builtin / show-branch.con commit merge script: improve log message subject (13dd255)
   1#include "cache.h"
   2#include "commit.h"
   3#include "refs.h"
   4#include "builtin.h"
   5#include "color.h"
   6#include "parse-options.h"
   7
   8static const char* show_branch_usage[] = {
   9    "git show-branch [-a|--all] [-r|--remotes] [--topo-order | --date-order] [--current] [--color[=<when>] | --no-color] [--sparse] [--more=<n> | --list | --independent | --merge-base] [--no-name | --sha1-name] [--topics] [<rev> | <glob>]...",
  10    "git show-branch (-g|--reflog)[=<n>[,<base>]] [--list] [<ref>]",
  11    NULL
  12};
  13
  14static int showbranch_use_color = -1;
  15static char column_colors[][COLOR_MAXLEN] = {
  16        GIT_COLOR_RED,
  17        GIT_COLOR_GREEN,
  18        GIT_COLOR_YELLOW,
  19        GIT_COLOR_BLUE,
  20        GIT_COLOR_MAGENTA,
  21        GIT_COLOR_CYAN,
  22};
  23
  24#define COLUMN_COLORS_MAX (ARRAY_SIZE(column_colors))
  25
  26static int default_num;
  27static int default_alloc;
  28static const char **default_arg;
  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
  37static const char *get_color_code(int idx)
  38{
  39        if (showbranch_use_color)
  40                return column_colors[idx];
  41        return "";
  42}
  43
  44static const char *get_color_reset_code(void)
  45{
  46        if (showbranch_use_color)
  47                return GIT_COLOR_RESET;
  48        return "";
  49}
  50
  51static 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
  63static struct commit *pop_one_commit(struct commit_list **list_p)
  64{
  65        struct commit *commit;
  66        struct commit_list *list;
  67        list = *list_p;
  68        commit = list->item;
  69        *list_p = list->next;
  70        free(list);
  71        return commit;
  72}
  73
  74struct commit_name {
  75        const char *head_name; /* which head's ancestor? */
  76        int generation; /* how many parents away from head_name */
  77};
  78
  79/* Name the commit as nth generation ancestor of head_name;
  80 * we count only the first-parent relationship for naming purposes.
  81 */
  82static void name_commit(struct commit *commit, const char *head_name, int nth)
  83{
  84        struct commit_name *name;
  85        if (!commit->util)
  86                commit->util = xmalloc(sizeof(struct commit_name));
  87        name = commit->util;
  88        name->head_name = head_name;
  89        name->generation = nth;
  90}
  91
  92/* Parent is the first parent of the commit.  We may name it
  93 * as (n+1)th generation ancestor of the same head_name as
  94 * commit is nth generation ancestor of, if that generation
  95 * number is better than the name it already has.
  96 */
  97static void name_parent(struct commit *commit, struct commit *parent)
  98{
  99        struct commit_name *commit_name = commit->util;
 100        struct commit_name *parent_name = parent->util;
 101        if (!commit_name)
 102                return;
 103        if (!parent_name ||
 104            commit_name->generation + 1 < parent_name->generation)
 105                name_commit(parent, commit_name->head_name,
 106                            commit_name->generation + 1);
 107}
 108
 109static int name_first_parent_chain(struct commit *c)
 110{
 111        int i = 0;
 112        while (c) {
 113                struct commit *p;
 114                if (!c->util)
 115                        break;
 116                if (!c->parents)
 117                        break;
 118                p = c->parents->item;
 119                if (!p->util) {
 120                        name_parent(c, p);
 121                        i++;
 122                }
 123                else
 124                        break;
 125                c = p;
 126        }
 127        return i;
 128}
 129
 130static void name_commits(struct commit_list *list,
 131                         struct commit **rev,
 132                         char **ref_name,
 133                         int num_rev)
 134{
 135        struct commit_list *cl;
 136        struct commit *c;
 137        int i;
 138
 139        /* First give names to the given heads */
 140        for (cl = list; cl; cl = cl->next) {
 141                c = cl->item;
 142                if (c->util)
 143                        continue;
 144                for (i = 0; i < num_rev; i++) {
 145                        if (rev[i] == c) {
 146                                name_commit(c, ref_name[i], 0);
 147                                break;
 148                        }
 149                }
 150        }
 151
 152        /* Then commits on the first parent ancestry chain */
 153        do {
 154                i = 0;
 155                for (cl = list; cl; cl = cl->next) {
 156                        i += name_first_parent_chain(cl->item);
 157                }
 158        } while (i);
 159
 160        /* Finally, any unnamed commits */
 161        do {
 162                i = 0;
 163                for (cl = list; cl; cl = cl->next) {
 164                        struct commit_list *parents;
 165                        struct commit_name *n;
 166                        int nth;
 167                        c = cl->item;
 168                        if (!c->util)
 169                                continue;
 170                        n = c->util;
 171                        parents = c->parents;
 172                        nth = 0;
 173                        while (parents) {
 174                                struct commit *p = parents->item;
 175                                char newname[1000], *en;
 176                                parents = parents->next;
 177                                nth++;
 178                                if (p->util)
 179                                        continue;
 180                                en = newname;
 181                                switch (n->generation) {
 182                                case 0:
 183                                        en += sprintf(en, "%s", n->head_name);
 184                                        break;
 185                                case 1:
 186                                        en += sprintf(en, "%s^", n->head_name);
 187                                        break;
 188                                default:
 189                                        en += sprintf(en, "%s~%d",
 190                                                n->head_name, n->generation);
 191                                        break;
 192                                }
 193                                if (nth == 1)
 194                                        en += sprintf(en, "^");
 195                                else
 196                                        en += sprintf(en, "^%d", nth);
 197                                name_commit(p, xstrdup(newname), 0);
 198                                i++;
 199                                name_first_parent_chain(p);
 200                        }
 201                }
 202        } while (i);
 203}
 204
 205static 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
 214static 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_one_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                        if (!p->object.parsed)
 242                                parse_commit(p);
 243                        if (mark_seen(p, seen_p) && !still_interesting)
 244                                extra--;
 245                        p->object.flags |= flags;
 246                        insert_by_date(p, list_p);
 247                }
 248        }
 249
 250        /*
 251         * Postprocess to complete well-poisoning.
 252         *
 253         * At this point we have all the commits we have seen in
 254         * seen_p list.  Mark anything that can be reached from
 255         * uninteresting commits not interesting.
 256         */
 257        for (;;) {
 258                int changed = 0;
 259                struct commit_list *s;
 260                for (s = *seen_p; s; s = s->next) {
 261                        struct commit *c = s->item;
 262                        struct commit_list *parents;
 263
 264                        if (((c->object.flags & all_revs) != all_revs) &&
 265                            !(c->object.flags & UNINTERESTING))
 266                                continue;
 267
 268                        /* The current commit is either a merge base or
 269                         * already uninteresting one.  Mark its parents
 270                         * as uninteresting commits _only_ if they are
 271                         * already parsed.  No reason to find new ones
 272                         * here.
 273                         */
 274                        parents = c->parents;
 275                        while (parents) {
 276                                struct commit *p = parents->item;
 277                                parents = parents->next;
 278                                if (!(p->object.flags & UNINTERESTING)) {
 279                                        p->object.flags |= UNINTERESTING;
 280                                        changed = 1;
 281                                }
 282                        }
 283                }
 284                if (!changed)
 285                        break;
 286        }
 287}
 288
 289static void show_one_commit(struct commit *commit, int no_name)
 290{
 291        struct strbuf pretty = STRBUF_INIT;
 292        const char *pretty_str = "(unavailable)";
 293        struct commit_name *name = commit->util;
 294
 295        if (commit->object.parsed) {
 296                struct pretty_print_context ctx = {0};
 297                pretty_print_commit(CMIT_FMT_ONELINE, commit, &pretty, &ctx);
 298                pretty_str = pretty.buf;
 299        }
 300        if (!prefixcmp(pretty_str, "[PATCH] "))
 301                pretty_str += 8;
 302
 303        if (!no_name) {
 304                if (name && name->head_name) {
 305                        printf("[%s", name->head_name);
 306                        if (name->generation) {
 307                                if (name->generation == 1)
 308                                        printf("^");
 309                                else
 310                                        printf("~%d", name->generation);
 311                        }
 312                        printf("] ");
 313                }
 314                else
 315                        printf("[%s] ",
 316                               find_unique_abbrev(commit->object.sha1,
 317                                                  DEFAULT_ABBREV));
 318        }
 319        puts(pretty_str);
 320        strbuf_release(&pretty);
 321}
 322
 323static char *ref_name[MAX_REVS + 1];
 324static int ref_name_cnt;
 325
 326static const char *find_digit_prefix(const char *s, int *v)
 327{
 328        const char *p;
 329        int ver;
 330        char ch;
 331
 332        for (p = s, ver = 0;
 333             '0' <= (ch = *p) && ch <= '9';
 334             p++)
 335                ver = ver * 10 + ch - '0';
 336        *v = ver;
 337        return p;
 338}
 339
 340
 341static int version_cmp(const char *a, const char *b)
 342{
 343        while (1) {
 344                int va, vb;
 345
 346                a = find_digit_prefix(a, &va);
 347                b = find_digit_prefix(b, &vb);
 348                if (va != vb)
 349                        return va - vb;
 350
 351                while (1) {
 352                        int ca = *a;
 353                        int cb = *b;
 354                        if ('0' <= ca && ca <= '9')
 355                                ca = 0;
 356                        if ('0' <= cb && cb <= '9')
 357                                cb = 0;
 358                        if (ca != cb)
 359                                return ca - cb;
 360                        if (!ca)
 361                                break;
 362                        a++;
 363                        b++;
 364                }
 365                if (!*a && !*b)
 366                        return 0;
 367        }
 368}
 369
 370static int compare_ref_name(const void *a_, const void *b_)
 371{
 372        const char * const*a = a_, * const*b = b_;
 373        return version_cmp(*a, *b);
 374}
 375
 376static void sort_ref_range(int bottom, int top)
 377{
 378        qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 379              compare_ref_name);
 380}
 381
 382static int append_ref(const char *refname, const unsigned char *sha1,
 383                      int allow_dups)
 384{
 385        struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 386        int i;
 387
 388        if (!commit)
 389                return 0;
 390
 391        if (!allow_dups) {
 392                /* Avoid adding the same thing twice */
 393                for (i = 0; i < ref_name_cnt; i++)
 394                        if (!strcmp(refname, ref_name[i]))
 395                                return 0;
 396        }
 397        if (MAX_REVS <= ref_name_cnt) {
 398                warning("ignoring %s; cannot handle more than %d refs",
 399                        refname, MAX_REVS);
 400                return 0;
 401        }
 402        ref_name[ref_name_cnt++] = xstrdup(refname);
 403        ref_name[ref_name_cnt] = NULL;
 404        return 0;
 405}
 406
 407static int append_head_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 408{
 409        unsigned char tmp[20];
 410        int ofs = 11;
 411        if (prefixcmp(refname, "refs/heads/"))
 412                return 0;
 413        /* If both heads/foo and tags/foo exists, get_sha1 would
 414         * get confused.
 415         */
 416        if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 417                ofs = 5;
 418        return append_ref(refname + ofs, sha1, 0);
 419}
 420
 421static int append_remote_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 422{
 423        unsigned char tmp[20];
 424        int ofs = 13;
 425        if (prefixcmp(refname, "refs/remotes/"))
 426                return 0;
 427        /* If both heads/foo and tags/foo exists, get_sha1 would
 428         * get confused.
 429         */
 430        if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 431                ofs = 5;
 432        return append_ref(refname + ofs, sha1, 0);
 433}
 434
 435static int append_tag_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 436{
 437        if (prefixcmp(refname, "refs/tags/"))
 438                return 0;
 439        return append_ref(refname + 5, sha1, 0);
 440}
 441
 442static const char *match_ref_pattern = NULL;
 443static int match_ref_slash = 0;
 444static int count_slash(const char *s)
 445{
 446        int cnt = 0;
 447        while (*s)
 448                if (*s++ == '/')
 449                        cnt++;
 450        return cnt;
 451}
 452
 453static int append_matching_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 454{
 455        /* we want to allow pattern hold/<asterisk> to show all
 456         * branches under refs/heads/hold/, and v0.99.9? to show
 457         * refs/tags/v0.99.9a and friends.
 458         */
 459        const char *tail;
 460        int slash = count_slash(refname);
 461        for (tail = refname; *tail && match_ref_slash < slash; )
 462                if (*tail++ == '/')
 463                        slash--;
 464        if (!*tail)
 465                return 0;
 466        if (fnmatch(match_ref_pattern, tail, 0))
 467                return 0;
 468        if (!prefixcmp(refname, "refs/heads/"))
 469                return append_head_ref(refname, sha1, flag, cb_data);
 470        if (!prefixcmp(refname, "refs/tags/"))
 471                return append_tag_ref(refname, sha1, flag, cb_data);
 472        return append_ref(refname, sha1, 0);
 473}
 474
 475static void snarf_refs(int head, int remotes)
 476{
 477        if (head) {
 478                int orig_cnt = ref_name_cnt;
 479                for_each_ref(append_head_ref, NULL);
 480                sort_ref_range(orig_cnt, ref_name_cnt);
 481        }
 482        if (remotes) {
 483                int orig_cnt = ref_name_cnt;
 484                for_each_ref(append_remote_ref, NULL);
 485                sort_ref_range(orig_cnt, ref_name_cnt);
 486        }
 487}
 488
 489static int rev_is_head(char *head, int headlen, char *name,
 490                       unsigned char *head_sha1, unsigned char *sha1)
 491{
 492        if ((!head[0]) ||
 493            (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
 494                return 0;
 495        if (!prefixcmp(head, "refs/heads/"))
 496                head += 11;
 497        if (!prefixcmp(name, "refs/heads/"))
 498                name += 11;
 499        else if (!prefixcmp(name, "heads/"))
 500                name += 6;
 501        return !strcmp(head, name);
 502}
 503
 504static int show_merge_base(struct commit_list *seen, int num_rev)
 505{
 506        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 507        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 508        int exit_status = 1;
 509
 510        while (seen) {
 511                struct commit *commit = pop_one_commit(&seen);
 512                int flags = commit->object.flags & all_mask;
 513                if (!(flags & UNINTERESTING) &&
 514                    ((flags & all_revs) == all_revs)) {
 515                        puts(sha1_to_hex(commit->object.sha1));
 516                        exit_status = 0;
 517                        commit->object.flags |= UNINTERESTING;
 518                }
 519        }
 520        return exit_status;
 521}
 522
 523static int show_independent(struct commit **rev,
 524                            int num_rev,
 525                            char **ref_name,
 526                            unsigned int *rev_mask)
 527{
 528        int i;
 529
 530        for (i = 0; i < num_rev; i++) {
 531                struct commit *commit = rev[i];
 532                unsigned int flag = rev_mask[i];
 533
 534                if (commit->object.flags == flag)
 535                        puts(sha1_to_hex(commit->object.sha1));
 536                commit->object.flags |= UNINTERESTING;
 537        }
 538        return 0;
 539}
 540
 541static void append_one_rev(const char *av)
 542{
 543        unsigned char revkey[20];
 544        if (!get_sha1(av, revkey)) {
 545                append_ref(av, revkey, 0);
 546                return;
 547        }
 548        if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
 549                /* glob style match */
 550                int saved_matches = ref_name_cnt;
 551                match_ref_pattern = av;
 552                match_ref_slash = count_slash(av);
 553                for_each_ref(append_matching_ref, NULL);
 554                if (saved_matches == ref_name_cnt &&
 555                    ref_name_cnt < MAX_REVS)
 556                        error("no matching refs with %s", av);
 557                if (saved_matches + 1 < ref_name_cnt)
 558                        sort_ref_range(saved_matches, ref_name_cnt);
 559                return;
 560        }
 561        die("bad sha1 reference %s", av);
 562}
 563
 564static int git_show_branch_config(const char *var, const char *value, void *cb)
 565{
 566        if (!strcmp(var, "showbranch.default")) {
 567                if (!value)
 568                        return config_error_nonbool(var);
 569                /*
 570                 * default_arg is now passed to parse_options(), so we need to
 571                 * mimic the real argv a bit better.
 572                 */
 573                if (!default_num) {
 574                        default_alloc = 20;
 575                        default_arg = xcalloc(default_alloc, sizeof(*default_arg));
 576                        default_arg[default_num++] = "show-branch";
 577                } else if (default_alloc <= default_num + 1) {
 578                        default_alloc = default_alloc * 3 / 2 + 20;
 579                        default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
 580                }
 581                default_arg[default_num++] = xstrdup(value);
 582                default_arg[default_num] = NULL;
 583                return 0;
 584        }
 585
 586        if (!strcmp(var, "color.showbranch")) {
 587                showbranch_use_color = git_config_colorbool(var, value, -1);
 588                return 0;
 589        }
 590
 591        return git_color_default_config(var, value, cb);
 592}
 593
 594static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
 595{
 596        /* If the commit is tip of the named branches, do not
 597         * omit it.
 598         * Otherwise, if it is a merge that is reachable from only one
 599         * tip, it is not that interesting.
 600         */
 601        int i, flag, count;
 602        for (i = 0; i < n; i++)
 603                if (rev[i] == commit)
 604                        return 0;
 605        flag = commit->object.flags;
 606        for (i = count = 0; i < n; i++) {
 607                if (flag & (1u << (i + REV_SHIFT)))
 608                        count++;
 609        }
 610        if (count == 1)
 611                return 1;
 612        return 0;
 613}
 614
 615static int reflog = 0;
 616
 617static int parse_reflog_param(const struct option *opt, const char *arg,
 618                              int unset)
 619{
 620        char *ep;
 621        const char **base = (const char **)opt->value;
 622        if (!arg)
 623                arg = "";
 624        reflog = strtoul(arg, &ep, 10);
 625        if (*ep == ',')
 626                *base = ep + 1;
 627        else if (*ep)
 628                return error("unrecognized reflog param '%s'", arg);
 629        else
 630                *base = NULL;
 631        if (reflog <= 0)
 632                reflog = DEFAULT_REFLOG;
 633        return 0;
 634}
 635
 636int cmd_show_branch(int ac, const char **av, const char *prefix)
 637{
 638        struct commit *rev[MAX_REVS], *commit;
 639        char *reflog_msg[MAX_REVS];
 640        struct commit_list *list = NULL, *seen = NULL;
 641        unsigned int rev_mask[MAX_REVS];
 642        int num_rev, i, extra = 0;
 643        int all_heads = 0, all_remotes = 0;
 644        int all_mask, all_revs;
 645        int lifo = 1;
 646        char head[128];
 647        const char *head_p;
 648        int head_len;
 649        unsigned char head_sha1[20];
 650        int merge_base = 0;
 651        int independent = 0;
 652        int no_name = 0;
 653        int sha1_name = 0;
 654        int shown_merge_point = 0;
 655        int with_current_branch = 0;
 656        int head_at = -1;
 657        int topics = 0;
 658        int dense = 1;
 659        const char *reflog_base = NULL;
 660        struct option builtin_show_branch_options[] = {
 661                OPT_BOOLEAN('a', "all", &all_heads,
 662                            "show remote-tracking and local branches"),
 663                OPT_BOOLEAN('r', "remotes", &all_remotes,
 664                            "show remote-tracking branches"),
 665                OPT__COLOR(&showbranch_use_color,
 666                            "color '*!+-' corresponding to the branch"),
 667                { OPTION_INTEGER, 0, "more", &extra, "n",
 668                            "show <n> more commits after the common ancestor",
 669                            PARSE_OPT_OPTARG, NULL, (intptr_t)1 },
 670                OPT_SET_INT(0, "list", &extra, "synonym to more=-1", -1),
 671                OPT_BOOLEAN(0, "no-name", &no_name, "suppress naming strings"),
 672                OPT_BOOLEAN(0, "current", &with_current_branch,
 673                            "include the current branch"),
 674                OPT_BOOLEAN(0, "sha1-name", &sha1_name,
 675                            "name commits with their object names"),
 676                OPT_BOOLEAN(0, "merge-base", &merge_base,
 677                            "show possible merge bases"),
 678                OPT_BOOLEAN(0, "independent", &independent,
 679                            "show refs unreachable from any other ref"),
 680                OPT_BOOLEAN(0, "topo-order", &lifo,
 681                            "show commits in topological order"),
 682                OPT_BOOLEAN(0, "topics", &topics,
 683                            "show only commits not on the first branch"),
 684                OPT_SET_INT(0, "sparse", &dense,
 685                            "show merges reachable from only one tip", 0),
 686                OPT_SET_INT(0, "date-order", &lifo,
 687                            "show commits where no parent comes before its "
 688                            "children", 0),
 689                { OPTION_CALLBACK, 'g', "reflog", &reflog_base, "<n>[,<base>]",
 690                            "show <n> most recent ref-log entries starting at "
 691                            "base",
 692                            PARSE_OPT_OPTARG | PARSE_OPT_LITERAL_ARGHELP,
 693                            parse_reflog_param },
 694                OPT_END()
 695        };
 696
 697        git_config(git_show_branch_config, NULL);
 698
 699        if (showbranch_use_color == -1)
 700                showbranch_use_color = git_use_color_default;
 701
 702        /* If nothing is specified, try the default first */
 703        if (ac == 1 && default_num) {
 704                ac = default_num;
 705                av = default_arg;
 706        }
 707
 708        ac = parse_options(ac, av, prefix, builtin_show_branch_options,
 709                           show_branch_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 710        if (all_heads)
 711                all_remotes = 1;
 712
 713        if (extra || reflog) {
 714                /* "listing" mode is incompatible with
 715                 * independent nor merge-base modes.
 716                 */
 717                if (independent || merge_base)
 718                        usage_with_options(show_branch_usage,
 719                                           builtin_show_branch_options);
 720                if (reflog && ((0 < extra) || all_heads || all_remotes))
 721                        /*
 722                         * Asking for --more in reflog mode does not
 723                         * make sense.  --list is Ok.
 724                         *
 725                         * Also --all and --remotes do not make sense either.
 726                         */
 727                        die("--reflog is incompatible with --all, --remotes, "
 728                            "--independent or --merge-base");
 729        }
 730
 731        /* If nothing is specified, show all branches by default */
 732        if (ac + all_heads + all_remotes == 0)
 733                all_heads = 1;
 734
 735        if (reflog) {
 736                unsigned char sha1[20];
 737                char nth_desc[256];
 738                char *ref;
 739                int base = 0;
 740
 741                if (ac == 0) {
 742                        static const char *fake_av[2];
 743                        const char *refname;
 744
 745                        refname = resolve_ref("HEAD", sha1, 1, NULL);
 746                        fake_av[0] = xstrdup(refname);
 747                        fake_av[1] = NULL;
 748                        av = fake_av;
 749                        ac = 1;
 750                }
 751                if (ac != 1)
 752                        die("--reflog option needs one branch name");
 753
 754                if (MAX_REVS < reflog)
 755                        die("Only %d entries can be shown at one time.",
 756                            MAX_REVS);
 757                if (!dwim_ref(*av, strlen(*av), sha1, &ref))
 758                        die("No such ref %s", *av);
 759
 760                /* Has the base been specified? */
 761                if (reflog_base) {
 762                        char *ep;
 763                        base = strtoul(reflog_base, &ep, 10);
 764                        if (*ep) {
 765                                /* Ah, that is a date spec... */
 766                                unsigned long at;
 767                                at = approxidate(reflog_base);
 768                                read_ref_at(ref, at, -1, sha1, NULL,
 769                                            NULL, NULL, &base);
 770                        }
 771                }
 772
 773                for (i = 0; i < reflog; i++) {
 774                        char *logmsg, *m;
 775                        const char *msg;
 776                        unsigned long timestamp;
 777                        int tz;
 778
 779                        if (read_ref_at(ref, 0, base+i, sha1, &logmsg,
 780                                        &timestamp, &tz, NULL)) {
 781                                reflog = i;
 782                                break;
 783                        }
 784                        msg = strchr(logmsg, '\t');
 785                        if (!msg)
 786                                msg = "(none)";
 787                        else
 788                                msg++;
 789                        m = xmalloc(strlen(msg) + 200);
 790                        sprintf(m, "(%s) %s",
 791                                show_date(timestamp, tz, 1),
 792                                msg);
 793                        reflog_msg[i] = m;
 794                        free(logmsg);
 795                        sprintf(nth_desc, "%s@{%d}", *av, base+i);
 796                        append_ref(nth_desc, sha1, 1);
 797                }
 798        }
 799        else if (all_heads + all_remotes)
 800                snarf_refs(all_heads, all_remotes);
 801        else {
 802                while (0 < ac) {
 803                        append_one_rev(*av);
 804                        ac--; av++;
 805                }
 806        }
 807
 808        head_p = resolve_ref("HEAD", head_sha1, 1, NULL);
 809        if (head_p) {
 810                head_len = strlen(head_p);
 811                memcpy(head, head_p, head_len + 1);
 812        }
 813        else {
 814                head_len = 0;
 815                head[0] = 0;
 816        }
 817
 818        if (with_current_branch && head_p) {
 819                int has_head = 0;
 820                for (i = 0; !has_head && i < ref_name_cnt; i++) {
 821                        /* We are only interested in adding the branch
 822                         * HEAD points at.
 823                         */
 824                        if (rev_is_head(head,
 825                                        head_len,
 826                                        ref_name[i],
 827                                        head_sha1, NULL))
 828                                has_head++;
 829                }
 830                if (!has_head) {
 831                        int offset = !prefixcmp(head, "refs/heads/") ? 11 : 0;
 832                        append_one_rev(head + offset);
 833                }
 834        }
 835
 836        if (!ref_name_cnt) {
 837                fprintf(stderr, "No revs to be shown.\n");
 838                exit(0);
 839        }
 840
 841        for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 842                unsigned char revkey[20];
 843                unsigned int flag = 1u << (num_rev + REV_SHIFT);
 844
 845                if (MAX_REVS <= num_rev)
 846                        die("cannot handle more than %d revs.", MAX_REVS);
 847                if (get_sha1(ref_name[num_rev], revkey))
 848                        die("'%s' is not a valid ref.", ref_name[num_rev]);
 849                commit = lookup_commit_reference(revkey);
 850                if (!commit)
 851                        die("cannot find commit %s (%s)",
 852                            ref_name[num_rev], revkey);
 853                parse_commit(commit);
 854                mark_seen(commit, &seen);
 855
 856                /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 857                 * and so on.  REV_SHIFT bits from bit 0 are used for
 858                 * internal bookkeeping.
 859                 */
 860                commit->object.flags |= flag;
 861                if (commit->object.flags == flag)
 862                        insert_by_date(commit, &list);
 863                rev[num_rev] = commit;
 864        }
 865        for (i = 0; i < num_rev; i++)
 866                rev_mask[i] = rev[i]->object.flags;
 867
 868        if (0 <= extra)
 869                join_revs(&list, &seen, num_rev, extra);
 870
 871        sort_by_date(&seen);
 872
 873        if (merge_base)
 874                return show_merge_base(seen, num_rev);
 875
 876        if (independent)
 877                return show_independent(rev, num_rev, ref_name, rev_mask);
 878
 879        /* Show list; --more=-1 means list-only */
 880        if (1 < num_rev || extra < 0) {
 881                for (i = 0; i < num_rev; i++) {
 882                        int j;
 883                        int is_head = rev_is_head(head,
 884                                                  head_len,
 885                                                  ref_name[i],
 886                                                  head_sha1,
 887                                                  rev[i]->object.sha1);
 888                        if (extra < 0)
 889                                printf("%c [%s] ",
 890                                       is_head ? '*' : ' ', ref_name[i]);
 891                        else {
 892                                for (j = 0; j < i; j++)
 893                                        putchar(' ');
 894                                printf("%s%c%s [%s] ",
 895                                       get_color_code(i % COLUMN_COLORS_MAX),
 896                                       is_head ? '*' : '!',
 897                                       get_color_reset_code(), ref_name[i]);
 898                        }
 899
 900                        if (!reflog) {
 901                                /* header lines never need name */
 902                                show_one_commit(rev[i], 1);
 903                        }
 904                        else
 905                                puts(reflog_msg[i]);
 906
 907                        if (is_head)
 908                                head_at = i;
 909                }
 910                if (0 <= extra) {
 911                        for (i = 0; i < num_rev; i++)
 912                                putchar('-');
 913                        putchar('\n');
 914                }
 915        }
 916        if (extra < 0)
 917                exit(0);
 918
 919        /* Sort topologically */
 920        sort_in_topological_order(&seen, lifo);
 921
 922        /* Give names to commits */
 923        if (!sha1_name && !no_name)
 924                name_commits(seen, rev, ref_name, num_rev);
 925
 926        all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 927        all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 928
 929        while (seen) {
 930                struct commit *commit = pop_one_commit(&seen);
 931                int this_flag = commit->object.flags;
 932                int is_merge_point = ((this_flag & all_revs) == all_revs);
 933
 934                shown_merge_point |= is_merge_point;
 935
 936                if (1 < num_rev) {
 937                        int is_merge = !!(commit->parents &&
 938                                          commit->parents->next);
 939                        if (topics &&
 940                            !is_merge_point &&
 941                            (this_flag & (1u << REV_SHIFT)))
 942                                continue;
 943                        if (dense && is_merge &&
 944                            omit_in_dense(commit, rev, num_rev))
 945                                continue;
 946                        for (i = 0; i < num_rev; i++) {
 947                                int mark;
 948                                if (!(this_flag & (1u << (i + REV_SHIFT))))
 949                                        mark = ' ';
 950                                else if (is_merge)
 951                                        mark = '-';
 952                                else if (i == head_at)
 953                                        mark = '*';
 954                                else
 955                                        mark = '+';
 956                                printf("%s%c%s",
 957                                       get_color_code(i % COLUMN_COLORS_MAX),
 958                                       mark, get_color_reset_code());
 959                        }
 960                        putchar(' ');
 961                }
 962                show_one_commit(commit, no_name);
 963
 964                if (shown_merge_point && --extra < 0)
 965                        break;
 966        }
 967        return 0;
 968}