Andrew's git - gitweb.git/blob - builtin-show-branch.c

   1#include "cache.h"
   2#include "commit.h"
   3#include "refs.h"
   4#include "builtin.h"
   5#include "color.h"
   6
   7static const char show_branch_usage[] =
   8"git show-branch [--sparse] [--current] [--all] [--remotes] [--topo-order] [--more=count | --list | --independent | --merge-base ] [--topics] [<refs>...] | --reflog[=n[,b]] <branch>";
   9static const char show_branch_usage_reflog[] =
  10"--reflog is incompatible with --all, --remotes, --independent or --merge-base";
  11
  12static int showbranch_use_color = -1;
  13static char column_colors[][COLOR_MAXLEN] = {
  14        GIT_COLOR_RED,
  15        GIT_COLOR_GREEN,
  16        GIT_COLOR_YELLOW,
  17        GIT_COLOR_BLUE,
  18        GIT_COLOR_MAGENTA,
  19        GIT_COLOR_CYAN,
  20};
  21
  22#define COLUMN_COLORS_MAX (ARRAY_SIZE(column_colors))
  23
  24static int default_num;
  25static int default_alloc;
  26static const char **default_arg;
  27
  28#define UNINTERESTING   01
  29
  30#define REV_SHIFT        2
  31#define MAX_REVS        (FLAG_BITS - REV_SHIFT) /* should not exceed bits_per_int - REV_SHIFT */
  32
  33#define DEFAULT_REFLOG  4
  34
  35static const char *get_color_code(int idx)
  36{
  37        if (showbranch_use_color)
  38                return column_colors[idx];
  39        return "";
  40}
  41
  42static const char *get_color_reset_code(void)
  43{
  44        if (showbranch_use_color)
  45                return GIT_COLOR_RESET;
  46        return "";
  47}
  48
  49static struct commit *interesting(struct commit_list *list)
  50{
  51        while (list) {
  52                struct commit *commit = list->item;
  53                list = list->next;
  54                if (commit->object.flags & UNINTERESTING)
  55                        continue;
  56                return commit;
  57        }
  58        return NULL;
  59}
  60
  61static struct commit *pop_one_commit(struct commit_list **list_p)
  62{
  63        struct commit *commit;
  64        struct commit_list *list;
  65        list = *list_p;
  66        commit = list->item;
  67        *list_p = list->next;
  68        free(list);
  69        return commit;
  70}
  71
  72struct commit_name {
  73        const char *head_name; /* which head's ancestor? */
  74        int generation; /* how many parents away from head_name */
  75};
  76
  77/* Name the commit as nth generation ancestor of head_name;
  78 * we count only the first-parent relationship for naming purposes.
  79 */
  80static void name_commit(struct commit *commit, const char *head_name, int nth)
  81{
  82        struct commit_name *name;
  83        if (!commit->util)
  84                commit->util = xmalloc(sizeof(struct commit_name));
  85        name = commit->util;
  86        name->head_name = head_name;
  87        name->generation = nth;
  88}
  89
  90/* Parent is the first parent of the commit.  We may name it
  91 * as (n+1)th generation ancestor of the same head_name as
  92 * commit is nth generation ancestor of, if that generation
  93 * number is better than the name it already has.
  94 */
  95static void name_parent(struct commit *commit, struct commit *parent)
  96{
  97        struct commit_name *commit_name = commit->util;
  98        struct commit_name *parent_name = parent->util;
  99        if (!commit_name)
 100                return;
 101        if (!parent_name ||
 102            commit_name->generation + 1 < parent_name->generation)
 103                name_commit(parent, commit_name->head_name,
 104                            commit_name->generation + 1);
 105}
 106
 107static int name_first_parent_chain(struct commit *c)
 108{
 109        int i = 0;
 110        while (c) {
 111                struct commit *p;
 112                if (!c->util)
 113                        break;
 114                if (!c->parents)
 115                        break;
 116                p = c->parents->item;
 117                if (!p->util) {
 118                        name_parent(c, p);
 119                        i++;
 120                }
 121                else
 122                        break;
 123                c = p;
 124        }
 125        return i;
 126}
 127
 128static void name_commits(struct commit_list *list,
 129                         struct commit **rev,
 130                         char **ref_name,
 131                         int num_rev)
 132{
 133        struct commit_list *cl;
 134        struct commit *c;
 135        int i;
 136
 137        /* First give names to the given heads */
 138        for (cl = list; cl; cl = cl->next) {
 139                c = cl->item;
 140                if (c->util)
 141                        continue;
 142                for (i = 0; i < num_rev; i++) {
 143                        if (rev[i] == c) {
 144                                name_commit(c, ref_name[i], 0);
 145                                break;
 146                        }
 147                }
 148        }
 149
 150        /* Then commits on the first parent ancestry chain */
 151        do {
 152                i = 0;
 153                for (cl = list; cl; cl = cl->next) {
 154                        i += name_first_parent_chain(cl->item);
 155                }
 156        } while (i);
 157
 158        /* Finally, any unnamed commits */
 159        do {
 160                i = 0;
 161                for (cl = list; cl; cl = cl->next) {
 162                        struct commit_list *parents;
 163                        struct commit_name *n;
 164                        int nth;
 165                        c = cl->item;
 166                        if (!c->util)
 167                                continue;
 168                        n = c->util;
 169                        parents = c->parents;
 170                        nth = 0;
 171                        while (parents) {
 172                                struct commit *p = parents->item;
 173                                char newname[1000], *en;
 174                                parents = parents->next;
 175                                nth++;
 176                                if (p->util)
 177                                        continue;
 178                                en = newname;
 179                                switch (n->generation) {
 180                                case 0:
 181                                        en += sprintf(en, "%s", n->head_name);
 182                                        break;
 183                                case 1:
 184                                        en += sprintf(en, "%s^", n->head_name);
 185                                        break;
 186                                default:
 187                                        en += sprintf(en, "%s~%d",
 188                                                n->head_name, n->generation);
 189                                        break;
 190                                }
 191                                if (nth == 1)
 192                                        en += sprintf(en, "^");
 193                                else
 194                                        en += sprintf(en, "^%d", nth);
 195                                name_commit(p, xstrdup(newname), 0);
 196                                i++;
 197                                name_first_parent_chain(p);
 198                        }
 199                }
 200        } while (i);
 201}
 202
 203static int mark_seen(struct commit *commit, struct commit_list **seen_p)
 204{
 205        if (!commit->object.flags) {
 206                commit_list_insert(commit, seen_p);
 207                return 1;
 208        }
 209        return 0;
 210}
 211
 212static void join_revs(struct commit_list **list_p,
 213                      struct commit_list **seen_p,
 214                      int num_rev, int extra)
 215{
 216        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 217        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 218
 219        while (*list_p) {
 220                struct commit_list *parents;
 221                int still_interesting = !!interesting(*list_p);
 222                struct commit *commit = pop_one_commit(list_p);
 223                int flags = commit->object.flags & all_mask;
 224
 225                if (!still_interesting && extra <= 0)
 226                        break;
 227
 228                mark_seen(commit, seen_p);
 229                if ((flags & all_revs) == all_revs)
 230                        flags |= UNINTERESTING;
 231                parents = commit->parents;
 232
 233                while (parents) {
 234                        struct commit *p = parents->item;
 235                        int this_flag = p->object.flags;
 236                        parents = parents->next;
 237                        if ((this_flag & flags) == flags)
 238                                continue;
 239                        if (!p->object.parsed)
 240                                parse_commit(p);
 241                        if (mark_seen(p, seen_p) && !still_interesting)
 242                                extra--;
 243                        p->object.flags |= flags;
 244                        insert_by_date(p, list_p);
 245                }
 246        }
 247
 248        /*
 249         * Postprocess to complete well-poisoning.
 250         *
 251         * At this point we have all the commits we have seen in
 252         * seen_p list.  Mark anything that can be reached from
 253         * uninteresting commits not interesting.
 254         */
 255        for (;;) {
 256                int changed = 0;
 257                struct commit_list *s;
 258                for (s = *seen_p; s; s = s->next) {
 259                        struct commit *c = s->item;
 260                        struct commit_list *parents;
 261
 262                        if (((c->object.flags & all_revs) != all_revs) &&
 263                            !(c->object.flags & UNINTERESTING))
 264                                continue;
 265
 266                        /* The current commit is either a merge base or
 267                         * already uninteresting one.  Mark its parents
 268                         * as uninteresting commits _only_ if they are
 269                         * already parsed.  No reason to find new ones
 270                         * here.
 271                         */
 272                        parents = c->parents;
 273                        while (parents) {
 274                                struct commit *p = parents->item;
 275                                parents = parents->next;
 276                                if (!(p->object.flags & UNINTERESTING)) {
 277                                        p->object.flags |= UNINTERESTING;
 278                                        changed = 1;
 279                                }
 280                        }
 281                }
 282                if (!changed)
 283                        break;
 284        }
 285}
 286
 287static void show_one_commit(struct commit *commit, int no_name)
 288{
 289        struct strbuf pretty = STRBUF_INIT;
 290        const char *pretty_str = "(unavailable)";
 291        struct commit_name *name = commit->util;
 292
 293        if (commit->object.parsed) {
 294                pretty_print_commit(CMIT_FMT_ONELINE, commit,
 295                                    &pretty, 0, NULL, NULL, 0, 0);
 296                pretty_str = pretty.buf;
 297        }
 298        if (!prefixcmp(pretty_str, "[PATCH] "))
 299                pretty_str += 8;
 300
 301        if (!no_name) {
 302                if (name && name->head_name) {
 303                        printf("[%s", name->head_name);
 304                        if (name->generation) {
 305                                if (name->generation == 1)
 306                                        printf("^");
 307                                else
 308                                        printf("~%d", name->generation);
 309                        }
 310                        printf("] ");
 311                }
 312                else
 313                        printf("[%s] ",
 314                               find_unique_abbrev(commit->object.sha1, 7));
 315        }
 316        puts(pretty_str);
 317        strbuf_release(&pretty);
 318}
 319
 320static char *ref_name[MAX_REVS + 1];
 321static int ref_name_cnt;
 322
 323static const char *find_digit_prefix(const char *s, int *v)
 324{
 325        const char *p;
 326        int ver;
 327        char ch;
 328
 329        for (p = s, ver = 0;
 330             '0' <= (ch = *p) && ch <= '9';
 331             p++)
 332                ver = ver * 10 + ch - '0';
 333        *v = ver;
 334        return p;
 335}
 336
 337
 338static int version_cmp(const char *a, const char *b)
 339{
 340        while (1) {
 341                int va, vb;
 342
 343                a = find_digit_prefix(a, &va);
 344                b = find_digit_prefix(b, &vb);
 345                if (va != vb)
 346                        return va - vb;
 347
 348                while (1) {
 349                        int ca = *a;
 350                        int cb = *b;
 351                        if ('0' <= ca && ca <= '9')
 352                                ca = 0;
 353                        if ('0' <= cb && cb <= '9')
 354                                cb = 0;
 355                        if (ca != cb)
 356                                return ca - cb;
 357                        if (!ca)
 358                                break;
 359                        a++;
 360                        b++;
 361                }
 362                if (!*a && !*b)
 363                        return 0;
 364        }
 365}
 366
 367static int compare_ref_name(const void *a_, const void *b_)
 368{
 369        const char * const*a = a_, * const*b = b_;
 370        return version_cmp(*a, *b);
 371}
 372
 373static void sort_ref_range(int bottom, int top)
 374{
 375        qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 376              compare_ref_name);
 377}
 378
 379static int append_ref(const char *refname, const unsigned char *sha1,
 380                      int allow_dups)
 381{
 382        struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 383        int i;
 384
 385        if (!commit)
 386                return 0;
 387
 388        if (!allow_dups) {
 389                /* Avoid adding the same thing twice */
 390                for (i = 0; i < ref_name_cnt; i++)
 391                        if (!strcmp(refname, ref_name[i]))
 392                                return 0;
 393        }
 394        if (MAX_REVS <= ref_name_cnt) {
 395                warning("ignoring %s; cannot handle more than %d refs",
 396                        refname, MAX_REVS);
 397                return 0;
 398        }
 399        ref_name[ref_name_cnt++] = xstrdup(refname);
 400        ref_name[ref_name_cnt] = NULL;
 401        return 0;
 402}
 403
 404static int append_head_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 405{
 406        unsigned char tmp[20];
 407        int ofs = 11;
 408        if (prefixcmp(refname, "refs/heads/"))
 409                return 0;
 410        /* If both heads/foo and tags/foo exists, get_sha1 would
 411         * get confused.
 412         */
 413        if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 414                ofs = 5;
 415        return append_ref(refname + ofs, sha1, 0);
 416}
 417
 418static int append_remote_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 419{
 420        unsigned char tmp[20];
 421        int ofs = 13;
 422        if (prefixcmp(refname, "refs/remotes/"))
 423                return 0;
 424        /* If both heads/foo and tags/foo exists, get_sha1 would
 425         * get confused.
 426         */
 427        if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 428                ofs = 5;
 429        return append_ref(refname + ofs, sha1, 0);
 430}
 431
 432static int append_tag_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 433{
 434        if (prefixcmp(refname, "refs/tags/"))
 435                return 0;
 436        return append_ref(refname + 5, sha1, 0);
 437}
 438
 439static const char *match_ref_pattern = NULL;
 440static int match_ref_slash = 0;
 441static int count_slash(const char *s)
 442{
 443        int cnt = 0;
 444        while (*s)
 445                if (*s++ == '/')
 446                        cnt++;
 447        return cnt;
 448}
 449
 450static int append_matching_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 451{
 452        /* we want to allow pattern hold/<asterisk> to show all
 453         * branches under refs/heads/hold/, and v0.99.9? to show
 454         * refs/tags/v0.99.9a and friends.
 455         */
 456        const char *tail;
 457        int slash = count_slash(refname);
 458        for (tail = refname; *tail && match_ref_slash < slash; )
 459                if (*tail++ == '/')
 460                        slash--;
 461        if (!*tail)
 462                return 0;
 463        if (fnmatch(match_ref_pattern, tail, 0))
 464                return 0;
 465        if (!prefixcmp(refname, "refs/heads/"))
 466                return append_head_ref(refname, sha1, flag, cb_data);
 467        if (!prefixcmp(refname, "refs/tags/"))
 468                return append_tag_ref(refname, sha1, flag, cb_data);
 469        return append_ref(refname, sha1, 0);
 470}
 471
 472static void snarf_refs(int head, int remotes)
 473{
 474        if (head) {
 475                int orig_cnt = ref_name_cnt;
 476                for_each_ref(append_head_ref, NULL);
 477                sort_ref_range(orig_cnt, ref_name_cnt);
 478        }
 479        if (remotes) {
 480                int orig_cnt = ref_name_cnt;
 481                for_each_ref(append_remote_ref, NULL);
 482                sort_ref_range(orig_cnt, ref_name_cnt);
 483        }
 484}
 485
 486static int rev_is_head(char *head, int headlen, char *name,
 487                       unsigned char *head_sha1, unsigned char *sha1)
 488{
 489        if ((!head[0]) ||
 490            (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
 491                return 0;
 492        if (!prefixcmp(head, "refs/heads/"))
 493                head += 11;
 494        if (!prefixcmp(name, "refs/heads/"))
 495                name += 11;
 496        else if (!prefixcmp(name, "heads/"))
 497                name += 6;
 498        return !strcmp(head, name);
 499}
 500
 501static int show_merge_base(struct commit_list *seen, int num_rev)
 502{
 503        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 504        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 505        int exit_status = 1;
 506
 507        while (seen) {
 508                struct commit *commit = pop_one_commit(&seen);
 509                int flags = commit->object.flags & all_mask;
 510                if (!(flags & UNINTERESTING) &&
 511                    ((flags & all_revs) == all_revs)) {
 512                        puts(sha1_to_hex(commit->object.sha1));
 513                        exit_status = 0;
 514                        commit->object.flags |= UNINTERESTING;
 515                }
 516        }
 517        return exit_status;
 518}
 519
 520static int show_independent(struct commit **rev,
 521                            int num_rev,
 522                            char **ref_name,
 523                            unsigned int *rev_mask)
 524{
 525        int i;
 526
 527        for (i = 0; i < num_rev; i++) {
 528                struct commit *commit = rev[i];
 529                unsigned int flag = rev_mask[i];
 530
 531                if (commit->object.flags == flag)
 532                        puts(sha1_to_hex(commit->object.sha1));
 533                commit->object.flags |= UNINTERESTING;
 534        }
 535        return 0;
 536}
 537
 538static void append_one_rev(const char *av)
 539{
 540        unsigned char revkey[20];
 541        if (!get_sha1(av, revkey)) {
 542                append_ref(av, revkey, 0);
 543                return;
 544        }
 545        if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
 546                /* glob style match */
 547                int saved_matches = ref_name_cnt;
 548                match_ref_pattern = av;
 549                match_ref_slash = count_slash(av);
 550                for_each_ref(append_matching_ref, NULL);
 551                if (saved_matches == ref_name_cnt &&
 552                    ref_name_cnt < MAX_REVS)
 553                        error("no matching refs with %s", av);
 554                if (saved_matches + 1 < ref_name_cnt)
 555                        sort_ref_range(saved_matches, ref_name_cnt);
 556                return;
 557        }
 558        die("bad sha1 reference %s", av);
 559}
 560
 561static int git_show_branch_config(const char *var, const char *value, void *cb)
 562{
 563        if (!strcmp(var, "showbranch.default")) {
 564                if (!value)
 565                        return config_error_nonbool(var);
 566                if (default_alloc <= default_num + 1) {
 567                        default_alloc = default_alloc * 3 / 2 + 20;
 568                        default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
 569                }
 570                default_arg[default_num++] = xstrdup(value);
 571                default_arg[default_num] = NULL;
 572                return 0;
 573        }
 574
 575        if (!strcmp(var, "color.showbranch")) {
 576                showbranch_use_color = git_config_colorbool(var, value, -1);
 577                return 0;
 578        }
 579
 580        return git_color_default_config(var, value, cb);
 581}
 582
 583static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
 584{
 585        /* If the commit is tip of the named branches, do not
 586         * omit it.
 587         * Otherwise, if it is a merge that is reachable from only one
 588         * tip, it is not that interesting.
 589         */
 590        int i, flag, count;
 591        for (i = 0; i < n; i++)
 592                if (rev[i] == commit)
 593                        return 0;
 594        flag = commit->object.flags;
 595        for (i = count = 0; i < n; i++) {
 596                if (flag & (1u << (i + REV_SHIFT)))
 597                        count++;
 598        }
 599        if (count == 1)
 600                return 1;
 601        return 0;
 602}
 603
 604static void parse_reflog_param(const char *arg, int *cnt, const char **base)
 605{
 606        char *ep;
 607        *cnt = strtoul(arg, &ep, 10);
 608        if (*ep == ',')
 609                *base = ep + 1;
 610        else if (*ep)
 611                die("unrecognized reflog param '%s'", arg);
 612        else
 613                *base = NULL;
 614        if (*cnt <= 0)
 615                *cnt = DEFAULT_REFLOG;
 616}
 617
 618int cmd_show_branch(int ac, const char **av, const char *prefix)
 619{
 620        struct commit *rev[MAX_REVS], *commit;
 621        char *reflog_msg[MAX_REVS];
 622        struct commit_list *list = NULL, *seen = NULL;
 623        unsigned int rev_mask[MAX_REVS];
 624        int num_rev, i, extra = 0;
 625        int all_heads = 0, all_remotes = 0;
 626        int all_mask, all_revs;
 627        int lifo = 1;
 628        char head[128];
 629        const char *head_p;
 630        int head_len;
 631        unsigned char head_sha1[20];
 632        int merge_base = 0;
 633        int independent = 0;
 634        int no_name = 0;
 635        int sha1_name = 0;
 636        int shown_merge_point = 0;
 637        int with_current_branch = 0;
 638        int head_at = -1;
 639        int topics = 0;
 640        int dense = 1;
 641        int reflog = 0;
 642        const char *reflog_base = NULL;
 643
 644        git_config(git_show_branch_config, NULL);
 645
 646        if (showbranch_use_color == -1)
 647                showbranch_use_color = git_use_color_default;
 648
 649        /* If nothing is specified, try the default first */
 650        if (ac == 1 && default_num) {
 651                ac = default_num + 1;
 652                av = default_arg - 1; /* ick; we would not address av[0] */
 653        }
 654
 655        while (1 < ac && av[1][0] == '-') {
 656                const char *arg = av[1];
 657                if (!strcmp(arg, "--")) {
 658                        ac--; av++;
 659                        break;
 660                }
 661                else if (!strcmp(arg, "--all") || !strcmp(arg, "-a"))
 662                        all_heads = all_remotes = 1;
 663                else if (!strcmp(arg, "--remotes") || !strcmp(arg, "-r"))
 664                        all_remotes = 1;
 665                else if (!strcmp(arg, "--more"))
 666                        extra = 1;
 667                else if (!strcmp(arg, "--list"))
 668                        extra = -1;
 669                else if (!strcmp(arg, "--no-name"))
 670                        no_name = 1;
 671                else if (!strcmp(arg, "--current"))
 672                        with_current_branch = 1;
 673                else if (!strcmp(arg, "--sha1-name"))
 674                        sha1_name = 1;
 675                else if (!prefixcmp(arg, "--more="))
 676                        extra = atoi(arg + 7);
 677                else if (!strcmp(arg, "--merge-base"))
 678                        merge_base = 1;
 679                else if (!strcmp(arg, "--independent"))
 680                        independent = 1;
 681                else if (!strcmp(arg, "--topo-order"))
 682                        lifo = 1;
 683                else if (!strcmp(arg, "--topics"))
 684                        topics = 1;
 685                else if (!strcmp(arg, "--sparse"))
 686                        dense = 0;
 687                else if (!strcmp(arg, "--date-order"))
 688                        lifo = 0;
 689                else if (!strcmp(arg, "--reflog") || !strcmp(arg, "-g")) {
 690                        reflog = DEFAULT_REFLOG;
 691                }
 692                else if (!prefixcmp(arg, "--reflog="))
 693                        parse_reflog_param(arg + 9, &reflog, &reflog_base);
 694                else if (!prefixcmp(arg, "-g="))
 695                        parse_reflog_param(arg + 3, &reflog, &reflog_base);
 696                else if (!strcmp(arg, "--color"))
 697                        showbranch_use_color = 1;
 698                else if (!strcmp(arg, "--no-color"))
 699                        showbranch_use_color = 0;
 700                else
 701                        usage(show_branch_usage);
 702                ac--; av++;
 703        }
 704        ac--; av++;
 705
 706        if (extra || reflog) {
 707                /* "listing" mode is incompatible with
 708                 * independent nor merge-base modes.
 709                 */
 710                if (independent || merge_base)
 711                        usage(show_branch_usage);
 712                if (reflog && ((0 < extra) || all_heads || all_remotes))
 713                        /*
 714                         * Asking for --more in reflog mode does not
 715                         * make sense.  --list is Ok.
 716                         *
 717                         * Also --all and --remotes do not make sense either.
 718                         */
 719                        usage(show_branch_usage_reflog);
 720        }
 721
 722        /* If nothing is specified, show all branches by default */
 723        if (ac + all_heads + all_remotes == 0)
 724                all_heads = 1;
 725
 726        if (reflog) {
 727                unsigned char sha1[20];
 728                char nth_desc[256];
 729                char *ref;
 730                int base = 0;
 731
 732                if (ac == 0) {
 733                        static const char *fake_av[2];
 734                        const char *refname;
 735
 736                        refname = resolve_ref("HEAD", sha1, 1, NULL);
 737                        fake_av[0] = xstrdup(refname);
 738                        fake_av[1] = NULL;
 739                        av = fake_av;
 740                        ac = 1;
 741                }
 742                if (ac != 1)
 743                        die("--reflog option needs one branch name");
 744
 745                if (MAX_REVS < reflog)
 746                        die("Only %d entries can be shown at one time.",
 747                            MAX_REVS);
 748                if (!dwim_ref(*av, strlen(*av), sha1, &ref))
 749                        die("No such ref %s", *av);
 750
 751                /* Has the base been specified? */
 752                if (reflog_base) {
 753                        char *ep;
 754                        base = strtoul(reflog_base, &ep, 10);
 755                        if (*ep) {
 756                                /* Ah, that is a date spec... */
 757                                unsigned long at;
 758                                at = approxidate(reflog_base);
 759                                read_ref_at(ref, at, -1, sha1, NULL,
 760                                            NULL, NULL, &base);
 761                        }
 762                }
 763
 764                for (i = 0; i < reflog; i++) {
 765                        char *logmsg, *m;
 766                        const char *msg;
 767                        unsigned long timestamp;
 768                        int tz;
 769
 770                        if (read_ref_at(ref, 0, base+i, sha1, &logmsg,
 771                                        &timestamp, &tz, NULL)) {
 772                                reflog = i;
 773                                break;
 774                        }
 775                        msg = strchr(logmsg, '\t');
 776                        if (!msg)
 777                                msg = "(none)";
 778                        else
 779                                msg++;
 780                        m = xmalloc(strlen(msg) + 200);
 781                        sprintf(m, "(%s) %s",
 782                                show_date(timestamp, tz, 1),
 783                                msg);
 784                        reflog_msg[i] = m;
 785                        free(logmsg);
 786                        sprintf(nth_desc, "%s@{%d}", *av, base+i);
 787                        append_ref(nth_desc, sha1, 1);
 788                }
 789        }
 790        else if (all_heads + all_remotes)
 791                snarf_refs(all_heads, all_remotes);
 792        else {
 793                while (0 < ac) {
 794                        append_one_rev(*av);
 795                        ac--; av++;
 796                }
 797        }
 798
 799        head_p = resolve_ref("HEAD", head_sha1, 1, NULL);
 800        if (head_p) {
 801                head_len = strlen(head_p);
 802                memcpy(head, head_p, head_len + 1);
 803        }
 804        else {
 805                head_len = 0;
 806                head[0] = 0;
 807        }
 808
 809        if (with_current_branch && head_p) {
 810                int has_head = 0;
 811                for (i = 0; !has_head && i < ref_name_cnt; i++) {
 812                        /* We are only interested in adding the branch
 813                         * HEAD points at.
 814                         */
 815                        if (rev_is_head(head,
 816                                        head_len,
 817                                        ref_name[i],
 818                                        head_sha1, NULL))
 819                                has_head++;
 820                }
 821                if (!has_head) {
 822                        int offset = !prefixcmp(head, "refs/heads/") ? 11 : 0;
 823                        append_one_rev(head + offset);
 824                }
 825        }
 826
 827        if (!ref_name_cnt) {
 828                fprintf(stderr, "No revs to be shown.\n");
 829                exit(0);
 830        }
 831
 832        for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 833                unsigned char revkey[20];
 834                unsigned int flag = 1u << (num_rev + REV_SHIFT);
 835
 836                if (MAX_REVS <= num_rev)
 837                        die("cannot handle more than %d revs.", MAX_REVS);
 838                if (get_sha1(ref_name[num_rev], revkey))
 839                        die("'%s' is not a valid ref.", ref_name[num_rev]);
 840                commit = lookup_commit_reference(revkey);
 841                if (!commit)
 842                        die("cannot find commit %s (%s)",
 843                            ref_name[num_rev], revkey);
 844                parse_commit(commit);
 845                mark_seen(commit, &seen);
 846
 847                /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 848                 * and so on.  REV_SHIFT bits from bit 0 are used for
 849                 * internal bookkeeping.
 850                 */
 851                commit->object.flags |= flag;
 852                if (commit->object.flags == flag)
 853                        insert_by_date(commit, &list);
 854                rev[num_rev] = commit;
 855        }
 856        for (i = 0; i < num_rev; i++)
 857                rev_mask[i] = rev[i]->object.flags;
 858
 859        if (0 <= extra)
 860                join_revs(&list, &seen, num_rev, extra);
 861
 862        sort_by_date(&seen);
 863
 864        if (merge_base)
 865                return show_merge_base(seen, num_rev);
 866
 867        if (independent)
 868                return show_independent(rev, num_rev, ref_name, rev_mask);
 869
 870        /* Show list; --more=-1 means list-only */
 871        if (1 < num_rev || extra < 0) {
 872                for (i = 0; i < num_rev; i++) {
 873                        int j;
 874                        int is_head = rev_is_head(head,
 875                                                  head_len,
 876                                                  ref_name[i],
 877                                                  head_sha1,
 878                                                  rev[i]->object.sha1);
 879                        if (extra < 0)
 880                                printf("%c [%s] ",
 881                                       is_head ? '*' : ' ', ref_name[i]);
 882                        else {
 883                                for (j = 0; j < i; j++)
 884                                        putchar(' ');
 885                                printf("%s%c%s [%s] ",
 886                                       get_color_code(i % COLUMN_COLORS_MAX),
 887                                       is_head ? '*' : '!',
 888                                       get_color_reset_code(), ref_name[i]);
 889                        }
 890
 891                        if (!reflog) {
 892                                /* header lines never need name */
 893                                show_one_commit(rev[i], 1);
 894                        }
 895                        else
 896                                puts(reflog_msg[i]);
 897
 898                        if (is_head)
 899                                head_at = i;
 900                }
 901                if (0 <= extra) {
 902                        for (i = 0; i < num_rev; i++)
 903                                putchar('-');
 904                        putchar('\n');
 905                }
 906        }
 907        if (extra < 0)
 908                exit(0);
 909
 910        /* Sort topologically */
 911        sort_in_topological_order(&seen, lifo);
 912
 913        /* Give names to commits */
 914        if (!sha1_name && !no_name)
 915                name_commits(seen, rev, ref_name, num_rev);
 916
 917        all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 918        all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 919
 920        while (seen) {
 921                struct commit *commit = pop_one_commit(&seen);
 922                int this_flag = commit->object.flags;
 923                int is_merge_point = ((this_flag & all_revs) == all_revs);
 924
 925                shown_merge_point |= is_merge_point;
 926
 927                if (1 < num_rev) {
 928                        int is_merge = !!(commit->parents &&
 929                                          commit->parents->next);
 930                        if (topics &&
 931                            !is_merge_point &&
 932                            (this_flag & (1u << REV_SHIFT)))
 933                                continue;
 934                        if (dense && is_merge &&
 935                            omit_in_dense(commit, rev, num_rev))
 936                                continue;
 937                        for (i = 0; i < num_rev; i++) {
 938                                int mark;
 939                                if (!(this_flag & (1u << (i + REV_SHIFT))))
 940                                        mark = ' ';
 941                                else if (is_merge)
 942                                        mark = '-';
 943                                else if (i == head_at)
 944                                        mark = '*';
 945                                else
 946                                        mark = '+';
 947                                printf("%s%c%s",
 948                                       get_color_code(i % COLUMN_COLORS_MAX),
 949                                       mark, get_color_reset_code());
 950                        }
 951                        putchar(' ');
 952                }
 953                show_one_commit(commit, no_name);
 954
 955                if (shown_merge_point && --extra < 0)
 956                        break;
 957        }
 958        return 0;
 959}