git-compat-util.h: xsize_t() - avoid -Wsign-compare warnings
[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
24 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
25
26 const char sign_off_header[] = "Signed-off-by: ";
27 static const char cherry_picked_prefix[] = "(cherry picked from commit ";
28
29 GIT_PATH_FUNC(git_path_seq_dir, "sequencer")
30
31 static GIT_PATH_FUNC(git_path_todo_file, "sequencer/todo")
32 static GIT_PATH_FUNC(git_path_opts_file, "sequencer/opts")
33 static GIT_PATH_FUNC(git_path_head_file, "sequencer/head")
34 static GIT_PATH_FUNC(git_path_abort_safety_file, "sequencer/abort-safety")
35
36 static GIT_PATH_FUNC(rebase_path, "rebase-merge")
37 /*
38  * The file containing rebase commands, comments, and empty lines.
39  * This file is created by "git rebase -i" then edited by the user. As
40  * the lines are processed, they are removed from the front of this
41  * file and written to the tail of 'done'.
42  */
43 static GIT_PATH_FUNC(rebase_path_todo, "rebase-merge/git-rebase-todo")
44 /*
45  * The rebase command lines that have already been processed. A line
46  * is moved here when it is first handled, before any associated user
47  * actions.
48  */
49 static GIT_PATH_FUNC(rebase_path_done, "rebase-merge/done")
50 /*
51  * The file to keep track of how many commands were already processed (e.g.
52  * for the prompt).
53  */
54 static GIT_PATH_FUNC(rebase_path_msgnum, "rebase-merge/msgnum");
55 /*
56  * The file to keep track of how many commands are to be processed in total
57  * (e.g. for the prompt).
58  */
59 static GIT_PATH_FUNC(rebase_path_msgtotal, "rebase-merge/end");
60 /*
61  * The commit message that is planned to be used for any changes that
62  * need to be committed following a user interaction.
63  */
64 static GIT_PATH_FUNC(rebase_path_message, "rebase-merge/message")
65 /*
66  * The file into which is accumulated the suggested commit message for
67  * squash/fixup commands. When the first of a series of squash/fixups
68  * is seen, the file is created and the commit message from the
69  * previous commit and from the first squash/fixup commit are written
70  * to it. The commit message for each subsequent squash/fixup commit
71  * is appended to the file as it is processed.
72  *
73  * The first line of the file is of the form
74  *     # This is a combination of $count commits.
75  * where $count is the number of commits whose messages have been
76  * written to the file so far (including the initial "pick" commit).
77  * Each time that a commit message is processed, this line is read and
78  * updated. It is deleted just before the combined commit is made.
79  */
80 static GIT_PATH_FUNC(rebase_path_squash_msg, "rebase-merge/message-squash")
81 /*
82  * If the current series of squash/fixups has not yet included a squash
83  * command, then this file exists and holds the commit message of the
84  * original "pick" commit.  (If the series ends without a "squash"
85  * command, then this can be used as the commit message of the combined
86  * commit without opening the editor.)
87  */
88 static GIT_PATH_FUNC(rebase_path_fixup_msg, "rebase-merge/message-fixup")
89 /*
90  * A script to set the GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
91  * GIT_AUTHOR_DATE that will be used for the commit that is currently
92  * being rebased.
93  */
94 static GIT_PATH_FUNC(rebase_path_author_script, "rebase-merge/author-script")
95 /*
96  * When an "edit" rebase command is being processed, the SHA1 of the
97  * commit to be edited is recorded in this file.  When "git rebase
98  * --continue" is executed, if there are any staged changes then they
99  * will be amended to the HEAD commit, but only provided the HEAD
100  * commit is still the commit to be edited.  When any other rebase
101  * command is processed, this file is deleted.
102  */
103 static GIT_PATH_FUNC(rebase_path_amend, "rebase-merge/amend")
104 /*
105  * When we stop at a given patch via the "edit" command, this file contains
106  * the abbreviated commit name of the corresponding patch.
107  */
108 static GIT_PATH_FUNC(rebase_path_stopped_sha, "rebase-merge/stopped-sha")
109 /*
110  * For the post-rewrite hook, we make a list of rewritten commits and
111  * their new sha1s.  The rewritten-pending list keeps the sha1s of
112  * commits that have been processed, but not committed yet,
113  * e.g. because they are waiting for a 'squash' command.
114  */
115 static GIT_PATH_FUNC(rebase_path_rewritten_list, "rebase-merge/rewritten-list")
116 static GIT_PATH_FUNC(rebase_path_rewritten_pending,
117         "rebase-merge/rewritten-pending")
118 /*
119  * The following files are written by git-rebase just after parsing the
120  * command-line (and are only consumed, not modified, by the sequencer).
121  */
122 static GIT_PATH_FUNC(rebase_path_gpg_sign_opt, "rebase-merge/gpg_sign_opt")
123 static GIT_PATH_FUNC(rebase_path_orig_head, "rebase-merge/orig-head")
124 static GIT_PATH_FUNC(rebase_path_verbose, "rebase-merge/verbose")
125 static GIT_PATH_FUNC(rebase_path_head_name, "rebase-merge/head-name")
126 static GIT_PATH_FUNC(rebase_path_onto, "rebase-merge/onto")
127 static GIT_PATH_FUNC(rebase_path_autostash, "rebase-merge/autostash")
128 static GIT_PATH_FUNC(rebase_path_strategy, "rebase-merge/strategy")
129 static GIT_PATH_FUNC(rebase_path_strategy_opts, "rebase-merge/strategy_opts")
130 static GIT_PATH_FUNC(rebase_path_allow_rerere_autoupdate, "rebase-merge/allow_rerere_autoupdate")
131
132 static inline int is_rebase_i(const struct replay_opts *opts)
133 {
134         return opts->action == REPLAY_INTERACTIVE_REBASE;
135 }
136
137 static const char *get_dir(const struct replay_opts *opts)
138 {
139         if (is_rebase_i(opts))
140                 return rebase_path();
141         return git_path_seq_dir();
142 }
143
144 static const char *get_todo_path(const struct replay_opts *opts)
145 {
146         if (is_rebase_i(opts))
147                 return rebase_path_todo();
148         return git_path_todo_file();
149 }
150
151 /*
152  * Returns 0 for non-conforming footer
153  * Returns 1 for conforming footer
154  * Returns 2 when sob exists within conforming footer
155  * Returns 3 when sob exists within conforming footer as last entry
156  */
157 static int has_conforming_footer(struct strbuf *sb, struct strbuf *sob,
158         int ignore_footer)
159 {
160         struct trailer_info info;
161         int i;
162         int found_sob = 0, found_sob_last = 0;
163
164         trailer_info_get(&info, sb->buf);
165
166         if (info.trailer_start == info.trailer_end)
167                 return 0;
168
169         for (i = 0; i < info.trailer_nr; i++)
170                 if (sob && !strncmp(info.trailers[i], sob->buf, sob->len)) {
171                         found_sob = 1;
172                         if (i == info.trailer_nr - 1)
173                                 found_sob_last = 1;
174                 }
175
176         trailer_info_release(&info);
177
178         if (found_sob_last)
179                 return 3;
180         if (found_sob)
181                 return 2;
182         return 1;
183 }
184
185 static const char *gpg_sign_opt_quoted(struct replay_opts *opts)
186 {
187         static struct strbuf buf = STRBUF_INIT;
188
189         strbuf_reset(&buf);
190         if (opts->gpg_sign)
191                 sq_quotef(&buf, "-S%s", opts->gpg_sign);
192         return buf.buf;
193 }
194
195 int sequencer_remove_state(struct replay_opts *opts)
196 {
197         struct strbuf dir = STRBUF_INIT;
198         int i;
199
200         free(opts->gpg_sign);
201         free(opts->strategy);
202         for (i = 0; i < opts->xopts_nr; i++)
203                 free(opts->xopts[i]);
204         free(opts->xopts);
205
206         strbuf_addf(&dir, "%s", get_dir(opts));
207         remove_dir_recursively(&dir, 0);
208         strbuf_release(&dir);
209
210         return 0;
211 }
212
213 static const char *action_name(const struct replay_opts *opts)
214 {
215         switch (opts->action) {
216         case REPLAY_REVERT:
217                 return N_("revert");
218         case REPLAY_PICK:
219                 return N_("cherry-pick");
220         case REPLAY_INTERACTIVE_REBASE:
221                 return N_("rebase -i");
222         }
223         die(_("Unknown action: %d"), opts->action);
224 }
225
226 struct commit_message {
227         char *parent_label;
228         char *label;
229         char *subject;
230         const char *message;
231 };
232
233 static const char *short_commit_name(struct commit *commit)
234 {
235         return find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV);
236 }
237
238 static int get_message(struct commit *commit, struct commit_message *out)
239 {
240         const char *abbrev, *subject;
241         int subject_len;
242
243         out->message = logmsg_reencode(commit, NULL, get_commit_output_encoding());
244         abbrev = short_commit_name(commit);
245
246         subject_len = find_commit_subject(out->message, &subject);
247
248         out->subject = xmemdupz(subject, subject_len);
249         out->label = xstrfmt("%s... %s", abbrev, out->subject);
250         out->parent_label = xstrfmt("parent of %s", out->label);
251
252         return 0;
253 }
254
255 static void free_message(struct commit *commit, struct commit_message *msg)
256 {
257         free(msg->parent_label);
258         free(msg->label);
259         free(msg->subject);
260         unuse_commit_buffer(commit, msg->message);
261 }
262
263 static void print_advice(int show_hint, struct replay_opts *opts)
264 {
265         char *msg = getenv("GIT_CHERRY_PICK_HELP");
266
267         if (msg) {
268                 fprintf(stderr, "%s\n", msg);
269                 /*
270                  * A conflict has occurred but the porcelain
271                  * (typically rebase --interactive) wants to take care
272                  * of the commit itself so remove CHERRY_PICK_HEAD
273                  */
274                 unlink(git_path_cherry_pick_head());
275                 return;
276         }
277
278         if (show_hint) {
279                 if (opts->no_commit)
280                         advise(_("after resolving the conflicts, mark the corrected paths\n"
281                                  "with 'git add <paths>' or 'git rm <paths>'"));
282                 else
283                         advise(_("after resolving the conflicts, mark the corrected paths\n"
284                                  "with 'git add <paths>' or 'git rm <paths>'\n"
285                                  "and commit the result with 'git commit'"));
286         }
287 }
288
289 static int write_message(const void *buf, size_t len, const char *filename,
290                          int append_eol)
291 {
292         static struct lock_file msg_file;
293
294         int msg_fd = hold_lock_file_for_update(&msg_file, filename, 0);
295         if (msg_fd < 0)
296                 return error_errno(_("could not lock '%s'"), filename);
297         if (write_in_full(msg_fd, buf, len) < 0) {
298                 rollback_lock_file(&msg_file);
299                 return error_errno(_("could not write to '%s'"), filename);
300         }
301         if (append_eol && write(msg_fd, "\n", 1) < 0) {
302                 rollback_lock_file(&msg_file);
303                 return error_errno(_("could not write eol to '%s'"), filename);
304         }
305         if (commit_lock_file(&msg_file) < 0) {
306                 rollback_lock_file(&msg_file);
307                 return error(_("failed to finalize '%s'."), filename);
308         }
309
310         return 0;
311 }
312
313 /*
314  * Reads a file that was presumably written by a shell script, i.e. with an
315  * end-of-line marker that needs to be stripped.
316  *
317  * Note that only the last end-of-line marker is stripped, consistent with the
318  * behavior of "$(cat path)" in a shell script.
319  *
320  * Returns 1 if the file was read, 0 if it could not be read or does not exist.
321  */
322 static int read_oneliner(struct strbuf *buf,
323         const char *path, int skip_if_empty)
324 {
325         int orig_len = buf->len;
326
327         if (!file_exists(path))
328                 return 0;
329
330         if (strbuf_read_file(buf, path, 0) < 0) {
331                 warning_errno(_("could not read '%s'"), path);
332                 return 0;
333         }
334
335         if (buf->len > orig_len && buf->buf[buf->len - 1] == '\n') {
336                 if (--buf->len > orig_len && buf->buf[buf->len - 1] == '\r')
337                         --buf->len;
338                 buf->buf[buf->len] = '\0';
339         }
340
341         if (skip_if_empty && buf->len == orig_len)
342                 return 0;
343
344         return 1;
345 }
346
347 static struct tree *empty_tree(void)
348 {
349         return lookup_tree(&empty_tree_oid);
350 }
351
352 static int error_dirty_index(struct replay_opts *opts)
353 {
354         if (read_cache_unmerged())
355                 return error_resolve_conflict(_(action_name(opts)));
356
357         error(_("your local changes would be overwritten by %s."),
358                 _(action_name(opts)));
359
360         if (advice_commit_before_merge)
361                 advise(_("commit your changes or stash them to proceed."));
362         return -1;
363 }
364
365 static void update_abort_safety_file(void)
366 {
367         struct object_id head;
368
369         /* Do nothing on a single-pick */
370         if (!file_exists(git_path_seq_dir()))
371                 return;
372
373         if (!get_oid("HEAD", &head))
374                 write_file(git_path_abort_safety_file(), "%s", oid_to_hex(&head));
375         else
376                 write_file(git_path_abort_safety_file(), "%s", "");
377 }
378
379 static int fast_forward_to(const struct object_id *to, const struct object_id *from,
380                         int unborn, struct replay_opts *opts)
381 {
382         struct ref_transaction *transaction;
383         struct strbuf sb = STRBUF_INIT;
384         struct strbuf err = STRBUF_INIT;
385
386         read_cache();
387         if (checkout_fast_forward(from, to, 1))
388                 return -1; /* the callee should have complained already */
389
390         strbuf_addf(&sb, _("%s: fast-forward"), _(action_name(opts)));
391
392         transaction = ref_transaction_begin(&err);
393         if (!transaction ||
394             ref_transaction_update(transaction, "HEAD",
395                                    to->hash, unborn ? null_sha1 : from->hash,
396                                    0, sb.buf, &err) ||
397             ref_transaction_commit(transaction, &err)) {
398                 ref_transaction_free(transaction);
399                 error("%s", err.buf);
400                 strbuf_release(&sb);
401                 strbuf_release(&err);
402                 return -1;
403         }
404
405         strbuf_release(&sb);
406         strbuf_release(&err);
407         ref_transaction_free(transaction);
408         update_abort_safety_file();
409         return 0;
410 }
411
412 void append_conflicts_hint(struct strbuf *msgbuf)
413 {
414         int i;
415
416         strbuf_addch(msgbuf, '\n');
417         strbuf_commented_addf(msgbuf, "Conflicts:\n");
418         for (i = 0; i < active_nr;) {
419                 const struct cache_entry *ce = active_cache[i++];
420                 if (ce_stage(ce)) {
421                         strbuf_commented_addf(msgbuf, "\t%s\n", ce->name);
422                         while (i < active_nr && !strcmp(ce->name,
423                                                         active_cache[i]->name))
424                                 i++;
425                 }
426         }
427 }
428
429 static int do_recursive_merge(struct commit *base, struct commit *next,
430                               const char *base_label, const char *next_label,
431                               struct object_id *head, struct strbuf *msgbuf,
432                               struct replay_opts *opts)
433 {
434         struct merge_options o;
435         struct tree *result, *next_tree, *base_tree, *head_tree;
436         int clean;
437         char **xopt;
438         static struct lock_file index_lock;
439
440         hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);
441
442         read_cache();
443
444         init_merge_options(&o);
445         o.ancestor = base ? base_label : "(empty tree)";
446         o.branch1 = "HEAD";
447         o.branch2 = next ? next_label : "(empty tree)";
448         if (is_rebase_i(opts))
449                 o.buffer_output = 2;
450
451         head_tree = parse_tree_indirect(head);
452         next_tree = next ? next->tree : empty_tree();
453         base_tree = base ? base->tree : empty_tree();
454
455         for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
456                 parse_merge_opt(&o, *xopt);
457
458         clean = merge_trees(&o,
459                             head_tree,
460                             next_tree, base_tree, &result);
461         if (is_rebase_i(opts) && clean <= 0)
462                 fputs(o.obuf.buf, stdout);
463         strbuf_release(&o.obuf);
464         if (clean < 0)
465                 return clean;
466
467         if (active_cache_changed &&
468             write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
469                 /*
470                  * TRANSLATORS: %s will be "revert", "cherry-pick" or
471                  * "rebase -i".
472                  */
473                 return error(_("%s: Unable to write new index file"),
474                         _(action_name(opts)));
475         rollback_lock_file(&index_lock);
476
477         if (opts->signoff)
478                 append_signoff(msgbuf, 0, 0);
479
480         if (!clean)
481                 append_conflicts_hint(msgbuf);
482
483         return !clean;
484 }
485
486 static int is_index_unchanged(void)
487 {
488         struct object_id head_oid;
489         struct commit *head_commit;
490
491         if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_oid.hash, NULL))
492                 return error(_("could not resolve HEAD commit\n"));
493
494         head_commit = lookup_commit(&head_oid);
495
496         /*
497          * If head_commit is NULL, check_commit, called from
498          * lookup_commit, would have indicated that head_commit is not
499          * a commit object already.  parse_commit() will return failure
500          * without further complaints in such a case.  Otherwise, if
501          * the commit is invalid, parse_commit() will complain.  So
502          * there is nothing for us to say here.  Just return failure.
503          */
504         if (parse_commit(head_commit))
505                 return -1;
506
507         if (!active_cache_tree)
508                 active_cache_tree = cache_tree();
509
510         if (!cache_tree_fully_valid(active_cache_tree))
511                 if (cache_tree_update(&the_index, 0))
512                         return error(_("unable to update cache tree\n"));
513
514         return !oidcmp(&active_cache_tree->oid,
515                        &head_commit->tree->object.oid);
516 }
517
518 static int write_author_script(const char *message)
519 {
520         struct strbuf buf = STRBUF_INIT;
521         const char *eol;
522         int res;
523
524         for (;;)
525                 if (!*message || starts_with(message, "\n")) {
526 missing_author:
527                         /* Missing 'author' line? */
528                         unlink(rebase_path_author_script());
529                         return 0;
530                 } else if (skip_prefix(message, "author ", &message))
531                         break;
532                 else if ((eol = strchr(message, '\n')))
533                         message = eol + 1;
534                 else
535                         goto missing_author;
536
537         strbuf_addstr(&buf, "GIT_AUTHOR_NAME='");
538         while (*message && *message != '\n' && *message != '\r')
539                 if (skip_prefix(message, " <", &message))
540                         break;
541                 else if (*message != '\'')
542                         strbuf_addch(&buf, *(message++));
543                 else
544                         strbuf_addf(&buf, "'\\\\%c'", *(message++));
545         strbuf_addstr(&buf, "'\nGIT_AUTHOR_EMAIL='");
546         while (*message && *message != '\n' && *message != '\r')
547                 if (skip_prefix(message, "> ", &message))
548                         break;
549                 else if (*message != '\'')
550                         strbuf_addch(&buf, *(message++));
551                 else
552                         strbuf_addf(&buf, "'\\\\%c'", *(message++));
553         strbuf_addstr(&buf, "'\nGIT_AUTHOR_DATE='@");
554         while (*message && *message != '\n' && *message != '\r')
555                 if (*message != '\'')
556                         strbuf_addch(&buf, *(message++));
557                 else
558                         strbuf_addf(&buf, "'\\\\%c'", *(message++));
559         res = write_message(buf.buf, buf.len, rebase_path_author_script(), 1);
560         strbuf_release(&buf);
561         return res;
562 }
563
564 /*
565  * Read a list of environment variable assignments (such as the author-script
566  * file) into an environment block. Returns -1 on error, 0 otherwise.
567  */
568 static int read_env_script(struct argv_array *env)
569 {
570         struct strbuf script = STRBUF_INIT;
571         int i, count = 0;
572         char *p, *p2;
573
574         if (strbuf_read_file(&script, rebase_path_author_script(), 256) <= 0)
575                 return -1;
576
577         for (p = script.buf; *p; p++)
578                 if (skip_prefix(p, "'\\\\''", (const char **)&p2))
579                         strbuf_splice(&script, p - script.buf, p2 - p, "'", 1);
580                 else if (*p == '\'')
581                         strbuf_splice(&script, p-- - script.buf, 1, "", 0);
582                 else if (*p == '\n') {
583                         *p = '\0';
584                         count++;
585                 }
586
587         for (i = 0, p = script.buf; i < count; i++) {
588                 argv_array_push(env, p);
589                 p += strlen(p) + 1;
590         }
591
592         return 0;
593 }
594
595 static const char staged_changes_advice[] =
596 N_("you have staged changes in your working tree\n"
597 "If these changes are meant to be squashed into the previous commit, run:\n"
598 "\n"
599 "  git commit --amend %s\n"
600 "\n"
601 "If they are meant to go into a new commit, run:\n"
602 "\n"
603 "  git commit %s\n"
604 "\n"
605 "In both cases, once you're done, continue with:\n"
606 "\n"
607 "  git rebase --continue\n");
608
609 #define ALLOW_EMPTY (1<<0)
610 #define EDIT_MSG    (1<<1)
611 #define AMEND_MSG   (1<<2)
612 #define CLEANUP_MSG (1<<3)
613 #define VERIFY_MSG  (1<<4)
614
615 /*
616  * If we are cherry-pick, and if the merge did not result in
617  * hand-editing, we will hit this commit and inherit the original
618  * author date and name.
619  *
620  * If we are revert, or if our cherry-pick results in a hand merge,
621  * we had better say that the current user is responsible for that.
622  *
623  * An exception is when run_git_commit() is called during an
624  * interactive rebase: in that case, we will want to retain the
625  * author metadata.
626  */
627 static int run_git_commit(const char *defmsg, struct replay_opts *opts,
628                           unsigned int flags)
629 {
630         struct child_process cmd = CHILD_PROCESS_INIT;
631         const char *value;
632
633         cmd.git_cmd = 1;
634
635         if (is_rebase_i(opts)) {
636                 if (!(flags & EDIT_MSG)) {
637                         cmd.stdout_to_stderr = 1;
638                         cmd.err = -1;
639                 }
640
641                 if (read_env_script(&cmd.env_array)) {
642                         const char *gpg_opt = gpg_sign_opt_quoted(opts);
643
644                         return error(_(staged_changes_advice),
645                                      gpg_opt, gpg_opt);
646                 }
647         }
648
649         argv_array_push(&cmd.args, "commit");
650
651         if (!(flags & VERIFY_MSG))
652                 argv_array_push(&cmd.args, "-n");
653         if ((flags & AMEND_MSG))
654                 argv_array_push(&cmd.args, "--amend");
655         if (opts->gpg_sign)
656                 argv_array_pushf(&cmd.args, "-S%s", opts->gpg_sign);
657         if (opts->signoff)
658                 argv_array_push(&cmd.args, "-s");
659         if (defmsg)
660                 argv_array_pushl(&cmd.args, "-F", defmsg, NULL);
661         if ((flags & CLEANUP_MSG))
662                 argv_array_push(&cmd.args, "--cleanup=strip");
663         if ((flags & EDIT_MSG))
664                 argv_array_push(&cmd.args, "-e");
665         else if (!(flags & CLEANUP_MSG) &&
666                  !opts->signoff && !opts->record_origin &&
667                  git_config_get_value("commit.cleanup", &value))
668                 argv_array_push(&cmd.args, "--cleanup=verbatim");
669
670         if ((flags & ALLOW_EMPTY))
671                 argv_array_push(&cmd.args, "--allow-empty");
672
673         if (opts->allow_empty_message)
674                 argv_array_push(&cmd.args, "--allow-empty-message");
675
676         if (cmd.err == -1) {
677                 /* hide stderr on success */
678                 struct strbuf buf = STRBUF_INIT;
679                 int rc = pipe_command(&cmd,
680                                       NULL, 0,
681                                       /* stdout is already redirected */
682                                       NULL, 0,
683                                       &buf, 0);
684                 if (rc)
685                         fputs(buf.buf, stderr);
686                 strbuf_release(&buf);
687                 return rc;
688         }
689
690         return run_command(&cmd);
691 }
692
693 static int is_original_commit_empty(struct commit *commit)
694 {
695         const unsigned char *ptree_sha1;
696
697         if (parse_commit(commit))
698                 return error(_("could not parse commit %s\n"),
699                              oid_to_hex(&commit->object.oid));
700         if (commit->parents) {
701                 struct commit *parent = commit->parents->item;
702                 if (parse_commit(parent))
703                         return error(_("could not parse parent commit %s\n"),
704                                 oid_to_hex(&parent->object.oid));
705                 ptree_sha1 = parent->tree->object.oid.hash;
706         } else {
707                 ptree_sha1 = EMPTY_TREE_SHA1_BIN; /* commit is root */
708         }
709
710         return !hashcmp(ptree_sha1, commit->tree->object.oid.hash);
711 }
712
713 /*
714  * Do we run "git commit" with "--allow-empty"?
715  */
716 static int allow_empty(struct replay_opts *opts, struct commit *commit)
717 {
718         int index_unchanged, empty_commit;
719
720         /*
721          * Three cases:
722          *
723          * (1) we do not allow empty at all and error out.
724          *
725          * (2) we allow ones that were initially empty, but
726          * forbid the ones that become empty;
727          *
728          * (3) we allow both.
729          */
730         if (!opts->allow_empty)
731                 return 0; /* let "git commit" barf as necessary */
732
733         index_unchanged = is_index_unchanged();
734         if (index_unchanged < 0)
735                 return index_unchanged;
736         if (!index_unchanged)
737                 return 0; /* we do not have to say --allow-empty */
738
739         if (opts->keep_redundant_commits)
740                 return 1;
741
742         empty_commit = is_original_commit_empty(commit);
743         if (empty_commit < 0)
744                 return empty_commit;
745         if (!empty_commit)
746                 return 0;
747         else
748                 return 1;
749 }
750
751 /*
752  * Note that ordering matters in this enum. Not only must it match the mapping
753  * below, it is also divided into several sections that matter.  When adding
754  * new commands, make sure you add it in the right section.
755  */
756 enum todo_command {
757         /* commands that handle commits */
758         TODO_PICK = 0,
759         TODO_REVERT,
760         TODO_EDIT,
761         TODO_REWORD,
762         TODO_FIXUP,
763         TODO_SQUASH,
764         /* commands that do something else than handling a single commit */
765         TODO_EXEC,
766         /* commands that do nothing but are counted for reporting progress */
767         TODO_NOOP,
768         TODO_DROP,
769         /* comments (not counted for reporting progress) */
770         TODO_COMMENT
771 };
772
773 static struct {
774         char c;
775         const char *str;
776 } todo_command_info[] = {
777         { 'p', "pick" },
778         { 0,   "revert" },
779         { 'e', "edit" },
780         { 'r', "reword" },
781         { 'f', "fixup" },
782         { 's', "squash" },
783         { 'x', "exec" },
784         { 0,   "noop" },
785         { 'd', "drop" },
786         { 0,   NULL }
787 };
788
789 static const char *command_to_string(const enum todo_command command)
790 {
791         if (command < TODO_COMMENT)
792                 return todo_command_info[command].str;
793         die("Unknown command: %d", command);
794 }
795
796 static int is_noop(const enum todo_command command)
797 {
798         return TODO_NOOP <= command;
799 }
800
801 static int is_fixup(enum todo_command command)
802 {
803         return command == TODO_FIXUP || command == TODO_SQUASH;
804 }
805
806 static int update_squash_messages(enum todo_command command,
807                 struct commit *commit, struct replay_opts *opts)
808 {
809         struct strbuf buf = STRBUF_INIT;
810         int count, res;
811         const char *message, *body;
812
813         if (file_exists(rebase_path_squash_msg())) {
814                 struct strbuf header = STRBUF_INIT;
815                 char *eol, *p;
816
817                 if (strbuf_read_file(&buf, rebase_path_squash_msg(), 2048) <= 0)
818                         return error(_("could not read '%s'"),
819                                 rebase_path_squash_msg());
820
821                 p = buf.buf + 1;
822                 eol = strchrnul(buf.buf, '\n');
823                 if (buf.buf[0] != comment_line_char ||
824                     (p += strcspn(p, "0123456789\n")) == eol)
825                         return error(_("unexpected 1st line of squash message:"
826                                        "\n\n\t%.*s"),
827                                      (int)(eol - buf.buf), buf.buf);
828                 count = strtol(p, NULL, 10);
829
830                 if (count < 1)
831                         return error(_("invalid 1st line of squash message:\n"
832                                        "\n\t%.*s"),
833                                      (int)(eol - buf.buf), buf.buf);
834
835                 strbuf_addf(&header, "%c ", comment_line_char);
836                 strbuf_addf(&header,
837                             _("This is a combination of %d commits."), ++count);
838                 strbuf_splice(&buf, 0, eol - buf.buf, header.buf, header.len);
839                 strbuf_release(&header);
840         } else {
841                 struct object_id head;
842                 struct commit *head_commit;
843                 const char *head_message, *body;
844
845                 if (get_oid("HEAD", &head))
846                         return error(_("need a HEAD to fixup"));
847                 if (!(head_commit = lookup_commit_reference(&head)))
848                         return error(_("could not read HEAD"));
849                 if (!(head_message = get_commit_buffer(head_commit, NULL)))
850                         return error(_("could not read HEAD's commit message"));
851
852                 find_commit_subject(head_message, &body);
853                 if (write_message(body, strlen(body),
854                                   rebase_path_fixup_msg(), 0)) {
855                         unuse_commit_buffer(head_commit, head_message);
856                         return error(_("cannot write '%s'"),
857                                      rebase_path_fixup_msg());
858                 }
859
860                 count = 2;
861                 strbuf_addf(&buf, "%c ", comment_line_char);
862                 strbuf_addf(&buf, _("This is a combination of %d commits."),
863                             count);
864                 strbuf_addf(&buf, "\n%c ", comment_line_char);
865                 strbuf_addstr(&buf, _("This is the 1st commit message:"));
866                 strbuf_addstr(&buf, "\n\n");
867                 strbuf_addstr(&buf, body);
868
869                 unuse_commit_buffer(head_commit, head_message);
870         }
871
872         if (!(message = get_commit_buffer(commit, NULL)))
873                 return error(_("could not read commit message of %s"),
874                              oid_to_hex(&commit->object.oid));
875         find_commit_subject(message, &body);
876
877         if (command == TODO_SQUASH) {
878                 unlink(rebase_path_fixup_msg());
879                 strbuf_addf(&buf, "\n%c ", comment_line_char);
880                 strbuf_addf(&buf, _("This is the commit message #%d:"), count);
881                 strbuf_addstr(&buf, "\n\n");
882                 strbuf_addstr(&buf, body);
883         } else if (command == TODO_FIXUP) {
884                 strbuf_addf(&buf, "\n%c ", comment_line_char);
885                 strbuf_addf(&buf, _("The commit message #%d will be skipped:"),
886                             count);
887                 strbuf_addstr(&buf, "\n\n");
888                 strbuf_add_commented_lines(&buf, body, strlen(body));
889         } else
890                 return error(_("unknown command: %d"), command);
891         unuse_commit_buffer(commit, message);
892
893         res = write_message(buf.buf, buf.len, rebase_path_squash_msg(), 0);
894         strbuf_release(&buf);
895         return res;
896 }
897
898 static void flush_rewritten_pending(void) {
899         struct strbuf buf = STRBUF_INIT;
900         unsigned char newsha1[20];
901         FILE *out;
902
903         if (strbuf_read_file(&buf, rebase_path_rewritten_pending(), 82) > 0 &&
904             !get_sha1("HEAD", newsha1) &&
905             (out = fopen_or_warn(rebase_path_rewritten_list(), "a"))) {
906                 char *bol = buf.buf, *eol;
907
908                 while (*bol) {
909                         eol = strchrnul(bol, '\n');
910                         fprintf(out, "%.*s %s\n", (int)(eol - bol),
911                                         bol, sha1_to_hex(newsha1));
912                         if (!*eol)
913                                 break;
914                         bol = eol + 1;
915                 }
916                 fclose(out);
917                 unlink(rebase_path_rewritten_pending());
918         }
919         strbuf_release(&buf);
920 }
921
922 static void record_in_rewritten(struct object_id *oid,
923                 enum todo_command next_command) {
924         FILE *out = fopen_or_warn(rebase_path_rewritten_pending(), "a");
925
926         if (!out)
927                 return;
928
929         fprintf(out, "%s\n", oid_to_hex(oid));
930         fclose(out);
931
932         if (!is_fixup(next_command))
933                 flush_rewritten_pending();
934 }
935
936 static int do_pick_commit(enum todo_command command, struct commit *commit,
937                 struct replay_opts *opts, int final_fixup)
938 {
939         unsigned int flags = opts->edit ? EDIT_MSG : 0;
940         const char *msg_file = opts->edit ? NULL : git_path_merge_msg();
941         struct object_id head;
942         struct commit *base, *next, *parent;
943         const char *base_label, *next_label;
944         struct commit_message msg = { NULL, NULL, NULL, NULL };
945         struct strbuf msgbuf = STRBUF_INIT;
946         int res, unborn = 0, allow;
947
948         if (opts->no_commit) {
949                 /*
950                  * We do not intend to commit immediately.  We just want to
951                  * merge the differences in, so let's compute the tree
952                  * that represents the "current" state for merge-recursive
953                  * to work on.
954                  */
955                 if (write_cache_as_tree(head.hash, 0, NULL))
956                         return error(_("your index file is unmerged."));
957         } else {
958                 unborn = get_oid("HEAD", &head);
959                 if (unborn)
960                         oidcpy(&head, &empty_tree_oid);
961                 if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0, 0))
962                         return error_dirty_index(opts);
963         }
964         discard_cache();
965
966         if (!commit->parents)
967                 parent = NULL;
968         else if (commit->parents->next) {
969                 /* Reverting or cherry-picking a merge commit */
970                 int cnt;
971                 struct commit_list *p;
972
973                 if (!opts->mainline)
974                         return error(_("commit %s is a merge but no -m option was given."),
975                                 oid_to_hex(&commit->object.oid));
976
977                 for (cnt = 1, p = commit->parents;
978                      cnt != opts->mainline && p;
979                      cnt++)
980                         p = p->next;
981                 if (cnt != opts->mainline || !p)
982                         return error(_("commit %s does not have parent %d"),
983                                 oid_to_hex(&commit->object.oid), opts->mainline);
984                 parent = p->item;
985         } else if (0 < opts->mainline)
986                 return error(_("mainline was specified but commit %s is not a merge."),
987                         oid_to_hex(&commit->object.oid));
988         else
989                 parent = commit->parents->item;
990
991         if (get_message(commit, &msg) != 0)
992                 return error(_("cannot get commit message for %s"),
993                         oid_to_hex(&commit->object.oid));
994
995         if (opts->allow_ff && !is_fixup(command) &&
996             ((parent && !oidcmp(&parent->object.oid, &head)) ||
997              (!parent && unborn))) {
998                 if (is_rebase_i(opts))
999                         write_author_script(msg.message);
1000                 res = fast_forward_to(&commit->object.oid, &head, unborn,
1001                         opts);
1002                 if (res || command != TODO_REWORD)
1003                         goto leave;
1004                 flags |= EDIT_MSG | AMEND_MSG;
1005                 if (command == TODO_REWORD)
1006                         flags |= VERIFY_MSG;
1007                 msg_file = NULL;
1008                 goto fast_forward_edit;
1009         }
1010         if (parent && parse_commit(parent) < 0)
1011                 /* TRANSLATORS: The first %s will be a "todo" command like
1012                    "revert" or "pick", the second %s a SHA1. */
1013                 return error(_("%s: cannot parse parent commit %s"),
1014                         command_to_string(command),
1015                         oid_to_hex(&parent->object.oid));
1016
1017         /*
1018          * "commit" is an existing commit.  We would want to apply
1019          * the difference it introduces since its first parent "prev"
1020          * on top of the current HEAD if we are cherry-pick.  Or the
1021          * reverse of it if we are revert.
1022          */
1023
1024         if (command == TODO_REVERT) {
1025                 base = commit;
1026                 base_label = msg.label;
1027                 next = parent;
1028                 next_label = msg.parent_label;
1029                 strbuf_addstr(&msgbuf, "Revert \"");
1030                 strbuf_addstr(&msgbuf, msg.subject);
1031                 strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
1032                 strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
1033
1034                 if (commit->parents && commit->parents->next) {
1035                         strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
1036                         strbuf_addstr(&msgbuf, oid_to_hex(&parent->object.oid));
1037                 }
1038                 strbuf_addstr(&msgbuf, ".\n");
1039         } else {
1040                 const char *p;
1041
1042                 base = parent;
1043                 base_label = msg.parent_label;
1044                 next = commit;
1045                 next_label = msg.label;
1046
1047                 /* Append the commit log message to msgbuf. */
1048                 if (find_commit_subject(msg.message, &p))
1049                         strbuf_addstr(&msgbuf, p);
1050
1051                 if (opts->record_origin) {
1052                         strbuf_complete_line(&msgbuf);
1053                         if (!has_conforming_footer(&msgbuf, NULL, 0))
1054                                 strbuf_addch(&msgbuf, '\n');
1055                         strbuf_addstr(&msgbuf, cherry_picked_prefix);
1056                         strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
1057                         strbuf_addstr(&msgbuf, ")\n");
1058                 }
1059         }
1060
1061         if (command == TODO_REWORD)
1062                 flags |= EDIT_MSG | VERIFY_MSG;
1063         else if (is_fixup(command)) {
1064                 if (update_squash_messages(command, commit, opts))
1065                         return -1;
1066                 flags |= AMEND_MSG;
1067                 if (!final_fixup)
1068                         msg_file = rebase_path_squash_msg();
1069                 else if (file_exists(rebase_path_fixup_msg())) {
1070                         flags |= CLEANUP_MSG;
1071                         msg_file = rebase_path_fixup_msg();
1072                 } else {
1073                         const char *dest = git_path_squash_msg();
1074                         unlink(dest);
1075                         if (copy_file(dest, rebase_path_squash_msg(), 0666))
1076                                 return error(_("could not rename '%s' to '%s'"),
1077                                              rebase_path_squash_msg(), dest);
1078                         unlink(git_path_merge_msg());
1079                         msg_file = dest;
1080                         flags |= EDIT_MSG;
1081                 }
1082         }
1083
1084         if (is_rebase_i(opts) && write_author_script(msg.message) < 0)
1085                 res = -1;
1086         else if (!opts->strategy || !strcmp(opts->strategy, "recursive") || command == TODO_REVERT) {
1087                 res = do_recursive_merge(base, next, base_label, next_label,
1088                                          &head, &msgbuf, opts);
1089                 if (res < 0)
1090                         return res;
1091                 res |= write_message(msgbuf.buf, msgbuf.len,
1092                                      git_path_merge_msg(), 0);
1093         } else {
1094                 struct commit_list *common = NULL;
1095                 struct commit_list *remotes = NULL;
1096
1097                 res = write_message(msgbuf.buf, msgbuf.len,
1098                                     git_path_merge_msg(), 0);
1099
1100                 commit_list_insert(base, &common);
1101                 commit_list_insert(next, &remotes);
1102                 res |= try_merge_command(opts->strategy,
1103                                          opts->xopts_nr, (const char **)opts->xopts,
1104                                         common, oid_to_hex(&head), remotes);
1105                 free_commit_list(common);
1106                 free_commit_list(remotes);
1107         }
1108         strbuf_release(&msgbuf);
1109
1110         /*
1111          * If the merge was clean or if it failed due to conflict, we write
1112          * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
1113          * However, if the merge did not even start, then we don't want to
1114          * write it at all.
1115          */
1116         if (command == TODO_PICK && !opts->no_commit && (res == 0 || res == 1) &&
1117             update_ref(NULL, "CHERRY_PICK_HEAD", commit->object.oid.hash, NULL,
1118                        REF_NODEREF, UPDATE_REFS_MSG_ON_ERR))
1119                 res = -1;
1120         if (command == TODO_REVERT && ((opts->no_commit && res == 0) || res == 1) &&
1121             update_ref(NULL, "REVERT_HEAD", commit->object.oid.hash, NULL,
1122                        REF_NODEREF, UPDATE_REFS_MSG_ON_ERR))
1123                 res = -1;
1124
1125         if (res) {
1126                 error(command == TODO_REVERT
1127                       ? _("could not revert %s... %s")
1128                       : _("could not apply %s... %s"),
1129                       short_commit_name(commit), msg.subject);
1130                 print_advice(res == 1, opts);
1131                 rerere(opts->allow_rerere_auto);
1132                 goto leave;
1133         }
1134
1135         allow = allow_empty(opts, commit);
1136         if (allow < 0) {
1137                 res = allow;
1138                 goto leave;
1139         } else if (allow)
1140                 flags |= ALLOW_EMPTY;
1141         if (!opts->no_commit)
1142 fast_forward_edit:
1143                 res = run_git_commit(msg_file, opts, flags);
1144
1145         if (!res && final_fixup) {
1146                 unlink(rebase_path_fixup_msg());
1147                 unlink(rebase_path_squash_msg());
1148         }
1149
1150 leave:
1151         free_message(commit, &msg);
1152         update_abort_safety_file();
1153
1154         return res;
1155 }
1156
1157 static int prepare_revs(struct replay_opts *opts)
1158 {
1159         /*
1160          * picking (but not reverting) ranges (but not individual revisions)
1161          * should be done in reverse
1162          */
1163         if (opts->action == REPLAY_PICK && !opts->revs->no_walk)
1164                 opts->revs->reverse ^= 1;
1165
1166         if (prepare_revision_walk(opts->revs))
1167                 return error(_("revision walk setup failed"));
1168
1169         if (!opts->revs->commits)
1170                 return error(_("empty commit set passed"));
1171         return 0;
1172 }
1173
1174 static int read_and_refresh_cache(struct replay_opts *opts)
1175 {
1176         static struct lock_file index_lock;
1177         int index_fd = hold_locked_index(&index_lock, 0);
1178         if (read_index_preload(&the_index, NULL) < 0) {
1179                 rollback_lock_file(&index_lock);
1180                 return error(_("git %s: failed to read the index"),
1181                         _(action_name(opts)));
1182         }
1183         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
1184         if (the_index.cache_changed && index_fd >= 0) {
1185                 if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK)) {
1186                         rollback_lock_file(&index_lock);
1187                         return error(_("git %s: failed to refresh the index"),
1188                                 _(action_name(opts)));
1189                 }
1190         }
1191         rollback_lock_file(&index_lock);
1192         return 0;
1193 }
1194
1195 struct todo_item {
1196         enum todo_command command;
1197         struct commit *commit;
1198         const char *arg;
1199         int arg_len;
1200         size_t offset_in_buf;
1201 };
1202
1203 struct todo_list {
1204         struct strbuf buf;
1205         struct todo_item *items;
1206         int nr, alloc, current;
1207         int done_nr, total_nr;
1208         struct stat_data stat;
1209 };
1210
1211 #define TODO_LIST_INIT { STRBUF_INIT }
1212
1213 static void todo_list_release(struct todo_list *todo_list)
1214 {
1215         strbuf_release(&todo_list->buf);
1216         FREE_AND_NULL(todo_list->items);
1217         todo_list->nr = todo_list->alloc = 0;
1218 }
1219
1220 static struct todo_item *append_new_todo(struct todo_list *todo_list)
1221 {
1222         ALLOC_GROW(todo_list->items, todo_list->nr + 1, todo_list->alloc);
1223         return todo_list->items + todo_list->nr++;
1224 }
1225
1226 static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
1227 {
1228         struct object_id commit_oid;
1229         char *end_of_object_name;
1230         int i, saved, status, padding;
1231
1232         /* left-trim */
1233         bol += strspn(bol, " \t");
1234
1235         if (bol == eol || *bol == '\r' || *bol == comment_line_char) {
1236                 item->command = TODO_COMMENT;
1237                 item->commit = NULL;
1238                 item->arg = bol;
1239                 item->arg_len = eol - bol;
1240                 return 0;
1241         }
1242
1243         for (i = 0; i < TODO_COMMENT; i++)
1244                 if (skip_prefix(bol, todo_command_info[i].str, &bol)) {
1245                         item->command = i;
1246                         break;
1247                 } else if (bol[1] == ' ' && *bol == todo_command_info[i].c) {
1248                         bol++;
1249                         item->command = i;
1250                         break;
1251                 }
1252         if (i >= TODO_COMMENT)
1253                 return -1;
1254
1255         if (item->command == TODO_NOOP) {
1256                 item->commit = NULL;
1257                 item->arg = bol;
1258                 item->arg_len = eol - bol;
1259                 return 0;
1260         }
1261
1262         /* Eat up extra spaces/ tabs before object name */
1263         padding = strspn(bol, " \t");
1264         if (!padding)
1265                 return -1;
1266         bol += padding;
1267
1268         if (item->command == TODO_EXEC) {
1269                 item->arg = bol;
1270                 item->arg_len = (int)(eol - bol);
1271                 return 0;
1272         }
1273
1274         end_of_object_name = (char *) bol + strcspn(bol, " \t\n");
1275         saved = *end_of_object_name;
1276         *end_of_object_name = '\0';
1277         status = get_oid(bol, &commit_oid);
1278         *end_of_object_name = saved;
1279
1280         item->arg = end_of_object_name + strspn(end_of_object_name, " \t");
1281         item->arg_len = (int)(eol - item->arg);
1282
1283         if (status < 0)
1284                 return -1;
1285
1286         item->commit = lookup_commit_reference(&commit_oid);
1287         return !item->commit;
1288 }
1289
1290 static int parse_insn_buffer(char *buf, struct todo_list *todo_list)
1291 {
1292         struct todo_item *item;
1293         char *p = buf, *next_p;
1294         int i, res = 0, fixup_okay = file_exists(rebase_path_done());
1295
1296         for (i = 1; *p; i++, p = next_p) {
1297                 char *eol = strchrnul(p, '\n');
1298
1299                 next_p = *eol ? eol + 1 /* skip LF */ : eol;
1300
1301                 if (p != eol && eol[-1] == '\r')
1302                         eol--; /* strip Carriage Return */
1303
1304                 item = append_new_todo(todo_list);
1305                 item->offset_in_buf = p - todo_list->buf.buf;
1306                 if (parse_insn_line(item, p, eol)) {
1307                         res = error(_("invalid line %d: %.*s"),
1308                                 i, (int)(eol - p), p);
1309                         item->command = TODO_NOOP;
1310                 }
1311
1312                 if (fixup_okay)
1313                         ; /* do nothing */
1314                 else if (is_fixup(item->command))
1315                         return error(_("cannot '%s' without a previous commit"),
1316                                 command_to_string(item->command));
1317                 else if (!is_noop(item->command))
1318                         fixup_okay = 1;
1319         }
1320
1321         return res;
1322 }
1323
1324 static int count_commands(struct todo_list *todo_list)
1325 {
1326         int count = 0, i;
1327
1328         for (i = 0; i < todo_list->nr; i++)
1329                 if (todo_list->items[i].command != TODO_COMMENT)
1330                         count++;
1331
1332         return count;
1333 }
1334
1335 static int read_populate_todo(struct todo_list *todo_list,
1336                         struct replay_opts *opts)
1337 {
1338         struct stat st;
1339         const char *todo_file = get_todo_path(opts);
1340         int fd, res;
1341
1342         strbuf_reset(&todo_list->buf);
1343         fd = open(todo_file, O_RDONLY);
1344         if (fd < 0)
1345                 return error_errno(_("could not open '%s'"), todo_file);
1346         if (strbuf_read(&todo_list->buf, fd, 0) < 0) {
1347                 close(fd);
1348                 return error(_("could not read '%s'."), todo_file);
1349         }
1350         close(fd);
1351
1352         res = stat(todo_file, &st);
1353         if (res)
1354                 return error(_("could not stat '%s'"), todo_file);
1355         fill_stat_data(&todo_list->stat, &st);
1356
1357         res = parse_insn_buffer(todo_list->buf.buf, todo_list);
1358         if (res) {
1359                 if (is_rebase_i(opts))
1360                         return error(_("please fix this using "
1361                                        "'git rebase --edit-todo'."));
1362                 return error(_("unusable instruction sheet: '%s'"), todo_file);
1363         }
1364
1365         if (!todo_list->nr &&
1366             (!is_rebase_i(opts) || !file_exists(rebase_path_done())))
1367                 return error(_("no commits parsed."));
1368
1369         if (!is_rebase_i(opts)) {
1370                 enum todo_command valid =
1371                         opts->action == REPLAY_PICK ? TODO_PICK : TODO_REVERT;
1372                 int i;
1373
1374                 for (i = 0; i < todo_list->nr; i++)
1375                         if (valid == todo_list->items[i].command)
1376                                 continue;
1377                         else if (valid == TODO_PICK)
1378                                 return error(_("cannot cherry-pick during a revert."));
1379                         else
1380                                 return error(_("cannot revert during a cherry-pick."));
1381         }
1382
1383         if (is_rebase_i(opts)) {
1384                 struct todo_list done = TODO_LIST_INIT;
1385                 FILE *f = fopen_or_warn(rebase_path_msgtotal(), "w");
1386
1387                 if (strbuf_read_file(&done.buf, rebase_path_done(), 0) > 0 &&
1388                                 !parse_insn_buffer(done.buf.buf, &done))
1389                         todo_list->done_nr = count_commands(&done);
1390                 else
1391                         todo_list->done_nr = 0;
1392
1393                 todo_list->total_nr = todo_list->done_nr
1394                         + count_commands(todo_list);
1395                 todo_list_release(&done);
1396
1397                 if (f) {
1398                         fprintf(f, "%d\n", todo_list->total_nr);
1399                         fclose(f);
1400                 }
1401         }
1402
1403         return 0;
1404 }
1405
1406 static int git_config_string_dup(char **dest,
1407                                  const char *var, const char *value)
1408 {
1409         if (!value)
1410                 return config_error_nonbool(var);
1411         free(*dest);
1412         *dest = xstrdup(value);
1413         return 0;
1414 }
1415
1416 static int populate_opts_cb(const char *key, const char *value, void *data)
1417 {
1418         struct replay_opts *opts = data;
1419         int error_flag = 1;
1420
1421         if (!value)
1422                 error_flag = 0;
1423         else if (!strcmp(key, "options.no-commit"))
1424                 opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
1425         else if (!strcmp(key, "options.edit"))
1426                 opts->edit = git_config_bool_or_int(key, value, &error_flag);
1427         else if (!strcmp(key, "options.signoff"))
1428                 opts->signoff = git_config_bool_or_int(key, value, &error_flag);
1429         else if (!strcmp(key, "options.record-origin"))
1430                 opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
1431         else if (!strcmp(key, "options.allow-ff"))
1432                 opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
1433         else if (!strcmp(key, "options.mainline"))
1434                 opts->mainline = git_config_int(key, value);
1435         else if (!strcmp(key, "options.strategy"))
1436                 git_config_string_dup(&opts->strategy, key, value);
1437         else if (!strcmp(key, "options.gpg-sign"))
1438                 git_config_string_dup(&opts->gpg_sign, key, value);
1439         else if (!strcmp(key, "options.strategy-option")) {
1440                 ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
1441                 opts->xopts[opts->xopts_nr++] = xstrdup(value);
1442         } else if (!strcmp(key, "options.allow-rerere-auto"))
1443                 opts->allow_rerere_auto =
1444                         git_config_bool_or_int(key, value, &error_flag) ?
1445                                 RERERE_AUTOUPDATE : RERERE_NOAUTOUPDATE;
1446         else
1447                 return error(_("invalid key: %s"), key);
1448
1449         if (!error_flag)
1450                 return error(_("invalid value for %s: %s"), key, value);
1451
1452         return 0;
1453 }
1454
1455 static void read_strategy_opts(struct replay_opts *opts, struct strbuf *buf)
1456 {
1457         int i;
1458
1459         strbuf_reset(buf);
1460         if (!read_oneliner(buf, rebase_path_strategy(), 0))
1461                 return;
1462         opts->strategy = strbuf_detach(buf, NULL);
1463         if (!read_oneliner(buf, rebase_path_strategy_opts(), 0))
1464                 return;
1465
1466         opts->xopts_nr = split_cmdline(buf->buf, (const char ***)&opts->xopts);
1467         for (i = 0; i < opts->xopts_nr; i++) {
1468                 const char *arg = opts->xopts[i];
1469
1470                 skip_prefix(arg, "--", &arg);
1471                 opts->xopts[i] = xstrdup(arg);
1472         }
1473 }
1474
1475 static int read_populate_opts(struct replay_opts *opts)
1476 {
1477         if (is_rebase_i(opts)) {
1478                 struct strbuf buf = STRBUF_INIT;
1479
1480                 if (read_oneliner(&buf, rebase_path_gpg_sign_opt(), 1)) {
1481                         if (!starts_with(buf.buf, "-S"))
1482                                 strbuf_reset(&buf);
1483                         else {
1484                                 free(opts->gpg_sign);
1485                                 opts->gpg_sign = xstrdup(buf.buf + 2);
1486                         }
1487                         strbuf_reset(&buf);
1488                 }
1489
1490                 if (read_oneliner(&buf, rebase_path_allow_rerere_autoupdate(), 1)) {
1491                         if (!strcmp(buf.buf, "--rerere-autoupdate"))
1492                                 opts->allow_rerere_auto = RERERE_AUTOUPDATE;
1493                         else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
1494                                 opts->allow_rerere_auto = RERERE_NOAUTOUPDATE;
1495                         strbuf_reset(&buf);
1496                 }
1497
1498                 if (file_exists(rebase_path_verbose()))
1499                         opts->verbose = 1;
1500
1501                 read_strategy_opts(opts, &buf);
1502                 strbuf_release(&buf);
1503
1504                 return 0;
1505         }
1506
1507         if (!file_exists(git_path_opts_file()))
1508                 return 0;
1509         /*
1510          * The function git_parse_source(), called from git_config_from_file(),
1511          * may die() in case of a syntactically incorrect file. We do not care
1512          * about this case, though, because we wrote that file ourselves, so we
1513          * are pretty certain that it is syntactically correct.
1514          */
1515         if (git_config_from_file(populate_opts_cb, git_path_opts_file(), opts) < 0)
1516                 return error(_("malformed options sheet: '%s'"),
1517                         git_path_opts_file());
1518         return 0;
1519 }
1520
1521 static int walk_revs_populate_todo(struct todo_list *todo_list,
1522                                 struct replay_opts *opts)
1523 {
1524         enum todo_command command = opts->action == REPLAY_PICK ?
1525                 TODO_PICK : TODO_REVERT;
1526         const char *command_string = todo_command_info[command].str;
1527         struct commit *commit;
1528
1529         if (prepare_revs(opts))
1530                 return -1;
1531
1532         while ((commit = get_revision(opts->revs))) {
1533                 struct todo_item *item = append_new_todo(todo_list);
1534                 const char *commit_buffer = get_commit_buffer(commit, NULL);
1535                 const char *subject;
1536                 int subject_len;
1537
1538                 item->command = command;
1539                 item->commit = commit;
1540                 item->arg = NULL;
1541                 item->arg_len = 0;
1542                 item->offset_in_buf = todo_list->buf.len;
1543                 subject_len = find_commit_subject(commit_buffer, &subject);
1544                 strbuf_addf(&todo_list->buf, "%s %s %.*s\n", command_string,
1545                         short_commit_name(commit), subject_len, subject);
1546                 unuse_commit_buffer(commit, commit_buffer);
1547         }
1548         return 0;
1549 }
1550
1551 static int create_seq_dir(void)
1552 {
1553         if (file_exists(git_path_seq_dir())) {
1554                 error(_("a cherry-pick or revert is already in progress"));
1555                 advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
1556                 return -1;
1557         } else if (mkdir(git_path_seq_dir(), 0777) < 0)
1558                 return error_errno(_("could not create sequencer directory '%s'"),
1559                                    git_path_seq_dir());
1560         return 0;
1561 }
1562
1563 static int save_head(const char *head)
1564 {
1565         static struct lock_file head_lock;
1566         struct strbuf buf = STRBUF_INIT;
1567         int fd;
1568
1569         fd = hold_lock_file_for_update(&head_lock, git_path_head_file(), 0);
1570         if (fd < 0) {
1571                 rollback_lock_file(&head_lock);
1572                 return error_errno(_("could not lock HEAD"));
1573         }
1574         strbuf_addf(&buf, "%s\n", head);
1575         if (write_in_full(fd, buf.buf, buf.len) < 0) {
1576                 rollback_lock_file(&head_lock);
1577                 return error_errno(_("could not write to '%s'"),
1578                                    git_path_head_file());
1579         }
1580         if (commit_lock_file(&head_lock) < 0) {
1581                 rollback_lock_file(&head_lock);
1582                 return error(_("failed to finalize '%s'."), git_path_head_file());
1583         }
1584         return 0;
1585 }
1586
1587 static int rollback_is_safe(void)
1588 {
1589         struct strbuf sb = STRBUF_INIT;
1590         struct object_id expected_head, actual_head;
1591
1592         if (strbuf_read_file(&sb, git_path_abort_safety_file(), 0) >= 0) {
1593                 strbuf_trim(&sb);
1594                 if (get_oid_hex(sb.buf, &expected_head)) {
1595                         strbuf_release(&sb);
1596                         die(_("could not parse %s"), git_path_abort_safety_file());
1597                 }
1598                 strbuf_release(&sb);
1599         }
1600         else if (errno == ENOENT)
1601                 oidclr(&expected_head);
1602         else
1603                 die_errno(_("could not read '%s'"), git_path_abort_safety_file());
1604
1605         if (get_oid("HEAD", &actual_head))
1606                 oidclr(&actual_head);
1607
1608         return !oidcmp(&actual_head, &expected_head);
1609 }
1610
1611 static int reset_for_rollback(const unsigned char *sha1)
1612 {
1613         const char *argv[4];    /* reset --merge <arg> + NULL */
1614
1615         argv[0] = "reset";
1616         argv[1] = "--merge";
1617         argv[2] = sha1_to_hex(sha1);
1618         argv[3] = NULL;
1619         return run_command_v_opt(argv, RUN_GIT_CMD);
1620 }
1621
1622 static int rollback_single_pick(void)
1623 {
1624         unsigned char head_sha1[20];
1625
1626         if (!file_exists(git_path_cherry_pick_head()) &&
1627             !file_exists(git_path_revert_head()))
1628                 return error(_("no cherry-pick or revert in progress"));
1629         if (read_ref_full("HEAD", 0, head_sha1, NULL))
1630                 return error(_("cannot resolve HEAD"));
1631         if (is_null_sha1(head_sha1))
1632                 return error(_("cannot abort from a branch yet to be born"));
1633         return reset_for_rollback(head_sha1);
1634 }
1635
1636 int sequencer_rollback(struct replay_opts *opts)
1637 {
1638         FILE *f;
1639         unsigned char sha1[20];
1640         struct strbuf buf = STRBUF_INIT;
1641
1642         f = fopen(git_path_head_file(), "r");
1643         if (!f && errno == ENOENT) {
1644                 /*
1645                  * There is no multiple-cherry-pick in progress.
1646                  * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
1647                  * a single-cherry-pick in progress, abort that.
1648                  */
1649                 return rollback_single_pick();
1650         }
1651         if (!f)
1652                 return error_errno(_("cannot open '%s'"), git_path_head_file());
1653         if (strbuf_getline_lf(&buf, f)) {
1654                 error(_("cannot read '%s': %s"), git_path_head_file(),
1655                       ferror(f) ?  strerror(errno) : _("unexpected end of file"));
1656                 fclose(f);
1657                 goto fail;
1658         }
1659         fclose(f);
1660         if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
1661                 error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
1662                         git_path_head_file());
1663                 goto fail;
1664         }
1665         if (is_null_sha1(sha1)) {
1666                 error(_("cannot abort from a branch yet to be born"));
1667                 goto fail;
1668         }
1669
1670         if (!rollback_is_safe()) {
1671                 /* Do not error, just do not rollback */
1672                 warning(_("You seem to have moved HEAD. "
1673                           "Not rewinding, check your HEAD!"));
1674         } else
1675         if (reset_for_rollback(sha1))
1676                 goto fail;
1677         strbuf_release(&buf);
1678         return sequencer_remove_state(opts);
1679 fail:
1680         strbuf_release(&buf);
1681         return -1;
1682 }
1683
1684 static int save_todo(struct todo_list *todo_list, struct replay_opts *opts)
1685 {
1686         static struct lock_file todo_lock;
1687         const char *todo_path = get_todo_path(opts);
1688         int next = todo_list->current, offset, fd;
1689
1690         /*
1691          * rebase -i writes "git-rebase-todo" without the currently executing
1692          * command, appending it to "done" instead.
1693          */
1694         if (is_rebase_i(opts))
1695                 next++;
1696
1697         fd = hold_lock_file_for_update(&todo_lock, todo_path, 0);
1698         if (fd < 0)
1699                 return error_errno(_("could not lock '%s'"), todo_path);
1700         offset = next < todo_list->nr ?
1701                 todo_list->items[next].offset_in_buf : todo_list->buf.len;
1702         if (write_in_full(fd, todo_list->buf.buf + offset,
1703                         todo_list->buf.len - offset) < 0)
1704                 return error_errno(_("could not write to '%s'"), todo_path);
1705         if (commit_lock_file(&todo_lock) < 0)
1706                 return error(_("failed to finalize '%s'."), todo_path);
1707
1708         if (is_rebase_i(opts)) {
1709                 const char *done_path = rebase_path_done();
1710                 int fd = open(done_path, O_CREAT | O_WRONLY | O_APPEND, 0666);
1711                 int prev_offset = !next ? 0 :
1712                         todo_list->items[next - 1].offset_in_buf;
1713
1714                 if (fd >= 0 && offset > prev_offset &&
1715                     write_in_full(fd, todo_list->buf.buf + prev_offset,
1716                                   offset - prev_offset) < 0) {
1717                         close(fd);
1718                         return error_errno(_("could not write to '%s'"),
1719                                            done_path);
1720                 }
1721                 if (fd >= 0)
1722                         close(fd);
1723         }
1724         return 0;
1725 }
1726
1727 static int save_opts(struct replay_opts *opts)
1728 {
1729         const char *opts_file = git_path_opts_file();
1730         int res = 0;
1731
1732         if (opts->no_commit)
1733                 res |= git_config_set_in_file_gently(opts_file, "options.no-commit", "true");
1734         if (opts->edit)
1735                 res |= git_config_set_in_file_gently(opts_file, "options.edit", "true");
1736         if (opts->signoff)
1737                 res |= git_config_set_in_file_gently(opts_file, "options.signoff", "true");
1738         if (opts->record_origin)
1739                 res |= git_config_set_in_file_gently(opts_file, "options.record-origin", "true");
1740         if (opts->allow_ff)
1741                 res |= git_config_set_in_file_gently(opts_file, "options.allow-ff", "true");
1742         if (opts->mainline) {
1743                 struct strbuf buf = STRBUF_INIT;
1744                 strbuf_addf(&buf, "%d", opts->mainline);
1745                 res |= git_config_set_in_file_gently(opts_file, "options.mainline", buf.buf);
1746                 strbuf_release(&buf);
1747         }
1748         if (opts->strategy)
1749                 res |= git_config_set_in_file_gently(opts_file, "options.strategy", opts->strategy);
1750         if (opts->gpg_sign)
1751                 res |= git_config_set_in_file_gently(opts_file, "options.gpg-sign", opts->gpg_sign);
1752         if (opts->xopts) {
1753                 int i;
1754                 for (i = 0; i < opts->xopts_nr; i++)
1755                         res |= git_config_set_multivar_in_file_gently(opts_file,
1756                                                         "options.strategy-option",
1757                                                         opts->xopts[i], "^$", 0);
1758         }
1759         if (opts->allow_rerere_auto)
1760                 res |= git_config_set_in_file_gently(opts_file, "options.allow-rerere-auto",
1761                                                      opts->allow_rerere_auto == RERERE_AUTOUPDATE ?
1762                                                      "true" : "false");
1763         return res;
1764 }
1765
1766 static int make_patch(struct commit *commit, struct replay_opts *opts)
1767 {
1768         struct strbuf buf = STRBUF_INIT;
1769         struct rev_info log_tree_opt;
1770         const char *subject, *p;
1771         int res = 0;
1772
1773         p = short_commit_name(commit);
1774         if (write_message(p, strlen(p), rebase_path_stopped_sha(), 1) < 0)
1775                 return -1;
1776
1777         strbuf_addf(&buf, "%s/patch", get_dir(opts));
1778         memset(&log_tree_opt, 0, sizeof(log_tree_opt));
1779         init_revisions(&log_tree_opt, NULL);
1780         log_tree_opt.abbrev = 0;
1781         log_tree_opt.diff = 1;
1782         log_tree_opt.diffopt.output_format = DIFF_FORMAT_PATCH;
1783         log_tree_opt.disable_stdin = 1;
1784         log_tree_opt.no_commit_id = 1;
1785         log_tree_opt.diffopt.file = fopen(buf.buf, "w");
1786         log_tree_opt.diffopt.use_color = GIT_COLOR_NEVER;
1787         if (!log_tree_opt.diffopt.file)
1788                 res |= error_errno(_("could not open '%s'"), buf.buf);
1789         else {
1790                 res |= log_tree_commit(&log_tree_opt, commit);
1791                 fclose(log_tree_opt.diffopt.file);
1792         }
1793         strbuf_reset(&buf);
1794
1795         strbuf_addf(&buf, "%s/message", get_dir(opts));
1796         if (!file_exists(buf.buf)) {
1797                 const char *commit_buffer = get_commit_buffer(commit, NULL);
1798                 find_commit_subject(commit_buffer, &subject);
1799                 res |= write_message(subject, strlen(subject), buf.buf, 1);
1800                 unuse_commit_buffer(commit, commit_buffer);
1801         }
1802         strbuf_release(&buf);
1803
1804         return res;
1805 }
1806
1807 static int intend_to_amend(void)
1808 {
1809         unsigned char head[20];
1810         char *p;
1811
1812         if (get_sha1("HEAD", head))
1813                 return error(_("cannot read HEAD"));
1814
1815         p = sha1_to_hex(head);
1816         return write_message(p, strlen(p), rebase_path_amend(), 1);
1817 }
1818
1819 static int error_with_patch(struct commit *commit,
1820         const char *subject, int subject_len,
1821         struct replay_opts *opts, int exit_code, int to_amend)
1822 {
1823         if (make_patch(commit, opts))
1824                 return -1;
1825
1826         if (to_amend) {
1827                 if (intend_to_amend())
1828                         return -1;
1829
1830                 fprintf(stderr, "You can amend the commit now, with\n"
1831                         "\n"
1832                         "  git commit --amend %s\n"
1833                         "\n"
1834                         "Once you are satisfied with your changes, run\n"
1835                         "\n"
1836                         "  git rebase --continue\n", gpg_sign_opt_quoted(opts));
1837         } else if (exit_code)
1838                 fprintf(stderr, "Could not apply %s... %.*s\n",
1839                         short_commit_name(commit), subject_len, subject);
1840
1841         return exit_code;
1842 }
1843
1844 static int error_failed_squash(struct commit *commit,
1845         struct replay_opts *opts, int subject_len, const char *subject)
1846 {
1847         if (rename(rebase_path_squash_msg(), rebase_path_message()))
1848                 return error(_("could not rename '%s' to '%s'"),
1849                         rebase_path_squash_msg(), rebase_path_message());
1850         unlink(rebase_path_fixup_msg());
1851         unlink(git_path_merge_msg());
1852         if (copy_file(git_path_merge_msg(), rebase_path_message(), 0666))
1853                 return error(_("could not copy '%s' to '%s'"),
1854                              rebase_path_message(), git_path_merge_msg());
1855         return error_with_patch(commit, subject, subject_len, opts, 1, 0);
1856 }
1857
1858 static int do_exec(const char *command_line)
1859 {
1860         const char *child_argv[] = { NULL, NULL };
1861         int dirty, status;
1862
1863         fprintf(stderr, "Executing: %s\n", command_line);
1864         child_argv[0] = command_line;
1865         status = run_command_v_opt(child_argv, RUN_USING_SHELL);
1866
1867         /* force re-reading of the cache */
1868         if (discard_cache() < 0 || read_cache() < 0)
1869                 return error(_("could not read index"));
1870
1871         dirty = require_clean_work_tree("rebase", NULL, 1, 1);
1872
1873         if (status) {
1874                 warning(_("execution failed: %s\n%s"
1875                           "You can fix the problem, and then run\n"
1876                           "\n"
1877                           "  git rebase --continue\n"
1878                           "\n"),
1879                         command_line,
1880                         dirty ? N_("and made changes to the index and/or the "
1881                                 "working tree\n") : "");
1882                 if (status == 127)
1883                         /* command not found */
1884                         status = 1;
1885         } else if (dirty) {
1886                 warning(_("execution succeeded: %s\nbut "
1887                           "left changes to the index and/or the working tree\n"
1888                           "Commit or stash your changes, and then run\n"
1889                           "\n"
1890                           "  git rebase --continue\n"
1891                           "\n"), command_line);
1892                 status = 1;
1893         }
1894
1895         return status;
1896 }
1897
1898 static int is_final_fixup(struct todo_list *todo_list)
1899 {
1900         int i = todo_list->current;
1901
1902         if (!is_fixup(todo_list->items[i].command))
1903                 return 0;
1904
1905         while (++i < todo_list->nr)
1906                 if (is_fixup(todo_list->items[i].command))
1907                         return 0;
1908                 else if (!is_noop(todo_list->items[i].command))
1909                         break;
1910         return 1;
1911 }
1912
1913 static enum todo_command peek_command(struct todo_list *todo_list, int offset)
1914 {
1915         int i;
1916
1917         for (i = todo_list->current + offset; i < todo_list->nr; i++)
1918                 if (!is_noop(todo_list->items[i].command))
1919                         return todo_list->items[i].command;
1920
1921         return -1;
1922 }
1923
1924 static int apply_autostash(struct replay_opts *opts)
1925 {
1926         struct strbuf stash_sha1 = STRBUF_INIT;
1927         struct child_process child = CHILD_PROCESS_INIT;
1928         int ret = 0;
1929
1930         if (!read_oneliner(&stash_sha1, rebase_path_autostash(), 1)) {
1931                 strbuf_release(&stash_sha1);
1932                 return 0;
1933         }
1934         strbuf_trim(&stash_sha1);
1935
1936         child.git_cmd = 1;
1937         child.no_stdout = 1;
1938         child.no_stderr = 1;
1939         argv_array_push(&child.args, "stash");
1940         argv_array_push(&child.args, "apply");
1941         argv_array_push(&child.args, stash_sha1.buf);
1942         if (!run_command(&child))
1943                 fprintf(stderr, _("Applied autostash.\n"));
1944         else {
1945                 struct child_process store = CHILD_PROCESS_INIT;
1946
1947                 store.git_cmd = 1;
1948                 argv_array_push(&store.args, "stash");
1949                 argv_array_push(&store.args, "store");
1950                 argv_array_push(&store.args, "-m");
1951                 argv_array_push(&store.args, "autostash");
1952                 argv_array_push(&store.args, "-q");
1953                 argv_array_push(&store.args, stash_sha1.buf);
1954                 if (run_command(&store))
1955                         ret = error(_("cannot store %s"), stash_sha1.buf);
1956                 else
1957                         fprintf(stderr,
1958                                 _("Applying autostash resulted in conflicts.\n"
1959                                   "Your changes are safe in the stash.\n"
1960                                   "You can run \"git stash pop\" or"
1961                                   " \"git stash drop\" at any time.\n"));
1962         }
1963
1964         strbuf_release(&stash_sha1);
1965         return ret;
1966 }
1967
1968 static const char *reflog_message(struct replay_opts *opts,
1969         const char *sub_action, const char *fmt, ...)
1970 {
1971         va_list ap;
1972         static struct strbuf buf = STRBUF_INIT;
1973
1974         va_start(ap, fmt);
1975         strbuf_reset(&buf);
1976         strbuf_addstr(&buf, action_name(opts));
1977         if (sub_action)
1978                 strbuf_addf(&buf, " (%s)", sub_action);
1979         if (fmt) {
1980                 strbuf_addstr(&buf, ": ");
1981                 strbuf_vaddf(&buf, fmt, ap);
1982         }
1983         va_end(ap);
1984
1985         return buf.buf;
1986 }
1987
1988 static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
1989 {
1990         int res = 0;
1991
1992         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
1993         if (opts->allow_ff)
1994                 assert(!(opts->signoff || opts->no_commit ||
1995                                 opts->record_origin || opts->edit));
1996         if (read_and_refresh_cache(opts))
1997                 return -1;
1998
1999         while (todo_list->current < todo_list->nr) {
2000                 struct todo_item *item = todo_list->items + todo_list->current;
2001                 if (save_todo(todo_list, opts))
2002                         return -1;
2003                 if (is_rebase_i(opts)) {
2004                         if (item->command != TODO_COMMENT) {
2005                                 FILE *f = fopen(rebase_path_msgnum(), "w");
2006
2007                                 todo_list->done_nr++;
2008
2009                                 if (f) {
2010                                         fprintf(f, "%d\n", todo_list->done_nr);
2011                                         fclose(f);
2012                                 }
2013                                 fprintf(stderr, "Rebasing (%d/%d)%s",
2014                                         todo_list->done_nr,
2015                                         todo_list->total_nr,
2016                                         opts->verbose ? "\n" : "\r");
2017                         }
2018                         unlink(rebase_path_message());
2019                         unlink(rebase_path_author_script());
2020                         unlink(rebase_path_stopped_sha());
2021                         unlink(rebase_path_amend());
2022                 }
2023                 if (item->command <= TODO_SQUASH) {
2024                         if (is_rebase_i(opts))
2025                                 setenv("GIT_REFLOG_ACTION", reflog_message(opts,
2026                                         command_to_string(item->command), NULL),
2027                                         1);
2028                         res = do_pick_commit(item->command, item->commit,
2029                                         opts, is_final_fixup(todo_list));
2030                         if (is_rebase_i(opts) && res < 0) {
2031                                 /* Reschedule */
2032                                 todo_list->current--;
2033                                 if (save_todo(todo_list, opts))
2034                                         return -1;
2035                         }
2036                         if (item->command == TODO_EDIT) {
2037                                 struct commit *commit = item->commit;
2038                                 if (!res)
2039                                         fprintf(stderr,
2040                                                 _("Stopped at %s...  %.*s\n"),
2041                                                 short_commit_name(commit),
2042                                                 item->arg_len, item->arg);
2043                                 return error_with_patch(commit,
2044                                         item->arg, item->arg_len, opts, res,
2045                                         !res);
2046                         }
2047                         if (is_rebase_i(opts) && !res)
2048                                 record_in_rewritten(&item->commit->object.oid,
2049                                         peek_command(todo_list, 1));
2050                         if (res && is_fixup(item->command)) {
2051                                 if (res == 1)
2052                                         intend_to_amend();
2053                                 return error_failed_squash(item->commit, opts,
2054                                         item->arg_len, item->arg);
2055                         } else if (res && is_rebase_i(opts))
2056                                 return res | error_with_patch(item->commit,
2057                                         item->arg, item->arg_len, opts, res,
2058                                         item->command == TODO_REWORD);
2059                 } else if (item->command == TODO_EXEC) {
2060                         char *end_of_arg = (char *)(item->arg + item->arg_len);
2061                         int saved = *end_of_arg;
2062                         struct stat st;
2063
2064                         *end_of_arg = '\0';
2065                         res = do_exec(item->arg);
2066                         *end_of_arg = saved;
2067
2068                         /* Reread the todo file if it has changed. */
2069                         if (res)
2070                                 ; /* fall through */
2071                         else if (stat(get_todo_path(opts), &st))
2072                                 res = error_errno(_("could not stat '%s'"),
2073                                                   get_todo_path(opts));
2074                         else if (match_stat_data(&todo_list->stat, &st)) {
2075                                 todo_list_release(todo_list);
2076                                 if (read_populate_todo(todo_list, opts))
2077                                         res = -1; /* message was printed */
2078                                 /* `current` will be incremented below */
2079                                 todo_list->current = -1;
2080                         }
2081                 } else if (!is_noop(item->command))
2082                         return error(_("unknown command %d"), item->command);
2083
2084                 todo_list->current++;
2085                 if (res)
2086                         return res;
2087         }
2088
2089         if (is_rebase_i(opts)) {
2090                 struct strbuf head_ref = STRBUF_INIT, buf = STRBUF_INIT;
2091                 struct stat st;
2092
2093                 /* Stopped in the middle, as planned? */
2094                 if (todo_list->current < todo_list->nr)
2095                         return 0;
2096
2097                 if (read_oneliner(&head_ref, rebase_path_head_name(), 0) &&
2098                                 starts_with(head_ref.buf, "refs/")) {
2099                         const char *msg;
2100                         unsigned char head[20], orig[20];
2101                         int res;
2102
2103                         if (get_sha1("HEAD", head)) {
2104                                 res = error(_("cannot read HEAD"));
2105 cleanup_head_ref:
2106                                 strbuf_release(&head_ref);
2107                                 strbuf_release(&buf);
2108                                 return res;
2109                         }
2110                         if (!read_oneliner(&buf, rebase_path_orig_head(), 0) ||
2111                                         get_sha1_hex(buf.buf, orig)) {
2112                                 res = error(_("could not read orig-head"));
2113                                 goto cleanup_head_ref;
2114                         }
2115                         strbuf_reset(&buf);
2116                         if (!read_oneliner(&buf, rebase_path_onto(), 0)) {
2117                                 res = error(_("could not read 'onto'"));
2118                                 goto cleanup_head_ref;
2119                         }
2120                         msg = reflog_message(opts, "finish", "%s onto %s",
2121                                 head_ref.buf, buf.buf);
2122                         if (update_ref(msg, head_ref.buf, head, orig,
2123                                         REF_NODEREF, UPDATE_REFS_MSG_ON_ERR)) {
2124                                 res = error(_("could not update %s"),
2125                                         head_ref.buf);
2126                                 goto cleanup_head_ref;
2127                         }
2128                         msg = reflog_message(opts, "finish", "returning to %s",
2129                                 head_ref.buf);
2130                         if (create_symref("HEAD", head_ref.buf, msg)) {
2131                                 res = error(_("could not update HEAD to %s"),
2132                                         head_ref.buf);
2133                                 goto cleanup_head_ref;
2134                         }
2135                         strbuf_reset(&buf);
2136                 }
2137
2138                 if (opts->verbose) {
2139                         struct rev_info log_tree_opt;
2140                         struct object_id orig, head;
2141
2142                         memset(&log_tree_opt, 0, sizeof(log_tree_opt));
2143                         init_revisions(&log_tree_opt, NULL);
2144                         log_tree_opt.diff = 1;
2145                         log_tree_opt.diffopt.output_format =
2146                                 DIFF_FORMAT_DIFFSTAT;
2147                         log_tree_opt.disable_stdin = 1;
2148
2149                         if (read_oneliner(&buf, rebase_path_orig_head(), 0) &&
2150                             !get_sha1(buf.buf, orig.hash) &&
2151                             !get_sha1("HEAD", head.hash)) {
2152                                 diff_tree_oid(&orig, &head, "",
2153                                               &log_tree_opt.diffopt);
2154                                 log_tree_diff_flush(&log_tree_opt);
2155                         }
2156                 }
2157                 flush_rewritten_pending();
2158                 if (!stat(rebase_path_rewritten_list(), &st) &&
2159                                 st.st_size > 0) {
2160                         struct child_process child = CHILD_PROCESS_INIT;
2161                         const char *post_rewrite_hook =
2162                                 find_hook("post-rewrite");
2163
2164                         child.in = open(rebase_path_rewritten_list(), O_RDONLY);
2165                         child.git_cmd = 1;
2166                         argv_array_push(&child.args, "notes");
2167                         argv_array_push(&child.args, "copy");
2168                         argv_array_push(&child.args, "--for-rewrite=rebase");
2169                         /* we don't care if this copying failed */
2170                         run_command(&child);
2171
2172                         if (post_rewrite_hook) {
2173                                 struct child_process hook = CHILD_PROCESS_INIT;
2174
2175                                 hook.in = open(rebase_path_rewritten_list(),
2176                                         O_RDONLY);
2177                                 hook.stdout_to_stderr = 1;
2178                                 argv_array_push(&hook.args, post_rewrite_hook);
2179                                 argv_array_push(&hook.args, "rebase");
2180                                 /* we don't care if this hook failed */
2181                                 run_command(&hook);
2182                         }
2183                 }
2184                 apply_autostash(opts);
2185
2186                 fprintf(stderr, "Successfully rebased and updated %s.\n",
2187                         head_ref.buf);
2188
2189                 strbuf_release(&buf);
2190                 strbuf_release(&head_ref);
2191         }
2192
2193         /*
2194          * Sequence of picks finished successfully; cleanup by
2195          * removing the .git/sequencer directory
2196          */
2197         return sequencer_remove_state(opts);
2198 }
2199
2200 static int continue_single_pick(void)
2201 {
2202         const char *argv[] = { "commit", NULL };
2203
2204         if (!file_exists(git_path_cherry_pick_head()) &&
2205             !file_exists(git_path_revert_head()))
2206                 return error(_("no cherry-pick or revert in progress"));
2207         return run_command_v_opt(argv, RUN_GIT_CMD);
2208 }
2209
2210 static int commit_staged_changes(struct replay_opts *opts)
2211 {
2212         unsigned int flags = ALLOW_EMPTY | EDIT_MSG;
2213
2214         if (has_unstaged_changes(1))
2215                 return error(_("cannot rebase: You have unstaged changes."));
2216         if (!has_uncommitted_changes(0)) {
2217                 const char *cherry_pick_head = git_path_cherry_pick_head();
2218
2219                 if (file_exists(cherry_pick_head) && unlink(cherry_pick_head))
2220                         return error(_("could not remove CHERRY_PICK_HEAD"));
2221                 return 0;
2222         }
2223
2224         if (file_exists(rebase_path_amend())) {
2225                 struct strbuf rev = STRBUF_INIT;
2226                 unsigned char head[20], to_amend[20];
2227
2228                 if (get_sha1("HEAD", head))
2229                         return error(_("cannot amend non-existing commit"));
2230                 if (!read_oneliner(&rev, rebase_path_amend(), 0))
2231                         return error(_("invalid file: '%s'"), rebase_path_amend());
2232                 if (get_sha1_hex(rev.buf, to_amend))
2233                         return error(_("invalid contents: '%s'"),
2234                                 rebase_path_amend());
2235                 if (hashcmp(head, to_amend))
2236                         return error(_("\nYou have uncommitted changes in your "
2237                                        "working tree. Please, commit them\n"
2238                                        "first and then run 'git rebase "
2239                                        "--continue' again."));
2240
2241                 strbuf_release(&rev);
2242                 flags |= AMEND_MSG;
2243         }
2244
2245         if (run_git_commit(rebase_path_message(), opts, flags))
2246                 return error(_("could not commit staged changes."));
2247         unlink(rebase_path_amend());
2248         return 0;
2249 }
2250
2251 int sequencer_continue(struct replay_opts *opts)
2252 {
2253         struct todo_list todo_list = TODO_LIST_INIT;
2254         int res;
2255
2256         if (read_and_refresh_cache(opts))
2257                 return -1;
2258
2259         if (is_rebase_i(opts)) {
2260                 if (commit_staged_changes(opts))
2261                         return -1;
2262         } else if (!file_exists(get_todo_path(opts)))
2263                 return continue_single_pick();
2264         if (read_populate_opts(opts))
2265                 return -1;
2266         if ((res = read_populate_todo(&todo_list, opts)))
2267                 goto release_todo_list;
2268
2269         if (!is_rebase_i(opts)) {
2270                 /* Verify that the conflict has been resolved */
2271                 if (file_exists(git_path_cherry_pick_head()) ||
2272                     file_exists(git_path_revert_head())) {
2273                         res = continue_single_pick();
2274                         if (res)
2275                                 goto release_todo_list;
2276                 }
2277                 if (index_differs_from("HEAD", 0, 0)) {
2278                         res = error_dirty_index(opts);
2279                         goto release_todo_list;
2280                 }
2281                 todo_list.current++;
2282         } else if (file_exists(rebase_path_stopped_sha())) {
2283                 struct strbuf buf = STRBUF_INIT;
2284                 struct object_id oid;
2285
2286                 if (read_oneliner(&buf, rebase_path_stopped_sha(), 1) &&
2287                     !get_sha1_committish(buf.buf, oid.hash))
2288                         record_in_rewritten(&oid, peek_command(&todo_list, 0));
2289                 strbuf_release(&buf);
2290         }
2291
2292         res = pick_commits(&todo_list, opts);
2293 release_todo_list:
2294         todo_list_release(&todo_list);
2295         return res;
2296 }
2297
2298 static int single_pick(struct commit *cmit, struct replay_opts *opts)
2299 {
2300         setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
2301         return do_pick_commit(opts->action == REPLAY_PICK ?
2302                 TODO_PICK : TODO_REVERT, cmit, opts, 0);
2303 }
2304
2305 int sequencer_pick_revisions(struct replay_opts *opts)
2306 {
2307         struct todo_list todo_list = TODO_LIST_INIT;
2308         struct object_id oid;
2309         int i, res;
2310
2311         assert(opts->revs);
2312         if (read_and_refresh_cache(opts))
2313                 return -1;
2314
2315         for (i = 0; i < opts->revs->pending.nr; i++) {
2316                 struct object_id oid;
2317                 const char *name = opts->revs->pending.objects[i].name;
2318
2319                 /* This happens when using --stdin. */
2320                 if (!strlen(name))
2321                         continue;
2322
2323                 if (!get_oid(name, &oid)) {
2324                         if (!lookup_commit_reference_gently(&oid, 1)) {
2325                                 enum object_type type = sha1_object_info(oid.hash, NULL);
2326                                 return error(_("%s: can't cherry-pick a %s"),
2327                                         name, typename(type));
2328                         }
2329                 } else
2330                         return error(_("%s: bad revision"), name);
2331         }
2332
2333         /*
2334          * If we were called as "git cherry-pick <commit>", just
2335          * cherry-pick/revert it, set CHERRY_PICK_HEAD /
2336          * REVERT_HEAD, and don't touch the sequencer state.
2337          * This means it is possible to cherry-pick in the middle
2338          * of a cherry-pick sequence.
2339          */
2340         if (opts->revs->cmdline.nr == 1 &&
2341             opts->revs->cmdline.rev->whence == REV_CMD_REV &&
2342             opts->revs->no_walk &&
2343             !opts->revs->cmdline.rev->flags) {
2344                 struct commit *cmit;
2345                 if (prepare_revision_walk(opts->revs))
2346                         return error(_("revision walk setup failed"));
2347                 cmit = get_revision(opts->revs);
2348                 if (!cmit || get_revision(opts->revs))
2349                         return error("BUG: expected exactly one commit from walk");
2350                 return single_pick(cmit, opts);
2351         }
2352
2353         /*
2354          * Start a new cherry-pick/ revert sequence; but
2355          * first, make sure that an existing one isn't in
2356          * progress
2357          */
2358
2359         if (walk_revs_populate_todo(&todo_list, opts) ||
2360                         create_seq_dir() < 0)
2361                 return -1;
2362         if (get_oid("HEAD", &oid) && (opts->action == REPLAY_REVERT))
2363                 return error(_("can't revert as initial commit"));
2364         if (save_head(oid_to_hex(&oid)))
2365                 return -1;
2366         if (save_opts(opts))
2367                 return -1;
2368         update_abort_safety_file();
2369         res = pick_commits(&todo_list, opts);
2370         todo_list_release(&todo_list);
2371         return res;
2372 }
2373
2374 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
2375 {
2376         unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
2377         struct strbuf sob = STRBUF_INIT;
2378         int has_footer;
2379
2380         strbuf_addstr(&sob, sign_off_header);
2381         strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
2382                                 getenv("GIT_COMMITTER_EMAIL")));
2383         strbuf_addch(&sob, '\n');
2384
2385         if (!ignore_footer)
2386                 strbuf_complete_line(msgbuf);
2387
2388         /*
2389          * If the whole message buffer is equal to the sob, pretend that we
2390          * found a conforming footer with a matching sob
2391          */
2392         if (msgbuf->len - ignore_footer == sob.len &&
2393             !strncmp(msgbuf->buf, sob.buf, sob.len))
2394                 has_footer = 3;
2395         else
2396                 has_footer = has_conforming_footer(msgbuf, &sob, ignore_footer);
2397
2398         if (!has_footer) {
2399                 const char *append_newlines = NULL;
2400                 size_t len = msgbuf->len - ignore_footer;
2401
2402                 if (!len) {
2403                         /*
2404                          * The buffer is completely empty.  Leave foom for
2405                          * the title and body to be filled in by the user.
2406                          */
2407                         append_newlines = "\n\n";
2408                 } else if (len == 1) {
2409                         /*
2410                          * Buffer contains a single newline.  Add another
2411                          * so that we leave room for the title and body.
2412                          */
2413                         append_newlines = "\n";
2414                 } else if (msgbuf->buf[len - 2] != '\n') {
2415                         /*
2416                          * Buffer ends with a single newline.  Add another
2417                          * so that there is an empty line between the message
2418                          * body and the sob.
2419                          */
2420                         append_newlines = "\n";
2421                 } /* else, the buffer already ends with two newlines. */
2422
2423                 if (append_newlines)
2424                         strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
2425                                 append_newlines, strlen(append_newlines));
2426         }
2427
2428         if (has_footer != 3 && (!no_dup_sob || has_footer != 2))
2429                 strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0,
2430                                 sob.buf, sob.len);
2431
2432         strbuf_release(&sob);
2433 }