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, xstrdup(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, 0);
 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, int flag, void *cb_data)
 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++] = xstrdup(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, int flag, void *cb_data)
 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) || hashcmp(tmp, sha1))
 382                 ofs = 5;
 383         return append_ref(refname + ofs, sha1, flag, cb_data);
 384 }
 385
 386 static int append_tag_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 387 {
 388         if (strncmp(refname, "refs/tags/", 10))
 389                 return 0;
 390         return append_ref(refname + 5, sha1, flag, cb_data);
 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, int flag, void *cb_data)
 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, flag, cb_data);
 421         if (!strncmp("refs/tags/", refname, 10))
 422                 return append_tag_ref(refname, sha1, flag, cb_data);
 423         return append_ref(refname, sha1, flag, cb_data);
 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, NULL);
 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, NULL);
 436                 sort_ref_range(orig_cnt, ref_name_cnt);
 437         }
 438 }
 439
 440 static int rev_is_head(char *head, int headlen, char *name,
 441                        unsigned char *head_sha1, unsigned char *sha1)
 442 {
 443         if ((!head[0]) ||
 444             (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
 445                 return 0;
 446         if (!strncmp(head, "refs/heads/", 11))
 447                 head += 11;
 448         if (!strncmp(name, "refs/heads/", 11))
 449                 name += 11;
 450         else if (!strncmp(name, "heads/", 6))
 451                 name += 6;
 452         return !strcmp(head, name);
 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, 0, NULL);
 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, NULL);
 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++] = xstrdup(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, const char *prefix)
 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[128];
 561         const char *head_p;
 562         int head_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         git_config(git_show_branch_config);
 575
 576         /* If nothing is specified, try the default first */
 577         if (ac == 1 && default_num) {
 578                 ac = default_num + 1;
 579                 av = default_arg - 1; /* ick; we would not address av[0] */
 580         }
 581
 582         while (1 < ac && av[1][0] == '-') {
 583                 const char *arg = av[1];
 584                 if (!strcmp(arg, "--")) {
 585                         ac--; av++;
 586                         break;
 587                 }
 588                 else if (!strcmp(arg, "--all"))
 589                         all_heads = all_tags = 1;
 590                 else if (!strcmp(arg, "--heads"))
 591                         all_heads = 1;
 592                 else if (!strcmp(arg, "--tags"))
 593                         all_tags = 1;
 594                 else if (!strcmp(arg, "--more"))
 595                         extra = 1;
 596                 else if (!strcmp(arg, "--list"))
 597                         extra = -1;
 598                 else if (!strcmp(arg, "--no-name"))
 599                         no_name = 1;
 600                 else if (!strcmp(arg, "--current"))
 601                         with_current_branch = 1;
 602                 else if (!strcmp(arg, "--sha1-name"))
 603                         sha1_name = 1;
 604                 else if (!strncmp(arg, "--more=", 7))
 605                         extra = atoi(arg + 7);
 606                 else if (!strcmp(arg, "--merge-base"))
 607                         merge_base = 1;
 608                 else if (!strcmp(arg, "--independent"))
 609                         independent = 1;
 610                 else if (!strcmp(arg, "--topo-order"))
 611                         lifo = 1;
 612                 else if (!strcmp(arg, "--topics"))
 613                         topics = 1;
 614                 else if (!strcmp(arg, "--sparse"))
 615                         dense = 0;
 616                 else if (!strcmp(arg, "--date-order"))
 617                         lifo = 0;
 618                 else
 619                         usage(show_branch_usage);
 620                 ac--; av++;
 621         }
 622         ac--; av++;
 623
 624         /* Only one of these is allowed */
 625         if (1 < independent + merge_base + (extra != 0))
 626                 usage(show_branch_usage);
 627
 628         /* If nothing is specified, show all branches by default */
 629         if (ac + all_heads + all_tags == 0)
 630                 all_heads = 1;
 631
 632         if (all_heads + all_tags)
 633                 snarf_refs(all_heads, all_tags);
 634         while (0 < ac) {
 635                 append_one_rev(*av);
 636                 ac--; av++;
 637         }
 638
 639         head_p = resolve_ref("HEAD", head_sha1, 1, NULL);
 640         if (head_p) {
 641                 head_len = strlen(head_p);
 642                 memcpy(head, head_p, head_len + 1);
 643         }
 644         else {
 645                 head_len = 0;
 646                 head[0] = 0;
 647         }
 648
 649         if (with_current_branch && head_p) {
 650                 int has_head = 0;
 651                 for (i = 0; !has_head && i < ref_name_cnt; i++) {
 652                         /* We are only interested in adding the branch
 653                          * HEAD points at.
 654                          */
 655                         if (rev_is_head(head,
 656                                         head_len,
 657                                         ref_name[i],
 658                                         head_sha1, NULL))
 659                                 has_head++;
 660                 }
 661                 if (!has_head) {
 662                         int pfxlen = strlen("refs/heads/");
 663                         append_one_rev(head + pfxlen);
 664                 }
 665         }
 666
 667         if (!ref_name_cnt) {
 668                 fprintf(stderr, "No revs to be shown.\n");
 669                 exit(0);
 670         }
 671
 672         for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 673                 unsigned char revkey[20];
 674                 unsigned int flag = 1u << (num_rev + REV_SHIFT);
 675
 676                 if (MAX_REVS <= num_rev)
 677                         die("cannot handle more than %d revs.", MAX_REVS);
 678                 if (get_sha1(ref_name[num_rev], revkey))
 679                         die("'%s' is not a valid ref.", ref_name[num_rev]);
 680                 commit = lookup_commit_reference(revkey);
 681                 if (!commit)
 682                         die("cannot find commit %s (%s)",
 683                             ref_name[num_rev], revkey);
 684                 parse_commit(commit);
 685                 mark_seen(commit, &seen);
 686
 687                 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 688                  * and so on.  REV_SHIFT bits from bit 0 are used for
 689                  * internal bookkeeping.
 690                  */
 691                 commit->object.flags |= flag;
 692                 if (commit->object.flags == flag)
 693                         insert_by_date(commit, &list);
 694                 rev[num_rev] = commit;
 695         }
 696         for (i = 0; i < num_rev; i++)
 697                 rev_mask[i] = rev[i]->object.flags;
 698
 699         if (0 <= extra)
 700                 join_revs(&list, &seen, num_rev, extra);
 701
 702         sort_by_date(&seen);
 703
 704         if (merge_base)
 705                 return show_merge_base(seen, num_rev);
 706
 707         if (independent)
 708                 return show_independent(rev, num_rev, ref_name, rev_mask);
 709
 710         /* Show list; --more=-1 means list-only */
 711         if (1 < num_rev || extra < 0) {
 712                 for (i = 0; i < num_rev; i++) {
 713                         int j;
 714                         int is_head = rev_is_head(head,
 715                                                   head_len,
 716                                                   ref_name[i],
 717                                                   head_sha1,
 718                                                   rev[i]->object.sha1);
 719                         if (extra < 0)
 720                                 printf("%c [%s] ",
 721                                        is_head ? '*' : ' ', ref_name[i]);
 722                         else {
 723                                 for (j = 0; j < i; j++)
 724                                         putchar(' ');
 725                                 printf("%c [%s] ",
 726                                        is_head ? '*' : '!', ref_name[i]);
 727                         }
 728                         /* header lines never need name */
 729                         show_one_commit(rev[i], 1);
 730                         if (is_head)
 731                                 head_at = i;
 732                 }
 733                 if (0 <= extra) {
 734                         for (i = 0; i < num_rev; i++)
 735                                 putchar('-');
 736                         putchar('\n');
 737                 }
 738         }
 739         if (extra < 0)
 740                 exit(0);
 741
 742         /* Sort topologically */
 743         sort_in_topological_order(&seen, lifo);
 744
 745         /* Give names to commits */
 746         if (!sha1_name && !no_name)
 747                 name_commits(seen, rev, ref_name, num_rev);
 748
 749         all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 750         all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 751
 752         while (seen) {
 753                 struct commit *commit = pop_one_commit(&seen);
 754                 int this_flag = commit->object.flags;
 755                 int is_merge_point = ((this_flag & all_revs) == all_revs);
 756
 757                 shown_merge_point |= is_merge_point;
 758
 759                 if (1 < num_rev) {
 760                         int is_merge = !!(commit->parents &&
 761                                           commit->parents->next);
 762                         if (topics &&
 763                             !is_merge_point &&
 764                             (this_flag & (1u << REV_SHIFT)))
 765                                 continue;
 766                         if (dense && is_merge &&
 767                             omit_in_dense(commit, rev, num_rev))
 768                                 continue;
 769                         for (i = 0; i < num_rev; i++) {
 770                                 int mark;
 771                                 if (!(this_flag & (1u << (i + REV_SHIFT))))
 772                                         mark = ' ';
 773                                 else if (is_merge)
 774                                         mark = '-';
 775                                 else if (i == head_at)
 776                                         mark = '*';
 777                                 else
 778                                         mark = '+';
 779                                 putchar(mark);
 780                         }
 781                         putchar(' ');
 782                 }
 783                 show_one_commit(commit, no_name);
 784
 785                 if (shown_merge_point && --extra < 0)
 786                         break;
 787         }
 788         return 0;
 789 }