Merge branch 'jh/fsmonitor-prework'
[git] / builtin / am.c
1 /*
2  * Builtin "git am"
3  *
4  * Based on git-am.sh by Junio C Hamano.
5  */
6 #define USE_THE_INDEX_COMPATIBILITY_MACROS
7 #include "cache.h"
8 #include "config.h"
9 #include "builtin.h"
10 #include "exec-cmd.h"
11 #include "parse-options.h"
12 #include "dir.h"
13 #include "run-command.h"
14 #include "quote.h"
15 #include "tempfile.h"
16 #include "lockfile.h"
17 #include "cache-tree.h"
18 #include "refs.h"
19 #include "commit.h"
20 #include "diff.h"
21 #include "diffcore.h"
22 #include "unpack-trees.h"
23 #include "branch.h"
24 #include "sequencer.h"
25 #include "revision.h"
26 #include "merge-recursive.h"
27 #include "log-tree.h"
28 #include "notes-utils.h"
29 #include "rerere.h"
30 #include "prompt.h"
31 #include "mailinfo.h"
32 #include "apply.h"
33 #include "string-list.h"
34 #include "packfile.h"
35 #include "repository.h"
36
37 /**
38  * Returns the length of the first line of msg.
39  */
40 static int linelen(const char *msg)
41 {
42         return strchrnul(msg, '\n') - msg;
43 }
44
45 /**
46  * Returns true if `str` consists of only whitespace, false otherwise.
47  */
48 static int str_isspace(const char *str)
49 {
50         for (; *str; str++)
51                 if (!isspace(*str))
52                         return 0;
53
54         return 1;
55 }
56
57 enum patch_format {
58         PATCH_FORMAT_UNKNOWN = 0,
59         PATCH_FORMAT_MBOX,
60         PATCH_FORMAT_STGIT,
61         PATCH_FORMAT_STGIT_SERIES,
62         PATCH_FORMAT_HG,
63         PATCH_FORMAT_MBOXRD
64 };
65
66 enum keep_type {
67         KEEP_FALSE = 0,
68         KEEP_TRUE,      /* pass -k flag to git-mailinfo */
69         KEEP_NON_PATCH  /* pass -b flag to git-mailinfo */
70 };
71
72 enum scissors_type {
73         SCISSORS_UNSET = -1,
74         SCISSORS_FALSE = 0,  /* pass --no-scissors to git-mailinfo */
75         SCISSORS_TRUE        /* pass --scissors to git-mailinfo */
76 };
77
78 enum signoff_type {
79         SIGNOFF_FALSE = 0,
80         SIGNOFF_TRUE = 1,
81         SIGNOFF_EXPLICIT /* --signoff was set on the command-line */
82 };
83
84 enum show_patch_type {
85         SHOW_PATCH_RAW = 0,
86         SHOW_PATCH_DIFF = 1,
87 };
88
89 struct am_state {
90         /* state directory path */
91         char *dir;
92
93         /* current and last patch numbers, 1-indexed */
94         int cur;
95         int last;
96
97         /* commit metadata and message */
98         char *author_name;
99         char *author_email;
100         char *author_date;
101         char *msg;
102         size_t msg_len;
103
104         /* when --rebasing, records the original commit the patch came from */
105         struct object_id orig_commit;
106
107         /* number of digits in patch filename */
108         int prec;
109
110         /* various operating modes and command line options */
111         int interactive;
112         int threeway;
113         int quiet;
114         int signoff; /* enum signoff_type */
115         int utf8;
116         int keep; /* enum keep_type */
117         int message_id;
118         int scissors; /* enum scissors_type */
119         struct strvec git_apply_opts;
120         const char *resolvemsg;
121         int committer_date_is_author_date;
122         int ignore_date;
123         int allow_rerere_autoupdate;
124         const char *sign_commit;
125         int rebasing;
126 };
127
128 /**
129  * Initializes am_state with the default values.
130  */
131 static void am_state_init(struct am_state *state)
132 {
133         int gpgsign;
134
135         memset(state, 0, sizeof(*state));
136
137         state->dir = git_pathdup("rebase-apply");
138
139         state->prec = 4;
140
141         git_config_get_bool("am.threeway", &state->threeway);
142
143         state->utf8 = 1;
144
145         git_config_get_bool("am.messageid", &state->message_id);
146
147         state->scissors = SCISSORS_UNSET;
148
149         strvec_init(&state->git_apply_opts);
150
151         if (!git_config_get_bool("commit.gpgsign", &gpgsign))
152                 state->sign_commit = gpgsign ? "" : NULL;
153 }
154
155 /**
156  * Releases memory allocated by an am_state.
157  */
158 static void am_state_release(struct am_state *state)
159 {
160         free(state->dir);
161         free(state->author_name);
162         free(state->author_email);
163         free(state->author_date);
164         free(state->msg);
165         strvec_clear(&state->git_apply_opts);
166 }
167
168 /**
169  * Returns path relative to the am_state directory.
170  */
171 static inline const char *am_path(const struct am_state *state, const char *path)
172 {
173         return mkpath("%s/%s", state->dir, path);
174 }
175
176 /**
177  * For convenience to call write_file()
178  */
179 static void write_state_text(const struct am_state *state,
180                              const char *name, const char *string)
181 {
182         write_file(am_path(state, name), "%s", string);
183 }
184
185 static void write_state_count(const struct am_state *state,
186                               const char *name, int value)
187 {
188         write_file(am_path(state, name), "%d", value);
189 }
190
191 static void write_state_bool(const struct am_state *state,
192                              const char *name, int value)
193 {
194         write_state_text(state, name, value ? "t" : "f");
195 }
196
197 /**
198  * If state->quiet is false, calls fprintf(fp, fmt, ...), and appends a newline
199  * at the end.
200  */
201 static void say(const struct am_state *state, FILE *fp, const char *fmt, ...)
202 {
203         va_list ap;
204
205         va_start(ap, fmt);
206         if (!state->quiet) {
207                 vfprintf(fp, fmt, ap);
208                 putc('\n', fp);
209         }
210         va_end(ap);
211 }
212
213 /**
214  * Returns 1 if there is an am session in progress, 0 otherwise.
215  */
216 static int am_in_progress(const struct am_state *state)
217 {
218         struct stat st;
219
220         if (lstat(state->dir, &st) < 0 || !S_ISDIR(st.st_mode))
221                 return 0;
222         if (lstat(am_path(state, "last"), &st) || !S_ISREG(st.st_mode))
223                 return 0;
224         if (lstat(am_path(state, "next"), &st) || !S_ISREG(st.st_mode))
225                 return 0;
226         return 1;
227 }
228
229 /**
230  * Reads the contents of `file` in the `state` directory into `sb`. Returns the
231  * number of bytes read on success, -1 if the file does not exist. If `trim` is
232  * set, trailing whitespace will be removed.
233  */
234 static int read_state_file(struct strbuf *sb, const struct am_state *state,
235                         const char *file, int trim)
236 {
237         strbuf_reset(sb);
238
239         if (strbuf_read_file(sb, am_path(state, file), 0) >= 0) {
240                 if (trim)
241                         strbuf_trim(sb);
242
243                 return sb->len;
244         }
245
246         if (errno == ENOENT)
247                 return -1;
248
249         die_errno(_("could not read '%s'"), am_path(state, file));
250 }
251
252 /**
253  * Reads and parses the state directory's "author-script" file, and sets
254  * state->author_name, state->author_email and state->author_date accordingly.
255  * Returns 0 on success, -1 if the file could not be parsed.
256  *
257  * The author script is of the format:
258  *
259  *      GIT_AUTHOR_NAME='$author_name'
260  *      GIT_AUTHOR_EMAIL='$author_email'
261  *      GIT_AUTHOR_DATE='$author_date'
262  *
263  * where $author_name, $author_email and $author_date are quoted. We are strict
264  * with our parsing, as the file was meant to be eval'd in the old git-am.sh
265  * script, and thus if the file differs from what this function expects, it is
266  * better to bail out than to do something that the user does not expect.
267  */
268 static int read_am_author_script(struct am_state *state)
269 {
270         const char *filename = am_path(state, "author-script");
271
272         assert(!state->author_name);
273         assert(!state->author_email);
274         assert(!state->author_date);
275
276         return read_author_script(filename, &state->author_name,
277                                   &state->author_email, &state->author_date, 1);
278 }
279
280 /**
281  * Saves state->author_name, state->author_email and state->author_date in the
282  * state directory's "author-script" file.
283  */
284 static void write_author_script(const struct am_state *state)
285 {
286         struct strbuf sb = STRBUF_INIT;
287
288         strbuf_addstr(&sb, "GIT_AUTHOR_NAME=");
289         sq_quote_buf(&sb, state->author_name);
290         strbuf_addch(&sb, '\n');
291
292         strbuf_addstr(&sb, "GIT_AUTHOR_EMAIL=");
293         sq_quote_buf(&sb, state->author_email);
294         strbuf_addch(&sb, '\n');
295
296         strbuf_addstr(&sb, "GIT_AUTHOR_DATE=");
297         sq_quote_buf(&sb, state->author_date);
298         strbuf_addch(&sb, '\n');
299
300         write_state_text(state, "author-script", sb.buf);
301
302         strbuf_release(&sb);
303 }
304
305 /**
306  * Reads the commit message from the state directory's "final-commit" file,
307  * setting state->msg to its contents and state->msg_len to the length of its
308  * contents in bytes.
309  *
310  * Returns 0 on success, -1 if the file does not exist.
311  */
312 static int read_commit_msg(struct am_state *state)
313 {
314         struct strbuf sb = STRBUF_INIT;
315
316         assert(!state->msg);
317
318         if (read_state_file(&sb, state, "final-commit", 0) < 0) {
319                 strbuf_release(&sb);
320                 return -1;
321         }
322
323         state->msg = strbuf_detach(&sb, &state->msg_len);
324         return 0;
325 }
326
327 /**
328  * Saves state->msg in the state directory's "final-commit" file.
329  */
330 static void write_commit_msg(const struct am_state *state)
331 {
332         const char *filename = am_path(state, "final-commit");
333         write_file_buf(filename, state->msg, state->msg_len);
334 }
335
336 /**
337  * Loads state from disk.
338  */
339 static void am_load(struct am_state *state)
340 {
341         struct strbuf sb = STRBUF_INIT;
342
343         if (read_state_file(&sb, state, "next", 1) < 0)
344                 BUG("state file 'next' does not exist");
345         state->cur = strtol(sb.buf, NULL, 10);
346
347         if (read_state_file(&sb, state, "last", 1) < 0)
348                 BUG("state file 'last' does not exist");
349         state->last = strtol(sb.buf, NULL, 10);
350
351         if (read_am_author_script(state) < 0)
352                 die(_("could not parse author script"));
353
354         read_commit_msg(state);
355
356         if (read_state_file(&sb, state, "original-commit", 1) < 0)
357                 oidclr(&state->orig_commit);
358         else if (get_oid_hex(sb.buf, &state->orig_commit) < 0)
359                 die(_("could not parse %s"), am_path(state, "original-commit"));
360
361         read_state_file(&sb, state, "threeway", 1);
362         state->threeway = !strcmp(sb.buf, "t");
363
364         read_state_file(&sb, state, "quiet", 1);
365         state->quiet = !strcmp(sb.buf, "t");
366
367         read_state_file(&sb, state, "sign", 1);
368         state->signoff = !strcmp(sb.buf, "t");
369
370         read_state_file(&sb, state, "utf8", 1);
371         state->utf8 = !strcmp(sb.buf, "t");
372
373         if (file_exists(am_path(state, "rerere-autoupdate"))) {
374                 read_state_file(&sb, state, "rerere-autoupdate", 1);
375                 state->allow_rerere_autoupdate = strcmp(sb.buf, "t") ?
376                         RERERE_NOAUTOUPDATE : RERERE_AUTOUPDATE;
377         } else {
378                 state->allow_rerere_autoupdate = 0;
379         }
380
381         read_state_file(&sb, state, "keep", 1);
382         if (!strcmp(sb.buf, "t"))
383                 state->keep = KEEP_TRUE;
384         else if (!strcmp(sb.buf, "b"))
385                 state->keep = KEEP_NON_PATCH;
386         else
387                 state->keep = KEEP_FALSE;
388
389         read_state_file(&sb, state, "messageid", 1);
390         state->message_id = !strcmp(sb.buf, "t");
391
392         read_state_file(&sb, state, "scissors", 1);
393         if (!strcmp(sb.buf, "t"))
394                 state->scissors = SCISSORS_TRUE;
395         else if (!strcmp(sb.buf, "f"))
396                 state->scissors = SCISSORS_FALSE;
397         else
398                 state->scissors = SCISSORS_UNSET;
399
400         read_state_file(&sb, state, "apply-opt", 1);
401         strvec_clear(&state->git_apply_opts);
402         if (sq_dequote_to_strvec(sb.buf, &state->git_apply_opts) < 0)
403                 die(_("could not parse %s"), am_path(state, "apply-opt"));
404
405         state->rebasing = !!file_exists(am_path(state, "rebasing"));
406
407         strbuf_release(&sb);
408 }
409
410 /**
411  * Removes the am_state directory, forcefully terminating the current am
412  * session.
413  */
414 static void am_destroy(const struct am_state *state)
415 {
416         struct strbuf sb = STRBUF_INIT;
417
418         strbuf_addstr(&sb, state->dir);
419         remove_dir_recursively(&sb, 0);
420         strbuf_release(&sb);
421 }
422
423 /**
424  * Runs applypatch-msg hook. Returns its exit code.
425  */
426 static int run_applypatch_msg_hook(struct am_state *state)
427 {
428         int ret;
429
430         assert(state->msg);
431         ret = run_hook_le(NULL, "applypatch-msg", am_path(state, "final-commit"), NULL);
432
433         if (!ret) {
434                 FREE_AND_NULL(state->msg);
435                 if (read_commit_msg(state) < 0)
436                         die(_("'%s' was deleted by the applypatch-msg hook"),
437                                 am_path(state, "final-commit"));
438         }
439
440         return ret;
441 }
442
443 /**
444  * Runs post-rewrite hook. Returns it exit code.
445  */
446 static int run_post_rewrite_hook(const struct am_state *state)
447 {
448         struct child_process cp = CHILD_PROCESS_INIT;
449         const char *hook = find_hook("post-rewrite");
450         int ret;
451
452         if (!hook)
453                 return 0;
454
455         strvec_push(&cp.args, hook);
456         strvec_push(&cp.args, "rebase");
457
458         cp.in = xopen(am_path(state, "rewritten"), O_RDONLY);
459         cp.stdout_to_stderr = 1;
460         cp.trace2_hook_name = "post-rewrite";
461
462         ret = run_command(&cp);
463
464         close(cp.in);
465         return ret;
466 }
467
468 /**
469  * Reads the state directory's "rewritten" file, and copies notes from the old
470  * commits listed in the file to their rewritten commits.
471  *
472  * Returns 0 on success, -1 on failure.
473  */
474 static int copy_notes_for_rebase(const struct am_state *state)
475 {
476         struct notes_rewrite_cfg *c;
477         struct strbuf sb = STRBUF_INIT;
478         const char *invalid_line = _("Malformed input line: '%s'.");
479         const char *msg = "Notes added by 'git rebase'";
480         FILE *fp;
481         int ret = 0;
482
483         assert(state->rebasing);
484
485         c = init_copy_notes_for_rewrite("rebase");
486         if (!c)
487                 return 0;
488
489         fp = xfopen(am_path(state, "rewritten"), "r");
490
491         while (!strbuf_getline_lf(&sb, fp)) {
492                 struct object_id from_obj, to_obj;
493                 const char *p;
494
495                 if (sb.len != the_hash_algo->hexsz * 2 + 1) {
496                         ret = error(invalid_line, sb.buf);
497                         goto finish;
498                 }
499
500                 if (parse_oid_hex(sb.buf, &from_obj, &p)) {
501                         ret = error(invalid_line, sb.buf);
502                         goto finish;
503                 }
504
505                 if (*p != ' ') {
506                         ret = error(invalid_line, sb.buf);
507                         goto finish;
508                 }
509
510                 if (get_oid_hex(p + 1, &to_obj)) {
511                         ret = error(invalid_line, sb.buf);
512                         goto finish;
513                 }
514
515                 if (copy_note_for_rewrite(c, &from_obj, &to_obj))
516                         ret = error(_("Failed to copy notes from '%s' to '%s'"),
517                                         oid_to_hex(&from_obj), oid_to_hex(&to_obj));
518         }
519
520 finish:
521         finish_copy_notes_for_rewrite(the_repository, c, msg);
522         fclose(fp);
523         strbuf_release(&sb);
524         return ret;
525 }
526
527 /**
528  * Determines if the file looks like a piece of RFC2822 mail by grabbing all
529  * non-indented lines and checking if they look like they begin with valid
530  * header field names.
531  *
532  * Returns 1 if the file looks like a piece of mail, 0 otherwise.
533  */
534 static int is_mail(FILE *fp)
535 {
536         const char *header_regex = "^[!-9;-~]+:";
537         struct strbuf sb = STRBUF_INIT;
538         regex_t regex;
539         int ret = 1;
540
541         if (fseek(fp, 0L, SEEK_SET))
542                 die_errno(_("fseek failed"));
543
544         if (regcomp(&regex, header_regex, REG_NOSUB | REG_EXTENDED))
545                 die("invalid pattern: %s", header_regex);
546
547         while (!strbuf_getline(&sb, fp)) {
548                 if (!sb.len)
549                         break; /* End of header */
550
551                 /* Ignore indented folded lines */
552                 if (*sb.buf == '\t' || *sb.buf == ' ')
553                         continue;
554
555                 /* It's a header if it matches header_regex */
556                 if (regexec(&regex, sb.buf, 0, NULL, 0)) {
557                         ret = 0;
558                         goto done;
559                 }
560         }
561
562 done:
563         regfree(&regex);
564         strbuf_release(&sb);
565         return ret;
566 }
567
568 /**
569  * Attempts to detect the patch_format of the patches contained in `paths`,
570  * returning the PATCH_FORMAT_* enum value. Returns PATCH_FORMAT_UNKNOWN if
571  * detection fails.
572  */
573 static int detect_patch_format(const char **paths)
574 {
575         enum patch_format ret = PATCH_FORMAT_UNKNOWN;
576         struct strbuf l1 = STRBUF_INIT;
577         struct strbuf l2 = STRBUF_INIT;
578         struct strbuf l3 = STRBUF_INIT;
579         FILE *fp;
580
581         /*
582          * We default to mbox format if input is from stdin and for directories
583          */
584         if (!*paths || !strcmp(*paths, "-") || is_directory(*paths))
585                 return PATCH_FORMAT_MBOX;
586
587         /*
588          * Otherwise, check the first few lines of the first patch, starting
589          * from the first non-blank line, to try to detect its format.
590          */
591
592         fp = xfopen(*paths, "r");
593
594         while (!strbuf_getline(&l1, fp)) {
595                 if (l1.len)
596                         break;
597         }
598
599         if (starts_with(l1.buf, "From ") || starts_with(l1.buf, "From: ")) {
600                 ret = PATCH_FORMAT_MBOX;
601                 goto done;
602         }
603
604         if (starts_with(l1.buf, "# This series applies on GIT commit")) {
605                 ret = PATCH_FORMAT_STGIT_SERIES;
606                 goto done;
607         }
608
609         if (!strcmp(l1.buf, "# HG changeset patch")) {
610                 ret = PATCH_FORMAT_HG;
611                 goto done;
612         }
613
614         strbuf_getline(&l2, fp);
615         strbuf_getline(&l3, fp);
616
617         /*
618          * If the second line is empty and the third is a From, Author or Date
619          * entry, this is likely an StGit patch.
620          */
621         if (l1.len && !l2.len &&
622                 (starts_with(l3.buf, "From:") ||
623                  starts_with(l3.buf, "Author:") ||
624                  starts_with(l3.buf, "Date:"))) {
625                 ret = PATCH_FORMAT_STGIT;
626                 goto done;
627         }
628
629         if (l1.len && is_mail(fp)) {
630                 ret = PATCH_FORMAT_MBOX;
631                 goto done;
632         }
633
634 done:
635         fclose(fp);
636         strbuf_release(&l1);
637         strbuf_release(&l2);
638         strbuf_release(&l3);
639         return ret;
640 }
641
642 /**
643  * Splits out individual email patches from `paths`, where each path is either
644  * a mbox file or a Maildir. Returns 0 on success, -1 on failure.
645  */
646 static int split_mail_mbox(struct am_state *state, const char **paths,
647                                 int keep_cr, int mboxrd)
648 {
649         struct child_process cp = CHILD_PROCESS_INIT;
650         struct strbuf last = STRBUF_INIT;
651         int ret;
652
653         cp.git_cmd = 1;
654         strvec_push(&cp.args, "mailsplit");
655         strvec_pushf(&cp.args, "-d%d", state->prec);
656         strvec_pushf(&cp.args, "-o%s", state->dir);
657         strvec_push(&cp.args, "-b");
658         if (keep_cr)
659                 strvec_push(&cp.args, "--keep-cr");
660         if (mboxrd)
661                 strvec_push(&cp.args, "--mboxrd");
662         strvec_push(&cp.args, "--");
663         strvec_pushv(&cp.args, paths);
664
665         ret = capture_command(&cp, &last, 8);
666         if (ret)
667                 goto exit;
668
669         state->cur = 1;
670         state->last = strtol(last.buf, NULL, 10);
671
672 exit:
673         strbuf_release(&last);
674         return ret ? -1 : 0;
675 }
676
677 /**
678  * Callback signature for split_mail_conv(). The foreign patch should be
679  * read from `in`, and the converted patch (in RFC2822 mail format) should be
680  * written to `out`. Return 0 on success, or -1 on failure.
681  */
682 typedef int (*mail_conv_fn)(FILE *out, FILE *in, int keep_cr);
683
684 /**
685  * Calls `fn` for each file in `paths` to convert the foreign patch to the
686  * RFC2822 mail format suitable for parsing with git-mailinfo.
687  *
688  * Returns 0 on success, -1 on failure.
689  */
690 static int split_mail_conv(mail_conv_fn fn, struct am_state *state,
691                         const char **paths, int keep_cr)
692 {
693         static const char *stdin_only[] = {"-", NULL};
694         int i;
695
696         if (!*paths)
697                 paths = stdin_only;
698
699         for (i = 0; *paths; paths++, i++) {
700                 FILE *in, *out;
701                 const char *mail;
702                 int ret;
703
704                 if (!strcmp(*paths, "-"))
705                         in = stdin;
706                 else
707                         in = fopen(*paths, "r");
708
709                 if (!in)
710                         return error_errno(_("could not open '%s' for reading"),
711                                            *paths);
712
713                 mail = mkpath("%s/%0*d", state->dir, state->prec, i + 1);
714
715                 out = fopen(mail, "w");
716                 if (!out) {
717                         if (in != stdin)
718                                 fclose(in);
719                         return error_errno(_("could not open '%s' for writing"),
720                                            mail);
721                 }
722
723                 ret = fn(out, in, keep_cr);
724
725                 fclose(out);
726                 if (in != stdin)
727                         fclose(in);
728
729                 if (ret)
730                         return error(_("could not parse patch '%s'"), *paths);
731         }
732
733         state->cur = 1;
734         state->last = i;
735         return 0;
736 }
737
738 /**
739  * A split_mail_conv() callback that converts an StGit patch to an RFC2822
740  * message suitable for parsing with git-mailinfo.
741  */
742 static int stgit_patch_to_mail(FILE *out, FILE *in, int keep_cr)
743 {
744         struct strbuf sb = STRBUF_INIT;
745         int subject_printed = 0;
746
747         while (!strbuf_getline_lf(&sb, in)) {
748                 const char *str;
749
750                 if (str_isspace(sb.buf))
751                         continue;
752                 else if (skip_prefix(sb.buf, "Author:", &str))
753                         fprintf(out, "From:%s\n", str);
754                 else if (starts_with(sb.buf, "From") || starts_with(sb.buf, "Date"))
755                         fprintf(out, "%s\n", sb.buf);
756                 else if (!subject_printed) {
757                         fprintf(out, "Subject: %s\n", sb.buf);
758                         subject_printed = 1;
759                 } else {
760                         fprintf(out, "\n%s\n", sb.buf);
761                         break;
762                 }
763         }
764
765         strbuf_reset(&sb);
766         while (strbuf_fread(&sb, 8192, in) > 0) {
767                 fwrite(sb.buf, 1, sb.len, out);
768                 strbuf_reset(&sb);
769         }
770
771         strbuf_release(&sb);
772         return 0;
773 }
774
775 /**
776  * This function only supports a single StGit series file in `paths`.
777  *
778  * Given an StGit series file, converts the StGit patches in the series into
779  * RFC2822 messages suitable for parsing with git-mailinfo, and queues them in
780  * the state directory.
781  *
782  * Returns 0 on success, -1 on failure.
783  */
784 static int split_mail_stgit_series(struct am_state *state, const char **paths,
785                                         int keep_cr)
786 {
787         const char *series_dir;
788         char *series_dir_buf;
789         FILE *fp;
790         struct strvec patches = STRVEC_INIT;
791         struct strbuf sb = STRBUF_INIT;
792         int ret;
793
794         if (!paths[0] || paths[1])
795                 return error(_("Only one StGIT patch series can be applied at once"));
796
797         series_dir_buf = xstrdup(*paths);
798         series_dir = dirname(series_dir_buf);
799
800         fp = fopen(*paths, "r");
801         if (!fp)
802                 return error_errno(_("could not open '%s' for reading"), *paths);
803
804         while (!strbuf_getline_lf(&sb, fp)) {
805                 if (*sb.buf == '#')
806                         continue; /* skip comment lines */
807
808                 strvec_push(&patches, mkpath("%s/%s", series_dir, sb.buf));
809         }
810
811         fclose(fp);
812         strbuf_release(&sb);
813         free(series_dir_buf);
814
815         ret = split_mail_conv(stgit_patch_to_mail, state, patches.v, keep_cr);
816
817         strvec_clear(&patches);
818         return ret;
819 }
820
821 /**
822  * A split_patches_conv() callback that converts a mercurial patch to a RFC2822
823  * message suitable for parsing with git-mailinfo.
824  */
825 static int hg_patch_to_mail(FILE *out, FILE *in, int keep_cr)
826 {
827         struct strbuf sb = STRBUF_INIT;
828         int rc = 0;
829
830         while (!strbuf_getline_lf(&sb, in)) {
831                 const char *str;
832
833                 if (skip_prefix(sb.buf, "# User ", &str))
834                         fprintf(out, "From: %s\n", str);
835                 else if (skip_prefix(sb.buf, "# Date ", &str)) {
836                         timestamp_t timestamp;
837                         long tz, tz2;
838                         char *end;
839
840                         errno = 0;
841                         timestamp = parse_timestamp(str, &end, 10);
842                         if (errno) {
843                                 rc = error(_("invalid timestamp"));
844                                 goto exit;
845                         }
846
847                         if (!skip_prefix(end, " ", &str)) {
848                                 rc = error(_("invalid Date line"));
849                                 goto exit;
850                         }
851
852                         errno = 0;
853                         tz = strtol(str, &end, 10);
854                         if (errno) {
855                                 rc = error(_("invalid timezone offset"));
856                                 goto exit;
857                         }
858
859                         if (*end) {
860                                 rc = error(_("invalid Date line"));
861                                 goto exit;
862                         }
863
864                         /*
865                          * mercurial's timezone is in seconds west of UTC,
866                          * however git's timezone is in hours + minutes east of
867                          * UTC. Convert it.
868                          */
869                         tz2 = labs(tz) / 3600 * 100 + labs(tz) % 3600 / 60;
870                         if (tz > 0)
871                                 tz2 = -tz2;
872
873                         fprintf(out, "Date: %s\n", show_date(timestamp, tz2, DATE_MODE(RFC2822)));
874                 } else if (starts_with(sb.buf, "# ")) {
875                         continue;
876                 } else {
877                         fprintf(out, "\n%s\n", sb.buf);
878                         break;
879                 }
880         }
881
882         strbuf_reset(&sb);
883         while (strbuf_fread(&sb, 8192, in) > 0) {
884                 fwrite(sb.buf, 1, sb.len, out);
885                 strbuf_reset(&sb);
886         }
887 exit:
888         strbuf_release(&sb);
889         return rc;
890 }
891
892 /**
893  * Splits a list of files/directories into individual email patches. Each path
894  * in `paths` must be a file/directory that is formatted according to
895  * `patch_format`.
896  *
897  * Once split out, the individual email patches will be stored in the state
898  * directory, with each patch's filename being its index, padded to state->prec
899  * digits.
900  *
901  * state->cur will be set to the index of the first mail, and state->last will
902  * be set to the index of the last mail.
903  *
904  * Set keep_cr to 0 to convert all lines ending with \r\n to end with \n, 1
905  * to disable this behavior, -1 to use the default configured setting.
906  *
907  * Returns 0 on success, -1 on failure.
908  */
909 static int split_mail(struct am_state *state, enum patch_format patch_format,
910                         const char **paths, int keep_cr)
911 {
912         if (keep_cr < 0) {
913                 keep_cr = 0;
914                 git_config_get_bool("am.keepcr", &keep_cr);
915         }
916
917         switch (patch_format) {
918         case PATCH_FORMAT_MBOX:
919                 return split_mail_mbox(state, paths, keep_cr, 0);
920         case PATCH_FORMAT_STGIT:
921                 return split_mail_conv(stgit_patch_to_mail, state, paths, keep_cr);
922         case PATCH_FORMAT_STGIT_SERIES:
923                 return split_mail_stgit_series(state, paths, keep_cr);
924         case PATCH_FORMAT_HG:
925                 return split_mail_conv(hg_patch_to_mail, state, paths, keep_cr);
926         case PATCH_FORMAT_MBOXRD:
927                 return split_mail_mbox(state, paths, keep_cr, 1);
928         default:
929                 BUG("invalid patch_format");
930         }
931         return -1;
932 }
933
934 /**
935  * Setup a new am session for applying patches
936  */
937 static void am_setup(struct am_state *state, enum patch_format patch_format,
938                         const char **paths, int keep_cr)
939 {
940         struct object_id curr_head;
941         const char *str;
942         struct strbuf sb = STRBUF_INIT;
943
944         if (!patch_format)
945                 patch_format = detect_patch_format(paths);
946
947         if (!patch_format) {
948                 fprintf_ln(stderr, _("Patch format detection failed."));
949                 exit(128);
950         }
951
952         if (mkdir(state->dir, 0777) < 0 && errno != EEXIST)
953                 die_errno(_("failed to create directory '%s'"), state->dir);
954         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
955
956         if (split_mail(state, patch_format, paths, keep_cr) < 0) {
957                 am_destroy(state);
958                 die(_("Failed to split patches."));
959         }
960
961         if (state->rebasing)
962                 state->threeway = 1;
963
964         write_state_bool(state, "threeway", state->threeway);
965         write_state_bool(state, "quiet", state->quiet);
966         write_state_bool(state, "sign", state->signoff);
967         write_state_bool(state, "utf8", state->utf8);
968
969         if (state->allow_rerere_autoupdate)
970                 write_state_bool(state, "rerere-autoupdate",
971                          state->allow_rerere_autoupdate == RERERE_AUTOUPDATE);
972
973         switch (state->keep) {
974         case KEEP_FALSE:
975                 str = "f";
976                 break;
977         case KEEP_TRUE:
978                 str = "t";
979                 break;
980         case KEEP_NON_PATCH:
981                 str = "b";
982                 break;
983         default:
984                 BUG("invalid value for state->keep");
985         }
986
987         write_state_text(state, "keep", str);
988         write_state_bool(state, "messageid", state->message_id);
989
990         switch (state->scissors) {
991         case SCISSORS_UNSET:
992                 str = "";
993                 break;
994         case SCISSORS_FALSE:
995                 str = "f";
996                 break;
997         case SCISSORS_TRUE:
998                 str = "t";
999                 break;
1000         default:
1001                 BUG("invalid value for state->scissors");
1002         }
1003         write_state_text(state, "scissors", str);
1004
1005         sq_quote_argv(&sb, state->git_apply_opts.v);
1006         write_state_text(state, "apply-opt", sb.buf);
1007
1008         if (state->rebasing)
1009                 write_state_text(state, "rebasing", "");
1010         else
1011                 write_state_text(state, "applying", "");
1012
1013         if (!get_oid("HEAD", &curr_head)) {
1014                 write_state_text(state, "abort-safety", oid_to_hex(&curr_head));
1015                 if (!state->rebasing)
1016                         update_ref("am", "ORIG_HEAD", &curr_head, NULL, 0,
1017                                    UPDATE_REFS_DIE_ON_ERR);
1018         } else {
1019                 write_state_text(state, "abort-safety", "");
1020                 if (!state->rebasing)
1021                         delete_ref(NULL, "ORIG_HEAD", NULL, 0);
1022         }
1023
1024         /*
1025          * NOTE: Since the "next" and "last" files determine if an am_state
1026          * session is in progress, they should be written last.
1027          */
1028
1029         write_state_count(state, "next", state->cur);
1030         write_state_count(state, "last", state->last);
1031
1032         strbuf_release(&sb);
1033 }
1034
1035 /**
1036  * Increments the patch pointer, and cleans am_state for the application of the
1037  * next patch.
1038  */
1039 static void am_next(struct am_state *state)
1040 {
1041         struct object_id head;
1042
1043         FREE_AND_NULL(state->author_name);
1044         FREE_AND_NULL(state->author_email);
1045         FREE_AND_NULL(state->author_date);
1046         FREE_AND_NULL(state->msg);
1047         state->msg_len = 0;
1048
1049         unlink(am_path(state, "author-script"));
1050         unlink(am_path(state, "final-commit"));
1051
1052         oidclr(&state->orig_commit);
1053         unlink(am_path(state, "original-commit"));
1054         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
1055
1056         if (!get_oid("HEAD", &head))
1057                 write_state_text(state, "abort-safety", oid_to_hex(&head));
1058         else
1059                 write_state_text(state, "abort-safety", "");
1060
1061         state->cur++;
1062         write_state_count(state, "next", state->cur);
1063 }
1064
1065 /**
1066  * Returns the filename of the current patch email.
1067  */
1068 static const char *msgnum(const struct am_state *state)
1069 {
1070         static struct strbuf sb = STRBUF_INIT;
1071
1072         strbuf_reset(&sb);
1073         strbuf_addf(&sb, "%0*d", state->prec, state->cur);
1074
1075         return sb.buf;
1076 }
1077
1078 /**
1079  * Dies with a user-friendly message on how to proceed after resolving the
1080  * problem. This message can be overridden with state->resolvemsg.
1081  */
1082 static void NORETURN die_user_resolve(const struct am_state *state)
1083 {
1084         if (state->resolvemsg) {
1085                 printf_ln("%s", state->resolvemsg);
1086         } else {
1087                 const char *cmdline = state->interactive ? "git am -i" : "git am";
1088
1089                 printf_ln(_("When you have resolved this problem, run \"%s --continue\"."), cmdline);
1090                 printf_ln(_("If you prefer to skip this patch, run \"%s --skip\" instead."), cmdline);
1091                 printf_ln(_("To restore the original branch and stop patching, run \"%s --abort\"."), cmdline);
1092         }
1093
1094         exit(128);
1095 }
1096
1097 /**
1098  * Appends signoff to the "msg" field of the am_state.
1099  */
1100 static void am_append_signoff(struct am_state *state)
1101 {
1102         struct strbuf sb = STRBUF_INIT;
1103
1104         strbuf_attach(&sb, state->msg, state->msg_len, state->msg_len);
1105         append_signoff(&sb, 0, 0);
1106         state->msg = strbuf_detach(&sb, &state->msg_len);
1107 }
1108
1109 /**
1110  * Parses `mail` using git-mailinfo, extracting its patch and authorship info.
1111  * state->msg will be set to the patch message. state->author_name,
1112  * state->author_email and state->author_date will be set to the patch author's
1113  * name, email and date respectively. The patch body will be written to the
1114  * state directory's "patch" file.
1115  *
1116  * Returns 1 if the patch should be skipped, 0 otherwise.
1117  */
1118 static int parse_mail(struct am_state *state, const char *mail)
1119 {
1120         FILE *fp;
1121         struct strbuf sb = STRBUF_INIT;
1122         struct strbuf msg = STRBUF_INIT;
1123         struct strbuf author_name = STRBUF_INIT;
1124         struct strbuf author_date = STRBUF_INIT;
1125         struct strbuf author_email = STRBUF_INIT;
1126         int ret = 0;
1127         struct mailinfo mi;
1128
1129         setup_mailinfo(&mi);
1130
1131         if (state->utf8)
1132                 mi.metainfo_charset = get_commit_output_encoding();
1133         else
1134                 mi.metainfo_charset = NULL;
1135
1136         switch (state->keep) {
1137         case KEEP_FALSE:
1138                 break;
1139         case KEEP_TRUE:
1140                 mi.keep_subject = 1;
1141                 break;
1142         case KEEP_NON_PATCH:
1143                 mi.keep_non_patch_brackets_in_subject = 1;
1144                 break;
1145         default:
1146                 BUG("invalid value for state->keep");
1147         }
1148
1149         if (state->message_id)
1150                 mi.add_message_id = 1;
1151
1152         switch (state->scissors) {
1153         case SCISSORS_UNSET:
1154                 break;
1155         case SCISSORS_FALSE:
1156                 mi.use_scissors = 0;
1157                 break;
1158         case SCISSORS_TRUE:
1159                 mi.use_scissors = 1;
1160                 break;
1161         default:
1162                 BUG("invalid value for state->scissors");
1163         }
1164
1165         mi.input = xfopen(mail, "r");
1166         mi.output = xfopen(am_path(state, "info"), "w");
1167         if (mailinfo(&mi, am_path(state, "msg"), am_path(state, "patch")))
1168                 die("could not parse patch");
1169
1170         fclose(mi.input);
1171         fclose(mi.output);
1172
1173         if (mi.format_flowed)
1174                 warning(_("Patch sent with format=flowed; "
1175                           "space at the end of lines might be lost."));
1176
1177         /* Extract message and author information */
1178         fp = xfopen(am_path(state, "info"), "r");
1179         while (!strbuf_getline_lf(&sb, fp)) {
1180                 const char *x;
1181
1182                 if (skip_prefix(sb.buf, "Subject: ", &x)) {
1183                         if (msg.len)
1184                                 strbuf_addch(&msg, '\n');
1185                         strbuf_addstr(&msg, x);
1186                 } else if (skip_prefix(sb.buf, "Author: ", &x))
1187                         strbuf_addstr(&author_name, x);
1188                 else if (skip_prefix(sb.buf, "Email: ", &x))
1189                         strbuf_addstr(&author_email, x);
1190                 else if (skip_prefix(sb.buf, "Date: ", &x))
1191                         strbuf_addstr(&author_date, x);
1192         }
1193         fclose(fp);
1194
1195         /* Skip pine's internal folder data */
1196         if (!strcmp(author_name.buf, "Mail System Internal Data")) {
1197                 ret = 1;
1198                 goto finish;
1199         }
1200
1201         if (is_empty_or_missing_file(am_path(state, "patch"))) {
1202                 printf_ln(_("Patch is empty."));
1203                 die_user_resolve(state);
1204         }
1205
1206         strbuf_addstr(&msg, "\n\n");
1207         strbuf_addbuf(&msg, &mi.log_message);
1208         strbuf_stripspace(&msg, 0);
1209
1210         assert(!state->author_name);
1211         state->author_name = strbuf_detach(&author_name, NULL);
1212
1213         assert(!state->author_email);
1214         state->author_email = strbuf_detach(&author_email, NULL);
1215
1216         assert(!state->author_date);
1217         state->author_date = strbuf_detach(&author_date, NULL);
1218
1219         assert(!state->msg);
1220         state->msg = strbuf_detach(&msg, &state->msg_len);
1221
1222 finish:
1223         strbuf_release(&msg);
1224         strbuf_release(&author_date);
1225         strbuf_release(&author_email);
1226         strbuf_release(&author_name);
1227         strbuf_release(&sb);
1228         clear_mailinfo(&mi);
1229         return ret;
1230 }
1231
1232 /**
1233  * Sets commit_id to the commit hash where the mail was generated from.
1234  * Returns 0 on success, -1 on failure.
1235  */
1236 static int get_mail_commit_oid(struct object_id *commit_id, const char *mail)
1237 {
1238         struct strbuf sb = STRBUF_INIT;
1239         FILE *fp = xfopen(mail, "r");
1240         const char *x;
1241         int ret = 0;
1242
1243         if (strbuf_getline_lf(&sb, fp) ||
1244             !skip_prefix(sb.buf, "From ", &x) ||
1245             get_oid_hex(x, commit_id) < 0)
1246                 ret = -1;
1247
1248         strbuf_release(&sb);
1249         fclose(fp);
1250         return ret;
1251 }
1252
1253 /**
1254  * Sets state->msg, state->author_name, state->author_email, state->author_date
1255  * to the commit's respective info.
1256  */
1257 static void get_commit_info(struct am_state *state, struct commit *commit)
1258 {
1259         const char *buffer, *ident_line, *msg;
1260         size_t ident_len;
1261         struct ident_split id;
1262
1263         buffer = logmsg_reencode(commit, NULL, get_commit_output_encoding());
1264
1265         ident_line = find_commit_header(buffer, "author", &ident_len);
1266         if (!ident_line)
1267                 die(_("missing author line in commit %s"),
1268                       oid_to_hex(&commit->object.oid));
1269         if (split_ident_line(&id, ident_line, ident_len) < 0)
1270                 die(_("invalid ident line: %.*s"), (int)ident_len, ident_line);
1271
1272         assert(!state->author_name);
1273         if (id.name_begin)
1274                 state->author_name =
1275                         xmemdupz(id.name_begin, id.name_end - id.name_begin);
1276         else
1277                 state->author_name = xstrdup("");
1278
1279         assert(!state->author_email);
1280         if (id.mail_begin)
1281                 state->author_email =
1282                         xmemdupz(id.mail_begin, id.mail_end - id.mail_begin);
1283         else
1284                 state->author_email = xstrdup("");
1285
1286         assert(!state->author_date);
1287         state->author_date = xstrdup(show_ident_date(&id, DATE_MODE(NORMAL)));
1288
1289         assert(!state->msg);
1290         msg = strstr(buffer, "\n\n");
1291         if (!msg)
1292                 die(_("unable to parse commit %s"), oid_to_hex(&commit->object.oid));
1293         state->msg = xstrdup(msg + 2);
1294         state->msg_len = strlen(state->msg);
1295         unuse_commit_buffer(commit, buffer);
1296 }
1297
1298 /**
1299  * Writes `commit` as a patch to the state directory's "patch" file.
1300  */
1301 static void write_commit_patch(const struct am_state *state, struct commit *commit)
1302 {
1303         struct rev_info rev_info;
1304         FILE *fp;
1305
1306         fp = xfopen(am_path(state, "patch"), "w");
1307         repo_init_revisions(the_repository, &rev_info, NULL);
1308         rev_info.diff = 1;
1309         rev_info.abbrev = 0;
1310         rev_info.disable_stdin = 1;
1311         rev_info.show_root_diff = 1;
1312         rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
1313         rev_info.no_commit_id = 1;
1314         rev_info.diffopt.flags.binary = 1;
1315         rev_info.diffopt.flags.full_index = 1;
1316         rev_info.diffopt.use_color = 0;
1317         rev_info.diffopt.file = fp;
1318         rev_info.diffopt.close_file = 1;
1319         add_pending_object(&rev_info, &commit->object, "");
1320         diff_setup_done(&rev_info.diffopt);
1321         log_tree_commit(&rev_info, commit);
1322 }
1323
1324 /**
1325  * Writes the diff of the index against HEAD as a patch to the state
1326  * directory's "patch" file.
1327  */
1328 static void write_index_patch(const struct am_state *state)
1329 {
1330         struct tree *tree;
1331         struct object_id head;
1332         struct rev_info rev_info;
1333         FILE *fp;
1334
1335         if (!get_oid("HEAD", &head)) {
1336                 struct commit *commit = lookup_commit_or_die(&head, "HEAD");
1337                 tree = get_commit_tree(commit);
1338         } else
1339                 tree = lookup_tree(the_repository,
1340                                    the_repository->hash_algo->empty_tree);
1341
1342         fp = xfopen(am_path(state, "patch"), "w");
1343         repo_init_revisions(the_repository, &rev_info, NULL);
1344         rev_info.diff = 1;
1345         rev_info.disable_stdin = 1;
1346         rev_info.no_commit_id = 1;
1347         rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
1348         rev_info.diffopt.use_color = 0;
1349         rev_info.diffopt.file = fp;
1350         rev_info.diffopt.close_file = 1;
1351         add_pending_object(&rev_info, &tree->object, "");
1352         diff_setup_done(&rev_info.diffopt);
1353         run_diff_index(&rev_info, 1);
1354 }
1355
1356 /**
1357  * Like parse_mail(), but parses the mail by looking up its commit ID
1358  * directly. This is used in --rebasing mode to bypass git-mailinfo's munging
1359  * of patches.
1360  *
1361  * state->orig_commit will be set to the original commit ID.
1362  *
1363  * Will always return 0 as the patch should never be skipped.
1364  */
1365 static int parse_mail_rebase(struct am_state *state, const char *mail)
1366 {
1367         struct commit *commit;
1368         struct object_id commit_oid;
1369
1370         if (get_mail_commit_oid(&commit_oid, mail) < 0)
1371                 die(_("could not parse %s"), mail);
1372
1373         commit = lookup_commit_or_die(&commit_oid, mail);
1374
1375         get_commit_info(state, commit);
1376
1377         write_commit_patch(state, commit);
1378
1379         oidcpy(&state->orig_commit, &commit_oid);
1380         write_state_text(state, "original-commit", oid_to_hex(&commit_oid));
1381         update_ref("am", "REBASE_HEAD", &commit_oid,
1382                    NULL, REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);
1383
1384         return 0;
1385 }
1386
1387 /**
1388  * Applies current patch with git-apply. Returns 0 on success, -1 otherwise. If
1389  * `index_file` is not NULL, the patch will be applied to that index.
1390  */
1391 static int run_apply(const struct am_state *state, const char *index_file)
1392 {
1393         struct strvec apply_paths = STRVEC_INIT;
1394         struct strvec apply_opts = STRVEC_INIT;
1395         struct apply_state apply_state;
1396         int res, opts_left;
1397         int force_apply = 0;
1398         int options = 0;
1399
1400         if (init_apply_state(&apply_state, the_repository, NULL))
1401                 BUG("init_apply_state() failed");
1402
1403         strvec_push(&apply_opts, "apply");
1404         strvec_pushv(&apply_opts, state->git_apply_opts.v);
1405
1406         opts_left = apply_parse_options(apply_opts.nr, apply_opts.v,
1407                                         &apply_state, &force_apply, &options,
1408                                         NULL);
1409
1410         if (opts_left != 0)
1411                 die("unknown option passed through to git apply");
1412
1413         if (index_file) {
1414                 apply_state.index_file = index_file;
1415                 apply_state.cached = 1;
1416         } else
1417                 apply_state.check_index = 1;
1418
1419         /*
1420          * If we are allowed to fall back on 3-way merge, don't give false
1421          * errors during the initial attempt.
1422          */
1423         if (state->threeway && !index_file)
1424                 apply_state.apply_verbosity = verbosity_silent;
1425
1426         if (check_apply_state(&apply_state, force_apply))
1427                 BUG("check_apply_state() failed");
1428
1429         strvec_push(&apply_paths, am_path(state, "patch"));
1430
1431         res = apply_all_patches(&apply_state, apply_paths.nr, apply_paths.v, options);
1432
1433         strvec_clear(&apply_paths);
1434         strvec_clear(&apply_opts);
1435         clear_apply_state(&apply_state);
1436
1437         if (res)
1438                 return res;
1439
1440         if (index_file) {
1441                 /* Reload index as apply_all_patches() will have modified it. */
1442                 discard_cache();
1443                 read_cache_from(index_file);
1444         }
1445
1446         return 0;
1447 }
1448
1449 /**
1450  * Builds an index that contains just the blobs needed for a 3way merge.
1451  */
1452 static int build_fake_ancestor(const struct am_state *state, const char *index_file)
1453 {
1454         struct child_process cp = CHILD_PROCESS_INIT;
1455
1456         cp.git_cmd = 1;
1457         strvec_push(&cp.args, "apply");
1458         strvec_pushv(&cp.args, state->git_apply_opts.v);
1459         strvec_pushf(&cp.args, "--build-fake-ancestor=%s", index_file);
1460         strvec_push(&cp.args, am_path(state, "patch"));
1461
1462         if (run_command(&cp))
1463                 return -1;
1464
1465         return 0;
1466 }
1467
1468 /**
1469  * Attempt a threeway merge, using index_path as the temporary index.
1470  */
1471 static int fall_back_threeway(const struct am_state *state, const char *index_path)
1472 {
1473         struct object_id orig_tree, their_tree, our_tree;
1474         const struct object_id *bases[1] = { &orig_tree };
1475         struct merge_options o;
1476         struct commit *result;
1477         char *their_tree_name;
1478
1479         if (get_oid("HEAD", &our_tree) < 0)
1480                 oidcpy(&our_tree, the_hash_algo->empty_tree);
1481
1482         if (build_fake_ancestor(state, index_path))
1483                 return error("could not build fake ancestor");
1484
1485         discard_cache();
1486         read_cache_from(index_path);
1487
1488         if (write_index_as_tree(&orig_tree, &the_index, index_path, 0, NULL))
1489                 return error(_("Repository lacks necessary blobs to fall back on 3-way merge."));
1490
1491         say(state, stdout, _("Using index info to reconstruct a base tree..."));
1492
1493         if (!state->quiet) {
1494                 /*
1495                  * List paths that needed 3-way fallback, so that the user can
1496                  * review them with extra care to spot mismerges.
1497                  */
1498                 struct rev_info rev_info;
1499
1500                 repo_init_revisions(the_repository, &rev_info, NULL);
1501                 rev_info.diffopt.output_format = DIFF_FORMAT_NAME_STATUS;
1502                 rev_info.diffopt.filter |= diff_filter_bit('A');
1503                 rev_info.diffopt.filter |= diff_filter_bit('M');
1504                 add_pending_oid(&rev_info, "HEAD", &our_tree, 0);
1505                 diff_setup_done(&rev_info.diffopt);
1506                 run_diff_index(&rev_info, 1);
1507         }
1508
1509         if (run_apply(state, index_path))
1510                 return error(_("Did you hand edit your patch?\n"
1511                                 "It does not apply to blobs recorded in its index."));
1512
1513         if (write_index_as_tree(&their_tree, &the_index, index_path, 0, NULL))
1514                 return error("could not write tree");
1515
1516         say(state, stdout, _("Falling back to patching base and 3-way merge..."));
1517
1518         discard_cache();
1519         read_cache();
1520
1521         /*
1522          * This is not so wrong. Depending on which base we picked, orig_tree
1523          * may be wildly different from ours, but their_tree has the same set of
1524          * wildly different changes in parts the patch did not touch, so
1525          * recursive ends up canceling them, saying that we reverted all those
1526          * changes.
1527          */
1528
1529         init_merge_options(&o, the_repository);
1530
1531         o.branch1 = "HEAD";
1532         their_tree_name = xstrfmt("%.*s", linelen(state->msg), state->msg);
1533         o.branch2 = their_tree_name;
1534         o.detect_directory_renames = MERGE_DIRECTORY_RENAMES_NONE;
1535
1536         if (state->quiet)
1537                 o.verbosity = 0;
1538
1539         if (merge_recursive_generic(&o, &our_tree, &their_tree, 1, bases, &result)) {
1540                 repo_rerere(the_repository, state->allow_rerere_autoupdate);
1541                 free(their_tree_name);
1542                 return error(_("Failed to merge in the changes."));
1543         }
1544
1545         free(their_tree_name);
1546         return 0;
1547 }
1548
1549 /**
1550  * Commits the current index with state->msg as the commit message and
1551  * state->author_name, state->author_email and state->author_date as the author
1552  * information.
1553  */
1554 static void do_commit(const struct am_state *state)
1555 {
1556         struct object_id tree, parent, commit;
1557         const struct object_id *old_oid;
1558         struct commit_list *parents = NULL;
1559         const char *reflog_msg, *author, *committer = NULL;
1560         struct strbuf sb = STRBUF_INIT;
1561
1562         if (run_hook_le(NULL, "pre-applypatch", NULL))
1563                 exit(1);
1564
1565         if (write_cache_as_tree(&tree, 0, NULL))
1566                 die(_("git write-tree failed to write a tree"));
1567
1568         if (!get_oid_commit("HEAD", &parent)) {
1569                 old_oid = &parent;
1570                 commit_list_insert(lookup_commit(the_repository, &parent),
1571                                    &parents);
1572         } else {
1573                 old_oid = NULL;
1574                 say(state, stderr, _("applying to an empty history"));
1575         }
1576
1577         author = fmt_ident(state->author_name, state->author_email,
1578                 WANT_AUTHOR_IDENT,
1579                         state->ignore_date ? NULL : state->author_date,
1580                         IDENT_STRICT);
1581
1582         if (state->committer_date_is_author_date)
1583                 committer = fmt_ident(getenv("GIT_COMMITTER_NAME"),
1584                                       getenv("GIT_COMMITTER_EMAIL"),
1585                                       WANT_COMMITTER_IDENT,
1586                                       state->ignore_date ? NULL
1587                                                          : state->author_date,
1588                                       IDENT_STRICT);
1589
1590         if (commit_tree_extended(state->msg, state->msg_len, &tree, parents,
1591                                  &commit, author, committer, state->sign_commit,
1592                                  NULL))
1593                 die(_("failed to write commit object"));
1594
1595         reflog_msg = getenv("GIT_REFLOG_ACTION");
1596         if (!reflog_msg)
1597                 reflog_msg = "am";
1598
1599         strbuf_addf(&sb, "%s: %.*s", reflog_msg, linelen(state->msg),
1600                         state->msg);
1601
1602         update_ref(sb.buf, "HEAD", &commit, old_oid, 0,
1603                    UPDATE_REFS_DIE_ON_ERR);
1604
1605         if (state->rebasing) {
1606                 FILE *fp = xfopen(am_path(state, "rewritten"), "a");
1607
1608                 assert(!is_null_oid(&state->orig_commit));
1609                 fprintf(fp, "%s ", oid_to_hex(&state->orig_commit));
1610                 fprintf(fp, "%s\n", oid_to_hex(&commit));
1611                 fclose(fp);
1612         }
1613
1614         run_hook_le(NULL, "post-applypatch", NULL);
1615
1616         strbuf_release(&sb);
1617 }
1618
1619 /**
1620  * Validates the am_state for resuming -- the "msg" and authorship fields must
1621  * be filled up.
1622  */
1623 static void validate_resume_state(const struct am_state *state)
1624 {
1625         if (!state->msg)
1626                 die(_("cannot resume: %s does not exist."),
1627                         am_path(state, "final-commit"));
1628
1629         if (!state->author_name || !state->author_email || !state->author_date)
1630                 die(_("cannot resume: %s does not exist."),
1631                         am_path(state, "author-script"));
1632 }
1633
1634 /**
1635  * Interactively prompt the user on whether the current patch should be
1636  * applied.
1637  *
1638  * Returns 0 if the user chooses to apply the patch, 1 if the user chooses to
1639  * skip it.
1640  */
1641 static int do_interactive(struct am_state *state)
1642 {
1643         assert(state->msg);
1644
1645         for (;;) {
1646                 char reply[64];
1647
1648                 puts(_("Commit Body is:"));
1649                 puts("--------------------------");
1650                 printf("%s", state->msg);
1651                 puts("--------------------------");
1652
1653                 /*
1654                  * TRANSLATORS: Make sure to include [y], [n], [e], [v] and [a]
1655                  * in your translation. The program will only accept English
1656                  * input at this point.
1657                  */
1658                 printf(_("Apply? [y]es/[n]o/[e]dit/[v]iew patch/[a]ccept all: "));
1659                 if (!fgets(reply, sizeof(reply), stdin))
1660                         die("unable to read from stdin; aborting");
1661
1662                 if (*reply == 'y' || *reply == 'Y') {
1663                         return 0;
1664                 } else if (*reply == 'a' || *reply == 'A') {
1665                         state->interactive = 0;
1666                         return 0;
1667                 } else if (*reply == 'n' || *reply == 'N') {
1668                         return 1;
1669                 } else if (*reply == 'e' || *reply == 'E') {
1670                         struct strbuf msg = STRBUF_INIT;
1671
1672                         if (!launch_editor(am_path(state, "final-commit"), &msg, NULL)) {
1673                                 free(state->msg);
1674                                 state->msg = strbuf_detach(&msg, &state->msg_len);
1675                         }
1676                         strbuf_release(&msg);
1677                 } else if (*reply == 'v' || *reply == 'V') {
1678                         const char *pager = git_pager(1);
1679                         struct child_process cp = CHILD_PROCESS_INIT;
1680
1681                         if (!pager)
1682                                 pager = "cat";
1683                         prepare_pager_args(&cp, pager);
1684                         strvec_push(&cp.args, am_path(state, "patch"));
1685                         run_command(&cp);
1686                 }
1687         }
1688 }
1689
1690 /**
1691  * Applies all queued mail.
1692  *
1693  * If `resume` is true, we are "resuming". The "msg" and authorship fields, as
1694  * well as the state directory's "patch" file is used as-is for applying the
1695  * patch and committing it.
1696  */
1697 static void am_run(struct am_state *state, int resume)
1698 {
1699         struct strbuf sb = STRBUF_INIT;
1700
1701         unlink(am_path(state, "dirtyindex"));
1702
1703         if (refresh_and_write_cache(REFRESH_QUIET, 0, 0) < 0)
1704                 die(_("unable to write index file"));
1705
1706         if (repo_index_has_changes(the_repository, NULL, &sb)) {
1707                 write_state_bool(state, "dirtyindex", 1);
1708                 die(_("Dirty index: cannot apply patches (dirty: %s)"), sb.buf);
1709         }
1710
1711         strbuf_release(&sb);
1712
1713         while (state->cur <= state->last) {
1714                 const char *mail = am_path(state, msgnum(state));
1715                 int apply_status;
1716
1717                 reset_ident_date();
1718
1719                 if (!file_exists(mail))
1720                         goto next;
1721
1722                 if (resume) {
1723                         validate_resume_state(state);
1724                 } else {
1725                         int skip;
1726
1727                         if (state->rebasing)
1728                                 skip = parse_mail_rebase(state, mail);
1729                         else
1730                                 skip = parse_mail(state, mail);
1731
1732                         if (skip)
1733                                 goto next; /* mail should be skipped */
1734
1735                         if (state->signoff)
1736                                 am_append_signoff(state);
1737
1738                         write_author_script(state);
1739                         write_commit_msg(state);
1740                 }
1741
1742                 if (state->interactive && do_interactive(state))
1743                         goto next;
1744
1745                 if (run_applypatch_msg_hook(state))
1746                         exit(1);
1747
1748                 say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
1749
1750                 apply_status = run_apply(state, NULL);
1751
1752                 if (apply_status && state->threeway) {
1753                         struct strbuf sb = STRBUF_INIT;
1754
1755                         strbuf_addstr(&sb, am_path(state, "patch-merge-index"));
1756                         apply_status = fall_back_threeway(state, sb.buf);
1757                         strbuf_release(&sb);
1758
1759                         /*
1760                          * Applying the patch to an earlier tree and merging
1761                          * the result may have produced the same tree as ours.
1762                          */
1763                         if (!apply_status &&
1764                             !repo_index_has_changes(the_repository, NULL, NULL)) {
1765                                 say(state, stdout, _("No changes -- Patch already applied."));
1766                                 goto next;
1767                         }
1768                 }
1769
1770                 if (apply_status) {
1771                         printf_ln(_("Patch failed at %s %.*s"), msgnum(state),
1772                                 linelen(state->msg), state->msg);
1773
1774                         if (advice_amworkdir)
1775                                 advise(_("Use 'git am --show-current-patch=diff' to see the failed patch"));
1776
1777                         die_user_resolve(state);
1778                 }
1779
1780                 do_commit(state);
1781
1782 next:
1783                 am_next(state);
1784
1785                 if (resume)
1786                         am_load(state);
1787                 resume = 0;
1788         }
1789
1790         if (!is_empty_or_missing_file(am_path(state, "rewritten"))) {
1791                 assert(state->rebasing);
1792                 copy_notes_for_rebase(state);
1793                 run_post_rewrite_hook(state);
1794         }
1795
1796         /*
1797          * In rebasing mode, it's up to the caller to take care of
1798          * housekeeping.
1799          */
1800         if (!state->rebasing) {
1801                 am_destroy(state);
1802                 close_object_store(the_repository->objects);
1803                 run_auto_maintenance(state->quiet);
1804         }
1805 }
1806
1807 /**
1808  * Resume the current am session after patch application failure. The user did
1809  * all the hard work, and we do not have to do any patch application. Just
1810  * trust and commit what the user has in the index and working tree.
1811  */
1812 static void am_resolve(struct am_state *state)
1813 {
1814         validate_resume_state(state);
1815
1816         say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
1817
1818         if (!repo_index_has_changes(the_repository, NULL, NULL)) {
1819                 printf_ln(_("No changes - did you forget to use 'git add'?\n"
1820                         "If there is nothing left to stage, chances are that something else\n"
1821                         "already introduced the same changes; you might want to skip this patch."));
1822                 die_user_resolve(state);
1823         }
1824
1825         if (unmerged_cache()) {
1826                 printf_ln(_("You still have unmerged paths in your index.\n"
1827                         "You should 'git add' each file with resolved conflicts to mark them as such.\n"
1828                         "You might run `git rm` on a file to accept \"deleted by them\" for it."));
1829                 die_user_resolve(state);
1830         }
1831
1832         if (state->interactive) {
1833                 write_index_patch(state);
1834                 if (do_interactive(state))
1835                         goto next;
1836         }
1837
1838         repo_rerere(the_repository, 0);
1839
1840         do_commit(state);
1841
1842 next:
1843         am_next(state);
1844         am_load(state);
1845         am_run(state, 0);
1846 }
1847
1848 /**
1849  * Performs a checkout fast-forward from `head` to `remote`. If `reset` is
1850  * true, any unmerged entries will be discarded. Returns 0 on success, -1 on
1851  * failure.
1852  */
1853 static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
1854 {
1855         struct lock_file lock_file = LOCK_INIT;
1856         struct unpack_trees_options opts;
1857         struct tree_desc t[2];
1858
1859         if (parse_tree(head) || parse_tree(remote))
1860                 return -1;
1861
1862         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
1863
1864         refresh_cache(REFRESH_QUIET);
1865
1866         memset(&opts, 0, sizeof(opts));
1867         opts.head_idx = 1;
1868         opts.src_index = &the_index;
1869         opts.dst_index = &the_index;
1870         opts.update = 1;
1871         opts.merge = 1;
1872         opts.reset = reset;
1873         opts.fn = twoway_merge;
1874         init_tree_desc(&t[0], head->buffer, head->size);
1875         init_tree_desc(&t[1], remote->buffer, remote->size);
1876
1877         if (unpack_trees(2, t, &opts)) {
1878                 rollback_lock_file(&lock_file);
1879                 return -1;
1880         }
1881
1882         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
1883                 die(_("unable to write new index file"));
1884
1885         return 0;
1886 }
1887
1888 /**
1889  * Merges a tree into the index. The index's stat info will take precedence
1890  * over the merged tree's. Returns 0 on success, -1 on failure.
1891  */
1892 static int merge_tree(struct tree *tree)
1893 {
1894         struct lock_file lock_file = LOCK_INIT;
1895         struct unpack_trees_options opts;
1896         struct tree_desc t[1];
1897
1898         if (parse_tree(tree))
1899                 return -1;
1900
1901         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
1902
1903         memset(&opts, 0, sizeof(opts));
1904         opts.head_idx = 1;
1905         opts.src_index = &the_index;
1906         opts.dst_index = &the_index;
1907         opts.merge = 1;
1908         opts.fn = oneway_merge;
1909         init_tree_desc(&t[0], tree->buffer, tree->size);
1910
1911         if (unpack_trees(1, t, &opts)) {
1912                 rollback_lock_file(&lock_file);
1913                 return -1;
1914         }
1915
1916         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
1917                 die(_("unable to write new index file"));
1918
1919         return 0;
1920 }
1921
1922 /**
1923  * Clean the index without touching entries that are not modified between
1924  * `head` and `remote`.
1925  */
1926 static int clean_index(const struct object_id *head, const struct object_id *remote)
1927 {
1928         struct tree *head_tree, *remote_tree, *index_tree;
1929         struct object_id index;
1930
1931         head_tree = parse_tree_indirect(head);
1932         if (!head_tree)
1933                 return error(_("Could not parse object '%s'."), oid_to_hex(head));
1934
1935         remote_tree = parse_tree_indirect(remote);
1936         if (!remote_tree)
1937                 return error(_("Could not parse object '%s'."), oid_to_hex(remote));
1938
1939         read_cache_unmerged();
1940
1941         if (fast_forward_to(head_tree, head_tree, 1))
1942                 return -1;
1943
1944         if (write_cache_as_tree(&index, 0, NULL))
1945                 return -1;
1946
1947         index_tree = parse_tree_indirect(&index);
1948         if (!index_tree)
1949                 return error(_("Could not parse object '%s'."), oid_to_hex(&index));
1950
1951         if (fast_forward_to(index_tree, remote_tree, 0))
1952                 return -1;
1953
1954         if (merge_tree(remote_tree))
1955                 return -1;
1956
1957         remove_branch_state(the_repository, 0);
1958
1959         return 0;
1960 }
1961
1962 /**
1963  * Resets rerere's merge resolution metadata.
1964  */
1965 static void am_rerere_clear(void)
1966 {
1967         struct string_list merge_rr = STRING_LIST_INIT_DUP;
1968         rerere_clear(the_repository, &merge_rr);
1969         string_list_clear(&merge_rr, 1);
1970 }
1971
1972 /**
1973  * Resume the current am session by skipping the current patch.
1974  */
1975 static void am_skip(struct am_state *state)
1976 {
1977         struct object_id head;
1978
1979         am_rerere_clear();
1980
1981         if (get_oid("HEAD", &head))
1982                 oidcpy(&head, the_hash_algo->empty_tree);
1983
1984         if (clean_index(&head, &head))
1985                 die(_("failed to clean index"));
1986
1987         if (state->rebasing) {
1988                 FILE *fp = xfopen(am_path(state, "rewritten"), "a");
1989
1990                 assert(!is_null_oid(&state->orig_commit));
1991                 fprintf(fp, "%s ", oid_to_hex(&state->orig_commit));
1992                 fprintf(fp, "%s\n", oid_to_hex(&head));
1993                 fclose(fp);
1994         }
1995
1996         am_next(state);
1997         am_load(state);
1998         am_run(state, 0);
1999 }
2000
2001 /**
2002  * Returns true if it is safe to reset HEAD to the ORIG_HEAD, false otherwise.
2003  *
2004  * It is not safe to reset HEAD when:
2005  * 1. git-am previously failed because the index was dirty.
2006  * 2. HEAD has moved since git-am previously failed.
2007  */
2008 static int safe_to_abort(const struct am_state *state)
2009 {
2010         struct strbuf sb = STRBUF_INIT;
2011         struct object_id abort_safety, head;
2012
2013         if (file_exists(am_path(state, "dirtyindex")))
2014                 return 0;
2015
2016         if (read_state_file(&sb, state, "abort-safety", 1) > 0) {
2017                 if (get_oid_hex(sb.buf, &abort_safety))
2018                         die(_("could not parse %s"), am_path(state, "abort-safety"));
2019         } else
2020                 oidclr(&abort_safety);
2021         strbuf_release(&sb);
2022
2023         if (get_oid("HEAD", &head))
2024                 oidclr(&head);
2025
2026         if (oideq(&head, &abort_safety))
2027                 return 1;
2028
2029         warning(_("You seem to have moved HEAD since the last 'am' failure.\n"
2030                 "Not rewinding to ORIG_HEAD"));
2031
2032         return 0;
2033 }
2034
2035 /**
2036  * Aborts the current am session if it is safe to do so.
2037  */
2038 static void am_abort(struct am_state *state)
2039 {
2040         struct object_id curr_head, orig_head;
2041         int has_curr_head, has_orig_head;
2042         char *curr_branch;
2043
2044         if (!safe_to_abort(state)) {
2045                 am_destroy(state);
2046                 return;
2047         }
2048
2049         am_rerere_clear();
2050
2051         curr_branch = resolve_refdup("HEAD", 0, &curr_head, NULL);
2052         has_curr_head = curr_branch && !is_null_oid(&curr_head);
2053         if (!has_curr_head)
2054                 oidcpy(&curr_head, the_hash_algo->empty_tree);
2055
2056         has_orig_head = !get_oid("ORIG_HEAD", &orig_head);
2057         if (!has_orig_head)
2058                 oidcpy(&orig_head, the_hash_algo->empty_tree);
2059
2060         clean_index(&curr_head, &orig_head);
2061
2062         if (has_orig_head)
2063                 update_ref("am --abort", "HEAD", &orig_head,
2064                            has_curr_head ? &curr_head : NULL, 0,
2065                            UPDATE_REFS_DIE_ON_ERR);
2066         else if (curr_branch)
2067                 delete_ref(NULL, curr_branch, NULL, REF_NO_DEREF);
2068
2069         free(curr_branch);
2070         am_destroy(state);
2071 }
2072
2073 static int show_patch(struct am_state *state, enum show_patch_type sub_mode)
2074 {
2075         struct strbuf sb = STRBUF_INIT;
2076         const char *patch_path;
2077         int len;
2078
2079         if (!is_null_oid(&state->orig_commit)) {
2080                 const char *av[4] = { "show", NULL, "--", NULL };
2081                 char *new_oid_str;
2082                 int ret;
2083
2084                 av[1] = new_oid_str = xstrdup(oid_to_hex(&state->orig_commit));
2085                 ret = run_command_v_opt(av, RUN_GIT_CMD);
2086                 free(new_oid_str);
2087                 return ret;
2088         }
2089
2090         switch (sub_mode) {
2091         case SHOW_PATCH_RAW:
2092                 patch_path = am_path(state, msgnum(state));
2093                 break;
2094         case SHOW_PATCH_DIFF:
2095                 patch_path = am_path(state, "patch");
2096                 break;
2097         default:
2098                 BUG("invalid mode for --show-current-patch");
2099         }
2100
2101         len = strbuf_read_file(&sb, patch_path, 0);
2102         if (len < 0)
2103                 die_errno(_("failed to read '%s'"), patch_path);
2104
2105         setup_pager();
2106         write_in_full(1, sb.buf, sb.len);
2107         strbuf_release(&sb);
2108         return 0;
2109 }
2110
2111 /**
2112  * parse_options() callback that validates and sets opt->value to the
2113  * PATCH_FORMAT_* enum value corresponding to `arg`.
2114  */
2115 static int parse_opt_patchformat(const struct option *opt, const char *arg, int unset)
2116 {
2117         int *opt_value = opt->value;
2118
2119         if (unset)
2120                 *opt_value = PATCH_FORMAT_UNKNOWN;
2121         else if (!strcmp(arg, "mbox"))
2122                 *opt_value = PATCH_FORMAT_MBOX;
2123         else if (!strcmp(arg, "stgit"))
2124                 *opt_value = PATCH_FORMAT_STGIT;
2125         else if (!strcmp(arg, "stgit-series"))
2126                 *opt_value = PATCH_FORMAT_STGIT_SERIES;
2127         else if (!strcmp(arg, "hg"))
2128                 *opt_value = PATCH_FORMAT_HG;
2129         else if (!strcmp(arg, "mboxrd"))
2130                 *opt_value = PATCH_FORMAT_MBOXRD;
2131         /*
2132          * Please update $__git_patchformat in git-completion.bash
2133          * when you add new options
2134          */
2135         else
2136                 return error(_("Invalid value for --patch-format: %s"), arg);
2137         return 0;
2138 }
2139
2140 enum resume_type {
2141         RESUME_FALSE = 0,
2142         RESUME_APPLY,
2143         RESUME_RESOLVED,
2144         RESUME_SKIP,
2145         RESUME_ABORT,
2146         RESUME_QUIT,
2147         RESUME_SHOW_PATCH
2148 };
2149
2150 struct resume_mode {
2151         enum resume_type mode;
2152         enum show_patch_type sub_mode;
2153 };
2154
2155 static int parse_opt_show_current_patch(const struct option *opt, const char *arg, int unset)
2156 {
2157         int *opt_value = opt->value;
2158         struct resume_mode *resume = container_of(opt_value, struct resume_mode, mode);
2159
2160         /*
2161          * Please update $__git_showcurrentpatch in git-completion.bash
2162          * when you add new options
2163          */
2164         const char *valid_modes[] = {
2165                 [SHOW_PATCH_DIFF] = "diff",
2166                 [SHOW_PATCH_RAW] = "raw"
2167         };
2168         int new_value = SHOW_PATCH_RAW;
2169
2170         BUG_ON_OPT_NEG(unset);
2171
2172         if (arg) {
2173                 for (new_value = 0; new_value < ARRAY_SIZE(valid_modes); new_value++) {
2174                         if (!strcmp(arg, valid_modes[new_value]))
2175                                 break;
2176                 }
2177                 if (new_value >= ARRAY_SIZE(valid_modes))
2178                         return error(_("Invalid value for --show-current-patch: %s"), arg);
2179         }
2180
2181         if (resume->mode == RESUME_SHOW_PATCH && new_value != resume->sub_mode)
2182                 return error(_("--show-current-patch=%s is incompatible with "
2183                                "--show-current-patch=%s"),
2184                              arg, valid_modes[resume->sub_mode]);
2185
2186         resume->mode = RESUME_SHOW_PATCH;
2187         resume->sub_mode = new_value;
2188         return 0;
2189 }
2190
2191 static int git_am_config(const char *k, const char *v, void *cb)
2192 {
2193         int status;
2194
2195         status = git_gpg_config(k, v, NULL);
2196         if (status)
2197                 return status;
2198
2199         return git_default_config(k, v, NULL);
2200 }
2201
2202 int cmd_am(int argc, const char **argv, const char *prefix)
2203 {
2204         struct am_state state;
2205         int binary = -1;
2206         int keep_cr = -1;
2207         int patch_format = PATCH_FORMAT_UNKNOWN;
2208         struct resume_mode resume = { .mode = RESUME_FALSE };
2209         int in_progress;
2210         int ret = 0;
2211
2212         const char * const usage[] = {
2213                 N_("git am [<options>] [(<mbox> | <Maildir>)...]"),
2214                 N_("git am [<options>] (--continue | --skip | --abort)"),
2215                 NULL
2216         };
2217
2218         struct option options[] = {
2219                 OPT_BOOL('i', "interactive", &state.interactive,
2220                         N_("run interactively")),
2221                 OPT_HIDDEN_BOOL('b', "binary", &binary,
2222                         N_("historical option -- no-op")),
2223                 OPT_BOOL('3', "3way", &state.threeway,
2224                         N_("allow fall back on 3way merging if needed")),
2225                 OPT__QUIET(&state.quiet, N_("be quiet")),
2226                 OPT_SET_INT('s', "signoff", &state.signoff,
2227                         N_("add a Signed-off-by trailer to the commit message"),
2228                         SIGNOFF_EXPLICIT),
2229                 OPT_BOOL('u', "utf8", &state.utf8,
2230                         N_("recode into utf8 (default)")),
2231                 OPT_SET_INT('k', "keep", &state.keep,
2232                         N_("pass -k flag to git-mailinfo"), KEEP_TRUE),
2233                 OPT_SET_INT(0, "keep-non-patch", &state.keep,
2234                         N_("pass -b flag to git-mailinfo"), KEEP_NON_PATCH),
2235                 OPT_BOOL('m', "message-id", &state.message_id,
2236                         N_("pass -m flag to git-mailinfo")),
2237                 OPT_SET_INT_F(0, "keep-cr", &keep_cr,
2238                         N_("pass --keep-cr flag to git-mailsplit for mbox format"),
2239                         1, PARSE_OPT_NONEG),
2240                 OPT_SET_INT_F(0, "no-keep-cr", &keep_cr,
2241                         N_("do not pass --keep-cr flag to git-mailsplit independent of am.keepcr"),
2242                         0, PARSE_OPT_NONEG),
2243                 OPT_BOOL('c', "scissors", &state.scissors,
2244                         N_("strip everything before a scissors line")),
2245                 OPT_PASSTHRU_ARGV(0, "whitespace", &state.git_apply_opts, N_("action"),
2246                         N_("pass it through git-apply"),
2247                         0),
2248                 OPT_PASSTHRU_ARGV(0, "ignore-space-change", &state.git_apply_opts, NULL,
2249                         N_("pass it through git-apply"),
2250                         PARSE_OPT_NOARG),
2251                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &state.git_apply_opts, NULL,
2252                         N_("pass it through git-apply"),
2253                         PARSE_OPT_NOARG),
2254                 OPT_PASSTHRU_ARGV(0, "directory", &state.git_apply_opts, N_("root"),
2255                         N_("pass it through git-apply"),
2256                         0),
2257                 OPT_PASSTHRU_ARGV(0, "exclude", &state.git_apply_opts, N_("path"),
2258                         N_("pass it through git-apply"),
2259                         0),
2260                 OPT_PASSTHRU_ARGV(0, "include", &state.git_apply_opts, N_("path"),
2261                         N_("pass it through git-apply"),
2262                         0),
2263                 OPT_PASSTHRU_ARGV('C', NULL, &state.git_apply_opts, N_("n"),
2264                         N_("pass it through git-apply"),
2265                         0),
2266                 OPT_PASSTHRU_ARGV('p', NULL, &state.git_apply_opts, N_("num"),
2267                         N_("pass it through git-apply"),
2268                         0),
2269                 OPT_CALLBACK(0, "patch-format", &patch_format, N_("format"),
2270                         N_("format the patch(es) are in"),
2271                         parse_opt_patchformat),
2272                 OPT_PASSTHRU_ARGV(0, "reject", &state.git_apply_opts, NULL,
2273                         N_("pass it through git-apply"),
2274                         PARSE_OPT_NOARG),
2275                 OPT_STRING(0, "resolvemsg", &state.resolvemsg, NULL,
2276                         N_("override error message when patch failure occurs")),
2277                 OPT_CMDMODE(0, "continue", &resume.mode,
2278                         N_("continue applying patches after resolving a conflict"),
2279                         RESUME_RESOLVED),
2280                 OPT_CMDMODE('r', "resolved", &resume.mode,
2281                         N_("synonyms for --continue"),
2282                         RESUME_RESOLVED),
2283                 OPT_CMDMODE(0, "skip", &resume.mode,
2284                         N_("skip the current patch"),
2285                         RESUME_SKIP),
2286                 OPT_CMDMODE(0, "abort", &resume.mode,
2287                         N_("restore the original branch and abort the patching operation"),
2288                         RESUME_ABORT),
2289                 OPT_CMDMODE(0, "quit", &resume.mode,
2290                         N_("abort the patching operation but keep HEAD where it is"),
2291                         RESUME_QUIT),
2292                 { OPTION_CALLBACK, 0, "show-current-patch", &resume.mode,
2293                   "(diff|raw)",
2294                   N_("show the patch being applied"),
2295                   PARSE_OPT_CMDMODE | PARSE_OPT_OPTARG | PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP,
2296                   parse_opt_show_current_patch, RESUME_SHOW_PATCH },
2297                 OPT_BOOL(0, "committer-date-is-author-date",
2298                         &state.committer_date_is_author_date,
2299                         N_("lie about committer date")),
2300                 OPT_BOOL(0, "ignore-date", &state.ignore_date,
2301                         N_("use current timestamp for author date")),
2302                 OPT_RERERE_AUTOUPDATE(&state.allow_rerere_autoupdate),
2303                 { OPTION_STRING, 'S', "gpg-sign", &state.sign_commit, N_("key-id"),
2304                   N_("GPG-sign commits"),
2305                   PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
2306                 OPT_HIDDEN_BOOL(0, "rebasing", &state.rebasing,
2307                         N_("(internal use for git-rebase)")),
2308                 OPT_END()
2309         };
2310
2311         if (argc == 2 && !strcmp(argv[1], "-h"))
2312                 usage_with_options(usage, options);
2313
2314         git_config(git_am_config, NULL);
2315
2316         am_state_init(&state);
2317
2318         in_progress = am_in_progress(&state);
2319         if (in_progress)
2320                 am_load(&state);
2321
2322         argc = parse_options(argc, argv, prefix, options, usage, 0);
2323
2324         if (binary >= 0)
2325                 fprintf_ln(stderr, _("The -b/--binary option has been a no-op for long time, and\n"
2326                                 "it will be removed. Please do not use it anymore."));
2327
2328         /* Ensure a valid committer ident can be constructed */
2329         git_committer_info(IDENT_STRICT);
2330
2331         if (repo_read_index_preload(the_repository, NULL, 0) < 0)
2332                 die(_("failed to read the index"));
2333
2334         if (in_progress) {
2335                 /*
2336                  * Catch user error to feed us patches when there is a session
2337                  * in progress:
2338                  *
2339                  * 1. mbox path(s) are provided on the command-line.
2340                  * 2. stdin is not a tty: the user is trying to feed us a patch
2341                  *    from standard input. This is somewhat unreliable -- stdin
2342                  *    could be /dev/null for example and the caller did not
2343                  *    intend to feed us a patch but wanted to continue
2344                  *    unattended.
2345                  */
2346                 if (argc || (resume.mode == RESUME_FALSE && !isatty(0)))
2347                         die(_("previous rebase directory %s still exists but mbox given."),
2348                                 state.dir);
2349
2350                 if (resume.mode == RESUME_FALSE)
2351                         resume.mode = RESUME_APPLY;
2352
2353                 if (state.signoff == SIGNOFF_EXPLICIT)
2354                         am_append_signoff(&state);
2355         } else {
2356                 struct strvec paths = STRVEC_INIT;
2357                 int i;
2358
2359                 /*
2360                  * Handle stray state directory in the independent-run case. In
2361                  * the --rebasing case, it is up to the caller to take care of
2362                  * stray directories.
2363                  */
2364                 if (file_exists(state.dir) && !state.rebasing) {
2365                         if (resume.mode == RESUME_ABORT || resume.mode == RESUME_QUIT) {
2366                                 am_destroy(&state);
2367                                 am_state_release(&state);
2368                                 return 0;
2369                         }
2370
2371                         die(_("Stray %s directory found.\n"
2372                                 "Use \"git am --abort\" to remove it."),
2373                                 state.dir);
2374                 }
2375
2376                 if (resume.mode)
2377                         die(_("Resolve operation not in progress, we are not resuming."));
2378
2379                 for (i = 0; i < argc; i++) {
2380                         if (is_absolute_path(argv[i]) || !prefix)
2381                                 strvec_push(&paths, argv[i]);
2382                         else
2383                                 strvec_push(&paths, mkpath("%s/%s", prefix, argv[i]));
2384                 }
2385
2386                 if (state.interactive && !paths.nr)
2387                         die(_("interactive mode requires patches on the command line"));
2388
2389                 am_setup(&state, patch_format, paths.v, keep_cr);
2390
2391                 strvec_clear(&paths);
2392         }
2393
2394         switch (resume.mode) {
2395         case RESUME_FALSE:
2396                 am_run(&state, 0);
2397                 break;
2398         case RESUME_APPLY:
2399                 am_run(&state, 1);
2400                 break;
2401         case RESUME_RESOLVED:
2402                 am_resolve(&state);
2403                 break;
2404         case RESUME_SKIP:
2405                 am_skip(&state);
2406                 break;
2407         case RESUME_ABORT:
2408                 am_abort(&state);
2409                 break;
2410         case RESUME_QUIT:
2411                 am_rerere_clear();
2412                 am_destroy(&state);
2413                 break;
2414         case RESUME_SHOW_PATCH:
2415                 ret = show_patch(&state, resume.sub_mode);
2416                 break;
2417         default:
2418                 BUG("invalid resume value");
2419         }
2420
2421         am_state_release(&state);
2422
2423         return ret;
2424 }