commit.c

   1 #include "cache.h"
   2 #include "tag.h"
   3 #include "commit.h"
   4 #include "pkt-line.h"
   5 #include "utf8.h"
   6
   7 int save_commit_buffer = 1;
   8
   9 struct 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
  25 const char *commit_type = "commit";
  26
  27 struct 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
  41 enum 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                     !strncmp(arg, cmt_fmts[i].n, strlen(arg)))
  52                         return cmt_fmts[i].v;
  53         }
  54
  55         die("invalid --pretty format: %s", arg);
  56 }
  57
  58 static struct commit *check_commit(struct object *obj,
  59                                    const unsigned char *sha1,
  60                                    int quiet)
  61 {
  62         if (obj->type != OBJ_COMMIT) {
  63                 if (!quiet)
  64                         error("Object %s is a %s, not a commit",
  65                               sha1_to_hex(sha1), typename(obj->type));
  66                 return NULL;
  67         }
  68         return (struct commit *) obj;
  69 }
  70
  71 struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
  72                                               int quiet)
  73 {
  74         struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
  75
  76         if (!obj)
  77                 return NULL;
  78         return check_commit(obj, sha1, quiet);
  79 }
  80
  81 struct commit *lookup_commit_reference(const unsigned char *sha1)
  82 {
  83         return lookup_commit_reference_gently(sha1, 0);
  84 }
  85
  86 struct commit *lookup_commit(const unsigned char *sha1)
  87 {
  88         struct object *obj = lookup_object(sha1);
  89         if (!obj) {
  90                 struct commit *ret = alloc_commit_node();
  91                 created_object(sha1, &ret->object);
  92                 ret->object.type = OBJ_COMMIT;
  93                 return ret;
  94         }
  95         if (!obj->type)
  96                 obj->type = OBJ_COMMIT;
  97         return check_commit(obj, sha1, 0);
  98 }
  99
 100 static unsigned long parse_commit_date(const char *buf)
 101 {
 102         unsigned long date;
 103
 104         if (memcmp(buf, "author", 6))
 105                 return 0;
 106         while (*buf++ != '\n')
 107                 /* nada */;
 108         if (memcmp(buf, "committer", 9))
 109                 return 0;
 110         while (*buf++ != '>')
 111                 /* nada */;
 112         date = strtoul(buf, NULL, 10);
 113         if (date == ULONG_MAX)
 114                 date = 0;
 115         return date;
 116 }
 117
 118 static struct commit_graft **commit_graft;
 119 static int commit_graft_alloc, commit_graft_nr;
 120
 121 static int commit_graft_pos(const unsigned char *sha1)
 122 {
 123         int lo, hi;
 124         lo = 0;
 125         hi = commit_graft_nr;
 126         while (lo < hi) {
 127                 int mi = (lo + hi) / 2;
 128                 struct commit_graft *graft = commit_graft[mi];
 129                 int cmp = hashcmp(sha1, graft->sha1);
 130                 if (!cmp)
 131                         return mi;
 132                 if (cmp < 0)
 133                         hi = mi;
 134                 else
 135                         lo = mi + 1;
 136         }
 137         return -lo - 1;
 138 }
 139
 140 int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 141 {
 142         int pos = commit_graft_pos(graft->sha1);
 143
 144         if (0 <= pos) {
 145                 if (ignore_dups)
 146                         free(graft);
 147                 else {
 148                         free(commit_graft[pos]);
 149                         commit_graft[pos] = graft;
 150                 }
 151                 return 1;
 152         }
 153         pos = -pos - 1;
 154         if (commit_graft_alloc <= ++commit_graft_nr) {
 155                 commit_graft_alloc = alloc_nr(commit_graft_alloc);
 156                 commit_graft = xrealloc(commit_graft,
 157                                         sizeof(*commit_graft) *
 158                                         commit_graft_alloc);
 159         }
 160         if (pos < commit_graft_nr)
 161                 memmove(commit_graft + pos + 1,
 162                         commit_graft + pos,
 163                         (commit_graft_nr - pos - 1) *
 164                         sizeof(*commit_graft));
 165         commit_graft[pos] = graft;
 166         return 0;
 167 }
 168
 169 struct commit_graft *read_graft_line(char *buf, int len)
 170 {
 171         /* The format is just "Commit Parent1 Parent2 ...\n" */
 172         int i;
 173         struct commit_graft *graft = NULL;
 174
 175         if (buf[len-1] == '\n')
 176                 buf[--len] = 0;
 177         if (buf[0] == '#' || buf[0] == '\0')
 178                 return NULL;
 179         if ((len + 1) % 41) {
 180         bad_graft_data:
 181                 error("bad graft data: %s", buf);
 182                 free(graft);
 183                 return NULL;
 184         }
 185         i = (len + 1) / 41 - 1;
 186         graft = xmalloc(sizeof(*graft) + 20 * i);
 187         graft->nr_parent = i;
 188         if (get_sha1_hex(buf, graft->sha1))
 189                 goto bad_graft_data;
 190         for (i = 40; i < len; i += 41) {
 191                 if (buf[i] != ' ')
 192                         goto bad_graft_data;
 193                 if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
 194                         goto bad_graft_data;
 195         }
 196         return graft;
 197 }
 198
 199 int read_graft_file(const char *graft_file)
 200 {
 201         FILE *fp = fopen(graft_file, "r");
 202         char buf[1024];
 203         if (!fp)
 204                 return -1;
 205         while (fgets(buf, sizeof(buf), fp)) {
 206                 /* The format is just "Commit Parent1 Parent2 ...\n" */
 207                 int len = strlen(buf);
 208                 struct commit_graft *graft = read_graft_line(buf, len);
 209                 if (!graft)
 210                         continue;
 211                 if (register_commit_graft(graft, 1))
 212                         error("duplicate graft data: %s", buf);
 213         }
 214         fclose(fp);
 215         return 0;
 216 }
 217
 218 static void prepare_commit_graft(void)
 219 {
 220         static int commit_graft_prepared;
 221         char *graft_file;
 222
 223         if (commit_graft_prepared)
 224                 return;
 225         graft_file = get_graft_file();
 226         read_graft_file(graft_file);
 227         /* make sure shallows are read */
 228         is_repository_shallow();
 229         commit_graft_prepared = 1;
 230 }
 231
 232 static struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 233 {
 234         int pos;
 235         prepare_commit_graft();
 236         pos = commit_graft_pos(sha1);
 237         if (pos < 0)
 238                 return NULL;
 239         return commit_graft[pos];
 240 }
 241
 242 int write_shallow_commits(int fd, int use_pack_protocol)
 243 {
 244         int i, count = 0;
 245         for (i = 0; i < commit_graft_nr; i++)
 246                 if (commit_graft[i]->nr_parent < 0) {
 247                         const char *hex =
 248                                 sha1_to_hex(commit_graft[i]->sha1);
 249                         count++;
 250                         if (use_pack_protocol)
 251                                 packet_write(fd, "shallow %s", hex);
 252                         else {
 253                                 if (write_in_full(fd, hex,  40) != 40)
 254                                         break;
 255                                 if (write_in_full(fd, "\n", 1) != 1)
 256                                         break;
 257                         }
 258                 }
 259         return count;
 260 }
 261
 262 int unregister_shallow(const unsigned char *sha1)
 263 {
 264         int pos = commit_graft_pos(sha1);
 265         if (pos < 0)
 266                 return -1;
 267         if (pos + 1 < commit_graft_nr)
 268                 memcpy(commit_graft + pos, commit_graft + pos + 1,
 269                                 sizeof(struct commit_graft *)
 270                                 * (commit_graft_nr - pos - 1));
 271         commit_graft_nr--;
 272         return 0;
 273 }
 274
 275 int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 276 {
 277         char *tail = buffer;
 278         char *bufptr = buffer;
 279         unsigned char parent[20];
 280         struct commit_list **pptr;
 281         struct commit_graft *graft;
 282         unsigned n_refs = 0;
 283
 284         if (item->object.parsed)
 285                 return 0;
 286         item->object.parsed = 1;
 287         tail += size;
 288         if (tail <= bufptr + 5 || memcmp(bufptr, "tree ", 5))
 289                 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 290         if (tail <= bufptr + 45 || get_sha1_hex(bufptr + 5, parent) < 0)
 291                 return error("bad tree pointer in commit %s",
 292                              sha1_to_hex(item->object.sha1));
 293         item->tree = lookup_tree(parent);
 294         if (item->tree)
 295                 n_refs++;
 296         bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 297         pptr = &item->parents;
 298
 299         graft = lookup_commit_graft(item->object.sha1);
 300         while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
 301                 struct commit *new_parent;
 302
 303                 if (tail <= bufptr + 48 ||
 304                     get_sha1_hex(bufptr + 7, parent) ||
 305                     bufptr[47] != '\n')
 306                         return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 307                 bufptr += 48;
 308                 if (graft)
 309                         continue;
 310                 new_parent = lookup_commit(parent);
 311                 if (new_parent) {
 312                         pptr = &commit_list_insert(new_parent, pptr)->next;
 313                         n_refs++;
 314                 }
 315         }
 316         if (graft) {
 317                 int i;
 318                 struct commit *new_parent;
 319                 for (i = 0; i < graft->nr_parent; i++) {
 320                         new_parent = lookup_commit(graft->parent[i]);
 321                         if (!new_parent)
 322                                 continue;
 323                         pptr = &commit_list_insert(new_parent, pptr)->next;
 324                         n_refs++;
 325                 }
 326         }
 327         item->date = parse_commit_date(bufptr);
 328
 329         if (track_object_refs) {
 330                 unsigned i = 0;
 331                 struct commit_list *p;
 332                 struct object_refs *refs = alloc_object_refs(n_refs);
 333                 if (item->tree)
 334                         refs->ref[i++] = &item->tree->object;
 335                 for (p = item->parents; p; p = p->next)
 336                         refs->ref[i++] = &p->item->object;
 337                 set_object_refs(&item->object, refs);
 338         }
 339
 340         return 0;
 341 }
 342
 343 int parse_commit(struct commit *item)
 344 {
 345         char type[20];
 346         void *buffer;
 347         unsigned long size;
 348         int ret;
 349
 350         if (item->object.parsed)
 351                 return 0;
 352         buffer = read_sha1_file(item->object.sha1, type, &size);
 353         if (!buffer)
 354                 return error("Could not read %s",
 355                              sha1_to_hex(item->object.sha1));
 356         if (strcmp(type, commit_type)) {
 357                 free(buffer);
 358                 return error("Object %s not a commit",
 359                              sha1_to_hex(item->object.sha1));
 360         }
 361         ret = parse_commit_buffer(item, buffer, size);
 362         if (save_commit_buffer && !ret) {
 363                 item->buffer = buffer;
 364                 return 0;
 365         }
 366         free(buffer);
 367         return ret;
 368 }
 369
 370 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 371 {
 372         struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 373         new_list->item = item;
 374         new_list->next = *list_p;
 375         *list_p = new_list;
 376         return new_list;
 377 }
 378
 379 void free_commit_list(struct commit_list *list)
 380 {
 381         while (list) {
 382                 struct commit_list *temp = list;
 383                 list = temp->next;
 384                 free(temp);
 385         }
 386 }
 387
 388 struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 389 {
 390         struct commit_list **pp = list;
 391         struct commit_list *p;
 392         while ((p = *pp) != NULL) {
 393                 if (p->item->date < item->date) {
 394                         break;
 395                 }
 396                 pp = &p->next;
 397         }
 398         return commit_list_insert(item, pp);
 399 }
 400
 401
 402 void sort_by_date(struct commit_list **list)
 403 {
 404         struct commit_list *ret = NULL;
 405         while (*list) {
 406                 insert_by_date((*list)->item, &ret);
 407                 *list = (*list)->next;
 408         }
 409         *list = ret;
 410 }
 411
 412 struct commit *pop_most_recent_commit(struct commit_list **list,
 413                                       unsigned int mark)
 414 {
 415         struct commit *ret = (*list)->item;
 416         struct commit_list *parents = ret->parents;
 417         struct commit_list *old = *list;
 418
 419         *list = (*list)->next;
 420         free(old);
 421
 422         while (parents) {
 423                 struct commit *commit = parents->item;
 424                 parse_commit(commit);
 425                 if (!(commit->object.flags & mark)) {
 426                         commit->object.flags |= mark;
 427                         insert_by_date(commit, list);
 428                 }
 429                 parents = parents->next;
 430         }
 431         return ret;
 432 }
 433
 434 void clear_commit_marks(struct commit *commit, unsigned int mark)
 435 {
 436         struct commit_list *parents;
 437
 438         commit->object.flags &= ~mark;
 439         parents = commit->parents;
 440         while (parents) {
 441                 struct commit *parent = parents->item;
 442
 443                 /* Have we already cleared this? */
 444                 if (mark & parent->object.flags)
 445                         clear_commit_marks(parent, mark);
 446                 parents = parents->next;
 447         }
 448 }
 449
 450 /*
 451  * Generic support for pretty-printing the header
 452  */
 453 static int get_one_line(const char *msg, unsigned long len)
 454 {
 455         int ret = 0;
 456
 457         while (len--) {
 458                 char c = *msg++;
 459                 if (!c)
 460                         break;
 461                 ret++;
 462                 if (c == '\n')
 463                         break;
 464         }
 465         return ret;
 466 }
 467
 468 /* High bit set, or ISO-2022-INT */
 469 static int non_ascii(int ch)
 470 {
 471         ch = (ch & 0xff);
 472         return ((ch & 0x80) || (ch == 0x1b));
 473 }
 474
 475 static int is_rfc2047_special(char ch)
 476 {
 477         return (non_ascii(ch) || (ch == '=') || (ch == '?') || (ch == '_'));
 478 }
 479
 480 static int add_rfc2047(char *buf, const char *line, int len,
 481                        const char *encoding)
 482 {
 483         char *bp = buf;
 484         int i, needquote;
 485         char q_encoding[128];
 486         const char *q_encoding_fmt = "=?%s?q?";
 487
 488         for (i = needquote = 0; !needquote && i < len; i++) {
 489                 int ch = line[i];
 490                 if (non_ascii(ch))
 491                         needquote++;
 492                 if ((i + 1 < len) &&
 493                     (ch == '=' && line[i+1] == '?'))
 494                         needquote++;
 495         }
 496         if (!needquote)
 497                 return sprintf(buf, "%.*s", len, line);
 498
 499         i = snprintf(q_encoding, sizeof(q_encoding), q_encoding_fmt, encoding);
 500         if (sizeof(q_encoding) < i)
 501                 die("Insanely long encoding name %s", encoding);
 502         memcpy(bp, q_encoding, i);
 503         bp += i;
 504         for (i = 0; i < len; i++) {
 505                 unsigned ch = line[i] & 0xFF;
 506                 if (is_rfc2047_special(ch)) {
 507                         sprintf(bp, "=%02X", ch);
 508                         bp += 3;
 509                 }
 510                 else if (ch == ' ')
 511                         *bp++ = '_';
 512                 else
 513                         *bp++ = ch;
 514         }
 515         memcpy(bp, "?=", 2);
 516         bp += 2;
 517         return bp - buf;
 518 }
 519
 520 static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf,
 521                          const char *line, int relative_date,
 522                          const char *encoding)
 523 {
 524         char *date;
 525         int namelen;
 526         unsigned long time;
 527         int tz, ret;
 528         const char *filler = "    ";
 529
 530         if (fmt == CMIT_FMT_ONELINE)
 531                 return 0;
 532         date = strchr(line, '>');
 533         if (!date)
 534                 return 0;
 535         namelen = ++date - line;
 536         time = strtoul(date, &date, 10);
 537         tz = strtol(date, NULL, 10);
 538
 539         if (fmt == CMIT_FMT_EMAIL) {
 540                 char *name_tail = strchr(line, '<');
 541                 int display_name_length;
 542                 if (!name_tail)
 543                         return 0;
 544                 while (line < name_tail && isspace(name_tail[-1]))
 545                         name_tail--;
 546                 display_name_length = name_tail - line;
 547                 filler = "";
 548                 strcpy(buf, "From: ");
 549                 ret = strlen(buf);
 550                 ret += add_rfc2047(buf + ret, line, display_name_length,
 551                                    encoding);
 552                 memcpy(buf + ret, name_tail, namelen - display_name_length);
 553                 ret += namelen - display_name_length;
 554                 buf[ret++] = '\n';
 555         }
 556         else {
 557                 ret = sprintf(buf, "%s: %.*s%.*s\n", what,
 558                               (fmt == CMIT_FMT_FULLER) ? 4 : 0,
 559                               filler, namelen, line);
 560         }
 561         switch (fmt) {
 562         case CMIT_FMT_MEDIUM:
 563                 ret += sprintf(buf + ret, "Date:   %s\n",
 564                                show_date(time, tz, relative_date));
 565                 break;
 566         case CMIT_FMT_EMAIL:
 567                 ret += sprintf(buf + ret, "Date: %s\n",
 568                                show_rfc2822_date(time, tz));
 569                 break;
 570         case CMIT_FMT_FULLER:
 571                 ret += sprintf(buf + ret, "%sDate: %s\n", what,
 572                                show_date(time, tz, relative_date));
 573                 break;
 574         default:
 575                 /* notin' */
 576                 break;
 577         }
 578         return ret;
 579 }
 580
 581 static int is_empty_line(const char *line, int *len_p)
 582 {
 583         int len = *len_p;
 584         while (len && isspace(line[len-1]))
 585                 len--;
 586         *len_p = len;
 587         return !len;
 588 }
 589
 590 static int add_merge_info(enum cmit_fmt fmt, char *buf, const struct commit *commit, int abbrev)
 591 {
 592         struct commit_list *parent = commit->parents;
 593         int offset;
 594
 595         if ((fmt == CMIT_FMT_ONELINE) || (fmt == CMIT_FMT_EMAIL) ||
 596             !parent || !parent->next)
 597                 return 0;
 598
 599         offset = sprintf(buf, "Merge:");
 600
 601         while (parent) {
 602                 struct commit *p = parent->item;
 603                 const char *hex = NULL;
 604                 const char *dots;
 605                 if (abbrev)
 606                         hex = find_unique_abbrev(p->object.sha1, abbrev);
 607                 if (!hex)
 608                         hex = sha1_to_hex(p->object.sha1);
 609                 dots = (abbrev && strlen(hex) != 40) ?  "..." : "";
 610                 parent = parent->next;
 611
 612                 offset += sprintf(buf + offset, " %s%s", hex, dots);
 613         }
 614         buf[offset++] = '\n';
 615         return offset;
 616 }
 617
 618 static char *get_header(const struct commit *commit, const char *key)
 619 {
 620         int key_len = strlen(key);
 621         const char *line = commit->buffer;
 622
 623         for (;;) {
 624                 const char *eol = strchr(line, '\n'), *next;
 625
 626                 if (line == eol)
 627                         return NULL;
 628                 if (!eol) {
 629                         eol = line + strlen(line);
 630                         next = NULL;
 631                 } else
 632                         next = eol + 1;
 633                 if (!strncmp(line, key, key_len) && line[key_len] == ' ') {
 634                         int len = eol - line - key_len;
 635                         char *ret = xmalloc(len);
 636                         memcpy(ret, line + key_len + 1, len - 1);
 637                         ret[len - 1] = '\0';
 638                         return ret;
 639                 }
 640                 line = next;
 641         }
 642 }
 643
 644 static char *replace_encoding_header(char *buf, char *encoding)
 645 {
 646         char *encoding_header = strstr(buf, "\nencoding ");
 647         char *end_of_encoding_header;
 648         int encoding_header_pos;
 649         int encoding_header_len;
 650         int new_len;
 651         int need_len;
 652         int buflen = strlen(buf) + 1;
 653
 654         if (!encoding_header)
 655                 return buf; /* should not happen but be defensive */
 656         encoding_header++;
 657         end_of_encoding_header = strchr(encoding_header, '\n');
 658         if (!end_of_encoding_header)
 659                 return buf; /* should not happen but be defensive */
 660         end_of_encoding_header++;
 661
 662         encoding_header_len = end_of_encoding_header - encoding_header;
 663         encoding_header_pos = encoding_header - buf;
 664
 665         if (is_encoding_utf8(encoding)) {
 666                 /* we have re-coded to UTF-8; drop the header */
 667                 memmove(encoding_header, end_of_encoding_header,
 668                         buflen - (encoding_header_pos + encoding_header_len));
 669                 return buf;
 670         }
 671         new_len = strlen(encoding);
 672         need_len = new_len + strlen("encoding \n");
 673         if (encoding_header_len < need_len) {
 674                 buf = xrealloc(buf, buflen + (need_len - encoding_header_len));
 675                 encoding_header = buf + encoding_header_pos;
 676                 end_of_encoding_header = encoding_header + encoding_header_len;
 677         }
 678         memmove(end_of_encoding_header + (need_len - encoding_header_len),
 679                 end_of_encoding_header,
 680                 buflen - (encoding_header_pos + encoding_header_len));
 681         memcpy(encoding_header + 9, encoding, strlen(encoding));
 682         encoding_header[9 + new_len] = '\n';
 683         return buf;
 684 }
 685
 686 static char *logmsg_reencode(const struct commit *commit,
 687                              char *output_encoding)
 688 {
 689         char *encoding;
 690         char *out;
 691         char *utf8 = "utf-8";
 692
 693         if (!*output_encoding)
 694                 return NULL;
 695         encoding = get_header(commit, "encoding");
 696         if (!encoding)
 697                 encoding = utf8;
 698         if (!strcmp(encoding, output_encoding))
 699                 out = strdup(commit->buffer);
 700         else
 701                 out = reencode_string(commit->buffer,
 702                                       output_encoding, encoding);
 703         if (out)
 704                 out = replace_encoding_header(out, output_encoding);
 705
 706         if (encoding != utf8)
 707                 free(encoding);
 708         if (!out)
 709                 return NULL;
 710         return out;
 711 }
 712
 713 unsigned long pretty_print_commit(enum cmit_fmt fmt,
 714                                   const struct commit *commit,
 715                                   unsigned long len,
 716                                   char *buf, unsigned long space,
 717                                   int abbrev, const char *subject,
 718                                   const char *after_subject,
 719                                   int relative_date)
 720 {
 721         int hdr = 1, body = 0, seen_title = 0;
 722         unsigned long offset = 0;
 723         int indent = 4;
 724         int parents_shown = 0;
 725         const char *msg = commit->buffer;
 726         int plain_non_ascii = 0;
 727         char *reencoded;
 728         char *encoding;
 729
 730         encoding = (git_log_output_encoding
 731                     ? git_log_output_encoding
 732                     : git_commit_encoding);
 733         if (!encoding)
 734                 encoding = "utf-8";
 735         reencoded = logmsg_reencode(commit, encoding);
 736         if (reencoded)
 737                 msg = reencoded;
 738
 739         if (fmt == CMIT_FMT_ONELINE || fmt == CMIT_FMT_EMAIL)
 740                 indent = 0;
 741
 742         /* After-subject is used to pass in Content-Type: multipart
 743          * MIME header; in that case we do not have to do the
 744          * plaintext content type even if the commit message has
 745          * non 7-bit ASCII character.  Otherwise, check if we need
 746          * to say this is not a 7-bit ASCII.
 747          */
 748         if (fmt == CMIT_FMT_EMAIL && !after_subject) {
 749                 int i, ch, in_body;
 750
 751                 for (in_body = i = 0; (ch = msg[i]) && i < len; i++) {
 752                         if (!in_body) {
 753                                 /* author could be non 7-bit ASCII but
 754                                  * the log may be so; skip over the
 755                                  * header part first.
 756                                  */
 757                                 if (ch == '\n' &&
 758                                     i + 1 < len && msg[i+1] == '\n')
 759                                         in_body = 1;
 760                         }
 761                         else if (non_ascii(ch)) {
 762                                 plain_non_ascii = 1;
 763                                 break;
 764                         }
 765                 }
 766         }
 767
 768         for (;;) {
 769                 const char *line = msg;
 770                 int linelen = get_one_line(msg, len);
 771
 772                 if (!linelen)
 773                         break;
 774
 775                 /*
 776                  * We want some slop for indentation and a possible
 777                  * final "...". Thus the "+ 20".
 778                  */
 779                 if (offset + linelen + 20 > space) {
 780                         memcpy(buf + offset, "    ...\n", 8);
 781                         offset += 8;
 782                         break;
 783                 }
 784
 785                 msg += linelen;
 786                 len -= linelen;
 787                 if (hdr) {
 788                         if (linelen == 1) {
 789                                 hdr = 0;
 790                                 if ((fmt != CMIT_FMT_ONELINE) && !subject)
 791                                         buf[offset++] = '\n';
 792                                 continue;
 793                         }
 794                         if (fmt == CMIT_FMT_RAW) {
 795                                 memcpy(buf + offset, line, linelen);
 796                                 offset += linelen;
 797                                 continue;
 798                         }
 799                         if (!memcmp(line, "parent ", 7)) {
 800                                 if (linelen != 48)
 801                                         die("bad parent line in commit");
 802                                 continue;
 803                         }
 804
 805                         if (!parents_shown) {
 806                                 offset += add_merge_info(fmt, buf + offset,
 807                                                          commit, abbrev);
 808                                 parents_shown = 1;
 809                                 continue;
 810                         }
 811                         /*
 812                          * MEDIUM == DEFAULT shows only author with dates.
 813                          * FULL shows both authors but not dates.
 814                          * FULLER shows both authors and dates.
 815                          */
 816                         if (!memcmp(line, "author ", 7))
 817                                 offset += add_user_info("Author", fmt,
 818                                                         buf + offset,
 819                                                         line + 7,
 820                                                         relative_date,
 821                                                         encoding);
 822                         if (!memcmp(line, "committer ", 10) &&
 823                             (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER))
 824                                 offset += add_user_info("Commit", fmt,
 825                                                         buf + offset,
 826                                                         line + 10,
 827                                                         relative_date,
 828                                                         encoding);
 829                         continue;
 830                 }
 831
 832                 if (!subject)
 833                         body = 1;
 834
 835                 if (is_empty_line(line, &linelen)) {
 836                         if (!seen_title)
 837                                 continue;
 838                         if (!body)
 839                                 continue;
 840                         if (subject)
 841                                 continue;
 842                         if (fmt == CMIT_FMT_SHORT)
 843                                 break;
 844                 }
 845
 846                 seen_title = 1;
 847                 if (subject) {
 848                         int slen = strlen(subject);
 849                         memcpy(buf + offset, subject, slen);
 850                         offset += slen;
 851                         offset += add_rfc2047(buf + offset, line, linelen,
 852                                               encoding);
 853                 }
 854                 else {
 855                         memset(buf + offset, ' ', indent);
 856                         memcpy(buf + offset + indent, line, linelen);
 857                         offset += linelen + indent;
 858                 }
 859                 buf[offset++] = '\n';
 860                 if (fmt == CMIT_FMT_ONELINE)
 861                         break;
 862                 if (subject && plain_non_ascii) {
 863                         int sz;
 864                         char header[512];
 865                         const char *header_fmt =
 866                                 "Content-Type: text/plain; charset=%s\n"
 867                                 "Content-Transfer-Encoding: 8bit\n";
 868                         sz = snprintf(header, sizeof(header), header_fmt,
 869                                       encoding);
 870                         if (sizeof(header) < sz)
 871                                 die("Encoding name %s too long", encoding);
 872                         memcpy(buf + offset, header, sz);
 873                         offset += sz;
 874                 }
 875                 if (after_subject) {
 876                         int slen = strlen(after_subject);
 877                         if (slen > space - offset - 1)
 878                                 slen = space - offset - 1;
 879                         memcpy(buf + offset, after_subject, slen);
 880                         offset += slen;
 881                         after_subject = NULL;
 882                 }
 883                 subject = NULL;
 884         }
 885         while (offset && isspace(buf[offset-1]))
 886                 offset--;
 887         /* Make sure there is an EOLN for the non-oneline case */
 888         if (fmt != CMIT_FMT_ONELINE)
 889                 buf[offset++] = '\n';
 890         /*
 891          * make sure there is another EOLN to separate the headers from whatever
 892          * body the caller appends if we haven't already written a body
 893          */
 894         if (fmt == CMIT_FMT_EMAIL && !body)
 895                 buf[offset++] = '\n';
 896         buf[offset] = '\0';
 897
 898         free(reencoded);
 899         return offset;
 900 }
 901
 902 struct commit *pop_commit(struct commit_list **stack)
 903 {
 904         struct commit_list *top = *stack;
 905         struct commit *item = top ? top->item : NULL;
 906
 907         if (top) {
 908                 *stack = top->next;
 909                 free(top);
 910         }
 911         return item;
 912 }
 913
 914 int count_parents(struct commit * commit)
 915 {
 916         int count;
 917         struct commit_list * parents = commit->parents;
 918         for (count = 0; parents; parents = parents->next,count++)
 919                 ;
 920         return count;
 921 }
 922
 923 void topo_sort_default_setter(struct commit *c, void *data)
 924 {
 925         c->util = data;
 926 }
 927
 928 void *topo_sort_default_getter(struct commit *c)
 929 {
 930         return c->util;
 931 }
 932
 933 /*
 934  * Performs an in-place topological sort on the list supplied.
 935  */
 936 void sort_in_topological_order(struct commit_list ** list, int lifo)
 937 {
 938         sort_in_topological_order_fn(list, lifo, topo_sort_default_setter,
 939                                      topo_sort_default_getter);
 940 }
 941
 942 void sort_in_topological_order_fn(struct commit_list ** list, int lifo,
 943                                   topo_sort_set_fn_t setter,
 944                                   topo_sort_get_fn_t getter)
 945 {
 946         struct commit_list * next = *list;
 947         struct commit_list * work = NULL, **insert;
 948         struct commit_list ** pptr = list;
 949         struct sort_node * nodes;
 950         struct sort_node * next_nodes;
 951         int count = 0;
 952
 953         /* determine the size of the list */
 954         while (next) {
 955                 next = next->next;
 956                 count++;
 957         }
 958
 959         if (!count)
 960                 return;
 961         /* allocate an array to help sort the list */
 962         nodes = xcalloc(count, sizeof(*nodes));
 963         /* link the list to the array */
 964         next_nodes = nodes;
 965         next=*list;
 966         while (next) {
 967                 next_nodes->list_item = next;
 968                 setter(next->item, next_nodes);
 969                 next_nodes++;
 970                 next = next->next;
 971         }
 972         /* update the indegree */
 973         next=*list;
 974         while (next) {
 975                 struct commit_list * parents = next->item->parents;
 976                 while (parents) {
 977                         struct commit * parent=parents->item;
 978                         struct sort_node * pn = (struct sort_node *) getter(parent);
 979
 980                         if (pn)
 981                                 pn->indegree++;
 982                         parents=parents->next;
 983                 }
 984                 next=next->next;
 985         }
 986         /*
 987          * find the tips
 988          *
 989          * tips are nodes not reachable from any other node in the list
 990          *
 991          * the tips serve as a starting set for the work queue.
 992          */
 993         next=*list;
 994         insert = &work;
 995         while (next) {
 996                 struct sort_node * node = (struct sort_node *) getter(next->item);
 997
 998                 if (node->indegree == 0) {
 999                         insert = &commit_list_insert(next->item, insert)->next;
1000                 }
1001                 next=next->next;
1002         }
1003
1004         /* process the list in topological order */
1005         if (!lifo)
1006                 sort_by_date(&work);
1007         while (work) {
1008                 struct commit * work_item = pop_commit(&work);
1009                 struct sort_node * work_node = (struct sort_node *) getter(work_item);
1010                 struct commit_list * parents = work_item->parents;
1011
1012                 while (parents) {
1013                         struct commit * parent=parents->item;
1014                         struct sort_node * pn = (struct sort_node *) getter(parent);
1015
1016                         if (pn) {
1017                                 /*
1018                                  * parents are only enqueued for emission
1019                                  * when all their children have been emitted thereby
1020                                  * guaranteeing topological order.
1021                                  */
1022                                 pn->indegree--;
1023                                 if (!pn->indegree) {
1024                                         if (!lifo)
1025                                                 insert_by_date(parent, &work);
1026                                         else
1027                                                 commit_list_insert(parent, &work);
1028                                 }
1029                         }
1030                         parents=parents->next;
1031                 }
1032                 /*
1033                  * work_item is a commit all of whose children
1034                  * have already been emitted. we can emit it now.
1035                  */
1036                 *pptr = work_node->list_item;
1037                 pptr = &(*pptr)->next;
1038                 *pptr = NULL;
1039                 setter(work_item, NULL);
1040         }
1041         free(nodes);
1042 }
1043
1044 /* merge-base stuff */
1045
1046 /* bits #0..15 in revision.h */
1047 #define PARENT1         (1u<<16)
1048 #define PARENT2         (1u<<17)
1049 #define STALE           (1u<<18)
1050 #define RESULT          (1u<<19)
1051
1052 static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
1053
1054 static struct commit *interesting(struct commit_list *list)
1055 {
1056         while (list) {
1057                 struct commit *commit = list->item;
1058                 list = list->next;
1059                 if (commit->object.flags & STALE)
1060                         continue;
1061                 return commit;
1062         }
1063         return NULL;
1064 }
1065
1066 static struct commit_list *merge_bases(struct commit *one, struct commit *two)
1067 {
1068         struct commit_list *list = NULL;
1069         struct commit_list *result = NULL;
1070
1071         if (one == two)
1072                 /* We do not mark this even with RESULT so we do not
1073                  * have to clean it up.
1074                  */
1075                 return commit_list_insert(one, &result);
1076
1077         parse_commit(one);
1078         parse_commit(two);
1079
1080         one->object.flags |= PARENT1;
1081         two->object.flags |= PARENT2;
1082         insert_by_date(one, &list);
1083         insert_by_date(two, &list);
1084
1085         while (interesting(list)) {
1086                 struct commit *commit;
1087                 struct commit_list *parents;
1088                 struct commit_list *n;
1089                 int flags;
1090
1091                 commit = list->item;
1092                 n = list->next;
1093                 free(list);
1094                 list = n;
1095
1096                 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
1097                 if (flags == (PARENT1 | PARENT2)) {
1098                         if (!(commit->object.flags & RESULT)) {
1099                                 commit->object.flags |= RESULT;
1100                                 insert_by_date(commit, &result);
1101                         }
1102                         /* Mark parents of a found merge stale */
1103                         flags |= STALE;
1104                 }
1105                 parents = commit->parents;
1106                 while (parents) {
1107                         struct commit *p = parents->item;
1108                         parents = parents->next;
1109                         if ((p->object.flags & flags) == flags)
1110                                 continue;
1111                         parse_commit(p);
1112                         p->object.flags |= flags;
1113                         insert_by_date(p, &list);
1114                 }
1115         }
1116
1117         /* Clean up the result to remove stale ones */
1118         free_commit_list(list);
1119         list = result; result = NULL;
1120         while (list) {
1121                 struct commit_list *n = list->next;
1122                 if (!(list->item->object.flags & STALE))
1123                         insert_by_date(list->item, &result);
1124                 free(list);
1125                 list = n;
1126         }
1127         return result;
1128 }
1129
1130 struct commit_list *get_merge_bases(struct commit *one,
1131                                     struct commit *two,
1132                                     int cleanup)
1133 {
1134         struct commit_list *list;
1135         struct commit **rslt;
1136         struct commit_list *result;
1137         int cnt, i, j;
1138
1139         result = merge_bases(one, two);
1140         if (one == two)
1141                 return result;
1142         if (!result || !result->next) {
1143                 if (cleanup) {
1144                         clear_commit_marks(one, all_flags);
1145                         clear_commit_marks(two, all_flags);
1146                 }
1147                 return result;
1148         }
1149
1150         /* There are more than one */
1151         cnt = 0;
1152         list = result;
1153         while (list) {
1154                 list = list->next;
1155                 cnt++;
1156         }
1157         rslt = xcalloc(cnt, sizeof(*rslt));
1158         for (list = result, i = 0; list; list = list->next)
1159                 rslt[i++] = list->item;
1160         free_commit_list(result);
1161
1162         clear_commit_marks(one, all_flags);
1163         clear_commit_marks(two, all_flags);
1164         for (i = 0; i < cnt - 1; i++) {
1165                 for (j = i+1; j < cnt; j++) {
1166                         if (!rslt[i] || !rslt[j])
1167                                 continue;
1168                         result = merge_bases(rslt[i], rslt[j]);
1169                         clear_commit_marks(rslt[i], all_flags);
1170                         clear_commit_marks(rslt[j], all_flags);
1171                         for (list = result; list; list = list->next) {
1172                                 if (rslt[i] == list->item)
1173                                         rslt[i] = NULL;
1174                                 if (rslt[j] == list->item)
1175                                         rslt[j] = NULL;
1176                         }
1177                 }
1178         }
1179
1180         /* Surviving ones in rslt[] are the independent results */
1181         result = NULL;
1182         for (i = 0; i < cnt; i++) {
1183                 if (rslt[i])
1184                         insert_by_date(rslt[i], &result);
1185         }
1186         free(rslt);
1187         return result;
1188 }
1189
1190 int in_merge_bases(struct commit *rev1, struct commit *rev2)
1191 {
1192         struct commit_list *bases, *b;
1193         int ret = 0;
1194
1195         bases = get_merge_bases(rev1, rev2, 1);
1196         for (b = bases; b; b = b->next) {
1197                 if (!hashcmp(rev1->object.sha1, b->item->object.sha1)) {
1198                         ret = 1;
1199                         break;
1200                 }
1201         }
1202
1203         free_commit_list(bases);
1204         return ret;
1205 }