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;
  12 static int default_alloc;
  13 static const char **default_arg;
  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                 else
  93                         break;
  94                 c = p;
  95         }
  96         return i;
  97 }
  98
  99 static void name_commits(struct commit_list *list,
 100                          struct commit **rev,
 101                          char **ref_name,
 102                          int num_rev)
 103 {
 104         struct commit_list *cl;
 105         struct commit *c;
 106         int i;
 107
 108         /* First give names to the given heads */
 109         for (cl = list; cl; cl = cl->next) {
 110                 c = cl->item;
 111                 if (c->util)
 112                         continue;
 113                 for (i = 0; i < num_rev; i++) {
 114                         if (rev[i] == c) {
 115                                 name_commit(c, ref_name[i], 0);
 116                                 break;
 117                         }
 118                 }
 119         }
 120
 121         /* Then commits on the first parent ancestry chain */
 122         do {
 123                 i = 0;
 124                 for (cl = list; cl; cl = cl->next) {
 125                         i += name_first_parent_chain(cl->item);
 126                 }
 127         } while (i);
 128
 129         /* Finally, any unnamed commits */
 130         do {
 131                 i = 0;
 132                 for (cl = list; cl; cl = cl->next) {
 133                         struct commit_list *parents;
 134                         struct commit_name *n;
 135                         int nth;
 136                         c = cl->item;
 137                         if (!c->util)
 138                                 continue;
 139                         n = c->util;
 140                         parents = c->parents;
 141                         nth = 0;
 142                         while (parents) {
 143                                 struct commit *p = parents->item;
 144                                 char newname[1000], *en;
 145                                 parents = parents->next;
 146                                 nth++;
 147                                 if (p->util)
 148                                         continue;
 149                                 en = newname;
 150                                 switch (n->generation) {
 151                                 case 0:
 152                                         en += sprintf(en, "%s", n->head_name);
 153                                         break;
 154                                 case 1:
 155                                         en += sprintf(en, "%s^", n->head_name);
 156                                         break;
 157                                 default:
 158                                         en += sprintf(en, "%s~%d",
 159                                                 n->head_name, n->generation);
 160                                         break;
 161                                 }
 162                                 if (nth == 1)
 163                                         en += sprintf(en, "^");
 164                                 else
 165                                         en += sprintf(en, "^%d", nth);
 166                                 name_commit(p, strdup(newname), 0);
 167                                 i++;
 168                                 name_first_parent_chain(p);
 169                         }
 170                 }
 171         } while (i);
 172 }
 173
 174 static int mark_seen(struct commit *commit, struct commit_list **seen_p)
 175 {
 176         if (!commit->object.flags) {
 177                 commit_list_insert(commit, seen_p);
 178                 return 1;
 179         }
 180         return 0;
 181 }
 182
 183 static void join_revs(struct commit_list **list_p,
 184                       struct commit_list **seen_p,
 185                       int num_rev, int extra)
 186 {
 187         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 188         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 189
 190         while (*list_p) {
 191                 struct commit_list *parents;
 192                 int still_interesting = !!interesting(*list_p);
 193                 struct commit *commit = pop_one_commit(list_p);
 194                 int flags = commit->object.flags & all_mask;
 195
 196                 if (!still_interesting && extra <= 0)
 197                         break;
 198
 199                 mark_seen(commit, seen_p);
 200                 if ((flags & all_revs) == all_revs)
 201                         flags |= UNINTERESTING;
 202                 parents = commit->parents;
 203
 204                 while (parents) {
 205                         struct commit *p = parents->item;
 206                         int this_flag = p->object.flags;
 207                         parents = parents->next;
 208                         if ((this_flag & flags) == flags)
 209                                 continue;
 210                         if (!p->object.parsed)
 211                                 parse_commit(p);
 212                         if (mark_seen(p, seen_p) && !still_interesting)
 213                                 extra--;
 214                         p->object.flags |= flags;
 215                         insert_by_date(p, list_p);
 216                 }
 217         }
 218
 219         /*
 220          * Postprocess to complete well-poisoning.
 221          *
 222          * At this point we have all the commits we have seen in
 223          * seen_p list.  Mark anything that can be reached from
 224          * uninteresting commits not interesting.
 225          */
 226         for (;;) {
 227                 int changed = 0;
 228                 struct commit_list *s;
 229                 for (s = *seen_p; s; s = s->next) {
 230                         struct commit *c = s->item;
 231                         struct commit_list *parents;
 232
 233                         if (((c->object.flags & all_revs) != all_revs) &&
 234                             !(c->object.flags & UNINTERESTING))
 235                                 continue;
 236
 237                         /* The current commit is either a merge base or
 238                          * already uninteresting one.  Mark its parents
 239                          * as uninteresting commits _only_ if they are
 240                          * already parsed.  No reason to find new ones
 241                          * here.
 242                          */
 243                         parents = c->parents;
 244                         while (parents) {
 245                                 struct commit *p = parents->item;
 246                                 parents = parents->next;
 247                                 if (!(p->object.flags & UNINTERESTING)) {
 248                                         p->object.flags |= UNINTERESTING;
 249                                         changed = 1;
 250                                 }
 251                         }
 252                 }
 253                 if (!changed)
 254                         break;
 255         }
 256 }
 257
 258 static void show_one_commit(struct commit *commit, int no_name)
 259 {
 260         char pretty[256], *cp;
 261         struct commit_name *name = commit->util;
 262         if (commit->object.parsed)
 263                 pretty_print_commit(CMIT_FMT_ONELINE, commit, ~0,
 264                                     pretty, sizeof(pretty), 0, NULL, NULL);
 265         else
 266                 strcpy(pretty, "(unavailable)");
 267         if (!strncmp(pretty, "[PATCH] ", 8))
 268                 cp = pretty + 8;
 269         else
 270                 cp = pretty;
 271
 272         if (!no_name) {
 273                 if (name && name->head_name) {
 274                         printf("[%s", name->head_name);
 275                         if (name->generation) {
 276                                 if (name->generation == 1)
 277                                         printf("^");
 278                                 else
 279                                         printf("~%d", name->generation);
 280                         }
 281                         printf("] ");
 282                 }
 283                 else
 284                         printf("[%s] ",
 285                                find_unique_abbrev(commit->object.sha1, 7));
 286         }
 287         puts(cp);
 288 }
 289
 290 static char *ref_name[MAX_REVS + 1];
 291 static int ref_name_cnt;
 292
 293 static const char *find_digit_prefix(const char *s, int *v)
 294 {
 295         const char *p;
 296         int ver;
 297         char ch;
 298
 299         for (p = s, ver = 0;
 300              '0' <= (ch = *p) && ch <= '9';
 301              p++)
 302                 ver = ver * 10 + ch - '0';
 303         *v = ver;
 304         return p;
 305 }
 306
 307
 308 static int version_cmp(const char *a, const char *b)
 309 {
 310         while (1) {
 311                 int va, vb;
 312
 313                 a = find_digit_prefix(a, &va);
 314                 b = find_digit_prefix(b, &vb);
 315                 if (va != vb)
 316                         return va - vb;
 317
 318                 while (1) {
 319                         int ca = *a;
 320                         int cb = *b;
 321                         if ('0' <= ca && ca <= '9')
 322                                 ca = 0;
 323                         if ('0' <= cb && cb <= '9')
 324                                 cb = 0;
 325                         if (ca != cb)
 326                                 return ca - cb;
 327                         if (!ca)
 328                                 break;
 329                         a++;
 330                         b++;
 331                 }
 332                 if (!*a && !*b)
 333                         return 0;
 334         }
 335 }
 336
 337 static int compare_ref_name(const void *a_, const void *b_)
 338 {
 339         const char * const*a = a_, * const*b = b_;
 340         return version_cmp(*a, *b);
 341 }
 342
 343 static void sort_ref_range(int bottom, int top)
 344 {
 345         qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 346               compare_ref_name);
 347 }
 348
 349 static int append_ref(const char *refname, const unsigned char *sha1)
 350 {
 351         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 352         int i;
 353
 354         if (!commit)
 355                 return 0;
 356         /* Avoid adding the same thing twice */
 357         for (i = 0; i < ref_name_cnt; i++)
 358                 if (!strcmp(refname, ref_name[i]))
 359                         return 0;
 360
 361         if (MAX_REVS <= ref_name_cnt) {
 362                 fprintf(stderr, "warning: ignoring %s; "
 363                         "cannot handle more than %d refs\n",
 364                         refname, MAX_REVS);
 365                 return 0;
 366         }
 367         ref_name[ref_name_cnt++] = strdup(refname);
 368         ref_name[ref_name_cnt] = NULL;
 369         return 0;
 370 }
 371
 372 static int append_head_ref(const char *refname, const unsigned char *sha1)
 373 {
 374         unsigned char tmp[20];
 375         int ofs = 11;
 376         if (strncmp(refname, "refs/heads/", ofs))
 377                 return 0;
 378         /* If both heads/foo and tags/foo exists, get_sha1 would
 379          * get confused.
 380          */
 381         if (get_sha1(refname + ofs, tmp) || memcmp(tmp, sha1, 20))
 382                 ofs = 5;
 383         return append_ref(refname + ofs, sha1);
 384 }
 385
 386 static int append_tag_ref(const char *refname, const unsigned char *sha1)
 387 {
 388         if (strncmp(refname, "refs/tags/", 10))
 389                 return 0;
 390         return append_ref(refname + 5, sha1);
 391 }
 392
 393 static const char *match_ref_pattern = NULL;
 394 static int match_ref_slash = 0;
 395 static int count_slash(const char *s)
 396 {
 397         int cnt = 0;
 398         while (*s)
 399                 if (*s++ == '/')
 400                         cnt++;
 401         return cnt;
 402 }
 403
 404 static int append_matching_ref(const char *refname, const unsigned char *sha1)
 405 {
 406         /* we want to allow pattern hold/<asterisk> to show all
 407          * branches under refs/heads/hold/, and v0.99.9? to show
 408          * refs/tags/v0.99.9a and friends.
 409          */
 410         const char *tail;
 411         int slash = count_slash(refname);
 412         for (tail = refname; *tail && match_ref_slash < slash; )
 413                 if (*tail++ == '/')
 414                         slash--;
 415         if (!*tail)
 416                 return 0;
 417         if (fnmatch(match_ref_pattern, tail, 0))
 418                 return 0;
 419         if (!strncmp("refs/heads/", refname, 11))
 420                 return append_head_ref(refname, sha1);
 421         if (!strncmp("refs/tags/", refname, 10))
 422                 return append_tag_ref(refname, sha1);
 423         return append_ref(refname, sha1);
 424 }
 425
 426 static void snarf_refs(int head, int tag)
 427 {
 428         if (head) {
 429                 int orig_cnt = ref_name_cnt;
 430                 for_each_ref(append_head_ref);
 431                 sort_ref_range(orig_cnt, ref_name_cnt);
 432         }
 433         if (tag) {
 434                 int orig_cnt = ref_name_cnt;
 435                 for_each_ref(append_tag_ref);
 436                 sort_ref_range(orig_cnt, ref_name_cnt);
 437         }
 438 }
 439
 440 static int rev_is_head(char *head_path, int headlen, char *name,
 441                        unsigned char *head_sha1, unsigned char *sha1)
 442 {
 443         int namelen;
 444         if ((!head_path[0]) ||
 445             (head_sha1 && sha1 && memcmp(head_sha1, sha1, 20)))
 446                 return 0;
 447         namelen = strlen(name);
 448         if ((headlen < namelen) ||
 449             memcmp(head_path + headlen - namelen, name, namelen))
 450                 return 0;
 451         if (headlen == namelen ||
 452             head_path[headlen - namelen - 1] == '/')
 453                 return 1;
 454         return 0;
 455 }
 456
 457 static int show_merge_base(struct commit_list *seen, int num_rev)
 458 {
 459         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 460         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 461         int exit_status = 1;
 462
 463         while (seen) {
 464                 struct commit *commit = pop_one_commit(&seen);
 465                 int flags = commit->object.flags & all_mask;
 466                 if (!(flags & UNINTERESTING) &&
 467                     ((flags & all_revs) == all_revs)) {
 468                         puts(sha1_to_hex(commit->object.sha1));
 469                         exit_status = 0;
 470                         commit->object.flags |= UNINTERESTING;
 471                 }
 472         }
 473         return exit_status;
 474 }
 475
 476 static int show_independent(struct commit **rev,
 477                             int num_rev,
 478                             char **ref_name,
 479                             unsigned int *rev_mask)
 480 {
 481         int i;
 482
 483         for (i = 0; i < num_rev; i++) {
 484                 struct commit *commit = rev[i];
 485                 unsigned int flag = rev_mask[i];
 486
 487                 if (commit->object.flags == flag)
 488                         puts(sha1_to_hex(commit->object.sha1));
 489                 commit->object.flags |= UNINTERESTING;
 490         }
 491         return 0;
 492 }
 493
 494 static void append_one_rev(const char *av)
 495 {
 496         unsigned char revkey[20];
 497         if (!get_sha1(av, revkey)) {
 498                 append_ref(av, revkey);
 499                 return;
 500         }
 501         if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
 502                 /* glob style match */
 503                 int saved_matches = ref_name_cnt;
 504                 match_ref_pattern = av;
 505                 match_ref_slash = count_slash(av);
 506                 for_each_ref(append_matching_ref);
 507                 if (saved_matches == ref_name_cnt &&
 508                     ref_name_cnt < MAX_REVS)
 509                         error("no matching refs with %s", av);
 510                 if (saved_matches + 1 < ref_name_cnt)
 511                         sort_ref_range(saved_matches, ref_name_cnt);
 512                 return;
 513         }
 514         die("bad sha1 reference %s", av);
 515 }
 516
 517 static int git_show_branch_config(const char *var, const char *value)
 518 {
 519         if (!strcmp(var, "showbranch.default")) {
 520                 if (default_alloc <= default_num + 1) {
 521                         default_alloc = default_alloc * 3 / 2 + 20;
 522                         default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
 523                 }
 524                 default_arg[default_num++] = strdup(value);
 525                 default_arg[default_num] = NULL;
 526                 return 0;
 527         }
 528
 529         return git_default_config(var, value);
 530 }
 531
 532 static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
 533 {
 534         /* If the commit is tip of the named branches, do not
 535          * omit it.
 536          * Otherwise, if it is a merge that is reachable from only one
 537          * tip, it is not that interesting.
 538          */
 539         int i, flag, count;
 540         for (i = 0; i < n; i++)
 541                 if (rev[i] == commit)
 542                         return 0;
 543         flag = commit->object.flags;
 544         for (i = count = 0; i < n; i++) {
 545                 if (flag & (1u << (i + REV_SHIFT)))
 546                         count++;
 547         }
 548         if (count == 1)
 549                 return 1;
 550         return 0;
 551 }
 552
 553 int cmd_show_branch(int ac, const char **av, const char *prefix)
 554 {
 555         struct commit *rev[MAX_REVS], *commit;
 556         struct commit_list *list = NULL, *seen = NULL;
 557         unsigned int rev_mask[MAX_REVS];
 558         int num_rev, i, extra = 0;
 559         int all_heads = 0, all_tags = 0;
 560         int all_mask, all_revs;
 561         int lifo = 1;
 562         char head_path[128];
 563         const char *head_path_p;
 564         int head_path_len;
 565         unsigned char head_sha1[20];
 566         int merge_base = 0;
 567         int independent = 0;
 568         int no_name = 0;
 569         int sha1_name = 0;
 570         int shown_merge_point = 0;
 571         int with_current_branch = 0;
 572         int head_at = -1;
 573         int topics = 0;
 574         int dense = 1;
 575
 576         git_config(git_show_branch_config);
 577
 578         /* If nothing is specified, try the default first */
 579         if (ac == 1 && default_num) {
 580                 ac = default_num + 1;
 581                 av = default_arg - 1; /* ick; we would not address av[0] */
 582         }
 583
 584         while (1 < ac && av[1][0] == '-') {
 585                 const char *arg = av[1];
 586                 if (!strcmp(arg, "--")) {
 587                         ac--; av++;
 588                         break;
 589                 }
 590                 else if (!strcmp(arg, "--all"))
 591                         all_heads = all_tags = 1;
 592                 else if (!strcmp(arg, "--heads"))
 593                         all_heads = 1;
 594                 else if (!strcmp(arg, "--tags"))
 595                         all_tags = 1;
 596                 else if (!strcmp(arg, "--more"))
 597                         extra = 1;
 598                 else if (!strcmp(arg, "--list"))
 599                         extra = -1;
 600                 else if (!strcmp(arg, "--no-name"))
 601                         no_name = 1;
 602                 else if (!strcmp(arg, "--current"))
 603                         with_current_branch = 1;
 604                 else if (!strcmp(arg, "--sha1-name"))
 605                         sha1_name = 1;
 606                 else if (!strncmp(arg, "--more=", 7))
 607                         extra = atoi(arg + 7);
 608                 else if (!strcmp(arg, "--merge-base"))
 609                         merge_base = 1;
 610                 else if (!strcmp(arg, "--independent"))
 611                         independent = 1;
 612                 else if (!strcmp(arg, "--topo-order"))
 613                         lifo = 1;
 614                 else if (!strcmp(arg, "--topics"))
 615                         topics = 1;
 616                 else if (!strcmp(arg, "--sparse"))
 617                         dense = 0;
 618                 else if (!strcmp(arg, "--date-order"))
 619                         lifo = 0;
 620                 else
 621                         usage(show_branch_usage);
 622                 ac--; av++;
 623         }
 624         ac--; av++;
 625
 626         /* Only one of these is allowed */
 627         if (1 < independent + merge_base + (extra != 0))
 628                 usage(show_branch_usage);
 629
 630         /* If nothing is specified, show all branches by default */
 631         if (ac + all_heads + all_tags == 0)
 632                 all_heads = 1;
 633
 634         if (all_heads + all_tags)
 635                 snarf_refs(all_heads, all_tags);
 636         while (0 < ac) {
 637                 append_one_rev(*av);
 638                 ac--; av++;
 639         }
 640
 641         head_path_p = resolve_ref(git_path("HEAD"), head_sha1, 1);
 642         if (head_path_p) {
 643                 head_path_len = strlen(head_path_p);
 644                 memcpy(head_path, head_path_p, head_path_len + 1);
 645         }
 646         else {
 647                 head_path_len = 0;
 648                 head_path[0] = 0;
 649         }
 650
 651         if (with_current_branch && head_path_p) {
 652                 int has_head = 0;
 653                 for (i = 0; !has_head && i < ref_name_cnt; i++) {
 654                         /* We are only interested in adding the branch
 655                          * HEAD points at.
 656                          */
 657                         if (rev_is_head(head_path,
 658                                         head_path_len,
 659                                         ref_name[i],
 660                                         head_sha1, NULL))
 661                                 has_head++;
 662                 }
 663                 if (!has_head) {
 664                         int pfxlen = strlen(git_path("refs/heads/"));
 665                         append_one_rev(head_path + pfxlen);
 666                 }
 667         }
 668
 669         if (!ref_name_cnt) {
 670                 fprintf(stderr, "No revs to be shown.\n");
 671                 exit(0);
 672         }
 673
 674         for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 675                 unsigned char revkey[20];
 676                 unsigned int flag = 1u << (num_rev + REV_SHIFT);
 677
 678                 if (MAX_REVS <= num_rev)
 679                         die("cannot handle more than %d revs.", MAX_REVS);
 680                 if (get_sha1(ref_name[num_rev], revkey))
 681                         die("'%s' is not a valid ref.", ref_name[num_rev]);
 682                 commit = lookup_commit_reference(revkey);
 683                 if (!commit)
 684                         die("cannot find commit %s (%s)",
 685                             ref_name[num_rev], revkey);
 686                 parse_commit(commit);
 687                 mark_seen(commit, &seen);
 688
 689                 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 690                  * and so on.  REV_SHIFT bits from bit 0 are used for
 691                  * internal bookkeeping.
 692                  */
 693                 commit->object.flags |= flag;
 694                 if (commit->object.flags == flag)
 695                         insert_by_date(commit, &list);
 696                 rev[num_rev] = commit;
 697         }
 698         for (i = 0; i < num_rev; i++)
 699                 rev_mask[i] = rev[i]->object.flags;
 700
 701         if (0 <= extra)
 702                 join_revs(&list, &seen, num_rev, extra);
 703
 704         sort_by_date(&seen);
 705
 706         if (merge_base)
 707                 return show_merge_base(seen, num_rev);
 708
 709         if (independent)
 710                 return show_independent(rev, num_rev, ref_name, rev_mask);
 711
 712         /* Show list; --more=-1 means list-only */
 713         if (1 < num_rev || extra < 0) {
 714                 for (i = 0; i < num_rev; i++) {
 715                         int j;
 716                         int is_head = rev_is_head(head_path,
 717                                                   head_path_len,
 718                                                   ref_name[i],
 719                                                   head_sha1,
 720                                                   rev[i]->object.sha1);
 721                         if (extra < 0)
 722                                 printf("%c [%s] ",
 723                                        is_head ? '*' : ' ', ref_name[i]);
 724                         else {
 725                                 for (j = 0; j < i; j++)
 726                                         putchar(' ');
 727                                 printf("%c [%s] ",
 728                                        is_head ? '*' : '!', ref_name[i]);
 729                         }
 730                         /* header lines never need name */
 731                         show_one_commit(rev[i], 1);
 732                         if (is_head)
 733                                 head_at = i;
 734                 }
 735                 if (0 <= extra) {
 736                         for (i = 0; i < num_rev; i++)
 737                                 putchar('-');
 738                         putchar('\n');
 739                 }
 740         }
 741         if (extra < 0)
 742                 exit(0);
 743
 744         /* Sort topologically */
 745         sort_in_topological_order(&seen, lifo);
 746
 747         /* Give names to commits */
 748         if (!sha1_name && !no_name)
 749                 name_commits(seen, rev, ref_name, num_rev);
 750
 751         all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 752         all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 753
 754         while (seen) {
 755                 struct commit *commit = pop_one_commit(&seen);
 756                 int this_flag = commit->object.flags;
 757                 int is_merge_point = ((this_flag & all_revs) == all_revs);
 758
 759                 shown_merge_point |= is_merge_point;
 760
 761                 if (1 < num_rev) {
 762                         int is_merge = !!(commit->parents &&
 763                                           commit->parents->next);
 764                         if (topics &&
 765                             !is_merge_point &&
 766                             (this_flag & (1u << REV_SHIFT)))
 767                                 continue;
 768                         if (dense && is_merge &&
 769                             omit_in_dense(commit, rev, num_rev))
 770                                 continue;
 771                         for (i = 0; i < num_rev; i++) {
 772                                 int mark;
 773                                 if (!(this_flag & (1u << (i + REV_SHIFT))))
 774                                         mark = ' ';
 775                                 else if (is_merge)
 776                                         mark = '-';
 777                                 else if (i == head_at)
 778                                         mark = '*';
 779                                 else
 780                                         mark = '+';
 781                                 putchar(mark);
 782                         }
 783                         putchar(' ');
 784                 }
 785                 show_one_commit(commit, no_name);
 786
 787                 if (shown_merge_point && --extra < 0)
 788                         break;
 789         }
 790         return 0;
 791 }