builtin-show-branch.c

   1 #include <stdlib.h>
   2 #include <fnmatch.h>
   3 #include "cache.h"
   4 #include "commit.h"
   5 #include "refs.h"
   6 #include "builtin.h"
   7
   8 static const char show_branch_usage[] =
   9 "git-show-branch [--sparse] [--current] [--all] [--heads] [--tags] [--topo-order] [--more=count | --list | --independent | --merge-base ] [--topics] [<refs>...]";
  10
  11 static int default_num = 0;
  12 static int default_alloc = 0;
  13 static const char **default_arg = NULL;
  14
  15 #define UNINTERESTING   01
  16
  17 #define REV_SHIFT        2
  18 #define MAX_REVS        (FLAG_BITS - REV_SHIFT) /* should not exceed bits_per_int - REV_SHIFT */
  19
  20 static struct commit *interesting(struct commit_list *list)
  21 {
  22         while (list) {
  23                 struct commit *commit = list->item;
  24                 list = list->next;
  25                 if (commit->object.flags & UNINTERESTING)
  26                         continue;
  27                 return commit;
  28         }
  29         return NULL;
  30 }
  31
  32 static struct commit *pop_one_commit(struct commit_list **list_p)
  33 {
  34         struct commit *commit;
  35         struct commit_list *list;
  36         list = *list_p;
  37         commit = list->item;
  38         *list_p = list->next;
  39         free(list);
  40         return commit;
  41 }
  42
  43 struct commit_name {
  44         const char *head_name; /* which head's ancestor? */
  45         int generation; /* how many parents away from head_name */
  46 };
  47
  48 /* Name the commit as nth generation ancestor of head_name;
  49  * we count only the first-parent relationship for naming purposes.
  50  */
  51 static void name_commit(struct commit *commit, const char *head_name, int nth)
  52 {
  53         struct commit_name *name;
  54         if (!commit->util)
  55                 commit->util = xmalloc(sizeof(struct commit_name));
  56         name = commit->util;
  57         name->head_name = head_name;
  58         name->generation = nth;
  59 }
  60
  61 /* Parent is the first parent of the commit.  We may name it
  62  * as (n+1)th generation ancestor of the same head_name as
  63  * commit is nth generation ancestor of, if that generation
  64  * number is better than the name it already has.
  65  */
  66 static void name_parent(struct commit *commit, struct commit *parent)
  67 {
  68         struct commit_name *commit_name = commit->util;
  69         struct commit_name *parent_name = parent->util;
  70         if (!commit_name)
  71                 return;
  72         if (!parent_name ||
  73             commit_name->generation + 1 < parent_name->generation)
  74                 name_commit(parent, commit_name->head_name,
  75                             commit_name->generation + 1);
  76 }
  77
  78 static int name_first_parent_chain(struct commit *c)
  79 {
  80         int i = 0;
  81         while (c) {
  82                 struct commit *p;
  83                 if (!c->util)
  84                         break;
  85                 if (!c->parents)
  86                         break;
  87                 p = c->parents->item;
  88                 if (!p->util) {
  89                         name_parent(c, p);
  90                         i++;
  91                 }
  92                 c = p;
  93         }
  94         return i;
  95 }
  96
  97 static void name_commits(struct commit_list *list,
  98                          struct commit **rev,
  99                          char **ref_name,
 100                          int num_rev)
 101 {
 102         struct commit_list *cl;
 103         struct commit *c;
 104         int i;
 105
 106         /* First give names to the given heads */
 107         for (cl = list; cl; cl = cl->next) {
 108                 c = cl->item;
 109                 if (c->util)
 110                         continue;
 111                 for (i = 0; i < num_rev; i++) {
 112                         if (rev[i] == c) {
 113                                 name_commit(c, ref_name[i], 0);
 114                                 break;
 115                         }
 116                 }
 117         }
 118
 119         /* Then commits on the first parent ancestry chain */
 120         do {
 121                 i = 0;
 122                 for (cl = list; cl; cl = cl->next) {
 123                         i += name_first_parent_chain(cl->item);
 124                 }
 125         } while (i);
 126
 127         /* Finally, any unnamed commits */
 128         do {
 129                 i = 0;
 130                 for (cl = list; cl; cl = cl->next) {
 131                         struct commit_list *parents;
 132                         struct commit_name *n;
 133                         int nth;
 134                         c = cl->item;
 135                         if (!c->util)
 136                                 continue;
 137                         n = c->util;
 138                         parents = c->parents;
 139                         nth = 0;
 140                         while (parents) {
 141                                 struct commit *p = parents->item;
 142                                 char newname[1000], *en;
 143                                 parents = parents->next;
 144                                 nth++;
 145                                 if (p->util)
 146                                         continue;
 147                                 en = newname;
 148                                 switch (n->generation) {
 149                                 case 0:
 150                                         en += sprintf(en, "%s", n->head_name);
 151                                         break;
 152                                 case 1:
 153                                         en += sprintf(en, "%s^", n->head_name);
 154                                         break;
 155                                 default:
 156                                         en += sprintf(en, "%s~%d",
 157                                                 n->head_name, n->generation);
 158                                         break;
 159                                 }
 160                                 if (nth == 1)
 161                                         en += sprintf(en, "^");
 162                                 else
 163                                         en += sprintf(en, "^%d", nth);
 164                                 name_commit(p, strdup(newname), 0);
 165                                 i++;
 166                                 name_first_parent_chain(p);
 167                         }
 168                 }
 169         } while (i);
 170 }
 171
 172 static int mark_seen(struct commit *commit, struct commit_list **seen_p)
 173 {
 174         if (!commit->object.flags) {
 175                 commit_list_insert(commit, seen_p);
 176                 return 1;
 177         }
 178         return 0;
 179 }
 180
 181 static void join_revs(struct commit_list **list_p,
 182                       struct commit_list **seen_p,
 183                       int num_rev, int extra)
 184 {
 185         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 186         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 187
 188         while (*list_p) {
 189                 struct commit_list *parents;
 190                 int still_interesting = !!interesting(*list_p);
 191                 struct commit *commit = pop_one_commit(list_p);
 192                 int flags = commit->object.flags & all_mask;
 193
 194                 if (!still_interesting && extra <= 0)
 195                         break;
 196
 197                 mark_seen(commit, seen_p);
 198                 if ((flags & all_revs) == all_revs)
 199                         flags |= UNINTERESTING;
 200                 parents = commit->parents;
 201
 202                 while (parents) {
 203                         struct commit *p = parents->item;
 204                         int this_flag = p->object.flags;
 205                         parents = parents->next;
 206                         if ((this_flag & flags) == flags)
 207                                 continue;
 208                         if (!p->object.parsed)
 209                                 parse_commit(p);
 210                         if (mark_seen(p, seen_p) && !still_interesting)
 211                                 extra--;
 212                         p->object.flags |= flags;
 213                         insert_by_date(p, list_p);
 214                 }
 215         }
 216
 217         /*
 218          * Postprocess to complete well-poisoning.
 219          *
 220          * At this point we have all the commits we have seen in
 221          * seen_p list.  Mark anything that can be reached from
 222          * uninteresting commits not interesting.
 223          */
 224         for (;;) {
 225                 int changed = 0;
 226                 struct commit_list *s;
 227                 for (s = *seen_p; s; s = s->next) {
 228                         struct commit *c = s->item;
 229                         struct commit_list *parents;
 230
 231                         if (((c->object.flags & all_revs) != all_revs) &&
 232                             !(c->object.flags & UNINTERESTING))
 233                                 continue;
 234
 235                         /* The current commit is either a merge base or
 236                          * already uninteresting one.  Mark its parents
 237                          * as uninteresting commits _only_ if they are
 238                          * already parsed.  No reason to find new ones
 239                          * here.
 240                          */
 241                         parents = c->parents;
 242                         while (parents) {
 243                                 struct commit *p = parents->item;
 244                                 parents = parents->next;
 245                                 if (!(p->object.flags & UNINTERESTING)) {
 246                                         p->object.flags |= UNINTERESTING;
 247                                         changed = 1;
 248                                 }
 249                         }
 250                 }
 251                 if (!changed)
 252                         break;
 253         }
 254 }
 255
 256 static void show_one_commit(struct commit *commit, int no_name)
 257 {
 258         char pretty[256], *cp;
 259         struct commit_name *name = commit->util;
 260         if (commit->object.parsed)
 261                 pretty_print_commit(CMIT_FMT_ONELINE, commit, ~0,
 262                                     pretty, sizeof(pretty), 0, NULL, NULL);
 263         else
 264                 strcpy(pretty, "(unavailable)");
 265         if (!strncmp(pretty, "[PATCH] ", 8))
 266                 cp = pretty + 8;
 267         else
 268                 cp = pretty;
 269
 270         if (!no_name) {
 271                 if (name && name->head_name) {
 272                         printf("[%s", name->head_name);
 273                         if (name->generation) {
 274                                 if (name->generation == 1)
 275                                         printf("^");
 276                                 else
 277                                         printf("~%d", name->generation);
 278                         }
 279                         printf("] ");
 280                 }
 281                 else
 282                         printf("[%s] ",
 283                                find_unique_abbrev(commit->object.sha1, 7));
 284         }
 285         puts(cp);
 286 }
 287
 288 static char *ref_name[MAX_REVS + 1];
 289 static int ref_name_cnt;
 290
 291 static const char *find_digit_prefix(const char *s, int *v)
 292 {
 293         const char *p;
 294         int ver;
 295         char ch;
 296
 297         for (p = s, ver = 0;
 298              '0' <= (ch = *p) && ch <= '9';
 299              p++)
 300                 ver = ver * 10 + ch - '0';
 301         *v = ver;
 302         return p;
 303 }
 304
 305
 306 static int version_cmp(const char *a, const char *b)
 307 {
 308         while (1) {
 309                 int va, vb;
 310
 311                 a = find_digit_prefix(a, &va);
 312                 b = find_digit_prefix(b, &vb);
 313                 if (va != vb)
 314                         return va - vb;
 315
 316                 while (1) {
 317                         int ca = *a;
 318                         int cb = *b;
 319                         if ('0' <= ca && ca <= '9')
 320                                 ca = 0;
 321                         if ('0' <= cb && cb <= '9')
 322                                 cb = 0;
 323                         if (ca != cb)
 324                                 return ca - cb;
 325                         if (!ca)
 326                                 break;
 327                         a++;
 328                         b++;
 329                 }
 330                 if (!*a && !*b)
 331                         return 0;
 332         }
 333 }
 334
 335 static int compare_ref_name(const void *a_, const void *b_)
 336 {
 337         const char * const*a = a_, * const*b = b_;
 338         return version_cmp(*a, *b);
 339 }
 340
 341 static void sort_ref_range(int bottom, int top)
 342 {
 343         qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 344               compare_ref_name);
 345 }
 346
 347 static int append_ref(const char *refname, const unsigned char *sha1)
 348 {
 349         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 350         int i;
 351
 352         if (!commit)
 353                 return 0;
 354         /* Avoid adding the same thing twice */
 355         for (i = 0; i < ref_name_cnt; i++)
 356                 if (!strcmp(refname, ref_name[i]))
 357                         return 0;
 358
 359         if (MAX_REVS <= ref_name_cnt) {
 360                 fprintf(stderr, "warning: ignoring %s; "
 361                         "cannot handle more than %d refs\n",
 362                         refname, MAX_REVS);
 363                 return 0;
 364         }
 365         ref_name[ref_name_cnt++] = strdup(refname);
 366         ref_name[ref_name_cnt] = NULL;
 367         return 0;
 368 }
 369
 370 static int append_head_ref(const char *refname, const unsigned char *sha1)
 371 {
 372         unsigned char tmp[20];
 373         int ofs = 11;
 374         if (strncmp(refname, "refs/heads/", ofs))
 375                 return 0;
 376         /* If both heads/foo and tags/foo exists, get_sha1 would
 377          * get confused.
 378          */
 379         if (get_sha1(refname + ofs, tmp) || memcmp(tmp, sha1, 20))
 380                 ofs = 5;
 381         return append_ref(refname + ofs, sha1);
 382 }
 383
 384 static int append_tag_ref(const char *refname, const unsigned char *sha1)
 385 {
 386         if (strncmp(refname, "refs/tags/", 10))
 387                 return 0;
 388         return append_ref(refname + 5, sha1);
 389 }
 390
 391 static const char *match_ref_pattern = NULL;
 392 static int match_ref_slash = 0;
 393 static int count_slash(const char *s)
 394 {
 395         int cnt = 0;
 396         while (*s)
 397                 if (*s++ == '/')
 398                         cnt++;
 399         return cnt;
 400 }
 401
 402 static int append_matching_ref(const char *refname, const unsigned char *sha1)
 403 {
 404         /* we want to allow pattern hold/<asterisk> to show all
 405          * branches under refs/heads/hold/, and v0.99.9? to show
 406          * refs/tags/v0.99.9a and friends.
 407          */
 408         const char *tail;
 409         int slash = count_slash(refname);
 410         for (tail = refname; *tail && match_ref_slash < slash; )
 411                 if (*tail++ == '/')
 412                         slash--;
 413         if (!*tail)
 414                 return 0;
 415         if (fnmatch(match_ref_pattern, tail, 0))
 416                 return 0;
 417         if (!strncmp("refs/heads/", refname, 11))
 418                 return append_head_ref(refname, sha1);
 419         if (!strncmp("refs/tags/", refname, 10))
 420                 return append_tag_ref(refname, sha1);
 421         return append_ref(refname, sha1);
 422 }
 423
 424 static void snarf_refs(int head, int tag)
 425 {
 426         if (head) {
 427                 int orig_cnt = ref_name_cnt;
 428                 for_each_ref(append_head_ref);
 429                 sort_ref_range(orig_cnt, ref_name_cnt);
 430         }
 431         if (tag) {
 432                 int orig_cnt = ref_name_cnt;
 433                 for_each_ref(append_tag_ref);
 434                 sort_ref_range(orig_cnt, ref_name_cnt);
 435         }
 436 }
 437
 438 static int rev_is_head(char *head_path, int headlen, char *name,
 439                        unsigned char *head_sha1, unsigned char *sha1)
 440 {
 441         int namelen;
 442         if ((!head_path[0]) ||
 443             (head_sha1 && sha1 && memcmp(head_sha1, sha1, 20)))
 444                 return 0;
 445         namelen = strlen(name);
 446         if ((headlen < namelen) ||
 447             memcmp(head_path + headlen - namelen, name, namelen))
 448                 return 0;
 449         if (headlen == namelen ||
 450             head_path[headlen - namelen - 1] == '/')
 451                 return 1;
 452         return 0;
 453 }
 454
 455 static int show_merge_base(struct commit_list *seen, int num_rev)
 456 {
 457         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 458         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 459         int exit_status = 1;
 460
 461         while (seen) {
 462                 struct commit *commit = pop_one_commit(&seen);
 463                 int flags = commit->object.flags & all_mask;
 464                 if (!(flags & UNINTERESTING) &&
 465                     ((flags & all_revs) == all_revs)) {
 466                         puts(sha1_to_hex(commit->object.sha1));
 467                         exit_status = 0;
 468                         commit->object.flags |= UNINTERESTING;
 469                 }
 470         }
 471         return exit_status;
 472 }
 473
 474 static int show_independent(struct commit **rev,
 475                             int num_rev,
 476                             char **ref_name,
 477                             unsigned int *rev_mask)
 478 {
 479         int i;
 480
 481         for (i = 0; i < num_rev; i++) {
 482                 struct commit *commit = rev[i];
 483                 unsigned int flag = rev_mask[i];
 484
 485                 if (commit->object.flags == flag)
 486                         puts(sha1_to_hex(commit->object.sha1));
 487                 commit->object.flags |= UNINTERESTING;
 488         }
 489         return 0;
 490 }
 491
 492 static void append_one_rev(const char *av)
 493 {
 494         unsigned char revkey[20];
 495         if (!get_sha1(av, revkey)) {
 496                 append_ref(av, revkey);
 497                 return;
 498         }
 499         if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
 500                 /* glob style match */
 501                 int saved_matches = ref_name_cnt;
 502                 match_ref_pattern = av;
 503                 match_ref_slash = count_slash(av);
 504                 for_each_ref(append_matching_ref);
 505                 if (saved_matches == ref_name_cnt &&
 506                     ref_name_cnt < MAX_REVS)
 507                         error("no matching refs with %s", av);
 508                 if (saved_matches + 1 < ref_name_cnt)
 509                         sort_ref_range(saved_matches, ref_name_cnt);
 510                 return;
 511         }
 512         die("bad sha1 reference %s", av);
 513 }
 514
 515 static int git_show_branch_config(const char *var, const char *value)
 516 {
 517         if (!strcmp(var, "showbranch.default")) {
 518                 if (default_alloc <= default_num + 1) {
 519                         default_alloc = default_alloc * 3 / 2 + 20;
 520                         default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
 521                 }
 522                 default_arg[default_num++] = strdup(value);
 523                 default_arg[default_num] = NULL;
 524                 return 0;
 525         }
 526
 527         return git_default_config(var, value);
 528 }
 529
 530 static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
 531 {
 532         /* If the commit is tip of the named branches, do not
 533          * omit it.
 534          * Otherwise, if it is a merge that is reachable from only one
 535          * tip, it is not that interesting.
 536          */
 537         int i, flag, count;
 538         for (i = 0; i < n; i++)
 539                 if (rev[i] == commit)
 540                         return 0;
 541         flag = commit->object.flags;
 542         for (i = count = 0; i < n; i++) {
 543                 if (flag & (1u << (i + REV_SHIFT)))
 544                         count++;
 545         }
 546         if (count == 1)
 547                 return 1;
 548         return 0;
 549 }
 550
 551 int cmd_show_branch(int ac, const char **av, char **envp)
 552 {
 553         struct commit *rev[MAX_REVS], *commit;
 554         struct commit_list *list = NULL, *seen = NULL;
 555         unsigned int rev_mask[MAX_REVS];
 556         int num_rev, i, extra = 0;
 557         int all_heads = 0, all_tags = 0;
 558         int all_mask, all_revs;
 559         int lifo = 1;
 560         char head_path[128];
 561         const char *head_path_p;
 562         int head_path_len;
 563         unsigned char head_sha1[20];
 564         int merge_base = 0;
 565         int independent = 0;
 566         int no_name = 0;
 567         int sha1_name = 0;
 568         int shown_merge_point = 0;
 569         int with_current_branch = 0;
 570         int head_at = -1;
 571         int topics = 0;
 572         int dense = 1;
 573
 574         setup_git_directory();
 575         git_config(git_show_branch_config);
 576
 577         /* If nothing is specified, try the default first */
 578         if (ac == 1 && default_num) {
 579                 ac = default_num + 1;
 580                 av = default_arg - 1; /* ick; we would not address av[0] */
 581         }
 582
 583         while (1 < ac && av[1][0] == '-') {
 584                 const char *arg = av[1];
 585                 if (!strcmp(arg, "--")) {
 586                         ac--; av++;
 587                         break;
 588                 }
 589                 else if (!strcmp(arg, "--all"))
 590                         all_heads = all_tags = 1;
 591                 else if (!strcmp(arg, "--heads"))
 592                         all_heads = 1;
 593                 else if (!strcmp(arg, "--tags"))
 594                         all_tags = 1;
 595                 else if (!strcmp(arg, "--more"))
 596                         extra = 1;
 597                 else if (!strcmp(arg, "--list"))
 598                         extra = -1;
 599                 else if (!strcmp(arg, "--no-name"))
 600                         no_name = 1;
 601                 else if (!strcmp(arg, "--current"))
 602                         with_current_branch = 1;
 603                 else if (!strcmp(arg, "--sha1-name"))
 604                         sha1_name = 1;
 605                 else if (!strncmp(arg, "--more=", 7))
 606                         extra = atoi(arg + 7);
 607                 else if (!strcmp(arg, "--merge-base"))
 608                         merge_base = 1;
 609                 else if (!strcmp(arg, "--independent"))
 610                         independent = 1;
 611                 else if (!strcmp(arg, "--topo-order"))
 612                         lifo = 1;
 613                 else if (!strcmp(arg, "--topics"))
 614                         topics = 1;
 615                 else if (!strcmp(arg, "--sparse"))
 616                         dense = 0;
 617                 else if (!strcmp(arg, "--date-order"))
 618                         lifo = 0;
 619                 else
 620                         usage(show_branch_usage);
 621                 ac--; av++;
 622         }
 623         ac--; av++;
 624
 625         /* Only one of these is allowed */
 626         if (1 < independent + merge_base + (extra != 0))
 627                 usage(show_branch_usage);
 628
 629         /* If nothing is specified, show all branches by default */
 630         if (ac + all_heads + all_tags == 0)
 631                 all_heads = 1;
 632
 633         if (all_heads + all_tags)
 634                 snarf_refs(all_heads, all_tags);
 635         while (0 < ac) {
 636                 append_one_rev(*av);
 637                 ac--; av++;
 638         }
 639
 640         head_path_p = resolve_ref(git_path("HEAD"), head_sha1, 1);
 641         if (head_path_p) {
 642                 head_path_len = strlen(head_path_p);
 643                 memcpy(head_path, head_path_p, head_path_len + 1);
 644         }
 645         else {
 646                 head_path_len = 0;
 647                 head_path[0] = 0;
 648         }
 649
 650         if (with_current_branch && head_path_p) {
 651                 int has_head = 0;
 652                 for (i = 0; !has_head && i < ref_name_cnt; i++) {
 653                         /* We are only interested in adding the branch
 654                          * HEAD points at.
 655                          */
 656                         if (rev_is_head(head_path,
 657                                         head_path_len,
 658                                         ref_name[i],
 659                                         head_sha1, NULL))
 660                                 has_head++;
 661                 }
 662                 if (!has_head) {
 663                         int pfxlen = strlen(git_path("refs/heads/"));
 664                         append_one_rev(head_path + pfxlen);
 665                 }
 666         }
 667
 668         if (!ref_name_cnt) {
 669                 fprintf(stderr, "No revs to be shown.\n");
 670                 exit(0);
 671         }
 672
 673         for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 674                 unsigned char revkey[20];
 675                 unsigned int flag = 1u << (num_rev + REV_SHIFT);
 676
 677                 if (MAX_REVS <= num_rev)
 678                         die("cannot handle more than %d revs.", MAX_REVS);
 679                 if (get_sha1(ref_name[num_rev], revkey))
 680                         die("'%s' is not a valid ref.", ref_name[num_rev]);
 681                 commit = lookup_commit_reference(revkey);
 682                 if (!commit)
 683                         die("cannot find commit %s (%s)",
 684                             ref_name[num_rev], revkey);
 685                 parse_commit(commit);
 686                 mark_seen(commit, &seen);
 687
 688                 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 689                  * and so on.  REV_SHIFT bits from bit 0 are used for
 690                  * internal bookkeeping.
 691                  */
 692                 commit->object.flags |= flag;
 693                 if (commit->object.flags == flag)
 694                         insert_by_date(commit, &list);
 695                 rev[num_rev] = commit;
 696         }
 697         for (i = 0; i < num_rev; i++)
 698                 rev_mask[i] = rev[i]->object.flags;
 699
 700         if (0 <= extra)
 701                 join_revs(&list, &seen, num_rev, extra);
 702
 703         sort_by_date(&seen);
 704
 705         if (merge_base)
 706                 return show_merge_base(seen, num_rev);
 707
 708         if (independent)
 709                 return show_independent(rev, num_rev, ref_name, rev_mask);
 710
 711         /* Show list; --more=-1 means list-only */
 712         if (1 < num_rev || extra < 0) {
 713                 for (i = 0; i < num_rev; i++) {
 714                         int j;
 715                         int is_head = rev_is_head(head_path,
 716                                                   head_path_len,
 717                                                   ref_name[i],
 718                                                   head_sha1,
 719                                                   rev[i]->object.sha1);
 720                         if (extra < 0)
 721                                 printf("%c [%s] ",
 722                                        is_head ? '*' : ' ', ref_name[i]);
 723                         else {
 724                                 for (j = 0; j < i; j++)
 725                                         putchar(' ');
 726                                 printf("%c [%s] ",
 727                                        is_head ? '*' : '!', ref_name[i]);
 728                         }
 729                         /* header lines never need name */
 730                         show_one_commit(rev[i], 1);
 731                         if (is_head)
 732                                 head_at = i;
 733                 }
 734                 if (0 <= extra) {
 735                         for (i = 0; i < num_rev; i++)
 736                                 putchar('-');
 737                         putchar('\n');
 738                 }
 739         }
 740         if (extra < 0)
 741                 exit(0);
 742
 743         /* Sort topologically */
 744         sort_in_topological_order(&seen, lifo);
 745
 746         /* Give names to commits */
 747         if (!sha1_name && !no_name)
 748                 name_commits(seen, rev, ref_name, num_rev);
 749
 750         all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 751         all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 752
 753         while (seen) {
 754                 struct commit *commit = pop_one_commit(&seen);
 755                 int this_flag = commit->object.flags;
 756                 int is_merge_point = ((this_flag & all_revs) == all_revs);
 757
 758                 shown_merge_point |= is_merge_point;
 759
 760                 if (1 < num_rev) {
 761                         int is_merge = !!(commit->parents &&
 762                                           commit->parents->next);
 763                         if (topics &&
 764                             !is_merge_point &&
 765                             (this_flag & (1u << REV_SHIFT)))
 766                                 continue;
 767                         if (dense && is_merge &&
 768                             omit_in_dense(commit, rev, num_rev))
 769                                 continue;
 770                         for (i = 0; i < num_rev; i++) {
 771                                 int mark;
 772                                 if (!(this_flag & (1u << (i + REV_SHIFT))))
 773                                         mark = ' ';
 774                                 else if (is_merge)
 775                                         mark = '-';
 776                                 else if (i == head_at)
 777                                         mark = '*';
 778                                 else
 779                                         mark = '+';
 780                                 putchar(mark);
 781                         }
 782                         putchar(' ');
 783                 }
 784                 show_one_commit(commit, no_name);
 785
 786                 if (shown_merge_point && --extra < 0)
 787                         break;
 788         }
 789         return 0;
 790 }