git-cherry-pick: add allow-empty option
[git/git.git] / sequencer.c
1 #include "cache.h"
2 #include "sequencer.h"
3 #include "dir.h"
4 #include "object.h"
5 #include "commit.h"
6 #include "tag.h"
7 #include "run-command.h"
8 #include "exec_cmd.h"
9 #include "utf8.h"
10 #include "cache-tree.h"
11 #include "diff.h"
12 #include "revision.h"
13 #include "rerere.h"
14 #include "merge-recursive.h"
15 #include "refs.h"
16
17 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
18
19 void remove_sequencer_state(void)
20 {
21 struct strbuf seq_dir = STRBUF_INIT;
22
23 strbuf_addf(&seq_dir, "%s", git_path(SEQ_DIR));
24 remove_dir_recursively(&seq_dir, 0);
25 strbuf_release(&seq_dir);
26 }
27
28 static const char *action_name(const struct replay_opts *opts)
29 {
30 return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
31 }
32
33 static char *get_encoding(const char *message);
34
35 struct commit_message {
36 char *parent_label;
37 const char *label;
38 const char *subject;
39 char *reencoded_message;
40 const char *message;
41 };
42
43 static int get_message(struct commit *commit, struct commit_message *out)
44 {
45 const char *encoding;
46 const char *abbrev, *subject;
47 int abbrev_len, subject_len;
48 char *q;
49
50 if (!commit->buffer)
51 return -1;
52 encoding = get_encoding(commit->buffer);
53 if (!encoding)
54 encoding = "UTF-8";
55 if (!git_commit_encoding)
56 git_commit_encoding = "UTF-8";
57
58 out->reencoded_message = NULL;
59 out->message = commit->buffer;
60 if (strcmp(encoding, git_commit_encoding))
61 out->reencoded_message = reencode_string(commit->buffer,
62 git_commit_encoding, encoding);
63 if (out->reencoded_message)
64 out->message = out->reencoded_message;
65
66 abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
67 abbrev_len = strlen(abbrev);
68
69 subject_len = find_commit_subject(out->message, &subject);
70
71 out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
72 strlen("... ") + subject_len + 1);
73 q = out->parent_label;
74 q = mempcpy(q, "parent of ", strlen("parent of "));
75 out->label = q;
76 q = mempcpy(q, abbrev, abbrev_len);
77 q = mempcpy(q, "... ", strlen("... "));
78 out->subject = q;
79 q = mempcpy(q, subject, subject_len);
80 *q = '\0';
81 return 0;
82 }
83
84 static void free_message(struct commit_message *msg)
85 {
86 free(msg->parent_label);
87 free(msg->reencoded_message);
88 }
89
90 static char *get_encoding(const char *message)
91 {
92 const char *p = message, *eol;
93
94 while (*p && *p != '\n') {
95 for (eol = p + 1; *eol && *eol != '\n'; eol++)
96 ; /* do nothing */
97 if (!prefixcmp(p, "encoding ")) {
98 char *result = xmalloc(eol - 8 - p);
99 strlcpy(result, p + 9, eol - 8 - p);
100 return result;
101 }
102 p = eol;
103 if (*p == '\n')
104 p++;
105 }
106 return NULL;
107 }
108
109 static void write_cherry_pick_head(struct commit *commit, const char *pseudoref)
110 {
111 const char *filename;
112 int fd;
113 struct strbuf buf = STRBUF_INIT;
114
115 strbuf_addf(&buf, "%s\n", sha1_to_hex(commit->object.sha1));
116
117 filename = git_path("%s", pseudoref);
118 fd = open(filename, O_WRONLY | O_CREAT, 0666);
119 if (fd < 0)
120 die_errno(_("Could not open '%s' for writing"), filename);
121 if (write_in_full(fd, buf.buf, buf.len) != buf.len || close(fd))
122 die_errno(_("Could not write to '%s'"), filename);
123 strbuf_release(&buf);
124 }
125
126 static void print_advice(int show_hint, struct replay_opts *opts)
127 {
128 char *msg = getenv("GIT_CHERRY_PICK_HELP");
129
130 if (msg) {
131 fprintf(stderr, "%s\n", msg);
132 /*
133 * A conflict has occured but the porcelain
134 * (typically rebase --interactive) wants to take care
135 * of the commit itself so remove CHERRY_PICK_HEAD
136 */
137 unlink(git_path("CHERRY_PICK_HEAD"));
138 return;
139 }
140
141 if (show_hint) {
142 if (opts->no_commit)
143 advise(_("after resolving the conflicts, mark the corrected paths\n"
144 "with 'git add <paths>' or 'git rm <paths>'"));
145 else
146 advise(_("after resolving the conflicts, mark the corrected paths\n"
147 "with 'git add <paths>' or 'git rm <paths>'\n"
148 "and commit the result with 'git commit'"));
149 }
150 }
151
152 static void write_message(struct strbuf *msgbuf, const char *filename)
153 {
154 static struct lock_file msg_file;
155
156 int msg_fd = hold_lock_file_for_update(&msg_file, filename,
157 LOCK_DIE_ON_ERROR);
158 if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
159 die_errno(_("Could not write to %s"), filename);
160 strbuf_release(msgbuf);
161 if (commit_lock_file(&msg_file) < 0)
162 die(_("Error wrapping up %s"), filename);
163 }
164
165 static struct tree *empty_tree(void)
166 {
167 return lookup_tree((const unsigned char *)EMPTY_TREE_SHA1_BIN);
168 }
169
170 static int error_dirty_index(struct replay_opts *opts)
171 {
172 if (read_cache_unmerged())
173 return error_resolve_conflict(action_name(opts));
174
175 /* Different translation strings for cherry-pick and revert */
176 if (opts->action == REPLAY_PICK)
177 error(_("Your local changes would be overwritten by cherry-pick."));
178 else
179 error(_("Your local changes would be overwritten by revert."));
180
181 if (advice_commit_before_merge)
182 advise(_("Commit your changes or stash them to proceed."));
183 return -1;
184 }
185
186 static int fast_forward_to(const unsigned char *to, const unsigned char *from)
187 {
188 struct ref_lock *ref_lock;
189
190 read_cache();
191 if (checkout_fast_forward(from, to))
192 exit(1); /* the callee should have complained already */
193 ref_lock = lock_any_ref_for_update("HEAD", from, 0);
194 return write_ref_sha1(ref_lock, to, "cherry-pick");
195 }
196
197 static int do_recursive_merge(struct commit *base, struct commit *next,
198 const char *base_label, const char *next_label,
199 unsigned char *head, struct strbuf *msgbuf,
200 struct replay_opts *opts)
201 {
202 struct merge_options o;
203 struct tree *result, *next_tree, *base_tree, *head_tree;
204 int clean, index_fd;
205 const char **xopt;
206 static struct lock_file index_lock;
207
208 index_fd = hold_locked_index(&index_lock, 1);
209
210 read_cache();
211
212 init_merge_options(&o);
213 o.ancestor = base ? base_label : "(empty tree)";
214 o.branch1 = "HEAD";
215 o.branch2 = next ? next_label : "(empty tree)";
216
217 head_tree = parse_tree_indirect(head);
218 next_tree = next ? next->tree : empty_tree();
219 base_tree = base ? base->tree : empty_tree();
220
221 for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
222 parse_merge_opt(&o, *xopt);
223
224 clean = merge_trees(&o,
225 head_tree,
226 next_tree, base_tree, &result);
227
228 if (active_cache_changed &&
229 (write_cache(index_fd, active_cache, active_nr) ||
230 commit_locked_index(&index_lock)))
231 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
232 die(_("%s: Unable to write new index file"), action_name(opts));
233 rollback_lock_file(&index_lock);
234
235 if (!clean) {
236 int i;
237 strbuf_addstr(msgbuf, "\nConflicts:\n\n");
238 for (i = 0; i < active_nr;) {
239 struct cache_entry *ce = active_cache[i++];
240 if (ce_stage(ce)) {
241 strbuf_addch(msgbuf, '\t');
242 strbuf_addstr(msgbuf, ce->name);
243 strbuf_addch(msgbuf, '\n');
244 while (i < active_nr && !strcmp(ce->name,
245 active_cache[i]->name))
246 i++;
247 }
248 }
249 }
250
251 return !clean;
252 }
253
254 /*
255 * If we are cherry-pick, and if the merge did not result in
256 * hand-editing, we will hit this commit and inherit the original
257 * author date and name.
258 * If we are revert, or if our cherry-pick results in a hand merge,
259 * we had better say that the current user is responsible for that.
260 */
261 static int run_git_commit(const char *defmsg, struct replay_opts *opts)
262 {
263 /* 7 is max possible length of our args array including NULL */
264 const char *args[7];
265 int i = 0;
266
267 args[i++] = "commit";
268 args[i++] = "-n";
269 if (opts->signoff)
270 args[i++] = "-s";
271 if (!opts->edit) {
272 args[i++] = "-F";
273 args[i++] = defmsg;
274 }
275 if (opts->allow_empty)
276 args[i++] = "--allow-empty";
277
278 args[i] = NULL;
279
280 return run_command_v_opt(args, RUN_GIT_CMD);
281 }
282
283 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
284 {
285 unsigned char head[20];
286 struct commit *base, *next, *parent;
287 const char *base_label, *next_label;
288 struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
289 char *defmsg = NULL;
290 struct strbuf msgbuf = STRBUF_INIT;
291 int res;
292
293 if (opts->no_commit) {
294 /*
295 * We do not intend to commit immediately. We just want to
296 * merge the differences in, so let's compute the tree
297 * that represents the "current" state for merge-recursive
298 * to work on.
299 */
300 if (write_cache_as_tree(head, 0, NULL))
301 die (_("Your index file is unmerged."));
302 } else {
303 if (get_sha1("HEAD", head))
304 return error(_("You do not have a valid HEAD"));
305 if (index_differs_from("HEAD", 0))
306 return error_dirty_index(opts);
307 }
308 discard_cache();
309
310 if (!commit->parents) {
311 parent = NULL;
312 }
313 else if (commit->parents->next) {
314 /* Reverting or cherry-picking a merge commit */
315 int cnt;
316 struct commit_list *p;
317
318 if (!opts->mainline)
319 return error(_("Commit %s is a merge but no -m option was given."),
320 sha1_to_hex(commit->object.sha1));
321
322 for (cnt = 1, p = commit->parents;
323 cnt != opts->mainline && p;
324 cnt++)
325 p = p->next;
326 if (cnt != opts->mainline || !p)
327 return error(_("Commit %s does not have parent %d"),
328 sha1_to_hex(commit->object.sha1), opts->mainline);
329 parent = p->item;
330 } else if (0 < opts->mainline)
331 return error(_("Mainline was specified but commit %s is not a merge."),
332 sha1_to_hex(commit->object.sha1));
333 else
334 parent = commit->parents->item;
335
336 if (opts->allow_ff && parent && !hashcmp(parent->object.sha1, head))
337 return fast_forward_to(commit->object.sha1, head);
338
339 if (parent && parse_commit(parent) < 0)
340 /* TRANSLATORS: The first %s will be "revert" or
341 "cherry-pick", the second %s a SHA1 */
342 return error(_("%s: cannot parse parent commit %s"),
343 action_name(opts), sha1_to_hex(parent->object.sha1));
344
345 if (get_message(commit, &msg) != 0)
346 return error(_("Cannot get commit message for %s"),
347 sha1_to_hex(commit->object.sha1));
348
349 /*
350 * "commit" is an existing commit. We would want to apply
351 * the difference it introduces since its first parent "prev"
352 * on top of the current HEAD if we are cherry-pick. Or the
353 * reverse of it if we are revert.
354 */
355
356 defmsg = git_pathdup("MERGE_MSG");
357
358 if (opts->action == REPLAY_REVERT) {
359 base = commit;
360 base_label = msg.label;
361 next = parent;
362 next_label = msg.parent_label;
363 strbuf_addstr(&msgbuf, "Revert \"");
364 strbuf_addstr(&msgbuf, msg.subject);
365 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
366 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
367
368 if (commit->parents && commit->parents->next) {
369 strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
370 strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
371 }
372 strbuf_addstr(&msgbuf, ".\n");
373 } else {
374 const char *p;
375
376 base = parent;
377 base_label = msg.parent_label;
378 next = commit;
379 next_label = msg.label;
380
381 /*
382 * Append the commit log message to msgbuf; it starts
383 * after the tree, parent, author, committer
384 * information followed by "\n\n".
385 */
386 p = strstr(msg.message, "\n\n");
387 if (p) {
388 p += 2;
389 strbuf_addstr(&msgbuf, p);
390 }
391
392 if (opts->record_origin) {
393 strbuf_addstr(&msgbuf, "(cherry picked from commit ");
394 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
395 strbuf_addstr(&msgbuf, ")\n");
396 }
397 }
398
399 if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
400 res = do_recursive_merge(base, next, base_label, next_label,
401 head, &msgbuf, opts);
402 write_message(&msgbuf, defmsg);
403 } else {
404 struct commit_list *common = NULL;
405 struct commit_list *remotes = NULL;
406
407 write_message(&msgbuf, defmsg);
408
409 commit_list_insert(base, &common);
410 commit_list_insert(next, &remotes);
411 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
412 common, sha1_to_hex(head), remotes);
413 free_commit_list(common);
414 free_commit_list(remotes);
415 }
416
417 /*
418 * If the merge was clean or if it failed due to conflict, we write
419 * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
420 * However, if the merge did not even start, then we don't want to
421 * write it at all.
422 */
423 if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
424 write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
425 if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
426 write_cherry_pick_head(commit, "REVERT_HEAD");
427
428 if (res) {
429 error(opts->action == REPLAY_REVERT
430 ? _("could not revert %s... %s")
431 : _("could not apply %s... %s"),
432 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
433 msg.subject);
434 print_advice(res == 1, opts);
435 rerere(opts->allow_rerere_auto);
436 } else {
437 if (!opts->no_commit)
438 res = run_git_commit(defmsg, opts);
439 }
440
441 free_message(&msg);
442 free(defmsg);
443
444 return res;
445 }
446
447 static void prepare_revs(struct replay_opts *opts)
448 {
449 if (opts->action != REPLAY_REVERT)
450 opts->revs->reverse ^= 1;
451
452 if (prepare_revision_walk(opts->revs))
453 die(_("revision walk setup failed"));
454
455 if (!opts->revs->commits)
456 die(_("empty commit set passed"));
457 }
458
459 static void read_and_refresh_cache(struct replay_opts *opts)
460 {
461 static struct lock_file index_lock;
462 int index_fd = hold_locked_index(&index_lock, 0);
463 if (read_index_preload(&the_index, NULL) < 0)
464 die(_("git %s: failed to read the index"), action_name(opts));
465 refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
466 if (the_index.cache_changed) {
467 if (write_index(&the_index, index_fd) ||
468 commit_locked_index(&index_lock))
469 die(_("git %s: failed to refresh the index"), action_name(opts));
470 }
471 rollback_lock_file(&index_lock);
472 }
473
474 /*
475 * Append a commit to the end of the commit_list.
476 *
477 * next starts by pointing to the variable that holds the head of an
478 * empty commit_list, and is updated to point to the "next" field of
479 * the last item on the list as new commits are appended.
480 *
481 * Usage example:
482 *
483 * struct commit_list *list;
484 * struct commit_list **next = &list;
485 *
486 * next = commit_list_append(c1, next);
487 * next = commit_list_append(c2, next);
488 * assert(commit_list_count(list) == 2);
489 * return list;
490 */
491 static struct commit_list **commit_list_append(struct commit *commit,
492 struct commit_list **next)
493 {
494 struct commit_list *new = xmalloc(sizeof(struct commit_list));
495 new->item = commit;
496 *next = new;
497 new->next = NULL;
498 return &new->next;
499 }
500
501 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
502 struct replay_opts *opts)
503 {
504 struct commit_list *cur = NULL;
505 const char *sha1_abbrev = NULL;
506 const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
507 const char *subject;
508 int subject_len;
509
510 for (cur = todo_list; cur; cur = cur->next) {
511 sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
512 subject_len = find_commit_subject(cur->item->buffer, &subject);
513 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
514 subject_len, subject);
515 }
516 return 0;
517 }
518
519 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
520 {
521 unsigned char commit_sha1[20];
522 enum replay_action action;
523 char *end_of_object_name;
524 int saved, status, padding;
525
526 if (!prefixcmp(bol, "pick")) {
527 action = REPLAY_PICK;
528 bol += strlen("pick");
529 } else if (!prefixcmp(bol, "revert")) {
530 action = REPLAY_REVERT;
531 bol += strlen("revert");
532 } else
533 return NULL;
534
535 /* Eat up extra spaces/ tabs before object name */
536 padding = strspn(bol, " \t");
537 if (!padding)
538 return NULL;
539 bol += padding;
540
541 end_of_object_name = bol + strcspn(bol, " \t\n");
542 saved = *end_of_object_name;
543 *end_of_object_name = '\0';
544 status = get_sha1(bol, commit_sha1);
545 *end_of_object_name = saved;
546
547 /*
548 * Verify that the action matches up with the one in
549 * opts; we don't support arbitrary instructions
550 */
551 if (action != opts->action) {
552 const char *action_str;
553 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
554 error(_("Cannot %s during a %s"), action_str, action_name(opts));
555 return NULL;
556 }
557
558 if (status < 0)
559 return NULL;
560
561 return lookup_commit_reference(commit_sha1);
562 }
563
564 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
565 struct replay_opts *opts)
566 {
567 struct commit_list **next = todo_list;
568 struct commit *commit;
569 char *p = buf;
570 int i;
571
572 for (i = 1; *p; i++) {
573 char *eol = strchrnul(p, '\n');
574 commit = parse_insn_line(p, eol, opts);
575 if (!commit)
576 return error(_("Could not parse line %d."), i);
577 next = commit_list_append(commit, next);
578 p = *eol ? eol + 1 : eol;
579 }
580 if (!*todo_list)
581 return error(_("No commits parsed."));
582 return 0;
583 }
584
585 static void read_populate_todo(struct commit_list **todo_list,
586 struct replay_opts *opts)
587 {
588 const char *todo_file = git_path(SEQ_TODO_FILE);
589 struct strbuf buf = STRBUF_INIT;
590 int fd, res;
591
592 fd = open(todo_file, O_RDONLY);
593 if (fd < 0)
594 die_errno(_("Could not open %s"), todo_file);
595 if (strbuf_read(&buf, fd, 0) < 0) {
596 close(fd);
597 strbuf_release(&buf);
598 die(_("Could not read %s."), todo_file);
599 }
600 close(fd);
601
602 res = parse_insn_buffer(buf.buf, todo_list, opts);
603 strbuf_release(&buf);
604 if (res)
605 die(_("Unusable instruction sheet: %s"), todo_file);
606 }
607
608 static int populate_opts_cb(const char *key, const char *value, void *data)
609 {
610 struct replay_opts *opts = data;
611 int error_flag = 1;
612
613 if (!value)
614 error_flag = 0;
615 else if (!strcmp(key, "options.no-commit"))
616 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
617 else if (!strcmp(key, "options.edit"))
618 opts->edit = git_config_bool_or_int(key, value, &error_flag);
619 else if (!strcmp(key, "options.signoff"))
620 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
621 else if (!strcmp(key, "options.record-origin"))
622 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
623 else if (!strcmp(key, "options.allow-ff"))
624 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
625 else if (!strcmp(key, "options.mainline"))
626 opts->mainline = git_config_int(key, value);
627 else if (!strcmp(key, "options.strategy"))
628 git_config_string(&opts->strategy, key, value);
629 else if (!strcmp(key, "options.strategy-option")) {
630 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
631 opts->xopts[opts->xopts_nr++] = xstrdup(value);
632 } else
633 return error(_("Invalid key: %s"), key);
634
635 if (!error_flag)
636 return error(_("Invalid value for %s: %s"), key, value);
637
638 return 0;
639 }
640
641 static void read_populate_opts(struct replay_opts **opts_ptr)
642 {
643 const char *opts_file = git_path(SEQ_OPTS_FILE);
644
645 if (!file_exists(opts_file))
646 return;
647 if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
648 die(_("Malformed options sheet: %s"), opts_file);
649 }
650
651 static void walk_revs_populate_todo(struct commit_list **todo_list,
652 struct replay_opts *opts)
653 {
654 struct commit *commit;
655 struct commit_list **next;
656
657 prepare_revs(opts);
658
659 next = todo_list;
660 while ((commit = get_revision(opts->revs)))
661 next = commit_list_append(commit, next);
662 }
663
664 static int create_seq_dir(void)
665 {
666 const char *seq_dir = git_path(SEQ_DIR);
667
668 if (file_exists(seq_dir)) {
669 error(_("a cherry-pick or revert is already in progress"));
670 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
671 return -1;
672 }
673 else if (mkdir(seq_dir, 0777) < 0)
674 die_errno(_("Could not create sequencer directory %s"), seq_dir);
675 return 0;
676 }
677
678 static void save_head(const char *head)
679 {
680 const char *head_file = git_path(SEQ_HEAD_FILE);
681 static struct lock_file head_lock;
682 struct strbuf buf = STRBUF_INIT;
683 int fd;
684
685 fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
686 strbuf_addf(&buf, "%s\n", head);
687 if (write_in_full(fd, buf.buf, buf.len) < 0)
688 die_errno(_("Could not write to %s"), head_file);
689 if (commit_lock_file(&head_lock) < 0)
690 die(_("Error wrapping up %s."), head_file);
691 }
692
693 static int reset_for_rollback(const unsigned char *sha1)
694 {
695 const char *argv[4]; /* reset --merge <arg> + NULL */
696 argv[0] = "reset";
697 argv[1] = "--merge";
698 argv[2] = sha1_to_hex(sha1);
699 argv[3] = NULL;
700 return run_command_v_opt(argv, RUN_GIT_CMD);
701 }
702
703 static int rollback_single_pick(void)
704 {
705 unsigned char head_sha1[20];
706
707 if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
708 !file_exists(git_path("REVERT_HEAD")))
709 return error(_("no cherry-pick or revert in progress"));
710 if (read_ref_full("HEAD", head_sha1, 0, NULL))
711 return error(_("cannot resolve HEAD"));
712 if (is_null_sha1(head_sha1))
713 return error(_("cannot abort from a branch yet to be born"));
714 return reset_for_rollback(head_sha1);
715 }
716
717 static int sequencer_rollback(struct replay_opts *opts)
718 {
719 const char *filename;
720 FILE *f;
721 unsigned char sha1[20];
722 struct strbuf buf = STRBUF_INIT;
723
724 filename = git_path(SEQ_HEAD_FILE);
725 f = fopen(filename, "r");
726 if (!f && errno == ENOENT) {
727 /*
728 * There is no multiple-cherry-pick in progress.
729 * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
730 * a single-cherry-pick in progress, abort that.
731 */
732 return rollback_single_pick();
733 }
734 if (!f)
735 return error(_("cannot open %s: %s"), filename,
736 strerror(errno));
737 if (strbuf_getline(&buf, f, '\n')) {
738 error(_("cannot read %s: %s"), filename, ferror(f) ?
739 strerror(errno) : _("unexpected end of file"));
740 fclose(f);
741 goto fail;
742 }
743 fclose(f);
744 if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
745 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
746 filename);
747 goto fail;
748 }
749 if (reset_for_rollback(sha1))
750 goto fail;
751 remove_sequencer_state();
752 strbuf_release(&buf);
753 return 0;
754 fail:
755 strbuf_release(&buf);
756 return -1;
757 }
758
759 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
760 {
761 const char *todo_file = git_path(SEQ_TODO_FILE);
762 static struct lock_file todo_lock;
763 struct strbuf buf = STRBUF_INIT;
764 int fd;
765
766 fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
767 if (format_todo(&buf, todo_list, opts) < 0)
768 die(_("Could not format %s."), todo_file);
769 if (write_in_full(fd, buf.buf, buf.len) < 0) {
770 strbuf_release(&buf);
771 die_errno(_("Could not write to %s"), todo_file);
772 }
773 if (commit_lock_file(&todo_lock) < 0) {
774 strbuf_release(&buf);
775 die(_("Error wrapping up %s."), todo_file);
776 }
777 strbuf_release(&buf);
778 }
779
780 static void save_opts(struct replay_opts *opts)
781 {
782 const char *opts_file = git_path(SEQ_OPTS_FILE);
783
784 if (opts->no_commit)
785 git_config_set_in_file(opts_file, "options.no-commit", "true");
786 if (opts->edit)
787 git_config_set_in_file(opts_file, "options.edit", "true");
788 if (opts->signoff)
789 git_config_set_in_file(opts_file, "options.signoff", "true");
790 if (opts->record_origin)
791 git_config_set_in_file(opts_file, "options.record-origin", "true");
792 if (opts->allow_ff)
793 git_config_set_in_file(opts_file, "options.allow-ff", "true");
794 if (opts->mainline) {
795 struct strbuf buf = STRBUF_INIT;
796 strbuf_addf(&buf, "%d", opts->mainline);
797 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
798 strbuf_release(&buf);
799 }
800 if (opts->strategy)
801 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
802 if (opts->xopts) {
803 int i;
804 for (i = 0; i < opts->xopts_nr; i++)
805 git_config_set_multivar_in_file(opts_file,
806 "options.strategy-option",
807 opts->xopts[i], "^$", 0);
808 }
809 }
810
811 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
812 {
813 struct commit_list *cur;
814 int res;
815
816 setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
817 if (opts->allow_ff)
818 assert(!(opts->signoff || opts->no_commit ||
819 opts->record_origin || opts->edit));
820 read_and_refresh_cache(opts);
821
822 for (cur = todo_list; cur; cur = cur->next) {
823 save_todo(cur, opts);
824 res = do_pick_commit(cur->item, opts);
825 if (res)
826 return res;
827 }
828
829 /*
830 * Sequence of picks finished successfully; cleanup by
831 * removing the .git/sequencer directory
832 */
833 remove_sequencer_state();
834 return 0;
835 }
836
837 static int continue_single_pick(void)
838 {
839 const char *argv[] = { "commit", NULL };
840
841 if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
842 !file_exists(git_path("REVERT_HEAD")))
843 return error(_("no cherry-pick or revert in progress"));
844 return run_command_v_opt(argv, RUN_GIT_CMD);
845 }
846
847 static int sequencer_continue(struct replay_opts *opts)
848 {
849 struct commit_list *todo_list = NULL;
850
851 if (!file_exists(git_path(SEQ_TODO_FILE)))
852 return continue_single_pick();
853 read_populate_opts(&opts);
854 read_populate_todo(&todo_list, opts);
855
856 /* Verify that the conflict has been resolved */
857 if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
858 file_exists(git_path("REVERT_HEAD"))) {
859 int ret = continue_single_pick();
860 if (ret)
861 return ret;
862 }
863 if (index_differs_from("HEAD", 0))
864 return error_dirty_index(opts);
865 todo_list = todo_list->next;
866 return pick_commits(todo_list, opts);
867 }
868
869 static int single_pick(struct commit *cmit, struct replay_opts *opts)
870 {
871 setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
872 return do_pick_commit(cmit, opts);
873 }
874
875 int sequencer_pick_revisions(struct replay_opts *opts)
876 {
877 struct commit_list *todo_list = NULL;
878 unsigned char sha1[20];
879
880 if (opts->subcommand == REPLAY_NONE)
881 assert(opts->revs);
882
883 read_and_refresh_cache(opts);
884
885 /*
886 * Decide what to do depending on the arguments; a fresh
887 * cherry-pick should be handled differently from an existing
888 * one that is being continued
889 */
890 if (opts->subcommand == REPLAY_REMOVE_STATE) {
891 remove_sequencer_state();
892 return 0;
893 }
894 if (opts->subcommand == REPLAY_ROLLBACK)
895 return sequencer_rollback(opts);
896 if (opts->subcommand == REPLAY_CONTINUE)
897 return sequencer_continue(opts);
898
899 /*
900 * If we were called as "git cherry-pick <commit>", just
901 * cherry-pick/revert it, set CHERRY_PICK_HEAD /
902 * REVERT_HEAD, and don't touch the sequencer state.
903 * This means it is possible to cherry-pick in the middle
904 * of a cherry-pick sequence.
905 */
906 if (opts->revs->cmdline.nr == 1 &&
907 opts->revs->cmdline.rev->whence == REV_CMD_REV &&
908 opts->revs->no_walk &&
909 !opts->revs->cmdline.rev->flags) {
910 struct commit *cmit;
911 if (prepare_revision_walk(opts->revs))
912 die(_("revision walk setup failed"));
913 cmit = get_revision(opts->revs);
914 if (!cmit || get_revision(opts->revs))
915 die("BUG: expected exactly one commit from walk");
916 return single_pick(cmit, opts);
917 }
918
919 /*
920 * Start a new cherry-pick/ revert sequence; but
921 * first, make sure that an existing one isn't in
922 * progress
923 */
924
925 walk_revs_populate_todo(&todo_list, opts);
926 if (create_seq_dir() < 0)
927 return -1;
928 if (get_sha1("HEAD", sha1)) {
929 if (opts->action == REPLAY_REVERT)
930 return error(_("Can't revert as initial commit"));
931 return error(_("Can't cherry-pick into empty head"));
932 }
933 save_head(sha1_to_hex(sha1));
934 save_opts(opts);
935 return pick_commits(todo_list, opts);
936 }