Andrew's git / gitweb.git / commit.c
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commit.con commit Doc/gitsubmodules: make some changes to improve readability and syntax (4f73a7f)
   1#include "cache.h"
   2#include "tag.h"
   3#include "commit.h"
   4#include "pkt-line.h"
   5#include "utf8.h"
   6#include "diff.h"
   7#include "revision.h"
   8#include "notes.h"
   9#include "gpg-interface.h"
  10#include "mergesort.h"
  11#include "commit-slab.h"
  12#include "prio-queue.h"
  13#include "sha1-lookup.h"
  14#include "wt-status.h"
  15
  16static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
  17
  18int save_commit_buffer = 1;
  19
  20const char *commit_type = "commit";
  21
  22struct commit *lookup_commit_reference_gently(const struct object_id *oid,
  23                                              int quiet)
  24{
  25        struct object *obj = deref_tag(parse_object(oid), NULL, 0);
  26
  27        if (!obj)
  28                return NULL;
  29        return object_as_type(obj, OBJ_COMMIT, quiet);
  30}
  31
  32struct commit *lookup_commit_reference(const struct object_id *oid)
  33{
  34        return lookup_commit_reference_gently(oid, 0);
  35}
  36
  37struct commit *lookup_commit_or_die(const struct object_id *oid, const char *ref_name)
  38{
  39        struct commit *c = lookup_commit_reference(oid);
  40        if (!c)
  41                die(_("could not parse %s"), ref_name);
  42        if (oidcmp(oid, &c->object.oid)) {
  43                warning(_("%s %s is not a commit!"),
  44                        ref_name, oid_to_hex(oid));
  45        }
  46        return c;
  47}
  48
  49struct commit *lookup_commit(const struct object_id *oid)
  50{
  51        struct object *obj = lookup_object(oid->hash);
  52        if (!obj)
  53                return create_object(oid->hash, alloc_commit_node());
  54        return object_as_type(obj, OBJ_COMMIT, 0);
  55}
  56
  57struct commit *lookup_commit_reference_by_name(const char *name)
  58{
  59        struct object_id oid;
  60        struct commit *commit;
  61
  62        if (get_oid_committish(name, &oid))
  63                return NULL;
  64        commit = lookup_commit_reference(&oid);
  65        if (parse_commit(commit))
  66                return NULL;
  67        return commit;
  68}
  69
  70static timestamp_t parse_commit_date(const char *buf, const char *tail)
  71{
  72        const char *dateptr;
  73
  74        if (buf + 6 >= tail)
  75                return 0;
  76        if (memcmp(buf, "author", 6))
  77                return 0;
  78        while (buf < tail && *buf++ != '\n')
  79                /* nada */;
  80        if (buf + 9 >= tail)
  81                return 0;
  82        if (memcmp(buf, "committer", 9))
  83                return 0;
  84        while (buf < tail && *buf++ != '>')
  85                /* nada */;
  86        if (buf >= tail)
  87                return 0;
  88        dateptr = buf;
  89        while (buf < tail && *buf++ != '\n')
  90                /* nada */;
  91        if (buf >= tail)
  92                return 0;
  93        /* dateptr < buf && buf[-1] == '\n', so parsing will stop at buf-1 */
  94        return parse_timestamp(dateptr, NULL, 10);
  95}
  96
  97static struct commit_graft **commit_graft;
  98static int commit_graft_alloc, commit_graft_nr;
  99
 100static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
 101{
 102        struct commit_graft **commit_graft_table = table;
 103        return commit_graft_table[index]->oid.hash;
 104}
 105
 106static int commit_graft_pos(const unsigned char *sha1)
 107{
 108        return sha1_pos(sha1, commit_graft, commit_graft_nr,
 109                        commit_graft_sha1_access);
 110}
 111
 112int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 113{
 114        int pos = commit_graft_pos(graft->oid.hash);
 115
 116        if (0 <= pos) {
 117                if (ignore_dups)
 118                        free(graft);
 119                else {
 120                        free(commit_graft[pos]);
 121                        commit_graft[pos] = graft;
 122                }
 123                return 1;
 124        }
 125        pos = -pos - 1;
 126        ALLOC_GROW(commit_graft, commit_graft_nr + 1, commit_graft_alloc);
 127        commit_graft_nr++;
 128        if (pos < commit_graft_nr)
 129                memmove(commit_graft + pos + 1,
 130                        commit_graft + pos,
 131                        (commit_graft_nr - pos - 1) *
 132                        sizeof(*commit_graft));
 133        commit_graft[pos] = graft;
 134        return 0;
 135}
 136
 137struct commit_graft *read_graft_line(struct strbuf *line)
 138{
 139        /* The format is just "Commit Parent1 Parent2 ...\n" */
 140        int i, phase;
 141        const char *tail = NULL;
 142        struct commit_graft *graft = NULL;
 143        struct object_id dummy_oid, *oid;
 144
 145        strbuf_rtrim(line);
 146        if (!line->len || line->buf[0] == '#')
 147                return NULL;
 148        /*
 149         * phase 0 verifies line, counts hashes in line and allocates graft
 150         * phase 1 fills graft
 151         */
 152        for (phase = 0; phase < 2; phase++) {
 153                oid = graft ? &graft->oid : &dummy_oid;
 154                if (parse_oid_hex(line->buf, oid, &tail))
 155                        goto bad_graft_data;
 156                for (i = 0; *tail != '\0'; i++) {
 157                        oid = graft ? &graft->parent[i] : &dummy_oid;
 158                        if (!isspace(*tail++) || parse_oid_hex(tail, oid, &tail))
 159                                goto bad_graft_data;
 160                }
 161                if (!graft) {
 162                        graft = xmalloc(st_add(sizeof(*graft),
 163                                               st_mult(sizeof(struct object_id), i)));
 164                        graft->nr_parent = i;
 165                }
 166        }
 167        return graft;
 168
 169bad_graft_data:
 170        error("bad graft data: %s", line->buf);
 171        assert(!graft);
 172        return NULL;
 173}
 174
 175static int read_graft_file(const char *graft_file)
 176{
 177        FILE *fp = fopen_or_warn(graft_file, "r");
 178        struct strbuf buf = STRBUF_INIT;
 179        if (!fp)
 180                return -1;
 181        while (!strbuf_getwholeline(&buf, fp, '\n')) {
 182                /* The format is just "Commit Parent1 Parent2 ...\n" */
 183                struct commit_graft *graft = read_graft_line(&buf);
 184                if (!graft)
 185                        continue;
 186                if (register_commit_graft(graft, 1))
 187                        error("duplicate graft data: %s", buf.buf);
 188        }
 189        fclose(fp);
 190        strbuf_release(&buf);
 191        return 0;
 192}
 193
 194static void prepare_commit_graft(void)
 195{
 196        static int commit_graft_prepared;
 197        char *graft_file;
 198
 199        if (commit_graft_prepared)
 200                return;
 201        graft_file = get_graft_file();
 202        read_graft_file(graft_file);
 203        /* make sure shallows are read */
 204        is_repository_shallow();
 205        commit_graft_prepared = 1;
 206}
 207
 208struct commit_graft *lookup_commit_graft(const struct object_id *oid)
 209{
 210        int pos;
 211        prepare_commit_graft();
 212        pos = commit_graft_pos(oid->hash);
 213        if (pos < 0)
 214                return NULL;
 215        return commit_graft[pos];
 216}
 217
 218int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
 219{
 220        int i, ret;
 221        for (i = ret = 0; i < commit_graft_nr && !ret; i++)
 222                ret = fn(commit_graft[i], cb_data);
 223        return ret;
 224}
 225
 226int unregister_shallow(const struct object_id *oid)
 227{
 228        int pos = commit_graft_pos(oid->hash);
 229        if (pos < 0)
 230                return -1;
 231        if (pos + 1 < commit_graft_nr)
 232                MOVE_ARRAY(commit_graft + pos, commit_graft + pos + 1,
 233                           commit_graft_nr - pos - 1);
 234        commit_graft_nr--;
 235        return 0;
 236}
 237
 238struct commit_buffer {
 239        void *buffer;
 240        unsigned long size;
 241};
 242define_commit_slab(buffer_slab, struct commit_buffer);
 243static struct buffer_slab buffer_slab = COMMIT_SLAB_INIT(1, buffer_slab);
 244
 245void set_commit_buffer(struct commit *commit, void *buffer, unsigned long size)
 246{
 247        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 248        v->buffer = buffer;
 249        v->size = size;
 250}
 251
 252const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
 253{
 254        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 255        if (!v) {
 256                if (sizep)
 257                        *sizep = 0;
 258                return NULL;
 259        }
 260        if (sizep)
 261                *sizep = v->size;
 262        return v->buffer;
 263}
 264
 265const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
 266{
 267        const void *ret = get_cached_commit_buffer(commit, sizep);
 268        if (!ret) {
 269                enum object_type type;
 270                unsigned long size;
 271                ret = read_sha1_file(commit->object.oid.hash, &type, &size);
 272                if (!ret)
 273                        die("cannot read commit object %s",
 274                            oid_to_hex(&commit->object.oid));
 275                if (type != OBJ_COMMIT)
 276                        die("expected commit for %s, got %s",
 277                            oid_to_hex(&commit->object.oid), typename(type));
 278                if (sizep)
 279                        *sizep = size;
 280        }
 281        return ret;
 282}
 283
 284void unuse_commit_buffer(const struct commit *commit, const void *buffer)
 285{
 286        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 287        if (!(v && v->buffer == buffer))
 288                free((void *)buffer);
 289}
 290
 291void free_commit_buffer(struct commit *commit)
 292{
 293        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 294        if (v) {
 295                FREE_AND_NULL(v->buffer);
 296                v->size = 0;
 297        }
 298}
 299
 300const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 301{
 302        struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 303        void *ret;
 304
 305        if (!v) {
 306                if (sizep)
 307                        *sizep = 0;
 308                return NULL;
 309        }
 310        ret = v->buffer;
 311        if (sizep)
 312                *sizep = v->size;
 313
 314        v->buffer = NULL;
 315        v->size = 0;
 316        return ret;
 317}
 318
 319int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
 320{
 321        const char *tail = buffer;
 322        const char *bufptr = buffer;
 323        struct object_id parent;
 324        struct commit_list **pptr;
 325        struct commit_graft *graft;
 326        const int tree_entry_len = GIT_SHA1_HEXSZ + 5;
 327        const int parent_entry_len = GIT_SHA1_HEXSZ + 7;
 328
 329        if (item->object.parsed)
 330                return 0;
 331        item->object.parsed = 1;
 332        tail += size;
 333        if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
 334                        bufptr[tree_entry_len] != '\n')
 335                return error("bogus commit object %s", oid_to_hex(&item->object.oid));
 336        if (get_sha1_hex(bufptr + 5, parent.hash) < 0)
 337                return error("bad tree pointer in commit %s",
 338                             oid_to_hex(&item->object.oid));
 339        item->tree = lookup_tree(&parent);
 340        bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
 341        pptr = &item->parents;
 342
 343        graft = lookup_commit_graft(&item->object.oid);
 344        while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
 345                struct commit *new_parent;
 346
 347                if (tail <= bufptr + parent_entry_len + 1 ||
 348                    get_sha1_hex(bufptr + 7, parent.hash) ||
 349                    bufptr[parent_entry_len] != '\n')
 350                        return error("bad parents in commit %s", oid_to_hex(&item->object.oid));
 351                bufptr += parent_entry_len + 1;
 352                /*
 353                 * The clone is shallow if nr_parent < 0, and we must
 354                 * not traverse its real parents even when we unhide them.
 355                 */
 356                if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
 357                        continue;
 358                new_parent = lookup_commit(&parent);
 359                if (new_parent)
 360                        pptr = &commit_list_insert(new_parent, pptr)->next;
 361        }
 362        if (graft) {
 363                int i;
 364                struct commit *new_parent;
 365                for (i = 0; i < graft->nr_parent; i++) {
 366                        new_parent = lookup_commit(&graft->parent[i]);
 367                        if (!new_parent)
 368                                continue;
 369                        pptr = &commit_list_insert(new_parent, pptr)->next;
 370                }
 371        }
 372        item->date = parse_commit_date(bufptr, tail);
 373
 374        return 0;
 375}
 376
 377int parse_commit_gently(struct commit *item, int quiet_on_missing)
 378{
 379        enum object_type type;
 380        void *buffer;
 381        unsigned long size;
 382        int ret;
 383
 384        if (!item)
 385                return -1;
 386        if (item->object.parsed)
 387                return 0;
 388        buffer = read_sha1_file(item->object.oid.hash, &type, &size);
 389        if (!buffer)
 390                return quiet_on_missing ? -1 :
 391                        error("Could not read %s",
 392                             oid_to_hex(&item->object.oid));
 393        if (type != OBJ_COMMIT) {
 394                free(buffer);
 395                return error("Object %s not a commit",
 396                             oid_to_hex(&item->object.oid));
 397        }
 398        ret = parse_commit_buffer(item, buffer, size);
 399        if (save_commit_buffer && !ret) {
 400                set_commit_buffer(item, buffer, size);
 401                return 0;
 402        }
 403        free(buffer);
 404        return ret;
 405}
 406
 407void parse_commit_or_die(struct commit *item)
 408{
 409        if (parse_commit(item))
 410                die("unable to parse commit %s",
 411                    item ? oid_to_hex(&item->object.oid) : "(null)");
 412}
 413
 414int find_commit_subject(const char *commit_buffer, const char **subject)
 415{
 416        const char *eol;
 417        const char *p = commit_buffer;
 418
 419        while (*p && (*p != '\n' || p[1] != '\n'))
 420                p++;
 421        if (*p) {
 422                p = skip_blank_lines(p + 2);
 423                eol = strchrnul(p, '\n');
 424        } else
 425                eol = p;
 426
 427        *subject = p;
 428
 429        return eol - p;
 430}
 431
 432struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 433{
 434        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 435        new_list->item = item;
 436        new_list->next = *list_p;
 437        *list_p = new_list;
 438        return new_list;
 439}
 440
 441unsigned commit_list_count(const struct commit_list *l)
 442{
 443        unsigned c = 0;
 444        for (; l; l = l->next )
 445                c++;
 446        return c;
 447}
 448
 449struct commit_list *copy_commit_list(struct commit_list *list)
 450{
 451        struct commit_list *head = NULL;
 452        struct commit_list **pp = &head;
 453        while (list) {
 454                pp = commit_list_append(list->item, pp);
 455                list = list->next;
 456        }
 457        return head;
 458}
 459
 460void free_commit_list(struct commit_list *list)
 461{
 462        while (list)
 463                pop_commit(&list);
 464}
 465
 466struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 467{
 468        struct commit_list **pp = list;
 469        struct commit_list *p;
 470        while ((p = *pp) != NULL) {
 471                if (p->item->date < item->date) {
 472                        break;
 473                }
 474                pp = &p->next;
 475        }
 476        return commit_list_insert(item, pp);
 477}
 478
 479static int commit_list_compare_by_date(const void *a, const void *b)
 480{
 481        timestamp_t a_date = ((const struct commit_list *)a)->item->date;
 482        timestamp_t b_date = ((const struct commit_list *)b)->item->date;
 483        if (a_date < b_date)
 484                return 1;
 485        if (a_date > b_date)
 486                return -1;
 487        return 0;
 488}
 489
 490static void *commit_list_get_next(const void *a)
 491{
 492        return ((const struct commit_list *)a)->next;
 493}
 494
 495static void commit_list_set_next(void *a, void *next)
 496{
 497        ((struct commit_list *)a)->next = next;
 498}
 499
 500void commit_list_sort_by_date(struct commit_list **list)
 501{
 502        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 503                                commit_list_compare_by_date);
 504}
 505
 506struct commit *pop_most_recent_commit(struct commit_list **list,
 507                                      unsigned int mark)
 508{
 509        struct commit *ret = pop_commit(list);
 510        struct commit_list *parents = ret->parents;
 511
 512        while (parents) {
 513                struct commit *commit = parents->item;
 514                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 515                        commit->object.flags |= mark;
 516                        commit_list_insert_by_date(commit, list);
 517                }
 518                parents = parents->next;
 519        }
 520        return ret;
 521}
 522
 523static void clear_commit_marks_1(struct commit_list **plist,
 524                                 struct commit *commit, unsigned int mark)
 525{
 526        while (commit) {
 527                struct commit_list *parents;
 528
 529                if (!(mark & commit->object.flags))
 530                        return;
 531
 532                commit->object.flags &= ~mark;
 533
 534                parents = commit->parents;
 535                if (!parents)
 536                        return;
 537
 538                while ((parents = parents->next))
 539                        commit_list_insert(parents->item, plist);
 540
 541                commit = commit->parents->item;
 542        }
 543}
 544
 545void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 546{
 547        struct commit_list *list = NULL;
 548
 549        while (nr--) {
 550                commit_list_insert(*commit, &list);
 551                commit++;
 552        }
 553        while (list)
 554                clear_commit_marks_1(&list, pop_commit(&list), mark);
 555}
 556
 557void clear_commit_marks(struct commit *commit, unsigned int mark)
 558{
 559        clear_commit_marks_many(1, &commit, mark);
 560}
 561
 562void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
 563{
 564        struct object *object;
 565        struct commit *commit;
 566        unsigned int i;
 567
 568        for (i = 0; i < a->nr; i++) {
 569                object = a->objects[i].item;
 570                commit = lookup_commit_reference_gently(&object->oid, 1);
 571                if (commit)
 572                        clear_commit_marks(commit, mark);
 573        }
 574}
 575
 576struct commit *pop_commit(struct commit_list **stack)
 577{
 578        struct commit_list *top = *stack;
 579        struct commit *item = top ? top->item : NULL;
 580
 581        if (top) {
 582                *stack = top->next;
 583                free(top);
 584        }
 585        return item;
 586}
 587
 588/*
 589 * Topological sort support
 590 */
 591
 592/* count number of children that have not been emitted */
 593define_commit_slab(indegree_slab, int);
 594
 595/* record author-date for each commit object */
 596define_commit_slab(author_date_slab, unsigned long);
 597
 598static void record_author_date(struct author_date_slab *author_date,
 599                               struct commit *commit)
 600{
 601        const char *buffer = get_commit_buffer(commit, NULL);
 602        struct ident_split ident;
 603        const char *ident_line;
 604        size_t ident_len;
 605        char *date_end;
 606        timestamp_t date;
 607
 608        ident_line = find_commit_header(buffer, "author", &ident_len);
 609        if (!ident_line)
 610                goto fail_exit; /* no author line */
 611        if (split_ident_line(&ident, ident_line, ident_len) ||
 612            !ident.date_begin || !ident.date_end)
 613                goto fail_exit; /* malformed "author" line */
 614
 615        date = parse_timestamp(ident.date_begin, &date_end, 10);
 616        if (date_end != ident.date_end)
 617                goto fail_exit; /* malformed date */
 618        *(author_date_slab_at(author_date, commit)) = date;
 619
 620fail_exit:
 621        unuse_commit_buffer(commit, buffer);
 622}
 623
 624static int compare_commits_by_author_date(const void *a_, const void *b_,
 625                                          void *cb_data)
 626{
 627        const struct commit *a = a_, *b = b_;
 628        struct author_date_slab *author_date = cb_data;
 629        timestamp_t a_date = *(author_date_slab_at(author_date, a));
 630        timestamp_t b_date = *(author_date_slab_at(author_date, b));
 631
 632        /* newer commits with larger date first */
 633        if (a_date < b_date)
 634                return 1;
 635        else if (a_date > b_date)
 636                return -1;
 637        return 0;
 638}
 639
 640int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 641{
 642        const struct commit *a = a_, *b = b_;
 643        /* newer commits with larger date first */
 644        if (a->date < b->date)
 645                return 1;
 646        else if (a->date > b->date)
 647                return -1;
 648        return 0;
 649}
 650
 651/*
 652 * Performs an in-place topological sort on the list supplied.
 653 */
 654void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 655{
 656        struct commit_list *next, *orig = *list;
 657        struct commit_list **pptr;
 658        struct indegree_slab indegree;
 659        struct prio_queue queue;
 660        struct commit *commit;
 661        struct author_date_slab author_date;
 662
 663        if (!orig)
 664                return;
 665        *list = NULL;
 666
 667        init_indegree_slab(&indegree);
 668        memset(&queue, '\0', sizeof(queue));
 669
 670        switch (sort_order) {
 671        default: /* REV_SORT_IN_GRAPH_ORDER */
 672                queue.compare = NULL;
 673                break;
 674        case REV_SORT_BY_COMMIT_DATE:
 675                queue.compare = compare_commits_by_commit_date;
 676                break;
 677        case REV_SORT_BY_AUTHOR_DATE:
 678                init_author_date_slab(&author_date);
 679                queue.compare = compare_commits_by_author_date;
 680                queue.cb_data = &author_date;
 681                break;
 682        }
 683
 684        /* Mark them and clear the indegree */
 685        for (next = orig; next; next = next->next) {
 686                struct commit *commit = next->item;
 687                *(indegree_slab_at(&indegree, commit)) = 1;
 688                /* also record the author dates, if needed */
 689                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 690                        record_author_date(&author_date, commit);
 691        }
 692
 693        /* update the indegree */
 694        for (next = orig; next; next = next->next) {
 695                struct commit_list *parents = next->item->parents;
 696                while (parents) {
 697                        struct commit *parent = parents->item;
 698                        int *pi = indegree_slab_at(&indegree, parent);
 699
 700                        if (*pi)
 701                                (*pi)++;
 702                        parents = parents->next;
 703                }
 704        }
 705
 706        /*
 707         * find the tips
 708         *
 709         * tips are nodes not reachable from any other node in the list
 710         *
 711         * the tips serve as a starting set for the work queue.
 712         */
 713        for (next = orig; next; next = next->next) {
 714                struct commit *commit = next->item;
 715
 716                if (*(indegree_slab_at(&indegree, commit)) == 1)
 717                        prio_queue_put(&queue, commit);
 718        }
 719
 720        /*
 721         * This is unfortunate; the initial tips need to be shown
 722         * in the order given from the revision traversal machinery.
 723         */
 724        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 725                prio_queue_reverse(&queue);
 726
 727        /* We no longer need the commit list */
 728        free_commit_list(orig);
 729
 730        pptr = list;
 731        *list = NULL;
 732        while ((commit = prio_queue_get(&queue)) != NULL) {
 733                struct commit_list *parents;
 734
 735                for (parents = commit->parents; parents ; parents = parents->next) {
 736                        struct commit *parent = parents->item;
 737                        int *pi = indegree_slab_at(&indegree, parent);
 738
 739                        if (!*pi)
 740                                continue;
 741
 742                        /*
 743                         * parents are only enqueued for emission
 744                         * when all their children have been emitted thereby
 745                         * guaranteeing topological order.
 746                         */
 747                        if (--(*pi) == 1)
 748                                prio_queue_put(&queue, parent);
 749                }
 750                /*
 751                 * all children of commit have already been
 752                 * emitted. we can emit it now.
 753                 */
 754                *(indegree_slab_at(&indegree, commit)) = 0;
 755
 756                pptr = &commit_list_insert(commit, pptr)->next;
 757        }
 758
 759        clear_indegree_slab(&indegree);
 760        clear_prio_queue(&queue);
 761        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 762                clear_author_date_slab(&author_date);
 763}
 764
 765/* merge-base stuff */
 766
 767/* Remember to update object flag allocation in object.h */
 768#define PARENT1         (1u<<16)
 769#define PARENT2         (1u<<17)
 770#define STALE           (1u<<18)
 771#define RESULT          (1u<<19)
 772
 773static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 774
 775static int queue_has_nonstale(struct prio_queue *queue)
 776{
 777        int i;
 778        for (i = 0; i < queue->nr; i++) {
 779                struct commit *commit = queue->array[i].data;
 780                if (!(commit->object.flags & STALE))
 781                        return 1;
 782        }
 783        return 0;
 784}
 785
 786/* all input commits in one and twos[] must have been parsed! */
 787static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
 788{
 789        struct prio_queue queue = { compare_commits_by_commit_date };
 790        struct commit_list *result = NULL;
 791        int i;
 792
 793        one->object.flags |= PARENT1;
 794        if (!n) {
 795                commit_list_append(one, &result);
 796                return result;
 797        }
 798        prio_queue_put(&queue, one);
 799
 800        for (i = 0; i < n; i++) {
 801                twos[i]->object.flags |= PARENT2;
 802                prio_queue_put(&queue, twos[i]);
 803        }
 804
 805        while (queue_has_nonstale(&queue)) {
 806                struct commit *commit = prio_queue_get(&queue);
 807                struct commit_list *parents;
 808                int flags;
 809
 810                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 811                if (flags == (PARENT1 | PARENT2)) {
 812                        if (!(commit->object.flags & RESULT)) {
 813                                commit->object.flags |= RESULT;
 814                                commit_list_insert_by_date(commit, &result);
 815                        }
 816                        /* Mark parents of a found merge stale */
 817                        flags |= STALE;
 818                }
 819                parents = commit->parents;
 820                while (parents) {
 821                        struct commit *p = parents->item;
 822                        parents = parents->next;
 823                        if ((p->object.flags & flags) == flags)
 824                                continue;
 825                        if (parse_commit(p))
 826                                return NULL;
 827                        p->object.flags |= flags;
 828                        prio_queue_put(&queue, p);
 829                }
 830        }
 831
 832        clear_prio_queue(&queue);
 833        return result;
 834}
 835
 836static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 837{
 838        struct commit_list *list = NULL;
 839        struct commit_list *result = NULL;
 840        int i;
 841
 842        for (i = 0; i < n; i++) {
 843                if (one == twos[i])
 844                        /*
 845                         * We do not mark this even with RESULT so we do not
 846                         * have to clean it up.
 847                         */
 848                        return commit_list_insert(one, &result);
 849        }
 850
 851        if (parse_commit(one))
 852                return NULL;
 853        for (i = 0; i < n; i++) {
 854                if (parse_commit(twos[i]))
 855                        return NULL;
 856        }
 857
 858        list = paint_down_to_common(one, n, twos);
 859
 860        while (list) {
 861                struct commit *commit = pop_commit(&list);
 862                if (!(commit->object.flags & STALE))
 863                        commit_list_insert_by_date(commit, &result);
 864        }
 865        return result;
 866}
 867
 868struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 869{
 870        struct commit_list *i, *j, *k, *ret = NULL;
 871
 872        if (!in)
 873                return ret;
 874
 875        commit_list_insert(in->item, &ret);
 876
 877        for (i = in->next; i; i = i->next) {
 878                struct commit_list *new = NULL, *end = NULL;
 879
 880                for (j = ret; j; j = j->next) {
 881                        struct commit_list *bases;
 882                        bases = get_merge_bases(i->item, j->item);
 883                        if (!new)
 884                                new = bases;
 885                        else
 886                                end->next = bases;
 887                        for (k = bases; k; k = k->next)
 888                                end = k;
 889                }
 890                ret = new;
 891        }
 892        return ret;
 893}
 894
 895static int remove_redundant(struct commit **array, int cnt)
 896{
 897        /*
 898         * Some commit in the array may be an ancestor of
 899         * another commit.  Move such commit to the end of
 900         * the array, and return the number of commits that
 901         * are independent from each other.
 902         */
 903        struct commit **work;
 904        unsigned char *redundant;
 905        int *filled_index;
 906        int i, j, filled;
 907
 908        work = xcalloc(cnt, sizeof(*work));
 909        redundant = xcalloc(cnt, 1);
 910        ALLOC_ARRAY(filled_index, cnt - 1);
 911
 912        for (i = 0; i < cnt; i++)
 913                parse_commit(array[i]);
 914        for (i = 0; i < cnt; i++) {
 915                struct commit_list *common;
 916
 917                if (redundant[i])
 918                        continue;
 919                for (j = filled = 0; j < cnt; j++) {
 920                        if (i == j || redundant[j])
 921                                continue;
 922                        filled_index[filled] = j;
 923                        work[filled++] = array[j];
 924                }
 925                common = paint_down_to_common(array[i], filled, work);
 926                if (array[i]->object.flags & PARENT2)
 927                        redundant[i] = 1;
 928                for (j = 0; j < filled; j++)
 929                        if (work[j]->object.flags & PARENT1)
 930                                redundant[filled_index[j]] = 1;
 931                clear_commit_marks(array[i], all_flags);
 932                for (j = 0; j < filled; j++)
 933                        clear_commit_marks(work[j], all_flags);
 934                free_commit_list(common);
 935        }
 936
 937        /* Now collect the result */
 938        COPY_ARRAY(work, array, cnt);
 939        for (i = filled = 0; i < cnt; i++)
 940                if (!redundant[i])
 941                        array[filled++] = work[i];
 942        for (j = filled, i = 0; i < cnt; i++)
 943                if (redundant[i])
 944                        array[j++] = work[i];
 945        free(work);
 946        free(redundant);
 947        free(filled_index);
 948        return filled;
 949}
 950
 951static struct commit_list *get_merge_bases_many_0(struct commit *one,
 952                                                  int n,
 953                                                  struct commit **twos,
 954                                                  int cleanup)
 955{
 956        struct commit_list *list;
 957        struct commit **rslt;
 958        struct commit_list *result;
 959        int cnt, i;
 960
 961        result = merge_bases_many(one, n, twos);
 962        for (i = 0; i < n; i++) {
 963                if (one == twos[i])
 964                        return result;
 965        }
 966        if (!result || !result->next) {
 967                if (cleanup) {
 968                        clear_commit_marks(one, all_flags);
 969                        clear_commit_marks_many(n, twos, all_flags);
 970                }
 971                return result;
 972        }
 973
 974        /* There are more than one */
 975        cnt = commit_list_count(result);
 976        rslt = xcalloc(cnt, sizeof(*rslt));
 977        for (list = result, i = 0; list; list = list->next)
 978                rslt[i++] = list->item;
 979        free_commit_list(result);
 980
 981        clear_commit_marks(one, all_flags);
 982        clear_commit_marks_many(n, twos, all_flags);
 983
 984        cnt = remove_redundant(rslt, cnt);
 985        result = NULL;
 986        for (i = 0; i < cnt; i++)
 987                commit_list_insert_by_date(rslt[i], &result);
 988        free(rslt);
 989        return result;
 990}
 991
 992struct commit_list *get_merge_bases_many(struct commit *one,
 993                                         int n,
 994                                         struct commit **twos)
 995{
 996        return get_merge_bases_many_0(one, n, twos, 1);
 997}
 998
 999struct commit_list *get_merge_bases_many_dirty(struct commit *one,
1000                                               int n,
1001                                               struct commit **twos)
1002{
1003        return get_merge_bases_many_0(one, n, twos, 0);
1004}
1005
1006struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
1007{
1008        return get_merge_bases_many_0(one, 1, &two, 1);
1009}
1010
1011/*
1012 * Is "commit" a descendant of one of the elements on the "with_commit" list?
1013 */
1014int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
1015{
1016        if (!with_commit)
1017                return 1;
1018        while (with_commit) {
1019                struct commit *other;
1020
1021                other = with_commit->item;
1022                with_commit = with_commit->next;
1023                if (in_merge_bases(other, commit))
1024                        return 1;
1025        }
1026        return 0;
1027}
1028
1029/*
1030 * Is "commit" an ancestor of one of the "references"?
1031 */
1032int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1033{
1034        struct commit_list *bases;
1035        int ret = 0, i;
1036
1037        if (parse_commit(commit))
1038                return ret;
1039        for (i = 0; i < nr_reference; i++)
1040                if (parse_commit(reference[i]))
1041                        return ret;
1042
1043        bases = paint_down_to_common(commit, nr_reference, reference);
1044        if (commit->object.flags & PARENT2)
1045                ret = 1;
1046        clear_commit_marks(commit, all_flags);
1047        clear_commit_marks_many(nr_reference, reference, all_flags);
1048        free_commit_list(bases);
1049        return ret;
1050}
1051
1052/*
1053 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1054 */
1055int in_merge_bases(struct commit *commit, struct commit *reference)
1056{
1057        return in_merge_bases_many(commit, 1, &reference);
1058}
1059
1060struct commit_list *reduce_heads(struct commit_list *heads)
1061{
1062        struct commit_list *p;
1063        struct commit_list *result = NULL, **tail = &result;
1064        struct commit **array;
1065        int num_head, i;
1066
1067        if (!heads)
1068                return NULL;
1069
1070        /* Uniquify */
1071        for (p = heads; p; p = p->next)
1072                p->item->object.flags &= ~STALE;
1073        for (p = heads, num_head = 0; p; p = p->next) {
1074                if (p->item->object.flags & STALE)
1075                        continue;
1076                p->item->object.flags |= STALE;
1077                num_head++;
1078        }
1079        array = xcalloc(num_head, sizeof(*array));
1080        for (p = heads, i = 0; p; p = p->next) {
1081                if (p->item->object.flags & STALE) {
1082                        array[i++] = p->item;
1083                        p->item->object.flags &= ~STALE;
1084                }
1085        }
1086        num_head = remove_redundant(array, num_head);
1087        for (i = 0; i < num_head; i++)
1088                tail = &commit_list_insert(array[i], tail)->next;
1089        free(array);
1090        return result;
1091}
1092
1093void reduce_heads_replace(struct commit_list **heads)
1094{
1095        struct commit_list *result = reduce_heads(*heads);
1096        free_commit_list(*heads);
1097        *heads = result;
1098}
1099
1100static const char gpg_sig_header[] = "gpgsig";
1101static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1102
1103static int do_sign_commit(struct strbuf *buf, const char *keyid)
1104{
1105        struct strbuf sig = STRBUF_INIT;
1106        int inspos, copypos;
1107        const char *eoh;
1108
1109        /* find the end of the header */
1110        eoh = strstr(buf->buf, "\n\n");
1111        if (!eoh)
1112                inspos = buf->len;
1113        else
1114                inspos = eoh - buf->buf + 1;
1115
1116        if (!keyid || !*keyid)
1117                keyid = get_signing_key();
1118        if (sign_buffer(buf, &sig, keyid)) {
1119                strbuf_release(&sig);
1120                return -1;
1121        }
1122
1123        for (copypos = 0; sig.buf[copypos]; ) {
1124                const char *bol = sig.buf + copypos;
1125                const char *eol = strchrnul(bol, '\n');
1126                int len = (eol - bol) + !!*eol;
1127
1128                if (!copypos) {
1129                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1130                        inspos += gpg_sig_header_len;
1131                }
1132                strbuf_insert(buf, inspos++, " ", 1);
1133                strbuf_insert(buf, inspos, bol, len);
1134                inspos += len;
1135                copypos += len;
1136        }
1137        strbuf_release(&sig);
1138        return 0;
1139}
1140
1141int parse_signed_commit(const struct commit *commit,
1142                        struct strbuf *payload, struct strbuf *signature)
1143{
1144
1145        unsigned long size;
1146        const char *buffer = get_commit_buffer(commit, &size);
1147        int in_signature, saw_signature = -1;
1148        const char *line, *tail;
1149
1150        line = buffer;
1151        tail = buffer + size;
1152        in_signature = 0;
1153        saw_signature = 0;
1154        while (line < tail) {
1155                const char *sig = NULL;
1156                const char *next = memchr(line, '\n', tail - line);
1157
1158                next = next ? next + 1 : tail;
1159                if (in_signature && line[0] == ' ')
1160                        sig = line + 1;
1161                else if (starts_with(line, gpg_sig_header) &&
1162                         line[gpg_sig_header_len] == ' ')
1163                        sig = line + gpg_sig_header_len + 1;
1164                if (sig) {
1165                        strbuf_add(signature, sig, next - sig);
1166                        saw_signature = 1;
1167                        in_signature = 1;
1168                } else {
1169                        if (*line == '\n')
1170                                /* dump the whole remainder of the buffer */
1171                                next = tail;
1172                        strbuf_add(payload, line, next - line);
1173                        in_signature = 0;
1174                }
1175                line = next;
1176        }
1177        unuse_commit_buffer(commit, buffer);
1178        return saw_signature;
1179}
1180
1181int remove_signature(struct strbuf *buf)
1182{
1183        const char *line = buf->buf;
1184        const char *tail = buf->buf + buf->len;
1185        int in_signature = 0;
1186        const char *sig_start = NULL;
1187        const char *sig_end = NULL;
1188
1189        while (line < tail) {
1190                const char *next = memchr(line, '\n', tail - line);
1191                next = next ? next + 1 : tail;
1192
1193                if (in_signature && line[0] == ' ')
1194                        sig_end = next;
1195                else if (starts_with(line, gpg_sig_header) &&
1196                         line[gpg_sig_header_len] == ' ') {
1197                        sig_start = line;
1198                        sig_end = next;
1199                        in_signature = 1;
1200                } else {
1201                        if (*line == '\n')
1202                                /* dump the whole remainder of the buffer */
1203                                next = tail;
1204                        in_signature = 0;
1205                }
1206                line = next;
1207        }
1208
1209        if (sig_start)
1210                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1211
1212        return sig_start != NULL;
1213}
1214
1215static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1216{
1217        struct merge_remote_desc *desc;
1218        struct commit_extra_header *mergetag;
1219        char *buf;
1220        unsigned long size, len;
1221        enum object_type type;
1222
1223        desc = merge_remote_util(parent);
1224        if (!desc || !desc->obj)
1225                return;
1226        buf = read_sha1_file(desc->obj->oid.hash, &type, &size);
1227        if (!buf || type != OBJ_TAG)
1228                goto free_return;
1229        len = parse_signature(buf, size);
1230        if (size == len)
1231                goto free_return;
1232        /*
1233         * We could verify this signature and either omit the tag when
1234         * it does not validate, but the integrator may not have the
1235         * public key of the signer of the tag he is merging, while a
1236         * later auditor may have it while auditing, so let's not run
1237         * verify-signed-buffer here for now...
1238         *
1239         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1240         *      warn("warning: signed tag unverified.");
1241         */
1242        mergetag = xcalloc(1, sizeof(*mergetag));
1243        mergetag->key = xstrdup("mergetag");
1244        mergetag->value = buf;
1245        mergetag->len = size;
1246
1247        **tail = mergetag;
1248        *tail = &mergetag->next;
1249        return;
1250
1251free_return:
1252        free(buf);
1253}
1254
1255int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1256{
1257        struct strbuf payload = STRBUF_INIT;
1258        struct strbuf signature = STRBUF_INIT;
1259        int ret = 1;
1260
1261        sigc->result = 'N';
1262
1263        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1264                goto out;
1265        ret = check_signature(payload.buf, payload.len, signature.buf,
1266                signature.len, sigc);
1267
1268 out:
1269        strbuf_release(&payload);
1270        strbuf_release(&signature);
1271
1272        return ret;
1273}
1274
1275
1276
1277void append_merge_tag_headers(struct commit_list *parents,
1278                              struct commit_extra_header ***tail)
1279{
1280        while (parents) {
1281                struct commit *parent = parents->item;
1282                handle_signed_tag(parent, tail);
1283                parents = parents->next;
1284        }
1285}
1286
1287static void add_extra_header(struct strbuf *buffer,
1288                             struct commit_extra_header *extra)
1289{
1290        strbuf_addstr(buffer, extra->key);
1291        if (extra->len)
1292                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1293        else
1294                strbuf_addch(buffer, '\n');
1295}
1296
1297struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1298                                                      const char **exclude)
1299{
1300        struct commit_extra_header *extra = NULL;
1301        unsigned long size;
1302        const char *buffer = get_commit_buffer(commit, &size);
1303        extra = read_commit_extra_header_lines(buffer, size, exclude);
1304        unuse_commit_buffer(commit, buffer);
1305        return extra;
1306}
1307
1308void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1309{
1310        struct commit_extra_header *extra, *to_free;
1311
1312        to_free = read_commit_extra_headers(commit, NULL);
1313        for (extra = to_free; extra; extra = extra->next) {
1314                if (strcmp(extra->key, "mergetag"))
1315                        continue; /* not a merge tag */
1316                fn(commit, extra, data);
1317        }
1318        free_commit_extra_headers(to_free);
1319}
1320
1321static inline int standard_header_field(const char *field, size_t len)
1322{
1323        return ((len == 4 && !memcmp(field, "tree", 4)) ||
1324                (len == 6 && !memcmp(field, "parent", 6)) ||
1325                (len == 6 && !memcmp(field, "author", 6)) ||
1326                (len == 9 && !memcmp(field, "committer", 9)) ||
1327                (len == 8 && !memcmp(field, "encoding", 8)));
1328}
1329
1330static int excluded_header_field(const char *field, size_t len, const char **exclude)
1331{
1332        if (!exclude)
1333                return 0;
1334
1335        while (*exclude) {
1336                size_t xlen = strlen(*exclude);
1337                if (len == xlen && !memcmp(field, *exclude, xlen))
1338                        return 1;
1339                exclude++;
1340        }
1341        return 0;
1342}
1343
1344static struct commit_extra_header *read_commit_extra_header_lines(
1345        const char *buffer, size_t size,
1346        const char **exclude)
1347{
1348        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1349        const char *line, *next, *eof, *eob;
1350        struct strbuf buf = STRBUF_INIT;
1351
1352        for (line = buffer, eob = line + size;
1353             line < eob && *line != '\n';
1354             line = next) {
1355                next = memchr(line, '\n', eob - line);
1356                next = next ? next + 1 : eob;
1357                if (*line == ' ') {
1358                        /* continuation */
1359                        if (it)
1360                                strbuf_add(&buf, line + 1, next - (line + 1));
1361                        continue;
1362                }
1363                if (it)
1364                        it->value = strbuf_detach(&buf, &it->len);
1365                strbuf_reset(&buf);
1366                it = NULL;
1367
1368                eof = memchr(line, ' ', next - line);
1369                if (!eof)
1370                        eof = next;
1371                else if (standard_header_field(line, eof - line) ||
1372                         excluded_header_field(line, eof - line, exclude))
1373                        continue;
1374
1375                it = xcalloc(1, sizeof(*it));
1376                it->key = xmemdupz(line, eof-line);
1377                *tail = it;
1378                tail = &it->next;
1379                if (eof + 1 < next)
1380                        strbuf_add(&buf, eof + 1, next - (eof + 1));
1381        }
1382        if (it)
1383                it->value = strbuf_detach(&buf, &it->len);
1384        return extra;
1385}
1386
1387void free_commit_extra_headers(struct commit_extra_header *extra)
1388{
1389        while (extra) {
1390                struct commit_extra_header *next = extra->next;
1391                free(extra->key);
1392                free(extra->value);
1393                free(extra);
1394                extra = next;
1395        }
1396}
1397
1398int commit_tree(const char *msg, size_t msg_len,
1399                const unsigned char *tree,
1400                struct commit_list *parents, unsigned char *ret,
1401                const char *author, const char *sign_commit)
1402{
1403        struct commit_extra_header *extra = NULL, **tail = &extra;
1404        int result;
1405
1406        append_merge_tag_headers(parents, &tail);
1407        result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1408                                      author, sign_commit, extra);
1409        free_commit_extra_headers(extra);
1410        return result;
1411}
1412
1413static int find_invalid_utf8(const char *buf, int len)
1414{
1415        int offset = 0;
1416        static const unsigned int max_codepoint[] = {
1417                0x7f, 0x7ff, 0xffff, 0x10ffff
1418        };
1419
1420        while (len) {
1421                unsigned char c = *buf++;
1422                int bytes, bad_offset;
1423                unsigned int codepoint;
1424                unsigned int min_val, max_val;
1425
1426                len--;
1427                offset++;
1428
1429                /* Simple US-ASCII? No worries. */
1430                if (c < 0x80)
1431                        continue;
1432
1433                bad_offset = offset-1;
1434
1435                /*
1436                 * Count how many more high bits set: that's how
1437                 * many more bytes this sequence should have.
1438                 */
1439                bytes = 0;
1440                while (c & 0x40) {
1441                        c <<= 1;
1442                        bytes++;
1443                }
1444
1445                /*
1446                 * Must be between 1 and 3 more bytes.  Longer sequences result in
1447                 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1448                 */
1449                if (bytes < 1 || 3 < bytes)
1450                        return bad_offset;
1451
1452                /* Do we *have* that many bytes? */
1453                if (len < bytes)
1454                        return bad_offset;
1455
1456                /*
1457                 * Place the encoded bits at the bottom of the value and compute the
1458                 * valid range.
1459                 */
1460                codepoint = (c & 0x7f) >> bytes;
1461                min_val = max_codepoint[bytes-1] + 1;
1462                max_val = max_codepoint[bytes];
1463
1464                offset += bytes;
1465                len -= bytes;
1466
1467                /* And verify that they are good continuation bytes */
1468                do {
1469                        codepoint <<= 6;
1470                        codepoint |= *buf & 0x3f;
1471                        if ((*buf++ & 0xc0) != 0x80)
1472                                return bad_offset;
1473                } while (--bytes);
1474
1475                /* Reject codepoints that are out of range for the sequence length. */
1476                if (codepoint < min_val || codepoint > max_val)
1477                        return bad_offset;
1478                /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1479                if ((codepoint & 0x1ff800) == 0xd800)
1480                        return bad_offset;
1481                /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1482                if ((codepoint & 0xfffe) == 0xfffe)
1483                        return bad_offset;
1484                /* So are anything in the range U+FDD0..U+FDEF. */
1485                if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1486                        return bad_offset;
1487        }
1488        return -1;
1489}
1490
1491/*
1492 * This verifies that the buffer is in proper utf8 format.
1493 *
1494 * If it isn't, it assumes any non-utf8 characters are Latin1,
1495 * and does the conversion.
1496 */
1497static int verify_utf8(struct strbuf *buf)
1498{
1499        int ok = 1;
1500        long pos = 0;
1501
1502        for (;;) {
1503                int bad;
1504                unsigned char c;
1505                unsigned char replace[2];
1506
1507                bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1508                if (bad < 0)
1509                        return ok;
1510                pos += bad;
1511                ok = 0;
1512                c = buf->buf[pos];
1513                strbuf_remove(buf, pos, 1);
1514
1515                /* We know 'c' must be in the range 128-255 */
1516                replace[0] = 0xc0 + (c >> 6);
1517                replace[1] = 0x80 + (c & 0x3f);
1518                strbuf_insert(buf, pos, replace, 2);
1519                pos += 2;
1520        }
1521}
1522
1523static const char commit_utf8_warn[] =
1524N_("Warning: commit message did not conform to UTF-8.\n"
1525   "You may want to amend it after fixing the message, or set the config\n"
1526   "variable i18n.commitencoding to the encoding your project uses.\n");
1527
1528int commit_tree_extended(const char *msg, size_t msg_len,
1529                         const unsigned char *tree,
1530                         struct commit_list *parents, unsigned char *ret,
1531                         const char *author, const char *sign_commit,
1532                         struct commit_extra_header *extra)
1533{
1534        int result;
1535        int encoding_is_utf8;
1536        struct strbuf buffer;
1537
1538        assert_sha1_type(tree, OBJ_TREE);
1539
1540        if (memchr(msg, '\0', msg_len))
1541                return error("a NUL byte in commit log message not allowed.");
1542
1543        /* Not having i18n.commitencoding is the same as having utf-8 */
1544        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1545
1546        strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1547        strbuf_addf(&buffer, "tree %s\n", sha1_to_hex(tree));
1548
1549        /*
1550         * NOTE! This ordering means that the same exact tree merged with a
1551         * different order of parents will be a _different_ changeset even
1552         * if everything else stays the same.
1553         */
1554        while (parents) {
1555                struct commit *parent = pop_commit(&parents);
1556                strbuf_addf(&buffer, "parent %s\n",
1557                            oid_to_hex(&parent->object.oid));
1558        }
1559
1560        /* Person/date information */
1561        if (!author)
1562                author = git_author_info(IDENT_STRICT);
1563        strbuf_addf(&buffer, "author %s\n", author);
1564        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1565        if (!encoding_is_utf8)
1566                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1567
1568        while (extra) {
1569                add_extra_header(&buffer, extra);
1570                extra = extra->next;
1571        }
1572        strbuf_addch(&buffer, '\n');
1573
1574        /* And add the comment */
1575        strbuf_add(&buffer, msg, msg_len);
1576
1577        /* And check the encoding */
1578        if (encoding_is_utf8 && !verify_utf8(&buffer))
1579                fprintf(stderr, _(commit_utf8_warn));
1580
1581        if (sign_commit && do_sign_commit(&buffer, sign_commit)) {
1582                result = -1;
1583                goto out;
1584        }
1585
1586        result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
1587out:
1588        strbuf_release(&buffer);
1589        return result;
1590}
1591
1592void set_merge_remote_desc(struct commit *commit,
1593                           const char *name, struct object *obj)
1594{
1595        struct merge_remote_desc *desc;
1596        FLEX_ALLOC_STR(desc, name, name);
1597        desc->obj = obj;
1598        commit->util = desc;
1599}
1600
1601struct commit *get_merge_parent(const char *name)
1602{
1603        struct object *obj;
1604        struct commit *commit;
1605        struct object_id oid;
1606        if (get_oid(name, &oid))
1607                return NULL;
1608        obj = parse_object(&oid);
1609        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1610        if (commit && !commit->util)
1611                set_merge_remote_desc(commit, name, obj);
1612        return commit;
1613}
1614
1615/*
1616 * Append a commit to the end of the commit_list.
1617 *
1618 * next starts by pointing to the variable that holds the head of an
1619 * empty commit_list, and is updated to point to the "next" field of
1620 * the last item on the list as new commits are appended.
1621 *
1622 * Usage example:
1623 *
1624 *     struct commit_list *list;
1625 *     struct commit_list **next = &list;
1626 *
1627 *     next = commit_list_append(c1, next);
1628 *     next = commit_list_append(c2, next);
1629 *     assert(commit_list_count(list) == 2);
1630 *     return list;
1631 */
1632struct commit_list **commit_list_append(struct commit *commit,
1633                                        struct commit_list **next)
1634{
1635        struct commit_list *new = xmalloc(sizeof(struct commit_list));
1636        new->item = commit;
1637        *next = new;
1638        new->next = NULL;
1639        return &new->next;
1640}
1641
1642const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1643{
1644        int key_len = strlen(key);
1645        const char *line = msg;
1646
1647        while (line) {
1648                const char *eol = strchrnul(line, '\n');
1649
1650                if (line == eol)
1651                        return NULL;
1652
1653                if (eol - line > key_len &&
1654                    !strncmp(line, key, key_len) &&
1655                    line[key_len] == ' ') {
1656                        *out_len = eol - line - key_len - 1;
1657                        return line + key_len + 1;
1658                }
1659                line = *eol ? eol + 1 : NULL;
1660        }
1661        return NULL;
1662}
1663
1664/*
1665 * Inspect the given string and determine the true "end" of the log message, in
1666 * order to find where to put a new Signed-off-by: line.  Ignored are
1667 * trailing comment lines and blank lines.  To support "git commit -s
1668 * --amend" on an existing commit, we also ignore "Conflicts:".  To
1669 * support "git commit -v", we truncate at cut lines.
1670 *
1671 * Returns the number of bytes from the tail to ignore, to be fed as
1672 * the second parameter to append_signoff().
1673 */
1674int ignore_non_trailer(const char *buf, size_t len)
1675{
1676        int boc = 0;
1677        int bol = 0;
1678        int in_old_conflicts_block = 0;
1679        size_t cutoff = wt_status_locate_end(buf, len);
1680
1681        while (bol < cutoff) {
1682                const char *next_line = memchr(buf + bol, '\n', len - bol);
1683
1684                if (!next_line)
1685                        next_line = buf + len;
1686                else
1687                        next_line++;
1688
1689                if (buf[bol] == comment_line_char || buf[bol] == '\n') {
1690                        /* is this the first of the run of comments? */
1691                        if (!boc)
1692                                boc = bol;
1693                        /* otherwise, it is just continuing */
1694                } else if (starts_with(buf + bol, "Conflicts:\n")) {
1695                        in_old_conflicts_block = 1;
1696                        if (!boc)
1697                                boc = bol;
1698                } else if (in_old_conflicts_block && buf[bol] == '\t') {
1699                        ; /* a pathname in the conflicts block */
1700                } else if (boc) {
1701                        /* the previous was not trailing comment */
1702                        boc = 0;
1703                        in_old_conflicts_block = 0;
1704                }
1705                bol = next_line - buf;
1706        }
1707        return boc ? len - boc : len - cutoff;
1708}