builtin-show-branch.con commit git-svn: several graft-branches improvements (c1927a8)
   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
   8static const char show_branch_usage[] =
   9"git-show-branch [--dense] [--current] [--all] [--heads] [--tags] [--topo-order] [--more=count | --list | --independent | --merge-base ] [--topics] [<refs>...]";
  10
  11static int default_num = 0;
  12static int default_alloc = 0;
  13static 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
  20static 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
  32static 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
  43struct 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 */
  51static 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 */
  66static 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
  78static 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
  97static 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
 172static int mark_seen(struct commit *commit, struct commit_list **seen_p)
 173{
 174        if (!commit->object.flags) {
 175                insert_by_date(commit, seen_p);
 176                return 1;
 177        }
 178        return 0;
 179}
 180
 181static 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 (which happens to be sorted chronologically but
 222         * it does not really matter).  Mark anything that can be
 223         * reached from uninteresting commits not interesting.
 224         */
 225        for (;;) {
 226                int changed = 0;
 227                struct commit_list *s;
 228                for (s = *seen_p; s; s = s->next) {
 229                        struct commit *c = s->item;
 230                        struct commit_list *parents;
 231
 232                        if (((c->object.flags & all_revs) != all_revs) &&
 233                            !(c->object.flags & UNINTERESTING))
 234                                continue;
 235
 236                        /* The current commit is either a merge base or
 237                         * already uninteresting one.  Mark its parents
 238                         * as uninteresting commits _only_ if they are
 239                         * already parsed.  No reason to find new ones
 240                         * here.
 241                         */
 242                        parents = c->parents;
 243                        while (parents) {
 244                                struct commit *p = parents->item;
 245                                parents = parents->next;
 246                                if (!(p->object.flags & UNINTERESTING)) {
 247                                        p->object.flags |= UNINTERESTING;
 248                                        changed = 1;
 249                                }
 250                        }
 251                }
 252                if (!changed)
 253                        break;
 254        }
 255}
 256
 257static void show_one_commit(struct commit *commit, int no_name)
 258{
 259        char pretty[256], *cp;
 260        struct commit_name *name = commit->util;
 261        if (commit->object.parsed)
 262                pretty_print_commit(CMIT_FMT_ONELINE, commit, ~0,
 263                                    pretty, sizeof(pretty), 0, NULL, NULL);
 264        else
 265                strcpy(pretty, "(unavailable)");
 266        if (!strncmp(pretty, "[PATCH] ", 8))
 267                cp = pretty + 8;
 268        else
 269                cp = pretty;
 270
 271        if (!no_name) {
 272                if (name && name->head_name) {
 273                        printf("[%s", name->head_name);
 274                        if (name->generation) {
 275                                if (name->generation == 1)
 276                                        printf("^");
 277                                else
 278                                        printf("~%d", name->generation);
 279                        }
 280                        printf("] ");
 281                }
 282                else
 283                        printf("[%s] ",
 284                               find_unique_abbrev(commit->object.sha1, 7));
 285        }
 286        puts(cp);
 287}
 288
 289static char *ref_name[MAX_REVS + 1];
 290static int ref_name_cnt;
 291
 292static const char *find_digit_prefix(const char *s, int *v)
 293{
 294        const char *p;
 295        int ver;
 296        char ch;
 297
 298        for (p = s, ver = 0;
 299             '0' <= (ch = *p) && ch <= '9';
 300             p++)
 301                ver = ver * 10 + ch - '0';
 302        *v = ver;
 303        return p;
 304}
 305
 306
 307static int version_cmp(const char *a, const char *b)
 308{
 309        while (1) {
 310                int va, vb;
 311
 312                a = find_digit_prefix(a, &va);
 313                b = find_digit_prefix(b, &vb);
 314                if (va != vb)
 315                        return va - vb;
 316
 317                while (1) {
 318                        int ca = *a;
 319                        int cb = *b;
 320                        if ('0' <= ca && ca <= '9')
 321                                ca = 0;
 322                        if ('0' <= cb && cb <= '9')
 323                                cb = 0;
 324                        if (ca != cb)
 325                                return ca - cb;
 326                        if (!ca)
 327                                break;
 328                        a++;
 329                        b++;
 330                }
 331                if (!*a && !*b)
 332                        return 0;
 333        }
 334}
 335
 336static int compare_ref_name(const void *a_, const void *b_)
 337{
 338        const char * const*a = a_, * const*b = b_;
 339        return version_cmp(*a, *b);
 340}
 341
 342static void sort_ref_range(int bottom, int top)
 343{
 344        qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 345              compare_ref_name);
 346}
 347
 348static int append_ref(const char *refname, const unsigned char *sha1)
 349{
 350        struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 351        int i;
 352
 353        if (!commit)
 354                return 0;
 355        /* Avoid adding the same thing twice */
 356        for (i = 0; i < ref_name_cnt; i++)
 357                if (!strcmp(refname, ref_name[i]))
 358                        return 0;
 359
 360        if (MAX_REVS <= ref_name_cnt) {
 361                fprintf(stderr, "warning: ignoring %s; "
 362                        "cannot handle more than %d refs\n",
 363                        refname, MAX_REVS);
 364                return 0;
 365        }
 366        ref_name[ref_name_cnt++] = strdup(refname);
 367        ref_name[ref_name_cnt] = NULL;
 368        return 0;
 369}
 370
 371static int append_head_ref(const char *refname, const unsigned char *sha1)
 372{
 373        unsigned char tmp[20];
 374        int ofs = 11;
 375        if (strncmp(refname, "refs/heads/", ofs))
 376                return 0;
 377        /* If both heads/foo and tags/foo exists, get_sha1 would
 378         * get confused.
 379         */
 380        if (get_sha1(refname + ofs, tmp) || memcmp(tmp, sha1, 20))
 381                ofs = 5;
 382        return append_ref(refname + ofs, sha1);
 383}
 384
 385static int append_tag_ref(const char *refname, const unsigned char *sha1)
 386{
 387        if (strncmp(refname, "refs/tags/", 10))
 388                return 0;
 389        return append_ref(refname + 5, sha1);
 390}
 391
 392static const char *match_ref_pattern = NULL;
 393static int match_ref_slash = 0;
 394static int count_slash(const char *s)
 395{
 396        int cnt = 0;
 397        while (*s)
 398                if (*s++ == '/')
 399                        cnt++;
 400        return cnt;
 401}
 402
 403static int append_matching_ref(const char *refname, const unsigned char *sha1)
 404{
 405        /* we want to allow pattern hold/<asterisk> to show all
 406         * branches under refs/heads/hold/, and v0.99.9? to show
 407         * refs/tags/v0.99.9a and friends.
 408         */
 409        const char *tail;
 410        int slash = count_slash(refname);
 411        for (tail = refname; *tail && match_ref_slash < slash; )
 412                if (*tail++ == '/')
 413                        slash--;
 414        if (!*tail)
 415                return 0;
 416        if (fnmatch(match_ref_pattern, tail, 0))
 417                return 0;
 418        if (!strncmp("refs/heads/", refname, 11))
 419                return append_head_ref(refname, sha1);
 420        if (!strncmp("refs/tags/", refname, 10))
 421                return append_tag_ref(refname, sha1);
 422        return append_ref(refname, sha1);
 423}
 424
 425static void snarf_refs(int head, int tag)
 426{
 427        if (head) {
 428                int orig_cnt = ref_name_cnt;
 429                for_each_ref(append_head_ref);
 430                sort_ref_range(orig_cnt, ref_name_cnt);
 431        }
 432        if (tag) {
 433                int orig_cnt = ref_name_cnt;
 434                for_each_ref(append_tag_ref);
 435                sort_ref_range(orig_cnt, ref_name_cnt);
 436        }
 437}
 438
 439static int rev_is_head(char *head_path, int headlen, char *name,
 440                       unsigned char *head_sha1, unsigned char *sha1)
 441{
 442        int namelen;
 443        if ((!head_path[0]) ||
 444            (head_sha1 && sha1 && memcmp(head_sha1, sha1, 20)))
 445                return 0;
 446        namelen = strlen(name);
 447        if ((headlen < namelen) ||
 448            memcmp(head_path + headlen - namelen, name, namelen))
 449                return 0;
 450        if (headlen == namelen ||
 451            head_path[headlen - namelen - 1] == '/')
 452                return 1;
 453        return 0;
 454}
 455
 456static int show_merge_base(struct commit_list *seen, int num_rev)
 457{
 458        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 459        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 460        int exit_status = 1;
 461
 462        while (seen) {
 463                struct commit *commit = pop_one_commit(&seen);
 464                int flags = commit->object.flags & all_mask;
 465                if (!(flags & UNINTERESTING) &&
 466                    ((flags & all_revs) == all_revs)) {
 467                        puts(sha1_to_hex(commit->object.sha1));
 468                        exit_status = 0;
 469                        commit->object.flags |= UNINTERESTING;
 470                }
 471        }
 472        return exit_status;
 473}
 474
 475static int show_independent(struct commit **rev,
 476                            int num_rev,
 477                            char **ref_name,
 478                            unsigned int *rev_mask)
 479{
 480        int i;
 481
 482        for (i = 0; i < num_rev; i++) {
 483                struct commit *commit = rev[i];
 484                unsigned int flag = rev_mask[i];
 485
 486                if (commit->object.flags == flag)
 487                        puts(sha1_to_hex(commit->object.sha1));
 488                commit->object.flags |= UNINTERESTING;
 489        }
 490        return 0;
 491}
 492
 493static void append_one_rev(const char *av)
 494{
 495        unsigned char revkey[20];
 496        if (!get_sha1(av, revkey)) {
 497                append_ref(av, revkey);
 498                return;
 499        }
 500        if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
 501                /* glob style match */
 502                int saved_matches = ref_name_cnt;
 503                match_ref_pattern = av;
 504                match_ref_slash = count_slash(av);
 505                for_each_ref(append_matching_ref);
 506                if (saved_matches == ref_name_cnt &&
 507                    ref_name_cnt < MAX_REVS)
 508                        error("no matching refs with %s", av);
 509                if (saved_matches + 1 < ref_name_cnt)
 510                        sort_ref_range(saved_matches, ref_name_cnt);
 511                return;
 512        }
 513        die("bad sha1 reference %s", av);
 514}
 515
 516static int git_show_branch_config(const char *var, const char *value)
 517{
 518        if (!strcmp(var, "showbranch.default")) {
 519                if (default_alloc <= default_num + 1) {
 520                        default_alloc = default_alloc * 3 / 2 + 20;
 521                        default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
 522                }
 523                default_arg[default_num++] = strdup(value);
 524                default_arg[default_num] = NULL;
 525                return 0;
 526        }
 527
 528        return git_default_config(var, value);
 529}
 530
 531static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
 532{
 533        /* If the commit is tip of the named branches, do not
 534         * omit it.
 535         * Otherwise, if it is a merge that is reachable from only one
 536         * tip, it is not that interesting.
 537         */
 538        int i, flag, count;
 539        for (i = 0; i < n; i++)
 540                if (rev[i] == commit)
 541                        return 0;
 542        flag = commit->object.flags;
 543        for (i = count = 0; i < n; i++) {
 544                if (flag & (1u << (i + REV_SHIFT)))
 545                        count++;
 546        }
 547        if (count == 1)
 548                return 1;
 549        return 0;
 550}
 551
 552int cmd_show_branch(int ac, const char **av, char **envp)
 553{
 554        struct commit *rev[MAX_REVS], *commit;
 555        struct commit_list *list = NULL, *seen = NULL;
 556        unsigned int rev_mask[MAX_REVS];
 557        int num_rev, i, extra = 0;
 558        int all_heads = 0, all_tags = 0;
 559        int all_mask, all_revs;
 560        int lifo = 1;
 561        char head_path[128];
 562        const char *head_path_p;
 563        int head_path_len;
 564        unsigned char head_sha1[20];
 565        int merge_base = 0;
 566        int independent = 0;
 567        int no_name = 0;
 568        int sha1_name = 0;
 569        int shown_merge_point = 0;
 570        int with_current_branch = 0;
 571        int head_at = -1;
 572        int topics = 0;
 573        int dense = 1;
 574
 575        setup_git_directory();
 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        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_path,
 715                                                  head_path_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}