Andrew's git / gitweb.git / commit.c
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commit.con commit list-objects: convert name_path to a strbuf (13528ab)
   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(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_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 += 2;
 418                for (eol = p; *eol && *eol != '\n'; eol++)
 419                        ; /* do nothing */
 420        } else
 421                eol = p;
 422
 423        *subject = p;
 424
 425        return eol - p;
 426}
 427
 428struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 429{
 430        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 431        new_list->item = item;
 432        new_list->next = *list_p;
 433        *list_p = new_list;
 434        return new_list;
 435}
 436
 437unsigned commit_list_count(const struct commit_list *l)
 438{
 439        unsigned c = 0;
 440        for (; l; l = l->next )
 441                c++;
 442        return c;
 443}
 444
 445struct commit_list *copy_commit_list(struct commit_list *list)
 446{
 447        struct commit_list *head = NULL;
 448        struct commit_list **pp = &head;
 449        while (list) {
 450                pp = commit_list_append(list->item, pp);
 451                list = list->next;
 452        }
 453        return head;
 454}
 455
 456void free_commit_list(struct commit_list *list)
 457{
 458        while (list)
 459                pop_commit(&list);
 460}
 461
 462struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 463{
 464        struct commit_list **pp = list;
 465        struct commit_list *p;
 466        while ((p = *pp) != NULL) {
 467                if (p->item->date < item->date) {
 468                        break;
 469                }
 470                pp = &p->next;
 471        }
 472        return commit_list_insert(item, pp);
 473}
 474
 475static int commit_list_compare_by_date(const void *a, const void *b)
 476{
 477        unsigned long a_date = ((const struct commit_list *)a)->item->date;
 478        unsigned long b_date = ((const struct commit_list *)b)->item->date;
 479        if (a_date < b_date)
 480                return 1;
 481        if (a_date > b_date)
 482                return -1;
 483        return 0;
 484}
 485
 486static void *commit_list_get_next(const void *a)
 487{
 488        return ((const struct commit_list *)a)->next;
 489}
 490
 491static void commit_list_set_next(void *a, void *next)
 492{
 493        ((struct commit_list *)a)->next = next;
 494}
 495
 496void commit_list_sort_by_date(struct commit_list **list)
 497{
 498        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 499                                commit_list_compare_by_date);
 500}
 501
 502struct commit *pop_most_recent_commit(struct commit_list **list,
 503                                      unsigned int mark)
 504{
 505        struct commit *ret = pop_commit(list);
 506        struct commit_list *parents = ret->parents;
 507
 508        while (parents) {
 509                struct commit *commit = parents->item;
 510                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 511                        commit->object.flags |= mark;
 512                        commit_list_insert_by_date(commit, list);
 513                }
 514                parents = parents->next;
 515        }
 516        return ret;
 517}
 518
 519static void clear_commit_marks_1(struct commit_list **plist,
 520                                 struct commit *commit, unsigned int mark)
 521{
 522        while (commit) {
 523                struct commit_list *parents;
 524
 525                if (!(mark & commit->object.flags))
 526                        return;
 527
 528                commit->object.flags &= ~mark;
 529
 530                parents = commit->parents;
 531                if (!parents)
 532                        return;
 533
 534                while ((parents = parents->next))
 535                        commit_list_insert(parents->item, plist);
 536
 537                commit = commit->parents->item;
 538        }
 539}
 540
 541void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 542{
 543        struct commit_list *list = NULL;
 544
 545        while (nr--) {
 546                commit_list_insert(*commit, &list);
 547                commit++;
 548        }
 549        while (list)
 550                clear_commit_marks_1(&list, pop_commit(&list), mark);
 551}
 552
 553void clear_commit_marks(struct commit *commit, unsigned int mark)
 554{
 555        clear_commit_marks_many(1, &commit, mark);
 556}
 557
 558void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
 559{
 560        struct object *object;
 561        struct commit *commit;
 562        unsigned int i;
 563
 564        for (i = 0; i < a->nr; i++) {
 565                object = a->objects[i].item;
 566                commit = lookup_commit_reference_gently(object->oid.hash, 1);
 567                if (commit)
 568                        clear_commit_marks(commit, mark);
 569        }
 570}
 571
 572struct commit *pop_commit(struct commit_list **stack)
 573{
 574        struct commit_list *top = *stack;
 575        struct commit *item = top ? top->item : NULL;
 576
 577        if (top) {
 578                *stack = top->next;
 579                free(top);
 580        }
 581        return item;
 582}
 583
 584/*
 585 * Topological sort support
 586 */
 587
 588/* count number of children that have not been emitted */
 589define_commit_slab(indegree_slab, int);
 590
 591/* record author-date for each commit object */
 592define_commit_slab(author_date_slab, unsigned long);
 593
 594static void record_author_date(struct author_date_slab *author_date,
 595                               struct commit *commit)
 596{
 597        const char *buffer = get_commit_buffer(commit, NULL);
 598        struct ident_split ident;
 599        const char *ident_line;
 600        size_t ident_len;
 601        char *date_end;
 602        unsigned long date;
 603
 604        ident_line = find_commit_header(buffer, "author", &ident_len);
 605        if (!ident_line)
 606                goto fail_exit; /* no author line */
 607        if (split_ident_line(&ident, ident_line, ident_len) ||
 608            !ident.date_begin || !ident.date_end)
 609                goto fail_exit; /* malformed "author" line */
 610
 611        date = strtoul(ident.date_begin, &date_end, 10);
 612        if (date_end != ident.date_end)
 613                goto fail_exit; /* malformed date */
 614        *(author_date_slab_at(author_date, commit)) = date;
 615
 616fail_exit:
 617        unuse_commit_buffer(commit, buffer);
 618}
 619
 620static int compare_commits_by_author_date(const void *a_, const void *b_,
 621                                          void *cb_data)
 622{
 623        const struct commit *a = a_, *b = b_;
 624        struct author_date_slab *author_date = cb_data;
 625        unsigned long a_date = *(author_date_slab_at(author_date, a));
 626        unsigned long b_date = *(author_date_slab_at(author_date, b));
 627
 628        /* newer commits with larger date first */
 629        if (a_date < b_date)
 630                return 1;
 631        else if (a_date > b_date)
 632                return -1;
 633        return 0;
 634}
 635
 636int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 637{
 638        const struct commit *a = a_, *b = b_;
 639        /* newer commits with larger date first */
 640        if (a->date < b->date)
 641                return 1;
 642        else if (a->date > b->date)
 643                return -1;
 644        return 0;
 645}
 646
 647/*
 648 * Performs an in-place topological sort on the list supplied.
 649 */
 650void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 651{
 652        struct commit_list *next, *orig = *list;
 653        struct commit_list **pptr;
 654        struct indegree_slab indegree;
 655        struct prio_queue queue;
 656        struct commit *commit;
 657        struct author_date_slab author_date;
 658
 659        if (!orig)
 660                return;
 661        *list = NULL;
 662
 663        init_indegree_slab(&indegree);
 664        memset(&queue, '\0', sizeof(queue));
 665
 666        switch (sort_order) {
 667        default: /* REV_SORT_IN_GRAPH_ORDER */
 668                queue.compare = NULL;
 669                break;
 670        case REV_SORT_BY_COMMIT_DATE:
 671                queue.compare = compare_commits_by_commit_date;
 672                break;
 673        case REV_SORT_BY_AUTHOR_DATE:
 674                init_author_date_slab(&author_date);
 675                queue.compare = compare_commits_by_author_date;
 676                queue.cb_data = &author_date;
 677                break;
 678        }
 679
 680        /* Mark them and clear the indegree */
 681        for (next = orig; next; next = next->next) {
 682                struct commit *commit = next->item;
 683                *(indegree_slab_at(&indegree, commit)) = 1;
 684                /* also record the author dates, if needed */
 685                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 686                        record_author_date(&author_date, commit);
 687        }
 688
 689        /* update the indegree */
 690        for (next = orig; next; next = next->next) {
 691                struct commit_list *parents = next->item->parents;
 692                while (parents) {
 693                        struct commit *parent = parents->item;
 694                        int *pi = indegree_slab_at(&indegree, parent);
 695
 696                        if (*pi)
 697                                (*pi)++;
 698                        parents = parents->next;
 699                }
 700        }
 701
 702        /*
 703         * find the tips
 704         *
 705         * tips are nodes not reachable from any other node in the list
 706         *
 707         * the tips serve as a starting set for the work queue.
 708         */
 709        for (next = orig; next; next = next->next) {
 710                struct commit *commit = next->item;
 711
 712                if (*(indegree_slab_at(&indegree, commit)) == 1)
 713                        prio_queue_put(&queue, commit);
 714        }
 715
 716        /*
 717         * This is unfortunate; the initial tips need to be shown
 718         * in the order given from the revision traversal machinery.
 719         */
 720        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 721                prio_queue_reverse(&queue);
 722
 723        /* We no longer need the commit list */
 724        free_commit_list(orig);
 725
 726        pptr = list;
 727        *list = NULL;
 728        while ((commit = prio_queue_get(&queue)) != NULL) {
 729                struct commit_list *parents;
 730
 731                for (parents = commit->parents; parents ; parents = parents->next) {
 732                        struct commit *parent = parents->item;
 733                        int *pi = indegree_slab_at(&indegree, parent);
 734
 735                        if (!*pi)
 736                                continue;
 737
 738                        /*
 739                         * parents are only enqueued for emission
 740                         * when all their children have been emitted thereby
 741                         * guaranteeing topological order.
 742                         */
 743                        if (--(*pi) == 1)
 744                                prio_queue_put(&queue, parent);
 745                }
 746                /*
 747                 * all children of commit have already been
 748                 * emitted. we can emit it now.
 749                 */
 750                *(indegree_slab_at(&indegree, commit)) = 0;
 751
 752                pptr = &commit_list_insert(commit, pptr)->next;
 753        }
 754
 755        clear_indegree_slab(&indegree);
 756        clear_prio_queue(&queue);
 757        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 758                clear_author_date_slab(&author_date);
 759}
 760
 761/* merge-base stuff */
 762
 763/* Remember to update object flag allocation in object.h */
 764#define PARENT1         (1u<<16)
 765#define PARENT2         (1u<<17)
 766#define STALE           (1u<<18)
 767#define RESULT          (1u<<19)
 768
 769static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 770
 771static int queue_has_nonstale(struct prio_queue *queue)
 772{
 773        int i;
 774        for (i = 0; i < queue->nr; i++) {
 775                struct commit *commit = queue->array[i].data;
 776                if (!(commit->object.flags & STALE))
 777                        return 1;
 778        }
 779        return 0;
 780}
 781
 782/* all input commits in one and twos[] must have been parsed! */
 783static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
 784{
 785        struct prio_queue queue = { compare_commits_by_commit_date };
 786        struct commit_list *result = NULL;
 787        int i;
 788
 789        one->object.flags |= PARENT1;
 790        if (!n) {
 791                commit_list_append(one, &result);
 792                return result;
 793        }
 794        prio_queue_put(&queue, one);
 795
 796        for (i = 0; i < n; i++) {
 797                twos[i]->object.flags |= PARENT2;
 798                prio_queue_put(&queue, twos[i]);
 799        }
 800
 801        while (queue_has_nonstale(&queue)) {
 802                struct commit *commit = prio_queue_get(&queue);
 803                struct commit_list *parents;
 804                int flags;
 805
 806                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 807                if (flags == (PARENT1 | PARENT2)) {
 808                        if (!(commit->object.flags & RESULT)) {
 809                                commit->object.flags |= RESULT;
 810                                commit_list_insert_by_date(commit, &result);
 811                        }
 812                        /* Mark parents of a found merge stale */
 813                        flags |= STALE;
 814                }
 815                parents = commit->parents;
 816                while (parents) {
 817                        struct commit *p = parents->item;
 818                        parents = parents->next;
 819                        if ((p->object.flags & flags) == flags)
 820                                continue;
 821                        if (parse_commit(p))
 822                                return NULL;
 823                        p->object.flags |= flags;
 824                        prio_queue_put(&queue, p);
 825                }
 826        }
 827
 828        clear_prio_queue(&queue);
 829        return result;
 830}
 831
 832static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 833{
 834        struct commit_list *list = NULL;
 835        struct commit_list *result = NULL;
 836        int i;
 837
 838        for (i = 0; i < n; i++) {
 839                if (one == twos[i])
 840                        /*
 841                         * We do not mark this even with RESULT so we do not
 842                         * have to clean it up.
 843                         */
 844                        return commit_list_insert(one, &result);
 845        }
 846
 847        if (parse_commit(one))
 848                return NULL;
 849        for (i = 0; i < n; i++) {
 850                if (parse_commit(twos[i]))
 851                        return NULL;
 852        }
 853
 854        list = paint_down_to_common(one, n, twos);
 855
 856        while (list) {
 857                struct commit *commit = pop_commit(&list);
 858                if (!(commit->object.flags & STALE))
 859                        commit_list_insert_by_date(commit, &result);
 860        }
 861        return result;
 862}
 863
 864struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 865{
 866        struct commit_list *i, *j, *k, *ret = NULL;
 867
 868        if (!in)
 869                return ret;
 870
 871        commit_list_insert(in->item, &ret);
 872
 873        for (i = in->next; i; i = i->next) {
 874                struct commit_list *new = NULL, *end = NULL;
 875
 876                for (j = ret; j; j = j->next) {
 877                        struct commit_list *bases;
 878                        bases = get_merge_bases(i->item, j->item);
 879                        if (!new)
 880                                new = bases;
 881                        else
 882                                end->next = bases;
 883                        for (k = bases; k; k = k->next)
 884                                end = k;
 885                }
 886                ret = new;
 887        }
 888        return ret;
 889}
 890
 891static int remove_redundant(struct commit **array, int cnt)
 892{
 893        /*
 894         * Some commit in the array may be an ancestor of
 895         * another commit.  Move such commit to the end of
 896         * the array, and return the number of commits that
 897         * are independent from each other.
 898         */
 899        struct commit **work;
 900        unsigned char *redundant;
 901        int *filled_index;
 902        int i, j, filled;
 903
 904        work = xcalloc(cnt, sizeof(*work));
 905        redundant = xcalloc(cnt, 1);
 906        filled_index = xmalloc(sizeof(*filled_index) * (cnt - 1));
 907
 908        for (i = 0; i < cnt; i++)
 909                parse_commit(array[i]);
 910        for (i = 0; i < cnt; i++) {
 911                struct commit_list *common;
 912
 913                if (redundant[i])
 914                        continue;
 915                for (j = filled = 0; j < cnt; j++) {
 916                        if (i == j || redundant[j])
 917                                continue;
 918                        filled_index[filled] = j;
 919                        work[filled++] = array[j];
 920                }
 921                common = paint_down_to_common(array[i], filled, work);
 922                if (array[i]->object.flags & PARENT2)
 923                        redundant[i] = 1;
 924                for (j = 0; j < filled; j++)
 925                        if (work[j]->object.flags & PARENT1)
 926                                redundant[filled_index[j]] = 1;
 927                clear_commit_marks(array[i], all_flags);
 928                for (j = 0; j < filled; j++)
 929                        clear_commit_marks(work[j], all_flags);
 930                free_commit_list(common);
 931        }
 932
 933        /* Now collect the result */
 934        memcpy(work, array, sizeof(*array) * cnt);
 935        for (i = filled = 0; i < cnt; i++)
 936                if (!redundant[i])
 937                        array[filled++] = work[i];
 938        for (j = filled, i = 0; i < cnt; i++)
 939                if (redundant[i])
 940                        array[j++] = work[i];
 941        free(work);
 942        free(redundant);
 943        free(filled_index);
 944        return filled;
 945}
 946
 947static struct commit_list *get_merge_bases_many_0(struct commit *one,
 948                                                  int n,
 949                                                  struct commit **twos,
 950                                                  int cleanup)
 951{
 952        struct commit_list *list;
 953        struct commit **rslt;
 954        struct commit_list *result;
 955        int cnt, i;
 956
 957        result = merge_bases_many(one, n, twos);
 958        for (i = 0; i < n; i++) {
 959                if (one == twos[i])
 960                        return result;
 961        }
 962        if (!result || !result->next) {
 963                if (cleanup) {
 964                        clear_commit_marks(one, all_flags);
 965                        clear_commit_marks_many(n, twos, all_flags);
 966                }
 967                return result;
 968        }
 969
 970        /* There are more than one */
 971        cnt = commit_list_count(result);
 972        rslt = xcalloc(cnt, sizeof(*rslt));
 973        for (list = result, i = 0; list; list = list->next)
 974                rslt[i++] = list->item;
 975        free_commit_list(result);
 976
 977        clear_commit_marks(one, all_flags);
 978        clear_commit_marks_many(n, twos, all_flags);
 979
 980        cnt = remove_redundant(rslt, cnt);
 981        result = NULL;
 982        for (i = 0; i < cnt; i++)
 983                commit_list_insert_by_date(rslt[i], &result);
 984        free(rslt);
 985        return result;
 986}
 987
 988struct commit_list *get_merge_bases_many(struct commit *one,
 989                                         int n,
 990                                         struct commit **twos)
 991{
 992        return get_merge_bases_many_0(one, n, twos, 1);
 993}
 994
 995struct commit_list *get_merge_bases_many_dirty(struct commit *one,
 996                                               int n,
 997                                               struct commit **twos)
 998{
 999        return get_merge_bases_many_0(one, n, twos, 0);
1000}
1001
1002struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
1003{
1004        return get_merge_bases_many_0(one, 1, &two, 1);
1005}
1006
1007/*
1008 * Is "commit" a descendant of one of the elements on the "with_commit" list?
1009 */
1010int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
1011{
1012        if (!with_commit)
1013                return 1;
1014        while (with_commit) {
1015                struct commit *other;
1016
1017                other = with_commit->item;
1018                with_commit = with_commit->next;
1019                if (in_merge_bases(other, commit))
1020                        return 1;
1021        }
1022        return 0;
1023}
1024
1025/*
1026 * Is "commit" an ancestor of one of the "references"?
1027 */
1028int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1029{
1030        struct commit_list *bases;
1031        int ret = 0, i;
1032
1033        if (parse_commit(commit))
1034                return ret;
1035        for (i = 0; i < nr_reference; i++)
1036                if (parse_commit(reference[i]))
1037                        return ret;
1038
1039        bases = paint_down_to_common(commit, nr_reference, reference);
1040        if (commit->object.flags & PARENT2)
1041                ret = 1;
1042        clear_commit_marks(commit, all_flags);
1043        clear_commit_marks_many(nr_reference, reference, all_flags);
1044        free_commit_list(bases);
1045        return ret;
1046}
1047
1048/*
1049 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1050 */
1051int in_merge_bases(struct commit *commit, struct commit *reference)
1052{
1053        return in_merge_bases_many(commit, 1, &reference);
1054}
1055
1056struct commit_list *reduce_heads(struct commit_list *heads)
1057{
1058        struct commit_list *p;
1059        struct commit_list *result = NULL, **tail = &result;
1060        struct commit **array;
1061        int num_head, i;
1062
1063        if (!heads)
1064                return NULL;
1065
1066        /* Uniquify */
1067        for (p = heads; p; p = p->next)
1068                p->item->object.flags &= ~STALE;
1069        for (p = heads, num_head = 0; p; p = p->next) {
1070                if (p->item->object.flags & STALE)
1071                        continue;
1072                p->item->object.flags |= STALE;
1073                num_head++;
1074        }
1075        array = xcalloc(num_head, sizeof(*array));
1076        for (p = heads, i = 0; p; p = p->next) {
1077                if (p->item->object.flags & STALE) {
1078                        array[i++] = p->item;
1079                        p->item->object.flags &= ~STALE;
1080                }
1081        }
1082        num_head = remove_redundant(array, num_head);
1083        for (i = 0; i < num_head; i++)
1084                tail = &commit_list_insert(array[i], tail)->next;
1085        return result;
1086}
1087
1088static const char gpg_sig_header[] = "gpgsig";
1089static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1090
1091static int do_sign_commit(struct strbuf *buf, const char *keyid)
1092{
1093        struct strbuf sig = STRBUF_INIT;
1094        int inspos, copypos;
1095
1096        /* find the end of the header */
1097        inspos = strstr(buf->buf, "\n\n") - buf->buf + 1;
1098
1099        if (!keyid || !*keyid)
1100                keyid = get_signing_key();
1101        if (sign_buffer(buf, &sig, keyid)) {
1102                strbuf_release(&sig);
1103                return -1;
1104        }
1105
1106        for (copypos = 0; sig.buf[copypos]; ) {
1107                const char *bol = sig.buf + copypos;
1108                const char *eol = strchrnul(bol, '\n');
1109                int len = (eol - bol) + !!*eol;
1110
1111                if (!copypos) {
1112                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1113                        inspos += gpg_sig_header_len;
1114                }
1115                strbuf_insert(buf, inspos++, " ", 1);
1116                strbuf_insert(buf, inspos, bol, len);
1117                inspos += len;
1118                copypos += len;
1119        }
1120        strbuf_release(&sig);
1121        return 0;
1122}
1123
1124int parse_signed_commit(const struct commit *commit,
1125                        struct strbuf *payload, struct strbuf *signature)
1126{
1127
1128        unsigned long size;
1129        const char *buffer = get_commit_buffer(commit, &size);
1130        int in_signature, saw_signature = -1;
1131        const char *line, *tail;
1132
1133        line = buffer;
1134        tail = buffer + size;
1135        in_signature = 0;
1136        saw_signature = 0;
1137        while (line < tail) {
1138                const char *sig = NULL;
1139                const char *next = memchr(line, '\n', tail - line);
1140
1141                next = next ? next + 1 : tail;
1142                if (in_signature && line[0] == ' ')
1143                        sig = line + 1;
1144                else if (starts_with(line, gpg_sig_header) &&
1145                         line[gpg_sig_header_len] == ' ')
1146                        sig = line + gpg_sig_header_len + 1;
1147                if (sig) {
1148                        strbuf_add(signature, sig, next - sig);
1149                        saw_signature = 1;
1150                        in_signature = 1;
1151                } else {
1152                        if (*line == '\n')
1153                                /* dump the whole remainder of the buffer */
1154                                next = tail;
1155                        strbuf_add(payload, line, next - line);
1156                        in_signature = 0;
1157                }
1158                line = next;
1159        }
1160        unuse_commit_buffer(commit, buffer);
1161        return saw_signature;
1162}
1163
1164int remove_signature(struct strbuf *buf)
1165{
1166        const char *line = buf->buf;
1167        const char *tail = buf->buf + buf->len;
1168        int in_signature = 0;
1169        const char *sig_start = NULL;
1170        const char *sig_end = NULL;
1171
1172        while (line < tail) {
1173                const char *next = memchr(line, '\n', tail - line);
1174                next = next ? next + 1 : tail;
1175
1176                if (in_signature && line[0] == ' ')
1177                        sig_end = next;
1178                else if (starts_with(line, gpg_sig_header) &&
1179                         line[gpg_sig_header_len] == ' ') {
1180                        sig_start = line;
1181                        sig_end = next;
1182                        in_signature = 1;
1183                } else {
1184                        if (*line == '\n')
1185                                /* dump the whole remainder of the buffer */
1186                                next = tail;
1187                        in_signature = 0;
1188                }
1189                line = next;
1190        }
1191
1192        if (sig_start)
1193                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1194
1195        return sig_start != NULL;
1196}
1197
1198static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1199{
1200        struct merge_remote_desc *desc;
1201        struct commit_extra_header *mergetag;
1202        char *buf;
1203        unsigned long size, len;
1204        enum object_type type;
1205
1206        desc = merge_remote_util(parent);
1207        if (!desc || !desc->obj)
1208                return;
1209        buf = read_sha1_file(desc->obj->oid.hash, &type, &size);
1210        if (!buf || type != OBJ_TAG)
1211                goto free_return;
1212        len = parse_signature(buf, size);
1213        if (size == len)
1214                goto free_return;
1215        /*
1216         * We could verify this signature and either omit the tag when
1217         * it does not validate, but the integrator may not have the
1218         * public key of the signer of the tag he is merging, while a
1219         * later auditor may have it while auditing, so let's not run
1220         * verify-signed-buffer here for now...
1221         *
1222         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1223         *      warn("warning: signed tag unverified.");
1224         */
1225        mergetag = xcalloc(1, sizeof(*mergetag));
1226        mergetag->key = xstrdup("mergetag");
1227        mergetag->value = buf;
1228        mergetag->len = size;
1229
1230        **tail = mergetag;
1231        *tail = &mergetag->next;
1232        return;
1233
1234free_return:
1235        free(buf);
1236}
1237
1238int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1239{
1240        struct strbuf payload = STRBUF_INIT;
1241        struct strbuf signature = STRBUF_INIT;
1242        int ret = 1;
1243
1244        sigc->result = 'N';
1245
1246        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1247                goto out;
1248        ret = check_signature(payload.buf, payload.len, signature.buf,
1249                signature.len, sigc);
1250
1251 out:
1252        strbuf_release(&payload);
1253        strbuf_release(&signature);
1254
1255        return ret;
1256}
1257
1258
1259
1260void append_merge_tag_headers(struct commit_list *parents,
1261                              struct commit_extra_header ***tail)
1262{
1263        while (parents) {
1264                struct commit *parent = parents->item;
1265                handle_signed_tag(parent, tail);
1266                parents = parents->next;
1267        }
1268}
1269
1270static void add_extra_header(struct strbuf *buffer,
1271                             struct commit_extra_header *extra)
1272{
1273        strbuf_addstr(buffer, extra->key);
1274        if (extra->len)
1275                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1276        else
1277                strbuf_addch(buffer, '\n');
1278}
1279
1280struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1281                                                      const char **exclude)
1282{
1283        struct commit_extra_header *extra = NULL;
1284        unsigned long size;
1285        const char *buffer = get_commit_buffer(commit, &size);
1286        extra = read_commit_extra_header_lines(buffer, size, exclude);
1287        unuse_commit_buffer(commit, buffer);
1288        return extra;
1289}
1290
1291void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1292{
1293        struct commit_extra_header *extra, *to_free;
1294
1295        to_free = read_commit_extra_headers(commit, NULL);
1296        for (extra = to_free; extra; extra = extra->next) {
1297                if (strcmp(extra->key, "mergetag"))
1298                        continue; /* not a merge tag */
1299                fn(commit, extra, data);
1300        }
1301        free_commit_extra_headers(to_free);
1302}
1303
1304static inline int standard_header_field(const char *field, size_t len)
1305{
1306        return ((len == 4 && !memcmp(field, "tree ", 5)) ||
1307                (len == 6 && !memcmp(field, "parent ", 7)) ||
1308                (len == 6 && !memcmp(field, "author ", 7)) ||
1309                (len == 9 && !memcmp(field, "committer ", 10)) ||
1310                (len == 8 && !memcmp(field, "encoding ", 9)));
1311}
1312
1313static int excluded_header_field(const char *field, size_t len, const char **exclude)
1314{
1315        if (!exclude)
1316                return 0;
1317
1318        while (*exclude) {
1319                size_t xlen = strlen(*exclude);
1320                if (len == xlen &&
1321                    !memcmp(field, *exclude, xlen) && field[xlen] == ' ')
1322                        return 1;
1323                exclude++;
1324        }
1325        return 0;
1326}
1327
1328static struct commit_extra_header *read_commit_extra_header_lines(
1329        const char *buffer, size_t size,
1330        const char **exclude)
1331{
1332        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1333        const char *line, *next, *eof, *eob;
1334        struct strbuf buf = STRBUF_INIT;
1335
1336        for (line = buffer, eob = line + size;
1337             line < eob && *line != '\n';
1338             line = next) {
1339                next = memchr(line, '\n', eob - line);
1340                next = next ? next + 1 : eob;
1341                if (*line == ' ') {
1342                        /* continuation */
1343                        if (it)
1344                                strbuf_add(&buf, line + 1, next - (line + 1));
1345                        continue;
1346                }
1347                if (it)
1348                        it->value = strbuf_detach(&buf, &it->len);
1349                strbuf_reset(&buf);
1350                it = NULL;
1351
1352                eof = strchr(line, ' ');
1353                if (next <= eof)
1354                        eof = next;
1355
1356                if (standard_header_field(line, eof - line) ||
1357                    excluded_header_field(line, eof - line, exclude))
1358                        continue;
1359
1360                it = xcalloc(1, sizeof(*it));
1361                it->key = xmemdupz(line, eof-line);
1362                *tail = it;
1363                tail = &it->next;
1364                if (eof + 1 < next)
1365                        strbuf_add(&buf, eof + 1, next - (eof + 1));
1366        }
1367        if (it)
1368                it->value = strbuf_detach(&buf, &it->len);
1369        return extra;
1370}
1371
1372void free_commit_extra_headers(struct commit_extra_header *extra)
1373{
1374        while (extra) {
1375                struct commit_extra_header *next = extra->next;
1376                free(extra->key);
1377                free(extra->value);
1378                free(extra);
1379                extra = next;
1380        }
1381}
1382
1383int commit_tree(const char *msg, size_t msg_len,
1384                const unsigned char *tree,
1385                struct commit_list *parents, unsigned char *ret,
1386                const char *author, const char *sign_commit)
1387{
1388        struct commit_extra_header *extra = NULL, **tail = &extra;
1389        int result;
1390
1391        append_merge_tag_headers(parents, &tail);
1392        result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1393                                      author, sign_commit, extra);
1394        free_commit_extra_headers(extra);
1395        return result;
1396}
1397
1398static int find_invalid_utf8(const char *buf, int len)
1399{
1400        int offset = 0;
1401        static const unsigned int max_codepoint[] = {
1402                0x7f, 0x7ff, 0xffff, 0x10ffff
1403        };
1404
1405        while (len) {
1406                unsigned char c = *buf++;
1407                int bytes, bad_offset;
1408                unsigned int codepoint;
1409                unsigned int min_val, max_val;
1410
1411                len--;
1412                offset++;
1413
1414                /* Simple US-ASCII? No worries. */
1415                if (c < 0x80)
1416                        continue;
1417
1418                bad_offset = offset-1;
1419
1420                /*
1421                 * Count how many more high bits set: that's how
1422                 * many more bytes this sequence should have.
1423                 */
1424                bytes = 0;
1425                while (c & 0x40) {
1426                        c <<= 1;
1427                        bytes++;
1428                }
1429
1430                /*
1431                 * Must be between 1 and 3 more bytes.  Longer sequences result in
1432                 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1433                 */
1434                if (bytes < 1 || 3 < bytes)
1435                        return bad_offset;
1436
1437                /* Do we *have* that many bytes? */
1438                if (len < bytes)
1439                        return bad_offset;
1440
1441                /*
1442                 * Place the encoded bits at the bottom of the value and compute the
1443                 * valid range.
1444                 */
1445                codepoint = (c & 0x7f) >> bytes;
1446                min_val = max_codepoint[bytes-1] + 1;
1447                max_val = max_codepoint[bytes];
1448
1449                offset += bytes;
1450                len -= bytes;
1451
1452                /* And verify that they are good continuation bytes */
1453                do {
1454                        codepoint <<= 6;
1455                        codepoint |= *buf & 0x3f;
1456                        if ((*buf++ & 0xc0) != 0x80)
1457                                return bad_offset;
1458                } while (--bytes);
1459
1460                /* Reject codepoints that are out of range for the sequence length. */
1461                if (codepoint < min_val || codepoint > max_val)
1462                        return bad_offset;
1463                /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1464                if ((codepoint & 0x1ff800) == 0xd800)
1465                        return bad_offset;
1466                /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1467                if ((codepoint & 0xfffe) == 0xfffe)
1468                        return bad_offset;
1469                /* So are anything in the range U+FDD0..U+FDEF. */
1470                if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1471                        return bad_offset;
1472        }
1473        return -1;
1474}
1475
1476/*
1477 * This verifies that the buffer is in proper utf8 format.
1478 *
1479 * If it isn't, it assumes any non-utf8 characters are Latin1,
1480 * and does the conversion.
1481 */
1482static int verify_utf8(struct strbuf *buf)
1483{
1484        int ok = 1;
1485        long pos = 0;
1486
1487        for (;;) {
1488                int bad;
1489                unsigned char c;
1490                unsigned char replace[2];
1491
1492                bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1493                if (bad < 0)
1494                        return ok;
1495                pos += bad;
1496                ok = 0;
1497                c = buf->buf[pos];
1498                strbuf_remove(buf, pos, 1);
1499
1500                /* We know 'c' must be in the range 128-255 */
1501                replace[0] = 0xc0 + (c >> 6);
1502                replace[1] = 0x80 + (c & 0x3f);
1503                strbuf_insert(buf, pos, replace, 2);
1504                pos += 2;
1505        }
1506}
1507
1508static const char commit_utf8_warn[] =
1509"Warning: commit message did not conform to UTF-8.\n"
1510"You may want to amend it after fixing the message, or set the config\n"
1511"variable i18n.commitencoding to the encoding your project uses.\n";
1512
1513int commit_tree_extended(const char *msg, size_t msg_len,
1514                         const unsigned char *tree,
1515                         struct commit_list *parents, unsigned char *ret,
1516                         const char *author, const char *sign_commit,
1517                         struct commit_extra_header *extra)
1518{
1519        int result;
1520        int encoding_is_utf8;
1521        struct strbuf buffer;
1522
1523        assert_sha1_type(tree, OBJ_TREE);
1524
1525        if (memchr(msg, '\0', msg_len))
1526                return error("a NUL byte in commit log message not allowed.");
1527
1528        /* Not having i18n.commitencoding is the same as having utf-8 */
1529        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1530
1531        strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1532        strbuf_addf(&buffer, "tree %s\n", sha1_to_hex(tree));
1533
1534        /*
1535         * NOTE! This ordering means that the same exact tree merged with a
1536         * different order of parents will be a _different_ changeset even
1537         * if everything else stays the same.
1538         */
1539        while (parents) {
1540                struct commit *parent = pop_commit(&parents);
1541                strbuf_addf(&buffer, "parent %s\n",
1542                            oid_to_hex(&parent->object.oid));
1543        }
1544
1545        /* Person/date information */
1546        if (!author)
1547                author = git_author_info(IDENT_STRICT);
1548        strbuf_addf(&buffer, "author %s\n", author);
1549        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1550        if (!encoding_is_utf8)
1551                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1552
1553        while (extra) {
1554                add_extra_header(&buffer, extra);
1555                extra = extra->next;
1556        }
1557        strbuf_addch(&buffer, '\n');
1558
1559        /* And add the comment */
1560        strbuf_add(&buffer, msg, msg_len);
1561
1562        /* And check the encoding */
1563        if (encoding_is_utf8 && !verify_utf8(&buffer))
1564                fprintf(stderr, commit_utf8_warn);
1565
1566        if (sign_commit && do_sign_commit(&buffer, sign_commit))
1567                return -1;
1568
1569        result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
1570        strbuf_release(&buffer);
1571        return result;
1572}
1573
1574struct commit *get_merge_parent(const char *name)
1575{
1576        struct object *obj;
1577        struct commit *commit;
1578        struct object_id oid;
1579        if (get_sha1(name, oid.hash))
1580                return NULL;
1581        obj = parse_object(oid.hash);
1582        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1583        if (commit && !commit->util) {
1584                struct merge_remote_desc *desc;
1585                desc = xmalloc(sizeof(*desc));
1586                desc->obj = obj;
1587                desc->name = strdup(name);
1588                commit->util = desc;
1589        }
1590        return commit;
1591}
1592
1593/*
1594 * Append a commit to the end of the commit_list.
1595 *
1596 * next starts by pointing to the variable that holds the head of an
1597 * empty commit_list, and is updated to point to the "next" field of
1598 * the last item on the list as new commits are appended.
1599 *
1600 * Usage example:
1601 *
1602 *     struct commit_list *list;
1603 *     struct commit_list **next = &list;
1604 *
1605 *     next = commit_list_append(c1, next);
1606 *     next = commit_list_append(c2, next);
1607 *     assert(commit_list_count(list) == 2);
1608 *     return list;
1609 */
1610struct commit_list **commit_list_append(struct commit *commit,
1611                                        struct commit_list **next)
1612{
1613        struct commit_list *new = xmalloc(sizeof(struct commit_list));
1614        new->item = commit;
1615        *next = new;
1616        new->next = NULL;
1617        return &new->next;
1618}
1619
1620void print_commit_list(struct commit_list *list,
1621                       const char *format_cur,
1622                       const char *format_last)
1623{
1624        for ( ; list; list = list->next) {
1625                const char *format = list->next ? format_cur : format_last;
1626                printf(format, oid_to_hex(&list->item->object.oid));
1627        }
1628}
1629
1630const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1631{
1632        int key_len = strlen(key);
1633        const char *line = msg;
1634
1635        while (line) {
1636                const char *eol = strchrnul(line, '\n');
1637
1638                if (line == eol)
1639                        return NULL;
1640
1641                if (eol - line > key_len &&
1642                    !strncmp(line, key, key_len) &&
1643                    line[key_len] == ' ') {
1644                        *out_len = eol - line - key_len - 1;
1645                        return line + key_len + 1;
1646                }
1647                line = *eol ? eol + 1 : NULL;
1648        }
1649        return NULL;
1650}
1651
1652/*
1653 * Inspect sb and determine the true "end" of the log message, in
1654 * order to find where to put a new Signed-off-by: line.  Ignored are
1655 * trailing comment lines and blank lines, and also the traditional
1656 * "Conflicts:" block that is not commented out, so that we can use
1657 * "git commit -s --amend" on an existing commit that forgot to remove
1658 * it.
1659 *
1660 * Returns the number of bytes from the tail to ignore, to be fed as
1661 * the second parameter to append_signoff().
1662 */
1663int ignore_non_trailer(struct strbuf *sb)
1664{
1665        int boc = 0;
1666        int bol = 0;
1667        int in_old_conflicts_block = 0;
1668
1669        while (bol < sb->len) {
1670                char *next_line;
1671
1672                if (!(next_line = memchr(sb->buf + bol, '\n', sb->len - bol)))
1673                        next_line = sb->buf + sb->len;
1674                else
1675                        next_line++;
1676
1677                if (sb->buf[bol] == comment_line_char || sb->buf[bol] == '\n') {
1678                        /* is this the first of the run of comments? */
1679                        if (!boc)
1680                                boc = bol;
1681                        /* otherwise, it is just continuing */
1682                } else if (starts_with(sb->buf + bol, "Conflicts:\n")) {
1683                        in_old_conflicts_block = 1;
1684                        if (!boc)
1685                                boc = bol;
1686                } else if (in_old_conflicts_block && sb->buf[bol] == '\t') {
1687                        ; /* a pathname in the conflicts block */
1688                } else if (boc) {
1689                        /* the previous was not trailing comment */
1690                        boc = 0;
1691                        in_old_conflicts_block = 0;
1692                }
1693                bol = next_line - sb->buf;
1694        }
1695        return boc ? sb->len - boc : 0;
1696}