Merge branch 'br/commit-tree-parseopt'
[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 "revision.h"
28 #include "log-tree.h"
29 #include "notes-utils.h"
30 #include "rerere.h"
31 #include "prompt.h"
32 #include "mailinfo.h"
33 #include "apply.h"
34 #include "string-list.h"
35 #include "packfile.h"
36 #include "repository.h"
37
38 /**
39  * Returns the length of the first line of msg.
40  */
41 static int linelen(const char *msg)
42 {
43         return strchrnul(msg, '\n') - msg;
44 }
45
46 /**
47  * Returns true if `str` consists of only whitespace, false otherwise.
48  */
49 static int str_isspace(const char *str)
50 {
51         for (; *str; str++)
52                 if (!isspace(*str))
53                         return 0;
54
55         return 1;
56 }
57
58 enum patch_format {
59         PATCH_FORMAT_UNKNOWN = 0,
60         PATCH_FORMAT_MBOX,
61         PATCH_FORMAT_STGIT,
62         PATCH_FORMAT_STGIT_SERIES,
63         PATCH_FORMAT_HG,
64         PATCH_FORMAT_MBOXRD
65 };
66
67 enum keep_type {
68         KEEP_FALSE = 0,
69         KEEP_TRUE,      /* pass -k flag to git-mailinfo */
70         KEEP_NON_PATCH  /* pass -b flag to git-mailinfo */
71 };
72
73 enum scissors_type {
74         SCISSORS_UNSET = -1,
75         SCISSORS_FALSE = 0,  /* pass --no-scissors to git-mailinfo */
76         SCISSORS_TRUE        /* pass --scissors to git-mailinfo */
77 };
78
79 enum signoff_type {
80         SIGNOFF_FALSE = 0,
81         SIGNOFF_TRUE = 1,
82         SIGNOFF_EXPLICIT /* --signoff was set on the command-line */
83 };
84
85 struct am_state {
86         /* state directory path */
87         char *dir;
88
89         /* current and last patch numbers, 1-indexed */
90         int cur;
91         int last;
92
93         /* commit metadata and message */
94         char *author_name;
95         char *author_email;
96         char *author_date;
97         char *msg;
98         size_t msg_len;
99
100         /* when --rebasing, records the original commit the patch came from */
101         struct object_id orig_commit;
102
103         /* number of digits in patch filename */
104         int prec;
105
106         /* various operating modes and command line options */
107         int interactive;
108         int threeway;
109         int quiet;
110         int signoff; /* enum signoff_type */
111         int utf8;
112         int keep; /* enum keep_type */
113         int message_id;
114         int scissors; /* enum scissors_type */
115         struct argv_array git_apply_opts;
116         const char *resolvemsg;
117         int committer_date_is_author_date;
118         int ignore_date;
119         int allow_rerere_autoupdate;
120         const char *sign_commit;
121         int rebasing;
122 };
123
124 /**
125  * Initializes am_state with the default values.
126  */
127 static void am_state_init(struct am_state *state)
128 {
129         int gpgsign;
130
131         memset(state, 0, sizeof(*state));
132
133         state->dir = git_pathdup("rebase-apply");
134
135         state->prec = 4;
136
137         git_config_get_bool("am.threeway", &state->threeway);
138
139         state->utf8 = 1;
140
141         git_config_get_bool("am.messageid", &state->message_id);
142
143         state->scissors = SCISSORS_UNSET;
144
145         argv_array_init(&state->git_apply_opts);
146
147         if (!git_config_get_bool("commit.gpgsign", &gpgsign))
148                 state->sign_commit = gpgsign ? "" : NULL;
149 }
150
151 /**
152  * Releases memory allocated by an am_state.
153  */
154 static void am_state_release(struct am_state *state)
155 {
156         free(state->dir);
157         free(state->author_name);
158         free(state->author_email);
159         free(state->author_date);
160         free(state->msg);
161         argv_array_clear(&state->git_apply_opts);
162 }
163
164 /**
165  * Returns path relative to the am_state directory.
166  */
167 static inline const char *am_path(const struct am_state *state, const char *path)
168 {
169         return mkpath("%s/%s", state->dir, path);
170 }
171
172 /**
173  * For convenience to call write_file()
174  */
175 static void write_state_text(const struct am_state *state,
176                              const char *name, const char *string)
177 {
178         write_file(am_path(state, name), "%s", string);
179 }
180
181 static void write_state_count(const struct am_state *state,
182                               const char *name, int value)
183 {
184         write_file(am_path(state, name), "%d", value);
185 }
186
187 static void write_state_bool(const struct am_state *state,
188                              const char *name, int value)
189 {
190         write_state_text(state, name, value ? "t" : "f");
191 }
192
193 /**
194  * If state->quiet is false, calls fprintf(fp, fmt, ...), and appends a newline
195  * at the end.
196  */
197 static void say(const struct am_state *state, FILE *fp, const char *fmt, ...)
198 {
199         va_list ap;
200
201         va_start(ap, fmt);
202         if (!state->quiet) {
203                 vfprintf(fp, fmt, ap);
204                 putc('\n', fp);
205         }
206         va_end(ap);
207 }
208
209 /**
210  * Returns 1 if there is an am session in progress, 0 otherwise.
211  */
212 static int am_in_progress(const struct am_state *state)
213 {
214         struct stat st;
215
216         if (lstat(state->dir, &st) < 0 || !S_ISDIR(st.st_mode))
217                 return 0;
218         if (lstat(am_path(state, "last"), &st) || !S_ISREG(st.st_mode))
219                 return 0;
220         if (lstat(am_path(state, "next"), &st) || !S_ISREG(st.st_mode))
221                 return 0;
222         return 1;
223 }
224
225 /**
226  * Reads the contents of `file` in the `state` directory into `sb`. Returns the
227  * number of bytes read on success, -1 if the file does not exist. If `trim` is
228  * set, trailing whitespace will be removed.
229  */
230 static int read_state_file(struct strbuf *sb, const struct am_state *state,
231                         const char *file, int trim)
232 {
233         strbuf_reset(sb);
234
235         if (strbuf_read_file(sb, am_path(state, file), 0) >= 0) {
236                 if (trim)
237                         strbuf_trim(sb);
238
239                 return sb->len;
240         }
241
242         if (errno == ENOENT)
243                 return -1;
244
245         die_errno(_("could not read '%s'"), am_path(state, file));
246 }
247
248 /**
249  * Reads and parses the state directory's "author-script" file, and sets
250  * state->author_name, state->author_email and state->author_date accordingly.
251  * Returns 0 on success, -1 if the file could not be parsed.
252  *
253  * The author script is of the format:
254  *
255  *      GIT_AUTHOR_NAME='$author_name'
256  *      GIT_AUTHOR_EMAIL='$author_email'
257  *      GIT_AUTHOR_DATE='$author_date'
258  *
259  * where $author_name, $author_email and $author_date are quoted. We are strict
260  * with our parsing, as the file was meant to be eval'd in the old git-am.sh
261  * script, and thus if the file differs from what this function expects, it is
262  * better to bail out than to do something that the user does not expect.
263  */
264 static int read_am_author_script(struct am_state *state)
265 {
266         const char *filename = am_path(state, "author-script");
267
268         assert(!state->author_name);
269         assert(!state->author_email);
270         assert(!state->author_date);
271
272         return read_author_script(filename, &state->author_name,
273                                   &state->author_email, &state->author_date, 1);
274 }
275
276 /**
277  * Saves state->author_name, state->author_email and state->author_date in the
278  * state directory's "author-script" file.
279  */
280 static void write_author_script(const struct am_state *state)
281 {
282         struct strbuf sb = STRBUF_INIT;
283
284         strbuf_addstr(&sb, "GIT_AUTHOR_NAME=");
285         sq_quote_buf(&sb, state->author_name);
286         strbuf_addch(&sb, '\n');
287
288         strbuf_addstr(&sb, "GIT_AUTHOR_EMAIL=");
289         sq_quote_buf(&sb, state->author_email);
290         strbuf_addch(&sb, '\n');
291
292         strbuf_addstr(&sb, "GIT_AUTHOR_DATE=");
293         sq_quote_buf(&sb, state->author_date);
294         strbuf_addch(&sb, '\n');
295
296         write_state_text(state, "author-script", sb.buf);
297
298         strbuf_release(&sb);
299 }
300
301 /**
302  * Reads the commit message from the state directory's "final-commit" file,
303  * setting state->msg to its contents and state->msg_len to the length of its
304  * contents in bytes.
305  *
306  * Returns 0 on success, -1 if the file does not exist.
307  */
308 static int read_commit_msg(struct am_state *state)
309 {
310         struct strbuf sb = STRBUF_INIT;
311
312         assert(!state->msg);
313
314         if (read_state_file(&sb, state, "final-commit", 0) < 0) {
315                 strbuf_release(&sb);
316                 return -1;
317         }
318
319         state->msg = strbuf_detach(&sb, &state->msg_len);
320         return 0;
321 }
322
323 /**
324  * Saves state->msg in the state directory's "final-commit" file.
325  */
326 static void write_commit_msg(const struct am_state *state)
327 {
328         const char *filename = am_path(state, "final-commit");
329         write_file_buf(filename, state->msg, state->msg_len);
330 }
331
332 /**
333  * Loads state from disk.
334  */
335 static void am_load(struct am_state *state)
336 {
337         struct strbuf sb = STRBUF_INIT;
338
339         if (read_state_file(&sb, state, "next", 1) < 0)
340                 BUG("state file 'next' does not exist");
341         state->cur = strtol(sb.buf, NULL, 10);
342
343         if (read_state_file(&sb, state, "last", 1) < 0)
344                 BUG("state file 'last' does not exist");
345         state->last = strtol(sb.buf, NULL, 10);
346
347         if (read_am_author_script(state) < 0)
348                 die(_("could not parse author script"));
349
350         read_commit_msg(state);
351
352         if (read_state_file(&sb, state, "original-commit", 1) < 0)
353                 oidclr(&state->orig_commit);
354         else if (get_oid_hex(sb.buf, &state->orig_commit) < 0)
355                 die(_("could not parse %s"), am_path(state, "original-commit"));
356
357         read_state_file(&sb, state, "threeway", 1);
358         state->threeway = !strcmp(sb.buf, "t");
359
360         read_state_file(&sb, state, "quiet", 1);
361         state->quiet = !strcmp(sb.buf, "t");
362
363         read_state_file(&sb, state, "sign", 1);
364         state->signoff = !strcmp(sb.buf, "t");
365
366         read_state_file(&sb, state, "utf8", 1);
367         state->utf8 = !strcmp(sb.buf, "t");
368
369         if (file_exists(am_path(state, "rerere-autoupdate"))) {
370                 read_state_file(&sb, state, "rerere-autoupdate", 1);
371                 state->allow_rerere_autoupdate = strcmp(sb.buf, "t") ?
372                         RERERE_NOAUTOUPDATE : RERERE_AUTOUPDATE;
373         } else {
374                 state->allow_rerere_autoupdate = 0;
375         }
376
377         read_state_file(&sb, state, "keep", 1);
378         if (!strcmp(sb.buf, "t"))
379                 state->keep = KEEP_TRUE;
380         else if (!strcmp(sb.buf, "b"))
381                 state->keep = KEEP_NON_PATCH;
382         else
383                 state->keep = KEEP_FALSE;
384
385         read_state_file(&sb, state, "messageid", 1);
386         state->message_id = !strcmp(sb.buf, "t");
387
388         read_state_file(&sb, state, "scissors", 1);
389         if (!strcmp(sb.buf, "t"))
390                 state->scissors = SCISSORS_TRUE;
391         else if (!strcmp(sb.buf, "f"))
392                 state->scissors = SCISSORS_FALSE;
393         else
394                 state->scissors = SCISSORS_UNSET;
395
396         read_state_file(&sb, state, "apply-opt", 1);
397         argv_array_clear(&state->git_apply_opts);
398         if (sq_dequote_to_argv_array(sb.buf, &state->git_apply_opts) < 0)
399                 die(_("could not parse %s"), am_path(state, "apply-opt"));
400
401         state->rebasing = !!file_exists(am_path(state, "rebasing"));
402
403         strbuf_release(&sb);
404 }
405
406 /**
407  * Removes the am_state directory, forcefully terminating the current am
408  * session.
409  */
410 static void am_destroy(const struct am_state *state)
411 {
412         struct strbuf sb = STRBUF_INIT;
413
414         strbuf_addstr(&sb, state->dir);
415         remove_dir_recursively(&sb, 0);
416         strbuf_release(&sb);
417 }
418
419 /**
420  * Runs applypatch-msg hook. Returns its exit code.
421  */
422 static int run_applypatch_msg_hook(struct am_state *state)
423 {
424         int ret;
425
426         assert(state->msg);
427         ret = run_hook_le(NULL, "applypatch-msg", am_path(state, "final-commit"), NULL);
428
429         if (!ret) {
430                 FREE_AND_NULL(state->msg);
431                 if (read_commit_msg(state) < 0)
432                         die(_("'%s' was deleted by the applypatch-msg hook"),
433                                 am_path(state, "final-commit"));
434         }
435
436         return ret;
437 }
438
439 /**
440  * Runs post-rewrite hook. Returns it exit code.
441  */
442 static int run_post_rewrite_hook(const struct am_state *state)
443 {
444         struct child_process cp = CHILD_PROCESS_INIT;
445         const char *hook = find_hook("post-rewrite");
446         int ret;
447
448         if (!hook)
449                 return 0;
450
451         argv_array_push(&cp.args, hook);
452         argv_array_push(&cp.args, "rebase");
453
454         cp.in = xopen(am_path(state, "rewritten"), O_RDONLY);
455         cp.stdout_to_stderr = 1;
456         cp.trace2_hook_name = "post-rewrite";
457
458         ret = run_command(&cp);
459
460         close(cp.in);
461         return ret;
462 }
463
464 /**
465  * Reads the state directory's "rewritten" file, and copies notes from the old
466  * commits listed in the file to their rewritten commits.
467  *
468  * Returns 0 on success, -1 on failure.
469  */
470 static int copy_notes_for_rebase(const struct am_state *state)
471 {
472         struct notes_rewrite_cfg *c;
473         struct strbuf sb = STRBUF_INIT;
474         const char *invalid_line = _("Malformed input line: '%s'.");
475         const char *msg = "Notes added by 'git rebase'";
476         FILE *fp;
477         int ret = 0;
478
479         assert(state->rebasing);
480
481         c = init_copy_notes_for_rewrite("rebase");
482         if (!c)
483                 return 0;
484
485         fp = xfopen(am_path(state, "rewritten"), "r");
486
487         while (!strbuf_getline_lf(&sb, fp)) {
488                 struct object_id from_obj, to_obj;
489
490                 if (sb.len != GIT_SHA1_HEXSZ * 2 + 1) {
491                         ret = error(invalid_line, sb.buf);
492                         goto finish;
493                 }
494
495                 if (get_oid_hex(sb.buf, &from_obj)) {
496                         ret = error(invalid_line, sb.buf);
497                         goto finish;
498                 }
499
500                 if (sb.buf[GIT_SHA1_HEXSZ] != ' ') {
501                         ret = error(invalid_line, sb.buf);
502                         goto finish;
503                 }
504
505                 if (get_oid_hex(sb.buf + GIT_SHA1_HEXSZ + 1, &to_obj)) {
506                         ret = error(invalid_line, sb.buf);
507                         goto finish;
508                 }
509
510                 if (copy_note_for_rewrite(c, &from_obj, &to_obj))
511                         ret = error(_("Failed to copy notes from '%s' to '%s'"),
512                                         oid_to_hex(&from_obj), oid_to_hex(&to_obj));
513         }
514
515 finish:
516         finish_copy_notes_for_rewrite(the_repository, c, msg);
517         fclose(fp);
518         strbuf_release(&sb);
519         return ret;
520 }
521
522 /**
523  * Determines if the file looks like a piece of RFC2822 mail by grabbing all
524  * non-indented lines and checking if they look like they begin with valid
525  * header field names.
526  *
527  * Returns 1 if the file looks like a piece of mail, 0 otherwise.
528  */
529 static int is_mail(FILE *fp)
530 {
531         const char *header_regex = "^[!-9;-~]+:";
532         struct strbuf sb = STRBUF_INIT;
533         regex_t regex;
534         int ret = 1;
535
536         if (fseek(fp, 0L, SEEK_SET))
537                 die_errno(_("fseek failed"));
538
539         if (regcomp(&regex, header_regex, REG_NOSUB | REG_EXTENDED))
540                 die("invalid pattern: %s", header_regex);
541
542         while (!strbuf_getline(&sb, fp)) {
543                 if (!sb.len)
544                         break; /* End of header */
545
546                 /* Ignore indented folded lines */
547                 if (*sb.buf == '\t' || *sb.buf == ' ')
548                         continue;
549
550                 /* It's a header if it matches header_regex */
551                 if (regexec(&regex, sb.buf, 0, NULL, 0)) {
552                         ret = 0;
553                         goto done;
554                 }
555         }
556
557 done:
558         regfree(&regex);
559         strbuf_release(&sb);
560         return ret;
561 }
562
563 /**
564  * Attempts to detect the patch_format of the patches contained in `paths`,
565  * returning the PATCH_FORMAT_* enum value. Returns PATCH_FORMAT_UNKNOWN if
566  * detection fails.
567  */
568 static int detect_patch_format(const char **paths)
569 {
570         enum patch_format ret = PATCH_FORMAT_UNKNOWN;
571         struct strbuf l1 = STRBUF_INIT;
572         struct strbuf l2 = STRBUF_INIT;
573         struct strbuf l3 = STRBUF_INIT;
574         FILE *fp;
575
576         /*
577          * We default to mbox format if input is from stdin and for directories
578          */
579         if (!*paths || !strcmp(*paths, "-") || is_directory(*paths))
580                 return PATCH_FORMAT_MBOX;
581
582         /*
583          * Otherwise, check the first few lines of the first patch, starting
584          * from the first non-blank line, to try to detect its format.
585          */
586
587         fp = xfopen(*paths, "r");
588
589         while (!strbuf_getline(&l1, fp)) {
590                 if (l1.len)
591                         break;
592         }
593
594         if (starts_with(l1.buf, "From ") || starts_with(l1.buf, "From: ")) {
595                 ret = PATCH_FORMAT_MBOX;
596                 goto done;
597         }
598
599         if (starts_with(l1.buf, "# This series applies on GIT commit")) {
600                 ret = PATCH_FORMAT_STGIT_SERIES;
601                 goto done;
602         }
603
604         if (!strcmp(l1.buf, "# HG changeset patch")) {
605                 ret = PATCH_FORMAT_HG;
606                 goto done;
607         }
608
609         strbuf_getline(&l2, fp);
610         strbuf_getline(&l3, fp);
611
612         /*
613          * If the second line is empty and the third is a From, Author or Date
614          * entry, this is likely an StGit patch.
615          */
616         if (l1.len && !l2.len &&
617                 (starts_with(l3.buf, "From:") ||
618                  starts_with(l3.buf, "Author:") ||
619                  starts_with(l3.buf, "Date:"))) {
620                 ret = PATCH_FORMAT_STGIT;
621                 goto done;
622         }
623
624         if (l1.len && is_mail(fp)) {
625                 ret = PATCH_FORMAT_MBOX;
626                 goto done;
627         }
628
629 done:
630         fclose(fp);
631         strbuf_release(&l1);
632         strbuf_release(&l2);
633         strbuf_release(&l3);
634         return ret;
635 }
636
637 /**
638  * Splits out individual email patches from `paths`, where each path is either
639  * a mbox file or a Maildir. Returns 0 on success, -1 on failure.
640  */
641 static int split_mail_mbox(struct am_state *state, const char **paths,
642                                 int keep_cr, int mboxrd)
643 {
644         struct child_process cp = CHILD_PROCESS_INIT;
645         struct strbuf last = STRBUF_INIT;
646         int ret;
647
648         cp.git_cmd = 1;
649         argv_array_push(&cp.args, "mailsplit");
650         argv_array_pushf(&cp.args, "-d%d", state->prec);
651         argv_array_pushf(&cp.args, "-o%s", state->dir);
652         argv_array_push(&cp.args, "-b");
653         if (keep_cr)
654                 argv_array_push(&cp.args, "--keep-cr");
655         if (mboxrd)
656                 argv_array_push(&cp.args, "--mboxrd");
657         argv_array_push(&cp.args, "--");
658         argv_array_pushv(&cp.args, paths);
659
660         ret = capture_command(&cp, &last, 8);
661         if (ret)
662                 goto exit;
663
664         state->cur = 1;
665         state->last = strtol(last.buf, NULL, 10);
666
667 exit:
668         strbuf_release(&last);
669         return ret ? -1 : 0;
670 }
671
672 /**
673  * Callback signature for split_mail_conv(). The foreign patch should be
674  * read from `in`, and the converted patch (in RFC2822 mail format) should be
675  * written to `out`. Return 0 on success, or -1 on failure.
676  */
677 typedef int (*mail_conv_fn)(FILE *out, FILE *in, int keep_cr);
678
679 /**
680  * Calls `fn` for each file in `paths` to convert the foreign patch to the
681  * RFC2822 mail format suitable for parsing with git-mailinfo.
682  *
683  * Returns 0 on success, -1 on failure.
684  */
685 static int split_mail_conv(mail_conv_fn fn, struct am_state *state,
686                         const char **paths, int keep_cr)
687 {
688         static const char *stdin_only[] = {"-", NULL};
689         int i;
690
691         if (!*paths)
692                 paths = stdin_only;
693
694         for (i = 0; *paths; paths++, i++) {
695                 FILE *in, *out;
696                 const char *mail;
697                 int ret;
698
699                 if (!strcmp(*paths, "-"))
700                         in = stdin;
701                 else
702                         in = fopen(*paths, "r");
703
704                 if (!in)
705                         return error_errno(_("could not open '%s' for reading"),
706                                            *paths);
707
708                 mail = mkpath("%s/%0*d", state->dir, state->prec, i + 1);
709
710                 out = fopen(mail, "w");
711                 if (!out) {
712                         if (in != stdin)
713                                 fclose(in);
714                         return error_errno(_("could not open '%s' for writing"),
715                                            mail);
716                 }
717
718                 ret = fn(out, in, keep_cr);
719
720                 fclose(out);
721                 if (in != stdin)
722                         fclose(in);
723
724                 if (ret)
725                         return error(_("could not parse patch '%s'"), *paths);
726         }
727
728         state->cur = 1;
729         state->last = i;
730         return 0;
731 }
732
733 /**
734  * A split_mail_conv() callback that converts an StGit patch to an RFC2822
735  * message suitable for parsing with git-mailinfo.
736  */
737 static int stgit_patch_to_mail(FILE *out, FILE *in, int keep_cr)
738 {
739         struct strbuf sb = STRBUF_INIT;
740         int subject_printed = 0;
741
742         while (!strbuf_getline_lf(&sb, in)) {
743                 const char *str;
744
745                 if (str_isspace(sb.buf))
746                         continue;
747                 else if (skip_prefix(sb.buf, "Author:", &str))
748                         fprintf(out, "From:%s\n", str);
749                 else if (starts_with(sb.buf, "From") || starts_with(sb.buf, "Date"))
750                         fprintf(out, "%s\n", sb.buf);
751                 else if (!subject_printed) {
752                         fprintf(out, "Subject: %s\n", sb.buf);
753                         subject_printed = 1;
754                 } else {
755                         fprintf(out, "\n%s\n", sb.buf);
756                         break;
757                 }
758         }
759
760         strbuf_reset(&sb);
761         while (strbuf_fread(&sb, 8192, in) > 0) {
762                 fwrite(sb.buf, 1, sb.len, out);
763                 strbuf_reset(&sb);
764         }
765
766         strbuf_release(&sb);
767         return 0;
768 }
769
770 /**
771  * This function only supports a single StGit series file in `paths`.
772  *
773  * Given an StGit series file, converts the StGit patches in the series into
774  * RFC2822 messages suitable for parsing with git-mailinfo, and queues them in
775  * the state directory.
776  *
777  * Returns 0 on success, -1 on failure.
778  */
779 static int split_mail_stgit_series(struct am_state *state, const char **paths,
780                                         int keep_cr)
781 {
782         const char *series_dir;
783         char *series_dir_buf;
784         FILE *fp;
785         struct argv_array patches = ARGV_ARRAY_INIT;
786         struct strbuf sb = STRBUF_INIT;
787         int ret;
788
789         if (!paths[0] || paths[1])
790                 return error(_("Only one StGIT patch series can be applied at once"));
791
792         series_dir_buf = xstrdup(*paths);
793         series_dir = dirname(series_dir_buf);
794
795         fp = fopen(*paths, "r");
796         if (!fp)
797                 return error_errno(_("could not open '%s' for reading"), *paths);
798
799         while (!strbuf_getline_lf(&sb, fp)) {
800                 if (*sb.buf == '#')
801                         continue; /* skip comment lines */
802
803                 argv_array_push(&patches, mkpath("%s/%s", series_dir, sb.buf));
804         }
805
806         fclose(fp);
807         strbuf_release(&sb);
808         free(series_dir_buf);
809
810         ret = split_mail_conv(stgit_patch_to_mail, state, patches.argv, keep_cr);
811
812         argv_array_clear(&patches);
813         return ret;
814 }
815
816 /**
817  * A split_patches_conv() callback that converts a mercurial patch to a RFC2822
818  * message suitable for parsing with git-mailinfo.
819  */
820 static int hg_patch_to_mail(FILE *out, FILE *in, int keep_cr)
821 {
822         struct strbuf sb = STRBUF_INIT;
823         int rc = 0;
824
825         while (!strbuf_getline_lf(&sb, in)) {
826                 const char *str;
827
828                 if (skip_prefix(sb.buf, "# User ", &str))
829                         fprintf(out, "From: %s\n", str);
830                 else if (skip_prefix(sb.buf, "# Date ", &str)) {
831                         timestamp_t timestamp;
832                         long tz, tz2;
833                         char *end;
834
835                         errno = 0;
836                         timestamp = parse_timestamp(str, &end, 10);
837                         if (errno) {
838                                 rc = error(_("invalid timestamp"));
839                                 goto exit;
840                         }
841
842                         if (!skip_prefix(end, " ", &str)) {
843                                 rc = error(_("invalid Date line"));
844                                 goto exit;
845                         }
846
847                         errno = 0;
848                         tz = strtol(str, &end, 10);
849                         if (errno) {
850                                 rc = error(_("invalid timezone offset"));
851                                 goto exit;
852                         }
853
854                         if (*end) {
855                                 rc = error(_("invalid Date line"));
856                                 goto exit;
857                         }
858
859                         /*
860                          * mercurial's timezone is in seconds west of UTC,
861                          * however git's timezone is in hours + minutes east of
862                          * UTC. Convert it.
863                          */
864                         tz2 = labs(tz) / 3600 * 100 + labs(tz) % 3600 / 60;
865                         if (tz > 0)
866                                 tz2 = -tz2;
867
868                         fprintf(out, "Date: %s\n", show_date(timestamp, tz2, DATE_MODE(RFC2822)));
869                 } else if (starts_with(sb.buf, "# ")) {
870                         continue;
871                 } else {
872                         fprintf(out, "\n%s\n", sb.buf);
873                         break;
874                 }
875         }
876
877         strbuf_reset(&sb);
878         while (strbuf_fread(&sb, 8192, in) > 0) {
879                 fwrite(sb.buf, 1, sb.len, out);
880                 strbuf_reset(&sb);
881         }
882 exit:
883         strbuf_release(&sb);
884         return rc;
885 }
886
887 /**
888  * Splits a list of files/directories into individual email patches. Each path
889  * in `paths` must be a file/directory that is formatted according to
890  * `patch_format`.
891  *
892  * Once split out, the individual email patches will be stored in the state
893  * directory, with each patch's filename being its index, padded to state->prec
894  * digits.
895  *
896  * state->cur will be set to the index of the first mail, and state->last will
897  * be set to the index of the last mail.
898  *
899  * Set keep_cr to 0 to convert all lines ending with \r\n to end with \n, 1
900  * to disable this behavior, -1 to use the default configured setting.
901  *
902  * Returns 0 on success, -1 on failure.
903  */
904 static int split_mail(struct am_state *state, enum patch_format patch_format,
905                         const char **paths, int keep_cr)
906 {
907         if (keep_cr < 0) {
908                 keep_cr = 0;
909                 git_config_get_bool("am.keepcr", &keep_cr);
910         }
911
912         switch (patch_format) {
913         case PATCH_FORMAT_MBOX:
914                 return split_mail_mbox(state, paths, keep_cr, 0);
915         case PATCH_FORMAT_STGIT:
916                 return split_mail_conv(stgit_patch_to_mail, state, paths, keep_cr);
917         case PATCH_FORMAT_STGIT_SERIES:
918                 return split_mail_stgit_series(state, paths, keep_cr);
919         case PATCH_FORMAT_HG:
920                 return split_mail_conv(hg_patch_to_mail, state, paths, keep_cr);
921         case PATCH_FORMAT_MBOXRD:
922                 return split_mail_mbox(state, paths, keep_cr, 1);
923         default:
924                 BUG("invalid patch_format");
925         }
926         return -1;
927 }
928
929 /**
930  * Setup a new am session for applying patches
931  */
932 static void am_setup(struct am_state *state, enum patch_format patch_format,
933                         const char **paths, int keep_cr)
934 {
935         struct object_id curr_head;
936         const char *str;
937         struct strbuf sb = STRBUF_INIT;
938
939         if (!patch_format)
940                 patch_format = detect_patch_format(paths);
941
942         if (!patch_format) {
943                 fprintf_ln(stderr, _("Patch format detection failed."));
944                 exit(128);
945         }
946
947         if (mkdir(state->dir, 0777) < 0 && errno != EEXIST)
948                 die_errno(_("failed to create directory '%s'"), state->dir);
949         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
950
951         if (split_mail(state, patch_format, paths, keep_cr) < 0) {
952                 am_destroy(state);
953                 die(_("Failed to split patches."));
954         }
955
956         if (state->rebasing)
957                 state->threeway = 1;
958
959         write_state_bool(state, "threeway", state->threeway);
960         write_state_bool(state, "quiet", state->quiet);
961         write_state_bool(state, "sign", state->signoff);
962         write_state_bool(state, "utf8", state->utf8);
963
964         if (state->allow_rerere_autoupdate)
965                 write_state_bool(state, "rerere-autoupdate",
966                          state->allow_rerere_autoupdate == RERERE_AUTOUPDATE);
967
968         switch (state->keep) {
969         case KEEP_FALSE:
970                 str = "f";
971                 break;
972         case KEEP_TRUE:
973                 str = "t";
974                 break;
975         case KEEP_NON_PATCH:
976                 str = "b";
977                 break;
978         default:
979                 BUG("invalid value for state->keep");
980         }
981
982         write_state_text(state, "keep", str);
983         write_state_bool(state, "messageid", state->message_id);
984
985         switch (state->scissors) {
986         case SCISSORS_UNSET:
987                 str = "";
988                 break;
989         case SCISSORS_FALSE:
990                 str = "f";
991                 break;
992         case SCISSORS_TRUE:
993                 str = "t";
994                 break;
995         default:
996                 BUG("invalid value for state->scissors");
997         }
998         write_state_text(state, "scissors", str);
999
1000         sq_quote_argv(&sb, state->git_apply_opts.argv);
1001         write_state_text(state, "apply-opt", sb.buf);
1002
1003         if (state->rebasing)
1004                 write_state_text(state, "rebasing", "");
1005         else
1006                 write_state_text(state, "applying", "");
1007
1008         if (!get_oid("HEAD", &curr_head)) {
1009                 write_state_text(state, "abort-safety", oid_to_hex(&curr_head));
1010                 if (!state->rebasing)
1011                         update_ref("am", "ORIG_HEAD", &curr_head, NULL, 0,
1012                                    UPDATE_REFS_DIE_ON_ERR);
1013         } else {
1014                 write_state_text(state, "abort-safety", "");
1015                 if (!state->rebasing)
1016                         delete_ref(NULL, "ORIG_HEAD", NULL, 0);
1017         }
1018
1019         /*
1020          * NOTE: Since the "next" and "last" files determine if an am_state
1021          * session is in progress, they should be written last.
1022          */
1023
1024         write_state_count(state, "next", state->cur);
1025         write_state_count(state, "last", state->last);
1026
1027         strbuf_release(&sb);
1028 }
1029
1030 /**
1031  * Increments the patch pointer, and cleans am_state for the application of the
1032  * next patch.
1033  */
1034 static void am_next(struct am_state *state)
1035 {
1036         struct object_id head;
1037
1038         FREE_AND_NULL(state->author_name);
1039         FREE_AND_NULL(state->author_email);
1040         FREE_AND_NULL(state->author_date);
1041         FREE_AND_NULL(state->msg);
1042         state->msg_len = 0;
1043
1044         unlink(am_path(state, "author-script"));
1045         unlink(am_path(state, "final-commit"));
1046
1047         oidclr(&state->orig_commit);
1048         unlink(am_path(state, "original-commit"));
1049         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
1050
1051         if (!get_oid("HEAD", &head))
1052                 write_state_text(state, "abort-safety", oid_to_hex(&head));
1053         else
1054                 write_state_text(state, "abort-safety", "");
1055
1056         state->cur++;
1057         write_state_count(state, "next", state->cur);
1058 }
1059
1060 /**
1061  * Returns the filename of the current patch email.
1062  */
1063 static const char *msgnum(const struct am_state *state)
1064 {
1065         static struct strbuf sb = STRBUF_INIT;
1066
1067         strbuf_reset(&sb);
1068         strbuf_addf(&sb, "%0*d", state->prec, state->cur);
1069
1070         return sb.buf;
1071 }
1072
1073 /**
1074  * Refresh and write index.
1075  */
1076 static void refresh_and_write_cache(void)
1077 {
1078         struct lock_file lock_file = LOCK_INIT;
1079
1080         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
1081         refresh_cache(REFRESH_QUIET);
1082         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
1083                 die(_("unable to write index file"));
1084 }
1085
1086 /**
1087  * Dies with a user-friendly message on how to proceed after resolving the
1088  * problem. This message can be overridden with state->resolvemsg.
1089  */
1090 static void NORETURN die_user_resolve(const struct am_state *state)
1091 {
1092         if (state->resolvemsg) {
1093                 printf_ln("%s", state->resolvemsg);
1094         } else {
1095                 const char *cmdline = state->interactive ? "git am -i" : "git am";
1096
1097                 printf_ln(_("When you have resolved this problem, run \"%s --continue\"."), cmdline);
1098                 printf_ln(_("If you prefer to skip this patch, run \"%s --skip\" instead."), cmdline);
1099                 printf_ln(_("To restore the original branch and stop patching, run \"%s --abort\"."), cmdline);
1100         }
1101
1102         exit(128);
1103 }
1104
1105 /**
1106  * Appends signoff to the "msg" field of the am_state.
1107  */
1108 static void am_append_signoff(struct am_state *state)
1109 {
1110         struct strbuf sb = STRBUF_INIT;
1111
1112         strbuf_attach(&sb, state->msg, state->msg_len, state->msg_len);
1113         append_signoff(&sb, 0, 0);
1114         state->msg = strbuf_detach(&sb, &state->msg_len);
1115 }
1116
1117 /**
1118  * Parses `mail` using git-mailinfo, extracting its patch and authorship info.
1119  * state->msg will be set to the patch message. state->author_name,
1120  * state->author_email and state->author_date will be set to the patch author's
1121  * name, email and date respectively. The patch body will be written to the
1122  * state directory's "patch" file.
1123  *
1124  * Returns 1 if the patch should be skipped, 0 otherwise.
1125  */
1126 static int parse_mail(struct am_state *state, const char *mail)
1127 {
1128         FILE *fp;
1129         struct strbuf sb = STRBUF_INIT;
1130         struct strbuf msg = STRBUF_INIT;
1131         struct strbuf author_name = STRBUF_INIT;
1132         struct strbuf author_date = STRBUF_INIT;
1133         struct strbuf author_email = STRBUF_INIT;
1134         int ret = 0;
1135         struct mailinfo mi;
1136
1137         setup_mailinfo(&mi);
1138
1139         if (state->utf8)
1140                 mi.metainfo_charset = get_commit_output_encoding();
1141         else
1142                 mi.metainfo_charset = NULL;
1143
1144         switch (state->keep) {
1145         case KEEP_FALSE:
1146                 break;
1147         case KEEP_TRUE:
1148                 mi.keep_subject = 1;
1149                 break;
1150         case KEEP_NON_PATCH:
1151                 mi.keep_non_patch_brackets_in_subject = 1;
1152                 break;
1153         default:
1154                 BUG("invalid value for state->keep");
1155         }
1156
1157         if (state->message_id)
1158                 mi.add_message_id = 1;
1159
1160         switch (state->scissors) {
1161         case SCISSORS_UNSET:
1162                 break;
1163         case SCISSORS_FALSE:
1164                 mi.use_scissors = 0;
1165                 break;
1166         case SCISSORS_TRUE:
1167                 mi.use_scissors = 1;
1168                 break;
1169         default:
1170                 BUG("invalid value for state->scissors");
1171         }
1172
1173         mi.input = xfopen(mail, "r");
1174         mi.output = xfopen(am_path(state, "info"), "w");
1175         if (mailinfo(&mi, am_path(state, "msg"), am_path(state, "patch")))
1176                 die("could not parse patch");
1177
1178         fclose(mi.input);
1179         fclose(mi.output);
1180
1181         if (mi.format_flowed)
1182                 warning(_("Patch sent with format=flowed; "
1183                           "space at the end of lines might be lost."));
1184
1185         /* Extract message and author information */
1186         fp = xfopen(am_path(state, "info"), "r");
1187         while (!strbuf_getline_lf(&sb, fp)) {
1188                 const char *x;
1189
1190                 if (skip_prefix(sb.buf, "Subject: ", &x)) {
1191                         if (msg.len)
1192                                 strbuf_addch(&msg, '\n');
1193                         strbuf_addstr(&msg, x);
1194                 } else if (skip_prefix(sb.buf, "Author: ", &x))
1195                         strbuf_addstr(&author_name, x);
1196                 else if (skip_prefix(sb.buf, "Email: ", &x))
1197                         strbuf_addstr(&author_email, x);
1198                 else if (skip_prefix(sb.buf, "Date: ", &x))
1199                         strbuf_addstr(&author_date, x);
1200         }
1201         fclose(fp);
1202
1203         /* Skip pine's internal folder data */
1204         if (!strcmp(author_name.buf, "Mail System Internal Data")) {
1205                 ret = 1;
1206                 goto finish;
1207         }
1208
1209         if (is_empty_or_missing_file(am_path(state, "patch"))) {
1210                 printf_ln(_("Patch is empty."));
1211                 die_user_resolve(state);
1212         }
1213
1214         strbuf_addstr(&msg, "\n\n");
1215         strbuf_addbuf(&msg, &mi.log_message);
1216         strbuf_stripspace(&msg, 0);
1217
1218         assert(!state->author_name);
1219         state->author_name = strbuf_detach(&author_name, NULL);
1220
1221         assert(!state->author_email);
1222         state->author_email = strbuf_detach(&author_email, NULL);
1223
1224         assert(!state->author_date);
1225         state->author_date = strbuf_detach(&author_date, NULL);
1226
1227         assert(!state->msg);
1228         state->msg = strbuf_detach(&msg, &state->msg_len);
1229
1230 finish:
1231         strbuf_release(&msg);
1232         strbuf_release(&author_date);
1233         strbuf_release(&author_email);
1234         strbuf_release(&author_name);
1235         strbuf_release(&sb);
1236         clear_mailinfo(&mi);
1237         return ret;
1238 }
1239
1240 /**
1241  * Sets commit_id to the commit hash where the mail was generated from.
1242  * Returns 0 on success, -1 on failure.
1243  */
1244 static int get_mail_commit_oid(struct object_id *commit_id, const char *mail)
1245 {
1246         struct strbuf sb = STRBUF_INIT;
1247         FILE *fp = xfopen(mail, "r");
1248         const char *x;
1249         int ret = 0;
1250
1251         if (strbuf_getline_lf(&sb, fp) ||
1252             !skip_prefix(sb.buf, "From ", &x) ||
1253             get_oid_hex(x, commit_id) < 0)
1254                 ret = -1;
1255
1256         strbuf_release(&sb);
1257         fclose(fp);
1258         return ret;
1259 }
1260
1261 /**
1262  * Sets state->msg, state->author_name, state->author_email, state->author_date
1263  * to the commit's respective info.
1264  */
1265 static void get_commit_info(struct am_state *state, struct commit *commit)
1266 {
1267         const char *buffer, *ident_line, *msg;
1268         size_t ident_len;
1269         struct ident_split id;
1270
1271         buffer = logmsg_reencode(commit, NULL, get_commit_output_encoding());
1272
1273         ident_line = find_commit_header(buffer, "author", &ident_len);
1274
1275         if (split_ident_line(&id, ident_line, ident_len) < 0)
1276                 die(_("invalid ident line: %.*s"), (int)ident_len, ident_line);
1277
1278         assert(!state->author_name);
1279         if (id.name_begin)
1280                 state->author_name =
1281                         xmemdupz(id.name_begin, id.name_end - id.name_begin);
1282         else
1283                 state->author_name = xstrdup("");
1284
1285         assert(!state->author_email);
1286         if (id.mail_begin)
1287                 state->author_email =
1288                         xmemdupz(id.mail_begin, id.mail_end - id.mail_begin);
1289         else
1290                 state->author_email = xstrdup("");
1291
1292         assert(!state->author_date);
1293         state->author_date = xstrdup(show_ident_date(&id, DATE_MODE(NORMAL)));
1294
1295         assert(!state->msg);
1296         msg = strstr(buffer, "\n\n");
1297         if (!msg)
1298                 die(_("unable to parse commit %s"), oid_to_hex(&commit->object.oid));
1299         state->msg = xstrdup(msg + 2);
1300         state->msg_len = strlen(state->msg);
1301         unuse_commit_buffer(commit, buffer);
1302 }
1303
1304 /**
1305  * Writes `commit` as a patch to the state directory's "patch" file.
1306  */
1307 static void write_commit_patch(const struct am_state *state, struct commit *commit)
1308 {
1309         struct rev_info rev_info;
1310         FILE *fp;
1311
1312         fp = xfopen(am_path(state, "patch"), "w");
1313         repo_init_revisions(the_repository, &rev_info, NULL);
1314         rev_info.diff = 1;
1315         rev_info.abbrev = 0;
1316         rev_info.disable_stdin = 1;
1317         rev_info.show_root_diff = 1;
1318         rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
1319         rev_info.no_commit_id = 1;
1320         rev_info.diffopt.flags.binary = 1;
1321         rev_info.diffopt.flags.full_index = 1;
1322         rev_info.diffopt.use_color = 0;
1323         rev_info.diffopt.file = fp;
1324         rev_info.diffopt.close_file = 1;
1325         add_pending_object(&rev_info, &commit->object, "");
1326         diff_setup_done(&rev_info.diffopt);
1327         log_tree_commit(&rev_info, commit);
1328 }
1329
1330 /**
1331  * Writes the diff of the index against HEAD as a patch to the state
1332  * directory's "patch" file.
1333  */
1334 static void write_index_patch(const struct am_state *state)
1335 {
1336         struct tree *tree;
1337         struct object_id head;
1338         struct rev_info rev_info;
1339         FILE *fp;
1340
1341         if (!get_oid_tree("HEAD", &head))
1342                 tree = lookup_tree(the_repository, &head);
1343         else
1344                 tree = lookup_tree(the_repository,
1345                                    the_repository->hash_algo->empty_tree);
1346
1347         fp = xfopen(am_path(state, "patch"), "w");
1348         repo_init_revisions(the_repository, &rev_info, NULL);
1349         rev_info.diff = 1;
1350         rev_info.disable_stdin = 1;
1351         rev_info.no_commit_id = 1;
1352         rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
1353         rev_info.diffopt.use_color = 0;
1354         rev_info.diffopt.file = fp;
1355         rev_info.diffopt.close_file = 1;
1356         add_pending_object(&rev_info, &tree->object, "");
1357         diff_setup_done(&rev_info.diffopt);
1358         run_diff_index(&rev_info, 1);
1359 }
1360
1361 /**
1362  * Like parse_mail(), but parses the mail by looking up its commit ID
1363  * directly. This is used in --rebasing mode to bypass git-mailinfo's munging
1364  * of patches.
1365  *
1366  * state->orig_commit will be set to the original commit ID.
1367  *
1368  * Will always return 0 as the patch should never be skipped.
1369  */
1370 static int parse_mail_rebase(struct am_state *state, const char *mail)
1371 {
1372         struct commit *commit;
1373         struct object_id commit_oid;
1374
1375         if (get_mail_commit_oid(&commit_oid, mail) < 0)
1376                 die(_("could not parse %s"), mail);
1377
1378         commit = lookup_commit_or_die(&commit_oid, mail);
1379
1380         get_commit_info(state, commit);
1381
1382         write_commit_patch(state, commit);
1383
1384         oidcpy(&state->orig_commit, &commit_oid);
1385         write_state_text(state, "original-commit", oid_to_hex(&commit_oid));
1386         update_ref("am", "REBASE_HEAD", &commit_oid,
1387                    NULL, REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);
1388
1389         return 0;
1390 }
1391
1392 /**
1393  * Applies current patch with git-apply. Returns 0 on success, -1 otherwise. If
1394  * `index_file` is not NULL, the patch will be applied to that index.
1395  */
1396 static int run_apply(const struct am_state *state, const char *index_file)
1397 {
1398         struct argv_array apply_paths = ARGV_ARRAY_INIT;
1399         struct argv_array apply_opts = ARGV_ARRAY_INIT;
1400         struct apply_state apply_state;
1401         int res, opts_left;
1402         int force_apply = 0;
1403         int options = 0;
1404
1405         if (init_apply_state(&apply_state, the_repository, NULL))
1406                 BUG("init_apply_state() failed");
1407
1408         argv_array_push(&apply_opts, "apply");
1409         argv_array_pushv(&apply_opts, state->git_apply_opts.argv);
1410
1411         opts_left = apply_parse_options(apply_opts.argc, apply_opts.argv,
1412                                         &apply_state, &force_apply, &options,
1413                                         NULL);
1414
1415         if (opts_left != 0)
1416                 die("unknown option passed through to git apply");
1417
1418         if (index_file) {
1419                 apply_state.index_file = index_file;
1420                 apply_state.cached = 1;
1421         } else
1422                 apply_state.check_index = 1;
1423
1424         /*
1425          * If we are allowed to fall back on 3-way merge, don't give false
1426          * errors during the initial attempt.
1427          */
1428         if (state->threeway && !index_file)
1429                 apply_state.apply_verbosity = verbosity_silent;
1430
1431         if (check_apply_state(&apply_state, force_apply))
1432                 BUG("check_apply_state() failed");
1433
1434         argv_array_push(&apply_paths, am_path(state, "patch"));
1435
1436         res = apply_all_patches(&apply_state, apply_paths.argc, apply_paths.argv, options);
1437
1438         argv_array_clear(&apply_paths);
1439         argv_array_clear(&apply_opts);
1440         clear_apply_state(&apply_state);
1441
1442         if (res)
1443                 return res;
1444
1445         if (index_file) {
1446                 /* Reload index as apply_all_patches() will have modified it. */
1447                 discard_cache();
1448                 read_cache_from(index_file);
1449         }
1450
1451         return 0;
1452 }
1453
1454 /**
1455  * Builds an index that contains just the blobs needed for a 3way merge.
1456  */
1457 static int build_fake_ancestor(const struct am_state *state, const char *index_file)
1458 {
1459         struct child_process cp = CHILD_PROCESS_INIT;
1460
1461         cp.git_cmd = 1;
1462         argv_array_push(&cp.args, "apply");
1463         argv_array_pushv(&cp.args, state->git_apply_opts.argv);
1464         argv_array_pushf(&cp.args, "--build-fake-ancestor=%s", index_file);
1465         argv_array_push(&cp.args, am_path(state, "patch"));
1466
1467         if (run_command(&cp))
1468                 return -1;
1469
1470         return 0;
1471 }
1472
1473 /**
1474  * Attempt a threeway merge, using index_path as the temporary index.
1475  */
1476 static int fall_back_threeway(const struct am_state *state, const char *index_path)
1477 {
1478         struct object_id orig_tree, their_tree, our_tree;
1479         const struct object_id *bases[1] = { &orig_tree };
1480         struct merge_options o;
1481         struct commit *result;
1482         char *their_tree_name;
1483
1484         if (get_oid("HEAD", &our_tree) < 0)
1485                 oidcpy(&our_tree, the_hash_algo->empty_tree);
1486
1487         if (build_fake_ancestor(state, index_path))
1488                 return error("could not build fake ancestor");
1489
1490         discard_cache();
1491         read_cache_from(index_path);
1492
1493         if (write_index_as_tree(&orig_tree, &the_index, index_path, 0, NULL))
1494                 return error(_("Repository lacks necessary blobs to fall back on 3-way merge."));
1495
1496         say(state, stdout, _("Using index info to reconstruct a base tree..."));
1497
1498         if (!state->quiet) {
1499                 /*
1500                  * List paths that needed 3-way fallback, so that the user can
1501                  * review them with extra care to spot mismerges.
1502                  */
1503                 struct rev_info rev_info;
1504                 const char *diff_filter_str = "--diff-filter=AM";
1505
1506                 repo_init_revisions(the_repository, &rev_info, NULL);
1507                 rev_info.diffopt.output_format = DIFF_FORMAT_NAME_STATUS;
1508                 diff_opt_parse(&rev_info.diffopt, &diff_filter_str, 1, rev_info.prefix);
1509                 add_pending_oid(&rev_info, "HEAD", &our_tree, 0);
1510                 diff_setup_done(&rev_info.diffopt);
1511                 run_diff_index(&rev_info, 1);
1512         }
1513
1514         if (run_apply(state, index_path))
1515                 return error(_("Did you hand edit your patch?\n"
1516                                 "It does not apply to blobs recorded in its index."));
1517
1518         if (write_index_as_tree(&their_tree, &the_index, index_path, 0, NULL))
1519                 return error("could not write tree");
1520
1521         say(state, stdout, _("Falling back to patching base and 3-way merge..."));
1522
1523         discard_cache();
1524         read_cache();
1525
1526         /*
1527          * This is not so wrong. Depending on which base we picked, orig_tree
1528          * may be wildly different from ours, but their_tree has the same set of
1529          * wildly different changes in parts the patch did not touch, so
1530          * recursive ends up canceling them, saying that we reverted all those
1531          * changes.
1532          */
1533
1534         init_merge_options(&o, the_repository);
1535
1536         o.branch1 = "HEAD";
1537         their_tree_name = xstrfmt("%.*s", linelen(state->msg), state->msg);
1538         o.branch2 = their_tree_name;
1539         o.detect_directory_renames = 0;
1540
1541         if (state->quiet)
1542                 o.verbosity = 0;
1543
1544         if (merge_recursive_generic(&o, &our_tree, &their_tree, 1, bases, &result)) {
1545                 repo_rerere(the_repository, state->allow_rerere_autoupdate);
1546                 free(their_tree_name);
1547                 return error(_("Failed to merge in the changes."));
1548         }
1549
1550         free(their_tree_name);
1551         return 0;
1552 }
1553
1554 /**
1555  * Commits the current index with state->msg as the commit message and
1556  * state->author_name, state->author_email and state->author_date as the author
1557  * information.
1558  */
1559 static void do_commit(const struct am_state *state)
1560 {
1561         struct object_id tree, parent, commit;
1562         const struct object_id *old_oid;
1563         struct commit_list *parents = NULL;
1564         const char *reflog_msg, *author;
1565         struct strbuf sb = STRBUF_INIT;
1566
1567         if (run_hook_le(NULL, "pre-applypatch", NULL))
1568                 exit(1);
1569
1570         if (write_cache_as_tree(&tree, 0, NULL))
1571                 die(_("git write-tree failed to write a tree"));
1572
1573         if (!get_oid_commit("HEAD", &parent)) {
1574                 old_oid = &parent;
1575                 commit_list_insert(lookup_commit(the_repository, &parent),
1576                                    &parents);
1577         } else {
1578                 old_oid = NULL;
1579                 say(state, stderr, _("applying to an empty history"));
1580         }
1581
1582         author = fmt_ident(state->author_name, state->author_email,
1583                 WANT_AUTHOR_IDENT,
1584                         state->ignore_date ? NULL : state->author_date,
1585                         IDENT_STRICT);
1586
1587         if (state->committer_date_is_author_date)
1588                 setenv("GIT_COMMITTER_DATE",
1589                         state->ignore_date ? "" : state->author_date, 1);
1590
1591         if (commit_tree(state->msg, state->msg_len, &tree, parents, &commit,
1592                         author, state->sign_commit))
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         if (!isatty(0))
1646                 die(_("cannot be interactive without stdin connected to a terminal."));
1647
1648         for (;;) {
1649                 const char *reply;
1650
1651                 puts(_("Commit Body is:"));
1652                 puts("--------------------------");
1653                 printf("%s", state->msg);
1654                 puts("--------------------------");
1655
1656                 /*
1657                  * TRANSLATORS: Make sure to include [y], [n], [e], [v] and [a]
1658                  * in your translation. The program will only accept English
1659                  * input at this point.
1660                  */
1661                 reply = git_prompt(_("Apply? [y]es/[n]o/[e]dit/[v]iew patch/[a]ccept all: "), PROMPT_ECHO);
1662
1663                 if (!reply) {
1664                         continue;
1665                 } else if (*reply == 'y' || *reply == 'Y') {
1666                         return 0;
1667                 } else if (*reply == 'a' || *reply == 'A') {
1668                         state->interactive = 0;
1669                         return 0;
1670                 } else if (*reply == 'n' || *reply == 'N') {
1671                         return 1;
1672                 } else if (*reply == 'e' || *reply == 'E') {
1673                         struct strbuf msg = STRBUF_INIT;
1674
1675                         if (!launch_editor(am_path(state, "final-commit"), &msg, NULL)) {
1676                                 free(state->msg);
1677                                 state->msg = strbuf_detach(&msg, &state->msg_len);
1678                         }
1679                         strbuf_release(&msg);
1680                 } else if (*reply == 'v' || *reply == 'V') {
1681                         const char *pager = git_pager(1);
1682                         struct child_process cp = CHILD_PROCESS_INIT;
1683
1684                         if (!pager)
1685                                 pager = "cat";
1686                         prepare_pager_args(&cp, pager);
1687                         argv_array_push(&cp.args, am_path(state, "patch"));
1688                         run_command(&cp);
1689                 }
1690         }
1691 }
1692
1693 /**
1694  * Applies all queued mail.
1695  *
1696  * If `resume` is true, we are "resuming". The "msg" and authorship fields, as
1697  * well as the state directory's "patch" file is used as-is for applying the
1698  * patch and committing it.
1699  */
1700 static void am_run(struct am_state *state, int resume)
1701 {
1702         const char *argv_gc_auto[] = {"gc", "--auto", NULL};
1703         struct strbuf sb = STRBUF_INIT;
1704
1705         unlink(am_path(state, "dirtyindex"));
1706
1707         refresh_and_write_cache();
1708
1709         if (repo_index_has_changes(the_repository, NULL, &sb)) {
1710                 write_state_bool(state, "dirtyindex", 1);
1711                 die(_("Dirty index: cannot apply patches (dirty: %s)"), sb.buf);
1712         }
1713
1714         strbuf_release(&sb);
1715
1716         while (state->cur <= state->last) {
1717                 const char *mail = am_path(state, msgnum(state));
1718                 int apply_status;
1719
1720                 reset_ident_date();
1721
1722                 if (!file_exists(mail))
1723                         goto next;
1724
1725                 if (resume) {
1726                         validate_resume_state(state);
1727                 } else {
1728                         int skip;
1729
1730                         if (state->rebasing)
1731                                 skip = parse_mail_rebase(state, mail);
1732                         else
1733                                 skip = parse_mail(state, mail);
1734
1735                         if (skip)
1736                                 goto next; /* mail should be skipped */
1737
1738                         if (state->signoff)
1739                                 am_append_signoff(state);
1740
1741                         write_author_script(state);
1742                         write_commit_msg(state);
1743                 }
1744
1745                 if (state->interactive && do_interactive(state))
1746                         goto next;
1747
1748                 if (run_applypatch_msg_hook(state))
1749                         exit(1);
1750
1751                 say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
1752
1753                 apply_status = run_apply(state, NULL);
1754
1755                 if (apply_status && state->threeway) {
1756                         struct strbuf sb = STRBUF_INIT;
1757
1758                         strbuf_addstr(&sb, am_path(state, "patch-merge-index"));
1759                         apply_status = fall_back_threeway(state, sb.buf);
1760                         strbuf_release(&sb);
1761
1762                         /*
1763                          * Applying the patch to an earlier tree and merging
1764                          * the result may have produced the same tree as ours.
1765                          */
1766                         if (!apply_status &&
1767                             !repo_index_has_changes(the_repository, NULL, NULL)) {
1768                                 say(state, stdout, _("No changes -- Patch already applied."));
1769                                 goto next;
1770                         }
1771                 }
1772
1773                 if (apply_status) {
1774                         printf_ln(_("Patch failed at %s %.*s"), msgnum(state),
1775                                 linelen(state->msg), state->msg);
1776
1777                         if (advice_amworkdir)
1778                                 advise(_("Use 'git am --show-current-patch' to see the failed patch"));
1779
1780                         die_user_resolve(state);
1781                 }
1782
1783                 do_commit(state);
1784
1785 next:
1786                 am_next(state);
1787
1788                 if (resume)
1789                         am_load(state);
1790                 resume = 0;
1791         }
1792
1793         if (!is_empty_or_missing_file(am_path(state, "rewritten"))) {
1794                 assert(state->rebasing);
1795                 copy_notes_for_rebase(state);
1796                 run_post_rewrite_hook(state);
1797         }
1798
1799         /*
1800          * In rebasing mode, it's up to the caller to take care of
1801          * housekeeping.
1802          */
1803         if (!state->rebasing) {
1804                 am_destroy(state);
1805                 close_all_packs(the_repository->objects);
1806                 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
1807         }
1808 }
1809
1810 /**
1811  * Resume the current am session after patch application failure. The user did
1812  * all the hard work, and we do not have to do any patch application. Just
1813  * trust and commit what the user has in the index and working tree.
1814  */
1815 static void am_resolve(struct am_state *state)
1816 {
1817         validate_resume_state(state);
1818
1819         say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
1820
1821         if (!repo_index_has_changes(the_repository, NULL, NULL)) {
1822                 printf_ln(_("No changes - did you forget to use 'git add'?\n"
1823                         "If there is nothing left to stage, chances are that something else\n"
1824                         "already introduced the same changes; you might want to skip this patch."));
1825                 die_user_resolve(state);
1826         }
1827
1828         if (unmerged_cache()) {
1829                 printf_ln(_("You still have unmerged paths in your index.\n"
1830                         "You should 'git add' each file with resolved conflicts to mark them as such.\n"
1831                         "You might run `git rm` on a file to accept \"deleted by them\" for it."));
1832                 die_user_resolve(state);
1833         }
1834
1835         if (state->interactive) {
1836                 write_index_patch(state);
1837                 if (do_interactive(state))
1838                         goto next;
1839         }
1840
1841         repo_rerere(the_repository, 0);
1842
1843         do_commit(state);
1844
1845 next:
1846         am_next(state);
1847         am_load(state);
1848         am_run(state, 0);
1849 }
1850
1851 /**
1852  * Performs a checkout fast-forward from `head` to `remote`. If `reset` is
1853  * true, any unmerged entries will be discarded. Returns 0 on success, -1 on
1854  * failure.
1855  */
1856 static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
1857 {
1858         struct lock_file lock_file = LOCK_INIT;
1859         struct unpack_trees_options opts;
1860         struct tree_desc t[2];
1861
1862         if (parse_tree(head) || parse_tree(remote))
1863                 return -1;
1864
1865         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
1866
1867         refresh_cache(REFRESH_QUIET);
1868
1869         memset(&opts, 0, sizeof(opts));
1870         opts.head_idx = 1;
1871         opts.src_index = &the_index;
1872         opts.dst_index = &the_index;
1873         opts.update = 1;
1874         opts.merge = 1;
1875         opts.reset = reset;
1876         opts.fn = twoway_merge;
1877         init_tree_desc(&t[0], head->buffer, head->size);
1878         init_tree_desc(&t[1], remote->buffer, remote->size);
1879
1880         if (unpack_trees(2, t, &opts)) {
1881                 rollback_lock_file(&lock_file);
1882                 return -1;
1883         }
1884
1885         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
1886                 die(_("unable to write new index file"));
1887
1888         return 0;
1889 }
1890
1891 /**
1892  * Merges a tree into the index. The index's stat info will take precedence
1893  * over the merged tree's. Returns 0 on success, -1 on failure.
1894  */
1895 static int merge_tree(struct tree *tree)
1896 {
1897         struct lock_file lock_file = LOCK_INIT;
1898         struct unpack_trees_options opts;
1899         struct tree_desc t[1];
1900
1901         if (parse_tree(tree))
1902                 return -1;
1903
1904         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
1905
1906         memset(&opts, 0, sizeof(opts));
1907         opts.head_idx = 1;
1908         opts.src_index = &the_index;
1909         opts.dst_index = &the_index;
1910         opts.merge = 1;
1911         opts.fn = oneway_merge;
1912         init_tree_desc(&t[0], tree->buffer, tree->size);
1913
1914         if (unpack_trees(1, t, &opts)) {
1915                 rollback_lock_file(&lock_file);
1916                 return -1;
1917         }
1918
1919         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
1920                 die(_("unable to write new index file"));
1921
1922         return 0;
1923 }
1924
1925 /**
1926  * Clean the index without touching entries that are not modified between
1927  * `head` and `remote`.
1928  */
1929 static int clean_index(const struct object_id *head, const struct object_id *remote)
1930 {
1931         struct tree *head_tree, *remote_tree, *index_tree;
1932         struct object_id index;
1933
1934         head_tree = parse_tree_indirect(head);
1935         if (!head_tree)
1936                 return error(_("Could not parse object '%s'."), oid_to_hex(head));
1937
1938         remote_tree = parse_tree_indirect(remote);
1939         if (!remote_tree)
1940                 return error(_("Could not parse object '%s'."), oid_to_hex(remote));
1941
1942         read_cache_unmerged();
1943
1944         if (fast_forward_to(head_tree, head_tree, 1))
1945                 return -1;
1946
1947         if (write_cache_as_tree(&index, 0, NULL))
1948                 return -1;
1949
1950         index_tree = parse_tree_indirect(&index);
1951         if (!index_tree)
1952                 return error(_("Could not parse object '%s'."), oid_to_hex(&index));
1953
1954         if (fast_forward_to(index_tree, remote_tree, 0))
1955                 return -1;
1956
1957         if (merge_tree(remote_tree))
1958                 return -1;
1959
1960         remove_branch_state(the_repository);
1961
1962         return 0;
1963 }
1964
1965 /**
1966  * Resets rerere's merge resolution metadata.
1967  */
1968 static void am_rerere_clear(void)
1969 {
1970         struct string_list merge_rr = STRING_LIST_INIT_DUP;
1971         rerere_clear(the_repository, &merge_rr);
1972         string_list_clear(&merge_rr, 1);
1973 }
1974
1975 /**
1976  * Resume the current am session by skipping the current patch.
1977  */
1978 static void am_skip(struct am_state *state)
1979 {
1980         struct object_id head;
1981
1982         am_rerere_clear();
1983
1984         if (get_oid("HEAD", &head))
1985                 oidcpy(&head, the_hash_algo->empty_tree);
1986
1987         if (clean_index(&head, &head))
1988                 die(_("failed to clean index"));
1989
1990         if (state->rebasing) {
1991                 FILE *fp = xfopen(am_path(state, "rewritten"), "a");
1992
1993                 assert(!is_null_oid(&state->orig_commit));
1994                 fprintf(fp, "%s ", oid_to_hex(&state->orig_commit));
1995                 fprintf(fp, "%s\n", oid_to_hex(&head));
1996                 fclose(fp);
1997         }
1998
1999         am_next(state);
2000         am_load(state);
2001         am_run(state, 0);
2002 }
2003
2004 /**
2005  * Returns true if it is safe to reset HEAD to the ORIG_HEAD, false otherwise.
2006  *
2007  * It is not safe to reset HEAD when:
2008  * 1. git-am previously failed because the index was dirty.
2009  * 2. HEAD has moved since git-am previously failed.
2010  */
2011 static int safe_to_abort(const struct am_state *state)
2012 {
2013         struct strbuf sb = STRBUF_INIT;
2014         struct object_id abort_safety, head;
2015
2016         if (file_exists(am_path(state, "dirtyindex")))
2017                 return 0;
2018
2019         if (read_state_file(&sb, state, "abort-safety", 1) > 0) {
2020                 if (get_oid_hex(sb.buf, &abort_safety))
2021                         die(_("could not parse %s"), am_path(state, "abort-safety"));
2022         } else
2023                 oidclr(&abort_safety);
2024         strbuf_release(&sb);
2025
2026         if (get_oid("HEAD", &head))
2027                 oidclr(&head);
2028
2029         if (oideq(&head, &abort_safety))
2030                 return 1;
2031
2032         warning(_("You seem to have moved HEAD since the last 'am' failure.\n"
2033                 "Not rewinding to ORIG_HEAD"));
2034
2035         return 0;
2036 }
2037
2038 /**
2039  * Aborts the current am session if it is safe to do so.
2040  */
2041 static void am_abort(struct am_state *state)
2042 {
2043         struct object_id curr_head, orig_head;
2044         int has_curr_head, has_orig_head;
2045         char *curr_branch;
2046
2047         if (!safe_to_abort(state)) {
2048                 am_destroy(state);
2049                 return;
2050         }
2051
2052         am_rerere_clear();
2053
2054         curr_branch = resolve_refdup("HEAD", 0, &curr_head, NULL);
2055         has_curr_head = curr_branch && !is_null_oid(&curr_head);
2056         if (!has_curr_head)
2057                 oidcpy(&curr_head, the_hash_algo->empty_tree);
2058
2059         has_orig_head = !get_oid("ORIG_HEAD", &orig_head);
2060         if (!has_orig_head)
2061                 oidcpy(&orig_head, the_hash_algo->empty_tree);
2062
2063         clean_index(&curr_head, &orig_head);
2064
2065         if (has_orig_head)
2066                 update_ref("am --abort", "HEAD", &orig_head,
2067                            has_curr_head ? &curr_head : NULL, 0,
2068                            UPDATE_REFS_DIE_ON_ERR);
2069         else if (curr_branch)
2070                 delete_ref(NULL, curr_branch, NULL, REF_NO_DEREF);
2071
2072         free(curr_branch);
2073         am_destroy(state);
2074 }
2075
2076 static int show_patch(struct am_state *state)
2077 {
2078         struct strbuf sb = STRBUF_INIT;
2079         const char *patch_path;
2080         int len;
2081
2082         if (!is_null_oid(&state->orig_commit)) {
2083                 const char *av[4] = { "show", NULL, "--", NULL };
2084                 char *new_oid_str;
2085                 int ret;
2086
2087                 av[1] = new_oid_str = xstrdup(oid_to_hex(&state->orig_commit));
2088                 ret = run_command_v_opt(av, RUN_GIT_CMD);
2089                 free(new_oid_str);
2090                 return ret;
2091         }
2092
2093         patch_path = am_path(state, msgnum(state));
2094         len = strbuf_read_file(&sb, patch_path, 0);
2095         if (len < 0)
2096                 die_errno(_("failed to read '%s'"), patch_path);
2097
2098         setup_pager();
2099         write_in_full(1, sb.buf, sb.len);
2100         strbuf_release(&sb);
2101         return 0;
2102 }
2103
2104 /**
2105  * parse_options() callback that validates and sets opt->value to the
2106  * PATCH_FORMAT_* enum value corresponding to `arg`.
2107  */
2108 static int parse_opt_patchformat(const struct option *opt, const char *arg, int unset)
2109 {
2110         int *opt_value = opt->value;
2111
2112         if (unset)
2113                 *opt_value = PATCH_FORMAT_UNKNOWN;
2114         else if (!strcmp(arg, "mbox"))
2115                 *opt_value = PATCH_FORMAT_MBOX;
2116         else if (!strcmp(arg, "stgit"))
2117                 *opt_value = PATCH_FORMAT_STGIT;
2118         else if (!strcmp(arg, "stgit-series"))
2119                 *opt_value = PATCH_FORMAT_STGIT_SERIES;
2120         else if (!strcmp(arg, "hg"))
2121                 *opt_value = PATCH_FORMAT_HG;
2122         else if (!strcmp(arg, "mboxrd"))
2123                 *opt_value = PATCH_FORMAT_MBOXRD;
2124         /*
2125          * Please update $__git_patchformat in git-completion.bash
2126          * when you add new options
2127          */
2128         else
2129                 return error(_("Invalid value for --patch-format: %s"), arg);
2130         return 0;
2131 }
2132
2133 enum resume_mode {
2134         RESUME_FALSE = 0,
2135         RESUME_APPLY,
2136         RESUME_RESOLVED,
2137         RESUME_SKIP,
2138         RESUME_ABORT,
2139         RESUME_QUIT,
2140         RESUME_SHOW_PATCH
2141 };
2142
2143 static int git_am_config(const char *k, const char *v, void *cb)
2144 {
2145         int status;
2146
2147         status = git_gpg_config(k, v, NULL);
2148         if (status)
2149                 return status;
2150
2151         return git_default_config(k, v, NULL);
2152 }
2153
2154 int cmd_am(int argc, const char **argv, const char *prefix)
2155 {
2156         struct am_state state;
2157         int binary = -1;
2158         int keep_cr = -1;
2159         int patch_format = PATCH_FORMAT_UNKNOWN;
2160         enum resume_mode resume = RESUME_FALSE;
2161         int in_progress;
2162         int ret = 0;
2163
2164         const char * const usage[] = {
2165                 N_("git am [<options>] [(<mbox> | <Maildir>)...]"),
2166                 N_("git am [<options>] (--continue | --skip | --abort)"),
2167                 NULL
2168         };
2169
2170         struct option options[] = {
2171                 OPT_BOOL('i', "interactive", &state.interactive,
2172                         N_("run interactively")),
2173                 OPT_HIDDEN_BOOL('b', "binary", &binary,
2174                         N_("historical option -- no-op")),
2175                 OPT_BOOL('3', "3way", &state.threeway,
2176                         N_("allow fall back on 3way merging if needed")),
2177                 OPT__QUIET(&state.quiet, N_("be quiet")),
2178                 OPT_SET_INT('s', "signoff", &state.signoff,
2179                         N_("add a Signed-off-by line to the commit message"),
2180                         SIGNOFF_EXPLICIT),
2181                 OPT_BOOL('u', "utf8", &state.utf8,
2182                         N_("recode into utf8 (default)")),
2183                 OPT_SET_INT('k', "keep", &state.keep,
2184                         N_("pass -k flag to git-mailinfo"), KEEP_TRUE),
2185                 OPT_SET_INT(0, "keep-non-patch", &state.keep,
2186                         N_("pass -b flag to git-mailinfo"), KEEP_NON_PATCH),
2187                 OPT_BOOL('m', "message-id", &state.message_id,
2188                         N_("pass -m flag to git-mailinfo")),
2189                 OPT_SET_INT_F(0, "keep-cr", &keep_cr,
2190                         N_("pass --keep-cr flag to git-mailsplit for mbox format"),
2191                         1, PARSE_OPT_NONEG),
2192                 OPT_SET_INT_F(0, "no-keep-cr", &keep_cr,
2193                         N_("do not pass --keep-cr flag to git-mailsplit independent of am.keepcr"),
2194                         0, PARSE_OPT_NONEG),
2195                 OPT_BOOL('c', "scissors", &state.scissors,
2196                         N_("strip everything before a scissors line")),
2197                 OPT_PASSTHRU_ARGV(0, "whitespace", &state.git_apply_opts, N_("action"),
2198                         N_("pass it through git-apply"),
2199                         0),
2200                 OPT_PASSTHRU_ARGV(0, "ignore-space-change", &state.git_apply_opts, NULL,
2201                         N_("pass it through git-apply"),
2202                         PARSE_OPT_NOARG),
2203                 OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &state.git_apply_opts, NULL,
2204                         N_("pass it through git-apply"),
2205                         PARSE_OPT_NOARG),
2206                 OPT_PASSTHRU_ARGV(0, "directory", &state.git_apply_opts, N_("root"),
2207                         N_("pass it through git-apply"),
2208                         0),
2209                 OPT_PASSTHRU_ARGV(0, "exclude", &state.git_apply_opts, N_("path"),
2210                         N_("pass it through git-apply"),
2211                         0),
2212                 OPT_PASSTHRU_ARGV(0, "include", &state.git_apply_opts, N_("path"),
2213                         N_("pass it through git-apply"),
2214                         0),
2215                 OPT_PASSTHRU_ARGV('C', NULL, &state.git_apply_opts, N_("n"),
2216                         N_("pass it through git-apply"),
2217                         0),
2218                 OPT_PASSTHRU_ARGV('p', NULL, &state.git_apply_opts, N_("num"),
2219                         N_("pass it through git-apply"),
2220                         0),
2221                 OPT_CALLBACK(0, "patch-format", &patch_format, N_("format"),
2222                         N_("format the patch(es) are in"),
2223                         parse_opt_patchformat),
2224                 OPT_PASSTHRU_ARGV(0, "reject", &state.git_apply_opts, NULL,
2225                         N_("pass it through git-apply"),
2226                         PARSE_OPT_NOARG),
2227                 OPT_STRING(0, "resolvemsg", &state.resolvemsg, NULL,
2228                         N_("override error message when patch failure occurs")),
2229                 OPT_CMDMODE(0, "continue", &resume,
2230                         N_("continue applying patches after resolving a conflict"),
2231                         RESUME_RESOLVED),
2232                 OPT_CMDMODE('r', "resolved", &resume,
2233                         N_("synonyms for --continue"),
2234                         RESUME_RESOLVED),
2235                 OPT_CMDMODE(0, "skip", &resume,
2236                         N_("skip the current patch"),
2237                         RESUME_SKIP),
2238                 OPT_CMDMODE(0, "abort", &resume,
2239                         N_("restore the original branch and abort the patching operation."),
2240                         RESUME_ABORT),
2241                 OPT_CMDMODE(0, "quit", &resume,
2242                         N_("abort the patching operation but keep HEAD where it is."),
2243                         RESUME_QUIT),
2244                 OPT_CMDMODE(0, "show-current-patch", &resume,
2245                         N_("show the patch being applied."),
2246                         RESUME_SHOW_PATCH),
2247                 OPT_BOOL(0, "committer-date-is-author-date",
2248                         &state.committer_date_is_author_date,
2249                         N_("lie about committer date")),
2250                 OPT_BOOL(0, "ignore-date", &state.ignore_date,
2251                         N_("use current timestamp for author date")),
2252                 OPT_RERERE_AUTOUPDATE(&state.allow_rerere_autoupdate),
2253                 { OPTION_STRING, 'S', "gpg-sign", &state.sign_commit, N_("key-id"),
2254                   N_("GPG-sign commits"),
2255                   PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
2256                 OPT_HIDDEN_BOOL(0, "rebasing", &state.rebasing,
2257                         N_("(internal use for git-rebase)")),
2258                 OPT_END()
2259         };
2260
2261         if (argc == 2 && !strcmp(argv[1], "-h"))
2262                 usage_with_options(usage, options);
2263
2264         git_config(git_am_config, NULL);
2265
2266         am_state_init(&state);
2267
2268         in_progress = am_in_progress(&state);
2269         if (in_progress)
2270                 am_load(&state);
2271
2272         argc = parse_options(argc, argv, prefix, options, usage, 0);
2273
2274         if (binary >= 0)
2275                 fprintf_ln(stderr, _("The -b/--binary option has been a no-op for long time, and\n"
2276                                 "it will be removed. Please do not use it anymore."));
2277
2278         /* Ensure a valid committer ident can be constructed */
2279         git_committer_info(IDENT_STRICT);
2280
2281         if (repo_read_index_preload(the_repository, NULL, 0) < 0)
2282                 die(_("failed to read the index"));
2283
2284         if (in_progress) {
2285                 /*
2286                  * Catch user error to feed us patches when there is a session
2287                  * in progress:
2288                  *
2289                  * 1. mbox path(s) are provided on the command-line.
2290                  * 2. stdin is not a tty: the user is trying to feed us a patch
2291                  *    from standard input. This is somewhat unreliable -- stdin
2292                  *    could be /dev/null for example and the caller did not
2293                  *    intend to feed us a patch but wanted to continue
2294                  *    unattended.
2295                  */
2296                 if (argc || (resume == RESUME_FALSE && !isatty(0)))
2297                         die(_("previous rebase directory %s still exists but mbox given."),
2298                                 state.dir);
2299
2300                 if (resume == RESUME_FALSE)
2301                         resume = RESUME_APPLY;
2302
2303                 if (state.signoff == SIGNOFF_EXPLICIT)
2304                         am_append_signoff(&state);
2305         } else {
2306                 struct argv_array paths = ARGV_ARRAY_INIT;
2307                 int i;
2308
2309                 /*
2310                  * Handle stray state directory in the independent-run case. In
2311                  * the --rebasing case, it is up to the caller to take care of
2312                  * stray directories.
2313                  */
2314                 if (file_exists(state.dir) && !state.rebasing) {
2315                         if (resume == RESUME_ABORT || resume == RESUME_QUIT) {
2316                                 am_destroy(&state);
2317                                 am_state_release(&state);
2318                                 return 0;
2319                         }
2320
2321                         die(_("Stray %s directory found.\n"
2322                                 "Use \"git am --abort\" to remove it."),
2323                                 state.dir);
2324                 }
2325
2326                 if (resume)
2327                         die(_("Resolve operation not in progress, we are not resuming."));
2328
2329                 for (i = 0; i < argc; i++) {
2330                         if (is_absolute_path(argv[i]) || !prefix)
2331                                 argv_array_push(&paths, argv[i]);
2332                         else
2333                                 argv_array_push(&paths, mkpath("%s/%s", prefix, argv[i]));
2334                 }
2335
2336                 am_setup(&state, patch_format, paths.argv, keep_cr);
2337
2338                 argv_array_clear(&paths);
2339         }
2340
2341         switch (resume) {
2342         case RESUME_FALSE:
2343                 am_run(&state, 0);
2344                 break;
2345         case RESUME_APPLY:
2346                 am_run(&state, 1);
2347                 break;
2348         case RESUME_RESOLVED:
2349                 am_resolve(&state);
2350                 break;
2351         case RESUME_SKIP:
2352                 am_skip(&state);
2353                 break;
2354         case RESUME_ABORT:
2355                 am_abort(&state);
2356                 break;
2357         case RESUME_QUIT:
2358                 am_rerere_clear();
2359                 am_destroy(&state);
2360                 break;
2361         case RESUME_SHOW_PATCH:
2362                 ret = show_patch(&state);
2363                 break;
2364         default:
2365                 BUG("invalid resume value");
2366         }
2367
2368         am_state_release(&state);
2369
2370         return ret;
2371 }