Merge branch 'jc/am-i-v-fix' 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_addf(&seq_dir, "%s", 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         const char *label;
128         const 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 abbrev_len, subject_len;
136         char *q;
137
138         if (!git_commit_encoding)
139                 git_commit_encoding = "UTF-8";
140
141         out->message = logmsg_reencode(commit, NULL, git_commit_encoding);
142         abbrev = find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV);
143         abbrev_len = strlen(abbrev);
144
145         subject_len = find_commit_subject(out->message, &subject);
146
147         out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
148                               strlen("... ") + subject_len + 1);
149         q = out->parent_label;
150         q = mempcpy(q, "parent of ", strlen("parent of "));
151         out->label = q;
152         q = mempcpy(q, abbrev, abbrev_len);
153         q = mempcpy(q, "... ", strlen("... "));
154         out->subject = q;
155         q = mempcpy(q, subject, subject_len);
156         *q = '\0';
157         return 0;
158 }
159
160 static void free_message(struct commit *commit, struct commit_message *msg)
161 {
162         free(msg->parent_label);
163         unuse_commit_buffer(commit, msg->message);
164 }
165
166 static void print_advice(int show_hint, struct replay_opts *opts)
167 {
168         char *msg = getenv("GIT_CHERRY_PICK_HELP");
169
170         if (msg) {
171                 fprintf(stderr, "%s\n", msg);
172                 /*
173                  * A conflict has occurred but the porcelain
174                  * (typically rebase --interactive) wants to take care
175                  * of the commit itself so remove CHERRY_PICK_HEAD
176                  */
177                 unlink(git_path_cherry_pick_head());
178                 return;
179         }
180
181         if (show_hint) {
182                 if (opts->no_commit)
183                         advise(_("after resolving the conflicts, mark the corrected paths\n"
184                                  "with 'git add <paths>' or 'git rm <paths>'"));
185                 else
186                         advise(_("after resolving the conflicts, mark the corrected paths\n"
187                                  "with 'git add <paths>' or 'git rm <paths>'\n"
188                                  "and commit the result with 'git commit'"));
189         }
190 }
191
192 static void write_message(struct strbuf *msgbuf, const char *filename)
193 {
194         static struct lock_file msg_file;
195
196         int msg_fd = hold_lock_file_for_update(&msg_file, filename,
197                                                LOCK_DIE_ON_ERROR);
198         if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
199                 die_errno(_("Could not write to %s"), filename);
200         strbuf_release(msgbuf);
201         if (commit_lock_file(&msg_file) < 0)
202                 die(_("Error wrapping up %s"), filename);
203 }
204
205 static struct tree *empty_tree(void)
206 {
207         return lookup_tree(EMPTY_TREE_SHA1_BIN);
208 }
209
210 static int error_dirty_index(struct replay_opts *opts)
211 {
212         if (read_cache_unmerged())
213                 return error_resolve_conflict(action_name(opts));
214
215         /* Different translation strings for cherry-pick and revert */
216         if (opts->action == REPLAY_PICK)
217                 error(_("Your local changes would be overwritten by cherry-pick."));
218         else
219                 error(_("Your local changes would be overwritten by revert."));
220
221         if (advice_commit_before_merge)
222                 advise(_("Commit your changes or stash them to proceed."));
223         return -1;
224 }
225
226 static int fast_forward_to(const unsigned char *to, const unsigned char *from,
227                         int unborn, struct replay_opts *opts)
228 {
229         struct ref_transaction *transaction;
230         struct strbuf sb = STRBUF_INIT;
231         struct strbuf err = STRBUF_INIT;
232
233         read_cache();
234         if (checkout_fast_forward(from, to, 1))
235                 exit(128); /* the callee should have complained already */
236
237         strbuf_addf(&sb, "%s: fast-forward", action_name(opts));
238
239         transaction = ref_transaction_begin(&err);
240         if (!transaction ||
241             ref_transaction_update(transaction, "HEAD",
242                                    to, unborn ? null_sha1 : from,
243                                    0, sb.buf, &err) ||
244             ref_transaction_commit(transaction, &err)) {
245                 ref_transaction_free(transaction);
246                 error("%s", err.buf);
247                 strbuf_release(&sb);
248                 strbuf_release(&err);
249                 return -1;
250         }
251
252         strbuf_release(&sb);
253         strbuf_release(&err);
254         ref_transaction_free(transaction);
255         return 0;
256 }
257
258 void append_conflicts_hint(struct strbuf *msgbuf)
259 {
260         int i;
261
262         strbuf_addch(msgbuf, '\n');
263         strbuf_commented_addf(msgbuf, "Conflicts:\n");
264         for (i = 0; i < active_nr;) {
265                 const struct cache_entry *ce = active_cache[i++];
266                 if (ce_stage(ce)) {
267                         strbuf_commented_addf(msgbuf, "\t%s\n", ce->name);
268                         while (i < active_nr && !strcmp(ce->name,
269                                                         active_cache[i]->name))
270                                 i++;
271                 }
272         }
273 }
274
275 static int do_recursive_merge(struct commit *base, struct commit *next,
276                               const char *base_label, const char *next_label,
277                               unsigned char *head, struct strbuf *msgbuf,
278                               struct replay_opts *opts)
279 {
280         struct merge_options o;
281         struct tree *result, *next_tree, *base_tree, *head_tree;
282         int clean;
283         const char **xopt;
284         static struct lock_file index_lock;
285
286         hold_locked_index(&index_lock, 1);
287
288         read_cache();
289
290         init_merge_options(&o);
291         o.ancestor = base ? base_label : "(empty tree)";
292         o.branch1 = "HEAD";
293         o.branch2 = next ? next_label : "(empty tree)";
294
295         head_tree = parse_tree_indirect(head);
296         next_tree = next ? next->tree : empty_tree();
297         base_tree = base ? base->tree : empty_tree();
298
299         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
300                 parse_merge_opt(&o, *xopt);
301
302         clean = merge_trees(&o,
303                             head_tree,
304                             next_tree, base_tree, &result);
305
306         if (active_cache_changed &&
307             write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
308                 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
309                 die(_("%s: Unable to write new index file"), action_name(opts));
310         rollback_lock_file(&index_lock);
311
312         if (opts->signoff)
313                 append_signoff(msgbuf, 0, 0);
314
315         if (!clean)
316                 append_conflicts_hint(msgbuf);
317
318         return !clean;
319 }
320
321 static int is_index_unchanged(void)
322 {
323         unsigned char head_sha1[20];
324         struct commit *head_commit;
325
326         if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_sha1, NULL))
327                 return error(_("Could not resolve HEAD commit\n"));
328
329         head_commit = lookup_commit(head_sha1);
330
331         /*
332          * If head_commit is NULL, check_commit, called from
333          * lookup_commit, would have indicated that head_commit is not
334          * a commit object already.  parse_commit() will return failure
335          * without further complaints in such a case.  Otherwise, if
336          * the commit is invalid, parse_commit() will complain.  So
337          * there is nothing for us to say here.  Just return failure.
338          */
339         if (parse_commit(head_commit))
340                 return -1;
341
342         if (!active_cache_tree)
343                 active_cache_tree = cache_tree();
344
345         if (!cache_tree_fully_valid(active_cache_tree))
346                 if (cache_tree_update(&the_index, 0))
347                         return error(_("Unable to update cache tree\n"));
348
349         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.oid.hash);
350 }
351
352 /*
353  * If we are cherry-pick, and if the merge did not result in
354  * hand-editing, we will hit this commit and inherit the original
355  * author date and name.
356  * If we are revert, or if our cherry-pick results in a hand merge,
357  * we had better say that the current user is responsible for that.
358  */
359 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
360                           int allow_empty)
361 {
362         struct argv_array array;
363         int rc;
364         const char *value;
365
366         argv_array_init(&array);
367         argv_array_push(&array, "commit");
368         argv_array_push(&array, "-n");
369
370         if (opts->gpg_sign)
371                 argv_array_pushf(&array, "-S%s", opts->gpg_sign);
372         if (opts->signoff)
373                 argv_array_push(&array, "-s");
374         if (!opts->edit) {
375                 argv_array_push(&array, "-F");
376                 argv_array_push(&array, defmsg);
377                 if (!opts->signoff &&
378                     !opts->record_origin &&
379                     git_config_get_value("commit.cleanup", &value))
380                         argv_array_push(&array, "--cleanup=verbatim");
381         }
382
383         if (allow_empty)
384                 argv_array_push(&array, "--allow-empty");
385
386         if (opts->allow_empty_message)
387                 argv_array_push(&array, "--allow-empty-message");
388
389         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
390         argv_array_clear(&array);
391         return rc;
392 }
393
394 static int is_original_commit_empty(struct commit *commit)
395 {
396         const unsigned char *ptree_sha1;
397
398         if (parse_commit(commit))
399                 return error(_("Could not parse commit %s\n"),
400                              oid_to_hex(&commit->object.oid));
401         if (commit->parents) {
402                 struct commit *parent = commit->parents->item;
403                 if (parse_commit(parent))
404                         return error(_("Could not parse parent commit %s\n"),
405                                 oid_to_hex(&parent->object.oid));
406                 ptree_sha1 = parent->tree->object.oid.hash;
407         } else {
408                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
409         }
410
411         return !hashcmp(ptree_sha1, commit->tree->object.oid.hash);
412 }
413
414 /*
415  * Do we run "git commit" with "--allow-empty"?
416  */
417 static int allow_empty(struct replay_opts *opts, struct commit *commit)
418 {
419         int index_unchanged, empty_commit;
420
421         /*
422          * Three cases:
423          *
424          * (1) we do not allow empty at all and error out.
425          *
426          * (2) we allow ones that were initially empty, but
427          * forbid the ones that become empty;
428          *
429          * (3) we allow both.
430          */
431         if (!opts->allow_empty)
432                 return 0; /* let "git commit" barf as necessary */
433
434         index_unchanged = is_index_unchanged();
435         if (index_unchanged < 0)
436                 return index_unchanged;
437         if (!index_unchanged)
438                 return 0; /* we do not have to say --allow-empty */
439
440         if (opts->keep_redundant_commits)
441                 return 1;
442
443         empty_commit = is_original_commit_empty(commit);
444         if (empty_commit < 0)
445                 return empty_commit;
446         if (!empty_commit)
447                 return 0;
448         else
449                 return 1;
450 }
451
452 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
453 {
454         unsigned char head[20];
455         struct commit *base, *next, *parent;
456         const char *base_label, *next_label;
457         struct commit_message msg = { NULL, NULL, NULL, NULL };
458         struct strbuf msgbuf = STRBUF_INIT;
459         int res, unborn = 0, allow;
460
461         if (opts->no_commit) {
462                 /*
463                  * We do not intend to commit immediately.  We just want to
464                  * merge the differences in, so let's compute the tree
465                  * that represents the "current" state for merge-recursive
466                  * to work on.
467                  */
468                 if (write_cache_as_tree(head, 0, NULL))
469                         die (_("Your index file is unmerged."));
470         } else {
471                 unborn = get_sha1("HEAD", head);
472                 if (unborn)
473                         hashcpy(head, EMPTY_TREE_SHA1_BIN);
474                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))
475                         return error_dirty_index(opts);
476         }
477         discard_cache();
478
479         if (!commit->parents) {
480                 parent = NULL;
481         }
482         else if (commit->parents->next) {
483                 /* Reverting or cherry-picking a merge commit */
484                 int cnt;
485                 struct commit_list *p;
486
487                 if (!opts->mainline)
488                         return error(_("Commit %s is a merge but no -m option was given."),
489                                 oid_to_hex(&commit->object.oid));
490
491                 for (cnt = 1, p = commit->parents;
492                      cnt != opts->mainline && p;
493                      cnt++)
494                         p = p->next;
495                 if (cnt != opts->mainline || !p)
496                         return error(_("Commit %s does not have parent %d"),
497                                 oid_to_hex(&commit->object.oid), opts->mainline);
498                 parent = p->item;
499         } else if (0 < opts->mainline)
500                 return error(_("Mainline was specified but commit %s is not a merge."),
501                         oid_to_hex(&commit->object.oid));
502         else
503                 parent = commit->parents->item;
504
505         if (opts->allow_ff &&
506             ((parent && !hashcmp(parent->object.oid.hash, head)) ||
507              (!parent && unborn)))
508                 return fast_forward_to(commit->object.oid.hash, head, unborn, opts);
509
510         if (parent && parse_commit(parent) < 0)
511                 /* TRANSLATORS: The first %s will be "revert" or
512                    "cherry-pick", the second %s a SHA1 */
513                 return error(_("%s: cannot parse parent commit %s"),
514                         action_name(opts), oid_to_hex(&parent->object.oid));
515
516         if (get_message(commit, &msg) != 0)
517                 return error(_("Cannot get commit message for %s"),
518                         oid_to_hex(&commit->object.oid));
519
520         /*
521          * "commit" is an existing commit.  We would want to apply
522          * the difference it introduces since its first parent "prev"
523          * on top of the current HEAD if we are cherry-pick.  Or the
524          * reverse of it if we are revert.
525          */
526
527         if (opts->action == REPLAY_REVERT) {
528                 base = commit;
529                 base_label = msg.label;
530                 next = parent;
531                 next_label = msg.parent_label;
532                 strbuf_addstr(&msgbuf, "Revert \"");
533                 strbuf_addstr(&msgbuf, msg.subject);
534                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
535                 strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
536
537                 if (commit->parents && commit->parents->next) {
538                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
539                         strbuf_addstr(&msgbuf, oid_to_hex(&parent->object.oid));
540                 }
541                 strbuf_addstr(&msgbuf, ".\n");
542         } else {
543                 const char *p;
544
545                 base = parent;
546                 base_label = msg.parent_label;
547                 next = commit;
548                 next_label = msg.label;
549
550                 /*
551                  * Append the commit log message to msgbuf; it starts
552                  * after the tree, parent, author, committer
553                  * information followed by "\n\n".
554                  */
555                 p = strstr(msg.message, "\n\n");
556                 if (p) {
557                         p += 2;
558                         strbuf_addstr(&msgbuf, p);
559                 }
560
561                 if (opts->record_origin) {
562                         if (!has_conforming_footer(&msgbuf, NULL, 0))
563                                 strbuf_addch(&msgbuf, '\n');
564                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
565                         strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
566                         strbuf_addstr(&msgbuf, ")\n");
567                 }
568         }
569
570         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
571                 res = do_recursive_merge(base, next, base_label, next_label,
572                                          head, &msgbuf, opts);
573                 write_message(&msgbuf, git_path_merge_msg());
574         } else {
575                 struct commit_list *common = NULL;
576                 struct commit_list *remotes = NULL;
577
578                 write_message(&msgbuf, git_path_merge_msg());
579
580                 commit_list_insert(base, &common);
581                 commit_list_insert(next, &remotes);
582                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
583                                         common, sha1_to_hex(head), remotes);
584                 free_commit_list(common);
585                 free_commit_list(remotes);
586         }
587
588         /*
589          * If the merge was clean or if it failed due to conflict, we write
590          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
591          * However, if the merge did not even start, then we don't want to
592          * write it at all.
593          */
594         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
595                 update_ref(NULL, "CHERRY_PICK_HEAD", commit->object.oid.hash, NULL,
596                            REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
597         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
598                 update_ref(NULL, "REVERT_HEAD", commit->object.oid.hash, NULL,
599                            REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
600
601         if (res) {
602                 error(opts->action == REPLAY_REVERT
603                       ? _("could not revert %s... %s")
604                       : _("could not apply %s... %s"),
605                       find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV),
606                       msg.subject);
607                 print_advice(res == 1, opts);
608                 rerere(opts->allow_rerere_auto);
609                 goto leave;
610         }
611
612         allow = allow_empty(opts, commit);
613         if (allow < 0) {
614                 res = allow;
615                 goto leave;
616         }
617         if (!opts->no_commit)
618                 res = run_git_commit(git_path_merge_msg(), opts, allow);
619
620 leave:
621         free_message(commit, &msg);
622
623         return res;
624 }
625
626 static void prepare_revs(struct replay_opts *opts)
627 {
628         /*
629          * picking (but not reverting) ranges (but not individual revisions)
630          * should be done in reverse
631          */
632         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
633                 opts->revs->reverse ^= 1;
634
635         if (prepare_revision_walk(opts->revs))
636                 die(_("revision walk setup failed"));
637
638         if (!opts->revs->commits)
639                 die(_("empty commit set passed"));
640 }
641
642 static void read_and_refresh_cache(struct replay_opts *opts)
643 {
644         static struct lock_file index_lock;
645         int index_fd = hold_locked_index(&index_lock, 0);
646         if (read_index_preload(&the_index, NULL) < 0)
647                 die(_("git %s: failed to read the index"), action_name(opts));
648         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
649         if (the_index.cache_changed && index_fd >= 0) {
650                 if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
651                         die(_("git %s: failed to refresh the index"), action_name(opts));
652         }
653         rollback_lock_file(&index_lock);
654 }
655
656 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
657                 struct replay_opts *opts)
658 {
659         struct commit_list *cur = NULL;
660         const char *sha1_abbrev = NULL;
661         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
662         const char *subject;
663         int subject_len;
664
665         for (cur = todo_list; cur; cur = cur->next) {
666                 const char *commit_buffer = get_commit_buffer(cur->item, NULL);
667                 sha1_abbrev = find_unique_abbrev(cur->item->object.oid.hash, DEFAULT_ABBREV);
668                 subject_len = find_commit_subject(commit_buffer, &subject);
669                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
670                         subject_len, subject);
671                 unuse_commit_buffer(cur->item, commit_buffer);
672         }
673         return 0;
674 }
675
676 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
677 {
678         unsigned char commit_sha1[20];
679         enum replay_action action;
680         char *end_of_object_name;
681         int saved, status, padding;
682
683         if (starts_with(bol, "pick")) {
684                 action = REPLAY_PICK;
685                 bol += strlen("pick");
686         } else if (starts_with(bol, "revert")) {
687                 action = REPLAY_REVERT;
688                 bol += strlen("revert");
689         } else
690                 return NULL;
691
692         /* Eat up extra spaces/ tabs before object name */
693         padding = strspn(bol, " \t");
694         if (!padding)
695                 return NULL;
696         bol += padding;
697
698         end_of_object_name = bol + strcspn(bol, " \t\n");
699         saved = *end_of_object_name;
700         *end_of_object_name = '\0';
701         status = get_sha1(bol, commit_sha1);
702         *end_of_object_name = saved;
703
704         /*
705          * Verify that the action matches up with the one in
706          * opts; we don't support arbitrary instructions
707          */
708         if (action != opts->action) {
709                 const char *action_str;
710                 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
711                 error(_("Cannot %s during a %s"), action_str, action_name(opts));
712                 return NULL;
713         }
714
715         if (status < 0)
716                 return NULL;
717
718         return lookup_commit_reference(commit_sha1);
719 }
720
721 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
722                         struct replay_opts *opts)
723 {
724         struct commit_list **next = todo_list;
725         struct commit *commit;
726         char *p = buf;
727         int i;
728
729         for (i = 1; *p; i++) {
730                 char *eol = strchrnul(p, '\n');
731                 commit = parse_insn_line(p, eol, opts);
732                 if (!commit)
733                         return error(_("Could not parse line %d."), i);
734                 next = commit_list_append(commit, next);
735                 p = *eol ? eol + 1 : eol;
736         }
737         if (!*todo_list)
738                 return error(_("No commits parsed."));
739         return 0;
740 }
741
742 static void read_populate_todo(struct commit_list **todo_list,
743                         struct replay_opts *opts)
744 {
745         struct strbuf buf = STRBUF_INIT;
746         int fd, res;
747
748         fd = open(git_path_todo_file(), O_RDONLY);
749         if (fd < 0)
750                 die_errno(_("Could not open %s"), git_path_todo_file());
751         if (strbuf_read(&buf, fd, 0) < 0) {
752                 close(fd);
753                 strbuf_release(&buf);
754                 die(_("Could not read %s."), git_path_todo_file());
755         }
756         close(fd);
757
758         res = parse_insn_buffer(buf.buf, todo_list, opts);
759         strbuf_release(&buf);
760         if (res)
761                 die(_("Unusable instruction sheet: %s"), git_path_todo_file());
762 }
763
764 static int populate_opts_cb(const char *key, const char *value, void *data)
765 {
766         struct replay_opts *opts = data;
767         int error_flag = 1;
768
769         if (!value)
770                 error_flag = 0;
771         else if (!strcmp(key, "options.no-commit"))
772                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
773         else if (!strcmp(key, "options.edit"))
774                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
775         else if (!strcmp(key, "options.signoff"))
776                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
777         else if (!strcmp(key, "options.record-origin"))
778                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
779         else if (!strcmp(key, "options.allow-ff"))
780                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
781         else if (!strcmp(key, "options.mainline"))
782                 opts->mainline = git_config_int(key, value);
783         else if (!strcmp(key, "options.strategy"))
784                 git_config_string(&opts->strategy, key, value);
785         else if (!strcmp(key, "options.gpg-sign"))
786                 git_config_string(&opts->gpg_sign, key, value);
787         else if (!strcmp(key, "options.strategy-option")) {
788                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
789                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
790         } else
791                 return error(_("Invalid key: %s"), key);
792
793         if (!error_flag)
794                 return error(_("Invalid value for %s: %s"), key, value);
795
796         return 0;
797 }
798
799 static void read_populate_opts(struct replay_opts **opts_ptr)
800 {
801         if (!file_exists(git_path_opts_file()))
802                 return;
803         if (git_config_from_file(populate_opts_cb, git_path_opts_file(), *opts_ptr) < 0)
804                 die(_("Malformed options sheet: %s"), git_path_opts_file());
805 }
806
807 static void walk_revs_populate_todo(struct commit_list **todo_list,
808                                 struct replay_opts *opts)
809 {
810         struct commit *commit;
811         struct commit_list **next;
812
813         prepare_revs(opts);
814
815         next = todo_list;
816         while ((commit = get_revision(opts->revs)))
817                 next = commit_list_append(commit, next);
818 }
819
820 static int create_seq_dir(void)
821 {
822         if (file_exists(git_path_seq_dir())) {
823                 error(_("a cherry-pick or revert is already in progress"));
824                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
825                 return -1;
826         }
827         else if (mkdir(git_path_seq_dir(), 0777) < 0)
828                 die_errno(_("Could not create sequencer directory %s"),
829                           git_path_seq_dir());
830         return 0;
831 }
832
833 static void save_head(const char *head)
834 {
835         static struct lock_file head_lock;
836         struct strbuf buf = STRBUF_INIT;
837         int fd;
838
839         fd = hold_lock_file_for_update(&head_lock, git_path_head_file(), LOCK_DIE_ON_ERROR);
840         strbuf_addf(&buf, "%s\n", head);
841         if (write_in_full(fd, buf.buf, buf.len) < 0)
842                 die_errno(_("Could not write to %s"), git_path_head_file());
843         if (commit_lock_file(&head_lock) < 0)
844                 die(_("Error wrapping up %s."), git_path_head_file());
845 }
846
847 static int reset_for_rollback(const unsigned char *sha1)
848 {
849         const char *argv[4];    /* reset --merge <arg> + NULL */
850         argv[0] = "reset";
851         argv[1] = "--merge";
852         argv[2] = sha1_to_hex(sha1);
853         argv[3] = NULL;
854         return run_command_v_opt(argv, RUN_GIT_CMD);
855 }
856
857 static int rollback_single_pick(void)
858 {
859         unsigned char head_sha1[20];
860
861         if (!file_exists(git_path_cherry_pick_head()) &&
862             !file_exists(git_path_revert_head()))
863                 return error(_("no cherry-pick or revert in progress"));
864         if (read_ref_full("HEAD", 0, head_sha1, NULL))
865                 return error(_("cannot resolve HEAD"));
866         if (is_null_sha1(head_sha1))
867                 return error(_("cannot abort from a branch yet to be born"));
868         return reset_for_rollback(head_sha1);
869 }
870
871 static int sequencer_rollback(struct replay_opts *opts)
872 {
873         FILE *f;
874         unsigned char sha1[20];
875         struct strbuf buf = STRBUF_INIT;
876
877         f = fopen(git_path_head_file(), "r");
878         if (!f && errno == ENOENT) {
879                 /*
880                  * There is no multiple-cherry-pick in progress.
881                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
882                  * a single-cherry-pick in progress, abort that.
883                  */
884                 return rollback_single_pick();
885         }
886         if (!f)
887                 return error(_("cannot open %s: %s"), git_path_head_file(),
888                                                 strerror(errno));
889         if (strbuf_getline(&buf, f, '\n')) {
890                 error(_("cannot read %s: %s"), git_path_head_file(),
891                       ferror(f) ?  strerror(errno) : _("unexpected end of file"));
892                 fclose(f);
893                 goto fail;
894         }
895         fclose(f);
896         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
897                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
898                         git_path_head_file());
899                 goto fail;
900         }
901         if (reset_for_rollback(sha1))
902                 goto fail;
903         remove_sequencer_state();
904         strbuf_release(&buf);
905         return 0;
906 fail:
907         strbuf_release(&buf);
908         return -1;
909 }
910
911 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
912 {
913         static struct lock_file todo_lock;
914         struct strbuf buf = STRBUF_INIT;
915         int fd;
916
917         fd = hold_lock_file_for_update(&todo_lock, git_path_todo_file(), LOCK_DIE_ON_ERROR);
918         if (format_todo(&buf, todo_list, opts) < 0)
919                 die(_("Could not format %s."), git_path_todo_file());
920         if (write_in_full(fd, buf.buf, buf.len) < 0) {
921                 strbuf_release(&buf);
922                 die_errno(_("Could not write to %s"), git_path_todo_file());
923         }
924         if (commit_lock_file(&todo_lock) < 0) {
925                 strbuf_release(&buf);
926                 die(_("Error wrapping up %s."), git_path_todo_file());
927         }
928         strbuf_release(&buf);
929 }
930
931 static void save_opts(struct replay_opts *opts)
932 {
933         const char *opts_file = git_path_opts_file();
934
935         if (opts->no_commit)
936                 git_config_set_in_file(opts_file, "options.no-commit", "true");
937         if (opts->edit)
938                 git_config_set_in_file(opts_file, "options.edit", "true");
939         if (opts->signoff)
940                 git_config_set_in_file(opts_file, "options.signoff", "true");
941         if (opts->record_origin)
942                 git_config_set_in_file(opts_file, "options.record-origin", "true");
943         if (opts->allow_ff)
944                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
945         if (opts->mainline) {
946                 struct strbuf buf = STRBUF_INIT;
947                 strbuf_addf(&buf, "%d", opts->mainline);
948                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
949                 strbuf_release(&buf);
950         }
951         if (opts->strategy)
952                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
953         if (opts->gpg_sign)
954                 git_config_set_in_file(opts_file, "options.gpg-sign", opts->gpg_sign);
955         if (opts->xopts) {
956                 int i;
957                 for (i = 0; i < opts->xopts_nr; i++)
958                         git_config_set_multivar_in_file(opts_file,
959                                                         "options.strategy-option",
960                                                         opts->xopts[i], "^$", 0);
961         }
962 }
963
964 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
965 {
966         struct commit_list *cur;
967         int res;
968
969         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
970         if (opts->allow_ff)
971                 assert(!(opts->signoff || opts->no_commit ||
972                                 opts->record_origin || opts->edit));
973         read_and_refresh_cache(opts);
974
975         for (cur = todo_list; cur; cur = cur->next) {
976                 save_todo(cur, opts);
977                 res = do_pick_commit(cur->item, opts);
978                 if (res)
979                         return res;
980         }
981
982         /*
983          * Sequence of picks finished successfully; cleanup by
984          * removing the .git/sequencer directory
985          */
986         remove_sequencer_state();
987         return 0;
988 }
989
990 static int continue_single_pick(void)
991 {
992         const char *argv[] = { "commit", NULL };
993
994         if (!file_exists(git_path_cherry_pick_head()) &&
995             !file_exists(git_path_revert_head()))
996                 return error(_("no cherry-pick or revert in progress"));
997         return run_command_v_opt(argv, RUN_GIT_CMD);
998 }
999
1000 static int sequencer_continue(struct replay_opts *opts)
1001 {
1002         struct commit_list *todo_list = NULL;
1003
1004         if (!file_exists(git_path_todo_file()))
1005                 return continue_single_pick();
1006         read_populate_opts(&opts);
1007         read_populate_todo(&todo_list, opts);
1008
1009         /* Verify that the conflict has been resolved */
1010         if (file_exists(git_path_cherry_pick_head()) ||
1011             file_exists(git_path_revert_head())) {
1012                 int ret = continue_single_pick();
1013                 if (ret)
1014                         return ret;
1015         }
1016         if (index_differs_from("HEAD", 0))
1017                 return error_dirty_index(opts);
1018         todo_list = todo_list->next;
1019         return pick_commits(todo_list, opts);
1020 }
1021
1022 static int single_pick(struct commit *cmit, struct replay_opts *opts)
1023 {
1024         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1025         return do_pick_commit(cmit, opts);
1026 }
1027
1028 int sequencer_pick_revisions(struct replay_opts *opts)
1029 {
1030         struct commit_list *todo_list = NULL;
1031         unsigned char sha1[20];
1032         int i;
1033
1034         if (opts->subcommand == REPLAY_NONE)
1035                 assert(opts->revs);
1036
1037         read_and_refresh_cache(opts);
1038
1039         /*
1040          * Decide what to do depending on the arguments; a fresh
1041          * cherry-pick should be handled differently from an existing
1042          * one that is being continued
1043          */
1044         if (opts->subcommand == REPLAY_REMOVE_STATE) {
1045                 remove_sequencer_state();
1046                 return 0;
1047         }
1048         if (opts->subcommand == REPLAY_ROLLBACK)
1049                 return sequencer_rollback(opts);
1050         if (opts->subcommand == REPLAY_CONTINUE)
1051                 return sequencer_continue(opts);
1052
1053         for (i = 0; i < opts->revs->pending.nr; i++) {
1054                 unsigned char sha1[20];
1055                 const char *name = opts->revs->pending.objects[i].name;
1056
1057                 /* This happens when using --stdin. */
1058                 if (!strlen(name))
1059                         continue;
1060
1061                 if (!get_sha1(name, sha1)) {
1062                         if (!lookup_commit_reference_gently(sha1, 1)) {
1063                                 enum object_type type = sha1_object_info(sha1, NULL);
1064                                 die(_("%s: can't cherry-pick a %s"), name, typename(type));
1065                         }
1066                 } else
1067                         die(_("%s: bad revision"), name);
1068         }
1069
1070         /*
1071          * If we were called as "git cherry-pick <commit>", just
1072          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
1073          * REVERT_HEAD, and don't touch the sequencer state.
1074          * This means it is possible to cherry-pick in the middle
1075          * of a cherry-pick sequence.
1076          */
1077         if (opts->revs->cmdline.nr == 1 &&
1078             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
1079             opts->revs->no_walk &&
1080             !opts->revs->cmdline.rev->flags) {
1081                 struct commit *cmit;
1082                 if (prepare_revision_walk(opts->revs))
1083                         die(_("revision walk setup failed"));
1084                 cmit = get_revision(opts->revs);
1085                 if (!cmit || get_revision(opts->revs))
1086                         die("BUG: expected exactly one commit from walk");
1087                 return single_pick(cmit, opts);
1088         }
1089
1090         /*
1091          * Start a new cherry-pick/ revert sequence; but
1092          * first, make sure that an existing one isn't in
1093          * progress
1094          */
1095
1096         walk_revs_populate_todo(&todo_list, opts);
1097         if (create_seq_dir() < 0)
1098                 return -1;
1099         if (get_sha1("HEAD", sha1)) {
1100                 if (opts->action == REPLAY_REVERT)
1101                         return error(_("Can't revert as initial commit"));
1102                 return error(_("Can't cherry-pick into empty head"));
1103         }
1104         save_head(sha1_to_hex(sha1));
1105         save_opts(opts);
1106         return pick_commits(todo_list, opts);
1107 }
1108
1109 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
1110 {
1111         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
1112         struct strbuf sob = STRBUF_INIT;
1113         int has_footer;
1114
1115         strbuf_addstr(&sob, sign_off_header);
1116         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1117                                 getenv("GIT_COMMITTER_EMAIL")));
1118         strbuf_addch(&sob, '\n');
1119
1120         /*
1121          * If the whole message buffer is equal to the sob, pretend that we
1122          * found a conforming footer with a matching sob
1123          */
1124         if (msgbuf->len - ignore_footer == sob.len &&
1125             !strncmp(msgbuf->buf, sob.buf, sob.len))
1126                 has_footer = 3;
1127         else
1128                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
1129
1130         if (!has_footer) {
1131                 const char *append_newlines = NULL;
1132                 size_t len = msgbuf->len - ignore_footer;
1133
1134                 if (!len) {
1135                         /*
1136                          * The buffer is completely empty.  Leave foom for
1137                          * the title and body to be filled in by the user.
1138                          */
1139                         append_newlines = "\n\n";
1140                 } else if (msgbuf->buf[len - 1] != '\n') {
1141                         /*
1142                          * Incomplete line.  Complete the line and add a
1143                          * blank one so that there is an empty line between
1144                          * the message body and the sob.
1145                          */
1146                         append_newlines = "\n\n";
1147                 } else if (len == 1) {
1148                         /*
1149                          * Buffer contains a single newline.  Add another
1150                          * so that we leave room for the title and body.
1151                          */
1152                         append_newlines = "\n";
1153                 } else if (msgbuf->buf[len - 2] != '\n') {
1154                         /*
1155                          * Buffer ends with a single newline.  Add another
1156                          * so that there is an empty line between the message
1157                          * body and the sob.
1158                          */
1159                         append_newlines = "\n";
1160                 } /* else, the buffer already ends with two newlines. */
1161
1162                 if (append_newlines)
1163                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1164                                 append_newlines, strlen(append_newlines));
1165         }
1166
1167         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
1168                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
1169                                 sob.buf, sob.len);
1170
1171         strbuf_release(&sob);
1172 }