git/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 static 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                 /*
 515                  * We encode ' ' using '=20' even though rfc2047
 516                  * allows using '_' for readability.  Unfortunately,
 517                  * many programs do not understand this and just
 518                  * leave the underscore in place.
 519                  */
 520                 if (is_rfc2047_special(ch) || ch == ' ') {
 521                         sprintf(bp, "=%02X", ch);
 522                         bp += 3;
 523                 }
 524                 else
 525                         *bp++ = ch;
 526         }
 527         memcpy(bp, "?=", 2);
 528         bp += 2;
 529         return bp - buf;
 530 }
 531
 532 static unsigned long bound_rfc2047(unsigned long len, const char *encoding)
 533 {
 534         /* upper bound of q encoded string of length 'len' */
 535         unsigned long elen = strlen(encoding);
 536
 537         return len * 3 + elen + 100;
 538 }
 539
 540 static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf,
 541                          const char *line, enum date_mode dmode,
 542                          const char *encoding)
 543 {
 544         char *date;
 545         int namelen;
 546         unsigned long time;
 547         int tz, ret;
 548         const char *filler = "    ";
 549
 550         if (fmt == CMIT_FMT_ONELINE)
 551                 return 0;
 552         date = strchr(line, '>');
 553         if (!date)
 554                 return 0;
 555         namelen = ++date - line;
 556         time = strtoul(date, &date, 10);
 557         tz = strtol(date, NULL, 10);
 558
 559         if (fmt == CMIT_FMT_EMAIL) {
 560                 char *name_tail = strchr(line, '<');
 561                 int display_name_length;
 562                 if (!name_tail)
 563                         return 0;
 564                 while (line < name_tail && isspace(name_tail[-1]))
 565                         name_tail--;
 566                 display_name_length = name_tail - line;
 567                 filler = "";
 568                 strcpy(buf, "From: ");
 569                 ret = strlen(buf);
 570                 ret += add_rfc2047(buf + ret, line, display_name_length,
 571                                    encoding);
 572                 memcpy(buf + ret, name_tail, namelen - display_name_length);
 573                 ret += namelen - display_name_length;
 574                 buf[ret++] = '\n';
 575         }
 576         else {
 577                 ret = sprintf(buf, "%s: %.*s%.*s\n", what,
 578                               (fmt == CMIT_FMT_FULLER) ? 4 : 0,
 579                               filler, namelen, line);
 580         }
 581         switch (fmt) {
 582         case CMIT_FMT_MEDIUM:
 583                 ret += sprintf(buf + ret, "Date:   %s\n",
 584                                show_date(time, tz, dmode));
 585                 break;
 586         case CMIT_FMT_EMAIL:
 587                 ret += sprintf(buf + ret, "Date: %s\n",
 588                                show_date(time, tz, DATE_RFC2822));
 589                 break;
 590         case CMIT_FMT_FULLER:
 591                 ret += sprintf(buf + ret, "%sDate: %s\n", what,
 592                                show_date(time, tz, dmode));
 593                 break;
 594         default:
 595                 /* notin' */
 596                 break;
 597         }
 598         return ret;
 599 }
 600
 601 static int is_empty_line(const char *line, int *len_p)
 602 {
 603         int len = *len_p;
 604         while (len && isspace(line[len-1]))
 605                 len--;
 606         *len_p = len;
 607         return !len;
 608 }
 609
 610 static int add_merge_info(enum cmit_fmt fmt, char *buf, const struct commit *commit, int abbrev)
 611 {
 612         struct commit_list *parent = commit->parents;
 613         int offset;
 614
 615         if ((fmt == CMIT_FMT_ONELINE) || (fmt == CMIT_FMT_EMAIL) ||
 616             !parent || !parent->next)
 617                 return 0;
 618
 619         offset = sprintf(buf, "Merge:");
 620
 621         while (parent) {
 622                 struct commit *p = parent->item;
 623                 const char *hex = NULL;
 624                 const char *dots;
 625                 if (abbrev)
 626                         hex = find_unique_abbrev(p->object.sha1, abbrev);
 627                 if (!hex)
 628                         hex = sha1_to_hex(p->object.sha1);
 629                 dots = (abbrev && strlen(hex) != 40) ?  "..." : "";
 630                 parent = parent->next;
 631
 632                 offset += sprintf(buf + offset, " %s%s", hex, dots);
 633         }
 634         buf[offset++] = '\n';
 635         return offset;
 636 }
 637
 638 static char *get_header(const struct commit *commit, const char *key)
 639 {
 640         int key_len = strlen(key);
 641         const char *line = commit->buffer;
 642
 643         for (;;) {
 644                 const char *eol = strchr(line, '\n'), *next;
 645
 646                 if (line == eol)
 647                         return NULL;
 648                 if (!eol) {
 649                         eol = line + strlen(line);
 650                         next = NULL;
 651                 } else
 652                         next = eol + 1;
 653                 if (eol - line > key_len &&
 654                     !strncmp(line, key, key_len) &&
 655                     line[key_len] == ' ') {
 656                         int len = eol - line - key_len;
 657                         char *ret = xmalloc(len);
 658                         memcpy(ret, line + key_len + 1, len - 1);
 659                         ret[len - 1] = '\0';
 660                         return ret;
 661                 }
 662                 line = next;
 663         }
 664 }
 665
 666 static char *replace_encoding_header(char *buf, const char *encoding)
 667 {
 668         char *encoding_header = strstr(buf, "\nencoding ");
 669         char *header_end = strstr(buf, "\n\n");
 670         char *end_of_encoding_header;
 671         int encoding_header_pos;
 672         int encoding_header_len;
 673         int new_len;
 674         int need_len;
 675         int buflen = strlen(buf) + 1;
 676
 677         if (!header_end)
 678                 header_end = buf + buflen;
 679         if (!encoding_header || encoding_header >= header_end)
 680                 return buf;
 681         encoding_header++;
 682         end_of_encoding_header = strchr(encoding_header, '\n');
 683         if (!end_of_encoding_header)
 684                 return buf; /* should not happen but be defensive */
 685         end_of_encoding_header++;
 686
 687         encoding_header_len = end_of_encoding_header - encoding_header;
 688         encoding_header_pos = encoding_header - buf;
 689
 690         if (is_encoding_utf8(encoding)) {
 691                 /* we have re-coded to UTF-8; drop the header */
 692                 memmove(encoding_header, end_of_encoding_header,
 693                         buflen - (encoding_header_pos + encoding_header_len));
 694                 return buf;
 695         }
 696         new_len = strlen(encoding);
 697         need_len = new_len + strlen("encoding \n");
 698         if (encoding_header_len < need_len) {
 699                 buf = xrealloc(buf, buflen + (need_len - encoding_header_len));
 700                 encoding_header = buf + encoding_header_pos;
 701                 end_of_encoding_header = encoding_header + encoding_header_len;
 702         }
 703         memmove(end_of_encoding_header + (need_len - encoding_header_len),
 704                 end_of_encoding_header,
 705                 buflen - (encoding_header_pos + encoding_header_len));
 706         memcpy(encoding_header + 9, encoding, strlen(encoding));
 707         encoding_header[9 + new_len] = '\n';
 708         return buf;
 709 }
 710
 711 static char *logmsg_reencode(const struct commit *commit,
 712                              const char *output_encoding)
 713 {
 714         static const char *utf8 = "utf-8";
 715         const char *use_encoding;
 716         char *encoding;
 717         char *out;
 718
 719         if (!*output_encoding)
 720                 return NULL;
 721         encoding = get_header(commit, "encoding");
 722         use_encoding = encoding ? encoding : utf8;
 723         if (!strcmp(use_encoding, output_encoding))
 724                 out = xstrdup(commit->buffer);
 725         else
 726                 out = reencode_string(commit->buffer,
 727                                       output_encoding, use_encoding);
 728         if (out)
 729                 out = replace_encoding_header(out, output_encoding);
 730
 731         free(encoding);
 732         return out;
 733 }
 734
 735 static void fill_person(struct interp *table, const char *msg, int len)
 736 {
 737         int start, end, tz = 0;
 738         unsigned long date;
 739         char *ep;
 740
 741         /* parse name */
 742         for (end = 0; end < len && msg[end] != '<'; end++)
 743                 ; /* do nothing */
 744         start = end + 1;
 745         while (end > 0 && isspace(msg[end - 1]))
 746                 end--;
 747         table[0].value = xstrndup(msg, end);
 748
 749         if (start >= len)
 750                 return;
 751
 752         /* parse email */
 753         for (end = start + 1; end < len && msg[end] != '>'; end++)
 754                 ; /* do nothing */
 755
 756         if (end >= len)
 757                 return;
 758
 759         table[1].value = xstrndup(msg + start, end - start);
 760
 761         /* parse date */
 762         for (start = end + 1; start < len && isspace(msg[start]); start++)
 763                 ; /* do nothing */
 764         if (start >= len)
 765                 return;
 766         date = strtoul(msg + start, &ep, 10);
 767         if (msg + start == ep)
 768                 return;
 769
 770         table[5].value = xstrndup(msg + start, ep - (msg + start));
 771
 772         /* parse tz */
 773         for (start = ep - msg + 1; start < len && isspace(msg[start]); start++)
 774                 ; /* do nothing */
 775         if (start + 1 < len) {
 776                 tz = strtoul(msg + start + 1, NULL, 10);
 777                 if (msg[start] == '-')
 778                         tz = -tz;
 779         }
 780
 781         interp_set_entry(table, 2, show_date(date, tz, DATE_NORMAL));
 782         interp_set_entry(table, 3, show_date(date, tz, DATE_RFC2822));
 783         interp_set_entry(table, 4, show_date(date, tz, DATE_RELATIVE));
 784         interp_set_entry(table, 6, show_date(date, tz, DATE_ISO8601));
 785 }
 786
 787 static long format_commit_message(const struct commit *commit,
 788                 const char *msg, char **buf_p, unsigned long *space_p)
 789 {
 790         struct interp table[] = {
 791                 { "%H" },       /* commit hash */
 792                 { "%h" },       /* abbreviated commit hash */
 793                 { "%T" },       /* tree hash */
 794                 { "%t" },       /* abbreviated tree hash */
 795                 { "%P" },       /* parent hashes */
 796                 { "%p" },       /* abbreviated parent hashes */
 797                 { "%an" },      /* author name */
 798                 { "%ae" },      /* author email */
 799                 { "%ad" },      /* author date */
 800                 { "%aD" },      /* author date, RFC2822 style */
 801                 { "%ar" },      /* author date, relative */
 802                 { "%at" },      /* author date, UNIX timestamp */
 803                 { "%ai" },      /* author date, ISO 8601 */
 804                 { "%cn" },      /* committer name */
 805                 { "%ce" },      /* committer email */
 806                 { "%cd" },      /* committer date */
 807                 { "%cD" },      /* committer date, RFC2822 style */
 808                 { "%cr" },      /* committer date, relative */
 809                 { "%ct" },      /* committer date, UNIX timestamp */
 810                 { "%ci" },      /* committer date, ISO 8601 */
 811                 { "%e" },       /* encoding */
 812                 { "%s" },       /* subject */
 813                 { "%b" },       /* body */
 814                 { "%Cred" },    /* red */
 815                 { "%Cgreen" },  /* green */
 816                 { "%Cblue" },   /* blue */
 817                 { "%Creset" },  /* reset color */
 818                 { "%n" },       /* newline */
 819                 { "%m" },       /* left/right/bottom */
 820         };
 821         enum interp_index {
 822                 IHASH = 0, IHASH_ABBREV,
 823                 ITREE, ITREE_ABBREV,
 824                 IPARENTS, IPARENTS_ABBREV,
 825                 IAUTHOR_NAME, IAUTHOR_EMAIL,
 826                 IAUTHOR_DATE, IAUTHOR_DATE_RFC2822, IAUTHOR_DATE_RELATIVE,
 827                 IAUTHOR_TIMESTAMP, IAUTHOR_ISO8601,
 828                 ICOMMITTER_NAME, ICOMMITTER_EMAIL,
 829                 ICOMMITTER_DATE, ICOMMITTER_DATE_RFC2822,
 830                 ICOMMITTER_DATE_RELATIVE, ICOMMITTER_TIMESTAMP,
 831                 ICOMMITTER_ISO8601,
 832                 IENCODING,
 833                 ISUBJECT,
 834                 IBODY,
 835                 IRED, IGREEN, IBLUE, IRESET_COLOR,
 836                 INEWLINE,
 837                 ILEFT_RIGHT,
 838         };
 839         struct commit_list *p;
 840         char parents[1024];
 841         int i;
 842         enum { HEADER, SUBJECT, BODY } state;
 843
 844         if (ILEFT_RIGHT + 1 != ARRAY_SIZE(table))
 845                 die("invalid interp table!");
 846
 847         /* these are independent of the commit */
 848         interp_set_entry(table, IRED, "\033[31m");
 849         interp_set_entry(table, IGREEN, "\033[32m");
 850         interp_set_entry(table, IBLUE, "\033[34m");
 851         interp_set_entry(table, IRESET_COLOR, "\033[m");
 852         interp_set_entry(table, INEWLINE, "\n");
 853
 854         /* these depend on the commit */
 855         if (!commit->object.parsed)
 856                 parse_object(commit->object.sha1);
 857         interp_set_entry(table, IHASH, sha1_to_hex(commit->object.sha1));
 858         interp_set_entry(table, IHASH_ABBREV,
 859                         find_unique_abbrev(commit->object.sha1,
 860                                 DEFAULT_ABBREV));
 861         interp_set_entry(table, ITREE, sha1_to_hex(commit->tree->object.sha1));
 862         interp_set_entry(table, ITREE_ABBREV,
 863                         find_unique_abbrev(commit->tree->object.sha1,
 864                                 DEFAULT_ABBREV));
 865         interp_set_entry(table, ILEFT_RIGHT,
 866                          (commit->object.flags & BOUNDARY)
 867                          ? "-"
 868                          : (commit->object.flags & SYMMETRIC_LEFT)
 869                          ? "<"
 870                          : ">");
 871
 872         parents[1] = 0;
 873         for (i = 0, p = commit->parents;
 874                         p && i < sizeof(parents) - 1;
 875                         p = p->next)
 876                 i += snprintf(parents + i, sizeof(parents) - i - 1, " %s",
 877                         sha1_to_hex(p->item->object.sha1));
 878         interp_set_entry(table, IPARENTS, parents + 1);
 879
 880         parents[1] = 0;
 881         for (i = 0, p = commit->parents;
 882                         p && i < sizeof(parents) - 1;
 883                         p = p->next)
 884                 i += snprintf(parents + i, sizeof(parents) - i - 1, " %s",
 885                         find_unique_abbrev(p->item->object.sha1,
 886                                 DEFAULT_ABBREV));
 887         interp_set_entry(table, IPARENTS_ABBREV, parents + 1);
 888
 889         for (i = 0, state = HEADER; msg[i] && state < BODY; i++) {
 890                 int eol;
 891                 for (eol = i; msg[eol] && msg[eol] != '\n'; eol++)
 892                         ; /* do nothing */
 893
 894                 if (state == SUBJECT) {
 895                         table[ISUBJECT].value = xstrndup(msg + i, eol - i);
 896                         i = eol;
 897                 }
 898                 if (i == eol) {
 899                         state++;
 900                         /* strip empty lines */
 901                         while (msg[eol + 1] == '\n')
 902                                 eol++;
 903                 } else if (!prefixcmp(msg + i, "author "))
 904                         fill_person(table + IAUTHOR_NAME,
 905                                         msg + i + 7, eol - i - 7);
 906                 else if (!prefixcmp(msg + i, "committer "))
 907                         fill_person(table + ICOMMITTER_NAME,
 908                                         msg + i + 10, eol - i - 10);
 909                 else if (!prefixcmp(msg + i, "encoding "))
 910                         table[IENCODING].value =
 911                                 xstrndup(msg + i + 9, eol - i - 9);
 912                 i = eol;
 913         }
 914         if (msg[i])
 915                 table[IBODY].value = xstrdup(msg + i);
 916         for (i = 0; i < ARRAY_SIZE(table); i++)
 917                 if (!table[i].value)
 918                         interp_set_entry(table, i, "<unknown>");
 919
 920         do {
 921                 char *buf = *buf_p;
 922                 unsigned long space = *space_p;
 923
 924                 space = interpolate(buf, space, user_format,
 925                                     table, ARRAY_SIZE(table));
 926                 if (!space)
 927                         break;
 928                 buf = xrealloc(buf, space);
 929                 *buf_p = buf;
 930                 *space_p = space;
 931         } while (1);
 932         interp_clear_table(table, ARRAY_SIZE(table));
 933
 934         return strlen(*buf_p);
 935 }
 936
 937 static void pp_header(enum cmit_fmt fmt,
 938                       int abbrev,
 939                       enum date_mode dmode,
 940                       const char *encoding,
 941                       const struct commit *commit,
 942                       const char **msg_p,
 943                       unsigned long *len_p,
 944                       unsigned long *ofs_p,
 945                       char **buf_p,
 946                       unsigned long *space_p)
 947 {
 948         int parents_shown = 0;
 949
 950         for (;;) {
 951                 const char *line = *msg_p;
 952                 char *dst;
 953                 int linelen = get_one_line(*msg_p, *len_p);
 954                 unsigned long len;
 955
 956                 if (!linelen)
 957                         return;
 958                 *msg_p += linelen;
 959                 *len_p -= linelen;
 960
 961                 if (linelen == 1)
 962                         /* End of header */
 963                         return;
 964
 965                 ALLOC_GROW(*buf_p, linelen + *ofs_p + 20, *space_p);
 966                 dst = *buf_p + *ofs_p;
 967
 968                 if (fmt == CMIT_FMT_RAW) {
 969                         memcpy(dst, line, linelen);
 970                         *ofs_p += linelen;
 971                         continue;
 972                 }
 973
 974                 if (!memcmp(line, "parent ", 7)) {
 975                         if (linelen != 48)
 976                                 die("bad parent line in commit");
 977                         continue;
 978                 }
 979
 980                 if (!parents_shown) {
 981                         struct commit_list *parent;
 982                         int num;
 983                         for (parent = commit->parents, num = 0;
 984                              parent;
 985                              parent = parent->next, num++)
 986                                 ;
 987                         /* with enough slop */
 988                         num = *ofs_p + num * 50 + 20;
 989                         ALLOC_GROW(*buf_p, num, *space_p);
 990                         dst = *buf_p + *ofs_p;
 991                         *ofs_p += add_merge_info(fmt, dst, commit, abbrev);
 992                         parents_shown = 1;
 993                 }
 994
 995                 /*
 996                  * MEDIUM == DEFAULT shows only author with dates.
 997                  * FULL shows both authors but not dates.
 998                  * FULLER shows both authors and dates.
 999                  */
1000                 if (!memcmp(line, "author ", 7)) {
1001                         len = linelen;
1002                         if (fmt == CMIT_FMT_EMAIL)
1003                                 len = bound_rfc2047(linelen, encoding);
1004                         ALLOC_GROW(*buf_p, *ofs_p + len + 80, *space_p);
1005                         dst = *buf_p + *ofs_p;
1006                         *ofs_p += add_user_info("Author", fmt, dst,
1007                                                 line + 7, dmode, encoding);
1008                 }
1009
1010                 if (!memcmp(line, "committer ", 10) &&
1011                     (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER)) {
1012                         len = linelen;
1013                         if (fmt == CMIT_FMT_EMAIL)
1014                                 len = bound_rfc2047(linelen, encoding);
1015                         ALLOC_GROW(*buf_p, *ofs_p + len + 80, *space_p);
1016                         dst = *buf_p + *ofs_p;
1017                         *ofs_p += add_user_info("Commit", fmt, dst,
1018                                                 line + 10, dmode, encoding);
1019                 }
1020         }
1021 }
1022
1023 static void pp_title_line(enum cmit_fmt fmt,
1024                           const char **msg_p,
1025                           unsigned long *len_p,
1026                           unsigned long *ofs_p,
1027                           char **buf_p,
1028                           unsigned long *space_p,
1029                           int indent,
1030                           const char *subject,
1031                           const char *after_subject,
1032                           const char *encoding,
1033                           int plain_non_ascii)
1034 {
1035         char *title;
1036         unsigned long title_alloc, title_len;
1037         unsigned long len;
1038
1039         title_len = 0;
1040         title_alloc = 80;
1041         title = xmalloc(title_alloc);
1042         for (;;) {
1043                 const char *line = *msg_p;
1044                 int linelen = get_one_line(line, *len_p);
1045                 *msg_p += linelen;
1046                 *len_p -= linelen;
1047
1048                 if (!linelen || is_empty_line(line, &linelen))
1049                         break;
1050
1051                 if (title_alloc <= title_len + linelen + 2) {
1052                         title_alloc = title_len + linelen + 80;
1053                         title = xrealloc(title, title_alloc);
1054                 }
1055                 len = 0;
1056                 if (title_len) {
1057                         if (fmt == CMIT_FMT_EMAIL) {
1058                                 len++;
1059                                 title[title_len++] = '\n';
1060                         }
1061                         len++;
1062                         title[title_len++] = ' ';
1063                 }
1064                 memcpy(title + title_len, line, linelen);
1065                 title_len += linelen;
1066         }
1067
1068         /* Enough slop for the MIME header and rfc2047 */
1069         len = bound_rfc2047(title_len, encoding)+ 1000;
1070         if (subject)
1071                 len += strlen(subject);
1072         if (after_subject)
1073                 len += strlen(after_subject);
1074         if (encoding)
1075                 len += strlen(encoding);
1076         ALLOC_GROW(*buf_p, title_len + *ofs_p + len, *space_p);
1077
1078         if (subject) {
1079                 len = strlen(subject);
1080                 memcpy(*buf_p + *ofs_p, subject, len);
1081                 *ofs_p += len;
1082                 *ofs_p += add_rfc2047(*buf_p + *ofs_p,
1083                                       title, title_len, encoding);
1084         } else {
1085                 memcpy(*buf_p + *ofs_p, title, title_len);
1086                 *ofs_p += title_len;
1087         }
1088         (*buf_p)[(*ofs_p)++] = '\n';
1089         if (plain_non_ascii) {
1090                 const char *header_fmt =
1091                         "MIME-Version: 1.0\n"
1092                         "Content-Type: text/plain; charset=%s\n"
1093                         "Content-Transfer-Encoding: 8bit\n";
1094                 *ofs_p += snprintf(*buf_p + *ofs_p,
1095                                    *space_p - *ofs_p,
1096                                    header_fmt, encoding);
1097         }
1098         if (after_subject) {
1099                 len = strlen(after_subject);
1100                 memcpy(*buf_p + *ofs_p, after_subject, len);
1101                 *ofs_p += len;
1102         }
1103         free(title);
1104         if (fmt == CMIT_FMT_EMAIL) {
1105                 ALLOC_GROW(*buf_p, *ofs_p + 20, *space_p);
1106                 (*buf_p)[(*ofs_p)++] = '\n';
1107         }
1108 }
1109
1110 static void pp_remainder(enum cmit_fmt fmt,
1111                          const char **msg_p,
1112                          unsigned long *len_p,
1113                          unsigned long *ofs_p,
1114                          char **buf_p,
1115                          unsigned long *space_p,
1116                          int indent)
1117 {
1118         int first = 1;
1119         for (;;) {
1120                 const char *line = *msg_p;
1121                 int linelen = get_one_line(line, *len_p);
1122                 *msg_p += linelen;
1123                 *len_p -= linelen;
1124
1125                 if (!linelen)
1126                         break;
1127
1128                 if (is_empty_line(line, &linelen)) {
1129                         if (first)
1130                                 continue;
1131                         if (fmt == CMIT_FMT_SHORT)
1132                                 break;
1133                 }
1134                 first = 0;
1135
1136                 ALLOC_GROW(*buf_p, *ofs_p + linelen + indent + 20, *space_p);
1137                 if (indent) {
1138                         memset(*buf_p + *ofs_p, ' ', indent);
1139                         *ofs_p += indent;
1140                 }
1141                 memcpy(*buf_p + *ofs_p, line, linelen);
1142                 *ofs_p += linelen;
1143                 (*buf_p)[(*ofs_p)++] = '\n';
1144         }
1145 }
1146
1147 unsigned long pretty_print_commit(enum cmit_fmt fmt,
1148                                   const struct commit *commit,
1149                                   unsigned long len,
1150                                   char **buf_p, unsigned long *space_p,
1151                                   int abbrev, const char *subject,
1152                                   const char *after_subject,
1153                                   enum date_mode dmode)
1154 {
1155         unsigned long offset = 0;
1156         unsigned long beginning_of_body;
1157         int indent = 4;
1158         const char *msg = commit->buffer;
1159         int plain_non_ascii = 0;
1160         char *reencoded;
1161         const char *encoding;
1162         char *buf;
1163
1164         if (fmt == CMIT_FMT_USERFORMAT)
1165                 return format_commit_message(commit, msg, buf_p, space_p);
1166
1167         encoding = (git_log_output_encoding
1168                     ? git_log_output_encoding
1169                     : git_commit_encoding);
1170         if (!encoding)
1171                 encoding = "utf-8";
1172         reencoded = logmsg_reencode(commit, encoding);
1173         if (reencoded) {
1174                 msg = reencoded;
1175                 len = strlen(reencoded);
1176         }
1177
1178         if (fmt == CMIT_FMT_ONELINE || fmt == CMIT_FMT_EMAIL)
1179                 indent = 0;
1180
1181         /* After-subject is used to pass in Content-Type: multipart
1182          * MIME header; in that case we do not have to do the
1183          * plaintext content type even if the commit message has
1184          * non 7-bit ASCII character.  Otherwise, check if we need
1185          * to say this is not a 7-bit ASCII.
1186          */
1187         if (fmt == CMIT_FMT_EMAIL && !after_subject) {
1188                 int i, ch, in_body;
1189
1190                 for (in_body = i = 0; (ch = msg[i]) && i < len; i++) {
1191                         if (!in_body) {
1192                                 /* author could be non 7-bit ASCII but
1193                                  * the log may be so; skip over the
1194                                  * header part first.
1195                                  */
1196                                 if (ch == '\n' &&
1197                                     i + 1 < len && msg[i+1] == '\n')
1198                                         in_body = 1;
1199                         }
1200                         else if (non_ascii(ch)) {
1201                                 plain_non_ascii = 1;
1202                                 break;
1203                         }
1204                 }
1205         }
1206
1207         pp_header(fmt, abbrev, dmode, encoding,
1208                   commit, &msg, &len,
1209                   &offset, buf_p, space_p);
1210         if (fmt != CMIT_FMT_ONELINE && !subject) {
1211                 ALLOC_GROW(*buf_p, offset + 20, *space_p);
1212                 (*buf_p)[offset++] = '\n';
1213         }
1214
1215         /* Skip excess blank lines at the beginning of body, if any... */
1216         for (;;) {
1217                 int linelen = get_one_line(msg, len);
1218                 int ll = linelen;
1219                 if (!linelen)
1220                         break;
1221                 if (!is_empty_line(msg, &ll))
1222                         break;
1223                 msg += linelen;
1224                 len -= linelen;
1225         }
1226
1227         /* These formats treat the title line specially. */
1228         if (fmt == CMIT_FMT_ONELINE
1229             || fmt == CMIT_FMT_EMAIL)
1230                 pp_title_line(fmt, &msg, &len, &offset,
1231                               buf_p, space_p, indent,
1232                               subject, after_subject, encoding,
1233                               plain_non_ascii);
1234
1235         beginning_of_body = offset;
1236         if (fmt != CMIT_FMT_ONELINE)
1237                 pp_remainder(fmt, &msg, &len, &offset,
1238                              buf_p, space_p, indent);
1239
1240         while (offset && isspace((*buf_p)[offset-1]))
1241                 offset--;
1242
1243         ALLOC_GROW(*buf_p, offset + 20, *space_p);
1244         buf = *buf_p;
1245
1246         /* Make sure there is an EOLN for the non-oneline case */
1247         if (fmt != CMIT_FMT_ONELINE)
1248                 buf[offset++] = '\n';
1249
1250         /*
1251          * The caller may append additional body text in e-mail
1252          * format.  Make sure we did not strip the blank line
1253          * between the header and the body.
1254          */
1255         if (fmt == CMIT_FMT_EMAIL && offset <= beginning_of_body)
1256                 buf[offset++] = '\n';
1257         buf[offset] = '\0';
1258         free(reencoded);
1259         return offset;
1260 }
1261
1262 struct commit *pop_commit(struct commit_list **stack)
1263 {
1264         struct commit_list *top = *stack;
1265         struct commit *item = top ? top->item : NULL;
1266
1267         if (top) {
1268                 *stack = top->next;
1269                 free(top);
1270         }
1271         return item;
1272 }
1273
1274 void topo_sort_default_setter(struct commit *c, void *data)
1275 {
1276         c->util = data;
1277 }
1278
1279 void *topo_sort_default_getter(struct commit *c)
1280 {
1281         return c->util;
1282 }
1283
1284 /*
1285  * Performs an in-place topological sort on the list supplied.
1286  */
1287 void sort_in_topological_order(struct commit_list ** list, int lifo)
1288 {
1289         sort_in_topological_order_fn(list, lifo, topo_sort_default_setter,
1290                                      topo_sort_default_getter);
1291 }
1292
1293 void sort_in_topological_order_fn(struct commit_list ** list, int lifo,
1294                                   topo_sort_set_fn_t setter,
1295                                   topo_sort_get_fn_t getter)
1296 {
1297         struct commit_list * next = *list;
1298         struct commit_list * work = NULL, **insert;
1299         struct commit_list ** pptr = list;
1300         struct sort_node * nodes;
1301         struct sort_node * next_nodes;
1302         int count = 0;
1303
1304         /* determine the size of the list */
1305         while (next) {
1306                 next = next->next;
1307                 count++;
1308         }
1309
1310         if (!count)
1311                 return;
1312         /* allocate an array to help sort the list */
1313         nodes = xcalloc(count, sizeof(*nodes));
1314         /* link the list to the array */
1315         next_nodes = nodes;
1316         next=*list;
1317         while (next) {
1318                 next_nodes->list_item = next;
1319                 setter(next->item, next_nodes);
1320                 next_nodes++;
1321                 next = next->next;
1322         }
1323         /* update the indegree */
1324         next=*list;
1325         while (next) {
1326                 struct commit_list * parents = next->item->parents;
1327                 while (parents) {
1328                         struct commit * parent=parents->item;
1329                         struct sort_node * pn = (struct sort_node *) getter(parent);
1330
1331                         if (pn)
1332                                 pn->indegree++;
1333                         parents=parents->next;
1334                 }
1335                 next=next->next;
1336         }
1337         /*
1338          * find the tips
1339          *
1340          * tips are nodes not reachable from any other node in the list
1341          *
1342          * the tips serve as a starting set for the work queue.
1343          */
1344         next=*list;
1345         insert = &work;
1346         while (next) {
1347                 struct sort_node * node = (struct sort_node *) getter(next->item);
1348
1349                 if (node->indegree == 0) {
1350                         insert = &commit_list_insert(next->item, insert)->next;
1351                 }
1352                 next=next->next;
1353         }
1354
1355         /* process the list in topological order */
1356         if (!lifo)
1357                 sort_by_date(&work);
1358         while (work) {
1359                 struct commit * work_item = pop_commit(&work);
1360                 struct sort_node * work_node = (struct sort_node *) getter(work_item);
1361                 struct commit_list * parents = work_item->parents;
1362
1363                 while (parents) {
1364                         struct commit * parent=parents->item;
1365                         struct sort_node * pn = (struct sort_node *) getter(parent);
1366
1367                         if (pn) {
1368                                 /*
1369                                  * parents are only enqueued for emission
1370                                  * when all their children have been emitted thereby
1371                                  * guaranteeing topological order.
1372                                  */
1373                                 pn->indegree--;
1374                                 if (!pn->indegree) {
1375                                         if (!lifo)
1376                                                 insert_by_date(parent, &work);
1377                                         else
1378                                                 commit_list_insert(parent, &work);
1379                                 }
1380                         }
1381                         parents=parents->next;
1382                 }
1383                 /*
1384                  * work_item is a commit all of whose children
1385                  * have already been emitted. we can emit it now.
1386                  */
1387                 *pptr = work_node->list_item;
1388                 pptr = &(*pptr)->next;
1389                 *pptr = NULL;
1390                 setter(work_item, NULL);
1391         }
1392         free(nodes);
1393 }
1394
1395 /* merge-base stuff */
1396
1397 /* bits #0..15 in revision.h */
1398 #define PARENT1         (1u<<16)
1399 #define PARENT2         (1u<<17)
1400 #define STALE           (1u<<18)
1401 #define RESULT          (1u<<19)
1402
1403 static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
1404
1405 static struct commit *interesting(struct commit_list *list)
1406 {
1407         while (list) {
1408                 struct commit *commit = list->item;
1409                 list = list->next;
1410                 if (commit->object.flags & STALE)
1411                         continue;
1412                 return commit;
1413         }
1414         return NULL;
1415 }
1416
1417 static struct commit_list *merge_bases(struct commit *one, struct commit *two)
1418 {
1419         struct commit_list *list = NULL;
1420         struct commit_list *result = NULL;
1421
1422         if (one == two)
1423                 /* We do not mark this even with RESULT so we do not
1424                  * have to clean it up.
1425                  */
1426                 return commit_list_insert(one, &result);
1427
1428         parse_commit(one);
1429         parse_commit(two);
1430
1431         one->object.flags |= PARENT1;
1432         two->object.flags |= PARENT2;
1433         insert_by_date(one, &list);
1434         insert_by_date(two, &list);
1435
1436         while (interesting(list)) {
1437                 struct commit *commit;
1438                 struct commit_list *parents;
1439                 struct commit_list *n;
1440                 int flags;
1441
1442                 commit = list->item;
1443                 n = list->next;
1444                 free(list);
1445                 list = n;
1446
1447                 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
1448                 if (flags == (PARENT1 | PARENT2)) {
1449                         if (!(commit->object.flags & RESULT)) {
1450                                 commit->object.flags |= RESULT;
1451                                 insert_by_date(commit, &result);
1452                         }
1453                         /* Mark parents of a found merge stale */
1454                         flags |= STALE;
1455                 }
1456                 parents = commit->parents;
1457                 while (parents) {
1458                         struct commit *p = parents->item;
1459                         parents = parents->next;
1460                         if ((p->object.flags & flags) == flags)
1461                                 continue;
1462                         parse_commit(p);
1463                         p->object.flags |= flags;
1464                         insert_by_date(p, &list);
1465                 }
1466         }
1467
1468         /* Clean up the result to remove stale ones */
1469         free_commit_list(list);
1470         list = result; result = NULL;
1471         while (list) {
1472                 struct commit_list *n = list->next;
1473                 if (!(list->item->object.flags & STALE))
1474                         insert_by_date(list->item, &result);
1475                 free(list);
1476                 list = n;
1477         }
1478         return result;
1479 }
1480
1481 struct commit_list *get_merge_bases(struct commit *one,
1482                                     struct commit *two,
1483                                     int cleanup)
1484 {
1485         struct commit_list *list;
1486         struct commit **rslt;
1487         struct commit_list *result;
1488         int cnt, i, j;
1489
1490         result = merge_bases(one, two);
1491         if (one == two)
1492                 return result;
1493         if (!result || !result->next) {
1494                 if (cleanup) {
1495                         clear_commit_marks(one, all_flags);
1496                         clear_commit_marks(two, all_flags);
1497                 }
1498                 return result;
1499         }
1500
1501         /* There are more than one */
1502         cnt = 0;
1503         list = result;
1504         while (list) {
1505                 list = list->next;
1506                 cnt++;
1507         }
1508         rslt = xcalloc(cnt, sizeof(*rslt));
1509         for (list = result, i = 0; list; list = list->next)
1510                 rslt[i++] = list->item;
1511         free_commit_list(result);
1512
1513         clear_commit_marks(one, all_flags);
1514         clear_commit_marks(two, all_flags);
1515         for (i = 0; i < cnt - 1; i++) {
1516                 for (j = i+1; j < cnt; j++) {
1517                         if (!rslt[i] || !rslt[j])
1518                                 continue;
1519                         result = merge_bases(rslt[i], rslt[j]);
1520                         clear_commit_marks(rslt[i], all_flags);
1521                         clear_commit_marks(rslt[j], all_flags);
1522                         for (list = result; list; list = list->next) {
1523                                 if (rslt[i] == list->item)
1524                                         rslt[i] = NULL;
1525                                 if (rslt[j] == list->item)
1526                                         rslt[j] = NULL;
1527                         }
1528                 }
1529         }
1530
1531         /* Surviving ones in rslt[] are the independent results */
1532         result = NULL;
1533         for (i = 0; i < cnt; i++) {
1534                 if (rslt[i])
1535                         insert_by_date(rslt[i], &result);
1536         }
1537         free(rslt);
1538         return result;
1539 }
1540
1541 int in_merge_bases(struct commit *commit, struct commit **reference, int num)
1542 {
1543         struct commit_list *bases, *b;
1544         int ret = 0;
1545
1546         if (num == 1)
1547                 bases = get_merge_bases(commit, *reference, 1);
1548         else
1549                 die("not yet");
1550         for (b = bases; b; b = b->next) {
1551                 if (!hashcmp(commit->object.sha1, b->item->object.sha1)) {
1552                         ret = 1;
1553                         break;
1554                 }
1555         }
1556
1557         free_commit_list(bases);
1558         return ret;
1559 }