builtin/show-branch.c

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "pretty.h"
   4 #include "refs.h"
   5 #include "builtin.h"
   6 #include "color.h"
   7 #include "argv-array.h"
   8 #include "parse-options.h"
   9 #include "dir.h"
  10 #include "commit-slab.h"
  11
  12 static const char* show_branch_usage[] = {
  13     N_("git show-branch [-a | --all] [-r | --remotes] [--topo-order | --date-order]\n"
  14        "                [--current] [--color[=<when>] | --no-color] [--sparse]\n"
  15        "                [--more=<n> | --list | --independent | --merge-base]\n"
  16        "                [--no-name | --sha1-name] [--topics] [(<rev> | <glob>)...]"),
  17     N_("git show-branch (-g | --reflog)[=<n>[,<base>]] [--list] [<ref>]"),
  18     NULL
  19 };
  20
  21 static int showbranch_use_color = -1;
  22
  23 static struct argv_array default_args = ARGV_ARRAY_INIT;
  24
  25 /*
  26  * TODO: convert this use of commit->object.flags to commit-slab
  27  * instead to store a pointer to ref name directly. Then use the same
  28  * UNINTERESTING definition from revision.h here.
  29  */
  30 #define UNINTERESTING   01
  31
  32 #define REV_SHIFT        2
  33 #define MAX_REVS        (FLAG_BITS - REV_SHIFT) /* should not exceed bits_per_int - REV_SHIFT */
  34
  35 #define DEFAULT_REFLOG  4
  36
  37 static const char *get_color_code(int idx)
  38 {
  39         if (want_color(showbranch_use_color))
  40                 return column_colors_ansi[idx % column_colors_ansi_max];
  41         return "";
  42 }
  43
  44 static const char *get_color_reset_code(void)
  45 {
  46         if (want_color(showbranch_use_color))
  47                 return GIT_COLOR_RESET;
  48         return "";
  49 }
  50
  51 static struct commit *interesting(struct commit_list *list)
  52 {
  53         while (list) {
  54                 struct commit *commit = list->item;
  55                 list = list->next;
  56                 if (commit->object.flags & UNINTERESTING)
  57                         continue;
  58                 return commit;
  59         }
  60         return NULL;
  61 }
  62
  63 struct commit_name {
  64         const char *head_name; /* which head's ancestor? */
  65         int generation; /* how many parents away from head_name */
  66 };
  67
  68 define_commit_slab(commit_name_slab, struct commit_name *);
  69 static struct commit_name_slab name_slab;
  70
  71 static struct commit_name *commit_to_name(struct commit *commit)
  72 {
  73         return *commit_name_slab_at(&name_slab, commit);
  74 }
  75
  76
  77 /* Name the commit as nth generation ancestor of head_name;
  78  * we count only the first-parent relationship for naming purposes.
  79  */
  80 static void name_commit(struct commit *commit, const char *head_name, int nth)
  81 {
  82         struct commit_name *name;
  83
  84         name = *commit_name_slab_at(&name_slab, commit);
  85         if (!name) {
  86                 name = xmalloc(sizeof(*name));
  87                 *commit_name_slab_at(&name_slab, commit) = name;
  88         }
  89         name->head_name = head_name;
  90         name->generation = nth;
  91 }
  92
  93 /* Parent is the first parent of the commit.  We may name it
  94  * as (n+1)th generation ancestor of the same head_name as
  95  * commit is nth generation ancestor of, if that generation
  96  * number is better than the name it already has.
  97  */
  98 static void name_parent(struct commit *commit, struct commit *parent)
  99 {
 100         struct commit_name *commit_name = commit_to_name(commit);
 101         struct commit_name *parent_name = commit_to_name(parent);
 102         if (!commit_name)
 103                 return;
 104         if (!parent_name ||
 105             commit_name->generation + 1 < parent_name->generation)
 106                 name_commit(parent, commit_name->head_name,
 107                             commit_name->generation + 1);
 108 }
 109
 110 static int name_first_parent_chain(struct commit *c)
 111 {
 112         int i = 0;
 113         while (c) {
 114                 struct commit *p;
 115                 if (!commit_to_name(c))
 116                         break;
 117                 if (!c->parents)
 118                         break;
 119                 p = c->parents->item;
 120                 if (!commit_to_name(p)) {
 121                         name_parent(c, p);
 122                         i++;
 123                 }
 124                 else
 125                         break;
 126                 c = p;
 127         }
 128         return i;
 129 }
 130
 131 static void name_commits(struct commit_list *list,
 132                          struct commit **rev,
 133                          char **ref_name,
 134                          int num_rev)
 135 {
 136         struct commit_list *cl;
 137         struct commit *c;
 138         int i;
 139
 140         /* First give names to the given heads */
 141         for (cl = list; cl; cl = cl->next) {
 142                 c = cl->item;
 143                 if (commit_to_name(c))
 144                         continue;
 145                 for (i = 0; i < num_rev; i++) {
 146                         if (rev[i] == c) {
 147                                 name_commit(c, ref_name[i], 0);
 148                                 break;
 149                         }
 150                 }
 151         }
 152
 153         /* Then commits on the first parent ancestry chain */
 154         do {
 155                 i = 0;
 156                 for (cl = list; cl; cl = cl->next) {
 157                         i += name_first_parent_chain(cl->item);
 158                 }
 159         } while (i);
 160
 161         /* Finally, any unnamed commits */
 162         do {
 163                 i = 0;
 164                 for (cl = list; cl; cl = cl->next) {
 165                         struct commit_list *parents;
 166                         struct commit_name *n;
 167                         int nth;
 168                         c = cl->item;
 169                         if (!commit_to_name(c))
 170                                 continue;
 171                         n = commit_to_name(c);
 172                         parents = c->parents;
 173                         nth = 0;
 174                         while (parents) {
 175                                 struct commit *p = parents->item;
 176                                 struct strbuf newname = STRBUF_INIT;
 177                                 parents = parents->next;
 178                                 nth++;
 179                                 if (commit_to_name(p))
 180                                         continue;
 181                                 switch (n->generation) {
 182                                 case 0:
 183                                         strbuf_addstr(&newname, n->head_name);
 184                                         break;
 185                                 case 1:
 186                                         strbuf_addf(&newname, "%s^", n->head_name);
 187                                         break;
 188                                 default:
 189                                         strbuf_addf(&newname, "%s~%d",
 190                                                     n->head_name, n->generation);
 191                                         break;
 192                                 }
 193                                 if (nth == 1)
 194                                         strbuf_addch(&newname, '^');
 195                                 else
 196                                         strbuf_addf(&newname, "^%d", nth);
 197                                 name_commit(p, strbuf_detach(&newname, NULL), 0);
 198                                 i++;
 199                                 name_first_parent_chain(p);
 200                         }
 201                 }
 202         } while (i);
 203 }
 204
 205 static int mark_seen(struct commit *commit, struct commit_list **seen_p)
 206 {
 207         if (!commit->object.flags) {
 208                 commit_list_insert(commit, seen_p);
 209                 return 1;
 210         }
 211         return 0;
 212 }
 213
 214 static void join_revs(struct commit_list **list_p,
 215                       struct commit_list **seen_p,
 216                       int num_rev, int extra)
 217 {
 218         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 219         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 220
 221         while (*list_p) {
 222                 struct commit_list *parents;
 223                 int still_interesting = !!interesting(*list_p);
 224                 struct commit *commit = pop_commit(list_p);
 225                 int flags = commit->object.flags & all_mask;
 226
 227                 if (!still_interesting && extra <= 0)
 228                         break;
 229
 230                 mark_seen(commit, seen_p);
 231                 if ((flags & all_revs) == all_revs)
 232                         flags |= UNINTERESTING;
 233                 parents = commit->parents;
 234
 235                 while (parents) {
 236                         struct commit *p = parents->item;
 237                         int this_flag = p->object.flags;
 238                         parents = parents->next;
 239                         if ((this_flag & flags) == flags)
 240                                 continue;
 241                         parse_commit(p);
 242                         if (mark_seen(p, seen_p) && !still_interesting)
 243                                 extra--;
 244                         p->object.flags |= flags;
 245                         commit_list_insert_by_date(p, list_p);
 246                 }
 247         }
 248
 249         /*
 250          * Postprocess to complete well-poisoning.
 251          *
 252          * At this point we have all the commits we have seen in
 253          * seen_p list.  Mark anything that can be reached from
 254          * uninteresting commits not interesting.
 255          */
 256         for (;;) {
 257                 int changed = 0;
 258                 struct commit_list *s;
 259                 for (s = *seen_p; s; s = s->next) {
 260                         struct commit *c = s->item;
 261                         struct commit_list *parents;
 262
 263                         if (((c->object.flags & all_revs) != all_revs) &&
 264                             !(c->object.flags & UNINTERESTING))
 265                                 continue;
 266
 267                         /* The current commit is either a merge base or
 268                          * already uninteresting one.  Mark its parents
 269                          * as uninteresting commits _only_ if they are
 270                          * already parsed.  No reason to find new ones
 271                          * here.
 272                          */
 273                         parents = c->parents;
 274                         while (parents) {
 275                                 struct commit *p = parents->item;
 276                                 parents = parents->next;
 277                                 if (!(p->object.flags & UNINTERESTING)) {
 278                                         p->object.flags |= UNINTERESTING;
 279                                         changed = 1;
 280                                 }
 281                         }
 282                 }
 283                 if (!changed)
 284                         break;
 285         }
 286 }
 287
 288 static void show_one_commit(struct commit *commit, int no_name)
 289 {
 290         struct strbuf pretty = STRBUF_INIT;
 291         const char *pretty_str = "(unavailable)";
 292         struct commit_name *name = commit_to_name(commit);
 293
 294         if (commit->object.parsed) {
 295                 pp_commit_easy(CMIT_FMT_ONELINE, commit, &pretty);
 296                 pretty_str = pretty.buf;
 297         }
 298         skip_prefix(pretty_str, "[PATCH] ", &pretty_str);
 299
 300         if (!no_name) {
 301                 if (name && name->head_name) {
 302                         printf("[%s", name->head_name);
 303                         if (name->generation) {
 304                                 if (name->generation == 1)
 305                                         printf("^");
 306                                 else
 307                                         printf("~%d", name->generation);
 308                         }
 309                         printf("] ");
 310                 }
 311                 else
 312                         printf("[%s] ",
 313                                find_unique_abbrev(&commit->object.oid,
 314                                                   DEFAULT_ABBREV));
 315         }
 316         puts(pretty_str);
 317         strbuf_release(&pretty);
 318 }
 319
 320 static char *ref_name[MAX_REVS + 1];
 321 static int ref_name_cnt;
 322
 323 static const char *find_digit_prefix(const char *s, int *v)
 324 {
 325         const char *p;
 326         int ver;
 327         char ch;
 328
 329         for (p = s, ver = 0;
 330              '0' <= (ch = *p) && ch <= '9';
 331              p++)
 332                 ver = ver * 10 + ch - '0';
 333         *v = ver;
 334         return p;
 335 }
 336
 337
 338 static int version_cmp(const char *a, const char *b)
 339 {
 340         while (1) {
 341                 int va, vb;
 342
 343                 a = find_digit_prefix(a, &va);
 344                 b = find_digit_prefix(b, &vb);
 345                 if (va != vb)
 346                         return va - vb;
 347
 348                 while (1) {
 349                         int ca = *a;
 350                         int cb = *b;
 351                         if ('0' <= ca && ca <= '9')
 352                                 ca = 0;
 353                         if ('0' <= cb && cb <= '9')
 354                                 cb = 0;
 355                         if (ca != cb)
 356                                 return ca - cb;
 357                         if (!ca)
 358                                 break;
 359                         a++;
 360                         b++;
 361                 }
 362                 if (!*a && !*b)
 363                         return 0;
 364         }
 365 }
 366
 367 static int compare_ref_name(const void *a_, const void *b_)
 368 {
 369         const char * const*a = a_, * const*b = b_;
 370         return version_cmp(*a, *b);
 371 }
 372
 373 static void sort_ref_range(int bottom, int top)
 374 {
 375         QSORT(ref_name + bottom, top - bottom, compare_ref_name);
 376 }
 377
 378 static int append_ref(const char *refname, const struct object_id *oid,
 379                       int allow_dups)
 380 {
 381         struct commit *commit = lookup_commit_reference_gently(oid, 1);
 382         int i;
 383
 384         if (!commit)
 385                 return 0;
 386
 387         if (!allow_dups) {
 388                 /* Avoid adding the same thing twice */
 389                 for (i = 0; i < ref_name_cnt; i++)
 390                         if (!strcmp(refname, ref_name[i]))
 391                                 return 0;
 392         }
 393         if (MAX_REVS <= ref_name_cnt) {
 394                 warning(Q_("ignoring %s; cannot handle more than %d ref",
 395                            "ignoring %s; cannot handle more than %d refs",
 396                            MAX_REVS), refname, MAX_REVS);
 397                 return 0;
 398         }
 399         ref_name[ref_name_cnt++] = xstrdup(refname);
 400         ref_name[ref_name_cnt] = NULL;
 401         return 0;
 402 }
 403
 404 static int append_head_ref(const char *refname, const struct object_id *oid,
 405                            int flag, void *cb_data)
 406 {
 407         struct object_id tmp;
 408         int ofs = 11;
 409         if (!starts_with(refname, "refs/heads/"))
 410                 return 0;
 411         /* If both heads/foo and tags/foo exists, get_sha1 would
 412          * get confused.
 413          */
 414         if (get_oid(refname + ofs, &tmp) || oidcmp(&tmp, oid))
 415                 ofs = 5;
 416         return append_ref(refname + ofs, oid, 0);
 417 }
 418
 419 static int append_remote_ref(const char *refname, const struct object_id *oid,
 420                              int flag, void *cb_data)
 421 {
 422         struct object_id tmp;
 423         int ofs = 13;
 424         if (!starts_with(refname, "refs/remotes/"))
 425                 return 0;
 426         /* If both heads/foo and tags/foo exists, get_sha1 would
 427          * get confused.
 428          */
 429         if (get_oid(refname + ofs, &tmp) || oidcmp(&tmp, oid))
 430                 ofs = 5;
 431         return append_ref(refname + ofs, oid, 0);
 432 }
 433
 434 static int append_tag_ref(const char *refname, const struct object_id *oid,
 435                           int flag, void *cb_data)
 436 {
 437         if (!starts_with(refname, "refs/tags/"))
 438                 return 0;
 439         return append_ref(refname + 5, oid, 0);
 440 }
 441
 442 static const char *match_ref_pattern = NULL;
 443 static int match_ref_slash = 0;
 444
 445 static int append_matching_ref(const char *refname, const struct object_id *oid,
 446                                int flag, void *cb_data)
 447 {
 448         /* we want to allow pattern hold/<asterisk> to show all
 449          * branches under refs/heads/hold/, and v0.99.9? to show
 450          * refs/tags/v0.99.9a and friends.
 451          */
 452         const char *tail;
 453         int slash = count_slashes(refname);
 454         for (tail = refname; *tail && match_ref_slash < slash; )
 455                 if (*tail++ == '/')
 456                         slash--;
 457         if (!*tail)
 458                 return 0;
 459         if (wildmatch(match_ref_pattern, tail, 0))
 460                 return 0;
 461         if (starts_with(refname, "refs/heads/"))
 462                 return append_head_ref(refname, oid, flag, cb_data);
 463         if (starts_with(refname, "refs/tags/"))
 464                 return append_tag_ref(refname, oid, flag, cb_data);
 465         return append_ref(refname, oid, 0);
 466 }
 467
 468 static void snarf_refs(int head, int remotes)
 469 {
 470         if (head) {
 471                 int orig_cnt = ref_name_cnt;
 472
 473                 for_each_ref(append_head_ref, NULL);
 474                 sort_ref_range(orig_cnt, ref_name_cnt);
 475         }
 476         if (remotes) {
 477                 int orig_cnt = ref_name_cnt;
 478
 479                 for_each_ref(append_remote_ref, NULL);
 480                 sort_ref_range(orig_cnt, ref_name_cnt);
 481         }
 482 }
 483
 484 static int rev_is_head(const char *head, const char *name,
 485                        unsigned char *head_sha1, unsigned char *sha1)
 486 {
 487         if (!head || (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
 488                 return 0;
 489         skip_prefix(head, "refs/heads/", &head);
 490         if (!skip_prefix(name, "refs/heads/", &name))
 491                 skip_prefix(name, "heads/", &name);
 492         return !strcmp(head, name);
 493 }
 494
 495 static int show_merge_base(struct commit_list *seen, int num_rev)
 496 {
 497         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 498         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 499         int exit_status = 1;
 500
 501         while (seen) {
 502                 struct commit *commit = pop_commit(&seen);
 503                 int flags = commit->object.flags & all_mask;
 504                 if (!(flags & UNINTERESTING) &&
 505                     ((flags & all_revs) == all_revs)) {
 506                         puts(oid_to_hex(&commit->object.oid));
 507                         exit_status = 0;
 508                         commit->object.flags |= UNINTERESTING;
 509                 }
 510         }
 511         return exit_status;
 512 }
 513
 514 static int show_independent(struct commit **rev,
 515                             int num_rev,
 516                             char **ref_name,
 517                             unsigned int *rev_mask)
 518 {
 519         int i;
 520
 521         for (i = 0; i < num_rev; i++) {
 522                 struct commit *commit = rev[i];
 523                 unsigned int flag = rev_mask[i];
 524
 525                 if (commit->object.flags == flag)
 526                         puts(oid_to_hex(&commit->object.oid));
 527                 commit->object.flags |= UNINTERESTING;
 528         }
 529         return 0;
 530 }
 531
 532 static void append_one_rev(const char *av)
 533 {
 534         struct object_id revkey;
 535         if (!get_oid(av, &revkey)) {
 536                 append_ref(av, &revkey, 0);
 537                 return;
 538         }
 539         if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
 540                 /* glob style match */
 541                 int saved_matches = ref_name_cnt;
 542
 543                 match_ref_pattern = av;
 544                 match_ref_slash = count_slashes(av);
 545                 for_each_ref(append_matching_ref, NULL);
 546                 if (saved_matches == ref_name_cnt &&
 547                     ref_name_cnt < MAX_REVS)
 548                         error(_("no matching refs with %s"), av);
 549                 sort_ref_range(saved_matches, ref_name_cnt);
 550                 return;
 551         }
 552         die("bad sha1 reference %s", av);
 553 }
 554
 555 static int git_show_branch_config(const char *var, const char *value, void *cb)
 556 {
 557         if (!strcmp(var, "showbranch.default")) {
 558                 if (!value)
 559                         return config_error_nonbool(var);
 560                 /*
 561                  * default_arg is now passed to parse_options(), so we need to
 562                  * mimic the real argv a bit better.
 563                  */
 564                 if (!default_args.argc)
 565                         argv_array_push(&default_args, "show-branch");
 566                 argv_array_push(&default_args, value);
 567                 return 0;
 568         }
 569
 570         if (!strcmp(var, "color.showbranch")) {
 571                 showbranch_use_color = git_config_colorbool(var, value);
 572                 return 0;
 573         }
 574
 575         return git_color_default_config(var, value, cb);
 576 }
 577
 578 static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
 579 {
 580         /* If the commit is tip of the named branches, do not
 581          * omit it.
 582          * Otherwise, if it is a merge that is reachable from only one
 583          * tip, it is not that interesting.
 584          */
 585         int i, flag, count;
 586         for (i = 0; i < n; i++)
 587                 if (rev[i] == commit)
 588                         return 0;
 589         flag = commit->object.flags;
 590         for (i = count = 0; i < n; i++) {
 591                 if (flag & (1u << (i + REV_SHIFT)))
 592                         count++;
 593         }
 594         if (count == 1)
 595                 return 1;
 596         return 0;
 597 }
 598
 599 static int reflog = 0;
 600
 601 static int parse_reflog_param(const struct option *opt, const char *arg,
 602                               int unset)
 603 {
 604         char *ep;
 605         const char **base = (const char **)opt->value;
 606         if (!arg)
 607                 arg = "";
 608         reflog = strtoul(arg, &ep, 10);
 609         if (*ep == ',')
 610                 *base = ep + 1;
 611         else if (*ep)
 612                 return error("unrecognized reflog param '%s'", arg);
 613         else
 614                 *base = NULL;
 615         if (reflog <= 0)
 616                 reflog = DEFAULT_REFLOG;
 617         return 0;
 618 }
 619
 620 int cmd_show_branch(int ac, const char **av, const char *prefix)
 621 {
 622         struct commit *rev[MAX_REVS], *commit;
 623         char *reflog_msg[MAX_REVS];
 624         struct commit_list *list = NULL, *seen = NULL;
 625         unsigned int rev_mask[MAX_REVS];
 626         int num_rev, i, extra = 0;
 627         int all_heads = 0, all_remotes = 0;
 628         int all_mask, all_revs;
 629         enum rev_sort_order sort_order = REV_SORT_IN_GRAPH_ORDER;
 630         char *head;
 631         struct object_id head_oid;
 632         int merge_base = 0;
 633         int independent = 0;
 634         int no_name = 0;
 635         int sha1_name = 0;
 636         int shown_merge_point = 0;
 637         int with_current_branch = 0;
 638         int head_at = -1;
 639         int topics = 0;
 640         int dense = 1;
 641         const char *reflog_base = NULL;
 642         struct option builtin_show_branch_options[] = {
 643                 OPT_BOOL('a', "all", &all_heads,
 644                          N_("show remote-tracking and local branches")),
 645                 OPT_BOOL('r', "remotes", &all_remotes,
 646                          N_("show remote-tracking branches")),
 647                 OPT__COLOR(&showbranch_use_color,
 648                             N_("color '*!+-' corresponding to the branch")),
 649                 { OPTION_INTEGER, 0, "more", &extra, N_("n"),
 650                             N_("show <n> more commits after the common ancestor"),
 651                             PARSE_OPT_OPTARG, NULL, (intptr_t)1 },
 652                 OPT_SET_INT(0, "list", &extra, N_("synonym to more=-1"), -1),
 653                 OPT_BOOL(0, "no-name", &no_name, N_("suppress naming strings")),
 654                 OPT_BOOL(0, "current", &with_current_branch,
 655                          N_("include the current branch")),
 656                 OPT_BOOL(0, "sha1-name", &sha1_name,
 657                          N_("name commits with their object names")),
 658                 OPT_BOOL(0, "merge-base", &merge_base,
 659                          N_("show possible merge bases")),
 660                 OPT_BOOL(0, "independent", &independent,
 661                             N_("show refs unreachable from any other ref")),
 662                 OPT_SET_INT(0, "topo-order", &sort_order,
 663                             N_("show commits in topological order"),
 664                             REV_SORT_IN_GRAPH_ORDER),
 665                 OPT_BOOL(0, "topics", &topics,
 666                          N_("show only commits not on the first branch")),
 667                 OPT_SET_INT(0, "sparse", &dense,
 668                             N_("show merges reachable from only one tip"), 0),
 669                 OPT_SET_INT(0, "date-order", &sort_order,
 670                             N_("topologically sort, maintaining date order "
 671                                "where possible"),
 672                             REV_SORT_BY_COMMIT_DATE),
 673                 { OPTION_CALLBACK, 'g', "reflog", &reflog_base, N_("<n>[,<base>]"),
 674                             N_("show <n> most recent ref-log entries starting at "
 675                                "base"),
 676                             PARSE_OPT_OPTARG | PARSE_OPT_LITERAL_ARGHELP,
 677                             parse_reflog_param },
 678                 OPT_END()
 679         };
 680
 681         init_commit_name_slab(&name_slab);
 682
 683         git_config(git_show_branch_config, NULL);
 684
 685         /* If nothing is specified, try the default first */
 686         if (ac == 1 && default_args.argc) {
 687                 ac = default_args.argc;
 688                 av = default_args.argv;
 689         }
 690
 691         ac = parse_options(ac, av, prefix, builtin_show_branch_options,
 692                            show_branch_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 693         if (all_heads)
 694                 all_remotes = 1;
 695
 696         if (extra || reflog) {
 697                 /* "listing" mode is incompatible with
 698                  * independent nor merge-base modes.
 699                  */
 700                 if (independent || merge_base)
 701                         usage_with_options(show_branch_usage,
 702                                            builtin_show_branch_options);
 703                 if (reflog && ((0 < extra) || all_heads || all_remotes))
 704                         /*
 705                          * Asking for --more in reflog mode does not
 706                          * make sense.  --list is Ok.
 707                          *
 708                          * Also --all and --remotes do not make sense either.
 709                          */
 710                         die(_("--reflog is incompatible with --all, --remotes, "
 711                               "--independent or --merge-base"));
 712         }
 713
 714         /* If nothing is specified, show all branches by default */
 715         if (ac <= topics && all_heads + all_remotes == 0)
 716                 all_heads = 1;
 717
 718         if (reflog) {
 719                 struct object_id oid;
 720                 char *ref;
 721                 int base = 0;
 722                 unsigned int flags = 0;
 723
 724                 if (ac == 0) {
 725                         static const char *fake_av[2];
 726
 727                         fake_av[0] = resolve_refdup("HEAD",
 728                                                     RESOLVE_REF_READING, &oid,
 729                                                     NULL);
 730                         fake_av[1] = NULL;
 731                         av = fake_av;
 732                         ac = 1;
 733                         if (!*av)
 734                                 die(_("no branches given, and HEAD is not valid"));
 735                 }
 736                 if (ac != 1)
 737                         die(_("--reflog option needs one branch name"));
 738
 739                 if (MAX_REVS < reflog)
 740                         die(Q_("only %d entry can be shown at one time.",
 741                                "only %d entries can be shown at one time.",
 742                                MAX_REVS), MAX_REVS);
 743                 if (!dwim_ref(*av, strlen(*av), &oid, &ref))
 744                         die(_("no such ref %s"), *av);
 745
 746                 /* Has the base been specified? */
 747                 if (reflog_base) {
 748                         char *ep;
 749                         base = strtoul(reflog_base, &ep, 10);
 750                         if (*ep) {
 751                                 /* Ah, that is a date spec... */
 752                                 timestamp_t at;
 753                                 at = approxidate(reflog_base);
 754                                 read_ref_at(ref, flags, at, -1, &oid, NULL,
 755                                             NULL, NULL, &base);
 756                         }
 757                 }
 758
 759                 for (i = 0; i < reflog; i++) {
 760                         char *logmsg;
 761                         char *nth_desc;
 762                         const char *msg;
 763                         timestamp_t timestamp;
 764                         int tz;
 765
 766                         if (read_ref_at(ref, flags, 0, base + i, &oid, &logmsg,
 767                                         &timestamp, &tz, NULL)) {
 768                                 reflog = i;
 769                                 break;
 770                         }
 771                         msg = strchr(logmsg, '\t');
 772                         if (!msg)
 773                                 msg = "(none)";
 774                         else
 775                                 msg++;
 776                         reflog_msg[i] = xstrfmt("(%s) %s",
 777                                                 show_date(timestamp, tz,
 778                                                           DATE_MODE(RELATIVE)),
 779                                                 msg);
 780                         free(logmsg);
 781
 782                         nth_desc = xstrfmt("%s@{%d}", *av, base+i);
 783                         append_ref(nth_desc, &oid, 1);
 784                         free(nth_desc);
 785                 }
 786                 free(ref);
 787         }
 788         else {
 789                 while (0 < ac) {
 790                         append_one_rev(*av);
 791                         ac--; av++;
 792                 }
 793                 if (all_heads + all_remotes)
 794                         snarf_refs(all_heads, all_remotes);
 795         }
 796
 797         head = resolve_refdup("HEAD", RESOLVE_REF_READING,
 798                               &head_oid, NULL);
 799
 800         if (with_current_branch && head) {
 801                 int has_head = 0;
 802                 for (i = 0; !has_head && i < ref_name_cnt; i++) {
 803                         /* We are only interested in adding the branch
 804                          * HEAD points at.
 805                          */
 806                         if (rev_is_head(head,
 807                                         ref_name[i],
 808                                         head_oid.hash, NULL))
 809                                 has_head++;
 810                 }
 811                 if (!has_head) {
 812                         const char *name = head;
 813                         skip_prefix(name, "refs/heads/", &name);
 814                         append_one_rev(name);
 815                 }
 816         }
 817
 818         if (!ref_name_cnt) {
 819                 fprintf(stderr, "No revs to be shown.\n");
 820                 exit(0);
 821         }
 822
 823         for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 824                 struct object_id revkey;
 825                 unsigned int flag = 1u << (num_rev + REV_SHIFT);
 826
 827                 if (MAX_REVS <= num_rev)
 828                         die(Q_("cannot handle more than %d rev.",
 829                                "cannot handle more than %d revs.",
 830                                MAX_REVS), MAX_REVS);
 831                 if (get_oid(ref_name[num_rev], &revkey))
 832                         die(_("'%s' is not a valid ref."), ref_name[num_rev]);
 833                 commit = lookup_commit_reference(&revkey);
 834                 if (!commit)
 835                         die(_("cannot find commit %s (%s)"),
 836                             ref_name[num_rev], oid_to_hex(&revkey));
 837                 parse_commit(commit);
 838                 mark_seen(commit, &seen);
 839
 840                 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 841                  * and so on.  REV_SHIFT bits from bit 0 are used for
 842                  * internal bookkeeping.
 843                  */
 844                 commit->object.flags |= flag;
 845                 if (commit->object.flags == flag)
 846                         commit_list_insert_by_date(commit, &list);
 847                 rev[num_rev] = commit;
 848         }
 849         for (i = 0; i < num_rev; i++)
 850                 rev_mask[i] = rev[i]->object.flags;
 851
 852         if (0 <= extra)
 853                 join_revs(&list, &seen, num_rev, extra);
 854
 855         commit_list_sort_by_date(&seen);
 856
 857         if (merge_base)
 858                 return show_merge_base(seen, num_rev);
 859
 860         if (independent)
 861                 return show_independent(rev, num_rev, ref_name, rev_mask);
 862
 863         /* Show list; --more=-1 means list-only */
 864         if (1 < num_rev || extra < 0) {
 865                 for (i = 0; i < num_rev; i++) {
 866                         int j;
 867                         int is_head = rev_is_head(head,
 868                                                   ref_name[i],
 869                                                   head_oid.hash,
 870                                                   rev[i]->object.oid.hash);
 871                         if (extra < 0)
 872                                 printf("%c [%s] ",
 873                                        is_head ? '*' : ' ', ref_name[i]);
 874                         else {
 875                                 for (j = 0; j < i; j++)
 876                                         putchar(' ');
 877                                 printf("%s%c%s [%s] ",
 878                                        get_color_code(i),
 879                                        is_head ? '*' : '!',
 880                                        get_color_reset_code(), ref_name[i]);
 881                         }
 882
 883                         if (!reflog) {
 884                                 /* header lines never need name */
 885                                 show_one_commit(rev[i], 1);
 886                         }
 887                         else
 888                                 puts(reflog_msg[i]);
 889
 890                         if (is_head)
 891                                 head_at = i;
 892                 }
 893                 if (0 <= extra) {
 894                         for (i = 0; i < num_rev; i++)
 895                                 putchar('-');
 896                         putchar('\n');
 897                 }
 898         }
 899         if (extra < 0)
 900                 exit(0);
 901
 902         /* Sort topologically */
 903         sort_in_topological_order(&seen, sort_order);
 904
 905         /* Give names to commits */
 906         if (!sha1_name && !no_name)
 907                 name_commits(seen, rev, ref_name, num_rev);
 908
 909         all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 910         all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 911
 912         while (seen) {
 913                 struct commit *commit = pop_commit(&seen);
 914                 int this_flag = commit->object.flags;
 915                 int is_merge_point = ((this_flag & all_revs) == all_revs);
 916
 917                 shown_merge_point |= is_merge_point;
 918
 919                 if (1 < num_rev) {
 920                         int is_merge = !!(commit->parents &&
 921                                           commit->parents->next);
 922                         if (topics &&
 923                             !is_merge_point &&
 924                             (this_flag & (1u << REV_SHIFT)))
 925                                 continue;
 926                         if (dense && is_merge &&
 927                             omit_in_dense(commit, rev, num_rev))
 928                                 continue;
 929                         for (i = 0; i < num_rev; i++) {
 930                                 int mark;
 931                                 if (!(this_flag & (1u << (i + REV_SHIFT))))
 932                                         mark = ' ';
 933                                 else if (is_merge)
 934                                         mark = '-';
 935                                 else if (i == head_at)
 936                                         mark = '*';
 937                                 else
 938                                         mark = '+';
 939                                 printf("%s%c%s",
 940                                        get_color_code(i),
 941                                        mark, get_color_reset_code());
 942                         }
 943                         putchar(' ');
 944                 }
 945                 show_one_commit(commit, no_name);
 946
 947                 if (shown_merge_point && --extra < 0)
 948                         break;
 949         }
 950         return 0;
 951 }