git

1
/*
2
 * Builtin "git am"
3
 *
4
 * Based on git-am.sh by Junio C Hamano.
5
 */
6

7
#include "builtin.h"
8
#include "abspath.h"
9
#include "advice.h"
10
#include "config.h"
11
#include "editor.h"
12
#include "environment.h"
13
#include "gettext.h"
14
#include "hex.h"
15
#include "parse-options.h"
16
#include "dir.h"
17
#include "run-command.h"
18
#include "hook.h"
19
#include "quote.h"
20
#include "tempfile.h"
21
#include "lockfile.h"
22
#include "cache-tree.h"
23
#include "refs.h"
24
#include "commit.h"
25
#include "diff.h"
26
#include "unpack-trees.h"
27
#include "branch.h"
28
#include "object-name.h"
29
#include "preload-index.h"
30
#include "sequencer.h"
31
#include "revision.h"
32
#include "merge-recursive.h"
33
#include "log-tree.h"
34
#include "notes-utils.h"
35
#include "rerere.h"
36
#include "mailinfo.h"
37
#include "apply.h"
38
#include "string-list.h"
39
#include "pager.h"
40
#include "path.h"
41
#include "repository.h"
42
#include "pretty.h"
43

44
/**
45
 * Returns the length of the first line of msg.
46
 */
47
static int linelen(const char *msg)
48
{
49
	return strchrnul(msg, '\n') - msg;
50
}
51

52
/**
53
 * Returns true if `str` consists of only whitespace, false otherwise.
54
 */
55
static int str_isspace(const char *str)
56
{
57
	for (; *str; str++)
58
		if (!isspace(*str))
59
			return 0;
60

61
	return 1;
62
}
63

64
enum patch_format {
65
	PATCH_FORMAT_UNKNOWN = 0,
66
	PATCH_FORMAT_MBOX,
67
	PATCH_FORMAT_STGIT,
68
	PATCH_FORMAT_STGIT_SERIES,
69
	PATCH_FORMAT_HG,
70
	PATCH_FORMAT_MBOXRD
71
};
72

73
enum keep_type {
74
	KEEP_FALSE = 0,
75
	KEEP_TRUE,      /* pass -k flag to git-mailinfo */
76
	KEEP_NON_PATCH  /* pass -b flag to git-mailinfo */
77
};
78

79
enum scissors_type {
80
	SCISSORS_UNSET = -1,
81
	SCISSORS_FALSE = 0,  /* pass --no-scissors to git-mailinfo */
82
	SCISSORS_TRUE        /* pass --scissors to git-mailinfo */
83
};
84

85
enum signoff_type {
86
	SIGNOFF_FALSE = 0,
87
	SIGNOFF_TRUE = 1,
88
	SIGNOFF_EXPLICIT /* --signoff was set on the command-line */
89
};
90

91
enum resume_type {
92
	RESUME_FALSE = 0,
93
	RESUME_APPLY,
94
	RESUME_RESOLVED,
95
	RESUME_SKIP,
96
	RESUME_ABORT,
97
	RESUME_QUIT,
98
	RESUME_SHOW_PATCH_RAW,
99
	RESUME_SHOW_PATCH_DIFF,
100
	RESUME_ALLOW_EMPTY,
101
};
102

103
enum empty_action {
104
	STOP_ON_EMPTY_COMMIT = 0,  /* output errors and stop in the middle of an am session */
105
	DROP_EMPTY_COMMIT,         /* skip with a notice message, unless "--quiet" has been passed */
106
	KEEP_EMPTY_COMMIT,         /* keep recording as empty commits */
107
};
108

109
struct am_state {
110
	/* state directory path */
111
	char *dir;
112

113
	/* current and last patch numbers, 1-indexed */
114
	int cur;
115
	int last;
116

117
	/* commit metadata and message */
118
	char *author_name;
119
	char *author_email;
120
	char *author_date;
121
	char *msg;
122
	size_t msg_len;
123

124
	/* when --rebasing, records the original commit the patch came from */
125
	struct object_id orig_commit;
126

127
	/* number of digits in patch filename */
128
	int prec;
129

130
	/* various operating modes and command line options */
131
	int interactive;
132
	int no_verify;
133
	int threeway;
134
	int quiet;
135
	int signoff; /* enum signoff_type */
136
	int utf8;
137
	int keep; /* enum keep_type */
138
	int message_id;
139
	int scissors; /* enum scissors_type */
140
	int quoted_cr; /* enum quoted_cr_action */
141
	int empty_type; /* enum empty_action */
142
	struct strvec git_apply_opts;
143
	const char *resolvemsg;
144
	int committer_date_is_author_date;
145
	int ignore_date;
146
	int allow_rerere_autoupdate;
147
	const char *sign_commit;
148
	int rebasing;
149
};
150

151
/**
152
 * Initializes am_state with the default values.
153
 */
154
static void am_state_init(struct am_state *state)
155
{
156
	int gpgsign;
157

158
	memset(state, 0, sizeof(*state));
159

160
	state->dir = git_pathdup("rebase-apply");
161

162
	state->prec = 4;
163

164
	git_config_get_bool("am.threeway", &state->threeway);
165

166
	state->utf8 = 1;
167

168
	git_config_get_bool("am.messageid", &state->message_id);
169

170
	state->scissors = SCISSORS_UNSET;
171
	state->quoted_cr = quoted_cr_unset;
172

173
	strvec_init(&state->git_apply_opts);
174

175
	if (!git_config_get_bool("commit.gpgsign", &gpgsign))
176
		state->sign_commit = gpgsign ? "" : NULL;
177
}
178

179
/**
180
 * Releases memory allocated by an am_state.
181
 */
182
static void am_state_release(struct am_state *state)
183
{
184
	free(state->dir);
185
	free(state->author_name);
186
	free(state->author_email);
187
	free(state->author_date);
188
	free(state->msg);
189
	strvec_clear(&state->git_apply_opts);
190
}
191

192
static int am_option_parse_quoted_cr(const struct option *opt,
193
				     const char *arg, int unset)
194
{
195
	BUG_ON_OPT_NEG(unset);
196

197
	if (mailinfo_parse_quoted_cr_action(arg, opt->value) != 0)
198
		return error(_("bad action '%s' for '%s'"), arg, "--quoted-cr");
199
	return 0;
200
}
201

202
static int am_option_parse_empty(const struct option *opt,
203
				     const char *arg, int unset)
204
{
205
	int *opt_value = opt->value;
206

207
	BUG_ON_OPT_NEG(unset);
208

209
	if (!strcmp(arg, "stop"))
210
		*opt_value = STOP_ON_EMPTY_COMMIT;
211
	else if (!strcmp(arg, "drop"))
212
		*opt_value = DROP_EMPTY_COMMIT;
213
	else if (!strcmp(arg, "keep"))
214
		*opt_value = KEEP_EMPTY_COMMIT;
215
	else
216
		return error(_("invalid value for '%s': '%s'"), "--empty", arg);
217

218
	return 0;
219
}
220

221
/**
222
 * Returns path relative to the am_state directory.
223
 */
224
static inline const char *am_path(const struct am_state *state, const char *path)
225
{
226
	return mkpath("%s/%s", state->dir, path);
227
}
228

229
/**
230
 * For convenience to call write_file()
231
 */
232
static void write_state_text(const struct am_state *state,
233
			     const char *name, const char *string)
234
{
235
	write_file(am_path(state, name), "%s", string);
236
}
237

238
static void write_state_count(const struct am_state *state,
239
			      const char *name, int value)
240
{
241
	write_file(am_path(state, name), "%d", value);
242
}
243

244
static void write_state_bool(const struct am_state *state,
245
			     const char *name, int value)
246
{
247
	write_state_text(state, name, value ? "t" : "f");
248
}
249

250
/**
251
 * If state->quiet is false, calls fprintf(fp, fmt, ...), and appends a newline
252
 * at the end.
253
 */
254
__attribute__((format (printf, 3, 4)))
255
static void say(const struct am_state *state, FILE *fp, const char *fmt, ...)
256
{
257
	va_list ap;
258

259
	va_start(ap, fmt);
260
	if (!state->quiet) {
261
		vfprintf(fp, fmt, ap);
262
		putc('\n', fp);
263
	}
264
	va_end(ap);
265
}
266

267
/**
268
 * Returns 1 if there is an am session in progress, 0 otherwise.
269
 */
270
static int am_in_progress(const struct am_state *state)
271
{
272
	struct stat st;
273

274
	if (lstat(state->dir, &st) < 0 || !S_ISDIR(st.st_mode))
275
		return 0;
276
	if (lstat(am_path(state, "last"), &st) || !S_ISREG(st.st_mode))
277
		return 0;
278
	if (lstat(am_path(state, "next"), &st) || !S_ISREG(st.st_mode))
279
		return 0;
280
	return 1;
281
}
282

283
/**
284
 * Reads the contents of `file` in the `state` directory into `sb`. Returns the
285
 * number of bytes read on success, -1 if the file does not exist. If `trim` is
286
 * set, trailing whitespace will be removed.
287
 */
288
static int read_state_file(struct strbuf *sb, const struct am_state *state,
289
			const char *file, int trim)
290
{
291
	strbuf_reset(sb);
292

293
	if (strbuf_read_file(sb, am_path(state, file), 0) >= 0) {
294
		if (trim)
295
			strbuf_trim(sb);
296

297
		return sb->len;
298
	}
299

300
	if (errno == ENOENT)
301
		return -1;
302

303
	die_errno(_("could not read '%s'"), am_path(state, file));
304
}
305

306
/**
307
 * Reads and parses the state directory's "author-script" file, and sets
308
 * state->author_name, state->author_email and state->author_date accordingly.
309
 * Returns 0 on success, -1 if the file could not be parsed.
310
 *
311
 * The author script is of the format:
312
 *
313
 *	GIT_AUTHOR_NAME='$author_name'
314
 *	GIT_AUTHOR_EMAIL='$author_email'
315
 *	GIT_AUTHOR_DATE='$author_date'
316
 *
317
 * where $author_name, $author_email and $author_date are quoted. We are strict
318
 * with our parsing, as the file was meant to be eval'd in the old git-am.sh
319
 * script, and thus if the file differs from what this function expects, it is
320
 * better to bail out than to do something that the user does not expect.
321
 */
322
static int read_am_author_script(struct am_state *state)
323
{
324
	const char *filename = am_path(state, "author-script");
325

326
	assert(!state->author_name);
327
	assert(!state->author_email);
328
	assert(!state->author_date);
329

330
	return read_author_script(filename, &state->author_name,
331
				  &state->author_email, &state->author_date, 1);
332
}
333

334
/**
335
 * Saves state->author_name, state->author_email and state->author_date in the
336
 * state directory's "author-script" file.
337
 */
338
static void write_author_script(const struct am_state *state)
339
{
340
	struct strbuf sb = STRBUF_INIT;
341

342
	strbuf_addstr(&sb, "GIT_AUTHOR_NAME=");
343
	sq_quote_buf(&sb, state->author_name);
344
	strbuf_addch(&sb, '\n');
345

346
	strbuf_addstr(&sb, "GIT_AUTHOR_EMAIL=");
347
	sq_quote_buf(&sb, state->author_email);
348
	strbuf_addch(&sb, '\n');
349

350
	strbuf_addstr(&sb, "GIT_AUTHOR_DATE=");
351
	sq_quote_buf(&sb, state->author_date);
352
	strbuf_addch(&sb, '\n');
353

354
	write_state_text(state, "author-script", sb.buf);
355

356
	strbuf_release(&sb);
357
}
358

359
/**
360
 * Reads the commit message from the state directory's "final-commit" file,
361
 * setting state->msg to its contents and state->msg_len to the length of its
362
 * contents in bytes.
363
 *
364
 * Returns 0 on success, -1 if the file does not exist.
365
 */
366
static int read_commit_msg(struct am_state *state)
367
{
368
	struct strbuf sb = STRBUF_INIT;
369

370
	assert(!state->msg);
371

372
	if (read_state_file(&sb, state, "final-commit", 0) < 0) {
373
		strbuf_release(&sb);
374
		return -1;
375
	}
376

377
	state->msg = strbuf_detach(&sb, &state->msg_len);
378
	return 0;
379
}
380

381
/**
382
 * Saves state->msg in the state directory's "final-commit" file.
383
 */
384
static void write_commit_msg(const struct am_state *state)
385
{
386
	const char *filename = am_path(state, "final-commit");
387
	write_file_buf(filename, state->msg, state->msg_len);
388
}
389

390
/**
391
 * Loads state from disk.
392
 */
393
static void am_load(struct am_state *state)
394
{
395
	struct strbuf sb = STRBUF_INIT;
396

397
	if (read_state_file(&sb, state, "next", 1) < 0)
398
		BUG("state file 'next' does not exist");
399
	state->cur = strtol(sb.buf, NULL, 10);
400

401
	if (read_state_file(&sb, state, "last", 1) < 0)
402
		BUG("state file 'last' does not exist");
403
	state->last = strtol(sb.buf, NULL, 10);
404

405
	if (read_am_author_script(state) < 0)
406
		die(_("could not parse author script"));
407

408
	read_commit_msg(state);
409

410
	if (read_state_file(&sb, state, "original-commit", 1) < 0)
411
		oidclr(&state->orig_commit, the_repository->hash_algo);
412
	else if (get_oid_hex(sb.buf, &state->orig_commit) < 0)
413
		die(_("could not parse %s"), am_path(state, "original-commit"));
414

415
	read_state_file(&sb, state, "threeway", 1);
416
	state->threeway = !strcmp(sb.buf, "t");
417

418
	read_state_file(&sb, state, "quiet", 1);
419
	state->quiet = !strcmp(sb.buf, "t");
420

421
	read_state_file(&sb, state, "sign", 1);
422
	state->signoff = !strcmp(sb.buf, "t");
423

424
	read_state_file(&sb, state, "utf8", 1);
425
	state->utf8 = !strcmp(sb.buf, "t");
426

427
	if (file_exists(am_path(state, "rerere-autoupdate"))) {
428
		read_state_file(&sb, state, "rerere-autoupdate", 1);
429
		state->allow_rerere_autoupdate = strcmp(sb.buf, "t") ?
430
			RERERE_NOAUTOUPDATE : RERERE_AUTOUPDATE;
431
	} else {
432
		state->allow_rerere_autoupdate = 0;
433
	}
434

435
	read_state_file(&sb, state, "keep", 1);
436
	if (!strcmp(sb.buf, "t"))
437
		state->keep = KEEP_TRUE;
438
	else if (!strcmp(sb.buf, "b"))
439
		state->keep = KEEP_NON_PATCH;
440
	else
441
		state->keep = KEEP_FALSE;
442

443
	read_state_file(&sb, state, "messageid", 1);
444
	state->message_id = !strcmp(sb.buf, "t");
445

446
	read_state_file(&sb, state, "scissors", 1);
447
	if (!strcmp(sb.buf, "t"))
448
		state->scissors = SCISSORS_TRUE;
449
	else if (!strcmp(sb.buf, "f"))
450
		state->scissors = SCISSORS_FALSE;
451
	else
452
		state->scissors = SCISSORS_UNSET;
453

454
	read_state_file(&sb, state, "quoted-cr", 1);
455
	if (!*sb.buf)
456
		state->quoted_cr = quoted_cr_unset;
457
	else if (mailinfo_parse_quoted_cr_action(sb.buf, &state->quoted_cr) != 0)
458
		die(_("could not parse %s"), am_path(state, "quoted-cr"));
459

460
	read_state_file(&sb, state, "apply-opt", 1);
461
	strvec_clear(&state->git_apply_opts);
462
	if (sq_dequote_to_strvec(sb.buf, &state->git_apply_opts) < 0)
463
		die(_("could not parse %s"), am_path(state, "apply-opt"));
464

465
	state->rebasing = !!file_exists(am_path(state, "rebasing"));
466

467
	strbuf_release(&sb);
468
}
469

470
/**
471
 * Removes the am_state directory, forcefully terminating the current am
472
 * session.
473
 */
474
static void am_destroy(const struct am_state *state)
475
{
476
	struct strbuf sb = STRBUF_INIT;
477

478
	strbuf_addstr(&sb, state->dir);
479
	remove_dir_recursively(&sb, 0);
480
	strbuf_release(&sb);
481
}
482

483
/**
484
 * Runs applypatch-msg hook. Returns its exit code.
485
 */
486
static int run_applypatch_msg_hook(struct am_state *state)
487
{
488
	int ret = 0;
489

490
	assert(state->msg);
491

492
	if (!state->no_verify)
493
		ret = run_hooks_l(the_repository, "applypatch-msg",
494
				  am_path(state, "final-commit"), NULL);
495

496
	if (!ret) {
497
		FREE_AND_NULL(state->msg);
498
		if (read_commit_msg(state) < 0)
499
			die(_("'%s' was deleted by the applypatch-msg hook"),
500
				am_path(state, "final-commit"));
501
	}
502

503
	return ret;
504
}
505

506
/**
507
 * Runs post-rewrite hook. Returns it exit code.
508
 */
509
static int run_post_rewrite_hook(const struct am_state *state)
510
{
511
	struct run_hooks_opt opt = RUN_HOOKS_OPT_INIT;
512

513
	strvec_push(&opt.args, "rebase");
514
	opt.path_to_stdin = am_path(state, "rewritten");
515

516
	return run_hooks_opt(the_repository, "post-rewrite", &opt);
517
}
518

519
/**
520
 * Reads the state directory's "rewritten" file, and copies notes from the old
521
 * commits listed in the file to their rewritten commits.
522
 *
523
 * Returns 0 on success, -1 on failure.
524
 */
525
static int copy_notes_for_rebase(const struct am_state *state)
526
{
527
	struct notes_rewrite_cfg *c;
528
	struct strbuf sb = STRBUF_INIT;
529
	const char *invalid_line = _("Malformed input line: '%s'.");
530
	const char *msg = "Notes added by 'git rebase'";
531
	FILE *fp;
532
	int ret = 0;
533

534
	assert(state->rebasing);
535

536
	c = init_copy_notes_for_rewrite("rebase");
537
	if (!c)
538
		return 0;
539

540
	fp = xfopen(am_path(state, "rewritten"), "r");
541

542
	while (!strbuf_getline_lf(&sb, fp)) {
543
		struct object_id from_obj, to_obj;
544
		const char *p;
545

546
		if (sb.len != the_hash_algo->hexsz * 2 + 1) {
547
			ret = error(invalid_line, sb.buf);
548
			goto finish;
549
		}
550

551
		if (parse_oid_hex(sb.buf, &from_obj, &p)) {
552
			ret = error(invalid_line, sb.buf);
553
			goto finish;
554
		}
555

556
		if (*p != ' ') {
557
			ret = error(invalid_line, sb.buf);
558
			goto finish;
559
		}
560

561
		if (get_oid_hex(p + 1, &to_obj)) {
562
			ret = error(invalid_line, sb.buf);
563
			goto finish;
564
		}
565

566
		if (copy_note_for_rewrite(c, &from_obj, &to_obj))
567
			ret = error(_("Failed to copy notes from '%s' to '%s'"),
568
					oid_to_hex(&from_obj), oid_to_hex(&to_obj));
569
	}
570

571
finish:
572
	finish_copy_notes_for_rewrite(the_repository, c, msg);
573
	fclose(fp);
574
	strbuf_release(&sb);
575
	return ret;
576
}
577

578
/**
579
 * Determines if the file looks like a piece of RFC2822 mail by grabbing all
580
 * non-indented lines and checking if they look like they begin with valid
581
 * header field names.
582
 *
583
 * Returns 1 if the file looks like a piece of mail, 0 otherwise.
584
 */
585
static int is_mail(FILE *fp)
586
{
587
	const char *header_regex = "^[!-9;-~]+:";
588
	struct strbuf sb = STRBUF_INIT;
589
	regex_t regex;
590
	int ret = 1;
591

592
	if (fseek(fp, 0L, SEEK_SET))
593
		die_errno(_("fseek failed"));
594

595
	if (regcomp(&regex, header_regex, REG_NOSUB | REG_EXTENDED))
596
		die("invalid pattern: %s", header_regex);
597

598
	while (!strbuf_getline(&sb, fp)) {
599
		if (!sb.len)
600
			break; /* End of header */
601

602
		/* Ignore indented folded lines */
603
		if (*sb.buf == '\t' || *sb.buf == ' ')
604
			continue;
605

606
		/* It's a header if it matches header_regex */
607
		if (regexec(&regex, sb.buf, 0, NULL, 0)) {
608
			ret = 0;
609
			goto done;
610
		}
611
	}
612

613
done:
614
	regfree(&regex);
615
	strbuf_release(&sb);
616
	return ret;
617
}
618

619
/**
620
 * Attempts to detect the patch_format of the patches contained in `paths`,
621
 * returning the PATCH_FORMAT_* enum value. Returns PATCH_FORMAT_UNKNOWN if
622
 * detection fails.
623
 */
624
static int detect_patch_format(const char **paths)
625
{
626
	enum patch_format ret = PATCH_FORMAT_UNKNOWN;
627
	struct strbuf l1 = STRBUF_INIT;
628
	struct strbuf l2 = STRBUF_INIT;
629
	struct strbuf l3 = STRBUF_INIT;
630
	FILE *fp;
631

632
	/*
633
	 * We default to mbox format if input is from stdin and for directories
634
	 */
635
	if (!*paths || !strcmp(*paths, "-") || is_directory(*paths))
636
		return PATCH_FORMAT_MBOX;
637

638
	/*
639
	 * Otherwise, check the first few lines of the first patch, starting
640
	 * from the first non-blank line, to try to detect its format.
641
	 */
642

643
	fp = xfopen(*paths, "r");
644

645
	while (!strbuf_getline(&l1, fp)) {
646
		if (l1.len)
647
			break;
648
	}
649

650
	if (starts_with(l1.buf, "From ") || starts_with(l1.buf, "From: ")) {
651
		ret = PATCH_FORMAT_MBOX;
652
		goto done;
653
	}
654

655
	if (starts_with(l1.buf, "# This series applies on GIT commit")) {
656
		ret = PATCH_FORMAT_STGIT_SERIES;
657
		goto done;
658
	}
659

660
	if (!strcmp(l1.buf, "# HG changeset patch")) {
661
		ret = PATCH_FORMAT_HG;
662
		goto done;
663
	}
664

665
	strbuf_getline(&l2, fp);
666
	strbuf_getline(&l3, fp);
667

668
	/*
669
	 * If the second line is empty and the third is a From, Author or Date
670
	 * entry, this is likely an StGit patch.
671
	 */
672
	if (l1.len && !l2.len &&
673
		(starts_with(l3.buf, "From:") ||
674
		 starts_with(l3.buf, "Author:") ||
675
		 starts_with(l3.buf, "Date:"))) {
676
		ret = PATCH_FORMAT_STGIT;
677
		goto done;
678
	}
679

680
	if (l1.len && is_mail(fp)) {
681
		ret = PATCH_FORMAT_MBOX;
682
		goto done;
683
	}
684

685
done:
686
	fclose(fp);
687
	strbuf_release(&l1);
688
	strbuf_release(&l2);
689
	strbuf_release(&l3);
690
	return ret;
691
}
692

693
/**
694
 * Splits out individual email patches from `paths`, where each path is either
695
 * a mbox file or a Maildir. Returns 0 on success, -1 on failure.
696
 */
697
static int split_mail_mbox(struct am_state *state, const char **paths,
698
				int keep_cr, int mboxrd)
699
{
700
	struct child_process cp = CHILD_PROCESS_INIT;
701
	struct strbuf last = STRBUF_INIT;
702
	int ret;
703

704
	cp.git_cmd = 1;
705
	strvec_push(&cp.args, "mailsplit");
706
	strvec_pushf(&cp.args, "-d%d", state->prec);
707
	strvec_pushf(&cp.args, "-o%s", state->dir);
708
	strvec_push(&cp.args, "-b");
709
	if (keep_cr)
710
		strvec_push(&cp.args, "--keep-cr");
711
	if (mboxrd)
712
		strvec_push(&cp.args, "--mboxrd");
713
	strvec_push(&cp.args, "--");
714
	strvec_pushv(&cp.args, paths);
715

716
	ret = capture_command(&cp, &last, 8);
717
	if (ret)
718
		goto exit;
719

720
	state->cur = 1;
721
	state->last = strtol(last.buf, NULL, 10);
722

723
exit:
724
	strbuf_release(&last);
725
	return ret ? -1 : 0;
726
}
727

728
/**
729
 * Callback signature for split_mail_conv(). The foreign patch should be
730
 * read from `in`, and the converted patch (in RFC2822 mail format) should be
731
 * written to `out`. Return 0 on success, or -1 on failure.
732
 */
733
typedef int (*mail_conv_fn)(FILE *out, FILE *in, int keep_cr);
734

735
/**
736
 * Calls `fn` for each file in `paths` to convert the foreign patch to the
737
 * RFC2822 mail format suitable for parsing with git-mailinfo.
738
 *
739
 * Returns 0 on success, -1 on failure.
740
 */
741
static int split_mail_conv(mail_conv_fn fn, struct am_state *state,
742
			const char **paths, int keep_cr)
743
{
744
	static const char *stdin_only[] = {"-", NULL};
745
	int i;
746

747
	if (!*paths)
748
		paths = stdin_only;
749

750
	for (i = 0; *paths; paths++, i++) {
751
		FILE *in, *out;
752
		const char *mail;
753
		int ret;
754

755
		if (!strcmp(*paths, "-"))
756
			in = stdin;
757
		else
758
			in = fopen(*paths, "r");
759

760
		if (!in)
761
			return error_errno(_("could not open '%s' for reading"),
762
					   *paths);
763

764
		mail = mkpath("%s/%0*d", state->dir, state->prec, i + 1);
765

766
		out = fopen(mail, "w");
767
		if (!out) {
768
			if (in != stdin)
769
				fclose(in);
770
			return error_errno(_("could not open '%s' for writing"),
771
					   mail);
772
		}
773

774
		ret = fn(out, in, keep_cr);
775

776
		fclose(out);
777
		if (in != stdin)
778
			fclose(in);
779

780
		if (ret)
781
			return error(_("could not parse patch '%s'"), *paths);
782
	}
783

784
	state->cur = 1;
785
	state->last = i;
786
	return 0;
787
}
788

789
/**
790
 * A split_mail_conv() callback that converts an StGit patch to an RFC2822
791
 * message suitable for parsing with git-mailinfo.
792
 */
793
static int stgit_patch_to_mail(FILE *out, FILE *in, int keep_cr UNUSED)
794
{
795
	struct strbuf sb = STRBUF_INIT;
796
	int subject_printed = 0;
797

798
	while (!strbuf_getline_lf(&sb, in)) {
799
		const char *str;
800

801
		if (str_isspace(sb.buf))
802
			continue;
803
		else if (skip_prefix(sb.buf, "Author:", &str))
804
			fprintf(out, "From:%s\n", str);
805
		else if (starts_with(sb.buf, "From") || starts_with(sb.buf, "Date"))
806
			fprintf(out, "%s\n", sb.buf);
807
		else if (!subject_printed) {
808
			fprintf(out, "Subject: %s\n", sb.buf);
809
			subject_printed = 1;
810
		} else {
811
			fprintf(out, "\n%s\n", sb.buf);
812
			break;
813
		}
814
	}
815

816
	strbuf_reset(&sb);
817
	while (strbuf_fread(&sb, 8192, in) > 0) {
818
		fwrite(sb.buf, 1, sb.len, out);
819
		strbuf_reset(&sb);
820
	}
821

822
	strbuf_release(&sb);
823
	return 0;
824
}
825

826
/**
827
 * This function only supports a single StGit series file in `paths`.
828
 *
829
 * Given an StGit series file, converts the StGit patches in the series into
830
 * RFC2822 messages suitable for parsing with git-mailinfo, and queues them in
831
 * the state directory.
832
 *
833
 * Returns 0 on success, -1 on failure.
834
 */
835
static int split_mail_stgit_series(struct am_state *state, const char **paths,
836
					int keep_cr)
837
{
838
	const char *series_dir;
839
	char *series_dir_buf;
840
	FILE *fp;
841
	struct strvec patches = STRVEC_INIT;
842
	struct strbuf sb = STRBUF_INIT;
843
	int ret;
844

845
	if (!paths[0] || paths[1])
846
		return error(_("Only one StGIT patch series can be applied at once"));
847

848
	series_dir_buf = xstrdup(*paths);
849
	series_dir = dirname(series_dir_buf);
850

851
	fp = fopen(*paths, "r");
852
	if (!fp)
853
		return error_errno(_("could not open '%s' for reading"), *paths);
854

855
	while (!strbuf_getline_lf(&sb, fp)) {
856
		if (*sb.buf == '#')
857
			continue; /* skip comment lines */
858

859
		strvec_push(&patches, mkpath("%s/%s", series_dir, sb.buf));
860
	}
861

862
	fclose(fp);
863
	strbuf_release(&sb);
864
	free(series_dir_buf);
865

866
	ret = split_mail_conv(stgit_patch_to_mail, state, patches.v, keep_cr);
867

868
	strvec_clear(&patches);
869
	return ret;
870
}
871

872
/**
873
 * A split_patches_conv() callback that converts a mercurial patch to a RFC2822
874
 * message suitable for parsing with git-mailinfo.
875
 */
876
static int hg_patch_to_mail(FILE *out, FILE *in, int keep_cr UNUSED)
877
{
878
	struct strbuf sb = STRBUF_INIT;
879
	int rc = 0;
880

881
	while (!strbuf_getline_lf(&sb, in)) {
882
		const char *str;
883

884
		if (skip_prefix(sb.buf, "# User ", &str))
885
			fprintf(out, "From: %s\n", str);
886
		else if (skip_prefix(sb.buf, "# Date ", &str)) {
887
			timestamp_t timestamp;
888
			long tz, tz2;
889
			char *end;
890

891
			errno = 0;
892
			timestamp = parse_timestamp(str, &end, 10);
893
			if (errno) {
894
				rc = error(_("invalid timestamp"));
895
				goto exit;
896
			}
897

898
			if (!skip_prefix(end, " ", &str)) {
899
				rc = error(_("invalid Date line"));
900
				goto exit;
901
			}
902

903
			errno = 0;
904
			tz = strtol(str, &end, 10);
905
			if (errno) {
906
				rc = error(_("invalid timezone offset"));
907
				goto exit;
908
			}
909

910
			if (*end) {
911
				rc = error(_("invalid Date line"));
912
				goto exit;
913
			}
914

915
			/*
916
			 * mercurial's timezone is in seconds west of UTC,
917
			 * however git's timezone is in hours + minutes east of
918
			 * UTC. Convert it.
919
			 */
920
			tz2 = labs(tz) / 3600 * 100 + labs(tz) % 3600 / 60;
921
			if (tz > 0)
922
				tz2 = -tz2;
923

924
			fprintf(out, "Date: %s\n", show_date(timestamp, tz2, DATE_MODE(RFC2822)));
925
		} else if (starts_with(sb.buf, "# ")) {
926
			continue;
927
		} else {
928
			fprintf(out, "\n%s\n", sb.buf);
929
			break;
930
		}
931
	}
932

933
	strbuf_reset(&sb);
934
	while (strbuf_fread(&sb, 8192, in) > 0) {
935
		fwrite(sb.buf, 1, sb.len, out);
936
		strbuf_reset(&sb);
937
	}
938
exit:
939
	strbuf_release(&sb);
940
	return rc;
941
}
942

943
/**
944
 * Splits a list of files/directories into individual email patches. Each path
945
 * in `paths` must be a file/directory that is formatted according to
946
 * `patch_format`.
947
 *
948
 * Once split out, the individual email patches will be stored in the state
949
 * directory, with each patch's filename being its index, padded to state->prec
950
 * digits.
951
 *
952
 * state->cur will be set to the index of the first mail, and state->last will
953
 * be set to the index of the last mail.
954
 *
955
 * Set keep_cr to 0 to convert all lines ending with \r\n to end with \n, 1
956
 * to disable this behavior, -1 to use the default configured setting.
957
 *
958
 * Returns 0 on success, -1 on failure.
959
 */
960
static int split_mail(struct am_state *state, enum patch_format patch_format,
961
			const char **paths, int keep_cr)
962
{
963
	if (keep_cr < 0) {
964
		keep_cr = 0;
965
		git_config_get_bool("am.keepcr", &keep_cr);
966
	}
967

968
	switch (patch_format) {
969
	case PATCH_FORMAT_MBOX:
970
		return split_mail_mbox(state, paths, keep_cr, 0);
971
	case PATCH_FORMAT_STGIT:
972
		return split_mail_conv(stgit_patch_to_mail, state, paths, keep_cr);
973
	case PATCH_FORMAT_STGIT_SERIES:
974
		return split_mail_stgit_series(state, paths, keep_cr);
975
	case PATCH_FORMAT_HG:
976
		return split_mail_conv(hg_patch_to_mail, state, paths, keep_cr);
977
	case PATCH_FORMAT_MBOXRD:
978
		return split_mail_mbox(state, paths, keep_cr, 1);
979
	default:
980
		BUG("invalid patch_format");
981
	}
982
	return -1;
983
}
984

985
/**
986
 * Setup a new am session for applying patches
987
 */
988
static void am_setup(struct am_state *state, enum patch_format patch_format,
989
			const char **paths, int keep_cr)
990
{
991
	struct object_id curr_head;
992
	const char *str;
993
	struct strbuf sb = STRBUF_INIT;
994

995
	if (!patch_format)
996
		patch_format = detect_patch_format(paths);
997

998
	if (!patch_format) {
999
		fprintf_ln(stderr, _("Patch format detection failed."));
1000
		exit(128);
1001
	}
1002

1003
	if (mkdir(state->dir, 0777) < 0 && errno != EEXIST)
1004
		die_errno(_("failed to create directory '%s'"), state->dir);
1005
	refs_delete_ref(get_main_ref_store(the_repository), NULL,
1006
			"REBASE_HEAD", NULL, REF_NO_DEREF);
1007

1008
	if (split_mail(state, patch_format, paths, keep_cr) < 0) {
1009
		am_destroy(state);
1010
		die(_("Failed to split patches."));
1011
	}
1012

1013
	if (state->rebasing)
1014
		state->threeway = 1;
1015

1016
	write_state_bool(state, "threeway", state->threeway);
1017
	write_state_bool(state, "quiet", state->quiet);
1018
	write_state_bool(state, "sign", state->signoff);
1019
	write_state_bool(state, "utf8", state->utf8);
1020

1021
	if (state->allow_rerere_autoupdate)
1022
		write_state_bool(state, "rerere-autoupdate",
1023
			 state->allow_rerere_autoupdate == RERERE_AUTOUPDATE);
1024

1025
	switch (state->keep) {
1026
	case KEEP_FALSE:
1027
		str = "f";
1028
		break;
1029
	case KEEP_TRUE:
1030
		str = "t";
1031
		break;
1032
	case KEEP_NON_PATCH:
1033
		str = "b";
1034
		break;
1035
	default:
1036
		BUG("invalid value for state->keep");
1037
	}
1038

1039
	write_state_text(state, "keep", str);
1040
	write_state_bool(state, "messageid", state->message_id);
1041

1042
	switch (state->scissors) {
1043
	case SCISSORS_UNSET:
1044
		str = "";
1045
		break;
1046
	case SCISSORS_FALSE:
1047
		str = "f";
1048
		break;
1049
	case SCISSORS_TRUE:
1050
		str = "t";
1051
		break;
1052
	default:
1053
		BUG("invalid value for state->scissors");
1054
	}
1055
	write_state_text(state, "scissors", str);
1056

1057
	switch (state->quoted_cr) {
1058
	case quoted_cr_unset:
1059
		str = "";
1060
		break;
1061
	case quoted_cr_nowarn:
1062
		str = "nowarn";
1063
		break;
1064
	case quoted_cr_warn:
1065
		str = "warn";
1066
		break;
1067
	case quoted_cr_strip:
1068
		str = "strip";
1069
		break;
1070
	default:
1071
		BUG("invalid value for state->quoted_cr");
1072
	}
1073
	write_state_text(state, "quoted-cr", str);
1074

1075
	sq_quote_argv(&sb, state->git_apply_opts.v);
1076
	write_state_text(state, "apply-opt", sb.buf);
1077

1078
	if (state->rebasing)
1079
		write_state_text(state, "rebasing", "");
1080
	else
1081
		write_state_text(state, "applying", "");
1082

1083
	if (!repo_get_oid(the_repository, "HEAD", &curr_head)) {
1084
		write_state_text(state, "abort-safety", oid_to_hex(&curr_head));
1085
		if (!state->rebasing)
1086
			refs_update_ref(get_main_ref_store(the_repository),
1087
					"am", "ORIG_HEAD", &curr_head, NULL,
1088
					0,
1089
					UPDATE_REFS_DIE_ON_ERR);
1090
	} else {
1091
		write_state_text(state, "abort-safety", "");
1092
		if (!state->rebasing)
1093
			refs_delete_ref(get_main_ref_store(the_repository),
1094
					NULL, "ORIG_HEAD", NULL, 0);
1095
	}
1096

1097
	/*
1098
	 * NOTE: Since the "next" and "last" files determine if an am_state
1099
	 * session is in progress, they should be written last.
1100
	 */
1101

1102
	write_state_count(state, "next", state->cur);
1103
	write_state_count(state, "last", state->last);
1104

1105
	strbuf_release(&sb);
1106
}
1107

1108
/**
1109
 * Increments the patch pointer, and cleans am_state for the application of the
1110
 * next patch.
1111
 */
1112
static void am_next(struct am_state *state)
1113
{
1114
	struct object_id head;
1115

1116
	FREE_AND_NULL(state->author_name);
1117
	FREE_AND_NULL(state->author_email);
1118
	FREE_AND_NULL(state->author_date);
1119
	FREE_AND_NULL(state->msg);
1120
	state->msg_len = 0;
1121

1122
	unlink(am_path(state, "author-script"));
1123
	unlink(am_path(state, "final-commit"));
1124

1125
	oidclr(&state->orig_commit, the_repository->hash_algo);
1126
	unlink(am_path(state, "original-commit"));
1127
	refs_delete_ref(get_main_ref_store(the_repository), NULL,
1128
			"REBASE_HEAD", NULL, REF_NO_DEREF);
1129

1130
	if (!repo_get_oid(the_repository, "HEAD", &head))
1131
		write_state_text(state, "abort-safety", oid_to_hex(&head));
1132
	else
1133
		write_state_text(state, "abort-safety", "");
1134

1135
	state->cur++;
1136
	write_state_count(state, "next", state->cur);
1137
}
1138

1139
/**
1140
 * Returns the filename of the current patch email.
1141
 */
1142
static const char *msgnum(const struct am_state *state)
1143
{
1144
	static struct strbuf sb = STRBUF_INIT;
1145

1146
	strbuf_reset(&sb);
1147
	strbuf_addf(&sb, "%0*d", state->prec, state->cur);
1148

1149
	return sb.buf;
1150
}
1151

1152
/**
1153
 * Dies with a user-friendly message on how to proceed after resolving the
1154
 * problem. This message can be overridden with state->resolvemsg.
1155
 */
1156
static void NORETURN die_user_resolve(const struct am_state *state)
1157
{
1158
	if (state->resolvemsg) {
1159
		advise_if_enabled(ADVICE_MERGE_CONFLICT, "%s", state->resolvemsg);
1160
	} else {
1161
		const char *cmdline = state->interactive ? "git am -i" : "git am";
1162
		struct strbuf sb = STRBUF_INIT;
1163

1164
		strbuf_addf(&sb, _("When you have resolved this problem, run \"%s --continue\".\n"), cmdline);
1165
		strbuf_addf(&sb, _("If you prefer to skip this patch, run \"%s --skip\" instead.\n"), cmdline);
1166

1167
		if (advice_enabled(ADVICE_AM_WORK_DIR) &&
1168
		    is_empty_or_missing_file(am_path(state, "patch")) &&
1169
		    !repo_index_has_changes(the_repository, NULL, NULL))
1170
			strbuf_addf(&sb, _("To record the empty patch as an empty commit, run \"%s --allow-empty\".\n"), cmdline);
1171

1172
		strbuf_addf(&sb, _("To restore the original branch and stop patching, run \"%s --abort\"."), cmdline);
1173

1174
		advise_if_enabled(ADVICE_MERGE_CONFLICT, "%s", sb.buf);
1175
		strbuf_release(&sb);
1176
	}
1177

1178
	exit(128);
1179
}
1180

1181
/**
1182
 * Appends signoff to the "msg" field of the am_state.
1183
 */
1184
static void am_append_signoff(struct am_state *state)
1185
{
1186
	struct strbuf sb = STRBUF_INIT;
1187

1188
	strbuf_attach(&sb, state->msg, state->msg_len, state->msg_len);
1189
	append_signoff(&sb, 0, 0);
1190
	state->msg = strbuf_detach(&sb, &state->msg_len);
1191
}
1192

1193
/**
1194
 * Parses `mail` using git-mailinfo, extracting its patch and authorship info.
1195
 * state->msg will be set to the patch message. state->author_name,
1196
 * state->author_email and state->author_date will be set to the patch author's
1197
 * name, email and date respectively. The patch body will be written to the
1198
 * state directory's "patch" file.
1199
 *
1200
 * Returns 1 if the patch should be skipped, 0 otherwise.
1201
 */
1202
static int parse_mail(struct am_state *state, const char *mail)
1203
{
1204
	FILE *fp;
1205
	struct strbuf sb = STRBUF_INIT;
1206
	struct strbuf msg = STRBUF_INIT;
1207
	struct strbuf author_name = STRBUF_INIT;
1208
	struct strbuf author_date = STRBUF_INIT;
1209
	struct strbuf author_email = STRBUF_INIT;
1210
	int ret = 0;
1211
	struct mailinfo mi;
1212

1213
	setup_mailinfo(&mi);
1214

1215
	if (state->utf8)
1216
		mi.metainfo_charset = get_commit_output_encoding();
1217
	else
1218
		mi.metainfo_charset = NULL;
1219

1220
	switch (state->keep) {
1221
	case KEEP_FALSE:
1222
		break;
1223
	case KEEP_TRUE:
1224
		mi.keep_subject = 1;
1225
		break;
1226
	case KEEP_NON_PATCH:
1227
		mi.keep_non_patch_brackets_in_subject = 1;
1228
		break;
1229
	default:
1230
		BUG("invalid value for state->keep");
1231
	}
1232

1233
	if (state->message_id)
1234
		mi.add_message_id = 1;
1235

1236
	switch (state->scissors) {
1237
	case SCISSORS_UNSET:
1238
		break;
1239
	case SCISSORS_FALSE:
1240
		mi.use_scissors = 0;
1241
		break;
1242
	case SCISSORS_TRUE:
1243
		mi.use_scissors = 1;
1244
		break;
1245
	default:
1246
		BUG("invalid value for state->scissors");
1247
	}
1248

1249
	switch (state->quoted_cr) {
1250
	case quoted_cr_unset:
1251
		break;
1252
	case quoted_cr_nowarn:
1253
	case quoted_cr_warn:
1254
	case quoted_cr_strip:
1255
		mi.quoted_cr = state->quoted_cr;
1256
		break;
1257
	default:
1258
		BUG("invalid value for state->quoted_cr");
1259
	}
1260

1261
	mi.input = xfopen(mail, "r");
1262
	mi.output = xfopen(am_path(state, "info"), "w");
1263
	if (mailinfo(&mi, am_path(state, "msg"), am_path(state, "patch")))
1264
		die("could not parse patch");
1265

1266
	fclose(mi.input);
1267
	fclose(mi.output);
1268

1269
	if (mi.format_flowed)
1270
		warning(_("Patch sent with format=flowed; "
1271
			  "space at the end of lines might be lost."));
1272

1273
	/* Extract message and author information */
1274
	fp = xfopen(am_path(state, "info"), "r");
1275
	while (!strbuf_getline_lf(&sb, fp)) {
1276
		const char *x;
1277

1278
		if (skip_prefix(sb.buf, "Subject: ", &x)) {
1279
			if (msg.len)
1280
				strbuf_addch(&msg, '\n');
1281
			strbuf_addstr(&msg, x);
1282
		} else if (skip_prefix(sb.buf, "Author: ", &x))
1283
			strbuf_addstr(&author_name, x);
1284
		else if (skip_prefix(sb.buf, "Email: ", &x))
1285
			strbuf_addstr(&author_email, x);
1286
		else if (skip_prefix(sb.buf, "Date: ", &x))
1287
			strbuf_addstr(&author_date, x);
1288
	}
1289
	fclose(fp);
1290

1291
	/* Skip pine's internal folder data */
1292
	if (!strcmp(author_name.buf, "Mail System Internal Data")) {
1293
		ret = 1;
1294
		goto finish;
1295
	}
1296

1297
	strbuf_addstr(&msg, "\n\n");
1298
	strbuf_addbuf(&msg, &mi.log_message);
1299
	strbuf_stripspace(&msg, NULL);
1300

1301
	assert(!state->author_name);
1302
	state->author_name = strbuf_detach(&author_name, NULL);
1303

1304
	assert(!state->author_email);
1305
	state->author_email = strbuf_detach(&author_email, NULL);
1306

1307
	assert(!state->author_date);
1308
	state->author_date = strbuf_detach(&author_date, NULL);
1309

1310
	assert(!state->msg);
1311
	state->msg = strbuf_detach(&msg, &state->msg_len);
1312

1313
finish:
1314
	strbuf_release(&msg);
1315
	strbuf_release(&author_date);
1316
	strbuf_release(&author_email);
1317
	strbuf_release(&author_name);
1318
	strbuf_release(&sb);
1319
	clear_mailinfo(&mi);
1320
	return ret;
1321
}
1322

1323
/**
1324
 * Sets commit_id to the commit hash where the mail was generated from.
1325
 * Returns 0 on success, -1 on failure.
1326
 */
1327
static int get_mail_commit_oid(struct object_id *commit_id, const char *mail)
1328
{
1329
	struct strbuf sb = STRBUF_INIT;
1330
	FILE *fp = xfopen(mail, "r");
1331
	const char *x;
1332
	int ret = 0;
1333

1334
	if (strbuf_getline_lf(&sb, fp) ||
1335
	    !skip_prefix(sb.buf, "From ", &x) ||
1336
	    get_oid_hex(x, commit_id) < 0)
1337
		ret = -1;
1338

1339
	strbuf_release(&sb);
1340
	fclose(fp);
1341
	return ret;
1342
}
1343

1344
/**
1345
 * Sets state->msg, state->author_name, state->author_email, state->author_date
1346
 * to the commit's respective info.
1347
 */
1348
static void get_commit_info(struct am_state *state, struct commit *commit)
1349
{
1350
	const char *buffer, *ident_line, *msg;
1351
	size_t ident_len;
1352
	struct ident_split id;
1353

1354
	buffer = repo_logmsg_reencode(the_repository, commit, NULL,
1355
				      get_commit_output_encoding());
1356

1357
	ident_line = find_commit_header(buffer, "author", &ident_len);
1358
	if (!ident_line)
1359
		die(_("missing author line in commit %s"),
1360
		      oid_to_hex(&commit->object.oid));
1361
	if (split_ident_line(&id, ident_line, ident_len) < 0)
1362
		die(_("invalid ident line: %.*s"), (int)ident_len, ident_line);
1363

1364
	assert(!state->author_name);
1365
	if (id.name_begin)
1366
		state->author_name =
1367
			xmemdupz(id.name_begin, id.name_end - id.name_begin);
1368
	else
1369
		state->author_name = xstrdup("");
1370

1371
	assert(!state->author_email);
1372
	if (id.mail_begin)
1373
		state->author_email =
1374
			xmemdupz(id.mail_begin, id.mail_end - id.mail_begin);
1375
	else
1376
		state->author_email = xstrdup("");
1377

1378
	assert(!state->author_date);
1379
	state->author_date = xstrdup(show_ident_date(&id, DATE_MODE(NORMAL)));
1380

1381
	assert(!state->msg);
1382
	msg = strstr(buffer, "\n\n");
1383
	if (!msg)
1384
		die(_("unable to parse commit %s"), oid_to_hex(&commit->object.oid));
1385
	state->msg = xstrdup(msg + 2);
1386
	state->msg_len = strlen(state->msg);
1387
	repo_unuse_commit_buffer(the_repository, commit, buffer);
1388
}
1389

1390
/**
1391
 * Writes `commit` as a patch to the state directory's "patch" file.
1392
 */
1393
static void write_commit_patch(const struct am_state *state, struct commit *commit)
1394
{
1395
	struct rev_info rev_info;
1396
	FILE *fp;
1397

1398
	fp = xfopen(am_path(state, "patch"), "w");
1399
	repo_init_revisions(the_repository, &rev_info, NULL);
1400
	rev_info.diff = 1;
1401
	rev_info.abbrev = 0;
1402
	rev_info.disable_stdin = 1;
1403
	rev_info.show_root_diff = 1;
1404
	rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
1405
	rev_info.no_commit_id = 1;
1406
	rev_info.diffopt.flags.binary = 1;
1407
	rev_info.diffopt.flags.full_index = 1;
1408
	rev_info.diffopt.use_color = 0;
1409
	rev_info.diffopt.file = fp;
1410
	rev_info.diffopt.close_file = 1;
1411
	add_pending_object(&rev_info, &commit->object, "");
1412
	diff_setup_done(&rev_info.diffopt);
1413
	log_tree_commit(&rev_info, commit);
1414
	release_revisions(&rev_info);
1415
}
1416

1417
/**
1418
 * Writes the diff of the index against HEAD as a patch to the state
1419
 * directory's "patch" file.
1420
 */
1421
static void write_index_patch(const struct am_state *state)
1422
{
1423
	struct tree *tree;
1424
	struct object_id head;
1425
	struct rev_info rev_info;
1426
	FILE *fp;
1427

1428
	if (!repo_get_oid(the_repository, "HEAD", &head)) {
1429
		struct commit *commit = lookup_commit_or_die(&head, "HEAD");
1430
		tree = repo_get_commit_tree(the_repository, commit);
1431
	} else
1432
		tree = lookup_tree(the_repository,
1433
				   the_repository->hash_algo->empty_tree);
1434

1435
	fp = xfopen(am_path(state, "patch"), "w");
1436
	repo_init_revisions(the_repository, &rev_info, NULL);
1437
	rev_info.diff = 1;
1438
	rev_info.disable_stdin = 1;
1439
	rev_info.no_commit_id = 1;
1440
	rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
1441
	rev_info.diffopt.use_color = 0;
1442
	rev_info.diffopt.file = fp;
1443
	rev_info.diffopt.close_file = 1;
1444
	add_pending_object(&rev_info, &tree->object, "");
1445
	diff_setup_done(&rev_info.diffopt);
1446
	run_diff_index(&rev_info, DIFF_INDEX_CACHED);
1447
	release_revisions(&rev_info);
1448
}
1449

1450
/**
1451
 * Like parse_mail(), but parses the mail by looking up its commit ID
1452
 * directly. This is used in --rebasing mode to bypass git-mailinfo's munging
1453
 * of patches.
1454
 *
1455
 * state->orig_commit will be set to the original commit ID.
1456
 *
1457
 * Will always return 0 as the patch should never be skipped.
1458
 */
1459
static int parse_mail_rebase(struct am_state *state, const char *mail)
1460
{
1461
	struct commit *commit;
1462
	struct object_id commit_oid;
1463

1464
	if (get_mail_commit_oid(&commit_oid, mail) < 0)
1465
		die(_("could not parse %s"), mail);
1466

1467
	commit = lookup_commit_or_die(&commit_oid, mail);
1468

1469
	get_commit_info(state, commit);
1470

1471
	write_commit_patch(state, commit);
1472

1473
	oidcpy(&state->orig_commit, &commit_oid);
1474
	write_state_text(state, "original-commit", oid_to_hex(&commit_oid));
1475
	refs_update_ref(get_main_ref_store(the_repository), "am",
1476
			"REBASE_HEAD", &commit_oid,
1477
			NULL, REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);
1478

1479
	return 0;
1480
}
1481

1482
/**
1483
 * Applies current patch with git-apply. Returns 0 on success, -1 otherwise. If
1484
 * `index_file` is not NULL, the patch will be applied to that index.
1485
 */
1486
static int run_apply(const struct am_state *state, const char *index_file)
1487
{
1488
	struct strvec apply_paths = STRVEC_INIT;
1489
	struct strvec apply_opts = STRVEC_INIT;
1490
	struct apply_state apply_state;
1491
	int res, opts_left;
1492
	int force_apply = 0;
1493
	int options = 0;
1494
	const char **apply_argv;
1495

1496
	if (init_apply_state(&apply_state, the_repository, NULL))
1497
		BUG("init_apply_state() failed");
1498

1499
	strvec_push(&apply_opts, "apply");
1500
	strvec_pushv(&apply_opts, state->git_apply_opts.v);
1501

1502
	/*
1503
	 * Build a copy that apply_parse_options() can rearrange.
1504
	 * apply_opts.v keeps referencing the allocated strings for
1505
	 * strvec_clear() to release.
1506
	 */
1507
	DUP_ARRAY(apply_argv, apply_opts.v, apply_opts.nr);
1508

1509
	opts_left = apply_parse_options(apply_opts.nr, apply_argv,
1510
					&apply_state, &force_apply, &options,
1511
					NULL);
1512

1513
	if (opts_left != 0)
1514
		die("unknown option passed through to git apply");
1515

1516
	if (index_file) {
1517
		apply_state.index_file = index_file;
1518
		apply_state.cached = 1;
1519
	} else
1520
		apply_state.check_index = 1;
1521

1522
	/*
1523
	 * If we are allowed to fall back on 3-way merge, don't give false
1524
	 * errors during the initial attempt.
1525
	 */
1526
	if (state->threeway && !index_file)
1527
		apply_state.apply_verbosity = verbosity_silent;
1528

1529
	if (check_apply_state(&apply_state, force_apply))
1530
		BUG("check_apply_state() failed");
1531

1532
	strvec_push(&apply_paths, am_path(state, "patch"));
1533

1534
	res = apply_all_patches(&apply_state, apply_paths.nr, apply_paths.v, options);
1535

1536
	strvec_clear(&apply_paths);
1537
	strvec_clear(&apply_opts);
1538
	clear_apply_state(&apply_state);
1539
	free(apply_argv);
1540

1541
	if (res)
1542
		return res;
1543

1544
	if (index_file) {
1545
		/* Reload index as apply_all_patches() will have modified it. */
1546
		discard_index(the_repository->index);
1547
		read_index_from(the_repository->index, index_file, get_git_dir());
1548
	}
1549

1550
	return 0;
1551
}
1552

1553
/**
1554
 * Builds an index that contains just the blobs needed for a 3way merge.
1555
 */
1556
static int build_fake_ancestor(const struct am_state *state, const char *index_file)
1557
{
1558
	struct child_process cp = CHILD_PROCESS_INIT;
1559

1560
	cp.git_cmd = 1;
1561
	strvec_push(&cp.args, "apply");
1562
	strvec_pushv(&cp.args, state->git_apply_opts.v);
1563
	strvec_pushf(&cp.args, "--build-fake-ancestor=%s", index_file);
1564
	strvec_push(&cp.args, am_path(state, "patch"));
1565

1566
	if (run_command(&cp))
1567
		return -1;
1568

1569
	return 0;
1570
}
1571

1572
/**
1573
 * Attempt a threeway merge, using index_path as the temporary index.
1574
 */
1575
static int fall_back_threeway(const struct am_state *state, const char *index_path)
1576
{
1577
	struct object_id their_tree, our_tree;
1578
	struct object_id bases[1] = { 0 };
1579
	struct merge_options o;
1580
	struct commit *result;
1581
	char *their_tree_name;
1582

1583
	if (repo_get_oid(the_repository, "HEAD", &our_tree) < 0)
1584
		oidcpy(&our_tree, the_hash_algo->empty_tree);
1585

1586
	if (build_fake_ancestor(state, index_path))
1587
		return error("could not build fake ancestor");
1588

1589
	discard_index(the_repository->index);
1590
	read_index_from(the_repository->index, index_path, get_git_dir());
1591

1592
	if (write_index_as_tree(&bases[0], the_repository->index, index_path, 0, NULL))
1593
		return error(_("Repository lacks necessary blobs to fall back on 3-way merge."));
1594

1595
	say(state, stdout, _("Using index info to reconstruct a base tree..."));
1596

1597
	if (!state->quiet) {
1598
		/*
1599
		 * List paths that needed 3-way fallback, so that the user can
1600
		 * review them with extra care to spot mismerges.
1601
		 */
1602
		struct rev_info rev_info;
1603

1604
		repo_init_revisions(the_repository, &rev_info, NULL);
1605
		rev_info.diffopt.output_format = DIFF_FORMAT_NAME_STATUS;
1606
		rev_info.diffopt.filter |= diff_filter_bit('A');
1607
		rev_info.diffopt.filter |= diff_filter_bit('M');
1608
		add_pending_oid(&rev_info, "HEAD", &our_tree, 0);
1609
		diff_setup_done(&rev_info.diffopt);
1610
		run_diff_index(&rev_info, DIFF_INDEX_CACHED);
1611
		release_revisions(&rev_info);
1612
	}
1613

1614
	if (run_apply(state, index_path))
1615
		return error(_("Did you hand edit your patch?\n"
1616
				"It does not apply to blobs recorded in its index."));
1617

1618
	if (write_index_as_tree(&their_tree, the_repository->index, index_path, 0, NULL))
1619
		return error("could not write tree");
1620

1621
	say(state, stdout, _("Falling back to patching base and 3-way merge..."));
1622

1623
	discard_index(the_repository->index);
1624
	repo_read_index(the_repository);
1625

1626
	/*
1627
	 * This is not so wrong. Depending on which base we picked, orig_tree
1628
	 * may be wildly different from ours, but their_tree has the same set of
1629
	 * wildly different changes in parts the patch did not touch, so
1630
	 * recursive ends up canceling them, saying that we reverted all those
1631
	 * changes.
1632
	 */
1633

1634
	init_ui_merge_options(&o, the_repository);
1635

1636
	o.branch1 = "HEAD";
1637
	their_tree_name = xstrfmt("%.*s", linelen(state->msg), state->msg);
1638
	o.branch2 = their_tree_name;
1639
	o.detect_directory_renames = MERGE_DIRECTORY_RENAMES_NONE;
1640

1641
	if (state->quiet)
1642
		o.verbosity = 0;
1643

1644
	if (merge_recursive_generic(&o, &our_tree, &their_tree, 1, bases, &result)) {
1645
		repo_rerere(the_repository, state->allow_rerere_autoupdate);
1646
		free(their_tree_name);
1647
		return error(_("Failed to merge in the changes."));
1648
	}
1649

1650
	free(their_tree_name);
1651
	return 0;
1652
}
1653

1654
/**
1655
 * Commits the current index with state->msg as the commit message and
1656
 * state->author_name, state->author_email and state->author_date as the author
1657
 * information.
1658
 */
1659
static void do_commit(const struct am_state *state)
1660
{
1661
	struct object_id tree, parent, commit;
1662
	const struct object_id *old_oid;
1663
	struct commit_list *parents = NULL;
1664
	const char *reflog_msg, *author, *committer = NULL;
1665
	struct strbuf sb = STRBUF_INIT;
1666

1667
	if (!state->no_verify && run_hooks(the_repository, "pre-applypatch"))
1668
		exit(1);
1669

1670
	if (write_index_as_tree(&tree, the_repository->index, get_index_file(), 0, NULL))
1671
		die(_("git write-tree failed to write a tree"));
1672

1673
	if (!repo_get_oid_commit(the_repository, "HEAD", &parent)) {
1674
		old_oid = &parent;
1675
		commit_list_insert(lookup_commit(the_repository, &parent),
1676
				   &parents);
1677
	} else {
1678
		old_oid = NULL;
1679
		say(state, stderr, _("applying to an empty history"));
1680
	}
1681

1682
	author = fmt_ident(state->author_name, state->author_email,
1683
		WANT_AUTHOR_IDENT,
1684
			state->ignore_date ? NULL : state->author_date,
1685
			IDENT_STRICT);
1686

1687
	if (state->committer_date_is_author_date)
1688
		committer = fmt_ident(getenv("GIT_COMMITTER_NAME"),
1689
				      getenv("GIT_COMMITTER_EMAIL"),
1690
				      WANT_COMMITTER_IDENT,
1691
				      state->ignore_date ? NULL
1692
							 : state->author_date,
1693
				      IDENT_STRICT);
1694

1695
	if (commit_tree_extended(state->msg, state->msg_len, &tree, parents,
1696
				 &commit, author, committer, state->sign_commit,
1697
				 NULL))
1698
		die(_("failed to write commit object"));
1699

1700
	reflog_msg = getenv("GIT_REFLOG_ACTION");
1701
	if (!reflog_msg)
1702
		reflog_msg = "am";
1703

1704
	strbuf_addf(&sb, "%s: %.*s", reflog_msg, linelen(state->msg),
1705
			state->msg);
1706

1707
	refs_update_ref(get_main_ref_store(the_repository), sb.buf, "HEAD",
1708
			&commit, old_oid, 0,
1709
			UPDATE_REFS_DIE_ON_ERR);
1710

1711
	if (state->rebasing) {
1712
		FILE *fp = xfopen(am_path(state, "rewritten"), "a");
1713

1714
		assert(!is_null_oid(&state->orig_commit));
1715
		fprintf(fp, "%s ", oid_to_hex(&state->orig_commit));
1716
		fprintf(fp, "%s\n", oid_to_hex(&commit));
1717
		fclose(fp);
1718
	}
1719

1720
	run_hooks(the_repository, "post-applypatch");
1721

1722
	free_commit_list(parents);
1723
	strbuf_release(&sb);
1724
}
1725

1726
/**
1727
 * Validates the am_state for resuming -- the "msg" and authorship fields must
1728
 * be filled up.
1729
 */
1730
static void validate_resume_state(const struct am_state *state)
1731
{
1732
	if (!state->msg)
1733
		die(_("cannot resume: %s does not exist."),
1734
			am_path(state, "final-commit"));
1735

1736
	if (!state->author_name || !state->author_email || !state->author_date)
1737
		die(_("cannot resume: %s does not exist."),
1738
			am_path(state, "author-script"));
1739
}
1740

1741
/**
1742
 * Interactively prompt the user on whether the current patch should be
1743
 * applied.
1744
 *
1745
 * Returns 0 if the user chooses to apply the patch, 1 if the user chooses to
1746
 * skip it.
1747
 */
1748
static int do_interactive(struct am_state *state)
1749
{
1750
	assert(state->msg);
1751

1752
	for (;;) {
1753
		char reply[64];
1754

1755
		puts(_("Commit Body is:"));
1756
		puts("--------------------------");
1757
		printf("%s", state->msg);
1758
		puts("--------------------------");
1759

1760
		/*
1761
		 * TRANSLATORS: Make sure to include [y], [n], [e], [v] and [a]
1762
		 * in your translation. The program will only accept English
1763
		 * input at this point.
1764
		 */
1765
		printf(_("Apply? [y]es/[n]o/[e]dit/[v]iew patch/[a]ccept all: "));
1766
		if (!fgets(reply, sizeof(reply), stdin))
1767
			die("unable to read from stdin; aborting");
1768

1769
		if (*reply == 'y' || *reply == 'Y') {
1770
			return 0;
1771
		} else if (*reply == 'a' || *reply == 'A') {
1772
			state->interactive = 0;
1773
			return 0;
1774
		} else if (*reply == 'n' || *reply == 'N') {
1775
			return 1;
1776
		} else if (*reply == 'e' || *reply == 'E') {
1777
			struct strbuf msg = STRBUF_INIT;
1778

1779
			if (!launch_editor(am_path(state, "final-commit"), &msg, NULL)) {
1780
				free(state->msg);
1781
				state->msg = strbuf_detach(&msg, &state->msg_len);
1782
			}
1783
			strbuf_release(&msg);
1784
		} else if (*reply == 'v' || *reply == 'V') {
1785
			const char *pager = git_pager(1);
1786
			struct child_process cp = CHILD_PROCESS_INIT;
1787

1788
			if (!pager)
1789
				pager = "cat";
1790
			prepare_pager_args(&cp, pager);
1791
			strvec_push(&cp.args, am_path(state, "patch"));
1792
			run_command(&cp);
1793
		}
1794
	}
1795
}
1796

1797
/**
1798
 * Applies all queued mail.
1799
 *
1800
 * If `resume` is true, we are "resuming". The "msg" and authorship fields, as
1801
 * well as the state directory's "patch" file is used as-is for applying the
1802
 * patch and committing it.
1803
 */
1804
static void am_run(struct am_state *state, int resume)
1805
{
1806
	struct strbuf sb = STRBUF_INIT;
1807

1808
	unlink(am_path(state, "dirtyindex"));
1809

1810
	if (repo_refresh_and_write_index(the_repository, REFRESH_QUIET, 0, 0,
1811
					 NULL, NULL, NULL) < 0)
1812
		die(_("unable to write index file"));
1813

1814
	if (repo_index_has_changes(the_repository, NULL, &sb)) {
1815
		write_state_bool(state, "dirtyindex", 1);
1816
		die(_("Dirty index: cannot apply patches (dirty: %s)"), sb.buf);
1817
	}
1818

1819
	strbuf_release(&sb);
1820

1821
	while (state->cur <= state->last) {
1822
		const char *mail = am_path(state, msgnum(state));
1823
		int apply_status;
1824
		int to_keep;
1825

1826
		reset_ident_date();
1827

1828
		if (!file_exists(mail))
1829
			goto next;
1830

1831
		if (resume) {
1832
			validate_resume_state(state);
1833
		} else {
1834
			int skip;
1835

1836
			if (state->rebasing)
1837
				skip = parse_mail_rebase(state, mail);
1838
			else
1839
				skip = parse_mail(state, mail);
1840

1841
			if (skip)
1842
				goto next; /* mail should be skipped */
1843

1844
			if (state->signoff)
1845
				am_append_signoff(state);
1846

1847
			write_author_script(state);
1848
			write_commit_msg(state);
1849
		}
1850

1851
		if (state->interactive && do_interactive(state))
1852
			goto next;
1853

1854
		to_keep = 0;
1855
		if (is_empty_or_missing_file(am_path(state, "patch"))) {
1856
			switch (state->empty_type) {
1857
			case DROP_EMPTY_COMMIT:
1858
				say(state, stdout, _("Skipping: %.*s"), linelen(state->msg), state->msg);
1859
				goto next;
1860
				break;
1861
			case KEEP_EMPTY_COMMIT:
1862
				to_keep = 1;
1863
				say(state, stdout, _("Creating an empty commit: %.*s"),
1864
					linelen(state->msg), state->msg);
1865
				break;
1866
			case STOP_ON_EMPTY_COMMIT:
1867
				printf_ln(_("Patch is empty."));
1868
				die_user_resolve(state);
1869
				break;
1870
			}
1871
		}
1872

1873
		if (run_applypatch_msg_hook(state))
1874
			exit(1);
1875
		if (to_keep)
1876
			goto commit;
1877

1878
		say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
1879

1880
		apply_status = run_apply(state, NULL);
1881

1882
		if (apply_status && state->threeway) {
1883
			struct strbuf sb = STRBUF_INIT;
1884

1885
			strbuf_addstr(&sb, am_path(state, "patch-merge-index"));
1886
			apply_status = fall_back_threeway(state, sb.buf);
1887
			strbuf_release(&sb);
1888

1889
			/*
1890
			 * Applying the patch to an earlier tree and merging
1891
			 * the result may have produced the same tree as ours.
1892
			 */
1893
			if (!apply_status &&
1894
			    !repo_index_has_changes(the_repository, NULL, NULL)) {
1895
				say(state, stdout, _("No changes -- Patch already applied."));
1896
				goto next;
1897
			}
1898
		}
1899

1900
		if (apply_status) {
1901
			printf_ln(_("Patch failed at %s %.*s"), msgnum(state),
1902
				linelen(state->msg), state->msg);
1903

1904
			if (advice_enabled(ADVICE_AM_WORK_DIR))
1905
				advise(_("Use 'git am --show-current-patch=diff' to see the failed patch"));
1906

1907
			die_user_resolve(state);
1908
		}
1909

1910
commit:
1911
		do_commit(state);
1912

1913
next:
1914
		am_next(state);
1915

1916
		if (resume)
1917
			am_load(state);
1918
		resume = 0;
1919
	}
1920

1921
	if (!is_empty_or_missing_file(am_path(state, "rewritten"))) {
1922
		assert(state->rebasing);
1923
		copy_notes_for_rebase(state);
1924
		run_post_rewrite_hook(state);
1925
	}
1926

1927
	/*
1928
	 * In rebasing mode, it's up to the caller to take care of
1929
	 * housekeeping.
1930
	 */
1931
	if (!state->rebasing) {
1932
		am_destroy(state);
1933
		run_auto_maintenance(state->quiet);
1934
	}
1935
}
1936

1937
/**
1938
 * Resume the current am session after patch application failure. The user did
1939
 * all the hard work, and we do not have to do any patch application. Just
1940
 * trust and commit what the user has in the index and working tree. If `allow_empty`
1941
 * is true, commit as an empty commit when index has not changed and lacking a patch.
1942
 */
1943
static void am_resolve(struct am_state *state, int allow_empty)
1944
{
1945
	validate_resume_state(state);
1946

1947
	say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
1948

1949
	if (!repo_index_has_changes(the_repository, NULL, NULL)) {
1950
		if (allow_empty && is_empty_or_missing_file(am_path(state, "patch"))) {
1951
			printf_ln(_("No changes - recorded it as an empty commit."));
1952
		} else {
1953
			printf_ln(_("No changes - did you forget to use 'git add'?\n"
1954
				    "If there is nothing left to stage, chances are that something else\n"
1955
				    "already introduced the same changes; you might want to skip this patch."));
1956
			die_user_resolve(state);
1957
		}
1958
	}
1959

1960
	if (unmerged_index(the_repository->index)) {
1961
		printf_ln(_("You still have unmerged paths in your index.\n"
1962
			"You should 'git add' each file with resolved conflicts to mark them as such.\n"
1963
			"You might run `git rm` on a file to accept \"deleted by them\" for it."));
1964
		die_user_resolve(state);
1965
	}
1966

1967
	if (state->interactive) {
1968
		write_index_patch(state);
1969
		if (do_interactive(state))
1970
			goto next;
1971
	}
1972

1973
	repo_rerere(the_repository, 0);
1974

1975
	do_commit(state);
1976

1977
next:
1978
	am_next(state);
1979
	am_load(state);
1980
	am_run(state, 0);
1981
}
1982

1983
/**
1984
 * Performs a checkout fast-forward from `head` to `remote`. If `reset` is
1985
 * true, any unmerged entries will be discarded. Returns 0 on success, -1 on
1986
 * failure.
1987
 */
1988
static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
1989
{
1990
	struct lock_file lock_file = LOCK_INIT;
1991
	struct unpack_trees_options opts;
1992
	struct tree_desc t[2];
1993

1994
	if (parse_tree(head) || parse_tree(remote))
1995
		return -1;
1996

1997
	repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
1998

1999
	refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL, NULL);
2000

2001
	memset(&opts, 0, sizeof(opts));
2002
	opts.head_idx = 1;
2003
	opts.src_index = the_repository->index;
2004
	opts.dst_index = the_repository->index;
2005
	opts.update = 1;
2006
	opts.merge = 1;
2007
	opts.reset = reset ? UNPACK_RESET_PROTECT_UNTRACKED : 0;
2008
	opts.preserve_ignored = 0; /* FIXME: !overwrite_ignore */
2009
	opts.fn = twoway_merge;
2010
	init_tree_desc(&t[0], &head->object.oid, head->buffer, head->size);
2011
	init_tree_desc(&t[1], &remote->object.oid, remote->buffer, remote->size);
2012

2013
	if (unpack_trees(2, t, &opts)) {
2014
		rollback_lock_file(&lock_file);
2015
		return -1;
2016
	}
2017

2018
	if (write_locked_index(the_repository->index, &lock_file, COMMIT_LOCK))
2019
		die(_("unable to write new index file"));
2020

2021
	return 0;
2022
}
2023

2024
/**
2025
 * Merges a tree into the index. The index's stat info will take precedence
2026
 * over the merged tree's. Returns 0 on success, -1 on failure.
2027
 */
2028
static int merge_tree(struct tree *tree)
2029
{
2030
	struct lock_file lock_file = LOCK_INIT;
2031
	struct unpack_trees_options opts;
2032
	struct tree_desc t[1];
2033

2034
	if (parse_tree(tree))
2035
		return -1;
2036

2037
	repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
2038

2039
	memset(&opts, 0, sizeof(opts));
2040
	opts.head_idx = 1;
2041
	opts.src_index = the_repository->index;
2042
	opts.dst_index = the_repository->index;
2043
	opts.merge = 1;
2044
	opts.fn = oneway_merge;
2045
	init_tree_desc(&t[0], &tree->object.oid, tree->buffer, tree->size);
2046

2047
	if (unpack_trees(1, t, &opts)) {
2048
		rollback_lock_file(&lock_file);
2049
		return -1;
2050
	}
2051

2052
	if (write_locked_index(the_repository->index, &lock_file, COMMIT_LOCK))
2053
		die(_("unable to write new index file"));
2054

2055
	return 0;
2056
}
2057

2058
/**
2059
 * Clean the index without touching entries that are not modified between
2060
 * `head` and `remote`.
2061
 */
2062
static int clean_index(const struct object_id *head, const struct object_id *remote)
2063
{
2064
	struct tree *head_tree, *remote_tree, *index_tree;
2065
	struct object_id index;
2066

2067
	head_tree = parse_tree_indirect(head);
2068
	if (!head_tree)
2069
		return error(_("Could not parse object '%s'."), oid_to_hex(head));
2070

2071
	remote_tree = parse_tree_indirect(remote);
2072
	if (!remote_tree)
2073
		return error(_("Could not parse object '%s'."), oid_to_hex(remote));
2074

2075
	repo_read_index_unmerged(the_repository);
2076

2077
	if (fast_forward_to(head_tree, head_tree, 1))
2078
		return -1;
2079

2080
	if (write_index_as_tree(&index, the_repository->index, get_index_file(), 0, NULL))
2081
		return -1;
2082

2083
	index_tree = parse_tree_indirect(&index);
2084
	if (!index_tree)
2085
		return error(_("Could not parse object '%s'."), oid_to_hex(&index));
2086

2087
	if (fast_forward_to(index_tree, remote_tree, 0))
2088
		return -1;
2089

2090
	if (merge_tree(remote_tree))
2091
		return -1;
2092

2093
	remove_branch_state(the_repository, 0);
2094

2095
	return 0;
2096
}
2097

2098
/**
2099
 * Resets rerere's merge resolution metadata.
2100
 */
2101
static void am_rerere_clear(void)
2102
{
2103
	struct string_list merge_rr = STRING_LIST_INIT_DUP;
2104
	rerere_clear(the_repository, &merge_rr);
2105
	string_list_clear(&merge_rr, 1);
2106
}
2107

2108
/**
2109
 * Resume the current am session by skipping the current patch.
2110
 */
2111
static void am_skip(struct am_state *state)
2112
{
2113
	struct object_id head;
2114

2115
	am_rerere_clear();
2116

2117
	if (repo_get_oid(the_repository, "HEAD", &head))
2118
		oidcpy(&head, the_hash_algo->empty_tree);
2119

2120
	if (clean_index(&head, &head))
2121
		die(_("failed to clean index"));
2122

2123
	if (state->rebasing) {
2124
		FILE *fp = xfopen(am_path(state, "rewritten"), "a");
2125

2126
		assert(!is_null_oid(&state->orig_commit));
2127
		fprintf(fp, "%s ", oid_to_hex(&state->orig_commit));
2128
		fprintf(fp, "%s\n", oid_to_hex(&head));
2129
		fclose(fp);
2130
	}
2131

2132
	am_next(state);
2133
	am_load(state);
2134
	am_run(state, 0);
2135
}
2136

2137
/**
2138
 * Returns true if it is safe to reset HEAD to the ORIG_HEAD, false otherwise.
2139
 *
2140
 * It is not safe to reset HEAD when:
2141
 * 1. git-am previously failed because the index was dirty.
2142
 * 2. HEAD has moved since git-am previously failed.
2143
 */
2144
static int safe_to_abort(const struct am_state *state)
2145
{
2146
	struct strbuf sb = STRBUF_INIT;
2147
	struct object_id abort_safety, head;
2148

2149
	if (file_exists(am_path(state, "dirtyindex")))
2150
		return 0;
2151

2152
	if (read_state_file(&sb, state, "abort-safety", 1) > 0) {
2153
		if (get_oid_hex(sb.buf, &abort_safety))
2154
			die(_("could not parse %s"), am_path(state, "abort-safety"));
2155
	} else
2156
		oidclr(&abort_safety, the_repository->hash_algo);
2157
	strbuf_release(&sb);
2158

2159
	if (repo_get_oid(the_repository, "HEAD", &head))
2160
		oidclr(&head, the_repository->hash_algo);
2161

2162
	if (oideq(&head, &abort_safety))
2163
		return 1;
2164

2165
	warning(_("You seem to have moved HEAD since the last 'am' failure.\n"
2166
		"Not rewinding to ORIG_HEAD"));
2167

2168
	return 0;
2169
}
2170

2171
/**
2172
 * Aborts the current am session if it is safe to do so.
2173
 */
2174
static void am_abort(struct am_state *state)
2175
{
2176
	struct object_id curr_head, orig_head;
2177
	int has_curr_head, has_orig_head;
2178
	char *curr_branch;
2179

2180
	if (!safe_to_abort(state)) {
2181
		am_destroy(state);
2182
		return;
2183
	}
2184

2185
	am_rerere_clear();
2186

2187
	curr_branch = refs_resolve_refdup(get_main_ref_store(the_repository),
2188
					  "HEAD", 0, &curr_head, NULL);
2189
	has_curr_head = curr_branch && !is_null_oid(&curr_head);
2190
	if (!has_curr_head)
2191
		oidcpy(&curr_head, the_hash_algo->empty_tree);
2192

2193
	has_orig_head = !repo_get_oid(the_repository, "ORIG_HEAD", &orig_head);
2194
	if (!has_orig_head)
2195
		oidcpy(&orig_head, the_hash_algo->empty_tree);
2196

2197
	if (clean_index(&curr_head, &orig_head))
2198
		die(_("failed to clean index"));
2199

2200
	if (has_orig_head)
2201
		refs_update_ref(get_main_ref_store(the_repository),
2202
				"am --abort", "HEAD", &orig_head,
2203
				has_curr_head ? &curr_head : NULL, 0,
2204
				UPDATE_REFS_DIE_ON_ERR);
2205
	else if (curr_branch)
2206
		refs_delete_ref(get_main_ref_store(the_repository), NULL,
2207
				curr_branch, NULL, REF_NO_DEREF);
2208

2209
	free(curr_branch);
2210
	am_destroy(state);
2211
}
2212

2213
static int show_patch(struct am_state *state, enum resume_type resume_mode)
2214
{
2215
	struct strbuf sb = STRBUF_INIT;
2216
	const char *patch_path;
2217
	int len;
2218

2219
	if (!is_null_oid(&state->orig_commit)) {
2220
		struct child_process cmd = CHILD_PROCESS_INIT;
2221

2222
		strvec_pushl(&cmd.args, "show", oid_to_hex(&state->orig_commit),
2223
			     "--", NULL);
2224
		cmd.git_cmd = 1;
2225
		return run_command(&cmd);
2226
	}
2227

2228
	switch (resume_mode) {
2229
	case RESUME_SHOW_PATCH_RAW:
2230
		patch_path = am_path(state, msgnum(state));
2231
		break;
2232
	case RESUME_SHOW_PATCH_DIFF:
2233
		patch_path = am_path(state, "patch");
2234
		break;
2235
	default:
2236
		BUG("invalid mode for --show-current-patch");
2237
	}
2238

2239
	len = strbuf_read_file(&sb, patch_path, 0);
2240
	if (len < 0)
2241
		die_errno(_("failed to read '%s'"), patch_path);
2242

2243
	setup_pager();
2244
	write_in_full(1, sb.buf, sb.len);
2245
	strbuf_release(&sb);
2246
	return 0;
2247
}
2248

2249
/**
2250
 * parse_options() callback that validates and sets opt->value to the
2251
 * PATCH_FORMAT_* enum value corresponding to `arg`.
2252
 */
2253
static int parse_opt_patchformat(const struct option *opt, const char *arg, int unset)
2254
{
2255
	int *opt_value = opt->value;
2256

2257
	if (unset)
2258
		*opt_value = PATCH_FORMAT_UNKNOWN;
2259
	else if (!strcmp(arg, "mbox"))
2260
		*opt_value = PATCH_FORMAT_MBOX;
2261
	else if (!strcmp(arg, "stgit"))
2262
		*opt_value = PATCH_FORMAT_STGIT;
2263
	else if (!strcmp(arg, "stgit-series"))
2264
		*opt_value = PATCH_FORMAT_STGIT_SERIES;
2265
	else if (!strcmp(arg, "hg"))
2266
		*opt_value = PATCH_FORMAT_HG;
2267
	else if (!strcmp(arg, "mboxrd"))
2268
		*opt_value = PATCH_FORMAT_MBOXRD;
2269
	/*
2270
	 * Please update $__git_patchformat in git-completion.bash
2271
	 * when you add new options
2272
	 */
2273
	else
2274
		return error(_("invalid value for '%s': '%s'"),
2275
			     "--patch-format", arg);
2276
	return 0;
2277
}
2278

2279
static int parse_opt_show_current_patch(const struct option *opt, const char *arg, int unset)
2280
{
2281
	int *opt_value = opt->value;
2282

2283
	BUG_ON_OPT_NEG(unset);
2284

2285
	if (!arg)
2286
		*opt_value = opt->defval;
2287
	else if (!strcmp(arg, "raw"))
2288
		*opt_value = RESUME_SHOW_PATCH_RAW;
2289
	else if (!strcmp(arg, "diff"))
2290
		*opt_value = RESUME_SHOW_PATCH_DIFF;
2291
	/*
2292
	 * Please update $__git_showcurrentpatch in git-completion.bash
2293
	 * when you add new options
2294
	 */
2295
	else
2296
		return error(_("invalid value for '%s': '%s'"),
2297
			     "--show-current-patch", arg);
2298
	return 0;
2299
}
2300

2301
int cmd_am(int argc, const char **argv, const char *prefix)
2302
{
2303
	struct am_state state;
2304
	int binary = -1;
2305
	int keep_cr = -1;
2306
	int patch_format = PATCH_FORMAT_UNKNOWN;
2307
	enum resume_type resume_mode = RESUME_FALSE;
2308
	int in_progress;
2309
	int ret = 0;
2310

2311
	const char * const usage[] = {
2312
		N_("git am [<options>] [(<mbox> | <Maildir>)...]"),
2313
		N_("git am [<options>] (--continue | --skip | --abort)"),
2314
		NULL
2315
	};
2316

2317
	struct option options[] = {
2318
		OPT_BOOL('i', "interactive", &state.interactive,
2319
			N_("run interactively")),
2320
		OPT_BOOL('n', "no-verify", &state.no_verify,
2321
			N_("bypass pre-applypatch and applypatch-msg hooks")),
2322
		OPT_HIDDEN_BOOL('b', "binary", &binary,
2323
			N_("historical option -- no-op")),
2324
		OPT_BOOL('3', "3way", &state.threeway,
2325
			N_("allow fall back on 3way merging if needed")),
2326
		OPT__QUIET(&state.quiet, N_("be quiet")),
2327
		OPT_SET_INT('s', "signoff", &state.signoff,
2328
			N_("add a Signed-off-by trailer to the commit message"),
2329
			SIGNOFF_EXPLICIT),
2330
		OPT_BOOL('u', "utf8", &state.utf8,
2331
			N_("recode into utf8 (default)")),
2332
		OPT_SET_INT('k', "keep", &state.keep,
2333
			N_("pass -k flag to git-mailinfo"), KEEP_TRUE),
2334
		OPT_SET_INT(0, "keep-non-patch", &state.keep,
2335
			N_("pass -b flag to git-mailinfo"), KEEP_NON_PATCH),
2336
		OPT_BOOL('m', "message-id", &state.message_id,
2337
			N_("pass -m flag to git-mailinfo")),
2338
		OPT_SET_INT(0, "keep-cr", &keep_cr,
2339
			    N_("pass --keep-cr flag to git-mailsplit for mbox format"),
2340
			    1),
2341
		OPT_BOOL('c', "scissors", &state.scissors,
2342
			N_("strip everything before a scissors line")),
2343
		OPT_CALLBACK_F(0, "quoted-cr", &state.quoted_cr, N_("action"),
2344
			       N_("pass it through git-mailinfo"),
2345
			       PARSE_OPT_NONEG, am_option_parse_quoted_cr),
2346
		OPT_PASSTHRU_ARGV(0, "whitespace", &state.git_apply_opts, N_("action"),
2347
			N_("pass it through git-apply"),
2348
			0),
2349
		OPT_PASSTHRU_ARGV(0, "ignore-space-change", &state.git_apply_opts, NULL,
2350
			N_("pass it through git-apply"),
2351
			PARSE_OPT_NOARG),
2352
		OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &state.git_apply_opts, NULL,
2353
			N_("pass it through git-apply"),
2354
			PARSE_OPT_NOARG),
2355
		OPT_PASSTHRU_ARGV(0, "directory", &state.git_apply_opts, N_("root"),
2356
			N_("pass it through git-apply"),
2357
			0),
2358
		OPT_PASSTHRU_ARGV(0, "exclude", &state.git_apply_opts, N_("path"),
2359
			N_("pass it through git-apply"),
2360
			0),
2361
		OPT_PASSTHRU_ARGV(0, "include", &state.git_apply_opts, N_("path"),
2362
			N_("pass it through git-apply"),
2363
			0),
2364
		OPT_PASSTHRU_ARGV('C', NULL, &state.git_apply_opts, N_("n"),
2365
			N_("pass it through git-apply"),
2366
			0),
2367
		OPT_PASSTHRU_ARGV('p', NULL, &state.git_apply_opts, N_("num"),
2368
			N_("pass it through git-apply"),
2369
			0),
2370
		OPT_CALLBACK(0, "patch-format", &patch_format, N_("format"),
2371
			N_("format the patch(es) are in"),
2372
			parse_opt_patchformat),
2373
		OPT_PASSTHRU_ARGV(0, "reject", &state.git_apply_opts, NULL,
2374
			N_("pass it through git-apply"),
2375
			PARSE_OPT_NOARG),
2376
		OPT_STRING(0, "resolvemsg", &state.resolvemsg, NULL,
2377
			N_("override error message when patch failure occurs")),
2378
		OPT_CMDMODE(0, "continue", &resume_mode,
2379
			N_("continue applying patches after resolving a conflict"),
2380
			RESUME_RESOLVED),
2381
		OPT_CMDMODE('r', "resolved", &resume_mode,
2382
			N_("synonyms for --continue"),
2383
			RESUME_RESOLVED),
2384
		OPT_CMDMODE(0, "skip", &resume_mode,
2385
			N_("skip the current patch"),
2386
			RESUME_SKIP),
2387
		OPT_CMDMODE(0, "abort", &resume_mode,
2388
			N_("restore the original branch and abort the patching operation"),
2389
			RESUME_ABORT),
2390
		OPT_CMDMODE(0, "quit", &resume_mode,
2391
			N_("abort the patching operation but keep HEAD where it is"),
2392
			RESUME_QUIT),
2393
		{ OPTION_CALLBACK, 0, "show-current-patch", &resume_mode,
2394
		  "(diff|raw)",
2395
		  N_("show the patch being applied"),
2396
		  PARSE_OPT_CMDMODE | PARSE_OPT_OPTARG | PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP,
2397
		  parse_opt_show_current_patch, RESUME_SHOW_PATCH_RAW },
2398
		OPT_CMDMODE(0, "retry", &resume_mode,
2399
			N_("try to apply current patch again"),
2400
			RESUME_APPLY),
2401
		OPT_CMDMODE(0, "allow-empty", &resume_mode,
2402
			N_("record the empty patch as an empty commit"),
2403
			RESUME_ALLOW_EMPTY),
2404
		OPT_BOOL(0, "committer-date-is-author-date",
2405
			&state.committer_date_is_author_date,
2406
			N_("lie about committer date")),
2407
		OPT_BOOL(0, "ignore-date", &state.ignore_date,
2408
			N_("use current timestamp for author date")),
2409
		OPT_RERERE_AUTOUPDATE(&state.allow_rerere_autoupdate),
2410
		{ OPTION_STRING, 'S', "gpg-sign", &state.sign_commit, N_("key-id"),
2411
		  N_("GPG-sign commits"),
2412
		  PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
2413
		OPT_CALLBACK_F(0, "empty", &state.empty_type, "(stop|drop|keep)",
2414
		  N_("how to handle empty patches"),
2415
		  PARSE_OPT_NONEG, am_option_parse_empty),
2416
		OPT_HIDDEN_BOOL(0, "rebasing", &state.rebasing,
2417
			N_("(internal use for git-rebase)")),
2418
		OPT_END()
2419
	};
2420

2421
	if (argc == 2 && !strcmp(argv[1], "-h"))
2422
		usage_with_options(usage, options);
2423

2424
	git_config(git_default_config, NULL);
2425

2426
	am_state_init(&state);
2427

2428
	in_progress = am_in_progress(&state);
2429
	if (in_progress)
2430
		am_load(&state);
2431

2432
	argc = parse_options(argc, argv, prefix, options, usage, 0);
2433

2434
	if (binary >= 0)
2435
		fprintf_ln(stderr, _("The -b/--binary option has been a no-op for long time, and\n"
2436
				"it will be removed. Please do not use it anymore."));
2437

2438
	/* Ensure a valid committer ident can be constructed */
2439
	git_committer_info(IDENT_STRICT);
2440

2441
	if (repo_read_index_preload(the_repository, NULL, 0) < 0)
2442
		die(_("failed to read the index"));
2443

2444
	if (in_progress) {
2445
		/*
2446
		 * Catch user error to feed us patches when there is a session
2447
		 * in progress:
2448
		 *
2449
		 * 1. mbox path(s) are provided on the command-line.
2450
		 * 2. stdin is not a tty: the user is trying to feed us a patch
2451
		 *    from standard input. This is somewhat unreliable -- stdin
2452
		 *    could be /dev/null for example and the caller did not
2453
		 *    intend to feed us a patch but wanted to continue
2454
		 *    unattended.
2455
		 */
2456
		if (argc || (resume_mode == RESUME_FALSE && !isatty(0)))
2457
			die(_("previous rebase directory %s still exists but mbox given."),
2458
				state.dir);
2459

2460
		if (resume_mode == RESUME_FALSE)
2461
			resume_mode = RESUME_APPLY;
2462

2463
		if (state.signoff == SIGNOFF_EXPLICIT)
2464
			am_append_signoff(&state);
2465
	} else {
2466
		struct strvec paths = STRVEC_INIT;
2467
		int i;
2468

2469
		/*
2470
		 * Handle stray state directory in the independent-run case. In
2471
		 * the --rebasing case, it is up to the caller to take care of
2472
		 * stray directories.
2473
		 */
2474
		if (file_exists(state.dir) && !state.rebasing) {
2475
			if (resume_mode == RESUME_ABORT || resume_mode == RESUME_QUIT) {
2476
				am_destroy(&state);
2477
				am_state_release(&state);
2478
				return 0;
2479
			}
2480

2481
			die(_("Stray %s directory found.\n"
2482
				"Use \"git am --abort\" to remove it."),
2483
				state.dir);
2484
		}
2485

2486
		if (resume_mode)
2487
			die(_("Resolve operation not in progress, we are not resuming."));
2488

2489
		for (i = 0; i < argc; i++) {
2490
			if (is_absolute_path(argv[i]) || !prefix)
2491
				strvec_push(&paths, argv[i]);
2492
			else
2493
				strvec_push(&paths, mkpath("%s/%s", prefix, argv[i]));
2494
		}
2495

2496
		if (state.interactive && !paths.nr)
2497
			die(_("interactive mode requires patches on the command line"));
2498

2499
		am_setup(&state, patch_format, paths.v, keep_cr);
2500

2501
		strvec_clear(&paths);
2502
	}
2503

2504
	switch (resume_mode) {
2505
	case RESUME_FALSE:
2506
		am_run(&state, 0);
2507
		break;
2508
	case RESUME_APPLY:
2509
		am_run(&state, 1);
2510
		break;
2511
	case RESUME_RESOLVED:
2512
	case RESUME_ALLOW_EMPTY:
2513
		am_resolve(&state, resume_mode == RESUME_ALLOW_EMPTY ? 1 : 0);
2514
		break;
2515
	case RESUME_SKIP:
2516
		am_skip(&state);
2517
		break;
2518
	case RESUME_ABORT:
2519
		am_abort(&state);
2520
		break;
2521
	case RESUME_QUIT:
2522
		am_rerere_clear();
2523
		am_destroy(&state);
2524
		break;
2525
	case RESUME_SHOW_PATCH_RAW:
2526
	case RESUME_SHOW_PATCH_DIFF:
2527
		ret = show_patch(&state, resume_mode);
2528
		break;
2529
	default:
2530
		BUG("invalid resume value");
2531
	}
2532

2533
	am_state_release(&state);
2534

2535
	return ret;
2536
}
2537