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.oid.hash,
 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, compare_ref_name);
 357 }
 358
 359 static int append_ref(const char *refname, const struct object_id *oid,
 360                       int allow_dups)
 361 {
 362         struct commit *commit = lookup_commit_reference_gently(oid->hash, 1);
 363         int i;
 364
 365         if (!commit)
 366                 return 0;
 367
 368         if (!allow_dups) {
 369                 /* Avoid adding the same thing twice */
 370                 for (i = 0; i < ref_name_cnt; i++)
 371                         if (!strcmp(refname, ref_name[i]))
 372                                 return 0;
 373         }
 374         if (MAX_REVS <= ref_name_cnt) {
 375                 warning(Q_("ignoring %s; cannot handle more than %d ref",
 376                            "ignoring %s; cannot handle more than %d refs",
 377                            MAX_REVS), 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(oid_to_hex(&commit->object.oid));
 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(oid_to_hex(&commit->object.oid));
 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                 sort_ref_range(saved_matches, ref_name_cnt);
 543                 return;
 544         }
 545         die("bad sha1 reference %s", av);
 546 }
 547
 548 static int git_show_branch_config(const char *var, const char *value, void *cb)
 549 {
 550         if (!strcmp(var, "showbranch.default")) {
 551                 if (!value)
 552                         return config_error_nonbool(var);
 553                 /*
 554                  * default_arg is now passed to parse_options(), so we need to
 555                  * mimic the real argv a bit better.
 556                  */
 557                 if (!default_args.argc)
 558                         argv_array_push(&default_args, "show-branch");
 559                 argv_array_push(&default_args, value);
 560                 return 0;
 561         }
 562
 563         if (!strcmp(var, "color.showbranch")) {
 564                 showbranch_use_color = git_config_colorbool(var, value);
 565                 return 0;
 566         }
 567
 568         return git_color_default_config(var, value, cb);
 569 }
 570
 571 static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
 572 {
 573         /* If the commit is tip of the named branches, do not
 574          * omit it.
 575          * Otherwise, if it is a merge that is reachable from only one
 576          * tip, it is not that interesting.
 577          */
 578         int i, flag, count;
 579         for (i = 0; i < n; i++)
 580                 if (rev[i] == commit)
 581                         return 0;
 582         flag = commit->object.flags;
 583         for (i = count = 0; i < n; i++) {
 584                 if (flag & (1u << (i + REV_SHIFT)))
 585                         count++;
 586         }
 587         if (count == 1)
 588                 return 1;
 589         return 0;
 590 }
 591
 592 static int reflog = 0;
 593
 594 static int parse_reflog_param(const struct option *opt, const char *arg,
 595                               int unset)
 596 {
 597         char *ep;
 598         const char **base = (const char **)opt->value;
 599         if (!arg)
 600                 arg = "";
 601         reflog = strtoul(arg, &ep, 10);
 602         if (*ep == ',')
 603                 *base = ep + 1;
 604         else if (*ep)
 605                 return error("unrecognized reflog param '%s'", arg);
 606         else
 607                 *base = NULL;
 608         if (reflog <= 0)
 609                 reflog = DEFAULT_REFLOG;
 610         return 0;
 611 }
 612
 613 int cmd_show_branch(int ac, const char **av, const char *prefix)
 614 {
 615         struct commit *rev[MAX_REVS], *commit;
 616         char *reflog_msg[MAX_REVS];
 617         struct commit_list *list = NULL, *seen = NULL;
 618         unsigned int rev_mask[MAX_REVS];
 619         int num_rev, i, extra = 0;
 620         int all_heads = 0, all_remotes = 0;
 621         int all_mask, all_revs;
 622         enum rev_sort_order sort_order = REV_SORT_IN_GRAPH_ORDER;
 623         char head[128];
 624         const char *head_p;
 625         int head_len;
 626         struct object_id head_oid;
 627         int merge_base = 0;
 628         int independent = 0;
 629         int no_name = 0;
 630         int sha1_name = 0;
 631         int shown_merge_point = 0;
 632         int with_current_branch = 0;
 633         int head_at = -1;
 634         int topics = 0;
 635         int dense = 1;
 636         const char *reflog_base = NULL;
 637         struct option builtin_show_branch_options[] = {
 638                 OPT_BOOL('a', "all", &all_heads,
 639                          N_("show remote-tracking and local branches")),
 640                 OPT_BOOL('r', "remotes", &all_remotes,
 641                          N_("show remote-tracking branches")),
 642                 OPT__COLOR(&showbranch_use_color,
 643                             N_("color '*!+-' corresponding to the branch")),
 644                 { OPTION_INTEGER, 0, "more", &extra, N_("n"),
 645                             N_("show <n> more commits after the common ancestor"),
 646                             PARSE_OPT_OPTARG, NULL, (intptr_t)1 },
 647                 OPT_SET_INT(0, "list", &extra, N_("synonym to more=-1"), -1),
 648                 OPT_BOOL(0, "no-name", &no_name, N_("suppress naming strings")),
 649                 OPT_BOOL(0, "current", &with_current_branch,
 650                          N_("include the current branch")),
 651                 OPT_BOOL(0, "sha1-name", &sha1_name,
 652                          N_("name commits with their object names")),
 653                 OPT_BOOL(0, "merge-base", &merge_base,
 654                          N_("show possible merge bases")),
 655                 OPT_BOOL(0, "independent", &independent,
 656                             N_("show refs unreachable from any other ref")),
 657                 OPT_SET_INT(0, "topo-order", &sort_order,
 658                             N_("show commits in topological order"),
 659                             REV_SORT_IN_GRAPH_ORDER),
 660                 OPT_BOOL(0, "topics", &topics,
 661                          N_("show only commits not on the first branch")),
 662                 OPT_SET_INT(0, "sparse", &dense,
 663                             N_("show merges reachable from only one tip"), 0),
 664                 OPT_SET_INT(0, "date-order", &sort_order,
 665                             N_("topologically sort, maintaining date order "
 666                                "where possible"),
 667                             REV_SORT_BY_COMMIT_DATE),
 668                 { OPTION_CALLBACK, 'g', "reflog", &reflog_base, N_("<n>[,<base>]"),
 669                             N_("show <n> most recent ref-log entries starting at "
 670                                "base"),
 671                             PARSE_OPT_OPTARG | PARSE_OPT_LITERAL_ARGHELP,
 672                             parse_reflog_param },
 673                 OPT_END()
 674         };
 675
 676         git_config(git_show_branch_config, NULL);
 677
 678         /* If nothing is specified, try the default first */
 679         if (ac == 1 && default_args.argc) {
 680                 ac = default_args.argc;
 681                 av = default_args.argv;
 682         }
 683
 684         ac = parse_options(ac, av, prefix, builtin_show_branch_options,
 685                            show_branch_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 686         if (all_heads)
 687                 all_remotes = 1;
 688
 689         if (extra || reflog) {
 690                 /* "listing" mode is incompatible with
 691                  * independent nor merge-base modes.
 692                  */
 693                 if (independent || merge_base)
 694                         usage_with_options(show_branch_usage,
 695                                            builtin_show_branch_options);
 696                 if (reflog && ((0 < extra) || all_heads || all_remotes))
 697                         /*
 698                          * Asking for --more in reflog mode does not
 699                          * make sense.  --list is Ok.
 700                          *
 701                          * Also --all and --remotes do not make sense either.
 702                          */
 703                         die(_("--reflog is incompatible with --all, --remotes, "
 704                               "--independent or --merge-base"));
 705         }
 706
 707         /* If nothing is specified, show all branches by default */
 708         if (ac <= topics && all_heads + all_remotes == 0)
 709                 all_heads = 1;
 710
 711         if (reflog) {
 712                 struct object_id oid;
 713                 char *ref;
 714                 int base = 0;
 715                 unsigned int flags = 0;
 716
 717                 if (ac == 0) {
 718                         static const char *fake_av[2];
 719
 720                         fake_av[0] = resolve_refdup("HEAD",
 721                                                     RESOLVE_REF_READING,
 722                                                     oid.hash, NULL);
 723                         fake_av[1] = NULL;
 724                         av = fake_av;
 725                         ac = 1;
 726                         if (!*av)
 727                                 die(_("no branches given, and HEAD is not valid"));
 728                 }
 729                 if (ac != 1)
 730                         die(_("--reflog option needs one branch name"));
 731
 732                 if (MAX_REVS < reflog)
 733                         die(Q_("only %d entry can be shown at one time.",
 734                                "only %d entries can be shown at one time.",
 735                                MAX_REVS), MAX_REVS);
 736                 if (!dwim_ref(*av, strlen(*av), oid.hash, &ref))
 737                         die(_("no such ref %s"), *av);
 738
 739                 /* Has the base been specified? */
 740                 if (reflog_base) {
 741                         char *ep;
 742                         base = strtoul(reflog_base, &ep, 10);
 743                         if (*ep) {
 744                                 /* Ah, that is a date spec... */
 745                                 unsigned long at;
 746                                 at = approxidate(reflog_base);
 747                                 read_ref_at(ref, flags, at, -1, oid.hash, NULL,
 748                                             NULL, NULL, &base);
 749                         }
 750                 }
 751
 752                 for (i = 0; i < reflog; i++) {
 753                         char *logmsg;
 754                         char *nth_desc;
 755                         const char *msg;
 756                         unsigned long timestamp;
 757                         int tz;
 758
 759                         if (read_ref_at(ref, flags, 0, base+i, oid.hash, &logmsg,
 760                                         &timestamp, &tz, NULL)) {
 761                                 reflog = i;
 762                                 break;
 763                         }
 764                         msg = strchr(logmsg, '\t');
 765                         if (!msg)
 766                                 msg = "(none)";
 767                         else
 768                                 msg++;
 769                         reflog_msg[i] = xstrfmt("(%s) %s",
 770                                                 show_date(timestamp, tz,
 771                                                           DATE_MODE(RELATIVE)),
 772                                                 msg);
 773                         free(logmsg);
 774
 775                         nth_desc = xstrfmt("%s@{%d}", *av, base+i);
 776                         append_ref(nth_desc, &oid, 1);
 777                         free(nth_desc);
 778                 }
 779                 free(ref);
 780         }
 781         else {
 782                 while (0 < ac) {
 783                         append_one_rev(*av);
 784                         ac--; av++;
 785                 }
 786                 if (all_heads + all_remotes)
 787                         snarf_refs(all_heads, all_remotes);
 788         }
 789
 790         head_p = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
 791                                     head_oid.hash, NULL);
 792         if (head_p) {
 793                 head_len = strlen(head_p);
 794                 memcpy(head, head_p, head_len + 1);
 795         }
 796         else {
 797                 head_len = 0;
 798                 head[0] = 0;
 799         }
 800
 801         if (with_current_branch && head_p) {
 802                 int has_head = 0;
 803                 for (i = 0; !has_head && i < ref_name_cnt; i++) {
 804                         /* We are only interested in adding the branch
 805                          * HEAD points at.
 806                          */
 807                         if (rev_is_head(head,
 808                                         head_len,
 809                                         ref_name[i],
 810                                         head_oid.hash, NULL))
 811                                 has_head++;
 812                 }
 813                 if (!has_head) {
 814                         int offset = starts_with(head, "refs/heads/") ? 11 : 0;
 815                         append_one_rev(head + offset);
 816                 }
 817         }
 818
 819         if (!ref_name_cnt) {
 820                 fprintf(stderr, "No revs to be shown.\n");
 821                 exit(0);
 822         }
 823
 824         for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 825                 struct object_id revkey;
 826                 unsigned int flag = 1u << (num_rev + REV_SHIFT);
 827
 828                 if (MAX_REVS <= num_rev)
 829                         die(Q_("cannot handle more than %d rev.",
 830                                "cannot handle more than %d revs.",
 831                                MAX_REVS), MAX_REVS);
 832                 if (get_sha1(ref_name[num_rev], revkey.hash))
 833                         die(_("'%s' is not a valid ref."), ref_name[num_rev]);
 834                 commit = lookup_commit_reference(revkey.hash);
 835                 if (!commit)
 836                         die(_("cannot find commit %s (%s)"),
 837                             ref_name[num_rev], oid_to_hex(&revkey));
 838                 parse_commit(commit);
 839                 mark_seen(commit, &seen);
 840
 841                 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 842                  * and so on.  REV_SHIFT bits from bit 0 are used for
 843                  * internal bookkeeping.
 844                  */
 845                 commit->object.flags |= flag;
 846                 if (commit->object.flags == flag)
 847                         commit_list_insert_by_date(commit, &list);
 848                 rev[num_rev] = commit;
 849         }
 850         for (i = 0; i < num_rev; i++)
 851                 rev_mask[i] = rev[i]->object.flags;
 852
 853         if (0 <= extra)
 854                 join_revs(&list, &seen, num_rev, extra);
 855
 856         commit_list_sort_by_date(&seen);
 857
 858         if (merge_base)
 859                 return show_merge_base(seen, num_rev);
 860
 861         if (independent)
 862                 return show_independent(rev, num_rev, ref_name, rev_mask);
 863
 864         /* Show list; --more=-1 means list-only */
 865         if (1 < num_rev || extra < 0) {
 866                 for (i = 0; i < num_rev; i++) {
 867                         int j;
 868                         int is_head = rev_is_head(head,
 869                                                   head_len,
 870                                                   ref_name[i],
 871                                                   head_oid.hash,
 872                                                   rev[i]->object.oid.hash);
 873                         if (extra < 0)
 874                                 printf("%c [%s] ",
 875                                        is_head ? '*' : ' ', ref_name[i]);
 876                         else {
 877                                 for (j = 0; j < i; j++)
 878                                         putchar(' ');
 879                                 printf("%s%c%s [%s] ",
 880                                        get_color_code(i),
 881                                        is_head ? '*' : '!',
 882                                        get_color_reset_code(), ref_name[i]);
 883                         }
 884
 885                         if (!reflog) {
 886                                 /* header lines never need name */
 887                                 show_one_commit(rev[i], 1);
 888                         }
 889                         else
 890                                 puts(reflog_msg[i]);
 891
 892                         if (is_head)
 893                                 head_at = i;
 894                 }
 895                 if (0 <= extra) {
 896                         for (i = 0; i < num_rev; i++)
 897                                 putchar('-');
 898                         putchar('\n');
 899                 }
 900         }
 901         if (extra < 0)
 902                 exit(0);
 903
 904         /* Sort topologically */
 905         sort_in_topological_order(&seen, sort_order);
 906
 907         /* Give names to commits */
 908         if (!sha1_name && !no_name)
 909                 name_commits(seen, rev, ref_name, num_rev);
 910
 911         all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 912         all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 913
 914         while (seen) {
 915                 struct commit *commit = pop_commit(&seen);
 916                 int this_flag = commit->object.flags;
 917                 int is_merge_point = ((this_flag & all_revs) == all_revs);
 918
 919                 shown_merge_point |= is_merge_point;
 920
 921                 if (1 < num_rev) {
 922                         int is_merge = !!(commit->parents &&
 923                                           commit->parents->next);
 924                         if (topics &&
 925                             !is_merge_point &&
 926                             (this_flag & (1u << REV_SHIFT)))
 927                                 continue;
 928                         if (dense && is_merge &&
 929                             omit_in_dense(commit, rev, num_rev))
 930                                 continue;
 931                         for (i = 0; i < num_rev; i++) {
 932                                 int mark;
 933                                 if (!(this_flag & (1u << (i + REV_SHIFT))))
 934                                         mark = ' ';
 935                                 else if (is_merge)
 936                                         mark = '-';
 937                                 else if (i == head_at)
 938                                         mark = '*';
 939                                 else
 940                                         mark = '+';
 941                                 printf("%s%c%s",
 942                                        get_color_code(i),
 943                                        mark, get_color_reset_code());
 944                         }
 945                         putchar(' ');
 946                 }
 947                 show_one_commit(commit, no_name);
 948
 949                 if (shown_merge_point && --extra < 0)
 950                         break;
 951         }
 952         return 0;
 953 }