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         char pretty[256], *cp;
 263         struct commit_name *name = commit->util;
 264         if (commit->object.parsed)
 265                 pretty_print_commit(CMIT_FMT_ONELINE, commit, ~0,
 266                                     pretty, sizeof(pretty), 0, NULL, NULL, 0);
 267         else
 268                 strcpy(pretty, "(unavailable)");
 269         if (!strncmp(pretty, "[PATCH] ", 8))
 270                 cp = pretty + 8;
 271         else
 272                 cp = pretty;
 273
 274         if (!no_name) {
 275                 if (name && name->head_name) {
 276                         printf("[%s", name->head_name);
 277                         if (name->generation) {
 278                                 if (name->generation == 1)
 279                                         printf("^");
 280                                 else
 281                                         printf("~%d", name->generation);
 282                         }
 283                         printf("] ");
 284                 }
 285                 else
 286                         printf("[%s] ",
 287                                find_unique_abbrev(commit->object.sha1, 7));
 288         }
 289         puts(cp);
 290 }
 291
 292 static char *ref_name[MAX_REVS + 1];
 293 static int ref_name_cnt;
 294
 295 static const char *find_digit_prefix(const char *s, int *v)
 296 {
 297         const char *p;
 298         int ver;
 299         char ch;
 300
 301         for (p = s, ver = 0;
 302              '0' <= (ch = *p) && ch <= '9';
 303              p++)
 304                 ver = ver * 10 + ch - '0';
 305         *v = ver;
 306         return p;
 307 }
 308
 309
 310 static int version_cmp(const char *a, const char *b)
 311 {
 312         while (1) {
 313                 int va, vb;
 314
 315                 a = find_digit_prefix(a, &va);
 316                 b = find_digit_prefix(b, &vb);
 317                 if (va != vb)
 318                         return va - vb;
 319
 320                 while (1) {
 321                         int ca = *a;
 322                         int cb = *b;
 323                         if ('0' <= ca && ca <= '9')
 324                                 ca = 0;
 325                         if ('0' <= cb && cb <= '9')
 326                                 cb = 0;
 327                         if (ca != cb)
 328                                 return ca - cb;
 329                         if (!ca)
 330                                 break;
 331                         a++;
 332                         b++;
 333                 }
 334                 if (!*a && !*b)
 335                         return 0;
 336         }
 337 }
 338
 339 static int compare_ref_name(const void *a_, const void *b_)
 340 {
 341         const char * const*a = a_, * const*b = b_;
 342         return version_cmp(*a, *b);
 343 }
 344
 345 static void sort_ref_range(int bottom, int top)
 346 {
 347         qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 348               compare_ref_name);
 349 }
 350
 351 static int append_ref(const char *refname, const unsigned char *sha1,
 352                       int allow_dups)
 353 {
 354         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 355         int i;
 356
 357         if (!commit)
 358                 return 0;
 359
 360         if (!allow_dups) {
 361                 /* Avoid adding the same thing twice */
 362                 for (i = 0; i < ref_name_cnt; i++)
 363                         if (!strcmp(refname, ref_name[i]))
 364                                 return 0;
 365         }
 366         if (MAX_REVS <= ref_name_cnt) {
 367                 fprintf(stderr, "warning: ignoring %s; "
 368                         "cannot handle more than %d refs\n",
 369                         refname, MAX_REVS);
 370                 return 0;
 371         }
 372         ref_name[ref_name_cnt++] = xstrdup(refname);
 373         ref_name[ref_name_cnt] = NULL;
 374         return 0;
 375 }
 376
 377 static int append_head_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 378 {
 379         unsigned char tmp[20];
 380         int ofs = 11;
 381         if (strncmp(refname, "refs/heads/", ofs))
 382                 return 0;
 383         /* If both heads/foo and tags/foo exists, get_sha1 would
 384          * get confused.
 385          */
 386         if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 387                 ofs = 5;
 388         return append_ref(refname + ofs, sha1, 0);
 389 }
 390
 391 static int append_remote_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 392 {
 393         unsigned char tmp[20];
 394         int ofs = 13;
 395         if (strncmp(refname, "refs/remotes/", ofs))
 396                 return 0;
 397         /* If both heads/foo and tags/foo exists, get_sha1 would
 398          * get confused.
 399          */
 400         if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 401                 ofs = 5;
 402         return append_ref(refname + ofs, sha1, 0);
 403 }
 404
 405 static int append_tag_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 406 {
 407         if (strncmp(refname, "refs/tags/", 10))
 408                 return 0;
 409         return append_ref(refname + 5, sha1, 0);
 410 }
 411
 412 static const char *match_ref_pattern = NULL;
 413 static int match_ref_slash = 0;
 414 static int count_slash(const char *s)
 415 {
 416         int cnt = 0;
 417         while (*s)
 418                 if (*s++ == '/')
 419                         cnt++;
 420         return cnt;
 421 }
 422
 423 static int append_matching_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 424 {
 425         /* we want to allow pattern hold/<asterisk> to show all
 426          * branches under refs/heads/hold/, and v0.99.9? to show
 427          * refs/tags/v0.99.9a and friends.
 428          */
 429         const char *tail;
 430         int slash = count_slash(refname);
 431         for (tail = refname; *tail && match_ref_slash < slash; )
 432                 if (*tail++ == '/')
 433                         slash--;
 434         if (!*tail)
 435                 return 0;
 436         if (fnmatch(match_ref_pattern, tail, 0))
 437                 return 0;
 438         if (!strncmp("refs/heads/", refname, 11))
 439                 return append_head_ref(refname, sha1, flag, cb_data);
 440         if (!strncmp("refs/tags/", refname, 10))
 441                 return append_tag_ref(refname, sha1, flag, cb_data);
 442         return append_ref(refname, sha1, 0);
 443 }
 444
 445 static void snarf_refs(int head, int remotes)
 446 {
 447         if (head) {
 448                 int orig_cnt = ref_name_cnt;
 449                 for_each_ref(append_head_ref, NULL);
 450                 sort_ref_range(orig_cnt, ref_name_cnt);
 451         }
 452         if (remotes) {
 453                 int orig_cnt = ref_name_cnt;
 454                 for_each_ref(append_remote_ref, NULL);
 455                 sort_ref_range(orig_cnt, ref_name_cnt);
 456         }
 457 }
 458
 459 static int rev_is_head(char *head, int headlen, char *name,
 460                        unsigned char *head_sha1, unsigned char *sha1)
 461 {
 462         if ((!head[0]) ||
 463             (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
 464                 return 0;
 465         if (!strncmp(head, "refs/heads/", 11))
 466                 head += 11;
 467         if (!strncmp(name, "refs/heads/", 11))
 468                 name += 11;
 469         else if (!strncmp(name, "heads/", 6))
 470                 name += 6;
 471         return !strcmp(head, name);
 472 }
 473
 474 static int show_merge_base(struct commit_list *seen, int num_rev)
 475 {
 476         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 477         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 478         int exit_status = 1;
 479
 480         while (seen) {
 481                 struct commit *commit = pop_one_commit(&seen);
 482                 int flags = commit->object.flags & all_mask;
 483                 if (!(flags & UNINTERESTING) &&
 484                     ((flags & all_revs) == all_revs)) {
 485                         puts(sha1_to_hex(commit->object.sha1));
 486                         exit_status = 0;
 487                         commit->object.flags |= UNINTERESTING;
 488                 }
 489         }
 490         return exit_status;
 491 }
 492
 493 static int show_independent(struct commit **rev,
 494                             int num_rev,
 495                             char **ref_name,
 496                             unsigned int *rev_mask)
 497 {
 498         int i;
 499
 500         for (i = 0; i < num_rev; i++) {
 501                 struct commit *commit = rev[i];
 502                 unsigned int flag = rev_mask[i];
 503
 504                 if (commit->object.flags == flag)
 505                         puts(sha1_to_hex(commit->object.sha1));
 506                 commit->object.flags |= UNINTERESTING;
 507         }
 508         return 0;
 509 }
 510
 511 static void append_one_rev(const char *av)
 512 {
 513         unsigned char revkey[20];
 514         if (!get_sha1(av, revkey)) {
 515                 append_ref(av, revkey, 0);
 516                 return;
 517         }
 518         if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
 519                 /* glob style match */
 520                 int saved_matches = ref_name_cnt;
 521                 match_ref_pattern = av;
 522                 match_ref_slash = count_slash(av);
 523                 for_each_ref(append_matching_ref, NULL);
 524                 if (saved_matches == ref_name_cnt &&
 525                     ref_name_cnt < MAX_REVS)
 526                         error("no matching refs with %s", av);
 527                 if (saved_matches + 1 < ref_name_cnt)
 528                         sort_ref_range(saved_matches, ref_name_cnt);
 529                 return;
 530         }
 531         die("bad sha1 reference %s", av);
 532 }
 533
 534 static int git_show_branch_config(const char *var, const char *value)
 535 {
 536         if (!strcmp(var, "showbranch.default")) {
 537                 if (default_alloc <= default_num + 1) {
 538                         default_alloc = default_alloc * 3 / 2 + 20;
 539                         default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
 540                 }
 541                 default_arg[default_num++] = xstrdup(value);
 542                 default_arg[default_num] = NULL;
 543                 return 0;
 544         }
 545
 546         return git_default_config(var, value);
 547 }
 548
 549 static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
 550 {
 551         /* If the commit is tip of the named branches, do not
 552          * omit it.
 553          * Otherwise, if it is a merge that is reachable from only one
 554          * tip, it is not that interesting.
 555          */
 556         int i, flag, count;
 557         for (i = 0; i < n; i++)
 558                 if (rev[i] == commit)
 559                         return 0;
 560         flag = commit->object.flags;
 561         for (i = count = 0; i < n; i++) {
 562                 if (flag & (1u << (i + REV_SHIFT)))
 563                         count++;
 564         }
 565         if (count == 1)
 566                 return 1;
 567         return 0;
 568 }
 569
 570 static void parse_reflog_param(const char *arg, int *cnt, const char **base)
 571 {
 572         char *ep;
 573         *cnt = strtoul(arg, &ep, 10);
 574         if (*ep == ',')
 575                 *base = ep + 1;
 576         else if (*ep)
 577                 die("unrecognized reflog param '%s'", arg + 9);
 578         else
 579                 *base = NULL;
 580         if (*cnt <= 0)
 581                 *cnt = DEFAULT_REFLOG;
 582 }
 583
 584 int cmd_show_branch(int ac, const char **av, const char *prefix)
 585 {
 586         struct commit *rev[MAX_REVS], *commit;
 587         char *reflog_msg[MAX_REVS];
 588         struct commit_list *list = NULL, *seen = NULL;
 589         unsigned int rev_mask[MAX_REVS];
 590         int num_rev, i, extra = 0;
 591         int all_heads = 0, all_remotes = 0;
 592         int all_mask, all_revs;
 593         int lifo = 1;
 594         char head[128];
 595         const char *head_p;
 596         int head_len;
 597         unsigned char head_sha1[20];
 598         int merge_base = 0;
 599         int independent = 0;
 600         int no_name = 0;
 601         int sha1_name = 0;
 602         int shown_merge_point = 0;
 603         int with_current_branch = 0;
 604         int head_at = -1;
 605         int topics = 0;
 606         int dense = 1;
 607         int reflog = 0;
 608         const char *reflog_base = NULL;
 609
 610         git_config(git_show_branch_config);
 611
 612         /* If nothing is specified, try the default first */
 613         if (ac == 1 && default_num) {
 614                 ac = default_num + 1;
 615                 av = default_arg - 1; /* ick; we would not address av[0] */
 616         }
 617
 618         while (1 < ac && av[1][0] == '-') {
 619                 const char *arg = av[1];
 620                 if (!strcmp(arg, "--")) {
 621                         ac--; av++;
 622                         break;
 623                 }
 624                 else if (!strcmp(arg, "--all") || !strcmp(arg, "-a"))
 625                         all_heads = all_remotes = 1;
 626                 else if (!strcmp(arg, "--remotes") || !strcmp(arg, "-r"))
 627                         all_remotes = 1;
 628                 else if (!strcmp(arg, "--more"))
 629                         extra = 1;
 630                 else if (!strcmp(arg, "--list"))
 631                         extra = -1;
 632                 else if (!strcmp(arg, "--no-name"))
 633                         no_name = 1;
 634                 else if (!strcmp(arg, "--current"))
 635                         with_current_branch = 1;
 636                 else if (!strcmp(arg, "--sha1-name"))
 637                         sha1_name = 1;
 638                 else if (!strncmp(arg, "--more=", 7))
 639                         extra = atoi(arg + 7);
 640                 else if (!strcmp(arg, "--merge-base"))
 641                         merge_base = 1;
 642                 else if (!strcmp(arg, "--independent"))
 643                         independent = 1;
 644                 else if (!strcmp(arg, "--topo-order"))
 645                         lifo = 1;
 646                 else if (!strcmp(arg, "--topics"))
 647                         topics = 1;
 648                 else if (!strcmp(arg, "--sparse"))
 649                         dense = 0;
 650                 else if (!strcmp(arg, "--date-order"))
 651                         lifo = 0;
 652                 else if (!strcmp(arg, "--reflog") || !strcmp(arg, "-g")) {
 653                         reflog = DEFAULT_REFLOG;
 654                 }
 655                 else if (!strncmp(arg, "--reflog=", 9))
 656                         parse_reflog_param(arg + 9, &reflog, &reflog_base);
 657                 else if (!strncmp(arg, "-g=", 3))
 658                         parse_reflog_param(arg + 3, &reflog, &reflog_base);
 659                 else
 660                         usage(show_branch_usage);
 661                 ac--; av++;
 662         }
 663         ac--; av++;
 664
 665         if (extra || reflog) {
 666                 /* "listing" mode is incompatible with
 667                  * independent nor merge-base modes.
 668                  */
 669                 if (independent || merge_base)
 670                         usage(show_branch_usage);
 671                 if (reflog && ((0 < extra) || all_heads || all_remotes))
 672                         /*
 673                          * Asking for --more in reflog mode does not
 674                          * make sense.  --list is Ok.
 675                          *
 676                          * Also --all and --remotes do not make sense either.
 677                          */
 678                         usage(show_branch_usage_reflog);
 679         }
 680
 681         /* If nothing is specified, show all branches by default */
 682         if (ac + all_heads + all_remotes == 0)
 683                 all_heads = 1;
 684
 685         if (reflog) {
 686                 unsigned char sha1[20];
 687                 char nth_desc[256];
 688                 char *ref;
 689                 int base = 0;
 690
 691                 if (ac == 0) {
 692                         static const char *fake_av[2];
 693                         const char *refname;
 694
 695                         refname = resolve_ref("HEAD", sha1, 1, NULL);
 696                         fake_av[0] = xstrdup(refname);
 697                         fake_av[1] = NULL;
 698                         av = fake_av;
 699                         ac = 1;
 700                 }
 701                 if (ac != 1)
 702                         die("--reflog option needs one branch name");
 703
 704                 if (MAX_REVS < reflog)
 705                         die("Only %d entries can be shown at one time.",
 706                             MAX_REVS);
 707                 if (!dwim_ref(*av, strlen(*av), sha1, &ref))
 708                         die("No such ref %s", *av);
 709
 710                 /* Has the base been specified? */
 711                 if (reflog_base) {
 712                         char *ep;
 713                         base = strtoul(reflog_base, &ep, 10);
 714                         if (*ep) {
 715                                 /* Ah, that is a date spec... */
 716                                 unsigned long at;
 717                                 at = approxidate(reflog_base);
 718                                 read_ref_at(ref, at, -1, sha1, NULL,
 719                                             NULL, NULL, &base);
 720                         }
 721                 }
 722
 723                 for (i = 0; i < reflog; i++) {
 724                         char *logmsg, *msg, *m;
 725                         unsigned long timestamp;
 726                         int tz;
 727
 728                         if (read_ref_at(ref, 0, base+i, sha1, &logmsg,
 729                                         &timestamp, &tz, NULL)) {
 730                                 reflog = i;
 731                                 break;
 732                         }
 733                         msg = strchr(logmsg, '\t');
 734                         if (!msg)
 735                                 msg = "(none)";
 736                         else
 737                                 msg++;
 738                         m = xmalloc(strlen(msg) + 200);
 739                         sprintf(m, "(%s) %s",
 740                                 show_date(timestamp, tz, 1),
 741                                 msg);
 742                         reflog_msg[i] = m;
 743                         free(logmsg);
 744                         sprintf(nth_desc, "%s@{%d}", *av, base+i);
 745                         append_ref(nth_desc, sha1, 1);
 746                 }
 747         }
 748         else if (all_heads + all_remotes)
 749                 snarf_refs(all_heads, all_remotes);
 750         else {
 751                 while (0 < ac) {
 752                         append_one_rev(*av);
 753                         ac--; av++;
 754                 }
 755         }
 756
 757         head_p = resolve_ref("HEAD", head_sha1, 1, NULL);
 758         if (head_p) {
 759                 head_len = strlen(head_p);
 760                 memcpy(head, head_p, head_len + 1);
 761         }
 762         else {
 763                 head_len = 0;
 764                 head[0] = 0;
 765         }
 766
 767         if (with_current_branch && head_p) {
 768                 int has_head = 0;
 769                 for (i = 0; !has_head && i < ref_name_cnt; i++) {
 770                         /* We are only interested in adding the branch
 771                          * HEAD points at.
 772                          */
 773                         if (rev_is_head(head,
 774                                         head_len,
 775                                         ref_name[i],
 776                                         head_sha1, NULL))
 777                                 has_head++;
 778                 }
 779                 if (!has_head) {
 780                         int pfxlen = strlen("refs/heads/");
 781                         append_one_rev(head + pfxlen);
 782                 }
 783         }
 784
 785         if (!ref_name_cnt) {
 786                 fprintf(stderr, "No revs to be shown.\n");
 787                 exit(0);
 788         }
 789
 790         for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 791                 unsigned char revkey[20];
 792                 unsigned int flag = 1u << (num_rev + REV_SHIFT);
 793
 794                 if (MAX_REVS <= num_rev)
 795                         die("cannot handle more than %d revs.", MAX_REVS);
 796                 if (get_sha1(ref_name[num_rev], revkey))
 797                         die("'%s' is not a valid ref.", ref_name[num_rev]);
 798                 commit = lookup_commit_reference(revkey);
 799                 if (!commit)
 800                         die("cannot find commit %s (%s)",
 801                             ref_name[num_rev], revkey);
 802                 parse_commit(commit);
 803                 mark_seen(commit, &seen);
 804
 805                 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 806                  * and so on.  REV_SHIFT bits from bit 0 are used for
 807                  * internal bookkeeping.
 808                  */
 809                 commit->object.flags |= flag;
 810                 if (commit->object.flags == flag)
 811                         insert_by_date(commit, &list);
 812                 rev[num_rev] = commit;
 813         }
 814         for (i = 0; i < num_rev; i++)
 815                 rev_mask[i] = rev[i]->object.flags;
 816
 817         if (0 <= extra)
 818                 join_revs(&list, &seen, num_rev, extra);
 819
 820         sort_by_date(&seen);
 821
 822         if (merge_base)
 823                 return show_merge_base(seen, num_rev);
 824
 825         if (independent)
 826                 return show_independent(rev, num_rev, ref_name, rev_mask);
 827
 828         /* Show list; --more=-1 means list-only */
 829         if (1 < num_rev || extra < 0) {
 830                 for (i = 0; i < num_rev; i++) {
 831                         int j;
 832                         int is_head = rev_is_head(head,
 833                                                   head_len,
 834                                                   ref_name[i],
 835                                                   head_sha1,
 836                                                   rev[i]->object.sha1);
 837                         if (extra < 0)
 838                                 printf("%c [%s] ",
 839                                        is_head ? '*' : ' ', ref_name[i]);
 840                         else {
 841                                 for (j = 0; j < i; j++)
 842                                         putchar(' ');
 843                                 printf("%c [%s] ",
 844                                        is_head ? '*' : '!', ref_name[i]);
 845                         }
 846
 847                         if (!reflog) {
 848                                 /* header lines never need name */
 849                                 show_one_commit(rev[i], 1);
 850                         }
 851                         else
 852                                 puts(reflog_msg[i]);
 853
 854                         if (is_head)
 855                                 head_at = i;
 856                 }
 857                 if (0 <= extra) {
 858                         for (i = 0; i < num_rev; i++)
 859                                 putchar('-');
 860                         putchar('\n');
 861                 }
 862         }
 863         if (extra < 0)
 864                 exit(0);
 865
 866         /* Sort topologically */
 867         sort_in_topological_order(&seen, lifo);
 868
 869         /* Give names to commits */
 870         if (!sha1_name && !no_name)
 871                 name_commits(seen, rev, ref_name, num_rev);
 872
 873         all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 874         all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 875
 876         while (seen) {
 877                 struct commit *commit = pop_one_commit(&seen);
 878                 int this_flag = commit->object.flags;
 879                 int is_merge_point = ((this_flag & all_revs) == all_revs);
 880
 881                 shown_merge_point |= is_merge_point;
 882
 883                 if (1 < num_rev) {
 884                         int is_merge = !!(commit->parents &&
 885                                           commit->parents->next);
 886                         if (topics &&
 887                             !is_merge_point &&
 888                             (this_flag & (1u << REV_SHIFT)))
 889                                 continue;
 890                         if (dense && is_merge &&
 891                             omit_in_dense(commit, rev, num_rev))
 892                                 continue;
 893                         for (i = 0; i < num_rev; i++) {
 894                                 int mark;
 895                                 if (!(this_flag & (1u << (i + REV_SHIFT))))
 896                                         mark = ' ';
 897                                 else if (is_merge)
 898                                         mark = '-';
 899                                 else if (i == head_at)
 900                                         mark = '*';
 901                                 else
 902                                         mark = '+';
 903                                 putchar(mark);
 904                         }
 905                         putchar(' ');
 906                 }
 907                 show_one_commit(commit, no_name);
 908
 909                 if (shown_merge_point && --extra < 0)
 910                         break;
 911         }
 912         return 0;
 913 }