replace {pre,suf}fixcmp() with {starts,ends}_with()
[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] [--current] [--color[=<when>] | --no-color] [--sparse] [--more=<n> | --list | --independent | --merge-base] [--no-name | --sha1-name] [--topics] [(<rev> | <glob>)...]"),
10     N_("git show-branch (-g|--reflog)[=<n>[,<base>]] [--list] [<ref>]"),
11     NULL
12 };
13
14 static int showbranch_use_color = -1;
15
16 static int default_num;
17 static int default_alloc;
18 static const char **default_arg;
19
20 #define UNINTERESTING   01
21
22 #define REV_SHIFT        2
23 #define MAX_REVS        (FLAG_BITS - REV_SHIFT) /* should not exceed bits_per_int - REV_SHIFT */
24
25 #define DEFAULT_REFLOG  4
26
27 static const char *get_color_code(int idx)
28 {
29         if (want_color(showbranch_use_color))
30                 return column_colors_ansi[idx % column_colors_ansi_max];
31         return "";
32 }
33
34 static const char *get_color_reset_code(void)
35 {
36         if (want_color(showbranch_use_color))
37                 return GIT_COLOR_RESET;
38         return "";
39 }
40
41 static struct commit *interesting(struct commit_list *list)
42 {
43         while (list) {
44                 struct commit *commit = list->item;
45                 list = list->next;
46                 if (commit->object.flags & UNINTERESTING)
47                         continue;
48                 return commit;
49         }
50         return NULL;
51 }
52
53 static struct commit *pop_one_commit(struct commit_list **list_p)
54 {
55         struct commit *commit;
56         struct commit_list *list;
57         list = *list_p;
58         commit = list->item;
59         *list_p = list->next;
60         free(list);
61         return commit;
62 }
63
64 struct commit_name {
65         const char *head_name; /* which head's ancestor? */
66         int generation; /* how many parents away from head_name */
67 };
68
69 /* Name the commit as nth generation ancestor of head_name;
70  * we count only the first-parent relationship for naming purposes.
71  */
72 static void name_commit(struct commit *commit, const char *head_name, int nth)
73 {
74         struct commit_name *name;
75         if (!commit->util)
76                 commit->util = xmalloc(sizeof(struct commit_name));
77         name = commit->util;
78         name->head_name = head_name;
79         name->generation = nth;
80 }
81
82 /* Parent is the first parent of the commit.  We may name it
83  * as (n+1)th generation ancestor of the same head_name as
84  * commit is nth generation ancestor of, if that generation
85  * number is better than the name it already has.
86  */
87 static void name_parent(struct commit *commit, struct commit *parent)
88 {
89         struct commit_name *commit_name = commit->util;
90         struct commit_name *parent_name = parent->util;
91         if (!commit_name)
92                 return;
93         if (!parent_name ||
94             commit_name->generation + 1 < parent_name->generation)
95                 name_commit(parent, commit_name->head_name,
96                             commit_name->generation + 1);
97 }
98
99 static int name_first_parent_chain(struct commit *c)
100 {
101         int i = 0;
102         while (c) {
103                 struct commit *p;
104                 if (!c->util)
105                         break;
106                 if (!c->parents)
107                         break;
108                 p = c->parents->item;
109                 if (!p->util) {
110                         name_parent(c, p);
111                         i++;
112                 }
113                 else
114                         break;
115                 c = p;
116         }
117         return i;
118 }
119
120 static void name_commits(struct commit_list *list,
121                          struct commit **rev,
122                          char **ref_name,
123                          int num_rev)
124 {
125         struct commit_list *cl;
126         struct commit *c;
127         int i;
128
129         /* First give names to the given heads */
130         for (cl = list; cl; cl = cl->next) {
131                 c = cl->item;
132                 if (c->util)
133                         continue;
134                 for (i = 0; i < num_rev; i++) {
135                         if (rev[i] == c) {
136                                 name_commit(c, ref_name[i], 0);
137                                 break;
138                         }
139                 }
140         }
141
142         /* Then commits on the first parent ancestry chain */
143         do {
144                 i = 0;
145                 for (cl = list; cl; cl = cl->next) {
146                         i += name_first_parent_chain(cl->item);
147                 }
148         } while (i);
149
150         /* Finally, any unnamed commits */
151         do {
152                 i = 0;
153                 for (cl = list; cl; cl = cl->next) {
154                         struct commit_list *parents;
155                         struct commit_name *n;
156                         int nth;
157                         c = cl->item;
158                         if (!c->util)
159                                 continue;
160                         n = c->util;
161                         parents = c->parents;
162                         nth = 0;
163                         while (parents) {
164                                 struct commit *p = parents->item;
165                                 struct strbuf newname = STRBUF_INIT;
166                                 parents = parents->next;
167                                 nth++;
168                                 if (p->util)
169                                         continue;
170                                 switch (n->generation) {
171                                 case 0:
172                                         strbuf_addstr(&newname, n->head_name);
173                                         break;
174                                 case 1:
175                                         strbuf_addf(&newname, "%s^", n->head_name);
176                                         break;
177                                 default:
178                                         strbuf_addf(&newname, "%s~%d",
179                                                     n->head_name, n->generation);
180                                         break;
181                                 }
182                                 if (nth == 1)
183                                         strbuf_addch(&newname, '^');
184                                 else
185                                         strbuf_addf(&newname, "^%d", nth);
186                                 name_commit(p, strbuf_detach(&newname, NULL), 0);
187                                 i++;
188                                 name_first_parent_chain(p);
189                         }
190                 }
191         } while (i);
192 }
193
194 static int mark_seen(struct commit *commit, struct commit_list **seen_p)
195 {
196         if (!commit->object.flags) {
197                 commit_list_insert(commit, seen_p);
198                 return 1;
199         }
200         return 0;
201 }
202
203 static void join_revs(struct commit_list **list_p,
204                       struct commit_list **seen_p,
205                       int num_rev, int extra)
206 {
207         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
208         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
209
210         while (*list_p) {
211                 struct commit_list *parents;
212                 int still_interesting = !!interesting(*list_p);
213                 struct commit *commit = pop_one_commit(list_p);
214                 int flags = commit->object.flags & all_mask;
215
216                 if (!still_interesting && extra <= 0)
217                         break;
218
219                 mark_seen(commit, seen_p);
220                 if ((flags & all_revs) == all_revs)
221                         flags |= UNINTERESTING;
222                 parents = commit->parents;
223
224                 while (parents) {
225                         struct commit *p = parents->item;
226                         int this_flag = p->object.flags;
227                         parents = parents->next;
228                         if ((this_flag & flags) == flags)
229                                 continue;
230                         if (!p->object.parsed)
231                                 parse_commit(p);
232                         if (mark_seen(p, seen_p) && !still_interesting)
233                                 extra--;
234                         p->object.flags |= flags;
235                         commit_list_insert_by_date(p, list_p);
236                 }
237         }
238
239         /*
240          * Postprocess to complete well-poisoning.
241          *
242          * At this point we have all the commits we have seen in
243          * seen_p list.  Mark anything that can be reached from
244          * uninteresting commits not interesting.
245          */
246         for (;;) {
247                 int changed = 0;
248                 struct commit_list *s;
249                 for (s = *seen_p; s; s = s->next) {
250                         struct commit *c = s->item;
251                         struct commit_list *parents;
252
253                         if (((c->object.flags & all_revs) != all_revs) &&
254                             !(c->object.flags & UNINTERESTING))
255                                 continue;
256
257                         /* The current commit is either a merge base or
258                          * already uninteresting one.  Mark its parents
259                          * as uninteresting commits _only_ if they are
260                          * already parsed.  No reason to find new ones
261                          * here.
262                          */
263                         parents = c->parents;
264                         while (parents) {
265                                 struct commit *p = parents->item;
266                                 parents = parents->next;
267                                 if (!(p->object.flags & UNINTERESTING)) {
268                                         p->object.flags |= UNINTERESTING;
269                                         changed = 1;
270                                 }
271                         }
272                 }
273                 if (!changed)
274                         break;
275         }
276 }
277
278 static void show_one_commit(struct commit *commit, int no_name)
279 {
280         struct strbuf pretty = STRBUF_INIT;
281         const char *pretty_str = "(unavailable)";
282         struct commit_name *name = commit->util;
283
284         if (commit->object.parsed) {
285                 pp_commit_easy(CMIT_FMT_ONELINE, commit, &pretty);
286                 pretty_str = pretty.buf;
287         }
288         if (starts_with(pretty_str, "[PATCH] "))
289                 pretty_str += 8;
290
291         if (!no_name) {
292                 if (name && name->head_name) {
293                         printf("[%s", name->head_name);
294                         if (name->generation) {
295                                 if (name->generation == 1)
296                                         printf("^");
297                                 else
298                                         printf("~%d", name->generation);
299                         }
300                         printf("] ");
301                 }
302                 else
303                         printf("[%s] ",
304                                find_unique_abbrev(commit->object.sha1,
305                                                   DEFAULT_ABBREV));
306         }
307         puts(pretty_str);
308         strbuf_release(&pretty);
309 }
310
311 static char *ref_name[MAX_REVS + 1];
312 static int ref_name_cnt;
313
314 static const char *find_digit_prefix(const char *s, int *v)
315 {
316         const char *p;
317         int ver;
318         char ch;
319
320         for (p = s, ver = 0;
321              '0' <= (ch = *p) && ch <= '9';
322              p++)
323                 ver = ver * 10 + ch - '0';
324         *v = ver;
325         return p;
326 }
327
328
329 static int version_cmp(const char *a, const char *b)
330 {
331         while (1) {
332                 int va, vb;
333
334                 a = find_digit_prefix(a, &va);
335                 b = find_digit_prefix(b, &vb);
336                 if (va != vb)
337                         return va - vb;
338
339                 while (1) {
340                         int ca = *a;
341                         int cb = *b;
342                         if ('0' <= ca && ca <= '9')
343                                 ca = 0;
344                         if ('0' <= cb && cb <= '9')
345                                 cb = 0;
346                         if (ca != cb)
347                                 return ca - cb;
348                         if (!ca)
349                                 break;
350                         a++;
351                         b++;
352                 }
353                 if (!*a && !*b)
354                         return 0;
355         }
356 }
357
358 static int compare_ref_name(const void *a_, const void *b_)
359 {
360         const char * const*a = a_, * const*b = b_;
361         return version_cmp(*a, *b);
362 }
363
364 static void sort_ref_range(int bottom, int top)
365 {
366         qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
367               compare_ref_name);
368 }
369
370 static int append_ref(const char *refname, const unsigned char *sha1,
371                       int allow_dups)
372 {
373         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
374         int i;
375
376         if (!commit)
377                 return 0;
378
379         if (!allow_dups) {
380                 /* Avoid adding the same thing twice */
381                 for (i = 0; i < ref_name_cnt; i++)
382                         if (!strcmp(refname, ref_name[i]))
383                                 return 0;
384         }
385         if (MAX_REVS <= ref_name_cnt) {
386                 warning("ignoring %s; cannot handle more than %d refs",
387                         refname, MAX_REVS);
388                 return 0;
389         }
390         ref_name[ref_name_cnt++] = xstrdup(refname);
391         ref_name[ref_name_cnt] = NULL;
392         return 0;
393 }
394
395 static int append_head_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
396 {
397         unsigned char tmp[20];
398         int ofs = 11;
399         if (!starts_with(refname, "refs/heads/"))
400                 return 0;
401         /* If both heads/foo and tags/foo exists, get_sha1 would
402          * get confused.
403          */
404         if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
405                 ofs = 5;
406         return append_ref(refname + ofs, sha1, 0);
407 }
408
409 static int append_remote_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
410 {
411         unsigned char tmp[20];
412         int ofs = 13;
413         if (!starts_with(refname, "refs/remotes/"))
414                 return 0;
415         /* If both heads/foo and tags/foo exists, get_sha1 would
416          * get confused.
417          */
418         if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
419                 ofs = 5;
420         return append_ref(refname + ofs, sha1, 0);
421 }
422
423 static int append_tag_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
424 {
425         if (!starts_with(refname, "refs/tags/"))
426                 return 0;
427         return append_ref(refname + 5, sha1, 0);
428 }
429
430 static const char *match_ref_pattern = NULL;
431 static int match_ref_slash = 0;
432 static int count_slash(const char *s)
433 {
434         int cnt = 0;
435         while (*s)
436                 if (*s++ == '/')
437                         cnt++;
438         return cnt;
439 }
440
441 static int append_matching_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
442 {
443         /* we want to allow pattern hold/<asterisk> to show all
444          * branches under refs/heads/hold/, and v0.99.9? to show
445          * refs/tags/v0.99.9a and friends.
446          */
447         const char *tail;
448         int slash = count_slash(refname);
449         for (tail = refname; *tail && match_ref_slash < slash; )
450                 if (*tail++ == '/')
451                         slash--;
452         if (!*tail)
453                 return 0;
454         if (fnmatch(match_ref_pattern, tail, 0))
455                 return 0;
456         if (starts_with(refname, "refs/heads/"))
457                 return append_head_ref(refname, sha1, flag, cb_data);
458         if (starts_with(refname, "refs/tags/"))
459                 return append_tag_ref(refname, sha1, flag, cb_data);
460         return append_ref(refname, sha1, 0);
461 }
462
463 static void snarf_refs(int head, int remotes)
464 {
465         if (head) {
466                 int orig_cnt = ref_name_cnt;
467                 for_each_ref(append_head_ref, NULL);
468                 sort_ref_range(orig_cnt, ref_name_cnt);
469         }
470         if (remotes) {
471                 int orig_cnt = ref_name_cnt;
472                 for_each_ref(append_remote_ref, NULL);
473                 sort_ref_range(orig_cnt, ref_name_cnt);
474         }
475 }
476
477 static int rev_is_head(char *head, int headlen, char *name,
478                        unsigned char *head_sha1, unsigned char *sha1)
479 {
480         if ((!head[0]) ||
481             (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
482                 return 0;
483         if (starts_with(head, "refs/heads/"))
484                 head += 11;
485         if (starts_with(name, "refs/heads/"))
486                 name += 11;
487         else if (starts_with(name, "heads/"))
488                 name += 6;
489         return !strcmp(head, name);
490 }
491
492 static int show_merge_base(struct commit_list *seen, int num_rev)
493 {
494         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
495         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
496         int exit_status = 1;
497
498         while (seen) {
499                 struct commit *commit = pop_one_commit(&seen);
500                 int flags = commit->object.flags & all_mask;
501                 if (!(flags & UNINTERESTING) &&
502                     ((flags & all_revs) == all_revs)) {
503                         puts(sha1_to_hex(commit->object.sha1));
504                         exit_status = 0;
505                         commit->object.flags |= UNINTERESTING;
506                 }
507         }
508         return exit_status;
509 }
510
511 static int show_independent(struct commit **rev,
512                             int num_rev,
513                             char **ref_name,
514                             unsigned int *rev_mask)
515 {
516         int i;
517
518         for (i = 0; i < num_rev; i++) {
519                 struct commit *commit = rev[i];
520                 unsigned int flag = rev_mask[i];
521
522                 if (commit->object.flags == flag)
523                         puts(sha1_to_hex(commit->object.sha1));
524                 commit->object.flags |= UNINTERESTING;
525         }
526         return 0;
527 }
528
529 static void append_one_rev(const char *av)
530 {
531         unsigned char revkey[20];
532         if (!get_sha1(av, revkey)) {
533                 append_ref(av, revkey, 0);
534                 return;
535         }
536         if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
537                 /* glob style match */
538                 int saved_matches = ref_name_cnt;
539                 match_ref_pattern = av;
540                 match_ref_slash = count_slash(av);
541                 for_each_ref(append_matching_ref, NULL);
542                 if (saved_matches == ref_name_cnt &&
543                     ref_name_cnt < MAX_REVS)
544                         error("no matching refs with %s", av);
545                 if (saved_matches + 1 < ref_name_cnt)
546                         sort_ref_range(saved_matches, ref_name_cnt);
547                 return;
548         }
549         die("bad sha1 reference %s", av);
550 }
551
552 static int git_show_branch_config(const char *var, const char *value, void *cb)
553 {
554         if (!strcmp(var, "showbranch.default")) {
555                 if (!value)
556                         return config_error_nonbool(var);
557                 /*
558                  * default_arg is now passed to parse_options(), so we need to
559                  * mimic the real argv a bit better.
560                  */
561                 if (!default_num) {
562                         default_alloc = 20;
563                         default_arg = xcalloc(default_alloc, sizeof(*default_arg));
564                         default_arg[default_num++] = "show-branch";
565                 } else if (default_alloc <= default_num + 1) {
566                         default_alloc = default_alloc * 3 / 2 + 20;
567                         default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
568                 }
569                 default_arg[default_num++] = xstrdup(value);
570                 default_arg[default_num] = NULL;
571                 return 0;
572         }
573
574         if (!strcmp(var, "color.showbranch")) {
575                 showbranch_use_color = git_config_colorbool(var, value);
576                 return 0;
577         }
578
579         return git_color_default_config(var, value, cb);
580 }
581
582 static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
583 {
584         /* If the commit is tip of the named branches, do not
585          * omit it.
586          * Otherwise, if it is a merge that is reachable from only one
587          * tip, it is not that interesting.
588          */
589         int i, flag, count;
590         for (i = 0; i < n; i++)
591                 if (rev[i] == commit)
592                         return 0;
593         flag = commit->object.flags;
594         for (i = count = 0; i < n; i++) {
595                 if (flag & (1u << (i + REV_SHIFT)))
596                         count++;
597         }
598         if (count == 1)
599                 return 1;
600         return 0;
601 }
602
603 static int reflog = 0;
604
605 static int parse_reflog_param(const struct option *opt, const char *arg,
606                               int unset)
607 {
608         char *ep;
609         const char **base = (const char **)opt->value;
610         if (!arg)
611                 arg = "";
612         reflog = strtoul(arg, &ep, 10);
613         if (*ep == ',')
614                 *base = ep + 1;
615         else if (*ep)
616                 return error("unrecognized reflog param '%s'", arg);
617         else
618                 *base = NULL;
619         if (reflog <= 0)
620                 reflog = DEFAULT_REFLOG;
621         return 0;
622 }
623
624 int cmd_show_branch(int ac, const char **av, const char *prefix)
625 {
626         struct commit *rev[MAX_REVS], *commit;
627         char *reflog_msg[MAX_REVS];
628         struct commit_list *list = NULL, *seen = NULL;
629         unsigned int rev_mask[MAX_REVS];
630         int num_rev, i, extra = 0;
631         int all_heads = 0, all_remotes = 0;
632         int all_mask, all_revs;
633         enum rev_sort_order sort_order = REV_SORT_IN_GRAPH_ORDER;
634         char head[128];
635         const char *head_p;
636         int head_len;
637         unsigned char head_sha1[20];
638         int merge_base = 0;
639         int independent = 0;
640         int no_name = 0;
641         int sha1_name = 0;
642         int shown_merge_point = 0;
643         int with_current_branch = 0;
644         int head_at = -1;
645         int topics = 0;
646         int dense = 1;
647         const char *reflog_base = NULL;
648         struct option builtin_show_branch_options[] = {
649                 OPT_BOOL('a', "all", &all_heads,
650                          N_("show remote-tracking and local branches")),
651                 OPT_BOOL('r', "remotes", &all_remotes,
652                          N_("show remote-tracking branches")),
653                 OPT__COLOR(&showbranch_use_color,
654                             N_("color '*!+-' corresponding to the branch")),
655                 { OPTION_INTEGER, 0, "more", &extra, N_("n"),
656                             N_("show <n> more commits after the common ancestor"),
657                             PARSE_OPT_OPTARG, NULL, (intptr_t)1 },
658                 OPT_SET_INT(0, "list", &extra, N_("synonym to more=-1"), -1),
659                 OPT_BOOL(0, "no-name", &no_name, N_("suppress naming strings")),
660                 OPT_BOOL(0, "current", &with_current_branch,
661                          N_("include the current branch")),
662                 OPT_BOOL(0, "sha1-name", &sha1_name,
663                          N_("name commits with their object names")),
664                 OPT_BOOL(0, "merge-base", &merge_base,
665                          N_("show possible merge bases")),
666                 OPT_BOOL(0, "independent", &independent,
667                             N_("show refs unreachable from any other ref")),
668                 OPT_SET_INT(0, "topo-order", &sort_order,
669                             N_("show commits in topological order"),
670                             REV_SORT_IN_GRAPH_ORDER),
671                 OPT_BOOL(0, "topics", &topics,
672                          N_("show only commits not on the first branch")),
673                 OPT_SET_INT(0, "sparse", &dense,
674                             N_("show merges reachable from only one tip"), 0),
675                 OPT_SET_INT(0, "date-order", &sort_order,
676                             N_("topologically sort, maintaining date order "
677                                "where possible"),
678                             REV_SORT_BY_COMMIT_DATE),
679                 { OPTION_CALLBACK, 'g', "reflog", &reflog_base, N_("<n>[,<base>]"),
680                             N_("show <n> most recent ref-log entries starting at "
681                                "base"),
682                             PARSE_OPT_OPTARG | PARSE_OPT_LITERAL_ARGHELP,
683                             parse_reflog_param },
684                 OPT_END()
685         };
686
687         git_config(git_show_branch_config, NULL);
688
689         /* If nothing is specified, try the default first */
690         if (ac == 1 && default_num) {
691                 ac = default_num;
692                 av = default_arg;
693         }
694
695         ac = parse_options(ac, av, prefix, builtin_show_branch_options,
696                            show_branch_usage, PARSE_OPT_STOP_AT_NON_OPTION);
697         if (all_heads)
698                 all_remotes = 1;
699
700         if (extra || reflog) {
701                 /* "listing" mode is incompatible with
702                  * independent nor merge-base modes.
703                  */
704                 if (independent || merge_base)
705                         usage_with_options(show_branch_usage,
706                                            builtin_show_branch_options);
707                 if (reflog && ((0 < extra) || all_heads || all_remotes))
708                         /*
709                          * Asking for --more in reflog mode does not
710                          * make sense.  --list is Ok.
711                          *
712                          * Also --all and --remotes do not make sense either.
713                          */
714                         die("--reflog is incompatible with --all, --remotes, "
715                             "--independent or --merge-base");
716         }
717
718         /* If nothing is specified, show all branches by default */
719         if (ac + all_heads + all_remotes == 0)
720                 all_heads = 1;
721
722         if (reflog) {
723                 unsigned char sha1[20];
724                 char nth_desc[256];
725                 char *ref;
726                 int base = 0;
727
728                 if (ac == 0) {
729                         static const char *fake_av[2];
730
731                         fake_av[0] = resolve_refdup("HEAD", sha1, 1, NULL);
732                         fake_av[1] = NULL;
733                         av = fake_av;
734                         ac = 1;
735                 }
736                 if (ac != 1)
737                         die("--reflog option needs one branch name");
738
739                 if (MAX_REVS < reflog)
740                         die("Only %d entries can be shown at one time.",
741                             MAX_REVS);
742                 if (!dwim_ref(*av, strlen(*av), sha1, &ref))
743                         die("No such ref %s", *av);
744
745                 /* Has the base been specified? */
746                 if (reflog_base) {
747                         char *ep;
748                         base = strtoul(reflog_base, &ep, 10);
749                         if (*ep) {
750                                 /* Ah, that is a date spec... */
751                                 unsigned long at;
752                                 at = approxidate(reflog_base);
753                                 read_ref_at(ref, at, -1, sha1, NULL,
754                                             NULL, NULL, &base);
755                         }
756                 }
757
758                 for (i = 0; i < reflog; i++) {
759                         char *logmsg, *m;
760                         const char *msg;
761                         unsigned long timestamp;
762                         int tz;
763
764                         if (read_ref_at(ref, 0, base+i, sha1, &logmsg,
765                                         &timestamp, &tz, NULL)) {
766                                 reflog = i;
767                                 break;
768                         }
769                         msg = strchr(logmsg, '\t');
770                         if (!msg)
771                                 msg = "(none)";
772                         else
773                                 msg++;
774                         m = xmalloc(strlen(msg) + 200);
775                         sprintf(m, "(%s) %s",
776                                 show_date(timestamp, tz, 1),
777                                 msg);
778                         reflog_msg[i] = m;
779                         free(logmsg);
780                         sprintf(nth_desc, "%s@{%d}", *av, base+i);
781                         append_ref(nth_desc, sha1, 1);
782                 }
783         }
784         else if (all_heads + all_remotes)
785                 snarf_refs(all_heads, all_remotes);
786         else {
787                 while (0 < ac) {
788                         append_one_rev(*av);
789                         ac--; av++;
790                 }
791         }
792
793         head_p = resolve_ref_unsafe("HEAD", head_sha1, 1, NULL);
794         if (head_p) {
795                 head_len = strlen(head_p);
796                 memcpy(head, head_p, head_len + 1);
797         }
798         else {
799                 head_len = 0;
800                 head[0] = 0;
801         }
802
803         if (with_current_branch && head_p) {
804                 int has_head = 0;
805                 for (i = 0; !has_head && i < ref_name_cnt; i++) {
806                         /* We are only interested in adding the branch
807                          * HEAD points at.
808                          */
809                         if (rev_is_head(head,
810                                         head_len,
811                                         ref_name[i],
812                                         head_sha1, NULL))
813                                 has_head++;
814                 }
815                 if (!has_head) {
816                         int offset = starts_with(head, "refs/heads/") ? 11 : 0;
817                         append_one_rev(head + offset);
818                 }
819         }
820
821         if (!ref_name_cnt) {
822                 fprintf(stderr, "No revs to be shown.\n");
823                 exit(0);
824         }
825
826         for (num_rev = 0; ref_name[num_rev]; num_rev++) {
827                 unsigned char revkey[20];
828                 unsigned int flag = 1u << (num_rev + REV_SHIFT);
829
830                 if (MAX_REVS <= num_rev)
831                         die("cannot handle more than %d revs.", MAX_REVS);
832                 if (get_sha1(ref_name[num_rev], revkey))
833                         die("'%s' is not a valid ref.", ref_name[num_rev]);
834                 commit = lookup_commit_reference(revkey);
835                 if (!commit)
836                         die("cannot find commit %s (%s)",
837                             ref_name[num_rev], revkey);
838                 parse_commit(commit);
839                 mark_seen(commit, &seen);
840
841                 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
842                  * and so on.  REV_SHIFT bits from bit 0 are used for
843                  * internal bookkeeping.
844                  */
845                 commit->object.flags |= flag;
846                 if (commit->object.flags == flag)
847                         commit_list_insert_by_date(commit, &list);
848                 rev[num_rev] = commit;
849         }
850         for (i = 0; i < num_rev; i++)
851                 rev_mask[i] = rev[i]->object.flags;
852
853         if (0 <= extra)
854                 join_revs(&list, &seen, num_rev, extra);
855
856         commit_list_sort_by_date(&seen);
857
858         if (merge_base)
859                 return show_merge_base(seen, num_rev);
860
861         if (independent)
862                 return show_independent(rev, num_rev, ref_name, rev_mask);
863
864         /* Show list; --more=-1 means list-only */
865         if (1 < num_rev || extra < 0) {
866                 for (i = 0; i < num_rev; i++) {
867                         int j;
868                         int is_head = rev_is_head(head,
869                                                   head_len,
870                                                   ref_name[i],
871                                                   head_sha1,
872                                                   rev[i]->object.sha1);
873                         if (extra < 0)
874                                 printf("%c [%s] ",
875                                        is_head ? '*' : ' ', ref_name[i]);
876                         else {
877                                 for (j = 0; j < i; j++)
878                                         putchar(' ');
879                                 printf("%s%c%s [%s] ",
880                                        get_color_code(i),
881                                        is_head ? '*' : '!',
882                                        get_color_reset_code(), ref_name[i]);
883                         }
884
885                         if (!reflog) {
886                                 /* header lines never need name */
887                                 show_one_commit(rev[i], 1);
888                         }
889                         else
890                                 puts(reflog_msg[i]);
891
892                         if (is_head)
893                                 head_at = i;
894                 }
895                 if (0 <= extra) {
896                         for (i = 0; i < num_rev; i++)
897                                 putchar('-');
898                         putchar('\n');
899                 }
900         }
901         if (extra < 0)
902                 exit(0);
903
904         /* Sort topologically */
905         sort_in_topological_order(&seen, sort_order);
906
907         /* Give names to commits */
908         if (!sha1_name && !no_name)
909                 name_commits(seen, rev, ref_name, num_rev);
910
911         all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
912         all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
913
914         while (seen) {
915                 struct commit *commit = pop_one_commit(&seen);
916                 int this_flag = commit->object.flags;
917                 int is_merge_point = ((this_flag & all_revs) == all_revs);
918
919                 shown_merge_point |= is_merge_point;
920
921                 if (1 < num_rev) {
922                         int is_merge = !!(commit->parents &&
923                                           commit->parents->next);
924                         if (topics &&
925                             !is_merge_point &&
926                             (this_flag & (1u << REV_SHIFT)))
927                                 continue;
928                         if (dense && is_merge &&
929                             omit_in_dense(commit, rev, num_rev))
930                                 continue;
931                         for (i = 0; i < num_rev; i++) {
932                                 int mark;
933                                 if (!(this_flag & (1u << (i + REV_SHIFT))))
934                                         mark = ' ';
935                                 else if (is_merge)
936                                         mark = '-';
937                                 else if (i == head_at)
938                                         mark = '*';
939                                 else
940                                         mark = '+';
941                                 printf("%s%c%s",
942                                        get_color_code(i),
943                                        mark, get_color_reset_code());
944                         }
945                         putchar(' ');
946                 }
947                 show_one_commit(commit, no_name);
948
949                 if (shown_merge_point && --extra < 0)
950                         break;
951         }
952         return 0;
953 }