Merge branch 'sg/t5310-jgit-bitmap-test'
[git] / sequencer.c
1 #include "cache.h"
2 #include "config.h"
3 #include "lockfile.h"
4 #include "dir.h"
5 #include "object.h"
6 #include "commit.h"
7 #include "sequencer.h"
8 #include "tag.h"
9 #include "run-command.h"
10 #include "exec-cmd.h"
11 #include "utf8.h"
12 #include "cache-tree.h"
13 #include "diff.h"
14 #include "revision.h"
15 #include "rerere.h"
16 #include "merge-recursive.h"
17 #include "refs.h"
18 #include "argv-array.h"
19 #include "quote.h"
20 #include "trailer.h"
21 #include "log-tree.h"
22 #include "wt-status.h"
23 #include "hashmap.h"
24 #include "notes-utils.h"
25 #include "sigchain.h"
26
27 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
28
29 const char sign_off_header[] = "Signed-off-by: ";
30 static const char cherry_picked_prefix[] = "(cherry picked from commit ";
31
32 GIT_PATH_FUNC(git_path_commit_editmsg, "COMMIT_EDITMSG")
33
34 GIT_PATH_FUNC(git_path_seq_dir, "sequencer")
35
36 static GIT_PATH_FUNC(git_path_todo_file, "sequencer/todo")
37 static GIT_PATH_FUNC(git_path_opts_file, "sequencer/opts")
38 static GIT_PATH_FUNC(git_path_head_file, "sequencer/head")
39 static GIT_PATH_FUNC(git_path_abort_safety_file, "sequencer/abort-safety")
40
41 static GIT_PATH_FUNC(rebase_path, "rebase-merge")
42 /*
43  * The file containing rebase commands, comments, and empty lines.
44  * This file is created by "git rebase -i" then edited by the user. As
45  * the lines are processed, they are removed from the front of this
46  * file and written to the tail of 'done'.
47  */
48 static GIT_PATH_FUNC(rebase_path_todo, "rebase-merge/git-rebase-todo")
49 /*
50  * The rebase command lines that have already been processed. A line
51  * is moved here when it is first handled, before any associated user
52  * actions.
53  */
54 static GIT_PATH_FUNC(rebase_path_done, "rebase-merge/done")
55 /*
56  * The file to keep track of how many commands were already processed (e.g.
57  * for the prompt).
58  */
59 static GIT_PATH_FUNC(rebase_path_msgnum, "rebase-merge/msgnum");
60 /*
61  * The file to keep track of how many commands are to be processed in total
62  * (e.g. for the prompt).
63  */
64 static GIT_PATH_FUNC(rebase_path_msgtotal, "rebase-merge/end");
65 /*
66  * The commit message that is planned to be used for any changes that
67  * need to be committed following a user interaction.
68  */
69 static GIT_PATH_FUNC(rebase_path_message, "rebase-merge/message")
70 /*
71  * The file into which is accumulated the suggested commit message for
72  * squash/fixup commands. When the first of a series of squash/fixups
73  * is seen, the file is created and the commit message from the
74  * previous commit and from the first squash/fixup commit are written
75  * to it. The commit message for each subsequent squash/fixup commit
76  * is appended to the file as it is processed.
77  *
78  * The first line of the file is of the form
79  *     # This is a combination of $count commits.
80  * where $count is the number of commits whose messages have been
81  * written to the file so far (including the initial "pick" commit).
82  * Each time that a commit message is processed, this line is read and
83  * updated. It is deleted just before the combined commit is made.
84  */
85 static GIT_PATH_FUNC(rebase_path_squash_msg, "rebase-merge/message-squash")
86 /*
87  * If the current series of squash/fixups has not yet included a squash
88  * command, then this file exists and holds the commit message of the
89  * original "pick" commit.  (If the series ends without a "squash"
90  * command, then this can be used as the commit message of the combined
91  * commit without opening the editor.)
92  */
93 static GIT_PATH_FUNC(rebase_path_fixup_msg, "rebase-merge/message-fixup")
94 /*
95  * A script to set the GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
96  * GIT_AUTHOR_DATE that will be used for the commit that is currently
97  * being rebased.
98  */
99 static GIT_PATH_FUNC(rebase_path_author_script, "rebase-merge/author-script")
100 /*
101  * When an "edit" rebase command is being processed, the SHA1 of the
102  * commit to be edited is recorded in this file.  When "git rebase
103  * --continue" is executed, if there are any staged changes then they
104  * will be amended to the HEAD commit, but only provided the HEAD
105  * commit is still the commit to be edited.  When any other rebase
106  * command is processed, this file is deleted.
107  */
108 static GIT_PATH_FUNC(rebase_path_amend, "rebase-merge/amend")
109 /*
110  * When we stop at a given patch via the "edit" command, this file contains
111  * the abbreviated commit name of the corresponding patch.
112  */
113 static GIT_PATH_FUNC(rebase_path_stopped_sha, "rebase-merge/stopped-sha")
114 /*
115  * For the post-rewrite hook, we make a list of rewritten commits and
116  * their new sha1s.  The rewritten-pending list keeps the sha1s of
117  * commits that have been processed, but not committed yet,
118  * e.g. because they are waiting for a 'squash' command.
119  */
120 static GIT_PATH_FUNC(rebase_path_rewritten_list, "rebase-merge/rewritten-list")
121 static GIT_PATH_FUNC(rebase_path_rewritten_pending,
122         "rebase-merge/rewritten-pending")
123 /*
124  * The following files are written by git-rebase just after parsing the
125  * command-line (and are only consumed, not modified, by the sequencer).
126  */
127 static GIT_PATH_FUNC(rebase_path_gpg_sign_opt, "rebase-merge/gpg_sign_opt")
128 static GIT_PATH_FUNC(rebase_path_orig_head, "rebase-merge/orig-head")
129 static GIT_PATH_FUNC(rebase_path_verbose, "rebase-merge/verbose")
130 static GIT_PATH_FUNC(rebase_path_signoff, "rebase-merge/signoff")
131 static GIT_PATH_FUNC(rebase_path_head_name, "rebase-merge/head-name")
132 static GIT_PATH_FUNC(rebase_path_onto, "rebase-merge/onto")
133 static GIT_PATH_FUNC(rebase_path_autostash, "rebase-merge/autostash")
134 static GIT_PATH_FUNC(rebase_path_strategy, "rebase-merge/strategy")
135 static GIT_PATH_FUNC(rebase_path_strategy_opts, "rebase-merge/strategy_opts")
136 static GIT_PATH_FUNC(rebase_path_allow_rerere_autoupdate, "rebase-merge/allow_rerere_autoupdate")
137
138 static int git_sequencer_config(const char *k, const char *v, void *cb)
139 {
140         struct replay_opts *opts = cb;
141         int status;
142
143         if (!strcmp(k, "commit.cleanup")) {
144                 const char *s;
145
146                 status = git_config_string(&s, k, v);
147                 if (status)
148                         return status;
149
150                 if (!strcmp(s, "verbatim"))
151                         opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_NONE;
152                 else if (!strcmp(s, "whitespace"))
153                         opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_SPACE;
154                 else if (!strcmp(s, "strip"))
155                         opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_ALL;
156                 else if (!strcmp(s, "scissors"))
157                         opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_SPACE;
158                 else
159                         warning(_("invalid commit message cleanup mode '%s'"),
160                                   s);
161
162                 return status;
163         }
164
165         if (!strcmp(k, "commit.gpgsign")) {
166                 opts->gpg_sign = git_config_bool(k, v) ? xstrdup("") : NULL;
167                 return 0;
168         }
169
170         status = git_gpg_config(k, v, NULL);
171         if (status)
172                 return status;
173
174         return git_diff_basic_config(k, v, NULL);
175 }
176
177 void sequencer_init_config(struct replay_opts *opts)
178 {
179         opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_NONE;
180         git_config(git_sequencer_config, opts);
181 }
182
183 static inline int is_rebase_i(const struct replay_opts *opts)
184 {
185         return opts->action == REPLAY_INTERACTIVE_REBASE;
186 }
187
188 static const char *get_dir(const struct replay_opts *opts)
189 {
190         if (is_rebase_i(opts))
191                 return rebase_path();
192         return git_path_seq_dir();
193 }
194
195 static const char *get_todo_path(const struct replay_opts *opts)
196 {
197         if (is_rebase_i(opts))
198                 return rebase_path_todo();
199         return git_path_todo_file();
200 }
201
202 /*
203  * Returns 0 for non-conforming footer
204  * Returns 1 for conforming footer
205  * Returns 2 when sob exists within conforming footer
206  * Returns 3 when sob exists within conforming footer as last entry
207  */
208 static int has_conforming_footer(struct strbuf *sb, struct strbuf *sob,
209         int ignore_footer)
210 {
211         struct trailer_info info;
212         int i;
213         int found_sob = 0, found_sob_last = 0;
214
215         trailer_info_get(&info, sb->buf);
216
217         if (info.trailer_start == info.trailer_end)
218                 return 0;
219
220         for (i = 0; i < info.trailer_nr; i++)
221                 if (sob && !strncmp(info.trailers[i], sob->buf, sob->len)) {
222                         found_sob = 1;
223                         if (i == info.trailer_nr - 1)
224                                 found_sob_last = 1;
225                 }
226
227         trailer_info_release(&info);
228
229         if (found_sob_last)
230                 return 3;
231         if (found_sob)
232                 return 2;
233         return 1;
234 }
235
236 static const char *gpg_sign_opt_quoted(struct replay_opts *opts)
237 {
238         static struct strbuf buf = STRBUF_INIT;
239
240         strbuf_reset(&buf);
241         if (opts->gpg_sign)
242                 sq_quotef(&buf, "-S%s", opts->gpg_sign);
243         return buf.buf;
244 }
245
246 int sequencer_remove_state(struct replay_opts *opts)
247 {
248         struct strbuf dir = STRBUF_INIT;
249         int i;
250
251         free(opts->gpg_sign);
252         free(opts->strategy);
253         for (i = 0; i < opts->xopts_nr; i++)
254                 free(opts->xopts[i]);
255         free(opts->xopts);
256
257         strbuf_addstr(&dir, get_dir(opts));
258         remove_dir_recursively(&dir, 0);
259         strbuf_release(&dir);
260
261         return 0;
262 }
263
264 static const char *action_name(const struct replay_opts *opts)
265 {
266         switch (opts->action) {
267         case REPLAY_REVERT:
268                 return N_("revert");
269         case REPLAY_PICK:
270                 return N_("cherry-pick");
271         case REPLAY_INTERACTIVE_REBASE:
272                 return N_("rebase -i");
273         }
274         die(_("Unknown action: %d"), opts->action);
275 }
276
277 struct commit_message {
278         char *parent_label;
279         char *label;
280         char *subject;
281         const char *message;
282 };
283
284 static const char *short_commit_name(struct commit *commit)
285 {
286         return find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV);
287 }
288
289 static int get_message(struct commit *commit, struct commit_message *out)
290 {
291         const char *abbrev, *subject;
292         int subject_len;
293
294         out->message = logmsg_reencode(commit, NULL, get_commit_output_encoding());
295         abbrev = short_commit_name(commit);
296
297         subject_len = find_commit_subject(out->message, &subject);
298
299         out->subject = xmemdupz(subject, subject_len);
300         out->label = xstrfmt("%s... %s", abbrev, out->subject);
301         out->parent_label = xstrfmt("parent of %s", out->label);
302
303         return 0;
304 }
305
306 static void free_message(struct commit *commit, struct commit_message *msg)
307 {
308         free(msg->parent_label);
309         free(msg->label);
310         free(msg->subject);
311         unuse_commit_buffer(commit, msg->message);
312 }
313
314 static void print_advice(int show_hint, struct replay_opts *opts)
315 {
316         char *msg = getenv("GIT_CHERRY_PICK_HELP");
317
318         if (msg) {
319                 fprintf(stderr, "%s\n", msg);
320                 /*
321                  * A conflict has occurred but the porcelain
322                  * (typically rebase --interactive) wants to take care
323                  * of the commit itself so remove CHERRY_PICK_HEAD
324                  */
325                 unlink(git_path_cherry_pick_head());
326                 return;
327         }
328
329         if (show_hint) {
330                 if (opts->no_commit)
331                         advise(_("after resolving the conflicts, mark the corrected paths\n"
332                                  "with 'git add <paths>' or 'git rm <paths>'"));
333                 else
334                         advise(_("after resolving the conflicts, mark the corrected paths\n"
335                                  "with 'git add <paths>' or 'git rm <paths>'\n"
336                                  "and commit the result with 'git commit'"));
337         }
338 }
339
340 static int write_message(const void *buf, size_t len, const char *filename,
341                          int append_eol)
342 {
343         struct lock_file msg_file = LOCK_INIT;
344
345         int msg_fd = hold_lock_file_for_update(&msg_file, filename, 0);
346         if (msg_fd < 0)
347                 return error_errno(_("could not lock '%s'"), filename);
348         if (write_in_full(msg_fd, buf, len) < 0) {
349                 rollback_lock_file(&msg_file);
350                 return error_errno(_("could not write to '%s'"), filename);
351         }
352         if (append_eol && write(msg_fd, "\n", 1) < 0) {
353                 rollback_lock_file(&msg_file);
354                 return error_errno(_("could not write eol to '%s'"), filename);
355         }
356         if (commit_lock_file(&msg_file) < 0)
357                 return error(_("failed to finalize '%s'"), filename);
358
359         return 0;
360 }
361
362 /*
363  * Reads a file that was presumably written by a shell script, i.e. with an
364  * end-of-line marker that needs to be stripped.
365  *
366  * Note that only the last end-of-line marker is stripped, consistent with the
367  * behavior of "$(cat path)" in a shell script.
368  *
369  * Returns 1 if the file was read, 0 if it could not be read or does not exist.
370  */
371 static int read_oneliner(struct strbuf *buf,
372         const char *path, int skip_if_empty)
373 {
374         int orig_len = buf->len;
375
376         if (!file_exists(path))
377                 return 0;
378
379         if (strbuf_read_file(buf, path, 0) < 0) {
380                 warning_errno(_("could not read '%s'"), path);
381                 return 0;
382         }
383
384         if (buf->len > orig_len && buf->buf[buf->len - 1] == '\n') {
385                 if (--buf->len > orig_len && buf->buf[buf->len - 1] == '\r')
386                         --buf->len;
387                 buf->buf[buf->len] = '\0';
388         }
389
390         if (skip_if_empty && buf->len == orig_len)
391                 return 0;
392
393         return 1;
394 }
395
396 static struct tree *empty_tree(void)
397 {
398         return lookup_tree(the_hash_algo->empty_tree);
399 }
400
401 static int error_dirty_index(struct replay_opts *opts)
402 {
403         if (read_cache_unmerged())
404                 return error_resolve_conflict(_(action_name(opts)));
405
406         error(_("your local changes would be overwritten by %s."),
407                 _(action_name(opts)));
408
409         if (advice_commit_before_merge)
410                 advise(_("commit your changes or stash them to proceed."));
411         return -1;
412 }
413
414 static void update_abort_safety_file(void)
415 {
416         struct object_id head;
417
418         /* Do nothing on a single-pick */
419         if (!file_exists(git_path_seq_dir()))
420                 return;
421
422         if (!get_oid("HEAD", &head))
423                 write_file(git_path_abort_safety_file(), "%s", oid_to_hex(&head));
424         else
425                 write_file(git_path_abort_safety_file(), "%s", "");
426 }
427
428 static int fast_forward_to(const struct object_id *to, const struct object_id *from,
429                         int unborn, struct replay_opts *opts)
430 {
431         struct ref_transaction *transaction;
432         struct strbuf sb = STRBUF_INIT;
433         struct strbuf err = STRBUF_INIT;
434
435         read_cache();
436         if (checkout_fast_forward(from, to, 1))
437                 return -1; /* the callee should have complained already */
438
439         strbuf_addf(&sb, _("%s: fast-forward"), _(action_name(opts)));
440
441         transaction = ref_transaction_begin(&err);
442         if (!transaction ||
443             ref_transaction_update(transaction, "HEAD",
444                                    to, unborn ? &null_oid : from,
445                                    0, sb.buf, &err) ||
446             ref_transaction_commit(transaction, &err)) {
447                 ref_transaction_free(transaction);
448                 error("%s", err.buf);
449                 strbuf_release(&sb);
450                 strbuf_release(&err);
451                 return -1;
452         }
453
454         strbuf_release(&sb);
455         strbuf_release(&err);
456         ref_transaction_free(transaction);
457         update_abort_safety_file();
458         return 0;
459 }
460
461 void append_conflicts_hint(struct strbuf *msgbuf)
462 {
463         int i;
464
465         strbuf_addch(msgbuf, '\n');
466         strbuf_commented_addf(msgbuf, "Conflicts:\n");
467         for (i = 0; i < active_nr;) {
468                 const struct cache_entry *ce = active_cache[i++];
469                 if (ce_stage(ce)) {
470                         strbuf_commented_addf(msgbuf, "\t%s\n", ce->name);
471                         while (i < active_nr && !strcmp(ce->name,
472                                                         active_cache[i]->name))
473                                 i++;
474                 }
475         }
476 }
477
478 static int do_recursive_merge(struct commit *base, struct commit *next,
479                               const char *base_label, const char *next_label,
480                               struct object_id *head, struct strbuf *msgbuf,
481                               struct replay_opts *opts)
482 {
483         struct merge_options o;
484         struct tree *result, *next_tree, *base_tree, *head_tree;
485         int clean;
486         char **xopt;
487         struct lock_file index_lock = LOCK_INIT;
488
489         if (hold_locked_index(&index_lock, LOCK_REPORT_ON_ERROR) < 0)
490                 return -1;
491
492         read_cache();
493
494         init_merge_options(&o);
495         o.ancestor = base ? base_label : "(empty tree)";
496         o.branch1 = "HEAD";
497         o.branch2 = next ? next_label : "(empty tree)";
498         if (is_rebase_i(opts))
499                 o.buffer_output = 2;
500         o.show_rename_progress = 1;
501
502         head_tree = parse_tree_indirect(head);
503         next_tree = next ? next->tree : empty_tree();
504         base_tree = base ? base->tree : empty_tree();
505
506         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
507                 parse_merge_opt(&o, *xopt);
508
509         clean = merge_trees(&o,
510                             head_tree,
511                             next_tree, base_tree, &result);
512         if (is_rebase_i(opts) && clean <= 0)
513                 fputs(o.obuf.buf, stdout);
514         strbuf_release(&o.obuf);
515         diff_warn_rename_limit("merge.renamelimit", o.needed_rename_limit, 0);
516         if (clean < 0) {
517                 rollback_lock_file(&index_lock);
518                 return clean;
519         }
520
521         if (write_locked_index(&the_index, &index_lock,
522                                COMMIT_LOCK | SKIP_IF_UNCHANGED))
523                 /*
524                  * TRANSLATORS: %s will be "revert", "cherry-pick" or
525                  * "rebase -i".
526                  */
527                 return error(_("%s: Unable to write new index file"),
528                         _(action_name(opts)));
529
530         if (!clean)
531                 append_conflicts_hint(msgbuf);
532
533         return !clean;
534 }
535
536 static int is_index_unchanged(void)
537 {
538         struct object_id head_oid;
539         struct commit *head_commit;
540
541         if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
542                 return error(_("could not resolve HEAD commit"));
543
544         head_commit = lookup_commit(&head_oid);
545
546         /*
547          * If head_commit is NULL, check_commit, called from
548          * lookup_commit, would have indicated that head_commit is not
549          * a commit object already.  parse_commit() will return failure
550          * without further complaints in such a case.  Otherwise, if
551          * the commit is invalid, parse_commit() will complain.  So
552          * there is nothing for us to say here.  Just return failure.
553          */
554         if (parse_commit(head_commit))
555                 return -1;
556
557         if (!active_cache_tree)
558                 active_cache_tree = cache_tree();
559
560         if (!cache_tree_fully_valid(active_cache_tree))
561                 if (cache_tree_update(&the_index, 0))
562                         return error(_("unable to update cache tree"));
563
564         return !oidcmp(&active_cache_tree->oid,
565                        &head_commit->tree->object.oid);
566 }
567
568 static int write_author_script(const char *message)
569 {
570         struct strbuf buf = STRBUF_INIT;
571         const char *eol;
572         int res;
573
574         for (;;)
575                 if (!*message || starts_with(message, "\n")) {
576 missing_author:
577                         /* Missing 'author' line? */
578                         unlink(rebase_path_author_script());
579                         return 0;
580                 } else if (skip_prefix(message, "author ", &message))
581                         break;
582                 else if ((eol = strchr(message, '\n')))
583                         message = eol + 1;
584                 else
585                         goto missing_author;
586
587         strbuf_addstr(&buf, "GIT_AUTHOR_NAME='");
588         while (*message && *message != '\n' && *message != '\r')
589                 if (skip_prefix(message, " <", &message))
590                         break;
591                 else if (*message != '\'')
592                         strbuf_addch(&buf, *(message++));
593                 else
594                         strbuf_addf(&buf, "'\\\\%c'", *(message++));
595         strbuf_addstr(&buf, "'\nGIT_AUTHOR_EMAIL='");
596         while (*message && *message != '\n' && *message != '\r')
597                 if (skip_prefix(message, "> ", &message))
598                         break;
599                 else if (*message != '\'')
600                         strbuf_addch(&buf, *(message++));
601                 else
602                         strbuf_addf(&buf, "'\\\\%c'", *(message++));
603         strbuf_addstr(&buf, "'\nGIT_AUTHOR_DATE='@");
604         while (*message && *message != '\n' && *message != '\r')
605                 if (*message != '\'')
606                         strbuf_addch(&buf, *(message++));
607                 else
608                         strbuf_addf(&buf, "'\\\\%c'", *(message++));
609         res = write_message(buf.buf, buf.len, rebase_path_author_script(), 1);
610         strbuf_release(&buf);
611         return res;
612 }
613
614 /*
615  * Read a list of environment variable assignments (such as the author-script
616  * file) into an environment block. Returns -1 on error, 0 otherwise.
617  */
618 static int read_env_script(struct argv_array *env)
619 {
620         struct strbuf script = STRBUF_INIT;
621         int i, count = 0;
622         char *p, *p2;
623
624         if (strbuf_read_file(&script, rebase_path_author_script(), 256) <= 0)
625                 return -1;
626
627         for (p = script.buf; *p; p++)
628                 if (skip_prefix(p, "'\\\\''", (const char **)&p2))
629                         strbuf_splice(&script, p - script.buf, p2 - p, "'", 1);
630                 else if (*p == '\'')
631                         strbuf_splice(&script, p-- - script.buf, 1, "", 0);
632                 else if (*p == '\n') {
633                         *p = '\0';
634                         count++;
635                 }
636
637         for (i = 0, p = script.buf; i < count; i++) {
638                 argv_array_push(env, p);
639                 p += strlen(p) + 1;
640         }
641
642         return 0;
643 }
644
645 static char *get_author(const char *message)
646 {
647         size_t len;
648         const char *a;
649
650         a = find_commit_header(message, "author", &len);
651         if (a)
652                 return xmemdupz(a, len);
653
654         return NULL;
655 }
656
657 static const char staged_changes_advice[] =
658 N_("you have staged changes in your working tree\n"
659 "If these changes are meant to be squashed into the previous commit, run:\n"
660 "\n"
661 "  git commit --amend %s\n"
662 "\n"
663 "If they are meant to go into a new commit, run:\n"
664 "\n"
665 "  git commit %s\n"
666 "\n"
667 "In both cases, once you're done, continue with:\n"
668 "\n"
669 "  git rebase --continue\n");
670
671 #define ALLOW_EMPTY (1<<0)
672 #define EDIT_MSG    (1<<1)
673 #define AMEND_MSG   (1<<2)
674 #define CLEANUP_MSG (1<<3)
675 #define VERIFY_MSG  (1<<4)
676
677 /*
678  * If we are cherry-pick, and if the merge did not result in
679  * hand-editing, we will hit this commit and inherit the original
680  * author date and name.
681  *
682  * If we are revert, or if our cherry-pick results in a hand merge,
683  * we had better say that the current user is responsible for that.
684  *
685  * An exception is when run_git_commit() is called during an
686  * interactive rebase: in that case, we will want to retain the
687  * author metadata.
688  */
689 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
690                           unsigned int flags)
691 {
692         struct child_process cmd = CHILD_PROCESS_INIT;
693         const char *value;
694
695         cmd.git_cmd = 1;
696
697         if (is_rebase_i(opts)) {
698                 if (!(flags & EDIT_MSG)) {
699                         cmd.stdout_to_stderr = 1;
700                         cmd.err = -1;
701                 }
702
703                 if (read_env_script(&cmd.env_array)) {
704                         const char *gpg_opt = gpg_sign_opt_quoted(opts);
705
706                         return error(_(staged_changes_advice),
707                                      gpg_opt, gpg_opt);
708                 }
709         }
710
711         argv_array_push(&cmd.args, "commit");
712
713         if (!(flags & VERIFY_MSG))
714                 argv_array_push(&cmd.args, "-n");
715         if ((flags & AMEND_MSG))
716                 argv_array_push(&cmd.args, "--amend");
717         if (opts->gpg_sign)
718                 argv_array_pushf(&cmd.args, "-S%s", opts->gpg_sign);
719         if (defmsg)
720                 argv_array_pushl(&cmd.args, "-F", defmsg, NULL);
721         if ((flags & CLEANUP_MSG))
722                 argv_array_push(&cmd.args, "--cleanup=strip");
723         if ((flags & EDIT_MSG))
724                 argv_array_push(&cmd.args, "-e");
725         else if (!(flags & CLEANUP_MSG) &&
726                  !opts->signoff && !opts->record_origin &&
727                  git_config_get_value("commit.cleanup", &value))
728                 argv_array_push(&cmd.args, "--cleanup=verbatim");
729
730         if ((flags & ALLOW_EMPTY))
731                 argv_array_push(&cmd.args, "--allow-empty");
732
733         if (opts->allow_empty_message)
734                 argv_array_push(&cmd.args, "--allow-empty-message");
735
736         if (cmd.err == -1) {
737                 /* hide stderr on success */
738                 struct strbuf buf = STRBUF_INIT;
739                 int rc = pipe_command(&cmd,
740                                       NULL, 0,
741                                       /* stdout is already redirected */
742                                       NULL, 0,
743                                       &buf, 0);
744                 if (rc)
745                         fputs(buf.buf, stderr);
746                 strbuf_release(&buf);
747                 return rc;
748         }
749
750         return run_command(&cmd);
751 }
752
753 static int rest_is_empty(const struct strbuf *sb, int start)
754 {
755         int i, eol;
756         const char *nl;
757
758         /* Check if the rest is just whitespace and Signed-off-by's. */
759         for (i = start; i < sb->len; i++) {
760                 nl = memchr(sb->buf + i, '\n', sb->len - i);
761                 if (nl)
762                         eol = nl - sb->buf;
763                 else
764                         eol = sb->len;
765
766                 if (strlen(sign_off_header) <= eol - i &&
767                     starts_with(sb->buf + i, sign_off_header)) {
768                         i = eol;
769                         continue;
770                 }
771                 while (i < eol)
772                         if (!isspace(sb->buf[i++]))
773                                 return 0;
774         }
775
776         return 1;
777 }
778
779 /*
780  * Find out if the message in the strbuf contains only whitespace and
781  * Signed-off-by lines.
782  */
783 int message_is_empty(const struct strbuf *sb,
784                      enum commit_msg_cleanup_mode cleanup_mode)
785 {
786         if (cleanup_mode == COMMIT_MSG_CLEANUP_NONE && sb->len)
787                 return 0;
788         return rest_is_empty(sb, 0);
789 }
790
791 /*
792  * See if the user edited the message in the editor or left what
793  * was in the template intact
794  */
795 int template_untouched(const struct strbuf *sb, const char *template_file,
796                        enum commit_msg_cleanup_mode cleanup_mode)
797 {
798         struct strbuf tmpl = STRBUF_INIT;
799         const char *start;
800
801         if (cleanup_mode == COMMIT_MSG_CLEANUP_NONE && sb->len)
802                 return 0;
803
804         if (!template_file || strbuf_read_file(&tmpl, template_file, 0) <= 0)
805                 return 0;
806
807         strbuf_stripspace(&tmpl, cleanup_mode == COMMIT_MSG_CLEANUP_ALL);
808         if (!skip_prefix(sb->buf, tmpl.buf, &start))
809                 start = sb->buf;
810         strbuf_release(&tmpl);
811         return rest_is_empty(sb, start - sb->buf);
812 }
813
814 int update_head_with_reflog(const struct commit *old_head,
815                             const struct object_id *new_head,
816                             const char *action, const struct strbuf *msg,
817                             struct strbuf *err)
818 {
819         struct ref_transaction *transaction;
820         struct strbuf sb = STRBUF_INIT;
821         const char *nl;
822         int ret = 0;
823
824         if (action) {
825                 strbuf_addstr(&sb, action);
826                 strbuf_addstr(&sb, ": ");
827         }
828
829         nl = strchr(msg->buf, '\n');
830         if (nl) {
831                 strbuf_add(&sb, msg->buf, nl + 1 - msg->buf);
832         } else {
833                 strbuf_addbuf(&sb, msg);
834                 strbuf_addch(&sb, '\n');
835         }
836
837         transaction = ref_transaction_begin(err);
838         if (!transaction ||
839             ref_transaction_update(transaction, "HEAD", new_head,
840                                    old_head ? &old_head->object.oid : &null_oid,
841                                    0, sb.buf, err) ||
842             ref_transaction_commit(transaction, err)) {
843                 ret = -1;
844         }
845         ref_transaction_free(transaction);
846         strbuf_release(&sb);
847
848         return ret;
849 }
850
851 static int run_rewrite_hook(const struct object_id *oldoid,
852                             const struct object_id *newoid)
853 {
854         struct child_process proc = CHILD_PROCESS_INIT;
855         const char *argv[3];
856         int code;
857         struct strbuf sb = STRBUF_INIT;
858
859         argv[0] = find_hook("post-rewrite");
860         if (!argv[0])
861                 return 0;
862
863         argv[1] = "amend";
864         argv[2] = NULL;
865
866         proc.argv = argv;
867         proc.in = -1;
868         proc.stdout_to_stderr = 1;
869
870         code = start_command(&proc);
871         if (code)
872                 return code;
873         strbuf_addf(&sb, "%s %s\n", oid_to_hex(oldoid), oid_to_hex(newoid));
874         sigchain_push(SIGPIPE, SIG_IGN);
875         write_in_full(proc.in, sb.buf, sb.len);
876         close(proc.in);
877         strbuf_release(&sb);
878         sigchain_pop(SIGPIPE);
879         return finish_command(&proc);
880 }
881
882 void commit_post_rewrite(const struct commit *old_head,
883                          const struct object_id *new_head)
884 {
885         struct notes_rewrite_cfg *cfg;
886
887         cfg = init_copy_notes_for_rewrite("amend");
888         if (cfg) {
889                 /* we are amending, so old_head is not NULL */
890                 copy_note_for_rewrite(cfg, &old_head->object.oid, new_head);
891                 finish_copy_notes_for_rewrite(cfg, "Notes added by 'git commit --amend'");
892         }
893         run_rewrite_hook(&old_head->object.oid, new_head);
894 }
895
896 static int run_prepare_commit_msg_hook(struct strbuf *msg, const char *commit)
897 {
898         struct argv_array hook_env = ARGV_ARRAY_INIT;
899         int ret;
900         const char *name;
901
902         name = git_path_commit_editmsg();
903         if (write_message(msg->buf, msg->len, name, 0))
904                 return -1;
905
906         argv_array_pushf(&hook_env, "GIT_INDEX_FILE=%s", get_index_file());
907         argv_array_push(&hook_env, "GIT_EDITOR=:");
908         if (commit)
909                 ret = run_hook_le(hook_env.argv, "prepare-commit-msg", name,
910                                   "commit", commit, NULL);
911         else
912                 ret = run_hook_le(hook_env.argv, "prepare-commit-msg", name,
913                                   "message", NULL);
914         if (ret)
915                 ret = error(_("'prepare-commit-msg' hook failed"));
916         argv_array_clear(&hook_env);
917
918         return ret;
919 }
920
921 static const char implicit_ident_advice_noconfig[] =
922 N_("Your name and email address were configured automatically based\n"
923 "on your username and hostname. Please check that they are accurate.\n"
924 "You can suppress this message by setting them explicitly. Run the\n"
925 "following command and follow the instructions in your editor to edit\n"
926 "your configuration file:\n"
927 "\n"
928 "    git config --global --edit\n"
929 "\n"
930 "After doing this, you may fix the identity used for this commit with:\n"
931 "\n"
932 "    git commit --amend --reset-author\n");
933
934 static const char implicit_ident_advice_config[] =
935 N_("Your name and email address were configured automatically based\n"
936 "on your username and hostname. Please check that they are accurate.\n"
937 "You can suppress this message by setting them explicitly:\n"
938 "\n"
939 "    git config --global user.name \"Your Name\"\n"
940 "    git config --global user.email you@example.com\n"
941 "\n"
942 "After doing this, you may fix the identity used for this commit with:\n"
943 "\n"
944 "    git commit --amend --reset-author\n");
945
946 static const char *implicit_ident_advice(void)
947 {
948         char *user_config = expand_user_path("~/.gitconfig", 0);
949         char *xdg_config = xdg_config_home("config");
950         int config_exists = file_exists(user_config) || file_exists(xdg_config);
951
952         free(user_config);
953         free(xdg_config);
954
955         if (config_exists)
956                 return _(implicit_ident_advice_config);
957         else
958                 return _(implicit_ident_advice_noconfig);
959
960 }
961
962 void print_commit_summary(const char *prefix, const struct object_id *oid,
963                           unsigned int flags)
964 {
965         struct rev_info rev;
966         struct commit *commit;
967         struct strbuf format = STRBUF_INIT;
968         const char *head;
969         struct pretty_print_context pctx = {0};
970         struct strbuf author_ident = STRBUF_INIT;
971         struct strbuf committer_ident = STRBUF_INIT;
972
973         commit = lookup_commit(oid);
974         if (!commit)
975                 die(_("couldn't look up newly created commit"));
976         if (parse_commit(commit))
977                 die(_("could not parse newly created commit"));
978
979         strbuf_addstr(&format, "format:%h] %s");
980
981         format_commit_message(commit, "%an <%ae>", &author_ident, &pctx);
982         format_commit_message(commit, "%cn <%ce>", &committer_ident, &pctx);
983         if (strbuf_cmp(&author_ident, &committer_ident)) {
984                 strbuf_addstr(&format, "\n Author: ");
985                 strbuf_addbuf_percentquote(&format, &author_ident);
986         }
987         if (flags & SUMMARY_SHOW_AUTHOR_DATE) {
988                 struct strbuf date = STRBUF_INIT;
989
990                 format_commit_message(commit, "%ad", &date, &pctx);
991                 strbuf_addstr(&format, "\n Date: ");
992                 strbuf_addbuf_percentquote(&format, &date);
993                 strbuf_release(&date);
994         }
995         if (!committer_ident_sufficiently_given()) {
996                 strbuf_addstr(&format, "\n Committer: ");
997                 strbuf_addbuf_percentquote(&format, &committer_ident);
998                 if (advice_implicit_identity) {
999                         strbuf_addch(&format, '\n');
1000                         strbuf_addstr(&format, implicit_ident_advice());
1001                 }
1002         }
1003         strbuf_release(&author_ident);
1004         strbuf_release(&committer_ident);
1005
1006         init_revisions(&rev, prefix);
1007         setup_revisions(0, NULL, &rev, NULL);
1008
1009         rev.diff = 1;
1010         rev.diffopt.output_format =
1011                 DIFF_FORMAT_SHORTSTAT | DIFF_FORMAT_SUMMARY;
1012
1013         rev.verbose_header = 1;
1014         rev.show_root_diff = 1;
1015         get_commit_format(format.buf, &rev);
1016         rev.always_show_header = 0;
1017         rev.diffopt.detect_rename = DIFF_DETECT_RENAME;
1018         rev.diffopt.break_opt = 0;
1019         diff_setup_done(&rev.diffopt);
1020
1021         head = resolve_ref_unsafe("HEAD", 0, NULL, NULL);
1022         if (!head)
1023                 die_errno(_("unable to resolve HEAD after creating commit"));
1024         if (!strcmp(head, "HEAD"))
1025                 head = _("detached HEAD");
1026         else
1027                 skip_prefix(head, "refs/heads/", &head);
1028         printf("[%s%s ", head, (flags & SUMMARY_INITIAL_COMMIT) ?
1029                                                 _(" (root-commit)") : "");
1030
1031         if (!log_tree_commit(&rev, commit)) {
1032                 rev.always_show_header = 1;
1033                 rev.use_terminator = 1;
1034                 log_tree_commit(&rev, commit);
1035         }
1036
1037         strbuf_release(&format);
1038 }
1039
1040 static int parse_head(struct commit **head)
1041 {
1042         struct commit *current_head;
1043         struct object_id oid;
1044
1045         if (get_oid("HEAD", &oid)) {
1046                 current_head = NULL;
1047         } else {
1048                 current_head = lookup_commit_reference(&oid);
1049                 if (!current_head)
1050                         return error(_("could not parse HEAD"));
1051                 if (oidcmp(&oid, &current_head->object.oid)) {
1052                         warning(_("HEAD %s is not a commit!"),
1053                                 oid_to_hex(&oid));
1054                 }
1055                 if (parse_commit(current_head))
1056                         return error(_("could not parse HEAD commit"));
1057         }
1058         *head = current_head;
1059
1060         return 0;
1061 }
1062
1063 /*
1064  * Try to commit without forking 'git commit'. In some cases we need
1065  * to run 'git commit' to display an error message
1066  *
1067  * Returns:
1068  *  -1 - error unable to commit
1069  *   0 - success
1070  *   1 - run 'git commit'
1071  */
1072 static int try_to_commit(struct strbuf *msg, const char *author,
1073                          struct replay_opts *opts, unsigned int flags,
1074                          struct object_id *oid)
1075 {
1076         struct object_id tree;
1077         struct commit *current_head;
1078         struct commit_list *parents = NULL;
1079         struct commit_extra_header *extra = NULL;
1080         struct strbuf err = STRBUF_INIT;
1081         struct strbuf commit_msg = STRBUF_INIT;
1082         char *amend_author = NULL;
1083         const char *hook_commit = NULL;
1084         enum commit_msg_cleanup_mode cleanup;
1085         int res = 0;
1086
1087         if (parse_head(&current_head))
1088                 return -1;
1089
1090         if (flags & AMEND_MSG) {
1091                 const char *exclude_gpgsig[] = { "gpgsig", NULL };
1092                 const char *out_enc = get_commit_output_encoding();
1093                 const char *message = logmsg_reencode(current_head, NULL,
1094                                                       out_enc);
1095
1096                 if (!msg) {
1097                         const char *orig_message = NULL;
1098
1099                         find_commit_subject(message, &orig_message);
1100                         msg = &commit_msg;
1101                         strbuf_addstr(msg, orig_message);
1102                         hook_commit = "HEAD";
1103                 }
1104                 author = amend_author = get_author(message);
1105                 unuse_commit_buffer(current_head, message);
1106                 if (!author) {
1107                         res = error(_("unable to parse commit author"));
1108                         goto out;
1109                 }
1110                 parents = copy_commit_list(current_head->parents);
1111                 extra = read_commit_extra_headers(current_head, exclude_gpgsig);
1112         } else if (current_head) {
1113                 commit_list_insert(current_head, &parents);
1114         }
1115
1116         if (write_cache_as_tree(&tree, 0, NULL)) {
1117                 res = error(_("git write-tree failed to write a tree"));
1118                 goto out;
1119         }
1120
1121         if (!(flags & ALLOW_EMPTY) && !oidcmp(current_head ?
1122                                               &current_head->tree->object.oid :
1123                                               &empty_tree_oid, &tree)) {
1124                 res = 1; /* run 'git commit' to display error message */
1125                 goto out;
1126         }
1127
1128         if (find_hook("prepare-commit-msg")) {
1129                 res = run_prepare_commit_msg_hook(msg, hook_commit);
1130                 if (res)
1131                         goto out;
1132                 if (strbuf_read_file(&commit_msg, git_path_commit_editmsg(),
1133                                      2048) < 0) {
1134                         res = error_errno(_("unable to read commit message "
1135                                               "from '%s'"),
1136                                             git_path_commit_editmsg());
1137                         goto out;
1138                 }
1139                 msg = &commit_msg;
1140         }
1141
1142         cleanup = (flags & CLEANUP_MSG) ? COMMIT_MSG_CLEANUP_ALL :
1143                                           opts->default_msg_cleanup;
1144
1145         if (cleanup != COMMIT_MSG_CLEANUP_NONE)
1146                 strbuf_stripspace(msg, cleanup == COMMIT_MSG_CLEANUP_ALL);
1147         if (!opts->allow_empty_message && message_is_empty(msg, cleanup)) {
1148                 res = 1; /* run 'git commit' to display error message */
1149                 goto out;
1150         }
1151
1152         reset_ident_date();
1153
1154         if (commit_tree_extended(msg->buf, msg->len, &tree, parents,
1155                                  oid, author, opts->gpg_sign, extra)) {
1156                 res = error(_("failed to write commit object"));
1157                 goto out;
1158         }
1159
1160         if (update_head_with_reflog(current_head, oid,
1161                                     getenv("GIT_REFLOG_ACTION"), msg, &err)) {
1162                 res = error("%s", err.buf);
1163                 goto out;
1164         }
1165
1166         if (flags & AMEND_MSG)
1167                 commit_post_rewrite(current_head, oid);
1168
1169 out:
1170         free_commit_extra_headers(extra);
1171         strbuf_release(&err);
1172         strbuf_release(&commit_msg);
1173         free(amend_author);
1174
1175         return res;
1176 }
1177
1178 static int do_commit(const char *msg_file, const char *author,
1179                      struct replay_opts *opts, unsigned int flags)
1180 {
1181         int res = 1;
1182
1183         if (!(flags & EDIT_MSG) && !(flags & VERIFY_MSG)) {
1184                 struct object_id oid;
1185                 struct strbuf sb = STRBUF_INIT;
1186
1187                 if (msg_file && strbuf_read_file(&sb, msg_file, 2048) < 0)
1188                         return error_errno(_("unable to read commit message "
1189                                              "from '%s'"),
1190                                            msg_file);
1191
1192                 res = try_to_commit(msg_file ? &sb : NULL, author, opts, flags,
1193                                     &oid);
1194                 strbuf_release(&sb);
1195                 if (!res) {
1196                         unlink(git_path_cherry_pick_head());
1197                         unlink(git_path_merge_msg());
1198                         if (!is_rebase_i(opts))
1199                                 print_commit_summary(NULL, &oid,
1200                                                 SUMMARY_SHOW_AUTHOR_DATE);
1201                         return res;
1202                 }
1203         }
1204         if (res == 1)
1205                 return run_git_commit(msg_file, opts, flags);
1206
1207         return res;
1208 }
1209
1210 static int is_original_commit_empty(struct commit *commit)
1211 {
1212         const struct object_id *ptree_oid;
1213
1214         if (parse_commit(commit))
1215                 return error(_("could not parse commit %s"),
1216                              oid_to_hex(&commit->object.oid));
1217         if (commit->parents) {
1218                 struct commit *parent = commit->parents->item;
1219                 if (parse_commit(parent))
1220                         return error(_("could not parse parent commit %s"),
1221                                 oid_to_hex(&parent->object.oid));
1222                 ptree_oid = &parent->tree->object.oid;
1223         } else {
1224                 ptree_oid = the_hash_algo->empty_tree; /* commit is root */
1225         }
1226
1227         return !oidcmp(ptree_oid, &commit->tree->object.oid);
1228 }
1229
1230 /*
1231  * Do we run "git commit" with "--allow-empty"?
1232  */
1233 static int allow_empty(struct replay_opts *opts, struct commit *commit)
1234 {
1235         int index_unchanged, empty_commit;
1236
1237         /*
1238          * Three cases:
1239          *
1240          * (1) we do not allow empty at all and error out.
1241          *
1242          * (2) we allow ones that were initially empty, but
1243          * forbid the ones that become empty;
1244          *
1245          * (3) we allow both.
1246          */
1247         if (!opts->allow_empty)
1248                 return 0; /* let "git commit" barf as necessary */
1249
1250         index_unchanged = is_index_unchanged();
1251         if (index_unchanged < 0)
1252                 return index_unchanged;
1253         if (!index_unchanged)
1254                 return 0; /* we do not have to say --allow-empty */
1255
1256         if (opts->keep_redundant_commits)
1257                 return 1;
1258
1259         empty_commit = is_original_commit_empty(commit);
1260         if (empty_commit < 0)
1261                 return empty_commit;
1262         if (!empty_commit)
1263                 return 0;
1264         else
1265                 return 1;
1266 }
1267
1268 /*
1269  * Note that ordering matters in this enum. Not only must it match the mapping
1270  * below, it is also divided into several sections that matter.  When adding
1271  * new commands, make sure you add it in the right section.
1272  */
1273 enum todo_command {
1274         /* commands that handle commits */
1275         TODO_PICK = 0,
1276         TODO_REVERT,
1277         TODO_EDIT,
1278         TODO_REWORD,
1279         TODO_FIXUP,
1280         TODO_SQUASH,
1281         /* commands that do something else than handling a single commit */
1282         TODO_EXEC,
1283         /* commands that do nothing but are counted for reporting progress */
1284         TODO_NOOP,
1285         TODO_DROP,
1286         /* comments (not counted for reporting progress) */
1287         TODO_COMMENT
1288 };
1289
1290 static struct {
1291         char c;
1292         const char *str;
1293 } todo_command_info[] = {
1294         { 'p', "pick" },
1295         { 0,   "revert" },
1296         { 'e', "edit" },
1297         { 'r', "reword" },
1298         { 'f', "fixup" },
1299         { 's', "squash" },
1300         { 'x', "exec" },
1301         { 0,   "noop" },
1302         { 'd', "drop" },
1303         { 0,   NULL }
1304 };
1305
1306 static const char *command_to_string(const enum todo_command command)
1307 {
1308         if (command < TODO_COMMENT)
1309                 return todo_command_info[command].str;
1310         die("Unknown command: %d", command);
1311 }
1312
1313 static char command_to_char(const enum todo_command command)
1314 {
1315         if (command < TODO_COMMENT && todo_command_info[command].c)
1316                 return todo_command_info[command].c;
1317         return comment_line_char;
1318 }
1319
1320 static int is_noop(const enum todo_command command)
1321 {
1322         return TODO_NOOP <= command;
1323 }
1324
1325 static int is_fixup(enum todo_command command)
1326 {
1327         return command == TODO_FIXUP || command == TODO_SQUASH;
1328 }
1329
1330 static int update_squash_messages(enum todo_command command,
1331                 struct commit *commit, struct replay_opts *opts)
1332 {
1333         struct strbuf buf = STRBUF_INIT;
1334         int count, res;
1335         const char *message, *body;
1336
1337         if (file_exists(rebase_path_squash_msg())) {
1338                 struct strbuf header = STRBUF_INIT;
1339                 char *eol, *p;
1340
1341                 if (strbuf_read_file(&buf, rebase_path_squash_msg(), 2048) <= 0)
1342                         return error(_("could not read '%s'"),
1343                                 rebase_path_squash_msg());
1344
1345                 p = buf.buf + 1;
1346                 eol = strchrnul(buf.buf, '\n');
1347                 if (buf.buf[0] != comment_line_char ||
1348                     (p += strcspn(p, "0123456789\n")) == eol)
1349                         return error(_("unexpected 1st line of squash message:"
1350                                        "\n\n\t%.*s"),
1351                                      (int)(eol - buf.buf), buf.buf);
1352                 count = strtol(p, NULL, 10);
1353
1354                 if (count < 1)
1355                         return error(_("invalid 1st line of squash message:\n"
1356                                        "\n\t%.*s"),
1357                                      (int)(eol - buf.buf), buf.buf);
1358
1359                 strbuf_addf(&header, "%c ", comment_line_char);
1360                 strbuf_addf(&header,
1361                             _("This is a combination of %d commits."), ++count);
1362                 strbuf_splice(&buf, 0, eol - buf.buf, header.buf, header.len);
1363                 strbuf_release(&header);
1364         } else {
1365                 struct object_id head;
1366                 struct commit *head_commit;
1367                 const char *head_message, *body;
1368
1369                 if (get_oid("HEAD", &head))
1370                         return error(_("need a HEAD to fixup"));
1371                 if (!(head_commit = lookup_commit_reference(&head)))
1372                         return error(_("could not read HEAD"));
1373                 if (!(head_message = get_commit_buffer(head_commit, NULL)))
1374                         return error(_("could not read HEAD's commit message"));
1375
1376                 find_commit_subject(head_message, &body);
1377                 if (write_message(body, strlen(body),
1378                                   rebase_path_fixup_msg(), 0)) {
1379                         unuse_commit_buffer(head_commit, head_message);
1380                         return error(_("cannot write '%s'"),
1381                                      rebase_path_fixup_msg());
1382                 }
1383
1384                 count = 2;
1385                 strbuf_addf(&buf, "%c ", comment_line_char);
1386                 strbuf_addf(&buf, _("This is a combination of %d commits."),
1387                             count);
1388                 strbuf_addf(&buf, "\n%c ", comment_line_char);
1389                 strbuf_addstr(&buf, _("This is the 1st commit message:"));
1390                 strbuf_addstr(&buf, "\n\n");
1391                 strbuf_addstr(&buf, body);
1392
1393                 unuse_commit_buffer(head_commit, head_message);
1394         }
1395
1396         if (!(message = get_commit_buffer(commit, NULL)))
1397                 return error(_("could not read commit message of %s"),
1398                              oid_to_hex(&commit->object.oid));
1399         find_commit_subject(message, &body);
1400
1401         if (command == TODO_SQUASH) {
1402                 unlink(rebase_path_fixup_msg());
1403                 strbuf_addf(&buf, "\n%c ", comment_line_char);
1404                 strbuf_addf(&buf, _("This is the commit message #%d:"), count);
1405                 strbuf_addstr(&buf, "\n\n");
1406                 strbuf_addstr(&buf, body);
1407         } else if (command == TODO_FIXUP) {
1408                 strbuf_addf(&buf, "\n%c ", comment_line_char);
1409                 strbuf_addf(&buf, _("The commit message #%d will be skipped:"),
1410                             count);
1411                 strbuf_addstr(&buf, "\n\n");
1412                 strbuf_add_commented_lines(&buf, body, strlen(body));
1413         } else
1414                 return error(_("unknown command: %d"), command);
1415         unuse_commit_buffer(commit, message);
1416
1417         res = write_message(buf.buf, buf.len, rebase_path_squash_msg(), 0);
1418         strbuf_release(&buf);
1419         return res;
1420 }
1421
1422 static void flush_rewritten_pending(void) {
1423         struct strbuf buf = STRBUF_INIT;
1424         struct object_id newoid;
1425         FILE *out;
1426
1427         if (strbuf_read_file(&buf, rebase_path_rewritten_pending(), (GIT_MAX_HEXSZ + 1) * 2) > 0 &&
1428             !get_oid("HEAD", &newoid) &&
1429             (out = fopen_or_warn(rebase_path_rewritten_list(), "a"))) {
1430                 char *bol = buf.buf, *eol;
1431
1432                 while (*bol) {
1433                         eol = strchrnul(bol, '\n');
1434                         fprintf(out, "%.*s %s\n", (int)(eol - bol),
1435                                         bol, oid_to_hex(&newoid));
1436                         if (!*eol)
1437                                 break;
1438                         bol = eol + 1;
1439                 }
1440                 fclose(out);
1441                 unlink(rebase_path_rewritten_pending());
1442         }
1443         strbuf_release(&buf);
1444 }
1445
1446 static void record_in_rewritten(struct object_id *oid,
1447                 enum todo_command next_command) {
1448         FILE *out = fopen_or_warn(rebase_path_rewritten_pending(), "a");
1449
1450         if (!out)
1451                 return;
1452
1453         fprintf(out, "%s\n", oid_to_hex(oid));
1454         fclose(out);
1455
1456         if (!is_fixup(next_command))
1457                 flush_rewritten_pending();
1458 }
1459
1460 static int do_pick_commit(enum todo_command command, struct commit *commit,
1461                 struct replay_opts *opts, int final_fixup)
1462 {
1463         unsigned int flags = opts->edit ? EDIT_MSG : 0;
1464         const char *msg_file = opts->edit ? NULL : git_path_merge_msg();
1465         struct object_id head;
1466         struct commit *base, *next, *parent;
1467         const char *base_label, *next_label;
1468         char *author = NULL;
1469         struct commit_message msg = { NULL, NULL, NULL, NULL };
1470         struct strbuf msgbuf = STRBUF_INIT;
1471         int res, unborn = 0, allow;
1472
1473         if (opts->no_commit) {
1474                 /*
1475                  * We do not intend to commit immediately.  We just want to
1476                  * merge the differences in, so let's compute the tree
1477                  * that represents the "current" state for merge-recursive
1478                  * to work on.
1479                  */
1480                 if (write_cache_as_tree(&head, 0, NULL))
1481                         return error(_("your index file is unmerged."));
1482         } else {
1483                 unborn = get_oid("HEAD", &head);
1484                 if (unborn)
1485                         oidcpy(&head, the_hash_algo->empty_tree);
1486                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD",
1487                                        NULL, 0))
1488                         return error_dirty_index(opts);
1489         }
1490         discard_cache();
1491
1492         if (!commit->parents)
1493                 parent = NULL;
1494         else if (commit->parents->next) {
1495                 /* Reverting or cherry-picking a merge commit */
1496                 int cnt;
1497                 struct commit_list *p;
1498
1499                 if (!opts->mainline)
1500                         return error(_("commit %s is a merge but no -m option was given."),
1501                                 oid_to_hex(&commit->object.oid));
1502
1503                 for (cnt = 1, p = commit->parents;
1504                      cnt != opts->mainline && p;
1505                      cnt++)
1506                         p = p->next;
1507                 if (cnt != opts->mainline || !p)
1508                         return error(_("commit %s does not have parent %d"),
1509                                 oid_to_hex(&commit->object.oid), opts->mainline);
1510                 parent = p->item;
1511         } else if (0 < opts->mainline)
1512                 return error(_("mainline was specified but commit %s is not a merge."),
1513                         oid_to_hex(&commit->object.oid));
1514         else
1515                 parent = commit->parents->item;
1516
1517         if (get_message(commit, &msg) != 0)
1518                 return error(_("cannot get commit message for %s"),
1519                         oid_to_hex(&commit->object.oid));
1520
1521         if (opts->allow_ff && !is_fixup(command) &&
1522             ((parent && !oidcmp(&parent->object.oid, &head)) ||
1523              (!parent && unborn))) {
1524                 if (is_rebase_i(opts))
1525                         write_author_script(msg.message);
1526                 res = fast_forward_to(&commit->object.oid, &head, unborn,
1527                         opts);
1528                 if (res || command != TODO_REWORD)
1529                         goto leave;
1530                 flags |= EDIT_MSG | AMEND_MSG | VERIFY_MSG;
1531                 msg_file = NULL;
1532                 goto fast_forward_edit;
1533         }
1534         if (parent && parse_commit(parent) < 0)
1535                 /* TRANSLATORS: The first %s will be a "todo" command like
1536                    "revert" or "pick", the second %s a SHA1. */
1537                 return error(_("%s: cannot parse parent commit %s"),
1538                         command_to_string(command),
1539                         oid_to_hex(&parent->object.oid));
1540
1541         /*
1542          * "commit" is an existing commit.  We would want to apply
1543          * the difference it introduces since its first parent "prev"
1544          * on top of the current HEAD if we are cherry-pick.  Or the
1545          * reverse of it if we are revert.
1546          */
1547
1548         if (command == TODO_REVERT) {
1549                 base = commit;
1550                 base_label = msg.label;
1551                 next = parent;
1552                 next_label = msg.parent_label;
1553                 strbuf_addstr(&msgbuf, "Revert \"");
1554                 strbuf_addstr(&msgbuf, msg.subject);
1555                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
1556                 strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
1557
1558                 if (commit->parents && commit->parents->next) {
1559                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
1560                         strbuf_addstr(&msgbuf, oid_to_hex(&parent->object.oid));
1561                 }
1562                 strbuf_addstr(&msgbuf, ".\n");
1563         } else {
1564                 const char *p;
1565
1566                 base = parent;
1567                 base_label = msg.parent_label;
1568                 next = commit;
1569                 next_label = msg.label;
1570
1571                 /* Append the commit log message to msgbuf. */
1572                 if (find_commit_subject(msg.message, &p))
1573                         strbuf_addstr(&msgbuf, p);
1574
1575                 if (opts->record_origin) {
1576                         strbuf_complete_line(&msgbuf);
1577                         if (!has_conforming_footer(&msgbuf, NULL, 0))
1578                                 strbuf_addch(&msgbuf, '\n');
1579                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
1580                         strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
1581                         strbuf_addstr(&msgbuf, ")\n");
1582                 }
1583                 if (!is_fixup(command))
1584                         author = get_author(msg.message);
1585         }
1586
1587         if (command == TODO_REWORD)
1588                 flags |= EDIT_MSG | VERIFY_MSG;
1589         else if (is_fixup(command)) {
1590                 if (update_squash_messages(command, commit, opts))
1591                         return -1;
1592                 flags |= AMEND_MSG;
1593                 if (!final_fixup)
1594                         msg_file = rebase_path_squash_msg();
1595                 else if (file_exists(rebase_path_fixup_msg())) {
1596                         flags |= CLEANUP_MSG;
1597                         msg_file = rebase_path_fixup_msg();
1598                 } else {
1599                         const char *dest = git_path_squash_msg();
1600                         unlink(dest);
1601                         if (copy_file(dest, rebase_path_squash_msg(), 0666))
1602                                 return error(_("could not rename '%s' to '%s'"),
1603                                              rebase_path_squash_msg(), dest);
1604                         unlink(git_path_merge_msg());
1605                         msg_file = dest;
1606                         flags |= EDIT_MSG;
1607                 }
1608         }
1609
1610         if (opts->signoff && !is_fixup(command))
1611                 append_signoff(&msgbuf, 0, 0);
1612
1613         if (is_rebase_i(opts) && write_author_script(msg.message) < 0)
1614                 res = -1;
1615         else if (!opts->strategy || !strcmp(opts->strategy, "recursive") || command == TODO_REVERT) {
1616                 res = do_recursive_merge(base, next, base_label, next_label,
1617                                          &head, &msgbuf, opts);
1618                 if (res < 0)
1619                         return res;
1620                 res |= write_message(msgbuf.buf, msgbuf.len,
1621                                      git_path_merge_msg(), 0);
1622         } else {
1623                 struct commit_list *common = NULL;
1624                 struct commit_list *remotes = NULL;
1625
1626                 res = write_message(msgbuf.buf, msgbuf.len,
1627                                     git_path_merge_msg(), 0);
1628
1629                 commit_list_insert(base, &common);
1630                 commit_list_insert(next, &remotes);
1631                 res |= try_merge_command(opts->strategy,
1632                                          opts->xopts_nr, (const char **)opts->xopts,
1633                                         common, oid_to_hex(&head), remotes);
1634                 free_commit_list(common);
1635                 free_commit_list(remotes);
1636         }
1637         strbuf_release(&msgbuf);
1638
1639         /*
1640          * If the merge was clean or if it failed due to conflict, we write
1641          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
1642          * However, if the merge did not even start, then we don't want to
1643          * write it at all.
1644          */
1645         if (command == TODO_PICK && !opts->no_commit && (res == 0 || res == 1) &&
1646             update_ref(NULL, "CHERRY_PICK_HEAD", &commit->object.oid, NULL,
1647                        REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR))
1648                 res = -1;
1649         if (command == TODO_REVERT && ((opts->no_commit && res == 0) || res == 1) &&
1650             update_ref(NULL, "REVERT_HEAD", &commit->object.oid, NULL,
1651                        REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR))
1652                 res = -1;
1653
1654         if (res) {
1655                 error(command == TODO_REVERT
1656                       ? _("could not revert %s... %s")
1657                       : _("could not apply %s... %s"),
1658                       short_commit_name(commit), msg.subject);
1659                 print_advice(res == 1, opts);
1660                 rerere(opts->allow_rerere_auto);
1661                 goto leave;
1662         }
1663
1664         allow = allow_empty(opts, commit);
1665         if (allow < 0) {
1666                 res = allow;
1667                 goto leave;
1668         } else if (allow)
1669                 flags |= ALLOW_EMPTY;
1670         if (!opts->no_commit) {
1671 fast_forward_edit:
1672                 if (author || command == TODO_REVERT || (flags & AMEND_MSG))
1673                         res = do_commit(msg_file, author, opts, flags);
1674                 else
1675                         res = error(_("unable to parse commit author"));
1676         }
1677
1678         if (!res && final_fixup) {
1679                 unlink(rebase_path_fixup_msg());
1680                 unlink(rebase_path_squash_msg());
1681         }
1682
1683 leave:
1684         free_message(commit, &msg);
1685         free(author);
1686         update_abort_safety_file();
1687
1688         return res;
1689 }
1690
1691 static int prepare_revs(struct replay_opts *opts)
1692 {
1693         /*
1694          * picking (but not reverting) ranges (but not individual revisions)
1695          * should be done in reverse
1696          */
1697         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
1698                 opts->revs->reverse ^= 1;
1699
1700         if (prepare_revision_walk(opts->revs))
1701                 return error(_("revision walk setup failed"));
1702
1703         if (!opts->revs->commits)
1704                 return error(_("empty commit set passed"));
1705         return 0;
1706 }
1707
1708 static int read_and_refresh_cache(struct replay_opts *opts)
1709 {
1710         struct lock_file index_lock = LOCK_INIT;
1711         int index_fd = hold_locked_index(&index_lock, 0);
1712         if (read_index_preload(&the_index, NULL) < 0) {
1713                 rollback_lock_file(&index_lock);
1714                 return error(_("git %s: failed to read the index"),
1715                         _(action_name(opts)));
1716         }
1717         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
1718         if (index_fd >= 0) {
1719                 if (write_locked_index(&the_index, &index_lock,
1720                                        COMMIT_LOCK | SKIP_IF_UNCHANGED)) {
1721                         return error(_("git %s: failed to refresh the index"),
1722                                 _(action_name(opts)));
1723                 }
1724         }
1725         return 0;
1726 }
1727
1728 struct todo_item {
1729         enum todo_command command;
1730         struct commit *commit;
1731         const char *arg;
1732         int arg_len;
1733         size_t offset_in_buf;
1734 };
1735
1736 struct todo_list {
1737         struct strbuf buf;
1738         struct todo_item *items;
1739         int nr, alloc, current;
1740         int done_nr, total_nr;
1741         struct stat_data stat;
1742 };
1743
1744 #define TODO_LIST_INIT { STRBUF_INIT }
1745
1746 static void todo_list_release(struct todo_list *todo_list)
1747 {
1748         strbuf_release(&todo_list->buf);
1749         FREE_AND_NULL(todo_list->items);
1750         todo_list->nr = todo_list->alloc = 0;
1751 }
1752
1753 static struct todo_item *append_new_todo(struct todo_list *todo_list)
1754 {
1755         ALLOC_GROW(todo_list->items, todo_list->nr + 1, todo_list->alloc);
1756         return todo_list->items + todo_list->nr++;
1757 }
1758
1759 static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
1760 {
1761         struct object_id commit_oid;
1762         char *end_of_object_name;
1763         int i, saved, status, padding;
1764
1765         /* left-trim */
1766         bol += strspn(bol, " \t");
1767
1768         if (bol == eol || *bol == '\r' || *bol == comment_line_char) {
1769                 item->command = TODO_COMMENT;
1770                 item->commit = NULL;
1771                 item->arg = bol;
1772                 item->arg_len = eol - bol;
1773                 return 0;
1774         }
1775
1776         for (i = 0; i < TODO_COMMENT; i++)
1777                 if (skip_prefix(bol, todo_command_info[i].str, &bol)) {
1778                         item->command = i;
1779                         break;
1780                 } else if (bol[1] == ' ' && *bol == todo_command_info[i].c) {
1781                         bol++;
1782                         item->command = i;
1783                         break;
1784                 }
1785         if (i >= TODO_COMMENT)
1786                 return -1;
1787
1788         /* Eat up extra spaces/ tabs before object name */
1789         padding = strspn(bol, " \t");
1790         bol += padding;
1791
1792         if (item->command == TODO_NOOP) {
1793                 if (bol != eol)
1794                         return error(_("%s does not accept arguments: '%s'"),
1795                                      command_to_string(item->command), bol);
1796                 item->commit = NULL;
1797                 item->arg = bol;
1798                 item->arg_len = eol - bol;
1799                 return 0;
1800         }
1801
1802         if (!padding)
1803                 return error(_("missing arguments for %s"),
1804                              command_to_string(item->command));
1805
1806         if (item->command == TODO_EXEC) {
1807                 item->commit = NULL;
1808                 item->arg = bol;
1809                 item->arg_len = (int)(eol - bol);
1810                 return 0;
1811         }
1812
1813         end_of_object_name = (char *) bol + strcspn(bol, " \t\n");
1814         saved = *end_of_object_name;
1815         *end_of_object_name = '\0';
1816         status = get_oid(bol, &commit_oid);
1817         *end_of_object_name = saved;
1818
1819         item->arg = end_of_object_name + strspn(end_of_object_name, " \t");
1820         item->arg_len = (int)(eol - item->arg);
1821
1822         if (status < 0)
1823                 return -1;
1824
1825         item->commit = lookup_commit_reference(&commit_oid);
1826         return !item->commit;
1827 }
1828
1829 static int parse_insn_buffer(char *buf, struct todo_list *todo_list)
1830 {
1831         struct todo_item *item;
1832         char *p = buf, *next_p;
1833         int i, res = 0, fixup_okay = file_exists(rebase_path_done());
1834
1835         for (i = 1; *p; i++, p = next_p) {
1836                 char *eol = strchrnul(p, '\n');
1837
1838                 next_p = *eol ? eol + 1 /* skip LF */ : eol;
1839
1840                 if (p != eol && eol[-1] == '\r')
1841                         eol--; /* strip Carriage Return */
1842
1843                 item = append_new_todo(todo_list);
1844                 item->offset_in_buf = p - todo_list->buf.buf;
1845                 if (parse_insn_line(item, p, eol)) {
1846                         res = error(_("invalid line %d: %.*s"),
1847                                 i, (int)(eol - p), p);
1848                         item->command = TODO_NOOP;
1849                 }
1850
1851                 if (fixup_okay)
1852                         ; /* do nothing */
1853                 else if (is_fixup(item->command))
1854                         return error(_("cannot '%s' without a previous commit"),
1855                                 command_to_string(item->command));
1856                 else if (!is_noop(item->command))
1857                         fixup_okay = 1;
1858         }
1859
1860         return res;
1861 }
1862
1863 static int count_commands(struct todo_list *todo_list)
1864 {
1865         int count = 0, i;
1866
1867         for (i = 0; i < todo_list->nr; i++)
1868                 if (todo_list->items[i].command != TODO_COMMENT)
1869                         count++;
1870
1871         return count;
1872 }
1873
1874 static ssize_t strbuf_read_file_or_whine(struct strbuf *sb, const char *path)
1875 {
1876         int fd;
1877         ssize_t len;
1878
1879         fd = open(path, O_RDONLY);
1880         if (fd < 0)
1881                 return error_errno(_("could not open '%s'"), path);
1882         len = strbuf_read(sb, fd, 0);
1883         close(fd);
1884         if (len < 0)
1885                 return error(_("could not read '%s'."), path);
1886         return len;
1887 }
1888
1889 static int read_populate_todo(struct todo_list *todo_list,
1890                         struct replay_opts *opts)
1891 {
1892         struct stat st;
1893         const char *todo_file = get_todo_path(opts);
1894         int res;
1895
1896         strbuf_reset(&todo_list->buf);
1897         if (strbuf_read_file_or_whine(&todo_list->buf, todo_file) < 0)
1898                 return -1;
1899
1900         res = stat(todo_file, &st);
1901         if (res)
1902                 return error(_("could not stat '%s'"), todo_file);
1903         fill_stat_data(&todo_list->stat, &st);
1904
1905         res = parse_insn_buffer(todo_list->buf.buf, todo_list);
1906         if (res) {
1907                 if (is_rebase_i(opts))
1908                         return error(_("please fix this using "
1909                                        "'git rebase --edit-todo'."));
1910                 return error(_("unusable instruction sheet: '%s'"), todo_file);
1911         }
1912
1913         if (!todo_list->nr &&
1914             (!is_rebase_i(opts) || !file_exists(rebase_path_done())))
1915                 return error(_("no commits parsed."));
1916
1917         if (!is_rebase_i(opts)) {
1918                 enum todo_command valid =
1919                         opts->action == REPLAY_PICK ? TODO_PICK : TODO_REVERT;
1920                 int i;
1921
1922                 for (i = 0; i < todo_list->nr; i++)
1923                         if (valid == todo_list->items[i].command)
1924                                 continue;
1925                         else if (valid == TODO_PICK)
1926                                 return error(_("cannot cherry-pick during a revert."));
1927                         else
1928                                 return error(_("cannot revert during a cherry-pick."));
1929         }
1930
1931         if (is_rebase_i(opts)) {
1932                 struct todo_list done = TODO_LIST_INIT;
1933                 FILE *f = fopen_or_warn(rebase_path_msgtotal(), "w");
1934
1935                 if (strbuf_read_file(&done.buf, rebase_path_done(), 0) > 0 &&
1936                                 !parse_insn_buffer(done.buf.buf, &done))
1937                         todo_list->done_nr = count_commands(&done);
1938                 else
1939                         todo_list->done_nr = 0;
1940
1941                 todo_list->total_nr = todo_list->done_nr
1942                         + count_commands(todo_list);
1943                 todo_list_release(&done);
1944
1945                 if (f) {
1946                         fprintf(f, "%d\n", todo_list->total_nr);
1947                         fclose(f);
1948                 }
1949         }
1950
1951         return 0;
1952 }
1953
1954 static int git_config_string_dup(char **dest,
1955                                  const char *var, const char *value)
1956 {
1957         if (!value)
1958                 return config_error_nonbool(var);
1959         free(*dest);
1960         *dest = xstrdup(value);
1961         return 0;
1962 }
1963
1964 static int populate_opts_cb(const char *key, const char *value, void *data)
1965 {
1966         struct replay_opts *opts = data;
1967         int error_flag = 1;
1968
1969         if (!value)
1970                 error_flag = 0;
1971         else if (!strcmp(key, "options.no-commit"))
1972                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
1973         else if (!strcmp(key, "options.edit"))
1974                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
1975         else if (!strcmp(key, "options.signoff"))
1976                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
1977         else if (!strcmp(key, "options.record-origin"))
1978                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
1979         else if (!strcmp(key, "options.allow-ff"))
1980                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
1981         else if (!strcmp(key, "options.mainline"))
1982                 opts->mainline = git_config_int(key, value);
1983         else if (!strcmp(key, "options.strategy"))
1984                 git_config_string_dup(&opts->strategy, key, value);
1985         else if (!strcmp(key, "options.gpg-sign"))
1986                 git_config_string_dup(&opts->gpg_sign, key, value);
1987         else if (!strcmp(key, "options.strategy-option")) {
1988                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
1989                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
1990         } else if (!strcmp(key, "options.allow-rerere-auto"))
1991                 opts->allow_rerere_auto =
1992                         git_config_bool_or_int(key, value, &error_flag) ?
1993                                 RERERE_AUTOUPDATE : RERERE_NOAUTOUPDATE;
1994         else
1995                 return error(_("invalid key: %s"), key);
1996
1997         if (!error_flag)
1998                 return error(_("invalid value for %s: %s"), key, value);
1999
2000         return 0;
2001 }
2002
2003 static void read_strategy_opts(struct replay_opts *opts, struct strbuf *buf)
2004 {
2005         int i;
2006
2007         strbuf_reset(buf);
2008         if (!read_oneliner(buf, rebase_path_strategy(), 0))
2009                 return;
2010         opts->strategy = strbuf_detach(buf, NULL);
2011         if (!read_oneliner(buf, rebase_path_strategy_opts(), 0))
2012                 return;
2013
2014         opts->xopts_nr = split_cmdline(buf->buf, (const char ***)&opts->xopts);
2015         for (i = 0; i < opts->xopts_nr; i++) {
2016                 const char *arg = opts->xopts[i];
2017
2018                 skip_prefix(arg, "--", &arg);
2019                 opts->xopts[i] = xstrdup(arg);
2020         }
2021 }
2022
2023 static int read_populate_opts(struct replay_opts *opts)
2024 {
2025         if (is_rebase_i(opts)) {
2026                 struct strbuf buf = STRBUF_INIT;
2027
2028                 if (read_oneliner(&buf, rebase_path_gpg_sign_opt(), 1)) {
2029                         if (!starts_with(buf.buf, "-S"))
2030                                 strbuf_reset(&buf);
2031                         else {
2032                                 free(opts->gpg_sign);
2033                                 opts->gpg_sign = xstrdup(buf.buf + 2);
2034                         }
2035                         strbuf_reset(&buf);
2036                 }
2037
2038                 if (read_oneliner(&buf, rebase_path_allow_rerere_autoupdate(), 1)) {
2039                         if (!strcmp(buf.buf, "--rerere-autoupdate"))
2040                                 opts->allow_rerere_auto = RERERE_AUTOUPDATE;
2041                         else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
2042                                 opts->allow_rerere_auto = RERERE_NOAUTOUPDATE;
2043                         strbuf_reset(&buf);
2044                 }
2045
2046                 if (file_exists(rebase_path_verbose()))
2047                         opts->verbose = 1;
2048
2049                 if (file_exists(rebase_path_signoff())) {
2050                         opts->allow_ff = 0;
2051                         opts->signoff = 1;
2052                 }
2053
2054                 read_strategy_opts(opts, &buf);
2055                 strbuf_release(&buf);
2056
2057                 return 0;
2058         }
2059
2060         if (!file_exists(git_path_opts_file()))
2061                 return 0;
2062         /*
2063          * The function git_parse_source(), called from git_config_from_file(),
2064          * may die() in case of a syntactically incorrect file. We do not care
2065          * about this case, though, because we wrote that file ourselves, so we
2066          * are pretty certain that it is syntactically correct.
2067          */
2068         if (git_config_from_file(populate_opts_cb, git_path_opts_file(), opts) < 0)
2069                 return error(_("malformed options sheet: '%s'"),
2070                         git_path_opts_file());
2071         return 0;
2072 }
2073
2074 static int walk_revs_populate_todo(struct todo_list *todo_list,
2075                                 struct replay_opts *opts)
2076 {
2077         enum todo_command command = opts->action == REPLAY_PICK ?
2078                 TODO_PICK : TODO_REVERT;
2079         const char *command_string = todo_command_info[command].str;
2080         struct commit *commit;
2081
2082         if (prepare_revs(opts))
2083                 return -1;
2084
2085         while ((commit = get_revision(opts->revs))) {
2086                 struct todo_item *item = append_new_todo(todo_list);
2087                 const char *commit_buffer = get_commit_buffer(commit, NULL);
2088                 const char *subject;
2089                 int subject_len;
2090
2091                 item->command = command;
2092                 item->commit = commit;
2093                 item->arg = NULL;
2094                 item->arg_len = 0;
2095                 item->offset_in_buf = todo_list->buf.len;
2096                 subject_len = find_commit_subject(commit_buffer, &subject);
2097                 strbuf_addf(&todo_list->buf, "%s %s %.*s\n", command_string,
2098                         short_commit_name(commit), subject_len, subject);
2099                 unuse_commit_buffer(commit, commit_buffer);
2100         }
2101         return 0;
2102 }
2103
2104 static int create_seq_dir(void)
2105 {
2106         if (file_exists(git_path_seq_dir())) {
2107                 error(_("a cherry-pick or revert is already in progress"));
2108                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
2109                 return -1;
2110         } else if (mkdir(git_path_seq_dir(), 0777) < 0)
2111                 return error_errno(_("could not create sequencer directory '%s'"),
2112                                    git_path_seq_dir());
2113         return 0;
2114 }
2115
2116 static int save_head(const char *head)
2117 {
2118         struct lock_file head_lock = LOCK_INIT;
2119         struct strbuf buf = STRBUF_INIT;
2120         int fd;
2121         ssize_t written;
2122
2123         fd = hold_lock_file_for_update(&head_lock, git_path_head_file(), 0);
2124         if (fd < 0)
2125                 return error_errno(_("could not lock HEAD"));
2126         strbuf_addf(&buf, "%s\n", head);
2127         written = write_in_full(fd, buf.buf, buf.len);
2128         strbuf_release(&buf);
2129         if (written < 0) {
2130                 rollback_lock_file(&head_lock);
2131                 return error_errno(_("could not write to '%s'"),
2132                                    git_path_head_file());
2133         }
2134         if (commit_lock_file(&head_lock) < 0)
2135                 return error(_("failed to finalize '%s'"), git_path_head_file());
2136         return 0;
2137 }
2138
2139 static int rollback_is_safe(void)
2140 {
2141         struct strbuf sb = STRBUF_INIT;
2142         struct object_id expected_head, actual_head;
2143
2144         if (strbuf_read_file(&sb, git_path_abort_safety_file(), 0) >= 0) {
2145                 strbuf_trim(&sb);
2146                 if (get_oid_hex(sb.buf, &expected_head)) {
2147                         strbuf_release(&sb);
2148                         die(_("could not parse %s"), git_path_abort_safety_file());
2149                 }
2150                 strbuf_release(&sb);
2151         }
2152         else if (errno == ENOENT)
2153                 oidclr(&expected_head);
2154         else
2155                 die_errno(_("could not read '%s'"), git_path_abort_safety_file());
2156
2157         if (get_oid("HEAD", &actual_head))
2158                 oidclr(&actual_head);
2159
2160         return !oidcmp(&actual_head, &expected_head);
2161 }
2162
2163 static int reset_for_rollback(const struct object_id *oid)
2164 {
2165         const char *argv[4];    /* reset --merge <arg> + NULL */
2166
2167         argv[0] = "reset";
2168         argv[1] = "--merge";
2169         argv[2] = oid_to_hex(oid);
2170         argv[3] = NULL;
2171         return run_command_v_opt(argv, RUN_GIT_CMD);
2172 }
2173
2174 static int rollback_single_pick(void)
2175 {
2176         struct object_id head_oid;
2177
2178         if (!file_exists(git_path_cherry_pick_head()) &&
2179             !file_exists(git_path_revert_head()))
2180                 return error(_("no cherry-pick or revert in progress"));
2181         if (read_ref_full("HEAD", 0, &head_oid, NULL))
2182                 return error(_("cannot resolve HEAD"));
2183         if (is_null_oid(&head_oid))
2184                 return error(_("cannot abort from a branch yet to be born"));
2185         return reset_for_rollback(&head_oid);
2186 }
2187
2188 int sequencer_rollback(struct replay_opts *opts)
2189 {
2190         FILE *f;
2191         struct object_id oid;
2192         struct strbuf buf = STRBUF_INIT;
2193         const char *p;
2194
2195         f = fopen(git_path_head_file(), "r");
2196         if (!f && errno == ENOENT) {
2197                 /*
2198                  * There is no multiple-cherry-pick in progress.
2199                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
2200                  * a single-cherry-pick in progress, abort that.
2201                  */
2202                 return rollback_single_pick();
2203         }
2204         if (!f)
2205                 return error_errno(_("cannot open '%s'"), git_path_head_file());
2206         if (strbuf_getline_lf(&buf, f)) {
2207                 error(_("cannot read '%s': %s"), git_path_head_file(),
2208                       ferror(f) ?  strerror(errno) : _("unexpected end of file"));
2209                 fclose(f);
2210                 goto fail;
2211         }
2212         fclose(f);
2213         if (parse_oid_hex(buf.buf, &oid, &p) || *p != '\0') {
2214                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
2215                         git_path_head_file());
2216                 goto fail;
2217         }
2218         if (is_null_oid(&oid)) {
2219                 error(_("cannot abort from a branch yet to be born"));
2220                 goto fail;
2221         }
2222
2223         if (!rollback_is_safe()) {
2224                 /* Do not error, just do not rollback */
2225                 warning(_("You seem to have moved HEAD. "
2226                           "Not rewinding, check your HEAD!"));
2227         } else
2228         if (reset_for_rollback(&oid))
2229                 goto fail;
2230         strbuf_release(&buf);
2231         return sequencer_remove_state(opts);
2232 fail:
2233         strbuf_release(&buf);
2234         return -1;
2235 }
2236
2237 static int save_todo(struct todo_list *todo_list, struct replay_opts *opts)
2238 {
2239         struct lock_file todo_lock = LOCK_INIT;
2240         const char *todo_path = get_todo_path(opts);
2241         int next = todo_list->current, offset, fd;
2242
2243         /*
2244          * rebase -i writes "git-rebase-todo" without the currently executing
2245          * command, appending it to "done" instead.
2246          */
2247         if (is_rebase_i(opts))
2248                 next++;
2249
2250         fd = hold_lock_file_for_update(&todo_lock, todo_path, 0);
2251         if (fd < 0)
2252                 return error_errno(_("could not lock '%s'"), todo_path);
2253         offset = next < todo_list->nr ?
2254                 todo_list->items[next].offset_in_buf : todo_list->buf.len;
2255         if (write_in_full(fd, todo_list->buf.buf + offset,
2256                         todo_list->buf.len - offset) < 0)
2257                 return error_errno(_("could not write to '%s'"), todo_path);
2258         if (commit_lock_file(&todo_lock) < 0)
2259                 return error(_("failed to finalize '%s'"), todo_path);
2260
2261         if (is_rebase_i(opts)) {
2262                 const char *done_path = rebase_path_done();
2263                 int fd = open(done_path, O_CREAT | O_WRONLY | O_APPEND, 0666);
2264                 int prev_offset = !next ? 0 :
2265                         todo_list->items[next - 1].offset_in_buf;
2266
2267                 if (fd >= 0 && offset > prev_offset &&
2268                     write_in_full(fd, todo_list->buf.buf + prev_offset,
2269                                   offset - prev_offset) < 0) {
2270                         close(fd);
2271                         return error_errno(_("could not write to '%s'"),
2272                                            done_path);
2273                 }
2274                 if (fd >= 0)
2275                         close(fd);
2276         }
2277         return 0;
2278 }
2279
2280 static int save_opts(struct replay_opts *opts)
2281 {
2282         const char *opts_file = git_path_opts_file();
2283         int res = 0;
2284
2285         if (opts->no_commit)
2286                 res |= git_config_set_in_file_gently(opts_file, "options.no-commit", "true");
2287         if (opts->edit)
2288                 res |= git_config_set_in_file_gently(opts_file, "options.edit", "true");
2289         if (opts->signoff)
2290                 res |= git_config_set_in_file_gently(opts_file, "options.signoff", "true");
2291         if (opts->record_origin)
2292                 res |= git_config_set_in_file_gently(opts_file, "options.record-origin", "true");
2293         if (opts->allow_ff)
2294                 res |= git_config_set_in_file_gently(opts_file, "options.allow-ff", "true");
2295         if (opts->mainline) {
2296                 struct strbuf buf = STRBUF_INIT;
2297                 strbuf_addf(&buf, "%d", opts->mainline);
2298                 res |= git_config_set_in_file_gently(opts_file, "options.mainline", buf.buf);
2299                 strbuf_release(&buf);
2300         }
2301         if (opts->strategy)
2302                 res |= git_config_set_in_file_gently(opts_file, "options.strategy", opts->strategy);
2303         if (opts->gpg_sign)
2304                 res |= git_config_set_in_file_gently(opts_file, "options.gpg-sign", opts->gpg_sign);
2305         if (opts->xopts) {
2306                 int i;
2307                 for (i = 0; i < opts->xopts_nr; i++)
2308                         res |= git_config_set_multivar_in_file_gently(opts_file,
2309                                                         "options.strategy-option",
2310                                                         opts->xopts[i], "^$", 0);
2311         }
2312         if (opts->allow_rerere_auto)
2313                 res |= git_config_set_in_file_gently(opts_file, "options.allow-rerere-auto",
2314                                                      opts->allow_rerere_auto == RERERE_AUTOUPDATE ?
2315                                                      "true" : "false");
2316         return res;
2317 }
2318
2319 static int make_patch(struct commit *commit, struct replay_opts *opts)
2320 {
2321         struct strbuf buf = STRBUF_INIT;
2322         struct rev_info log_tree_opt;
2323         const char *subject, *p;
2324         int res = 0;
2325
2326         p = short_commit_name(commit);
2327         if (write_message(p, strlen(p), rebase_path_stopped_sha(), 1) < 0)
2328                 return -1;
2329         if (update_ref("rebase", "REBASE_HEAD", &commit->object.oid,
2330                        NULL, REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR))
2331                 res |= error(_("could not update %s"), "REBASE_HEAD");
2332
2333         strbuf_addf(&buf, "%s/patch", get_dir(opts));
2334         memset(&log_tree_opt, 0, sizeof(log_tree_opt));
2335         init_revisions(&log_tree_opt, NULL);
2336         log_tree_opt.abbrev = 0;
2337         log_tree_opt.diff = 1;
2338         log_tree_opt.diffopt.output_format = DIFF_FORMAT_PATCH;
2339         log_tree_opt.disable_stdin = 1;
2340         log_tree_opt.no_commit_id = 1;
2341         log_tree_opt.diffopt.file = fopen(buf.buf, "w");
2342         log_tree_opt.diffopt.use_color = GIT_COLOR_NEVER;
2343         if (!log_tree_opt.diffopt.file)
2344                 res |= error_errno(_("could not open '%s'"), buf.buf);
2345         else {
2346                 res |= log_tree_commit(&log_tree_opt, commit);
2347                 fclose(log_tree_opt.diffopt.file);
2348         }
2349         strbuf_reset(&buf);
2350
2351         strbuf_addf(&buf, "%s/message", get_dir(opts));
2352         if (!file_exists(buf.buf)) {
2353                 const char *commit_buffer = get_commit_buffer(commit, NULL);
2354                 find_commit_subject(commit_buffer, &subject);
2355                 res |= write_message(subject, strlen(subject), buf.buf, 1);
2356                 unuse_commit_buffer(commit, commit_buffer);
2357         }
2358         strbuf_release(&buf);
2359
2360         return res;
2361 }
2362
2363 static int intend_to_amend(void)
2364 {
2365         struct object_id head;
2366         char *p;
2367
2368         if (get_oid("HEAD", &head))
2369                 return error(_("cannot read HEAD"));
2370
2371         p = oid_to_hex(&head);
2372         return write_message(p, strlen(p), rebase_path_amend(), 1);
2373 }
2374
2375 static int error_with_patch(struct commit *commit,
2376         const char *subject, int subject_len,
2377         struct replay_opts *opts, int exit_code, int to_amend)
2378 {
2379         if (make_patch(commit, opts))
2380                 return -1;
2381
2382         if (to_amend) {
2383                 if (intend_to_amend())
2384                         return -1;
2385
2386                 fprintf(stderr, "You can amend the commit now, with\n"
2387                         "\n"
2388                         "  git commit --amend %s\n"
2389                         "\n"
2390                         "Once you are satisfied with your changes, run\n"
2391                         "\n"
2392                         "  git rebase --continue\n", gpg_sign_opt_quoted(opts));
2393         } else if (exit_code)
2394                 fprintf(stderr, "Could not apply %s... %.*s\n",
2395                         short_commit_name(commit), subject_len, subject);
2396
2397         return exit_code;
2398 }
2399
2400 static int error_failed_squash(struct commit *commit,
2401         struct replay_opts *opts, int subject_len, const char *subject)
2402 {
2403         if (rename(rebase_path_squash_msg(), rebase_path_message()))
2404                 return error(_("could not rename '%s' to '%s'"),
2405                         rebase_path_squash_msg(), rebase_path_message());
2406         unlink(rebase_path_fixup_msg());
2407         unlink(git_path_merge_msg());
2408         if (copy_file(git_path_merge_msg(), rebase_path_message(), 0666))
2409                 return error(_("could not copy '%s' to '%s'"),
2410                              rebase_path_message(), git_path_merge_msg());
2411         return error_with_patch(commit, subject, subject_len, opts, 1, 0);
2412 }
2413
2414 static int do_exec(const char *command_line)
2415 {
2416         struct argv_array child_env = ARGV_ARRAY_INIT;
2417         const char *child_argv[] = { NULL, NULL };
2418         int dirty, status;
2419
2420         fprintf(stderr, "Executing: %s\n", command_line);
2421         child_argv[0] = command_line;
2422         argv_array_pushf(&child_env, "GIT_DIR=%s", absolute_path(get_git_dir()));
2423         status = run_command_v_opt_cd_env(child_argv, RUN_USING_SHELL, NULL,
2424                                           child_env.argv);
2425
2426         /* force re-reading of the cache */
2427         if (discard_cache() < 0 || read_cache() < 0)
2428                 return error(_("could not read index"));
2429
2430         dirty = require_clean_work_tree("rebase", NULL, 1, 1);
2431
2432         if (status) {
2433                 warning(_("execution failed: %s\n%s"
2434                           "You can fix the problem, and then run\n"
2435                           "\n"
2436                           "  git rebase --continue\n"
2437                           "\n"),
2438                         command_line,
2439                         dirty ? N_("and made changes to the index and/or the "
2440                                 "working tree\n") : "");
2441                 if (status == 127)
2442                         /* command not found */
2443                         status = 1;
2444         } else if (dirty) {
2445                 warning(_("execution succeeded: %s\nbut "
2446                           "left changes to the index and/or the working tree\n"
2447                           "Commit or stash your changes, and then run\n"
2448                           "\n"
2449                           "  git rebase --continue\n"
2450                           "\n"), command_line);
2451                 status = 1;
2452         }
2453
2454         argv_array_clear(&child_env);
2455
2456         return status;
2457 }
2458
2459 static int is_final_fixup(struct todo_list *todo_list)
2460 {
2461         int i = todo_list->current;
2462
2463         if (!is_fixup(todo_list->items[i].command))
2464                 return 0;
2465
2466         while (++i < todo_list->nr)
2467                 if (is_fixup(todo_list->items[i].command))
2468                         return 0;
2469                 else if (!is_noop(todo_list->items[i].command))
2470                         break;
2471         return 1;
2472 }
2473
2474 static enum todo_command peek_command(struct todo_list *todo_list, int offset)
2475 {
2476         int i;
2477
2478         for (i = todo_list->current + offset; i < todo_list->nr; i++)
2479                 if (!is_noop(todo_list->items[i].command))
2480                         return todo_list->items[i].command;
2481
2482         return -1;
2483 }
2484
2485 static int apply_autostash(struct replay_opts *opts)
2486 {
2487         struct strbuf stash_sha1 = STRBUF_INIT;
2488         struct child_process child = CHILD_PROCESS_INIT;
2489         int ret = 0;
2490
2491         if (!read_oneliner(&stash_sha1, rebase_path_autostash(), 1)) {
2492                 strbuf_release(&stash_sha1);
2493                 return 0;
2494         }
2495         strbuf_trim(&stash_sha1);
2496
2497         child.git_cmd = 1;
2498         child.no_stdout = 1;
2499         child.no_stderr = 1;
2500         argv_array_push(&child.args, "stash");
2501         argv_array_push(&child.args, "apply");
2502         argv_array_push(&child.args, stash_sha1.buf);
2503         if (!run_command(&child))
2504                 fprintf(stderr, _("Applied autostash.\n"));
2505         else {
2506                 struct child_process store = CHILD_PROCESS_INIT;
2507
2508                 store.git_cmd = 1;
2509                 argv_array_push(&store.args, "stash");
2510                 argv_array_push(&store.args, "store");
2511                 argv_array_push(&store.args, "-m");
2512                 argv_array_push(&store.args, "autostash");
2513                 argv_array_push(&store.args, "-q");
2514                 argv_array_push(&store.args, stash_sha1.buf);
2515                 if (run_command(&store))
2516                         ret = error(_("cannot store %s"), stash_sha1.buf);
2517                 else
2518                         fprintf(stderr,
2519                                 _("Applying autostash resulted in conflicts.\n"
2520                                   "Your changes are safe in the stash.\n"
2521                                   "You can run \"git stash pop\" or"
2522                                   " \"git stash drop\" at any time.\n"));
2523         }
2524
2525         strbuf_release(&stash_sha1);
2526         return ret;
2527 }
2528
2529 static const char *reflog_message(struct replay_opts *opts,
2530         const char *sub_action, const char *fmt, ...)
2531 {
2532         va_list ap;
2533         static struct strbuf buf = STRBUF_INIT;
2534
2535         va_start(ap, fmt);
2536         strbuf_reset(&buf);
2537         strbuf_addstr(&buf, action_name(opts));
2538         if (sub_action)
2539                 strbuf_addf(&buf, " (%s)", sub_action);
2540         if (fmt) {
2541                 strbuf_addstr(&buf, ": ");
2542                 strbuf_vaddf(&buf, fmt, ap);
2543         }
2544         va_end(ap);
2545
2546         return buf.buf;
2547 }
2548
2549 static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
2550 {
2551         int res = 0;
2552
2553         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
2554         if (opts->allow_ff)
2555                 assert(!(opts->signoff || opts->no_commit ||
2556                                 opts->record_origin || opts->edit));
2557         if (read_and_refresh_cache(opts))
2558                 return -1;
2559
2560         while (todo_list->current < todo_list->nr) {
2561                 struct todo_item *item = todo_list->items + todo_list->current;
2562                 if (save_todo(todo_list, opts))
2563                         return -1;
2564                 if (is_rebase_i(opts)) {
2565                         if (item->command != TODO_COMMENT) {
2566                                 FILE *f = fopen(rebase_path_msgnum(), "w");
2567
2568                                 todo_list->done_nr++;
2569
2570                                 if (f) {
2571                                         fprintf(f, "%d\n", todo_list->done_nr);
2572                                         fclose(f);
2573                                 }
2574                                 fprintf(stderr, "Rebasing (%d/%d)%s",
2575                                         todo_list->done_nr,
2576                                         todo_list->total_nr,
2577                                         opts->verbose ? "\n" : "\r");
2578                         }
2579                         unlink(rebase_path_message());
2580                         unlink(rebase_path_author_script());
2581                         unlink(rebase_path_stopped_sha());
2582                         unlink(rebase_path_amend());
2583                         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
2584                 }
2585                 if (item->command <= TODO_SQUASH) {
2586                         if (is_rebase_i(opts))
2587                                 setenv("GIT_REFLOG_ACTION", reflog_message(opts,
2588                                         command_to_string(item->command), NULL),
2589                                         1);
2590                         res = do_pick_commit(item->command, item->commit,
2591                                         opts, is_final_fixup(todo_list));
2592                         if (is_rebase_i(opts) && res < 0) {
2593                                 /* Reschedule */
2594                                 todo_list->current--;
2595                                 if (save_todo(todo_list, opts))
2596                                         return -1;
2597                         }
2598                         if (item->command == TODO_EDIT) {
2599                                 struct commit *commit = item->commit;
2600                                 if (!res)
2601                                         fprintf(stderr,
2602                                                 _("Stopped at %s...  %.*s\n"),
2603                                                 short_commit_name(commit),
2604                                                 item->arg_len, item->arg);
2605                                 return error_with_patch(commit,
2606                                         item->arg, item->arg_len, opts, res,
2607                                         !res);
2608                         }
2609                         if (is_rebase_i(opts) && !res)
2610                                 record_in_rewritten(&item->commit->object.oid,
2611                                         peek_command(todo_list, 1));
2612                         if (res && is_fixup(item->command)) {
2613                                 if (res == 1)
2614                                         intend_to_amend();
2615                                 return error_failed_squash(item->commit, opts,
2616                                         item->arg_len, item->arg);
2617                         } else if (res && is_rebase_i(opts))
2618                                 return res | error_with_patch(item->commit,
2619                                         item->arg, item->arg_len, opts, res,
2620                                         item->command == TODO_REWORD);
2621                 } else if (item->command == TODO_EXEC) {
2622                         char *end_of_arg = (char *)(item->arg + item->arg_len);
2623                         int saved = *end_of_arg;
2624                         struct stat st;
2625
2626                         *end_of_arg = '\0';
2627                         res = do_exec(item->arg);
2628                         *end_of_arg = saved;
2629
2630                         /* Reread the todo file if it has changed. */
2631                         if (res)
2632                                 ; /* fall through */
2633                         else if (stat(get_todo_path(opts), &st))
2634                                 res = error_errno(_("could not stat '%s'"),
2635                                                   get_todo_path(opts));
2636                         else if (match_stat_data(&todo_list->stat, &st)) {
2637                                 todo_list_release(todo_list);
2638                                 if (read_populate_todo(todo_list, opts))
2639                                         res = -1; /* message was printed */
2640                                 /* `current` will be incremented below */
2641                                 todo_list->current = -1;
2642                         }
2643                 } else if (!is_noop(item->command))
2644                         return error(_("unknown command %d"), item->command);
2645
2646                 todo_list->current++;
2647                 if (res)
2648                         return res;
2649         }
2650
2651         if (is_rebase_i(opts)) {
2652                 struct strbuf head_ref = STRBUF_INIT, buf = STRBUF_INIT;
2653                 struct stat st;
2654
2655                 /* Stopped in the middle, as planned? */
2656                 if (todo_list->current < todo_list->nr)
2657                         return 0;
2658
2659                 if (read_oneliner(&head_ref, rebase_path_head_name(), 0) &&
2660                                 starts_with(head_ref.buf, "refs/")) {
2661                         const char *msg;
2662                         struct object_id head, orig;
2663                         int res;
2664
2665                         if (get_oid("HEAD", &head)) {
2666                                 res = error(_("cannot read HEAD"));
2667 cleanup_head_ref:
2668                                 strbuf_release(&head_ref);
2669                                 strbuf_release(&buf);
2670                                 return res;
2671                         }
2672                         if (!read_oneliner(&buf, rebase_path_orig_head(), 0) ||
2673                                         get_oid_hex(buf.buf, &orig)) {
2674                                 res = error(_("could not read orig-head"));
2675                                 goto cleanup_head_ref;
2676                         }
2677                         strbuf_reset(&buf);
2678                         if (!read_oneliner(&buf, rebase_path_onto(), 0)) {
2679                                 res = error(_("could not read 'onto'"));
2680                                 goto cleanup_head_ref;
2681                         }
2682                         msg = reflog_message(opts, "finish", "%s onto %s",
2683                                 head_ref.buf, buf.buf);
2684                         if (update_ref(msg, head_ref.buf, &head, &orig,
2685                                        REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR)) {
2686                                 res = error(_("could not update %s"),
2687                                         head_ref.buf);
2688                                 goto cleanup_head_ref;
2689                         }
2690                         msg = reflog_message(opts, "finish", "returning to %s",
2691                                 head_ref.buf);
2692                         if (create_symref("HEAD", head_ref.buf, msg)) {
2693                                 res = error(_("could not update HEAD to %s"),
2694                                         head_ref.buf);
2695                                 goto cleanup_head_ref;
2696                         }
2697                         strbuf_reset(&buf);
2698                 }
2699
2700                 if (opts->verbose) {
2701                         struct rev_info log_tree_opt;
2702                         struct object_id orig, head;
2703
2704                         memset(&log_tree_opt, 0, sizeof(log_tree_opt));
2705                         init_revisions(&log_tree_opt, NULL);
2706                         log_tree_opt.diff = 1;
2707                         log_tree_opt.diffopt.output_format =
2708                                 DIFF_FORMAT_DIFFSTAT;
2709                         log_tree_opt.disable_stdin = 1;
2710
2711                         if (read_oneliner(&buf, rebase_path_orig_head(), 0) &&
2712                             !get_oid(buf.buf, &orig) &&
2713                             !get_oid("HEAD", &head)) {
2714                                 diff_tree_oid(&orig, &head, "",
2715                                               &log_tree_opt.diffopt);
2716                                 log_tree_diff_flush(&log_tree_opt);
2717                         }
2718                 }
2719                 flush_rewritten_pending();
2720                 if (!stat(rebase_path_rewritten_list(), &st) &&
2721                                 st.st_size > 0) {
2722                         struct child_process child = CHILD_PROCESS_INIT;
2723                         const char *post_rewrite_hook =
2724                                 find_hook("post-rewrite");
2725
2726                         child.in = open(rebase_path_rewritten_list(), O_RDONLY);
2727                         child.git_cmd = 1;
2728                         argv_array_push(&child.args, "notes");
2729                         argv_array_push(&child.args, "copy");
2730                         argv_array_push(&child.args, "--for-rewrite=rebase");
2731                         /* we don't care if this copying failed */
2732                         run_command(&child);
2733
2734                         if (post_rewrite_hook) {
2735                                 struct child_process hook = CHILD_PROCESS_INIT;
2736
2737                                 hook.in = open(rebase_path_rewritten_list(),
2738                                         O_RDONLY);
2739                                 hook.stdout_to_stderr = 1;
2740                                 argv_array_push(&hook.args, post_rewrite_hook);
2741                                 argv_array_push(&hook.args, "rebase");
2742                                 /* we don't care if this hook failed */
2743                                 run_command(&hook);
2744                         }
2745                 }
2746                 apply_autostash(opts);
2747
2748                 fprintf(stderr, "Successfully rebased and updated %s.\n",
2749                         head_ref.buf);
2750
2751                 strbuf_release(&buf);
2752                 strbuf_release(&head_ref);
2753         }
2754
2755         /*
2756          * Sequence of picks finished successfully; cleanup by
2757          * removing the .git/sequencer directory
2758          */
2759         return sequencer_remove_state(opts);
2760 }
2761
2762 static int continue_single_pick(void)
2763 {
2764         const char *argv[] = { "commit", NULL };
2765
2766         if (!file_exists(git_path_cherry_pick_head()) &&
2767             !file_exists(git_path_revert_head()))
2768                 return error(_("no cherry-pick or revert in progress"));
2769         return run_command_v_opt(argv, RUN_GIT_CMD);
2770 }
2771
2772 static int commit_staged_changes(struct replay_opts *opts)
2773 {
2774         unsigned int flags = ALLOW_EMPTY | EDIT_MSG;
2775
2776         if (has_unstaged_changes(1))
2777                 return error(_("cannot rebase: You have unstaged changes."));
2778         if (!has_uncommitted_changes(0)) {
2779                 const char *cherry_pick_head = git_path_cherry_pick_head();
2780
2781                 if (file_exists(cherry_pick_head) && unlink(cherry_pick_head))
2782                         return error(_("could not remove CHERRY_PICK_HEAD"));
2783                 return 0;
2784         }
2785
2786         if (file_exists(rebase_path_amend())) {
2787                 struct strbuf rev = STRBUF_INIT;
2788                 struct object_id head, to_amend;
2789
2790                 if (get_oid("HEAD", &head))
2791                         return error(_("cannot amend non-existing commit"));
2792                 if (!read_oneliner(&rev, rebase_path_amend(), 0))
2793                         return error(_("invalid file: '%s'"), rebase_path_amend());
2794                 if (get_oid_hex(rev.buf, &to_amend))
2795                         return error(_("invalid contents: '%s'"),
2796                                 rebase_path_amend());
2797                 if (oidcmp(&head, &to_amend))
2798                         return error(_("\nYou have uncommitted changes in your "
2799                                        "working tree. Please, commit them\n"
2800                                        "first and then run 'git rebase "
2801                                        "--continue' again."));
2802
2803                 strbuf_release(&rev);
2804                 flags |= AMEND_MSG;
2805         }
2806
2807         if (run_git_commit(rebase_path_message(), opts, flags))
2808                 return error(_("could not commit staged changes."));
2809         unlink(rebase_path_amend());
2810         return 0;
2811 }
2812
2813 int sequencer_continue(struct replay_opts *opts)
2814 {
2815         struct todo_list todo_list = TODO_LIST_INIT;
2816         int res;
2817
2818         if (read_and_refresh_cache(opts))
2819                 return -1;
2820
2821         if (is_rebase_i(opts)) {
2822                 if (commit_staged_changes(opts))
2823                         return -1;
2824         } else if (!file_exists(get_todo_path(opts)))
2825                 return continue_single_pick();
2826         if (read_populate_opts(opts))
2827                 return -1;
2828         if ((res = read_populate_todo(&todo_list, opts)))
2829                 goto release_todo_list;
2830
2831         if (!is_rebase_i(opts)) {
2832                 /* Verify that the conflict has been resolved */
2833                 if (file_exists(git_path_cherry_pick_head()) ||
2834                     file_exists(git_path_revert_head())) {
2835                         res = continue_single_pick();
2836                         if (res)
2837                                 goto release_todo_list;
2838                 }
2839                 if (index_differs_from("HEAD", NULL, 0)) {
2840                         res = error_dirty_index(opts);
2841                         goto release_todo_list;
2842                 }
2843                 todo_list.current++;
2844         } else if (file_exists(rebase_path_stopped_sha())) {
2845                 struct strbuf buf = STRBUF_INIT;
2846                 struct object_id oid;
2847
2848                 if (read_oneliner(&buf, rebase_path_stopped_sha(), 1) &&
2849                     !get_oid_committish(buf.buf, &oid))
2850                         record_in_rewritten(&oid, peek_command(&todo_list, 0));
2851                 strbuf_release(&buf);
2852         }
2853
2854         res = pick_commits(&todo_list, opts);
2855 release_todo_list:
2856         todo_list_release(&todo_list);
2857         return res;
2858 }
2859
2860 static int single_pick(struct commit *cmit, struct replay_opts *opts)
2861 {
2862         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
2863         return do_pick_commit(opts->action == REPLAY_PICK ?
2864                 TODO_PICK : TODO_REVERT, cmit, opts, 0);
2865 }
2866
2867 int sequencer_pick_revisions(struct replay_opts *opts)
2868 {
2869         struct todo_list todo_list = TODO_LIST_INIT;
2870         struct object_id oid;
2871         int i, res;
2872
2873         assert(opts->revs);
2874         if (read_and_refresh_cache(opts))
2875                 return -1;
2876
2877         for (i = 0; i < opts->revs->pending.nr; i++) {
2878                 struct object_id oid;
2879                 const char *name = opts->revs->pending.objects[i].name;
2880
2881                 /* This happens when using --stdin. */
2882                 if (!strlen(name))
2883                         continue;
2884
2885                 if (!get_oid(name, &oid)) {
2886                         if (!lookup_commit_reference_gently(&oid, 1)) {
2887                                 enum object_type type = oid_object_info(&oid,
2888                                                                         NULL);
2889                                 return error(_("%s: can't cherry-pick a %s"),
2890                                         name, type_name(type));
2891                         }
2892                 } else
2893                         return error(_("%s: bad revision"), name);
2894         }
2895
2896         /*
2897          * If we were called as "git cherry-pick <commit>", just
2898          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
2899          * REVERT_HEAD, and don't touch the sequencer state.
2900          * This means it is possible to cherry-pick in the middle
2901          * of a cherry-pick sequence.
2902          */
2903         if (opts->revs->cmdline.nr == 1 &&
2904             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
2905             opts->revs->no_walk &&
2906             !opts->revs->cmdline.rev->flags) {
2907                 struct commit *cmit;
2908                 if (prepare_revision_walk(opts->revs))
2909                         return error(_("revision walk setup failed"));
2910                 cmit = get_revision(opts->revs);
2911                 if (!cmit || get_revision(opts->revs))
2912                         return error("BUG: expected exactly one commit from walk");
2913                 return single_pick(cmit, opts);
2914         }
2915
2916         /*
2917          * Start a new cherry-pick/ revert sequence; but
2918          * first, make sure that an existing one isn't in
2919          * progress
2920          */
2921
2922         if (walk_revs_populate_todo(&todo_list, opts) ||
2923                         create_seq_dir() < 0)
2924                 return -1;
2925         if (get_oid("HEAD", &oid) && (opts->action == REPLAY_REVERT))
2926                 return error(_("can't revert as initial commit"));
2927         if (save_head(oid_to_hex(&oid)))
2928                 return -1;
2929         if (save_opts(opts))
2930                 return -1;
2931         update_abort_safety_file();
2932         res = pick_commits(&todo_list, opts);
2933         todo_list_release(&todo_list);
2934         return res;
2935 }
2936
2937 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
2938 {
2939         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
2940         struct strbuf sob = STRBUF_INIT;
2941         int has_footer;
2942
2943         strbuf_addstr(&sob, sign_off_header);
2944         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
2945                                 getenv("GIT_COMMITTER_EMAIL")));
2946         strbuf_addch(&sob, '\n');
2947
2948         if (!ignore_footer)
2949                 strbuf_complete_line(msgbuf);
2950
2951         /*
2952          * If the whole message buffer is equal to the sob, pretend that we
2953          * found a conforming footer with a matching sob
2954          */
2955         if (msgbuf->len - ignore_footer == sob.len &&
2956             !strncmp(msgbuf->buf, sob.buf, sob.len))
2957                 has_footer = 3;
2958         else
2959                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
2960
2961         if (!has_footer) {
2962                 const char *append_newlines = NULL;
2963                 size_t len = msgbuf->len - ignore_footer;
2964
2965                 if (!len) {
2966                         /*
2967                          * The buffer is completely empty.  Leave foom for
2968                          * the title and body to be filled in by the user.
2969                          */
2970                         append_newlines = "\n\n";
2971                 } else if (len == 1) {
2972                         /*
2973                          * Buffer contains a single newline.  Add another
2974                          * so that we leave room for the title and body.
2975                          */
2976                         append_newlines = "\n";
2977                 } else if (msgbuf->buf[len - 2] != '\n') {
2978                         /*
2979                          * Buffer ends with a single newline.  Add another
2980                          * so that there is an empty line between the message
2981                          * body and the sob.
2982                          */
2983                         append_newlines = "\n";
2984                 } /* else, the buffer already ends with two newlines. */
2985
2986                 if (append_newlines)
2987                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
2988                                 append_newlines, strlen(append_newlines));
2989         }
2990
2991         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
2992                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
2993                                 sob.buf, sob.len);
2994
2995         strbuf_release(&sob);
2996 }
2997
2998 int sequencer_make_script(FILE *out, int argc, const char **argv,
2999                           unsigned flags)
3000 {
3001         char *format = NULL;
3002         struct pretty_print_context pp = {0};
3003         struct strbuf buf = STRBUF_INIT;
3004         struct rev_info revs;
3005         struct commit *commit;
3006         int keep_empty = flags & TODO_LIST_KEEP_EMPTY;
3007         const char *insn = flags & TODO_LIST_ABBREVIATE_CMDS ? "p" : "pick";
3008
3009         init_revisions(&revs, NULL);
3010         revs.verbose_header = 1;
3011         revs.max_parents = 1;
3012         revs.cherry_mark = 1;
3013         revs.limited = 1;
3014         revs.reverse = 1;
3015         revs.right_only = 1;
3016         revs.sort_order = REV_SORT_IN_GRAPH_ORDER;
3017         revs.topo_order = 1;
3018
3019         revs.pretty_given = 1;
3020         git_config_get_string("rebase.instructionFormat", &format);
3021         if (!format || !*format) {
3022                 free(format);
3023                 format = xstrdup("%s");
3024         }
3025         get_commit_format(format, &revs);
3026         free(format);
3027         pp.fmt = revs.commit_format;
3028         pp.output_encoding = get_log_output_encoding();
3029
3030         if (setup_revisions(argc, argv, &revs, NULL) > 1)
3031                 return error(_("make_script: unhandled options"));
3032
3033         if (prepare_revision_walk(&revs) < 0)
3034                 return error(_("make_script: error preparing revisions"));
3035
3036         while ((commit = get_revision(&revs))) {
3037                 int is_empty  = is_original_commit_empty(commit);
3038
3039                 if (!is_empty && (commit->object.flags & PATCHSAME))
3040                         continue;
3041                 strbuf_reset(&buf);
3042                 if (!keep_empty && is_empty)
3043                         strbuf_addf(&buf, "%c ", comment_line_char);
3044                 strbuf_addf(&buf, "%s %s ", insn,
3045                             oid_to_hex(&commit->object.oid));
3046                 pretty_print_commit(&pp, commit, &buf);
3047                 strbuf_addch(&buf, '\n');
3048                 fputs(buf.buf, out);
3049         }
3050         strbuf_release(&buf);
3051         return 0;
3052 }
3053
3054 /*
3055  * Add commands after pick and (series of) squash/fixup commands
3056  * in the todo list.
3057  */
3058 int sequencer_add_exec_commands(const char *commands)
3059 {
3060         const char *todo_file = rebase_path_todo();
3061         struct todo_list todo_list = TODO_LIST_INIT;
3062         struct todo_item *item;
3063         struct strbuf *buf = &todo_list.buf;
3064         size_t offset = 0, commands_len = strlen(commands);
3065         int i, first;
3066
3067         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
3068                 return error(_("could not read '%s'."), todo_file);
3069
3070         if (parse_insn_buffer(todo_list.buf.buf, &todo_list)) {
3071                 todo_list_release(&todo_list);
3072                 return error(_("unusable todo list: '%s'"), todo_file);
3073         }
3074
3075         first = 1;
3076         /* insert <commands> before every pick except the first one */
3077         for (item = todo_list.items, i = 0; i < todo_list.nr; i++, item++) {
3078                 if (item->command == TODO_PICK && !first) {
3079                         strbuf_insert(buf, item->offset_in_buf + offset,
3080                                       commands, commands_len);
3081                         offset += commands_len;
3082                 }
3083                 first = 0;
3084         }
3085
3086         /* append final <commands> */
3087         strbuf_add(buf, commands, commands_len);
3088
3089         i = write_message(buf->buf, buf->len, todo_file, 0);
3090         todo_list_release(&todo_list);
3091         return i;
3092 }
3093
3094 int transform_todos(unsigned flags)
3095 {
3096         const char *todo_file = rebase_path_todo();
3097         struct todo_list todo_list = TODO_LIST_INIT;
3098         struct strbuf buf = STRBUF_INIT;
3099         struct todo_item *item;
3100         int i;
3101
3102         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
3103                 return error(_("could not read '%s'."), todo_file);
3104
3105         if (parse_insn_buffer(todo_list.buf.buf, &todo_list)) {
3106                 todo_list_release(&todo_list);
3107                 return error(_("unusable todo list: '%s'"), todo_file);
3108         }
3109
3110         for (item = todo_list.items, i = 0; i < todo_list.nr; i++, item++) {
3111                 /* if the item is not a command write it and continue */
3112                 if (item->command >= TODO_COMMENT) {
3113                         strbuf_addf(&buf, "%.*s\n", item->arg_len, item->arg);
3114                         continue;
3115                 }
3116
3117                 /* add command to the buffer */
3118                 if (flags & TODO_LIST_ABBREVIATE_CMDS)
3119                         strbuf_addch(&buf, command_to_char(item->command));
3120                 else
3121                         strbuf_addstr(&buf, command_to_string(item->command));
3122
3123                 /* add commit id */
3124                 if (item->commit) {
3125                         const char *oid = flags & TODO_LIST_SHORTEN_IDS ?
3126                                           short_commit_name(item->commit) :
3127                                           oid_to_hex(&item->commit->object.oid);
3128
3129                         strbuf_addf(&buf, " %s", oid);
3130                 }
3131                 /* add all the rest */
3132                 if (!item->arg_len)
3133                         strbuf_addch(&buf, '\n');
3134                 else
3135                         strbuf_addf(&buf, " %.*s\n", item->arg_len, item->arg);
3136         }
3137
3138         i = write_message(buf.buf, buf.len, todo_file, 0);
3139         todo_list_release(&todo_list);
3140         return i;
3141 }
3142
3143 enum check_level {
3144         CHECK_IGNORE = 0, CHECK_WARN, CHECK_ERROR
3145 };
3146
3147 static enum check_level get_missing_commit_check_level(void)
3148 {
3149         const char *value;
3150
3151         if (git_config_get_value("rebase.missingcommitscheck", &value) ||
3152                         !strcasecmp("ignore", value))
3153                 return CHECK_IGNORE;
3154         if (!strcasecmp("warn", value))
3155                 return CHECK_WARN;
3156         if (!strcasecmp("error", value))
3157                 return CHECK_ERROR;
3158         warning(_("unrecognized setting %s for option "
3159                   "rebase.missingCommitsCheck. Ignoring."), value);
3160         return CHECK_IGNORE;
3161 }
3162
3163 /*
3164  * Check if the user dropped some commits by mistake
3165  * Behaviour determined by rebase.missingCommitsCheck.
3166  * Check if there is an unrecognized command or a
3167  * bad SHA-1 in a command.
3168  */
3169 int check_todo_list(void)
3170 {
3171         enum check_level check_level = get_missing_commit_check_level();
3172         struct strbuf todo_file = STRBUF_INIT;
3173         struct todo_list todo_list = TODO_LIST_INIT;
3174         struct strbuf missing = STRBUF_INIT;
3175         int advise_to_edit_todo = 0, res = 0, i;
3176
3177         strbuf_addstr(&todo_file, rebase_path_todo());
3178         if (strbuf_read_file_or_whine(&todo_list.buf, todo_file.buf) < 0) {
3179                 res = -1;
3180                 goto leave_check;
3181         }
3182         advise_to_edit_todo = res =
3183                 parse_insn_buffer(todo_list.buf.buf, &todo_list);
3184
3185         if (res || check_level == CHECK_IGNORE)
3186                 goto leave_check;
3187
3188         /* Mark the commits in git-rebase-todo as seen */
3189         for (i = 0; i < todo_list.nr; i++) {
3190                 struct commit *commit = todo_list.items[i].commit;
3191                 if (commit)
3192                         commit->util = (void *)1;
3193         }
3194
3195         todo_list_release(&todo_list);
3196         strbuf_addstr(&todo_file, ".backup");
3197         if (strbuf_read_file_or_whine(&todo_list.buf, todo_file.buf) < 0) {
3198                 res = -1;
3199                 goto leave_check;
3200         }
3201         strbuf_release(&todo_file);
3202         res = !!parse_insn_buffer(todo_list.buf.buf, &todo_list);
3203
3204         /* Find commits in git-rebase-todo.backup yet unseen */
3205         for (i = todo_list.nr - 1; i >= 0; i--) {
3206                 struct todo_item *item = todo_list.items + i;
3207                 struct commit *commit = item->commit;
3208                 if (commit && !commit->util) {
3209                         strbuf_addf(&missing, " - %s %.*s\n",
3210                                     short_commit_name(commit),
3211                                     item->arg_len, item->arg);
3212                         commit->util = (void *)1;
3213                 }
3214         }
3215
3216         /* Warn about missing commits */
3217         if (!missing.len)
3218                 goto leave_check;
3219
3220         if (check_level == CHECK_ERROR)
3221                 advise_to_edit_todo = res = 1;
3222
3223         fprintf(stderr,
3224                 _("Warning: some commits may have been dropped accidentally.\n"
3225                 "Dropped commits (newer to older):\n"));
3226
3227         /* Make the list user-friendly and display */
3228         fputs(missing.buf, stderr);
3229         strbuf_release(&missing);
3230
3231         fprintf(stderr, _("To avoid this message, use \"drop\" to "
3232                 "explicitly remove a commit.\n\n"
3233                 "Use 'git config rebase.missingCommitsCheck' to change "
3234                 "the level of warnings.\n"
3235                 "The possible behaviours are: ignore, warn, error.\n\n"));
3236
3237 leave_check:
3238         strbuf_release(&todo_file);
3239         todo_list_release(&todo_list);
3240
3241         if (advise_to_edit_todo)
3242                 fprintf(stderr,
3243                         _("You can fix this with 'git rebase --edit-todo' "
3244                           "and then run 'git rebase --continue'.\n"
3245                           "Or you can abort the rebase with 'git rebase"
3246                           " --abort'.\n"));
3247
3248         return res;
3249 }
3250
3251 static int rewrite_file(const char *path, const char *buf, size_t len)
3252 {
3253         int rc = 0;
3254         int fd = open(path, O_WRONLY | O_TRUNC);
3255         if (fd < 0)
3256                 return error_errno(_("could not open '%s' for writing"), path);
3257         if (write_in_full(fd, buf, len) < 0)
3258                 rc = error_errno(_("could not write to '%s'"), path);
3259         if (close(fd) && !rc)
3260                 rc = error_errno(_("could not close '%s'"), path);
3261         return rc;
3262 }
3263
3264 /* skip picking commits whose parents are unchanged */
3265 int skip_unnecessary_picks(void)
3266 {
3267         const char *todo_file = rebase_path_todo();
3268         struct strbuf buf = STRBUF_INIT;
3269         struct todo_list todo_list = TODO_LIST_INIT;
3270         struct object_id onto_oid, *oid = &onto_oid, *parent_oid;
3271         int fd, i;
3272
3273         if (!read_oneliner(&buf, rebase_path_onto(), 0))
3274                 return error(_("could not read 'onto'"));
3275         if (get_oid(buf.buf, &onto_oid)) {
3276                 strbuf_release(&buf);
3277                 return error(_("need a HEAD to fixup"));
3278         }
3279         strbuf_release(&buf);
3280
3281         if (strbuf_read_file_or_whine(&todo_list.buf, todo_file) < 0)
3282                 return -1;
3283         if (parse_insn_buffer(todo_list.buf.buf, &todo_list) < 0) {
3284                 todo_list_release(&todo_list);
3285                 return -1;
3286         }
3287
3288         for (i = 0; i < todo_list.nr; i++) {
3289                 struct todo_item *item = todo_list.items + i;
3290
3291                 if (item->command >= TODO_NOOP)
3292                         continue;
3293                 if (item->command != TODO_PICK)
3294                         break;
3295                 if (parse_commit(item->commit)) {
3296                         todo_list_release(&todo_list);
3297                         return error(_("could not parse commit '%s'"),
3298                                 oid_to_hex(&item->commit->object.oid));
3299                 }
3300                 if (!item->commit->parents)
3301                         break; /* root commit */
3302                 if (item->commit->parents->next)
3303                         break; /* merge commit */
3304                 parent_oid = &item->commit->parents->item->object.oid;
3305                 if (hashcmp(parent_oid->hash, oid->hash))
3306                         break;
3307                 oid = &item->commit->object.oid;
3308         }
3309         if (i > 0) {
3310                 int offset = i < todo_list.nr ?
3311                         todo_list.items[i].offset_in_buf : todo_list.buf.len;
3312                 const char *done_path = rebase_path_done();
3313
3314                 fd = open(done_path, O_CREAT | O_WRONLY | O_APPEND, 0666);
3315                 if (fd < 0) {
3316                         error_errno(_("could not open '%s' for writing"),
3317                                     done_path);
3318                         todo_list_release(&todo_list);
3319                         return -1;
3320                 }
3321                 if (write_in_full(fd, todo_list.buf.buf, offset) < 0) {
3322                         error_errno(_("could not write to '%s'"), done_path);
3323                         todo_list_release(&todo_list);
3324                         close(fd);
3325                         return -1;
3326                 }
3327                 close(fd);
3328
3329                 if (rewrite_file(rebase_path_todo(), todo_list.buf.buf + offset,
3330                                  todo_list.buf.len - offset) < 0) {
3331                         todo_list_release(&todo_list);
3332                         return -1;
3333                 }
3334
3335                 todo_list.current = i;
3336                 if (is_fixup(peek_command(&todo_list, 0)))
3337                         record_in_rewritten(oid, peek_command(&todo_list, 0));
3338         }
3339
3340         todo_list_release(&todo_list);
3341         printf("%s\n", oid_to_hex(oid));
3342
3343         return 0;
3344 }
3345
3346 struct subject2item_entry {
3347         struct hashmap_entry entry;
3348         int i;
3349         char subject[FLEX_ARRAY];
3350 };
3351
3352 static int subject2item_cmp(const void *fndata,
3353                             const struct subject2item_entry *a,
3354                             const struct subject2item_entry *b, const void *key)
3355 {
3356         return key ? strcmp(a->subject, key) : strcmp(a->subject, b->subject);
3357 }
3358
3359 /*
3360  * Rearrange the todo list that has both "pick commit-id msg" and "pick
3361  * commit-id fixup!/squash! msg" in it so that the latter is put immediately
3362  * after the former, and change "pick" to "fixup"/"squash".
3363  *
3364  * Note that if the config has specified a custom instruction format, each log
3365  * message will have to be retrieved from the commit (as the oneline in the
3366  * script cannot be trusted) in order to normalize the autosquash arrangement.
3367  */
3368 int rearrange_squash(void)
3369 {
3370         const char *todo_file = rebase_path_todo();
3371         struct todo_list todo_list = TODO_LIST_INIT;
3372         struct hashmap subject2item;
3373         int res = 0, rearranged = 0, *next, *tail, i;
3374         char **subjects;
3375
3376         if (strbuf_read_file_or_whine(&todo_list.buf, todo_file) < 0)
3377                 return -1;
3378         if (parse_insn_buffer(todo_list.buf.buf, &todo_list) < 0) {
3379                 todo_list_release(&todo_list);
3380                 return -1;
3381         }
3382
3383         /*
3384          * The hashmap maps onelines to the respective todo list index.
3385          *
3386          * If any items need to be rearranged, the next[i] value will indicate
3387          * which item was moved directly after the i'th.
3388          *
3389          * In that case, last[i] will indicate the index of the latest item to
3390          * be moved to appear after the i'th.
3391          */
3392         hashmap_init(&subject2item, (hashmap_cmp_fn) subject2item_cmp,
3393                      NULL, todo_list.nr);
3394         ALLOC_ARRAY(next, todo_list.nr);
3395         ALLOC_ARRAY(tail, todo_list.nr);
3396         ALLOC_ARRAY(subjects, todo_list.nr);
3397         for (i = 0; i < todo_list.nr; i++) {
3398                 struct strbuf buf = STRBUF_INIT;
3399                 struct todo_item *item = todo_list.items + i;
3400                 const char *commit_buffer, *subject, *p;
3401                 size_t subject_len;
3402                 int i2 = -1;
3403                 struct subject2item_entry *entry;
3404
3405                 next[i] = tail[i] = -1;
3406                 if (item->command >= TODO_EXEC) {
3407                         subjects[i] = NULL;
3408                         continue;
3409                 }
3410
3411                 if (is_fixup(item->command)) {
3412                         todo_list_release(&todo_list);
3413                         return error(_("the script was already rearranged."));
3414                 }
3415
3416                 item->commit->util = item;
3417
3418                 parse_commit(item->commit);
3419                 commit_buffer = get_commit_buffer(item->commit, NULL);
3420                 find_commit_subject(commit_buffer, &subject);
3421                 format_subject(&buf, subject, " ");
3422                 subject = subjects[i] = strbuf_detach(&buf, &subject_len);
3423                 unuse_commit_buffer(item->commit, commit_buffer);
3424                 if ((skip_prefix(subject, "fixup! ", &p) ||
3425                      skip_prefix(subject, "squash! ", &p))) {
3426                         struct commit *commit2;
3427
3428                         for (;;) {
3429                                 while (isspace(*p))
3430                                         p++;
3431                                 if (!skip_prefix(p, "fixup! ", &p) &&
3432                                     !skip_prefix(p, "squash! ", &p))
3433                                         break;
3434                         }
3435
3436                         if ((entry = hashmap_get_from_hash(&subject2item,
3437                                                            strhash(p), p)))
3438                                 /* found by title */
3439                                 i2 = entry->i;
3440                         else if (!strchr(p, ' ') &&
3441                                  (commit2 =
3442                                   lookup_commit_reference_by_name(p)) &&
3443                                  commit2->util)
3444                                 /* found by commit name */
3445                                 i2 = (struct todo_item *)commit2->util
3446                                         - todo_list.items;
3447                         else {
3448                                 /* copy can be a prefix of the commit subject */
3449                                 for (i2 = 0; i2 < i; i2++)
3450                                         if (subjects[i2] &&
3451                                             starts_with(subjects[i2], p))
3452                                                 break;
3453                                 if (i2 == i)
3454                                         i2 = -1;
3455                         }
3456                 }
3457                 if (i2 >= 0) {
3458                         rearranged = 1;
3459                         todo_list.items[i].command =
3460                                 starts_with(subject, "fixup!") ?
3461                                 TODO_FIXUP : TODO_SQUASH;
3462                         if (next[i2] < 0)
3463                                 next[i2] = i;
3464                         else
3465                                 next[tail[i2]] = i;
3466                         tail[i2] = i;
3467                 } else if (!hashmap_get_from_hash(&subject2item,
3468                                                 strhash(subject), subject)) {
3469                         FLEX_ALLOC_MEM(entry, subject, subject, subject_len);
3470                         entry->i = i;
3471                         hashmap_entry_init(entry, strhash(entry->subject));
3472                         hashmap_put(&subject2item, entry);
3473                 }
3474         }
3475
3476         if (rearranged) {
3477                 struct strbuf buf = STRBUF_INIT;
3478
3479                 for (i = 0; i < todo_list.nr; i++) {
3480                         enum todo_command command = todo_list.items[i].command;
3481                         int cur = i;
3482
3483                         /*
3484                          * Initially, all commands are 'pick's. If it is a
3485                          * fixup or a squash now, we have rearranged it.
3486                          */
3487                         if (is_fixup(command))
3488                                 continue;
3489
3490                         while (cur >= 0) {
3491                                 int offset = todo_list.items[cur].offset_in_buf;
3492                                 int end_offset = cur + 1 < todo_list.nr ?
3493                                         todo_list.items[cur + 1].offset_in_buf :
3494                                         todo_list.buf.len;
3495                                 char *bol = todo_list.buf.buf + offset;
3496                                 char *eol = todo_list.buf.buf + end_offset;
3497
3498                                 /* replace 'pick', by 'fixup' or 'squash' */
3499                                 command = todo_list.items[cur].command;
3500                                 if (is_fixup(command)) {
3501                                         strbuf_addstr(&buf,
3502                                                 todo_command_info[command].str);
3503                                         bol += strcspn(bol, " \t");
3504                                 }
3505
3506                                 strbuf_add(&buf, bol, eol - bol);
3507
3508                                 cur = next[cur];
3509                         }
3510                 }
3511
3512                 res = rewrite_file(todo_file, buf.buf, buf.len);
3513                 strbuf_release(&buf);
3514         }
3515
3516         free(next);
3517         free(tail);
3518         for (i = 0; i < todo_list.nr; i++)
3519                 free(subjects[i]);
3520         free(subjects);
3521         hashmap_free(&subject2item, 1);
3522         todo_list_release(&todo_list);
3523
3524         return res;
3525 }