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