Merge branch 'bw/submodule-branch-dot-doc' into maint
[git] / sequencer.c
1 #include "cache.h"
2 #include "lockfile.h"
3 #include "sequencer.h"
4 #include "dir.h"
5 #include "object.h"
6 #include "commit.h"
7 #include "tag.h"
8 #include "run-command.h"
9 #include "exec_cmd.h"
10 #include "utf8.h"
11 #include "cache-tree.h"
12 #include "diff.h"
13 #include "revision.h"
14 #include "rerere.h"
15 #include "merge-recursive.h"
16 #include "refs.h"
17 #include "argv-array.h"
18
19 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
20
21 const char sign_off_header[] = "Signed-off-by: ";
22 static const char cherry_picked_prefix[] = "(cherry picked from commit ";
23
24 static GIT_PATH_FUNC(git_path_todo_file, SEQ_TODO_FILE)
25 static GIT_PATH_FUNC(git_path_opts_file, SEQ_OPTS_FILE)
26 static GIT_PATH_FUNC(git_path_seq_dir, SEQ_DIR)
27 static GIT_PATH_FUNC(git_path_head_file, SEQ_HEAD_FILE)
28
29 static int is_rfc2822_line(const char *buf, int len)
30 {
31         int i;
32
33         for (i = 0; i < len; i++) {
34                 int ch = buf[i];
35                 if (ch == ':')
36                         return 1;
37                 if (!isalnum(ch) && ch != '-')
38                         break;
39         }
40
41         return 0;
42 }
43
44 static int is_cherry_picked_from_line(const char *buf, int len)
45 {
46         /*
47          * We only care that it looks roughly like (cherry picked from ...)
48          */
49         return len > strlen(cherry_picked_prefix) + 1 &&
50                 starts_with(buf, cherry_picked_prefix) && buf[len - 1] == ')';
51 }
52
53 /*
54  * Returns 0 for non-conforming footer
55  * Returns 1 for conforming footer
56  * Returns 2 when sob exists within conforming footer
57  * Returns 3 when sob exists within conforming footer as last entry
58  */
59 static int has_conforming_footer(struct strbuf *sb, struct strbuf *sob,
60         int ignore_footer)
61 {
62         char prev;
63         int i, k;
64         int len = sb->len - ignore_footer;
65         const char *buf = sb->buf;
66         int found_sob = 0;
67
68         /* footer must end with newline */
69         if (!len || buf[len - 1] != '\n')
70                 return 0;
71
72         prev = '\0';
73         for (i = len - 1; i > 0; i--) {
74                 char ch = buf[i];
75                 if (prev == '\n' && ch == '\n') /* paragraph break */
76                         break;
77                 prev = ch;
78         }
79
80         /* require at least one blank line */
81         if (prev != '\n' || buf[i] != '\n')
82                 return 0;
83
84         /* advance to start of last paragraph */
85         while (i < len - 1 && buf[i] == '\n')
86                 i++;
87
88         for (; i < len; i = k) {
89                 int found_rfc2822;
90
91                 for (k = i; k < len && buf[k] != '\n'; k++)
92                         ; /* do nothing */
93                 k++;
94
95                 found_rfc2822 = is_rfc2822_line(buf + i, k - i - 1);
96                 if (found_rfc2822 && sob &&
97                     !strncmp(buf + i, sob->buf, sob->len))
98                         found_sob = k;
99
100                 if (!(found_rfc2822 ||
101                       is_cherry_picked_from_line(buf + i, k - i - 1)))
102                         return 0;
103         }
104         if (found_sob == i)
105                 return 3;
106         if (found_sob)
107                 return 2;
108         return 1;
109 }
110
111 static void remove_sequencer_state(void)
112 {
113         struct strbuf seq_dir = STRBUF_INIT;
114
115         strbuf_addstr(&seq_dir, git_path(SEQ_DIR));
116         remove_dir_recursively(&seq_dir, 0);
117         strbuf_release(&seq_dir);
118 }
119
120 static const char *action_name(const struct replay_opts *opts)
121 {
122         return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
123 }
124
125 struct commit_message {
126         char *parent_label;
127         char *label;
128         char *subject;
129         const char *message;
130 };
131
132 static int get_message(struct commit *commit, struct commit_message *out)
133 {
134         const char *abbrev, *subject;
135         int subject_len;
136
137         out->message = logmsg_reencode(commit, NULL, get_commit_output_encoding());
138         abbrev = find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV);
139
140         subject_len = find_commit_subject(out->message, &subject);
141
142         out->subject = xmemdupz(subject, subject_len);
143         out->label = xstrfmt("%s... %s", abbrev, out->subject);
144         out->parent_label = xstrfmt("parent of %s", out->label);
145
146         return 0;
147 }
148
149 static void free_message(struct commit *commit, struct commit_message *msg)
150 {
151         free(msg->parent_label);
152         free(msg->label);
153         free(msg->subject);
154         unuse_commit_buffer(commit, msg->message);
155 }
156
157 static void print_advice(int show_hint, struct replay_opts *opts)
158 {
159         char *msg = getenv("GIT_CHERRY_PICK_HELP");
160
161         if (msg) {
162                 fprintf(stderr, "%s\n", msg);
163                 /*
164                  * A conflict has occurred but the porcelain
165                  * (typically rebase --interactive) wants to take care
166                  * of the commit itself so remove CHERRY_PICK_HEAD
167                  */
168                 unlink(git_path_cherry_pick_head());
169                 return;
170         }
171
172         if (show_hint) {
173                 if (opts->no_commit)
174                         advise(_("after resolving the conflicts, mark the corrected paths\n"
175                                  "with 'git add <paths>' or 'git rm <paths>'"));
176                 else
177                         advise(_("after resolving the conflicts, mark the corrected paths\n"
178                                  "with 'git add <paths>' or 'git rm <paths>'\n"
179                                  "and commit the result with 'git commit'"));
180         }
181 }
182
183 static void write_message(struct strbuf *msgbuf, const char *filename)
184 {
185         static struct lock_file msg_file;
186
187         int msg_fd = hold_lock_file_for_update(&msg_file, filename,
188                                                LOCK_DIE_ON_ERROR);
189         if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
190                 die_errno(_("Could not write to %s"), filename);
191         strbuf_release(msgbuf);
192         if (commit_lock_file(&msg_file) < 0)
193                 die(_("Error wrapping up %s."), filename);
194 }
195
196 static struct tree *empty_tree(void)
197 {
198         return lookup_tree(EMPTY_TREE_SHA1_BIN);
199 }
200
201 static int error_dirty_index(struct replay_opts *opts)
202 {
203         if (read_cache_unmerged())
204                 return error_resolve_conflict(action_name(opts));
205
206         /* Different translation strings for cherry-pick and revert */
207         if (opts->action == REPLAY_PICK)
208                 error(_("Your local changes would be overwritten by cherry-pick."));
209         else
210                 error(_("Your local changes would be overwritten by revert."));
211
212         if (advice_commit_before_merge)
213                 advise(_("Commit your changes or stash them to proceed."));
214         return -1;
215 }
216
217 static int fast_forward_to(const unsigned char *to, const unsigned char *from,
218                         int unborn, struct replay_opts *opts)
219 {
220         struct ref_transaction *transaction;
221         struct strbuf sb = STRBUF_INIT;
222         struct strbuf err = STRBUF_INIT;
223
224         read_cache();
225         if (checkout_fast_forward(from, to, 1))
226                 exit(128); /* the callee should have complained already */
227
228         strbuf_addf(&sb, _("%s: fast-forward"), action_name(opts));
229
230         transaction = ref_transaction_begin(&err);
231         if (!transaction ||
232             ref_transaction_update(transaction, "HEAD",
233                                    to, unborn ? null_sha1 : from,
234                                    0, sb.buf, &err) ||
235             ref_transaction_commit(transaction, &err)) {
236                 ref_transaction_free(transaction);
237                 error("%s", err.buf);
238                 strbuf_release(&sb);
239                 strbuf_release(&err);
240                 return -1;
241         }
242
243         strbuf_release(&sb);
244         strbuf_release(&err);
245         ref_transaction_free(transaction);
246         return 0;
247 }
248
249 void append_conflicts_hint(struct strbuf *msgbuf)
250 {
251         int i;
252
253         strbuf_addch(msgbuf, '\n');
254         strbuf_commented_addf(msgbuf, "Conflicts:\n");
255         for (i = 0; i < active_nr;) {
256                 const struct cache_entry *ce = active_cache[i++];
257                 if (ce_stage(ce)) {
258                         strbuf_commented_addf(msgbuf, "\t%s\n", ce->name);
259                         while (i < active_nr && !strcmp(ce->name,
260                                                         active_cache[i]->name))
261                                 i++;
262                 }
263         }
264 }
265
266 static int do_recursive_merge(struct commit *base, struct commit *next,
267                               const char *base_label, const char *next_label,
268                               unsigned char *head, struct strbuf *msgbuf,
269                               struct replay_opts *opts)
270 {
271         struct merge_options o;
272         struct tree *result, *next_tree, *base_tree, *head_tree;
273         int clean;
274         const char **xopt;
275         static struct lock_file index_lock;
276
277         hold_locked_index(&index_lock, 1);
278
279         read_cache();
280
281         init_merge_options(&o);
282         o.ancestor = base ? base_label : "(empty tree)";
283         o.branch1 = "HEAD";
284         o.branch2 = next ? next_label : "(empty tree)";
285
286         head_tree = parse_tree_indirect(head);
287         next_tree = next ? next->tree : empty_tree();
288         base_tree = base ? base->tree : empty_tree();
289
290         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
291                 parse_merge_opt(&o, *xopt);
292
293         clean = merge_trees(&o,
294                             head_tree,
295                             next_tree, base_tree, &result);
296         strbuf_release(&o.obuf);
297         if (clean < 0)
298                 return clean;
299
300         if (active_cache_changed &&
301             write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
302                 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
303                 die(_("%s: Unable to write new index file"), action_name(opts));
304         rollback_lock_file(&index_lock);
305
306         if (opts->signoff)
307                 append_signoff(msgbuf, 0, 0);
308
309         if (!clean)
310                 append_conflicts_hint(msgbuf);
311
312         return !clean;
313 }
314
315 static int is_index_unchanged(void)
316 {
317         unsigned char head_sha1[20];
318         struct commit *head_commit;
319
320         if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_sha1, NULL))
321                 return error(_("Could not resolve HEAD commit\n"));
322
323         head_commit = lookup_commit(head_sha1);
324
325         /*
326          * If head_commit is NULL, check_commit, called from
327          * lookup_commit, would have indicated that head_commit is not
328          * a commit object already.  parse_commit() will return failure
329          * without further complaints in such a case.  Otherwise, if
330          * the commit is invalid, parse_commit() will complain.  So
331          * there is nothing for us to say here.  Just return failure.
332          */
333         if (parse_commit(head_commit))
334                 return -1;
335
336         if (!active_cache_tree)
337                 active_cache_tree = cache_tree();
338
339         if (!cache_tree_fully_valid(active_cache_tree))
340                 if (cache_tree_update(&the_index, 0))
341                         return error(_("Unable to update cache tree\n"));
342
343         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.oid.hash);
344 }
345
346 /*
347  * If we are cherry-pick, and if the merge did not result in
348  * hand-editing, we will hit this commit and inherit the original
349  * author date and name.
350  * If we are revert, or if our cherry-pick results in a hand merge,
351  * we had better say that the current user is responsible for that.
352  */
353 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
354                           int allow_empty)
355 {
356         struct argv_array array;
357         int rc;
358         const char *value;
359
360         argv_array_init(&array);
361         argv_array_push(&array, "commit");
362         argv_array_push(&array, "-n");
363
364         if (opts->gpg_sign)
365                 argv_array_pushf(&array, "-S%s", opts->gpg_sign);
366         if (opts->signoff)
367                 argv_array_push(&array, "-s");
368         if (!opts->edit) {
369                 argv_array_push(&array, "-F");
370                 argv_array_push(&array, defmsg);
371                 if (!opts->signoff &&
372                     !opts->record_origin &&
373                     git_config_get_value("commit.cleanup", &value))
374                         argv_array_push(&array, "--cleanup=verbatim");
375         }
376
377         if (allow_empty)
378                 argv_array_push(&array, "--allow-empty");
379
380         if (opts->allow_empty_message)
381                 argv_array_push(&array, "--allow-empty-message");
382
383         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
384         argv_array_clear(&array);
385         return rc;
386 }
387
388 static int is_original_commit_empty(struct commit *commit)
389 {
390         const unsigned char *ptree_sha1;
391
392         if (parse_commit(commit))
393                 return error(_("Could not parse commit %s\n"),
394                              oid_to_hex(&commit->object.oid));
395         if (commit->parents) {
396                 struct commit *parent = commit->parents->item;
397                 if (parse_commit(parent))
398                         return error(_("Could not parse parent commit %s\n"),
399                                 oid_to_hex(&parent->object.oid));
400                 ptree_sha1 = parent->tree->object.oid.hash;
401         } else {
402                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
403         }
404
405         return !hashcmp(ptree_sha1, commit->tree->object.oid.hash);
406 }
407
408 /*
409  * Do we run "git commit" with "--allow-empty"?
410  */
411 static int allow_empty(struct replay_opts *opts, struct commit *commit)
412 {
413         int index_unchanged, empty_commit;
414
415         /*
416          * Three cases:
417          *
418          * (1) we do not allow empty at all and error out.
419          *
420          * (2) we allow ones that were initially empty, but
421          * forbid the ones that become empty;
422          *
423          * (3) we allow both.
424          */
425         if (!opts->allow_empty)
426                 return 0; /* let "git commit" barf as necessary */
427
428         index_unchanged = is_index_unchanged();
429         if (index_unchanged < 0)
430                 return index_unchanged;
431         if (!index_unchanged)
432                 return 0; /* we do not have to say --allow-empty */
433
434         if (opts->keep_redundant_commits)
435                 return 1;
436
437         empty_commit = is_original_commit_empty(commit);
438         if (empty_commit < 0)
439                 return empty_commit;
440         if (!empty_commit)
441                 return 0;
442         else
443                 return 1;
444 }
445
446 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
447 {
448         unsigned char head[20];
449         struct commit *base, *next, *parent;
450         const char *base_label, *next_label;
451         struct commit_message msg = { NULL, NULL, NULL, NULL };
452         struct strbuf msgbuf = STRBUF_INIT;
453         int res, unborn = 0, allow;
454
455         if (opts->no_commit) {
456                 /*
457                  * We do not intend to commit immediately.  We just want to
458                  * merge the differences in, so let's compute the tree
459                  * that represents the "current" state for merge-recursive
460                  * to work on.
461                  */
462                 if (write_cache_as_tree(head, 0, NULL))
463                         die (_("Your index file is unmerged."));
464         } else {
465                 unborn = get_sha1("HEAD", head);
466                 if (unborn)
467                         hashcpy(head, EMPTY_TREE_SHA1_BIN);
468                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
469                         return error_dirty_index(opts);
470         }
471         discard_cache();
472
473         if (!commit->parents) {
474                 parent = NULL;
475         }
476         else if (commit->parents->next) {
477                 /* Reverting or cherry-picking a merge commit */
478                 int cnt;
479                 struct commit_list *p;
480
481                 if (!opts->mainline)
482                         return error(_("Commit %s is a merge but no -m option was given."),
483                                 oid_to_hex(&commit->object.oid));
484
485                 for (cnt = 1, p = commit->parents;
486                      cnt != opts->mainline && p;
487                      cnt++)
488                         p = p->next;
489                 if (cnt != opts->mainline || !p)
490                         return error(_("Commit %s does not have parent %d"),
491                                 oid_to_hex(&commit->object.oid), opts->mainline);
492                 parent = p->item;
493         } else if (0 < opts->mainline)
494                 return error(_("Mainline was specified but commit %s is not a merge."),
495                         oid_to_hex(&commit->object.oid));
496         else
497                 parent = commit->parents->item;
498
499         if (opts->allow_ff &&
500             ((parent && !hashcmp(parent->object.oid.hash, head)) ||
501              (!parent && unborn)))
502                 return fast_forward_to(commit->object.oid.hash, head, unborn, opts);
503
504         if (parent && parse_commit(parent) < 0)
505                 /* TRANSLATORS: The first %s will be "revert" or
506                    "cherry-pick", the second %s a SHA1 */
507                 return error(_("%s: cannot parse parent commit %s"),
508                         action_name(opts), oid_to_hex(&parent->object.oid));
509
510         if (get_message(commit, &msg) != 0)
511                 return error(_("Cannot get commit message for %s"),
512                         oid_to_hex(&commit->object.oid));
513
514         /*
515          * "commit" is an existing commit.  We would want to apply
516          * the difference it introduces since its first parent "prev"
517          * on top of the current HEAD if we are cherry-pick.  Or the
518          * reverse of it if we are revert.
519          */
520
521         if (opts->action == REPLAY_REVERT) {
522                 base = commit;
523                 base_label = msg.label;
524                 next = parent;
525                 next_label = msg.parent_label;
526                 strbuf_addstr(&msgbuf, "Revert \"");
527                 strbuf_addstr(&msgbuf, msg.subject);
528                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
529                 strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
530
531                 if (commit->parents && commit->parents->next) {
532                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
533                         strbuf_addstr(&msgbuf, oid_to_hex(&parent->object.oid));
534                 }
535                 strbuf_addstr(&msgbuf, ".\n");
536         } else {
537                 const char *p;
538
539                 base = parent;
540                 base_label = msg.parent_label;
541                 next = commit;
542                 next_label = msg.label;
543
544                 /*
545                  * Append the commit log message to msgbuf; it starts
546                  * after the tree, parent, author, committer
547                  * information followed by "\n\n".
548                  */
549                 p = strstr(msg.message, "\n\n");
550                 if (p)
551                         strbuf_addstr(&msgbuf, skip_blank_lines(p + 2));
552
553                 if (opts->record_origin) {
554                         if (!has_conforming_footer(&msgbuf, NULL, 0))
555                                 strbuf_addch(&msgbuf, '\n');
556                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
557                         strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
558                         strbuf_addstr(&msgbuf, ")\n");
559                 }
560         }
561
562         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
563                 res = do_recursive_merge(base, next, base_label, next_label,
564                                          head, &msgbuf, opts);
565                 if (res < 0)
566                         return res;
567                 write_message(&msgbuf, git_path_merge_msg());
568         } else {
569                 struct commit_list *common = NULL;
570                 struct commit_list *remotes = NULL;
571
572                 write_message(&msgbuf, git_path_merge_msg());
573
574                 commit_list_insert(base, &common);
575                 commit_list_insert(next, &remotes);
576                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
577                                         common, sha1_to_hex(head), remotes);
578                 free_commit_list(common);
579                 free_commit_list(remotes);
580         }
581
582         /*
583          * If the merge was clean or if it failed due to conflict, we write
584          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
585          * However, if the merge did not even start, then we don't want to
586          * write it at all.
587          */
588         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
589                 update_ref(NULL, "CHERRY_PICK_HEAD", commit->object.oid.hash, NULL,
590                            REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
591         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
592                 update_ref(NULL, "REVERT_HEAD", commit->object.oid.hash, NULL,
593                            REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
594
595         if (res) {
596                 error(opts->action == REPLAY_REVERT
597                       ? _("could not revert %s... %s")
598                       : _("could not apply %s... %s"),
599                       find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV),
600                       msg.subject);
601                 print_advice(res == 1, opts);
602                 rerere(opts->allow_rerere_auto);
603                 goto leave;
604         }
605
606         allow = allow_empty(opts, commit);
607         if (allow < 0) {
608                 res = allow;
609                 goto leave;
610         }
611         if (!opts->no_commit)
612                 res = run_git_commit(git_path_merge_msg(), opts, allow);
613
614 leave:
615         free_message(commit, &msg);
616
617         return res;
618 }
619
620 static void prepare_revs(struct replay_opts *opts)
621 {
622         /*
623          * picking (but not reverting) ranges (but not individual revisions)
624          * should be done in reverse
625          */
626         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
627                 opts->revs->reverse ^= 1;
628
629         if (prepare_revision_walk(opts->revs))
630                 die(_("revision walk setup failed"));
631
632         if (!opts->revs->commits)
633                 die(_("empty commit set passed"));
634 }
635
636 static void read_and_refresh_cache(struct replay_opts *opts)
637 {
638         static struct lock_file index_lock;
639         int index_fd = hold_locked_index(&index_lock, 0);
640         if (read_index_preload(&the_index, NULL) < 0)
641                 die(_("git %s: failed to read the index"), action_name(opts));
642         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
643         if (the_index.cache_changed && index_fd >= 0) {
644                 if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
645                         die(_("git %s: failed to refresh the index"), action_name(opts));
646         }
647         rollback_lock_file(&index_lock);
648 }
649
650 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
651                 struct replay_opts *opts)
652 {
653         struct commit_list *cur = NULL;
654         const char *sha1_abbrev = NULL;
655         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
656         const char *subject;
657         int subject_len;
658
659         for (cur = todo_list; cur; cur = cur->next) {
660                 const char *commit_buffer = get_commit_buffer(cur->item, NULL);
661                 sha1_abbrev = find_unique_abbrev(cur->item->object.oid.hash, DEFAULT_ABBREV);
662                 subject_len = find_commit_subject(commit_buffer, &subject);
663                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
664                         subject_len, subject);
665                 unuse_commit_buffer(cur->item, commit_buffer);
666         }
667         return 0;
668 }
669
670 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
671 {
672         unsigned char commit_sha1[20];
673         enum replay_action action;
674         char *end_of_object_name;
675         int saved, status, padding;
676
677         if (starts_with(bol, "pick")) {
678                 action = REPLAY_PICK;
679                 bol += strlen("pick");
680         } else if (starts_with(bol, "revert")) {
681                 action = REPLAY_REVERT;
682                 bol += strlen("revert");
683         } else
684                 return NULL;
685
686         /* Eat up extra spaces/ tabs before object name */
687         padding = strspn(bol, " \t");
688         if (!padding)
689                 return NULL;
690         bol += padding;
691
692         end_of_object_name = bol + strcspn(bol, " \t\n");
693         saved = *end_of_object_name;
694         *end_of_object_name = '\0';
695         status = get_sha1(bol, commit_sha1);
696         *end_of_object_name = saved;
697
698         /*
699          * Verify that the action matches up with the one in
700          * opts; we don't support arbitrary instructions
701          */
702         if (action != opts->action) {
703                 if (action == REPLAY_REVERT)
704                       error((opts->action == REPLAY_REVERT)
705                             ? _("Cannot revert during another revert.")
706                             : _("Cannot revert during a cherry-pick."));
707                 else
708                       error((opts->action == REPLAY_REVERT)
709                             ? _("Cannot cherry-pick during a revert.")
710                             : _("Cannot cherry-pick during another cherry-pick."));
711                 return NULL;
712         }
713
714         if (status < 0)
715                 return NULL;
716
717         return lookup_commit_reference(commit_sha1);
718 }
719
720 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
721                         struct replay_opts *opts)
722 {
723         struct commit_list **next = todo_list;
724         struct commit *commit;
725         char *p = buf;
726         int i;
727
728         for (i = 1; *p; i++) {
729                 char *eol = strchrnul(p, '\n');
730                 commit = parse_insn_line(p, eol, opts);
731                 if (!commit)
732                         return error(_("Could not parse line %d."), i);
733                 next = commit_list_append(commit, next);
734                 p = *eol ? eol + 1 : eol;
735         }
736         if (!*todo_list)
737                 return error(_("No commits parsed."));
738         return 0;
739 }
740
741 static void read_populate_todo(struct commit_list **todo_list,
742                         struct replay_opts *opts)
743 {
744         struct strbuf buf = STRBUF_INIT;
745         int fd, res;
746
747         fd = open(git_path_todo_file(), O_RDONLY);
748         if (fd < 0)
749                 die_errno(_("Could not open %s"), git_path_todo_file());
750         if (strbuf_read(&buf, fd, 0) < 0) {
751                 close(fd);
752                 strbuf_release(&buf);
753                 die(_("Could not read %s."), git_path_todo_file());
754         }
755         close(fd);
756
757         res = parse_insn_buffer(buf.buf, todo_list, opts);
758         strbuf_release(&buf);
759         if (res)
760                 die(_("Unusable instruction sheet: %s"), git_path_todo_file());
761 }
762
763 static int populate_opts_cb(const char *key, const char *value, void *data)
764 {
765         struct replay_opts *opts = data;
766         int error_flag = 1;
767
768         if (!value)
769                 error_flag = 0;
770         else if (!strcmp(key, "options.no-commit"))
771                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
772         else if (!strcmp(key, "options.edit"))
773                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
774         else if (!strcmp(key, "options.signoff"))
775                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
776         else if (!strcmp(key, "options.record-origin"))
777                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
778         else if (!strcmp(key, "options.allow-ff"))
779                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
780         else if (!strcmp(key, "options.mainline"))
781                 opts->mainline = git_config_int(key, value);
782         else if (!strcmp(key, "options.strategy"))
783                 git_config_string(&opts->strategy, key, value);
784         else if (!strcmp(key, "options.gpg-sign"))
785                 git_config_string(&opts->gpg_sign, key, value);
786         else if (!strcmp(key, "options.strategy-option")) {
787                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
788                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
789         } else
790                 return error(_("Invalid key: %s"), key);
791
792         if (!error_flag)
793                 return error(_("Invalid value for %s: %s"), key, value);
794
795         return 0;
796 }
797
798 static void read_populate_opts(struct replay_opts **opts_ptr)
799 {
800         if (!file_exists(git_path_opts_file()))
801                 return;
802         if (git_config_from_file(populate_opts_cb, git_path_opts_file(), *opts_ptr) < 0)
803                 die(_("Malformed options sheet: %s"), git_path_opts_file());
804 }
805
806 static void walk_revs_populate_todo(struct commit_list **todo_list,
807                                 struct replay_opts *opts)
808 {
809         struct commit *commit;
810         struct commit_list **next;
811
812         prepare_revs(opts);
813
814         next = todo_list;
815         while ((commit = get_revision(opts->revs)))
816                 next = commit_list_append(commit, next);
817 }
818
819 static int create_seq_dir(void)
820 {
821         if (file_exists(git_path_seq_dir())) {
822                 error(_("a cherry-pick or revert is already in progress"));
823                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
824                 return -1;
825         }
826         else if (mkdir(git_path_seq_dir(), 0777) < 0)
827                 die_errno(_("Could not create sequencer directory %s"),
828                           git_path_seq_dir());
829         return 0;
830 }
831
832 static void save_head(const char *head)
833 {
834         static struct lock_file head_lock;
835         struct strbuf buf = STRBUF_INIT;
836         int fd;
837
838         fd = hold_lock_file_for_update(&head_lock, git_path_head_file(), LOCK_DIE_ON_ERROR);
839         strbuf_addf(&buf, "%s\n", head);
840         if (write_in_full(fd, buf.buf, buf.len) < 0)
841                 die_errno(_("Could not write to %s"), git_path_head_file());
842         if (commit_lock_file(&head_lock) < 0)
843                 die(_("Error wrapping up %s."), git_path_head_file());
844 }
845
846 static int reset_for_rollback(const unsigned char *sha1)
847 {
848         const char *argv[4];    /* reset --merge <arg> + NULL */
849         argv[0] = "reset";
850         argv[1] = "--merge";
851         argv[2] = sha1_to_hex(sha1);
852         argv[3] = NULL;
853         return run_command_v_opt(argv, RUN_GIT_CMD);
854 }
855
856 static int rollback_single_pick(void)
857 {
858         unsigned char head_sha1[20];
859
860         if (!file_exists(git_path_cherry_pick_head()) &&
861             !file_exists(git_path_revert_head()))
862                 return error(_("no cherry-pick or revert in progress"));
863         if (read_ref_full("HEAD", 0, head_sha1, NULL))
864                 return error(_("cannot resolve HEAD"));
865         if (is_null_sha1(head_sha1))
866                 return error(_("cannot abort from a branch yet to be born"));
867         return reset_for_rollback(head_sha1);
868 }
869
870 static int sequencer_rollback(struct replay_opts *opts)
871 {
872         FILE *f;
873         unsigned char sha1[20];
874         struct strbuf buf = STRBUF_INIT;
875
876         f = fopen(git_path_head_file(), "r");
877         if (!f && errno == ENOENT) {
878                 /*
879                  * There is no multiple-cherry-pick in progress.
880                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
881                  * a single-cherry-pick in progress, abort that.
882                  */
883                 return rollback_single_pick();
884         }
885         if (!f)
886                 return error_errno(_("cannot open %s"), git_path_head_file());
887         if (strbuf_getline_lf(&buf, f)) {
888                 error(_("cannot read %s: %s"), git_path_head_file(),
889                       ferror(f) ?  strerror(errno) : _("unexpected end of file"));
890                 fclose(f);
891                 goto fail;
892         }
893         fclose(f);
894         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
895                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
896                         git_path_head_file());
897                 goto fail;
898         }
899         if (is_null_sha1(sha1)) {
900                 error(_("cannot abort from a branch yet to be born"));
901                 goto fail;
902         }
903         if (reset_for_rollback(sha1))
904                 goto fail;
905         remove_sequencer_state();
906         strbuf_release(&buf);
907         return 0;
908 fail:
909         strbuf_release(&buf);
910         return -1;
911 }
912
913 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
914 {
915         static struct lock_file todo_lock;
916         struct strbuf buf = STRBUF_INIT;
917         int fd;
918
919         fd = hold_lock_file_for_update(&todo_lock, git_path_todo_file(), LOCK_DIE_ON_ERROR);
920         if (format_todo(&buf, todo_list, opts) < 0)
921                 die(_("Could not format %s."), git_path_todo_file());
922         if (write_in_full(fd, buf.buf, buf.len) < 0) {
923                 strbuf_release(&buf);
924                 die_errno(_("Could not write to %s"), git_path_todo_file());
925         }
926         if (commit_lock_file(&todo_lock) < 0) {
927                 strbuf_release(&buf);
928                 die(_("Error wrapping up %s."), git_path_todo_file());
929         }
930         strbuf_release(&buf);
931 }
932
933 static void save_opts(struct replay_opts *opts)
934 {
935         const char *opts_file = git_path_opts_file();
936
937         if (opts->no_commit)
938                 git_config_set_in_file(opts_file, "options.no-commit", "true");
939         if (opts->edit)
940                 git_config_set_in_file(opts_file, "options.edit", "true");
941         if (opts->signoff)
942                 git_config_set_in_file(opts_file, "options.signoff", "true");
943         if (opts->record_origin)
944                 git_config_set_in_file(opts_file, "options.record-origin", "true");
945         if (opts->allow_ff)
946                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
947         if (opts->mainline) {
948                 struct strbuf buf = STRBUF_INIT;
949                 strbuf_addf(&buf, "%d", opts->mainline);
950                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
951                 strbuf_release(&buf);
952         }
953         if (opts->strategy)
954                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
955         if (opts->gpg_sign)
956                 git_config_set_in_file(opts_file, "options.gpg-sign", opts->gpg_sign);
957         if (opts->xopts) {
958                 int i;
959                 for (i = 0; i < opts->xopts_nr; i++)
960                         git_config_set_multivar_in_file(opts_file,
961                                                         "options.strategy-option",
962                                                         opts->xopts[i], "^$", 0);
963         }
964 }
965
966 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
967 {
968         struct commit_list *cur;
969         int res;
970
971         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
972         if (opts->allow_ff)
973                 assert(!(opts->signoff || opts->no_commit ||
974                                 opts->record_origin || opts->edit));
975         read_and_refresh_cache(opts);
976
977         for (cur = todo_list; cur; cur = cur->next) {
978                 save_todo(cur, opts);
979                 res = do_pick_commit(cur->item, opts);
980                 if (res)
981                         return res;
982         }
983
984         /*
985          * Sequence of picks finished successfully; cleanup by
986          * removing the .git/sequencer directory
987          */
988         remove_sequencer_state();
989         return 0;
990 }
991
992 static int continue_single_pick(void)
993 {
994         const char *argv[] = { "commit", NULL };
995
996         if (!file_exists(git_path_cherry_pick_head()) &&
997             !file_exists(git_path_revert_head()))
998                 return error(_("no cherry-pick or revert in progress"));
999         return run_command_v_opt(argv, RUN_GIT_CMD);
1000 }
1001
1002 static int sequencer_continue(struct replay_opts *opts)
1003 {
1004         struct commit_list *todo_list = NULL;
1005
1006         if (!file_exists(git_path_todo_file()))
1007                 return continue_single_pick();
1008         read_populate_opts(&opts);
1009         read_populate_todo(&todo_list, opts);
1010
1011         /* Verify that the conflict has been resolved */
1012         if (file_exists(git_path_cherry_pick_head()) ||
1013             file_exists(git_path_revert_head())) {
1014                 int ret = continue_single_pick();
1015                 if (ret)
1016                         return ret;
1017         }
1018         if (index_differs_from("HEAD", 0))
1019                 return error_dirty_index(opts);
1020         todo_list = todo_list->next;
1021         return pick_commits(todo_list, opts);
1022 }
1023
1024 static int single_pick(struct commit *cmit, struct replay_opts *opts)
1025 {
1026         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1027         return do_pick_commit(cmit, opts);
1028 }
1029
1030 int sequencer_pick_revisions(struct replay_opts *opts)
1031 {
1032         struct commit_list *todo_list = NULL;
1033         unsigned char sha1[20];
1034         int i;
1035
1036         if (opts->subcommand == REPLAY_NONE)
1037                 assert(opts->revs);
1038
1039         read_and_refresh_cache(opts);
1040
1041         /*
1042          * Decide what to do depending on the arguments; a fresh
1043          * cherry-pick should be handled differently from an existing
1044          * one that is being continued
1045          */
1046         if (opts->subcommand == REPLAY_REMOVE_STATE) {
1047                 remove_sequencer_state();
1048                 return 0;
1049         }
1050         if (opts->subcommand == REPLAY_ROLLBACK)
1051                 return sequencer_rollback(opts);
1052         if (opts->subcommand == REPLAY_CONTINUE)
1053                 return sequencer_continue(opts);
1054
1055         for (i = 0; i < opts->revs->pending.nr; i++) {
1056                 unsigned char sha1[20];
1057                 const char *name = opts->revs->pending.objects[i].name;
1058
1059                 /* This happens when using --stdin. */
1060                 if (!strlen(name))
1061                         continue;
1062
1063                 if (!get_sha1(name, sha1)) {
1064                         if (!lookup_commit_reference_gently(sha1, 1)) {
1065                                 enum object_type type = sha1_object_info(sha1, NULL);
1066                                 die(_("%s: can't cherry-pick a %s"), name, typename(type));
1067                         }
1068                 } else
1069                         die(_("%s: bad revision"), name);
1070         }
1071
1072         /*
1073          * If we were called as "git cherry-pick <commit>", just
1074          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1075          * REVERT_HEAD, and don't touch the sequencer state.
1076          * This means it is possible to cherry-pick in the middle
1077          * of a cherry-pick sequence.
1078          */
1079         if (opts->revs->cmdline.nr == 1 &&
1080             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1081             opts->revs->no_walk &&
1082             !opts->revs->cmdline.rev->flags) {
1083                 struct commit *cmit;
1084                 if (prepare_revision_walk(opts->revs))
1085                         die(_("revision walk setup failed"));
1086                 cmit = get_revision(opts->revs);
1087                 if (!cmit || get_revision(opts->revs))
1088                         die("BUG: expected exactly one commit from walk");
1089                 return single_pick(cmit, opts);
1090         }
1091
1092         /*
1093          * Start a new cherry-pick/ revert sequence; but
1094          * first, make sure that an existing one isn't in
1095          * progress
1096          */
1097
1098         walk_revs_populate_todo(&todo_list, opts);
1099         if (create_seq_dir() < 0)
1100                 return -1;
1101         if (get_sha1("HEAD", sha1) && (opts->action == REPLAY_REVERT))
1102                 return error(_("Can't revert as initial commit"));
1103         save_head(sha1_to_hex(sha1));
1104         save_opts(opts);
1105         return pick_commits(todo_list, opts);
1106 }
1107
1108 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1109 {
1110         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1111         struct strbuf sob = STRBUF_INIT;
1112         int has_footer;
1113
1114         strbuf_addstr(&sob, sign_off_header);
1115         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1116                                 getenv("GIT_COMMITTER_EMAIL")));
1117         strbuf_addch(&sob, '\n');
1118
1119         /*
1120          * If the whole message buffer is equal to the sob, pretend that we
1121          * found a conforming footer with a matching sob
1122          */
1123         if (msgbuf->len - ignore_footer == sob.len &&
1124             !strncmp(msgbuf->buf, sob.buf, sob.len))
1125                 has_footer = 3;
1126         else
1127                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1128
1129         if (!has_footer) {
1130                 const char *append_newlines = NULL;
1131                 size_t len = msgbuf->len - ignore_footer;
1132
1133                 if (!len) {
1134                         /*
1135                          * The buffer is completely empty.  Leave foom for
1136                          * the title and body to be filled in by the user.
1137                          */
1138                         append_newlines = "\n\n";
1139                 } else if (msgbuf->buf[len - 1] != '\n') {
1140                         /*
1141                          * Incomplete line.  Complete the line and add a
1142                          * blank one so that there is an empty line between
1143                          * the message body and the sob.
1144                          */
1145                         append_newlines = "\n\n";
1146                 } else if (len == 1) {
1147                         /*
1148                          * Buffer contains a single newline.  Add another
1149                          * so that we leave room for the title and body.
1150                          */
1151                         append_newlines = "\n";
1152                 } else if (msgbuf->buf[len - 2] != '\n') {
1153                         /*
1154                          * Buffer ends with a single newline.  Add another
1155                          * so that there is an empty line between the message
1156                          * body and the sob.
1157                          */
1158                         append_newlines = "\n";
1159                 } /* else, the buffer already ends with two newlines. */
1160
1161                 if (append_newlines)
1162                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1163                                 append_newlines, strlen(append_newlines));
1164         }
1165
1166         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1167                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1168                                 sob.buf, sob.len);
1169
1170         strbuf_release(&sob);
1171 }