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