commit.c

   1 #include "cache.h"
   2 #include "tag.h"
   3 #include "commit.h"
   4 #include "pkt-line.h"
   5 #include "utf8.h"
   6 #include "interpolate.h"
   7 #include "diff.h"
   8 #include "revision.h"
   9
  10 int save_commit_buffer = 1;
  11
  12 struct sort_node
  13 {
  14         /*
  15          * the number of children of the associated commit
  16          * that also occur in the list being sorted.
  17          */
  18         unsigned int indegree;
  19
  20         /*
  21          * reference to original list item that we will re-use
  22          * on output.
  23          */
  24         struct commit_list * list_item;
  25
  26 };
  27
  28 const char *commit_type = "commit";
  29
  30 struct cmt_fmt_map {
  31         const char *n;
  32         size_t cmp_len;
  33         enum cmit_fmt v;
  34 } cmt_fmts[] = {
  35         { "raw",        1,      CMIT_FMT_RAW },
  36         { "medium",     1,      CMIT_FMT_MEDIUM },
  37         { "short",      1,      CMIT_FMT_SHORT },
  38         { "email",      1,      CMIT_FMT_EMAIL },
  39         { "full",       5,      CMIT_FMT_FULL },
  40         { "fuller",     5,      CMIT_FMT_FULLER },
  41         { "oneline",    1,      CMIT_FMT_ONELINE },
  42         { "format:",    7,      CMIT_FMT_USERFORMAT},
  43 };
  44
  45 static char *user_format;
  46
  47 enum cmit_fmt get_commit_format(const char *arg)
  48 {
  49         int i;
  50
  51         if (!arg || !*arg)
  52                 return CMIT_FMT_DEFAULT;
  53         if (*arg == '=')
  54                 arg++;
  55         if (!prefixcmp(arg, "format:")) {
  56                 if (user_format)
  57                         free(user_format);
  58                 user_format = xstrdup(arg + 7);
  59                 return CMIT_FMT_USERFORMAT;
  60         }
  61         for (i = 0; i < ARRAY_SIZE(cmt_fmts); i++) {
  62                 if (!strncmp(arg, cmt_fmts[i].n, cmt_fmts[i].cmp_len) &&
  63                     !strncmp(arg, cmt_fmts[i].n, strlen(arg)))
  64                         return cmt_fmts[i].v;
  65         }
  66
  67         die("invalid --pretty format: %s", arg);
  68 }
  69
  70 static struct commit *check_commit(struct object *obj,
  71                                    const unsigned char *sha1,
  72                                    int quiet)
  73 {
  74         if (obj->type != OBJ_COMMIT) {
  75                 if (!quiet)
  76                         error("Object %s is a %s, not a commit",
  77                               sha1_to_hex(sha1), typename(obj->type));
  78                 return NULL;
  79         }
  80         return (struct commit *) obj;
  81 }
  82
  83 struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
  84                                               int quiet)
  85 {
  86         struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
  87
  88         if (!obj)
  89                 return NULL;
  90         return check_commit(obj, sha1, quiet);
  91 }
  92
  93 struct commit *lookup_commit_reference(const unsigned char *sha1)
  94 {
  95         return lookup_commit_reference_gently(sha1, 0);
  96 }
  97
  98 struct commit *lookup_commit(const unsigned char *sha1)
  99 {
 100         struct object *obj = lookup_object(sha1);
 101         if (!obj)
 102                 return create_object(sha1, OBJ_COMMIT, alloc_commit_node());
 103         if (!obj->type)
 104                 obj->type = OBJ_COMMIT;
 105         return check_commit(obj, sha1, 0);
 106 }
 107
 108 static unsigned long parse_commit_date(const char *buf)
 109 {
 110         unsigned long date;
 111
 112         if (memcmp(buf, "author", 6))
 113                 return 0;
 114         while (*buf++ != '\n')
 115                 /* nada */;
 116         if (memcmp(buf, "committer", 9))
 117                 return 0;
 118         while (*buf++ != '>')
 119                 /* nada */;
 120         date = strtoul(buf, NULL, 10);
 121         if (date == ULONG_MAX)
 122                 date = 0;
 123         return date;
 124 }
 125
 126 static struct commit_graft **commit_graft;
 127 static int commit_graft_alloc, commit_graft_nr;
 128
 129 static int commit_graft_pos(const unsigned char *sha1)
 130 {
 131         int lo, hi;
 132         lo = 0;
 133         hi = commit_graft_nr;
 134         while (lo < hi) {
 135                 int mi = (lo + hi) / 2;
 136                 struct commit_graft *graft = commit_graft[mi];
 137                 int cmp = hashcmp(sha1, graft->sha1);
 138                 if (!cmp)
 139                         return mi;
 140                 if (cmp < 0)
 141                         hi = mi;
 142                 else
 143                         lo = mi + 1;
 144         }
 145         return -lo - 1;
 146 }
 147
 148 int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 149 {
 150         int pos = commit_graft_pos(graft->sha1);
 151
 152         if (0 <= pos) {
 153                 if (ignore_dups)
 154                         free(graft);
 155                 else {
 156                         free(commit_graft[pos]);
 157                         commit_graft[pos] = graft;
 158                 }
 159                 return 1;
 160         }
 161         pos = -pos - 1;
 162         if (commit_graft_alloc <= ++commit_graft_nr) {
 163                 commit_graft_alloc = alloc_nr(commit_graft_alloc);
 164                 commit_graft = xrealloc(commit_graft,
 165                                         sizeof(*commit_graft) *
 166                                         commit_graft_alloc);
 167         }
 168         if (pos < commit_graft_nr)
 169                 memmove(commit_graft + pos + 1,
 170                         commit_graft + pos,
 171                         (commit_graft_nr - pos - 1) *
 172                         sizeof(*commit_graft));
 173         commit_graft[pos] = graft;
 174         return 0;
 175 }
 176
 177 struct commit_graft *read_graft_line(char *buf, int len)
 178 {
 179         /* The format is just "Commit Parent1 Parent2 ...\n" */
 180         int i;
 181         struct commit_graft *graft = NULL;
 182
 183         if (buf[len-1] == '\n')
 184                 buf[--len] = 0;
 185         if (buf[0] == '#' || buf[0] == '\0')
 186                 return NULL;
 187         if ((len + 1) % 41) {
 188         bad_graft_data:
 189                 error("bad graft data: %s", buf);
 190                 free(graft);
 191                 return NULL;
 192         }
 193         i = (len + 1) / 41 - 1;
 194         graft = xmalloc(sizeof(*graft) + 20 * i);
 195         graft->nr_parent = i;
 196         if (get_sha1_hex(buf, graft->sha1))
 197                 goto bad_graft_data;
 198         for (i = 40; i < len; i += 41) {
 199                 if (buf[i] != ' ')
 200                         goto bad_graft_data;
 201                 if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
 202                         goto bad_graft_data;
 203         }
 204         return graft;
 205 }
 206
 207 int read_graft_file(const char *graft_file)
 208 {
 209         FILE *fp = fopen(graft_file, "r");
 210         char buf[1024];
 211         if (!fp)
 212                 return -1;
 213         while (fgets(buf, sizeof(buf), fp)) {
 214                 /* The format is just "Commit Parent1 Parent2 ...\n" */
 215                 int len = strlen(buf);
 216                 struct commit_graft *graft = read_graft_line(buf, len);
 217                 if (!graft)
 218                         continue;
 219                 if (register_commit_graft(graft, 1))
 220                         error("duplicate graft data: %s", buf);
 221         }
 222         fclose(fp);
 223         return 0;
 224 }
 225
 226 static void prepare_commit_graft(void)
 227 {
 228         static int commit_graft_prepared;
 229         char *graft_file;
 230
 231         if (commit_graft_prepared)
 232                 return;
 233         graft_file = get_graft_file();
 234         read_graft_file(graft_file);
 235         /* make sure shallows are read */
 236         is_repository_shallow();
 237         commit_graft_prepared = 1;
 238 }
 239
 240 static struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 241 {
 242         int pos;
 243         prepare_commit_graft();
 244         pos = commit_graft_pos(sha1);
 245         if (pos < 0)
 246                 return NULL;
 247         return commit_graft[pos];
 248 }
 249
 250 int write_shallow_commits(int fd, int use_pack_protocol)
 251 {
 252         int i, count = 0;
 253         for (i = 0; i < commit_graft_nr; i++)
 254                 if (commit_graft[i]->nr_parent < 0) {
 255                         const char *hex =
 256                                 sha1_to_hex(commit_graft[i]->sha1);
 257                         count++;
 258                         if (use_pack_protocol)
 259                                 packet_write(fd, "shallow %s", hex);
 260                         else {
 261                                 if (write_in_full(fd, hex,  40) != 40)
 262                                         break;
 263                                 if (write_in_full(fd, "\n", 1) != 1)
 264                                         break;
 265                         }
 266                 }
 267         return count;
 268 }
 269
 270 int unregister_shallow(const unsigned char *sha1)
 271 {
 272         int pos = commit_graft_pos(sha1);
 273         if (pos < 0)
 274                 return -1;
 275         if (pos + 1 < commit_graft_nr)
 276                 memcpy(commit_graft + pos, commit_graft + pos + 1,
 277                                 sizeof(struct commit_graft *)
 278                                 * (commit_graft_nr - pos - 1));
 279         commit_graft_nr--;
 280         return 0;
 281 }
 282
 283 int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 284 {
 285         char *tail = buffer;
 286         char *bufptr = buffer;
 287         unsigned char parent[20];
 288         struct commit_list **pptr;
 289         struct commit_graft *graft;
 290         unsigned n_refs = 0;
 291
 292         if (item->object.parsed)
 293                 return 0;
 294         item->object.parsed = 1;
 295         tail += size;
 296         if (tail <= bufptr + 5 || memcmp(bufptr, "tree ", 5))
 297                 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 298         if (tail <= bufptr + 45 || get_sha1_hex(bufptr + 5, parent) < 0)
 299                 return error("bad tree pointer in commit %s",
 300                              sha1_to_hex(item->object.sha1));
 301         item->tree = lookup_tree(parent);
 302         if (item->tree)
 303                 n_refs++;
 304         bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 305         pptr = &item->parents;
 306
 307         graft = lookup_commit_graft(item->object.sha1);
 308         while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
 309                 struct commit *new_parent;
 310
 311                 if (tail <= bufptr + 48 ||
 312                     get_sha1_hex(bufptr + 7, parent) ||
 313                     bufptr[47] != '\n')
 314                         return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 315                 bufptr += 48;
 316                 if (graft)
 317                         continue;
 318                 new_parent = lookup_commit(parent);
 319                 if (new_parent) {
 320                         pptr = &commit_list_insert(new_parent, pptr)->next;
 321                         n_refs++;
 322                 }
 323         }
 324         if (graft) {
 325                 int i;
 326                 struct commit *new_parent;
 327                 for (i = 0; i < graft->nr_parent; i++) {
 328                         new_parent = lookup_commit(graft->parent[i]);
 329                         if (!new_parent)
 330                                 continue;
 331                         pptr = &commit_list_insert(new_parent, pptr)->next;
 332                         n_refs++;
 333                 }
 334         }
 335         item->date = parse_commit_date(bufptr);
 336
 337         if (track_object_refs) {
 338                 unsigned i = 0;
 339                 struct commit_list *p;
 340                 struct object_refs *refs = alloc_object_refs(n_refs);
 341                 if (item->tree)
 342                         refs->ref[i++] = &item->tree->object;
 343                 for (p = item->parents; p; p = p->next)
 344                         refs->ref[i++] = &p->item->object;
 345                 set_object_refs(&item->object, refs);
 346         }
 347
 348         return 0;
 349 }
 350
 351 int parse_commit(struct commit *item)
 352 {
 353         enum object_type type;
 354         void *buffer;
 355         unsigned long size;
 356         int ret;
 357
 358         if (item->object.parsed)
 359                 return 0;
 360         buffer = read_sha1_file(item->object.sha1, &type, &size);
 361         if (!buffer)
 362                 return error("Could not read %s",
 363                              sha1_to_hex(item->object.sha1));
 364         if (type != OBJ_COMMIT) {
 365                 free(buffer);
 366                 return error("Object %s not a commit",
 367                              sha1_to_hex(item->object.sha1));
 368         }
 369         ret = parse_commit_buffer(item, buffer, size);
 370         if (save_commit_buffer && !ret) {
 371                 item->buffer = buffer;
 372                 return 0;
 373         }
 374         free(buffer);
 375         return ret;
 376 }
 377
 378 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 379 {
 380         struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 381         new_list->item = item;
 382         new_list->next = *list_p;
 383         *list_p = new_list;
 384         return new_list;
 385 }
 386
 387 void free_commit_list(struct commit_list *list)
 388 {
 389         while (list) {
 390                 struct commit_list *temp = list;
 391                 list = temp->next;
 392                 free(temp);
 393         }
 394 }
 395
 396 struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 397 {
 398         struct commit_list **pp = list;
 399         struct commit_list *p;
 400         while ((p = *pp) != NULL) {
 401                 if (p->item->date < item->date) {
 402                         break;
 403                 }
 404                 pp = &p->next;
 405         }
 406         return commit_list_insert(item, pp);
 407 }
 408
 409
 410 void sort_by_date(struct commit_list **list)
 411 {
 412         struct commit_list *ret = NULL;
 413         while (*list) {
 414                 insert_by_date((*list)->item, &ret);
 415                 *list = (*list)->next;
 416         }
 417         *list = ret;
 418 }
 419
 420 struct commit *pop_most_recent_commit(struct commit_list **list,
 421                                       unsigned int mark)
 422 {
 423         struct commit *ret = (*list)->item;
 424         struct commit_list *parents = ret->parents;
 425         struct commit_list *old = *list;
 426
 427         *list = (*list)->next;
 428         free(old);
 429
 430         while (parents) {
 431                 struct commit *commit = parents->item;
 432                 parse_commit(commit);
 433                 if (!(commit->object.flags & mark)) {
 434                         commit->object.flags |= mark;
 435                         insert_by_date(commit, list);
 436                 }
 437                 parents = parents->next;
 438         }
 439         return ret;
 440 }
 441
 442 void clear_commit_marks(struct commit *commit, unsigned int mark)
 443 {
 444         struct commit_list *parents;
 445
 446         commit->object.flags &= ~mark;
 447         parents = commit->parents;
 448         while (parents) {
 449                 struct commit *parent = parents->item;
 450
 451                 /* Have we already cleared this? */
 452                 if (mark & parent->object.flags)
 453                         clear_commit_marks(parent, mark);
 454                 parents = parents->next;
 455         }
 456 }
 457
 458 /*
 459  * Generic support for pretty-printing the header
 460  */
 461 static int get_one_line(const char *msg, unsigned long len)
 462 {
 463         int ret = 0;
 464
 465         while (len--) {
 466                 char c = *msg++;
 467                 if (!c)
 468                         break;
 469                 ret++;
 470                 if (c == '\n')
 471                         break;
 472         }
 473         return ret;
 474 }
 475
 476 /* High bit set, or ISO-2022-INT */
 477 static int non_ascii(int ch)
 478 {
 479         ch = (ch & 0xff);
 480         return ((ch & 0x80) || (ch == 0x1b));
 481 }
 482
 483 static int is_rfc2047_special(char ch)
 484 {
 485         return (non_ascii(ch) || (ch == '=') || (ch == '?') || (ch == '_'));
 486 }
 487
 488 static int add_rfc2047(char *buf, const char *line, int len,
 489                        const char *encoding)
 490 {
 491         char *bp = buf;
 492         int i, needquote;
 493         char q_encoding[128];
 494         const char *q_encoding_fmt = "=?%s?q?";
 495
 496         for (i = needquote = 0; !needquote && i < len; i++) {
 497                 int ch = line[i];
 498                 if (non_ascii(ch))
 499                         needquote++;
 500                 if ((i + 1 < len) &&
 501                     (ch == '=' && line[i+1] == '?'))
 502                         needquote++;
 503         }
 504         if (!needquote)
 505                 return sprintf(buf, "%.*s", len, line);
 506
 507         i = snprintf(q_encoding, sizeof(q_encoding), q_encoding_fmt, encoding);
 508         if (sizeof(q_encoding) < i)
 509                 die("Insanely long encoding name %s", encoding);
 510         memcpy(bp, q_encoding, i);
 511         bp += i;
 512         for (i = 0; i < len; i++) {
 513                 unsigned ch = line[i] & 0xFF;
 514                 if (is_rfc2047_special(ch)) {
 515                         sprintf(bp, "=%02X", ch);
 516                         bp += 3;
 517                 }
 518                 else if (ch == ' ')
 519                         *bp++ = '_';
 520                 else
 521                         *bp++ = ch;
 522         }
 523         memcpy(bp, "?=", 2);
 524         bp += 2;
 525         return bp - buf;
 526 }
 527
 528 static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf,
 529                          const char *line, enum date_mode dmode,
 530                          const char *encoding)
 531 {
 532         char *date;
 533         int namelen;
 534         unsigned long time;
 535         int tz, ret;
 536         const char *filler = "    ";
 537
 538         if (fmt == CMIT_FMT_ONELINE)
 539                 return 0;
 540         date = strchr(line, '>');
 541         if (!date)
 542                 return 0;
 543         namelen = ++date - line;
 544         time = strtoul(date, &date, 10);
 545         tz = strtol(date, NULL, 10);
 546
 547         if (fmt == CMIT_FMT_EMAIL) {
 548                 char *name_tail = strchr(line, '<');
 549                 int display_name_length;
 550                 if (!name_tail)
 551                         return 0;
 552                 while (line < name_tail && isspace(name_tail[-1]))
 553                         name_tail--;
 554                 display_name_length = name_tail - line;
 555                 filler = "";
 556                 strcpy(buf, "From: ");
 557                 ret = strlen(buf);
 558                 ret += add_rfc2047(buf + ret, line, display_name_length,
 559                                    encoding);
 560                 memcpy(buf + ret, name_tail, namelen - display_name_length);
 561                 ret += namelen - display_name_length;
 562                 buf[ret++] = '\n';
 563         }
 564         else {
 565                 ret = sprintf(buf, "%s: %.*s%.*s\n", what,
 566                               (fmt == CMIT_FMT_FULLER) ? 4 : 0,
 567                               filler, namelen, line);
 568         }
 569         switch (fmt) {
 570         case CMIT_FMT_MEDIUM:
 571                 ret += sprintf(buf + ret, "Date:   %s\n",
 572                                show_date(time, tz, dmode));
 573                 break;
 574         case CMIT_FMT_EMAIL:
 575                 ret += sprintf(buf + ret, "Date: %s\n",
 576                                show_rfc2822_date(time, tz));
 577                 break;
 578         case CMIT_FMT_FULLER:
 579                 ret += sprintf(buf + ret, "%sDate: %s\n", what,
 580                                show_date(time, tz, dmode));
 581                 break;
 582         default:
 583                 /* notin' */
 584                 break;
 585         }
 586         return ret;
 587 }
 588
 589 static int is_empty_line(const char *line, int *len_p)
 590 {
 591         int len = *len_p;
 592         while (len && isspace(line[len-1]))
 593                 len--;
 594         *len_p = len;
 595         return !len;
 596 }
 597
 598 static int add_merge_info(enum cmit_fmt fmt, char *buf, const struct commit *commit, int abbrev)
 599 {
 600         struct commit_list *parent = commit->parents;
 601         int offset;
 602
 603         if ((fmt == CMIT_FMT_ONELINE) || (fmt == CMIT_FMT_EMAIL) ||
 604             !parent || !parent->next)
 605                 return 0;
 606
 607         offset = sprintf(buf, "Merge:");
 608
 609         while (parent) {
 610                 struct commit *p = parent->item;
 611                 const char *hex = NULL;
 612                 const char *dots;
 613                 if (abbrev)
 614                         hex = find_unique_abbrev(p->object.sha1, abbrev);
 615                 if (!hex)
 616                         hex = sha1_to_hex(p->object.sha1);
 617                 dots = (abbrev && strlen(hex) != 40) ?  "..." : "";
 618                 parent = parent->next;
 619
 620                 offset += sprintf(buf + offset, " %s%s", hex, dots);
 621         }
 622         buf[offset++] = '\n';
 623         return offset;
 624 }
 625
 626 static char *get_header(const struct commit *commit, const char *key)
 627 {
 628         int key_len = strlen(key);
 629         const char *line = commit->buffer;
 630
 631         for (;;) {
 632                 const char *eol = strchr(line, '\n'), *next;
 633
 634                 if (line == eol)
 635                         return NULL;
 636                 if (!eol) {
 637                         eol = line + strlen(line);
 638                         next = NULL;
 639                 } else
 640                         next = eol + 1;
 641                 if (eol - line > key_len &&
 642                     !strncmp(line, key, key_len) &&
 643                     line[key_len] == ' ') {
 644                         int len = eol - line - key_len;
 645                         char *ret = xmalloc(len);
 646                         memcpy(ret, line + key_len + 1, len - 1);
 647                         ret[len - 1] = '\0';
 648                         return ret;
 649                 }
 650                 line = next;
 651         }
 652 }
 653
 654 static char *replace_encoding_header(char *buf, const char *encoding)
 655 {
 656         char *encoding_header = strstr(buf, "\nencoding ");
 657         char *header_end = strstr(buf, "\n\n");
 658         char *end_of_encoding_header;
 659         int encoding_header_pos;
 660         int encoding_header_len;
 661         int new_len;
 662         int need_len;
 663         int buflen = strlen(buf) + 1;
 664
 665         if (!header_end)
 666                 header_end = buf + buflen;
 667         if (!encoding_header || encoding_header >= header_end)
 668                 return buf;
 669         encoding_header++;
 670         end_of_encoding_header = strchr(encoding_header, '\n');
 671         if (!end_of_encoding_header)
 672                 return buf; /* should not happen but be defensive */
 673         end_of_encoding_header++;
 674
 675         encoding_header_len = end_of_encoding_header - encoding_header;
 676         encoding_header_pos = encoding_header - buf;
 677
 678         if (is_encoding_utf8(encoding)) {
 679                 /* we have re-coded to UTF-8; drop the header */
 680                 memmove(encoding_header, end_of_encoding_header,
 681                         buflen - (encoding_header_pos + encoding_header_len));
 682                 return buf;
 683         }
 684         new_len = strlen(encoding);
 685         need_len = new_len + strlen("encoding \n");
 686         if (encoding_header_len < need_len) {
 687                 buf = xrealloc(buf, buflen + (need_len - encoding_header_len));
 688                 encoding_header = buf + encoding_header_pos;
 689                 end_of_encoding_header = encoding_header + encoding_header_len;
 690         }
 691         memmove(end_of_encoding_header + (need_len - encoding_header_len),
 692                 end_of_encoding_header,
 693                 buflen - (encoding_header_pos + encoding_header_len));
 694         memcpy(encoding_header + 9, encoding, strlen(encoding));
 695         encoding_header[9 + new_len] = '\n';
 696         return buf;
 697 }
 698
 699 static char *logmsg_reencode(const struct commit *commit,
 700                              const char *output_encoding)
 701 {
 702         static const char *utf8 = "utf-8";
 703         const char *use_encoding;
 704         char *encoding;
 705         char *out;
 706
 707         if (!*output_encoding)
 708                 return NULL;
 709         encoding = get_header(commit, "encoding");
 710         use_encoding = encoding ? encoding : utf8;
 711         if (!strcmp(use_encoding, output_encoding))
 712                 out = xstrdup(commit->buffer);
 713         else
 714                 out = reencode_string(commit->buffer,
 715                                       output_encoding, use_encoding);
 716         if (out)
 717                 out = replace_encoding_header(out, output_encoding);
 718
 719         free(encoding);
 720         return out;
 721 }
 722
 723 static void fill_person(struct interp *table, const char *msg, int len)
 724 {
 725         int start, end, tz = 0;
 726         unsigned long date;
 727         char *ep;
 728
 729         /* parse name */
 730         for (end = 0; end < len && msg[end] != '<'; end++)
 731                 ; /* do nothing */
 732         start = end + 1;
 733         while (end > 0 && isspace(msg[end - 1]))
 734                 end--;
 735         table[0].value = xstrndup(msg, end);
 736
 737         if (start >= len)
 738                 return;
 739
 740         /* parse email */
 741         for (end = start + 1; end < len && msg[end] != '>'; end++)
 742                 ; /* do nothing */
 743
 744         if (end >= len)
 745                 return;
 746
 747         table[1].value = xstrndup(msg + start, end - start);
 748
 749         /* parse date */
 750         for (start = end + 1; start < len && isspace(msg[start]); start++)
 751                 ; /* do nothing */
 752         if (start >= len)
 753                 return;
 754         date = strtoul(msg + start, &ep, 10);
 755         if (msg + start == ep)
 756                 return;
 757
 758         table[5].value = xstrndup(msg + start, ep - (msg + start));
 759
 760         /* parse tz */
 761         for (start = ep - msg + 1; start < len && isspace(msg[start]); start++)
 762                 ; /* do nothing */
 763         if (start + 1 < len) {
 764                 tz = strtoul(msg + start + 1, NULL, 10);
 765                 if (msg[start] == '-')
 766                         tz = -tz;
 767         }
 768
 769         interp_set_entry(table, 2, show_date(date, tz, 0));
 770         interp_set_entry(table, 3, show_rfc2822_date(date, tz));
 771         interp_set_entry(table, 4, show_date(date, tz, 1));
 772 }
 773
 774 static long format_commit_message(const struct commit *commit,
 775                 const char *msg, char *buf, unsigned long space)
 776 {
 777         struct interp table[] = {
 778                 { "%H" },       /* commit hash */
 779                 { "%h" },       /* abbreviated commit hash */
 780                 { "%T" },       /* tree hash */
 781                 { "%t" },       /* abbreviated tree hash */
 782                 { "%P" },       /* parent hashes */
 783                 { "%p" },       /* abbreviated parent hashes */
 784                 { "%an" },      /* author name */
 785                 { "%ae" },      /* author email */
 786                 { "%ad" },      /* author date */
 787                 { "%aD" },      /* author date, RFC2822 style */
 788                 { "%ar" },      /* author date, relative */
 789                 { "%at" },      /* author date, UNIX timestamp */
 790                 { "%cn" },      /* committer name */
 791                 { "%ce" },      /* committer email */
 792                 { "%cd" },      /* committer date */
 793                 { "%cD" },      /* committer date, RFC2822 style */
 794                 { "%cr" },      /* committer date, relative */
 795                 { "%ct" },      /* committer date, UNIX timestamp */
 796                 { "%e" },       /* encoding */
 797                 { "%s" },       /* subject */
 798                 { "%b" },       /* body */
 799                 { "%Cred" },    /* red */
 800                 { "%Cgreen" },  /* green */
 801                 { "%Cblue" },   /* blue */
 802                 { "%Creset" },  /* reset color */
 803                 { "%n" },       /* newline */
 804                 { "%m" },       /* left/right/bottom */
 805         };
 806         enum interp_index {
 807                 IHASH = 0, IHASH_ABBREV,
 808                 ITREE, ITREE_ABBREV,
 809                 IPARENTS, IPARENTS_ABBREV,
 810                 IAUTHOR_NAME, IAUTHOR_EMAIL,
 811                 IAUTHOR_DATE, IAUTHOR_DATE_RFC2822, IAUTHOR_DATE_RELATIVE,
 812                 IAUTHOR_TIMESTAMP,
 813                 ICOMMITTER_NAME, ICOMMITTER_EMAIL,
 814                 ICOMMITTER_DATE, ICOMMITTER_DATE_RFC2822,
 815                 ICOMMITTER_DATE_RELATIVE, ICOMMITTER_TIMESTAMP,
 816                 IENCODING,
 817                 ISUBJECT,
 818                 IBODY,
 819                 IRED, IGREEN, IBLUE, IRESET_COLOR,
 820                 INEWLINE,
 821                 ILEFT_RIGHT,
 822         };
 823         struct commit_list *p;
 824         char parents[1024];
 825         int i;
 826         enum { HEADER, SUBJECT, BODY } state;
 827
 828         if (ILEFT_RIGHT + 1 != ARRAY_SIZE(table))
 829                 die("invalid interp table!");
 830
 831         /* these are independent of the commit */
 832         interp_set_entry(table, IRED, "\033[31m");
 833         interp_set_entry(table, IGREEN, "\033[32m");
 834         interp_set_entry(table, IBLUE, "\033[34m");
 835         interp_set_entry(table, IRESET_COLOR, "\033[m");
 836         interp_set_entry(table, INEWLINE, "\n");
 837
 838         /* these depend on the commit */
 839         if (!commit->object.parsed)
 840                 parse_object(commit->object.sha1);
 841         interp_set_entry(table, IHASH, sha1_to_hex(commit->object.sha1));
 842         interp_set_entry(table, IHASH_ABBREV,
 843                         find_unique_abbrev(commit->object.sha1,
 844                                 DEFAULT_ABBREV));
 845         interp_set_entry(table, ITREE, sha1_to_hex(commit->tree->object.sha1));
 846         interp_set_entry(table, ITREE_ABBREV,
 847                         find_unique_abbrev(commit->tree->object.sha1,
 848                                 DEFAULT_ABBREV));
 849         interp_set_entry(table, ILEFT_RIGHT,
 850                          (commit->object.flags & BOUNDARY)
 851                          ? "-"
 852                          : (commit->object.flags & SYMMETRIC_LEFT)
 853                          ? "<"
 854                          : ">");
 855
 856         parents[1] = 0;
 857         for (i = 0, p = commit->parents;
 858                         p && i < sizeof(parents) - 1;
 859                         p = p->next)
 860                 i += snprintf(parents + i, sizeof(parents) - i - 1, " %s",
 861                         sha1_to_hex(p->item->object.sha1));
 862         interp_set_entry(table, IPARENTS, parents + 1);
 863
 864         parents[1] = 0;
 865         for (i = 0, p = commit->parents;
 866                         p && i < sizeof(parents) - 1;
 867                         p = p->next)
 868                 i += snprintf(parents + i, sizeof(parents) - i - 1, " %s",
 869                         find_unique_abbrev(p->item->object.sha1,
 870                                 DEFAULT_ABBREV));
 871         interp_set_entry(table, IPARENTS_ABBREV, parents + 1);
 872
 873         for (i = 0, state = HEADER; msg[i] && state < BODY; i++) {
 874                 int eol;
 875                 for (eol = i; msg[eol] && msg[eol] != '\n'; eol++)
 876                         ; /* do nothing */
 877
 878                 if (state == SUBJECT) {
 879                         table[ISUBJECT].value = xstrndup(msg + i, eol - i);
 880                         i = eol;
 881                 }
 882                 if (i == eol) {
 883                         state++;
 884                         /* strip empty lines */
 885                         while (msg[eol + 1] == '\n')
 886                                 eol++;
 887                 } else if (!prefixcmp(msg + i, "author "))
 888                         fill_person(table + IAUTHOR_NAME,
 889                                         msg + i + 7, eol - i - 7);
 890                 else if (!prefixcmp(msg + i, "committer "))
 891                         fill_person(table + ICOMMITTER_NAME,
 892                                         msg + i + 10, eol - i - 10);
 893                 else if (!prefixcmp(msg + i, "encoding "))
 894                         table[IENCODING].value =
 895                                 xstrndup(msg + i + 9, eol - i - 9);
 896                 i = eol;
 897         }
 898         if (msg[i])
 899                 table[IBODY].value = xstrdup(msg + i);
 900         for (i = 0; i < ARRAY_SIZE(table); i++)
 901                 if (!table[i].value)
 902                         interp_set_entry(table, i, "<unknown>");
 903
 904         interpolate(buf, space, user_format, table, ARRAY_SIZE(table));
 905         interp_clear_table(table, ARRAY_SIZE(table));
 906
 907         return strlen(buf);
 908 }
 909
 910 unsigned long pretty_print_commit(enum cmit_fmt fmt,
 911                                   const struct commit *commit,
 912                                   unsigned long len,
 913                                   char *buf, unsigned long space,
 914                                   int abbrev, const char *subject,
 915                                   const char *after_subject,
 916                                   enum date_mode dmode)
 917 {
 918         int hdr = 1, body = 0, seen_title = 0;
 919         unsigned long offset = 0;
 920         int indent = 4;
 921         int parents_shown = 0;
 922         const char *msg = commit->buffer;
 923         int plain_non_ascii = 0;
 924         char *reencoded;
 925         const char *encoding;
 926
 927         if (fmt == CMIT_FMT_USERFORMAT)
 928                 return format_commit_message(commit, msg, buf, space);
 929
 930         encoding = (git_log_output_encoding
 931                     ? git_log_output_encoding
 932                     : git_commit_encoding);
 933         if (!encoding)
 934                 encoding = "utf-8";
 935         reencoded = logmsg_reencode(commit, encoding);
 936         if (reencoded)
 937                 msg = reencoded;
 938
 939         if (fmt == CMIT_FMT_ONELINE || fmt == CMIT_FMT_EMAIL)
 940                 indent = 0;
 941
 942         /* After-subject is used to pass in Content-Type: multipart
 943          * MIME header; in that case we do not have to do the
 944          * plaintext content type even if the commit message has
 945          * non 7-bit ASCII character.  Otherwise, check if we need
 946          * to say this is not a 7-bit ASCII.
 947          */
 948         if (fmt == CMIT_FMT_EMAIL && !after_subject) {
 949                 int i, ch, in_body;
 950
 951                 for (in_body = i = 0; (ch = msg[i]) && i < len; i++) {
 952                         if (!in_body) {
 953                                 /* author could be non 7-bit ASCII but
 954                                  * the log may be so; skip over the
 955                                  * header part first.
 956                                  */
 957                                 if (ch == '\n' &&
 958                                     i + 1 < len && msg[i+1] == '\n')
 959                                         in_body = 1;
 960                         }
 961                         else if (non_ascii(ch)) {
 962                                 plain_non_ascii = 1;
 963                                 break;
 964                         }
 965                 }
 966         }
 967
 968         for (;;) {
 969                 const char *line = msg;
 970                 int linelen = get_one_line(msg, len);
 971
 972                 if (!linelen)
 973                         break;
 974
 975                 /*
 976                  * We want some slop for indentation and a possible
 977                  * final "...". Thus the "+ 20".
 978                  */
 979                 if (offset + linelen + 20 > space) {
 980                         memcpy(buf + offset, "    ...\n", 8);
 981                         offset += 8;
 982                         break;
 983                 }
 984
 985                 msg += linelen;
 986                 len -= linelen;
 987                 if (hdr) {
 988                         if (linelen == 1) {
 989                                 hdr = 0;
 990                                 if ((fmt != CMIT_FMT_ONELINE) && !subject)
 991                                         buf[offset++] = '\n';
 992                                 continue;
 993                         }
 994                         if (fmt == CMIT_FMT_RAW) {
 995                                 memcpy(buf + offset, line, linelen);
 996                                 offset += linelen;
 997                                 continue;
 998                         }
 999                         if (!memcmp(line, "parent ", 7)) {
1000                                 if (linelen != 48)
1001                                         die("bad parent line in commit");
1002                                 continue;
1003                         }
1004
1005                         if (!parents_shown) {
1006                                 offset += add_merge_info(fmt, buf + offset,
1007                                                          commit, abbrev);
1008                                 parents_shown = 1;
1009                                 continue;
1010                         }
1011                         /*
1012                          * MEDIUM == DEFAULT shows only author with dates.
1013                          * FULL shows both authors but not dates.
1014                          * FULLER shows both authors and dates.
1015                          */
1016                         if (!memcmp(line, "author ", 7))
1017                                 offset += add_user_info("Author", fmt,
1018                                                         buf + offset,
1019                                                         line + 7,
1020                                                         dmode,
1021                                                         encoding);
1022                         if (!memcmp(line, "committer ", 10) &&
1023                             (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER))
1024                                 offset += add_user_info("Commit", fmt,
1025                                                         buf + offset,
1026                                                         line + 10,
1027                                                         dmode,
1028                                                         encoding);
1029                         continue;
1030                 }
1031
1032                 if (!subject)
1033                         body = 1;
1034
1035                 if (is_empty_line(line, &linelen)) {
1036                         if (!seen_title)
1037                                 continue;
1038                         if (!body)
1039                                 continue;
1040                         if (subject)
1041                                 continue;
1042                         if (fmt == CMIT_FMT_SHORT)
1043                                 break;
1044                 }
1045
1046                 seen_title = 1;
1047                 if (subject) {
1048                         int slen = strlen(subject);
1049                         memcpy(buf + offset, subject, slen);
1050                         offset += slen;
1051                         offset += add_rfc2047(buf + offset, line, linelen,
1052                                               encoding);
1053                 }
1054                 else {
1055                         memset(buf + offset, ' ', indent);
1056                         memcpy(buf + offset + indent, line, linelen);
1057                         offset += linelen + indent;
1058                 }
1059                 buf[offset++] = '\n';
1060                 if (fmt == CMIT_FMT_ONELINE)
1061                         break;
1062                 if (subject && plain_non_ascii) {
1063                         int sz;
1064                         char header[512];
1065                         const char *header_fmt =
1066                                 "MIME-Version: 1.0\n"
1067                                 "Content-Type: text/plain; charset=%s\n"
1068                                 "Content-Transfer-Encoding: 8bit\n";
1069                         sz = snprintf(header, sizeof(header), header_fmt,
1070                                       encoding);
1071                         if (sizeof(header) < sz)
1072                                 die("Encoding name %s too long", encoding);
1073                         memcpy(buf + offset, header, sz);
1074                         offset += sz;
1075                 }
1076                 if (after_subject) {
1077                         int slen = strlen(after_subject);
1078                         if (slen > space - offset - 1)
1079                                 slen = space - offset - 1;
1080                         memcpy(buf + offset, after_subject, slen);
1081                         offset += slen;
1082                         after_subject = NULL;
1083                 }
1084                 subject = NULL;
1085         }
1086         while (offset && isspace(buf[offset-1]))
1087                 offset--;
1088         /* Make sure there is an EOLN for the non-oneline case */
1089         if (fmt != CMIT_FMT_ONELINE)
1090                 buf[offset++] = '\n';
1091         /*
1092          * make sure there is another EOLN to separate the headers from whatever
1093          * body the caller appends if we haven't already written a body
1094          */
1095         if (fmt == CMIT_FMT_EMAIL && !body)
1096                 buf[offset++] = '\n';
1097         buf[offset] = '\0';
1098
1099         free(reencoded);
1100         return offset;
1101 }
1102
1103 struct commit *pop_commit(struct commit_list **stack)
1104 {
1105         struct commit_list *top = *stack;
1106         struct commit *item = top ? top->item : NULL;
1107
1108         if (top) {
1109                 *stack = top->next;
1110                 free(top);
1111         }
1112         return item;
1113 }
1114
1115 int count_parents(struct commit * commit)
1116 {
1117         int count;
1118         struct commit_list * parents = commit->parents;
1119         for (count = 0; parents; parents = parents->next,count++)
1120                 ;
1121         return count;
1122 }
1123
1124 void topo_sort_default_setter(struct commit *c, void *data)
1125 {
1126         c->util = data;
1127 }
1128
1129 void *topo_sort_default_getter(struct commit *c)
1130 {
1131         return c->util;
1132 }
1133
1134 /*
1135  * Performs an in-place topological sort on the list supplied.
1136  */
1137 void sort_in_topological_order(struct commit_list ** list, int lifo)
1138 {
1139         sort_in_topological_order_fn(list, lifo, topo_sort_default_setter,
1140                                      topo_sort_default_getter);
1141 }
1142
1143 void sort_in_topological_order_fn(struct commit_list ** list, int lifo,
1144                                   topo_sort_set_fn_t setter,
1145                                   topo_sort_get_fn_t getter)
1146 {
1147         struct commit_list * next = *list;
1148         struct commit_list * work = NULL, **insert;
1149         struct commit_list ** pptr = list;
1150         struct sort_node * nodes;
1151         struct sort_node * next_nodes;
1152         int count = 0;
1153
1154         /* determine the size of the list */
1155         while (next) {
1156                 next = next->next;
1157                 count++;
1158         }
1159
1160         if (!count)
1161                 return;
1162         /* allocate an array to help sort the list */
1163         nodes = xcalloc(count, sizeof(*nodes));
1164         /* link the list to the array */
1165         next_nodes = nodes;
1166         next=*list;
1167         while (next) {
1168                 next_nodes->list_item = next;
1169                 setter(next->item, next_nodes);
1170                 next_nodes++;
1171                 next = next->next;
1172         }
1173         /* update the indegree */
1174         next=*list;
1175         while (next) {
1176                 struct commit_list * parents = next->item->parents;
1177                 while (parents) {
1178                         struct commit * parent=parents->item;
1179                         struct sort_node * pn = (struct sort_node *) getter(parent);
1180
1181                         if (pn)
1182                                 pn->indegree++;
1183                         parents=parents->next;
1184                 }
1185                 next=next->next;
1186         }
1187         /*
1188          * find the tips
1189          *
1190          * tips are nodes not reachable from any other node in the list
1191          *
1192          * the tips serve as a starting set for the work queue.
1193          */
1194         next=*list;
1195         insert = &work;
1196         while (next) {
1197                 struct sort_node * node = (struct sort_node *) getter(next->item);
1198
1199                 if (node->indegree == 0) {
1200                         insert = &commit_list_insert(next->item, insert)->next;
1201                 }
1202                 next=next->next;
1203         }
1204
1205         /* process the list in topological order */
1206         if (!lifo)
1207                 sort_by_date(&work);
1208         while (work) {
1209                 struct commit * work_item = pop_commit(&work);
1210                 struct sort_node * work_node = (struct sort_node *) getter(work_item);
1211                 struct commit_list * parents = work_item->parents;
1212
1213                 while (parents) {
1214                         struct commit * parent=parents->item;
1215                         struct sort_node * pn = (struct sort_node *) getter(parent);
1216
1217                         if (pn) {
1218                                 /*
1219                                  * parents are only enqueued for emission
1220                                  * when all their children have been emitted thereby
1221                                  * guaranteeing topological order.
1222                                  */
1223                                 pn->indegree--;
1224                                 if (!pn->indegree) {
1225                                         if (!lifo)
1226                                                 insert_by_date(parent, &work);
1227                                         else
1228                                                 commit_list_insert(parent, &work);
1229                                 }
1230                         }
1231                         parents=parents->next;
1232                 }
1233                 /*
1234                  * work_item is a commit all of whose children
1235                  * have already been emitted. we can emit it now.
1236                  */
1237                 *pptr = work_node->list_item;
1238                 pptr = &(*pptr)->next;
1239                 *pptr = NULL;
1240                 setter(work_item, NULL);
1241         }
1242         free(nodes);
1243 }
1244
1245 /* merge-base stuff */
1246
1247 /* bits #0..15 in revision.h */
1248 #define PARENT1         (1u<<16)
1249 #define PARENT2         (1u<<17)
1250 #define STALE           (1u<<18)
1251 #define RESULT          (1u<<19)
1252
1253 static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
1254
1255 static struct commit *interesting(struct commit_list *list)
1256 {
1257         while (list) {
1258                 struct commit *commit = list->item;
1259                 list = list->next;
1260                 if (commit->object.flags & STALE)
1261                         continue;
1262                 return commit;
1263         }
1264         return NULL;
1265 }
1266
1267 static struct commit_list *merge_bases(struct commit *one, struct commit *two)
1268 {
1269         struct commit_list *list = NULL;
1270         struct commit_list *result = NULL;
1271
1272         if (one == two)
1273                 /* We do not mark this even with RESULT so we do not
1274                  * have to clean it up.
1275                  */
1276                 return commit_list_insert(one, &result);
1277
1278         parse_commit(one);
1279         parse_commit(two);
1280
1281         one->object.flags |= PARENT1;
1282         two->object.flags |= PARENT2;
1283         insert_by_date(one, &list);
1284         insert_by_date(two, &list);
1285
1286         while (interesting(list)) {
1287                 struct commit *commit;
1288                 struct commit_list *parents;
1289                 struct commit_list *n;
1290                 int flags;
1291
1292                 commit = list->item;
1293                 n = list->next;
1294                 free(list);
1295                 list = n;
1296
1297                 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
1298                 if (flags == (PARENT1 | PARENT2)) {
1299                         if (!(commit->object.flags & RESULT)) {
1300                                 commit->object.flags |= RESULT;
1301                                 insert_by_date(commit, &result);
1302                         }
1303                         /* Mark parents of a found merge stale */
1304                         flags |= STALE;
1305                 }
1306                 parents = commit->parents;
1307                 while (parents) {
1308                         struct commit *p = parents->item;
1309                         parents = parents->next;
1310                         if ((p->object.flags & flags) == flags)
1311                                 continue;
1312                         parse_commit(p);
1313                         p->object.flags |= flags;
1314                         insert_by_date(p, &list);
1315                 }
1316         }
1317
1318         /* Clean up the result to remove stale ones */
1319         free_commit_list(list);
1320         list = result; result = NULL;
1321         while (list) {
1322                 struct commit_list *n = list->next;
1323                 if (!(list->item->object.flags & STALE))
1324                         insert_by_date(list->item, &result);
1325                 free(list);
1326                 list = n;
1327         }
1328         return result;
1329 }
1330
1331 struct commit_list *get_merge_bases(struct commit *one,
1332                                     struct commit *two,
1333                                     int cleanup)
1334 {
1335         struct commit_list *list;
1336         struct commit **rslt;
1337         struct commit_list *result;
1338         int cnt, i, j;
1339
1340         result = merge_bases(one, two);
1341         if (one == two)
1342                 return result;
1343         if (!result || !result->next) {
1344                 if (cleanup) {
1345                         clear_commit_marks(one, all_flags);
1346                         clear_commit_marks(two, all_flags);
1347                 }
1348                 return result;
1349         }
1350
1351         /* There are more than one */
1352         cnt = 0;
1353         list = result;
1354         while (list) {
1355                 list = list->next;
1356                 cnt++;
1357         }
1358         rslt = xcalloc(cnt, sizeof(*rslt));
1359         for (list = result, i = 0; list; list = list->next)
1360                 rslt[i++] = list->item;
1361         free_commit_list(result);
1362
1363         clear_commit_marks(one, all_flags);
1364         clear_commit_marks(two, all_flags);
1365         for (i = 0; i < cnt - 1; i++) {
1366                 for (j = i+1; j < cnt; j++) {
1367                         if (!rslt[i] || !rslt[j])
1368                                 continue;
1369                         result = merge_bases(rslt[i], rslt[j]);
1370                         clear_commit_marks(rslt[i], all_flags);
1371                         clear_commit_marks(rslt[j], all_flags);
1372                         for (list = result; list; list = list->next) {
1373                                 if (rslt[i] == list->item)
1374                                         rslt[i] = NULL;
1375                                 if (rslt[j] == list->item)
1376                                         rslt[j] = NULL;
1377                         }
1378                 }
1379         }
1380
1381         /* Surviving ones in rslt[] are the independent results */
1382         result = NULL;
1383         for (i = 0; i < cnt; i++) {
1384                 if (rslt[i])
1385                         insert_by_date(rslt[i], &result);
1386         }
1387         free(rslt);
1388         return result;
1389 }
1390
1391 int in_merge_bases(struct commit *commit, struct commit **reference, int num)
1392 {
1393         struct commit_list *bases, *b;
1394         int ret = 0;
1395
1396         if (num == 1)
1397                 bases = get_merge_bases(commit, *reference, 1);
1398         else
1399                 die("not yet");
1400         for (b = bases; b; b = b->next) {
1401                 if (!hashcmp(commit->object.sha1, b->item->object.sha1)) {
1402                         ret = 1;
1403                         break;
1404                 }
1405         }
1406
1407         free_commit_list(bases);
1408         return ret;
1409 }