builtin-show-branch.c

   1 #include "cache.h"
   2 #include "commit.h"
   3 #include "refs.h"
   4 #include "builtin.h"
   5
   6 static const char show_branch_usage[] =
   7 "git show-branch [--sparse] [--current] [--all] [--remotes] [--topo-order] [--more=count | --list | --independent | --merge-base ] [--topics] [<refs>...] | --reflog[=n[,b]] <branch>";
   8 static const char show_branch_usage_reflog[] =
   9 "--reflog is incompatible with --all, --remotes, --independent or --merge-base";
  10
  11 static int default_num;
  12 static int default_alloc;
  13 static const char **default_arg;
  14
  15 #define UNINTERESTING   01
  16
  17 #define REV_SHIFT        2
  18 #define MAX_REVS        (FLAG_BITS - REV_SHIFT) /* should not exceed bits_per_int - REV_SHIFT */
  19
  20 #define DEFAULT_REFLOG  4
  21
  22 static struct commit *interesting(struct commit_list *list)
  23 {
  24         while (list) {
  25                 struct commit *commit = list->item;
  26                 list = list->next;
  27                 if (commit->object.flags & UNINTERESTING)
  28                         continue;
  29                 return commit;
  30         }
  31         return NULL;
  32 }
  33
  34 static struct commit *pop_one_commit(struct commit_list **list_p)
  35 {
  36         struct commit *commit;
  37         struct commit_list *list;
  38         list = *list_p;
  39         commit = list->item;
  40         *list_p = list->next;
  41         free(list);
  42         return commit;
  43 }
  44
  45 struct commit_name {
  46         const char *head_name; /* which head's ancestor? */
  47         int generation; /* how many parents away from head_name */
  48 };
  49
  50 /* Name the commit as nth generation ancestor of head_name;
  51  * we count only the first-parent relationship for naming purposes.
  52  */
  53 static void name_commit(struct commit *commit, const char *head_name, int nth)
  54 {
  55         struct commit_name *name;
  56         if (!commit->util)
  57                 commit->util = xmalloc(sizeof(struct commit_name));
  58         name = commit->util;
  59         name->head_name = head_name;
  60         name->generation = nth;
  61 }
  62
  63 /* Parent is the first parent of the commit.  We may name it
  64  * as (n+1)th generation ancestor of the same head_name as
  65  * commit is nth generation ancestor of, if that generation
  66  * number is better than the name it already has.
  67  */
  68 static void name_parent(struct commit *commit, struct commit *parent)
  69 {
  70         struct commit_name *commit_name = commit->util;
  71         struct commit_name *parent_name = parent->util;
  72         if (!commit_name)
  73                 return;
  74         if (!parent_name ||
  75             commit_name->generation + 1 < parent_name->generation)
  76                 name_commit(parent, commit_name->head_name,
  77                             commit_name->generation + 1);
  78 }
  79
  80 static int name_first_parent_chain(struct commit *c)
  81 {
  82         int i = 0;
  83         while (c) {
  84                 struct commit *p;
  85                 if (!c->util)
  86                         break;
  87                 if (!c->parents)
  88                         break;
  89                 p = c->parents->item;
  90                 if (!p->util) {
  91                         name_parent(c, p);
  92                         i++;
  93                 }
  94                 else
  95                         break;
  96                 c = p;
  97         }
  98         return i;
  99 }
 100
 101 static void name_commits(struct commit_list *list,
 102                          struct commit **rev,
 103                          char **ref_name,
 104                          int num_rev)
 105 {
 106         struct commit_list *cl;
 107         struct commit *c;
 108         int i;
 109
 110         /* First give names to the given heads */
 111         for (cl = list; cl; cl = cl->next) {
 112                 c = cl->item;
 113                 if (c->util)
 114                         continue;
 115                 for (i = 0; i < num_rev; i++) {
 116                         if (rev[i] == c) {
 117                                 name_commit(c, ref_name[i], 0);
 118                                 break;
 119                         }
 120                 }
 121         }
 122
 123         /* Then commits on the first parent ancestry chain */
 124         do {
 125                 i = 0;
 126                 for (cl = list; cl; cl = cl->next) {
 127                         i += name_first_parent_chain(cl->item);
 128                 }
 129         } while (i);
 130
 131         /* Finally, any unnamed commits */
 132         do {
 133                 i = 0;
 134                 for (cl = list; cl; cl = cl->next) {
 135                         struct commit_list *parents;
 136                         struct commit_name *n;
 137                         int nth;
 138                         c = cl->item;
 139                         if (!c->util)
 140                                 continue;
 141                         n = c->util;
 142                         parents = c->parents;
 143                         nth = 0;
 144                         while (parents) {
 145                                 struct commit *p = parents->item;
 146                                 char newname[1000], *en;
 147                                 parents = parents->next;
 148                                 nth++;
 149                                 if (p->util)
 150                                         continue;
 151                                 en = newname;
 152                                 switch (n->generation) {
 153                                 case 0:
 154                                         en += sprintf(en, "%s", n->head_name);
 155                                         break;
 156                                 case 1:
 157                                         en += sprintf(en, "%s^", n->head_name);
 158                                         break;
 159                                 default:
 160                                         en += sprintf(en, "%s~%d",
 161                                                 n->head_name, n->generation);
 162                                         break;
 163                                 }
 164                                 if (nth == 1)
 165                                         en += sprintf(en, "^");
 166                                 else
 167                                         en += sprintf(en, "^%d", nth);
 168                                 name_commit(p, xstrdup(newname), 0);
 169                                 i++;
 170                                 name_first_parent_chain(p);
 171                         }
 172                 }
 173         } while (i);
 174 }
 175
 176 static int mark_seen(struct commit *commit, struct commit_list **seen_p)
 177 {
 178         if (!commit->object.flags) {
 179                 commit_list_insert(commit, seen_p);
 180                 return 1;
 181         }
 182         return 0;
 183 }
 184
 185 static void join_revs(struct commit_list **list_p,
 186                       struct commit_list **seen_p,
 187                       int num_rev, int extra)
 188 {
 189         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 190         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 191
 192         while (*list_p) {
 193                 struct commit_list *parents;
 194                 int still_interesting = !!interesting(*list_p);
 195                 struct commit *commit = pop_one_commit(list_p);
 196                 int flags = commit->object.flags & all_mask;
 197
 198                 if (!still_interesting && extra <= 0)
 199                         break;
 200
 201                 mark_seen(commit, seen_p);
 202                 if ((flags & all_revs) == all_revs)
 203                         flags |= UNINTERESTING;
 204                 parents = commit->parents;
 205
 206                 while (parents) {
 207                         struct commit *p = parents->item;
 208                         int this_flag = p->object.flags;
 209                         parents = parents->next;
 210                         if ((this_flag & flags) == flags)
 211                                 continue;
 212                         if (!p->object.parsed)
 213                                 parse_commit(p);
 214                         if (mark_seen(p, seen_p) && !still_interesting)
 215                                 extra--;
 216                         p->object.flags |= flags;
 217                         insert_by_date(p, list_p);
 218                 }
 219         }
 220
 221         /*
 222          * Postprocess to complete well-poisoning.
 223          *
 224          * At this point we have all the commits we have seen in
 225          * seen_p list.  Mark anything that can be reached from
 226          * uninteresting commits not interesting.
 227          */
 228         for (;;) {
 229                 int changed = 0;
 230                 struct commit_list *s;
 231                 for (s = *seen_p; s; s = s->next) {
 232                         struct commit *c = s->item;
 233                         struct commit_list *parents;
 234
 235                         if (((c->object.flags & all_revs) != all_revs) &&
 236                             !(c->object.flags & UNINTERESTING))
 237                                 continue;
 238
 239                         /* The current commit is either a merge base or
 240                          * already uninteresting one.  Mark its parents
 241                          * as uninteresting commits _only_ if they are
 242                          * already parsed.  No reason to find new ones
 243                          * here.
 244                          */
 245                         parents = c->parents;
 246                         while (parents) {
 247                                 struct commit *p = parents->item;
 248                                 parents = parents->next;
 249                                 if (!(p->object.flags & UNINTERESTING)) {
 250                                         p->object.flags |= UNINTERESTING;
 251                                         changed = 1;
 252                                 }
 253                         }
 254                 }
 255                 if (!changed)
 256                         break;
 257         }
 258 }
 259
 260 static void show_one_commit(struct commit *commit, int no_name)
 261 {
 262         struct strbuf pretty;
 263         const char *pretty_str = "(unavailable)";
 264         struct commit_name *name = commit->util;
 265
 266         strbuf_init(&pretty, 0);
 267         if (commit->object.parsed) {
 268                 pretty_print_commit(CMIT_FMT_ONELINE, commit,
 269                                     &pretty, 0, NULL, NULL, 0, 0);
 270                 pretty_str = pretty.buf;
 271         }
 272         if (!prefixcmp(pretty_str, "[PATCH] "))
 273                 pretty_str += 8;
 274
 275         if (!no_name) {
 276                 if (name && name->head_name) {
 277                         printf("[%s", name->head_name);
 278                         if (name->generation) {
 279                                 if (name->generation == 1)
 280                                         printf("^");
 281                                 else
 282                                         printf("~%d", name->generation);
 283                         }
 284                         printf("] ");
 285                 }
 286                 else
 287                         printf("[%s] ",
 288                                find_unique_abbrev(commit->object.sha1, 7));
 289         }
 290         puts(pretty_str);
 291         strbuf_release(&pretty);
 292 }
 293
 294 static char *ref_name[MAX_REVS + 1];
 295 static int ref_name_cnt;
 296
 297 static const char *find_digit_prefix(const char *s, int *v)
 298 {
 299         const char *p;
 300         int ver;
 301         char ch;
 302
 303         for (p = s, ver = 0;
 304              '0' <= (ch = *p) && ch <= '9';
 305              p++)
 306                 ver = ver * 10 + ch - '0';
 307         *v = ver;
 308         return p;
 309 }
 310
 311
 312 static int version_cmp(const char *a, const char *b)
 313 {
 314         while (1) {
 315                 int va, vb;
 316
 317                 a = find_digit_prefix(a, &va);
 318                 b = find_digit_prefix(b, &vb);
 319                 if (va != vb)
 320                         return va - vb;
 321
 322                 while (1) {
 323                         int ca = *a;
 324                         int cb = *b;
 325                         if ('0' <= ca && ca <= '9')
 326                                 ca = 0;
 327                         if ('0' <= cb && cb <= '9')
 328                                 cb = 0;
 329                         if (ca != cb)
 330                                 return ca - cb;
 331                         if (!ca)
 332                                 break;
 333                         a++;
 334                         b++;
 335                 }
 336                 if (!*a && !*b)
 337                         return 0;
 338         }
 339 }
 340
 341 static int compare_ref_name(const void *a_, const void *b_)
 342 {
 343         const char * const*a = a_, * const*b = b_;
 344         return version_cmp(*a, *b);
 345 }
 346
 347 static void sort_ref_range(int bottom, int top)
 348 {
 349         qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 350               compare_ref_name);
 351 }
 352
 353 static int append_ref(const char *refname, const unsigned char *sha1,
 354                       int allow_dups)
 355 {
 356         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 357         int i;
 358
 359         if (!commit)
 360                 return 0;
 361
 362         if (!allow_dups) {
 363                 /* Avoid adding the same thing twice */
 364                 for (i = 0; i < ref_name_cnt; i++)
 365                         if (!strcmp(refname, ref_name[i]))
 366                                 return 0;
 367         }
 368         if (MAX_REVS <= ref_name_cnt) {
 369                 fprintf(stderr, "warning: ignoring %s; "
 370                         "cannot handle more than %d refs\n",
 371                         refname, MAX_REVS);
 372                 return 0;
 373         }
 374         ref_name[ref_name_cnt++] = xstrdup(refname);
 375         ref_name[ref_name_cnt] = NULL;
 376         return 0;
 377 }
 378
 379 static int append_head_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 380 {
 381         unsigned char tmp[20];
 382         int ofs = 11;
 383         if (prefixcmp(refname, "refs/heads/"))
 384                 return 0;
 385         /* If both heads/foo and tags/foo exists, get_sha1 would
 386          * get confused.
 387          */
 388         if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 389                 ofs = 5;
 390         return append_ref(refname + ofs, sha1, 0);
 391 }
 392
 393 static int append_remote_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 394 {
 395         unsigned char tmp[20];
 396         int ofs = 13;
 397         if (prefixcmp(refname, "refs/remotes/"))
 398                 return 0;
 399         /* If both heads/foo and tags/foo exists, get_sha1 would
 400          * get confused.
 401          */
 402         if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 403                 ofs = 5;
 404         return append_ref(refname + ofs, sha1, 0);
 405 }
 406
 407 static int append_tag_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 408 {
 409         if (prefixcmp(refname, "refs/tags/"))
 410                 return 0;
 411         return append_ref(refname + 5, sha1, 0);
 412 }
 413
 414 static const char *match_ref_pattern = NULL;
 415 static int match_ref_slash = 0;
 416 static int count_slash(const char *s)
 417 {
 418         int cnt = 0;
 419         while (*s)
 420                 if (*s++ == '/')
 421                         cnt++;
 422         return cnt;
 423 }
 424
 425 static int append_matching_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 426 {
 427         /* we want to allow pattern hold/<asterisk> to show all
 428          * branches under refs/heads/hold/, and v0.99.9? to show
 429          * refs/tags/v0.99.9a and friends.
 430          */
 431         const char *tail;
 432         int slash = count_slash(refname);
 433         for (tail = refname; *tail && match_ref_slash < slash; )
 434                 if (*tail++ == '/')
 435                         slash--;
 436         if (!*tail)
 437                 return 0;
 438         if (fnmatch(match_ref_pattern, tail, 0))
 439                 return 0;
 440         if (!prefixcmp(refname, "refs/heads/"))
 441                 return append_head_ref(refname, sha1, flag, cb_data);
 442         if (!prefixcmp(refname, "refs/tags/"))
 443                 return append_tag_ref(refname, sha1, flag, cb_data);
 444         return append_ref(refname, sha1, 0);
 445 }
 446
 447 static void snarf_refs(int head, int remotes)
 448 {
 449         if (head) {
 450                 int orig_cnt = ref_name_cnt;
 451                 for_each_ref(append_head_ref, NULL);
 452                 sort_ref_range(orig_cnt, ref_name_cnt);
 453         }
 454         if (remotes) {
 455                 int orig_cnt = ref_name_cnt;
 456                 for_each_ref(append_remote_ref, NULL);
 457                 sort_ref_range(orig_cnt, ref_name_cnt);
 458         }
 459 }
 460
 461 static int rev_is_head(char *head, int headlen, char *name,
 462                        unsigned char *head_sha1, unsigned char *sha1)
 463 {
 464         if ((!head[0]) ||
 465             (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
 466                 return 0;
 467         if (!prefixcmp(head, "refs/heads/"))
 468                 head += 11;
 469         if (!prefixcmp(name, "refs/heads/"))
 470                 name += 11;
 471         else if (!prefixcmp(name, "heads/"))
 472                 name += 6;
 473         return !strcmp(head, name);
 474 }
 475
 476 static int show_merge_base(struct commit_list *seen, int num_rev)
 477 {
 478         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 479         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 480         int exit_status = 1;
 481
 482         while (seen) {
 483                 struct commit *commit = pop_one_commit(&seen);
 484                 int flags = commit->object.flags & all_mask;
 485                 if (!(flags & UNINTERESTING) &&
 486                     ((flags & all_revs) == all_revs)) {
 487                         puts(sha1_to_hex(commit->object.sha1));
 488                         exit_status = 0;
 489                         commit->object.flags |= UNINTERESTING;
 490                 }
 491         }
 492         return exit_status;
 493 }
 494
 495 static int show_independent(struct commit **rev,
 496                             int num_rev,
 497                             char **ref_name,
 498                             unsigned int *rev_mask)
 499 {
 500         int i;
 501
 502         for (i = 0; i < num_rev; i++) {
 503                 struct commit *commit = rev[i];
 504                 unsigned int flag = rev_mask[i];
 505
 506                 if (commit->object.flags == flag)
 507                         puts(sha1_to_hex(commit->object.sha1));
 508                 commit->object.flags |= UNINTERESTING;
 509         }
 510         return 0;
 511 }
 512
 513 static void append_one_rev(const char *av)
 514 {
 515         unsigned char revkey[20];
 516         if (!get_sha1(av, revkey)) {
 517                 append_ref(av, revkey, 0);
 518                 return;
 519         }
 520         if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
 521                 /* glob style match */
 522                 int saved_matches = ref_name_cnt;
 523                 match_ref_pattern = av;
 524                 match_ref_slash = count_slash(av);
 525                 for_each_ref(append_matching_ref, NULL);
 526                 if (saved_matches == ref_name_cnt &&
 527                     ref_name_cnt < MAX_REVS)
 528                         error("no matching refs with %s", av);
 529                 if (saved_matches + 1 < ref_name_cnt)
 530                         sort_ref_range(saved_matches, ref_name_cnt);
 531                 return;
 532         }
 533         die("bad sha1 reference %s", av);
 534 }
 535
 536 static int git_show_branch_config(const char *var, const char *value, void *cb)
 537 {
 538         if (!strcmp(var, "showbranch.default")) {
 539                 if (!value)
 540                         return config_error_nonbool(var);
 541                 if (default_alloc <= default_num + 1) {
 542                         default_alloc = default_alloc * 3 / 2 + 20;
 543                         default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
 544                 }
 545                 default_arg[default_num++] = xstrdup(value);
 546                 default_arg[default_num] = NULL;
 547                 return 0;
 548         }
 549
 550         return git_default_config(var, value, cb);
 551 }
 552
 553 static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
 554 {
 555         /* If the commit is tip of the named branches, do not
 556          * omit it.
 557          * Otherwise, if it is a merge that is reachable from only one
 558          * tip, it is not that interesting.
 559          */
 560         int i, flag, count;
 561         for (i = 0; i < n; i++)
 562                 if (rev[i] == commit)
 563                         return 0;
 564         flag = commit->object.flags;
 565         for (i = count = 0; i < n; i++) {
 566                 if (flag & (1u << (i + REV_SHIFT)))
 567                         count++;
 568         }
 569         if (count == 1)
 570                 return 1;
 571         return 0;
 572 }
 573
 574 static void parse_reflog_param(const char *arg, int *cnt, const char **base)
 575 {
 576         char *ep;
 577         *cnt = strtoul(arg, &ep, 10);
 578         if (*ep == ',')
 579                 *base = ep + 1;
 580         else if (*ep)
 581                 die("unrecognized reflog param '%s'", arg + 9);
 582         else
 583                 *base = NULL;
 584         if (*cnt <= 0)
 585                 *cnt = DEFAULT_REFLOG;
 586 }
 587
 588 int cmd_show_branch(int ac, const char **av, const char *prefix)
 589 {
 590         struct commit *rev[MAX_REVS], *commit;
 591         char *reflog_msg[MAX_REVS];
 592         struct commit_list *list = NULL, *seen = NULL;
 593         unsigned int rev_mask[MAX_REVS];
 594         int num_rev, i, extra = 0;
 595         int all_heads = 0, all_remotes = 0;
 596         int all_mask, all_revs;
 597         int lifo = 1;
 598         char head[128];
 599         const char *head_p;
 600         int head_len;
 601         unsigned char head_sha1[20];
 602         int merge_base = 0;
 603         int independent = 0;
 604         int no_name = 0;
 605         int sha1_name = 0;
 606         int shown_merge_point = 0;
 607         int with_current_branch = 0;
 608         int head_at = -1;
 609         int topics = 0;
 610         int dense = 1;
 611         int reflog = 0;
 612         const char *reflog_base = NULL;
 613
 614         git_config(git_show_branch_config, NULL);
 615
 616         /* If nothing is specified, try the default first */
 617         if (ac == 1 && default_num) {
 618                 ac = default_num + 1;
 619                 av = default_arg - 1; /* ick; we would not address av[0] */
 620         }
 621
 622         while (1 < ac && av[1][0] == '-') {
 623                 const char *arg = av[1];
 624                 if (!strcmp(arg, "--")) {
 625                         ac--; av++;
 626                         break;
 627                 }
 628                 else if (!strcmp(arg, "--all") || !strcmp(arg, "-a"))
 629                         all_heads = all_remotes = 1;
 630                 else if (!strcmp(arg, "--remotes") || !strcmp(arg, "-r"))
 631                         all_remotes = 1;
 632                 else if (!strcmp(arg, "--more"))
 633                         extra = 1;
 634                 else if (!strcmp(arg, "--list"))
 635                         extra = -1;
 636                 else if (!strcmp(arg, "--no-name"))
 637                         no_name = 1;
 638                 else if (!strcmp(arg, "--current"))
 639                         with_current_branch = 1;
 640                 else if (!strcmp(arg, "--sha1-name"))
 641                         sha1_name = 1;
 642                 else if (!prefixcmp(arg, "--more="))
 643                         extra = atoi(arg + 7);
 644                 else if (!strcmp(arg, "--merge-base"))
 645                         merge_base = 1;
 646                 else if (!strcmp(arg, "--independent"))
 647                         independent = 1;
 648                 else if (!strcmp(arg, "--topo-order"))
 649                         lifo = 1;
 650                 else if (!strcmp(arg, "--topics"))
 651                         topics = 1;
 652                 else if (!strcmp(arg, "--sparse"))
 653                         dense = 0;
 654                 else if (!strcmp(arg, "--date-order"))
 655                         lifo = 0;
 656                 else if (!strcmp(arg, "--reflog") || !strcmp(arg, "-g")) {
 657                         reflog = DEFAULT_REFLOG;
 658                 }
 659                 else if (!prefixcmp(arg, "--reflog="))
 660                         parse_reflog_param(arg + 9, &reflog, &reflog_base);
 661                 else if (!prefixcmp(arg, "-g="))
 662                         parse_reflog_param(arg + 3, &reflog, &reflog_base);
 663                 else
 664                         usage(show_branch_usage);
 665                 ac--; av++;
 666         }
 667         ac--; av++;
 668
 669         if (extra || reflog) {
 670                 /* "listing" mode is incompatible with
 671                  * independent nor merge-base modes.
 672                  */
 673                 if (independent || merge_base)
 674                         usage(show_branch_usage);
 675                 if (reflog && ((0 < extra) || all_heads || all_remotes))
 676                         /*
 677                          * Asking for --more in reflog mode does not
 678                          * make sense.  --list is Ok.
 679                          *
 680                          * Also --all and --remotes do not make sense either.
 681                          */
 682                         usage(show_branch_usage_reflog);
 683         }
 684
 685         /* If nothing is specified, show all branches by default */
 686         if (ac + all_heads + all_remotes == 0)
 687                 all_heads = 1;
 688
 689         if (reflog) {
 690                 unsigned char sha1[20];
 691                 char nth_desc[256];
 692                 char *ref;
 693                 int base = 0;
 694
 695                 if (ac == 0) {
 696                         static const char *fake_av[2];
 697                         const char *refname;
 698
 699                         refname = resolve_ref("HEAD", sha1, 1, NULL);
 700                         fake_av[0] = xstrdup(refname);
 701                         fake_av[1] = NULL;
 702                         av = fake_av;
 703                         ac = 1;
 704                 }
 705                 if (ac != 1)
 706                         die("--reflog option needs one branch name");
 707
 708                 if (MAX_REVS < reflog)
 709                         die("Only %d entries can be shown at one time.",
 710                             MAX_REVS);
 711                 if (!dwim_ref(*av, strlen(*av), sha1, &ref))
 712                         die("No such ref %s", *av);
 713
 714                 /* Has the base been specified? */
 715                 if (reflog_base) {
 716                         char *ep;
 717                         base = strtoul(reflog_base, &ep, 10);
 718                         if (*ep) {
 719                                 /* Ah, that is a date spec... */
 720                                 unsigned long at;
 721                                 at = approxidate(reflog_base);
 722                                 read_ref_at(ref, at, -1, sha1, NULL,
 723                                             NULL, NULL, &base);
 724                         }
 725                 }
 726
 727                 for (i = 0; i < reflog; i++) {
 728                         char *logmsg, *m;
 729                         const char *msg;
 730                         unsigned long timestamp;
 731                         int tz;
 732
 733                         if (read_ref_at(ref, 0, base+i, sha1, &logmsg,
 734                                         &timestamp, &tz, NULL)) {
 735                                 reflog = i;
 736                                 break;
 737                         }
 738                         msg = strchr(logmsg, '\t');
 739                         if (!msg)
 740                                 msg = "(none)";
 741                         else
 742                                 msg++;
 743                         m = xmalloc(strlen(msg) + 200);
 744                         sprintf(m, "(%s) %s",
 745                                 show_date(timestamp, tz, 1),
 746                                 msg);
 747                         reflog_msg[i] = m;
 748                         free(logmsg);
 749                         sprintf(nth_desc, "%s@{%d}", *av, base+i);
 750                         append_ref(nth_desc, sha1, 1);
 751                 }
 752         }
 753         else if (all_heads + all_remotes)
 754                 snarf_refs(all_heads, all_remotes);
 755         else {
 756                 while (0 < ac) {
 757                         append_one_rev(*av);
 758                         ac--; av++;
 759                 }
 760         }
 761
 762         head_p = resolve_ref("HEAD", head_sha1, 1, NULL);
 763         if (head_p) {
 764                 head_len = strlen(head_p);
 765                 memcpy(head, head_p, head_len + 1);
 766         }
 767         else {
 768                 head_len = 0;
 769                 head[0] = 0;
 770         }
 771
 772         if (with_current_branch && head_p) {
 773                 int has_head = 0;
 774                 for (i = 0; !has_head && i < ref_name_cnt; i++) {
 775                         /* We are only interested in adding the branch
 776                          * HEAD points at.
 777                          */
 778                         if (rev_is_head(head,
 779                                         head_len,
 780                                         ref_name[i],
 781                                         head_sha1, NULL))
 782                                 has_head++;
 783                 }
 784                 if (!has_head) {
 785                         int offset = !prefixcmp(head, "refs/heads/") ? 11 : 0;
 786                         append_one_rev(head + offset);
 787                 }
 788         }
 789
 790         if (!ref_name_cnt) {
 791                 fprintf(stderr, "No revs to be shown.\n");
 792                 exit(0);
 793         }
 794
 795         for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 796                 unsigned char revkey[20];
 797                 unsigned int flag = 1u << (num_rev + REV_SHIFT);
 798
 799                 if (MAX_REVS <= num_rev)
 800                         die("cannot handle more than %d revs.", MAX_REVS);
 801                 if (get_sha1(ref_name[num_rev], revkey))
 802                         die("'%s' is not a valid ref.", ref_name[num_rev]);
 803                 commit = lookup_commit_reference(revkey);
 804                 if (!commit)
 805                         die("cannot find commit %s (%s)",
 806                             ref_name[num_rev], revkey);
 807                 parse_commit(commit);
 808                 mark_seen(commit, &seen);
 809
 810                 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 811                  * and so on.  REV_SHIFT bits from bit 0 are used for
 812                  * internal bookkeeping.
 813                  */
 814                 commit->object.flags |= flag;
 815                 if (commit->object.flags == flag)
 816                         insert_by_date(commit, &list);
 817                 rev[num_rev] = commit;
 818         }
 819         for (i = 0; i < num_rev; i++)
 820                 rev_mask[i] = rev[i]->object.flags;
 821
 822         if (0 <= extra)
 823                 join_revs(&list, &seen, num_rev, extra);
 824
 825         sort_by_date(&seen);
 826
 827         if (merge_base)
 828                 return show_merge_base(seen, num_rev);
 829
 830         if (independent)
 831                 return show_independent(rev, num_rev, ref_name, rev_mask);
 832
 833         /* Show list; --more=-1 means list-only */
 834         if (1 < num_rev || extra < 0) {
 835                 for (i = 0; i < num_rev; i++) {
 836                         int j;
 837                         int is_head = rev_is_head(head,
 838                                                   head_len,
 839                                                   ref_name[i],
 840                                                   head_sha1,
 841                                                   rev[i]->object.sha1);
 842                         if (extra < 0)
 843                                 printf("%c [%s] ",
 844                                        is_head ? '*' : ' ', ref_name[i]);
 845                         else {
 846                                 for (j = 0; j < i; j++)
 847                                         putchar(' ');
 848                                 printf("%c [%s] ",
 849                                        is_head ? '*' : '!', ref_name[i]);
 850                         }
 851
 852                         if (!reflog) {
 853                                 /* header lines never need name */
 854                                 show_one_commit(rev[i], 1);
 855                         }
 856                         else
 857                                 puts(reflog_msg[i]);
 858
 859                         if (is_head)
 860                                 head_at = i;
 861                 }
 862                 if (0 <= extra) {
 863                         for (i = 0; i < num_rev; i++)
 864                                 putchar('-');
 865                         putchar('\n');
 866                 }
 867         }
 868         if (extra < 0)
 869                 exit(0);
 870
 871         /* Sort topologically */
 872         sort_in_topological_order(&seen, lifo);
 873
 874         /* Give names to commits */
 875         if (!sha1_name && !no_name)
 876                 name_commits(seen, rev, ref_name, num_rev);
 877
 878         all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 879         all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 880
 881         while (seen) {
 882                 struct commit *commit = pop_one_commit(&seen);
 883                 int this_flag = commit->object.flags;
 884                 int is_merge_point = ((this_flag & all_revs) == all_revs);
 885
 886                 shown_merge_point |= is_merge_point;
 887
 888                 if (1 < num_rev) {
 889                         int is_merge = !!(commit->parents &&
 890                                           commit->parents->next);
 891                         if (topics &&
 892                             !is_merge_point &&
 893                             (this_flag & (1u << REV_SHIFT)))
 894                                 continue;
 895                         if (dense && is_merge &&
 896                             omit_in_dense(commit, rev, num_rev))
 897                                 continue;
 898                         for (i = 0; i < num_rev; i++) {
 899                                 int mark;
 900                                 if (!(this_flag & (1u << (i + REV_SHIFT))))
 901                                         mark = ' ';
 902                                 else if (is_merge)
 903                                         mark = '-';
 904                                 else if (i == head_at)
 905                                         mark = '*';
 906                                 else
 907                                         mark = '+';
 908                                 putchar(mark);
 909                         }
 910                         putchar(' ');
 911                 }
 912                 show_one_commit(commit, no_name);
 913
 914                 if (shown_merge_point && --extra < 0)
 915                         break;
 916         }
 917         return 0;
 918 }