builtin/show-branch.c

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