builtin / show-branch.con commit receive-pack: crash when checking with non-exist HEAD (b112b14)
   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    N_("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    N_("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 (want_color(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 (want_color(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                                struct strbuf newname = STRBUF_INIT;
 166                                parents = parents->next;
 167                                nth++;
 168                                if (p->util)
 169                                        continue;
 170                                switch (n->generation) {
 171                                case 0:
 172                                        strbuf_addstr(&newname, n->head_name);
 173                                        break;
 174                                case 1:
 175                                        strbuf_addf(&newname, "%s^", n->head_name);
 176                                        break;
 177                                default:
 178                                        strbuf_addf(&newname, "%s~%d",
 179                                                    n->head_name, n->generation);
 180                                        break;
 181                                }
 182                                if (nth == 1)
 183                                        strbuf_addch(&newname, '^');
 184                                else
 185                                        strbuf_addf(&newname, "^%d", nth);
 186                                name_commit(p, strbuf_detach(&newname, NULL), 0);
 187                                i++;
 188                                name_first_parent_chain(p);
 189                        }
 190                }
 191        } while (i);
 192}
 193
 194static int mark_seen(struct commit *commit, struct commit_list **seen_p)
 195{
 196        if (!commit->object.flags) {
 197                commit_list_insert(commit, seen_p);
 198                return 1;
 199        }
 200        return 0;
 201}
 202
 203static void join_revs(struct commit_list **list_p,
 204                      struct commit_list **seen_p,
 205                      int num_rev, int extra)
 206{
 207        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 208        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 209
 210        while (*list_p) {
 211                struct commit_list *parents;
 212                int still_interesting = !!interesting(*list_p);
 213                struct commit *commit = pop_one_commit(list_p);
 214                int flags = commit->object.flags & all_mask;
 215
 216                if (!still_interesting && extra <= 0)
 217                        break;
 218
 219                mark_seen(commit, seen_p);
 220                if ((flags & all_revs) == all_revs)
 221                        flags |= UNINTERESTING;
 222                parents = commit->parents;
 223
 224                while (parents) {
 225                        struct commit *p = parents->item;
 226                        int this_flag = p->object.flags;
 227                        parents = parents->next;
 228                        if ((this_flag & flags) == flags)
 229                                continue;
 230                        parse_commit(p);
 231                        if (mark_seen(p, seen_p) && !still_interesting)
 232                                extra--;
 233                        p->object.flags |= flags;
 234                        commit_list_insert_by_date(p, list_p);
 235                }
 236        }
 237
 238        /*
 239         * Postprocess to complete well-poisoning.
 240         *
 241         * At this point we have all the commits we have seen in
 242         * seen_p list.  Mark anything that can be reached from
 243         * uninteresting commits not interesting.
 244         */
 245        for (;;) {
 246                int changed = 0;
 247                struct commit_list *s;
 248                for (s = *seen_p; s; s = s->next) {
 249                        struct commit *c = s->item;
 250                        struct commit_list *parents;
 251
 252                        if (((c->object.flags & all_revs) != all_revs) &&
 253                            !(c->object.flags & UNINTERESTING))
 254                                continue;
 255
 256                        /* The current commit is either a merge base or
 257                         * already uninteresting one.  Mark its parents
 258                         * as uninteresting commits _only_ if they are
 259                         * already parsed.  No reason to find new ones
 260                         * here.
 261                         */
 262                        parents = c->parents;
 263                        while (parents) {
 264                                struct commit *p = parents->item;
 265                                parents = parents->next;
 266                                if (!(p->object.flags & UNINTERESTING)) {
 267                                        p->object.flags |= UNINTERESTING;
 268                                        changed = 1;
 269                                }
 270                        }
 271                }
 272                if (!changed)
 273                        break;
 274        }
 275}
 276
 277static void show_one_commit(struct commit *commit, int no_name)
 278{
 279        struct strbuf pretty = STRBUF_INIT;
 280        const char *pretty_str = "(unavailable)";
 281        struct commit_name *name = commit->util;
 282
 283        if (commit->object.parsed) {
 284                pp_commit_easy(CMIT_FMT_ONELINE, commit, &pretty);
 285                pretty_str = pretty.buf;
 286        }
 287        if (starts_with(pretty_str, "[PATCH] "))
 288                pretty_str += 8;
 289
 290        if (!no_name) {
 291                if (name && name->head_name) {
 292                        printf("[%s", name->head_name);
 293                        if (name->generation) {
 294                                if (name->generation == 1)
 295                                        printf("^");
 296                                else
 297                                        printf("~%d", name->generation);
 298                        }
 299                        printf("] ");
 300                }
 301                else
 302                        printf("[%s] ",
 303                               find_unique_abbrev(commit->object.sha1,
 304                                                  DEFAULT_ABBREV));
 305        }
 306        puts(pretty_str);
 307        strbuf_release(&pretty);
 308}
 309
 310static char *ref_name[MAX_REVS + 1];
 311static int ref_name_cnt;
 312
 313static const char *find_digit_prefix(const char *s, int *v)
 314{
 315        const char *p;
 316        int ver;
 317        char ch;
 318
 319        for (p = s, ver = 0;
 320             '0' <= (ch = *p) && ch <= '9';
 321             p++)
 322                ver = ver * 10 + ch - '0';
 323        *v = ver;
 324        return p;
 325}
 326
 327
 328static int version_cmp(const char *a, const char *b)
 329{
 330        while (1) {
 331                int va, vb;
 332
 333                a = find_digit_prefix(a, &va);
 334                b = find_digit_prefix(b, &vb);
 335                if (va != vb)
 336                        return va - vb;
 337
 338                while (1) {
 339                        int ca = *a;
 340                        int cb = *b;
 341                        if ('0' <= ca && ca <= '9')
 342                                ca = 0;
 343                        if ('0' <= cb && cb <= '9')
 344                                cb = 0;
 345                        if (ca != cb)
 346                                return ca - cb;
 347                        if (!ca)
 348                                break;
 349                        a++;
 350                        b++;
 351                }
 352                if (!*a && !*b)
 353                        return 0;
 354        }
 355}
 356
 357static int compare_ref_name(const void *a_, const void *b_)
 358{
 359        const char * const*a = a_, * const*b = b_;
 360        return version_cmp(*a, *b);
 361}
 362
 363static void sort_ref_range(int bottom, int top)
 364{
 365        qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 366              compare_ref_name);
 367}
 368
 369static int append_ref(const char *refname, const unsigned char *sha1,
 370                      int allow_dups)
 371{
 372        struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 373        int i;
 374
 375        if (!commit)
 376                return 0;
 377
 378        if (!allow_dups) {
 379                /* Avoid adding the same thing twice */
 380                for (i = 0; i < ref_name_cnt; i++)
 381                        if (!strcmp(refname, ref_name[i]))
 382                                return 0;
 383        }
 384        if (MAX_REVS <= ref_name_cnt) {
 385                warning("ignoring %s; cannot handle more than %d refs",
 386                        refname, MAX_REVS);
 387                return 0;
 388        }
 389        ref_name[ref_name_cnt++] = xstrdup(refname);
 390        ref_name[ref_name_cnt] = NULL;
 391        return 0;
 392}
 393
 394static int append_head_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 395{
 396        unsigned char tmp[20];
 397        int ofs = 11;
 398        if (!starts_with(refname, "refs/heads/"))
 399                return 0;
 400        /* If both heads/foo and tags/foo exists, get_sha1 would
 401         * get confused.
 402         */
 403        if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 404                ofs = 5;
 405        return append_ref(refname + ofs, sha1, 0);
 406}
 407
 408static int append_remote_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 409{
 410        unsigned char tmp[20];
 411        int ofs = 13;
 412        if (!starts_with(refname, "refs/remotes/"))
 413                return 0;
 414        /* If both heads/foo and tags/foo exists, get_sha1 would
 415         * get confused.
 416         */
 417        if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 418                ofs = 5;
 419        return append_ref(refname + ofs, sha1, 0);
 420}
 421
 422static int append_tag_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 423{
 424        if (!starts_with(refname, "refs/tags/"))
 425                return 0;
 426        return append_ref(refname + 5, sha1, 0);
 427}
 428
 429static const char *match_ref_pattern = NULL;
 430static int match_ref_slash = 0;
 431static int count_slash(const char *s)
 432{
 433        int cnt = 0;
 434        while (*s)
 435                if (*s++ == '/')
 436                        cnt++;
 437        return cnt;
 438}
 439
 440static int append_matching_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 441{
 442        /* we want to allow pattern hold/<asterisk> to show all
 443         * branches under refs/heads/hold/, and v0.99.9? to show
 444         * refs/tags/v0.99.9a and friends.
 445         */
 446        const char *tail;
 447        int slash = count_slash(refname);
 448        for (tail = refname; *tail && match_ref_slash < slash; )
 449                if (*tail++ == '/')
 450                        slash--;
 451        if (!*tail)
 452                return 0;
 453        if (wildmatch(match_ref_pattern, tail, 0, NULL))
 454                return 0;
 455        if (starts_with(refname, "refs/heads/"))
 456                return append_head_ref(refname, sha1, flag, cb_data);
 457        if (starts_with(refname, "refs/tags/"))
 458                return append_tag_ref(refname, sha1, flag, cb_data);
 459        return append_ref(refname, sha1, 0);
 460}
 461
 462static void snarf_refs(int head, int remotes)
 463{
 464        if (head) {
 465                int orig_cnt = ref_name_cnt;
 466                for_each_ref(append_head_ref, NULL);
 467                sort_ref_range(orig_cnt, ref_name_cnt);
 468        }
 469        if (remotes) {
 470                int orig_cnt = ref_name_cnt;
 471                for_each_ref(append_remote_ref, NULL);
 472                sort_ref_range(orig_cnt, ref_name_cnt);
 473        }
 474}
 475
 476static int rev_is_head(char *head, int headlen, char *name,
 477                       unsigned char *head_sha1, unsigned char *sha1)
 478{
 479        if ((!head[0]) ||
 480            (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
 481                return 0;
 482        if (starts_with(head, "refs/heads/"))
 483                head += 11;
 484        if (starts_with(name, "refs/heads/"))
 485                name += 11;
 486        else if (starts_with(name, "heads/"))
 487                name += 6;
 488        return !strcmp(head, name);
 489}
 490
 491static int show_merge_base(struct commit_list *seen, int num_rev)
 492{
 493        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 494        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 495        int exit_status = 1;
 496
 497        while (seen) {
 498                struct commit *commit = pop_one_commit(&seen);
 499                int flags = commit->object.flags & all_mask;
 500                if (!(flags & UNINTERESTING) &&
 501                    ((flags & all_revs) == all_revs)) {
 502                        puts(sha1_to_hex(commit->object.sha1));
 503                        exit_status = 0;
 504                        commit->object.flags |= UNINTERESTING;
 505                }
 506        }
 507        return exit_status;
 508}
 509
 510static int show_independent(struct commit **rev,
 511                            int num_rev,
 512                            char **ref_name,
 513                            unsigned int *rev_mask)
 514{
 515        int i;
 516
 517        for (i = 0; i < num_rev; i++) {
 518                struct commit *commit = rev[i];
 519                unsigned int flag = rev_mask[i];
 520
 521                if (commit->object.flags == flag)
 522                        puts(sha1_to_hex(commit->object.sha1));
 523                commit->object.flags |= UNINTERESTING;
 524        }
 525        return 0;
 526}
 527
 528static void append_one_rev(const char *av)
 529{
 530        unsigned char revkey[20];
 531        if (!get_sha1(av, revkey)) {
 532                append_ref(av, revkey, 0);
 533                return;
 534        }
 535        if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
 536                /* glob style match */
 537                int saved_matches = ref_name_cnt;
 538                match_ref_pattern = av;
 539                match_ref_slash = count_slash(av);
 540                for_each_ref(append_matching_ref, NULL);
 541                if (saved_matches == ref_name_cnt &&
 542                    ref_name_cnt < MAX_REVS)
 543                        error("no matching refs with %s", av);
 544                if (saved_matches + 1 < ref_name_cnt)
 545                        sort_ref_range(saved_matches, ref_name_cnt);
 546                return;
 547        }
 548        die("bad sha1 reference %s", av);
 549}
 550
 551static int git_show_branch_config(const char *var, const char *value, void *cb)
 552{
 553        if (!strcmp(var, "showbranch.default")) {
 554                if (!value)
 555                        return config_error_nonbool(var);
 556                /*
 557                 * default_arg is now passed to parse_options(), so we need to
 558                 * mimic the real argv a bit better.
 559                 */
 560                if (!default_num) {
 561                        default_alloc = 20;
 562                        default_arg = xcalloc(default_alloc, sizeof(*default_arg));
 563                        default_arg[default_num++] = "show-branch";
 564                } else if (default_alloc <= default_num + 1) {
 565                        default_alloc = default_alloc * 3 / 2 + 20;
 566                        default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
 567                }
 568                default_arg[default_num++] = xstrdup(value);
 569                default_arg[default_num] = NULL;
 570                return 0;
 571        }
 572
 573        if (!strcmp(var, "color.showbranch")) {
 574                showbranch_use_color = git_config_colorbool(var, value);
 575                return 0;
 576        }
 577
 578        return git_color_default_config(var, value, cb);
 579}
 580
 581static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
 582{
 583        /* If the commit is tip of the named branches, do not
 584         * omit it.
 585         * Otherwise, if it is a merge that is reachable from only one
 586         * tip, it is not that interesting.
 587         */
 588        int i, flag, count;
 589        for (i = 0; i < n; i++)
 590                if (rev[i] == commit)
 591                        return 0;
 592        flag = commit->object.flags;
 593        for (i = count = 0; i < n; i++) {
 594                if (flag & (1u << (i + REV_SHIFT)))
 595                        count++;
 596        }
 597        if (count == 1)
 598                return 1;
 599        return 0;
 600}
 601
 602static int reflog = 0;
 603
 604static int parse_reflog_param(const struct option *opt, const char *arg,
 605                              int unset)
 606{
 607        char *ep;
 608        const char **base = (const char **)opt->value;
 609        if (!arg)
 610                arg = "";
 611        reflog = strtoul(arg, &ep, 10);
 612        if (*ep == ',')
 613                *base = ep + 1;
 614        else if (*ep)
 615                return error("unrecognized reflog param '%s'", arg);
 616        else
 617                *base = NULL;
 618        if (reflog <= 0)
 619                reflog = DEFAULT_REFLOG;
 620        return 0;
 621}
 622
 623int cmd_show_branch(int ac, const char **av, const char *prefix)
 624{
 625        struct commit *rev[MAX_REVS], *commit;
 626        char *reflog_msg[MAX_REVS];
 627        struct commit_list *list = NULL, *seen = NULL;
 628        unsigned int rev_mask[MAX_REVS];
 629        int num_rev, i, extra = 0;
 630        int all_heads = 0, all_remotes = 0;
 631        int all_mask, all_revs;
 632        enum rev_sort_order sort_order = REV_SORT_IN_GRAPH_ORDER;
 633        char head[128];
 634        const char *head_p;
 635        int head_len;
 636        unsigned char head_sha1[20];
 637        int merge_base = 0;
 638        int independent = 0;
 639        int no_name = 0;
 640        int sha1_name = 0;
 641        int shown_merge_point = 0;
 642        int with_current_branch = 0;
 643        int head_at = -1;
 644        int topics = 0;
 645        int dense = 1;
 646        const char *reflog_base = NULL;
 647        struct option builtin_show_branch_options[] = {
 648                OPT_BOOL('a', "all", &all_heads,
 649                         N_("show remote-tracking and local branches")),
 650                OPT_BOOL('r', "remotes", &all_remotes,
 651                         N_("show remote-tracking branches")),
 652                OPT__COLOR(&showbranch_use_color,
 653                            N_("color '*!+-' corresponding to the branch")),
 654                { OPTION_INTEGER, 0, "more", &extra, N_("n"),
 655                            N_("show <n> more commits after the common ancestor"),
 656                            PARSE_OPT_OPTARG, NULL, (intptr_t)1 },
 657                OPT_SET_INT(0, "list", &extra, N_("synonym to more=-1"), -1),
 658                OPT_BOOL(0, "no-name", &no_name, N_("suppress naming strings")),
 659                OPT_BOOL(0, "current", &with_current_branch,
 660                         N_("include the current branch")),
 661                OPT_BOOL(0, "sha1-name", &sha1_name,
 662                         N_("name commits with their object names")),
 663                OPT_BOOL(0, "merge-base", &merge_base,
 664                         N_("show possible merge bases")),
 665                OPT_BOOL(0, "independent", &independent,
 666                            N_("show refs unreachable from any other ref")),
 667                OPT_SET_INT(0, "topo-order", &sort_order,
 668                            N_("show commits in topological order"),
 669                            REV_SORT_IN_GRAPH_ORDER),
 670                OPT_BOOL(0, "topics", &topics,
 671                         N_("show only commits not on the first branch")),
 672                OPT_SET_INT(0, "sparse", &dense,
 673                            N_("show merges reachable from only one tip"), 0),
 674                OPT_SET_INT(0, "date-order", &sort_order,
 675                            N_("topologically sort, maintaining date order "
 676                               "where possible"),
 677                            REV_SORT_BY_COMMIT_DATE),
 678                { OPTION_CALLBACK, 'g', "reflog", &reflog_base, N_("<n>[,<base>]"),
 679                            N_("show <n> most recent ref-log entries starting at "
 680                               "base"),
 681                            PARSE_OPT_OPTARG | PARSE_OPT_LITERAL_ARGHELP,
 682                            parse_reflog_param },
 683                OPT_END()
 684        };
 685
 686        git_config(git_show_branch_config, NULL);
 687
 688        /* If nothing is specified, try the default first */
 689        if (ac == 1 && default_num) {
 690                ac = default_num;
 691                av = default_arg;
 692        }
 693
 694        ac = parse_options(ac, av, prefix, builtin_show_branch_options,
 695                           show_branch_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 696        if (all_heads)
 697                all_remotes = 1;
 698
 699        if (extra || reflog) {
 700                /* "listing" mode is incompatible with
 701                 * independent nor merge-base modes.
 702                 */
 703                if (independent || merge_base)
 704                        usage_with_options(show_branch_usage,
 705                                           builtin_show_branch_options);
 706                if (reflog && ((0 < extra) || all_heads || all_remotes))
 707                        /*
 708                         * Asking for --more in reflog mode does not
 709                         * make sense.  --list is Ok.
 710                         *
 711                         * Also --all and --remotes do not make sense either.
 712                         */
 713                        die("--reflog is incompatible with --all, --remotes, "
 714                            "--independent or --merge-base");
 715        }
 716
 717        /* If nothing is specified, show all branches by default */
 718        if (ac + all_heads + all_remotes == 0)
 719                all_heads = 1;
 720
 721        if (reflog) {
 722                unsigned char sha1[20];
 723                char nth_desc[256];
 724                char *ref;
 725                int base = 0;
 726
 727                if (ac == 0) {
 728                        static const char *fake_av[2];
 729
 730                        fake_av[0] = resolve_refdup("HEAD", sha1, 1, NULL);
 731                        fake_av[1] = NULL;
 732                        av = fake_av;
 733                        ac = 1;
 734                }
 735                if (ac != 1)
 736                        die("--reflog option needs one branch name");
 737
 738                if (MAX_REVS < reflog)
 739                        die("Only %d entries can be shown at one time.",
 740                            MAX_REVS);
 741                if (!dwim_ref(*av, strlen(*av), sha1, &ref))
 742                        die("No such ref %s", *av);
 743
 744                /* Has the base been specified? */
 745                if (reflog_base) {
 746                        char *ep;
 747                        base = strtoul(reflog_base, &ep, 10);
 748                        if (*ep) {
 749                                /* Ah, that is a date spec... */
 750                                unsigned long at;
 751                                at = approxidate(reflog_base);
 752                                read_ref_at(ref, at, -1, sha1, NULL,
 753                                            NULL, NULL, &base);
 754                        }
 755                }
 756
 757                for (i = 0; i < reflog; i++) {
 758                        char *logmsg, *m;
 759                        const char *msg;
 760                        unsigned long timestamp;
 761                        int tz;
 762
 763                        if (read_ref_at(ref, 0, base+i, sha1, &logmsg,
 764                                        &timestamp, &tz, NULL)) {
 765                                reflog = i;
 766                                break;
 767                        }
 768                        msg = strchr(logmsg, '\t');
 769                        if (!msg)
 770                                msg = "(none)";
 771                        else
 772                                msg++;
 773                        m = xmalloc(strlen(msg) + 200);
 774                        sprintf(m, "(%s) %s",
 775                                show_date(timestamp, tz, 1),
 776                                msg);
 777                        reflog_msg[i] = m;
 778                        free(logmsg);
 779                        sprintf(nth_desc, "%s@{%d}", *av, base+i);
 780                        append_ref(nth_desc, sha1, 1);
 781                }
 782        }
 783        else if (all_heads + all_remotes)
 784                snarf_refs(all_heads, all_remotes);
 785        else {
 786                while (0 < ac) {
 787                        append_one_rev(*av);
 788                        ac--; av++;
 789                }
 790        }
 791
 792        head_p = resolve_ref_unsafe("HEAD", head_sha1, 1, NULL);
 793        if (head_p) {
 794                head_len = strlen(head_p);
 795                memcpy(head, head_p, head_len + 1);
 796        }
 797        else {
 798                head_len = 0;
 799                head[0] = 0;
 800        }
 801
 802        if (with_current_branch && head_p) {
 803                int has_head = 0;
 804                for (i = 0; !has_head && i < ref_name_cnt; i++) {
 805                        /* We are only interested in adding the branch
 806                         * HEAD points at.
 807                         */
 808                        if (rev_is_head(head,
 809                                        head_len,
 810                                        ref_name[i],
 811                                        head_sha1, NULL))
 812                                has_head++;
 813                }
 814                if (!has_head) {
 815                        int offset = starts_with(head, "refs/heads/") ? 11 : 0;
 816                        append_one_rev(head + offset);
 817                }
 818        }
 819
 820        if (!ref_name_cnt) {
 821                fprintf(stderr, "No revs to be shown.\n");
 822                exit(0);
 823        }
 824
 825        for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 826                unsigned char revkey[20];
 827                unsigned int flag = 1u << (num_rev + REV_SHIFT);
 828
 829                if (MAX_REVS <= num_rev)
 830                        die("cannot handle more than %d revs.", MAX_REVS);
 831                if (get_sha1(ref_name[num_rev], revkey))
 832                        die("'%s' is not a valid ref.", ref_name[num_rev]);
 833                commit = lookup_commit_reference(revkey);
 834                if (!commit)
 835                        die("cannot find commit %s (%s)",
 836                            ref_name[num_rev], revkey);
 837                parse_commit(commit);
 838                mark_seen(commit, &seen);
 839
 840                /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 841                 * and so on.  REV_SHIFT bits from bit 0 are used for
 842                 * internal bookkeeping.
 843                 */
 844                commit->object.flags |= flag;
 845                if (commit->object.flags == flag)
 846                        commit_list_insert_by_date(commit, &list);
 847                rev[num_rev] = commit;
 848        }
 849        for (i = 0; i < num_rev; i++)
 850                rev_mask[i] = rev[i]->object.flags;
 851
 852        if (0 <= extra)
 853                join_revs(&list, &seen, num_rev, extra);
 854
 855        commit_list_sort_by_date(&seen);
 856
 857        if (merge_base)
 858                return show_merge_base(seen, num_rev);
 859
 860        if (independent)
 861                return show_independent(rev, num_rev, ref_name, rev_mask);
 862
 863        /* Show list; --more=-1 means list-only */
 864        if (1 < num_rev || extra < 0) {
 865                for (i = 0; i < num_rev; i++) {
 866                        int j;
 867                        int is_head = rev_is_head(head,
 868                                                  head_len,
 869                                                  ref_name[i],
 870                                                  head_sha1,
 871                                                  rev[i]->object.sha1);
 872                        if (extra < 0)
 873                                printf("%c [%s] ",
 874                                       is_head ? '*' : ' ', ref_name[i]);
 875                        else {
 876                                for (j = 0; j < i; j++)
 877                                        putchar(' ');
 878                                printf("%s%c%s [%s] ",
 879                                       get_color_code(i),
 880                                       is_head ? '*' : '!',
 881                                       get_color_reset_code(), ref_name[i]);
 882                        }
 883
 884                        if (!reflog) {
 885                                /* header lines never need name */
 886                                show_one_commit(rev[i], 1);
 887                        }
 888                        else
 889                                puts(reflog_msg[i]);
 890
 891                        if (is_head)
 892                                head_at = i;
 893                }
 894                if (0 <= extra) {
 895                        for (i = 0; i < num_rev; i++)
 896                                putchar('-');
 897                        putchar('\n');
 898                }
 899        }
 900        if (extra < 0)
 901                exit(0);
 902
 903        /* Sort topologically */
 904        sort_in_topological_order(&seen, sort_order);
 905
 906        /* Give names to commits */
 907        if (!sha1_name && !no_name)
 908                name_commits(seen, rev, ref_name, num_rev);
 909
 910        all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 911        all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 912
 913        while (seen) {
 914                struct commit *commit = pop_one_commit(&seen);
 915                int this_flag = commit->object.flags;
 916                int is_merge_point = ((this_flag & all_revs) == all_revs);
 917
 918                shown_merge_point |= is_merge_point;
 919
 920                if (1 < num_rev) {
 921                        int is_merge = !!(commit->parents &&
 922                                          commit->parents->next);
 923                        if (topics &&
 924                            !is_merge_point &&
 925                            (this_flag & (1u << REV_SHIFT)))
 926                                continue;
 927                        if (dense && is_merge &&
 928                            omit_in_dense(commit, rev, num_rev))
 929                                continue;
 930                        for (i = 0; i < num_rev; i++) {
 931                                int mark;
 932                                if (!(this_flag & (1u << (i + REV_SHIFT))))
 933                                        mark = ' ';
 934                                else if (is_merge)
 935                                        mark = '-';
 936                                else if (i == head_at)
 937                                        mark = '*';
 938                                else
 939                                        mark = '+';
 940                                printf("%s%c%s",
 941                                       get_color_code(i),
 942                                       mark, get_color_reset_code());
 943                        }
 944                        putchar(' ');
 945                }
 946                show_one_commit(commit, no_name);
 947
 948                if (shown_merge_point && --extra < 0)
 949                        break;
 950        }
 951        return 0;
 952}