builtin / show-branch.con commit Merge branch 'mg/merge-ff-config' (36a45b4)
   1#include "cache.h"
   2#include "commit.h"
   3#include "refs.h"
   4#include "builtin.h"
   5#include "color.h"
   6#include "parse-options.h"
   7
   8static const char* show_branch_usage[] = {
   9    "git show-branch [-a|--all] [-r|--remotes] [--topo-order | --date-order] [--current] [--color[=<when>] | --no-color] [--sparse] [--more=<n> | --list | --independent | --merge-base] [--no-name | --sha1-name] [--topics] [(<rev> | <glob>)...]",
  10    "git show-branch (-g|--reflog)[=<n>[,<base>]] [--list] [<ref>]",
  11    NULL
  12};
  13
  14static int showbranch_use_color = -1;
  15
  16static int default_num;
  17static int default_alloc;
  18static const char **default_arg;
  19
  20#define UNINTERESTING   01
  21
  22#define REV_SHIFT        2
  23#define MAX_REVS        (FLAG_BITS - REV_SHIFT) /* should not exceed bits_per_int - REV_SHIFT */
  24
  25#define DEFAULT_REFLOG  4
  26
  27static const char *get_color_code(int idx)
  28{
  29        if (showbranch_use_color)
  30                return column_colors_ansi[idx % column_colors_ansi_max];
  31        return "";
  32}
  33
  34static const char *get_color_reset_code(void)
  35{
  36        if (showbranch_use_color)
  37                return GIT_COLOR_RESET;
  38        return "";
  39}
  40
  41static struct commit *interesting(struct commit_list *list)
  42{
  43        while (list) {
  44                struct commit *commit = list->item;
  45                list = list->next;
  46                if (commit->object.flags & UNINTERESTING)
  47                        continue;
  48                return commit;
  49        }
  50        return NULL;
  51}
  52
  53static struct commit *pop_one_commit(struct commit_list **list_p)
  54{
  55        struct commit *commit;
  56        struct commit_list *list;
  57        list = *list_p;
  58        commit = list->item;
  59        *list_p = list->next;
  60        free(list);
  61        return commit;
  62}
  63
  64struct commit_name {
  65        const char *head_name; /* which head's ancestor? */
  66        int generation; /* how many parents away from head_name */
  67};
  68
  69/* Name the commit as nth generation ancestor of head_name;
  70 * we count only the first-parent relationship for naming purposes.
  71 */
  72static void name_commit(struct commit *commit, const char *head_name, int nth)
  73{
  74        struct commit_name *name;
  75        if (!commit->util)
  76                commit->util = xmalloc(sizeof(struct commit_name));
  77        name = commit->util;
  78        name->head_name = head_name;
  79        name->generation = nth;
  80}
  81
  82/* Parent is the first parent of the commit.  We may name it
  83 * as (n+1)th generation ancestor of the same head_name as
  84 * commit is nth generation ancestor of, if that generation
  85 * number is better than the name it already has.
  86 */
  87static void name_parent(struct commit *commit, struct commit *parent)
  88{
  89        struct commit_name *commit_name = commit->util;
  90        struct commit_name *parent_name = parent->util;
  91        if (!commit_name)
  92                return;
  93        if (!parent_name ||
  94            commit_name->generation + 1 < parent_name->generation)
  95                name_commit(parent, commit_name->head_name,
  96                            commit_name->generation + 1);
  97}
  98
  99static int name_first_parent_chain(struct commit *c)
 100{
 101        int i = 0;
 102        while (c) {
 103                struct commit *p;
 104                if (!c->util)
 105                        break;
 106                if (!c->parents)
 107                        break;
 108                p = c->parents->item;
 109                if (!p->util) {
 110                        name_parent(c, p);
 111                        i++;
 112                }
 113                else
 114                        break;
 115                c = p;
 116        }
 117        return i;
 118}
 119
 120static void name_commits(struct commit_list *list,
 121                         struct commit **rev,
 122                         char **ref_name,
 123                         int num_rev)
 124{
 125        struct commit_list *cl;
 126        struct commit *c;
 127        int i;
 128
 129        /* First give names to the given heads */
 130        for (cl = list; cl; cl = cl->next) {
 131                c = cl->item;
 132                if (c->util)
 133                        continue;
 134                for (i = 0; i < num_rev; i++) {
 135                        if (rev[i] == c) {
 136                                name_commit(c, ref_name[i], 0);
 137                                break;
 138                        }
 139                }
 140        }
 141
 142        /* Then commits on the first parent ancestry chain */
 143        do {
 144                i = 0;
 145                for (cl = list; cl; cl = cl->next) {
 146                        i += name_first_parent_chain(cl->item);
 147                }
 148        } while (i);
 149
 150        /* Finally, any unnamed commits */
 151        do {
 152                i = 0;
 153                for (cl = list; cl; cl = cl->next) {
 154                        struct commit_list *parents;
 155                        struct commit_name *n;
 156                        int nth;
 157                        c = cl->item;
 158                        if (!c->util)
 159                                continue;
 160                        n = c->util;
 161                        parents = c->parents;
 162                        nth = 0;
 163                        while (parents) {
 164                                struct commit *p = parents->item;
 165                                char newname[1000], *en;
 166                                parents = parents->next;
 167                                nth++;
 168                                if (p->util)
 169                                        continue;
 170                                en = newname;
 171                                switch (n->generation) {
 172                                case 0:
 173                                        en += sprintf(en, "%s", n->head_name);
 174                                        break;
 175                                case 1:
 176                                        en += sprintf(en, "%s^", n->head_name);
 177                                        break;
 178                                default:
 179                                        en += sprintf(en, "%s~%d",
 180                                                n->head_name, n->generation);
 181                                        break;
 182                                }
 183                                if (nth == 1)
 184                                        en += sprintf(en, "^");
 185                                else
 186                                        en += sprintf(en, "^%d", nth);
 187                                name_commit(p, xstrdup(newname), 0);
 188                                i++;
 189                                name_first_parent_chain(p);
 190                        }
 191                }
 192        } while (i);
 193}
 194
 195static int mark_seen(struct commit *commit, struct commit_list **seen_p)
 196{
 197        if (!commit->object.flags) {
 198                commit_list_insert(commit, seen_p);
 199                return 1;
 200        }
 201        return 0;
 202}
 203
 204static void join_revs(struct commit_list **list_p,
 205                      struct commit_list **seen_p,
 206                      int num_rev, int extra)
 207{
 208        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 209        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 210
 211        while (*list_p) {
 212                struct commit_list *parents;
 213                int still_interesting = !!interesting(*list_p);
 214                struct commit *commit = pop_one_commit(list_p);
 215                int flags = commit->object.flags & all_mask;
 216
 217                if (!still_interesting && extra <= 0)
 218                        break;
 219
 220                mark_seen(commit, seen_p);
 221                if ((flags & all_revs) == all_revs)
 222                        flags |= UNINTERESTING;
 223                parents = commit->parents;
 224
 225                while (parents) {
 226                        struct commit *p = parents->item;
 227                        int this_flag = p->object.flags;
 228                        parents = parents->next;
 229                        if ((this_flag & flags) == flags)
 230                                continue;
 231                        if (!p->object.parsed)
 232                                parse_commit(p);
 233                        if (mark_seen(p, seen_p) && !still_interesting)
 234                                extra--;
 235                        p->object.flags |= flags;
 236                        commit_list_insert_by_date(p, list_p);
 237                }
 238        }
 239
 240        /*
 241         * Postprocess to complete well-poisoning.
 242         *
 243         * At this point we have all the commits we have seen in
 244         * seen_p list.  Mark anything that can be reached from
 245         * uninteresting commits not interesting.
 246         */
 247        for (;;) {
 248                int changed = 0;
 249                struct commit_list *s;
 250                for (s = *seen_p; s; s = s->next) {
 251                        struct commit *c = s->item;
 252                        struct commit_list *parents;
 253
 254                        if (((c->object.flags & all_revs) != all_revs) &&
 255                            !(c->object.flags & UNINTERESTING))
 256                                continue;
 257
 258                        /* The current commit is either a merge base or
 259                         * already uninteresting one.  Mark its parents
 260                         * as uninteresting commits _only_ if they are
 261                         * already parsed.  No reason to find new ones
 262                         * here.
 263                         */
 264                        parents = c->parents;
 265                        while (parents) {
 266                                struct commit *p = parents->item;
 267                                parents = parents->next;
 268                                if (!(p->object.flags & UNINTERESTING)) {
 269                                        p->object.flags |= UNINTERESTING;
 270                                        changed = 1;
 271                                }
 272                        }
 273                }
 274                if (!changed)
 275                        break;
 276        }
 277}
 278
 279static void show_one_commit(struct commit *commit, int no_name)
 280{
 281        struct strbuf pretty = STRBUF_INIT;
 282        const char *pretty_str = "(unavailable)";
 283        struct commit_name *name = commit->util;
 284
 285        if (commit->object.parsed) {
 286                struct pretty_print_context ctx = {0};
 287                pretty_print_commit(CMIT_FMT_ONELINE, commit, &pretty, &ctx);
 288                pretty_str = pretty.buf;
 289        }
 290        if (!prefixcmp(pretty_str, "[PATCH] "))
 291                pretty_str += 8;
 292
 293        if (!no_name) {
 294                if (name && name->head_name) {
 295                        printf("[%s", name->head_name);
 296                        if (name->generation) {
 297                                if (name->generation == 1)
 298                                        printf("^");
 299                                else
 300                                        printf("~%d", name->generation);
 301                        }
 302                        printf("] ");
 303                }
 304                else
 305                        printf("[%s] ",
 306                               find_unique_abbrev(commit->object.sha1,
 307                                                  DEFAULT_ABBREV));
 308        }
 309        puts(pretty_str);
 310        strbuf_release(&pretty);
 311}
 312
 313static char *ref_name[MAX_REVS + 1];
 314static int ref_name_cnt;
 315
 316static const char *find_digit_prefix(const char *s, int *v)
 317{
 318        const char *p;
 319        int ver;
 320        char ch;
 321
 322        for (p = s, ver = 0;
 323             '0' <= (ch = *p) && ch <= '9';
 324             p++)
 325                ver = ver * 10 + ch - '0';
 326        *v = ver;
 327        return p;
 328}
 329
 330
 331static int version_cmp(const char *a, const char *b)
 332{
 333        while (1) {
 334                int va, vb;
 335
 336                a = find_digit_prefix(a, &va);
 337                b = find_digit_prefix(b, &vb);
 338                if (va != vb)
 339                        return va - vb;
 340
 341                while (1) {
 342                        int ca = *a;
 343                        int cb = *b;
 344                        if ('0' <= ca && ca <= '9')
 345                                ca = 0;
 346                        if ('0' <= cb && cb <= '9')
 347                                cb = 0;
 348                        if (ca != cb)
 349                                return ca - cb;
 350                        if (!ca)
 351                                break;
 352                        a++;
 353                        b++;
 354                }
 355                if (!*a && !*b)
 356                        return 0;
 357        }
 358}
 359
 360static int compare_ref_name(const void *a_, const void *b_)
 361{
 362        const char * const*a = a_, * const*b = b_;
 363        return version_cmp(*a, *b);
 364}
 365
 366static void sort_ref_range(int bottom, int top)
 367{
 368        qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 369              compare_ref_name);
 370}
 371
 372static int append_ref(const char *refname, const unsigned char *sha1,
 373                      int allow_dups)
 374{
 375        struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 376        int i;
 377
 378        if (!commit)
 379                return 0;
 380
 381        if (!allow_dups) {
 382                /* Avoid adding the same thing twice */
 383                for (i = 0; i < ref_name_cnt; i++)
 384                        if (!strcmp(refname, ref_name[i]))
 385                                return 0;
 386        }
 387        if (MAX_REVS <= ref_name_cnt) {
 388                warning("ignoring %s; cannot handle more than %d refs",
 389                        refname, MAX_REVS);
 390                return 0;
 391        }
 392        ref_name[ref_name_cnt++] = xstrdup(refname);
 393        ref_name[ref_name_cnt] = NULL;
 394        return 0;
 395}
 396
 397static int append_head_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 398{
 399        unsigned char tmp[20];
 400        int ofs = 11;
 401        if (prefixcmp(refname, "refs/heads/"))
 402                return 0;
 403        /* If both heads/foo and tags/foo exists, get_sha1 would
 404         * get confused.
 405         */
 406        if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 407                ofs = 5;
 408        return append_ref(refname + ofs, sha1, 0);
 409}
 410
 411static int append_remote_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 412{
 413        unsigned char tmp[20];
 414        int ofs = 13;
 415        if (prefixcmp(refname, "refs/remotes/"))
 416                return 0;
 417        /* If both heads/foo and tags/foo exists, get_sha1 would
 418         * get confused.
 419         */
 420        if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 421                ofs = 5;
 422        return append_ref(refname + ofs, sha1, 0);
 423}
 424
 425static int append_tag_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 426{
 427        if (prefixcmp(refname, "refs/tags/"))
 428                return 0;
 429        return append_ref(refname + 5, sha1, 0);
 430}
 431
 432static const char *match_ref_pattern = NULL;
 433static int match_ref_slash = 0;
 434static int count_slash(const char *s)
 435{
 436        int cnt = 0;
 437        while (*s)
 438                if (*s++ == '/')
 439                        cnt++;
 440        return cnt;
 441}
 442
 443static int append_matching_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 444{
 445        /* we want to allow pattern hold/<asterisk> to show all
 446         * branches under refs/heads/hold/, and v0.99.9? to show
 447         * refs/tags/v0.99.9a and friends.
 448         */
 449        const char *tail;
 450        int slash = count_slash(refname);
 451        for (tail = refname; *tail && match_ref_slash < slash; )
 452                if (*tail++ == '/')
 453                        slash--;
 454        if (!*tail)
 455                return 0;
 456        if (fnmatch(match_ref_pattern, tail, 0))
 457                return 0;
 458        if (!prefixcmp(refname, "refs/heads/"))
 459                return append_head_ref(refname, sha1, flag, cb_data);
 460        if (!prefixcmp(refname, "refs/tags/"))
 461                return append_tag_ref(refname, sha1, flag, cb_data);
 462        return append_ref(refname, sha1, 0);
 463}
 464
 465static void snarf_refs(int head, int remotes)
 466{
 467        if (head) {
 468                int orig_cnt = ref_name_cnt;
 469                for_each_ref(append_head_ref, NULL);
 470                sort_ref_range(orig_cnt, ref_name_cnt);
 471        }
 472        if (remotes) {
 473                int orig_cnt = ref_name_cnt;
 474                for_each_ref(append_remote_ref, NULL);
 475                sort_ref_range(orig_cnt, ref_name_cnt);
 476        }
 477}
 478
 479static int rev_is_head(char *head, int headlen, char *name,
 480                       unsigned char *head_sha1, unsigned char *sha1)
 481{
 482        if ((!head[0]) ||
 483            (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
 484                return 0;
 485        if (!prefixcmp(head, "refs/heads/"))
 486                head += 11;
 487        if (!prefixcmp(name, "refs/heads/"))
 488                name += 11;
 489        else if (!prefixcmp(name, "heads/"))
 490                name += 6;
 491        return !strcmp(head, name);
 492}
 493
 494static int show_merge_base(struct commit_list *seen, int num_rev)
 495{
 496        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 497        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 498        int exit_status = 1;
 499
 500        while (seen) {
 501                struct commit *commit = pop_one_commit(&seen);
 502                int flags = commit->object.flags & all_mask;
 503                if (!(flags & UNINTERESTING) &&
 504                    ((flags & all_revs) == all_revs)) {
 505                        puts(sha1_to_hex(commit->object.sha1));
 506                        exit_status = 0;
 507                        commit->object.flags |= UNINTERESTING;
 508                }
 509        }
 510        return exit_status;
 511}
 512
 513static int show_independent(struct commit **rev,
 514                            int num_rev,
 515                            char **ref_name,
 516                            unsigned int *rev_mask)
 517{
 518        int i;
 519
 520        for (i = 0; i < num_rev; i++) {
 521                struct commit *commit = rev[i];
 522                unsigned int flag = rev_mask[i];
 523
 524                if (commit->object.flags == flag)
 525                        puts(sha1_to_hex(commit->object.sha1));
 526                commit->object.flags |= UNINTERESTING;
 527        }
 528        return 0;
 529}
 530
 531static void append_one_rev(const char *av)
 532{
 533        unsigned char revkey[20];
 534        if (!get_sha1(av, revkey)) {
 535                append_ref(av, revkey, 0);
 536                return;
 537        }
 538        if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
 539                /* glob style match */
 540                int saved_matches = ref_name_cnt;
 541                match_ref_pattern = av;
 542                match_ref_slash = count_slash(av);
 543                for_each_ref(append_matching_ref, NULL);
 544                if (saved_matches == ref_name_cnt &&
 545                    ref_name_cnt < MAX_REVS)
 546                        error("no matching refs with %s", av);
 547                if (saved_matches + 1 < ref_name_cnt)
 548                        sort_ref_range(saved_matches, ref_name_cnt);
 549                return;
 550        }
 551        die("bad sha1 reference %s", av);
 552}
 553
 554static int git_show_branch_config(const char *var, const char *value, void *cb)
 555{
 556        if (!strcmp(var, "showbranch.default")) {
 557                if (!value)
 558                        return config_error_nonbool(var);
 559                /*
 560                 * default_arg is now passed to parse_options(), so we need to
 561                 * mimic the real argv a bit better.
 562                 */
 563                if (!default_num) {
 564                        default_alloc = 20;
 565                        default_arg = xcalloc(default_alloc, sizeof(*default_arg));
 566                        default_arg[default_num++] = "show-branch";
 567                } else if (default_alloc <= default_num + 1) {
 568                        default_alloc = default_alloc * 3 / 2 + 20;
 569                        default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
 570                }
 571                default_arg[default_num++] = xstrdup(value);
 572                default_arg[default_num] = NULL;
 573                return 0;
 574        }
 575
 576        if (!strcmp(var, "color.showbranch")) {
 577                showbranch_use_color = git_config_colorbool(var, value, -1);
 578                return 0;
 579        }
 580
 581        return git_color_default_config(var, value, cb);
 582}
 583
 584static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
 585{
 586        /* If the commit is tip of the named branches, do not
 587         * omit it.
 588         * Otherwise, if it is a merge that is reachable from only one
 589         * tip, it is not that interesting.
 590         */
 591        int i, flag, count;
 592        for (i = 0; i < n; i++)
 593                if (rev[i] == commit)
 594                        return 0;
 595        flag = commit->object.flags;
 596        for (i = count = 0; i < n; i++) {
 597                if (flag & (1u << (i + REV_SHIFT)))
 598                        count++;
 599        }
 600        if (count == 1)
 601                return 1;
 602        return 0;
 603}
 604
 605static int reflog = 0;
 606
 607static int parse_reflog_param(const struct option *opt, const char *arg,
 608                              int unset)
 609{
 610        char *ep;
 611        const char **base = (const char **)opt->value;
 612        if (!arg)
 613                arg = "";
 614        reflog = strtoul(arg, &ep, 10);
 615        if (*ep == ',')
 616                *base = ep + 1;
 617        else if (*ep)
 618                return error("unrecognized reflog param '%s'", arg);
 619        else
 620                *base = NULL;
 621        if (reflog <= 0)
 622                reflog = DEFAULT_REFLOG;
 623        return 0;
 624}
 625
 626int cmd_show_branch(int ac, const char **av, const char *prefix)
 627{
 628        struct commit *rev[MAX_REVS], *commit;
 629        char *reflog_msg[MAX_REVS];
 630        struct commit_list *list = NULL, *seen = NULL;
 631        unsigned int rev_mask[MAX_REVS];
 632        int num_rev, i, extra = 0;
 633        int all_heads = 0, all_remotes = 0;
 634        int all_mask, all_revs;
 635        int lifo = 1;
 636        char head[128];
 637        const char *head_p;
 638        int head_len;
 639        unsigned char head_sha1[20];
 640        int merge_base = 0;
 641        int independent = 0;
 642        int no_name = 0;
 643        int sha1_name = 0;
 644        int shown_merge_point = 0;
 645        int with_current_branch = 0;
 646        int head_at = -1;
 647        int topics = 0;
 648        int dense = 1;
 649        const char *reflog_base = NULL;
 650        struct option builtin_show_branch_options[] = {
 651                OPT_BOOLEAN('a', "all", &all_heads,
 652                            "show remote-tracking and local branches"),
 653                OPT_BOOLEAN('r', "remotes", &all_remotes,
 654                            "show remote-tracking branches"),
 655                OPT__COLOR(&showbranch_use_color,
 656                            "color '*!+-' corresponding to the branch"),
 657                { OPTION_INTEGER, 0, "more", &extra, "n",
 658                            "show <n> more commits after the common ancestor",
 659                            PARSE_OPT_OPTARG, NULL, (intptr_t)1 },
 660                OPT_SET_INT(0, "list", &extra, "synonym to more=-1", -1),
 661                OPT_BOOLEAN(0, "no-name", &no_name, "suppress naming strings"),
 662                OPT_BOOLEAN(0, "current", &with_current_branch,
 663                            "include the current branch"),
 664                OPT_BOOLEAN(0, "sha1-name", &sha1_name,
 665                            "name commits with their object names"),
 666                OPT_BOOLEAN(0, "merge-base", &merge_base,
 667                            "show possible merge bases"),
 668                OPT_BOOLEAN(0, "independent", &independent,
 669                            "show refs unreachable from any other ref"),
 670                OPT_BOOLEAN(0, "topo-order", &lifo,
 671                            "show commits in topological order"),
 672                OPT_BOOLEAN(0, "topics", &topics,
 673                            "show only commits not on the first branch"),
 674                OPT_SET_INT(0, "sparse", &dense,
 675                            "show merges reachable from only one tip", 0),
 676                OPT_SET_INT(0, "date-order", &lifo,
 677                            "show commits where no parent comes before its "
 678                            "children", 0),
 679                { OPTION_CALLBACK, 'g', "reflog", &reflog_base, "<n>[,<base>]",
 680                            "show <n> most recent ref-log entries starting at "
 681                            "base",
 682                            PARSE_OPT_OPTARG | PARSE_OPT_LITERAL_ARGHELP,
 683                            parse_reflog_param },
 684                OPT_END()
 685        };
 686
 687        git_config(git_show_branch_config, NULL);
 688
 689        if (showbranch_use_color == -1)
 690                showbranch_use_color = git_use_color_default;
 691
 692        /* If nothing is specified, try the default first */
 693        if (ac == 1 && default_num) {
 694                ac = default_num;
 695                av = default_arg;
 696        }
 697
 698        ac = parse_options(ac, av, prefix, builtin_show_branch_options,
 699                           show_branch_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 700        if (all_heads)
 701                all_remotes = 1;
 702
 703        if (extra || reflog) {
 704                /* "listing" mode is incompatible with
 705                 * independent nor merge-base modes.
 706                 */
 707                if (independent || merge_base)
 708                        usage_with_options(show_branch_usage,
 709                                           builtin_show_branch_options);
 710                if (reflog && ((0 < extra) || all_heads || all_remotes))
 711                        /*
 712                         * Asking for --more in reflog mode does not
 713                         * make sense.  --list is Ok.
 714                         *
 715                         * Also --all and --remotes do not make sense either.
 716                         */
 717                        die("--reflog is incompatible with --all, --remotes, "
 718                            "--independent or --merge-base");
 719        }
 720
 721        /* If nothing is specified, show all branches by default */
 722        if (ac + all_heads + all_remotes == 0)
 723                all_heads = 1;
 724
 725        if (reflog) {
 726                unsigned char sha1[20];
 727                char nth_desc[256];
 728                char *ref;
 729                int base = 0;
 730
 731                if (ac == 0) {
 732                        static const char *fake_av[2];
 733                        const char *refname;
 734
 735                        refname = resolve_ref("HEAD", sha1, 1, NULL);
 736                        fake_av[0] = xstrdup(refname);
 737                        fake_av[1] = NULL;
 738                        av = fake_av;
 739                        ac = 1;
 740                }
 741                if (ac != 1)
 742                        die("--reflog option needs one branch name");
 743
 744                if (MAX_REVS < reflog)
 745                        die("Only %d entries can be shown at one time.",
 746                            MAX_REVS);
 747                if (!dwim_ref(*av, strlen(*av), sha1, &ref))
 748                        die("No such ref %s", *av);
 749
 750                /* Has the base been specified? */
 751                if (reflog_base) {
 752                        char *ep;
 753                        base = strtoul(reflog_base, &ep, 10);
 754                        if (*ep) {
 755                                /* Ah, that is a date spec... */
 756                                unsigned long at;
 757                                at = approxidate(reflog_base);
 758                                read_ref_at(ref, at, -1, sha1, NULL,
 759                                            NULL, NULL, &base);
 760                        }
 761                }
 762
 763                for (i = 0; i < reflog; i++) {
 764                        char *logmsg, *m;
 765                        const char *msg;
 766                        unsigned long timestamp;
 767                        int tz;
 768
 769                        if (read_ref_at(ref, 0, base+i, sha1, &logmsg,
 770                                        &timestamp, &tz, NULL)) {
 771                                reflog = i;
 772                                break;
 773                        }
 774                        msg = strchr(logmsg, '\t');
 775                        if (!msg)
 776                                msg = "(none)";
 777                        else
 778                                msg++;
 779                        m = xmalloc(strlen(msg) + 200);
 780                        sprintf(m, "(%s) %s",
 781                                show_date(timestamp, tz, 1),
 782                                msg);
 783                        reflog_msg[i] = m;
 784                        free(logmsg);
 785                        sprintf(nth_desc, "%s@{%d}", *av, base+i);
 786                        append_ref(nth_desc, sha1, 1);
 787                }
 788        }
 789        else if (all_heads + all_remotes)
 790                snarf_refs(all_heads, all_remotes);
 791        else {
 792                while (0 < ac) {
 793                        append_one_rev(*av);
 794                        ac--; av++;
 795                }
 796        }
 797
 798        head_p = resolve_ref("HEAD", head_sha1, 1, NULL);
 799        if (head_p) {
 800                head_len = strlen(head_p);
 801                memcpy(head, head_p, head_len + 1);
 802        }
 803        else {
 804                head_len = 0;
 805                head[0] = 0;
 806        }
 807
 808        if (with_current_branch && head_p) {
 809                int has_head = 0;
 810                for (i = 0; !has_head && i < ref_name_cnt; i++) {
 811                        /* We are only interested in adding the branch
 812                         * HEAD points at.
 813                         */
 814                        if (rev_is_head(head,
 815                                        head_len,
 816                                        ref_name[i],
 817                                        head_sha1, NULL))
 818                                has_head++;
 819                }
 820                if (!has_head) {
 821                        int offset = !prefixcmp(head, "refs/heads/") ? 11 : 0;
 822                        append_one_rev(head + offset);
 823                }
 824        }
 825
 826        if (!ref_name_cnt) {
 827                fprintf(stderr, "No revs to be shown.\n");
 828                exit(0);
 829        }
 830
 831        for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 832                unsigned char revkey[20];
 833                unsigned int flag = 1u << (num_rev + REV_SHIFT);
 834
 835                if (MAX_REVS <= num_rev)
 836                        die("cannot handle more than %d revs.", MAX_REVS);
 837                if (get_sha1(ref_name[num_rev], revkey))
 838                        die("'%s' is not a valid ref.", ref_name[num_rev]);
 839                commit = lookup_commit_reference(revkey);
 840                if (!commit)
 841                        die("cannot find commit %s (%s)",
 842                            ref_name[num_rev], revkey);
 843                parse_commit(commit);
 844                mark_seen(commit, &seen);
 845
 846                /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 847                 * and so on.  REV_SHIFT bits from bit 0 are used for
 848                 * internal bookkeeping.
 849                 */
 850                commit->object.flags |= flag;
 851                if (commit->object.flags == flag)
 852                        commit_list_insert_by_date(commit, &list);
 853                rev[num_rev] = commit;
 854        }
 855        for (i = 0; i < num_rev; i++)
 856                rev_mask[i] = rev[i]->object.flags;
 857
 858        if (0 <= extra)
 859                join_revs(&list, &seen, num_rev, extra);
 860
 861        commit_list_sort_by_date(&seen);
 862
 863        if (merge_base)
 864                return show_merge_base(seen, num_rev);
 865
 866        if (independent)
 867                return show_independent(rev, num_rev, ref_name, rev_mask);
 868
 869        /* Show list; --more=-1 means list-only */
 870        if (1 < num_rev || extra < 0) {
 871                for (i = 0; i < num_rev; i++) {
 872                        int j;
 873                        int is_head = rev_is_head(head,
 874                                                  head_len,
 875                                                  ref_name[i],
 876                                                  head_sha1,
 877                                                  rev[i]->object.sha1);
 878                        if (extra < 0)
 879                                printf("%c [%s] ",
 880                                       is_head ? '*' : ' ', ref_name[i]);
 881                        else {
 882                                for (j = 0; j < i; j++)
 883                                        putchar(' ');
 884                                printf("%s%c%s [%s] ",
 885                                       get_color_code(i),
 886                                       is_head ? '*' : '!',
 887                                       get_color_reset_code(), ref_name[i]);
 888                        }
 889
 890                        if (!reflog) {
 891                                /* header lines never need name */
 892                                show_one_commit(rev[i], 1);
 893                        }
 894                        else
 895                                puts(reflog_msg[i]);
 896
 897                        if (is_head)
 898                                head_at = i;
 899                }
 900                if (0 <= extra) {
 901                        for (i = 0; i < num_rev; i++)
 902                                putchar('-');
 903                        putchar('\n');
 904                }
 905        }
 906        if (extra < 0)
 907                exit(0);
 908
 909        /* Sort topologically */
 910        sort_in_topological_order(&seen, lifo);
 911
 912        /* Give names to commits */
 913        if (!sha1_name && !no_name)
 914                name_commits(seen, rev, ref_name, num_rev);
 915
 916        all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 917        all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 918
 919        while (seen) {
 920                struct commit *commit = pop_one_commit(&seen);
 921                int this_flag = commit->object.flags;
 922                int is_merge_point = ((this_flag & all_revs) == all_revs);
 923
 924                shown_merge_point |= is_merge_point;
 925
 926                if (1 < num_rev) {
 927                        int is_merge = !!(commit->parents &&
 928                                          commit->parents->next);
 929                        if (topics &&
 930                            !is_merge_point &&
 931                            (this_flag & (1u << REV_SHIFT)))
 932                                continue;
 933                        if (dense && is_merge &&
 934                            omit_in_dense(commit, rev, num_rev))
 935                                continue;
 936                        for (i = 0; i < num_rev; i++) {
 937                                int mark;
 938                                if (!(this_flag & (1u << (i + REV_SHIFT))))
 939                                        mark = ' ';
 940                                else if (is_merge)
 941                                        mark = '-';
 942                                else if (i == head_at)
 943                                        mark = '*';
 944                                else
 945                                        mark = '+';
 946                                printf("%s%c%s",
 947                                       get_color_code(i),
 948                                       mark, get_color_reset_code());
 949                        }
 950                        putchar(' ');
 951                }
 952                show_one_commit(commit, no_name);
 953
 954                if (shown_merge_point && --extra < 0)
 955                        break;
 956        }
 957        return 0;
 958}