git.oblomov.eu Git - git/blob - builtin/show-branch.c

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