Andrew's git / gitweb.git / builtin-show-branch.c
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builtin-show-branch.con commit checkout: notice when the switched branch is behind or forked (79a1e6b)
   1#include "cache.h"
   2#include "commit.h"
   3#include "refs.h"
   4#include "builtin.h"
   5
   6static const char show_branch_usage[] =
   7"git-show-branch [--sparse] [--current] [--all] [--remotes] [--topo-order] [--more=count | --list | --independent | --merge-base ] [--topics] [<refs>...] | --reflog[=n[,b]] <branch>";
   8static const char show_branch_usage_reflog[] =
   9"--reflog is incompatible with --all, --remotes, --independent or --merge-base";
  10
  11static int default_num;
  12static int default_alloc;
  13static const char **default_arg;
  14
  15#define UNINTERESTING   01
  16
  17#define REV_SHIFT        2
  18#define MAX_REVS        (FLAG_BITS - REV_SHIFT) /* should not exceed bits_per_int - REV_SHIFT */
  19
  20#define DEFAULT_REFLOG  4
  21
  22static struct commit *interesting(struct commit_list *list)
  23{
  24        while (list) {
  25                struct commit *commit = list->item;
  26                list = list->next;
  27                if (commit->object.flags & UNINTERESTING)
  28                        continue;
  29                return commit;
  30        }
  31        return NULL;
  32}
  33
  34static struct commit *pop_one_commit(struct commit_list **list_p)
  35{
  36        struct commit *commit;
  37        struct commit_list *list;
  38        list = *list_p;
  39        commit = list->item;
  40        *list_p = list->next;
  41        free(list);
  42        return commit;
  43}
  44
  45struct commit_name {
  46        const char *head_name; /* which head's ancestor? */
  47        int generation; /* how many parents away from head_name */
  48};
  49
  50/* Name the commit as nth generation ancestor of head_name;
  51 * we count only the first-parent relationship for naming purposes.
  52 */
  53static void name_commit(struct commit *commit, const char *head_name, int nth)
  54{
  55        struct commit_name *name;
  56        if (!commit->util)
  57                commit->util = xmalloc(sizeof(struct commit_name));
  58        name = commit->util;
  59        name->head_name = head_name;
  60        name->generation = nth;
  61}
  62
  63/* Parent is the first parent of the commit.  We may name it
  64 * as (n+1)th generation ancestor of the same head_name as
  65 * commit is nth generation ancestor of, if that generation
  66 * number is better than the name it already has.
  67 */
  68static void name_parent(struct commit *commit, struct commit *parent)
  69{
  70        struct commit_name *commit_name = commit->util;
  71        struct commit_name *parent_name = parent->util;
  72        if (!commit_name)
  73                return;
  74        if (!parent_name ||
  75            commit_name->generation + 1 < parent_name->generation)
  76                name_commit(parent, commit_name->head_name,
  77                            commit_name->generation + 1);
  78}
  79
  80static int name_first_parent_chain(struct commit *c)
  81{
  82        int i = 0;
  83        while (c) {
  84                struct commit *p;
  85                if (!c->util)
  86                        break;
  87                if (!c->parents)
  88                        break;
  89                p = c->parents->item;
  90                if (!p->util) {
  91                        name_parent(c, p);
  92                        i++;
  93                }
  94                else
  95                        break;
  96                c = p;
  97        }
  98        return i;
  99}
 100
 101static void name_commits(struct commit_list *list,
 102                         struct commit **rev,
 103                         char **ref_name,
 104                         int num_rev)
 105{
 106        struct commit_list *cl;
 107        struct commit *c;
 108        int i;
 109
 110        /* First give names to the given heads */
 111        for (cl = list; cl; cl = cl->next) {
 112                c = cl->item;
 113                if (c->util)
 114                        continue;
 115                for (i = 0; i < num_rev; i++) {
 116                        if (rev[i] == c) {
 117                                name_commit(c, ref_name[i], 0);
 118                                break;
 119                        }
 120                }
 121        }
 122
 123        /* Then commits on the first parent ancestry chain */
 124        do {
 125                i = 0;
 126                for (cl = list; cl; cl = cl->next) {
 127                        i += name_first_parent_chain(cl->item);
 128                }
 129        } while (i);
 130
 131        /* Finally, any unnamed commits */
 132        do {
 133                i = 0;
 134                for (cl = list; cl; cl = cl->next) {
 135                        struct commit_list *parents;
 136                        struct commit_name *n;
 137                        int nth;
 138                        c = cl->item;
 139                        if (!c->util)
 140                                continue;
 141                        n = c->util;
 142                        parents = c->parents;
 143                        nth = 0;
 144                        while (parents) {
 145                                struct commit *p = parents->item;
 146                                char newname[1000], *en;
 147                                parents = parents->next;
 148                                nth++;
 149                                if (p->util)
 150                                        continue;
 151                                en = newname;
 152                                switch (n->generation) {
 153                                case 0:
 154                                        en += sprintf(en, "%s", n->head_name);
 155                                        break;
 156                                case 1:
 157                                        en += sprintf(en, "%s^", n->head_name);
 158                                        break;
 159                                default:
 160                                        en += sprintf(en, "%s~%d",
 161                                                n->head_name, n->generation);
 162                                        break;
 163                                }
 164                                if (nth == 1)
 165                                        en += sprintf(en, "^");
 166                                else
 167                                        en += sprintf(en, "^%d", nth);
 168                                name_commit(p, xstrdup(newname), 0);
 169                                i++;
 170                                name_first_parent_chain(p);
 171                        }
 172                }
 173        } while (i);
 174}
 175
 176static int mark_seen(struct commit *commit, struct commit_list **seen_p)
 177{
 178        if (!commit->object.flags) {
 179                commit_list_insert(commit, seen_p);
 180                return 1;
 181        }
 182        return 0;
 183}
 184
 185static void join_revs(struct commit_list **list_p,
 186                      struct commit_list **seen_p,
 187                      int num_rev, int extra)
 188{
 189        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 190        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 191
 192        while (*list_p) {
 193                struct commit_list *parents;
 194                int still_interesting = !!interesting(*list_p);
 195                struct commit *commit = pop_one_commit(list_p);
 196                int flags = commit->object.flags & all_mask;
 197
 198                if (!still_interesting && extra <= 0)
 199                        break;
 200
 201                mark_seen(commit, seen_p);
 202                if ((flags & all_revs) == all_revs)
 203                        flags |= UNINTERESTING;
 204                parents = commit->parents;
 205
 206                while (parents) {
 207                        struct commit *p = parents->item;
 208                        int this_flag = p->object.flags;
 209                        parents = parents->next;
 210                        if ((this_flag & flags) == flags)
 211                                continue;
 212                        if (!p->object.parsed)
 213                                parse_commit(p);
 214                        if (mark_seen(p, seen_p) && !still_interesting)
 215                                extra--;
 216                        p->object.flags |= flags;
 217                        insert_by_date(p, list_p);
 218                }
 219        }
 220
 221        /*
 222         * Postprocess to complete well-poisoning.
 223         *
 224         * At this point we have all the commits we have seen in
 225         * seen_p list.  Mark anything that can be reached from
 226         * uninteresting commits not interesting.
 227         */
 228        for (;;) {
 229                int changed = 0;
 230                struct commit_list *s;
 231                for (s = *seen_p; s; s = s->next) {
 232                        struct commit *c = s->item;
 233                        struct commit_list *parents;
 234
 235                        if (((c->object.flags & all_revs) != all_revs) &&
 236                            !(c->object.flags & UNINTERESTING))
 237                                continue;
 238
 239                        /* The current commit is either a merge base or
 240                         * already uninteresting one.  Mark its parents
 241                         * as uninteresting commits _only_ if they are
 242                         * already parsed.  No reason to find new ones
 243                         * here.
 244                         */
 245                        parents = c->parents;
 246                        while (parents) {
 247                                struct commit *p = parents->item;
 248                                parents = parents->next;
 249                                if (!(p->object.flags & UNINTERESTING)) {
 250                                        p->object.flags |= UNINTERESTING;
 251                                        changed = 1;
 252                                }
 253                        }
 254                }
 255                if (!changed)
 256                        break;
 257        }
 258}
 259
 260static void show_one_commit(struct commit *commit, int no_name)
 261{
 262        struct strbuf pretty;
 263        const char *pretty_str = "(unavailable)";
 264        struct commit_name *name = commit->util;
 265
 266        strbuf_init(&pretty, 0);
 267        if (commit->object.parsed) {
 268                pretty_print_commit(CMIT_FMT_ONELINE, commit,
 269                                    &pretty, 0, NULL, NULL, 0, 0);
 270                pretty_str = pretty.buf;
 271        }
 272        if (!prefixcmp(pretty_str, "[PATCH] "))
 273                pretty_str += 8;
 274
 275        if (!no_name) {
 276                if (name && name->head_name) {
 277                        printf("[%s", name->head_name);
 278                        if (name->generation) {
 279                                if (name->generation == 1)
 280                                        printf("^");
 281                                else
 282                                        printf("~%d", name->generation);
 283                        }
 284                        printf("] ");
 285                }
 286                else
 287                        printf("[%s] ",
 288                               find_unique_abbrev(commit->object.sha1, 7));
 289        }
 290        puts(pretty_str);
 291        strbuf_release(&pretty);
 292}
 293
 294static char *ref_name[MAX_REVS + 1];
 295static int ref_name_cnt;
 296
 297static const char *find_digit_prefix(const char *s, int *v)
 298{
 299        const char *p;
 300        int ver;
 301        char ch;
 302
 303        for (p = s, ver = 0;
 304             '0' <= (ch = *p) && ch <= '9';
 305             p++)
 306                ver = ver * 10 + ch - '0';
 307        *v = ver;
 308        return p;
 309}
 310
 311
 312static int version_cmp(const char *a, const char *b)
 313{
 314        while (1) {
 315                int va, vb;
 316
 317                a = find_digit_prefix(a, &va);
 318                b = find_digit_prefix(b, &vb);
 319                if (va != vb)
 320                        return va - vb;
 321
 322                while (1) {
 323                        int ca = *a;
 324                        int cb = *b;
 325                        if ('0' <= ca && ca <= '9')
 326                                ca = 0;
 327                        if ('0' <= cb && cb <= '9')
 328                                cb = 0;
 329                        if (ca != cb)
 330                                return ca - cb;
 331                        if (!ca)
 332                                break;
 333                        a++;
 334                        b++;
 335                }
 336                if (!*a && !*b)
 337                        return 0;
 338        }
 339}
 340
 341static int compare_ref_name(const void *a_, const void *b_)
 342{
 343        const char * const*a = a_, * const*b = b_;
 344        return version_cmp(*a, *b);
 345}
 346
 347static void sort_ref_range(int bottom, int top)
 348{
 349        qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 350              compare_ref_name);
 351}
 352
 353static int append_ref(const char *refname, const unsigned char *sha1,
 354                      int allow_dups)
 355{
 356        struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 357        int i;
 358
 359        if (!commit)
 360                return 0;
 361
 362        if (!allow_dups) {
 363                /* Avoid adding the same thing twice */
 364                for (i = 0; i < ref_name_cnt; i++)
 365                        if (!strcmp(refname, ref_name[i]))
 366                                return 0;
 367        }
 368        if (MAX_REVS <= ref_name_cnt) {
 369                fprintf(stderr, "warning: ignoring %s; "
 370                        "cannot handle more than %d refs\n",
 371                        refname, MAX_REVS);
 372                return 0;
 373        }
 374        ref_name[ref_name_cnt++] = xstrdup(refname);
 375        ref_name[ref_name_cnt] = NULL;
 376        return 0;
 377}
 378
 379static int append_head_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 380{
 381        unsigned char tmp[20];
 382        int ofs = 11;
 383        if (prefixcmp(refname, "refs/heads/"))
 384                return 0;
 385        /* If both heads/foo and tags/foo exists, get_sha1 would
 386         * get confused.
 387         */
 388        if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 389                ofs = 5;
 390        return append_ref(refname + ofs, sha1, 0);
 391}
 392
 393static int append_remote_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 394{
 395        unsigned char tmp[20];
 396        int ofs = 13;
 397        if (prefixcmp(refname, "refs/remotes/"))
 398                return 0;
 399        /* If both heads/foo and tags/foo exists, get_sha1 would
 400         * get confused.
 401         */
 402        if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 403                ofs = 5;
 404        return append_ref(refname + ofs, sha1, 0);
 405}
 406
 407static int append_tag_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 408{
 409        if (prefixcmp(refname, "refs/tags/"))
 410                return 0;
 411        return append_ref(refname + 5, sha1, 0);
 412}
 413
 414static const char *match_ref_pattern = NULL;
 415static int match_ref_slash = 0;
 416static int count_slash(const char *s)
 417{
 418        int cnt = 0;
 419        while (*s)
 420                if (*s++ == '/')
 421                        cnt++;
 422        return cnt;
 423}
 424
 425static int append_matching_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 426{
 427        /* we want to allow pattern hold/<asterisk> to show all
 428         * branches under refs/heads/hold/, and v0.99.9? to show
 429         * refs/tags/v0.99.9a and friends.
 430         */
 431        const char *tail;
 432        int slash = count_slash(refname);
 433        for (tail = refname; *tail && match_ref_slash < slash; )
 434                if (*tail++ == '/')
 435                        slash--;
 436        if (!*tail)
 437                return 0;
 438        if (fnmatch(match_ref_pattern, tail, 0))
 439                return 0;
 440        if (!prefixcmp(refname, "refs/heads/"))
 441                return append_head_ref(refname, sha1, flag, cb_data);
 442        if (!prefixcmp(refname, "refs/tags/"))
 443                return append_tag_ref(refname, sha1, flag, cb_data);
 444        return append_ref(refname, sha1, 0);
 445}
 446
 447static void snarf_refs(int head, int remotes)
 448{
 449        if (head) {
 450                int orig_cnt = ref_name_cnt;
 451                for_each_ref(append_head_ref, NULL);
 452                sort_ref_range(orig_cnt, ref_name_cnt);
 453        }
 454        if (remotes) {
 455                int orig_cnt = ref_name_cnt;
 456                for_each_ref(append_remote_ref, NULL);
 457                sort_ref_range(orig_cnt, ref_name_cnt);
 458        }
 459}
 460
 461static int rev_is_head(char *head, int headlen, char *name,
 462                       unsigned char *head_sha1, unsigned char *sha1)
 463{
 464        if ((!head[0]) ||
 465            (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
 466                return 0;
 467        if (!prefixcmp(head, "refs/heads/"))
 468                head += 11;
 469        if (!prefixcmp(name, "refs/heads/"))
 470                name += 11;
 471        else if (!prefixcmp(name, "heads/"))
 472                name += 6;
 473        return !strcmp(head, name);
 474}
 475
 476static int show_merge_base(struct commit_list *seen, int num_rev)
 477{
 478        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 479        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 480        int exit_status = 1;
 481
 482        while (seen) {
 483                struct commit *commit = pop_one_commit(&seen);
 484                int flags = commit->object.flags & all_mask;
 485                if (!(flags & UNINTERESTING) &&
 486                    ((flags & all_revs) == all_revs)) {
 487                        puts(sha1_to_hex(commit->object.sha1));
 488                        exit_status = 0;
 489                        commit->object.flags |= UNINTERESTING;
 490                }
 491        }
 492        return exit_status;
 493}
 494
 495static int show_independent(struct commit **rev,
 496                            int num_rev,
 497                            char **ref_name,
 498                            unsigned int *rev_mask)
 499{
 500        int i;
 501
 502        for (i = 0; i < num_rev; i++) {
 503                struct commit *commit = rev[i];
 504                unsigned int flag = rev_mask[i];
 505
 506                if (commit->object.flags == flag)
 507                        puts(sha1_to_hex(commit->object.sha1));
 508                commit->object.flags |= UNINTERESTING;
 509        }
 510        return 0;
 511}
 512
 513static void append_one_rev(const char *av)
 514{
 515        unsigned char revkey[20];
 516        if (!get_sha1(av, revkey)) {
 517                append_ref(av, revkey, 0);
 518                return;
 519        }
 520        if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
 521                /* glob style match */
 522                int saved_matches = ref_name_cnt;
 523                match_ref_pattern = av;
 524                match_ref_slash = count_slash(av);
 525                for_each_ref(append_matching_ref, NULL);
 526                if (saved_matches == ref_name_cnt &&
 527                    ref_name_cnt < MAX_REVS)
 528                        error("no matching refs with %s", av);
 529                if (saved_matches + 1 < ref_name_cnt)
 530                        sort_ref_range(saved_matches, ref_name_cnt);
 531                return;
 532        }
 533        die("bad sha1 reference %s", av);
 534}
 535
 536static int git_show_branch_config(const char *var, const char *value)
 537{
 538        if (!strcmp(var, "showbranch.default")) {
 539                if (default_alloc <= default_num + 1) {
 540                        default_alloc = default_alloc * 3 / 2 + 20;
 541                        default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
 542                }
 543                default_arg[default_num++] = xstrdup(value);
 544                default_arg[default_num] = NULL;
 545                return 0;
 546        }
 547
 548        return git_default_config(var, value);
 549}
 550
 551static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
 552{
 553        /* If the commit is tip of the named branches, do not
 554         * omit it.
 555         * Otherwise, if it is a merge that is reachable from only one
 556         * tip, it is not that interesting.
 557         */
 558        int i, flag, count;
 559        for (i = 0; i < n; i++)
 560                if (rev[i] == commit)
 561                        return 0;
 562        flag = commit->object.flags;
 563        for (i = count = 0; i < n; i++) {
 564                if (flag & (1u << (i + REV_SHIFT)))
 565                        count++;
 566        }
 567        if (count == 1)
 568                return 1;
 569        return 0;
 570}
 571
 572static void parse_reflog_param(const char *arg, int *cnt, const char **base)
 573{
 574        char *ep;
 575        *cnt = strtoul(arg, &ep, 10);
 576        if (*ep == ',')
 577                *base = ep + 1;
 578        else if (*ep)
 579                die("unrecognized reflog param '%s'", arg + 9);
 580        else
 581                *base = NULL;
 582        if (*cnt <= 0)
 583                *cnt = DEFAULT_REFLOG;
 584}
 585
 586int cmd_show_branch(int ac, const char **av, const char *prefix)
 587{
 588        struct commit *rev[MAX_REVS], *commit;
 589        char *reflog_msg[MAX_REVS];
 590        struct commit_list *list = NULL, *seen = NULL;
 591        unsigned int rev_mask[MAX_REVS];
 592        int num_rev, i, extra = 0;
 593        int all_heads = 0, all_remotes = 0;
 594        int all_mask, all_revs;
 595        int lifo = 1;
 596        char head[128];
 597        const char *head_p;
 598        int head_len;
 599        unsigned char head_sha1[20];
 600        int merge_base = 0;
 601        int independent = 0;
 602        int no_name = 0;
 603        int sha1_name = 0;
 604        int shown_merge_point = 0;
 605        int with_current_branch = 0;
 606        int head_at = -1;
 607        int topics = 0;
 608        int dense = 1;
 609        int reflog = 0;
 610        const char *reflog_base = NULL;
 611
 612        git_config(git_show_branch_config);
 613
 614        /* If nothing is specified, try the default first */
 615        if (ac == 1 && default_num) {
 616                ac = default_num + 1;
 617                av = default_arg - 1; /* ick; we would not address av[0] */
 618        }
 619
 620        while (1 < ac && av[1][0] == '-') {
 621                const char *arg = av[1];
 622                if (!strcmp(arg, "--")) {
 623                        ac--; av++;
 624                        break;
 625                }
 626                else if (!strcmp(arg, "--all") || !strcmp(arg, "-a"))
 627                        all_heads = all_remotes = 1;
 628                else if (!strcmp(arg, "--remotes") || !strcmp(arg, "-r"))
 629                        all_remotes = 1;
 630                else if (!strcmp(arg, "--more"))
 631                        extra = 1;
 632                else if (!strcmp(arg, "--list"))
 633                        extra = -1;
 634                else if (!strcmp(arg, "--no-name"))
 635                        no_name = 1;
 636                else if (!strcmp(arg, "--current"))
 637                        with_current_branch = 1;
 638                else if (!strcmp(arg, "--sha1-name"))
 639                        sha1_name = 1;
 640                else if (!prefixcmp(arg, "--more="))
 641                        extra = atoi(arg + 7);
 642                else if (!strcmp(arg, "--merge-base"))
 643                        merge_base = 1;
 644                else if (!strcmp(arg, "--independent"))
 645                        independent = 1;
 646                else if (!strcmp(arg, "--topo-order"))
 647                        lifo = 1;
 648                else if (!strcmp(arg, "--topics"))
 649                        topics = 1;
 650                else if (!strcmp(arg, "--sparse"))
 651                        dense = 0;
 652                else if (!strcmp(arg, "--date-order"))
 653                        lifo = 0;
 654                else if (!strcmp(arg, "--reflog") || !strcmp(arg, "-g")) {
 655                        reflog = DEFAULT_REFLOG;
 656                }
 657                else if (!prefixcmp(arg, "--reflog="))
 658                        parse_reflog_param(arg + 9, &reflog, &reflog_base);
 659                else if (!prefixcmp(arg, "-g="))
 660                        parse_reflog_param(arg + 3, &reflog, &reflog_base);
 661                else
 662                        usage(show_branch_usage);
 663                ac--; av++;
 664        }
 665        ac--; av++;
 666
 667        if (extra || reflog) {
 668                /* "listing" mode is incompatible with
 669                 * independent nor merge-base modes.
 670                 */
 671                if (independent || merge_base)
 672                        usage(show_branch_usage);
 673                if (reflog && ((0 < extra) || all_heads || all_remotes))
 674                        /*
 675                         * Asking for --more in reflog mode does not
 676                         * make sense.  --list is Ok.
 677                         *
 678                         * Also --all and --remotes do not make sense either.
 679                         */
 680                        usage(show_branch_usage_reflog);
 681        }
 682
 683        /* If nothing is specified, show all branches by default */
 684        if (ac + all_heads + all_remotes == 0)
 685                all_heads = 1;
 686
 687        if (reflog) {
 688                unsigned char sha1[20];
 689                char nth_desc[256];
 690                char *ref;
 691                int base = 0;
 692
 693                if (ac == 0) {
 694                        static const char *fake_av[2];
 695                        const char *refname;
 696
 697                        refname = resolve_ref("HEAD", sha1, 1, NULL);
 698                        fake_av[0] = xstrdup(refname);
 699                        fake_av[1] = NULL;
 700                        av = fake_av;
 701                        ac = 1;
 702                }
 703                if (ac != 1)
 704                        die("--reflog option needs one branch name");
 705
 706                if (MAX_REVS < reflog)
 707                        die("Only %d entries can be shown at one time.",
 708                            MAX_REVS);
 709                if (!dwim_ref(*av, strlen(*av), sha1, &ref))
 710                        die("No such ref %s", *av);
 711
 712                /* Has the base been specified? */
 713                if (reflog_base) {
 714                        char *ep;
 715                        base = strtoul(reflog_base, &ep, 10);
 716                        if (*ep) {
 717                                /* Ah, that is a date spec... */
 718                                unsigned long at;
 719                                at = approxidate(reflog_base);
 720                                read_ref_at(ref, at, -1, sha1, NULL,
 721                                            NULL, NULL, &base);
 722                        }
 723                }
 724
 725                for (i = 0; i < reflog; i++) {
 726                        char *logmsg, *m;
 727                        const char *msg;
 728                        unsigned long timestamp;
 729                        int tz;
 730
 731                        if (read_ref_at(ref, 0, base+i, sha1, &logmsg,
 732                                        &timestamp, &tz, NULL)) {
 733                                reflog = i;
 734                                break;
 735                        }
 736                        msg = strchr(logmsg, '\t');
 737                        if (!msg)
 738                                msg = "(none)";
 739                        else
 740                                msg++;
 741                        m = xmalloc(strlen(msg) + 200);
 742                        sprintf(m, "(%s) %s",
 743                                show_date(timestamp, tz, 1),
 744                                msg);
 745                        reflog_msg[i] = m;
 746                        free(logmsg);
 747                        sprintf(nth_desc, "%s@{%d}", *av, base+i);
 748                        append_ref(nth_desc, sha1, 1);
 749                }
 750        }
 751        else if (all_heads + all_remotes)
 752                snarf_refs(all_heads, all_remotes);
 753        else {
 754                while (0 < ac) {
 755                        append_one_rev(*av);
 756                        ac--; av++;
 757                }
 758        }
 759
 760        head_p = resolve_ref("HEAD", head_sha1, 1, NULL);
 761        if (head_p) {
 762                head_len = strlen(head_p);
 763                memcpy(head, head_p, head_len + 1);
 764        }
 765        else {
 766                head_len = 0;
 767                head[0] = 0;
 768        }
 769
 770        if (with_current_branch && head_p) {
 771                int has_head = 0;
 772                for (i = 0; !has_head && i < ref_name_cnt; i++) {
 773                        /* We are only interested in adding the branch
 774                         * HEAD points at.
 775                         */
 776                        if (rev_is_head(head,
 777                                        head_len,
 778                                        ref_name[i],
 779                                        head_sha1, NULL))
 780                                has_head++;
 781                }
 782                if (!has_head) {
 783                        int pfxlen = strlen("refs/heads/");
 784                        append_one_rev(head + pfxlen);
 785                }
 786        }
 787
 788        if (!ref_name_cnt) {
 789                fprintf(stderr, "No revs to be shown.\n");
 790                exit(0);
 791        }
 792
 793        for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 794                unsigned char revkey[20];
 795                unsigned int flag = 1u << (num_rev + REV_SHIFT);
 796
 797                if (MAX_REVS <= num_rev)
 798                        die("cannot handle more than %d revs.", MAX_REVS);
 799                if (get_sha1(ref_name[num_rev], revkey))
 800                        die("'%s' is not a valid ref.", ref_name[num_rev]);
 801                commit = lookup_commit_reference(revkey);
 802                if (!commit)
 803                        die("cannot find commit %s (%s)",
 804                            ref_name[num_rev], revkey);
 805                parse_commit(commit);
 806                mark_seen(commit, &seen);
 807
 808                /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 809                 * and so on.  REV_SHIFT bits from bit 0 are used for
 810                 * internal bookkeeping.
 811                 */
 812                commit->object.flags |= flag;
 813                if (commit->object.flags == flag)
 814                        insert_by_date(commit, &list);
 815                rev[num_rev] = commit;
 816        }
 817        for (i = 0; i < num_rev; i++)
 818                rev_mask[i] = rev[i]->object.flags;
 819
 820        if (0 <= extra)
 821                join_revs(&list, &seen, num_rev, extra);
 822
 823        sort_by_date(&seen);
 824
 825        if (merge_base)
 826                return show_merge_base(seen, num_rev);
 827
 828        if (independent)
 829                return show_independent(rev, num_rev, ref_name, rev_mask);
 830
 831        /* Show list; --more=-1 means list-only */
 832        if (1 < num_rev || extra < 0) {
 833                for (i = 0; i < num_rev; i++) {
 834                        int j;
 835                        int is_head = rev_is_head(head,
 836                                                  head_len,
 837                                                  ref_name[i],
 838                                                  head_sha1,
 839                                                  rev[i]->object.sha1);
 840                        if (extra < 0)
 841                                printf("%c [%s] ",
 842                                       is_head ? '*' : ' ', ref_name[i]);
 843                        else {
 844                                for (j = 0; j < i; j++)
 845                                        putchar(' ');
 846                                printf("%c [%s] ",
 847                                       is_head ? '*' : '!', ref_name[i]);
 848                        }
 849
 850                        if (!reflog) {
 851                                /* header lines never need name */
 852                                show_one_commit(rev[i], 1);
 853                        }
 854                        else
 855                                puts(reflog_msg[i]);
 856
 857                        if (is_head)
 858                                head_at = i;
 859                }
 860                if (0 <= extra) {
 861                        for (i = 0; i < num_rev; i++)
 862                                putchar('-');
 863                        putchar('\n');
 864                }
 865        }
 866        if (extra < 0)
 867                exit(0);
 868
 869        /* Sort topologically */
 870        sort_in_topological_order(&seen, lifo);
 871
 872        /* Give names to commits */
 873        if (!sha1_name && !no_name)
 874                name_commits(seen, rev, ref_name, num_rev);
 875
 876        all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 877        all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 878
 879        while (seen) {
 880                struct commit *commit = pop_one_commit(&seen);
 881                int this_flag = commit->object.flags;
 882                int is_merge_point = ((this_flag & all_revs) == all_revs);
 883
 884                shown_merge_point |= is_merge_point;
 885
 886                if (1 < num_rev) {
 887                        int is_merge = !!(commit->parents &&
 888                                          commit->parents->next);
 889                        if (topics &&
 890                            !is_merge_point &&
 891                            (this_flag & (1u << REV_SHIFT)))
 892                                continue;
 893                        if (dense && is_merge &&
 894                            omit_in_dense(commit, rev, num_rev))
 895                                continue;
 896                        for (i = 0; i < num_rev; i++) {
 897                                int mark;
 898                                if (!(this_flag & (1u << (i + REV_SHIFT))))
 899                                        mark = ' ';
 900                                else if (is_merge)
 901                                        mark = '-';
 902                                else if (i == head_at)
 903                                        mark = '*';
 904                                else
 905                                        mark = '+';
 906                                putchar(mark);
 907                        }
 908                        putchar(' ');
 909                }
 910                show_one_commit(commit, no_name);
 911
 912                if (shown_merge_point && --extra < 0)
 913                        break;
 914        }
 915        return 0;
 916}