builtin-am: exit with user friendly message on failure
[git/git.git] / builtin / am.c
CommitLineData
73c2779f
PT
1/*
2 * Builtin "git am"
3 *
4 * Based on git-am.sh by Junio C Hamano.
5 */
6#include "cache.h"
7#include "builtin.h"
8#include "exec_cmd.h"
8c3bd9e2
PT
9#include "parse-options.h"
10#include "dir.h"
11c2177f 11#include "run-command.h"
3e20dcf3 12#include "quote.h"
38a824fe 13#include "lockfile.h"
c9e8d960
PT
14#include "cache-tree.h"
15#include "refs.h"
16#include "commit.h"
32a5fcbf
PT
17#include "diff.h"
18#include "diffcore.h"
9990080c
PT
19#include "unpack-trees.h"
20#include "branch.h"
3e20dcf3
PT
21
22/**
23 * Returns 1 if the file is empty or does not exist, 0 otherwise.
24 */
25static int is_empty_file(const char *filename)
26{
27 struct stat st;
28
29 if (stat(filename, &st) < 0) {
30 if (errno == ENOENT)
31 return 1;
32 die_errno(_("could not stat %s"), filename);
33 }
34
35 return !st.st_size;
36}
11c2177f 37
c29807b2
PT
38/**
39 * Like strbuf_getline(), but treats both '\n' and "\r\n" as line terminators.
40 */
41static int strbuf_getline_crlf(struct strbuf *sb, FILE *fp)
42{
43 if (strbuf_getwholeline(sb, fp, '\n'))
44 return EOF;
45 if (sb->buf[sb->len - 1] == '\n') {
46 strbuf_setlen(sb, sb->len - 1);
47 if (sb->len > 0 && sb->buf[sb->len - 1] == '\r')
48 strbuf_setlen(sb, sb->len - 1);
49 }
50 return 0;
51}
52
38a824fe
PT
53/**
54 * Returns the length of the first line of msg.
55 */
56static int linelen(const char *msg)
57{
58 return strchrnul(msg, '\n') - msg;
59}
60
11c2177f
PT
61enum patch_format {
62 PATCH_FORMAT_UNKNOWN = 0,
63 PATCH_FORMAT_MBOX
64};
8c3bd9e2
PT
65
66struct am_state {
67 /* state directory path */
68 char *dir;
69
70 /* current and last patch numbers, 1-indexed */
71 int cur;
72 int last;
11c2177f 73
3e20dcf3
PT
74 /* commit metadata and message */
75 char *author_name;
76 char *author_email;
77 char *author_date;
78 char *msg;
79 size_t msg_len;
80
11c2177f
PT
81 /* number of digits in patch filename */
82 int prec;
5d28cf78
PT
83
84 /* various operating modes and command line options */
85 int quiet;
2d83109a 86 const char *resolvemsg;
8c3bd9e2
PT
87};
88
89/**
90 * Initializes am_state with the default values. The state directory is set to
91 * dir.
92 */
93static void am_state_init(struct am_state *state, const char *dir)
94{
95 memset(state, 0, sizeof(*state));
96
97 assert(dir);
98 state->dir = xstrdup(dir);
11c2177f
PT
99
100 state->prec = 4;
8c3bd9e2
PT
101}
102
103/**
104 * Releases memory allocated by an am_state.
105 */
106static void am_state_release(struct am_state *state)
107{
108 free(state->dir);
3e20dcf3
PT
109 free(state->author_name);
110 free(state->author_email);
111 free(state->author_date);
112 free(state->msg);
8c3bd9e2
PT
113}
114
115/**
116 * Returns path relative to the am_state directory.
117 */
118static inline const char *am_path(const struct am_state *state, const char *path)
119{
120 return mkpath("%s/%s", state->dir, path);
121}
122
5d28cf78
PT
123/**
124 * If state->quiet is false, calls fprintf(fp, fmt, ...), and appends a newline
125 * at the end.
126 */
127static void say(const struct am_state *state, FILE *fp, const char *fmt, ...)
128{
129 va_list ap;
130
131 va_start(ap, fmt);
132 if (!state->quiet) {
133 vfprintf(fp, fmt, ap);
134 putc('\n', fp);
135 }
136 va_end(ap);
137}
138
8c3bd9e2
PT
139/**
140 * Returns 1 if there is an am session in progress, 0 otherwise.
141 */
142static int am_in_progress(const struct am_state *state)
143{
144 struct stat st;
145
146 if (lstat(state->dir, &st) < 0 || !S_ISDIR(st.st_mode))
147 return 0;
148 if (lstat(am_path(state, "last"), &st) || !S_ISREG(st.st_mode))
149 return 0;
150 if (lstat(am_path(state, "next"), &st) || !S_ISREG(st.st_mode))
151 return 0;
152 return 1;
153}
154
155/**
156 * Reads the contents of `file` in the `state` directory into `sb`. Returns the
157 * number of bytes read on success, -1 if the file does not exist. If `trim` is
158 * set, trailing whitespace will be removed.
159 */
160static int read_state_file(struct strbuf *sb, const struct am_state *state,
161 const char *file, int trim)
162{
163 strbuf_reset(sb);
164
165 if (strbuf_read_file(sb, am_path(state, file), 0) >= 0) {
166 if (trim)
167 strbuf_trim(sb);
168
169 return sb->len;
170 }
171
172 if (errno == ENOENT)
173 return -1;
174
175 die_errno(_("could not read '%s'"), am_path(state, file));
176}
177
3e20dcf3
PT
178/**
179 * Reads a KEY=VALUE shell variable assignment from `fp`, returning the VALUE
180 * as a newly-allocated string. VALUE must be a quoted string, and the KEY must
181 * match `key`. Returns NULL on failure.
182 *
183 * This is used by read_author_script() to read the GIT_AUTHOR_* variables from
184 * the author-script.
185 */
186static char *read_shell_var(FILE *fp, const char *key)
187{
188 struct strbuf sb = STRBUF_INIT;
189 const char *str;
190
191 if (strbuf_getline(&sb, fp, '\n'))
192 goto fail;
193
194 if (!skip_prefix(sb.buf, key, &str))
195 goto fail;
196
197 if (!skip_prefix(str, "=", &str))
198 goto fail;
199
200 strbuf_remove(&sb, 0, str - sb.buf);
201
202 str = sq_dequote(sb.buf);
203 if (!str)
204 goto fail;
205
206 return strbuf_detach(&sb, NULL);
207
208fail:
209 strbuf_release(&sb);
210 return NULL;
211}
212
213/**
214 * Reads and parses the state directory's "author-script" file, and sets
215 * state->author_name, state->author_email and state->author_date accordingly.
216 * Returns 0 on success, -1 if the file could not be parsed.
217 *
218 * The author script is of the format:
219 *
220 * GIT_AUTHOR_NAME='$author_name'
221 * GIT_AUTHOR_EMAIL='$author_email'
222 * GIT_AUTHOR_DATE='$author_date'
223 *
224 * where $author_name, $author_email and $author_date are quoted. We are strict
225 * with our parsing, as the file was meant to be eval'd in the old git-am.sh
226 * script, and thus if the file differs from what this function expects, it is
227 * better to bail out than to do something that the user does not expect.
228 */
229static int read_author_script(struct am_state *state)
230{
231 const char *filename = am_path(state, "author-script");
232 FILE *fp;
233
234 assert(!state->author_name);
235 assert(!state->author_email);
236 assert(!state->author_date);
237
238 fp = fopen(filename, "r");
239 if (!fp) {
240 if (errno == ENOENT)
241 return 0;
242 die_errno(_("could not open '%s' for reading"), filename);
243 }
244
245 state->author_name = read_shell_var(fp, "GIT_AUTHOR_NAME");
246 if (!state->author_name) {
247 fclose(fp);
248 return -1;
249 }
250
251 state->author_email = read_shell_var(fp, "GIT_AUTHOR_EMAIL");
252 if (!state->author_email) {
253 fclose(fp);
254 return -1;
255 }
256
257 state->author_date = read_shell_var(fp, "GIT_AUTHOR_DATE");
258 if (!state->author_date) {
259 fclose(fp);
260 return -1;
261 }
262
263 if (fgetc(fp) != EOF) {
264 fclose(fp);
265 return -1;
266 }
267
268 fclose(fp);
269 return 0;
270}
271
272/**
273 * Saves state->author_name, state->author_email and state->author_date in the
274 * state directory's "author-script" file.
275 */
276static void write_author_script(const struct am_state *state)
277{
278 struct strbuf sb = STRBUF_INIT;
279
280 strbuf_addstr(&sb, "GIT_AUTHOR_NAME=");
281 sq_quote_buf(&sb, state->author_name);
282 strbuf_addch(&sb, '\n');
283
284 strbuf_addstr(&sb, "GIT_AUTHOR_EMAIL=");
285 sq_quote_buf(&sb, state->author_email);
286 strbuf_addch(&sb, '\n');
287
288 strbuf_addstr(&sb, "GIT_AUTHOR_DATE=");
289 sq_quote_buf(&sb, state->author_date);
290 strbuf_addch(&sb, '\n');
291
292 write_file(am_path(state, "author-script"), 1, "%s", sb.buf);
293
294 strbuf_release(&sb);
295}
296
297/**
298 * Reads the commit message from the state directory's "final-commit" file,
299 * setting state->msg to its contents and state->msg_len to the length of its
300 * contents in bytes.
301 *
302 * Returns 0 on success, -1 if the file does not exist.
303 */
304static int read_commit_msg(struct am_state *state)
305{
306 struct strbuf sb = STRBUF_INIT;
307
308 assert(!state->msg);
309
310 if (read_state_file(&sb, state, "final-commit", 0) < 0) {
311 strbuf_release(&sb);
312 return -1;
313 }
314
315 state->msg = strbuf_detach(&sb, &state->msg_len);
316 return 0;
317}
318
319/**
320 * Saves state->msg in the state directory's "final-commit" file.
321 */
322static void write_commit_msg(const struct am_state *state)
323{
324 int fd;
325 const char *filename = am_path(state, "final-commit");
326
327 fd = xopen(filename, O_WRONLY | O_CREAT, 0666);
328 if (write_in_full(fd, state->msg, state->msg_len) < 0)
329 die_errno(_("could not write to %s"), filename);
330 close(fd);
331}
332
8c3bd9e2
PT
333/**
334 * Loads state from disk.
335 */
336static void am_load(struct am_state *state)
337{
338 struct strbuf sb = STRBUF_INIT;
339
340 if (read_state_file(&sb, state, "next", 1) < 0)
341 die("BUG: state file 'next' does not exist");
342 state->cur = strtol(sb.buf, NULL, 10);
343
344 if (read_state_file(&sb, state, "last", 1) < 0)
345 die("BUG: state file 'last' does not exist");
346 state->last = strtol(sb.buf, NULL, 10);
347
3e20dcf3
PT
348 if (read_author_script(state) < 0)
349 die(_("could not parse author script"));
350
351 read_commit_msg(state);
352
5d28cf78
PT
353 read_state_file(&sb, state, "quiet", 1);
354 state->quiet = !strcmp(sb.buf, "t");
355
8c3bd9e2
PT
356 strbuf_release(&sb);
357}
358
359/**
360 * Removes the am_state directory, forcefully terminating the current am
361 * session.
362 */
363static void am_destroy(const struct am_state *state)
364{
365 struct strbuf sb = STRBUF_INIT;
366
367 strbuf_addstr(&sb, state->dir);
368 remove_dir_recursively(&sb, 0);
369 strbuf_release(&sb);
370}
371
c29807b2
PT
372/**
373 * Determines if the file looks like a piece of RFC2822 mail by grabbing all
374 * non-indented lines and checking if they look like they begin with valid
375 * header field names.
376 *
377 * Returns 1 if the file looks like a piece of mail, 0 otherwise.
378 */
379static int is_mail(FILE *fp)
380{
381 const char *header_regex = "^[!-9;-~]+:";
382 struct strbuf sb = STRBUF_INIT;
383 regex_t regex;
384 int ret = 1;
385
386 if (fseek(fp, 0L, SEEK_SET))
387 die_errno(_("fseek failed"));
388
389 if (regcomp(&regex, header_regex, REG_NOSUB | REG_EXTENDED))
390 die("invalid pattern: %s", header_regex);
391
392 while (!strbuf_getline_crlf(&sb, fp)) {
393 if (!sb.len)
394 break; /* End of header */
395
396 /* Ignore indented folded lines */
397 if (*sb.buf == '\t' || *sb.buf == ' ')
398 continue;
399
400 /* It's a header if it matches header_regex */
401 if (regexec(&regex, sb.buf, 0, NULL, 0)) {
402 ret = 0;
403 goto done;
404 }
405 }
406
407done:
408 regfree(&regex);
409 strbuf_release(&sb);
410 return ret;
411}
412
413/**
414 * Attempts to detect the patch_format of the patches contained in `paths`,
415 * returning the PATCH_FORMAT_* enum value. Returns PATCH_FORMAT_UNKNOWN if
416 * detection fails.
417 */
418static int detect_patch_format(const char **paths)
419{
420 enum patch_format ret = PATCH_FORMAT_UNKNOWN;
421 struct strbuf l1 = STRBUF_INIT;
422 FILE *fp;
423
424 /*
425 * We default to mbox format if input is from stdin and for directories
426 */
427 if (!*paths || !strcmp(*paths, "-") || is_directory(*paths))
428 return PATCH_FORMAT_MBOX;
429
430 /*
431 * Otherwise, check the first few lines of the first patch, starting
432 * from the first non-blank line, to try to detect its format.
433 */
434
435 fp = xfopen(*paths, "r");
436
437 while (!strbuf_getline_crlf(&l1, fp)) {
438 if (l1.len)
439 break;
440 }
441
442 if (starts_with(l1.buf, "From ") || starts_with(l1.buf, "From: ")) {
443 ret = PATCH_FORMAT_MBOX;
444 goto done;
445 }
446
447 if (l1.len && is_mail(fp)) {
448 ret = PATCH_FORMAT_MBOX;
449 goto done;
450 }
451
452done:
453 fclose(fp);
454 strbuf_release(&l1);
455 return ret;
456}
457
11c2177f
PT
458/**
459 * Splits out individual email patches from `paths`, where each path is either
460 * a mbox file or a Maildir. Returns 0 on success, -1 on failure.
461 */
462static int split_mail_mbox(struct am_state *state, const char **paths)
463{
464 struct child_process cp = CHILD_PROCESS_INIT;
465 struct strbuf last = STRBUF_INIT;
466
467 cp.git_cmd = 1;
468 argv_array_push(&cp.args, "mailsplit");
469 argv_array_pushf(&cp.args, "-d%d", state->prec);
470 argv_array_pushf(&cp.args, "-o%s", state->dir);
471 argv_array_push(&cp.args, "-b");
472 argv_array_push(&cp.args, "--");
473 argv_array_pushv(&cp.args, paths);
474
475 if (capture_command(&cp, &last, 8))
476 return -1;
477
478 state->cur = 1;
479 state->last = strtol(last.buf, NULL, 10);
480
481 return 0;
482}
483
484/**
485 * Splits a list of files/directories into individual email patches. Each path
486 * in `paths` must be a file/directory that is formatted according to
487 * `patch_format`.
488 *
489 * Once split out, the individual email patches will be stored in the state
490 * directory, with each patch's filename being its index, padded to state->prec
491 * digits.
492 *
493 * state->cur will be set to the index of the first mail, and state->last will
494 * be set to the index of the last mail.
495 *
496 * Returns 0 on success, -1 on failure.
497 */
498static int split_mail(struct am_state *state, enum patch_format patch_format,
499 const char **paths)
500{
501 switch (patch_format) {
502 case PATCH_FORMAT_MBOX:
503 return split_mail_mbox(state, paths);
504 default:
505 die("BUG: invalid patch_format");
506 }
507 return -1;
508}
509
8c3bd9e2
PT
510/**
511 * Setup a new am session for applying patches
512 */
11c2177f
PT
513static void am_setup(struct am_state *state, enum patch_format patch_format,
514 const char **paths)
8c3bd9e2 515{
33388a71
PT
516 unsigned char curr_head[GIT_SHA1_RAWSZ];
517
c29807b2
PT
518 if (!patch_format)
519 patch_format = detect_patch_format(paths);
520
521 if (!patch_format) {
522 fprintf_ln(stderr, _("Patch format detection failed."));
523 exit(128);
524 }
525
8c3bd9e2
PT
526 if (mkdir(state->dir, 0777) < 0 && errno != EEXIST)
527 die_errno(_("failed to create directory '%s'"), state->dir);
528
11c2177f
PT
529 if (split_mail(state, patch_format, paths) < 0) {
530 am_destroy(state);
531 die(_("Failed to split patches."));
532 }
533
5d28cf78
PT
534 write_file(am_path(state, "quiet"), 1, state->quiet ? "t" : "f");
535
33388a71
PT
536 if (!get_sha1("HEAD", curr_head)) {
537 write_file(am_path(state, "abort-safety"), 1, "%s", sha1_to_hex(curr_head));
538 update_ref("am", "ORIG_HEAD", curr_head, NULL, 0, UPDATE_REFS_DIE_ON_ERR);
539 } else {
540 write_file(am_path(state, "abort-safety"), 1, "%s", "");
541 delete_ref("ORIG_HEAD", NULL, 0);
542 }
543
8c3bd9e2
PT
544 /*
545 * NOTE: Since the "next" and "last" files determine if an am_state
546 * session is in progress, they should be written last.
547 */
548
549 write_file(am_path(state, "next"), 1, "%d", state->cur);
550
551 write_file(am_path(state, "last"), 1, "%d", state->last);
552}
553
554/**
555 * Increments the patch pointer, and cleans am_state for the application of the
556 * next patch.
557 */
558static void am_next(struct am_state *state)
559{
33388a71
PT
560 unsigned char head[GIT_SHA1_RAWSZ];
561
3e20dcf3
PT
562 free(state->author_name);
563 state->author_name = NULL;
564
565 free(state->author_email);
566 state->author_email = NULL;
567
568 free(state->author_date);
569 state->author_date = NULL;
570
571 free(state->msg);
572 state->msg = NULL;
573 state->msg_len = 0;
574
575 unlink(am_path(state, "author-script"));
576 unlink(am_path(state, "final-commit"));
577
33388a71
PT
578 if (!get_sha1("HEAD", head))
579 write_file(am_path(state, "abort-safety"), 1, "%s", sha1_to_hex(head));
580 else
581 write_file(am_path(state, "abort-safety"), 1, "%s", "");
582
8c3bd9e2
PT
583 state->cur++;
584 write_file(am_path(state, "next"), 1, "%d", state->cur);
585}
586
3e20dcf3
PT
587/**
588 * Returns the filename of the current patch email.
589 */
590static const char *msgnum(const struct am_state *state)
591{
592 static struct strbuf sb = STRBUF_INIT;
593
594 strbuf_reset(&sb);
595 strbuf_addf(&sb, "%0*d", state->prec, state->cur);
596
597 return sb.buf;
598}
599
38a824fe
PT
600/**
601 * Refresh and write index.
602 */
603static void refresh_and_write_cache(void)
604{
605 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
606
607 hold_locked_index(lock_file, 1);
608 refresh_cache(REFRESH_QUIET);
609 if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
610 die(_("unable to write index file"));
611}
612
32a5fcbf
PT
613/**
614 * Returns 1 if the index differs from HEAD, 0 otherwise. When on an unborn
615 * branch, returns 1 if there are entries in the index, 0 otherwise. If an
616 * strbuf is provided, the space-separated list of files that differ will be
617 * appended to it.
618 */
619static int index_has_changes(struct strbuf *sb)
620{
621 unsigned char head[GIT_SHA1_RAWSZ];
622 int i;
623
624 if (!get_sha1_tree("HEAD", head)) {
625 struct diff_options opt;
626
627 diff_setup(&opt);
628 DIFF_OPT_SET(&opt, EXIT_WITH_STATUS);
629 if (!sb)
630 DIFF_OPT_SET(&opt, QUICK);
631 do_diff_cache(head, &opt);
632 diffcore_std(&opt);
633 for (i = 0; sb && i < diff_queued_diff.nr; i++) {
634 if (i)
635 strbuf_addch(sb, ' ');
636 strbuf_addstr(sb, diff_queued_diff.queue[i]->two->path);
637 }
638 diff_flush(&opt);
639 return DIFF_OPT_TST(&opt, HAS_CHANGES) != 0;
640 } else {
641 for (i = 0; sb && i < active_nr; i++) {
642 if (i)
643 strbuf_addch(sb, ' ');
644 strbuf_addstr(sb, active_cache[i]->name);
645 }
646 return !!active_nr;
647 }
648}
649
2d83109a
PT
650/**
651 * Dies with a user-friendly message on how to proceed after resolving the
652 * problem. This message can be overridden with state->resolvemsg.
653 */
654static void NORETURN die_user_resolve(const struct am_state *state)
655{
656 if (state->resolvemsg) {
657 printf_ln("%s", state->resolvemsg);
658 } else {
659 const char *cmdline = "git am";
660
661 printf_ln(_("When you have resolved this problem, run \"%s --continue\"."), cmdline);
662 printf_ln(_("If you prefer to skip this patch, run \"%s --skip\" instead."), cmdline);
663 printf_ln(_("To restore the original branch and stop patching, run \"%s --abort\"."), cmdline);
664 }
665
666 exit(128);
667}
668
3e20dcf3
PT
669/**
670 * Parses `mail` using git-mailinfo, extracting its patch and authorship info.
671 * state->msg will be set to the patch message. state->author_name,
672 * state->author_email and state->author_date will be set to the patch author's
673 * name, email and date respectively. The patch body will be written to the
674 * state directory's "patch" file.
675 *
676 * Returns 1 if the patch should be skipped, 0 otherwise.
677 */
678static int parse_mail(struct am_state *state, const char *mail)
679{
680 FILE *fp;
681 struct child_process cp = CHILD_PROCESS_INIT;
682 struct strbuf sb = STRBUF_INIT;
683 struct strbuf msg = STRBUF_INIT;
684 struct strbuf author_name = STRBUF_INIT;
685 struct strbuf author_date = STRBUF_INIT;
686 struct strbuf author_email = STRBUF_INIT;
687 int ret = 0;
688
689 cp.git_cmd = 1;
690 cp.in = xopen(mail, O_RDONLY, 0);
691 cp.out = xopen(am_path(state, "info"), O_WRONLY | O_CREAT, 0777);
692
693 argv_array_push(&cp.args, "mailinfo");
694 argv_array_push(&cp.args, am_path(state, "msg"));
695 argv_array_push(&cp.args, am_path(state, "patch"));
696
697 if (run_command(&cp) < 0)
698 die("could not parse patch");
699
700 close(cp.in);
701 close(cp.out);
702
703 /* Extract message and author information */
704 fp = xfopen(am_path(state, "info"), "r");
705 while (!strbuf_getline(&sb, fp, '\n')) {
706 const char *x;
707
708 if (skip_prefix(sb.buf, "Subject: ", &x)) {
709 if (msg.len)
710 strbuf_addch(&msg, '\n');
711 strbuf_addstr(&msg, x);
712 } else if (skip_prefix(sb.buf, "Author: ", &x))
713 strbuf_addstr(&author_name, x);
714 else if (skip_prefix(sb.buf, "Email: ", &x))
715 strbuf_addstr(&author_email, x);
716 else if (skip_prefix(sb.buf, "Date: ", &x))
717 strbuf_addstr(&author_date, x);
718 }
719 fclose(fp);
720
721 /* Skip pine's internal folder data */
722 if (!strcmp(author_name.buf, "Mail System Internal Data")) {
723 ret = 1;
724 goto finish;
725 }
726
727 if (is_empty_file(am_path(state, "patch"))) {
728 printf_ln(_("Patch is empty. Was it split wrong?"));
2d83109a 729 die_user_resolve(state);
3e20dcf3
PT
730 }
731
732 strbuf_addstr(&msg, "\n\n");
733 if (strbuf_read_file(&msg, am_path(state, "msg"), 0) < 0)
734 die_errno(_("could not read '%s'"), am_path(state, "msg"));
735 stripspace(&msg, 0);
736
737 assert(!state->author_name);
738 state->author_name = strbuf_detach(&author_name, NULL);
739
740 assert(!state->author_email);
741 state->author_email = strbuf_detach(&author_email, NULL);
742
743 assert(!state->author_date);
744 state->author_date = strbuf_detach(&author_date, NULL);
745
746 assert(!state->msg);
747 state->msg = strbuf_detach(&msg, &state->msg_len);
748
749finish:
750 strbuf_release(&msg);
751 strbuf_release(&author_date);
752 strbuf_release(&author_email);
753 strbuf_release(&author_name);
754 strbuf_release(&sb);
755 return ret;
756}
757
38a824fe
PT
758/**
759 * Applies current patch with git-apply. Returns 0 on success, -1 otherwise.
760 */
761static int run_apply(const struct am_state *state)
762{
763 struct child_process cp = CHILD_PROCESS_INIT;
764
765 cp.git_cmd = 1;
766
767 argv_array_push(&cp.args, "apply");
768 argv_array_push(&cp.args, "--index");
769 argv_array_push(&cp.args, am_path(state, "patch"));
770
771 if (run_command(&cp))
772 return -1;
773
774 /* Reload index as git-apply will have modified it. */
775 discard_cache();
776 read_cache();
777
778 return 0;
779}
780
c9e8d960
PT
781/**
782 * Commits the current index with state->msg as the commit message and
783 * state->author_name, state->author_email and state->author_date as the author
784 * information.
785 */
786static void do_commit(const struct am_state *state)
787{
788 unsigned char tree[GIT_SHA1_RAWSZ], parent[GIT_SHA1_RAWSZ],
789 commit[GIT_SHA1_RAWSZ];
790 unsigned char *ptr;
791 struct commit_list *parents = NULL;
792 const char *reflog_msg, *author;
793 struct strbuf sb = STRBUF_INIT;
794
795 if (write_cache_as_tree(tree, 0, NULL))
796 die(_("git write-tree failed to write a tree"));
797
798 if (!get_sha1_commit("HEAD", parent)) {
799 ptr = parent;
800 commit_list_insert(lookup_commit(parent), &parents);
801 } else {
802 ptr = NULL;
5d28cf78 803 say(state, stderr, _("applying to an empty history"));
c9e8d960
PT
804 }
805
806 author = fmt_ident(state->author_name, state->author_email,
807 state->author_date, IDENT_STRICT);
808
809 if (commit_tree(state->msg, state->msg_len, tree, parents, commit,
810 author, NULL))
811 die(_("failed to write commit object"));
812
813 reflog_msg = getenv("GIT_REFLOG_ACTION");
814 if (!reflog_msg)
815 reflog_msg = "am";
816
817 strbuf_addf(&sb, "%s: %.*s", reflog_msg, linelen(state->msg),
818 state->msg);
819
820 update_ref(sb.buf, "HEAD", commit, ptr, 0, UPDATE_REFS_DIE_ON_ERR);
821
822 strbuf_release(&sb);
823}
824
240bfd2d
PT
825/**
826 * Validates the am_state for resuming -- the "msg" and authorship fields must
827 * be filled up.
828 */
829static void validate_resume_state(const struct am_state *state)
830{
831 if (!state->msg)
832 die(_("cannot resume: %s does not exist."),
833 am_path(state, "final-commit"));
834
835 if (!state->author_name || !state->author_email || !state->author_date)
836 die(_("cannot resume: %s does not exist."),
837 am_path(state, "author-script"));
838}
839
8c3bd9e2
PT
840/**
841 * Applies all queued mail.
8c7b1563
PT
842 *
843 * If `resume` is true, we are "resuming". The "msg" and authorship fields, as
844 * well as the state directory's "patch" file is used as-is for applying the
845 * patch and committing it.
8c3bd9e2 846 */
8c7b1563 847static void am_run(struct am_state *state, int resume)
8c3bd9e2 848{
c9e8d960 849 const char *argv_gc_auto[] = {"gc", "--auto", NULL};
32a5fcbf 850 struct strbuf sb = STRBUF_INIT;
c9e8d960 851
33388a71
PT
852 unlink(am_path(state, "dirtyindex"));
853
38a824fe
PT
854 refresh_and_write_cache();
855
33388a71
PT
856 if (index_has_changes(&sb)) {
857 write_file(am_path(state, "dirtyindex"), 1, "t");
32a5fcbf 858 die(_("Dirty index: cannot apply patches (dirty: %s)"), sb.buf);
33388a71 859 }
32a5fcbf
PT
860
861 strbuf_release(&sb);
862
8c3bd9e2 863 while (state->cur <= state->last) {
3e20dcf3
PT
864 const char *mail = am_path(state, msgnum(state));
865
866 if (!file_exists(mail))
867 goto next;
868
8c7b1563
PT
869 if (resume) {
870 validate_resume_state(state);
871 resume = 0;
872 } else {
873 if (parse_mail(state, mail))
874 goto next; /* mail should be skipped */
3e20dcf3 875
8c7b1563
PT
876 write_author_script(state);
877 write_commit_msg(state);
878 }
8c3bd9e2 879
5d28cf78 880 say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
38a824fe
PT
881
882 if (run_apply(state) < 0) {
883 int advice_amworkdir = 1;
884
885 printf_ln(_("Patch failed at %s %.*s"), msgnum(state),
886 linelen(state->msg), state->msg);
887
888 git_config_get_bool("advice.amworkdir", &advice_amworkdir);
889
890 if (advice_amworkdir)
891 printf_ln(_("The copy of the patch that failed is found in: %s"),
892 am_path(state, "patch"));
893
2d83109a 894 die_user_resolve(state);
38a824fe
PT
895 }
896
c9e8d960 897 do_commit(state);
8c3bd9e2 898
3e20dcf3 899next:
8c3bd9e2
PT
900 am_next(state);
901 }
902
903 am_destroy(state);
c9e8d960 904 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
8c3bd9e2 905}
73c2779f 906
240bfd2d
PT
907/**
908 * Resume the current am session after patch application failure. The user did
909 * all the hard work, and we do not have to do any patch application. Just
910 * trust and commit what the user has in the index and working tree.
911 */
912static void am_resolve(struct am_state *state)
913{
914 validate_resume_state(state);
915
5d28cf78 916 say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
240bfd2d
PT
917
918 if (!index_has_changes(NULL)) {
919 printf_ln(_("No changes - did you forget to use 'git add'?\n"
920 "If there is nothing left to stage, chances are that something else\n"
921 "already introduced the same changes; you might want to skip this patch."));
2d83109a 922 die_user_resolve(state);
240bfd2d
PT
923 }
924
925 if (unmerged_cache()) {
926 printf_ln(_("You still have unmerged paths in your index.\n"
927 "Did you forget to use 'git add'?"));
2d83109a 928 die_user_resolve(state);
240bfd2d
PT
929 }
930
931 do_commit(state);
932
933 am_next(state);
8c7b1563 934 am_run(state, 0);
240bfd2d
PT
935}
936
9990080c
PT
937/**
938 * Performs a checkout fast-forward from `head` to `remote`. If `reset` is
939 * true, any unmerged entries will be discarded. Returns 0 on success, -1 on
940 * failure.
941 */
942static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
943{
944 struct lock_file *lock_file;
945 struct unpack_trees_options opts;
946 struct tree_desc t[2];
947
948 if (parse_tree(head) || parse_tree(remote))
949 return -1;
950
951 lock_file = xcalloc(1, sizeof(struct lock_file));
952 hold_locked_index(lock_file, 1);
953
954 refresh_cache(REFRESH_QUIET);
955
956 memset(&opts, 0, sizeof(opts));
957 opts.head_idx = 1;
958 opts.src_index = &the_index;
959 opts.dst_index = &the_index;
960 opts.update = 1;
961 opts.merge = 1;
962 opts.reset = reset;
963 opts.fn = twoway_merge;
964 init_tree_desc(&t[0], head->buffer, head->size);
965 init_tree_desc(&t[1], remote->buffer, remote->size);
966
967 if (unpack_trees(2, t, &opts)) {
968 rollback_lock_file(lock_file);
969 return -1;
970 }
971
972 if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
973 die(_("unable to write new index file"));
974
975 return 0;
976}
977
978/**
979 * Clean the index without touching entries that are not modified between
980 * `head` and `remote`.
981 */
982static int clean_index(const unsigned char *head, const unsigned char *remote)
983{
984 struct lock_file *lock_file;
985 struct tree *head_tree, *remote_tree, *index_tree;
986 unsigned char index[GIT_SHA1_RAWSZ];
987 struct pathspec pathspec;
988
989 head_tree = parse_tree_indirect(head);
990 if (!head_tree)
991 return error(_("Could not parse object '%s'."), sha1_to_hex(head));
992
993 remote_tree = parse_tree_indirect(remote);
994 if (!remote_tree)
995 return error(_("Could not parse object '%s'."), sha1_to_hex(remote));
996
997 read_cache_unmerged();
998
999 if (fast_forward_to(head_tree, head_tree, 1))
1000 return -1;
1001
1002 if (write_cache_as_tree(index, 0, NULL))
1003 return -1;
1004
1005 index_tree = parse_tree_indirect(index);
1006 if (!index_tree)
1007 return error(_("Could not parse object '%s'."), sha1_to_hex(index));
1008
1009 if (fast_forward_to(index_tree, remote_tree, 0))
1010 return -1;
1011
1012 memset(&pathspec, 0, sizeof(pathspec));
1013
1014 lock_file = xcalloc(1, sizeof(struct lock_file));
1015 hold_locked_index(lock_file, 1);
1016
1017 if (read_tree(remote_tree, 0, &pathspec)) {
1018 rollback_lock_file(lock_file);
1019 return -1;
1020 }
1021
1022 if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
1023 die(_("unable to write new index file"));
1024
1025 remove_branch_state();
1026
1027 return 0;
1028}
1029
1030/**
1031 * Resume the current am session by skipping the current patch.
1032 */
1033static void am_skip(struct am_state *state)
1034{
1035 unsigned char head[GIT_SHA1_RAWSZ];
1036
1037 if (get_sha1("HEAD", head))
1038 hashcpy(head, EMPTY_TREE_SHA1_BIN);
1039
1040 if (clean_index(head, head))
1041 die(_("failed to clean index"));
1042
1043 am_next(state);
1044 am_run(state, 0);
1045}
1046
33388a71
PT
1047/**
1048 * Returns true if it is safe to reset HEAD to the ORIG_HEAD, false otherwise.
1049 *
1050 * It is not safe to reset HEAD when:
1051 * 1. git-am previously failed because the index was dirty.
1052 * 2. HEAD has moved since git-am previously failed.
1053 */
1054static int safe_to_abort(const struct am_state *state)
1055{
1056 struct strbuf sb = STRBUF_INIT;
1057 unsigned char abort_safety[GIT_SHA1_RAWSZ], head[GIT_SHA1_RAWSZ];
1058
1059 if (file_exists(am_path(state, "dirtyindex")))
1060 return 0;
1061
1062 if (read_state_file(&sb, state, "abort-safety", 1) > 0) {
1063 if (get_sha1_hex(sb.buf, abort_safety))
1064 die(_("could not parse %s"), am_path(state, "abort_safety"));
1065 } else
1066 hashclr(abort_safety);
1067
1068 if (get_sha1("HEAD", head))
1069 hashclr(head);
1070
1071 if (!hashcmp(head, abort_safety))
1072 return 1;
1073
1074 error(_("You seem to have moved HEAD since the last 'am' failure.\n"
1075 "Not rewinding to ORIG_HEAD"));
1076
1077 return 0;
1078}
1079
1080/**
1081 * Aborts the current am session if it is safe to do so.
1082 */
1083static void am_abort(struct am_state *state)
1084{
1085 unsigned char curr_head[GIT_SHA1_RAWSZ], orig_head[GIT_SHA1_RAWSZ];
1086 int has_curr_head, has_orig_head;
1087 char *curr_branch;
1088
1089 if (!safe_to_abort(state)) {
1090 am_destroy(state);
1091 return;
1092 }
1093
1094 curr_branch = resolve_refdup("HEAD", 0, curr_head, NULL);
1095 has_curr_head = !is_null_sha1(curr_head);
1096 if (!has_curr_head)
1097 hashcpy(curr_head, EMPTY_TREE_SHA1_BIN);
1098
1099 has_orig_head = !get_sha1("ORIG_HEAD", orig_head);
1100 if (!has_orig_head)
1101 hashcpy(orig_head, EMPTY_TREE_SHA1_BIN);
1102
1103 clean_index(curr_head, orig_head);
1104
1105 if (has_orig_head)
1106 update_ref("am --abort", "HEAD", orig_head,
1107 has_curr_head ? curr_head : NULL, 0,
1108 UPDATE_REFS_DIE_ON_ERR);
1109 else if (curr_branch)
1110 delete_ref(curr_branch, NULL, REF_NODEREF);
1111
1112 free(curr_branch);
1113 am_destroy(state);
1114}
1115
11c2177f
PT
1116/**
1117 * parse_options() callback that validates and sets opt->value to the
1118 * PATCH_FORMAT_* enum value corresponding to `arg`.
1119 */
1120static int parse_opt_patchformat(const struct option *opt, const char *arg, int unset)
1121{
1122 int *opt_value = opt->value;
1123
1124 if (!strcmp(arg, "mbox"))
1125 *opt_value = PATCH_FORMAT_MBOX;
1126 else
1127 return error(_("Invalid value for --patch-format: %s"), arg);
1128 return 0;
1129}
1130
240bfd2d
PT
1131enum resume_mode {
1132 RESUME_FALSE = 0,
8c7b1563 1133 RESUME_APPLY,
9990080c 1134 RESUME_RESOLVED,
33388a71
PT
1135 RESUME_SKIP,
1136 RESUME_ABORT
240bfd2d
PT
1137};
1138
73c2779f
PT
1139int cmd_am(int argc, const char **argv, const char *prefix)
1140{
8c3bd9e2 1141 struct am_state state;
11c2177f 1142 int patch_format = PATCH_FORMAT_UNKNOWN;
240bfd2d 1143 enum resume_mode resume = RESUME_FALSE;
8c3bd9e2
PT
1144
1145 const char * const usage[] = {
1146 N_("git am [options] [(<mbox>|<Maildir>)...]"),
33388a71 1147 N_("git am [options] (--continue | --skip | --abort)"),
8c3bd9e2
PT
1148 NULL
1149 };
1150
1151 struct option options[] = {
5d28cf78 1152 OPT__QUIET(&state.quiet, N_("be quiet")),
11c2177f
PT
1153 OPT_CALLBACK(0, "patch-format", &patch_format, N_("format"),
1154 N_("format the patch(es) are in"),
1155 parse_opt_patchformat),
2d83109a
PT
1156 OPT_STRING(0, "resolvemsg", &state.resolvemsg, NULL,
1157 N_("override error message when patch failure occurs")),
240bfd2d
PT
1158 OPT_CMDMODE(0, "continue", &resume,
1159 N_("continue applying patches after resolving a conflict"),
1160 RESUME_RESOLVED),
1161 OPT_CMDMODE('r', "resolved", &resume,
1162 N_("synonyms for --continue"),
1163 RESUME_RESOLVED),
9990080c
PT
1164 OPT_CMDMODE(0, "skip", &resume,
1165 N_("skip the current patch"),
1166 RESUME_SKIP),
33388a71
PT
1167 OPT_CMDMODE(0, "abort", &resume,
1168 N_("restore the original branch and abort the patching operation."),
1169 RESUME_ABORT),
8c3bd9e2
PT
1170 OPT_END()
1171 };
73c2779f
PT
1172
1173 /*
1174 * NEEDSWORK: Once all the features of git-am.sh have been
1175 * re-implemented in builtin/am.c, this preamble can be removed.
1176 */
1177 if (!getenv("_GIT_USE_BUILTIN_AM")) {
1178 const char *path = mkpath("%s/git-am", git_exec_path());
1179
1180 if (sane_execvp(path, (char **)argv) < 0)
1181 die_errno("could not exec %s", path);
1182 } else {
1183 prefix = setup_git_directory();
1184 trace_repo_setup(prefix);
1185 setup_work_tree();
1186 }
1187
8c3bd9e2
PT
1188 git_config(git_default_config, NULL);
1189
1190 am_state_init(&state, git_path("rebase-apply"));
1191
1192 argc = parse_options(argc, argv, prefix, options, usage, 0);
1193
38a824fe
PT
1194 if (read_index_preload(&the_index, NULL) < 0)
1195 die(_("failed to read the index"));
1196
8c7b1563 1197 if (am_in_progress(&state)) {
8d185503
PT
1198 /*
1199 * Catch user error to feed us patches when there is a session
1200 * in progress:
1201 *
1202 * 1. mbox path(s) are provided on the command-line.
1203 * 2. stdin is not a tty: the user is trying to feed us a patch
1204 * from standard input. This is somewhat unreliable -- stdin
1205 * could be /dev/null for example and the caller did not
1206 * intend to feed us a patch but wanted to continue
1207 * unattended.
1208 */
1209 if (argc || (resume == RESUME_FALSE && !isatty(0)))
1210 die(_("previous rebase directory %s still exists but mbox given."),
1211 state.dir);
1212
8c7b1563
PT
1213 if (resume == RESUME_FALSE)
1214 resume = RESUME_APPLY;
1215
8c3bd9e2 1216 am_load(&state);
8c7b1563 1217 } else {
11c2177f
PT
1218 struct argv_array paths = ARGV_ARRAY_INIT;
1219 int i;
1220
240bfd2d
PT
1221 if (resume)
1222 die(_("Resolve operation not in progress, we are not resuming."));
1223
11c2177f
PT
1224 for (i = 0; i < argc; i++) {
1225 if (is_absolute_path(argv[i]) || !prefix)
1226 argv_array_push(&paths, argv[i]);
1227 else
1228 argv_array_push(&paths, mkpath("%s/%s", prefix, argv[i]));
1229 }
1230
1231 am_setup(&state, patch_format, paths.argv);
1232
1233 argv_array_clear(&paths);
1234 }
8c3bd9e2 1235
240bfd2d
PT
1236 switch (resume) {
1237 case RESUME_FALSE:
8c7b1563
PT
1238 am_run(&state, 0);
1239 break;
1240 case RESUME_APPLY:
1241 am_run(&state, 1);
240bfd2d
PT
1242 break;
1243 case RESUME_RESOLVED:
1244 am_resolve(&state);
1245 break;
9990080c
PT
1246 case RESUME_SKIP:
1247 am_skip(&state);
1248 break;
33388a71
PT
1249 case RESUME_ABORT:
1250 am_abort(&state);
1251 break;
240bfd2d
PT
1252 default:
1253 die("BUG: invalid resume value");
1254 }
8c3bd9e2
PT
1255
1256 am_state_release(&state);
1257
73c2779f
PT
1258 return 0;
1259}