Andrew's git / gitweb.git / commit.c
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commit.con commit Merge branch 'master' of git://git.kernel.org/pub/scm/git/git (6758391)
   1#include "cache.h"
   2#include "tag.h"
   3#include "commit.h"
   4#include "pkt-line.h"
   5#include "utf8.h"
   6
   7int save_commit_buffer = 1;
   8
   9struct sort_node
  10{
  11        /*
  12         * the number of children of the associated commit
  13         * that also occur in the list being sorted.
  14         */
  15        unsigned int indegree;
  16
  17        /*
  18         * reference to original list item that we will re-use
  19         * on output.
  20         */
  21        struct commit_list * list_item;
  22
  23};
  24
  25const char *commit_type = "commit";
  26
  27struct cmt_fmt_map {
  28        const char *n;
  29        size_t cmp_len;
  30        enum cmit_fmt v;
  31} cmt_fmts[] = {
  32        { "raw",        1,      CMIT_FMT_RAW },
  33        { "medium",     1,      CMIT_FMT_MEDIUM },
  34        { "short",      1,      CMIT_FMT_SHORT },
  35        { "email",      1,      CMIT_FMT_EMAIL },
  36        { "full",       5,      CMIT_FMT_FULL },
  37        { "fuller",     5,      CMIT_FMT_FULLER },
  38        { "oneline",    1,      CMIT_FMT_ONELINE },
  39};
  40
  41enum cmit_fmt get_commit_format(const char *arg)
  42{
  43        int i;
  44
  45        if (!arg || !*arg)
  46                return CMIT_FMT_DEFAULT;
  47        if (*arg == '=')
  48                arg++;
  49        for (i = 0; i < ARRAY_SIZE(cmt_fmts); i++) {
  50                if (!strncmp(arg, cmt_fmts[i].n, cmt_fmts[i].cmp_len))
  51                        return cmt_fmts[i].v;
  52        }
  53
  54        die("invalid --pretty format: %s", arg);
  55}
  56
  57static struct commit *check_commit(struct object *obj,
  58                                   const unsigned char *sha1,
  59                                   int quiet)
  60{
  61        if (obj->type != OBJ_COMMIT) {
  62                if (!quiet)
  63                        error("Object %s is a %s, not a commit",
  64                              sha1_to_hex(sha1), typename(obj->type));
  65                return NULL;
  66        }
  67        return (struct commit *) obj;
  68}
  69
  70struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
  71                                              int quiet)
  72{
  73        struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
  74
  75        if (!obj)
  76                return NULL;
  77        return check_commit(obj, sha1, quiet);
  78}
  79
  80struct commit *lookup_commit_reference(const unsigned char *sha1)
  81{
  82        return lookup_commit_reference_gently(sha1, 0);
  83}
  84
  85struct commit *lookup_commit(const unsigned char *sha1)
  86{
  87        struct object *obj = lookup_object(sha1);
  88        if (!obj) {
  89                struct commit *ret = alloc_commit_node();
  90                created_object(sha1, &ret->object);
  91                ret->object.type = OBJ_COMMIT;
  92                return ret;
  93        }
  94        if (!obj->type)
  95                obj->type = OBJ_COMMIT;
  96        return check_commit(obj, sha1, 0);
  97}
  98
  99static unsigned long parse_commit_date(const char *buf)
 100{
 101        unsigned long date;
 102
 103        if (memcmp(buf, "author", 6))
 104                return 0;
 105        while (*buf++ != '\n')
 106                /* nada */;
 107        if (memcmp(buf, "committer", 9))
 108                return 0;
 109        while (*buf++ != '>')
 110                /* nada */;
 111        date = strtoul(buf, NULL, 10);
 112        if (date == ULONG_MAX)
 113                date = 0;
 114        return date;
 115}
 116
 117static struct commit_graft **commit_graft;
 118static int commit_graft_alloc, commit_graft_nr;
 119
 120static int commit_graft_pos(const unsigned char *sha1)
 121{
 122        int lo, hi;
 123        lo = 0;
 124        hi = commit_graft_nr;
 125        while (lo < hi) {
 126                int mi = (lo + hi) / 2;
 127                struct commit_graft *graft = commit_graft[mi];
 128                int cmp = hashcmp(sha1, graft->sha1);
 129                if (!cmp)
 130                        return mi;
 131                if (cmp < 0)
 132                        hi = mi;
 133                else
 134                        lo = mi + 1;
 135        }
 136        return -lo - 1;
 137}
 138
 139int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 140{
 141        int pos = commit_graft_pos(graft->sha1);
 142        
 143        if (0 <= pos) {
 144                if (ignore_dups)
 145                        free(graft);
 146                else {
 147                        free(commit_graft[pos]);
 148                        commit_graft[pos] = graft;
 149                }
 150                return 1;
 151        }
 152        pos = -pos - 1;
 153        if (commit_graft_alloc <= ++commit_graft_nr) {
 154                commit_graft_alloc = alloc_nr(commit_graft_alloc);
 155                commit_graft = xrealloc(commit_graft,
 156                                        sizeof(*commit_graft) *
 157                                        commit_graft_alloc);
 158        }
 159        if (pos < commit_graft_nr)
 160                memmove(commit_graft + pos + 1,
 161                        commit_graft + pos,
 162                        (commit_graft_nr - pos - 1) *
 163                        sizeof(*commit_graft));
 164        commit_graft[pos] = graft;
 165        return 0;
 166}
 167
 168struct commit_graft *read_graft_line(char *buf, int len)
 169{
 170        /* The format is just "Commit Parent1 Parent2 ...\n" */
 171        int i;
 172        struct commit_graft *graft = NULL;
 173
 174        if (buf[len-1] == '\n')
 175                buf[--len] = 0;
 176        if (buf[0] == '#' || buf[0] == '\0')
 177                return NULL;
 178        if ((len + 1) % 41) {
 179        bad_graft_data:
 180                error("bad graft data: %s", buf);
 181                free(graft);
 182                return NULL;
 183        }
 184        i = (len + 1) / 41 - 1;
 185        graft = xmalloc(sizeof(*graft) + 20 * i);
 186        graft->nr_parent = i;
 187        if (get_sha1_hex(buf, graft->sha1))
 188                goto bad_graft_data;
 189        for (i = 40; i < len; i += 41) {
 190                if (buf[i] != ' ')
 191                        goto bad_graft_data;
 192                if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
 193                        goto bad_graft_data;
 194        }
 195        return graft;
 196}
 197
 198int read_graft_file(const char *graft_file)
 199{
 200        FILE *fp = fopen(graft_file, "r");
 201        char buf[1024];
 202        if (!fp)
 203                return -1;
 204        while (fgets(buf, sizeof(buf), fp)) {
 205                /* The format is just "Commit Parent1 Parent2 ...\n" */
 206                int len = strlen(buf);
 207                struct commit_graft *graft = read_graft_line(buf, len);
 208                if (!graft)
 209                        continue;
 210                if (register_commit_graft(graft, 1))
 211                        error("duplicate graft data: %s", buf);
 212        }
 213        fclose(fp);
 214        return 0;
 215}
 216
 217static void prepare_commit_graft(void)
 218{
 219        static int commit_graft_prepared;
 220        char *graft_file;
 221
 222        if (commit_graft_prepared)
 223                return;
 224        graft_file = get_graft_file();
 225        read_graft_file(graft_file);
 226        /* make sure shallows are read */
 227        is_repository_shallow();
 228        commit_graft_prepared = 1;
 229}
 230
 231static struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 232{
 233        int pos;
 234        prepare_commit_graft();
 235        pos = commit_graft_pos(sha1);
 236        if (pos < 0)
 237                return NULL;
 238        return commit_graft[pos];
 239}
 240
 241int write_shallow_commits(int fd, int use_pack_protocol)
 242{
 243        int i, count = 0;
 244        for (i = 0; i < commit_graft_nr; i++)
 245                if (commit_graft[i]->nr_parent < 0) {
 246                        const char *hex =
 247                                sha1_to_hex(commit_graft[i]->sha1);
 248                        count++;
 249                        if (use_pack_protocol)
 250                                packet_write(fd, "shallow %s", hex);
 251                        else {
 252                                if (write_in_full(fd, hex,  40) != 40)
 253                                        break;
 254                                if (write_in_full(fd, "\n", 1) != 1)
 255                                        break;
 256                        }
 257                }
 258        return count;
 259}
 260
 261int unregister_shallow(const unsigned char *sha1)
 262{
 263        int pos = commit_graft_pos(sha1);
 264        if (pos < 0)
 265                return -1;
 266        if (pos + 1 < commit_graft_nr)
 267                memcpy(commit_graft + pos, commit_graft + pos + 1,
 268                                sizeof(struct commit_graft *)
 269                                * (commit_graft_nr - pos - 1));
 270        commit_graft_nr--;
 271        return 0;
 272}
 273
 274int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 275{
 276        char *tail = buffer;
 277        char *bufptr = buffer;
 278        unsigned char parent[20];
 279        struct commit_list **pptr;
 280        struct commit_graft *graft;
 281        unsigned n_refs = 0;
 282
 283        if (item->object.parsed)
 284                return 0;
 285        item->object.parsed = 1;
 286        tail += size;
 287        if (tail <= bufptr + 5 || memcmp(bufptr, "tree ", 5))
 288                return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 289        if (tail <= bufptr + 45 || get_sha1_hex(bufptr + 5, parent) < 0)
 290                return error("bad tree pointer in commit %s",
 291                             sha1_to_hex(item->object.sha1));
 292        item->tree = lookup_tree(parent);
 293        if (item->tree)
 294                n_refs++;
 295        bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 296        pptr = &item->parents;
 297
 298        graft = lookup_commit_graft(item->object.sha1);
 299        while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
 300                struct commit *new_parent;
 301
 302                if (tail <= bufptr + 48 ||
 303                    get_sha1_hex(bufptr + 7, parent) ||
 304                    bufptr[47] != '\n')
 305                        return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 306                bufptr += 48;
 307                if (graft)
 308                        continue;
 309                new_parent = lookup_commit(parent);
 310                if (new_parent) {
 311                        pptr = &commit_list_insert(new_parent, pptr)->next;
 312                        n_refs++;
 313                }
 314        }
 315        if (graft) {
 316                int i;
 317                struct commit *new_parent;
 318                for (i = 0; i < graft->nr_parent; i++) {
 319                        new_parent = lookup_commit(graft->parent[i]);
 320                        if (!new_parent)
 321                                continue;
 322                        pptr = &commit_list_insert(new_parent, pptr)->next;
 323                        n_refs++;
 324                }
 325        }
 326        item->date = parse_commit_date(bufptr);
 327
 328        if (track_object_refs) {
 329                unsigned i = 0;
 330                struct commit_list *p;
 331                struct object_refs *refs = alloc_object_refs(n_refs);
 332                if (item->tree)
 333                        refs->ref[i++] = &item->tree->object;
 334                for (p = item->parents; p; p = p->next)
 335                        refs->ref[i++] = &p->item->object;
 336                set_object_refs(&item->object, refs);
 337        }
 338
 339        return 0;
 340}
 341
 342int parse_commit(struct commit *item)
 343{
 344        char type[20];
 345        void *buffer;
 346        unsigned long size;
 347        int ret;
 348
 349        if (item->object.parsed)
 350                return 0;
 351        buffer = read_sha1_file(item->object.sha1, type, &size);
 352        if (!buffer)
 353                return error("Could not read %s",
 354                             sha1_to_hex(item->object.sha1));
 355        if (strcmp(type, commit_type)) {
 356                free(buffer);
 357                return error("Object %s not a commit",
 358                             sha1_to_hex(item->object.sha1));
 359        }
 360        ret = parse_commit_buffer(item, buffer, size);
 361        if (save_commit_buffer && !ret) {
 362                item->buffer = buffer;
 363                return 0;
 364        }
 365        free(buffer);
 366        return ret;
 367}
 368
 369struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 370{
 371        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 372        new_list->item = item;
 373        new_list->next = *list_p;
 374        *list_p = new_list;
 375        return new_list;
 376}
 377
 378void free_commit_list(struct commit_list *list)
 379{
 380        while (list) {
 381                struct commit_list *temp = list;
 382                list = temp->next;
 383                free(temp);
 384        }
 385}
 386
 387struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 388{
 389        struct commit_list **pp = list;
 390        struct commit_list *p;
 391        while ((p = *pp) != NULL) {
 392                if (p->item->date < item->date) {
 393                        break;
 394                }
 395                pp = &p->next;
 396        }
 397        return commit_list_insert(item, pp);
 398}
 399
 400        
 401void sort_by_date(struct commit_list **list)
 402{
 403        struct commit_list *ret = NULL;
 404        while (*list) {
 405                insert_by_date((*list)->item, &ret);
 406                *list = (*list)->next;
 407        }
 408        *list = ret;
 409}
 410
 411struct commit *pop_most_recent_commit(struct commit_list **list,
 412                                      unsigned int mark)
 413{
 414        struct commit *ret = (*list)->item;
 415        struct commit_list *parents = ret->parents;
 416        struct commit_list *old = *list;
 417
 418        *list = (*list)->next;
 419        free(old);
 420
 421        while (parents) {
 422                struct commit *commit = parents->item;
 423                parse_commit(commit);
 424                if (!(commit->object.flags & mark)) {
 425                        commit->object.flags |= mark;
 426                        insert_by_date(commit, list);
 427                }
 428                parents = parents->next;
 429        }
 430        return ret;
 431}
 432
 433void clear_commit_marks(struct commit *commit, unsigned int mark)
 434{
 435        struct commit_list *parents;
 436
 437        commit->object.flags &= ~mark;
 438        parents = commit->parents;
 439        while (parents) {
 440                struct commit *parent = parents->item;
 441
 442                /* Have we already cleared this? */
 443                if (mark & parent->object.flags)
 444                        clear_commit_marks(parent, mark);
 445                parents = parents->next;
 446        }
 447}
 448
 449/*
 450 * Generic support for pretty-printing the header
 451 */
 452static int get_one_line(const char *msg, unsigned long len)
 453{
 454        int ret = 0;
 455
 456        while (len--) {
 457                char c = *msg++;
 458                if (!c)
 459                        break;
 460                ret++;
 461                if (c == '\n')
 462                        break;
 463        }
 464        return ret;
 465}
 466
 467/* High bit set, or ISO-2022-INT */
 468static int non_ascii(int ch)
 469{
 470        ch = (ch & 0xff);
 471        return ((ch & 0x80) || (ch == 0x1b));
 472}
 473
 474static int is_rfc2047_special(char ch)
 475{
 476        return (non_ascii(ch) || (ch == '=') || (ch == '?') || (ch == '_'));
 477}
 478
 479static int add_rfc2047(char *buf, const char *line, int len,
 480                       const char *encoding)
 481{
 482        char *bp = buf;
 483        int i, needquote;
 484        char q_encoding[128];
 485        const char *q_encoding_fmt = "=?%s?q?";
 486
 487        for (i = needquote = 0; !needquote && i < len; i++) {
 488                int ch = line[i];
 489                if (non_ascii(ch))
 490                        needquote++;
 491                if ((i + 1 < len) &&
 492                    (ch == '=' && line[i+1] == '?'))
 493                        needquote++;
 494        }
 495        if (!needquote)
 496                return sprintf(buf, "%.*s", len, line);
 497
 498        i = snprintf(q_encoding, sizeof(q_encoding), q_encoding_fmt, encoding);
 499        if (sizeof(q_encoding) < i)
 500                die("Insanely long encoding name %s", encoding);
 501        memcpy(bp, q_encoding, i);
 502        bp += i;
 503        for (i = 0; i < len; i++) {
 504                unsigned ch = line[i] & 0xFF;
 505                if (is_rfc2047_special(ch)) {
 506                        sprintf(bp, "=%02X", ch);
 507                        bp += 3;
 508                }
 509                else if (ch == ' ')
 510                        *bp++ = '_';
 511                else
 512                        *bp++ = ch;
 513        }
 514        memcpy(bp, "?=", 2);
 515        bp += 2;
 516        return bp - buf;
 517}
 518
 519static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf,
 520                         const char *line, int relative_date,
 521                         const char *encoding)
 522{
 523        char *date;
 524        int namelen;
 525        unsigned long time;
 526        int tz, ret;
 527        const char *filler = "    ";
 528
 529        if (fmt == CMIT_FMT_ONELINE)
 530                return 0;
 531        date = strchr(line, '>');
 532        if (!date)
 533                return 0;
 534        namelen = ++date - line;
 535        time = strtoul(date, &date, 10);
 536        tz = strtol(date, NULL, 10);
 537
 538        if (fmt == CMIT_FMT_EMAIL) {
 539                char *name_tail = strchr(line, '<');
 540                int display_name_length;
 541                if (!name_tail)
 542                        return 0;
 543                while (line < name_tail && isspace(name_tail[-1]))
 544                        name_tail--;
 545                display_name_length = name_tail - line;
 546                filler = "";
 547                strcpy(buf, "From: ");
 548                ret = strlen(buf);
 549                ret += add_rfc2047(buf + ret, line, display_name_length,
 550                                   encoding);
 551                memcpy(buf + ret, name_tail, namelen - display_name_length);
 552                ret += namelen - display_name_length;
 553                buf[ret++] = '\n';
 554        }
 555        else {
 556                ret = sprintf(buf, "%s: %.*s%.*s\n", what,
 557                              (fmt == CMIT_FMT_FULLER) ? 4 : 0,
 558                              filler, namelen, line);
 559        }
 560        switch (fmt) {
 561        case CMIT_FMT_MEDIUM:
 562                ret += sprintf(buf + ret, "Date:   %s\n",
 563                               show_date(time, tz, relative_date));
 564                break;
 565        case CMIT_FMT_EMAIL:
 566                ret += sprintf(buf + ret, "Date: %s\n",
 567                               show_rfc2822_date(time, tz));
 568                break;
 569        case CMIT_FMT_FULLER:
 570                ret += sprintf(buf + ret, "%sDate: %s\n", what,
 571                               show_date(time, tz, relative_date));
 572                break;
 573        default:
 574                /* notin' */
 575                break;
 576        }
 577        return ret;
 578}
 579
 580static int is_empty_line(const char *line, int *len_p)
 581{
 582        int len = *len_p;
 583        while (len && isspace(line[len-1]))
 584                len--;
 585        *len_p = len;
 586        return !len;
 587}
 588
 589static int add_merge_info(enum cmit_fmt fmt, char *buf, const struct commit *commit, int abbrev)
 590{
 591        struct commit_list *parent = commit->parents;
 592        int offset;
 593
 594        if ((fmt == CMIT_FMT_ONELINE) || (fmt == CMIT_FMT_EMAIL) ||
 595            !parent || !parent->next)
 596                return 0;
 597
 598        offset = sprintf(buf, "Merge:");
 599
 600        while (parent) {
 601                struct commit *p = parent->item;
 602                const char *hex = NULL;
 603                const char *dots;
 604                if (abbrev)
 605                        hex = find_unique_abbrev(p->object.sha1, abbrev);
 606                if (!hex)
 607                        hex = sha1_to_hex(p->object.sha1);
 608                dots = (abbrev && strlen(hex) != 40) ?  "..." : "";
 609                parent = parent->next;
 610
 611                offset += sprintf(buf + offset, " %s%s", hex, dots);
 612        }
 613        buf[offset++] = '\n';
 614        return offset;
 615}
 616
 617static char *get_header(const struct commit *commit, const char *key)
 618{
 619        int key_len = strlen(key);
 620        const char *line = commit->buffer;
 621
 622        for (;;) {
 623                const char *eol = strchr(line, '\n'), *next;
 624
 625                if (line == eol)
 626                        return NULL;
 627                if (!eol) {
 628                        eol = line + strlen(line);
 629                        next = NULL;
 630                } else
 631                        next = eol + 1;
 632                if (!strncmp(line, key, key_len) && line[key_len] == ' ') {
 633                        int len = eol - line - key_len;
 634                        char *ret = xmalloc(len);
 635                        memcpy(ret, line + key_len + 1, len - 1);
 636                        ret[len - 1] = '\0';
 637                        return ret;
 638                }
 639                line = next;
 640        }
 641}
 642
 643static char *replace_encoding_header(char *buf, char *encoding)
 644{
 645        char *encoding_header = strstr(buf, "\nencoding ");
 646        char *end_of_encoding_header;
 647        int encoding_header_pos;
 648        int encoding_header_len;
 649        int new_len;
 650        int need_len;
 651        int buflen = strlen(buf) + 1;
 652
 653        if (!encoding_header)
 654                return buf; /* should not happen but be defensive */
 655        encoding_header++;
 656        end_of_encoding_header = strchr(encoding_header, '\n');
 657        if (!end_of_encoding_header)
 658                return buf; /* should not happen but be defensive */
 659        end_of_encoding_header++;
 660
 661        encoding_header_len = end_of_encoding_header - encoding_header;
 662        encoding_header_pos = encoding_header - buf;
 663
 664        if (is_encoding_utf8(encoding)) {
 665                /* we have re-coded to UTF-8; drop the header */
 666                memmove(encoding_header, end_of_encoding_header,
 667                        buflen - (encoding_header_pos + encoding_header_len));
 668                return buf;
 669        }
 670        new_len = strlen(encoding);
 671        need_len = new_len + strlen("encoding \n");
 672        if (encoding_header_len < need_len) {
 673                buf = xrealloc(buf, buflen + (need_len - encoding_header_len));
 674                encoding_header = buf + encoding_header_pos;
 675                end_of_encoding_header = encoding_header + encoding_header_len;
 676        }
 677        memmove(end_of_encoding_header + (need_len - encoding_header_len),
 678                end_of_encoding_header,
 679                buflen - (encoding_header_pos + encoding_header_len));
 680        memcpy(encoding_header + 9, encoding, strlen(encoding));
 681        encoding_header[9 + new_len] = '\n';
 682        return buf;
 683}
 684
 685static char *logmsg_reencode(const struct commit *commit,
 686                             char *output_encoding)
 687{
 688        char *encoding;
 689        char *out;
 690        char *utf8 = "utf-8";
 691
 692        if (!*output_encoding)
 693                return NULL;
 694        encoding = get_header(commit, "encoding");
 695        if (!encoding)
 696                encoding = utf8;
 697        if (!strcmp(encoding, output_encoding))
 698                out = strdup(commit->buffer);
 699        else
 700                out = reencode_string(commit->buffer,
 701                                      output_encoding, encoding);
 702        if (out)
 703                out = replace_encoding_header(out, output_encoding);
 704
 705        if (encoding != utf8)
 706                free(encoding);
 707        if (!out)
 708                return NULL;
 709        return out;
 710}
 711
 712unsigned long pretty_print_commit(enum cmit_fmt fmt,
 713                                  const struct commit *commit,
 714                                  unsigned long len,
 715                                  char *buf, unsigned long space,
 716                                  int abbrev, const char *subject,
 717                                  const char *after_subject,
 718                                  int relative_date)
 719{
 720        int hdr = 1, body = 0, seen_title = 0;
 721        unsigned long offset = 0;
 722        int indent = 4;
 723        int parents_shown = 0;
 724        const char *msg = commit->buffer;
 725        int plain_non_ascii = 0;
 726        char *reencoded;
 727        char *encoding;
 728
 729        encoding = (git_log_output_encoding
 730                    ? git_log_output_encoding
 731                    : git_commit_encoding);
 732        if (!encoding)
 733                encoding = "utf-8";
 734        reencoded = logmsg_reencode(commit, encoding);
 735        if (reencoded)
 736                msg = reencoded;
 737
 738        if (fmt == CMIT_FMT_ONELINE || fmt == CMIT_FMT_EMAIL)
 739                indent = 0;
 740
 741        /* After-subject is used to pass in Content-Type: multipart
 742         * MIME header; in that case we do not have to do the
 743         * plaintext content type even if the commit message has
 744         * non 7-bit ASCII character.  Otherwise, check if we need
 745         * to say this is not a 7-bit ASCII.
 746         */
 747        if (fmt == CMIT_FMT_EMAIL && !after_subject) {
 748                int i, ch, in_body;
 749
 750                for (in_body = i = 0; (ch = msg[i]) && i < len; i++) {
 751                        if (!in_body) {
 752                                /* author could be non 7-bit ASCII but
 753                                 * the log may be so; skip over the
 754                                 * header part first.
 755                                 */
 756                                if (ch == '\n' &&
 757                                    i + 1 < len && msg[i+1] == '\n')
 758                                        in_body = 1;
 759                        }
 760                        else if (non_ascii(ch)) {
 761                                plain_non_ascii = 1;
 762                                break;
 763                        }
 764                }
 765        }
 766
 767        for (;;) {
 768                const char *line = msg;
 769                int linelen = get_one_line(msg, len);
 770
 771                if (!linelen)
 772                        break;
 773
 774                /*
 775                 * We want some slop for indentation and a possible
 776                 * final "...". Thus the "+ 20".
 777                 */
 778                if (offset + linelen + 20 > space) {
 779                        memcpy(buf + offset, "    ...\n", 8);
 780                        offset += 8;
 781                        break;
 782                }
 783
 784                msg += linelen;
 785                len -= linelen;
 786                if (hdr) {
 787                        if (linelen == 1) {
 788                                hdr = 0;
 789                                if ((fmt != CMIT_FMT_ONELINE) && !subject)
 790                                        buf[offset++] = '\n';
 791                                continue;
 792                        }
 793                        if (fmt == CMIT_FMT_RAW) {
 794                                memcpy(buf + offset, line, linelen);
 795                                offset += linelen;
 796                                continue;
 797                        }
 798                        if (!memcmp(line, "parent ", 7)) {
 799                                if (linelen != 48)
 800                                        die("bad parent line in commit");
 801                                continue;
 802                        }
 803
 804                        if (!parents_shown) {
 805                                offset += add_merge_info(fmt, buf + offset,
 806                                                         commit, abbrev);
 807                                parents_shown = 1;
 808                                continue;
 809                        }
 810                        /*
 811                         * MEDIUM == DEFAULT shows only author with dates.
 812                         * FULL shows both authors but not dates.
 813                         * FULLER shows both authors and dates.
 814                         */
 815                        if (!memcmp(line, "author ", 7))
 816                                offset += add_user_info("Author", fmt,
 817                                                        buf + offset,
 818                                                        line + 7,
 819                                                        relative_date,
 820                                                        encoding);
 821                        if (!memcmp(line, "committer ", 10) &&
 822                            (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER))
 823                                offset += add_user_info("Commit", fmt,
 824                                                        buf + offset,
 825                                                        line + 10,
 826                                                        relative_date,
 827                                                        encoding);
 828                        continue;
 829                }
 830
 831                if (!subject)
 832                        body = 1;
 833
 834                if (is_empty_line(line, &linelen)) {
 835                        if (!seen_title)
 836                                continue;
 837                        if (!body)
 838                                continue;
 839                        if (subject)
 840                                continue;
 841                        if (fmt == CMIT_FMT_SHORT)
 842                                break;
 843                }
 844
 845                seen_title = 1;
 846                if (subject) {
 847                        int slen = strlen(subject);
 848                        memcpy(buf + offset, subject, slen);
 849                        offset += slen;
 850                        offset += add_rfc2047(buf + offset, line, linelen,
 851                                              encoding);
 852                }
 853                else {
 854                        memset(buf + offset, ' ', indent);
 855                        memcpy(buf + offset + indent, line, linelen);
 856                        offset += linelen + indent;
 857                }
 858                buf[offset++] = '\n';
 859                if (fmt == CMIT_FMT_ONELINE)
 860                        break;
 861                if (subject && plain_non_ascii) {
 862                        int sz;
 863                        char header[512];
 864                        const char *header_fmt =
 865                                "Content-Type: text/plain; charset=%s\n"
 866                                "Content-Transfer-Encoding: 8bit\n";
 867                        sz = snprintf(header, sizeof(header), header_fmt,
 868                                      encoding);
 869                        if (sizeof(header) < sz)
 870                                die("Encoding name %s too long", encoding);
 871                        memcpy(buf + offset, header, sz);
 872                        offset += sz;
 873                }
 874                if (after_subject) {
 875                        int slen = strlen(after_subject);
 876                        if (slen > space - offset - 1)
 877                                slen = space - offset - 1;
 878                        memcpy(buf + offset, after_subject, slen);
 879                        offset += slen;
 880                        after_subject = NULL;
 881                }
 882                subject = NULL;
 883        }
 884        while (offset && isspace(buf[offset-1]))
 885                offset--;
 886        /* Make sure there is an EOLN for the non-oneline case */
 887        if (fmt != CMIT_FMT_ONELINE)
 888                buf[offset++] = '\n';
 889        /*
 890         * make sure there is another EOLN to separate the headers from whatever
 891         * body the caller appends if we haven't already written a body
 892         */
 893        if (fmt == CMIT_FMT_EMAIL && !body)
 894                buf[offset++] = '\n';
 895        buf[offset] = '\0';
 896
 897        free(reencoded);
 898        return offset;
 899}
 900
 901struct commit *pop_commit(struct commit_list **stack)
 902{
 903        struct commit_list *top = *stack;
 904        struct commit *item = top ? top->item : NULL;
 905
 906        if (top) {
 907                *stack = top->next;
 908                free(top);
 909        }
 910        return item;
 911}
 912
 913int count_parents(struct commit * commit)
 914{
 915        int count;
 916        struct commit_list * parents = commit->parents;
 917        for (count = 0; parents; parents = parents->next,count++)
 918                ;
 919        return count;
 920}
 921
 922void topo_sort_default_setter(struct commit *c, void *data)
 923{
 924        c->util = data;
 925}
 926
 927void *topo_sort_default_getter(struct commit *c)
 928{
 929        return c->util;
 930}
 931
 932/*
 933 * Performs an in-place topological sort on the list supplied.
 934 */
 935void sort_in_topological_order(struct commit_list ** list, int lifo)
 936{
 937        sort_in_topological_order_fn(list, lifo, topo_sort_default_setter,
 938                                     topo_sort_default_getter);
 939}
 940
 941void sort_in_topological_order_fn(struct commit_list ** list, int lifo,
 942                                  topo_sort_set_fn_t setter,
 943                                  topo_sort_get_fn_t getter)
 944{
 945        struct commit_list * next = *list;
 946        struct commit_list * work = NULL, **insert;
 947        struct commit_list ** pptr = list;
 948        struct sort_node * nodes;
 949        struct sort_node * next_nodes;
 950        int count = 0;
 951
 952        /* determine the size of the list */
 953        while (next) {
 954                next = next->next;
 955                count++;
 956        }
 957        
 958        if (!count)
 959                return;
 960        /* allocate an array to help sort the list */
 961        nodes = xcalloc(count, sizeof(*nodes));
 962        /* link the list to the array */
 963        next_nodes = nodes;
 964        next=*list;
 965        while (next) {
 966                next_nodes->list_item = next;
 967                setter(next->item, next_nodes);
 968                next_nodes++;
 969                next = next->next;
 970        }
 971        /* update the indegree */
 972        next=*list;
 973        while (next) {
 974                struct commit_list * parents = next->item->parents;
 975                while (parents) {
 976                        struct commit * parent=parents->item;
 977                        struct sort_node * pn = (struct sort_node *) getter(parent);
 978
 979                        if (pn)
 980                                pn->indegree++;
 981                        parents=parents->next;
 982                }
 983                next=next->next;
 984        }
 985        /* 
 986         * find the tips
 987         *
 988         * tips are nodes not reachable from any other node in the list 
 989         * 
 990         * the tips serve as a starting set for the work queue.
 991         */
 992        next=*list;
 993        insert = &work;
 994        while (next) {
 995                struct sort_node * node = (struct sort_node *) getter(next->item);
 996
 997                if (node->indegree == 0) {
 998                        insert = &commit_list_insert(next->item, insert)->next;
 999                }
1000                next=next->next;
1001        }
1002
1003        /* process the list in topological order */
1004        if (!lifo)
1005                sort_by_date(&work);
1006        while (work) {
1007                struct commit * work_item = pop_commit(&work);
1008                struct sort_node * work_node = (struct sort_node *) getter(work_item);
1009                struct commit_list * parents = work_item->parents;
1010
1011                while (parents) {
1012                        struct commit * parent=parents->item;
1013                        struct sort_node * pn = (struct sort_node *) getter(parent);
1014
1015                        if (pn) {
1016                                /*
1017                                 * parents are only enqueued for emission 
1018                                 * when all their children have been emitted thereby
1019                                 * guaranteeing topological order.
1020                                 */
1021                                pn->indegree--;
1022                                if (!pn->indegree) {
1023                                        if (!lifo)
1024                                                insert_by_date(parent, &work);
1025                                        else
1026                                                commit_list_insert(parent, &work);
1027                                }
1028                        }
1029                        parents=parents->next;
1030                }
1031                /*
1032                 * work_item is a commit all of whose children
1033                 * have already been emitted. we can emit it now.
1034                 */
1035                *pptr = work_node->list_item;
1036                pptr = &(*pptr)->next;
1037                *pptr = NULL;
1038                setter(work_item, NULL);
1039        }
1040        free(nodes);
1041}
1042
1043/* merge-base stuff */
1044
1045/* bits #0..15 in revision.h */
1046#define PARENT1         (1u<<16)
1047#define PARENT2         (1u<<17)
1048#define STALE           (1u<<18)
1049#define RESULT          (1u<<19)
1050
1051static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
1052
1053static struct commit *interesting(struct commit_list *list)
1054{
1055        while (list) {
1056                struct commit *commit = list->item;
1057                list = list->next;
1058                if (commit->object.flags & STALE)
1059                        continue;
1060                return commit;
1061        }
1062        return NULL;
1063}
1064
1065static struct commit_list *merge_bases(struct commit *one, struct commit *two)
1066{
1067        struct commit_list *list = NULL;
1068        struct commit_list *result = NULL;
1069
1070        if (one == two)
1071                /* We do not mark this even with RESULT so we do not
1072                 * have to clean it up.
1073                 */
1074                return commit_list_insert(one, &result);
1075
1076        parse_commit(one);
1077        parse_commit(two);
1078
1079        one->object.flags |= PARENT1;
1080        two->object.flags |= PARENT2;
1081        insert_by_date(one, &list);
1082        insert_by_date(two, &list);
1083
1084        while (interesting(list)) {
1085                struct commit *commit;
1086                struct commit_list *parents;
1087                struct commit_list *n;
1088                int flags;
1089
1090                commit = list->item;
1091                n = list->next;
1092                free(list);
1093                list = n;
1094
1095                flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
1096                if (flags == (PARENT1 | PARENT2)) {
1097                        if (!(commit->object.flags & RESULT)) {
1098                                commit->object.flags |= RESULT;
1099                                insert_by_date(commit, &result);
1100                        }
1101                        /* Mark parents of a found merge stale */
1102                        flags |= STALE;
1103                }
1104                parents = commit->parents;
1105                while (parents) {
1106                        struct commit *p = parents->item;
1107                        parents = parents->next;
1108                        if ((p->object.flags & flags) == flags)
1109                                continue;
1110                        parse_commit(p);
1111                        p->object.flags |= flags;
1112                        insert_by_date(p, &list);
1113                }
1114        }
1115
1116        /* Clean up the result to remove stale ones */
1117        free_commit_list(list);
1118        list = result; result = NULL;
1119        while (list) {
1120                struct commit_list *n = list->next;
1121                if (!(list->item->object.flags & STALE))
1122                        insert_by_date(list->item, &result);
1123                free(list);
1124                list = n;
1125        }
1126        return result;
1127}
1128
1129struct commit_list *get_merge_bases(struct commit *one,
1130                                    struct commit *two,
1131                                    int cleanup)
1132{
1133        struct commit_list *list;
1134        struct commit **rslt;
1135        struct commit_list *result;
1136        int cnt, i, j;
1137
1138        result = merge_bases(one, two);
1139        if (one == two)
1140                return result;
1141        if (!result || !result->next) {
1142                if (cleanup) {
1143                        clear_commit_marks(one, all_flags);
1144                        clear_commit_marks(two, all_flags);
1145                }
1146                return result;
1147        }
1148
1149        /* There are more than one */
1150        cnt = 0;
1151        list = result;
1152        while (list) {
1153                list = list->next;
1154                cnt++;
1155        }
1156        rslt = xcalloc(cnt, sizeof(*rslt));
1157        for (list = result, i = 0; list; list = list->next)
1158                rslt[i++] = list->item;
1159        free_commit_list(result);
1160
1161        clear_commit_marks(one, all_flags);
1162        clear_commit_marks(two, all_flags);
1163        for (i = 0; i < cnt - 1; i++) {
1164                for (j = i+1; j < cnt; j++) {
1165                        if (!rslt[i] || !rslt[j])
1166                                continue;
1167                        result = merge_bases(rslt[i], rslt[j]);
1168                        clear_commit_marks(rslt[i], all_flags);
1169                        clear_commit_marks(rslt[j], all_flags);
1170                        for (list = result; list; list = list->next) {
1171                                if (rslt[i] == list->item)
1172                                        rslt[i] = NULL;
1173                                if (rslt[j] == list->item)
1174                                        rslt[j] = NULL;
1175                        }
1176                }
1177        }
1178
1179        /* Surviving ones in rslt[] are the independent results */
1180        result = NULL;
1181        for (i = 0; i < cnt; i++) {
1182                if (rslt[i])
1183                        insert_by_date(rslt[i], &result);
1184        }
1185        free(rslt);
1186        return result;
1187}
1188
1189int in_merge_bases(struct commit *rev1, struct commit *rev2)
1190{
1191        struct commit_list *bases, *b;
1192        int ret = 0;
1193
1194        bases = get_merge_bases(rev1, rev2, 1);
1195        for (b = bases; b; b = b->next) {
1196                if (!hashcmp(rev1->object.sha1, b->item->object.sha1)) {
1197                        ret = 1;
1198                        break;
1199                }
1200        }
1201
1202        free_commit_list(bases);
1203        return ret;
1204}