Merge branch 'sg/ref-filter-parse-optim'
[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 "argv-array.h"
7 #include "parse-options.h"
8
9 static const char* show_branch_usage[] = {
10     N_("git show-branch [-a | --all] [-r | --remotes] [--topo-order | --date-order]\n"
11        "                [--current] [--color[=<when>] | --no-color] [--sparse]\n"
12        "                [--more=<n> | --list | --independent | --merge-base]\n"
13        "                [--no-name | --sha1-name] [--topics] [(<rev> | <glob>)...]"),
14     N_("git show-branch (-g | --reflog)[=<n>[,<base>]] [--list] [<ref>]"),
15     NULL
16 };
17
18 static int showbranch_use_color = -1;
19
20 static struct argv_array default_args = ARGV_ARRAY_INIT;
21
22 #define UNINTERESTING   01
23
24 #define REV_SHIFT        2
25 #define MAX_REVS        (FLAG_BITS - REV_SHIFT) /* should not exceed bits_per_int - REV_SHIFT */
26
27 #define DEFAULT_REFLOG  4
28
29 static const char *get_color_code(int idx)
30 {
31         if (want_color(showbranch_use_color))
32                 return column_colors_ansi[idx % column_colors_ansi_max];
33         return "";
34 }
35
36 static const char *get_color_reset_code(void)
37 {
38         if (want_color(showbranch_use_color))
39                 return GIT_COLOR_RESET;
40         return "";
41 }
42
43 static struct commit *interesting(struct commit_list *list)
44 {
45         while (list) {
46                 struct commit *commit = list->item;
47                 list = list->next;
48                 if (commit->object.flags & UNINTERESTING)
49                         continue;
50                 return commit;
51         }
52         return NULL;
53 }
54
55 struct commit_name {
56         const char *head_name; /* which head's ancestor? */
57         int generation; /* how many parents away from head_name */
58 };
59
60 /* Name the commit as nth generation ancestor of head_name;
61  * we count only the first-parent relationship for naming purposes.
62  */
63 static void name_commit(struct commit *commit, const char *head_name, int nth)
64 {
65         struct commit_name *name;
66         if (!commit->util)
67                 commit->util = xmalloc(sizeof(struct commit_name));
68         name = commit->util;
69         name->head_name = head_name;
70         name->generation = nth;
71 }
72
73 /* Parent is the first parent of the commit.  We may name it
74  * as (n+1)th generation ancestor of the same head_name as
75  * commit is nth generation ancestor of, if that generation
76  * number is better than the name it already has.
77  */
78 static void name_parent(struct commit *commit, struct commit *parent)
79 {
80         struct commit_name *commit_name = commit->util;
81         struct commit_name *parent_name = parent->util;
82         if (!commit_name)
83                 return;
84         if (!parent_name ||
85             commit_name->generation + 1 < parent_name->generation)
86                 name_commit(parent, commit_name->head_name,
87                             commit_name->generation + 1);
88 }
89
90 static int name_first_parent_chain(struct commit *c)
91 {
92         int i = 0;
93         while (c) {
94                 struct commit *p;
95                 if (!c->util)
96                         break;
97                 if (!c->parents)
98                         break;
99                 p = c->parents->item;
100                 if (!p->util) {
101                         name_parent(c, p);
102                         i++;
103                 }
104                 else
105                         break;
106                 c = p;
107         }
108         return i;
109 }
110
111 static void name_commits(struct commit_list *list,
112                          struct commit **rev,
113                          char **ref_name,
114                          int num_rev)
115 {
116         struct commit_list *cl;
117         struct commit *c;
118         int i;
119
120         /* First give names to the given heads */
121         for (cl = list; cl; cl = cl->next) {
122                 c = cl->item;
123                 if (c->util)
124                         continue;
125                 for (i = 0; i < num_rev; i++) {
126                         if (rev[i] == c) {
127                                 name_commit(c, ref_name[i], 0);
128                                 break;
129                         }
130                 }
131         }
132
133         /* Then commits on the first parent ancestry chain */
134         do {
135                 i = 0;
136                 for (cl = list; cl; cl = cl->next) {
137                         i += name_first_parent_chain(cl->item);
138                 }
139         } while (i);
140
141         /* Finally, any unnamed commits */
142         do {
143                 i = 0;
144                 for (cl = list; cl; cl = cl->next) {
145                         struct commit_list *parents;
146                         struct commit_name *n;
147                         int nth;
148                         c = cl->item;
149                         if (!c->util)
150                                 continue;
151                         n = c->util;
152                         parents = c->parents;
153                         nth = 0;
154                         while (parents) {
155                                 struct commit *p = parents->item;
156                                 struct strbuf newname = STRBUF_INIT;
157                                 parents = parents->next;
158                                 nth++;
159                                 if (p->util)
160                                         continue;
161                                 switch (n->generation) {
162                                 case 0:
163                                         strbuf_addstr(&newname, n->head_name);
164                                         break;
165                                 case 1:
166                                         strbuf_addf(&newname, "%s^", n->head_name);
167                                         break;
168                                 default:
169                                         strbuf_addf(&newname, "%s~%d",
170                                                     n->head_name, n->generation);
171                                         break;
172                                 }
173                                 if (nth == 1)
174                                         strbuf_addch(&newname, '^');
175                                 else
176                                         strbuf_addf(&newname, "^%d", nth);
177                                 name_commit(p, strbuf_detach(&newname, NULL), 0);
178                                 i++;
179                                 name_first_parent_chain(p);
180                         }
181                 }
182         } while (i);
183 }
184
185 static int mark_seen(struct commit *commit, struct commit_list **seen_p)
186 {
187         if (!commit->object.flags) {
188                 commit_list_insert(commit, seen_p);
189                 return 1;
190         }
191         return 0;
192 }
193
194 static void join_revs(struct commit_list **list_p,
195                       struct commit_list **seen_p,
196                       int num_rev, int extra)
197 {
198         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
199         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
200
201         while (*list_p) {
202                 struct commit_list *parents;
203                 int still_interesting = !!interesting(*list_p);
204                 struct commit *commit = pop_commit(list_p);
205                 int flags = commit->object.flags & all_mask;
206
207                 if (!still_interesting && extra <= 0)
208                         break;
209
210                 mark_seen(commit, seen_p);
211                 if ((flags & all_revs) == all_revs)
212                         flags |= UNINTERESTING;
213                 parents = commit->parents;
214
215                 while (parents) {
216                         struct commit *p = parents->item;
217                         int this_flag = p->object.flags;
218                         parents = parents->next;
219                         if ((this_flag & flags) == flags)
220                                 continue;
221                         parse_commit(p);
222                         if (mark_seen(p, seen_p) && !still_interesting)
223                                 extra--;
224                         p->object.flags |= flags;
225                         commit_list_insert_by_date(p, list_p);
226                 }
227         }
228
229         /*
230          * Postprocess to complete well-poisoning.
231          *
232          * At this point we have all the commits we have seen in
233          * seen_p list.  Mark anything that can be reached from
234          * uninteresting commits not interesting.
235          */
236         for (;;) {
237                 int changed = 0;
238                 struct commit_list *s;
239                 for (s = *seen_p; s; s = s->next) {
240                         struct commit *c = s->item;
241                         struct commit_list *parents;
242
243                         if (((c->object.flags & all_revs) != all_revs) &&
244                             !(c->object.flags & UNINTERESTING))
245                                 continue;
246
247                         /* The current commit is either a merge base or
248                          * already uninteresting one.  Mark its parents
249                          * as uninteresting commits _only_ if they are
250                          * already parsed.  No reason to find new ones
251                          * here.
252                          */
253                         parents = c->parents;
254                         while (parents) {
255                                 struct commit *p = parents->item;
256                                 parents = parents->next;
257                                 if (!(p->object.flags & UNINTERESTING)) {
258                                         p->object.flags |= UNINTERESTING;
259                                         changed = 1;
260                                 }
261                         }
262                 }
263                 if (!changed)
264                         break;
265         }
266 }
267
268 static void show_one_commit(struct commit *commit, int no_name)
269 {
270         struct strbuf pretty = STRBUF_INIT;
271         const char *pretty_str = "(unavailable)";
272         struct commit_name *name = commit->util;
273
274         if (commit->object.parsed) {
275                 pp_commit_easy(CMIT_FMT_ONELINE, commit, &pretty);
276                 pretty_str = pretty.buf;
277         }
278         if (starts_with(pretty_str, "[PATCH] "))
279                 pretty_str += 8;
280
281         if (!no_name) {
282                 if (name && name->head_name) {
283                         printf("[%s", name->head_name);
284                         if (name->generation) {
285                                 if (name->generation == 1)
286                                         printf("^");
287                                 else
288                                         printf("~%d", name->generation);
289                         }
290                         printf("] ");
291                 }
292                 else
293                         printf("[%s] ",
294                                find_unique_abbrev(commit->object.oid.hash,
295                                                   DEFAULT_ABBREV));
296         }
297         puts(pretty_str);
298         strbuf_release(&pretty);
299 }
300
301 static char *ref_name[MAX_REVS + 1];
302 static int ref_name_cnt;
303
304 static const char *find_digit_prefix(const char *s, int *v)
305 {
306         const char *p;
307         int ver;
308         char ch;
309
310         for (p = s, ver = 0;
311              '0' <= (ch = *p) && ch <= '9';
312              p++)
313                 ver = ver * 10 + ch - '0';
314         *v = ver;
315         return p;
316 }
317
318
319 static int version_cmp(const char *a, const char *b)
320 {
321         while (1) {
322                 int va, vb;
323
324                 a = find_digit_prefix(a, &va);
325                 b = find_digit_prefix(b, &vb);
326                 if (va != vb)
327                         return va - vb;
328
329                 while (1) {
330                         int ca = *a;
331                         int cb = *b;
332                         if ('0' <= ca && ca <= '9')
333                                 ca = 0;
334                         if ('0' <= cb && cb <= '9')
335                                 cb = 0;
336                         if (ca != cb)
337                                 return ca - cb;
338                         if (!ca)
339                                 break;
340                         a++;
341                         b++;
342                 }
343                 if (!*a && !*b)
344                         return 0;
345         }
346 }
347
348 static int compare_ref_name(const void *a_, const void *b_)
349 {
350         const char * const*a = a_, * const*b = b_;
351         return version_cmp(*a, *b);
352 }
353
354 static void sort_ref_range(int bottom, int top)
355 {
356         qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
357               compare_ref_name);
358 }
359
360 static int append_ref(const char *refname, const struct object_id *oid,
361                       int allow_dups)
362 {
363         struct commit *commit = lookup_commit_reference_gently(oid->hash, 1);
364         int i;
365
366         if (!commit)
367                 return 0;
368
369         if (!allow_dups) {
370                 /* Avoid adding the same thing twice */
371                 for (i = 0; i < ref_name_cnt; i++)
372                         if (!strcmp(refname, ref_name[i]))
373                                 return 0;
374         }
375         if (MAX_REVS <= ref_name_cnt) {
376                 warning(Q_("ignoring %s; cannot handle more than %d ref",
377                            "ignoring %s; cannot handle more than %d refs",
378                            MAX_REVS), refname, MAX_REVS);
379                 return 0;
380         }
381         ref_name[ref_name_cnt++] = xstrdup(refname);
382         ref_name[ref_name_cnt] = NULL;
383         return 0;
384 }
385
386 static int append_head_ref(const char *refname, const struct object_id *oid,
387                            int flag, void *cb_data)
388 {
389         struct object_id tmp;
390         int ofs = 11;
391         if (!starts_with(refname, "refs/heads/"))
392                 return 0;
393         /* If both heads/foo and tags/foo exists, get_sha1 would
394          * get confused.
395          */
396         if (get_sha1(refname + ofs, tmp.hash) || oidcmp(&tmp, oid))
397                 ofs = 5;
398         return append_ref(refname + ofs, oid, 0);
399 }
400
401 static int append_remote_ref(const char *refname, const struct object_id *oid,
402                              int flag, void *cb_data)
403 {
404         struct object_id tmp;
405         int ofs = 13;
406         if (!starts_with(refname, "refs/remotes/"))
407                 return 0;
408         /* If both heads/foo and tags/foo exists, get_sha1 would
409          * get confused.
410          */
411         if (get_sha1(refname + ofs, tmp.hash) || oidcmp(&tmp, oid))
412                 ofs = 5;
413         return append_ref(refname + ofs, oid, 0);
414 }
415
416 static int append_tag_ref(const char *refname, const struct object_id *oid,
417                           int flag, void *cb_data)
418 {
419         if (!starts_with(refname, "refs/tags/"))
420                 return 0;
421         return append_ref(refname + 5, oid, 0);
422 }
423
424 static const char *match_ref_pattern = NULL;
425 static int match_ref_slash = 0;
426 static int count_slash(const char *s)
427 {
428         int cnt = 0;
429         while (*s)
430                 if (*s++ == '/')
431                         cnt++;
432         return cnt;
433 }
434
435 static int append_matching_ref(const char *refname, const struct object_id *oid,
436                                int flag, void *cb_data)
437 {
438         /* we want to allow pattern hold/<asterisk> to show all
439          * branches under refs/heads/hold/, and v0.99.9? to show
440          * refs/tags/v0.99.9a and friends.
441          */
442         const char *tail;
443         int slash = count_slash(refname);
444         for (tail = refname; *tail && match_ref_slash < slash; )
445                 if (*tail++ == '/')
446                         slash--;
447         if (!*tail)
448                 return 0;
449         if (wildmatch(match_ref_pattern, tail, 0, NULL))
450                 return 0;
451         if (starts_with(refname, "refs/heads/"))
452                 return append_head_ref(refname, oid, flag, cb_data);
453         if (starts_with(refname, "refs/tags/"))
454                 return append_tag_ref(refname, oid, flag, cb_data);
455         return append_ref(refname, oid, 0);
456 }
457
458 static void snarf_refs(int head, int remotes)
459 {
460         if (head) {
461                 int orig_cnt = ref_name_cnt;
462
463                 for_each_ref(append_head_ref, NULL);
464                 sort_ref_range(orig_cnt, ref_name_cnt);
465         }
466         if (remotes) {
467                 int orig_cnt = ref_name_cnt;
468
469                 for_each_ref(append_remote_ref, NULL);
470                 sort_ref_range(orig_cnt, ref_name_cnt);
471         }
472 }
473
474 static int rev_is_head(char *head, int headlen, char *name,
475                        unsigned char *head_sha1, unsigned char *sha1)
476 {
477         if ((!head[0]) ||
478             (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
479                 return 0;
480         if (starts_with(head, "refs/heads/"))
481                 head += 11;
482         if (starts_with(name, "refs/heads/"))
483                 name += 11;
484         else if (starts_with(name, "heads/"))
485                 name += 6;
486         return !strcmp(head, name);
487 }
488
489 static int show_merge_base(struct commit_list *seen, int num_rev)
490 {
491         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
492         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
493         int exit_status = 1;
494
495         while (seen) {
496                 struct commit *commit = pop_commit(&seen);
497                 int flags = commit->object.flags & all_mask;
498                 if (!(flags & UNINTERESTING) &&
499                     ((flags & all_revs) == all_revs)) {
500                         puts(oid_to_hex(&commit->object.oid));
501                         exit_status = 0;
502                         commit->object.flags |= UNINTERESTING;
503                 }
504         }
505         return exit_status;
506 }
507
508 static int show_independent(struct commit **rev,
509                             int num_rev,
510                             char **ref_name,
511                             unsigned int *rev_mask)
512 {
513         int i;
514
515         for (i = 0; i < num_rev; i++) {
516                 struct commit *commit = rev[i];
517                 unsigned int flag = rev_mask[i];
518
519                 if (commit->object.flags == flag)
520                         puts(oid_to_hex(&commit->object.oid));
521                 commit->object.flags |= UNINTERESTING;
522         }
523         return 0;
524 }
525
526 static void append_one_rev(const char *av)
527 {
528         struct object_id revkey;
529         if (!get_sha1(av, revkey.hash)) {
530                 append_ref(av, &revkey, 0);
531                 return;
532         }
533         if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
534                 /* glob style match */
535                 int saved_matches = ref_name_cnt;
536
537                 match_ref_pattern = av;
538                 match_ref_slash = count_slash(av);
539                 for_each_ref(append_matching_ref, NULL);
540                 if (saved_matches == ref_name_cnt &&
541                     ref_name_cnt < MAX_REVS)
542                         error(_("no matching refs with %s"), av);
543                 if (saved_matches + 1 < ref_name_cnt)
544                         sort_ref_range(saved_matches, ref_name_cnt);
545                 return;
546         }
547         die("bad sha1 reference %s", av);
548 }
549
550 static int git_show_branch_config(const char *var, const char *value, void *cb)
551 {
552         if (!strcmp(var, "showbranch.default")) {
553                 if (!value)
554                         return config_error_nonbool(var);
555                 /*
556                  * default_arg is now passed to parse_options(), so we need to
557                  * mimic the real argv a bit better.
558                  */
559                 if (!default_args.argc)
560                         argv_array_push(&default_args, "show-branch");
561                 argv_array_push(&default_args, value);
562                 return 0;
563         }
564
565         if (!strcmp(var, "color.showbranch")) {
566                 showbranch_use_color = git_config_colorbool(var, value);
567                 return 0;
568         }
569
570         return git_color_default_config(var, value, cb);
571 }
572
573 static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
574 {
575         /* If the commit is tip of the named branches, do not
576          * omit it.
577          * Otherwise, if it is a merge that is reachable from only one
578          * tip, it is not that interesting.
579          */
580         int i, flag, count;
581         for (i = 0; i < n; i++)
582                 if (rev[i] == commit)
583                         return 0;
584         flag = commit->object.flags;
585         for (i = count = 0; i < n; i++) {
586                 if (flag & (1u << (i + REV_SHIFT)))
587                         count++;
588         }
589         if (count == 1)
590                 return 1;
591         return 0;
592 }
593
594 static int reflog = 0;
595
596 static int parse_reflog_param(const struct option *opt, const char *arg,
597                               int unset)
598 {
599         char *ep;
600         const char **base = (const char **)opt->value;
601         if (!arg)
602                 arg = "";
603         reflog = strtoul(arg, &ep, 10);
604         if (*ep == ',')
605                 *base = ep + 1;
606         else if (*ep)
607                 return error("unrecognized reflog param '%s'", arg);
608         else
609                 *base = NULL;
610         if (reflog <= 0)
611                 reflog = DEFAULT_REFLOG;
612         return 0;
613 }
614
615 int cmd_show_branch(int ac, const char **av, const char *prefix)
616 {
617         struct commit *rev[MAX_REVS], *commit;
618         char *reflog_msg[MAX_REVS];
619         struct commit_list *list = NULL, *seen = NULL;
620         unsigned int rev_mask[MAX_REVS];
621         int num_rev, i, extra = 0;
622         int all_heads = 0, all_remotes = 0;
623         int all_mask, all_revs;
624         enum rev_sort_order sort_order = REV_SORT_IN_GRAPH_ORDER;
625         char head[128];
626         const char *head_p;
627         int head_len;
628         struct object_id head_oid;
629         int merge_base = 0;
630         int independent = 0;
631         int no_name = 0;
632         int sha1_name = 0;
633         int shown_merge_point = 0;
634         int with_current_branch = 0;
635         int head_at = -1;
636         int topics = 0;
637         int dense = 1;
638         const char *reflog_base = NULL;
639         struct option builtin_show_branch_options[] = {
640                 OPT_BOOL('a', "all", &all_heads,
641                          N_("show remote-tracking and local branches")),
642                 OPT_BOOL('r', "remotes", &all_remotes,
643                          N_("show remote-tracking branches")),
644                 OPT__COLOR(&showbranch_use_color,
645                             N_("color '*!+-' corresponding to the branch")),
646                 { OPTION_INTEGER, 0, "more", &extra, N_("n"),
647                             N_("show <n> more commits after the common ancestor"),
648                             PARSE_OPT_OPTARG, NULL, (intptr_t)1 },
649                 OPT_SET_INT(0, "list", &extra, N_("synonym to more=-1"), -1),
650                 OPT_BOOL(0, "no-name", &no_name, N_("suppress naming strings")),
651                 OPT_BOOL(0, "current", &with_current_branch,
652                          N_("include the current branch")),
653                 OPT_BOOL(0, "sha1-name", &sha1_name,
654                          N_("name commits with their object names")),
655                 OPT_BOOL(0, "merge-base", &merge_base,
656                          N_("show possible merge bases")),
657                 OPT_BOOL(0, "independent", &independent,
658                             N_("show refs unreachable from any other ref")),
659                 OPT_SET_INT(0, "topo-order", &sort_order,
660                             N_("show commits in topological order"),
661                             REV_SORT_IN_GRAPH_ORDER),
662                 OPT_BOOL(0, "topics", &topics,
663                          N_("show only commits not on the first branch")),
664                 OPT_SET_INT(0, "sparse", &dense,
665                             N_("show merges reachable from only one tip"), 0),
666                 OPT_SET_INT(0, "date-order", &sort_order,
667                             N_("topologically sort, maintaining date order "
668                                "where possible"),
669                             REV_SORT_BY_COMMIT_DATE),
670                 { OPTION_CALLBACK, 'g', "reflog", &reflog_base, N_("<n>[,<base>]"),
671                             N_("show <n> most recent ref-log entries starting at "
672                                "base"),
673                             PARSE_OPT_OPTARG | PARSE_OPT_LITERAL_ARGHELP,
674                             parse_reflog_param },
675                 OPT_END()
676         };
677
678         git_config(git_show_branch_config, NULL);
679
680         /* If nothing is specified, try the default first */
681         if (ac == 1 && default_args.argc) {
682                 ac = default_args.argc;
683                 av = default_args.argv;
684         }
685
686         ac = parse_options(ac, av, prefix, builtin_show_branch_options,
687                            show_branch_usage, PARSE_OPT_STOP_AT_NON_OPTION);
688         if (all_heads)
689                 all_remotes = 1;
690
691         if (extra || reflog) {
692                 /* "listing" mode is incompatible with
693                  * independent nor merge-base modes.
694                  */
695                 if (independent || merge_base)
696                         usage_with_options(show_branch_usage,
697                                            builtin_show_branch_options);
698                 if (reflog && ((0 < extra) || all_heads || all_remotes))
699                         /*
700                          * Asking for --more in reflog mode does not
701                          * make sense.  --list is Ok.
702                          *
703                          * Also --all and --remotes do not make sense either.
704                          */
705                         die(_("--reflog is incompatible with --all, --remotes, "
706                               "--independent or --merge-base"));
707         }
708
709         /* If nothing is specified, show all branches by default */
710         if (ac <= topics && all_heads + all_remotes == 0)
711                 all_heads = 1;
712
713         if (reflog) {
714                 struct object_id oid;
715                 char *ref;
716                 int base = 0;
717                 unsigned int flags = 0;
718
719                 if (ac == 0) {
720                         static const char *fake_av[2];
721
722                         fake_av[0] = resolve_refdup("HEAD",
723                                                     RESOLVE_REF_READING,
724                                                     oid.hash, NULL);
725                         fake_av[1] = NULL;
726                         av = fake_av;
727                         ac = 1;
728                         if (!*av)
729                                 die(_("no branches given, and HEAD is not valid"));
730                 }
731                 if (ac != 1)
732                         die(_("--reflog option needs one branch name"));
733
734                 if (MAX_REVS < reflog)
735                         die(Q_("only %d entry can be shown at one time.",
736                                "only %d entries can be shown at one time.",
737                                MAX_REVS), MAX_REVS);
738                 if (!dwim_ref(*av, strlen(*av), oid.hash, &ref))
739                         die(_("no such ref %s"), *av);
740
741                 /* Has the base been specified? */
742                 if (reflog_base) {
743                         char *ep;
744                         base = strtoul(reflog_base, &ep, 10);
745                         if (*ep) {
746                                 /* Ah, that is a date spec... */
747                                 unsigned long at;
748                                 at = approxidate(reflog_base);
749                                 read_ref_at(ref, flags, at, -1, oid.hash, NULL,
750                                             NULL, NULL, &base);
751                         }
752                 }
753
754                 for (i = 0; i < reflog; i++) {
755                         char *logmsg;
756                         char *nth_desc;
757                         const char *msg;
758                         unsigned long timestamp;
759                         int tz;
760
761                         if (read_ref_at(ref, flags, 0, base+i, oid.hash, &logmsg,
762                                         &timestamp, &tz, NULL)) {
763                                 reflog = i;
764                                 break;
765                         }
766                         msg = strchr(logmsg, '\t');
767                         if (!msg)
768                                 msg = "(none)";
769                         else
770                                 msg++;
771                         reflog_msg[i] = xstrfmt("(%s) %s",
772                                                 show_date(timestamp, tz,
773                                                           DATE_MODE(RELATIVE)),
774                                                 msg);
775                         free(logmsg);
776
777                         nth_desc = xstrfmt("%s@{%d}", *av, base+i);
778                         append_ref(nth_desc, &oid, 1);
779                         free(nth_desc);
780                 }
781                 free(ref);
782         }
783         else {
784                 while (0 < ac) {
785                         append_one_rev(*av);
786                         ac--; av++;
787                 }
788                 if (all_heads + all_remotes)
789                         snarf_refs(all_heads, all_remotes);
790         }
791
792         head_p = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
793                                     head_oid.hash, 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_oid.hash, 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                 struct object_id revkey;
828                 unsigned int flag = 1u << (num_rev + REV_SHIFT);
829
830                 if (MAX_REVS <= num_rev)
831                         die(Q_("cannot handle more than %d rev.",
832                                "cannot handle more than %d revs.",
833                                MAX_REVS), MAX_REVS);
834                 if (get_sha1(ref_name[num_rev], revkey.hash))
835                         die(_("'%s' is not a valid ref."), ref_name[num_rev]);
836                 commit = lookup_commit_reference(revkey.hash);
837                 if (!commit)
838                         die(_("cannot find commit %s (%s)"),
839                             ref_name[num_rev], oid_to_hex(&revkey));
840                 parse_commit(commit);
841                 mark_seen(commit, &seen);
842
843                 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
844                  * and so on.  REV_SHIFT bits from bit 0 are used for
845                  * internal bookkeeping.
846                  */
847                 commit->object.flags |= flag;
848                 if (commit->object.flags == flag)
849                         commit_list_insert_by_date(commit, &list);
850                 rev[num_rev] = commit;
851         }
852         for (i = 0; i < num_rev; i++)
853                 rev_mask[i] = rev[i]->object.flags;
854
855         if (0 <= extra)
856                 join_revs(&list, &seen, num_rev, extra);
857
858         commit_list_sort_by_date(&seen);
859
860         if (merge_base)
861                 return show_merge_base(seen, num_rev);
862
863         if (independent)
864                 return show_independent(rev, num_rev, ref_name, rev_mask);
865
866         /* Show list; --more=-1 means list-only */
867         if (1 < num_rev || extra < 0) {
868                 for (i = 0; i < num_rev; i++) {
869                         int j;
870                         int is_head = rev_is_head(head,
871                                                   head_len,
872                                                   ref_name[i],
873                                                   head_oid.hash,
874                                                   rev[i]->object.oid.hash);
875                         if (extra < 0)
876                                 printf("%c [%s] ",
877                                        is_head ? '*' : ' ', ref_name[i]);
878                         else {
879                                 for (j = 0; j < i; j++)
880                                         putchar(' ');
881                                 printf("%s%c%s [%s] ",
882                                        get_color_code(i),
883                                        is_head ? '*' : '!',
884                                        get_color_reset_code(), ref_name[i]);
885                         }
886
887                         if (!reflog) {
888                                 /* header lines never need name */
889                                 show_one_commit(rev[i], 1);
890                         }
891                         else
892                                 puts(reflog_msg[i]);
893
894                         if (is_head)
895                                 head_at = i;
896                 }
897                 if (0 <= extra) {
898                         for (i = 0; i < num_rev; i++)
899                                 putchar('-');
900                         putchar('\n');
901                 }
902         }
903         if (extra < 0)
904                 exit(0);
905
906         /* Sort topologically */
907         sort_in_topological_order(&seen, sort_order);
908
909         /* Give names to commits */
910         if (!sha1_name && !no_name)
911                 name_commits(seen, rev, ref_name, num_rev);
912
913         all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
914         all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
915
916         while (seen) {
917                 struct commit *commit = pop_commit(&seen);
918                 int this_flag = commit->object.flags;
919                 int is_merge_point = ((this_flag & all_revs) == all_revs);
920
921                 shown_merge_point |= is_merge_point;
922
923                 if (1 < num_rev) {
924                         int is_merge = !!(commit->parents &&
925                                           commit->parents->next);
926                         if (topics &&
927                             !is_merge_point &&
928                             (this_flag & (1u << REV_SHIFT)))
929                                 continue;
930                         if (dense && is_merge &&
931                             omit_in_dense(commit, rev, num_rev))
932                                 continue;
933                         for (i = 0; i < num_rev; i++) {
934                                 int mark;
935                                 if (!(this_flag & (1u << (i + REV_SHIFT))))
936                                         mark = ' ';
937                                 else if (is_merge)
938                                         mark = '-';
939                                 else if (i == head_at)
940                                         mark = '*';
941                                 else
942                                         mark = '+';
943                                 printf("%s%c%s",
944                                        get_color_code(i),
945                                        mark, get_color_reset_code());
946                         }
947                         putchar(' ');
948                 }
949                 show_one_commit(commit, no_name);
950
951                 if (shown_merge_point && --extra < 0)
952                         break;
953         }
954         return 0;
955 }