Merge branch 'maint' of git://github.com/git-l10n/git-po
[git] / sequencer.c
1 #include "cache.h"
2 #include "config.h"
3 #include "lockfile.h"
4 #include "sequencer.h"
5 #include "dir.h"
6 #include "object.h"
7 #include "commit.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
25 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
26
27 const char sign_off_header[] = "Signed-off-by: ";
28 static const char cherry_picked_prefix[] = "(cherry picked from commit ";
29
30 GIT_PATH_FUNC(git_path_seq_dir, "sequencer")
31
32 static GIT_PATH_FUNC(git_path_todo_file, "sequencer/todo")
33 static GIT_PATH_FUNC(git_path_opts_file, "sequencer/opts")
34 static GIT_PATH_FUNC(git_path_head_file, "sequencer/head")
35 static GIT_PATH_FUNC(git_path_abort_safety_file, "sequencer/abort-safety")
36
37 static GIT_PATH_FUNC(rebase_path, "rebase-merge")
38 /*
39  * The file containing rebase commands, comments, and empty lines.
40  * This file is created by "git rebase -i" then edited by the user. As
41  * the lines are processed, they are removed from the front of this
42  * file and written to the tail of 'done'.
43  */
44 static GIT_PATH_FUNC(rebase_path_todo, "rebase-merge/git-rebase-todo")
45 /*
46  * The rebase command lines that have already been processed. A line
47  * is moved here when it is first handled, before any associated user
48  * actions.
49  */
50 static GIT_PATH_FUNC(rebase_path_done, "rebase-merge/done")
51 /*
52  * The file to keep track of how many commands were already processed (e.g.
53  * for the prompt).
54  */
55 static GIT_PATH_FUNC(rebase_path_msgnum, "rebase-merge/msgnum");
56 /*
57  * The file to keep track of how many commands are to be processed in total
58  * (e.g. for the prompt).
59  */
60 static GIT_PATH_FUNC(rebase_path_msgtotal, "rebase-merge/end");
61 /*
62  * The commit message that is planned to be used for any changes that
63  * need to be committed following a user interaction.
64  */
65 static GIT_PATH_FUNC(rebase_path_message, "rebase-merge/message")
66 /*
67  * The file into which is accumulated the suggested commit message for
68  * squash/fixup commands. When the first of a series of squash/fixups
69  * is seen, the file is created and the commit message from the
70  * previous commit and from the first squash/fixup commit are written
71  * to it. The commit message for each subsequent squash/fixup commit
72  * is appended to the file as it is processed.
73  *
74  * The first line of the file is of the form
75  *     # This is a combination of $count commits.
76  * where $count is the number of commits whose messages have been
77  * written to the file so far (including the initial "pick" commit).
78  * Each time that a commit message is processed, this line is read and
79  * updated. It is deleted just before the combined commit is made.
80  */
81 static GIT_PATH_FUNC(rebase_path_squash_msg, "rebase-merge/message-squash")
82 /*
83  * If the current series of squash/fixups has not yet included a squash
84  * command, then this file exists and holds the commit message of the
85  * original "pick" commit.  (If the series ends without a "squash"
86  * command, then this can be used as the commit message of the combined
87  * commit without opening the editor.)
88  */
89 static GIT_PATH_FUNC(rebase_path_fixup_msg, "rebase-merge/message-fixup")
90 /*
91  * A script to set the GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
92  * GIT_AUTHOR_DATE that will be used for the commit that is currently
93  * being rebased.
94  */
95 static GIT_PATH_FUNC(rebase_path_author_script, "rebase-merge/author-script")
96 /*
97  * When an "edit" rebase command is being processed, the SHA1 of the
98  * commit to be edited is recorded in this file.  When "git rebase
99  * --continue" is executed, if there are any staged changes then they
100  * will be amended to the HEAD commit, but only provided the HEAD
101  * commit is still the commit to be edited.  When any other rebase
102  * command is processed, this file is deleted.
103  */
104 static GIT_PATH_FUNC(rebase_path_amend, "rebase-merge/amend")
105 /*
106  * When we stop at a given patch via the "edit" command, this file contains
107  * the abbreviated commit name of the corresponding patch.
108  */
109 static GIT_PATH_FUNC(rebase_path_stopped_sha, "rebase-merge/stopped-sha")
110 /*
111  * For the post-rewrite hook, we make a list of rewritten commits and
112  * their new sha1s.  The rewritten-pending list keeps the sha1s of
113  * commits that have been processed, but not committed yet,
114  * e.g. because they are waiting for a 'squash' command.
115  */
116 static GIT_PATH_FUNC(rebase_path_rewritten_list, "rebase-merge/rewritten-list")
117 static GIT_PATH_FUNC(rebase_path_rewritten_pending,
118         "rebase-merge/rewritten-pending")
119 /*
120  * The following files are written by git-rebase just after parsing the
121  * command-line (and are only consumed, not modified, by the sequencer).
122  */
123 static GIT_PATH_FUNC(rebase_path_gpg_sign_opt, "rebase-merge/gpg_sign_opt")
124 static GIT_PATH_FUNC(rebase_path_orig_head, "rebase-merge/orig-head")
125 static GIT_PATH_FUNC(rebase_path_verbose, "rebase-merge/verbose")
126 static GIT_PATH_FUNC(rebase_path_head_name, "rebase-merge/head-name")
127 static GIT_PATH_FUNC(rebase_path_onto, "rebase-merge/onto")
128 static GIT_PATH_FUNC(rebase_path_autostash, "rebase-merge/autostash")
129 static GIT_PATH_FUNC(rebase_path_strategy, "rebase-merge/strategy")
130 static GIT_PATH_FUNC(rebase_path_strategy_opts, "rebase-merge/strategy_opts")
131 static GIT_PATH_FUNC(rebase_path_allow_rerere_autoupdate, "rebase-merge/allow_rerere_autoupdate")
132
133 static inline int is_rebase_i(const struct replay_opts *opts)
134 {
135         return opts->action == REPLAY_INTERACTIVE_REBASE;
136 }
137
138 static const char *get_dir(const struct replay_opts *opts)
139 {
140         if (is_rebase_i(opts))
141                 return rebase_path();
142         return git_path_seq_dir();
143 }
144
145 static const char *get_todo_path(const struct replay_opts *opts)
146 {
147         if (is_rebase_i(opts))
148                 return rebase_path_todo();
149         return git_path_todo_file();
150 }
151
152 /*
153  * Returns 0 for non-conforming footer
154  * Returns 1 for conforming footer
155  * Returns 2 when sob exists within conforming footer
156  * Returns 3 when sob exists within conforming footer as last entry
157  */
158 static int has_conforming_footer(struct strbuf *sb, struct strbuf *sob,
159         int ignore_footer)
160 {
161         struct trailer_info info;
162         int i;
163         int found_sob = 0, found_sob_last = 0;
164
165         trailer_info_get(&info, sb->buf);
166
167         if (info.trailer_start == info.trailer_end)
168                 return 0;
169
170         for (i = 0; i < info.trailer_nr; i++)
171                 if (sob && !strncmp(info.trailers[i], sob->buf, sob->len)) {
172                         found_sob = 1;
173                         if (i == info.trailer_nr - 1)
174                                 found_sob_last = 1;
175                 }
176
177         trailer_info_release(&info);
178
179         if (found_sob_last)
180                 return 3;
181         if (found_sob)
182                 return 2;
183         return 1;
184 }
185
186 static const char *gpg_sign_opt_quoted(struct replay_opts *opts)
187 {
188         static struct strbuf buf = STRBUF_INIT;
189
190         strbuf_reset(&buf);
191         if (opts->gpg_sign)
192                 sq_quotef(&buf, "-S%s", opts->gpg_sign);
193         return buf.buf;
194 }
195
196 int sequencer_remove_state(struct replay_opts *opts)
197 {
198         struct strbuf dir = STRBUF_INIT;
199         int i;
200
201         free(opts->gpg_sign);
202         free(opts->strategy);
203         for (i = 0; i < opts->xopts_nr; i++)
204                 free(opts->xopts[i]);
205         free(opts->xopts);
206
207         strbuf_addstr(&dir, get_dir(opts));
208         remove_dir_recursively(&dir, 0);
209         strbuf_release(&dir);
210
211         return 0;
212 }
213
214 static const char *action_name(const struct replay_opts *opts)
215 {
216         switch (opts->action) {
217         case REPLAY_REVERT:
218                 return N_("revert");
219         case REPLAY_PICK:
220                 return N_("cherry-pick");
221         case REPLAY_INTERACTIVE_REBASE:
222                 return N_("rebase -i");
223         }
224         die(_("Unknown action: %d"), opts->action);
225 }
226
227 struct commit_message {
228         char *parent_label;
229         char *label;
230         char *subject;
231         const char *message;
232 };
233
234 static const char *short_commit_name(struct commit *commit)
235 {
236         return find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV);
237 }
238
239 static int get_message(struct commit *commit, struct commit_message *out)
240 {
241         const char *abbrev, *subject;
242         int subject_len;
243
244         out->message = logmsg_reencode(commit, NULL, get_commit_output_encoding());
245         abbrev = short_commit_name(commit);
246
247         subject_len = find_commit_subject(out->message, &subject);
248
249         out->subject = xmemdupz(subject, subject_len);
250         out->label = xstrfmt("%s... %s", abbrev, out->subject);
251         out->parent_label = xstrfmt("parent of %s", out->label);
252
253         return 0;
254 }
255
256 static void free_message(struct commit *commit, struct commit_message *msg)
257 {
258         free(msg->parent_label);
259         free(msg->label);
260         free(msg->subject);
261         unuse_commit_buffer(commit, msg->message);
262 }
263
264 static void print_advice(int show_hint, struct replay_opts *opts)
265 {
266         char *msg = getenv("GIT_CHERRY_PICK_HELP");
267
268         if (msg) {
269                 fprintf(stderr, "%s\n", msg);
270                 /*
271                  * A conflict has occurred but the porcelain
272                  * (typically rebase --interactive) wants to take care
273                  * of the commit itself so remove CHERRY_PICK_HEAD
274                  */
275                 unlink(git_path_cherry_pick_head());
276                 return;
277         }
278
279         if (show_hint) {
280                 if (opts->no_commit)
281                         advise(_("after resolving the conflicts, mark the corrected paths\n"
282                                  "with 'git add <paths>' or 'git rm <paths>'"));
283                 else
284                         advise(_("after resolving the conflicts, mark the corrected paths\n"
285                                  "with 'git add <paths>' or 'git rm <paths>'\n"
286                                  "and commit the result with 'git commit'"));
287         }
288 }
289
290 static int write_message(const void *buf, size_t len, const char *filename,
291                          int append_eol)
292 {
293         static struct lock_file msg_file;
294
295         int msg_fd = hold_lock_file_for_update(&msg_file, filename, 0);
296         if (msg_fd < 0)
297                 return error_errno(_("could not lock '%s'"), filename);
298         if (write_in_full(msg_fd, buf, len) < 0) {
299                 rollback_lock_file(&msg_file);
300                 return error_errno(_("could not write to '%s'"), filename);
301         }
302         if (append_eol && write(msg_fd, "\n", 1) < 0) {
303                 rollback_lock_file(&msg_file);
304                 return error_errno(_("could not write eol to '%s'"), filename);
305         }
306         if (commit_lock_file(&msg_file) < 0) {
307                 rollback_lock_file(&msg_file);
308                 return error(_("failed to finalize '%s'."), filename);
309         }
310
311         return 0;
312 }
313
314 /*
315  * Reads a file that was presumably written by a shell script, i.e. with an
316  * end-of-line marker that needs to be stripped.
317  *
318  * Note that only the last end-of-line marker is stripped, consistent with the
319  * behavior of "$(cat path)" in a shell script.
320  *
321  * Returns 1 if the file was read, 0 if it could not be read or does not exist.
322  */
323 static int read_oneliner(struct strbuf *buf,
324         const char *path, int skip_if_empty)
325 {
326         int orig_len = buf->len;
327
328         if (!file_exists(path))
329                 return 0;
330
331         if (strbuf_read_file(buf, path, 0) < 0) {
332                 warning_errno(_("could not read '%s'"), path);
333                 return 0;
334         }
335
336         if (buf->len > orig_len && buf->buf[buf->len - 1] == '\n') {
337                 if (--buf->len > orig_len && buf->buf[buf->len - 1] == '\r')
338                         --buf->len;
339                 buf->buf[buf->len] = '\0';
340         }
341
342         if (skip_if_empty && buf->len == orig_len)
343                 return 0;
344
345         return 1;
346 }
347
348 static struct tree *empty_tree(void)
349 {
350         return lookup_tree(the_hash_algo->empty_tree);
351 }
352
353 static int error_dirty_index(struct replay_opts *opts)
354 {
355         if (read_cache_unmerged())
356                 return error_resolve_conflict(_(action_name(opts)));
357
358         error(_("your local changes would be overwritten by %s."),
359                 _(action_name(opts)));
360
361         if (advice_commit_before_merge)
362                 advise(_("commit your changes or stash them to proceed."));
363         return -1;
364 }
365
366 static void update_abort_safety_file(void)
367 {
368         struct object_id head;
369
370         /* Do nothing on a single-pick */
371         if (!file_exists(git_path_seq_dir()))
372                 return;
373
374         if (!get_oid("HEAD", &head))
375                 write_file(git_path_abort_safety_file(), "%s", oid_to_hex(&head));
376         else
377                 write_file(git_path_abort_safety_file(), "%s", "");
378 }
379
380 static int fast_forward_to(const struct object_id *to, const struct object_id *from,
381                         int unborn, struct replay_opts *opts)
382 {
383         struct ref_transaction *transaction;
384         struct strbuf sb = STRBUF_INIT;
385         struct strbuf err = STRBUF_INIT;
386
387         read_cache();
388         if (checkout_fast_forward(from, to, 1))
389                 return -1; /* the callee should have complained already */
390
391         strbuf_addf(&sb, _("%s: fast-forward"), _(action_name(opts)));
392
393         transaction = ref_transaction_begin(&err);
394         if (!transaction ||
395             ref_transaction_update(transaction, "HEAD",
396                                    to, unborn ? &null_oid : from,
397                                    0, sb.buf, &err) ||
398             ref_transaction_commit(transaction, &err)) {
399                 ref_transaction_free(transaction);
400                 error("%s", err.buf);
401                 strbuf_release(&sb);
402                 strbuf_release(&err);
403                 return -1;
404         }
405
406         strbuf_release(&sb);
407         strbuf_release(&err);
408         ref_transaction_free(transaction);
409         update_abort_safety_file();
410         return 0;
411 }
412
413 void append_conflicts_hint(struct strbuf *msgbuf)
414 {
415         int i;
416
417         strbuf_addch(msgbuf, '\n');
418         strbuf_commented_addf(msgbuf, "Conflicts:\n");
419         for (i = 0; i < active_nr;) {
420                 const struct cache_entry *ce = active_cache[i++];
421                 if (ce_stage(ce)) {
422                         strbuf_commented_addf(msgbuf, "\t%s\n", ce->name);
423                         while (i < active_nr && !strcmp(ce->name,
424                                                         active_cache[i]->name))
425                                 i++;
426                 }
427         }
428 }
429
430 static int do_recursive_merge(struct commit *base, struct commit *next,
431                               const char *base_label, const char *next_label,
432                               struct object_id *head, struct strbuf *msgbuf,
433                               struct replay_opts *opts)
434 {
435         struct merge_options o;
436         struct tree *result, *next_tree, *base_tree, *head_tree;
437         int clean;
438         char **xopt;
439         static struct lock_file index_lock;
440
441         if (hold_locked_index(&index_lock, LOCK_REPORT_ON_ERROR) < 0)
442                 return -1;
443
444         read_cache();
445
446         init_merge_options(&o);
447         o.ancestor = base ? base_label : "(empty tree)";
448         o.branch1 = "HEAD";
449         o.branch2 = next ? next_label : "(empty tree)";
450         if (is_rebase_i(opts))
451                 o.buffer_output = 2;
452         o.show_rename_progress = 1;
453
454         head_tree = parse_tree_indirect(head);
455         next_tree = next ? next->tree : empty_tree();
456         base_tree = base ? base->tree : empty_tree();
457
458         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
459                 parse_merge_opt(&o, *xopt);
460
461         clean = merge_trees(&o,
462                             head_tree,
463                             next_tree, base_tree, &result);
464         if (is_rebase_i(opts) && clean <= 0)
465                 fputs(o.obuf.buf, stdout);
466         strbuf_release(&o.obuf);
467         diff_warn_rename_limit("merge.renamelimit", o.needed_rename_limit, 0);
468         if (clean < 0)
469                 return clean;
470
471         if (active_cache_changed &&
472             write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
473                 /*
474                  * TRANSLATORS: %s will be "revert", "cherry-pick" or
475                  * "rebase -i".
476                  */
477                 return error(_("%s: Unable to write new index file"),
478                         _(action_name(opts)));
479         rollback_lock_file(&index_lock);
480
481         if (opts->signoff)
482                 append_signoff(msgbuf, 0, 0);
483
484         if (!clean)
485                 append_conflicts_hint(msgbuf);
486
487         return !clean;
488 }
489
490 static int is_index_unchanged(void)
491 {
492         struct object_id head_oid;
493         struct commit *head_commit;
494
495         if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
496                 return error(_("could not resolve HEAD commit\n"));
497
498         head_commit = lookup_commit(&head_oid);
499
500         /*
501          * If head_commit is NULL, check_commit, called from
502          * lookup_commit, would have indicated that head_commit is not
503          * a commit object already.  parse_commit() will return failure
504          * without further complaints in such a case.  Otherwise, if
505          * the commit is invalid, parse_commit() will complain.  So
506          * there is nothing for us to say here.  Just return failure.
507          */
508         if (parse_commit(head_commit))
509                 return -1;
510
511         if (!active_cache_tree)
512                 active_cache_tree = cache_tree();
513
514         if (!cache_tree_fully_valid(active_cache_tree))
515                 if (cache_tree_update(&the_index, 0))
516                         return error(_("unable to update cache tree\n"));
517
518         return !oidcmp(&active_cache_tree->oid,
519                        &head_commit->tree->object.oid);
520 }
521
522 static int write_author_script(const char *message)
523 {
524         struct strbuf buf = STRBUF_INIT;
525         const char *eol;
526         int res;
527
528         for (;;)
529                 if (!*message || starts_with(message, "\n")) {
530 missing_author:
531                         /* Missing 'author' line? */
532                         unlink(rebase_path_author_script());
533                         return 0;
534                 } else if (skip_prefix(message, "author ", &message))
535                         break;
536                 else if ((eol = strchr(message, '\n')))
537                         message = eol + 1;
538                 else
539                         goto missing_author;
540
541         strbuf_addstr(&buf, "GIT_AUTHOR_NAME='");
542         while (*message && *message != '\n' && *message != '\r')
543                 if (skip_prefix(message, " <", &message))
544                         break;
545                 else if (*message != '\'')
546                         strbuf_addch(&buf, *(message++));
547                 else
548                         strbuf_addf(&buf, "'\\\\%c'", *(message++));
549         strbuf_addstr(&buf, "'\nGIT_AUTHOR_EMAIL='");
550         while (*message && *message != '\n' && *message != '\r')
551                 if (skip_prefix(message, "> ", &message))
552                         break;
553                 else if (*message != '\'')
554                         strbuf_addch(&buf, *(message++));
555                 else
556                         strbuf_addf(&buf, "'\\\\%c'", *(message++));
557         strbuf_addstr(&buf, "'\nGIT_AUTHOR_DATE='@");
558         while (*message && *message != '\n' && *message != '\r')
559                 if (*message != '\'')
560                         strbuf_addch(&buf, *(message++));
561                 else
562                         strbuf_addf(&buf, "'\\\\%c'", *(message++));
563         res = write_message(buf.buf, buf.len, rebase_path_author_script(), 1);
564         strbuf_release(&buf);
565         return res;
566 }
567
568 /*
569  * Read a list of environment variable assignments (such as the author-script
570  * file) into an environment block. Returns -1 on error, 0 otherwise.
571  */
572 static int read_env_script(struct argv_array *env)
573 {
574         struct strbuf script = STRBUF_INIT;
575         int i, count = 0;
576         char *p, *p2;
577
578         if (strbuf_read_file(&script, rebase_path_author_script(), 256) <= 0)
579                 return -1;
580
581         for (p = script.buf; *p; p++)
582                 if (skip_prefix(p, "'\\\\''", (const char **)&p2))
583                         strbuf_splice(&script, p - script.buf, p2 - p, "'", 1);
584                 else if (*p == '\'')
585                         strbuf_splice(&script, p-- - script.buf, 1, "", 0);
586                 else if (*p == '\n') {
587                         *p = '\0';
588                         count++;
589                 }
590
591         for (i = 0, p = script.buf; i < count; i++) {
592                 argv_array_push(env, p);
593                 p += strlen(p) + 1;
594         }
595
596         return 0;
597 }
598
599 static const char staged_changes_advice[] =
600 N_("you have staged changes in your working tree\n"
601 "If these changes are meant to be squashed into the previous commit, run:\n"
602 "\n"
603 "  git commit --amend %s\n"
604 "\n"
605 "If they are meant to go into a new commit, run:\n"
606 "\n"
607 "  git commit %s\n"
608 "\n"
609 "In both cases, once you're done, continue with:\n"
610 "\n"
611 "  git rebase --continue\n");
612
613 #define ALLOW_EMPTY (1<<0)
614 #define EDIT_MSG    (1<<1)
615 #define AMEND_MSG   (1<<2)
616 #define CLEANUP_MSG (1<<3)
617 #define VERIFY_MSG  (1<<4)
618
619 /*
620  * If we are cherry-pick, and if the merge did not result in
621  * hand-editing, we will hit this commit and inherit the original
622  * author date and name.
623  *
624  * If we are revert, or if our cherry-pick results in a hand merge,
625  * we had better say that the current user is responsible for that.
626  *
627  * An exception is when run_git_commit() is called during an
628  * interactive rebase: in that case, we will want to retain the
629  * author metadata.
630  */
631 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
632                           unsigned int flags)
633 {
634         struct child_process cmd = CHILD_PROCESS_INIT;
635         const char *value;
636
637         cmd.git_cmd = 1;
638
639         if (is_rebase_i(opts)) {
640                 if (!(flags & EDIT_MSG)) {
641                         cmd.stdout_to_stderr = 1;
642                         cmd.err = -1;
643                 }
644
645                 if (read_env_script(&cmd.env_array)) {
646                         const char *gpg_opt = gpg_sign_opt_quoted(opts);
647
648                         return error(_(staged_changes_advice),
649                                      gpg_opt, gpg_opt);
650                 }
651         }
652
653         argv_array_push(&cmd.args, "commit");
654
655         if (!(flags & VERIFY_MSG))
656                 argv_array_push(&cmd.args, "-n");
657         if ((flags & AMEND_MSG))
658                 argv_array_push(&cmd.args, "--amend");
659         if (opts->gpg_sign)
660                 argv_array_pushf(&cmd.args, "-S%s", opts->gpg_sign);
661         if (opts->signoff)
662                 argv_array_push(&cmd.args, "-s");
663         if (defmsg)
664                 argv_array_pushl(&cmd.args, "-F", defmsg, NULL);
665         if ((flags & CLEANUP_MSG))
666                 argv_array_push(&cmd.args, "--cleanup=strip");
667         if ((flags & EDIT_MSG))
668                 argv_array_push(&cmd.args, "-e");
669         else if (!(flags & CLEANUP_MSG) &&
670                  !opts->signoff && !opts->record_origin &&
671                  git_config_get_value("commit.cleanup", &value))
672                 argv_array_push(&cmd.args, "--cleanup=verbatim");
673
674         if ((flags & ALLOW_EMPTY))
675                 argv_array_push(&cmd.args, "--allow-empty");
676
677         if (opts->allow_empty_message)
678                 argv_array_push(&cmd.args, "--allow-empty-message");
679
680         if (cmd.err == -1) {
681                 /* hide stderr on success */
682                 struct strbuf buf = STRBUF_INIT;
683                 int rc = pipe_command(&cmd,
684                                       NULL, 0,
685                                       /* stdout is already redirected */
686                                       NULL, 0,
687                                       &buf, 0);
688                 if (rc)
689                         fputs(buf.buf, stderr);
690                 strbuf_release(&buf);
691                 return rc;
692         }
693
694         return run_command(&cmd);
695 }
696
697 static int is_original_commit_empty(struct commit *commit)
698 {
699         const struct object_id *ptree_oid;
700
701         if (parse_commit(commit))
702                 return error(_("could not parse commit %s\n"),
703                              oid_to_hex(&commit->object.oid));
704         if (commit->parents) {
705                 struct commit *parent = commit->parents->item;
706                 if (parse_commit(parent))
707                         return error(_("could not parse parent commit %s\n"),
708                                 oid_to_hex(&parent->object.oid));
709                 ptree_oid = &parent->tree->object.oid;
710         } else {
711                 ptree_oid = the_hash_algo->empty_tree; /* commit is root */
712         }
713
714         return !oidcmp(ptree_oid, &commit->tree->object.oid);
715 }
716
717 /*
718  * Do we run "git commit" with "--allow-empty"?
719  */
720 static int allow_empty(struct replay_opts *opts, struct commit *commit)
721 {
722         int index_unchanged, empty_commit;
723
724         /*
725          * Three cases:
726          *
727          * (1) we do not allow empty at all and error out.
728          *
729          * (2) we allow ones that were initially empty, but
730          * forbid the ones that become empty;
731          *
732          * (3) we allow both.
733          */
734         if (!opts->allow_empty)
735                 return 0; /* let "git commit" barf as necessary */
736
737         index_unchanged = is_index_unchanged();
738         if (index_unchanged < 0)
739                 return index_unchanged;
740         if (!index_unchanged)
741                 return 0; /* we do not have to say --allow-empty */
742
743         if (opts->keep_redundant_commits)
744                 return 1;
745
746         empty_commit = is_original_commit_empty(commit);
747         if (empty_commit < 0)
748                 return empty_commit;
749         if (!empty_commit)
750                 return 0;
751         else
752                 return 1;
753 }
754
755 /*
756  * Note that ordering matters in this enum. Not only must it match the mapping
757  * below, it is also divided into several sections that matter.  When adding
758  * new commands, make sure you add it in the right section.
759  */
760 enum todo_command {
761         /* commands that handle commits */
762         TODO_PICK = 0,
763         TODO_REVERT,
764         TODO_EDIT,
765         TODO_REWORD,
766         TODO_FIXUP,
767         TODO_SQUASH,
768         /* commands that do something else than handling a single commit */
769         TODO_EXEC,
770         /* commands that do nothing but are counted for reporting progress */
771         TODO_NOOP,
772         TODO_DROP,
773         /* comments (not counted for reporting progress) */
774         TODO_COMMENT
775 };
776
777 static struct {
778         char c;
779         const char *str;
780 } todo_command_info[] = {
781         { 'p', "pick" },
782         { 0,   "revert" },
783         { 'e', "edit" },
784         { 'r', "reword" },
785         { 'f', "fixup" },
786         { 's', "squash" },
787         { 'x', "exec" },
788         { 0,   "noop" },
789         { 'd', "drop" },
790         { 0,   NULL }
791 };
792
793 static const char *command_to_string(const enum todo_command command)
794 {
795         if (command < TODO_COMMENT)
796                 return todo_command_info[command].str;
797         die("Unknown command: %d", command);
798 }
799
800 static char command_to_char(const enum todo_command command)
801 {
802         if (command < TODO_COMMENT && todo_command_info[command].c)
803                 return todo_command_info[command].c;
804         return comment_line_char;
805 }
806
807 static int is_noop(const enum todo_command command)
808 {
809         return TODO_NOOP <= command;
810 }
811
812 static int is_fixup(enum todo_command command)
813 {
814         return command == TODO_FIXUP || command == TODO_SQUASH;
815 }
816
817 static int update_squash_messages(enum todo_command command,
818                 struct commit *commit, struct replay_opts *opts)
819 {
820         struct strbuf buf = STRBUF_INIT;
821         int count, res;
822         const char *message, *body;
823
824         if (file_exists(rebase_path_squash_msg())) {
825                 struct strbuf header = STRBUF_INIT;
826                 char *eol, *p;
827
828                 if (strbuf_read_file(&buf, rebase_path_squash_msg(), 2048) <= 0)
829                         return error(_("could not read '%s'"),
830                                 rebase_path_squash_msg());
831
832                 p = buf.buf + 1;
833                 eol = strchrnul(buf.buf, '\n');
834                 if (buf.buf[0] != comment_line_char ||
835                     (p += strcspn(p, "0123456789\n")) == eol)
836                         return error(_("unexpected 1st line of squash message:"
837                                        "\n\n\t%.*s"),
838                                      (int)(eol - buf.buf), buf.buf);
839                 count = strtol(p, NULL, 10);
840
841                 if (count < 1)
842                         return error(_("invalid 1st line of squash message:\n"
843                                        "\n\t%.*s"),
844                                      (int)(eol - buf.buf), buf.buf);
845
846                 strbuf_addf(&header, "%c ", comment_line_char);
847                 strbuf_addf(&header,
848                             _("This is a combination of %d commits."), ++count);
849                 strbuf_splice(&buf, 0, eol - buf.buf, header.buf, header.len);
850                 strbuf_release(&header);
851         } else {
852                 struct object_id head;
853                 struct commit *head_commit;
854                 const char *head_message, *body;
855
856                 if (get_oid("HEAD", &head))
857                         return error(_("need a HEAD to fixup"));
858                 if (!(head_commit = lookup_commit_reference(&head)))
859                         return error(_("could not read HEAD"));
860                 if (!(head_message = get_commit_buffer(head_commit, NULL)))
861                         return error(_("could not read HEAD's commit message"));
862
863                 find_commit_subject(head_message, &body);
864                 if (write_message(body, strlen(body),
865                                   rebase_path_fixup_msg(), 0)) {
866                         unuse_commit_buffer(head_commit, head_message);
867                         return error(_("cannot write '%s'"),
868                                      rebase_path_fixup_msg());
869                 }
870
871                 count = 2;
872                 strbuf_addf(&buf, "%c ", comment_line_char);
873                 strbuf_addf(&buf, _("This is a combination of %d commits."),
874                             count);
875                 strbuf_addf(&buf, "\n%c ", comment_line_char);
876                 strbuf_addstr(&buf, _("This is the 1st commit message:"));
877                 strbuf_addstr(&buf, "\n\n");
878                 strbuf_addstr(&buf, body);
879
880                 unuse_commit_buffer(head_commit, head_message);
881         }
882
883         if (!(message = get_commit_buffer(commit, NULL)))
884                 return error(_("could not read commit message of %s"),
885                              oid_to_hex(&commit->object.oid));
886         find_commit_subject(message, &body);
887
888         if (command == TODO_SQUASH) {
889                 unlink(rebase_path_fixup_msg());
890                 strbuf_addf(&buf, "\n%c ", comment_line_char);
891                 strbuf_addf(&buf, _("This is the commit message #%d:"), count);
892                 strbuf_addstr(&buf, "\n\n");
893                 strbuf_addstr(&buf, body);
894         } else if (command == TODO_FIXUP) {
895                 strbuf_addf(&buf, "\n%c ", comment_line_char);
896                 strbuf_addf(&buf, _("The commit message #%d will be skipped:"),
897                             count);
898                 strbuf_addstr(&buf, "\n\n");
899                 strbuf_add_commented_lines(&buf, body, strlen(body));
900         } else
901                 return error(_("unknown command: %d"), command);
902         unuse_commit_buffer(commit, message);
903
904         res = write_message(buf.buf, buf.len, rebase_path_squash_msg(), 0);
905         strbuf_release(&buf);
906         return res;
907 }
908
909 static void flush_rewritten_pending(void) {
910         struct strbuf buf = STRBUF_INIT;
911         struct object_id newoid;
912         FILE *out;
913
914         if (strbuf_read_file(&buf, rebase_path_rewritten_pending(), (GIT_MAX_HEXSZ + 1) * 2) > 0 &&
915             !get_oid("HEAD", &newoid) &&
916             (out = fopen_or_warn(rebase_path_rewritten_list(), "a"))) {
917                 char *bol = buf.buf, *eol;
918
919                 while (*bol) {
920                         eol = strchrnul(bol, '\n');
921                         fprintf(out, "%.*s %s\n", (int)(eol - bol),
922                                         bol, oid_to_hex(&newoid));
923                         if (!*eol)
924                                 break;
925                         bol = eol + 1;
926                 }
927                 fclose(out);
928                 unlink(rebase_path_rewritten_pending());
929         }
930         strbuf_release(&buf);
931 }
932
933 static void record_in_rewritten(struct object_id *oid,
934                 enum todo_command next_command) {
935         FILE *out = fopen_or_warn(rebase_path_rewritten_pending(), "a");
936
937         if (!out)
938                 return;
939
940         fprintf(out, "%s\n", oid_to_hex(oid));
941         fclose(out);
942
943         if (!is_fixup(next_command))
944                 flush_rewritten_pending();
945 }
946
947 static int do_pick_commit(enum todo_command command, struct commit *commit,
948                 struct replay_opts *opts, int final_fixup)
949 {
950         unsigned int flags = opts->edit ? EDIT_MSG : 0;
951         const char *msg_file = opts->edit ? NULL : git_path_merge_msg();
952         struct object_id head;
953         struct commit *base, *next, *parent;
954         const char *base_label, *next_label;
955         struct commit_message msg = { NULL, NULL, NULL, NULL };
956         struct strbuf msgbuf = STRBUF_INIT;
957         int res, unborn = 0, allow;
958
959         if (opts->no_commit) {
960                 /*
961                  * We do not intend to commit immediately.  We just want to
962                  * merge the differences in, so let's compute the tree
963                  * that represents the "current" state for merge-recursive
964                  * to work on.
965                  */
966                 if (write_cache_as_tree(head.hash, 0, NULL))
967                         return error(_("your index file is unmerged."));
968         } else {
969                 unborn = get_oid("HEAD", &head);
970                 if (unborn)
971                         oidcpy(&head, the_hash_algo->empty_tree);
972                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD",
973                                        NULL, 0))
974                         return error_dirty_index(opts);
975         }
976         discard_cache();
977
978         if (!commit->parents)
979                 parent = NULL;
980         else if (commit->parents->next) {
981                 /* Reverting or cherry-picking a merge commit */
982                 int cnt;
983                 struct commit_list *p;
984
985                 if (!opts->mainline)
986                         return error(_("commit %s is a merge but no -m option was given."),
987                                 oid_to_hex(&commit->object.oid));
988
989                 for (cnt = 1, p = commit->parents;
990                      cnt != opts->mainline && p;
991                      cnt++)
992                         p = p->next;
993                 if (cnt != opts->mainline || !p)
994                         return error(_("commit %s does not have parent %d"),
995                                 oid_to_hex(&commit->object.oid), opts->mainline);
996                 parent = p->item;
997         } else if (0 < opts->mainline)
998                 return error(_("mainline was specified but commit %s is not a merge."),
999                         oid_to_hex(&commit->object.oid));
1000         else
1001                 parent = commit->parents->item;
1002
1003         if (get_message(commit, &msg) != 0)
1004                 return error(_("cannot get commit message for %s"),
1005                         oid_to_hex(&commit->object.oid));
1006
1007         if (opts->allow_ff && !is_fixup(command) &&
1008             ((parent && !oidcmp(&parent->object.oid, &head)) ||
1009              (!parent && unborn))) {
1010                 if (is_rebase_i(opts))
1011                         write_author_script(msg.message);
1012                 res = fast_forward_to(&commit->object.oid, &head, unborn,
1013                         opts);
1014                 if (res || command != TODO_REWORD)
1015                         goto leave;
1016                 flags |= EDIT_MSG | AMEND_MSG;
1017                 if (command == TODO_REWORD)
1018                         flags |= VERIFY_MSG;
1019                 msg_file = NULL;
1020                 goto fast_forward_edit;
1021         }
1022         if (parent && parse_commit(parent) < 0)
1023                 /* TRANSLATORS: The first %s will be a "todo" command like
1024                    "revert" or "pick", the second %s a SHA1. */
1025                 return error(_("%s: cannot parse parent commit %s"),
1026                         command_to_string(command),
1027                         oid_to_hex(&parent->object.oid));
1028
1029         /*
1030          * "commit" is an existing commit.  We would want to apply
1031          * the difference it introduces since its first parent "prev"
1032          * on top of the current HEAD if we are cherry-pick.  Or the
1033          * reverse of it if we are revert.
1034          */
1035
1036         if (command == TODO_REVERT) {
1037                 base = commit;
1038                 base_label = msg.label;
1039                 next = parent;
1040                 next_label = msg.parent_label;
1041                 strbuf_addstr(&msgbuf, "Revert \"");
1042                 strbuf_addstr(&msgbuf, msg.subject);
1043                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
1044                 strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
1045
1046                 if (commit->parents && commit->parents->next) {
1047                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
1048                         strbuf_addstr(&msgbuf, oid_to_hex(&parent->object.oid));
1049                 }
1050                 strbuf_addstr(&msgbuf, ".\n");
1051         } else {
1052                 const char *p;
1053
1054                 base = parent;
1055                 base_label = msg.parent_label;
1056                 next = commit;
1057                 next_label = msg.label;
1058
1059                 /* Append the commit log message to msgbuf. */
1060                 if (find_commit_subject(msg.message, &p))
1061                         strbuf_addstr(&msgbuf, p);
1062
1063                 if (opts->record_origin) {
1064                         strbuf_complete_line(&msgbuf);
1065                         if (!has_conforming_footer(&msgbuf, NULL, 0))
1066                                 strbuf_addch(&msgbuf, '\n');
1067                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
1068                         strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
1069                         strbuf_addstr(&msgbuf, ")\n");
1070                 }
1071         }
1072
1073         if (command == TODO_REWORD)
1074                 flags |= EDIT_MSG | VERIFY_MSG;
1075         else if (is_fixup(command)) {
1076                 if (update_squash_messages(command, commit, opts))
1077                         return -1;
1078                 flags |= AMEND_MSG;
1079                 if (!final_fixup)
1080                         msg_file = rebase_path_squash_msg();
1081                 else if (file_exists(rebase_path_fixup_msg())) {
1082                         flags |= CLEANUP_MSG;
1083                         msg_file = rebase_path_fixup_msg();
1084                 } else {
1085                         const char *dest = git_path_squash_msg();
1086                         unlink(dest);
1087                         if (copy_file(dest, rebase_path_squash_msg(), 0666))
1088                                 return error(_("could not rename '%s' to '%s'"),
1089                                              rebase_path_squash_msg(), dest);
1090                         unlink(git_path_merge_msg());
1091                         msg_file = dest;
1092                         flags |= EDIT_MSG;
1093                 }
1094         }
1095
1096         if (is_rebase_i(opts) && write_author_script(msg.message) < 0)
1097                 res = -1;
1098         else if (!opts->strategy || !strcmp(opts->strategy, "recursive") || command == TODO_REVERT) {
1099                 res = do_recursive_merge(base, next, base_label, next_label,
1100                                          &head, &msgbuf, opts);
1101                 if (res < 0)
1102                         return res;
1103                 res |= write_message(msgbuf.buf, msgbuf.len,
1104                                      git_path_merge_msg(), 0);
1105         } else {
1106                 struct commit_list *common = NULL;
1107                 struct commit_list *remotes = NULL;
1108
1109                 res = write_message(msgbuf.buf, msgbuf.len,
1110                                     git_path_merge_msg(), 0);
1111
1112                 commit_list_insert(base, &common);
1113                 commit_list_insert(next, &remotes);
1114                 res |= try_merge_command(opts->strategy,
1115                                          opts->xopts_nr, (const char **)opts->xopts,
1116                                         common, oid_to_hex(&head), remotes);
1117                 free_commit_list(common);
1118                 free_commit_list(remotes);
1119         }
1120         strbuf_release(&msgbuf);
1121
1122         /*
1123          * If the merge was clean or if it failed due to conflict, we write
1124          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
1125          * However, if the merge did not even start, then we don't want to
1126          * write it at all.
1127          */
1128         if (command == TODO_PICK && !opts->no_commit && (res == 0 || res == 1) &&
1129             update_ref(NULL, "CHERRY_PICK_HEAD", &commit->object.oid, NULL,
1130                        REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR))
1131                 res = -1;
1132         if (command == TODO_REVERT && ((opts->no_commit && res == 0) || res == 1) &&
1133             update_ref(NULL, "REVERT_HEAD", &commit->object.oid, NULL,
1134                        REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR))
1135                 res = -1;
1136
1137         if (res) {
1138                 error(command == TODO_REVERT
1139                       ? _("could not revert %s... %s")
1140                       : _("could not apply %s... %s"),
1141                       short_commit_name(commit), msg.subject);
1142                 print_advice(res == 1, opts);
1143                 rerere(opts->allow_rerere_auto);
1144                 goto leave;
1145         }
1146
1147         allow = allow_empty(opts, commit);
1148         if (allow < 0) {
1149                 res = allow;
1150                 goto leave;
1151         } else if (allow)
1152                 flags |= ALLOW_EMPTY;
1153         if (!opts->no_commit)
1154 fast_forward_edit:
1155                 res = run_git_commit(msg_file, opts, flags);
1156
1157         if (!res && final_fixup) {
1158                 unlink(rebase_path_fixup_msg());
1159                 unlink(rebase_path_squash_msg());
1160         }
1161
1162 leave:
1163         free_message(commit, &msg);
1164         update_abort_safety_file();
1165
1166         return res;
1167 }
1168
1169 static int prepare_revs(struct replay_opts *opts)
1170 {
1171         /*
1172          * picking (but not reverting) ranges (but not individual revisions)
1173          * should be done in reverse
1174          */
1175         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
1176                 opts->revs->reverse ^= 1;
1177
1178         if (prepare_revision_walk(opts->revs))
1179                 return error(_("revision walk setup failed"));
1180
1181         if (!opts->revs->commits)
1182                 return error(_("empty commit set passed"));
1183         return 0;
1184 }
1185
1186 static int read_and_refresh_cache(struct replay_opts *opts)
1187 {
1188         static struct lock_file index_lock;
1189         int index_fd = hold_locked_index(&index_lock, 0);
1190         if (read_index_preload(&the_index, NULL) < 0) {
1191                 rollback_lock_file(&index_lock);
1192                 return error(_("git %s: failed to read the index"),
1193                         _(action_name(opts)));
1194         }
1195         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
1196         if (the_index.cache_changed && index_fd >= 0) {
1197                 if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK)) {
1198                         return error(_("git %s: failed to refresh the index"),
1199                                 _(action_name(opts)));
1200                 }
1201         }
1202         rollback_lock_file(&index_lock);
1203         return 0;
1204 }
1205
1206 struct todo_item {
1207         enum todo_command command;
1208         struct commit *commit;
1209         const char *arg;
1210         int arg_len;
1211         size_t offset_in_buf;
1212 };
1213
1214 struct todo_list {
1215         struct strbuf buf;
1216         struct todo_item *items;
1217         int nr, alloc, current;
1218         int done_nr, total_nr;
1219         struct stat_data stat;
1220 };
1221
1222 #define TODO_LIST_INIT { STRBUF_INIT }
1223
1224 static void todo_list_release(struct todo_list *todo_list)
1225 {
1226         strbuf_release(&todo_list->buf);
1227         FREE_AND_NULL(todo_list->items);
1228         todo_list->nr = todo_list->alloc = 0;
1229 }
1230
1231 static struct todo_item *append_new_todo(struct todo_list *todo_list)
1232 {
1233         ALLOC_GROW(todo_list->items, todo_list->nr + 1, todo_list->alloc);
1234         return todo_list->items + todo_list->nr++;
1235 }
1236
1237 static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
1238 {
1239         struct object_id commit_oid;
1240         char *end_of_object_name;
1241         int i, saved, status, padding;
1242
1243         /* left-trim */
1244         bol += strspn(bol, " \t");
1245
1246         if (bol == eol || *bol == '\r' || *bol == comment_line_char) {
1247                 item->command = TODO_COMMENT;
1248                 item->commit = NULL;
1249                 item->arg = bol;
1250                 item->arg_len = eol - bol;
1251                 return 0;
1252         }
1253
1254         for (i = 0; i < TODO_COMMENT; i++)
1255                 if (skip_prefix(bol, todo_command_info[i].str, &bol)) {
1256                         item->command = i;
1257                         break;
1258                 } else if (bol[1] == ' ' && *bol == todo_command_info[i].c) {
1259                         bol++;
1260                         item->command = i;
1261                         break;
1262                 }
1263         if (i >= TODO_COMMENT)
1264                 return -1;
1265
1266         if (item->command == TODO_NOOP) {
1267                 item->commit = NULL;
1268                 item->arg = bol;
1269                 item->arg_len = eol - bol;
1270                 return 0;
1271         }
1272
1273         /* Eat up extra spaces/ tabs before object name */
1274         padding = strspn(bol, " \t");
1275         if (!padding)
1276                 return -1;
1277         bol += padding;
1278
1279         if (item->command == TODO_EXEC) {
1280                 item->commit = NULL;
1281                 item->arg = bol;
1282                 item->arg_len = (int)(eol - bol);
1283                 return 0;
1284         }
1285
1286         end_of_object_name = (char *) bol + strcspn(bol, " \t\n");
1287         saved = *end_of_object_name;
1288         *end_of_object_name = '\0';
1289         status = get_oid(bol, &commit_oid);
1290         *end_of_object_name = saved;
1291
1292         item->arg = end_of_object_name + strspn(end_of_object_name, " \t");
1293         item->arg_len = (int)(eol - item->arg);
1294
1295         if (status < 0)
1296                 return -1;
1297
1298         item->commit = lookup_commit_reference(&commit_oid);
1299         return !item->commit;
1300 }
1301
1302 static int parse_insn_buffer(char *buf, struct todo_list *todo_list)
1303 {
1304         struct todo_item *item;
1305         char *p = buf, *next_p;
1306         int i, res = 0, fixup_okay = file_exists(rebase_path_done());
1307
1308         for (i = 1; *p; i++, p = next_p) {
1309                 char *eol = strchrnul(p, '\n');
1310
1311                 next_p = *eol ? eol + 1 /* skip LF */ : eol;
1312
1313                 if (p != eol && eol[-1] == '\r')
1314                         eol--; /* strip Carriage Return */
1315
1316                 item = append_new_todo(todo_list);
1317                 item->offset_in_buf = p - todo_list->buf.buf;
1318                 if (parse_insn_line(item, p, eol)) {
1319                         res = error(_("invalid line %d: %.*s"),
1320                                 i, (int)(eol - p), p);
1321                         item->command = TODO_NOOP;
1322                 }
1323
1324                 if (fixup_okay)
1325                         ; /* do nothing */
1326                 else if (is_fixup(item->command))
1327                         return error(_("cannot '%s' without a previous commit"),
1328                                 command_to_string(item->command));
1329                 else if (!is_noop(item->command))
1330                         fixup_okay = 1;
1331         }
1332
1333         return res;
1334 }
1335
1336 static int count_commands(struct todo_list *todo_list)
1337 {
1338         int count = 0, i;
1339
1340         for (i = 0; i < todo_list->nr; i++)
1341                 if (todo_list->items[i].command != TODO_COMMENT)
1342                         count++;
1343
1344         return count;
1345 }
1346
1347 static int read_populate_todo(struct todo_list *todo_list,
1348                         struct replay_opts *opts)
1349 {
1350         struct stat st;
1351         const char *todo_file = get_todo_path(opts);
1352         int fd, res;
1353
1354         strbuf_reset(&todo_list->buf);
1355         fd = open(todo_file, O_RDONLY);
1356         if (fd < 0)
1357                 return error_errno(_("could not open '%s'"), todo_file);
1358         if (strbuf_read(&todo_list->buf, fd, 0) < 0) {
1359                 close(fd);
1360                 return error(_("could not read '%s'."), todo_file);
1361         }
1362         close(fd);
1363
1364         res = stat(todo_file, &st);
1365         if (res)
1366                 return error(_("could not stat '%s'"), todo_file);
1367         fill_stat_data(&todo_list->stat, &st);
1368
1369         res = parse_insn_buffer(todo_list->buf.buf, todo_list);
1370         if (res) {
1371                 if (is_rebase_i(opts))
1372                         return error(_("please fix this using "
1373                                        "'git rebase --edit-todo'."));
1374                 return error(_("unusable instruction sheet: '%s'"), todo_file);
1375         }
1376
1377         if (!todo_list->nr &&
1378             (!is_rebase_i(opts) || !file_exists(rebase_path_done())))
1379                 return error(_("no commits parsed."));
1380
1381         if (!is_rebase_i(opts)) {
1382                 enum todo_command valid =
1383                         opts->action == REPLAY_PICK ? TODO_PICK : TODO_REVERT;
1384                 int i;
1385
1386                 for (i = 0; i < todo_list->nr; i++)
1387                         if (valid == todo_list->items[i].command)
1388                                 continue;
1389                         else if (valid == TODO_PICK)
1390                                 return error(_("cannot cherry-pick during a revert."));
1391                         else
1392                                 return error(_("cannot revert during a cherry-pick."));
1393         }
1394
1395         if (is_rebase_i(opts)) {
1396                 struct todo_list done = TODO_LIST_INIT;
1397                 FILE *f = fopen_or_warn(rebase_path_msgtotal(), "w");
1398
1399                 if (strbuf_read_file(&done.buf, rebase_path_done(), 0) > 0 &&
1400                                 !parse_insn_buffer(done.buf.buf, &done))
1401                         todo_list->done_nr = count_commands(&done);
1402                 else
1403                         todo_list->done_nr = 0;
1404
1405                 todo_list->total_nr = todo_list->done_nr
1406                         + count_commands(todo_list);
1407                 todo_list_release(&done);
1408
1409                 if (f) {
1410                         fprintf(f, "%d\n", todo_list->total_nr);
1411                         fclose(f);
1412                 }
1413         }
1414
1415         return 0;
1416 }
1417
1418 static int git_config_string_dup(char **dest,
1419                                  const char *var, const char *value)
1420 {
1421         if (!value)
1422                 return config_error_nonbool(var);
1423         free(*dest);
1424         *dest = xstrdup(value);
1425         return 0;
1426 }
1427
1428 static int populate_opts_cb(const char *key, const char *value, void *data)
1429 {
1430         struct replay_opts *opts = data;
1431         int error_flag = 1;
1432
1433         if (!value)
1434                 error_flag = 0;
1435         else if (!strcmp(key, "options.no-commit"))
1436                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
1437         else if (!strcmp(key, "options.edit"))
1438                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
1439         else if (!strcmp(key, "options.signoff"))
1440                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
1441         else if (!strcmp(key, "options.record-origin"))
1442                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
1443         else if (!strcmp(key, "options.allow-ff"))
1444                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
1445         else if (!strcmp(key, "options.mainline"))
1446                 opts->mainline = git_config_int(key, value);
1447         else if (!strcmp(key, "options.strategy"))
1448                 git_config_string_dup(&opts->strategy, key, value);
1449         else if (!strcmp(key, "options.gpg-sign"))
1450                 git_config_string_dup(&opts->gpg_sign, key, value);
1451         else if (!strcmp(key, "options.strategy-option")) {
1452                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
1453                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
1454         } else if (!strcmp(key, "options.allow-rerere-auto"))
1455                 opts->allow_rerere_auto =
1456                         git_config_bool_or_int(key, value, &error_flag) ?
1457                                 RERERE_AUTOUPDATE : RERERE_NOAUTOUPDATE;
1458         else
1459                 return error(_("invalid key: %s"), key);
1460
1461         if (!error_flag)
1462                 return error(_("invalid value for %s: %s"), key, value);
1463
1464         return 0;
1465 }
1466
1467 static void read_strategy_opts(struct replay_opts *opts, struct strbuf *buf)
1468 {
1469         int i;
1470
1471         strbuf_reset(buf);
1472         if (!read_oneliner(buf, rebase_path_strategy(), 0))
1473                 return;
1474         opts->strategy = strbuf_detach(buf, NULL);
1475         if (!read_oneliner(buf, rebase_path_strategy_opts(), 0))
1476                 return;
1477
1478         opts->xopts_nr = split_cmdline(buf->buf, (const char ***)&opts->xopts);
1479         for (i = 0; i < opts->xopts_nr; i++) {
1480                 const char *arg = opts->xopts[i];
1481
1482                 skip_prefix(arg, "--", &arg);
1483                 opts->xopts[i] = xstrdup(arg);
1484         }
1485 }
1486
1487 static int read_populate_opts(struct replay_opts *opts)
1488 {
1489         if (is_rebase_i(opts)) {
1490                 struct strbuf buf = STRBUF_INIT;
1491
1492                 if (read_oneliner(&buf, rebase_path_gpg_sign_opt(), 1)) {
1493                         if (!starts_with(buf.buf, "-S"))
1494                                 strbuf_reset(&buf);
1495                         else {
1496                                 free(opts->gpg_sign);
1497                                 opts->gpg_sign = xstrdup(buf.buf + 2);
1498                         }
1499                         strbuf_reset(&buf);
1500                 }
1501
1502                 if (read_oneliner(&buf, rebase_path_allow_rerere_autoupdate(), 1)) {
1503                         if (!strcmp(buf.buf, "--rerere-autoupdate"))
1504                                 opts->allow_rerere_auto = RERERE_AUTOUPDATE;
1505                         else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
1506                                 opts->allow_rerere_auto = RERERE_NOAUTOUPDATE;
1507                         strbuf_reset(&buf);
1508                 }
1509
1510                 if (file_exists(rebase_path_verbose()))
1511                         opts->verbose = 1;
1512
1513                 read_strategy_opts(opts, &buf);
1514                 strbuf_release(&buf);
1515
1516                 return 0;
1517         }
1518
1519         if (!file_exists(git_path_opts_file()))
1520                 return 0;
1521         /*
1522          * The function git_parse_source(), called from git_config_from_file(),
1523          * may die() in case of a syntactically incorrect file. We do not care
1524          * about this case, though, because we wrote that file ourselves, so we
1525          * are pretty certain that it is syntactically correct.
1526          */
1527         if (git_config_from_file(populate_opts_cb, git_path_opts_file(), opts) < 0)
1528                 return error(_("malformed options sheet: '%s'"),
1529                         git_path_opts_file());
1530         return 0;
1531 }
1532
1533 static int walk_revs_populate_todo(struct todo_list *todo_list,
1534                                 struct replay_opts *opts)
1535 {
1536         enum todo_command command = opts->action == REPLAY_PICK ?
1537                 TODO_PICK : TODO_REVERT;
1538         const char *command_string = todo_command_info[command].str;
1539         struct commit *commit;
1540
1541         if (prepare_revs(opts))
1542                 return -1;
1543
1544         while ((commit = get_revision(opts->revs))) {
1545                 struct todo_item *item = append_new_todo(todo_list);
1546                 const char *commit_buffer = get_commit_buffer(commit, NULL);
1547                 const char *subject;
1548                 int subject_len;
1549
1550                 item->command = command;
1551                 item->commit = commit;
1552                 item->arg = NULL;
1553                 item->arg_len = 0;
1554                 item->offset_in_buf = todo_list->buf.len;
1555                 subject_len = find_commit_subject(commit_buffer, &subject);
1556                 strbuf_addf(&todo_list->buf, "%s %s %.*s\n", command_string,
1557                         short_commit_name(commit), subject_len, subject);
1558                 unuse_commit_buffer(commit, commit_buffer);
1559         }
1560         return 0;
1561 }
1562
1563 static int create_seq_dir(void)
1564 {
1565         if (file_exists(git_path_seq_dir())) {
1566                 error(_("a cherry-pick or revert is already in progress"));
1567                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
1568                 return -1;
1569         } else if (mkdir(git_path_seq_dir(), 0777) < 0)
1570                 return error_errno(_("could not create sequencer directory '%s'"),
1571                                    git_path_seq_dir());
1572         return 0;
1573 }
1574
1575 static int save_head(const char *head)
1576 {
1577         static struct lock_file head_lock;
1578         struct strbuf buf = STRBUF_INIT;
1579         int fd;
1580         ssize_t written;
1581
1582         fd = hold_lock_file_for_update(&head_lock, git_path_head_file(), 0);
1583         if (fd < 0) {
1584                 rollback_lock_file(&head_lock);
1585                 return error_errno(_("could not lock HEAD"));
1586         }
1587         strbuf_addf(&buf, "%s\n", head);
1588         written = write_in_full(fd, buf.buf, buf.len);
1589         strbuf_release(&buf);
1590         if (written < 0) {
1591                 rollback_lock_file(&head_lock);
1592                 return error_errno(_("could not write to '%s'"),
1593                                    git_path_head_file());
1594         }
1595         if (commit_lock_file(&head_lock) < 0) {
1596                 rollback_lock_file(&head_lock);
1597                 return error(_("failed to finalize '%s'."), git_path_head_file());
1598         }
1599         return 0;
1600 }
1601
1602 static int rollback_is_safe(void)
1603 {
1604         struct strbuf sb = STRBUF_INIT;
1605         struct object_id expected_head, actual_head;
1606
1607         if (strbuf_read_file(&sb, git_path_abort_safety_file(), 0) >= 0) {
1608                 strbuf_trim(&sb);
1609                 if (get_oid_hex(sb.buf, &expected_head)) {
1610                         strbuf_release(&sb);
1611                         die(_("could not parse %s"), git_path_abort_safety_file());
1612                 }
1613                 strbuf_release(&sb);
1614         }
1615         else if (errno == ENOENT)
1616                 oidclr(&expected_head);
1617         else
1618                 die_errno(_("could not read '%s'"), git_path_abort_safety_file());
1619
1620         if (get_oid("HEAD", &actual_head))
1621                 oidclr(&actual_head);
1622
1623         return !oidcmp(&actual_head, &expected_head);
1624 }
1625
1626 static int reset_for_rollback(const struct object_id *oid)
1627 {
1628         const char *argv[4];    /* reset --merge <arg> + NULL */
1629
1630         argv[0] = "reset";
1631         argv[1] = "--merge";
1632         argv[2] = oid_to_hex(oid);
1633         argv[3] = NULL;
1634         return run_command_v_opt(argv, RUN_GIT_CMD);
1635 }
1636
1637 static int rollback_single_pick(void)
1638 {
1639         struct object_id head_oid;
1640
1641         if (!file_exists(git_path_cherry_pick_head()) &&
1642             !file_exists(git_path_revert_head()))
1643                 return error(_("no cherry-pick or revert in progress"));
1644         if (read_ref_full("HEAD", 0, &head_oid, NULL))
1645                 return error(_("cannot resolve HEAD"));
1646         if (is_null_oid(&head_oid))
1647                 return error(_("cannot abort from a branch yet to be born"));
1648         return reset_for_rollback(&head_oid);
1649 }
1650
1651 int sequencer_rollback(struct replay_opts *opts)
1652 {
1653         FILE *f;
1654         struct object_id oid;
1655         struct strbuf buf = STRBUF_INIT;
1656         const char *p;
1657
1658         f = fopen(git_path_head_file(), "r");
1659         if (!f && errno == ENOENT) {
1660                 /*
1661                  * There is no multiple-cherry-pick in progress.
1662                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
1663                  * a single-cherry-pick in progress, abort that.
1664                  */
1665                 return rollback_single_pick();
1666         }
1667         if (!f)
1668                 return error_errno(_("cannot open '%s'"), git_path_head_file());
1669         if (strbuf_getline_lf(&buf, f)) {
1670                 error(_("cannot read '%s': %s"), git_path_head_file(),
1671                       ferror(f) ?  strerror(errno) : _("unexpected end of file"));
1672                 fclose(f);
1673                 goto fail;
1674         }
1675         fclose(f);
1676         if (parse_oid_hex(buf.buf, &oid, &p) || *p != '\0') {
1677                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
1678                         git_path_head_file());
1679                 goto fail;
1680         }
1681         if (is_null_oid(&oid)) {
1682                 error(_("cannot abort from a branch yet to be born"));
1683                 goto fail;
1684         }
1685
1686         if (!rollback_is_safe()) {
1687                 /* Do not error, just do not rollback */
1688                 warning(_("You seem to have moved HEAD. "
1689                           "Not rewinding, check your HEAD!"));
1690         } else
1691         if (reset_for_rollback(&oid))
1692                 goto fail;
1693         strbuf_release(&buf);
1694         return sequencer_remove_state(opts);
1695 fail:
1696         strbuf_release(&buf);
1697         return -1;
1698 }
1699
1700 static int save_todo(struct todo_list *todo_list, struct replay_opts *opts)
1701 {
1702         static struct lock_file todo_lock;
1703         const char *todo_path = get_todo_path(opts);
1704         int next = todo_list->current, offset, fd;
1705
1706         /*
1707          * rebase -i writes "git-rebase-todo" without the currently executing
1708          * command, appending it to "done" instead.
1709          */
1710         if (is_rebase_i(opts))
1711                 next++;
1712
1713         fd = hold_lock_file_for_update(&todo_lock, todo_path, 0);
1714         if (fd < 0)
1715                 return error_errno(_("could not lock '%s'"), todo_path);
1716         offset = next < todo_list->nr ?
1717                 todo_list->items[next].offset_in_buf : todo_list->buf.len;
1718         if (write_in_full(fd, todo_list->buf.buf + offset,
1719                         todo_list->buf.len - offset) < 0)
1720                 return error_errno(_("could not write to '%s'"), todo_path);
1721         if (commit_lock_file(&todo_lock) < 0)
1722                 return error(_("failed to finalize '%s'."), todo_path);
1723
1724         if (is_rebase_i(opts)) {
1725                 const char *done_path = rebase_path_done();
1726                 int fd = open(done_path, O_CREAT | O_WRONLY | O_APPEND, 0666);
1727                 int prev_offset = !next ? 0 :
1728                         todo_list->items[next - 1].offset_in_buf;
1729
1730                 if (fd >= 0 && offset > prev_offset &&
1731                     write_in_full(fd, todo_list->buf.buf + prev_offset,
1732                                   offset - prev_offset) < 0) {
1733                         close(fd);
1734                         return error_errno(_("could not write to '%s'"),
1735                                            done_path);
1736                 }
1737                 if (fd >= 0)
1738                         close(fd);
1739         }
1740         return 0;
1741 }
1742
1743 static int save_opts(struct replay_opts *opts)
1744 {
1745         const char *opts_file = git_path_opts_file();
1746         int res = 0;
1747
1748         if (opts->no_commit)
1749                 res |= git_config_set_in_file_gently(opts_file, "options.no-commit", "true");
1750         if (opts->edit)
1751                 res |= git_config_set_in_file_gently(opts_file, "options.edit", "true");
1752         if (opts->signoff)
1753                 res |= git_config_set_in_file_gently(opts_file, "options.signoff", "true");
1754         if (opts->record_origin)
1755                 res |= git_config_set_in_file_gently(opts_file, "options.record-origin", "true");
1756         if (opts->allow_ff)
1757                 res |= git_config_set_in_file_gently(opts_file, "options.allow-ff", "true");
1758         if (opts->mainline) {
1759                 struct strbuf buf = STRBUF_INIT;
1760                 strbuf_addf(&buf, "%d", opts->mainline);
1761                 res |= git_config_set_in_file_gently(opts_file, "options.mainline", buf.buf);
1762                 strbuf_release(&buf);
1763         }
1764         if (opts->strategy)
1765                 res |= git_config_set_in_file_gently(opts_file, "options.strategy", opts->strategy);
1766         if (opts->gpg_sign)
1767                 res |= git_config_set_in_file_gently(opts_file, "options.gpg-sign", opts->gpg_sign);
1768         if (opts->xopts) {
1769                 int i;
1770                 for (i = 0; i < opts->xopts_nr; i++)
1771                         res |= git_config_set_multivar_in_file_gently(opts_file,
1772                                                         "options.strategy-option",
1773                                                         opts->xopts[i], "^$", 0);
1774         }
1775         if (opts->allow_rerere_auto)
1776                 res |= git_config_set_in_file_gently(opts_file, "options.allow-rerere-auto",
1777                                                      opts->allow_rerere_auto == RERERE_AUTOUPDATE ?
1778                                                      "true" : "false");
1779         return res;
1780 }
1781
1782 static int make_patch(struct commit *commit, struct replay_opts *opts)
1783 {
1784         struct strbuf buf = STRBUF_INIT;
1785         struct rev_info log_tree_opt;
1786         const char *subject, *p;
1787         int res = 0;
1788
1789         p = short_commit_name(commit);
1790         if (write_message(p, strlen(p), rebase_path_stopped_sha(), 1) < 0)
1791                 return -1;
1792
1793         strbuf_addf(&buf, "%s/patch", get_dir(opts));
1794         memset(&log_tree_opt, 0, sizeof(log_tree_opt));
1795         init_revisions(&log_tree_opt, NULL);
1796         log_tree_opt.abbrev = 0;
1797         log_tree_opt.diff = 1;
1798         log_tree_opt.diffopt.output_format = DIFF_FORMAT_PATCH;
1799         log_tree_opt.disable_stdin = 1;
1800         log_tree_opt.no_commit_id = 1;
1801         log_tree_opt.diffopt.file = fopen(buf.buf, "w");
1802         log_tree_opt.diffopt.use_color = GIT_COLOR_NEVER;
1803         if (!log_tree_opt.diffopt.file)
1804                 res |= error_errno(_("could not open '%s'"), buf.buf);
1805         else {
1806                 res |= log_tree_commit(&log_tree_opt, commit);
1807                 fclose(log_tree_opt.diffopt.file);
1808         }
1809         strbuf_reset(&buf);
1810
1811         strbuf_addf(&buf, "%s/message", get_dir(opts));
1812         if (!file_exists(buf.buf)) {
1813                 const char *commit_buffer = get_commit_buffer(commit, NULL);
1814                 find_commit_subject(commit_buffer, &subject);
1815                 res |= write_message(subject, strlen(subject), buf.buf, 1);
1816                 unuse_commit_buffer(commit, commit_buffer);
1817         }
1818         strbuf_release(&buf);
1819
1820         return res;
1821 }
1822
1823 static int intend_to_amend(void)
1824 {
1825         struct object_id head;
1826         char *p;
1827
1828         if (get_oid("HEAD", &head))
1829                 return error(_("cannot read HEAD"));
1830
1831         p = oid_to_hex(&head);
1832         return write_message(p, strlen(p), rebase_path_amend(), 1);
1833 }
1834
1835 static int error_with_patch(struct commit *commit,
1836         const char *subject, int subject_len,
1837         struct replay_opts *opts, int exit_code, int to_amend)
1838 {
1839         if (make_patch(commit, opts))
1840                 return -1;
1841
1842         if (to_amend) {
1843                 if (intend_to_amend())
1844                         return -1;
1845
1846                 fprintf(stderr, "You can amend the commit now, with\n"
1847                         "\n"
1848                         "  git commit --amend %s\n"
1849                         "\n"
1850                         "Once you are satisfied with your changes, run\n"
1851                         "\n"
1852                         "  git rebase --continue\n", gpg_sign_opt_quoted(opts));
1853         } else if (exit_code)
1854                 fprintf(stderr, "Could not apply %s... %.*s\n",
1855                         short_commit_name(commit), subject_len, subject);
1856
1857         return exit_code;
1858 }
1859
1860 static int error_failed_squash(struct commit *commit,
1861         struct replay_opts *opts, int subject_len, const char *subject)
1862 {
1863         if (rename(rebase_path_squash_msg(), rebase_path_message()))
1864                 return error(_("could not rename '%s' to '%s'"),
1865                         rebase_path_squash_msg(), rebase_path_message());
1866         unlink(rebase_path_fixup_msg());
1867         unlink(git_path_merge_msg());
1868         if (copy_file(git_path_merge_msg(), rebase_path_message(), 0666))
1869                 return error(_("could not copy '%s' to '%s'"),
1870                              rebase_path_message(), git_path_merge_msg());
1871         return error_with_patch(commit, subject, subject_len, opts, 1, 0);
1872 }
1873
1874 static int do_exec(const char *command_line)
1875 {
1876         struct argv_array child_env = ARGV_ARRAY_INIT;
1877         const char *child_argv[] = { NULL, NULL };
1878         int dirty, status;
1879
1880         fprintf(stderr, "Executing: %s\n", command_line);
1881         child_argv[0] = command_line;
1882         argv_array_pushf(&child_env, "GIT_DIR=%s", absolute_path(get_git_dir()));
1883         status = run_command_v_opt_cd_env(child_argv, RUN_USING_SHELL, NULL,
1884                                           child_env.argv);
1885
1886         /* force re-reading of the cache */
1887         if (discard_cache() < 0 || read_cache() < 0)
1888                 return error(_("could not read index"));
1889
1890         dirty = require_clean_work_tree("rebase", NULL, 1, 1);
1891
1892         if (status) {
1893                 warning(_("execution failed: %s\n%s"
1894                           "You can fix the problem, and then run\n"
1895                           "\n"
1896                           "  git rebase --continue\n"
1897                           "\n"),
1898                         command_line,
1899                         dirty ? N_("and made changes to the index and/or the "
1900                                 "working tree\n") : "");
1901                 if (status == 127)
1902                         /* command not found */
1903                         status = 1;
1904         } else if (dirty) {
1905                 warning(_("execution succeeded: %s\nbut "
1906                           "left changes to the index and/or the working tree\n"
1907                           "Commit or stash your changes, and then run\n"
1908                           "\n"
1909                           "  git rebase --continue\n"
1910                           "\n"), command_line);
1911                 status = 1;
1912         }
1913
1914         argv_array_clear(&child_env);
1915
1916         return status;
1917 }
1918
1919 static int is_final_fixup(struct todo_list *todo_list)
1920 {
1921         int i = todo_list->current;
1922
1923         if (!is_fixup(todo_list->items[i].command))
1924                 return 0;
1925
1926         while (++i < todo_list->nr)
1927                 if (is_fixup(todo_list->items[i].command))
1928                         return 0;
1929                 else if (!is_noop(todo_list->items[i].command))
1930                         break;
1931         return 1;
1932 }
1933
1934 static enum todo_command peek_command(struct todo_list *todo_list, int offset)
1935 {
1936         int i;
1937
1938         for (i = todo_list->current + offset; i < todo_list->nr; i++)
1939                 if (!is_noop(todo_list->items[i].command))
1940                         return todo_list->items[i].command;
1941
1942         return -1;
1943 }
1944
1945 static int apply_autostash(struct replay_opts *opts)
1946 {
1947         struct strbuf stash_sha1 = STRBUF_INIT;
1948         struct child_process child = CHILD_PROCESS_INIT;
1949         int ret = 0;
1950
1951         if (!read_oneliner(&stash_sha1, rebase_path_autostash(), 1)) {
1952                 strbuf_release(&stash_sha1);
1953                 return 0;
1954         }
1955         strbuf_trim(&stash_sha1);
1956
1957         child.git_cmd = 1;
1958         child.no_stdout = 1;
1959         child.no_stderr = 1;
1960         argv_array_push(&child.args, "stash");
1961         argv_array_push(&child.args, "apply");
1962         argv_array_push(&child.args, stash_sha1.buf);
1963         if (!run_command(&child))
1964                 fprintf(stderr, _("Applied autostash.\n"));
1965         else {
1966                 struct child_process store = CHILD_PROCESS_INIT;
1967
1968                 store.git_cmd = 1;
1969                 argv_array_push(&store.args, "stash");
1970                 argv_array_push(&store.args, "store");
1971                 argv_array_push(&store.args, "-m");
1972                 argv_array_push(&store.args, "autostash");
1973                 argv_array_push(&store.args, "-q");
1974                 argv_array_push(&store.args, stash_sha1.buf);
1975                 if (run_command(&store))
1976                         ret = error(_("cannot store %s"), stash_sha1.buf);
1977                 else
1978                         fprintf(stderr,
1979                                 _("Applying autostash resulted in conflicts.\n"
1980                                   "Your changes are safe in the stash.\n"
1981                                   "You can run \"git stash pop\" or"
1982                                   " \"git stash drop\" at any time.\n"));
1983         }
1984
1985         strbuf_release(&stash_sha1);
1986         return ret;
1987 }
1988
1989 static const char *reflog_message(struct replay_opts *opts,
1990         const char *sub_action, const char *fmt, ...)
1991 {
1992         va_list ap;
1993         static struct strbuf buf = STRBUF_INIT;
1994
1995         va_start(ap, fmt);
1996         strbuf_reset(&buf);
1997         strbuf_addstr(&buf, action_name(opts));
1998         if (sub_action)
1999                 strbuf_addf(&buf, " (%s)", sub_action);
2000         if (fmt) {
2001                 strbuf_addstr(&buf, ": ");
2002                 strbuf_vaddf(&buf, fmt, ap);
2003         }
2004         va_end(ap);
2005
2006         return buf.buf;
2007 }
2008
2009 static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
2010 {
2011         int res = 0;
2012
2013         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
2014         if (opts->allow_ff)
2015                 assert(!(opts->signoff || opts->no_commit ||
2016                                 opts->record_origin || opts->edit));
2017         if (read_and_refresh_cache(opts))
2018                 return -1;
2019
2020         while (todo_list->current < todo_list->nr) {
2021                 struct todo_item *item = todo_list->items + todo_list->current;
2022                 if (save_todo(todo_list, opts))
2023                         return -1;
2024                 if (is_rebase_i(opts)) {
2025                         if (item->command != TODO_COMMENT) {
2026                                 FILE *f = fopen(rebase_path_msgnum(), "w");
2027
2028                                 todo_list->done_nr++;
2029
2030                                 if (f) {
2031                                         fprintf(f, "%d\n", todo_list->done_nr);
2032                                         fclose(f);
2033                                 }
2034                                 fprintf(stderr, "Rebasing (%d/%d)%s",
2035                                         todo_list->done_nr,
2036                                         todo_list->total_nr,
2037                                         opts->verbose ? "\n" : "\r");
2038                         }
2039                         unlink(rebase_path_message());
2040                         unlink(rebase_path_author_script());
2041                         unlink(rebase_path_stopped_sha());
2042                         unlink(rebase_path_amend());
2043                 }
2044                 if (item->command <= TODO_SQUASH) {
2045                         if (is_rebase_i(opts))
2046                                 setenv("GIT_REFLOG_ACTION", reflog_message(opts,
2047                                         command_to_string(item->command), NULL),
2048                                         1);
2049                         res = do_pick_commit(item->command, item->commit,
2050                                         opts, is_final_fixup(todo_list));
2051                         if (is_rebase_i(opts) && res < 0) {
2052                                 /* Reschedule */
2053                                 todo_list->current--;
2054                                 if (save_todo(todo_list, opts))
2055                                         return -1;
2056                         }
2057                         if (item->command == TODO_EDIT) {
2058                                 struct commit *commit = item->commit;
2059                                 if (!res)
2060                                         fprintf(stderr,
2061                                                 _("Stopped at %s...  %.*s\n"),
2062                                                 short_commit_name(commit),
2063                                                 item->arg_len, item->arg);
2064                                 return error_with_patch(commit,
2065                                         item->arg, item->arg_len, opts, res,
2066                                         !res);
2067                         }
2068                         if (is_rebase_i(opts) && !res)
2069                                 record_in_rewritten(&item->commit->object.oid,
2070                                         peek_command(todo_list, 1));
2071                         if (res && is_fixup(item->command)) {
2072                                 if (res == 1)
2073                                         intend_to_amend();
2074                                 return error_failed_squash(item->commit, opts,
2075                                         item->arg_len, item->arg);
2076                         } else if (res && is_rebase_i(opts))
2077                                 return res | error_with_patch(item->commit,
2078                                         item->arg, item->arg_len, opts, res,
2079                                         item->command == TODO_REWORD);
2080                 } else if (item->command == TODO_EXEC) {
2081                         char *end_of_arg = (char *)(item->arg + item->arg_len);
2082                         int saved = *end_of_arg;
2083                         struct stat st;
2084
2085                         *end_of_arg = '\0';
2086                         res = do_exec(item->arg);
2087                         *end_of_arg = saved;
2088
2089                         /* Reread the todo file if it has changed. */
2090                         if (res)
2091                                 ; /* fall through */
2092                         else if (stat(get_todo_path(opts), &st))
2093                                 res = error_errno(_("could not stat '%s'"),
2094                                                   get_todo_path(opts));
2095                         else if (match_stat_data(&todo_list->stat, &st)) {
2096                                 todo_list_release(todo_list);
2097                                 if (read_populate_todo(todo_list, opts))
2098                                         res = -1; /* message was printed */
2099                                 /* `current` will be incremented below */
2100                                 todo_list->current = -1;
2101                         }
2102                 } else if (!is_noop(item->command))
2103                         return error(_("unknown command %d"), item->command);
2104
2105                 todo_list->current++;
2106                 if (res)
2107                         return res;
2108         }
2109
2110         if (is_rebase_i(opts)) {
2111                 struct strbuf head_ref = STRBUF_INIT, buf = STRBUF_INIT;
2112                 struct stat st;
2113
2114                 /* Stopped in the middle, as planned? */
2115                 if (todo_list->current < todo_list->nr)
2116                         return 0;
2117
2118                 if (read_oneliner(&head_ref, rebase_path_head_name(), 0) &&
2119                                 starts_with(head_ref.buf, "refs/")) {
2120                         const char *msg;
2121                         struct object_id head, orig;
2122                         int res;
2123
2124                         if (get_oid("HEAD", &head)) {
2125                                 res = error(_("cannot read HEAD"));
2126 cleanup_head_ref:
2127                                 strbuf_release(&head_ref);
2128                                 strbuf_release(&buf);
2129                                 return res;
2130                         }
2131                         if (!read_oneliner(&buf, rebase_path_orig_head(), 0) ||
2132                                         get_oid_hex(buf.buf, &orig)) {
2133                                 res = error(_("could not read orig-head"));
2134                                 goto cleanup_head_ref;
2135                         }
2136                         strbuf_reset(&buf);
2137                         if (!read_oneliner(&buf, rebase_path_onto(), 0)) {
2138                                 res = error(_("could not read 'onto'"));
2139                                 goto cleanup_head_ref;
2140                         }
2141                         msg = reflog_message(opts, "finish", "%s onto %s",
2142                                 head_ref.buf, buf.buf);
2143                         if (update_ref(msg, head_ref.buf, &head, &orig,
2144                                        REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR)) {
2145                                 res = error(_("could not update %s"),
2146                                         head_ref.buf);
2147                                 goto cleanup_head_ref;
2148                         }
2149                         msg = reflog_message(opts, "finish", "returning to %s",
2150                                 head_ref.buf);
2151                         if (create_symref("HEAD", head_ref.buf, msg)) {
2152                                 res = error(_("could not update HEAD to %s"),
2153                                         head_ref.buf);
2154                                 goto cleanup_head_ref;
2155                         }
2156                         strbuf_reset(&buf);
2157                 }
2158
2159                 if (opts->verbose) {
2160                         struct rev_info log_tree_opt;
2161                         struct object_id orig, head;
2162
2163                         memset(&log_tree_opt, 0, sizeof(log_tree_opt));
2164                         init_revisions(&log_tree_opt, NULL);
2165                         log_tree_opt.diff = 1;
2166                         log_tree_opt.diffopt.output_format =
2167                                 DIFF_FORMAT_DIFFSTAT;
2168                         log_tree_opt.disable_stdin = 1;
2169
2170                         if (read_oneliner(&buf, rebase_path_orig_head(), 0) &&
2171                             !get_oid(buf.buf, &orig) &&
2172                             !get_oid("HEAD", &head)) {
2173                                 diff_tree_oid(&orig, &head, "",
2174                                               &log_tree_opt.diffopt);
2175                                 log_tree_diff_flush(&log_tree_opt);
2176                         }
2177                 }
2178                 flush_rewritten_pending();
2179                 if (!stat(rebase_path_rewritten_list(), &st) &&
2180                                 st.st_size > 0) {
2181                         struct child_process child = CHILD_PROCESS_INIT;
2182                         const char *post_rewrite_hook =
2183                                 find_hook("post-rewrite");
2184
2185                         child.in = open(rebase_path_rewritten_list(), O_RDONLY);
2186                         child.git_cmd = 1;
2187                         argv_array_push(&child.args, "notes");
2188                         argv_array_push(&child.args, "copy");
2189                         argv_array_push(&child.args, "--for-rewrite=rebase");
2190                         /* we don't care if this copying failed */
2191                         run_command(&child);
2192
2193                         if (post_rewrite_hook) {
2194                                 struct child_process hook = CHILD_PROCESS_INIT;
2195
2196                                 hook.in = open(rebase_path_rewritten_list(),
2197                                         O_RDONLY);
2198                                 hook.stdout_to_stderr = 1;
2199                                 argv_array_push(&hook.args, post_rewrite_hook);
2200                                 argv_array_push(&hook.args, "rebase");
2201                                 /* we don't care if this hook failed */
2202                                 run_command(&hook);
2203                         }
2204                 }
2205                 apply_autostash(opts);
2206
2207                 fprintf(stderr, "Successfully rebased and updated %s.\n",
2208                         head_ref.buf);
2209
2210                 strbuf_release(&buf);
2211                 strbuf_release(&head_ref);
2212         }
2213
2214         /*
2215          * Sequence of picks finished successfully; cleanup by
2216          * removing the .git/sequencer directory
2217          */
2218         return sequencer_remove_state(opts);
2219 }
2220
2221 static int continue_single_pick(void)
2222 {
2223         const char *argv[] = { "commit", NULL };
2224
2225         if (!file_exists(git_path_cherry_pick_head()) &&
2226             !file_exists(git_path_revert_head()))
2227                 return error(_("no cherry-pick or revert in progress"));
2228         return run_command_v_opt(argv, RUN_GIT_CMD);
2229 }
2230
2231 static int commit_staged_changes(struct replay_opts *opts)
2232 {
2233         unsigned int flags = ALLOW_EMPTY | EDIT_MSG;
2234
2235         if (has_unstaged_changes(1))
2236                 return error(_("cannot rebase: You have unstaged changes."));
2237         if (!has_uncommitted_changes(0)) {
2238                 const char *cherry_pick_head = git_path_cherry_pick_head();
2239
2240                 if (file_exists(cherry_pick_head) && unlink(cherry_pick_head))
2241                         return error(_("could not remove CHERRY_PICK_HEAD"));
2242                 return 0;
2243         }
2244
2245         if (file_exists(rebase_path_amend())) {
2246                 struct strbuf rev = STRBUF_INIT;
2247                 struct object_id head, to_amend;
2248
2249                 if (get_oid("HEAD", &head))
2250                         return error(_("cannot amend non-existing commit"));
2251                 if (!read_oneliner(&rev, rebase_path_amend(), 0))
2252                         return error(_("invalid file: '%s'"), rebase_path_amend());
2253                 if (get_oid_hex(rev.buf, &to_amend))
2254                         return error(_("invalid contents: '%s'"),
2255                                 rebase_path_amend());
2256                 if (oidcmp(&head, &to_amend))
2257                         return error(_("\nYou have uncommitted changes in your "
2258                                        "working tree. Please, commit them\n"
2259                                        "first and then run 'git rebase "
2260                                        "--continue' again."));
2261
2262                 strbuf_release(&rev);
2263                 flags |= AMEND_MSG;
2264         }
2265
2266         if (run_git_commit(rebase_path_message(), opts, flags))
2267                 return error(_("could not commit staged changes."));
2268         unlink(rebase_path_amend());
2269         return 0;
2270 }
2271
2272 int sequencer_continue(struct replay_opts *opts)
2273 {
2274         struct todo_list todo_list = TODO_LIST_INIT;
2275         int res;
2276
2277         if (read_and_refresh_cache(opts))
2278                 return -1;
2279
2280         if (is_rebase_i(opts)) {
2281                 if (commit_staged_changes(opts))
2282                         return -1;
2283         } else if (!file_exists(get_todo_path(opts)))
2284                 return continue_single_pick();
2285         if (read_populate_opts(opts))
2286                 return -1;
2287         if ((res = read_populate_todo(&todo_list, opts)))
2288                 goto release_todo_list;
2289
2290         if (!is_rebase_i(opts)) {
2291                 /* Verify that the conflict has been resolved */
2292                 if (file_exists(git_path_cherry_pick_head()) ||
2293                     file_exists(git_path_revert_head())) {
2294                         res = continue_single_pick();
2295                         if (res)
2296                                 goto release_todo_list;
2297                 }
2298                 if (index_differs_from("HEAD", NULL, 0)) {
2299                         res = error_dirty_index(opts);
2300                         goto release_todo_list;
2301                 }
2302                 todo_list.current++;
2303         } else if (file_exists(rebase_path_stopped_sha())) {
2304                 struct strbuf buf = STRBUF_INIT;
2305                 struct object_id oid;
2306
2307                 if (read_oneliner(&buf, rebase_path_stopped_sha(), 1) &&
2308                     !get_oid_committish(buf.buf, &oid))
2309                         record_in_rewritten(&oid, peek_command(&todo_list, 0));
2310                 strbuf_release(&buf);
2311         }
2312
2313         res = pick_commits(&todo_list, opts);
2314 release_todo_list:
2315         todo_list_release(&todo_list);
2316         return res;
2317 }
2318
2319 static int single_pick(struct commit *cmit, struct replay_opts *opts)
2320 {
2321         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
2322         return do_pick_commit(opts->action == REPLAY_PICK ?
2323                 TODO_PICK : TODO_REVERT, cmit, opts, 0);
2324 }
2325
2326 int sequencer_pick_revisions(struct replay_opts *opts)
2327 {
2328         struct todo_list todo_list = TODO_LIST_INIT;
2329         struct object_id oid;
2330         int i, res;
2331
2332         assert(opts->revs);
2333         if (read_and_refresh_cache(opts))
2334                 return -1;
2335
2336         for (i = 0; i < opts->revs->pending.nr; i++) {
2337                 struct object_id oid;
2338                 const char *name = opts->revs->pending.objects[i].name;
2339
2340                 /* This happens when using --stdin. */
2341                 if (!strlen(name))
2342                         continue;
2343
2344                 if (!get_oid(name, &oid)) {
2345                         if (!lookup_commit_reference_gently(&oid, 1)) {
2346                                 enum object_type type = sha1_object_info(oid.hash, NULL);
2347                                 return error(_("%s: can't cherry-pick a %s"),
2348                                         name, typename(type));
2349                         }
2350                 } else
2351                         return error(_("%s: bad revision"), name);
2352         }
2353
2354         /*
2355          * If we were called as "git cherry-pick <commit>", just
2356          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
2357          * REVERT_HEAD, and don't touch the sequencer state.
2358          * This means it is possible to cherry-pick in the middle
2359          * of a cherry-pick sequence.
2360          */
2361         if (opts->revs->cmdline.nr == 1 &&
2362             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
2363             opts->revs->no_walk &&
2364             !opts->revs->cmdline.rev->flags) {
2365                 struct commit *cmit;
2366                 if (prepare_revision_walk(opts->revs))
2367                         return error(_("revision walk setup failed"));
2368                 cmit = get_revision(opts->revs);
2369                 if (!cmit || get_revision(opts->revs))
2370                         return error("BUG: expected exactly one commit from walk");
2371                 return single_pick(cmit, opts);
2372         }
2373
2374         /*
2375          * Start a new cherry-pick/ revert sequence; but
2376          * first, make sure that an existing one isn't in
2377          * progress
2378          */
2379
2380         if (walk_revs_populate_todo(&todo_list, opts) ||
2381                         create_seq_dir() < 0)
2382                 return -1;
2383         if (get_oid("HEAD", &oid) && (opts->action == REPLAY_REVERT))
2384                 return error(_("can't revert as initial commit"));
2385         if (save_head(oid_to_hex(&oid)))
2386                 return -1;
2387         if (save_opts(opts))
2388                 return -1;
2389         update_abort_safety_file();
2390         res = pick_commits(&todo_list, opts);
2391         todo_list_release(&todo_list);
2392         return res;
2393 }
2394
2395 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
2396 {
2397         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
2398         struct strbuf sob = STRBUF_INIT;
2399         int has_footer;
2400
2401         strbuf_addstr(&sob, sign_off_header);
2402         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
2403                                 getenv("GIT_COMMITTER_EMAIL")));
2404         strbuf_addch(&sob, '\n');
2405
2406         if (!ignore_footer)
2407                 strbuf_complete_line(msgbuf);
2408
2409         /*
2410          * If the whole message buffer is equal to the sob, pretend that we
2411          * found a conforming footer with a matching sob
2412          */
2413         if (msgbuf->len - ignore_footer == sob.len &&
2414             !strncmp(msgbuf->buf, sob.buf, sob.len))
2415                 has_footer = 3;
2416         else
2417                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
2418
2419         if (!has_footer) {
2420                 const char *append_newlines = NULL;
2421                 size_t len = msgbuf->len - ignore_footer;
2422
2423                 if (!len) {
2424                         /*
2425                          * The buffer is completely empty.  Leave foom for
2426                          * the title and body to be filled in by the user.
2427                          */
2428                         append_newlines = "\n\n";
2429                 } else if (len == 1) {
2430                         /*
2431                          * Buffer contains a single newline.  Add another
2432                          * so that we leave room for the title and body.
2433                          */
2434                         append_newlines = "\n";
2435                 } else if (msgbuf->buf[len - 2] != '\n') {
2436                         /*
2437                          * Buffer ends with a single newline.  Add another
2438                          * so that there is an empty line between the message
2439                          * body and the sob.
2440                          */
2441                         append_newlines = "\n";
2442                 } /* else, the buffer already ends with two newlines. */
2443
2444                 if (append_newlines)
2445                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
2446                                 append_newlines, strlen(append_newlines));
2447         }
2448
2449         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
2450                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
2451                                 sob.buf, sob.len);
2452
2453         strbuf_release(&sob);
2454 }
2455
2456 int sequencer_make_script(FILE *out, int argc, const char **argv,
2457                           unsigned flags)
2458 {
2459         char *format = NULL;
2460         struct pretty_print_context pp = {0};
2461         struct strbuf buf = STRBUF_INIT;
2462         struct rev_info revs;
2463         struct commit *commit;
2464         int keep_empty = flags & TODO_LIST_KEEP_EMPTY;
2465         const char *insn = flags & TODO_LIST_ABBREVIATE_CMDS ? "p" : "pick";
2466
2467         init_revisions(&revs, NULL);
2468         revs.verbose_header = 1;
2469         revs.max_parents = 1;
2470         revs.cherry_pick = 1;
2471         revs.limited = 1;
2472         revs.reverse = 1;
2473         revs.right_only = 1;
2474         revs.sort_order = REV_SORT_IN_GRAPH_ORDER;
2475         revs.topo_order = 1;
2476
2477         revs.pretty_given = 1;
2478         git_config_get_string("rebase.instructionFormat", &format);
2479         if (!format || !*format) {
2480                 free(format);
2481                 format = xstrdup("%s");
2482         }
2483         get_commit_format(format, &revs);
2484         free(format);
2485         pp.fmt = revs.commit_format;
2486         pp.output_encoding = get_log_output_encoding();
2487
2488         if (setup_revisions(argc, argv, &revs, NULL) > 1)
2489                 return error(_("make_script: unhandled options"));
2490
2491         if (prepare_revision_walk(&revs) < 0)
2492                 return error(_("make_script: error preparing revisions"));
2493
2494         while ((commit = get_revision(&revs))) {
2495                 strbuf_reset(&buf);
2496                 if (!keep_empty && is_original_commit_empty(commit))
2497                         strbuf_addf(&buf, "%c ", comment_line_char);
2498                 strbuf_addf(&buf, "%s %s ", insn,
2499                             oid_to_hex(&commit->object.oid));
2500                 pretty_print_commit(&pp, commit, &buf);
2501                 strbuf_addch(&buf, '\n');
2502                 fputs(buf.buf, out);
2503         }
2504         strbuf_release(&buf);
2505         return 0;
2506 }
2507
2508 /*
2509  * Add commands after pick and (series of) squash/fixup commands
2510  * in the todo list.
2511  */
2512 int sequencer_add_exec_commands(const char *commands)
2513 {
2514         const char *todo_file = rebase_path_todo();
2515         struct todo_list todo_list = TODO_LIST_INIT;
2516         struct todo_item *item;
2517         struct strbuf *buf = &todo_list.buf;
2518         size_t offset = 0, commands_len = strlen(commands);
2519         int i, first;
2520
2521         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
2522                 return error(_("could not read '%s'."), todo_file);
2523
2524         if (parse_insn_buffer(todo_list.buf.buf, &todo_list)) {
2525                 todo_list_release(&todo_list);
2526                 return error(_("unusable todo list: '%s'"), todo_file);
2527         }
2528
2529         first = 1;
2530         /* insert <commands> before every pick except the first one */
2531         for (item = todo_list.items, i = 0; i < todo_list.nr; i++, item++) {
2532                 if (item->command == TODO_PICK && !first) {
2533                         strbuf_insert(buf, item->offset_in_buf + offset,
2534                                       commands, commands_len);
2535                         offset += commands_len;
2536                 }
2537                 first = 0;
2538         }
2539
2540         /* append final <commands> */
2541         strbuf_add(buf, commands, commands_len);
2542
2543         i = write_message(buf->buf, buf->len, todo_file, 0);
2544         todo_list_release(&todo_list);
2545         return i;
2546 }
2547
2548 int transform_todos(unsigned flags)
2549 {
2550         const char *todo_file = rebase_path_todo();
2551         struct todo_list todo_list = TODO_LIST_INIT;
2552         struct strbuf buf = STRBUF_INIT;
2553         struct todo_item *item;
2554         int i;
2555
2556         if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
2557                 return error(_("could not read '%s'."), todo_file);
2558
2559         if (parse_insn_buffer(todo_list.buf.buf, &todo_list)) {
2560                 todo_list_release(&todo_list);
2561                 return error(_("unusable todo list: '%s'"), todo_file);
2562         }
2563
2564         for (item = todo_list.items, i = 0; i < todo_list.nr; i++, item++) {
2565                 /* if the item is not a command write it and continue */
2566                 if (item->command >= TODO_COMMENT) {
2567                         strbuf_addf(&buf, "%.*s\n", item->arg_len, item->arg);
2568                         continue;
2569                 }
2570
2571                 /* add command to the buffer */
2572                 if (flags & TODO_LIST_ABBREVIATE_CMDS)
2573                         strbuf_addch(&buf, command_to_char(item->command));
2574                 else
2575                         strbuf_addstr(&buf, command_to_string(item->command));
2576
2577                 /* add commit id */
2578                 if (item->commit) {
2579                         const char *oid = flags & TODO_LIST_SHORTEN_IDS ?
2580                                           short_commit_name(item->commit) :
2581                                           oid_to_hex(&item->commit->object.oid);
2582
2583                         strbuf_addf(&buf, " %s", oid);
2584                 }
2585                 /* add all the rest */
2586                 strbuf_addf(&buf, " %.*s\n", item->arg_len, item->arg);
2587         }
2588
2589         i = write_message(buf.buf, buf.len, todo_file, 0);
2590         todo_list_release(&todo_list);
2591         return i;
2592 }
2593
2594 enum check_level {
2595         CHECK_IGNORE = 0, CHECK_WARN, CHECK_ERROR
2596 };
2597
2598 static enum check_level get_missing_commit_check_level(void)
2599 {
2600         const char *value;
2601
2602         if (git_config_get_value("rebase.missingcommitscheck", &value) ||
2603                         !strcasecmp("ignore", value))
2604                 return CHECK_IGNORE;
2605         if (!strcasecmp("warn", value))
2606                 return CHECK_WARN;
2607         if (!strcasecmp("error", value))
2608                 return CHECK_ERROR;
2609         warning(_("unrecognized setting %s for option "
2610                   "rebase.missingCommitsCheck. Ignoring."), value);
2611         return CHECK_IGNORE;
2612 }
2613
2614 /*
2615  * Check if the user dropped some commits by mistake
2616  * Behaviour determined by rebase.missingCommitsCheck.
2617  * Check if there is an unrecognized command or a
2618  * bad SHA-1 in a command.
2619  */
2620 int check_todo_list(void)
2621 {
2622         enum check_level check_level = get_missing_commit_check_level();
2623         struct strbuf todo_file = STRBUF_INIT;
2624         struct todo_list todo_list = TODO_LIST_INIT;
2625         struct strbuf missing = STRBUF_INIT;
2626         int advise_to_edit_todo = 0, res = 0, fd, i;
2627
2628         strbuf_addstr(&todo_file, rebase_path_todo());
2629         fd = open(todo_file.buf, O_RDONLY);
2630         if (fd < 0) {
2631                 res = error_errno(_("could not open '%s'"), todo_file.buf);
2632                 goto leave_check;
2633         }
2634         if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
2635                 close(fd);
2636                 res = error(_("could not read '%s'."), todo_file.buf);
2637                 goto leave_check;
2638         }
2639         close(fd);
2640         advise_to_edit_todo = res =
2641                 parse_insn_buffer(todo_list.buf.buf, &todo_list);
2642
2643         if (res || check_level == CHECK_IGNORE)
2644                 goto leave_check;
2645
2646         /* Mark the commits in git-rebase-todo as seen */
2647         for (i = 0; i < todo_list.nr; i++) {
2648                 struct commit *commit = todo_list.items[i].commit;
2649                 if (commit)
2650                         commit->util = (void *)1;
2651         }
2652
2653         todo_list_release(&todo_list);
2654         strbuf_addstr(&todo_file, ".backup");
2655         fd = open(todo_file.buf, O_RDONLY);
2656         if (fd < 0) {
2657                 res = error_errno(_("could not open '%s'"), todo_file.buf);
2658                 goto leave_check;
2659         }
2660         if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
2661                 close(fd);
2662                 res = error(_("could not read '%s'."), todo_file.buf);
2663                 goto leave_check;
2664         }
2665         close(fd);
2666         strbuf_release(&todo_file);
2667         res = !!parse_insn_buffer(todo_list.buf.buf, &todo_list);
2668
2669         /* Find commits in git-rebase-todo.backup yet unseen */
2670         for (i = todo_list.nr - 1; i >= 0; i--) {
2671                 struct todo_item *item = todo_list.items + i;
2672                 struct commit *commit = item->commit;
2673                 if (commit && !commit->util) {
2674                         strbuf_addf(&missing, " - %s %.*s\n",
2675                                     short_commit_name(commit),
2676                                     item->arg_len, item->arg);
2677                         commit->util = (void *)1;
2678                 }
2679         }
2680
2681         /* Warn about missing commits */
2682         if (!missing.len)
2683                 goto leave_check;
2684
2685         if (check_level == CHECK_ERROR)
2686                 advise_to_edit_todo = res = 1;
2687
2688         fprintf(stderr,
2689                 _("Warning: some commits may have been dropped accidentally.\n"
2690                 "Dropped commits (newer to older):\n"));
2691
2692         /* Make the list user-friendly and display */
2693         fputs(missing.buf, stderr);
2694         strbuf_release(&missing);
2695
2696         fprintf(stderr, _("To avoid this message, use \"drop\" to "
2697                 "explicitly remove a commit.\n\n"
2698                 "Use 'git config rebase.missingCommitsCheck' to change "
2699                 "the level of warnings.\n"
2700                 "The possible behaviours are: ignore, warn, error.\n\n"));
2701
2702 leave_check:
2703         strbuf_release(&todo_file);
2704         todo_list_release(&todo_list);
2705
2706         if (advise_to_edit_todo)
2707                 fprintf(stderr,
2708                         _("You can fix this with 'git rebase --edit-todo' "
2709                           "and then run 'git rebase --continue'.\n"
2710                           "Or you can abort the rebase with 'git rebase"
2711                           " --abort'.\n"));
2712
2713         return res;
2714 }
2715
2716 static int rewrite_file(const char *path, const char *buf, size_t len)
2717 {
2718         int rc = 0;
2719         int fd = open(path, O_WRONLY | O_TRUNC);
2720         if (fd < 0)
2721                 return error_errno(_("could not open '%s' for writing"), path);
2722         if (write_in_full(fd, buf, len) < 0)
2723                 rc = error_errno(_("could not write to '%s'"), path);
2724         if (close(fd) && !rc)
2725                 rc = error_errno(_("could not close '%s'"), path);
2726         return rc;
2727 }
2728
2729 /* skip picking commits whose parents are unchanged */
2730 int skip_unnecessary_picks(void)
2731 {
2732         const char *todo_file = rebase_path_todo();
2733         struct strbuf buf = STRBUF_INIT;
2734         struct todo_list todo_list = TODO_LIST_INIT;
2735         struct object_id onto_oid, *oid = &onto_oid, *parent_oid;
2736         int fd, i;
2737
2738         if (!read_oneliner(&buf, rebase_path_onto(), 0))
2739                 return error(_("could not read 'onto'"));
2740         if (get_oid(buf.buf, &onto_oid)) {
2741                 strbuf_release(&buf);
2742                 return error(_("need a HEAD to fixup"));
2743         }
2744         strbuf_release(&buf);
2745
2746         fd = open(todo_file, O_RDONLY);
2747         if (fd < 0) {
2748                 return error_errno(_("could not open '%s'"), todo_file);
2749         }
2750         if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
2751                 close(fd);
2752                 return error(_("could not read '%s'."), todo_file);
2753         }
2754         close(fd);
2755         if (parse_insn_buffer(todo_list.buf.buf, &todo_list) < 0) {
2756                 todo_list_release(&todo_list);
2757                 return -1;
2758         }
2759
2760         for (i = 0; i < todo_list.nr; i++) {
2761                 struct todo_item *item = todo_list.items + i;
2762
2763                 if (item->command >= TODO_NOOP)
2764                         continue;
2765                 if (item->command != TODO_PICK)
2766                         break;
2767                 if (parse_commit(item->commit)) {
2768                         todo_list_release(&todo_list);
2769                         return error(_("could not parse commit '%s'"),
2770                                 oid_to_hex(&item->commit->object.oid));
2771                 }
2772                 if (!item->commit->parents)
2773                         break; /* root commit */
2774                 if (item->commit->parents->next)
2775                         break; /* merge commit */
2776                 parent_oid = &item->commit->parents->item->object.oid;
2777                 if (hashcmp(parent_oid->hash, oid->hash))
2778                         break;
2779                 oid = &item->commit->object.oid;
2780         }
2781         if (i > 0) {
2782                 int offset = i < todo_list.nr ?
2783                         todo_list.items[i].offset_in_buf : todo_list.buf.len;
2784                 const char *done_path = rebase_path_done();
2785
2786                 fd = open(done_path, O_CREAT | O_WRONLY | O_APPEND, 0666);
2787                 if (fd < 0) {
2788                         error_errno(_("could not open '%s' for writing"),
2789                                     done_path);
2790                         todo_list_release(&todo_list);
2791                         return -1;
2792                 }
2793                 if (write_in_full(fd, todo_list.buf.buf, offset) < 0) {
2794                         error_errno(_("could not write to '%s'"), done_path);
2795                         todo_list_release(&todo_list);
2796                         close(fd);
2797                         return -1;
2798                 }
2799                 close(fd);
2800
2801                 if (rewrite_file(rebase_path_todo(), todo_list.buf.buf + offset,
2802                                  todo_list.buf.len - offset) < 0) {
2803                         todo_list_release(&todo_list);
2804                         return -1;
2805                 }
2806
2807                 todo_list.current = i;
2808                 if (is_fixup(peek_command(&todo_list, 0)))
2809                         record_in_rewritten(oid, peek_command(&todo_list, 0));
2810         }
2811
2812         todo_list_release(&todo_list);
2813         printf("%s\n", oid_to_hex(oid));
2814
2815         return 0;
2816 }
2817
2818 struct subject2item_entry {
2819         struct hashmap_entry entry;
2820         int i;
2821         char subject[FLEX_ARRAY];
2822 };
2823
2824 static int subject2item_cmp(const void *fndata,
2825                             const struct subject2item_entry *a,
2826                             const struct subject2item_entry *b, const void *key)
2827 {
2828         return key ? strcmp(a->subject, key) : strcmp(a->subject, b->subject);
2829 }
2830
2831 /*
2832  * Rearrange the todo list that has both "pick commit-id msg" and "pick
2833  * commit-id fixup!/squash! msg" in it so that the latter is put immediately
2834  * after the former, and change "pick" to "fixup"/"squash".
2835  *
2836  * Note that if the config has specified a custom instruction format, each log
2837  * message will have to be retrieved from the commit (as the oneline in the
2838  * script cannot be trusted) in order to normalize the autosquash arrangement.
2839  */
2840 int rearrange_squash(void)
2841 {
2842         const char *todo_file = rebase_path_todo();
2843         struct todo_list todo_list = TODO_LIST_INIT;
2844         struct hashmap subject2item;
2845         int res = 0, rearranged = 0, *next, *tail, fd, i;
2846         char **subjects;
2847
2848         fd = open(todo_file, O_RDONLY);
2849         if (fd < 0)
2850                 return error_errno(_("could not open '%s'"), todo_file);
2851         if (strbuf_read(&todo_list.buf, fd, 0) < 0) {
2852                 close(fd);
2853                 return error(_("could not read '%s'."), todo_file);
2854         }
2855         close(fd);
2856         if (parse_insn_buffer(todo_list.buf.buf, &todo_list) < 0) {
2857                 todo_list_release(&todo_list);
2858                 return -1;
2859         }
2860
2861         /*
2862          * The hashmap maps onelines to the respective todo list index.
2863          *
2864          * If any items need to be rearranged, the next[i] value will indicate
2865          * which item was moved directly after the i'th.
2866          *
2867          * In that case, last[i] will indicate the index of the latest item to
2868          * be moved to appear after the i'th.
2869          */
2870         hashmap_init(&subject2item, (hashmap_cmp_fn) subject2item_cmp,
2871                      NULL, todo_list.nr);
2872         ALLOC_ARRAY(next, todo_list.nr);
2873         ALLOC_ARRAY(tail, todo_list.nr);
2874         ALLOC_ARRAY(subjects, todo_list.nr);
2875         for (i = 0; i < todo_list.nr; i++) {
2876                 struct strbuf buf = STRBUF_INIT;
2877                 struct todo_item *item = todo_list.items + i;
2878                 const char *commit_buffer, *subject, *p;
2879                 size_t subject_len;
2880                 int i2 = -1;
2881                 struct subject2item_entry *entry;
2882
2883                 next[i] = tail[i] = -1;
2884                 if (item->command >= TODO_EXEC) {
2885                         subjects[i] = NULL;
2886                         continue;
2887                 }
2888
2889                 if (is_fixup(item->command)) {
2890                         todo_list_release(&todo_list);
2891                         return error(_("the script was already rearranged."));
2892                 }
2893
2894                 item->commit->util = item;
2895
2896                 parse_commit(item->commit);
2897                 commit_buffer = get_commit_buffer(item->commit, NULL);
2898                 find_commit_subject(commit_buffer, &subject);
2899                 format_subject(&buf, subject, " ");
2900                 subject = subjects[i] = strbuf_detach(&buf, &subject_len);
2901                 unuse_commit_buffer(item->commit, commit_buffer);
2902                 if ((skip_prefix(subject, "fixup! ", &p) ||
2903                      skip_prefix(subject, "squash! ", &p))) {
2904                         struct commit *commit2;
2905
2906                         for (;;) {
2907                                 while (isspace(*p))
2908                                         p++;
2909                                 if (!skip_prefix(p, "fixup! ", &p) &&
2910                                     !skip_prefix(p, "squash! ", &p))
2911                                         break;
2912                         }
2913
2914                         if ((entry = hashmap_get_from_hash(&subject2item,
2915                                                            strhash(p), p)))
2916                                 /* found by title */
2917                                 i2 = entry->i;
2918                         else if (!strchr(p, ' ') &&
2919                                  (commit2 =
2920                                   lookup_commit_reference_by_name(p)) &&
2921                                  commit2->util)
2922                                 /* found by commit name */
2923                                 i2 = (struct todo_item *)commit2->util
2924                                         - todo_list.items;
2925                         else {
2926                                 /* copy can be a prefix of the commit subject */
2927                                 for (i2 = 0; i2 < i; i2++)
2928                                         if (subjects[i2] &&
2929                                             starts_with(subjects[i2], p))
2930                                                 break;
2931                                 if (i2 == i)
2932                                         i2 = -1;
2933                         }
2934                 }
2935                 if (i2 >= 0) {
2936                         rearranged = 1;
2937                         todo_list.items[i].command =
2938                                 starts_with(subject, "fixup!") ?
2939                                 TODO_FIXUP : TODO_SQUASH;
2940                         if (next[i2] < 0)
2941                                 next[i2] = i;
2942                         else
2943                                 next[tail[i2]] = i;
2944                         tail[i2] = i;
2945                 } else if (!hashmap_get_from_hash(&subject2item,
2946                                                 strhash(subject), subject)) {
2947                         FLEX_ALLOC_MEM(entry, subject, subject, subject_len);
2948                         entry->i = i;
2949                         hashmap_entry_init(entry, strhash(entry->subject));
2950                         hashmap_put(&subject2item, entry);
2951                 }
2952         }
2953
2954         if (rearranged) {
2955                 struct strbuf buf = STRBUF_INIT;
2956
2957                 for (i = 0; i < todo_list.nr; i++) {
2958                         enum todo_command command = todo_list.items[i].command;
2959                         int cur = i;
2960
2961                         /*
2962                          * Initially, all commands are 'pick's. If it is a
2963                          * fixup or a squash now, we have rearranged it.
2964                          */
2965                         if (is_fixup(command))
2966                                 continue;
2967
2968                         while (cur >= 0) {
2969                                 int offset = todo_list.items[cur].offset_in_buf;
2970                                 int end_offset = cur + 1 < todo_list.nr ?
2971                                         todo_list.items[cur + 1].offset_in_buf :
2972                                         todo_list.buf.len;
2973                                 char *bol = todo_list.buf.buf + offset;
2974                                 char *eol = todo_list.buf.buf + end_offset;
2975
2976                                 /* replace 'pick', by 'fixup' or 'squash' */
2977                                 command = todo_list.items[cur].command;
2978                                 if (is_fixup(command)) {
2979                                         strbuf_addstr(&buf,
2980                                                 todo_command_info[command].str);
2981                                         bol += strcspn(bol, " \t");
2982                                 }
2983
2984                                 strbuf_add(&buf, bol, eol - bol);
2985
2986                                 cur = next[cur];
2987                         }
2988                 }
2989
2990                 res = rewrite_file(todo_file, buf.buf, buf.len);
2991                 strbuf_release(&buf);
2992         }
2993
2994         free(next);
2995         free(tail);
2996         for (i = 0; i < todo_list.nr; i++)
2997                 free(subjects[i]);
2998         free(subjects);
2999         hashmap_free(&subject2item, 1);
3000         todo_list_release(&todo_list);
3001
3002         return res;
3003 }