revert: prepare to move replay_action to header
[git/git.git] / builtin / revert.c
1 #include "cache.h"
2 #include "builtin.h"
3 #include "object.h"
4 #include "commit.h"
5 #include "tag.h"
6 #include "run-command.h"
7 #include "exec_cmd.h"
8 #include "utf8.h"
9 #include "parse-options.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 #include "dir.h"
17 #include "sequencer.h"
18
19 /*
20 * This implements the builtins revert and cherry-pick.
21 *
22 * Copyright (c) 2007 Johannes E. Schindelin
23 *
24 * Based on git-revert.sh, which is
25 *
26 * Copyright (c) 2005 Linus Torvalds
27 * Copyright (c) 2005 Junio C Hamano
28 */
29
30 static const char * const revert_usage[] = {
31 "git revert [options] <commit-ish>",
32 "git revert <subcommand>",
33 NULL
34 };
35
36 static const char * const cherry_pick_usage[] = {
37 "git cherry-pick [options] <commit-ish>",
38 "git cherry-pick <subcommand>",
39 NULL
40 };
41
42 enum replay_action {
43 REPLAY_REVERT,
44 REPLAY_PICK
45 };
46
47 enum replay_subcommand {
48 REPLAY_NONE,
49 REPLAY_REMOVE_STATE,
50 REPLAY_CONTINUE,
51 REPLAY_ROLLBACK
52 };
53
54 struct replay_opts {
55 enum replay_action action;
56 enum replay_subcommand subcommand;
57
58 /* Boolean options */
59 int edit;
60 int record_origin;
61 int no_commit;
62 int signoff;
63 int allow_ff;
64 int allow_rerere_auto;
65
66 int mainline;
67
68 /* Merge strategy */
69 const char *strategy;
70 const char **xopts;
71 size_t xopts_nr, xopts_alloc;
72
73 /* Only used by REPLAY_NONE */
74 struct rev_info *revs;
75 };
76
77 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
78
79 static const char *action_name(const struct replay_opts *opts)
80 {
81 return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
82 }
83
84 static char *get_encoding(const char *message);
85
86 static const char * const *revert_or_cherry_pick_usage(struct replay_opts *opts)
87 {
88 return opts->action == REPLAY_REVERT ? revert_usage : cherry_pick_usage;
89 }
90
91 static int option_parse_x(const struct option *opt,
92 const char *arg, int unset)
93 {
94 struct replay_opts **opts_ptr = opt->value;
95 struct replay_opts *opts = *opts_ptr;
96
97 if (unset)
98 return 0;
99
100 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
101 opts->xopts[opts->xopts_nr++] = xstrdup(arg);
102 return 0;
103 }
104
105 static void verify_opt_compatible(const char *me, const char *base_opt, ...)
106 {
107 const char *this_opt;
108 va_list ap;
109
110 va_start(ap, base_opt);
111 while ((this_opt = va_arg(ap, const char *))) {
112 if (va_arg(ap, int))
113 break;
114 }
115 va_end(ap);
116
117 if (this_opt)
118 die(_("%s: %s cannot be used with %s"), me, this_opt, base_opt);
119 }
120
121 static void verify_opt_mutually_compatible(const char *me, ...)
122 {
123 const char *opt1, *opt2 = NULL;
124 va_list ap;
125
126 va_start(ap, me);
127 while ((opt1 = va_arg(ap, const char *))) {
128 if (va_arg(ap, int))
129 break;
130 }
131 if (opt1) {
132 while ((opt2 = va_arg(ap, const char *))) {
133 if (va_arg(ap, int))
134 break;
135 }
136 }
137
138 if (opt1 && opt2)
139 die(_("%s: %s cannot be used with %s"), me, opt1, opt2);
140 }
141
142 static void parse_args(int argc, const char **argv, struct replay_opts *opts)
143 {
144 const char * const * usage_str = revert_or_cherry_pick_usage(opts);
145 const char *me = action_name(opts);
146 int remove_state = 0;
147 int contin = 0;
148 int rollback = 0;
149 struct option options[] = {
150 OPT_BOOLEAN(0, "quit", &remove_state, "end revert or cherry-pick sequence"),
151 OPT_BOOLEAN(0, "continue", &contin, "resume revert or cherry-pick sequence"),
152 OPT_BOOLEAN(0, "abort", &rollback, "cancel revert or cherry-pick sequence"),
153 OPT_BOOLEAN('n', "no-commit", &opts->no_commit, "don't automatically commit"),
154 OPT_BOOLEAN('e', "edit", &opts->edit, "edit the commit message"),
155 OPT_NOOP_NOARG('r', NULL),
156 OPT_BOOLEAN('s', "signoff", &opts->signoff, "add Signed-off-by:"),
157 OPT_INTEGER('m', "mainline", &opts->mainline, "parent number"),
158 OPT_RERERE_AUTOUPDATE(&opts->allow_rerere_auto),
159 OPT_STRING(0, "strategy", &opts->strategy, "strategy", "merge strategy"),
160 OPT_CALLBACK('X', "strategy-option", &opts, "option",
161 "option for merge strategy", option_parse_x),
162 OPT_END(),
163 OPT_END(),
164 OPT_END(),
165 };
166
167 if (opts->action == REPLAY_PICK) {
168 struct option cp_extra[] = {
169 OPT_BOOLEAN('x', NULL, &opts->record_origin, "append commit name"),
170 OPT_BOOLEAN(0, "ff", &opts->allow_ff, "allow fast-forward"),
171 OPT_END(),
172 };
173 if (parse_options_concat(options, ARRAY_SIZE(options), cp_extra))
174 die(_("program error"));
175 }
176
177 argc = parse_options(argc, argv, NULL, options, usage_str,
178 PARSE_OPT_KEEP_ARGV0 |
179 PARSE_OPT_KEEP_UNKNOWN);
180
181 /* Check for incompatible subcommands */
182 verify_opt_mutually_compatible(me,
183 "--quit", remove_state,
184 "--continue", contin,
185 "--abort", rollback,
186 NULL);
187
188 /* Set the subcommand */
189 if (remove_state)
190 opts->subcommand = REPLAY_REMOVE_STATE;
191 else if (contin)
192 opts->subcommand = REPLAY_CONTINUE;
193 else if (rollback)
194 opts->subcommand = REPLAY_ROLLBACK;
195 else
196 opts->subcommand = REPLAY_NONE;
197
198 /* Check for incompatible command line arguments */
199 if (opts->subcommand != REPLAY_NONE) {
200 char *this_operation;
201 if (opts->subcommand == REPLAY_REMOVE_STATE)
202 this_operation = "--quit";
203 else if (opts->subcommand == REPLAY_CONTINUE)
204 this_operation = "--continue";
205 else {
206 assert(opts->subcommand == REPLAY_ROLLBACK);
207 this_operation = "--abort";
208 }
209
210 verify_opt_compatible(me, this_operation,
211 "--no-commit", opts->no_commit,
212 "--signoff", opts->signoff,
213 "--mainline", opts->mainline,
214 "--strategy", opts->strategy ? 1 : 0,
215 "--strategy-option", opts->xopts ? 1 : 0,
216 "-x", opts->record_origin,
217 "--ff", opts->allow_ff,
218 NULL);
219 }
220
221 if (opts->allow_ff)
222 verify_opt_compatible(me, "--ff",
223 "--signoff", opts->signoff,
224 "--no-commit", opts->no_commit,
225 "-x", opts->record_origin,
226 "--edit", opts->edit,
227 NULL);
228
229 if (opts->subcommand != REPLAY_NONE) {
230 opts->revs = NULL;
231 } else {
232 opts->revs = xmalloc(sizeof(*opts->revs));
233 init_revisions(opts->revs, NULL);
234 opts->revs->no_walk = 1;
235 if (argc < 2)
236 usage_with_options(usage_str, options);
237 argc = setup_revisions(argc, argv, opts->revs, NULL);
238 }
239
240 if (argc > 1)
241 usage_with_options(usage_str, options);
242 }
243
244 struct commit_message {
245 char *parent_label;
246 const char *label;
247 const char *subject;
248 char *reencoded_message;
249 const char *message;
250 };
251
252 static int get_message(struct commit *commit, struct commit_message *out)
253 {
254 const char *encoding;
255 const char *abbrev, *subject;
256 int abbrev_len, subject_len;
257 char *q;
258
259 if (!commit->buffer)
260 return -1;
261 encoding = get_encoding(commit->buffer);
262 if (!encoding)
263 encoding = "UTF-8";
264 if (!git_commit_encoding)
265 git_commit_encoding = "UTF-8";
266
267 out->reencoded_message = NULL;
268 out->message = commit->buffer;
269 if (strcmp(encoding, git_commit_encoding))
270 out->reencoded_message = reencode_string(commit->buffer,
271 git_commit_encoding, encoding);
272 if (out->reencoded_message)
273 out->message = out->reencoded_message;
274
275 abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
276 abbrev_len = strlen(abbrev);
277
278 subject_len = find_commit_subject(out->message, &subject);
279
280 out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
281 strlen("... ") + subject_len + 1);
282 q = out->parent_label;
283 q = mempcpy(q, "parent of ", strlen("parent of "));
284 out->label = q;
285 q = mempcpy(q, abbrev, abbrev_len);
286 q = mempcpy(q, "... ", strlen("... "));
287 out->subject = q;
288 q = mempcpy(q, subject, subject_len);
289 *q = '\0';
290 return 0;
291 }
292
293 static void free_message(struct commit_message *msg)
294 {
295 free(msg->parent_label);
296 free(msg->reencoded_message);
297 }
298
299 static char *get_encoding(const char *message)
300 {
301 const char *p = message, *eol;
302
303 while (*p && *p != '\n') {
304 for (eol = p + 1; *eol && *eol != '\n'; eol++)
305 ; /* do nothing */
306 if (!prefixcmp(p, "encoding ")) {
307 char *result = xmalloc(eol - 8 - p);
308 strlcpy(result, p + 9, eol - 8 - p);
309 return result;
310 }
311 p = eol;
312 if (*p == '\n')
313 p++;
314 }
315 return NULL;
316 }
317
318 static void write_cherry_pick_head(struct commit *commit, const char *pseudoref)
319 {
320 const char *filename;
321 int fd;
322 struct strbuf buf = STRBUF_INIT;
323
324 strbuf_addf(&buf, "%s\n", sha1_to_hex(commit->object.sha1));
325
326 filename = git_path("%s", pseudoref);
327 fd = open(filename, O_WRONLY | O_CREAT, 0666);
328 if (fd < 0)
329 die_errno(_("Could not open '%s' for writing"), filename);
330 if (write_in_full(fd, buf.buf, buf.len) != buf.len || close(fd))
331 die_errno(_("Could not write to '%s'"), filename);
332 strbuf_release(&buf);
333 }
334
335 static void print_advice(int show_hint)
336 {
337 char *msg = getenv("GIT_CHERRY_PICK_HELP");
338
339 if (msg) {
340 fprintf(stderr, "%s\n", msg);
341 /*
342 * A conflict has occured but the porcelain
343 * (typically rebase --interactive) wants to take care
344 * of the commit itself so remove CHERRY_PICK_HEAD
345 */
346 unlink(git_path("CHERRY_PICK_HEAD"));
347 return;
348 }
349
350 if (show_hint) {
351 advise("after resolving the conflicts, mark the corrected paths");
352 advise("with 'git add <paths>' or 'git rm <paths>'");
353 advise("and commit the result with 'git commit'");
354 }
355 }
356
357 static void write_message(struct strbuf *msgbuf, const char *filename)
358 {
359 static struct lock_file msg_file;
360
361 int msg_fd = hold_lock_file_for_update(&msg_file, filename,
362 LOCK_DIE_ON_ERROR);
363 if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
364 die_errno(_("Could not write to %s"), filename);
365 strbuf_release(msgbuf);
366 if (commit_lock_file(&msg_file) < 0)
367 die(_("Error wrapping up %s"), filename);
368 }
369
370 static struct tree *empty_tree(void)
371 {
372 return lookup_tree((const unsigned char *)EMPTY_TREE_SHA1_BIN);
373 }
374
375 static int error_dirty_index(struct replay_opts *opts)
376 {
377 if (read_cache_unmerged())
378 return error_resolve_conflict(action_name(opts));
379
380 /* Different translation strings for cherry-pick and revert */
381 if (opts->action == REPLAY_PICK)
382 error(_("Your local changes would be overwritten by cherry-pick."));
383 else
384 error(_("Your local changes would be overwritten by revert."));
385
386 if (advice_commit_before_merge)
387 advise(_("Commit your changes or stash them to proceed."));
388 return -1;
389 }
390
391 static int fast_forward_to(const unsigned char *to, const unsigned char *from)
392 {
393 struct ref_lock *ref_lock;
394
395 read_cache();
396 if (checkout_fast_forward(from, to))
397 exit(1); /* the callee should have complained already */
398 ref_lock = lock_any_ref_for_update("HEAD", from, 0);
399 return write_ref_sha1(ref_lock, to, "cherry-pick");
400 }
401
402 static int do_recursive_merge(struct commit *base, struct commit *next,
403 const char *base_label, const char *next_label,
404 unsigned char *head, struct strbuf *msgbuf,
405 struct replay_opts *opts)
406 {
407 struct merge_options o;
408 struct tree *result, *next_tree, *base_tree, *head_tree;
409 int clean, index_fd;
410 const char **xopt;
411 static struct lock_file index_lock;
412
413 index_fd = hold_locked_index(&index_lock, 1);
414
415 read_cache();
416
417 init_merge_options(&o);
418 o.ancestor = base ? base_label : "(empty tree)";
419 o.branch1 = "HEAD";
420 o.branch2 = next ? next_label : "(empty tree)";
421
422 head_tree = parse_tree_indirect(head);
423 next_tree = next ? next->tree : empty_tree();
424 base_tree = base ? base->tree : empty_tree();
425
426 for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
427 parse_merge_opt(&o, *xopt);
428
429 clean = merge_trees(&o,
430 head_tree,
431 next_tree, base_tree, &result);
432
433 if (active_cache_changed &&
434 (write_cache(index_fd, active_cache, active_nr) ||
435 commit_locked_index(&index_lock)))
436 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
437 die(_("%s: Unable to write new index file"), action_name(opts));
438 rollback_lock_file(&index_lock);
439
440 if (!clean) {
441 int i;
442 strbuf_addstr(msgbuf, "\nConflicts:\n\n");
443 for (i = 0; i < active_nr;) {
444 struct cache_entry *ce = active_cache[i++];
445 if (ce_stage(ce)) {
446 strbuf_addch(msgbuf, '\t');
447 strbuf_addstr(msgbuf, ce->name);
448 strbuf_addch(msgbuf, '\n');
449 while (i < active_nr && !strcmp(ce->name,
450 active_cache[i]->name))
451 i++;
452 }
453 }
454 }
455
456 return !clean;
457 }
458
459 /*
460 * If we are cherry-pick, and if the merge did not result in
461 * hand-editing, we will hit this commit and inherit the original
462 * author date and name.
463 * If we are revert, or if our cherry-pick results in a hand merge,
464 * we had better say that the current user is responsible for that.
465 */
466 static int run_git_commit(const char *defmsg, struct replay_opts *opts)
467 {
468 /* 6 is max possible length of our args array including NULL */
469 const char *args[6];
470 int i = 0;
471
472 args[i++] = "commit";
473 args[i++] = "-n";
474 if (opts->signoff)
475 args[i++] = "-s";
476 if (!opts->edit) {
477 args[i++] = "-F";
478 args[i++] = defmsg;
479 }
480 args[i] = NULL;
481
482 return run_command_v_opt(args, RUN_GIT_CMD);
483 }
484
485 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
486 {
487 unsigned char head[20];
488 struct commit *base, *next, *parent;
489 const char *base_label, *next_label;
490 struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
491 char *defmsg = NULL;
492 struct strbuf msgbuf = STRBUF_INIT;
493 int res;
494
495 if (opts->no_commit) {
496 /*
497 * We do not intend to commit immediately. We just want to
498 * merge the differences in, so let's compute the tree
499 * that represents the "current" state for merge-recursive
500 * to work on.
501 */
502 if (write_cache_as_tree(head, 0, NULL))
503 die (_("Your index file is unmerged."));
504 } else {
505 if (get_sha1("HEAD", head))
506 return error(_("You do not have a valid HEAD"));
507 if (index_differs_from("HEAD", 0))
508 return error_dirty_index(opts);
509 }
510 discard_cache();
511
512 if (!commit->parents) {
513 parent = NULL;
514 }
515 else if (commit->parents->next) {
516 /* Reverting or cherry-picking a merge commit */
517 int cnt;
518 struct commit_list *p;
519
520 if (!opts->mainline)
521 return error(_("Commit %s is a merge but no -m option was given."),
522 sha1_to_hex(commit->object.sha1));
523
524 for (cnt = 1, p = commit->parents;
525 cnt != opts->mainline && p;
526 cnt++)
527 p = p->next;
528 if (cnt != opts->mainline || !p)
529 return error(_("Commit %s does not have parent %d"),
530 sha1_to_hex(commit->object.sha1), opts->mainline);
531 parent = p->item;
532 } else if (0 < opts->mainline)
533 return error(_("Mainline was specified but commit %s is not a merge."),
534 sha1_to_hex(commit->object.sha1));
535 else
536 parent = commit->parents->item;
537
538 if (opts->allow_ff && parent && !hashcmp(parent->object.sha1, head))
539 return fast_forward_to(commit->object.sha1, head);
540
541 if (parent && parse_commit(parent) < 0)
542 /* TRANSLATORS: The first %s will be "revert" or
543 "cherry-pick", the second %s a SHA1 */
544 return error(_("%s: cannot parse parent commit %s"),
545 action_name(opts), sha1_to_hex(parent->object.sha1));
546
547 if (get_message(commit, &msg) != 0)
548 return error(_("Cannot get commit message for %s"),
549 sha1_to_hex(commit->object.sha1));
550
551 /*
552 * "commit" is an existing commit. We would want to apply
553 * the difference it introduces since its first parent "prev"
554 * on top of the current HEAD if we are cherry-pick. Or the
555 * reverse of it if we are revert.
556 */
557
558 defmsg = git_pathdup("MERGE_MSG");
559
560 if (opts->action == REPLAY_REVERT) {
561 base = commit;
562 base_label = msg.label;
563 next = parent;
564 next_label = msg.parent_label;
565 strbuf_addstr(&msgbuf, "Revert \"");
566 strbuf_addstr(&msgbuf, msg.subject);
567 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
568 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
569
570 if (commit->parents && commit->parents->next) {
571 strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
572 strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
573 }
574 strbuf_addstr(&msgbuf, ".\n");
575 } else {
576 const char *p;
577
578 base = parent;
579 base_label = msg.parent_label;
580 next = commit;
581 next_label = msg.label;
582
583 /*
584 * Append the commit log message to msgbuf; it starts
585 * after the tree, parent, author, committer
586 * information followed by "\n\n".
587 */
588 p = strstr(msg.message, "\n\n");
589 if (p) {
590 p += 2;
591 strbuf_addstr(&msgbuf, p);
592 }
593
594 if (opts->record_origin) {
595 strbuf_addstr(&msgbuf, "(cherry picked from commit ");
596 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
597 strbuf_addstr(&msgbuf, ")\n");
598 }
599 }
600
601 if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
602 res = do_recursive_merge(base, next, base_label, next_label,
603 head, &msgbuf, opts);
604 write_message(&msgbuf, defmsg);
605 } else {
606 struct commit_list *common = NULL;
607 struct commit_list *remotes = NULL;
608
609 write_message(&msgbuf, defmsg);
610
611 commit_list_insert(base, &common);
612 commit_list_insert(next, &remotes);
613 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
614 common, sha1_to_hex(head), remotes);
615 free_commit_list(common);
616 free_commit_list(remotes);
617 }
618
619 /*
620 * If the merge was clean or if it failed due to conflict, we write
621 * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
622 * However, if the merge did not even start, then we don't want to
623 * write it at all.
624 */
625 if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
626 write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
627 if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
628 write_cherry_pick_head(commit, "REVERT_HEAD");
629
630 if (res) {
631 error(opts->action == REPLAY_REVERT
632 ? _("could not revert %s... %s")
633 : _("could not apply %s... %s"),
634 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
635 msg.subject);
636 print_advice(res == 1);
637 rerere(opts->allow_rerere_auto);
638 } else {
639 if (!opts->no_commit)
640 res = run_git_commit(defmsg, opts);
641 }
642
643 free_message(&msg);
644 free(defmsg);
645
646 return res;
647 }
648
649 static void prepare_revs(struct replay_opts *opts)
650 {
651 if (opts->action != REPLAY_REVERT)
652 opts->revs->reverse ^= 1;
653
654 if (prepare_revision_walk(opts->revs))
655 die(_("revision walk setup failed"));
656
657 if (!opts->revs->commits)
658 die(_("empty commit set passed"));
659 }
660
661 static void read_and_refresh_cache(struct replay_opts *opts)
662 {
663 static struct lock_file index_lock;
664 int index_fd = hold_locked_index(&index_lock, 0);
665 if (read_index_preload(&the_index, NULL) < 0)
666 die(_("git %s: failed to read the index"), action_name(opts));
667 refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
668 if (the_index.cache_changed) {
669 if (write_index(&the_index, index_fd) ||
670 commit_locked_index(&index_lock))
671 die(_("git %s: failed to refresh the index"), action_name(opts));
672 }
673 rollback_lock_file(&index_lock);
674 }
675
676 /*
677 * Append a commit to the end of the commit_list.
678 *
679 * next starts by pointing to the variable that holds the head of an
680 * empty commit_list, and is updated to point to the "next" field of
681 * the last item on the list as new commits are appended.
682 *
683 * Usage example:
684 *
685 * struct commit_list *list;
686 * struct commit_list **next = &list;
687 *
688 * next = commit_list_append(c1, next);
689 * next = commit_list_append(c2, next);
690 * assert(commit_list_count(list) == 2);
691 * return list;
692 */
693 static struct commit_list **commit_list_append(struct commit *commit,
694 struct commit_list **next)
695 {
696 struct commit_list *new = xmalloc(sizeof(struct commit_list));
697 new->item = commit;
698 *next = new;
699 new->next = NULL;
700 return &new->next;
701 }
702
703 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
704 struct replay_opts *opts)
705 {
706 struct commit_list *cur = NULL;
707 const char *sha1_abbrev = NULL;
708 const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
709 const char *subject;
710 int subject_len;
711
712 for (cur = todo_list; cur; cur = cur->next) {
713 sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
714 subject_len = find_commit_subject(cur->item->buffer, &subject);
715 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
716 subject_len, subject);
717 }
718 return 0;
719 }
720
721 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
722 {
723 unsigned char commit_sha1[20];
724 enum replay_action action;
725 char *end_of_object_name;
726 int saved, status, padding;
727
728 if (!prefixcmp(bol, "pick")) {
729 action = REPLAY_PICK;
730 bol += strlen("pick");
731 } else if (!prefixcmp(bol, "revert")) {
732 action = REPLAY_REVERT;
733 bol += strlen("revert");
734 } else
735 return NULL;
736
737 /* Eat up extra spaces/ tabs before object name */
738 padding = strspn(bol, " \t");
739 if (!padding)
740 return NULL;
741 bol += padding;
742
743 end_of_object_name = bol + strcspn(bol, " \t\n");
744 saved = *end_of_object_name;
745 *end_of_object_name = '\0';
746 status = get_sha1(bol, commit_sha1);
747 *end_of_object_name = saved;
748
749 /*
750 * Verify that the action matches up with the one in
751 * opts; we don't support arbitrary instructions
752 */
753 if (action != opts->action) {
754 const char *action_str;
755 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
756 error(_("Cannot %s during a %s"), action_str, action_name(opts));
757 return NULL;
758 }
759
760 if (status < 0)
761 return NULL;
762
763 return lookup_commit_reference(commit_sha1);
764 }
765
766 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
767 struct replay_opts *opts)
768 {
769 struct commit_list **next = todo_list;
770 struct commit *commit;
771 char *p = buf;
772 int i;
773
774 for (i = 1; *p; i++) {
775 char *eol = strchrnul(p, '\n');
776 commit = parse_insn_line(p, eol, opts);
777 if (!commit)
778 return error(_("Could not parse line %d."), i);
779 next = commit_list_append(commit, next);
780 p = *eol ? eol + 1 : eol;
781 }
782 if (!*todo_list)
783 return error(_("No commits parsed."));
784 return 0;
785 }
786
787 static void read_populate_todo(struct commit_list **todo_list,
788 struct replay_opts *opts)
789 {
790 const char *todo_file = git_path(SEQ_TODO_FILE);
791 struct strbuf buf = STRBUF_INIT;
792 int fd, res;
793
794 fd = open(todo_file, O_RDONLY);
795 if (fd < 0)
796 die_errno(_("Could not open %s"), todo_file);
797 if (strbuf_read(&buf, fd, 0) < 0) {
798 close(fd);
799 strbuf_release(&buf);
800 die(_("Could not read %s."), todo_file);
801 }
802 close(fd);
803
804 res = parse_insn_buffer(buf.buf, todo_list, opts);
805 strbuf_release(&buf);
806 if (res)
807 die(_("Unusable instruction sheet: %s"), todo_file);
808 }
809
810 static int populate_opts_cb(const char *key, const char *value, void *data)
811 {
812 struct replay_opts *opts = data;
813 int error_flag = 1;
814
815 if (!value)
816 error_flag = 0;
817 else if (!strcmp(key, "options.no-commit"))
818 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
819 else if (!strcmp(key, "options.edit"))
820 opts->edit = git_config_bool_or_int(key, value, &error_flag);
821 else if (!strcmp(key, "options.signoff"))
822 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
823 else if (!strcmp(key, "options.record-origin"))
824 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
825 else if (!strcmp(key, "options.allow-ff"))
826 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
827 else if (!strcmp(key, "options.mainline"))
828 opts->mainline = git_config_int(key, value);
829 else if (!strcmp(key, "options.strategy"))
830 git_config_string(&opts->strategy, key, value);
831 else if (!strcmp(key, "options.strategy-option")) {
832 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
833 opts->xopts[opts->xopts_nr++] = xstrdup(value);
834 } else
835 return error(_("Invalid key: %s"), key);
836
837 if (!error_flag)
838 return error(_("Invalid value for %s: %s"), key, value);
839
840 return 0;
841 }
842
843 static void read_populate_opts(struct replay_opts **opts_ptr)
844 {
845 const char *opts_file = git_path(SEQ_OPTS_FILE);
846
847 if (!file_exists(opts_file))
848 return;
849 if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
850 die(_("Malformed options sheet: %s"), opts_file);
851 }
852
853 static void walk_revs_populate_todo(struct commit_list **todo_list,
854 struct replay_opts *opts)
855 {
856 struct commit *commit;
857 struct commit_list **next;
858
859 prepare_revs(opts);
860
861 next = todo_list;
862 while ((commit = get_revision(opts->revs)))
863 next = commit_list_append(commit, next);
864 }
865
866 static int create_seq_dir(void)
867 {
868 const char *seq_dir = git_path(SEQ_DIR);
869
870 if (file_exists(seq_dir)) {
871 error(_("a cherry-pick or revert is already in progress"));
872 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
873 return -1;
874 }
875 else if (mkdir(seq_dir, 0777) < 0)
876 die_errno(_("Could not create sequencer directory %s"), seq_dir);
877 return 0;
878 }
879
880 static void save_head(const char *head)
881 {
882 const char *head_file = git_path(SEQ_HEAD_FILE);
883 static struct lock_file head_lock;
884 struct strbuf buf = STRBUF_INIT;
885 int fd;
886
887 fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
888 strbuf_addf(&buf, "%s\n", head);
889 if (write_in_full(fd, buf.buf, buf.len) < 0)
890 die_errno(_("Could not write to %s"), head_file);
891 if (commit_lock_file(&head_lock) < 0)
892 die(_("Error wrapping up %s."), head_file);
893 }
894
895 static int reset_for_rollback(const unsigned char *sha1)
896 {
897 const char *argv[4]; /* reset --merge <arg> + NULL */
898 argv[0] = "reset";
899 argv[1] = "--merge";
900 argv[2] = sha1_to_hex(sha1);
901 argv[3] = NULL;
902 return run_command_v_opt(argv, RUN_GIT_CMD);
903 }
904
905 static int rollback_single_pick(void)
906 {
907 unsigned char head_sha1[20];
908
909 if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
910 !file_exists(git_path("REVERT_HEAD")))
911 return error(_("no cherry-pick or revert in progress"));
912 if (read_ref_full("HEAD", head_sha1, 0, NULL))
913 return error(_("cannot resolve HEAD"));
914 if (is_null_sha1(head_sha1))
915 return error(_("cannot abort from a branch yet to be born"));
916 return reset_for_rollback(head_sha1);
917 }
918
919 static int sequencer_rollback(struct replay_opts *opts)
920 {
921 const char *filename;
922 FILE *f;
923 unsigned char sha1[20];
924 struct strbuf buf = STRBUF_INIT;
925
926 filename = git_path(SEQ_HEAD_FILE);
927 f = fopen(filename, "r");
928 if (!f && errno == ENOENT) {
929 /*
930 * There is no multiple-cherry-pick in progress.
931 * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
932 * a single-cherry-pick in progress, abort that.
933 */
934 return rollback_single_pick();
935 }
936 if (!f)
937 return error(_("cannot open %s: %s"), filename,
938 strerror(errno));
939 if (strbuf_getline(&buf, f, '\n')) {
940 error(_("cannot read %s: %s"), filename, ferror(f) ?
941 strerror(errno) : _("unexpected end of file"));
942 fclose(f);
943 goto fail;
944 }
945 fclose(f);
946 if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
947 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
948 filename);
949 goto fail;
950 }
951 if (reset_for_rollback(sha1))
952 goto fail;
953 remove_sequencer_state();
954 strbuf_release(&buf);
955 return 0;
956 fail:
957 strbuf_release(&buf);
958 return -1;
959 }
960
961 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
962 {
963 const char *todo_file = git_path(SEQ_TODO_FILE);
964 static struct lock_file todo_lock;
965 struct strbuf buf = STRBUF_INIT;
966 int fd;
967
968 fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
969 if (format_todo(&buf, todo_list, opts) < 0)
970 die(_("Could not format %s."), todo_file);
971 if (write_in_full(fd, buf.buf, buf.len) < 0) {
972 strbuf_release(&buf);
973 die_errno(_("Could not write to %s"), todo_file);
974 }
975 if (commit_lock_file(&todo_lock) < 0) {
976 strbuf_release(&buf);
977 die(_("Error wrapping up %s."), todo_file);
978 }
979 strbuf_release(&buf);
980 }
981
982 static void save_opts(struct replay_opts *opts)
983 {
984 const char *opts_file = git_path(SEQ_OPTS_FILE);
985
986 if (opts->no_commit)
987 git_config_set_in_file(opts_file, "options.no-commit", "true");
988 if (opts->edit)
989 git_config_set_in_file(opts_file, "options.edit", "true");
990 if (opts->signoff)
991 git_config_set_in_file(opts_file, "options.signoff", "true");
992 if (opts->record_origin)
993 git_config_set_in_file(opts_file, "options.record-origin", "true");
994 if (opts->allow_ff)
995 git_config_set_in_file(opts_file, "options.allow-ff", "true");
996 if (opts->mainline) {
997 struct strbuf buf = STRBUF_INIT;
998 strbuf_addf(&buf, "%d", opts->mainline);
999 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
1000 strbuf_release(&buf);
1001 }
1002 if (opts->strategy)
1003 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
1004 if (opts->xopts) {
1005 int i;
1006 for (i = 0; i < opts->xopts_nr; i++)
1007 git_config_set_multivar_in_file(opts_file,
1008 "options.strategy-option",
1009 opts->xopts[i], "^$", 0);
1010 }
1011 }
1012
1013 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
1014 {
1015 struct commit_list *cur;
1016 int res;
1017
1018 setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1019 if (opts->allow_ff)
1020 assert(!(opts->signoff || opts->no_commit ||
1021 opts->record_origin || opts->edit));
1022 read_and_refresh_cache(opts);
1023
1024 for (cur = todo_list; cur; cur = cur->next) {
1025 save_todo(cur, opts);
1026 res = do_pick_commit(cur->item, opts);
1027 if (res)
1028 return res;
1029 }
1030
1031 /*
1032 * Sequence of picks finished successfully; cleanup by
1033 * removing the .git/sequencer directory
1034 */
1035 remove_sequencer_state();
1036 return 0;
1037 }
1038
1039 static int continue_single_pick(void)
1040 {
1041 const char *argv[] = { "commit", NULL };
1042
1043 if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
1044 !file_exists(git_path("REVERT_HEAD")))
1045 return error(_("no cherry-pick or revert in progress"));
1046 return run_command_v_opt(argv, RUN_GIT_CMD);
1047 }
1048
1049 static int sequencer_continue(struct replay_opts *opts)
1050 {
1051 struct commit_list *todo_list = NULL;
1052
1053 if (!file_exists(git_path(SEQ_TODO_FILE)))
1054 return continue_single_pick();
1055 read_populate_opts(&opts);
1056 read_populate_todo(&todo_list, opts);
1057
1058 /* Verify that the conflict has been resolved */
1059 if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
1060 file_exists(git_path("REVERT_HEAD"))) {
1061 int ret = continue_single_pick();
1062 if (ret)
1063 return ret;
1064 }
1065 if (index_differs_from("HEAD", 0))
1066 return error_dirty_index(opts);
1067 todo_list = todo_list->next;
1068 return pick_commits(todo_list, opts);
1069 }
1070
1071 static int single_pick(struct commit *cmit, struct replay_opts *opts)
1072 {
1073 setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1074 return do_pick_commit(cmit, opts);
1075 }
1076
1077 static int pick_revisions(struct replay_opts *opts)
1078 {
1079 struct commit_list *todo_list = NULL;
1080 unsigned char sha1[20];
1081
1082 if (opts->subcommand == REPLAY_NONE)
1083 assert(opts->revs);
1084
1085 read_and_refresh_cache(opts);
1086
1087 /*
1088 * Decide what to do depending on the arguments; a fresh
1089 * cherry-pick should be handled differently from an existing
1090 * one that is being continued
1091 */
1092 if (opts->subcommand == REPLAY_REMOVE_STATE) {
1093 remove_sequencer_state();
1094 return 0;
1095 }
1096 if (opts->subcommand == REPLAY_ROLLBACK)
1097 return sequencer_rollback(opts);
1098 if (opts->subcommand == REPLAY_CONTINUE)
1099 return sequencer_continue(opts);
1100
1101 /*
1102 * If we were called as "git cherry-pick <commit>", just
1103 * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1104 * REVERT_HEAD, and don't touch the sequencer state.
1105 * This means it is possible to cherry-pick in the middle
1106 * of a cherry-pick sequence.
1107 */
1108 if (opts->revs->cmdline.nr == 1 &&
1109 opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1110 opts->revs->no_walk &&
1111 !opts->revs->cmdline.rev->flags) {
1112 struct commit *cmit;
1113 if (prepare_revision_walk(opts->revs))
1114 die(_("revision walk setup failed"));
1115 cmit = get_revision(opts->revs);
1116 if (!cmit || get_revision(opts->revs))
1117 die("BUG: expected exactly one commit from walk");
1118 return single_pick(cmit, opts);
1119 }
1120
1121 /*
1122 * Start a new cherry-pick/ revert sequence; but
1123 * first, make sure that an existing one isn't in
1124 * progress
1125 */
1126
1127 walk_revs_populate_todo(&todo_list, opts);
1128 if (create_seq_dir() < 0)
1129 return -1;
1130 if (get_sha1("HEAD", sha1)) {
1131 if (opts->action == REPLAY_REVERT)
1132 return error(_("Can't revert as initial commit"));
1133 return error(_("Can't cherry-pick into empty head"));
1134 }
1135 save_head(sha1_to_hex(sha1));
1136 save_opts(opts);
1137 return pick_commits(todo_list, opts);
1138 }
1139
1140 int cmd_revert(int argc, const char **argv, const char *prefix)
1141 {
1142 struct replay_opts opts;
1143 int res;
1144
1145 memset(&opts, 0, sizeof(opts));
1146 if (isatty(0))
1147 opts.edit = 1;
1148 opts.action = REPLAY_REVERT;
1149 git_config(git_default_config, NULL);
1150 parse_args(argc, argv, &opts);
1151 res = pick_revisions(&opts);
1152 if (res < 0)
1153 die(_("revert failed"));
1154 return res;
1155 }
1156
1157 int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
1158 {
1159 struct replay_opts opts;
1160 int res;
1161
1162 memset(&opts, 0, sizeof(opts));
1163 opts.action = REPLAY_PICK;
1164 git_config(git_default_config, NULL);
1165 parse_args(argc, argv, &opts);
1166 res = pick_revisions(&opts);
1167 if (res < 0)
1168 die(_("cherry-pick failed"));
1169 return res;
1170 }