append_matching_ref(): rewrite to take an object_id argument
[git] / builtin / show-branch.c
1 #include "cache.h"
2 #include "commit.h"
3 #include "refs.h"
4 #include "builtin.h"
5 #include "color.h"
6 #include "parse-options.h"
7
8 static const char* show_branch_usage[] = {
9     N_("git show-branch [-a | --all] [-r | --remotes] [--topo-order | --date-order]\n"
10        "                [--current] [--color[=<when>] | --no-color] [--sparse]\n"
11        "                [--more=<n> | --list | --independent | --merge-base]\n"
12        "                [--no-name | --sha1-name] [--topics] [(<rev> | <glob>)...]"),
13     N_("git show-branch (-g | --reflog)[=<n>[,<base>]] [--list] [<ref>]"),
14     NULL
15 };
16
17 static int showbranch_use_color = -1;
18
19 static int default_num;
20 static int default_alloc;
21 static const char **default_arg;
22
23 #define UNINTERESTING   01
24
25 #define REV_SHIFT        2
26 #define MAX_REVS        (FLAG_BITS - REV_SHIFT) /* should not exceed bits_per_int - REV_SHIFT */
27
28 #define DEFAULT_REFLOG  4
29
30 static const char *get_color_code(int idx)
31 {
32         if (want_color(showbranch_use_color))
33                 return column_colors_ansi[idx % column_colors_ansi_max];
34         return "";
35 }
36
37 static const char *get_color_reset_code(void)
38 {
39         if (want_color(showbranch_use_color))
40                 return GIT_COLOR_RESET;
41         return "";
42 }
43
44 static struct commit *interesting(struct commit_list *list)
45 {
46         while (list) {
47                 struct commit *commit = list->item;
48                 list = list->next;
49                 if (commit->object.flags & UNINTERESTING)
50                         continue;
51                 return commit;
52         }
53         return NULL;
54 }
55
56 static struct commit *pop_one_commit(struct commit_list **list_p)
57 {
58         struct commit *commit;
59         struct commit_list *list;
60         list = *list_p;
61         commit = list->item;
62         *list_p = list->next;
63         free(list);
64         return commit;
65 }
66
67 struct commit_name {
68         const char *head_name; /* which head's ancestor? */
69         int generation; /* how many parents away from head_name */
70 };
71
72 /* Name the commit as nth generation ancestor of head_name;
73  * we count only the first-parent relationship for naming purposes.
74  */
75 static void name_commit(struct commit *commit, const char *head_name, int nth)
76 {
77         struct commit_name *name;
78         if (!commit->util)
79                 commit->util = xmalloc(sizeof(struct commit_name));
80         name = commit->util;
81         name->head_name = head_name;
82         name->generation = nth;
83 }
84
85 /* Parent is the first parent of the commit.  We may name it
86  * as (n+1)th generation ancestor of the same head_name as
87  * commit is nth generation ancestor of, if that generation
88  * number is better than the name it already has.
89  */
90 static void name_parent(struct commit *commit, struct commit *parent)
91 {
92         struct commit_name *commit_name = commit->util;
93         struct commit_name *parent_name = parent->util;
94         if (!commit_name)
95                 return;
96         if (!parent_name ||
97             commit_name->generation + 1 < parent_name->generation)
98                 name_commit(parent, commit_name->head_name,
99                             commit_name->generation + 1);
100 }
101
102 static int name_first_parent_chain(struct commit *c)
103 {
104         int i = 0;
105         while (c) {
106                 struct commit *p;
107                 if (!c->util)
108                         break;
109                 if (!c->parents)
110                         break;
111                 p = c->parents->item;
112                 if (!p->util) {
113                         name_parent(c, p);
114                         i++;
115                 }
116                 else
117                         break;
118                 c = p;
119         }
120         return i;
121 }
122
123 static void name_commits(struct commit_list *list,
124                          struct commit **rev,
125                          char **ref_name,
126                          int num_rev)
127 {
128         struct commit_list *cl;
129         struct commit *c;
130         int i;
131
132         /* First give names to the given heads */
133         for (cl = list; cl; cl = cl->next) {
134                 c = cl->item;
135                 if (c->util)
136                         continue;
137                 for (i = 0; i < num_rev; i++) {
138                         if (rev[i] == c) {
139                                 name_commit(c, ref_name[i], 0);
140                                 break;
141                         }
142                 }
143         }
144
145         /* Then commits on the first parent ancestry chain */
146         do {
147                 i = 0;
148                 for (cl = list; cl; cl = cl->next) {
149                         i += name_first_parent_chain(cl->item);
150                 }
151         } while (i);
152
153         /* Finally, any unnamed commits */
154         do {
155                 i = 0;
156                 for (cl = list; cl; cl = cl->next) {
157                         struct commit_list *parents;
158                         struct commit_name *n;
159                         int nth;
160                         c = cl->item;
161                         if (!c->util)
162                                 continue;
163                         n = c->util;
164                         parents = c->parents;
165                         nth = 0;
166                         while (parents) {
167                                 struct commit *p = parents->item;
168                                 struct strbuf newname = STRBUF_INIT;
169                                 parents = parents->next;
170                                 nth++;
171                                 if (p->util)
172                                         continue;
173                                 switch (n->generation) {
174                                 case 0:
175                                         strbuf_addstr(&newname, n->head_name);
176                                         break;
177                                 case 1:
178                                         strbuf_addf(&newname, "%s^", n->head_name);
179                                         break;
180                                 default:
181                                         strbuf_addf(&newname, "%s~%d",
182                                                     n->head_name, n->generation);
183                                         break;
184                                 }
185                                 if (nth == 1)
186                                         strbuf_addch(&newname, '^');
187                                 else
188                                         strbuf_addf(&newname, "^%d", nth);
189                                 name_commit(p, strbuf_detach(&newname, NULL), 0);
190                                 i++;
191                                 name_first_parent_chain(p);
192                         }
193                 }
194         } while (i);
195 }
196
197 static int mark_seen(struct commit *commit, struct commit_list **seen_p)
198 {
199         if (!commit->object.flags) {
200                 commit_list_insert(commit, seen_p);
201                 return 1;
202         }
203         return 0;
204 }
205
206 static void join_revs(struct commit_list **list_p,
207                       struct commit_list **seen_p,
208                       int num_rev, int extra)
209 {
210         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
211         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
212
213         while (*list_p) {
214                 struct commit_list *parents;
215                 int still_interesting = !!interesting(*list_p);
216                 struct commit *commit = pop_one_commit(list_p);
217                 int flags = commit->object.flags & all_mask;
218
219                 if (!still_interesting && extra <= 0)
220                         break;
221
222                 mark_seen(commit, seen_p);
223                 if ((flags & all_revs) == all_revs)
224                         flags |= UNINTERESTING;
225                 parents = commit->parents;
226
227                 while (parents) {
228                         struct commit *p = parents->item;
229                         int this_flag = p->object.flags;
230                         parents = parents->next;
231                         if ((this_flag & flags) == flags)
232                                 continue;
233                         parse_commit(p);
234                         if (mark_seen(p, seen_p) && !still_interesting)
235                                 extra--;
236                         p->object.flags |= flags;
237                         commit_list_insert_by_date(p, list_p);
238                 }
239         }
240
241         /*
242          * Postprocess to complete well-poisoning.
243          *
244          * At this point we have all the commits we have seen in
245          * seen_p list.  Mark anything that can be reached from
246          * uninteresting commits not interesting.
247          */
248         for (;;) {
249                 int changed = 0;
250                 struct commit_list *s;
251                 for (s = *seen_p; s; s = s->next) {
252                         struct commit *c = s->item;
253                         struct commit_list *parents;
254
255                         if (((c->object.flags & all_revs) != all_revs) &&
256                             !(c->object.flags & UNINTERESTING))
257                                 continue;
258
259                         /* The current commit is either a merge base or
260                          * already uninteresting one.  Mark its parents
261                          * as uninteresting commits _only_ if they are
262                          * already parsed.  No reason to find new ones
263                          * here.
264                          */
265                         parents = c->parents;
266                         while (parents) {
267                                 struct commit *p = parents->item;
268                                 parents = parents->next;
269                                 if (!(p->object.flags & UNINTERESTING)) {
270                                         p->object.flags |= UNINTERESTING;
271                                         changed = 1;
272                                 }
273                         }
274                 }
275                 if (!changed)
276                         break;
277         }
278 }
279
280 static void show_one_commit(struct commit *commit, int no_name)
281 {
282         struct strbuf pretty = STRBUF_INIT;
283         const char *pretty_str = "(unavailable)";
284         struct commit_name *name = commit->util;
285
286         if (commit->object.parsed) {
287                 pp_commit_easy(CMIT_FMT_ONELINE, commit, &pretty);
288                 pretty_str = pretty.buf;
289         }
290         if (starts_with(pretty_str, "[PATCH] "))
291                 pretty_str += 8;
292
293         if (!no_name) {
294                 if (name && name->head_name) {
295                         printf("[%s", name->head_name);
296                         if (name->generation) {
297                                 if (name->generation == 1)
298                                         printf("^");
299                                 else
300                                         printf("~%d", name->generation);
301                         }
302                         printf("] ");
303                 }
304                 else
305                         printf("[%s] ",
306                                find_unique_abbrev(commit->object.sha1,
307                                                   DEFAULT_ABBREV));
308         }
309         puts(pretty_str);
310         strbuf_release(&pretty);
311 }
312
313 static char *ref_name[MAX_REVS + 1];
314 static int ref_name_cnt;
315
316 static const char *find_digit_prefix(const char *s, int *v)
317 {
318         const char *p;
319         int ver;
320         char ch;
321
322         for (p = s, ver = 0;
323              '0' <= (ch = *p) && ch <= '9';
324              p++)
325                 ver = ver * 10 + ch - '0';
326         *v = ver;
327         return p;
328 }
329
330
331 static int version_cmp(const char *a, const char *b)
332 {
333         while (1) {
334                 int va, vb;
335
336                 a = find_digit_prefix(a, &va);
337                 b = find_digit_prefix(b, &vb);
338                 if (va != vb)
339                         return va - vb;
340
341                 while (1) {
342                         int ca = *a;
343                         int cb = *b;
344                         if ('0' <= ca && ca <= '9')
345                                 ca = 0;
346                         if ('0' <= cb && cb <= '9')
347                                 cb = 0;
348                         if (ca != cb)
349                                 return ca - cb;
350                         if (!ca)
351                                 break;
352                         a++;
353                         b++;
354                 }
355                 if (!*a && !*b)
356                         return 0;
357         }
358 }
359
360 static int compare_ref_name(const void *a_, const void *b_)
361 {
362         const char * const*a = a_, * const*b = b_;
363         return version_cmp(*a, *b);
364 }
365
366 static void sort_ref_range(int bottom, int top)
367 {
368         qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
369               compare_ref_name);
370 }
371
372 static int append_ref(const char *refname, const unsigned char *sha1,
373                       int allow_dups)
374 {
375         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
376         int i;
377
378         if (!commit)
379                 return 0;
380
381         if (!allow_dups) {
382                 /* Avoid adding the same thing twice */
383                 for (i = 0; i < ref_name_cnt; i++)
384                         if (!strcmp(refname, ref_name[i]))
385                                 return 0;
386         }
387         if (MAX_REVS <= ref_name_cnt) {
388                 warning("ignoring %s; cannot handle more than %d refs",
389                         refname, MAX_REVS);
390                 return 0;
391         }
392         ref_name[ref_name_cnt++] = xstrdup(refname);
393         ref_name[ref_name_cnt] = NULL;
394         return 0;
395 }
396
397 static int append_head_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
398 {
399         unsigned char tmp[20];
400         int ofs = 11;
401         if (!starts_with(refname, "refs/heads/"))
402                 return 0;
403         /* If both heads/foo and tags/foo exists, get_sha1 would
404          * get confused.
405          */
406         if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
407                 ofs = 5;
408         return append_ref(refname + ofs, sha1, 0);
409 }
410
411 static int append_remote_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
412 {
413         unsigned char tmp[20];
414         int ofs = 13;
415         if (!starts_with(refname, "refs/remotes/"))
416                 return 0;
417         /* If both heads/foo and tags/foo exists, get_sha1 would
418          * get confused.
419          */
420         if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
421                 ofs = 5;
422         return append_ref(refname + ofs, sha1, 0);
423 }
424
425 static int append_tag_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
426 {
427         if (!starts_with(refname, "refs/tags/"))
428                 return 0;
429         return append_ref(refname + 5, sha1, 0);
430 }
431
432 static const char *match_ref_pattern = NULL;
433 static int match_ref_slash = 0;
434 static int count_slash(const char *s)
435 {
436         int cnt = 0;
437         while (*s)
438                 if (*s++ == '/')
439                         cnt++;
440         return cnt;
441 }
442
443 static int append_matching_ref(const char *refname, const struct object_id *oid,
444                                int flag, void *cb_data)
445 {
446         /* we want to allow pattern hold/<asterisk> to show all
447          * branches under refs/heads/hold/, and v0.99.9? to show
448          * refs/tags/v0.99.9a and friends.
449          */
450         const char *tail;
451         int slash = count_slash(refname);
452         for (tail = refname; *tail && match_ref_slash < slash; )
453                 if (*tail++ == '/')
454                         slash--;
455         if (!*tail)
456                 return 0;
457         if (wildmatch(match_ref_pattern, tail, 0, NULL))
458                 return 0;
459         if (starts_with(refname, "refs/heads/"))
460                 return append_head_ref(refname, oid->hash, flag, cb_data);
461         if (starts_with(refname, "refs/tags/"))
462                 return append_tag_ref(refname, oid->hash, flag, cb_data);
463         return append_ref(refname, oid->hash, 0);
464 }
465
466 static void snarf_refs(int head, int remotes)
467 {
468         if (head) {
469                 int orig_cnt = ref_name_cnt;
470                 struct each_ref_fn_sha1_adapter wrapped_append_head_ref =
471                         {append_head_ref, NULL};
472
473                 for_each_ref(each_ref_fn_adapter, &wrapped_append_head_ref);
474                 sort_ref_range(orig_cnt, ref_name_cnt);
475         }
476         if (remotes) {
477                 int orig_cnt = ref_name_cnt;
478                 struct each_ref_fn_sha1_adapter wrapped_append_remote_ref =
479                         {append_remote_ref, NULL};
480
481                 for_each_ref(each_ref_fn_adapter, &wrapped_append_remote_ref);
482                 sort_ref_range(orig_cnt, ref_name_cnt);
483         }
484 }
485
486 static int rev_is_head(char *head, int headlen, char *name,
487                        unsigned char *head_sha1, unsigned char *sha1)
488 {
489         if ((!head[0]) ||
490             (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
491                 return 0;
492         if (starts_with(head, "refs/heads/"))
493                 head += 11;
494         if (starts_with(name, "refs/heads/"))
495                 name += 11;
496         else if (starts_with(name, "heads/"))
497                 name += 6;
498         return !strcmp(head, name);
499 }
500
501 static int show_merge_base(struct commit_list *seen, int num_rev)
502 {
503         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
504         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
505         int exit_status = 1;
506
507         while (seen) {
508                 struct commit *commit = pop_one_commit(&seen);
509                 int flags = commit->object.flags & all_mask;
510                 if (!(flags & UNINTERESTING) &&
511                     ((flags & all_revs) == all_revs)) {
512                         puts(sha1_to_hex(commit->object.sha1));
513                         exit_status = 0;
514                         commit->object.flags |= UNINTERESTING;
515                 }
516         }
517         return exit_status;
518 }
519
520 static int show_independent(struct commit **rev,
521                             int num_rev,
522                             char **ref_name,
523                             unsigned int *rev_mask)
524 {
525         int i;
526
527         for (i = 0; i < num_rev; i++) {
528                 struct commit *commit = rev[i];
529                 unsigned int flag = rev_mask[i];
530
531                 if (commit->object.flags == flag)
532                         puts(sha1_to_hex(commit->object.sha1));
533                 commit->object.flags |= UNINTERESTING;
534         }
535         return 0;
536 }
537
538 static void append_one_rev(const char *av)
539 {
540         unsigned char revkey[20];
541         if (!get_sha1(av, revkey)) {
542                 append_ref(av, revkey, 0);
543                 return;
544         }
545         if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
546                 /* glob style match */
547                 int saved_matches = ref_name_cnt;
548
549                 match_ref_pattern = av;
550                 match_ref_slash = count_slash(av);
551                 for_each_ref(append_matching_ref, NULL);
552                 if (saved_matches == ref_name_cnt &&
553                     ref_name_cnt < MAX_REVS)
554                         error("no matching refs with %s", av);
555                 if (saved_matches + 1 < ref_name_cnt)
556                         sort_ref_range(saved_matches, ref_name_cnt);
557                 return;
558         }
559         die("bad sha1 reference %s", av);
560 }
561
562 static int git_show_branch_config(const char *var, const char *value, void *cb)
563 {
564         if (!strcmp(var, "showbranch.default")) {
565                 if (!value)
566                         return config_error_nonbool(var);
567                 /*
568                  * default_arg is now passed to parse_options(), so we need to
569                  * mimic the real argv a bit better.
570                  */
571                 if (!default_num) {
572                         default_alloc = 20;
573                         default_arg = xcalloc(default_alloc, sizeof(*default_arg));
574                         default_arg[default_num++] = "show-branch";
575                 } else if (default_alloc <= default_num + 1) {
576                         default_alloc = default_alloc * 3 / 2 + 20;
577                         REALLOC_ARRAY(default_arg, default_alloc);
578                 }
579                 default_arg[default_num++] = xstrdup(value);
580                 default_arg[default_num] = NULL;
581                 return 0;
582         }
583
584         if (!strcmp(var, "color.showbranch")) {
585                 showbranch_use_color = git_config_colorbool(var, value);
586                 return 0;
587         }
588
589         return git_color_default_config(var, value, cb);
590 }
591
592 static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
593 {
594         /* If the commit is tip of the named branches, do not
595          * omit it.
596          * Otherwise, if it is a merge that is reachable from only one
597          * tip, it is not that interesting.
598          */
599         int i, flag, count;
600         for (i = 0; i < n; i++)
601                 if (rev[i] == commit)
602                         return 0;
603         flag = commit->object.flags;
604         for (i = count = 0; i < n; i++) {
605                 if (flag & (1u << (i + REV_SHIFT)))
606                         count++;
607         }
608         if (count == 1)
609                 return 1;
610         return 0;
611 }
612
613 static int reflog = 0;
614
615 static int parse_reflog_param(const struct option *opt, const char *arg,
616                               int unset)
617 {
618         char *ep;
619         const char **base = (const char **)opt->value;
620         if (!arg)
621                 arg = "";
622         reflog = strtoul(arg, &ep, 10);
623         if (*ep == ',')
624                 *base = ep + 1;
625         else if (*ep)
626                 return error("unrecognized reflog param '%s'", arg);
627         else
628                 *base = NULL;
629         if (reflog <= 0)
630                 reflog = DEFAULT_REFLOG;
631         return 0;
632 }
633
634 int cmd_show_branch(int ac, const char **av, const char *prefix)
635 {
636         struct commit *rev[MAX_REVS], *commit;
637         char *reflog_msg[MAX_REVS];
638         struct commit_list *list = NULL, *seen = NULL;
639         unsigned int rev_mask[MAX_REVS];
640         int num_rev, i, extra = 0;
641         int all_heads = 0, all_remotes = 0;
642         int all_mask, all_revs;
643         enum rev_sort_order sort_order = REV_SORT_IN_GRAPH_ORDER;
644         char head[128];
645         const char *head_p;
646         int head_len;
647         unsigned char head_sha1[20];
648         int merge_base = 0;
649         int independent = 0;
650         int no_name = 0;
651         int sha1_name = 0;
652         int shown_merge_point = 0;
653         int with_current_branch = 0;
654         int head_at = -1;
655         int topics = 0;
656         int dense = 1;
657         const char *reflog_base = NULL;
658         struct option builtin_show_branch_options[] = {
659                 OPT_BOOL('a', "all", &all_heads,
660                          N_("show remote-tracking and local branches")),
661                 OPT_BOOL('r', "remotes", &all_remotes,
662                          N_("show remote-tracking branches")),
663                 OPT__COLOR(&showbranch_use_color,
664                             N_("color '*!+-' corresponding to the branch")),
665                 { OPTION_INTEGER, 0, "more", &extra, N_("n"),
666                             N_("show <n> more commits after the common ancestor"),
667                             PARSE_OPT_OPTARG, NULL, (intptr_t)1 },
668                 OPT_SET_INT(0, "list", &extra, N_("synonym to more=-1"), -1),
669                 OPT_BOOL(0, "no-name", &no_name, N_("suppress naming strings")),
670                 OPT_BOOL(0, "current", &with_current_branch,
671                          N_("include the current branch")),
672                 OPT_BOOL(0, "sha1-name", &sha1_name,
673                          N_("name commits with their object names")),
674                 OPT_BOOL(0, "merge-base", &merge_base,
675                          N_("show possible merge bases")),
676                 OPT_BOOL(0, "independent", &independent,
677                             N_("show refs unreachable from any other ref")),
678                 OPT_SET_INT(0, "topo-order", &sort_order,
679                             N_("show commits in topological order"),
680                             REV_SORT_IN_GRAPH_ORDER),
681                 OPT_BOOL(0, "topics", &topics,
682                          N_("show only commits not on the first branch")),
683                 OPT_SET_INT(0, "sparse", &dense,
684                             N_("show merges reachable from only one tip"), 0),
685                 OPT_SET_INT(0, "date-order", &sort_order,
686                             N_("topologically sort, maintaining date order "
687                                "where possible"),
688                             REV_SORT_BY_COMMIT_DATE),
689                 { OPTION_CALLBACK, 'g', "reflog", &reflog_base, N_("<n>[,<base>]"),
690                             N_("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 nothing is specified, try the default first */
700         if (ac == 1 && default_num) {
701                 ac = default_num;
702                 av = default_arg;
703         }
704
705         ac = parse_options(ac, av, prefix, builtin_show_branch_options,
706                            show_branch_usage, PARSE_OPT_STOP_AT_NON_OPTION);
707         if (all_heads)
708                 all_remotes = 1;
709
710         if (extra || reflog) {
711                 /* "listing" mode is incompatible with
712                  * independent nor merge-base modes.
713                  */
714                 if (independent || merge_base)
715                         usage_with_options(show_branch_usage,
716                                            builtin_show_branch_options);
717                 if (reflog && ((0 < extra) || all_heads || all_remotes))
718                         /*
719                          * Asking for --more in reflog mode does not
720                          * make sense.  --list is Ok.
721                          *
722                          * Also --all and --remotes do not make sense either.
723                          */
724                         die("--reflog is incompatible with --all, --remotes, "
725                             "--independent or --merge-base");
726         }
727
728         /* If nothing is specified, show all branches by default */
729         if (ac <= topics && all_heads + all_remotes == 0)
730                 all_heads = 1;
731
732         if (reflog) {
733                 unsigned char sha1[20];
734                 char nth_desc[256];
735                 char *ref;
736                 int base = 0;
737                 unsigned int flags = 0;
738
739                 if (ac == 0) {
740                         static const char *fake_av[2];
741
742                         fake_av[0] = resolve_refdup("HEAD",
743                                                     RESOLVE_REF_READING,
744                                                     sha1, NULL);
745                         fake_av[1] = NULL;
746                         av = fake_av;
747                         ac = 1;
748                 }
749                 if (ac != 1)
750                         die("--reflog option needs one branch name");
751
752                 if (MAX_REVS < reflog)
753                         die("Only %d entries can be shown at one time.",
754                             MAX_REVS);
755                 if (!dwim_ref(*av, strlen(*av), sha1, &ref))
756                         die("No such ref %s", *av);
757
758                 /* Has the base been specified? */
759                 if (reflog_base) {
760                         char *ep;
761                         base = strtoul(reflog_base, &ep, 10);
762                         if (*ep) {
763                                 /* Ah, that is a date spec... */
764                                 unsigned long at;
765                                 at = approxidate(reflog_base);
766                                 read_ref_at(ref, flags, at, -1, sha1, NULL,
767                                             NULL, NULL, &base);
768                         }
769                 }
770
771                 for (i = 0; i < reflog; i++) {
772                         char *logmsg;
773                         const char *msg;
774                         unsigned long timestamp;
775                         int tz;
776
777                         if (read_ref_at(ref, flags, 0, base+i, sha1, &logmsg,
778                                         &timestamp, &tz, NULL)) {
779                                 reflog = i;
780                                 break;
781                         }
782                         msg = strchr(logmsg, '\t');
783                         if (!msg)
784                                 msg = "(none)";
785                         else
786                                 msg++;
787                         reflog_msg[i] = xstrfmt("(%s) %s",
788                                                 show_date(timestamp, tz, 1),
789                                                 msg);
790                         free(logmsg);
791                         sprintf(nth_desc, "%s@{%d}", *av, base+i);
792                         append_ref(nth_desc, sha1, 1);
793                 }
794                 free(ref);
795         }
796         else {
797                 while (0 < ac) {
798                         append_one_rev(*av);
799                         ac--; av++;
800                 }
801                 if (all_heads + all_remotes)
802                         snarf_refs(all_heads, all_remotes);
803         }
804
805         head_p = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
806                                     head_sha1, NULL);
807         if (head_p) {
808                 head_len = strlen(head_p);
809                 memcpy(head, head_p, head_len + 1);
810         }
811         else {
812                 head_len = 0;
813                 head[0] = 0;
814         }
815
816         if (with_current_branch && head_p) {
817                 int has_head = 0;
818                 for (i = 0; !has_head && i < ref_name_cnt; i++) {
819                         /* We are only interested in adding the branch
820                          * HEAD points at.
821                          */
822                         if (rev_is_head(head,
823                                         head_len,
824                                         ref_name[i],
825                                         head_sha1, NULL))
826                                 has_head++;
827                 }
828                 if (!has_head) {
829                         int offset = starts_with(head, "refs/heads/") ? 11 : 0;
830                         append_one_rev(head + offset);
831                 }
832         }
833
834         if (!ref_name_cnt) {
835                 fprintf(stderr, "No revs to be shown.\n");
836                 exit(0);
837         }
838
839         for (num_rev = 0; ref_name[num_rev]; num_rev++) {
840                 unsigned char revkey[20];
841                 unsigned int flag = 1u << (num_rev + REV_SHIFT);
842
843                 if (MAX_REVS <= num_rev)
844                         die("cannot handle more than %d revs.", MAX_REVS);
845                 if (get_sha1(ref_name[num_rev], revkey))
846                         die("'%s' is not a valid ref.", ref_name[num_rev]);
847                 commit = lookup_commit_reference(revkey);
848                 if (!commit)
849                         die("cannot find commit %s (%s)",
850                             ref_name[num_rev], revkey);
851                 parse_commit(commit);
852                 mark_seen(commit, &seen);
853
854                 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
855                  * and so on.  REV_SHIFT bits from bit 0 are used for
856                  * internal bookkeeping.
857                  */
858                 commit->object.flags |= flag;
859                 if (commit->object.flags == flag)
860                         commit_list_insert_by_date(commit, &list);
861                 rev[num_rev] = commit;
862         }
863         for (i = 0; i < num_rev; i++)
864                 rev_mask[i] = rev[i]->object.flags;
865
866         if (0 <= extra)
867                 join_revs(&list, &seen, num_rev, extra);
868
869         commit_list_sort_by_date(&seen);
870
871         if (merge_base)
872                 return show_merge_base(seen, num_rev);
873
874         if (independent)
875                 return show_independent(rev, num_rev, ref_name, rev_mask);
876
877         /* Show list; --more=-1 means list-only */
878         if (1 < num_rev || extra < 0) {
879                 for (i = 0; i < num_rev; i++) {
880                         int j;
881                         int is_head = rev_is_head(head,
882                                                   head_len,
883                                                   ref_name[i],
884                                                   head_sha1,
885                                                   rev[i]->object.sha1);
886                         if (extra < 0)
887                                 printf("%c [%s] ",
888                                        is_head ? '*' : ' ', ref_name[i]);
889                         else {
890                                 for (j = 0; j < i; j++)
891                                         putchar(' ');
892                                 printf("%s%c%s [%s] ",
893                                        get_color_code(i),
894                                        is_head ? '*' : '!',
895                                        get_color_reset_code(), ref_name[i]);
896                         }
897
898                         if (!reflog) {
899                                 /* header lines never need name */
900                                 show_one_commit(rev[i], 1);
901                         }
902                         else
903                                 puts(reflog_msg[i]);
904
905                         if (is_head)
906                                 head_at = i;
907                 }
908                 if (0 <= extra) {
909                         for (i = 0; i < num_rev; i++)
910                                 putchar('-');
911                         putchar('\n');
912                 }
913         }
914         if (extra < 0)
915                 exit(0);
916
917         /* Sort topologically */
918         sort_in_topological_order(&seen, sort_order);
919
920         /* Give names to commits */
921         if (!sha1_name && !no_name)
922                 name_commits(seen, rev, ref_name, num_rev);
923
924         all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
925         all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
926
927         while (seen) {
928                 struct commit *commit = pop_one_commit(&seen);
929                 int this_flag = commit->object.flags;
930                 int is_merge_point = ((this_flag & all_revs) == all_revs);
931
932                 shown_merge_point |= is_merge_point;
933
934                 if (1 < num_rev) {
935                         int is_merge = !!(commit->parents &&
936                                           commit->parents->next);
937                         if (topics &&
938                             !is_merge_point &&
939                             (this_flag & (1u << REV_SHIFT)))
940                                 continue;
941                         if (dense && is_merge &&
942                             omit_in_dense(commit, rev, num_rev))
943                                 continue;
944                         for (i = 0; i < num_rev; i++) {
945                                 int mark;
946                                 if (!(this_flag & (1u << (i + REV_SHIFT))))
947                                         mark = ' ';
948                                 else if (is_merge)
949                                         mark = '-';
950                                 else if (i == head_at)
951                                         mark = '*';
952                                 else
953                                         mark = '+';
954                                 printf("%s%c%s",
955                                        get_color_code(i),
956                                        mark, get_color_reset_code());
957                         }
958                         putchar(' ');
959                 }
960                 show_one_commit(commit, no_name);
961
962                 if (shown_merge_point && --extra < 0)
963                         break;
964         }
965         return 0;
966 }