Merge branch 'ss/svn-prompt' into maint
[git] / sequencer.c
1 #include "cache.h"
2 #include "sequencer.h"
3 #include "dir.h"
4 #include "object.h"
5 #include "commit.h"
6 #include "tag.h"
7 #include "run-command.h"
8 #include "exec_cmd.h"
9 #include "utf8.h"
10 #include "cache-tree.h"
11 #include "diff.h"
12 #include "revision.h"
13 #include "rerere.h"
14 #include "merge-recursive.h"
15 #include "refs.h"
16 #include "argv-array.h"
17
18 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
19
20 const char sign_off_header[] = "Signed-off-by: ";
21
22 static void remove_sequencer_state(void)
23 {
24         struct strbuf seq_dir = STRBUF_INIT;
25
26         strbuf_addf(&seq_dir, "%s", git_path(SEQ_DIR));
27         remove_dir_recursively(&seq_dir, 0);
28         strbuf_release(&seq_dir);
29 }
30
31 static const char *action_name(const struct replay_opts *opts)
32 {
33         return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
34 }
35
36 static char *get_encoding(const char *message);
37
38 struct commit_message {
39         char *parent_label;
40         const char *label;
41         const char *subject;
42         char *reencoded_message;
43         const char *message;
44 };
45
46 static int get_message(struct commit *commit, struct commit_message *out)
47 {
48         const char *encoding;
49         const char *abbrev, *subject;
50         int abbrev_len, subject_len;
51         char *q;
52
53         if (!commit->buffer)
54                 return -1;
55         encoding = get_encoding(commit->buffer);
56         if (!encoding)
57                 encoding = "UTF-8";
58         if (!git_commit_encoding)
59                 git_commit_encoding = "UTF-8";
60
61         out->reencoded_message = NULL;
62         out->message = commit->buffer;
63         if (same_encoding(encoding, git_commit_encoding))
64                 out->reencoded_message = reencode_string(commit->buffer,
65                                         git_commit_encoding, encoding);
66         if (out->reencoded_message)
67                 out->message = out->reencoded_message;
68
69         abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
70         abbrev_len = strlen(abbrev);
71
72         subject_len = find_commit_subject(out->message, &subject);
73
74         out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
75                               strlen("... ") + subject_len + 1);
76         q = out->parent_label;
77         q = mempcpy(q, "parent of ", strlen("parent of "));
78         out->label = q;
79         q = mempcpy(q, abbrev, abbrev_len);
80         q = mempcpy(q, "... ", strlen("... "));
81         out->subject = q;
82         q = mempcpy(q, subject, subject_len);
83         *q = '\0';
84         return 0;
85 }
86
87 static void free_message(struct commit_message *msg)
88 {
89         free(msg->parent_label);
90         free(msg->reencoded_message);
91 }
92
93 static char *get_encoding(const char *message)
94 {
95         const char *p = message, *eol;
96
97         while (*p && *p != '\n') {
98                 for (eol = p + 1; *eol && *eol != '\n'; eol++)
99                         ; /* do nothing */
100                 if (!prefixcmp(p, "encoding ")) {
101                         char *result = xmalloc(eol - 8 - p);
102                         strlcpy(result, p + 9, eol - 8 - p);
103                         return result;
104                 }
105                 p = eol;
106                 if (*p == '\n')
107                         p++;
108         }
109         return NULL;
110 }
111
112 static void write_cherry_pick_head(struct commit *commit, const char *pseudoref)
113 {
114         const char *filename;
115         int fd;
116         struct strbuf buf = STRBUF_INIT;
117
118         strbuf_addf(&buf, "%s\n", sha1_to_hex(commit->object.sha1));
119
120         filename = git_path("%s", pseudoref);
121         fd = open(filename, O_WRONLY | O_CREAT, 0666);
122         if (fd < 0)
123                 die_errno(_("Could not open '%s' for writing"), filename);
124         if (write_in_full(fd, buf.buf, buf.len) != buf.len || close(fd))
125                 die_errno(_("Could not write to '%s'"), filename);
126         strbuf_release(&buf);
127 }
128
129 static void print_advice(int show_hint, struct replay_opts *opts)
130 {
131         char *msg = getenv("GIT_CHERRY_PICK_HELP");
132
133         if (msg) {
134                 fprintf(stderr, "%s\n", msg);
135                 /*
136                  * A conflict has occured but the porcelain
137                  * (typically rebase --interactive) wants to take care
138                  * of the commit itself so remove CHERRY_PICK_HEAD
139                  */
140                 unlink(git_path("CHERRY_PICK_HEAD"));
141                 return;
142         }
143
144         if (show_hint) {
145                 if (opts->no_commit)
146                         advise(_("after resolving the conflicts, mark the corrected paths\n"
147                                  "with 'git add <paths>' or 'git rm <paths>'"));
148                 else
149                         advise(_("after resolving the conflicts, mark the corrected paths\n"
150                                  "with 'git add <paths>' or 'git rm <paths>'\n"
151                                  "and commit the result with 'git commit'"));
152         }
153 }
154
155 static void write_message(struct strbuf *msgbuf, const char *filename)
156 {
157         static struct lock_file msg_file;
158
159         int msg_fd = hold_lock_file_for_update(&msg_file, filename,
160                                                LOCK_DIE_ON_ERROR);
161         if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
162                 die_errno(_("Could not write to %s"), filename);
163         strbuf_release(msgbuf);
164         if (commit_lock_file(&msg_file) < 0)
165                 die(_("Error wrapping up %s"), filename);
166 }
167
168 static struct tree *empty_tree(void)
169 {
170         return lookup_tree(EMPTY_TREE_SHA1_BIN);
171 }
172
173 static int error_dirty_index(struct replay_opts *opts)
174 {
175         if (read_cache_unmerged())
176                 return error_resolve_conflict(action_name(opts));
177
178         /* Different translation strings for cherry-pick and revert */
179         if (opts->action == REPLAY_PICK)
180                 error(_("Your local changes would be overwritten by cherry-pick."));
181         else
182                 error(_("Your local changes would be overwritten by revert."));
183
184         if (advice_commit_before_merge)
185                 advise(_("Commit your changes or stash them to proceed."));
186         return -1;
187 }
188
189 static int fast_forward_to(const unsigned char *to, const unsigned char *from)
190 {
191         struct ref_lock *ref_lock;
192
193         read_cache();
194         if (checkout_fast_forward(from, to, 1))
195                 exit(1); /* the callee should have complained already */
196         ref_lock = lock_any_ref_for_update("HEAD", from, 0);
197         return write_ref_sha1(ref_lock, to, "cherry-pick");
198 }
199
200 static int do_recursive_merge(struct commit *base, struct commit *next,
201                               const char *base_label, const char *next_label,
202                               unsigned char *head, struct strbuf *msgbuf,
203                               struct replay_opts *opts)
204 {
205         struct merge_options o;
206         struct tree *result, *next_tree, *base_tree, *head_tree;
207         int clean, index_fd;
208         const char **xopt;
209         static struct lock_file index_lock;
210
211         index_fd = hold_locked_index(&index_lock, 1);
212
213         read_cache();
214
215         init_merge_options(&o);
216         o.ancestor = base ? base_label : "(empty tree)";
217         o.branch1 = "HEAD";
218         o.branch2 = next ? next_label : "(empty tree)";
219
220         head_tree = parse_tree_indirect(head);
221         next_tree = next ? next->tree : empty_tree();
222         base_tree = base ? base->tree : empty_tree();
223
224         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
225                 parse_merge_opt(&o, *xopt);
226
227         clean = merge_trees(&o,
228                             head_tree,
229                             next_tree, base_tree, &result);
230
231         if (active_cache_changed &&
232             (write_cache(index_fd, active_cache, active_nr) ||
233              commit_locked_index(&index_lock)))
234                 /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
235                 die(_("%s: Unable to write new index file"), action_name(opts));
236         rollback_lock_file(&index_lock);
237
238         if (opts->signoff)
239                 append_signoff(msgbuf, 0);
240
241         if (!clean) {
242                 int i;
243                 strbuf_addstr(msgbuf, "\nConflicts:\n");
244                 for (i = 0; i < active_nr;) {
245                         struct cache_entry *ce = active_cache[i++];
246                         if (ce_stage(ce)) {
247                                 strbuf_addch(msgbuf, '\t');
248                                 strbuf_addstr(msgbuf, ce->name);
249                                 strbuf_addch(msgbuf, '\n');
250                                 while (i < active_nr && !strcmp(ce->name,
251                                                 active_cache[i]->name))
252                                         i++;
253                         }
254                 }
255         }
256
257         return !clean;
258 }
259
260 static int is_index_unchanged(void)
261 {
262         unsigned char head_sha1[20];
263         struct commit *head_commit;
264
265         if (!resolve_ref_unsafe("HEAD", head_sha1, 1, NULL))
266                 return error(_("Could not resolve HEAD commit\n"));
267
268         head_commit = lookup_commit(head_sha1);
269
270         /*
271          * If head_commit is NULL, check_commit, called from
272          * lookup_commit, would have indicated that head_commit is not
273          * a commit object already.  parse_commit() will return failure
274          * without further complaints in such a case.  Otherwise, if
275          * the commit is invalid, parse_commit() will complain.  So
276          * there is nothing for us to say here.  Just return failure.
277          */
278         if (parse_commit(head_commit))
279                 return -1;
280
281         if (!active_cache_tree)
282                 active_cache_tree = cache_tree();
283
284         if (!cache_tree_fully_valid(active_cache_tree))
285                 if (cache_tree_update(active_cache_tree, active_cache,
286                                   active_nr, 0))
287                         return error(_("Unable to update cache tree\n"));
288
289         return !hashcmp(active_cache_tree->sha1, head_commit->tree->object.sha1);
290 }
291
292 /*
293  * If we are cherry-pick, and if the merge did not result in
294  * hand-editing, we will hit this commit and inherit the original
295  * author date and name.
296  * If we are revert, or if our cherry-pick results in a hand merge,
297  * we had better say that the current user is responsible for that.
298  */
299 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
300                           int allow_empty)
301 {
302         struct argv_array array;
303         int rc;
304
305         argv_array_init(&array);
306         argv_array_push(&array, "commit");
307         argv_array_push(&array, "-n");
308
309         if (opts->signoff)
310                 argv_array_push(&array, "-s");
311         if (!opts->edit) {
312                 argv_array_push(&array, "-F");
313                 argv_array_push(&array, defmsg);
314         }
315
316         if (allow_empty)
317                 argv_array_push(&array, "--allow-empty");
318
319         if (opts->allow_empty_message)
320                 argv_array_push(&array, "--allow-empty-message");
321
322         rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
323         argv_array_clear(&array);
324         return rc;
325 }
326
327 static int is_original_commit_empty(struct commit *commit)
328 {
329         const unsigned char *ptree_sha1;
330
331         if (parse_commit(commit))
332                 return error(_("Could not parse commit %s\n"),
333                              sha1_to_hex(commit->object.sha1));
334         if (commit->parents) {
335                 struct commit *parent = commit->parents->item;
336                 if (parse_commit(parent))
337                         return error(_("Could not parse parent commit %s\n"),
338                                 sha1_to_hex(parent->object.sha1));
339                 ptree_sha1 = parent->tree->object.sha1;
340         } else {
341                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
342         }
343
344         return !hashcmp(ptree_sha1, commit->tree->object.sha1);
345 }
346
347 /*
348  * Do we run "git commit" with "--allow-empty"?
349  */
350 static int allow_empty(struct replay_opts *opts, struct commit *commit)
351 {
352         int index_unchanged, empty_commit;
353
354         /*
355          * Three cases:
356          *
357          * (1) we do not allow empty at all and error out.
358          *
359          * (2) we allow ones that were initially empty, but
360          * forbid the ones that become empty;
361          *
362          * (3) we allow both.
363          */
364         if (!opts->allow_empty)
365                 return 0; /* let "git commit" barf as necessary */
366
367         index_unchanged = is_index_unchanged();
368         if (index_unchanged < 0)
369                 return index_unchanged;
370         if (!index_unchanged)
371                 return 0; /* we do not have to say --allow-empty */
372
373         if (opts->keep_redundant_commits)
374                 return 1;
375
376         empty_commit = is_original_commit_empty(commit);
377         if (empty_commit < 0)
378                 return empty_commit;
379         if (!empty_commit)
380                 return 0;
381         else
382                 return 1;
383 }
384
385 static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
386 {
387         unsigned char head[20];
388         struct commit *base, *next, *parent;
389         const char *base_label, *next_label;
390         struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
391         char *defmsg = NULL;
392         struct strbuf msgbuf = STRBUF_INIT;
393         int res;
394
395         if (opts->no_commit) {
396                 /*
397                  * We do not intend to commit immediately.  We just want to
398                  * merge the differences in, so let's compute the tree
399                  * that represents the "current" state for merge-recursive
400                  * to work on.
401                  */
402                 if (write_cache_as_tree(head, 0, NULL))
403                         die (_("Your index file is unmerged."));
404         } else {
405                 if (get_sha1("HEAD", head))
406                         return error(_("You do not have a valid HEAD"));
407                 if (index_differs_from("HEAD", 0))
408                         return error_dirty_index(opts);
409         }
410         discard_cache();
411
412         if (!commit->parents) {
413                 parent = NULL;
414         }
415         else if (commit->parents->next) {
416                 /* Reverting or cherry-picking a merge commit */
417                 int cnt;
418                 struct commit_list *p;
419
420                 if (!opts->mainline)
421                         return error(_("Commit %s is a merge but no -m option was given."),
422                                 sha1_to_hex(commit->object.sha1));
423
424                 for (cnt = 1, p = commit->parents;
425                      cnt != opts->mainline && p;
426                      cnt++)
427                         p = p->next;
428                 if (cnt != opts->mainline || !p)
429                         return error(_("Commit %s does not have parent %d"),
430                                 sha1_to_hex(commit->object.sha1), opts->mainline);
431                 parent = p->item;
432         } else if (0 < opts->mainline)
433                 return error(_("Mainline was specified but commit %s is not a merge."),
434                         sha1_to_hex(commit->object.sha1));
435         else
436                 parent = commit->parents->item;
437
438         if (opts->allow_ff && parent && !hashcmp(parent->object.sha1, head))
439                 return fast_forward_to(commit->object.sha1, head);
440
441         if (parent && parse_commit(parent) < 0)
442                 /* TRANSLATORS: The first %s will be "revert" or
443                    "cherry-pick", the second %s a SHA1 */
444                 return error(_("%s: cannot parse parent commit %s"),
445                         action_name(opts), sha1_to_hex(parent->object.sha1));
446
447         if (get_message(commit, &msg) != 0)
448                 return error(_("Cannot get commit message for %s"),
449                         sha1_to_hex(commit->object.sha1));
450
451         /*
452          * "commit" is an existing commit.  We would want to apply
453          * the difference it introduces since its first parent "prev"
454          * on top of the current HEAD if we are cherry-pick.  Or the
455          * reverse of it if we are revert.
456          */
457
458         defmsg = git_pathdup("MERGE_MSG");
459
460         if (opts->action == REPLAY_REVERT) {
461                 base = commit;
462                 base_label = msg.label;
463                 next = parent;
464                 next_label = msg.parent_label;
465                 strbuf_addstr(&msgbuf, "Revert \"");
466                 strbuf_addstr(&msgbuf, msg.subject);
467                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
468                 strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
469
470                 if (commit->parents && commit->parents->next) {
471                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
472                         strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
473                 }
474                 strbuf_addstr(&msgbuf, ".\n");
475         } else {
476                 const char *p;
477
478                 base = parent;
479                 base_label = msg.parent_label;
480                 next = commit;
481                 next_label = msg.label;
482
483                 /*
484                  * Append the commit log message to msgbuf; it starts
485                  * after the tree, parent, author, committer
486                  * information followed by "\n\n".
487                  */
488                 p = strstr(msg.message, "\n\n");
489                 if (p) {
490                         p += 2;
491                         strbuf_addstr(&msgbuf, p);
492                 }
493
494                 if (opts->record_origin) {
495                         strbuf_addstr(&msgbuf, "(cherry picked from commit ");
496                         strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
497                         strbuf_addstr(&msgbuf, ")\n");
498                 }
499         }
500
501         if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
502                 res = do_recursive_merge(base, next, base_label, next_label,
503                                          head, &msgbuf, opts);
504                 write_message(&msgbuf, defmsg);
505         } else {
506                 struct commit_list *common = NULL;
507                 struct commit_list *remotes = NULL;
508
509                 write_message(&msgbuf, defmsg);
510
511                 commit_list_insert(base, &common);
512                 commit_list_insert(next, &remotes);
513                 res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
514                                         common, sha1_to_hex(head), remotes);
515                 free_commit_list(common);
516                 free_commit_list(remotes);
517         }
518
519         /*
520          * If the merge was clean or if it failed due to conflict, we write
521          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
522          * However, if the merge did not even start, then we don't want to
523          * write it at all.
524          */
525         if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
526                 write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
527         if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
528                 write_cherry_pick_head(commit, "REVERT_HEAD");
529
530         if (res) {
531                 error(opts->action == REPLAY_REVERT
532                       ? _("could not revert %s... %s")
533                       : _("could not apply %s... %s"),
534                       find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
535                       msg.subject);
536                 print_advice(res == 1, opts);
537                 rerere(opts->allow_rerere_auto);
538         } else {
539                 int allow = allow_empty(opts, commit);
540                 if (allow < 0)
541                         return allow;
542                 if (!opts->no_commit)
543                         res = run_git_commit(defmsg, opts, allow);
544         }
545
546         free_message(&msg);
547         free(defmsg);
548
549         return res;
550 }
551
552 static void prepare_revs(struct replay_opts *opts)
553 {
554         /*
555          * picking (but not reverting) ranges (but not individual revisions)
556          * should be done in reverse
557          */
558         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
559                 opts->revs->reverse ^= 1;
560
561         if (prepare_revision_walk(opts->revs))
562                 die(_("revision walk setup failed"));
563
564         if (!opts->revs->commits)
565                 die(_("empty commit set passed"));
566 }
567
568 static void read_and_refresh_cache(struct replay_opts *opts)
569 {
570         static struct lock_file index_lock;
571         int index_fd = hold_locked_index(&index_lock, 0);
572         if (read_index_preload(&the_index, NULL) < 0)
573                 die(_("git %s: failed to read the index"), action_name(opts));
574         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
575         if (the_index.cache_changed) {
576                 if (write_index(&the_index, index_fd) ||
577                     commit_locked_index(&index_lock))
578                         die(_("git %s: failed to refresh the index"), action_name(opts));
579         }
580         rollback_lock_file(&index_lock);
581 }
582
583 static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
584                 struct replay_opts *opts)
585 {
586         struct commit_list *cur = NULL;
587         const char *sha1_abbrev = NULL;
588         const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
589         const char *subject;
590         int subject_len;
591
592         for (cur = todo_list; cur; cur = cur->next) {
593                 sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
594                 subject_len = find_commit_subject(cur->item->buffer, &subject);
595                 strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
596                         subject_len, subject);
597         }
598         return 0;
599 }
600
601 static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
602 {
603         unsigned char commit_sha1[20];
604         enum replay_action action;
605         char *end_of_object_name;
606         int saved, status, padding;
607
608         if (!prefixcmp(bol, "pick")) {
609                 action = REPLAY_PICK;
610                 bol += strlen("pick");
611         } else if (!prefixcmp(bol, "revert")) {
612                 action = REPLAY_REVERT;
613                 bol += strlen("revert");
614         } else
615                 return NULL;
616
617         /* Eat up extra spaces/ tabs before object name */
618         padding = strspn(bol, " \t");
619         if (!padding)
620                 return NULL;
621         bol += padding;
622
623         end_of_object_name = bol + strcspn(bol, " \t\n");
624         saved = *end_of_object_name;
625         *end_of_object_name = '\0';
626         status = get_sha1(bol, commit_sha1);
627         *end_of_object_name = saved;
628
629         /*
630          * Verify that the action matches up with the one in
631          * opts; we don't support arbitrary instructions
632          */
633         if (action != opts->action) {
634                 const char *action_str;
635                 action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
636                 error(_("Cannot %s during a %s"), action_str, action_name(opts));
637                 return NULL;
638         }
639
640         if (status < 0)
641                 return NULL;
642
643         return lookup_commit_reference(commit_sha1);
644 }
645
646 static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
647                         struct replay_opts *opts)
648 {
649         struct commit_list **next = todo_list;
650         struct commit *commit;
651         char *p = buf;
652         int i;
653
654         for (i = 1; *p; i++) {
655                 char *eol = strchrnul(p, '\n');
656                 commit = parse_insn_line(p, eol, opts);
657                 if (!commit)
658                         return error(_("Could not parse line %d."), i);
659                 next = commit_list_append(commit, next);
660                 p = *eol ? eol + 1 : eol;
661         }
662         if (!*todo_list)
663                 return error(_("No commits parsed."));
664         return 0;
665 }
666
667 static void read_populate_todo(struct commit_list **todo_list,
668                         struct replay_opts *opts)
669 {
670         const char *todo_file = git_path(SEQ_TODO_FILE);
671         struct strbuf buf = STRBUF_INIT;
672         int fd, res;
673
674         fd = open(todo_file, O_RDONLY);
675         if (fd < 0)
676                 die_errno(_("Could not open %s"), todo_file);
677         if (strbuf_read(&buf, fd, 0) < 0) {
678                 close(fd);
679                 strbuf_release(&buf);
680                 die(_("Could not read %s."), todo_file);
681         }
682         close(fd);
683
684         res = parse_insn_buffer(buf.buf, todo_list, opts);
685         strbuf_release(&buf);
686         if (res)
687                 die(_("Unusable instruction sheet: %s"), todo_file);
688 }
689
690 static int populate_opts_cb(const char *key, const char *value, void *data)
691 {
692         struct replay_opts *opts = data;
693         int error_flag = 1;
694
695         if (!value)
696                 error_flag = 0;
697         else if (!strcmp(key, "options.no-commit"))
698                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
699         else if (!strcmp(key, "options.edit"))
700                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
701         else if (!strcmp(key, "options.signoff"))
702                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
703         else if (!strcmp(key, "options.record-origin"))
704                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
705         else if (!strcmp(key, "options.allow-ff"))
706                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
707         else if (!strcmp(key, "options.mainline"))
708                 opts->mainline = git_config_int(key, value);
709         else if (!strcmp(key, "options.strategy"))
710                 git_config_string(&opts->strategy, key, value);
711         else if (!strcmp(key, "options.strategy-option")) {
712                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
713                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
714         } else
715                 return error(_("Invalid key: %s"), key);
716
717         if (!error_flag)
718                 return error(_("Invalid value for %s: %s"), key, value);
719
720         return 0;
721 }
722
723 static void read_populate_opts(struct replay_opts **opts_ptr)
724 {
725         const char *opts_file = git_path(SEQ_OPTS_FILE);
726
727         if (!file_exists(opts_file))
728                 return;
729         if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
730                 die(_("Malformed options sheet: %s"), opts_file);
731 }
732
733 static void walk_revs_populate_todo(struct commit_list **todo_list,
734                                 struct replay_opts *opts)
735 {
736         struct commit *commit;
737         struct commit_list **next;
738
739         prepare_revs(opts);
740
741         next = todo_list;
742         while ((commit = get_revision(opts->revs)))
743                 next = commit_list_append(commit, next);
744 }
745
746 static int create_seq_dir(void)
747 {
748         const char *seq_dir = git_path(SEQ_DIR);
749
750         if (file_exists(seq_dir)) {
751                 error(_("a cherry-pick or revert is already in progress"));
752                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
753                 return -1;
754         }
755         else if (mkdir(seq_dir, 0777) < 0)
756                 die_errno(_("Could not create sequencer directory %s"), seq_dir);
757         return 0;
758 }
759
760 static void save_head(const char *head)
761 {
762         const char *head_file = git_path(SEQ_HEAD_FILE);
763         static struct lock_file head_lock;
764         struct strbuf buf = STRBUF_INIT;
765         int fd;
766
767         fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
768         strbuf_addf(&buf, "%s\n", head);
769         if (write_in_full(fd, buf.buf, buf.len) < 0)
770                 die_errno(_("Could not write to %s"), head_file);
771         if (commit_lock_file(&head_lock) < 0)
772                 die(_("Error wrapping up %s."), head_file);
773 }
774
775 static int reset_for_rollback(const unsigned char *sha1)
776 {
777         const char *argv[4];    /* reset --merge <arg> + NULL */
778         argv[0] = "reset";
779         argv[1] = "--merge";
780         argv[2] = sha1_to_hex(sha1);
781         argv[3] = NULL;
782         return run_command_v_opt(argv, RUN_GIT_CMD);
783 }
784
785 static int rollback_single_pick(void)
786 {
787         unsigned char head_sha1[20];
788
789         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
790             !file_exists(git_path("REVERT_HEAD")))
791                 return error(_("no cherry-pick or revert in progress"));
792         if (read_ref_full("HEAD", head_sha1, 0, NULL))
793                 return error(_("cannot resolve HEAD"));
794         if (is_null_sha1(head_sha1))
795                 return error(_("cannot abort from a branch yet to be born"));
796         return reset_for_rollback(head_sha1);
797 }
798
799 static int sequencer_rollback(struct replay_opts *opts)
800 {
801         const char *filename;
802         FILE *f;
803         unsigned char sha1[20];
804         struct strbuf buf = STRBUF_INIT;
805
806         filename = git_path(SEQ_HEAD_FILE);
807         f = fopen(filename, "r");
808         if (!f && errno == ENOENT) {
809                 /*
810                  * There is no multiple-cherry-pick in progress.
811                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
812                  * a single-cherry-pick in progress, abort that.
813                  */
814                 return rollback_single_pick();
815         }
816         if (!f)
817                 return error(_("cannot open %s: %s"), filename,
818                                                 strerror(errno));
819         if (strbuf_getline(&buf, f, '\n')) {
820                 error(_("cannot read %s: %s"), filename, ferror(f) ?
821                         strerror(errno) : _("unexpected end of file"));
822                 fclose(f);
823                 goto fail;
824         }
825         fclose(f);
826         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
827                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
828                         filename);
829                 goto fail;
830         }
831         if (reset_for_rollback(sha1))
832                 goto fail;
833         remove_sequencer_state();
834         strbuf_release(&buf);
835         return 0;
836 fail:
837         strbuf_release(&buf);
838         return -1;
839 }
840
841 static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
842 {
843         const char *todo_file = git_path(SEQ_TODO_FILE);
844         static struct lock_file todo_lock;
845         struct strbuf buf = STRBUF_INIT;
846         int fd;
847
848         fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
849         if (format_todo(&buf, todo_list, opts) < 0)
850                 die(_("Could not format %s."), todo_file);
851         if (write_in_full(fd, buf.buf, buf.len) < 0) {
852                 strbuf_release(&buf);
853                 die_errno(_("Could not write to %s"), todo_file);
854         }
855         if (commit_lock_file(&todo_lock) < 0) {
856                 strbuf_release(&buf);
857                 die(_("Error wrapping up %s."), todo_file);
858         }
859         strbuf_release(&buf);
860 }
861
862 static void save_opts(struct replay_opts *opts)
863 {
864         const char *opts_file = git_path(SEQ_OPTS_FILE);
865
866         if (opts->no_commit)
867                 git_config_set_in_file(opts_file, "options.no-commit", "true");
868         if (opts->edit)
869                 git_config_set_in_file(opts_file, "options.edit", "true");
870         if (opts->signoff)
871                 git_config_set_in_file(opts_file, "options.signoff", "true");
872         if (opts->record_origin)
873                 git_config_set_in_file(opts_file, "options.record-origin", "true");
874         if (opts->allow_ff)
875                 git_config_set_in_file(opts_file, "options.allow-ff", "true");
876         if (opts->mainline) {
877                 struct strbuf buf = STRBUF_INIT;
878                 strbuf_addf(&buf, "%d", opts->mainline);
879                 git_config_set_in_file(opts_file, "options.mainline", buf.buf);
880                 strbuf_release(&buf);
881         }
882         if (opts->strategy)
883                 git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
884         if (opts->xopts) {
885                 int i;
886                 for (i = 0; i < opts->xopts_nr; i++)
887                         git_config_set_multivar_in_file(opts_file,
888                                                         "options.strategy-option",
889                                                         opts->xopts[i], "^$", 0);
890         }
891 }
892
893 static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
894 {
895         struct commit_list *cur;
896         int res;
897
898         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
899         if (opts->allow_ff)
900                 assert(!(opts->signoff || opts->no_commit ||
901                                 opts->record_origin || opts->edit));
902         read_and_refresh_cache(opts);
903
904         for (cur = todo_list; cur; cur = cur->next) {
905                 save_todo(cur, opts);
906                 res = do_pick_commit(cur->item, opts);
907                 if (res)
908                         return res;
909         }
910
911         /*
912          * Sequence of picks finished successfully; cleanup by
913          * removing the .git/sequencer directory
914          */
915         remove_sequencer_state();
916         return 0;
917 }
918
919 static int continue_single_pick(void)
920 {
921         const char *argv[] = { "commit", NULL };
922
923         if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
924             !file_exists(git_path("REVERT_HEAD")))
925                 return error(_("no cherry-pick or revert in progress"));
926         return run_command_v_opt(argv, RUN_GIT_CMD);
927 }
928
929 static int sequencer_continue(struct replay_opts *opts)
930 {
931         struct commit_list *todo_list = NULL;
932
933         if (!file_exists(git_path(SEQ_TODO_FILE)))
934                 return continue_single_pick();
935         read_populate_opts(&opts);
936         read_populate_todo(&todo_list, opts);
937
938         /* Verify that the conflict has been resolved */
939         if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
940             file_exists(git_path("REVERT_HEAD"))) {
941                 int ret = continue_single_pick();
942                 if (ret)
943                         return ret;
944         }
945         if (index_differs_from("HEAD", 0))
946                 return error_dirty_index(opts);
947         todo_list = todo_list->next;
948         return pick_commits(todo_list, opts);
949 }
950
951 static int single_pick(struct commit *cmit, struct replay_opts *opts)
952 {
953         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
954         return do_pick_commit(cmit, opts);
955 }
956
957 int sequencer_pick_revisions(struct replay_opts *opts)
958 {
959         struct commit_list *todo_list = NULL;
960         unsigned char sha1[20];
961
962         if (opts->subcommand == REPLAY_NONE)
963                 assert(opts->revs);
964
965         read_and_refresh_cache(opts);
966
967         /*
968          * Decide what to do depending on the arguments; a fresh
969          * cherry-pick should be handled differently from an existing
970          * one that is being continued
971          */
972         if (opts->subcommand == REPLAY_REMOVE_STATE) {
973                 remove_sequencer_state();
974                 return 0;
975         }
976         if (opts->subcommand == REPLAY_ROLLBACK)
977                 return sequencer_rollback(opts);
978         if (opts->subcommand == REPLAY_CONTINUE)
979                 return sequencer_continue(opts);
980
981         /*
982          * If we were called as "git cherry-pick <commit>", just
983          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
984          * REVERT_HEAD, and don't touch the sequencer state.
985          * This means it is possible to cherry-pick in the middle
986          * of a cherry-pick sequence.
987          */
988         if (opts->revs->cmdline.nr == 1 &&
989             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
990             opts->revs->no_walk &&
991             !opts->revs->cmdline.rev->flags) {
992                 struct commit *cmit;
993                 if (prepare_revision_walk(opts->revs))
994                         die(_("revision walk setup failed"));
995                 cmit = get_revision(opts->revs);
996                 if (!cmit || get_revision(opts->revs))
997                         die("BUG: expected exactly one commit from walk");
998                 return single_pick(cmit, opts);
999         }
1000
1001         /*
1002          * Start a new cherry-pick/ revert sequence; but
1003          * first, make sure that an existing one isn't in
1004          * progress
1005          */
1006
1007         walk_revs_populate_todo(&todo_list, opts);
1008         if (create_seq_dir() < 0)
1009                 return -1;
1010         if (get_sha1("HEAD", sha1)) {
1011                 if (opts->action == REPLAY_REVERT)
1012                         return error(_("Can't revert as initial commit"));
1013                 return error(_("Can't cherry-pick into empty head"));
1014         }
1015         save_head(sha1_to_hex(sha1));
1016         save_opts(opts);
1017         return pick_commits(todo_list, opts);
1018 }
1019
1020 static int ends_rfc2822_footer(struct strbuf *sb, int ignore_footer)
1021 {
1022         int ch;
1023         int hit = 0;
1024         int i, j, k;
1025         int len = sb->len - ignore_footer;
1026         int first = 1;
1027         const char *buf = sb->buf;
1028
1029         for (i = len - 1; i > 0; i--) {
1030                 if (hit && buf[i] == '\n')
1031                         break;
1032                 hit = (buf[i] == '\n');
1033         }
1034
1035         while (i < len - 1 && buf[i] == '\n')
1036                 i++;
1037
1038         for (; i < len; i = k) {
1039                 for (k = i; k < len && buf[k] != '\n'; k++)
1040                         ; /* do nothing */
1041                 k++;
1042
1043                 if ((buf[k] == ' ' || buf[k] == '\t') && !first)
1044                         continue;
1045
1046                 first = 0;
1047
1048                 for (j = 0; i + j < len; j++) {
1049                         ch = buf[i + j];
1050                         if (ch == ':')
1051                                 break;
1052                         if (isalnum(ch) ||
1053                             (ch == '-'))
1054                                 continue;
1055                         return 0;
1056                 }
1057         }
1058         return 1;
1059 }
1060
1061 void append_signoff(struct strbuf *msgbuf, int ignore_footer)
1062 {
1063         struct strbuf sob = STRBUF_INIT;
1064         int i;
1065
1066         strbuf_addstr(&sob, sign_off_header);
1067         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
1068                                 getenv("GIT_COMMITTER_EMAIL")));
1069         strbuf_addch(&sob, '\n');
1070         for (i = msgbuf->len - 1 - ignore_footer; i > 0 && msgbuf->buf[i - 1] != '\n'; i--)
1071                 ; /* do nothing */
1072         if (prefixcmp(msgbuf->buf + i, sob.buf)) {
1073                 if (!i || !ends_rfc2822_footer(msgbuf, ignore_footer))
1074                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0, "\n", 1);
1075                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0, sob.buf, sob.len);
1076         }
1077         strbuf_release(&sob);
1078 }