Fix "do not DWIM" patch to enter_repo"
[git/git.git] / show-branch.c
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1#include <stdlib.h>
2#include "cache.h"
3#include "commit.h"
4#include "refs.h"
5
6static const char show_branch_usage[] =
1f8af483 7"git-show-branch [--all] [--heads] [--tags] [--more=count | --list | --independent | --merge-base ] [<refs>...]";
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8
9#define UNINTERESTING 01
10
11#define REV_SHIFT 2
12#define MAX_REVS 29 /* should not exceed bits_per_int - REV_SHIFT */
13
14static struct commit *interesting(struct commit_list *list)
15{
16 while (list) {
17 struct commit *commit = list->item;
18 list = list->next;
19 if (commit->object.flags & UNINTERESTING)
20 continue;
21 return commit;
22 }
23 return NULL;
24}
25
26static struct commit *pop_one_commit(struct commit_list **list_p)
27{
28 struct commit *commit;
29 struct commit_list *list;
30 list = *list_p;
31 commit = list->item;
32 *list_p = list->next;
33 free(list);
34 return commit;
35}
36
37struct commit_name {
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38 const char *head_name; /* which head's ancestor? */
39 int generation; /* how many parents away from head_name */
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40};
41
8e5dd22b 42/* Name the commit as nth generation ancestor of head_name;
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43 * we count only the first-parent relationship for naming purposes.
44 */
8e5dd22b 45static void name_commit(struct commit *commit, const char *head_name, int nth)
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46{
47 struct commit_name *name;
48 if (!commit->object.util)
49 commit->object.util = xmalloc(sizeof(struct commit_name));
50 name = commit->object.util;
8e5dd22b 51 name->head_name = head_name;
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52 name->generation = nth;
53}
54
55/* Parent is the first parent of the commit. We may name it
8e5dd22b 56 * as (n+1)th generation ancestor of the same head_name as
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57 * commit is nth generation ancestore of, if that generation
58 * number is better than the name it already has.
59 */
60static void name_parent(struct commit *commit, struct commit *parent)
61{
62 struct commit_name *commit_name = commit->object.util;
63 struct commit_name *parent_name = parent->object.util;
64 if (!commit_name)
65 return;
66 if (!parent_name ||
67 commit_name->generation + 1 < parent_name->generation)
8e5dd22b 68 name_commit(parent, commit_name->head_name,
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69 commit_name->generation + 1);
70}
71
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72static int name_first_parent_chain(struct commit *c)
73{
74 int i = 0;
75 while (c) {
76 struct commit *p;
77 if (!c->object.util)
78 break;
79 if (!c->parents)
80 break;
81 p = c->parents->item;
82 if (!p->object.util) {
83 name_parent(c, p);
84 i++;
85 }
86 c = p;
87 }
88 return i;
89}
90
91static void name_commits(struct commit_list *list,
92 struct commit **rev,
93 char **ref_name,
94 int num_rev)
95{
96 struct commit_list *cl;
97 struct commit *c;
98 int i;
99
100 /* First give names to the given heads */
101 for (cl = list; cl; cl = cl->next) {
102 c = cl->item;
103 if (c->object.util)
104 continue;
105 for (i = 0; i < num_rev; i++) {
106 if (rev[i] == c) {
107 name_commit(c, ref_name[i], 0);
108 break;
109 }
110 }
111 }
112
113 /* Then commits on the first parent ancestry chain */
114 do {
115 i = 0;
116 for (cl = list; cl; cl = cl->next) {
117 i += name_first_parent_chain(cl->item);
118 }
119 } while (i);
120
121 /* Finally, any unnamed commits */
122 do {
123 i = 0;
124 for (cl = list; cl; cl = cl->next) {
125 struct commit_list *parents;
126 struct commit_name *n;
127 int nth;
128 c = cl->item;
129 if (!c->object.util)
130 continue;
131 n = c->object.util;
132 parents = c->parents;
133 nth = 0;
134 while (parents) {
135 struct commit *p = parents->item;
013f276e 136 char newname[1000], *en;
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137 parents = parents->next;
138 nth++;
139 if (p->object.util)
140 continue;
013f276e 141 en = newname;
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142 switch (n->generation) {
143 case 0:
013f276e 144 en += sprintf(en, "%s", n->head_name);
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145 break;
146 case 1:
013f276e 147 en += sprintf(en, "%s^", n->head_name);
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148 break;
149 default:
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150 en += sprintf(en, "%s~%d",
151 n->head_name, n->generation);
152 break;
fbaf834d 153 }
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154 if (nth == 1)
155 en += sprintf(en, "^");
156 else
157 en += sprintf(en, "^%d", nth);
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158 name_commit(p, strdup(newname), 0);
159 i++;
160 name_first_parent_chain(p);
161 }
162 }
163 } while (i);
164}
165
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166static int mark_seen(struct commit *commit, struct commit_list **seen_p)
167{
168 if (!commit->object.flags) {
169 insert_by_date(commit, seen_p);
170 return 1;
171 }
172 return 0;
173}
174
175static void join_revs(struct commit_list **list_p,
176 struct commit_list **seen_p,
177 int num_rev, int extra)
178{
179 int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
180 int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
181
182 while (*list_p) {
183 struct commit_list *parents;
9ce70285 184 int still_interesting = !!interesting(*list_p);
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185 struct commit *commit = pop_one_commit(list_p);
186 int flags = commit->object.flags & all_mask;
f76412ed 187
9ce70285 188 if (!still_interesting && extra <= 0)
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189 break;
190
191 mark_seen(commit, seen_p);
192 if ((flags & all_revs) == all_revs)
193 flags |= UNINTERESTING;
194 parents = commit->parents;
195
196 while (parents) {
197 struct commit *p = parents->item;
198 int this_flag = p->object.flags;
199 parents = parents->next;
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200 if ((this_flag & flags) == flags)
201 continue;
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202 if (!p->object.parsed)
203 parse_commit(p);
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204 if (mark_seen(p, seen_p) && !still_interesting)
205 extra--;
206 p->object.flags |= flags;
207 insert_by_date(p, list_p);
208 }
209 }
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210
211 /*
212 * Postprocess to complete well-poisoning.
213 *
214 * At this point we have all the commits we have seen in
215 * seen_p list (which happens to be sorted chronologically but
216 * it does not really matter). Mark anything that can be
217 * reached from uninteresting commits not interesting.
218 */
219 for (;;) {
220 int changed = 0;
221 struct commit_list *s;
222 for (s = *seen_p; s; s = s->next) {
223 struct commit *c = s->item;
224 struct commit_list *parents;
225
226 if (((c->object.flags & all_revs) != all_revs) &&
227 !(c->object.flags & UNINTERESTING))
228 continue;
229
230 /* The current commit is either a merge base or
231 * already uninteresting one. Mark its parents
232 * as uninteresting commits _only_ if they are
233 * already parsed. No reason to find new ones
234 * here.
235 */
236 parents = c->parents;
237 while (parents) {
238 struct commit *p = parents->item;
239 parents = parents->next;
240 if (!(p->object.flags & UNINTERESTING)) {
241 p->object.flags |= UNINTERESTING;
242 changed = 1;
243 }
244 }
245 }
246 if (!changed)
247 break;
248 }
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249}
250
013f276e 251static void show_one_commit(struct commit *commit, int no_name)
f76412ed 252{
6b209d47 253 char pretty[256], *cp;
f76412ed 254 struct commit_name *name = commit->object.util;
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255 if (commit->object.parsed)
256 pretty_print_commit(CMIT_FMT_ONELINE, commit->buffer, ~0,
257 pretty, sizeof(pretty));
258 else
259 strcpy(pretty, "(unavailable)");
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260 if (!strncmp(pretty, "[PATCH] ", 8))
261 cp = pretty + 8;
262 else
263 cp = pretty;
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264
265 if (!no_name) {
266 if (name && name->head_name) {
267 printf("[%s", name->head_name);
268 if (name->generation) {
269 if (name->generation == 1)
270 printf("^");
271 else
272 printf("~%d", name->generation);
273 }
274 printf("] ");
275 }
276 else
277 printf("[%s] ",
278 find_unique_abbrev(commit->object.sha1, 7));
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279 }
280 puts(cp);
281}
282
283static char *ref_name[MAX_REVS + 1];
284static int ref_name_cnt;
285
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286static int compare_ref_name(const void *a_, const void *b_)
287{
288 const char * const*a = a_, * const*b = b_;
289 return strcmp(*a, *b);
290}
291
292static void sort_ref_range(int bottom, int top)
293{
294 qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
295 compare_ref_name);
296}
297
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298static int append_ref(const char *refname, const unsigned char *sha1)
299{
300 struct commit *commit = lookup_commit_reference_gently(sha1, 1);
301 if (!commit)
302 return 0;
79778e46 303 if (MAX_REVS <= ref_name_cnt) {
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304 fprintf(stderr, "warning: ignoring %s; "
305 "cannot handle more than %d refs",
306 refname, MAX_REVS);
307 return 0;
308 }
309 ref_name[ref_name_cnt++] = strdup(refname);
310 ref_name[ref_name_cnt] = NULL;
311 return 0;
312}
313
314static int append_head_ref(const char *refname, const unsigned char *sha1)
315{
316 if (strncmp(refname, "refs/heads/", 11))
317 return 0;
628894b2 318 return append_ref(refname + 11, sha1);
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319}
320
321static int append_tag_ref(const char *refname, const unsigned char *sha1)
322{
323 if (strncmp(refname, "refs/tags/", 10))
324 return 0;
325 return append_ref(refname + 5, sha1);
326}
327
328static void snarf_refs(int head, int tag)
329{
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330 if (head) {
331 int orig_cnt = ref_name_cnt;
f76412ed 332 for_each_ref(append_head_ref);
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333 sort_ref_range(orig_cnt, ref_name_cnt);
334 }
335 if (tag) {
336 int orig_cnt = ref_name_cnt;
f76412ed 337 for_each_ref(append_tag_ref);
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338 sort_ref_range(orig_cnt, ref_name_cnt);
339 }
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340}
341
342static int rev_is_head(char *head_path, int headlen,
343 char *name,
344 unsigned char *head_sha1, unsigned char *sha1)
345{
346 int namelen;
347 if ((!head_path[0]) || memcmp(head_sha1, sha1, 20))
348 return 0;
349 namelen = strlen(name);
350 if ((headlen < namelen) ||
351 memcmp(head_path + headlen - namelen, name, namelen))
352 return 0;
353 if (headlen == namelen ||
354 head_path[headlen - namelen - 1] == '/')
355 return 1;
356 return 0;
357}
358
359static int show_merge_base(struct commit_list *seen, int num_rev)
360{
361 int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
362 int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
2f0f8b71 363 int exit_status = 1;
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364
365 while (seen) {
366 struct commit *commit = pop_one_commit(&seen);
367 int flags = commit->object.flags & all_mask;
368 if (!(flags & UNINTERESTING) &&
369 ((flags & all_revs) == all_revs)) {
370 puts(sha1_to_hex(commit->object.sha1));
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371 exit_status = 0;
372 commit->object.flags |= UNINTERESTING;
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373 }
374 }
2f0f8b71 375 return exit_status;
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376}
377
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378static int show_independent(struct commit **rev,
379 int num_rev,
380 char **ref_name,
381 unsigned int *rev_mask)
382{
383 int i;
384
385 for (i = 0; i < num_rev; i++) {
386 struct commit *commit = rev[i];
387 unsigned int flag = rev_mask[i];
388
389 if (commit->object.flags == flag)
390 puts(sha1_to_hex(commit->object.sha1));
391 commit->object.flags |= UNINTERESTING;
392 }
393 return 0;
394}
395
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396int main(int ac, char **av)
397{
398 struct commit *rev[MAX_REVS], *commit;
399 struct commit_list *list = NULL, *seen = NULL;
1f8af483 400 unsigned int rev_mask[MAX_REVS];
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401 int num_rev, i, extra = 0;
402 int all_heads = 0, all_tags = 0;
6b209d47 403 int all_mask, all_revs;
f76412ed 404 char head_path[128];
8098a178 405 const char *head_path_p;
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406 int head_path_len;
407 unsigned char head_sha1[20];
408 int merge_base = 0;
1f8af483 409 int independent = 0;
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410 int no_name = 0;
411 int sha1_name = 0;
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412 int shown_merge_point = 0;
413 int topo_order = 0;
f76412ed 414
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415 setup_git_directory();
416
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417 while (1 < ac && av[1][0] == '-') {
418 char *arg = av[1];
419 if (!strcmp(arg, "--all"))
420 all_heads = all_tags = 1;
421 else if (!strcmp(arg, "--heads"))
422 all_heads = 1;
423 else if (!strcmp(arg, "--tags"))
424 all_tags = 1;
425 else if (!strcmp(arg, "--more"))
426 extra = 1;
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427 else if (!strcmp(arg, "--list"))
428 extra = -1;
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429 else if (!strcmp(arg, "--no-name"))
430 no_name = 1;
431 else if (!strcmp(arg, "--sha1-name"))
432 sha1_name = 1;
1f8af483 433 else if (!strncmp(arg, "--more=", 7))
f76412ed 434 extra = atoi(arg + 7);
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435 else if (!strcmp(arg, "--merge-base"))
436 merge_base = 1;
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437 else if (!strcmp(arg, "--independent"))
438 independent = 1;
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439 else if (!strcmp(arg, "--topo-order"))
440 topo_order = 1;
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441 else
442 usage(show_branch_usage);
443 ac--; av++;
444 }
445 ac--; av++;
446
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447 /* Only one of these is allowed */
448 if (1 < independent + merge_base + (extra != 0))
449 usage(show_branch_usage);
450
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451 if (all_heads + all_tags)
452 snarf_refs(all_heads, all_tags);
453
454 while (0 < ac) {
455 unsigned char revkey[20];
456 if (get_sha1(*av, revkey))
457 die("bad sha1 reference %s", *av);
458 append_ref(*av, revkey);
459 ac--; av++;
460 }
461
462 /* If still no revs, then add heads */
463 if (!ref_name_cnt)
464 snarf_refs(1, 0);
465
466 for (num_rev = 0; ref_name[num_rev]; num_rev++) {
467 unsigned char revkey[20];
1f8af483 468 unsigned int flag = 1u << (num_rev + REV_SHIFT);
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469
470 if (MAX_REVS <= num_rev)
471 die("cannot handle more than %d revs.", MAX_REVS);
472 if (get_sha1(ref_name[num_rev], revkey))
473 usage(show_branch_usage);
474 commit = lookup_commit_reference(revkey);
475 if (!commit)
476 die("cannot find commit %s (%s)",
477 ref_name[num_rev], revkey);
478 parse_commit(commit);
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479 mark_seen(commit, &seen);
480
481 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
482 * and so on. REV_SHIFT bits from bit 0 are used for
483 * internal bookkeeping.
484 */
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485 commit->object.flags |= flag;
486 if (commit->object.flags == flag)
487 insert_by_date(commit, &list);
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488 rev[num_rev] = commit;
489 }
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490 for (i = 0; i < num_rev; i++)
491 rev_mask[i] = rev[i]->object.flags;
492
493 if (0 <= extra)
494 join_revs(&list, &seen, num_rev, extra);
f76412ed 495
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496 head_path_p = resolve_ref(git_path("HEAD"), head_sha1, 1);
497 if (head_path_p) {
498 head_path_len = strlen(head_path_p);
499 memcpy(head_path, head_path_p, head_path_len + 1);
500 }
501 else {
502 head_path_len = 0;
f76412ed 503 head_path[0] = 0;
8098a178 504 }
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505
506 if (merge_base)
507 return show_merge_base(seen, num_rev);
508
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509 if (independent)
510 return show_independent(rev, num_rev, ref_name, rev_mask);
511
512 /* Show list; --more=-1 means list-only */
c9d023b2 513 if (1 < num_rev || extra < 0) {
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514 for (i = 0; i < num_rev; i++) {
515 int j;
516 int is_head = rev_is_head(head_path,
517 head_path_len,
518 ref_name[i],
519 head_sha1,
520 rev[i]->object.sha1);
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521 if (extra < 0)
522 printf("%c [%s] ",
523 is_head ? '*' : ' ', ref_name[i]);
524 else {
525 for (j = 0; j < i; j++)
526 putchar(' ');
527 printf("%c [%s] ",
528 is_head ? '*' : '!', ref_name[i]);
529 }
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530 /* header lines never need name */
531 show_one_commit(rev[i], 1);
f76412ed 532 }
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533 if (0 <= extra) {
534 for (i = 0; i < num_rev; i++)
535 putchar('-');
536 putchar('\n');
537 }
f5e375c9 538 }
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539 if (extra < 0)
540 exit(0);
f5e375c9 541
8e5dd22b 542 /* Sort topologically */
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543 if (topo_order)
544 sort_in_topological_order(&seen);
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545
546 /* Give names to commits */
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547 if (!sha1_name && !no_name)
548 name_commits(seen, rev, ref_name, num_rev);
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549
550 all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
551 all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
8e5dd22b 552
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553 while (seen) {
554 struct commit *commit = pop_one_commit(&seen);
555 int this_flag = commit->object.flags;
f5e375c9 556
6b209d47 557 shown_merge_point |= ((this_flag & all_revs) == all_revs);
8e5dd22b 558
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559 if (1 < num_rev) {
560 for (i = 0; i < num_rev; i++)
561 putchar((this_flag & (1u << (i + REV_SHIFT)))
562 ? '+' : ' ');
563 putchar(' ');
564 }
013f276e 565 show_one_commit(commit, no_name);
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566
567 if (shown_merge_point && --extra < 0)
568 break;
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569 }
570 return 0;
571}