Andrew's git / gitweb.git / commit.c
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commit.con commit Documentation/git-push.txt: document when --signed may fail (f9e0952)
   1#include "cache.h"
   2#include "tag.h"
   3#include "commit.h"
   4#include "pkt-line.h"
   5#include "utf8.h"
   6#include "diff.h"
   7#include "revision.h"
   8#include "notes.h"
   9#include "gpg-interface.h"
  10#include "mergesort.h"
  11#include "commit-slab.h"
  12#include "prio-queue.h"
  13#include "sha1-lookup.h"
  14
  15static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
  16
  17int save_commit_buffer = 1;
  18
  19const char *commit_type = "commit";
  20
  21struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
  22                                              int quiet)
  23{
  24        struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
  25
  26        if (!obj)
  27                return NULL;
  28        return object_as_type(obj, OBJ_COMMIT, quiet);
  29}
  30
  31struct commit *lookup_commit_reference(const unsigned char *sha1)
  32{
  33        return lookup_commit_reference_gently(sha1, 0);
  34}
  35
  36struct commit *lookup_commit_or_die(const unsigned char *sha1, const char *ref_name)
  37{
  38        struct commit *c = lookup_commit_reference(sha1);
  39        if (!c)
  40                die(_("could not parse %s"), ref_name);
  41        if (hashcmp(sha1, c->object.sha1)) {
  42                warning(_("%s %s is not a commit!"),
  43                        ref_name, sha1_to_hex(sha1));
  44        }
  45        return c;
  46}
  47
  48struct commit *lookup_commit(const unsigned char *sha1)
  49{
  50        struct object *obj = lookup_object(sha1);
  51        if (!obj)
  52                return create_object(sha1, alloc_commit_node());
  53        return object_as_type(obj, OBJ_COMMIT, 0);
  54}
  55
  56struct commit *lookup_commit_reference_by_name(const char *name)
  57{
  58        unsigned char sha1[20];
  59        struct commit *commit;
  60
  61        if (get_sha1_committish(name, sha1))
  62                return NULL;
  63        commit = lookup_commit_reference(sha1);
  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]->sha1;
 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->sha1);
 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
 142        while (len && isspace(buf[len-1]))
 143                buf[--len] = '\0';
 144        if (buf[0] == '#' || buf[0] == '\0')
 145                return NULL;
 146        if ((len + 1) % 41)
 147                goto bad_graft_data;
 148        i = (len + 1) / 41 - 1;
 149        graft = xmalloc(sizeof(*graft) + 20 * i);
 150        graft->nr_parent = i;
 151        if (get_sha1_hex(buf, graft->sha1))
 152                goto bad_graft_data;
 153        for (i = 40; i < len; i += 41) {
 154                if (buf[i] != ' ')
 155                        goto bad_graft_data;
 156                if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
 157                        goto bad_graft_data;
 158        }
 159        return graft;
 160
 161bad_graft_data:
 162        error("bad graft data: %s", buf);
 163        free(graft);
 164        return NULL;
 165}
 166
 167static int read_graft_file(const char *graft_file)
 168{
 169        FILE *fp = fopen(graft_file, "r");
 170        struct strbuf buf = STRBUF_INIT;
 171        if (!fp)
 172                return -1;
 173        while (!strbuf_getwholeline(&buf, fp, '\n')) {
 174                /* The format is just "Commit Parent1 Parent2 ...\n" */
 175                struct commit_graft *graft = read_graft_line(buf.buf, buf.len);
 176                if (!graft)
 177                        continue;
 178                if (register_commit_graft(graft, 1))
 179                        error("duplicate graft data: %s", buf.buf);
 180        }
 181        fclose(fp);
 182        strbuf_release(&buf);
 183        return 0;
 184}
 185
 186static void prepare_commit_graft(void)
 187{
 188        static int commit_graft_prepared;
 189        char *graft_file;
 190
 191        if (commit_graft_prepared)
 192                return;
 193        graft_file = get_graft_file();
 194        read_graft_file(graft_file);
 195        /* make sure shallows are read */
 196        is_repository_shallow();
 197        commit_graft_prepared = 1;
 198}
 199
 200struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 201{
 202        int pos;
 203        prepare_commit_graft();
 204        pos = commit_graft_pos(sha1);
 205        if (pos < 0)
 206                return NULL;
 207        return commit_graft[pos];
 208}
 209
 210int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
 211{
 212        int i, ret;
 213        for (i = ret = 0; i < commit_graft_nr && !ret; i++)
 214                ret = fn(commit_graft[i], cb_data);
 215        return ret;
 216}
 217
 218int unregister_shallow(const unsigned char *sha1)
 219{
 220        int pos = commit_graft_pos(sha1);
 221        if (pos < 0)
 222                return -1;
 223        if (pos + 1 < commit_graft_nr)
 224                memmove(commit_graft + pos, commit_graft + pos + 1,
 225                                sizeof(struct commit_graft *)
 226                                * (commit_graft_nr - pos - 1));
 227        commit_graft_nr--;
 228        return 0;
 229}
 230
 231struct commit_buffer {
 232        void *buffer;
 233        unsigned long size;
 234};
 235define_commit_slab(buffer_slab, struct commit_buffer);
 236static struct buffer_slab buffer_slab = COMMIT_SLAB_INIT(1, buffer_slab);
 237
 238void set_commit_buffer(struct commit *commit, void *buffer, unsigned long size)
 239{
 240        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 241        v->buffer = buffer;
 242        v->size = size;
 243}
 244
 245const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
 246{
 247        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 248        if (sizep)
 249                *sizep = v->size;
 250        return v->buffer;
 251}
 252
 253const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
 254{
 255        const void *ret = get_cached_commit_buffer(commit, sizep);
 256        if (!ret) {
 257                enum object_type type;
 258                unsigned long size;
 259                ret = read_sha1_file(commit->object.sha1, &type, &size);
 260                if (!ret)
 261                        die("cannot read commit object %s",
 262                            sha1_to_hex(commit->object.sha1));
 263                if (type != OBJ_COMMIT)
 264                        die("expected commit for %s, got %s",
 265                            sha1_to_hex(commit->object.sha1), typename(type));
 266                if (sizep)
 267                        *sizep = size;
 268        }
 269        return ret;
 270}
 271
 272void unuse_commit_buffer(const struct commit *commit, const void *buffer)
 273{
 274        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 275        if (v->buffer != buffer)
 276                free((void *)buffer);
 277}
 278
 279void free_commit_buffer(struct commit *commit)
 280{
 281        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 282        free(v->buffer);
 283        v->buffer = NULL;
 284        v->size = 0;
 285}
 286
 287const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 288{
 289        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 290        void *ret;
 291
 292        ret = v->buffer;
 293        if (sizep)
 294                *sizep = v->size;
 295
 296        v->buffer = NULL;
 297        v->size = 0;
 298        return ret;
 299}
 300
 301int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
 302{
 303        const char *tail = buffer;
 304        const char *bufptr = buffer;
 305        unsigned char parent[20];
 306        struct commit_list **pptr;
 307        struct commit_graft *graft;
 308
 309        if (item->object.parsed)
 310                return 0;
 311        item->object.parsed = 1;
 312        tail += size;
 313        if (tail <= bufptr + 46 || memcmp(bufptr, "tree ", 5) || bufptr[45] != '\n')
 314                return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 315        if (get_sha1_hex(bufptr + 5, parent) < 0)
 316                return error("bad tree pointer in commit %s",
 317                             sha1_to_hex(item->object.sha1));
 318        item->tree = lookup_tree(parent);
 319        bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 320        pptr = &item->parents;
 321
 322        graft = lookup_commit_graft(item->object.sha1);
 323        while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
 324                struct commit *new_parent;
 325
 326                if (tail <= bufptr + 48 ||
 327                    get_sha1_hex(bufptr + 7, parent) ||
 328                    bufptr[47] != '\n')
 329                        return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 330                bufptr += 48;
 331                /*
 332                 * The clone is shallow if nr_parent < 0, and we must
 333                 * not traverse its real parents even when we unhide them.
 334                 */
 335                if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
 336                        continue;
 337                new_parent = lookup_commit(parent);
 338                if (new_parent)
 339                        pptr = &commit_list_insert(new_parent, pptr)->next;
 340        }
 341        if (graft) {
 342                int i;
 343                struct commit *new_parent;
 344                for (i = 0; i < graft->nr_parent; i++) {
 345                        new_parent = lookup_commit(graft->parent[i]);
 346                        if (!new_parent)
 347                                continue;
 348                        pptr = &commit_list_insert(new_parent, pptr)->next;
 349                }
 350        }
 351        item->date = parse_commit_date(bufptr, tail);
 352
 353        return 0;
 354}
 355
 356int parse_commit_gently(struct commit *item, int quiet_on_missing)
 357{
 358        enum object_type type;
 359        void *buffer;
 360        unsigned long size;
 361        int ret;
 362
 363        if (!item)
 364                return -1;
 365        if (item->object.parsed)
 366                return 0;
 367        buffer = read_sha1_file(item->object.sha1, &type, &size);
 368        if (!buffer)
 369                return quiet_on_missing ? -1 :
 370                        error("Could not read %s",
 371                             sha1_to_hex(item->object.sha1));
 372        if (type != OBJ_COMMIT) {
 373                free(buffer);
 374                return error("Object %s not a commit",
 375                             sha1_to_hex(item->object.sha1));
 376        }
 377        ret = parse_commit_buffer(item, buffer, size);
 378        if (save_commit_buffer && !ret) {
 379                set_commit_buffer(item, buffer, size);
 380                return 0;
 381        }
 382        free(buffer);
 383        return ret;
 384}
 385
 386void parse_commit_or_die(struct commit *item)
 387{
 388        if (parse_commit(item))
 389                die("unable to parse commit %s",
 390                    item ? sha1_to_hex(item->object.sha1) : "(null)");
 391}
 392
 393int find_commit_subject(const char *commit_buffer, const char **subject)
 394{
 395        const char *eol;
 396        const char *p = commit_buffer;
 397
 398        while (*p && (*p != '\n' || p[1] != '\n'))
 399                p++;
 400        if (*p) {
 401                p += 2;
 402                for (eol = p; *eol && *eol != '\n'; eol++)
 403                        ; /* do nothing */
 404        } else
 405                eol = p;
 406
 407        *subject = p;
 408
 409        return eol - p;
 410}
 411
 412struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 413{
 414        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 415        new_list->item = item;
 416        new_list->next = *list_p;
 417        *list_p = new_list;
 418        return new_list;
 419}
 420
 421unsigned commit_list_count(const struct commit_list *l)
 422{
 423        unsigned c = 0;
 424        for (; l; l = l->next )
 425                c++;
 426        return c;
 427}
 428
 429struct commit_list *copy_commit_list(struct commit_list *list)
 430{
 431        struct commit_list *head = NULL;
 432        struct commit_list **pp = &head;
 433        while (list) {
 434                pp = commit_list_append(list->item, pp);
 435                list = list->next;
 436        }
 437        return head;
 438}
 439
 440void free_commit_list(struct commit_list *list)
 441{
 442        while (list) {
 443                struct commit_list *temp = list;
 444                list = temp->next;
 445                free(temp);
 446        }
 447}
 448
 449struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 450{
 451        struct commit_list **pp = list;
 452        struct commit_list *p;
 453        while ((p = *pp) != NULL) {
 454                if (p->item->date < item->date) {
 455                        break;
 456                }
 457                pp = &p->next;
 458        }
 459        return commit_list_insert(item, pp);
 460}
 461
 462static int commit_list_compare_by_date(const void *a, const void *b)
 463{
 464        unsigned long a_date = ((const struct commit_list *)a)->item->date;
 465        unsigned long b_date = ((const struct commit_list *)b)->item->date;
 466        if (a_date < b_date)
 467                return 1;
 468        if (a_date > b_date)
 469                return -1;
 470        return 0;
 471}
 472
 473static void *commit_list_get_next(const void *a)
 474{
 475        return ((const struct commit_list *)a)->next;
 476}
 477
 478static void commit_list_set_next(void *a, void *next)
 479{
 480        ((struct commit_list *)a)->next = next;
 481}
 482
 483void commit_list_sort_by_date(struct commit_list **list)
 484{
 485        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 486                                commit_list_compare_by_date);
 487}
 488
 489struct commit *pop_most_recent_commit(struct commit_list **list,
 490                                      unsigned int mark)
 491{
 492        struct commit *ret = (*list)->item;
 493        struct commit_list *parents = ret->parents;
 494        struct commit_list *old = *list;
 495
 496        *list = (*list)->next;
 497        free(old);
 498
 499        while (parents) {
 500                struct commit *commit = parents->item;
 501                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 502                        commit->object.flags |= mark;
 503                        commit_list_insert_by_date(commit, list);
 504                }
 505                parents = parents->next;
 506        }
 507        return ret;
 508}
 509
 510static void clear_commit_marks_1(struct commit_list **plist,
 511                                 struct commit *commit, unsigned int mark)
 512{
 513        while (commit) {
 514                struct commit_list *parents;
 515
 516                if (!(mark & commit->object.flags))
 517                        return;
 518
 519                commit->object.flags &= ~mark;
 520
 521                parents = commit->parents;
 522                if (!parents)
 523                        return;
 524
 525                while ((parents = parents->next))
 526                        commit_list_insert(parents->item, plist);
 527
 528                commit = commit->parents->item;
 529        }
 530}
 531
 532void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 533{
 534        struct commit_list *list = NULL;
 535
 536        while (nr--) {
 537                commit_list_insert(*commit, &list);
 538                commit++;
 539        }
 540        while (list)
 541                clear_commit_marks_1(&list, pop_commit(&list), mark);
 542}
 543
 544void clear_commit_marks(struct commit *commit, unsigned int mark)
 545{
 546        clear_commit_marks_many(1, &commit, mark);
 547}
 548
 549void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
 550{
 551        struct object *object;
 552        struct commit *commit;
 553        unsigned int i;
 554
 555        for (i = 0; i < a->nr; i++) {
 556                object = a->objects[i].item;
 557                commit = lookup_commit_reference_gently(object->sha1, 1);
 558                if (commit)
 559                        clear_commit_marks(commit, mark);
 560        }
 561}
 562
 563struct commit *pop_commit(struct commit_list **stack)
 564{
 565        struct commit_list *top = *stack;
 566        struct commit *item = top ? top->item : NULL;
 567
 568        if (top) {
 569                *stack = top->next;
 570                free(top);
 571        }
 572        return item;
 573}
 574
 575/*
 576 * Topological sort support
 577 */
 578
 579/* count number of children that have not been emitted */
 580define_commit_slab(indegree_slab, int);
 581
 582/* record author-date for each commit object */
 583define_commit_slab(author_date_slab, unsigned long);
 584
 585static void record_author_date(struct author_date_slab *author_date,
 586                               struct commit *commit)
 587{
 588        const char *buffer = get_commit_buffer(commit, NULL);
 589        struct ident_split ident;
 590        const char *ident_line;
 591        size_t ident_len;
 592        char *date_end;
 593        unsigned long date;
 594
 595        ident_line = find_commit_header(buffer, "author", &ident_len);
 596        if (!ident_line)
 597                goto fail_exit; /* no author line */
 598        if (split_ident_line(&ident, ident_line, ident_len) ||
 599            !ident.date_begin || !ident.date_end)
 600                goto fail_exit; /* malformed "author" line */
 601
 602        date = strtoul(ident.date_begin, &date_end, 10);
 603        if (date_end != ident.date_end)
 604                goto fail_exit; /* malformed date */
 605        *(author_date_slab_at(author_date, commit)) = date;
 606
 607fail_exit:
 608        unuse_commit_buffer(commit, buffer);
 609}
 610
 611static int compare_commits_by_author_date(const void *a_, const void *b_,
 612                                          void *cb_data)
 613{
 614        const struct commit *a = a_, *b = b_;
 615        struct author_date_slab *author_date = cb_data;
 616        unsigned long a_date = *(author_date_slab_at(author_date, a));
 617        unsigned long b_date = *(author_date_slab_at(author_date, b));
 618
 619        /* newer commits with larger date first */
 620        if (a_date < b_date)
 621                return 1;
 622        else if (a_date > b_date)
 623                return -1;
 624        return 0;
 625}
 626
 627int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 628{
 629        const struct commit *a = a_, *b = b_;
 630        /* newer commits with larger date first */
 631        if (a->date < b->date)
 632                return 1;
 633        else if (a->date > b->date)
 634                return -1;
 635        return 0;
 636}
 637
 638/*
 639 * Performs an in-place topological sort on the list supplied.
 640 */
 641void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 642{
 643        struct commit_list *next, *orig = *list;
 644        struct commit_list **pptr;
 645        struct indegree_slab indegree;
 646        struct prio_queue queue;
 647        struct commit *commit;
 648        struct author_date_slab author_date;
 649
 650        if (!orig)
 651                return;
 652        *list = NULL;
 653
 654        init_indegree_slab(&indegree);
 655        memset(&queue, '\0', sizeof(queue));
 656
 657        switch (sort_order) {
 658        default: /* REV_SORT_IN_GRAPH_ORDER */
 659                queue.compare = NULL;
 660                break;
 661        case REV_SORT_BY_COMMIT_DATE:
 662                queue.compare = compare_commits_by_commit_date;
 663                break;
 664        case REV_SORT_BY_AUTHOR_DATE:
 665                init_author_date_slab(&author_date);
 666                queue.compare = compare_commits_by_author_date;
 667                queue.cb_data = &author_date;
 668                break;
 669        }
 670
 671        /* Mark them and clear the indegree */
 672        for (next = orig; next; next = next->next) {
 673                struct commit *commit = next->item;
 674                *(indegree_slab_at(&indegree, commit)) = 1;
 675                /* also record the author dates, if needed */
 676                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 677                        record_author_date(&author_date, commit);
 678        }
 679
 680        /* update the indegree */
 681        for (next = orig; next; next = next->next) {
 682                struct commit_list *parents = next->item->parents;
 683                while (parents) {
 684                        struct commit *parent = parents->item;
 685                        int *pi = indegree_slab_at(&indegree, parent);
 686
 687                        if (*pi)
 688                                (*pi)++;
 689                        parents = parents->next;
 690                }
 691        }
 692
 693        /*
 694         * find the tips
 695         *
 696         * tips are nodes not reachable from any other node in the list
 697         *
 698         * the tips serve as a starting set for the work queue.
 699         */
 700        for (next = orig; next; next = next->next) {
 701                struct commit *commit = next->item;
 702
 703                if (*(indegree_slab_at(&indegree, commit)) == 1)
 704                        prio_queue_put(&queue, commit);
 705        }
 706
 707        /*
 708         * This is unfortunate; the initial tips need to be shown
 709         * in the order given from the revision traversal machinery.
 710         */
 711        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 712                prio_queue_reverse(&queue);
 713
 714        /* We no longer need the commit list */
 715        free_commit_list(orig);
 716
 717        pptr = list;
 718        *list = NULL;
 719        while ((commit = prio_queue_get(&queue)) != NULL) {
 720                struct commit_list *parents;
 721
 722                for (parents = commit->parents; parents ; parents = parents->next) {
 723                        struct commit *parent = parents->item;
 724                        int *pi = indegree_slab_at(&indegree, parent);
 725
 726                        if (!*pi)
 727                                continue;
 728
 729                        /*
 730                         * parents are only enqueued for emission
 731                         * when all their children have been emitted thereby
 732                         * guaranteeing topological order.
 733                         */
 734                        if (--(*pi) == 1)
 735                                prio_queue_put(&queue, parent);
 736                }
 737                /*
 738                 * all children of commit have already been
 739                 * emitted. we can emit it now.
 740                 */
 741                *(indegree_slab_at(&indegree, commit)) = 0;
 742
 743                pptr = &commit_list_insert(commit, pptr)->next;
 744        }
 745
 746        clear_indegree_slab(&indegree);
 747        clear_prio_queue(&queue);
 748        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 749                clear_author_date_slab(&author_date);
 750}
 751
 752/* merge-base stuff */
 753
 754/* Remember to update object flag allocation in object.h */
 755#define PARENT1         (1u<<16)
 756#define PARENT2         (1u<<17)
 757#define STALE           (1u<<18)
 758#define RESULT          (1u<<19)
 759
 760static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 761
 762static int queue_has_nonstale(struct prio_queue *queue)
 763{
 764        int i;
 765        for (i = 0; i < queue->nr; i++) {
 766                struct commit *commit = queue->array[i].data;
 767                if (!(commit->object.flags & STALE))
 768                        return 1;
 769        }
 770        return 0;
 771}
 772
 773/* all input commits in one and twos[] must have been parsed! */
 774static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
 775{
 776        struct prio_queue queue = { compare_commits_by_commit_date };
 777        struct commit_list *result = NULL;
 778        int i;
 779
 780        one->object.flags |= PARENT1;
 781        if (!n) {
 782                commit_list_append(one, &result);
 783                return result;
 784        }
 785        prio_queue_put(&queue, one);
 786
 787        for (i = 0; i < n; i++) {
 788                twos[i]->object.flags |= PARENT2;
 789                prio_queue_put(&queue, twos[i]);
 790        }
 791
 792        while (queue_has_nonstale(&queue)) {
 793                struct commit *commit = prio_queue_get(&queue);
 794                struct commit_list *parents;
 795                int flags;
 796
 797                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 798                if (flags == (PARENT1 | PARENT2)) {
 799                        if (!(commit->object.flags & RESULT)) {
 800                                commit->object.flags |= RESULT;
 801                                commit_list_insert_by_date(commit, &result);
 802                        }
 803                        /* Mark parents of a found merge stale */
 804                        flags |= STALE;
 805                }
 806                parents = commit->parents;
 807                while (parents) {
 808                        struct commit *p = parents->item;
 809                        parents = parents->next;
 810                        if ((p->object.flags & flags) == flags)
 811                                continue;
 812                        if (parse_commit(p))
 813                                return NULL;
 814                        p->object.flags |= flags;
 815                        prio_queue_put(&queue, p);
 816                }
 817        }
 818
 819        clear_prio_queue(&queue);
 820        return result;
 821}
 822
 823static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 824{
 825        struct commit_list *list = NULL;
 826        struct commit_list *result = NULL;
 827        int i;
 828
 829        for (i = 0; i < n; i++) {
 830                if (one == twos[i])
 831                        /*
 832                         * We do not mark this even with RESULT so we do not
 833                         * have to clean it up.
 834                         */
 835                        return commit_list_insert(one, &result);
 836        }
 837
 838        if (parse_commit(one))
 839                return NULL;
 840        for (i = 0; i < n; i++) {
 841                if (parse_commit(twos[i]))
 842                        return NULL;
 843        }
 844
 845        list = paint_down_to_common(one, n, twos);
 846
 847        while (list) {
 848                struct commit_list *next = list->next;
 849                if (!(list->item->object.flags & STALE))
 850                        commit_list_insert_by_date(list->item, &result);
 851                free(list);
 852                list = next;
 853        }
 854        return result;
 855}
 856
 857struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 858{
 859        struct commit_list *i, *j, *k, *ret = NULL;
 860
 861        if (!in)
 862                return ret;
 863
 864        commit_list_insert(in->item, &ret);
 865
 866        for (i = in->next; i; i = i->next) {
 867                struct commit_list *new = NULL, *end = NULL;
 868
 869                for (j = ret; j; j = j->next) {
 870                        struct commit_list *bases;
 871                        bases = get_merge_bases(i->item, j->item);
 872                        if (!new)
 873                                new = bases;
 874                        else
 875                                end->next = bases;
 876                        for (k = bases; k; k = k->next)
 877                                end = k;
 878                }
 879                ret = new;
 880        }
 881        return ret;
 882}
 883
 884static int remove_redundant(struct commit **array, int cnt)
 885{
 886        /*
 887         * Some commit in the array may be an ancestor of
 888         * another commit.  Move such commit to the end of
 889         * the array, and return the number of commits that
 890         * are independent from each other.
 891         */
 892        struct commit **work;
 893        unsigned char *redundant;
 894        int *filled_index;
 895        int i, j, filled;
 896
 897        work = xcalloc(cnt, sizeof(*work));
 898        redundant = xcalloc(cnt, 1);
 899        filled_index = xmalloc(sizeof(*filled_index) * (cnt - 1));
 900
 901        for (i = 0; i < cnt; i++)
 902                parse_commit(array[i]);
 903        for (i = 0; i < cnt; i++) {
 904                struct commit_list *common;
 905
 906                if (redundant[i])
 907                        continue;
 908                for (j = filled = 0; j < cnt; j++) {
 909                        if (i == j || redundant[j])
 910                                continue;
 911                        filled_index[filled] = j;
 912                        work[filled++] = array[j];
 913                }
 914                common = paint_down_to_common(array[i], filled, work);
 915                if (array[i]->object.flags & PARENT2)
 916                        redundant[i] = 1;
 917                for (j = 0; j < filled; j++)
 918                        if (work[j]->object.flags & PARENT1)
 919                                redundant[filled_index[j]] = 1;
 920                clear_commit_marks(array[i], all_flags);
 921                for (j = 0; j < filled; j++)
 922                        clear_commit_marks(work[j], all_flags);
 923                free_commit_list(common);
 924        }
 925
 926        /* Now collect the result */
 927        memcpy(work, array, sizeof(*array) * cnt);
 928        for (i = filled = 0; i < cnt; i++)
 929                if (!redundant[i])
 930                        array[filled++] = work[i];
 931        for (j = filled, i = 0; i < cnt; i++)
 932                if (redundant[i])
 933                        array[j++] = work[i];
 934        free(work);
 935        free(redundant);
 936        free(filled_index);
 937        return filled;
 938}
 939
 940static struct commit_list *get_merge_bases_many_0(struct commit *one,
 941                                                  int n,
 942                                                  struct commit **twos,
 943                                                  int cleanup)
 944{
 945        struct commit_list *list;
 946        struct commit **rslt;
 947        struct commit_list *result;
 948        int cnt, i;
 949
 950        result = merge_bases_many(one, n, twos);
 951        for (i = 0; i < n; i++) {
 952                if (one == twos[i])
 953                        return result;
 954        }
 955        if (!result || !result->next) {
 956                if (cleanup) {
 957                        clear_commit_marks(one, all_flags);
 958                        clear_commit_marks_many(n, twos, all_flags);
 959                }
 960                return result;
 961        }
 962
 963        /* There are more than one */
 964        cnt = commit_list_count(result);
 965        rslt = xcalloc(cnt, sizeof(*rslt));
 966        for (list = result, i = 0; list; list = list->next)
 967                rslt[i++] = list->item;
 968        free_commit_list(result);
 969
 970        clear_commit_marks(one, all_flags);
 971        clear_commit_marks_many(n, twos, all_flags);
 972
 973        cnt = remove_redundant(rslt, cnt);
 974        result = NULL;
 975        for (i = 0; i < cnt; i++)
 976                commit_list_insert_by_date(rslt[i], &result);
 977        free(rslt);
 978        return result;
 979}
 980
 981struct commit_list *get_merge_bases_many(struct commit *one,
 982                                         int n,
 983                                         struct commit **twos)
 984{
 985        return get_merge_bases_many_0(one, n, twos, 1);
 986}
 987
 988struct commit_list *get_merge_bases_many_dirty(struct commit *one,
 989                                               int n,
 990                                               struct commit **twos)
 991{
 992        return get_merge_bases_many_0(one, n, twos, 0);
 993}
 994
 995struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
 996{
 997        return get_merge_bases_many_0(one, 1, &two, 1);
 998}
 999
1000/*
1001 * Is "commit" a descendant of one of the elements on the "with_commit" list?
1002 */
1003int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
1004{
1005        if (!with_commit)
1006                return 1;
1007        while (with_commit) {
1008                struct commit *other;
1009
1010                other = with_commit->item;
1011                with_commit = with_commit->next;
1012                if (in_merge_bases(other, commit))
1013                        return 1;
1014        }
1015        return 0;
1016}
1017
1018/*
1019 * Is "commit" an ancestor of one of the "references"?
1020 */
1021int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1022{
1023        struct commit_list *bases;
1024        int ret = 0, i;
1025
1026        if (parse_commit(commit))
1027                return ret;
1028        for (i = 0; i < nr_reference; i++)
1029                if (parse_commit(reference[i]))
1030                        return ret;
1031
1032        bases = paint_down_to_common(commit, nr_reference, reference);
1033        if (commit->object.flags & PARENT2)
1034                ret = 1;
1035        clear_commit_marks(commit, all_flags);
1036        clear_commit_marks_many(nr_reference, reference, all_flags);
1037        free_commit_list(bases);
1038        return ret;
1039}
1040
1041/*
1042 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1043 */
1044int in_merge_bases(struct commit *commit, struct commit *reference)
1045{
1046        return in_merge_bases_many(commit, 1, &reference);
1047}
1048
1049struct commit_list *reduce_heads(struct commit_list *heads)
1050{
1051        struct commit_list *p;
1052        struct commit_list *result = NULL, **tail = &result;
1053        struct commit **array;
1054        int num_head, i;
1055
1056        if (!heads)
1057                return NULL;
1058
1059        /* Uniquify */
1060        for (p = heads; p; p = p->next)
1061                p->item->object.flags &= ~STALE;
1062        for (p = heads, num_head = 0; p; p = p->next) {
1063                if (p->item->object.flags & STALE)
1064                        continue;
1065                p->item->object.flags |= STALE;
1066                num_head++;
1067        }
1068        array = xcalloc(num_head, sizeof(*array));
1069        for (p = heads, i = 0; p; p = p->next) {
1070                if (p->item->object.flags & STALE) {
1071                        array[i++] = p->item;
1072                        p->item->object.flags &= ~STALE;
1073                }
1074        }
1075        num_head = remove_redundant(array, num_head);
1076        for (i = 0; i < num_head; i++)
1077                tail = &commit_list_insert(array[i], tail)->next;
1078        return result;
1079}
1080
1081static const char gpg_sig_header[] = "gpgsig";
1082static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1083
1084static int do_sign_commit(struct strbuf *buf, const char *keyid)
1085{
1086        struct strbuf sig = STRBUF_INIT;
1087        int inspos, copypos;
1088
1089        /* find the end of the header */
1090        inspos = strstr(buf->buf, "\n\n") - buf->buf + 1;
1091
1092        if (!keyid || !*keyid)
1093                keyid = get_signing_key();
1094        if (sign_buffer(buf, &sig, keyid)) {
1095                strbuf_release(&sig);
1096                return -1;
1097        }
1098
1099        for (copypos = 0; sig.buf[copypos]; ) {
1100                const char *bol = sig.buf + copypos;
1101                const char *eol = strchrnul(bol, '\n');
1102                int len = (eol - bol) + !!*eol;
1103
1104                if (!copypos) {
1105                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1106                        inspos += gpg_sig_header_len;
1107                }
1108                strbuf_insert(buf, inspos++, " ", 1);
1109                strbuf_insert(buf, inspos, bol, len);
1110                inspos += len;
1111                copypos += len;
1112        }
1113        strbuf_release(&sig);
1114        return 0;
1115}
1116
1117int parse_signed_commit(const struct commit *commit,
1118                        struct strbuf *payload, struct strbuf *signature)
1119{
1120
1121        unsigned long size;
1122        const char *buffer = get_commit_buffer(commit, &size);
1123        int in_signature, saw_signature = -1;
1124        const char *line, *tail;
1125
1126        line = buffer;
1127        tail = buffer + size;
1128        in_signature = 0;
1129        saw_signature = 0;
1130        while (line < tail) {
1131                const char *sig = NULL;
1132                const char *next = memchr(line, '\n', tail - line);
1133
1134                next = next ? next + 1 : tail;
1135                if (in_signature && line[0] == ' ')
1136                        sig = line + 1;
1137                else if (starts_with(line, gpg_sig_header) &&
1138                         line[gpg_sig_header_len] == ' ')
1139                        sig = line + gpg_sig_header_len + 1;
1140                if (sig) {
1141                        strbuf_add(signature, sig, next - sig);
1142                        saw_signature = 1;
1143                        in_signature = 1;
1144                } else {
1145                        if (*line == '\n')
1146                                /* dump the whole remainder of the buffer */
1147                                next = tail;
1148                        strbuf_add(payload, line, next - line);
1149                        in_signature = 0;
1150                }
1151                line = next;
1152        }
1153        unuse_commit_buffer(commit, buffer);
1154        return saw_signature;
1155}
1156
1157int remove_signature(struct strbuf *buf)
1158{
1159        const char *line = buf->buf;
1160        const char *tail = buf->buf + buf->len;
1161        int in_signature = 0;
1162        const char *sig_start = NULL;
1163        const char *sig_end = NULL;
1164
1165        while (line < tail) {
1166                const char *next = memchr(line, '\n', tail - line);
1167                next = next ? next + 1 : tail;
1168
1169                if (in_signature && line[0] == ' ')
1170                        sig_end = next;
1171                else if (starts_with(line, gpg_sig_header) &&
1172                         line[gpg_sig_header_len] == ' ') {
1173                        sig_start = line;
1174                        sig_end = next;
1175                        in_signature = 1;
1176                } else {
1177                        if (*line == '\n')
1178                                /* dump the whole remainder of the buffer */
1179                                next = tail;
1180                        in_signature = 0;
1181                }
1182                line = next;
1183        }
1184
1185        if (sig_start)
1186                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1187
1188        return sig_start != NULL;
1189}
1190
1191static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1192{
1193        struct merge_remote_desc *desc;
1194        struct commit_extra_header *mergetag;
1195        char *buf;
1196        unsigned long size, len;
1197        enum object_type type;
1198
1199        desc = merge_remote_util(parent);
1200        if (!desc || !desc->obj)
1201                return;
1202        buf = read_sha1_file(desc->obj->sha1, &type, &size);
1203        if (!buf || type != OBJ_TAG)
1204                goto free_return;
1205        len = parse_signature(buf, size);
1206        if (size == len)
1207                goto free_return;
1208        /*
1209         * We could verify this signature and either omit the tag when
1210         * it does not validate, but the integrator may not have the
1211         * public key of the signer of the tag he is merging, while a
1212         * later auditor may have it while auditing, so let's not run
1213         * verify-signed-buffer here for now...
1214         *
1215         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1216         *      warn("warning: signed tag unverified.");
1217         */
1218        mergetag = xcalloc(1, sizeof(*mergetag));
1219        mergetag->key = xstrdup("mergetag");
1220        mergetag->value = buf;
1221        mergetag->len = size;
1222
1223        **tail = mergetag;
1224        *tail = &mergetag->next;
1225        return;
1226
1227free_return:
1228        free(buf);
1229}
1230
1231void check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1232{
1233        struct strbuf payload = STRBUF_INIT;
1234        struct strbuf signature = STRBUF_INIT;
1235        struct strbuf gpg_output = STRBUF_INIT;
1236        struct strbuf gpg_status = STRBUF_INIT;
1237        int status;
1238
1239        sigc->result = 'N';
1240
1241        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1242                goto out;
1243        status = verify_signed_buffer(payload.buf, payload.len,
1244                                      signature.buf, signature.len,
1245                                      &gpg_output, &gpg_status);
1246        if (status && !gpg_output.len)
1247                goto out;
1248        sigc->payload = strbuf_detach(&payload, NULL);
1249        sigc->gpg_output = strbuf_detach(&gpg_output, NULL);
1250        sigc->gpg_status = strbuf_detach(&gpg_status, NULL);
1251        parse_gpg_output(sigc);
1252
1253 out:
1254        strbuf_release(&gpg_status);
1255        strbuf_release(&gpg_output);
1256        strbuf_release(&payload);
1257        strbuf_release(&signature);
1258}
1259
1260
1261
1262void append_merge_tag_headers(struct commit_list *parents,
1263                              struct commit_extra_header ***tail)
1264{
1265        while (parents) {
1266                struct commit *parent = parents->item;
1267                handle_signed_tag(parent, tail);
1268                parents = parents->next;
1269        }
1270}
1271
1272static void add_extra_header(struct strbuf *buffer,
1273                             struct commit_extra_header *extra)
1274{
1275        strbuf_addstr(buffer, extra->key);
1276        if (extra->len)
1277                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1278        else
1279                strbuf_addch(buffer, '\n');
1280}
1281
1282struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1283                                                      const char **exclude)
1284{
1285        struct commit_extra_header *extra = NULL;
1286        unsigned long size;
1287        const char *buffer = get_commit_buffer(commit, &size);
1288        extra = read_commit_extra_header_lines(buffer, size, exclude);
1289        unuse_commit_buffer(commit, buffer);
1290        return extra;
1291}
1292
1293void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1294{
1295        struct commit_extra_header *extra, *to_free;
1296
1297        to_free = read_commit_extra_headers(commit, NULL);
1298        for (extra = to_free; extra; extra = extra->next) {
1299                if (strcmp(extra->key, "mergetag"))
1300                        continue; /* not a merge tag */
1301                fn(commit, extra, data);
1302        }
1303        free_commit_extra_headers(to_free);
1304}
1305
1306static inline int standard_header_field(const char *field, size_t len)
1307{
1308        return ((len == 4 && !memcmp(field, "tree ", 5)) ||
1309                (len == 6 && !memcmp(field, "parent ", 7)) ||
1310                (len == 6 && !memcmp(field, "author ", 7)) ||
1311                (len == 9 && !memcmp(field, "committer ", 10)) ||
1312                (len == 8 && !memcmp(field, "encoding ", 9)));
1313}
1314
1315static int excluded_header_field(const char *field, size_t len, const char **exclude)
1316{
1317        if (!exclude)
1318                return 0;
1319
1320        while (*exclude) {
1321                size_t xlen = strlen(*exclude);
1322                if (len == xlen &&
1323                    !memcmp(field, *exclude, xlen) && field[xlen] == ' ')
1324                        return 1;
1325                exclude++;
1326        }
1327        return 0;
1328}
1329
1330static struct commit_extra_header *read_commit_extra_header_lines(
1331        const char *buffer, size_t size,
1332        const char **exclude)
1333{
1334        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1335        const char *line, *next, *eof, *eob;
1336        struct strbuf buf = STRBUF_INIT;
1337
1338        for (line = buffer, eob = line + size;
1339             line < eob && *line != '\n';
1340             line = next) {
1341                next = memchr(line, '\n', eob - line);
1342                next = next ? next + 1 : eob;
1343                if (*line == ' ') {
1344                        /* continuation */
1345                        if (it)
1346                                strbuf_add(&buf, line + 1, next - (line + 1));
1347                        continue;
1348                }
1349                if (it)
1350                        it->value = strbuf_detach(&buf, &it->len);
1351                strbuf_reset(&buf);
1352                it = NULL;
1353
1354                eof = strchr(line, ' ');
1355                if (next <= eof)
1356                        eof = next;
1357
1358                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[] =
1511"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_list *next = parents->next;
1543                struct commit *parent = parents->item;
1544
1545                strbuf_addf(&buffer, "parent %s\n",
1546                            sha1_to_hex(parent->object.sha1));
1547                free(parents);
1548                parents = next;
1549        }
1550
1551        /* Person/date information */
1552        if (!author)
1553                author = git_author_info(IDENT_STRICT);
1554        strbuf_addf(&buffer, "author %s\n", author);
1555        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1556        if (!encoding_is_utf8)
1557                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1558
1559        while (extra) {
1560                add_extra_header(&buffer, extra);
1561                extra = extra->next;
1562        }
1563        strbuf_addch(&buffer, '\n');
1564
1565        /* And add the comment */
1566        strbuf_add(&buffer, msg, msg_len);
1567
1568        /* And check the encoding */
1569        if (encoding_is_utf8 && !verify_utf8(&buffer))
1570                fprintf(stderr, commit_utf8_warn);
1571
1572        if (sign_commit && do_sign_commit(&buffer, sign_commit))
1573                return -1;
1574
1575        result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
1576        strbuf_release(&buffer);
1577        return result;
1578}
1579
1580struct commit *get_merge_parent(const char *name)
1581{
1582        struct object *obj;
1583        struct commit *commit;
1584        unsigned char sha1[20];
1585        if (get_sha1(name, sha1))
1586                return NULL;
1587        obj = parse_object(sha1);
1588        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1589        if (commit && !commit->util) {
1590                struct merge_remote_desc *desc;
1591                desc = xmalloc(sizeof(*desc));
1592                desc->obj = obj;
1593                desc->name = strdup(name);
1594                commit->util = desc;
1595        }
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
1626void print_commit_list(struct commit_list *list,
1627                       const char *format_cur,
1628                       const char *format_last)
1629{
1630        for ( ; list; list = list->next) {
1631                const char *format = list->next ? format_cur : format_last;
1632                printf(format, sha1_to_hex(list->item->object.sha1));
1633        }
1634}
1635
1636const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1637{
1638        int key_len = strlen(key);
1639        const char *line = msg;
1640
1641        while (line) {
1642                const char *eol = strchrnul(line, '\n');
1643
1644                if (line == eol)
1645                        return NULL;
1646
1647                if (eol - line > key_len &&
1648                    !strncmp(line, key, key_len) &&
1649                    line[key_len] == ' ') {
1650                        *out_len = eol - line - key_len - 1;
1651                        return line + key_len + 1;
1652                }
1653                line = *eol ? eol + 1 : NULL;
1654        }
1655        return NULL;
1656}
1657
1658/*
1659 * Inspect sb and determine the true "end" of the log message, in
1660 * order to find where to put a new Signed-off-by: line.  Ignored are
1661 * trailing comment lines and blank lines, and also the traditional
1662 * "Conflicts:" block that is not commented out, so that we can use
1663 * "git commit -s --amend" on an existing commit that forgot to remove
1664 * it.
1665 *
1666 * Returns the number of bytes from the tail to ignore, to be fed as
1667 * the second parameter to append_signoff().
1668 */
1669int ignore_non_trailer(struct strbuf *sb)
1670{
1671        int boc = 0;
1672        int bol = 0;
1673        int in_old_conflicts_block = 0;
1674
1675        while (bol < sb->len) {
1676                char *next_line;
1677
1678                if (!(next_line = memchr(sb->buf + bol, '\n', sb->len - bol)))
1679                        next_line = sb->buf + sb->len;
1680                else
1681                        next_line++;
1682
1683                if (sb->buf[bol] == comment_line_char || sb->buf[bol] == '\n') {
1684                        /* is this the first of the run of comments? */
1685                        if (!boc)
1686                                boc = bol;
1687                        /* otherwise, it is just continuing */
1688                } else if (starts_with(sb->buf + bol, "Conflicts:\n")) {
1689                        in_old_conflicts_block = 1;
1690                        if (!boc)
1691                                boc = bol;
1692                } else if (in_old_conflicts_block && sb->buf[bol] == '\t') {
1693                        ; /* a pathname in the conflicts block */
1694                } else if (boc) {
1695                        /* the previous was not trailing comment */
1696                        boc = 0;
1697                        in_old_conflicts_block = 0;
1698                }
1699                bol = next_line - sb->buf;
1700        }
1701        return boc ? sb->len - boc : 0;
1702}