Andrew's git / gitweb.git / commit.c
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commit.con commit use pop_commit() for consuming the first entry of a struct commit_list (e510ab8)
   1#include "cache.h"
   2#include "tag.h"
   3#include "commit.h"
   4#include "pkt-line.h"
   5#include "utf8.h"
   6#include "diff.h"
   7#include "revision.h"
   8#include "notes.h"
   9#include "gpg-interface.h"
  10#include "mergesort.h"
  11#include "commit-slab.h"
  12#include "prio-queue.h"
  13#include "sha1-lookup.h"
  14
  15static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
  16
  17int save_commit_buffer = 1;
  18
  19const char *commit_type = "commit";
  20
  21struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
  22                                              int quiet)
  23{
  24        struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
  25
  26        if (!obj)
  27                return NULL;
  28        return object_as_type(obj, OBJ_COMMIT, quiet);
  29}
  30
  31struct commit *lookup_commit_reference(const unsigned char *sha1)
  32{
  33        return lookup_commit_reference_gently(sha1, 0);
  34}
  35
  36struct commit *lookup_commit_or_die(const unsigned char *sha1, const char *ref_name)
  37{
  38        struct commit *c = lookup_commit_reference(sha1);
  39        if (!c)
  40                die(_("could not parse %s"), ref_name);
  41        if (hashcmp(sha1, c->object.sha1)) {
  42                warning(_("%s %s is not a commit!"),
  43                        ref_name, sha1_to_hex(sha1));
  44        }
  45        return c;
  46}
  47
  48struct commit *lookup_commit(const unsigned char *sha1)
  49{
  50        struct object *obj = lookup_object(sha1);
  51        if (!obj)
  52                return create_object(sha1, alloc_commit_node());
  53        return object_as_type(obj, OBJ_COMMIT, 0);
  54}
  55
  56struct commit *lookup_commit_reference_by_name(const char *name)
  57{
  58        struct object_id oid;
  59        struct commit *commit;
  60
  61        if (get_sha1_committish(name, oid.hash))
  62                return NULL;
  63        commit = lookup_commit_reference(oid.hash);
  64        if (parse_commit(commit))
  65                return NULL;
  66        return commit;
  67}
  68
  69static unsigned long parse_commit_date(const char *buf, const char *tail)
  70{
  71        const char *dateptr;
  72
  73        if (buf + 6 >= tail)
  74                return 0;
  75        if (memcmp(buf, "author", 6))
  76                return 0;
  77        while (buf < tail && *buf++ != '\n')
  78                /* nada */;
  79        if (buf + 9 >= tail)
  80                return 0;
  81        if (memcmp(buf, "committer", 9))
  82                return 0;
  83        while (buf < tail && *buf++ != '>')
  84                /* nada */;
  85        if (buf >= tail)
  86                return 0;
  87        dateptr = buf;
  88        while (buf < tail && *buf++ != '\n')
  89                /* nada */;
  90        if (buf >= tail)
  91                return 0;
  92        /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
  93        return strtoul(dateptr, NULL, 10);
  94}
  95
  96static struct commit_graft **commit_graft;
  97static int commit_graft_alloc, commit_graft_nr;
  98
  99static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
 100{
 101        struct commit_graft **commit_graft_table = table;
 102        return commit_graft_table[index]->oid.hash;
 103}
 104
 105static int commit_graft_pos(const unsigned char *sha1)
 106{
 107        return sha1_pos(sha1, commit_graft, commit_graft_nr,
 108                        commit_graft_sha1_access);
 109}
 110
 111int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 112{
 113        int pos = commit_graft_pos(graft->oid.hash);
 114
 115        if (0 <= pos) {
 116                if (ignore_dups)
 117                        free(graft);
 118                else {
 119                        free(commit_graft[pos]);
 120                        commit_graft[pos] = graft;
 121                }
 122                return 1;
 123        }
 124        pos = -pos - 1;
 125        ALLOC_GROW(commit_graft, commit_graft_nr + 1, commit_graft_alloc);
 126        commit_graft_nr++;
 127        if (pos < commit_graft_nr)
 128                memmove(commit_graft + pos + 1,
 129                        commit_graft + pos,
 130                        (commit_graft_nr - pos - 1) *
 131                        sizeof(*commit_graft));
 132        commit_graft[pos] = graft;
 133        return 0;
 134}
 135
 136struct commit_graft *read_graft_line(char *buf, int len)
 137{
 138        /* The format is just "Commit Parent1 Parent2 ...\n" */
 139        int i;
 140        struct commit_graft *graft = NULL;
 141        const int entry_size = GIT_SHA1_HEXSZ + 1;
 142
 143        while (len && isspace(buf[len-1]))
 144                buf[--len] = '\0';
 145        if (buf[0] == '#' || buf[0] == '\0')
 146                return NULL;
 147        if ((len + 1) % entry_size)
 148                goto bad_graft_data;
 149        i = (len + 1) / entry_size - 1;
 150        graft = xmalloc(sizeof(*graft) + GIT_SHA1_RAWSZ * i);
 151        graft->nr_parent = i;
 152        if (get_oid_hex(buf, &graft->oid))
 153                goto bad_graft_data;
 154        for (i = GIT_SHA1_HEXSZ; i < len; i += entry_size) {
 155                if (buf[i] != ' ')
 156                        goto bad_graft_data;
 157                if (get_sha1_hex(buf + i + 1, graft->parent[i/entry_size].hash))
 158                        goto bad_graft_data;
 159        }
 160        return graft;
 161
 162bad_graft_data:
 163        error("bad graft data: %s", buf);
 164        free(graft);
 165        return NULL;
 166}
 167
 168static int read_graft_file(const char *graft_file)
 169{
 170        FILE *fp = fopen(graft_file, "r");
 171        struct strbuf buf = STRBUF_INIT;
 172        if (!fp)
 173                return -1;
 174        while (!strbuf_getwholeline(&buf, fp, '\n')) {
 175                /* The format is just "Commit Parent1 Parent2 ...\n" */
 176                struct commit_graft *graft = read_graft_line(buf.buf, buf.len);
 177                if (!graft)
 178                        continue;
 179                if (register_commit_graft(graft, 1))
 180                        error("duplicate graft data: %s", buf.buf);
 181        }
 182        fclose(fp);
 183        strbuf_release(&buf);
 184        return 0;
 185}
 186
 187static void prepare_commit_graft(void)
 188{
 189        static int commit_graft_prepared;
 190        char *graft_file;
 191
 192        if (commit_graft_prepared)
 193                return;
 194        graft_file = get_graft_file();
 195        read_graft_file(graft_file);
 196        /* make sure shallows are read */
 197        is_repository_shallow();
 198        commit_graft_prepared = 1;
 199}
 200
 201struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 202{
 203        int pos;
 204        prepare_commit_graft();
 205        pos = commit_graft_pos(sha1);
 206        if (pos < 0)
 207                return NULL;
 208        return commit_graft[pos];
 209}
 210
 211int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
 212{
 213        int i, ret;
 214        for (i = ret = 0; i < commit_graft_nr && !ret; i++)
 215                ret = fn(commit_graft[i], cb_data);
 216        return ret;
 217}
 218
 219int unregister_shallow(const unsigned char *sha1)
 220{
 221        int pos = commit_graft_pos(sha1);
 222        if (pos < 0)
 223                return -1;
 224        if (pos + 1 < commit_graft_nr)
 225                memmove(commit_graft + pos, commit_graft + pos + 1,
 226                                sizeof(struct commit_graft *)
 227                                * (commit_graft_nr - pos - 1));
 228        commit_graft_nr--;
 229        return 0;
 230}
 231
 232struct commit_buffer {
 233        void *buffer;
 234        unsigned long size;
 235};
 236define_commit_slab(buffer_slab, struct commit_buffer);
 237static struct buffer_slab buffer_slab = COMMIT_SLAB_INIT(1, buffer_slab);
 238
 239void set_commit_buffer(struct commit *commit, void *buffer, unsigned long size)
 240{
 241        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 242        v->buffer = buffer;
 243        v->size = size;
 244}
 245
 246const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
 247{
 248        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 249        if (sizep)
 250                *sizep = v->size;
 251        return v->buffer;
 252}
 253
 254const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
 255{
 256        const void *ret = get_cached_commit_buffer(commit, sizep);
 257        if (!ret) {
 258                enum object_type type;
 259                unsigned long size;
 260                ret = read_sha1_file(commit->object.sha1, &type, &size);
 261                if (!ret)
 262                        die("cannot read commit object %s",
 263                            sha1_to_hex(commit->object.sha1));
 264                if (type != OBJ_COMMIT)
 265                        die("expected commit for %s, got %s",
 266                            sha1_to_hex(commit->object.sha1), typename(type));
 267                if (sizep)
 268                        *sizep = size;
 269        }
 270        return ret;
 271}
 272
 273void unuse_commit_buffer(const struct commit *commit, const void *buffer)
 274{
 275        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 276        if (v->buffer != buffer)
 277                free((void *)buffer);
 278}
 279
 280void free_commit_buffer(struct commit *commit)
 281{
 282        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 283        free(v->buffer);
 284        v->buffer = NULL;
 285        v->size = 0;
 286}
 287
 288const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 289{
 290        struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
 291        void *ret;
 292
 293        ret = v->buffer;
 294        if (sizep)
 295                *sizep = v->size;
 296
 297        v->buffer = NULL;
 298        v->size = 0;
 299        return ret;
 300}
 301
 302int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
 303{
 304        const char *tail = buffer;
 305        const char *bufptr = buffer;
 306        struct object_id parent;
 307        struct commit_list **pptr;
 308        struct commit_graft *graft;
 309        const int tree_entry_len = GIT_SHA1_HEXSZ + 5;
 310        const int parent_entry_len = GIT_SHA1_HEXSZ + 7;
 311
 312        if (item->object.parsed)
 313                return 0;
 314        item->object.parsed = 1;
 315        tail += size;
 316        if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
 317                        bufptr[tree_entry_len] != '\n')
 318                return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 319        if (get_sha1_hex(bufptr + 5, parent.hash) < 0)
 320                return error("bad tree pointer in commit %s",
 321                             sha1_to_hex(item->object.sha1));
 322        item->tree = lookup_tree(parent.hash);
 323        bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
 324        pptr = &item->parents;
 325
 326        graft = lookup_commit_graft(item->object.sha1);
 327        while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
 328                struct commit *new_parent;
 329
 330                if (tail <= bufptr + parent_entry_len + 1 ||
 331                    get_sha1_hex(bufptr + 7, parent.hash) ||
 332                    bufptr[parent_entry_len] != '\n')
 333                        return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 334                bufptr += parent_entry_len + 1;
 335                /*
 336                 * The clone is shallow if nr_parent < 0, and we must
 337                 * not traverse its real parents even when we unhide them.
 338                 */
 339                if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
 340                        continue;
 341                new_parent = lookup_commit(parent.hash);
 342                if (new_parent)
 343                        pptr = &commit_list_insert(new_parent, pptr)->next;
 344        }
 345        if (graft) {
 346                int i;
 347                struct commit *new_parent;
 348                for (i = 0; i < graft->nr_parent; i++) {
 349                        new_parent = lookup_commit(graft->parent[i].hash);
 350                        if (!new_parent)
 351                                continue;
 352                        pptr = &commit_list_insert(new_parent, pptr)->next;
 353                }
 354        }
 355        item->date = parse_commit_date(bufptr, tail);
 356
 357        return 0;
 358}
 359
 360int parse_commit_gently(struct commit *item, int quiet_on_missing)
 361{
 362        enum object_type type;
 363        void *buffer;
 364        unsigned long size;
 365        int ret;
 366
 367        if (!item)
 368                return -1;
 369        if (item->object.parsed)
 370                return 0;
 371        buffer = read_sha1_file(item->object.sha1, &type, &size);
 372        if (!buffer)
 373                return quiet_on_missing ? -1 :
 374                        error("Could not read %s",
 375                             sha1_to_hex(item->object.sha1));
 376        if (type != OBJ_COMMIT) {
 377                free(buffer);
 378                return error("Object %s not a commit",
 379                             sha1_to_hex(item->object.sha1));
 380        }
 381        ret = parse_commit_buffer(item, buffer, size);
 382        if (save_commit_buffer && !ret) {
 383                set_commit_buffer(item, buffer, size);
 384                return 0;
 385        }
 386        free(buffer);
 387        return ret;
 388}
 389
 390void parse_commit_or_die(struct commit *item)
 391{
 392        if (parse_commit(item))
 393                die("unable to parse commit %s",
 394                    item ? sha1_to_hex(item->object.sha1) : "(null)");
 395}
 396
 397int find_commit_subject(const char *commit_buffer, const char **subject)
 398{
 399        const char *eol;
 400        const char *p = commit_buffer;
 401
 402        while (*p && (*p != '\n' || p[1] != '\n'))
 403                p++;
 404        if (*p) {
 405                p += 2;
 406                for (eol = p; *eol && *eol != '\n'; eol++)
 407                        ; /* do nothing */
 408        } else
 409                eol = p;
 410
 411        *subject = p;
 412
 413        return eol - p;
 414}
 415
 416struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 417{
 418        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 419        new_list->item = item;
 420        new_list->next = *list_p;
 421        *list_p = new_list;
 422        return new_list;
 423}
 424
 425unsigned commit_list_count(const struct commit_list *l)
 426{
 427        unsigned c = 0;
 428        for (; l; l = l->next )
 429                c++;
 430        return c;
 431}
 432
 433struct commit_list *copy_commit_list(struct commit_list *list)
 434{
 435        struct commit_list *head = NULL;
 436        struct commit_list **pp = &head;
 437        while (list) {
 438                pp = commit_list_append(list->item, pp);
 439                list = list->next;
 440        }
 441        return head;
 442}
 443
 444void free_commit_list(struct commit_list *list)
 445{
 446        while (list)
 447                pop_commit(&list);
 448}
 449
 450struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
 451{
 452        struct commit_list **pp = list;
 453        struct commit_list *p;
 454        while ((p = *pp) != NULL) {
 455                if (p->item->date < item->date) {
 456                        break;
 457                }
 458                pp = &p->next;
 459        }
 460        return commit_list_insert(item, pp);
 461}
 462
 463static int commit_list_compare_by_date(const void *a, const void *b)
 464{
 465        unsigned long a_date = ((const struct commit_list *)a)->item->date;
 466        unsigned long b_date = ((const struct commit_list *)b)->item->date;
 467        if (a_date < b_date)
 468                return 1;
 469        if (a_date > b_date)
 470                return -1;
 471        return 0;
 472}
 473
 474static void *commit_list_get_next(const void *a)
 475{
 476        return ((const struct commit_list *)a)->next;
 477}
 478
 479static void commit_list_set_next(void *a, void *next)
 480{
 481        ((struct commit_list *)a)->next = next;
 482}
 483
 484void commit_list_sort_by_date(struct commit_list **list)
 485{
 486        *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
 487                                commit_list_compare_by_date);
 488}
 489
 490struct commit *pop_most_recent_commit(struct commit_list **list,
 491                                      unsigned int mark)
 492{
 493        struct commit *ret = pop_commit(list);
 494        struct commit_list *parents = ret->parents;
 495
 496        while (parents) {
 497                struct commit *commit = parents->item;
 498                if (!parse_commit(commit) && !(commit->object.flags & mark)) {
 499                        commit->object.flags |= mark;
 500                        commit_list_insert_by_date(commit, list);
 501                }
 502                parents = parents->next;
 503        }
 504        return ret;
 505}
 506
 507static void clear_commit_marks_1(struct commit_list **plist,
 508                                 struct commit *commit, unsigned int mark)
 509{
 510        while (commit) {
 511                struct commit_list *parents;
 512
 513                if (!(mark & commit->object.flags))
 514                        return;
 515
 516                commit->object.flags &= ~mark;
 517
 518                parents = commit->parents;
 519                if (!parents)
 520                        return;
 521
 522                while ((parents = parents->next))
 523                        commit_list_insert(parents->item, plist);
 524
 525                commit = commit->parents->item;
 526        }
 527}
 528
 529void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 530{
 531        struct commit_list *list = NULL;
 532
 533        while (nr--) {
 534                commit_list_insert(*commit, &list);
 535                commit++;
 536        }
 537        while (list)
 538                clear_commit_marks_1(&list, pop_commit(&list), mark);
 539}
 540
 541void clear_commit_marks(struct commit *commit, unsigned int mark)
 542{
 543        clear_commit_marks_many(1, &commit, mark);
 544}
 545
 546void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
 547{
 548        struct object *object;
 549        struct commit *commit;
 550        unsigned int i;
 551
 552        for (i = 0; i < a->nr; i++) {
 553                object = a->objects[i].item;
 554                commit = lookup_commit_reference_gently(object->sha1, 1);
 555                if (commit)
 556                        clear_commit_marks(commit, mark);
 557        }
 558}
 559
 560struct commit *pop_commit(struct commit_list **stack)
 561{
 562        struct commit_list *top = *stack;
 563        struct commit *item = top ? top->item : NULL;
 564
 565        if (top) {
 566                *stack = top->next;
 567                free(top);
 568        }
 569        return item;
 570}
 571
 572/*
 573 * Topological sort support
 574 */
 575
 576/* count number of children that have not been emitted */
 577define_commit_slab(indegree_slab, int);
 578
 579/* record author-date for each commit object */
 580define_commit_slab(author_date_slab, unsigned long);
 581
 582static void record_author_date(struct author_date_slab *author_date,
 583                               struct commit *commit)
 584{
 585        const char *buffer = get_commit_buffer(commit, NULL);
 586        struct ident_split ident;
 587        const char *ident_line;
 588        size_t ident_len;
 589        char *date_end;
 590        unsigned long date;
 591
 592        ident_line = find_commit_header(buffer, "author", &ident_len);
 593        if (!ident_line)
 594                goto fail_exit; /* no author line */
 595        if (split_ident_line(&ident, ident_line, ident_len) ||
 596            !ident.date_begin || !ident.date_end)
 597                goto fail_exit; /* malformed "author" line */
 598
 599        date = strtoul(ident.date_begin, &date_end, 10);
 600        if (date_end != ident.date_end)
 601                goto fail_exit; /* malformed date */
 602        *(author_date_slab_at(author_date, commit)) = date;
 603
 604fail_exit:
 605        unuse_commit_buffer(commit, buffer);
 606}
 607
 608static int compare_commits_by_author_date(const void *a_, const void *b_,
 609                                          void *cb_data)
 610{
 611        const struct commit *a = a_, *b = b_;
 612        struct author_date_slab *author_date = cb_data;
 613        unsigned long a_date = *(author_date_slab_at(author_date, a));
 614        unsigned long b_date = *(author_date_slab_at(author_date, b));
 615
 616        /* newer commits with larger date first */
 617        if (a_date < b_date)
 618                return 1;
 619        else if (a_date > b_date)
 620                return -1;
 621        return 0;
 622}
 623
 624int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 625{
 626        const struct commit *a = a_, *b = b_;
 627        /* newer commits with larger date first */
 628        if (a->date < b->date)
 629                return 1;
 630        else if (a->date > b->date)
 631                return -1;
 632        return 0;
 633}
 634
 635/*
 636 * Performs an in-place topological sort on the list supplied.
 637 */
 638void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
 639{
 640        struct commit_list *next, *orig = *list;
 641        struct commit_list **pptr;
 642        struct indegree_slab indegree;
 643        struct prio_queue queue;
 644        struct commit *commit;
 645        struct author_date_slab author_date;
 646
 647        if (!orig)
 648                return;
 649        *list = NULL;
 650
 651        init_indegree_slab(&indegree);
 652        memset(&queue, '\0', sizeof(queue));
 653
 654        switch (sort_order) {
 655        default: /* REV_SORT_IN_GRAPH_ORDER */
 656                queue.compare = NULL;
 657                break;
 658        case REV_SORT_BY_COMMIT_DATE:
 659                queue.compare = compare_commits_by_commit_date;
 660                break;
 661        case REV_SORT_BY_AUTHOR_DATE:
 662                init_author_date_slab(&author_date);
 663                queue.compare = compare_commits_by_author_date;
 664                queue.cb_data = &author_date;
 665                break;
 666        }
 667
 668        /* Mark them and clear the indegree */
 669        for (next = orig; next; next = next->next) {
 670                struct commit *commit = next->item;
 671                *(indegree_slab_at(&indegree, commit)) = 1;
 672                /* also record the author dates, if needed */
 673                if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 674                        record_author_date(&author_date, commit);
 675        }
 676
 677        /* update the indegree */
 678        for (next = orig; next; next = next->next) {
 679                struct commit_list *parents = next->item->parents;
 680                while (parents) {
 681                        struct commit *parent = parents->item;
 682                        int *pi = indegree_slab_at(&indegree, parent);
 683
 684                        if (*pi)
 685                                (*pi)++;
 686                        parents = parents->next;
 687                }
 688        }
 689
 690        /*
 691         * find the tips
 692         *
 693         * tips are nodes not reachable from any other node in the list
 694         *
 695         * the tips serve as a starting set for the work queue.
 696         */
 697        for (next = orig; next; next = next->next) {
 698                struct commit *commit = next->item;
 699
 700                if (*(indegree_slab_at(&indegree, commit)) == 1)
 701                        prio_queue_put(&queue, commit);
 702        }
 703
 704        /*
 705         * This is unfortunate; the initial tips need to be shown
 706         * in the order given from the revision traversal machinery.
 707         */
 708        if (sort_order == REV_SORT_IN_GRAPH_ORDER)
 709                prio_queue_reverse(&queue);
 710
 711        /* We no longer need the commit list */
 712        free_commit_list(orig);
 713
 714        pptr = list;
 715        *list = NULL;
 716        while ((commit = prio_queue_get(&queue)) != NULL) {
 717                struct commit_list *parents;
 718
 719                for (parents = commit->parents; parents ; parents = parents->next) {
 720                        struct commit *parent = parents->item;
 721                        int *pi = indegree_slab_at(&indegree, parent);
 722
 723                        if (!*pi)
 724                                continue;
 725
 726                        /*
 727                         * parents are only enqueued for emission
 728                         * when all their children have been emitted thereby
 729                         * guaranteeing topological order.
 730                         */
 731                        if (--(*pi) == 1)
 732                                prio_queue_put(&queue, parent);
 733                }
 734                /*
 735                 * all children of commit have already been
 736                 * emitted. we can emit it now.
 737                 */
 738                *(indegree_slab_at(&indegree, commit)) = 0;
 739
 740                pptr = &commit_list_insert(commit, pptr)->next;
 741        }
 742
 743        clear_indegree_slab(&indegree);
 744        clear_prio_queue(&queue);
 745        if (sort_order == REV_SORT_BY_AUTHOR_DATE)
 746                clear_author_date_slab(&author_date);
 747}
 748
 749/* merge-base stuff */
 750
 751/* Remember to update object flag allocation in object.h */
 752#define PARENT1         (1u<<16)
 753#define PARENT2         (1u<<17)
 754#define STALE           (1u<<18)
 755#define RESULT          (1u<<19)
 756
 757static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
 758
 759static int queue_has_nonstale(struct prio_queue *queue)
 760{
 761        int i;
 762        for (i = 0; i < queue->nr; i++) {
 763                struct commit *commit = queue->array[i].data;
 764                if (!(commit->object.flags & STALE))
 765                        return 1;
 766        }
 767        return 0;
 768}
 769
 770/* all input commits in one and twos[] must have been parsed! */
 771static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
 772{
 773        struct prio_queue queue = { compare_commits_by_commit_date };
 774        struct commit_list *result = NULL;
 775        int i;
 776
 777        one->object.flags |= PARENT1;
 778        if (!n) {
 779                commit_list_append(one, &result);
 780                return result;
 781        }
 782        prio_queue_put(&queue, one);
 783
 784        for (i = 0; i < n; i++) {
 785                twos[i]->object.flags |= PARENT2;
 786                prio_queue_put(&queue, twos[i]);
 787        }
 788
 789        while (queue_has_nonstale(&queue)) {
 790                struct commit *commit = prio_queue_get(&queue);
 791                struct commit_list *parents;
 792                int flags;
 793
 794                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 795                if (flags == (PARENT1 | PARENT2)) {
 796                        if (!(commit->object.flags & RESULT)) {
 797                                commit->object.flags |= RESULT;
 798                                commit_list_insert_by_date(commit, &result);
 799                        }
 800                        /* Mark parents of a found merge stale */
 801                        flags |= STALE;
 802                }
 803                parents = commit->parents;
 804                while (parents) {
 805                        struct commit *p = parents->item;
 806                        parents = parents->next;
 807                        if ((p->object.flags & flags) == flags)
 808                                continue;
 809                        if (parse_commit(p))
 810                                return NULL;
 811                        p->object.flags |= flags;
 812                        prio_queue_put(&queue, p);
 813                }
 814        }
 815
 816        clear_prio_queue(&queue);
 817        return result;
 818}
 819
 820static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 821{
 822        struct commit_list *list = NULL;
 823        struct commit_list *result = NULL;
 824        int i;
 825
 826        for (i = 0; i < n; i++) {
 827                if (one == twos[i])
 828                        /*
 829                         * We do not mark this even with RESULT so we do not
 830                         * have to clean it up.
 831                         */
 832                        return commit_list_insert(one, &result);
 833        }
 834
 835        if (parse_commit(one))
 836                return NULL;
 837        for (i = 0; i < n; i++) {
 838                if (parse_commit(twos[i]))
 839                        return NULL;
 840        }
 841
 842        list = paint_down_to_common(one, n, twos);
 843
 844        while (list) {
 845                struct commit *commit = pop_commit(&list);
 846                if (!(commit->object.flags & STALE))
 847                        commit_list_insert_by_date(commit, &result);
 848        }
 849        return result;
 850}
 851
 852struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 853{
 854        struct commit_list *i, *j, *k, *ret = NULL;
 855
 856        if (!in)
 857                return ret;
 858
 859        commit_list_insert(in->item, &ret);
 860
 861        for (i = in->next; i; i = i->next) {
 862                struct commit_list *new = NULL, *end = NULL;
 863
 864                for (j = ret; j; j = j->next) {
 865                        struct commit_list *bases;
 866                        bases = get_merge_bases(i->item, j->item);
 867                        if (!new)
 868                                new = bases;
 869                        else
 870                                end->next = bases;
 871                        for (k = bases; k; k = k->next)
 872                                end = k;
 873                }
 874                ret = new;
 875        }
 876        return ret;
 877}
 878
 879static int remove_redundant(struct commit **array, int cnt)
 880{
 881        /*
 882         * Some commit in the array may be an ancestor of
 883         * another commit.  Move such commit to the end of
 884         * the array, and return the number of commits that
 885         * are independent from each other.
 886         */
 887        struct commit **work;
 888        unsigned char *redundant;
 889        int *filled_index;
 890        int i, j, filled;
 891
 892        work = xcalloc(cnt, sizeof(*work));
 893        redundant = xcalloc(cnt, 1);
 894        filled_index = xmalloc(sizeof(*filled_index) * (cnt - 1));
 895
 896        for (i = 0; i < cnt; i++)
 897                parse_commit(array[i]);
 898        for (i = 0; i < cnt; i++) {
 899                struct commit_list *common;
 900
 901                if (redundant[i])
 902                        continue;
 903                for (j = filled = 0; j < cnt; j++) {
 904                        if (i == j || redundant[j])
 905                                continue;
 906                        filled_index[filled] = j;
 907                        work[filled++] = array[j];
 908                }
 909                common = paint_down_to_common(array[i], filled, work);
 910                if (array[i]->object.flags & PARENT2)
 911                        redundant[i] = 1;
 912                for (j = 0; j < filled; j++)
 913                        if (work[j]->object.flags & PARENT1)
 914                                redundant[filled_index[j]] = 1;
 915                clear_commit_marks(array[i], all_flags);
 916                for (j = 0; j < filled; j++)
 917                        clear_commit_marks(work[j], all_flags);
 918                free_commit_list(common);
 919        }
 920
 921        /* Now collect the result */
 922        memcpy(work, array, sizeof(*array) * cnt);
 923        for (i = filled = 0; i < cnt; i++)
 924                if (!redundant[i])
 925                        array[filled++] = work[i];
 926        for (j = filled, i = 0; i < cnt; i++)
 927                if (redundant[i])
 928                        array[j++] = work[i];
 929        free(work);
 930        free(redundant);
 931        free(filled_index);
 932        return filled;
 933}
 934
 935static struct commit_list *get_merge_bases_many_0(struct commit *one,
 936                                                  int n,
 937                                                  struct commit **twos,
 938                                                  int cleanup)
 939{
 940        struct commit_list *list;
 941        struct commit **rslt;
 942        struct commit_list *result;
 943        int cnt, i;
 944
 945        result = merge_bases_many(one, n, twos);
 946        for (i = 0; i < n; i++) {
 947                if (one == twos[i])
 948                        return result;
 949        }
 950        if (!result || !result->next) {
 951                if (cleanup) {
 952                        clear_commit_marks(one, all_flags);
 953                        clear_commit_marks_many(n, twos, all_flags);
 954                }
 955                return result;
 956        }
 957
 958        /* There are more than one */
 959        cnt = commit_list_count(result);
 960        rslt = xcalloc(cnt, sizeof(*rslt));
 961        for (list = result, i = 0; list; list = list->next)
 962                rslt[i++] = list->item;
 963        free_commit_list(result);
 964
 965        clear_commit_marks(one, all_flags);
 966        clear_commit_marks_many(n, twos, all_flags);
 967
 968        cnt = remove_redundant(rslt, cnt);
 969        result = NULL;
 970        for (i = 0; i < cnt; i++)
 971                commit_list_insert_by_date(rslt[i], &result);
 972        free(rslt);
 973        return result;
 974}
 975
 976struct commit_list *get_merge_bases_many(struct commit *one,
 977                                         int n,
 978                                         struct commit **twos)
 979{
 980        return get_merge_bases_many_0(one, n, twos, 1);
 981}
 982
 983struct commit_list *get_merge_bases_many_dirty(struct commit *one,
 984                                               int n,
 985                                               struct commit **twos)
 986{
 987        return get_merge_bases_many_0(one, n, twos, 0);
 988}
 989
 990struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
 991{
 992        return get_merge_bases_many_0(one, 1, &two, 1);
 993}
 994
 995/*
 996 * Is "commit" a descendant of one of the elements on the "with_commit" list?
 997 */
 998int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
 999{
1000        if (!with_commit)
1001                return 1;
1002        while (with_commit) {
1003                struct commit *other;
1004
1005                other = with_commit->item;
1006                with_commit = with_commit->next;
1007                if (in_merge_bases(other, commit))
1008                        return 1;
1009        }
1010        return 0;
1011}
1012
1013/*
1014 * Is "commit" an ancestor of one of the "references"?
1015 */
1016int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1017{
1018        struct commit_list *bases;
1019        int ret = 0, i;
1020
1021        if (parse_commit(commit))
1022                return ret;
1023        for (i = 0; i < nr_reference; i++)
1024                if (parse_commit(reference[i]))
1025                        return ret;
1026
1027        bases = paint_down_to_common(commit, nr_reference, reference);
1028        if (commit->object.flags & PARENT2)
1029                ret = 1;
1030        clear_commit_marks(commit, all_flags);
1031        clear_commit_marks_many(nr_reference, reference, all_flags);
1032        free_commit_list(bases);
1033        return ret;
1034}
1035
1036/*
1037 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1038 */
1039int in_merge_bases(struct commit *commit, struct commit *reference)
1040{
1041        return in_merge_bases_many(commit, 1, &reference);
1042}
1043
1044struct commit_list *reduce_heads(struct commit_list *heads)
1045{
1046        struct commit_list *p;
1047        struct commit_list *result = NULL, **tail = &result;
1048        struct commit **array;
1049        int num_head, i;
1050
1051        if (!heads)
1052                return NULL;
1053
1054        /* Uniquify */
1055        for (p = heads; p; p = p->next)
1056                p->item->object.flags &= ~STALE;
1057        for (p = heads, num_head = 0; p; p = p->next) {
1058                if (p->item->object.flags & STALE)
1059                        continue;
1060                p->item->object.flags |= STALE;
1061                num_head++;
1062        }
1063        array = xcalloc(num_head, sizeof(*array));
1064        for (p = heads, i = 0; p; p = p->next) {
1065                if (p->item->object.flags & STALE) {
1066                        array[i++] = p->item;
1067                        p->item->object.flags &= ~STALE;
1068                }
1069        }
1070        num_head = remove_redundant(array, num_head);
1071        for (i = 0; i < num_head; i++)
1072                tail = &commit_list_insert(array[i], tail)->next;
1073        return result;
1074}
1075
1076static const char gpg_sig_header[] = "gpgsig";
1077static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1078
1079static int do_sign_commit(struct strbuf *buf, const char *keyid)
1080{
1081        struct strbuf sig = STRBUF_INIT;
1082        int inspos, copypos;
1083
1084        /* find the end of the header */
1085        inspos = strstr(buf->buf, "\n\n") - buf->buf + 1;
1086
1087        if (!keyid || !*keyid)
1088                keyid = get_signing_key();
1089        if (sign_buffer(buf, &sig, keyid)) {
1090                strbuf_release(&sig);
1091                return -1;
1092        }
1093
1094        for (copypos = 0; sig.buf[copypos]; ) {
1095                const char *bol = sig.buf + copypos;
1096                const char *eol = strchrnul(bol, '\n');
1097                int len = (eol - bol) + !!*eol;
1098
1099                if (!copypos) {
1100                        strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1101                        inspos += gpg_sig_header_len;
1102                }
1103                strbuf_insert(buf, inspos++, " ", 1);
1104                strbuf_insert(buf, inspos, bol, len);
1105                inspos += len;
1106                copypos += len;
1107        }
1108        strbuf_release(&sig);
1109        return 0;
1110}
1111
1112int parse_signed_commit(const struct commit *commit,
1113                        struct strbuf *payload, struct strbuf *signature)
1114{
1115
1116        unsigned long size;
1117        const char *buffer = get_commit_buffer(commit, &size);
1118        int in_signature, saw_signature = -1;
1119        const char *line, *tail;
1120
1121        line = buffer;
1122        tail = buffer + size;
1123        in_signature = 0;
1124        saw_signature = 0;
1125        while (line < tail) {
1126                const char *sig = NULL;
1127                const char *next = memchr(line, '\n', tail - line);
1128
1129                next = next ? next + 1 : tail;
1130                if (in_signature && line[0] == ' ')
1131                        sig = line + 1;
1132                else if (starts_with(line, gpg_sig_header) &&
1133                         line[gpg_sig_header_len] == ' ')
1134                        sig = line + gpg_sig_header_len + 1;
1135                if (sig) {
1136                        strbuf_add(signature, sig, next - sig);
1137                        saw_signature = 1;
1138                        in_signature = 1;
1139                } else {
1140                        if (*line == '\n')
1141                                /* dump the whole remainder of the buffer */
1142                                next = tail;
1143                        strbuf_add(payload, line, next - line);
1144                        in_signature = 0;
1145                }
1146                line = next;
1147        }
1148        unuse_commit_buffer(commit, buffer);
1149        return saw_signature;
1150}
1151
1152int remove_signature(struct strbuf *buf)
1153{
1154        const char *line = buf->buf;
1155        const char *tail = buf->buf + buf->len;
1156        int in_signature = 0;
1157        const char *sig_start = NULL;
1158        const char *sig_end = NULL;
1159
1160        while (line < tail) {
1161                const char *next = memchr(line, '\n', tail - line);
1162                next = next ? next + 1 : tail;
1163
1164                if (in_signature && line[0] == ' ')
1165                        sig_end = next;
1166                else if (starts_with(line, gpg_sig_header) &&
1167                         line[gpg_sig_header_len] == ' ') {
1168                        sig_start = line;
1169                        sig_end = next;
1170                        in_signature = 1;
1171                } else {
1172                        if (*line == '\n')
1173                                /* dump the whole remainder of the buffer */
1174                                next = tail;
1175                        in_signature = 0;
1176                }
1177                line = next;
1178        }
1179
1180        if (sig_start)
1181                strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1182
1183        return sig_start != NULL;
1184}
1185
1186static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1187{
1188        struct merge_remote_desc *desc;
1189        struct commit_extra_header *mergetag;
1190        char *buf;
1191        unsigned long size, len;
1192        enum object_type type;
1193
1194        desc = merge_remote_util(parent);
1195        if (!desc || !desc->obj)
1196                return;
1197        buf = read_sha1_file(desc->obj->sha1, &type, &size);
1198        if (!buf || type != OBJ_TAG)
1199                goto free_return;
1200        len = parse_signature(buf, size);
1201        if (size == len)
1202                goto free_return;
1203        /*
1204         * We could verify this signature and either omit the tag when
1205         * it does not validate, but the integrator may not have the
1206         * public key of the signer of the tag he is merging, while a
1207         * later auditor may have it while auditing, so let's not run
1208         * verify-signed-buffer here for now...
1209         *
1210         * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1211         *      warn("warning: signed tag unverified.");
1212         */
1213        mergetag = xcalloc(1, sizeof(*mergetag));
1214        mergetag->key = xstrdup("mergetag");
1215        mergetag->value = buf;
1216        mergetag->len = size;
1217
1218        **tail = mergetag;
1219        *tail = &mergetag->next;
1220        return;
1221
1222free_return:
1223        free(buf);
1224}
1225
1226void check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1227{
1228        struct strbuf payload = STRBUF_INIT;
1229        struct strbuf signature = STRBUF_INIT;
1230        struct strbuf gpg_output = STRBUF_INIT;
1231        struct strbuf gpg_status = STRBUF_INIT;
1232        int status;
1233
1234        sigc->result = 'N';
1235
1236        if (parse_signed_commit(commit, &payload, &signature) <= 0)
1237                goto out;
1238        status = verify_signed_buffer(payload.buf, payload.len,
1239                                      signature.buf, signature.len,
1240                                      &gpg_output, &gpg_status);
1241        if (status && !gpg_output.len)
1242                goto out;
1243        sigc->payload = strbuf_detach(&payload, NULL);
1244        sigc->gpg_output = strbuf_detach(&gpg_output, NULL);
1245        sigc->gpg_status = strbuf_detach(&gpg_status, NULL);
1246        parse_gpg_output(sigc);
1247
1248 out:
1249        strbuf_release(&gpg_status);
1250        strbuf_release(&gpg_output);
1251        strbuf_release(&payload);
1252        strbuf_release(&signature);
1253}
1254
1255
1256
1257void append_merge_tag_headers(struct commit_list *parents,
1258                              struct commit_extra_header ***tail)
1259{
1260        while (parents) {
1261                struct commit *parent = parents->item;
1262                handle_signed_tag(parent, tail);
1263                parents = parents->next;
1264        }
1265}
1266
1267static void add_extra_header(struct strbuf *buffer,
1268                             struct commit_extra_header *extra)
1269{
1270        strbuf_addstr(buffer, extra->key);
1271        if (extra->len)
1272                strbuf_add_lines(buffer, " ", extra->value, extra->len);
1273        else
1274                strbuf_addch(buffer, '\n');
1275}
1276
1277struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1278                                                      const char **exclude)
1279{
1280        struct commit_extra_header *extra = NULL;
1281        unsigned long size;
1282        const char *buffer = get_commit_buffer(commit, &size);
1283        extra = read_commit_extra_header_lines(buffer, size, exclude);
1284        unuse_commit_buffer(commit, buffer);
1285        return extra;
1286}
1287
1288void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1289{
1290        struct commit_extra_header *extra, *to_free;
1291
1292        to_free = read_commit_extra_headers(commit, NULL);
1293        for (extra = to_free; extra; extra = extra->next) {
1294                if (strcmp(extra->key, "mergetag"))
1295                        continue; /* not a merge tag */
1296                fn(commit, extra, data);
1297        }
1298        free_commit_extra_headers(to_free);
1299}
1300
1301static inline int standard_header_field(const char *field, size_t len)
1302{
1303        return ((len == 4 && !memcmp(field, "tree ", 5)) ||
1304                (len == 6 && !memcmp(field, "parent ", 7)) ||
1305                (len == 6 && !memcmp(field, "author ", 7)) ||
1306                (len == 9 && !memcmp(field, "committer ", 10)) ||
1307                (len == 8 && !memcmp(field, "encoding ", 9)));
1308}
1309
1310static int excluded_header_field(const char *field, size_t len, const char **exclude)
1311{
1312        if (!exclude)
1313                return 0;
1314
1315        while (*exclude) {
1316                size_t xlen = strlen(*exclude);
1317                if (len == xlen &&
1318                    !memcmp(field, *exclude, xlen) && field[xlen] == ' ')
1319                        return 1;
1320                exclude++;
1321        }
1322        return 0;
1323}
1324
1325static struct commit_extra_header *read_commit_extra_header_lines(
1326        const char *buffer, size_t size,
1327        const char **exclude)
1328{
1329        struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1330        const char *line, *next, *eof, *eob;
1331        struct strbuf buf = STRBUF_INIT;
1332
1333        for (line = buffer, eob = line + size;
1334             line < eob && *line != '\n';
1335             line = next) {
1336                next = memchr(line, '\n', eob - line);
1337                next = next ? next + 1 : eob;
1338                if (*line == ' ') {
1339                        /* continuation */
1340                        if (it)
1341                                strbuf_add(&buf, line + 1, next - (line + 1));
1342                        continue;
1343                }
1344                if (it)
1345                        it->value = strbuf_detach(&buf, &it->len);
1346                strbuf_reset(&buf);
1347                it = NULL;
1348
1349                eof = strchr(line, ' ');
1350                if (next <= eof)
1351                        eof = next;
1352
1353                if (standard_header_field(line, eof - line) ||
1354                    excluded_header_field(line, eof - line, exclude))
1355                        continue;
1356
1357                it = xcalloc(1, sizeof(*it));
1358                it->key = xmemdupz(line, eof-line);
1359                *tail = it;
1360                tail = &it->next;
1361                if (eof + 1 < next)
1362                        strbuf_add(&buf, eof + 1, next - (eof + 1));
1363        }
1364        if (it)
1365                it->value = strbuf_detach(&buf, &it->len);
1366        return extra;
1367}
1368
1369void free_commit_extra_headers(struct commit_extra_header *extra)
1370{
1371        while (extra) {
1372                struct commit_extra_header *next = extra->next;
1373                free(extra->key);
1374                free(extra->value);
1375                free(extra);
1376                extra = next;
1377        }
1378}
1379
1380int commit_tree(const char *msg, size_t msg_len,
1381                const unsigned char *tree,
1382                struct commit_list *parents, unsigned char *ret,
1383                const char *author, const char *sign_commit)
1384{
1385        struct commit_extra_header *extra = NULL, **tail = &extra;
1386        int result;
1387
1388        append_merge_tag_headers(parents, &tail);
1389        result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1390                                      author, sign_commit, extra);
1391        free_commit_extra_headers(extra);
1392        return result;
1393}
1394
1395static int find_invalid_utf8(const char *buf, int len)
1396{
1397        int offset = 0;
1398        static const unsigned int max_codepoint[] = {
1399                0x7f, 0x7ff, 0xffff, 0x10ffff
1400        };
1401
1402        while (len) {
1403                unsigned char c = *buf++;
1404                int bytes, bad_offset;
1405                unsigned int codepoint;
1406                unsigned int min_val, max_val;
1407
1408                len--;
1409                offset++;
1410
1411                /* Simple US-ASCII? No worries. */
1412                if (c < 0x80)
1413                        continue;
1414
1415                bad_offset = offset-1;
1416
1417                /*
1418                 * Count how many more high bits set: that's how
1419                 * many more bytes this sequence should have.
1420                 */
1421                bytes = 0;
1422                while (c & 0x40) {
1423                        c <<= 1;
1424                        bytes++;
1425                }
1426
1427                /*
1428                 * Must be between 1 and 3 more bytes.  Longer sequences result in
1429                 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1430                 */
1431                if (bytes < 1 || 3 < bytes)
1432                        return bad_offset;
1433
1434                /* Do we *have* that many bytes? */
1435                if (len < bytes)
1436                        return bad_offset;
1437
1438                /*
1439                 * Place the encoded bits at the bottom of the value and compute the
1440                 * valid range.
1441                 */
1442                codepoint = (c & 0x7f) >> bytes;
1443                min_val = max_codepoint[bytes-1] + 1;
1444                max_val = max_codepoint[bytes];
1445
1446                offset += bytes;
1447                len -= bytes;
1448
1449                /* And verify that they are good continuation bytes */
1450                do {
1451                        codepoint <<= 6;
1452                        codepoint |= *buf & 0x3f;
1453                        if ((*buf++ & 0xc0) != 0x80)
1454                                return bad_offset;
1455                } while (--bytes);
1456
1457                /* Reject codepoints that are out of range for the sequence length. */
1458                if (codepoint < min_val || codepoint > max_val)
1459                        return bad_offset;
1460                /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1461                if ((codepoint & 0x1ff800) == 0xd800)
1462                        return bad_offset;
1463                /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1464                if ((codepoint & 0xfffe) == 0xfffe)
1465                        return bad_offset;
1466                /* So are anything in the range U+FDD0..U+FDEF. */
1467                if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1468                        return bad_offset;
1469        }
1470        return -1;
1471}
1472
1473/*
1474 * This verifies that the buffer is in proper utf8 format.
1475 *
1476 * If it isn't, it assumes any non-utf8 characters are Latin1,
1477 * and does the conversion.
1478 */
1479static int verify_utf8(struct strbuf *buf)
1480{
1481        int ok = 1;
1482        long pos = 0;
1483
1484        for (;;) {
1485                int bad;
1486                unsigned char c;
1487                unsigned char replace[2];
1488
1489                bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1490                if (bad < 0)
1491                        return ok;
1492                pos += bad;
1493                ok = 0;
1494                c = buf->buf[pos];
1495                strbuf_remove(buf, pos, 1);
1496
1497                /* We know 'c' must be in the range 128-255 */
1498                replace[0] = 0xc0 + (c >> 6);
1499                replace[1] = 0x80 + (c & 0x3f);
1500                strbuf_insert(buf, pos, replace, 2);
1501                pos += 2;
1502        }
1503}
1504
1505static const char commit_utf8_warn[] =
1506"Warning: commit message did not conform to UTF-8.\n"
1507"You may want to amend it after fixing the message, or set the config\n"
1508"variable i18n.commitencoding to the encoding your project uses.\n";
1509
1510int commit_tree_extended(const char *msg, size_t msg_len,
1511                         const unsigned char *tree,
1512                         struct commit_list *parents, unsigned char *ret,
1513                         const char *author, const char *sign_commit,
1514                         struct commit_extra_header *extra)
1515{
1516        int result;
1517        int encoding_is_utf8;
1518        struct strbuf buffer;
1519
1520        assert_sha1_type(tree, OBJ_TREE);
1521
1522        if (memchr(msg, '\0', msg_len))
1523                return error("a NUL byte in commit log message not allowed.");
1524
1525        /* Not having i18n.commitencoding is the same as having utf-8 */
1526        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1527
1528        strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1529        strbuf_addf(&buffer, "tree %s\n", sha1_to_hex(tree));
1530
1531        /*
1532         * NOTE! This ordering means that the same exact tree merged with a
1533         * different order of parents will be a _different_ changeset even
1534         * if everything else stays the same.
1535         */
1536        while (parents) {
1537                struct commit *parent = pop_commit(&parents);
1538                strbuf_addf(&buffer, "parent %s\n",
1539                            sha1_to_hex(parent->object.sha1));
1540        }
1541
1542        /* Person/date information */
1543        if (!author)
1544                author = git_author_info(IDENT_STRICT);
1545        strbuf_addf(&buffer, "author %s\n", author);
1546        strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1547        if (!encoding_is_utf8)
1548                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1549
1550        while (extra) {
1551                add_extra_header(&buffer, extra);
1552                extra = extra->next;
1553        }
1554        strbuf_addch(&buffer, '\n');
1555
1556        /* And add the comment */
1557        strbuf_add(&buffer, msg, msg_len);
1558
1559        /* And check the encoding */
1560        if (encoding_is_utf8 && !verify_utf8(&buffer))
1561                fprintf(stderr, commit_utf8_warn);
1562
1563        if (sign_commit && do_sign_commit(&buffer, sign_commit))
1564                return -1;
1565
1566        result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
1567        strbuf_release(&buffer);
1568        return result;
1569}
1570
1571struct commit *get_merge_parent(const char *name)
1572{
1573        struct object *obj;
1574        struct commit *commit;
1575        struct object_id oid;
1576        if (get_sha1(name, oid.hash))
1577                return NULL;
1578        obj = parse_object(oid.hash);
1579        commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1580        if (commit && !commit->util) {
1581                struct merge_remote_desc *desc;
1582                desc = xmalloc(sizeof(*desc));
1583                desc->obj = obj;
1584                desc->name = strdup(name);
1585                commit->util = desc;
1586        }
1587        return commit;
1588}
1589
1590/*
1591 * Append a commit to the end of the commit_list.
1592 *
1593 * next starts by pointing to the variable that holds the head of an
1594 * empty commit_list, and is updated to point to the "next" field of
1595 * the last item on the list as new commits are appended.
1596 *
1597 * Usage example:
1598 *
1599 *     struct commit_list *list;
1600 *     struct commit_list **next = &list;
1601 *
1602 *     next = commit_list_append(c1, next);
1603 *     next = commit_list_append(c2, next);
1604 *     assert(commit_list_count(list) == 2);
1605 *     return list;
1606 */
1607struct commit_list **commit_list_append(struct commit *commit,
1608                                        struct commit_list **next)
1609{
1610        struct commit_list *new = xmalloc(sizeof(struct commit_list));
1611        new->item = commit;
1612        *next = new;
1613        new->next = NULL;
1614        return &new->next;
1615}
1616
1617void print_commit_list(struct commit_list *list,
1618                       const char *format_cur,
1619                       const char *format_last)
1620{
1621        for ( ; list; list = list->next) {
1622                const char *format = list->next ? format_cur : format_last;
1623                printf(format, sha1_to_hex(list->item->object.sha1));
1624        }
1625}
1626
1627const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1628{
1629        int key_len = strlen(key);
1630        const char *line = msg;
1631
1632        while (line) {
1633                const char *eol = strchrnul(line, '\n');
1634
1635                if (line == eol)
1636                        return NULL;
1637
1638                if (eol - line > key_len &&
1639                    !strncmp(line, key, key_len) &&
1640                    line[key_len] == ' ') {
1641                        *out_len = eol - line - key_len - 1;
1642                        return line + key_len + 1;
1643                }
1644                line = *eol ? eol + 1 : NULL;
1645        }
1646        return NULL;
1647}
1648
1649/*
1650 * Inspect sb and determine the true "end" of the log message, in
1651 * order to find where to put a new Signed-off-by: line.  Ignored are
1652 * trailing comment lines and blank lines, and also the traditional
1653 * "Conflicts:" block that is not commented out, so that we can use
1654 * "git commit -s --amend" on an existing commit that forgot to remove
1655 * it.
1656 *
1657 * Returns the number of bytes from the tail to ignore, to be fed as
1658 * the second parameter to append_signoff().
1659 */
1660int ignore_non_trailer(struct strbuf *sb)
1661{
1662        int boc = 0;
1663        int bol = 0;
1664        int in_old_conflicts_block = 0;
1665
1666        while (bol < sb->len) {
1667                char *next_line;
1668
1669                if (!(next_line = memchr(sb->buf + bol, '\n', sb->len - bol)))
1670                        next_line = sb->buf + sb->len;
1671                else
1672                        next_line++;
1673
1674                if (sb->buf[bol] == comment_line_char || sb->buf[bol] == '\n') {
1675                        /* is this the first of the run of comments? */
1676                        if (!boc)
1677                                boc = bol;
1678                        /* otherwise, it is just continuing */
1679                } else if (starts_with(sb->buf + bol, "Conflicts:\n")) {
1680                        in_old_conflicts_block = 1;
1681                        if (!boc)
1682                                boc = bol;
1683                } else if (in_old_conflicts_block && sb->buf[bol] == '\t') {
1684                        ; /* a pathname in the conflicts block */
1685                } else if (boc) {
1686                        /* the previous was not trailing comment */
1687                        boc = 0;
1688                        in_old_conflicts_block = 0;
1689                }
1690                bol = next_line - sb->buf;
1691        }
1692        return boc ? sb->len - boc : 0;
1693}