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