Merge branch 'jn/paginate-fix'
[git/git.git] / builtin / revert.c
CommitLineData
9509af68
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1#include "cache.h"
2#include "builtin.h"
3#include "object.h"
4#include "commit.h"
5#include "tag.h"
6#include "wt-status.h"
7#include "run-command.h"
8#include "exec_cmd.h"
9#include "utf8.h"
f8103794 10#include "parse-options.h"
45525bd0 11#include "cache-tree.h"
0f2d4476
JK
12#include "diff.h"
13#include "revision.h"
aa1a0111 14#include "rerere.h"
6eb1b437 15#include "merge-recursive.h"
c62f6ec3 16#include "refs.h"
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17
18/*
19 * This implements the builtins revert and cherry-pick.
20 *
21 * Copyright (c) 2007 Johannes E. Schindelin
22 *
23 * Based on git-revert.sh, which is
24 *
25 * Copyright (c) 2005 Linus Torvalds
26 * Copyright (c) 2005 Junio C Hamano
27 */
28
f8103794 29static const char * const revert_usage[] = {
1b1dd23f 30 "git revert [options] <commit-ish>",
f8103794
PH
31 NULL
32};
9509af68 33
f8103794 34static const char * const cherry_pick_usage[] = {
1b1dd23f 35 "git cherry-pick [options] <commit-ish>",
f8103794
PH
36 NULL
37};
9509af68 38
c62f6ec3 39static int edit, no_replay, no_commit, mainline, signoff, allow_ff;
4175e9e3 40static enum { REVERT, CHERRY_PICK } action;
9509af68 41static struct commit *commit;
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CC
42static int commit_argc;
43static const char **commit_argv;
cb6020bb 44static int allow_rerere_auto;
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45
46static const char *me;
91e52598 47static const char *strategy;
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48
49#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
50
d6856540
JN
51static char *get_encoding(const char *message);
52
e0ef8495
JN
53static const char * const *revert_or_cherry_pick_usage(void)
54{
55 return action == REVERT ? revert_usage : cherry_pick_usage;
56}
57
f8103794 58static void parse_args(int argc, const char **argv)
9509af68 59{
e0ef8495 60 const char * const * usage_str = revert_or_cherry_pick_usage();
f8103794
PH
61 int noop;
62 struct option options[] = {
63 OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
64 OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
f8103794 65 OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
cfd9c277 66 OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
02273fdb 67 OPT_INTEGER('m', "mainline", &mainline, "parent number"),
cb6020bb 68 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
91e52598 69 OPT_STRING(0, "strategy", &strategy, "strategy", "merge strategy"),
f8103794 70 OPT_END(),
c62f6ec3
JH
71 OPT_END(),
72 OPT_END(),
f8103794
PH
73 };
74
c62f6ec3
JH
75 if (action == CHERRY_PICK) {
76 struct option cp_extra[] = {
831244bd 77 OPT_BOOLEAN('x', NULL, &no_replay, "append commit name"),
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JH
78 OPT_BOOLEAN(0, "ff", &allow_ff, "allow fast-forward"),
79 OPT_END(),
80 };
81 if (parse_options_concat(options, ARRAY_SIZE(options), cp_extra))
82 die("program error");
83 }
84
f873a273 85 commit_argc = parse_options(argc, argv, NULL, options, usage_str,
e0ef8495 86 PARSE_OPT_KEEP_ARGV0 |
f873a273 87 PARSE_OPT_KEEP_UNKNOWN);
e0ef8495 88 if (commit_argc < 2)
f8103794 89 usage_with_options(usage_str, options);
9509af68 90
7e2bfd3f 91 commit_argv = argv;
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92}
93
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94struct commit_message {
95 char *parent_label;
96 const char *label;
97 const char *subject;
98 char *reencoded_message;
99 const char *message;
100};
101
102static int get_message(const char *raw_message, struct commit_message *out)
9509af68 103{
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JN
104 const char *encoding;
105 const char *p, *abbrev, *eol;
106 char *q;
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107 int abbrev_len, oneline_len;
108
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109 if (!raw_message)
110 return -1;
111 encoding = get_encoding(raw_message);
112 if (!encoding)
113 encoding = "UTF-8";
114 if (!git_commit_encoding)
115 git_commit_encoding = "UTF-8";
43acff34
JN
116
117 out->reencoded_message = NULL;
118 out->message = raw_message;
119 if (strcmp(encoding, git_commit_encoding))
120 out->reencoded_message = reencode_string(raw_message,
121 git_commit_encoding, encoding);
122 if (out->reencoded_message)
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123 out->message = out->reencoded_message;
124
125 abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
126 abbrev_len = strlen(abbrev);
127
128 /* Find beginning and end of commit subject. */
129 p = out->message;
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130 while (*p && (*p != '\n' || p[1] != '\n'))
131 p++;
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132 if (*p) {
133 p += 2;
134 for (eol = p + 1; *eol && *eol != '\n'; eol++)
135 ; /* do nothing */
136 } else
137 eol = p;
9509af68 138 oneline_len = eol - p;
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139
140 out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
141 strlen("... ") + oneline_len + 1);
142 q = out->parent_label;
143 q = mempcpy(q, "parent of ", strlen("parent of "));
144 out->label = q;
145 q = mempcpy(q, abbrev, abbrev_len);
146 q = mempcpy(q, "... ", strlen("... "));
147 out->subject = q;
148 q = mempcpy(q, p, oneline_len);
149 *q = '\0';
150 return 0;
151}
152
153static void free_message(struct commit_message *msg)
154{
155 free(msg->parent_label);
156 free(msg->reencoded_message);
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157}
158
52fae7de 159static char *get_encoding(const char *message)
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160{
161 const char *p = message, *eol;
162
163 if (!p)
164 die ("Could not read commit message of %s",
165 sha1_to_hex(commit->object.sha1));
166 while (*p && *p != '\n') {
167 for (eol = p + 1; *eol && *eol != '\n'; eol++)
168 ; /* do nothing */
169 if (!prefixcmp(p, "encoding ")) {
170 char *result = xmalloc(eol - 8 - p);
171 strlcpy(result, p + 9, eol - 8 - p);
172 return result;
173 }
174 p = eol;
175 if (*p == '\n')
176 p++;
177 }
178 return NULL;
179}
180
bc84a7fb 181static void add_message_to_msg(struct strbuf *msgbuf, const char *message)
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182{
183 const char *p = message;
184 while (*p && (*p != '\n' || p[1] != '\n'))
185 p++;
186
187 if (!*p)
bc84a7fb 188 strbuf_addstr(msgbuf, sha1_to_hex(commit->object.sha1));
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189
190 p += 2;
bc84a7fb 191 strbuf_addstr(msgbuf, p);
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192}
193
194static void set_author_ident_env(const char *message)
195{
196 const char *p = message;
197 if (!p)
198 die ("Could not read commit message of %s",
199 sha1_to_hex(commit->object.sha1));
200 while (*p && *p != '\n') {
201 const char *eol;
202
203 for (eol = p; *eol && *eol != '\n'; eol++)
204 ; /* do nothing */
205 if (!prefixcmp(p, "author ")) {
206 char *line, *pend, *email, *timestamp;
207
208 p += 7;
182af834 209 line = xmemdupz(p, eol - p);
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210 email = strchr(line, '<');
211 if (!email)
212 die ("Could not extract author email from %s",
213 sha1_to_hex(commit->object.sha1));
214 if (email == line)
215 pend = line;
216 else
217 for (pend = email; pend != line + 1 &&
218 isspace(pend[-1]); pend--);
219 ; /* do nothing */
220 *pend = '\0';
221 email++;
222 timestamp = strchr(email, '>');
223 if (!timestamp)
1e5f7add 224 die ("Could not extract author time from %s",
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225 sha1_to_hex(commit->object.sha1));
226 *timestamp = '\0';
227 for (timestamp++; *timestamp && isspace(*timestamp);
228 timestamp++)
229 ; /* do nothing */
230 setenv("GIT_AUTHOR_NAME", line, 1);
231 setenv("GIT_AUTHOR_EMAIL", email, 1);
232 setenv("GIT_AUTHOR_DATE", timestamp, 1);
233 free(line);
234 return;
235 }
236 p = eol;
237 if (*p == '\n')
238 p++;
239 }
240 die ("No author information found in %s",
241 sha1_to_hex(commit->object.sha1));
242}
243
4b209562 244static char *help_msg(void)
804c7174 245{
08565bdb 246 struct strbuf helpbuf = STRBUF_INIT;
804c7174
WC
247 char *msg = getenv("GIT_CHERRY_PICK_HELP");
248
249 if (msg)
250 return msg;
251
08565bdb 252 strbuf_addstr(&helpbuf, " After resolving the conflicts,\n"
6e359978 253 "mark the corrected paths with 'git add <paths>' or 'git rm <paths>'\n"
4d128884 254 "and commit the result");
804c7174
WC
255
256 if (action == CHERRY_PICK) {
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257 strbuf_addf(&helpbuf, " with: \n"
258 "\n"
259 " git commit -c %s\n",
4b209562 260 sha1_to_hex(commit->object.sha1));
804c7174 261 }
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262 else
263 strbuf_addch(&helpbuf, '.');
08565bdb 264 return strbuf_detach(&helpbuf, NULL);
804c7174
WC
265}
266
bc84a7fb
CC
267static void write_message(struct strbuf *msgbuf, const char *filename)
268{
269 static struct lock_file msg_file;
270
271 int msg_fd = hold_lock_file_for_update(&msg_file, filename,
272 LOCK_DIE_ON_ERROR);
273 if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
274 die_errno("Could not write to %s.", filename);
275 strbuf_release(msgbuf);
276 if (commit_lock_file(&msg_file) < 0)
277 die("Error wrapping up %s", filename);
278}
279
6eb1b437
MV
280static struct tree *empty_tree(void)
281{
282 struct tree *tree = xcalloc(1, sizeof(struct tree));
283
284 tree->object.parsed = 1;
285 tree->object.type = OBJ_TREE;
286 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
287 return tree;
288}
289
d38a30df
MM
290static NORETURN void die_dirty_index(const char *me)
291{
292 if (read_cache_unmerged()) {
293 die_resolve_conflict(me);
294 } else {
295 if (advice_commit_before_merge)
296 die("Your local changes would be overwritten by %s.\n"
297 "Please, commit your changes or stash them to proceed.", me);
298 else
299 die("Your local changes would be overwritten by %s.\n", me);
300 }
301}
302
c62f6ec3
JH
303static int fast_forward_to(const unsigned char *to, const unsigned char *from)
304{
305 struct ref_lock *ref_lock;
306
307 read_cache();
308 if (checkout_fast_forward(from, to))
309 exit(1); /* the callee should have complained already */
310 ref_lock = lock_any_ref_for_update("HEAD", from, 0);
311 return write_ref_sha1(ref_lock, to, "cherry-pick");
312}
313
ae8c79fd
CC
314static void do_recursive_merge(struct commit *base, struct commit *next,
315 const char *base_label, const char *next_label,
316 unsigned char *head, struct strbuf *msgbuf,
317 char *defmsg)
318{
319 struct merge_options o;
320 struct tree *result, *next_tree, *base_tree, *head_tree;
321 int clean, index_fd;
322 static struct lock_file index_lock;
323
324 index_fd = hold_locked_index(&index_lock, 1);
325
326 read_cache();
327 init_merge_options(&o);
328 o.ancestor = base ? base_label : "(empty tree)";
329 o.branch1 = "HEAD";
330 o.branch2 = next ? next_label : "(empty tree)";
331
332 head_tree = parse_tree_indirect(head);
333 next_tree = next ? next->tree : empty_tree();
334 base_tree = base ? base->tree : empty_tree();
335
336 clean = merge_trees(&o,
337 head_tree,
338 next_tree, base_tree, &result);
339
340 if (active_cache_changed &&
341 (write_cache(index_fd, active_cache, active_nr) ||
342 commit_locked_index(&index_lock)))
343 die("%s: Unable to write new index file", me);
344 rollback_lock_file(&index_lock);
345
346 if (!clean) {
347 int i;
348 strbuf_addstr(msgbuf, "\nConflicts:\n\n");
349 for (i = 0; i < active_nr;) {
350 struct cache_entry *ce = active_cache[i++];
351 if (ce_stage(ce)) {
352 strbuf_addch(msgbuf, '\t');
353 strbuf_addstr(msgbuf, ce->name);
354 strbuf_addch(msgbuf, '\n');
355 while (i < active_nr && !strcmp(ce->name,
356 active_cache[i]->name))
357 i++;
358 }
359 }
360 write_message(msgbuf, defmsg);
361 fprintf(stderr, "Automatic %s failed.%s\n",
4b209562 362 me, help_msg());
ae8c79fd
CC
363 rerere(allow_rerere_auto);
364 exit(1);
365 }
366 write_message(msgbuf, defmsg);
367 fprintf(stderr, "Finished one %s.\n", me);
368}
369
7af46595 370static int do_pick_commit(void)
9509af68
JS
371{
372 unsigned char head[20];
7791ecbc 373 struct commit *base, *next, *parent;
bf975d37 374 const char *base_label, *next_label;
d6856540 375 struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
28db756f 376 char *defmsg = NULL;
bc84a7fb 377 struct strbuf msgbuf = STRBUF_INIT;
9509af68 378
9509af68
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379 if (no_commit) {
380 /*
381 * We do not intend to commit immediately. We just want to
71aa2b8f
JH
382 * merge the differences in, so let's compute the tree
383 * that represents the "current" state for merge-recursive
384 * to work on.
9509af68 385 */
45525bd0 386 if (write_cache_as_tree(head, 0, NULL))
9509af68
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387 die ("Your index file is unmerged.");
388 } else {
9509af68
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389 if (get_sha1("HEAD", head))
390 die ("You do not have a valid HEAD");
75f3ff2e 391 if (index_differs_from("HEAD", 0))
d38a30df 392 die_dirty_index(me);
9509af68 393 }
6eb1b437
MV
394 discard_cache();
395
f95ebf74
JS
396 if (!commit->parents) {
397 if (action == REVERT)
398 die ("Cannot revert a root commit");
399 parent = NULL;
400 }
401 else if (commit->parents->next) {
7791ecbc
JH
402 /* Reverting or cherry-picking a merge commit */
403 int cnt;
404 struct commit_list *p;
405
406 if (!mainline)
407 die("Commit %s is a merge but no -m option was given.",
408 sha1_to_hex(commit->object.sha1));
409
410 for (cnt = 1, p = commit->parents;
411 cnt != mainline && p;
412 cnt++)
413 p = p->next;
414 if (cnt != mainline || !p)
415 die("Commit %s does not have parent %d",
416 sha1_to_hex(commit->object.sha1), mainline);
417 parent = p->item;
418 } else if (0 < mainline)
419 die("Mainline was specified but commit %s is not a merge.",
420 sha1_to_hex(commit->object.sha1));
421 else
422 parent = commit->parents->item;
423
c62f6ec3
JH
424 if (allow_ff && !hashcmp(parent->object.sha1, head))
425 return fast_forward_to(commit->object.sha1, head);
426
6eb1b437
MV
427 if (parent && parse_commit(parent) < 0)
428 die("%s: cannot parse parent commit %s",
429 me, sha1_to_hex(parent->object.sha1));
430
d6856540
JN
431 if (get_message(commit->buffer, &msg) != 0)
432 die("Cannot get commit message for %s",
433 sha1_to_hex(commit->object.sha1));
434
9509af68
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435 /*
436 * "commit" is an existing commit. We would want to apply
437 * the difference it introduces since its first parent "prev"
438 * on top of the current HEAD if we are cherry-pick. Or the
439 * reverse of it if we are revert.
440 */
441
28db756f 442 defmsg = git_pathdup("MERGE_MSG");
c62f6ec3 443
9509af68
JS
444 if (action == REVERT) {
445 base = commit;
bf975d37 446 base_label = msg.label;
7791ecbc 447 next = parent;
d6856540 448 next_label = msg.parent_label;
bc84a7fb
CC
449 strbuf_addstr(&msgbuf, "Revert \"");
450 strbuf_addstr(&msgbuf, msg.subject);
451 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
452 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
d5be89d8
RR
453
454 if (commit->parents->next) {
bc84a7fb
CC
455 strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
456 strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
d5be89d8 457 }
bc84a7fb 458 strbuf_addstr(&msgbuf, ".\n");
9509af68 459 } else {
7791ecbc 460 base = parent;
bf975d37 461 base_label = msg.parent_label;
9509af68 462 next = commit;
d6856540
JN
463 next_label = msg.label;
464 set_author_ident_env(msg.message);
bc84a7fb 465 add_message_to_msg(&msgbuf, msg.message);
f8103794 466 if (no_replay) {
bc84a7fb
CC
467 strbuf_addstr(&msgbuf, "(cherry picked from commit ");
468 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
469 strbuf_addstr(&msgbuf, ")\n");
9509af68
JS
470 }
471 }
9509af68 472
91e52598
CC
473 if (!strategy || !strcmp(strategy, "recursive") || action == REVERT)
474 do_recursive_merge(base, next, base_label, next_label,
475 head, &msgbuf, defmsg);
476 else {
477 int res;
478 struct commit_list *common = NULL;
479 struct commit_list *remotes = NULL;
480 write_message(&msgbuf, defmsg);
481 commit_list_insert(base, &common);
482 commit_list_insert(next, &remotes);
483 res = try_merge_command(strategy, common,
484 sha1_to_hex(head), remotes);
485 free_commit_list(common);
486 free_commit_list(remotes);
487 if (res) {
488 fprintf(stderr, "Automatic %s with strategy %s failed.%s\n",
4b209562 489 me, strategy, help_msg());
91e52598
CC
490 rerere(allow_rerere_auto);
491 exit(1);
9509af68 492 }
9509af68 493 }
9509af68 494
2fb0e14f
CC
495 free_message(&msg);
496
9509af68
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497 /*
498 *
499 * If we are cherry-pick, and if the merge did not result in
500 * hand-editing, we will hit this commit and inherit the original
501 * author date and name.
502 * If we are revert, or if our cherry-pick results in a hand merge,
503 * we had better say that the current user is responsible for that.
504 */
505
506 if (!no_commit) {
cfd9c277
DM
507 /* 6 is max possible length of our args array including NULL */
508 const char *args[6];
2fb0e14f 509 int res;
cfd9c277 510 int i = 0;
2fb0e14f 511
cfd9c277
DM
512 args[i++] = "commit";
513 args[i++] = "-n";
514 if (signoff)
515 args[i++] = "-s";
516 if (!edit) {
517 args[i++] = "-F";
518 args[i++] = defmsg;
519 }
520 args[i] = NULL;
2fb0e14f
CC
521 res = run_command_v_opt(args, RUN_GIT_CMD);
522 free(defmsg);
523
524 return res;
9509af68 525 }
2fb0e14f 526
d258b258 527 free(defmsg);
9509af68
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528
529 return 0;
530}
531
7e2bfd3f
CC
532static void prepare_revs(struct rev_info *revs)
533{
e0ef8495 534 int argc;
7e2bfd3f 535
e0ef8495
JN
536 init_revisions(revs, NULL);
537 revs->no_walk = 1;
7e2bfd3f 538 if (action != REVERT)
e0ef8495
JN
539 revs->reverse = 1;
540
541 argc = setup_revisions(commit_argc, commit_argv, revs, NULL);
542 if (argc > 1)
543 usage(*revert_or_cherry_pick_usage());
7e2bfd3f 544
7e2bfd3f
CC
545 if (prepare_revision_walk(revs))
546 die("revision walk setup failed");
547
548 if (!revs->commits)
549 die("empty commit set passed");
7e2bfd3f
CC
550}
551
7af46595
CC
552static int revert_or_cherry_pick(int argc, const char **argv)
553{
7e2bfd3f
CC
554 struct rev_info revs;
555
7af46595
CC
556 git_config(git_default_config, NULL);
557 me = action == REVERT ? "revert" : "cherry-pick";
558 setenv(GIT_REFLOG_ACTION, me, 0);
559 parse_args(argc, argv);
560
561 if (allow_ff) {
562 if (signoff)
563 die("cherry-pick --ff cannot be used with --signoff");
564 if (no_commit)
565 die("cherry-pick --ff cannot be used with --no-commit");
566 if (no_replay)
567 die("cherry-pick --ff cannot be used with -x");
568 if (edit)
569 die("cherry-pick --ff cannot be used with --edit");
570 }
571
572 if (read_cache() < 0)
573 die("git %s: failed to read the index", me);
574
7e2bfd3f
CC
575 prepare_revs(&revs);
576
577 while ((commit = get_revision(&revs))) {
578 int res = do_pick_commit();
579 if (res)
580 return res;
581 }
582
583 return 0;
7af46595
CC
584}
585
9509af68
JS
586int cmd_revert(int argc, const char **argv, const char *prefix)
587{
588 if (isatty(0))
589 edit = 1;
590 action = REVERT;
591 return revert_or_cherry_pick(argc, argv);
592}
593
594int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
595{
9509af68
JS
596 action = CHERRY_PICK;
597 return revert_or_cherry_pick(argc, argv);
598}