commit_list_append(list->item, pp);
 450                list = list->next;
 451        }
 452        return head;
 453}
 454
 455void free_commit_list(struct commit_list *list)
 456{
 457        while (list)
 458                pop_commit(&list);
 459}
 460
 461struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 462{
 463        struct commit_list **pp = list;
 464        struct commit_list *p;
 465        while ((p = *pp) != NULL) {
 466                if (p->item->date < item->date) {
 467                        break;
 468                }
 469                pp = &p->next;
 470        }
 471        return commit_list_insert(item, pp);
 472}
 473
 474static int commit_list_compare_by_date(const void *a, const void *b)
 475{
 476        unsigned long a_date = ((const struct commit_list *)a)->item->date;
 477        unsigned long b_date = ((const struct commit_list *)b)->item->date;
 478        if (a_date < b_date)
 479                return 1;
 480        if (a_date > b_date)
 481                return -1;
 482        return 0;
 483}
 484
 485static void *commit_list_get_next(const void *a)
 486{
 487        return ((const struct commit_list *)a)->next;
 488}
 489
 490static void commit_list_set_next(void *a, void *next)
 491{
 492        ((struct commit_list *)a)->next = next;
 493}
 494
 495void commit_list_sort_by_date(struct commit_list **list)
 496{
 497        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 498                                commit_list_compare_by_date);
 499}
 500
 501struct commit *pop_most_recent_commit(struct commit_list **list,
 502                                      unsigned int mark)
 503{
 504        struct commit *ret = pop_commit(list);
 505        struct commit_list *parents = ret->parents;
 506
 507        while (parents) {
 508                struct commit *commit = parents->item;
 509                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 510                        commit->object.flags |= mark;
 511                        commit_list_insert_by_date(commit, list);
 512                }
 513                parents = parents->next;
 514        }
 515        return ret;
 516}
 517
 518static void clear_commit_marks_1(struct commit_list **plist,
 519                                 struct commit *commit, unsigned int mark)
 520{
 521        while (commit) {
 522                struct commit_list *parents;
 523
 524                if (!(mark & commit->object.flags))
 525                        return;
 526
 527                commit->object.flags &= ~mark;
 528
 529                parents = commit->parents;
 530                if (!parents)
 531                        return;
 532
 533                while ((parents = parents->next))
 534                        commit_list_insert(parents->item, plist);
 535
 536                commit = commit->parents->item;
 537        }
 538}
 539
 540void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 541{
 542        struct commit_list *list = NULL;
 543
 544        while (nr--) {
 545                commit_list_insert(*commit, &list);
 546                commit++;
 547        }
 548        while (list)
 549                clear_commit_marks_1(&list, pop_commit(&list), mark);
 550}
 551
 552void clear_commit_marks(struct commit *commit, unsigned int mark)
 553{
 554        clear_commit_marks_many(1, &commit, mark);
 555}
 556
 557void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
 558{
 559        struct object *object;
 560        struct commit *commit;
 561        unsigned int i;
 562
 563        for (i = 0; i < a->nr; i++) {
 564                object = a->objects[i].item;
 565                commit = lookup_commit_reference_gently(object->oid.hash, 1);
 566                if (commit)
 567                        clear_commit_marks(commit, mark);
 568        }
 569}
 570
 571struct commit *pop_commit(struct commit_list **stack)
 572{
 573        struct commit_list *top = *stack;
 574        struct commit *item = top ? top->item : NULL;
 575
 576        if (top) {
 577                *stack = top->next;
 578                free(top);
 579        }
 580        return item;
 581}
 582
 583/*
 584 * Topological sort support
 585 */
 586
 587/* count number of children that have not been emitted */
 588define_commit_slab(indegree_slab, int);
 589
 590/* record author-date for each commit object */
 591define_commit_slab(author_date_slab, unsigned long);
 592
 593static void record_author_date(struct author_date_slab *author_date,
 594                               struct commit *commit)
 595{
 596        const char *buffer = get_commit_buffer(commit, NULL);
 597        struct ident_split ident;
 598        const char *ident_line;
 599        size_t ident_len;
 600        char *date_end;
 601        unsigned long date;
 602
 603        ident_line = find_commit_header(buffer, "author", &ident_len);
 604        if (!ident_line)
 605                goto fail_exit; /* no author line */
 606        if (split_ident_line(&ident, ident_line, ident_len) ||
 607            !ident.date_begin || !ident.date_end)
 608                goto fail_exit; /* malformed "author" line */
 609
 610        date = strtoul(ident.date_begin, &date_end, 10);
 611        if (date_end != ident.date_end)
 612                goto fail_exit; /* malformed date */
 613        *(author_date_slab_at(author_date, commit)) = date;
 614
 615fail_exit:
 616        unuse_commit_buffer(commit, buffer);
 617}
 618
 619static int compare_commits_by_author_date(const void *a_, const void *b_,
 620                                          void *cb_data)
 621{
 622        const struct commit *a = a_, *b = b_;
 623        struct author_date_slab *author_date = cb_data;
 624        unsigned long a_date = *(author_date_slab_at(author_date, a));
 625        unsigned long b_date = *(author_date_slab_at(author_date, b));
 626
 627        /* newer commits with larger date first */
 628        if (a_date < b_date)
 629                return 1;
 630        else if (a_date > b_date)
 631                return -1;
 632        return 0;
 633}
 634
 635int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 636{
 637        const struct commit *a = a_, *b = b_;
 638        /* newer commits with larger date first */
 639        if (a->date < b->date)
 640                return 1;
 641        else if (a->date > b->date)
 642                return -1;
 643        return 0;
 644}
 645
 646/*
 647 * Performs an in-place topological sort on the list supplied.
 648 */
 649void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 650{
 651        struct commit_list *next, *orig = *list;
 652        struct commit_list **pptr;
 653        struct indegree_slab indegree;
 654        struct prio_queue queue;
 655        struct commit *commit;
 656        struct author_date_slab author_date;
 657
 658        if (!orig)
 659                return;
 660        *list = NULL;
 661
 662        init_indegree_slab(&indegree);
 663        memset(&queue, '\0', sizeof(queue));
 664
 665        switch (sort_order) {
 666        default: /* REV_SORT_IN_GRAPH_ORDER */
 667                queue.compare = NULL;
 668                break;
 669        case REV_SORT_BY_COMMIT_DATE:
 670                queue.compare = compare_commits_by_commit_date;
 671                break;
 672        case REV_SORT_BY_AUTHOR_DATE:
 673                init_author_date_slab(&author_date);
 674                queue.compare = compare_commits_by_author_date;
 675                queue.cb_data = &author_date;
 676                break;
 677        }
 678
 679        /* Mark them and clear the indegree */
 680        for (next = orig; next; next = next->next) {
 681                struct commit *commit = next->item;
 682                *(indegree_slab_at(&indegree, commit)) = 1;
 683                /* also record the author dates, if needed */
 684                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 685                        record_author_date(&author_date, commit);
 686        }
 687
 688        /* update the indegree */
 689        for (next = orig; next; next = next->next) {
 690                struct commit_list *parents = next->item->parents;
 691                while (parents) {
 692                        struct commit *parent = parents->item;
 693                        int *pi = indegree_slab_at(&indegree, parent);
 694
 695                        if (*pi)
 696                                (*pi)++;
 697                        parents = parents->next;
 698                }
 699        }
 700
 701        /*
 702         * find the tips
 703         *
 704         * tips are nodes not reachable from any other node in the list
 705         *
 706         * the tips serve as a starting set for the work queue.
 707         */
 708        for (next = orig; next; next = next->next) {
 709                struct commit *commit = next->item;
 710
 711                if (*(indegree_slab_at(&indegree, commit)) == 1)
 712                        prio_queue_put(&queue, commit);
 713        }
 714
 715        /*
 716         * This is unfortunate; the initial tips need to be shown
 717         * in the order given from the revision traversal machinery.
 718         */
 719        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 720                prio_queue_reverse(&queue);
 721
 722        /* We no longer need the commit list */
 723        free_commit_list(orig);
 724
 725        pptr = list;
 726        *list = NULL;
 727        while ((commit = prio_queue_get(&queue)) != NULL) {
 728                struct commit_list *parents;
 729
 730                for (parents = commit->parents; parents ; parents = parents->next) {
 731                        struct commit *parent = parents->item;
 732                        int *pi = indegree_slab_at(&indegree, parent);
 733
 734                        if (!*pi)
 735                                continue;
 736
 737                        /*
 738                         * parents are only enqueued for emission
 739                         * when all their children have been emitted thereby
 740                         * guaranteeing topological order.
 741                         */
 742                        if (--(*pi) == 1)
 743                                prio_queue_put(&queue, parent);
 744                }
 745                /*
 746                 * all children of commit have already been
 747                 * emitted. we can emit it now.
 748                 */
 749                *(indegree_slab_at(&indegree, commit)) = 0;
 750
 751                pptr = &commit_list_insert(commit, pptr)->next;
 752        }
 753
 754        clear_indegree_slab(&indegree);
 755        clear_prio_queue(&queue);
 756        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 757                clear_author_date_slab(&author_date);
 758}
 759
 760/* merge-base stuff */
 761
 762/* Remember to update object flag allocation in object.h */
 763#define PARENT1         (1u<<16)
 764#define PARENT2         (1u<<17)
 765#define STALE           (1u<<18)
 766#define RESULT          (1u<<19)
 767
 768static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 769
 770static int queue_has_nonstale(struct prio_queue *queue)
 771{
 772        int i;
 773        for (i = 0; i < queue->nr; i++) {
 774                struct commit *commit = queue->array[i].data;
 775                if (!(commit->object.flags & STALE))
 776                        return 1;
 777        }
 778        return 0;
 779}
 780
 781/* all input commits in one and twos[] must have been parsed! */
 782static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
 783{
 784        struct prio_queue queue = { compare_commits_by_commit_date };
 785        struct commit_list *result = NULL;
 786        int i;
 787
 788        one->object.flags |= PARENT1;
 789        if (!n) {
 790                commit_list_append(one, &result);
 791                return result;
 792        }
 793        prio_queue_put(&queue, one);
 794
 795        for (i = 0; i < n; i++) {
 796                twos[i]->object.flags |= PARENT2;
 797                prio_queue_put(&queue, twos[i]);
 798        }
 799
 800        while (queue_has_nonstale(&queue)) {
 801                struct commit *commit = prio_queue_get(&queue);
 802                struct commit_list *parents;
 803                int flags;
 804
 805                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 806                if (flags == (PARENT1 | PARENT2)) {
 807                        if (!(commit->object.flags & RESULT)) {
 808                                commit->object.flags |= RESULT;
 809                                commit_list_insert_by_date(commit, &result);
 810                        }
 811                        /* Mark parents of a found merge stale */
 812                        flags |= STALE;
 813                }
 814                parents = commit->parents;
 815                while (parents) {
 816                        struct commit *p = parents->item;
 817                        parents = parents->next;
 818                        if ((p->object.flags & flags) == flags)
 819                                continue;
 820                        if (parse_commit(p))
 821                                return NULL;
 822                        p->object.flags |= flags;
 823                        prio_queue_put(&queue, p);
 824                }
 825        }
 826
 827        clear_prio_queue(&queue);
 828        return result;
 829}
 830
 831static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 832{
 833        struct commit_list *list = NULL;
 834        struct commit_list *result = NULL;
 835        int i;
 836
 837        for (i = 0; i < n; i++) {
 838                if (one == twos[i])
 839                        /*
 840                         * We do not mark this even with RESULT so we do not
 841                         * have to clean it up.
 842                         */
 843                        return commit_list_insert(one, &result);
 844        }
 845
 846        if (parse_commit(one))
 847                return NULL;
 848        for (i = 0; i < n; i++) {
 849                if (parse_commit(twos[i]))
 850                        return NULL;
 851        }
 852
 853        list = paint_down_to_common(one, n, twos);
 854
 855        while (list) {
 856                struct commit *commit = pop_commit(&list);
 857                if (!(commit->object.flags & STALE))
 858                        commit_list_insert_by_date(commit, &result);
 859        }
 860        return result;
 861}
 862
 863struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 864{
 865        struct commit_list *i, *j, *k, *ret = NULL;
 866
 867        if (!in)
 868                return ret;
 869
 870        commit_list_insert(in->item, &ret);
 871
 872        for (i = in->next; i; i = i->next) {
 873                struct commit_list *new = NULL, *end = NULL;
 874
 875                for (j = ret; j; j = j->next) {
 876                        struct commit_list *bases;
 877                        bases = get_merge_bases(i->item, j->item);
 878                        if (!new)
 879                                new = bases;
 880                        else
 881                                end->next = bases;
 882                        for (k = bases; k; k = k->next)
 883                                end = k;
 884                }
 885                ret = new;
 886        }
 887        return ret;
 888}
 889
 890static int remove_redundant(struct commit **array, int cnt)
 891{
 892        /*
 893         * Some commit in the array may be an ancestor of
 894         * another commit.  Move such commit to the end of
 895         * the array, and return the number of commits that
 896         * are independent from each other.
 897         */
 898        struct commit **work;
 899        unsigned char *redundant;
 900        int *filled_index;
 901        int i, j, filled;
 902
 903        work = xcalloc(cnt, sizeof(*work));
 904        redundant = xcalloc(cnt, 1);
 905        ALLOC_ARRAY(filled_index, cnt - 1);
 906
 907        for (i = 0; i < cnt; i++)
 908                parse_commit(array[i]);
 909        for (i = 0; i < cnt; i++) {
 910                struct commit_list *common;
 911
 912                if (redundant[i])
 913                        continue;
 914                for (j = filled = 0; j < cnt; j++) {
 915                        if (i == j || redundant[j])
 916                                continue;
 917                        filled_index[filled] = j;
 918                        work[filled++] = array[j];
 919                }
 920                common = paint_down_to_common(array[i], filled, work);
 921                if (array[i]->object.flags & PARENT2)
 922                        redundant[i] = 1;
 923                for (j = 0; j < filled; j++)
 924                        if (work[j]->object.flags & PARENT1)
 925                                redundant[filled_index[j]] = 1;
 926                clear_commit_marks(array[i], all_flags);
 927                for (j = 0; j < filled; j++)
 928                        clear_commit_marks(work[j], all_flags);
 929                free_commit_list(common);
 930        }
 931
 932        /* Now collect the result */
 933        COPY_ARRAY(work, array, cnt);
 934        for (i = filled = 0; i < cnt; i++)
 935                if (!redundant[i])
 936                        array[filled++] = work[i];
 937        for (j = filled, i = 0; i < cnt; i++)
 938                if (redundant[i])
 939                        array[j++] = work[i];
 940        free(work);
 941        free(redundant);
 942        free(filled_index);
 943        return filled;
 944}
 945
 946static struct commit_list *get_merge_bases_many_0(struct commit *one,
 947                                                  int n,
 948                                                  struct commit **twos,
 949                                                  int cleanup)
 950{
 951        struct commit_list *list;
 952        struct commit **rslt;
 953        struct commit_list *result;
 954        int cnt, i;
 955
 956        result = merge_bases_many(one, n, twos);
 957        for (i = 0; i < n; i++) {
 958                if (one == twos[i])
 959                        return result;
 960        }
 961        if (!result || !result->next) {
 962                if (cleanup) {
 963                        clear_commit_marks(one, all_flags);
 964                        clear_commit_marks_many(n, twos, all_flags);
 965                }
 966                return result;
 967        }
 968
 969        /* There are more than one */
 970        cnt = commit_list_count(result);
 971        rslt = xcalloc(cnt, sizeof(*rslt));
 972        for (list = result, i = 0; list; list = list->next)
 973                rslt[i++] = list->item;
 974        free_commit_list(result);
 975
 976        clear_commit_marks(one, all_flags);
 977        clear_commit_marks_many(n, twos, all_flags);
 978
 979        cnt = remove_redundant(rslt, cnt);
 980        result = NULL;
 981        for (i = 0; i < cnt; i++)
 982                commit_list_insert_by_date(rslt[i], &result);
 983        free(rslt);
 984        return result;
 985}
 986
 987struct commit_list *get_merge_bases_many(struct commit *one,
 988                                         int n,
 989                                         struct commit **twos)
 990{
 991        return get_merge_bases_many_0(one, n, twos, 1);
 992}
 993
 994struct commit_list *get_merge_bases_many_dirty(struct commit *one,
 995                                               int n,
 996                                               struct commit **twos)
 997{
 998        return get_merge_bases_many_0(one, n, twos, 0);
 999}
1000
1001struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
1002{
1003        return get_merge_bases_many_0(one, 1, &two, 1);
1004}
1005
1006/*
1007 * Is "commit" a descendant of one of the elements on the "with_commit" list?
1008 */
1009int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
1010{
1011        if (!with_commit)
1012                return 1;
1013        while (with_commit) {
1014                struct commit *other;
1015
1016                other = with_commit->item;
1017                with_commit = with_commit->next;
1018                if (in_merge_bases(other, commit))
1019                        return 1;
1020        }
1021        return 0;
1022}
1023
1024/*
1025 * Is "commit" an ancestor of one of the "references"?
1026 */
1027int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1028{
1029        struct commit_list *bases;
1030        int ret = 0, i;
1031
1032        if (parse_commit(commit))
1033                return ret;
1034        for (i = 0; i < nr_reference; i++)
1035                if (parse_commit(reference[i]))
1036                        return ret;
1037
1038        bases = paint_down_to_common(commit, nr_reference, reference);
1039        if (commit->object.flags & PARENT2)
1040                ret = 1;
1041        clear_commit_marks(commit, all_flags);
1042        clear_commit_marks_many(nr_reference, reference, all_flags);
1043        free_commit_list(bases);
1044        return ret;
1045}
1046
1047/*
1048 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1049 */
1050int in_merge_bases(struct commit *commit, struct commit *reference)
1051{
1052        return in_merge_bases_many(commit, 1, &reference);
1053}
1054
1055struct commit_list *reduce_heads(struct commit_list *heads)
1056{
1057        struct commit_list *p;
1058        struct commit_list *result = NULL, **tail = &result;
1059        struct commit **array;
1060        int num_head, i;
1061
1062        if (!heads)
1063                return NULL;
1064
1065        /* Uniquify */
1066        for (p = heads; p; p = p->next)
1067                p->item->object.flags &= ~STALE;
1068        for (p = heads, num_head = 0; p; p = p->next) {
1069                if (p->item->object.flags & STALE)
1070                        continue;
1071                p->item->object.flags |= STALE;
1072                num_head++;
1073        }
1074        array = xcalloc(num_head, sizeof(*array));
1075        for (p = heads, i = 0; p; p = p->next) {
1076                if (p->item->object.flags & STALE) {
1077                        array[i++] = p->item;
1078                        p->item->object.flags &= ~STALE;
1079                }
1080        }
1081        num_head = remove_redundant(array, num_head);
1082        for (i = 0; i < num_head; i++)
1083                tail = &commit_list_insert(array[i], tail)->next;
1084        return result;
1085}
1086
1087static const char gpg_sig_header[] = "gpgsig";
1088static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1089
1090static int do_sign_commit(struct strbuf *buf, const char *keyid)
1091{
1092        struct strbuf sig = STRBUF_INIT;
1093        int inspos, copypos;
1094        const char *eoh;
1095
1096        /* find the end of the header */
1097        eoh = strstr(buf->buf, "\n\n");
1098        if (!eoh)
1099                inspos = buf->len;
1100        else
1101                inspos = eoh - buf->buf + 1;
1102
1103        if (!keyid || !*keyid)
1104                keyid = get_signing_key();
1105        if (sign_buffer(buf, &sig, keyid)) {
1106                strbuf_release(&sig);
1107                return -1;
1108        }
1109
1110        for (copypos = 0; sig.buf[copypos]; ) {
1111                const char *bol = sig.buf + copypos;
1112                const char *eol = strchrnul(bol, '\n');
1113                int len = (eol - bol) + !!*eol;
1114
1115                if (!copypos) {
1116                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1117                        inspos += gpg_sig_header_len;
1118                }
1119                strbuf_insert(buf, inspos++, " ", 1);
1120                strbuf_insert(buf, inspos, bol, len);
1121                inspos += len;
1122                copypos += len;
1123        }
1124        strbuf_release(&sig);
1125        return 0;
1126}
1127
1128int parse_signed_commit(const struct commit *commit,
1129                        struct strbuf *payload, struct strbuf *signature)
1130{
1131
1132        unsigned long size;
1133        const char *buffer = get_commit_buffer(commit, &size);
1134        int in_signature, saw_signature = -1;
1135        const char *line, *tail;
1136
1137        line = buffer;
1138        tail = buffer + size;
1139        in_signature = 0;
1140        saw_signature = 0;
1141        while (line < tail) {
1142                const char *sig = NULL;
1143                const char *next = memchr(line, '\n', tail - line);
1144
1145                next = next ? next + 1 : tail;
1146                if (in_signature && line[0] == ' ')
1147                        sig = line + 1;
1148                else if (starts_with(line, gpg_sig_header) &&
1149                         line[gpg_sig_header_len] == ' ')
1150                        sig = line + gpg_sig_header_len + 1;
1151                if (sig) {
1152                        strbuf_add(signature, sig, next - sig);
1153                        saw_signature = 1;
1154                        in_signature = 1;
1155                } else {
1156                        if (*line == '\n')
1157                                /* dump the whole remainder of the buffer */
1158                                next = tail;
1159                        strbuf_add(payload, line, next - line);
1160                        in_signature = 0;
1161                }
1162                line = next;
1163        }
1164        unuse_commit_buffer(commit, buffer);
1165        return saw_signature;
1166}
1167
1168int remove_signature(struct strbuf *buf)
1169{
1170        const char *line = buf->buf;
1171        const char *tail = buf->buf + buf->len;
1172        int in_signature = 0;
1173        const char *sig_start = NULL;
1174        const char *sig_end = NULL;
1175
1176        while (line < tail) {
1177                const char *next = memchr(line, '\n', tail - line);
1178                next = next ? next + 1 : tail;
1179
1180                if (in_signature && line[0] == ' ')
1181                        sig_end = next;
1182                else if (starts_with(line, gpg_sig_header) &&
1183                         line[gpg_sig_header_len] == ' ') {
1184                        sig_start = line;
1185                        sig_end = next;
1186                        in_signature = 1;
1187                } else {
1188                        if (*line == '\n')
1189                                /* dump the whole remainder of the buffer */
1190                                next = tail;
1191                        in_signature = 0;
1192                }
1193                line = next;
1194        }
1195
1196        if (sig_start)
1197                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1198
1199        return sig_start != NULL;
1200}
1201
1202static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1203{
1204        struct merge_remote_desc *desc;
1205        struct commit_extra_header *mergetag;
1206        char *buf;
1207        unsigned long size, len;
1208        enum object_type type;
1209
1210        desc = merge_remote_util(parent);
1211        if (!desc || !desc->obj)
1212                return;
1213        buf = read_sha1_file(desc->obj->oid.hash, &type, &size);
1214        if (!buf || type != OBJ_TAG)
1215                goto free_return;
1216        len = parse_signature(buf, size);
1217        if (size == len)
1218                goto free_return;
1219        /*
1220         * We could verify this signature and either omit the tag when
1221         * it does not validate, but the integrator may not have the
1222         * public key of the signer of the tag he is merging, while a
1223         * later auditor may have it while auditing, so let's not run
1224         * verify-signed-buffer here for now...
1225         *
1226         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1227         *      warn("warning: signed tag unverified.");
1228         */
1229        mergetag = xcalloc(1, sizeof(*mergetag));
1230        mergetag->key = xstrdup("mergetag");
1231        mergetag->value = buf;
1232        mergetag->len = size;
1233
1234        **tail = mergetag;
1235        *tail = &mergetag->next;
1236        return;
1237
1238free_return:
1239        free(buf);
1240}
1241
1242int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1243{
1244        struct strbuf payload = STRBUF_INIT;
1245        struct strbuf signature = STRBUF_INIT;
1246        int ret = 1;
1247
1248        sigc->result = 'N';
1249
1250        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1251                goto out;
1252        ret = check_signature(payload.buf, payload.len, signature.buf,
1253                signature.len, sigc);
1254
1255 out:
1256        strbuf_release(&payload);
1257        strbuf_release(&signature);
1258
1259        return ret;
1260}
1261
1262
1263
1264void append_merge_tag_headers(struct commit_list *parents,
1265                              struct commit_extra_header ***tail)
1266{
1267        while (parents) {
1268                struct commit *parent = parents->item;
1269                handle_signed_tag(parent, tail);
1270                parents = parents->next;
1271        }
1272}
1273
1274static void add_extra_header(struct strbuf *buffer,
1275                             struct commit_extra_header *extra)
1276{
1277        strbuf_addstr(buffer, extra->key);
1278        if (extra->len)
1279                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1280        else
1281                strbuf_addch(buffer, '\n');
1282}
1283
1284struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1285                                                      const char **exclude)
1286{
1287        struct commit_extra_header *extra = NULL;
1288        unsigned long size;
1289        const char *buffer = get_commit_buffer(commit, &size);
1290        extra = read_commit_extra_header_lines(buffer, size, exclude);
1291        unuse_commit_buffer(commit, buffer);
1292        return extra;
1293}
1294
1295void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1296{
1297        struct commit_extra_header *extra, *to_free;
1298
1299        to_free = read_commit_extra_headers(commit, NULL);
1300        for (extra = to_free; extra; extra = extra->next) {
1301                if (strcmp(extra->key, "mergetag"))
1302                        continue; /* not a merge tag */
1303                fn(commit, extra, data);
1304        }
1305        free_commit_extra_headers(to_free);
1306}
1307
1308static inline int standard_header_field(const char *field, size_t len)
1309{
1310        return ((len == 4 && !memcmp(field, "tree", 4)) ||
1311                (len == 6 && !memcmp(field, "parent", 6)) ||
1312                (len == 6 && !memcmp(field, "author", 6)) ||
1313                (len == 9 && !memcmp(field, "committer", 9)) ||
1314                (len == 8 && !memcmp(field, "encoding", 8)));
1315}
1316
1317static int excluded_header_field(const char *field, size_t len, const char **exclude)
1318{
1319        if (!exclude)
1320                return 0;
1321
1322        while (*exclude) {
1323                size_t xlen = strlen(*exclude);
1324                if (len == xlen && !memcmp(field, *exclude, xlen))
1325                        return 1;
1326                exclude++;
1327        }
1328        return 0;
1329}
1330
1331static struct commit_extra_header *read_commit_extra_header_lines(
1332        const char *buffer, size_t size,
1333        const char **exclude)
1334{
1335        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1336        const char *line, *next, *eof, *eob;
1337        struct strbuf buf = STRBUF_INIT;
1338
1339        for (line = buffer, eob = line + size;
1340             line < eob && *line != '\n';
1341             line = next) {
1342                next = memchr(line, '\n', eob - line);
1343                next = next ? next + 1 : eob;
1344                if (*line == ' ') {
1345                        /* continuation */
1346                        if (it)
1347                                strbuf_add(&buf, line + 1, next - (line + 1));
1348                        continue;
1349                }
1350                if (it)
1351                        it->value = strbuf_detach(&buf, &it->len);
1352                strbuf_reset(&buf);
1353                it = NULL;
1354
1355                eof = memchr(line, ' ', next - line);
1356                if (!eof)
1357                        eof = next;
1358                else if (standard_header_field(line, eof - line) ||
1359                         excluded_header_field(line, eof - line, exclude))
1360                        continue;
1361
1362                it = xcalloc(1, sizeof(*it));
1363                it->key = xmemdupz(line, eof-line);
1364                *tail = it;
1365                tail = &it->next;
1366                if (eof + 1 < next)
1367                        strbuf_add(&buf, eof + 1, next - (eof + 1));
1368        }
1369        if (it)
1370                it->value = strbuf_detach(&buf, &it->len);
1371        return extra;
1372}
1373
1374void free_commit_extra_headers(struct commit_extra_header *extra)
1375{
1376        while (extra) {
1377                struct commit_extra_header *next = extra->next;
1378                free(extra->key);
1379                free(extra->value);
1380                free(extra);
1381                extra = next;
1382        }
1383}
1384
1385int commit_tree(const char *msg, size_t msg_len,
1386                const unsigned char *tree,
1387                struct commit_list *parents, unsigned char *ret,
1388                const char *author, const char *sign_commit)
1389{
1390        struct commit_extra_header *extra = NULL, **tail = &extra;
1391        int result;
1392
1393        append_merge_tag_headers(parents, &tail);
1394        result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1395                                      author, sign_commit, extra);
1396        free_commit_extra_headers(extra);
1397        return result;
1398}
1399
1400static int find_invalid_utf8(const char *buf, int len)
1401{
1402        int offset = 0;
1403        static const unsigned int max_codepoint[] = {
1404                0x7f, 0x7ff, 0xffff, 0x10ffff
1405        };
1406
1407        while (len) {
1408                unsigned char c = *buf++;
1409                int bytes, bad_offset;
1410                unsigned int codepoint;
1411                unsigned int min_val, max_val;
1412
1413                len--;
1414                offset++;
1415
1416                /* Simple US-ASCII? No worries. */
1417                if (c < 0x80)
1418                        continue;
1419
1420                bad_offset = offset-1;
1421
1422                /*
1423                 * Count how many more high bits set: that's how
1424                 * many more bytes this sequence should have.
1425                 */
1426                bytes = 0;
1427                while (c & 0x40) {
1428                        c <<= 1;
1429                        bytes++;
1430                }
1431
1432                /*
1433                 * Must be between 1 and 3 more bytes.  Longer sequences result in
1434                 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1435                 */
1436                if (bytes < 1 || 3 < bytes)
1437                        return bad_offset;
1438
1439                /* Do we *have* that many bytes? */
1440                if (len < bytes)
1441                        return bad_offset;
1442
1443                /*
1444                 * Place the encoded bits at the bottom of the value and compute the
1445                 * valid range.
1446                 */
1447                codepoint = (c & 0x7f) >> bytes;
1448                min_val = max_codepoint[bytes-1] + 1;
1449                max_val = max_codepoint[bytes];
1450
1451                offset += bytes;
1452                len -= bytes;
1453
1454                /* And verify that they are good continuation bytes */
1455                do {
1456                        codepoint <<= 6;
1457                        codepoint |= *buf & 0x3f;
1458                        if ((*buf++ & 0xc0) != 0x80)
1459                                return bad_offset;
1460                } while (--bytes);
1461
1462                /* Reject codepoints that are out of range for the sequence length. */
1463                if (codepoint < min_val || codepoint > max_val)
1464                        return bad_offset;
1465                /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1466                if ((codepoint & 0x1ff800) == 0xd800)
1467                        return bad_offset;
1468                /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1469                if ((codepoint & 0xfffe) == 0xfffe)
1470                        return bad_offset;
1471                /* So are anything in the range U+FDD0..U+FDEF. */
1472                if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1473                        return bad_offset;
1474        }
1475        return -1;
1476}
1477
1478/*
1479 * This verifies that the buffer is in proper utf8 format.
1480 *
1481 * If it isn't, it assumes any non-utf8 characters are Latin1,
1482 * and does the conversion.
1483 */
1484static int verify_utf8(struct strbuf *buf)
1485{
1486        int ok = 1;
1487        long pos = 0;
1488
1489        for (;;) {
1490                int bad;
1491                unsigned char c;
1492                unsigned char replace[2];
1493
1494                bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1495                if (bad < 0)
1496                        return ok;
1497                pos += bad;
1498                ok = 0;
1499                c = buf->buf[pos];
1500                strbuf_remove(buf, pos, 1);
1501
1502                /* We know 'c' must be in the range 128-255 */
1503                replace[0] = 0xc0 + (c >> 6);
1504                replace[1] = 0x80 + (c & 0x3f);
1505                strbuf_insert(buf, pos, replace, 2);
1506                pos += 2;
1507        }
1508}
1509
1510static const char commit_utf8_warn[] =
1511N_("Warning: commit message did not conform to UTF-8.\n"
1512   "You may want to amend it after fixing the message, or set the config\n"
1513   "variable i18n.commitencoding to the encoding your project uses.\n");
1514
1515int commit_tree_extended(const char *msg, size_t msg_len,
1516                         const unsigned char *tree,
1517                         struct commit_list *parents, unsigned char *ret,
1518                         const char *author, const char *sign_commit,
1519                         struct commit_extra_header *extra)
1520{
1521        int result;
1522        int encoding_is_utf8;
1523        struct strbuf buffer;
1524
1525        assert_sha1_type(tree, OBJ_TREE);
1526
1527        if (memchr(msg, '\0', msg_len))
1528                return error("a NUL byte in commit log message not allowed.");
1529
1530        /* Not having i18n.commitencoding is the same as having utf-8 */
1531        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1532
1533        strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1534        strbuf_addf(&buffer, "tree %s\n", sha1_to_hex(tree));
1535
1536        /*
1537         * NOTE! This ordering means that the same exact tree merged with a
1538         * different order of parents will be a _different_ changeset even
1539         * if everything else stays the same.
1540         */
1541        while (parents) {
1542                struct commit *parent = pop_commit(&parents);
1543                strbuf_addf(&buffer, "parent %s\n",
1544                            oid_to_hex(&parent->object.oid));
1545        }
1546
1547        /* Person/date information */
1548        if (!author)
1549                author = git_author_info(IDENT_STRICT);
1550        strbuf_addf(&buffer, "author %s\n", author);
1551        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1552        if (!encoding_is_utf8)
1553                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1554
1555        while (extra) {
1556                add_extra_header(&buffer, extra);
1557                extra = extra->next;
1558        }
1559        strbuf_addch(&buffer, '\n');
1560
1561        /* And add the comment */
1562        strbuf_add(&buffer, msg, msg_len);
1563
1564        /* And check the encoding */
1565        if (encoding_is_utf8 && !verify_utf8(&buffer))
1566                fprintf(stderr, _(commit_utf8_warn));
1567
1568        if (sign_commit && do_sign_commit(&buffer, sign_commit))
1569                return -1;
1570
1571        result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
1572        strbuf_release(&buffer);
1573        return result;
1574}
1575
1576void set_merge_remote_desc(struct commit *commit,
1577                           const char *name, struct object *obj)
1578{
1579        struct merge_remote_desc *desc;
1580        FLEX_ALLOC_STR(desc, name, name);
1581        desc->obj = obj;
1582        commit->util = desc;
1583}
1584
1585struct commit *get_merge_parent(const char *name)
1586{
1587        struct object *obj;
1588        struct commit *commit;
1589        struct object_id oid;
1590        if (get_sha1(name, oid.hash))
1591                return NULL;
1592        obj = parse_object(oid.hash);
1593        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1594        if (commit && !commit->util)
1595                set_merge_remote_desc(commit, name, obj);
1596        return commit;
1597}
1598
1599/*
1600 * Append a commit to the end of the commit_list.
1601 *
1602 * next starts by pointing to the variable that holds the head of an
1603 * empty commit_list, and is updated to point to the "next" field of
1604 * the last item on the list as new commits are appended.
1605 *
1606 * Usage example:
1607 *
1608 *     struct commit_list *list;
1609 *     struct commit_list **next = &list;
1610 *
1611 *     next = commit_list_append(c1, next);
1612 *     next = commit_list_append(c2, next);
1613 *     assert(commit_list_count(list) == 2);
1614 *     return list;
1615 */
1616struct commit_list **commit_list_append(struct commit *commit,
1617                                        struct commit_list **next)
1618{
1619        struct commit_list *new = xmalloc(sizeof(struct commit_list));
1620        new->item = commit;
1621        *next = new;
1622        new->next = NULL;
1623        return &new->next;
1624}
1625
1626const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1627{
1628        int key_len = strlen(key);
1629        const char *line = msg;
1630
1631        while (line) {
1632                const char *eol = strchrnul(line, '\n');
1633
1634                if (line == eol)
1635                        return NULL;
1636
1637                if (eol - line > key_len &&
1638                    !strncmp(line, key, key_len) &&
1639                    line[key_len] == ' ') {
1640                        *out_len = eol - line - key_len - 1;
1641                        return line + key_len + 1;
1642                }
1643                line = *eol ? eol + 1 : NULL;
1644        }
1645        return NULL;
1646}
1647
1648/*
1649 * Inspect the given string and determine the true "end" of the log message, in
1650 * order to find where to put a new Signed-off-by: line.  Ignored are
1651 * trailing comment lines and blank lines, and also the traditional
1652 * "Conflicts:" block that is not commented out, so that we can use
1653 * "git commit -s --amend" on an existing commit that forgot to remove
1654 * it.
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
1665        while (bol < len) {
1666                const char *next_line = memchr(buf + bol, '\n', len - bol);
1667
1668                if (!next_line)
1669                        next_line = buf + len;
1670                else
1671                        next_line++;
1672
1673                if (buf[bol] == comment_line_char || buf[bol] == '\n') {
1674                        /* is this the first of the run of comments? */
1675                        if (!boc)
1676                                boc = bol;
1677                        /* otherwise, it is just continuing */
1678                } else if (starts_with(buf + bol, "Conflicts:\n")) {
1679                        in_old_conflicts_block = 1;
1680                        if (!boc)
1681                                boc = bol;
1682                } else if (in_old_conflicts_block && buf[bol] == '\t') {
1683                        ; /* a pathname in the conflicts block */
1684                } else if (boc) {
1685                        /* the previous was not trailing comment */
1686                        boc = 0;
1687                        in_old_conflicts_block = 0;
1688                }
1689                bol = next_line - buf;
1690        }
1691        return boc ? len - boc : 0;
1692}