Merge branch 'bs/maint-rename-populate-filespec'
[git] / builtin-show-branch.c
1 #include "cache.h"
2 #include "commit.h"
3 #include "refs.h"
4 #include "builtin.h"
5
6 static const char show_branch_usage[] =
7 "git show-branch [--sparse] [--current] [--all] [--remotes] [--topo-order] [--more=count | --list | --independent | --merge-base ] [--topics] [<refs>...] | --reflog[=n[,b]] <branch>";
8 static const char show_branch_usage_reflog[] =
9 "--reflog is incompatible with --all, --remotes, --independent or --merge-base";
10
11 static int default_num;
12 static int default_alloc;
13 static const char **default_arg;
14
15 #define UNINTERESTING   01
16
17 #define REV_SHIFT        2
18 #define MAX_REVS        (FLAG_BITS - REV_SHIFT) /* should not exceed bits_per_int - REV_SHIFT */
19
20 #define DEFAULT_REFLOG  4
21
22 static struct commit *interesting(struct commit_list *list)
23 {
24         while (list) {
25                 struct commit *commit = list->item;
26                 list = list->next;
27                 if (commit->object.flags & UNINTERESTING)
28                         continue;
29                 return commit;
30         }
31         return NULL;
32 }
33
34 static struct commit *pop_one_commit(struct commit_list **list_p)
35 {
36         struct commit *commit;
37         struct commit_list *list;
38         list = *list_p;
39         commit = list->item;
40         *list_p = list->next;
41         free(list);
42         return commit;
43 }
44
45 struct commit_name {
46         const char *head_name; /* which head's ancestor? */
47         int generation; /* how many parents away from head_name */
48 };
49
50 /* Name the commit as nth generation ancestor of head_name;
51  * we count only the first-parent relationship for naming purposes.
52  */
53 static void name_commit(struct commit *commit, const char *head_name, int nth)
54 {
55         struct commit_name *name;
56         if (!commit->util)
57                 commit->util = xmalloc(sizeof(struct commit_name));
58         name = commit->util;
59         name->head_name = head_name;
60         name->generation = nth;
61 }
62
63 /* Parent is the first parent of the commit.  We may name it
64  * as (n+1)th generation ancestor of the same head_name as
65  * commit is nth generation ancestor of, if that generation
66  * number is better than the name it already has.
67  */
68 static void name_parent(struct commit *commit, struct commit *parent)
69 {
70         struct commit_name *commit_name = commit->util;
71         struct commit_name *parent_name = parent->util;
72         if (!commit_name)
73                 return;
74         if (!parent_name ||
75             commit_name->generation + 1 < parent_name->generation)
76                 name_commit(parent, commit_name->head_name,
77                             commit_name->generation + 1);
78 }
79
80 static int name_first_parent_chain(struct commit *c)
81 {
82         int i = 0;
83         while (c) {
84                 struct commit *p;
85                 if (!c->util)
86                         break;
87                 if (!c->parents)
88                         break;
89                 p = c->parents->item;
90                 if (!p->util) {
91                         name_parent(c, p);
92                         i++;
93                 }
94                 else
95                         break;
96                 c = p;
97         }
98         return i;
99 }
100
101 static void name_commits(struct commit_list *list,
102                          struct commit **rev,
103                          char **ref_name,
104                          int num_rev)
105 {
106         struct commit_list *cl;
107         struct commit *c;
108         int i;
109
110         /* First give names to the given heads */
111         for (cl = list; cl; cl = cl->next) {
112                 c = cl->item;
113                 if (c->util)
114                         continue;
115                 for (i = 0; i < num_rev; i++) {
116                         if (rev[i] == c) {
117                                 name_commit(c, ref_name[i], 0);
118                                 break;
119                         }
120                 }
121         }
122
123         /* Then commits on the first parent ancestry chain */
124         do {
125                 i = 0;
126                 for (cl = list; cl; cl = cl->next) {
127                         i += name_first_parent_chain(cl->item);
128                 }
129         } while (i);
130
131         /* Finally, any unnamed commits */
132         do {
133                 i = 0;
134                 for (cl = list; cl; cl = cl->next) {
135                         struct commit_list *parents;
136                         struct commit_name *n;
137                         int nth;
138                         c = cl->item;
139                         if (!c->util)
140                                 continue;
141                         n = c->util;
142                         parents = c->parents;
143                         nth = 0;
144                         while (parents) {
145                                 struct commit *p = parents->item;
146                                 char newname[1000], *en;
147                                 parents = parents->next;
148                                 nth++;
149                                 if (p->util)
150                                         continue;
151                                 en = newname;
152                                 switch (n->generation) {
153                                 case 0:
154                                         en += sprintf(en, "%s", n->head_name);
155                                         break;
156                                 case 1:
157                                         en += sprintf(en, "%s^", n->head_name);
158                                         break;
159                                 default:
160                                         en += sprintf(en, "%s~%d",
161                                                 n->head_name, n->generation);
162                                         break;
163                                 }
164                                 if (nth == 1)
165                                         en += sprintf(en, "^");
166                                 else
167                                         en += sprintf(en, "^%d", nth);
168                                 name_commit(p, xstrdup(newname), 0);
169                                 i++;
170                                 name_first_parent_chain(p);
171                         }
172                 }
173         } while (i);
174 }
175
176 static int mark_seen(struct commit *commit, struct commit_list **seen_p)
177 {
178         if (!commit->object.flags) {
179                 commit_list_insert(commit, seen_p);
180                 return 1;
181         }
182         return 0;
183 }
184
185 static void join_revs(struct commit_list **list_p,
186                       struct commit_list **seen_p,
187                       int num_rev, int extra)
188 {
189         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
190         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
191
192         while (*list_p) {
193                 struct commit_list *parents;
194                 int still_interesting = !!interesting(*list_p);
195                 struct commit *commit = pop_one_commit(list_p);
196                 int flags = commit->object.flags & all_mask;
197
198                 if (!still_interesting && extra <= 0)
199                         break;
200
201                 mark_seen(commit, seen_p);
202                 if ((flags & all_revs) == all_revs)
203                         flags |= UNINTERESTING;
204                 parents = commit->parents;
205
206                 while (parents) {
207                         struct commit *p = parents->item;
208                         int this_flag = p->object.flags;
209                         parents = parents->next;
210                         if ((this_flag & flags) == flags)
211                                 continue;
212                         if (!p->object.parsed)
213                                 parse_commit(p);
214                         if (mark_seen(p, seen_p) && !still_interesting)
215                                 extra--;
216                         p->object.flags |= flags;
217                         insert_by_date(p, list_p);
218                 }
219         }
220
221         /*
222          * Postprocess to complete well-poisoning.
223          *
224          * At this point we have all the commits we have seen in
225          * seen_p list.  Mark anything that can be reached from
226          * uninteresting commits not interesting.
227          */
228         for (;;) {
229                 int changed = 0;
230                 struct commit_list *s;
231                 for (s = *seen_p; s; s = s->next) {
232                         struct commit *c = s->item;
233                         struct commit_list *parents;
234
235                         if (((c->object.flags & all_revs) != all_revs) &&
236                             !(c->object.flags & UNINTERESTING))
237                                 continue;
238
239                         /* The current commit is either a merge base or
240                          * already uninteresting one.  Mark its parents
241                          * as uninteresting commits _only_ if they are
242                          * already parsed.  No reason to find new ones
243                          * here.
244                          */
245                         parents = c->parents;
246                         while (parents) {
247                                 struct commit *p = parents->item;
248                                 parents = parents->next;
249                                 if (!(p->object.flags & UNINTERESTING)) {
250                                         p->object.flags |= UNINTERESTING;
251                                         changed = 1;
252                                 }
253                         }
254                 }
255                 if (!changed)
256                         break;
257         }
258 }
259
260 static void show_one_commit(struct commit *commit, int no_name)
261 {
262         struct strbuf pretty = STRBUF_INIT;
263         const char *pretty_str = "(unavailable)";
264         struct commit_name *name = commit->util;
265
266         if (commit->object.parsed) {
267                 pretty_print_commit(CMIT_FMT_ONELINE, commit,
268                                     &pretty, 0, NULL, NULL, 0, 0);
269                 pretty_str = pretty.buf;
270         }
271         if (!prefixcmp(pretty_str, "[PATCH] "))
272                 pretty_str += 8;
273
274         if (!no_name) {
275                 if (name && name->head_name) {
276                         printf("[%s", name->head_name);
277                         if (name->generation) {
278                                 if (name->generation == 1)
279                                         printf("^");
280                                 else
281                                         printf("~%d", name->generation);
282                         }
283                         printf("] ");
284                 }
285                 else
286                         printf("[%s] ",
287                                find_unique_abbrev(commit->object.sha1, 7));
288         }
289         puts(pretty_str);
290         strbuf_release(&pretty);
291 }
292
293 static char *ref_name[MAX_REVS + 1];
294 static int ref_name_cnt;
295
296 static const char *find_digit_prefix(const char *s, int *v)
297 {
298         const char *p;
299         int ver;
300         char ch;
301
302         for (p = s, ver = 0;
303              '0' <= (ch = *p) && ch <= '9';
304              p++)
305                 ver = ver * 10 + ch - '0';
306         *v = ver;
307         return p;
308 }
309
310
311 static int version_cmp(const char *a, const char *b)
312 {
313         while (1) {
314                 int va, vb;
315
316                 a = find_digit_prefix(a, &va);
317                 b = find_digit_prefix(b, &vb);
318                 if (va != vb)
319                         return va - vb;
320
321                 while (1) {
322                         int ca = *a;
323                         int cb = *b;
324                         if ('0' <= ca && ca <= '9')
325                                 ca = 0;
326                         if ('0' <= cb && cb <= '9')
327                                 cb = 0;
328                         if (ca != cb)
329                                 return ca - cb;
330                         if (!ca)
331                                 break;
332                         a++;
333                         b++;
334                 }
335                 if (!*a && !*b)
336                         return 0;
337         }
338 }
339
340 static int compare_ref_name(const void *a_, const void *b_)
341 {
342         const char * const*a = a_, * const*b = b_;
343         return version_cmp(*a, *b);
344 }
345
346 static void sort_ref_range(int bottom, int top)
347 {
348         qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
349               compare_ref_name);
350 }
351
352 static int append_ref(const char *refname, const unsigned char *sha1,
353                       int allow_dups)
354 {
355         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
356         int i;
357
358         if (!commit)
359                 return 0;
360
361         if (!allow_dups) {
362                 /* Avoid adding the same thing twice */
363                 for (i = 0; i < ref_name_cnt; i++)
364                         if (!strcmp(refname, ref_name[i]))
365                                 return 0;
366         }
367         if (MAX_REVS <= ref_name_cnt) {
368                 fprintf(stderr, "warning: ignoring %s; "
369                         "cannot handle more than %d refs\n",
370                         refname, MAX_REVS);
371                 return 0;
372         }
373         ref_name[ref_name_cnt++] = xstrdup(refname);
374         ref_name[ref_name_cnt] = NULL;
375         return 0;
376 }
377
378 static int append_head_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
379 {
380         unsigned char tmp[20];
381         int ofs = 11;
382         if (prefixcmp(refname, "refs/heads/"))
383                 return 0;
384         /* If both heads/foo and tags/foo exists, get_sha1 would
385          * get confused.
386          */
387         if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
388                 ofs = 5;
389         return append_ref(refname + ofs, sha1, 0);
390 }
391
392 static int append_remote_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
393 {
394         unsigned char tmp[20];
395         int ofs = 13;
396         if (prefixcmp(refname, "refs/remotes/"))
397                 return 0;
398         /* If both heads/foo and tags/foo exists, get_sha1 would
399          * get confused.
400          */
401         if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
402                 ofs = 5;
403         return append_ref(refname + ofs, sha1, 0);
404 }
405
406 static int append_tag_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
407 {
408         if (prefixcmp(refname, "refs/tags/"))
409                 return 0;
410         return append_ref(refname + 5, sha1, 0);
411 }
412
413 static const char *match_ref_pattern = NULL;
414 static int match_ref_slash = 0;
415 static int count_slash(const char *s)
416 {
417         int cnt = 0;
418         while (*s)
419                 if (*s++ == '/')
420                         cnt++;
421         return cnt;
422 }
423
424 static int append_matching_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
425 {
426         /* we want to allow pattern hold/<asterisk> to show all
427          * branches under refs/heads/hold/, and v0.99.9? to show
428          * refs/tags/v0.99.9a and friends.
429          */
430         const char *tail;
431         int slash = count_slash(refname);
432         for (tail = refname; *tail && match_ref_slash < slash; )
433                 if (*tail++ == '/')
434                         slash--;
435         if (!*tail)
436                 return 0;
437         if (fnmatch(match_ref_pattern, tail, 0))
438                 return 0;
439         if (!prefixcmp(refname, "refs/heads/"))
440                 return append_head_ref(refname, sha1, flag, cb_data);
441         if (!prefixcmp(refname, "refs/tags/"))
442                 return append_tag_ref(refname, sha1, flag, cb_data);
443         return append_ref(refname, sha1, 0);
444 }
445
446 static void snarf_refs(int head, int remotes)
447 {
448         if (head) {
449                 int orig_cnt = ref_name_cnt;
450                 for_each_ref(append_head_ref, NULL);
451                 sort_ref_range(orig_cnt, ref_name_cnt);
452         }
453         if (remotes) {
454                 int orig_cnt = ref_name_cnt;
455                 for_each_ref(append_remote_ref, NULL);
456                 sort_ref_range(orig_cnt, ref_name_cnt);
457         }
458 }
459
460 static int rev_is_head(char *head, int headlen, char *name,
461                        unsigned char *head_sha1, unsigned char *sha1)
462 {
463         if ((!head[0]) ||
464             (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
465                 return 0;
466         if (!prefixcmp(head, "refs/heads/"))
467                 head += 11;
468         if (!prefixcmp(name, "refs/heads/"))
469                 name += 11;
470         else if (!prefixcmp(name, "heads/"))
471                 name += 6;
472         return !strcmp(head, name);
473 }
474
475 static int show_merge_base(struct commit_list *seen, int num_rev)
476 {
477         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
478         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
479         int exit_status = 1;
480
481         while (seen) {
482                 struct commit *commit = pop_one_commit(&seen);
483                 int flags = commit->object.flags & all_mask;
484                 if (!(flags & UNINTERESTING) &&
485                     ((flags & all_revs) == all_revs)) {
486                         puts(sha1_to_hex(commit->object.sha1));
487                         exit_status = 0;
488                         commit->object.flags |= UNINTERESTING;
489                 }
490         }
491         return exit_status;
492 }
493
494 static int show_independent(struct commit **rev,
495                             int num_rev,
496                             char **ref_name,
497                             unsigned int *rev_mask)
498 {
499         int i;
500
501         for (i = 0; i < num_rev; i++) {
502                 struct commit *commit = rev[i];
503                 unsigned int flag = rev_mask[i];
504
505                 if (commit->object.flags == flag)
506                         puts(sha1_to_hex(commit->object.sha1));
507                 commit->object.flags |= UNINTERESTING;
508         }
509         return 0;
510 }
511
512 static void append_one_rev(const char *av)
513 {
514         unsigned char revkey[20];
515         if (!get_sha1(av, revkey)) {
516                 append_ref(av, revkey, 0);
517                 return;
518         }
519         if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
520                 /* glob style match */
521                 int saved_matches = ref_name_cnt;
522                 match_ref_pattern = av;
523                 match_ref_slash = count_slash(av);
524                 for_each_ref(append_matching_ref, NULL);
525                 if (saved_matches == ref_name_cnt &&
526                     ref_name_cnt < MAX_REVS)
527                         error("no matching refs with %s", av);
528                 if (saved_matches + 1 < ref_name_cnt)
529                         sort_ref_range(saved_matches, ref_name_cnt);
530                 return;
531         }
532         die("bad sha1 reference %s", av);
533 }
534
535 static int git_show_branch_config(const char *var, const char *value, void *cb)
536 {
537         if (!strcmp(var, "showbranch.default")) {
538                 if (!value)
539                         return config_error_nonbool(var);
540                 if (default_alloc <= default_num + 1) {
541                         default_alloc = default_alloc * 3 / 2 + 20;
542                         default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
543                 }
544                 default_arg[default_num++] = xstrdup(value);
545                 default_arg[default_num] = NULL;
546                 return 0;
547         }
548
549         return git_default_config(var, value, cb);
550 }
551
552 static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
553 {
554         /* If the commit is tip of the named branches, do not
555          * omit it.
556          * Otherwise, if it is a merge that is reachable from only one
557          * tip, it is not that interesting.
558          */
559         int i, flag, count;
560         for (i = 0; i < n; i++)
561                 if (rev[i] == commit)
562                         return 0;
563         flag = commit->object.flags;
564         for (i = count = 0; i < n; i++) {
565                 if (flag & (1u << (i + REV_SHIFT)))
566                         count++;
567         }
568         if (count == 1)
569                 return 1;
570         return 0;
571 }
572
573 static void parse_reflog_param(const char *arg, int *cnt, const char **base)
574 {
575         char *ep;
576         *cnt = strtoul(arg, &ep, 10);
577         if (*ep == ',')
578                 *base = ep + 1;
579         else if (*ep)
580                 die("unrecognized reflog param '%s'", arg + 9);
581         else
582                 *base = NULL;
583         if (*cnt <= 0)
584                 *cnt = DEFAULT_REFLOG;
585 }
586
587 int cmd_show_branch(int ac, const char **av, const char *prefix)
588 {
589         struct commit *rev[MAX_REVS], *commit;
590         char *reflog_msg[MAX_REVS];
591         struct commit_list *list = NULL, *seen = NULL;
592         unsigned int rev_mask[MAX_REVS];
593         int num_rev, i, extra = 0;
594         int all_heads = 0, all_remotes = 0;
595         int all_mask, all_revs;
596         int lifo = 1;
597         char head[128];
598         const char *head_p;
599         int head_len;
600         unsigned char head_sha1[20];
601         int merge_base = 0;
602         int independent = 0;
603         int no_name = 0;
604         int sha1_name = 0;
605         int shown_merge_point = 0;
606         int with_current_branch = 0;
607         int head_at = -1;
608         int topics = 0;
609         int dense = 1;
610         int reflog = 0;
611         const char *reflog_base = NULL;
612
613         git_config(git_show_branch_config, NULL);
614
615         /* If nothing is specified, try the default first */
616         if (ac == 1 && default_num) {
617                 ac = default_num + 1;
618                 av = default_arg - 1; /* ick; we would not address av[0] */
619         }
620
621         while (1 < ac && av[1][0] == '-') {
622                 const char *arg = av[1];
623                 if (!strcmp(arg, "--")) {
624                         ac--; av++;
625                         break;
626                 }
627                 else if (!strcmp(arg, "--all") || !strcmp(arg, "-a"))
628                         all_heads = all_remotes = 1;
629                 else if (!strcmp(arg, "--remotes") || !strcmp(arg, "-r"))
630                         all_remotes = 1;
631                 else if (!strcmp(arg, "--more"))
632                         extra = 1;
633                 else if (!strcmp(arg, "--list"))
634                         extra = -1;
635                 else if (!strcmp(arg, "--no-name"))
636                         no_name = 1;
637                 else if (!strcmp(arg, "--current"))
638                         with_current_branch = 1;
639                 else if (!strcmp(arg, "--sha1-name"))
640                         sha1_name = 1;
641                 else if (!prefixcmp(arg, "--more="))
642                         extra = atoi(arg + 7);
643                 else if (!strcmp(arg, "--merge-base"))
644                         merge_base = 1;
645                 else if (!strcmp(arg, "--independent"))
646                         independent = 1;
647                 else if (!strcmp(arg, "--topo-order"))
648                         lifo = 1;
649                 else if (!strcmp(arg, "--topics"))
650                         topics = 1;
651                 else if (!strcmp(arg, "--sparse"))
652                         dense = 0;
653                 else if (!strcmp(arg, "--date-order"))
654                         lifo = 0;
655                 else if (!strcmp(arg, "--reflog") || !strcmp(arg, "-g")) {
656                         reflog = DEFAULT_REFLOG;
657                 }
658                 else if (!prefixcmp(arg, "--reflog="))
659                         parse_reflog_param(arg + 9, &reflog, &reflog_base);
660                 else if (!prefixcmp(arg, "-g="))
661                         parse_reflog_param(arg + 3, &reflog, &reflog_base);
662                 else
663                         usage(show_branch_usage);
664                 ac--; av++;
665         }
666         ac--; av++;
667
668         if (extra || reflog) {
669                 /* "listing" mode is incompatible with
670                  * independent nor merge-base modes.
671                  */
672                 if (independent || merge_base)
673                         usage(show_branch_usage);
674                 if (reflog && ((0 < extra) || all_heads || all_remotes))
675                         /*
676                          * Asking for --more in reflog mode does not
677                          * make sense.  --list is Ok.
678                          *
679                          * Also --all and --remotes do not make sense either.
680                          */
681                         usage(show_branch_usage_reflog);
682         }
683
684         /* If nothing is specified, show all branches by default */
685         if (ac + all_heads + all_remotes == 0)
686                 all_heads = 1;
687
688         if (reflog) {
689                 unsigned char sha1[20];
690                 char nth_desc[256];
691                 char *ref;
692                 int base = 0;
693
694                 if (ac == 0) {
695                         static const char *fake_av[2];
696                         const char *refname;
697
698                         refname = resolve_ref("HEAD", sha1, 1, NULL);
699                         fake_av[0] = xstrdup(refname);
700                         fake_av[1] = NULL;
701                         av = fake_av;
702                         ac = 1;
703                 }
704                 if (ac != 1)
705                         die("--reflog option needs one branch name");
706
707                 if (MAX_REVS < reflog)
708                         die("Only %d entries can be shown at one time.",
709                             MAX_REVS);
710                 if (!dwim_ref(*av, strlen(*av), sha1, &ref))
711                         die("No such ref %s", *av);
712
713                 /* Has the base been specified? */
714                 if (reflog_base) {
715                         char *ep;
716                         base = strtoul(reflog_base, &ep, 10);
717                         if (*ep) {
718                                 /* Ah, that is a date spec... */
719                                 unsigned long at;
720                                 at = approxidate(reflog_base);
721                                 read_ref_at(ref, at, -1, sha1, NULL,
722                                             NULL, NULL, &base);
723                         }
724                 }
725
726                 for (i = 0; i < reflog; i++) {
727                         char *logmsg, *m;
728                         const char *msg;
729                         unsigned long timestamp;
730                         int tz;
731
732                         if (read_ref_at(ref, 0, base+i, sha1, &logmsg,
733                                         &timestamp, &tz, NULL)) {
734                                 reflog = i;
735                                 break;
736                         }
737                         msg = strchr(logmsg, '\t');
738                         if (!msg)
739                                 msg = "(none)";
740                         else
741                                 msg++;
742                         m = xmalloc(strlen(msg) + 200);
743                         sprintf(m, "(%s) %s",
744                                 show_date(timestamp, tz, 1),
745                                 msg);
746                         reflog_msg[i] = m;
747                         free(logmsg);
748                         sprintf(nth_desc, "%s@{%d}", *av, base+i);
749                         append_ref(nth_desc, sha1, 1);
750                 }
751         }
752         else if (all_heads + all_remotes)
753                 snarf_refs(all_heads, all_remotes);
754         else {
755                 while (0 < ac) {
756                         append_one_rev(*av);
757                         ac--; av++;
758                 }
759         }
760
761         head_p = resolve_ref("HEAD", head_sha1, 1, NULL);
762         if (head_p) {
763                 head_len = strlen(head_p);
764                 memcpy(head, head_p, head_len + 1);
765         }
766         else {
767                 head_len = 0;
768                 head[0] = 0;
769         }
770
771         if (with_current_branch && head_p) {
772                 int has_head = 0;
773                 for (i = 0; !has_head && i < ref_name_cnt; i++) {
774                         /* We are only interested in adding the branch
775                          * HEAD points at.
776                          */
777                         if (rev_is_head(head,
778                                         head_len,
779                                         ref_name[i],
780                                         head_sha1, NULL))
781                                 has_head++;
782                 }
783                 if (!has_head) {
784                         int offset = !prefixcmp(head, "refs/heads/") ? 11 : 0;
785                         append_one_rev(head + offset);
786                 }
787         }
788
789         if (!ref_name_cnt) {
790                 fprintf(stderr, "No revs to be shown.\n");
791                 exit(0);
792         }
793
794         for (num_rev = 0; ref_name[num_rev]; num_rev++) {
795                 unsigned char revkey[20];
796                 unsigned int flag = 1u << (num_rev + REV_SHIFT);
797
798                 if (MAX_REVS <= num_rev)
799                         die("cannot handle more than %d revs.", MAX_REVS);
800                 if (get_sha1(ref_name[num_rev], revkey))
801                         die("'%s' is not a valid ref.", ref_name[num_rev]);
802                 commit = lookup_commit_reference(revkey);
803                 if (!commit)
804                         die("cannot find commit %s (%s)",
805                             ref_name[num_rev], revkey);
806                 parse_commit(commit);
807                 mark_seen(commit, &seen);
808
809                 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
810                  * and so on.  REV_SHIFT bits from bit 0 are used for
811                  * internal bookkeeping.
812                  */
813                 commit->object.flags |= flag;
814                 if (commit->object.flags == flag)
815                         insert_by_date(commit, &list);
816                 rev[num_rev] = commit;
817         }
818         for (i = 0; i < num_rev; i++)
819                 rev_mask[i] = rev[i]->object.flags;
820
821         if (0 <= extra)
822                 join_revs(&list, &seen, num_rev, extra);
823
824         sort_by_date(&seen);
825
826         if (merge_base)
827                 return show_merge_base(seen, num_rev);
828
829         if (independent)
830                 return show_independent(rev, num_rev, ref_name, rev_mask);
831
832         /* Show list; --more=-1 means list-only */
833         if (1 < num_rev || extra < 0) {
834                 for (i = 0; i < num_rev; i++) {
835                         int j;
836                         int is_head = rev_is_head(head,
837                                                   head_len,
838                                                   ref_name[i],
839                                                   head_sha1,
840                                                   rev[i]->object.sha1);
841                         if (extra < 0)
842                                 printf("%c [%s] ",
843                                        is_head ? '*' : ' ', ref_name[i]);
844                         else {
845                                 for (j = 0; j < i; j++)
846                                         putchar(' ');
847                                 printf("%c [%s] ",
848                                        is_head ? '*' : '!', ref_name[i]);
849                         }
850
851                         if (!reflog) {
852                                 /* header lines never need name */
853                                 show_one_commit(rev[i], 1);
854                         }
855                         else
856                                 puts(reflog_msg[i]);
857
858                         if (is_head)
859                                 head_at = i;
860                 }
861                 if (0 <= extra) {
862                         for (i = 0; i < num_rev; i++)
863                                 putchar('-');
864                         putchar('\n');
865                 }
866         }
867         if (extra < 0)
868                 exit(0);
869
870         /* Sort topologically */
871         sort_in_topological_order(&seen, lifo);
872
873         /* Give names to commits */
874         if (!sha1_name && !no_name)
875                 name_commits(seen, rev, ref_name, num_rev);
876
877         all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
878         all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
879
880         while (seen) {
881                 struct commit *commit = pop_one_commit(&seen);
882                 int this_flag = commit->object.flags;
883                 int is_merge_point = ((this_flag & all_revs) == all_revs);
884
885                 shown_merge_point |= is_merge_point;
886
887                 if (1 < num_rev) {
888                         int is_merge = !!(commit->parents &&
889                                           commit->parents->next);
890                         if (topics &&
891                             !is_merge_point &&
892                             (this_flag & (1u << REV_SHIFT)))
893                                 continue;
894                         if (dense && is_merge &&
895                             omit_in_dense(commit, rev, num_rev))
896                                 continue;
897                         for (i = 0; i < num_rev; i++) {
898                                 int mark;
899                                 if (!(this_flag & (1u << (i + REV_SHIFT))))
900                                         mark = ' ';
901                                 else if (is_merge)
902                                         mark = '-';
903                                 else if (i == head_at)
904                                         mark = '*';
905                                 else
906                                         mark = '+';
907                                 putchar(mark);
908                         }
909                         putchar(' ');
910                 }
911                 show_one_commit(commit, no_name);
912
913                 if (shown_merge_point && --extra < 0)
914                         break;
915         }
916         return 0;
917 }