Andrew's git / gitweb.git / builtin-show-branch.c
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builtin-show-branch.con commit show-branch: Fix another performance problem. (f8263c5)
   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 [--sparse] [--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                else
  93                        break;
  94                c = p;
  95        }
  96        return i;
  97}
  98
  99static 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
 174static 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
 183static 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
 258static 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
 290static char *ref_name[MAX_REVS + 1];
 291static int ref_name_cnt;
 292
 293static 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
 308static 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
 337static 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
 343static 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
 349static 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
 372static 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
 386static 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
 393static const char *match_ref_pattern = NULL;
 394static int match_ref_slash = 0;
 395static int count_slash(const char *s)
 396{
 397        int cnt = 0;
 398        while (*s)
 399                if (*s++ == '/')
 400                        cnt++;
 401        return cnt;
 402}
 403
 404static 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
 426static 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
 440static 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
 457static 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
 476static 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
 494static 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
 517static 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
 532static 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
 553int cmd_show_branch(int ac, const char **av, char **envp)
 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        setup_git_directory();
 577        git_config(git_show_branch_config);
 578
 579        /* If nothing is specified, try the default first */
 580        if (ac == 1 && default_num) {
 581                ac = default_num + 1;
 582                av = default_arg - 1; /* ick; we would not address av[0] */
 583        }
 584
 585        while (1 < ac && av[1][0] == '-') {
 586                const char *arg = av[1];
 587                if (!strcmp(arg, "--")) {
 588                        ac--; av++;
 589                        break;
 590                }
 591                else if (!strcmp(arg, "--all"))
 592                        all_heads = all_tags = 1;
 593                else if (!strcmp(arg, "--heads"))
 594                        all_heads = 1;
 595                else if (!strcmp(arg, "--tags"))
 596                        all_tags = 1;
 597                else if (!strcmp(arg, "--more"))
 598                        extra = 1;
 599                else if (!strcmp(arg, "--list"))
 600                        extra = -1;
 601                else if (!strcmp(arg, "--no-name"))
 602                        no_name = 1;
 603                else if (!strcmp(arg, "--current"))
 604                        with_current_branch = 1;
 605                else if (!strcmp(arg, "--sha1-name"))
 606                        sha1_name = 1;
 607                else if (!strncmp(arg, "--more=", 7))
 608                        extra = atoi(arg + 7);
 609                else if (!strcmp(arg, "--merge-base"))
 610                        merge_base = 1;
 611                else if (!strcmp(arg, "--independent"))
 612                        independent = 1;
 613                else if (!strcmp(arg, "--topo-order"))
 614                        lifo = 1;
 615                else if (!strcmp(arg, "--topics"))
 616                        topics = 1;
 617                else if (!strcmp(arg, "--sparse"))
 618                        dense = 0;
 619                else if (!strcmp(arg, "--date-order"))
 620                        lifo = 0;
 621                else
 622                        usage(show_branch_usage);
 623                ac--; av++;
 624        }
 625        ac--; av++;
 626
 627        /* Only one of these is allowed */
 628        if (1 < independent + merge_base + (extra != 0))
 629                usage(show_branch_usage);
 630
 631        /* If nothing is specified, show all branches by default */
 632        if (ac + all_heads + all_tags == 0)
 633                all_heads = 1;
 634
 635        if (all_heads + all_tags)
 636                snarf_refs(all_heads, all_tags);
 637        while (0 < ac) {
 638                append_one_rev(*av);
 639                ac--; av++;
 640        }
 641
 642        head_path_p = resolve_ref(git_path("HEAD"), head_sha1, 1);
 643        if (head_path_p) {
 644                head_path_len = strlen(head_path_p);
 645                memcpy(head_path, head_path_p, head_path_len + 1);
 646        }
 647        else {
 648                head_path_len = 0;
 649                head_path[0] = 0;
 650        }
 651
 652        if (with_current_branch && head_path_p) {
 653                int has_head = 0;
 654                for (i = 0; !has_head && i < ref_name_cnt; i++) {
 655                        /* We are only interested in adding the branch
 656                         * HEAD points at.
 657                         */
 658                        if (rev_is_head(head_path,
 659                                        head_path_len,
 660                                        ref_name[i],
 661                                        head_sha1, NULL))
 662                                has_head++;
 663                }
 664                if (!has_head) {
 665                        int pfxlen = strlen(git_path("refs/heads/"));
 666                        append_one_rev(head_path + pfxlen);
 667                }
 668        }
 669
 670        if (!ref_name_cnt) {
 671                fprintf(stderr, "No revs to be shown.\n");
 672                exit(0);
 673        }
 674
 675        for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 676                unsigned char revkey[20];
 677                unsigned int flag = 1u << (num_rev + REV_SHIFT);
 678
 679                if (MAX_REVS <= num_rev)
 680                        die("cannot handle more than %d revs.", MAX_REVS);
 681                if (get_sha1(ref_name[num_rev], revkey))
 682                        die("'%s' is not a valid ref.", ref_name[num_rev]);
 683                commit = lookup_commit_reference(revkey);
 684                if (!commit)
 685                        die("cannot find commit %s (%s)",
 686                            ref_name[num_rev], revkey);
 687                parse_commit(commit);
 688                mark_seen(commit, &seen);
 689
 690                /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 691                 * and so on.  REV_SHIFT bits from bit 0 are used for
 692                 * internal bookkeeping.
 693                 */
 694                commit->object.flags |= flag;
 695                if (commit->object.flags == flag)
 696                        insert_by_date(commit, &list);
 697                rev[num_rev] = commit;
 698        }
 699        for (i = 0; i < num_rev; i++)
 700                rev_mask[i] = rev[i]->object.flags;
 701
 702        if (0 <= extra)
 703                join_revs(&list, &seen, num_rev, extra);
 704
 705        sort_by_date(&seen);
 706
 707        if (merge_base)
 708                return show_merge_base(seen, num_rev);
 709
 710        if (independent)
 711                return show_independent(rev, num_rev, ref_name, rev_mask);
 712
 713        /* Show list; --more=-1 means list-only */
 714        if (1 < num_rev || extra < 0) {
 715                for (i = 0; i < num_rev; i++) {
 716                        int j;
 717                        int is_head = rev_is_head(head_path,
 718                                                  head_path_len,
 719                                                  ref_name[i],
 720                                                  head_sha1,
 721                                                  rev[i]->object.sha1);
 722                        if (extra < 0)
 723                                printf("%c [%s] ",
 724                                       is_head ? '*' : ' ', ref_name[i]);
 725                        else {
 726                                for (j = 0; j < i; j++)
 727                                        putchar(' ');
 728                                printf("%c [%s] ",
 729                                       is_head ? '*' : '!', ref_name[i]);
 730                        }
 731                        /* header lines never need name */
 732                        show_one_commit(rev[i], 1);
 733                        if (is_head)
 734                                head_at = i;
 735                }
 736                if (0 <= extra) {
 737                        for (i = 0; i < num_rev; i++)
 738                                putchar('-');
 739                        putchar('\n');
 740                }
 741        }
 742        if (extra < 0)
 743                exit(0);
 744
 745        /* Sort topologically */
 746        sort_in_topological_order(&seen, lifo);
 747
 748        /* Give names to commits */
 749        if (!sha1_name && !no_name)
 750                name_commits(seen, rev, ref_name, num_rev);
 751
 752        all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 753        all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 754
 755        while (seen) {
 756                struct commit *commit = pop_one_commit(&seen);
 757                int this_flag = commit->object.flags;
 758                int is_merge_point = ((this_flag & all_revs) == all_revs);
 759
 760                shown_merge_point |= is_merge_point;
 761
 762                if (1 < num_rev) {
 763                        int is_merge = !!(commit->parents &&
 764                                          commit->parents->next);
 765                        if (topics &&
 766                            !is_merge_point &&
 767                            (this_flag & (1u << REV_SHIFT)))
 768                                continue;
 769                        if (dense && is_merge &&
 770                            omit_in_dense(commit, rev, num_rev))
 771                                continue;
 772                        for (i = 0; i < num_rev; i++) {
 773                                int mark;
 774                                if (!(this_flag & (1u << (i + REV_SHIFT))))
 775                                        mark = ' ';
 776                                else if (is_merge)
 777                                        mark = '-';
 778                                else if (i == head_at)
 779                                        mark = '*';
 780                                else
 781                                        mark = '+';
 782                                putchar(mark);
 783                        }
 784                        putchar(' ');
 785                }
 786                show_one_commit(commit, no_name);
 787
 788                if (shown_merge_point && --extra < 0)
 789                        break;
 790        }
 791        return 0;
 792}