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                         return cmt_fmts[i].v;
  52         }
  53
  54         die("invalid --pretty format: %s", arg);
  55 }
  56
  57 static 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
  70 struct 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
  80 struct commit *lookup_commit_reference(const unsigned char *sha1)
  81 {
  82         return lookup_commit_reference_gently(sha1, 0);
  83 }
  84
  85 struct 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
  99 static 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
 117 static struct commit_graft **commit_graft;
 118 static int commit_graft_alloc, commit_graft_nr;
 119
 120 static 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
 139 int 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
 168 struct 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
 198 int 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
 217 static 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
 231 static 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
 241 int 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                                 write(fd, hex,  40);
 253                                 write(fd, "\n", 1);
 254                         }
 255                 }
 256         return count;
 257 }
 258
 259 int unregister_shallow(const unsigned char *sha1)
 260 {
 261         int pos = commit_graft_pos(sha1);
 262         if (pos < 0)
 263                 return -1;
 264         if (pos + 1 < commit_graft_nr)
 265                 memcpy(commit_graft + pos, commit_graft + pos + 1,
 266                                 sizeof(struct commit_graft *)
 267                                 * (commit_graft_nr - pos - 1));
 268         commit_graft_nr--;
 269         return 0;
 270 }
 271
 272 int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 273 {
 274         char *tail = buffer;
 275         char *bufptr = buffer;
 276         unsigned char parent[20];
 277         struct commit_list **pptr;
 278         struct commit_graft *graft;
 279         unsigned n_refs = 0;
 280
 281         if (item->object.parsed)
 282                 return 0;
 283         item->object.parsed = 1;
 284         tail += size;
 285         if (tail <= bufptr + 5 || memcmp(bufptr, "tree ", 5))
 286                 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 287         if (tail <= bufptr + 45 || get_sha1_hex(bufptr + 5, parent) < 0)
 288                 return error("bad tree pointer in commit %s",
 289                              sha1_to_hex(item->object.sha1));
 290         item->tree = lookup_tree(parent);
 291         if (item->tree)
 292                 n_refs++;
 293         bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 294         pptr = &item->parents;
 295
 296         graft = lookup_commit_graft(item->object.sha1);
 297         while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
 298                 struct commit *new_parent;
 299
 300                 if (tail <= bufptr + 48 ||
 301                     get_sha1_hex(bufptr + 7, parent) ||
 302                     bufptr[47] != '\n')
 303                         return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 304                 bufptr += 48;
 305                 if (graft)
 306                         continue;
 307                 new_parent = lookup_commit(parent);
 308                 if (new_parent) {
 309                         pptr = &commit_list_insert(new_parent, pptr)->next;
 310                         n_refs++;
 311                 }
 312         }
 313         if (graft) {
 314                 int i;
 315                 struct commit *new_parent;
 316                 for (i = 0; i < graft->nr_parent; i++) {
 317                         new_parent = lookup_commit(graft->parent[i]);
 318                         if (!new_parent)
 319                                 continue;
 320                         pptr = &commit_list_insert(new_parent, pptr)->next;
 321                         n_refs++;
 322                 }
 323         }
 324         item->date = parse_commit_date(bufptr);
 325
 326         if (track_object_refs) {
 327                 unsigned i = 0;
 328                 struct commit_list *p;
 329                 struct object_refs *refs = alloc_object_refs(n_refs);
 330                 if (item->tree)
 331                         refs->ref[i++] = &item->tree->object;
 332                 for (p = item->parents; p; p = p->next)
 333                         refs->ref[i++] = &p->item->object;
 334                 set_object_refs(&item->object, refs);
 335         }
 336
 337         return 0;
 338 }
 339
 340 int parse_commit(struct commit *item)
 341 {
 342         char type[20];
 343         void *buffer;
 344         unsigned long size;
 345         int ret;
 346
 347         if (item->object.parsed)
 348                 return 0;
 349         buffer = read_sha1_file(item->object.sha1, type, &size);
 350         if (!buffer)
 351                 return error("Could not read %s",
 352                              sha1_to_hex(item->object.sha1));
 353         if (strcmp(type, commit_type)) {
 354                 free(buffer);
 355                 return error("Object %s not a commit",
 356                              sha1_to_hex(item->object.sha1));
 357         }
 358         ret = parse_commit_buffer(item, buffer, size);
 359         if (save_commit_buffer && !ret) {
 360                 item->buffer = buffer;
 361                 return 0;
 362         }
 363         free(buffer);
 364         return ret;
 365 }
 366
 367 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 368 {
 369         struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 370         new_list->item = item;
 371         new_list->next = *list_p;
 372         *list_p = new_list;
 373         return new_list;
 374 }
 375
 376 void free_commit_list(struct commit_list *list)
 377 {
 378         while (list) {
 379                 struct commit_list *temp = list;
 380                 list = temp->next;
 381                 free(temp);
 382         }
 383 }
 384
 385 struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 386 {
 387         struct commit_list **pp = list;
 388         struct commit_list *p;
 389         while ((p = *pp) != NULL) {
 390                 if (p->item->date < item->date) {
 391                         break;
 392                 }
 393                 pp = &p->next;
 394         }
 395         return commit_list_insert(item, pp);
 396 }
 397
 398
 399 void sort_by_date(struct commit_list **list)
 400 {
 401         struct commit_list *ret = NULL;
 402         while (*list) {
 403                 insert_by_date((*list)->item, &ret);
 404                 *list = (*list)->next;
 405         }
 406         *list = ret;
 407 }
 408
 409 struct commit *pop_most_recent_commit(struct commit_list **list,
 410                                       unsigned int mark)
 411 {
 412         struct commit *ret = (*list)->item;
 413         struct commit_list *parents = ret->parents;
 414         struct commit_list *old = *list;
 415
 416         *list = (*list)->next;
 417         free(old);
 418
 419         while (parents) {
 420                 struct commit *commit = parents->item;
 421                 parse_commit(commit);
 422                 if (!(commit->object.flags & mark)) {
 423                         commit->object.flags |= mark;
 424                         insert_by_date(commit, list);
 425                 }
 426                 parents = parents->next;
 427         }
 428         return ret;
 429 }
 430
 431 void clear_commit_marks(struct commit *commit, unsigned int mark)
 432 {
 433         struct commit_list *parents;
 434
 435         commit->object.flags &= ~mark;
 436         parents = commit->parents;
 437         while (parents) {
 438                 struct commit *parent = parents->item;
 439
 440                 /* Have we already cleared this? */
 441                 if (mark & parent->object.flags)
 442                         clear_commit_marks(parent, mark);
 443                 parents = parents->next;
 444         }
 445 }
 446
 447 /*
 448  * Generic support for pretty-printing the header
 449  */
 450 static int get_one_line(const char *msg, unsigned long len)
 451 {
 452         int ret = 0;
 453
 454         while (len--) {
 455                 char c = *msg++;
 456                 if (!c)
 457                         break;
 458                 ret++;
 459                 if (c == '\n')
 460                         break;
 461         }
 462         return ret;
 463 }
 464
 465 static int is_rfc2047_special(char ch)
 466 {
 467         return ((ch & 0x80) || (ch == '=') || (ch == '?') || (ch == '_'));
 468 }
 469
 470 static int add_rfc2047(char *buf, const char *line, int len)
 471 {
 472         char *bp = buf;
 473         int i, needquote;
 474         static const char q_utf8[] = "=?utf-8?q?";
 475
 476         for (i = needquote = 0; !needquote && i < len; i++) {
 477                 unsigned ch = line[i];
 478                 if (ch & 0x80)
 479                         needquote++;
 480                 if ((i + 1 < len) &&
 481                     (ch == '=' && line[i+1] == '?'))
 482                         needquote++;
 483         }
 484         if (!needquote)
 485                 return sprintf(buf, "%.*s", len, line);
 486
 487         memcpy(bp, q_utf8, sizeof(q_utf8)-1);
 488         bp += sizeof(q_utf8)-1;
 489         for (i = 0; i < len; i++) {
 490                 unsigned ch = line[i] & 0xFF;
 491                 if (is_rfc2047_special(ch)) {
 492                         sprintf(bp, "=%02X", ch);
 493                         bp += 3;
 494                 }
 495                 else if (ch == ' ')
 496                         *bp++ = '_';
 497                 else
 498                         *bp++ = ch;
 499         }
 500         memcpy(bp, "?=", 2);
 501         bp += 2;
 502         return bp - buf;
 503 }
 504
 505 static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf,
 506                          const char *line, int relative_date)
 507 {
 508         char *date;
 509         int namelen;
 510         unsigned long time;
 511         int tz, ret;
 512         const char *filler = "    ";
 513
 514         if (fmt == CMIT_FMT_ONELINE)
 515                 return 0;
 516         date = strchr(line, '>');
 517         if (!date)
 518                 return 0;
 519         namelen = ++date - line;
 520         time = strtoul(date, &date, 10);
 521         tz = strtol(date, NULL, 10);
 522
 523         if (fmt == CMIT_FMT_EMAIL) {
 524                 char *name_tail = strchr(line, '<');
 525                 int display_name_length;
 526                 if (!name_tail)
 527                         return 0;
 528                 while (line < name_tail && isspace(name_tail[-1]))
 529                         name_tail--;
 530                 display_name_length = name_tail - line;
 531                 filler = "";
 532                 strcpy(buf, "From: ");
 533                 ret = strlen(buf);
 534                 ret += add_rfc2047(buf + ret, line, display_name_length);
 535                 memcpy(buf + ret, name_tail, namelen - display_name_length);
 536                 ret += namelen - display_name_length;
 537                 buf[ret++] = '\n';
 538         }
 539         else {
 540                 ret = sprintf(buf, "%s: %.*s%.*s\n", what,
 541                               (fmt == CMIT_FMT_FULLER) ? 4 : 0,
 542                               filler, namelen, line);
 543         }
 544         switch (fmt) {
 545         case CMIT_FMT_MEDIUM:
 546                 ret += sprintf(buf + ret, "Date:   %s\n",
 547                                show_date(time, tz, relative_date));
 548                 break;
 549         case CMIT_FMT_EMAIL:
 550                 ret += sprintf(buf + ret, "Date: %s\n",
 551                                show_rfc2822_date(time, tz));
 552                 break;
 553         case CMIT_FMT_FULLER:
 554                 ret += sprintf(buf + ret, "%sDate: %s\n", what,
 555                                show_date(time, tz, relative_date));
 556                 break;
 557         default:
 558                 /* notin' */
 559                 break;
 560         }
 561         return ret;
 562 }
 563
 564 static int is_empty_line(const char *line, int *len_p)
 565 {
 566         int len = *len_p;
 567         while (len && isspace(line[len-1]))
 568                 len--;
 569         *len_p = len;
 570         return !len;
 571 }
 572
 573 static int add_merge_info(enum cmit_fmt fmt, char *buf, const struct commit *commit, int abbrev)
 574 {
 575         struct commit_list *parent = commit->parents;
 576         int offset;
 577
 578         if ((fmt == CMIT_FMT_ONELINE) || (fmt == CMIT_FMT_EMAIL) ||
 579             !parent || !parent->next)
 580                 return 0;
 581
 582         offset = sprintf(buf, "Merge:");
 583
 584         while (parent) {
 585                 struct commit *p = parent->item;
 586                 const char *hex = NULL;
 587                 const char *dots;
 588                 if (abbrev)
 589                         hex = find_unique_abbrev(p->object.sha1, abbrev);
 590                 if (!hex)
 591                         hex = sha1_to_hex(p->object.sha1);
 592                 dots = (abbrev && strlen(hex) != 40) ?  "..." : "";
 593                 parent = parent->next;
 594
 595                 offset += sprintf(buf + offset, " %s%s", hex, dots);
 596         }
 597         buf[offset++] = '\n';
 598         return offset;
 599 }
 600
 601 static char *get_header(const struct commit *commit, const char *key)
 602 {
 603         int key_len = strlen(key);
 604         const char *line = commit->buffer;
 605
 606         for (;;) {
 607                 const char *eol = strchr(line, '\n'), *next;
 608
 609                 if (line == eol)
 610                         return NULL;
 611                 if (!eol) {
 612                         eol = line + strlen(line);
 613                         next = NULL;
 614                 } else
 615                         next = eol + 1;
 616                 if (!strncmp(line, key, key_len) && line[key_len] == ' ') {
 617                         int len = eol - line - key_len;
 618                         char *ret = xmalloc(len);
 619                         memcpy(ret, line + key_len + 1, len - 1);
 620                         ret[len - 1] = '\0';
 621                         return ret;
 622                 }
 623                 line = next;
 624         }
 625 }
 626
 627 static char *replace_encoding_header(char *buf, char *encoding)
 628 {
 629         char *encoding_header = strstr(buf, "\nencoding ");
 630         char *end_of_encoding_header;
 631         int encoding_header_pos;
 632         int encoding_header_len;
 633         int new_len;
 634         int need_len;
 635         int buflen = strlen(buf) + 1;
 636
 637         if (!encoding_header)
 638                 return buf; /* should not happen but be defensive */
 639         encoding_header++;
 640         end_of_encoding_header = strchr(encoding_header, '\n');
 641         if (!end_of_encoding_header)
 642                 return buf; /* should not happen but be defensive */
 643         end_of_encoding_header++;
 644
 645         encoding_header_len = end_of_encoding_header - encoding_header;
 646         encoding_header_pos = encoding_header - buf;
 647
 648         if (is_encoding_utf8(encoding)) {
 649                 /* we have re-coded to UTF-8; drop the header */
 650                 memmove(encoding_header, end_of_encoding_header,
 651                         buflen - (encoding_header_pos + encoding_header_len));
 652                 return buf;
 653         }
 654         new_len = strlen(encoding);
 655         need_len = new_len + strlen("encoding \n");
 656         if (encoding_header_len < need_len) {
 657                 buf = xrealloc(buf, buflen + (need_len - encoding_header_len));
 658                 encoding_header = buf + encoding_header_pos;
 659                 end_of_encoding_header = encoding_header + encoding_header_len;
 660         }
 661         memmove(end_of_encoding_header + (need_len - encoding_header_len),
 662                 end_of_encoding_header,
 663                 buflen - (encoding_header_pos + encoding_header_len));
 664         memcpy(encoding_header + 9, encoding, strlen(encoding));
 665         encoding_header[9 + new_len] = '\n';
 666         return buf;
 667 }
 668
 669 static char *logmsg_reencode(const struct commit *commit)
 670 {
 671         char *encoding;
 672         char *out;
 673         char *output_encoding = (git_log_output_encoding
 674                                  ? git_log_output_encoding
 675                                  : git_commit_encoding);
 676
 677         if (!output_encoding)
 678                 output_encoding = "utf-8";
 679         else if (!*output_encoding)
 680                 return NULL;
 681         encoding = get_header(commit, "encoding");
 682         if (!encoding || !strcmp(encoding, output_encoding)) {
 683                 free(encoding);
 684                 return NULL;
 685         }
 686         out = reencode_string(commit->buffer, output_encoding, encoding);
 687         if (out)
 688                 out = replace_encoding_header(out, output_encoding);
 689
 690         free(encoding);
 691         if (!out)
 692                 return NULL;
 693         return out;
 694 }
 695
 696 unsigned long pretty_print_commit(enum cmit_fmt fmt,
 697                                   const struct commit *commit,
 698                                   unsigned long len,
 699                                   char *buf, unsigned long space,
 700                                   int abbrev, const char *subject,
 701                                   const char *after_subject,
 702                                   int relative_date)
 703 {
 704         int hdr = 1, body = 0;
 705         unsigned long offset = 0;
 706         int indent = 4;
 707         int parents_shown = 0;
 708         const char *msg = commit->buffer;
 709         int plain_non_ascii = 0;
 710         char *reencoded = logmsg_reencode(commit);
 711
 712         if (reencoded)
 713                 msg = reencoded;
 714
 715         if (fmt == CMIT_FMT_ONELINE || fmt == CMIT_FMT_EMAIL)
 716                 indent = 0;
 717
 718         /* After-subject is used to pass in Content-Type: multipart
 719          * MIME header; in that case we do not have to do the
 720          * plaintext content type even if the commit message has
 721          * non 7-bit ASCII character.  Otherwise, check if we need
 722          * to say this is not a 7-bit ASCII.
 723          */
 724         if (fmt == CMIT_FMT_EMAIL && !after_subject) {
 725                 int i, ch, in_body;
 726
 727                 for (in_body = i = 0; (ch = msg[i]) && i < len; i++) {
 728                         if (!in_body) {
 729                                 /* author could be non 7-bit ASCII but
 730                                  * the log may be so; skip over the
 731                                  * header part first.
 732                                  */
 733                                 if (ch == '\n' &&
 734                                     i + 1 < len && msg[i+1] == '\n')
 735                                         in_body = 1;
 736                         }
 737                         else if (ch & 0x80) {
 738                                 plain_non_ascii = 1;
 739                                 break;
 740                         }
 741                 }
 742         }
 743
 744         for (;;) {
 745                 const char *line = msg;
 746                 int linelen = get_one_line(msg, len);
 747
 748                 if (!linelen)
 749                         break;
 750
 751                 /*
 752                  * We want some slop for indentation and a possible
 753                  * final "...". Thus the "+ 20".
 754                  */
 755                 if (offset + linelen + 20 > space) {
 756                         memcpy(buf + offset, "    ...\n", 8);
 757                         offset += 8;
 758                         break;
 759                 }
 760
 761                 msg += linelen;
 762                 len -= linelen;
 763                 if (hdr) {
 764                         if (linelen == 1) {
 765                                 hdr = 0;
 766                                 if ((fmt != CMIT_FMT_ONELINE) && !subject)
 767                                         buf[offset++] = '\n';
 768                                 continue;
 769                         }
 770                         if (fmt == CMIT_FMT_RAW) {
 771                                 memcpy(buf + offset, line, linelen);
 772                                 offset += linelen;
 773                                 continue;
 774                         }
 775                         if (!memcmp(line, "parent ", 7)) {
 776                                 if (linelen != 48)
 777                                         die("bad parent line in commit");
 778                                 continue;
 779                         }
 780
 781                         if (!parents_shown) {
 782                                 offset += add_merge_info(fmt, buf + offset,
 783                                                          commit, abbrev);
 784                                 parents_shown = 1;
 785                                 continue;
 786                         }
 787                         /*
 788                          * MEDIUM == DEFAULT shows only author with dates.
 789                          * FULL shows both authors but not dates.
 790                          * FULLER shows both authors and dates.
 791                          */
 792                         if (!memcmp(line, "author ", 7))
 793                                 offset += add_user_info("Author", fmt,
 794                                                         buf + offset,
 795                                                         line + 7,
 796                                                         relative_date);
 797                         if (!memcmp(line, "committer ", 10) &&
 798                             (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER))
 799                                 offset += add_user_info("Commit", fmt,
 800                                                         buf + offset,
 801                                                         line + 10,
 802                                                         relative_date);
 803                         continue;
 804                 }
 805
 806                 if (!subject)
 807                         body = 1;
 808
 809                 if (is_empty_line(line, &linelen)) {
 810                         if (!body)
 811                                 continue;
 812                         if (subject)
 813                                 continue;
 814                         if (fmt == CMIT_FMT_SHORT)
 815                                 break;
 816                 }
 817
 818                 if (subject) {
 819                         int slen = strlen(subject);
 820                         memcpy(buf + offset, subject, slen);
 821                         offset += slen;
 822                         offset += add_rfc2047(buf + offset, line, linelen);
 823                 }
 824                 else {
 825                         memset(buf + offset, ' ', indent);
 826                         memcpy(buf + offset + indent, line, linelen);
 827                         offset += linelen + indent;
 828                 }
 829                 buf[offset++] = '\n';
 830                 if (fmt == CMIT_FMT_ONELINE)
 831                         break;
 832                 if (subject && plain_non_ascii) {
 833                         static const char header[] =
 834                                 "Content-Type: text/plain; charset=UTF-8\n"
 835                                 "Content-Transfer-Encoding: 8bit\n";
 836                         memcpy(buf + offset, header, sizeof(header)-1);
 837                         offset += sizeof(header)-1;
 838                 }
 839                 if (after_subject) {
 840                         int slen = strlen(after_subject);
 841                         if (slen > space - offset - 1)
 842                                 slen = space - offset - 1;
 843                         memcpy(buf + offset, after_subject, slen);
 844                         offset += slen;
 845                         after_subject = NULL;
 846                 }
 847                 subject = NULL;
 848         }
 849         while (offset && isspace(buf[offset-1]))
 850                 offset--;
 851         /* Make sure there is an EOLN for the non-oneline case */
 852         if (fmt != CMIT_FMT_ONELINE)
 853                 buf[offset++] = '\n';
 854         /*
 855          * make sure there is another EOLN to separate the headers from whatever
 856          * body the caller appends if we haven't already written a body
 857          */
 858         if (fmt == CMIT_FMT_EMAIL && !body)
 859                 buf[offset++] = '\n';
 860         buf[offset] = '\0';
 861
 862         free(reencoded);
 863         return offset;
 864 }
 865
 866 struct commit *pop_commit(struct commit_list **stack)
 867 {
 868         struct commit_list *top = *stack;
 869         struct commit *item = top ? top->item : NULL;
 870
 871         if (top) {
 872                 *stack = top->next;
 873                 free(top);
 874         }
 875         return item;
 876 }
 877
 878 int count_parents(struct commit * commit)
 879 {
 880         int count;
 881         struct commit_list * parents = commit->parents;
 882         for (count = 0; parents; parents = parents->next,count++)
 883                 ;
 884         return count;
 885 }
 886
 887 void topo_sort_default_setter(struct commit *c, void *data)
 888 {
 889         c->util = data;
 890 }
 891
 892 void *topo_sort_default_getter(struct commit *c)
 893 {
 894         return c->util;
 895 }
 896
 897 /*
 898  * Performs an in-place topological sort on the list supplied.
 899  */
 900 void sort_in_topological_order(struct commit_list ** list, int lifo)
 901 {
 902         sort_in_topological_order_fn(list, lifo, topo_sort_default_setter,
 903                                      topo_sort_default_getter);
 904 }
 905
 906 void sort_in_topological_order_fn(struct commit_list ** list, int lifo,
 907                                   topo_sort_set_fn_t setter,
 908                                   topo_sort_get_fn_t getter)
 909 {
 910         struct commit_list * next = *list;
 911         struct commit_list * work = NULL, **insert;
 912         struct commit_list ** pptr = list;
 913         struct sort_node * nodes;
 914         struct sort_node * next_nodes;
 915         int count = 0;
 916
 917         /* determine the size of the list */
 918         while (next) {
 919                 next = next->next;
 920                 count++;
 921         }
 922
 923         if (!count)
 924                 return;
 925         /* allocate an array to help sort the list */
 926         nodes = xcalloc(count, sizeof(*nodes));
 927         /* link the list to the array */
 928         next_nodes = nodes;
 929         next=*list;
 930         while (next) {
 931                 next_nodes->list_item = next;
 932                 setter(next->item, next_nodes);
 933                 next_nodes++;
 934                 next = next->next;
 935         }
 936         /* update the indegree */
 937         next=*list;
 938         while (next) {
 939                 struct commit_list * parents = next->item->parents;
 940                 while (parents) {
 941                         struct commit * parent=parents->item;
 942                         struct sort_node * pn = (struct sort_node *) getter(parent);
 943
 944                         if (pn)
 945                                 pn->indegree++;
 946                         parents=parents->next;
 947                 }
 948                 next=next->next;
 949         }
 950         /*
 951          * find the tips
 952          *
 953          * tips are nodes not reachable from any other node in the list
 954          *
 955          * the tips serve as a starting set for the work queue.
 956          */
 957         next=*list;
 958         insert = &work;
 959         while (next) {
 960                 struct sort_node * node = (struct sort_node *) getter(next->item);
 961
 962                 if (node->indegree == 0) {
 963                         insert = &commit_list_insert(next->item, insert)->next;
 964                 }
 965                 next=next->next;
 966         }
 967
 968         /* process the list in topological order */
 969         if (!lifo)
 970                 sort_by_date(&work);
 971         while (work) {
 972                 struct commit * work_item = pop_commit(&work);
 973                 struct sort_node * work_node = (struct sort_node *) getter(work_item);
 974                 struct commit_list * parents = work_item->parents;
 975
 976                 while (parents) {
 977                         struct commit * parent=parents->item;
 978                         struct sort_node * pn = (struct sort_node *) getter(parent);
 979
 980                         if (pn) {
 981                                 /*
 982                                  * parents are only enqueued for emission
 983                                  * when all their children have been emitted thereby
 984                                  * guaranteeing topological order.
 985                                  */
 986                                 pn->indegree--;
 987                                 if (!pn->indegree) {
 988                                         if (!lifo)
 989                                                 insert_by_date(parent, &work);
 990                                         else
 991                                                 commit_list_insert(parent, &work);
 992                                 }
 993                         }
 994                         parents=parents->next;
 995                 }
 996                 /*
 997                  * work_item is a commit all of whose children
 998                  * have already been emitted. we can emit it now.
 999                  */
1000                 *pptr = work_node->list_item;
1001                 pptr = &(*pptr)->next;
1002                 *pptr = NULL;
1003                 setter(work_item, NULL);
1004         }
1005         free(nodes);
1006 }
1007
1008 /* merge-rebase stuff */
1009
1010 /* bits #0..15 in revision.h */
1011 #define PARENT1         (1u<<16)
1012 #define PARENT2         (1u<<17)
1013 #define STALE           (1u<<18)
1014 #define RESULT          (1u<<19)
1015
1016 static struct commit *interesting(struct commit_list *list)
1017 {
1018         while (list) {
1019                 struct commit *commit = list->item;
1020                 list = list->next;
1021                 if (commit->object.flags & STALE)
1022                         continue;
1023                 return commit;
1024         }
1025         return NULL;
1026 }
1027
1028 static struct commit_list *merge_bases(struct commit *one, struct commit *two)
1029 {
1030         struct commit_list *list = NULL;
1031         struct commit_list *result = NULL;
1032
1033         if (one == two)
1034                 /* We do not mark this even with RESULT so we do not
1035                  * have to clean it up.
1036                  */
1037                 return commit_list_insert(one, &result);
1038
1039         parse_commit(one);
1040         parse_commit(two);
1041
1042         one->object.flags |= PARENT1;
1043         two->object.flags |= PARENT2;
1044         insert_by_date(one, &list);
1045         insert_by_date(two, &list);
1046
1047         while (interesting(list)) {
1048                 struct commit *commit;
1049                 struct commit_list *parents;
1050                 struct commit_list *n;
1051                 int flags;
1052
1053                 commit = list->item;
1054                 n = list->next;
1055                 free(list);
1056                 list = n;
1057
1058                 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
1059                 if (flags == (PARENT1 | PARENT2)) {
1060                         if (!(commit->object.flags & RESULT)) {
1061                                 commit->object.flags |= RESULT;
1062                                 insert_by_date(commit, &result);
1063                         }
1064                         /* Mark parents of a found merge stale */
1065                         flags |= STALE;
1066                 }
1067                 parents = commit->parents;
1068                 while (parents) {
1069                         struct commit *p = parents->item;
1070                         parents = parents->next;
1071                         if ((p->object.flags & flags) == flags)
1072                                 continue;
1073                         parse_commit(p);
1074                         p->object.flags |= flags;
1075                         insert_by_date(p, &list);
1076                 }
1077         }
1078
1079         /* Clean up the result to remove stale ones */
1080         list = result; result = NULL;
1081         while (list) {
1082                 struct commit_list *n = list->next;
1083                 if (!(list->item->object.flags & STALE))
1084                         insert_by_date(list->item, &result);
1085                 free(list);
1086                 list = n;
1087         }
1088         return result;
1089 }
1090
1091 struct commit_list *get_merge_bases(struct commit *one,
1092                                     struct commit *two,
1093                                     int cleanup)
1094 {
1095         const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
1096         struct commit_list *list;
1097         struct commit **rslt;
1098         struct commit_list *result;
1099         int cnt, i, j;
1100
1101         result = merge_bases(one, two);
1102         if (one == two)
1103                 return result;
1104         if (!result || !result->next) {
1105                 if (cleanup) {
1106                         clear_commit_marks(one, all_flags);
1107                         clear_commit_marks(two, all_flags);
1108                 }
1109                 return result;
1110         }
1111
1112         /* There are more than one */
1113         cnt = 0;
1114         list = result;
1115         while (list) {
1116                 list = list->next;
1117                 cnt++;
1118         }
1119         rslt = xcalloc(cnt, sizeof(*rslt));
1120         for (list = result, i = 0; list; list = list->next)
1121                 rslt[i++] = list->item;
1122         free_commit_list(result);
1123
1124         clear_commit_marks(one, all_flags);
1125         clear_commit_marks(two, all_flags);
1126         for (i = 0; i < cnt - 1; i++) {
1127                 for (j = i+1; j < cnt; j++) {
1128                         if (!rslt[i] || !rslt[j])
1129                                 continue;
1130                         result = merge_bases(rslt[i], rslt[j]);
1131                         clear_commit_marks(rslt[i], all_flags);
1132                         clear_commit_marks(rslt[j], all_flags);
1133                         for (list = result; list; list = list->next) {
1134                                 if (rslt[i] == list->item)
1135                                         rslt[i] = NULL;
1136                                 if (rslt[j] == list->item)
1137                                         rslt[j] = NULL;
1138                         }
1139                 }
1140         }
1141
1142         /* Surviving ones in rslt[] are the independent results */
1143         result = NULL;
1144         for (i = 0; i < cnt; i++) {
1145                 if (rslt[i])
1146                         insert_by_date(rslt[i], &result);
1147         }
1148         free(rslt);
1149         return result;
1150 }
1151
1152 int in_merge_bases(struct commit *rev1, struct commit *rev2)
1153 {
1154         struct commit_list *bases, *b;
1155         int ret = 0;
1156
1157         bases = get_merge_bases(rev1, rev2, 1);
1158         for (b = bases; b; b = b->next) {
1159                 if (!hashcmp(rev1->object.sha1, b->item->object.sha1)) {
1160                         ret = 1;
1161                         break;
1162                 }
1163         }
1164
1165         free_commit_list(bases);
1166         return ret;
1167 }