1 /*
2  * Copyright (c) 2022 Omar Polo <op@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  *
16  * Apply patches.
17  *
18  * Things that we may want to support:
19  *     + support indented patches?
20  *     + support other kinds of patches?
21  */
22 
23 #include <sys/types.h>
24 #include <sys/queue.h>
25 #include <sys/socket.h>
26 #include <sys/stat.h>
27 #include <sys/uio.h>
28 
29 #include <errno.h>
30 #include <limits.h>
31 #include <sha1.h>
32 #include <stdint.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <unistd.h>
37 #include <imsg.h>
38 
39 #include "got_error.h"
40 #include "got_object.h"
41 #include "got_path.h"
42 #include "got_reference.h"
43 #include "got_cancel.h"
44 #include "got_worktree.h"
45 #include "got_opentemp.h"
46 #include "got_patch.h"
47 
48 #include "got_lib_delta.h"
49 #include "got_lib_object.h"
50 #include "got_lib_privsep.h"
51 
52 #define MIN(a, b) ((a) < (b) ? (a) : (b))
53 
54 struct got_patch_hunk {
55 	STAILQ_ENTRY(got_patch_hunk) entries;
56 	const struct got_error *err;
57 	long	offset;
58 	int	old_nonl;
59 	int	new_nonl;
60 	long	old_from;
61 	long	old_lines;
62 	long	new_from;
63 	long	new_lines;
64 	size_t	len;
65 	size_t	cap;
66 	char	**lines;
67 };
68 
69 STAILQ_HEAD(got_patch_hunk_head, got_patch_hunk);
70 struct got_patch {
71 	char	*old;
72 	char	*new;
73 	struct got_patch_hunk_head head;
74 };
75 
76 struct patch_args {
77 	got_patch_progress_cb progress_cb;
78 	void	*progress_arg;
79 	struct got_patch_hunk_head *head;
80 };
81 
82 static const struct got_error *
83 send_patch(struct imsgbuf *ibuf, int fd)
84 {
85 	const struct got_error *err = NULL;
86 
87 	if (imsg_compose(ibuf, GOT_IMSG_PATCH_FILE, 0, 0, fd,
88 	    NULL, 0) == -1) {
89 		err = got_error_from_errno(
90 		    "imsg_compose GOT_IMSG_PATCH_FILE");
91 		close(fd);
92 		return err;
93 	}
94 
95 	if (imsg_flush(ibuf) == -1) {
96 		err = got_error_from_errno("imsg_flush");
97 		imsg_clear(ibuf);
98 	}
99 
100 	return err;
101 }
102 
103 static void
104 patch_free(struct got_patch *p)
105 {
106 	struct got_patch_hunk *h;
107 	size_t i;
108 
109 	while (!STAILQ_EMPTY(&p->head)) {
110 		h = STAILQ_FIRST(&p->head);
111 		STAILQ_REMOVE_HEAD(&p->head, entries);
112 
113 		for (i = 0; i < h->len; ++i)
114 			free(h->lines[i]);
115 		free(h->lines);
116 		free(h);
117 	}
118 
119 	free(p->new);
120 	free(p->old);
121 }
122 
123 static const struct got_error *
124 pushline(struct got_patch_hunk *h, const char *line)
125 {
126 	void 	*t;
127 	size_t	 newcap;
128 
129 	if (h->len == h->cap) {
130 		if ((newcap = h->cap * 1.5) == 0)
131 			newcap = 16;
132 		t = recallocarray(h->lines, h->cap, newcap,
133 		    sizeof(h->lines[0]));
134 		if (t == NULL)
135 			return got_error_from_errno("recallocarray");
136 		h->lines = t;
137 		h->cap = newcap;
138 	}
139 
140 	if ((t = strdup(line)) == NULL)
141 		return got_error_from_errno("strdup");
142 
143 	h->lines[h->len++] = t;
144 	return NULL;
145 }
146 
147 static const struct got_error *
148 recv_patch(struct imsgbuf *ibuf, int *done, struct got_patch *p, int strip)
149 {
150 	const struct got_error *err = NULL;
151 	struct imsg imsg;
152 	struct got_imsg_patch_hunk hdr;
153 	struct got_imsg_patch patch;
154 	struct got_patch_hunk *h = NULL;
155 	size_t datalen;
156 	int lastmode = -1;
157 
158 	memset(p, 0, sizeof(*p));
159 	STAILQ_INIT(&p->head);
160 
161 	err = got_privsep_recv_imsg(&imsg, ibuf, 0);
162 	if (err)
163 		return err;
164 	if (imsg.hdr.type == GOT_IMSG_PATCH_EOF) {
165 		*done = 1;
166 		goto done;
167 	}
168 	if (imsg.hdr.type != GOT_IMSG_PATCH) {
169 		err = got_error(GOT_ERR_PRIVSEP_MSG);
170 		goto done;
171 	}
172 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
173 	if (datalen != sizeof(patch)) {
174 		err = got_error(GOT_ERR_PRIVSEP_LEN);
175 		goto done;
176 	}
177 	memcpy(&patch, imsg.data, sizeof(patch));
178 
179 	/* automatically set strip=1 for git-style diffs */
180 	if (strip == -1 && patch.git &&
181 	    (*patch.old == '\0' || !strncmp(patch.old, "a/", 2)) &&
182 	    (*patch.new == '\0' || !strncmp(patch.new, "b/", 2)))
183 		strip = 1;
184 
185 	/* prefer the new name if not /dev/null for not git-style diffs */
186 	if (!patch.git && *patch.new != '\0' && *patch.old != '\0') {
187 		err = got_path_strip(&p->old, patch.new, strip);
188 		if (err)
189 			goto done;
190 	} else if (*patch.old != '\0') {
191 		err = got_path_strip(&p->old, patch.old, strip);
192 		if (err)
193 			goto done;
194 	}
195 
196 	if (*patch.new != '\0') {
197 		err = got_path_strip(&p->new, patch.new, strip);
198 		if (err)
199 			goto done;
200 	}
201 
202 	if (p->old == NULL && p->new == NULL) {
203 		err = got_error(GOT_ERR_PATCH_MALFORMED);
204 		goto done;
205 	}
206 
207 	imsg_free(&imsg);
208 
209 	for (;;) {
210 		char *t;
211 
212 		err = got_privsep_recv_imsg(&imsg, ibuf, 0);
213 		if (err)
214 			return err;
215 
216 		switch (imsg.hdr.type) {
217 		case GOT_IMSG_PATCH_DONE:
218 			if (h != NULL && h->len == 0)
219 				err = got_error(GOT_ERR_PATCH_MALFORMED);
220 			goto done;
221 		case GOT_IMSG_PATCH_HUNK:
222 			if (h != NULL &&
223 			    (h->len == 0 || h->old_nonl || h->new_nonl)) {
224 				err = got_error(GOT_ERR_PATCH_MALFORMED);
225 				goto done;
226 			}
227 			lastmode = -1;
228 			datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
229 			if (datalen != sizeof(hdr)) {
230 				err = got_error(GOT_ERR_PRIVSEP_LEN);
231 				goto done;
232 			}
233 			memcpy(&hdr, imsg.data, sizeof(hdr));
234 			if ((h = calloc(1, sizeof(*h))) == NULL) {
235 				err = got_error_from_errno("calloc");
236 				goto done;
237 			}
238 			h->old_from = hdr.oldfrom;
239 			h->old_lines = hdr.oldlines;
240 			h->new_from = hdr.newfrom;
241 			h->new_lines = hdr.newlines;
242 			STAILQ_INSERT_TAIL(&p->head, h, entries);
243 			break;
244 		case GOT_IMSG_PATCH_LINE:
245 			if (h == NULL) {
246 				err = got_error(GOT_ERR_PRIVSEP_MSG);
247 				goto done;
248 			}
249 			datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
250 			t = imsg.data;
251 			/* at least one char */
252 			if (datalen < 2 || t[datalen-1] != '\0') {
253 				err = got_error(GOT_ERR_PRIVSEP_MSG);
254 				goto done;
255 			}
256 			if (*t != ' ' && *t != '-' && *t != '+' &&
257 			    *t != '\\') {
258 				err = got_error(GOT_ERR_PRIVSEP_MSG);
259 				goto done;
260 			}
261 
262 			if (*t != '\\')
263 				err = pushline(h, t);
264 			else if (lastmode == '-')
265 				h->old_nonl = 1;
266 			else if (lastmode == '+')
267 				h->new_nonl = 1;
268 			else
269 				err = got_error(GOT_ERR_PATCH_MALFORMED);
270 
271 			if (err)
272 				goto done;
273 
274 			lastmode = *t;
275 			break;
276 		default:
277 			err = got_error(GOT_ERR_PRIVSEP_MSG);
278 			goto done;
279 		}
280 
281 		imsg_free(&imsg);
282 	}
283 
284 done:
285 	imsg_free(&imsg);
286 	return err;
287 }
288 
289 /*
290  * Copy data from orig starting at copypos until pos into tmp.
291  * If pos is -1, copy until EOF.
292  */
293 static const struct got_error *
294 copy(FILE *tmp, FILE *orig, off_t copypos, off_t pos)
295 {
296 	char buf[BUFSIZ];
297 	size_t len, r, w;
298 
299 	if (fseeko(orig, copypos, SEEK_SET) == -1)
300 		return got_error_from_errno("fseeko");
301 
302 	while (pos == -1 || copypos < pos) {
303 		len = sizeof(buf);
304 		if (pos > 0)
305 			len = MIN(len, (size_t)pos - copypos);
306 		r = fread(buf, 1, len, orig);
307 		if (r != len && ferror(orig))
308 			return got_error_from_errno("fread");
309 		w = fwrite(buf, 1, r, tmp);
310 		if (w != r)
311 			return got_error_from_errno("fwrite");
312 		copypos += len;
313 		if (r != len && feof(orig)) {
314 			if (pos == -1)
315 				return NULL;
316 			return got_error(GOT_ERR_HUNK_FAILED);
317 		}
318 	}
319 	return NULL;
320 }
321 
322 static const struct got_error *
323 locate_hunk(FILE *orig, struct got_patch_hunk *h, off_t *pos, long *lineno)
324 {
325 	const struct got_error *err = NULL;
326 	char *line = NULL;
327 	char mode = *h->lines[0];
328 	size_t linesize = 0;
329 	ssize_t linelen;
330 	off_t match = -1;
331 	long match_lineno = -1;
332 
333 	for (;;) {
334 		linelen = getline(&line, &linesize, orig);
335 		if (linelen == -1) {
336 			if (ferror(orig))
337 				err = got_error_from_errno("getline");
338 			else if (match == -1)
339 				err = got_error(GOT_ERR_HUNK_FAILED);
340 			break;
341 		}
342 		if (line[linelen - 1] == '\n')
343 			line[linelen - 1] = '\0';
344 		(*lineno)++;
345 
346 		if ((mode == ' ' && !strcmp(h->lines[0] + 1, line)) ||
347 		    (mode == '-' && !strcmp(h->lines[0] + 1, line)) ||
348 		    (mode == '+' && *lineno == h->old_from)) {
349 			match = ftello(orig);
350 			if (match == -1) {
351 				err = got_error_from_errno("ftello");
352 				break;
353 			}
354 			match -= linelen;
355 			match_lineno = (*lineno)-1;
356 		}
357 
358 		if (*lineno >= h->old_from && match != -1)
359 			break;
360 	}
361 
362 	if (err == NULL) {
363 		*pos = match;
364 		*lineno = match_lineno;
365 		if (fseeko(orig, match, SEEK_SET) == -1)
366 			err = got_error_from_errno("fseeko");
367 	}
368 
369 	free(line);
370 	return err;
371 }
372 
373 static const struct got_error *
374 test_hunk(FILE *orig, struct got_patch_hunk *h)
375 {
376 	const struct got_error *err = NULL;
377 	char *line = NULL;
378 	size_t linesize = 0, i = 0;
379 	ssize_t linelen;
380 
381 	for (i = 0; i < h->len; ++i) {
382 		switch (*h->lines[i]) {
383 		case '+':
384 			continue;
385 		case ' ':
386 		case '-':
387 			linelen = getline(&line, &linesize, orig);
388 			if (linelen == -1) {
389 				if (ferror(orig))
390 					err = got_error_from_errno("getline");
391 				else
392 					err = got_error(
393 					    GOT_ERR_HUNK_FAILED);
394 				goto done;
395 			}
396 			if (line[linelen - 1] == '\n')
397 				line[linelen - 1] = '\0';
398 			if (strcmp(h->lines[i] + 1, line)) {
399 				err = got_error(GOT_ERR_HUNK_FAILED);
400 				goto done;
401 			}
402 			break;
403 		}
404 	}
405 
406 done:
407 	free(line);
408 	return err;
409 }
410 
411 static const struct got_error *
412 apply_hunk(FILE *tmp, struct got_patch_hunk *h, long *lineno)
413 {
414 	size_t i, new = 0;
415 
416 	for (i = 0; i < h->len; ++i) {
417 		switch (*h->lines[i]) {
418 		case ' ':
419 			if (fprintf(tmp, "%s\n", h->lines[i] + 1) < 0)
420 				return got_error_from_errno("fprintf");
421 			/* fallthrough */
422 		case '-':
423 			(*lineno)++;
424 			break;
425 		case '+':
426 			new++;
427 			if (fprintf(tmp, "%s", h->lines[i] + 1) < 0)
428 				return got_error_from_errno("fprintf");
429 			if (new != h->new_lines || !h->new_nonl) {
430 				if (fprintf(tmp, "\n") < 0)
431 					return got_error_from_errno(
432 					    "fprintf");
433 			}
434 			break;
435 		}
436 	}
437 	return NULL;
438 }
439 
440 static const struct got_error *
441 patch_file(struct got_patch *p, const char *path, FILE *tmp, int nop,
442     mode_t *mode)
443 {
444 	const struct got_error *err = NULL;
445 	struct got_patch_hunk *h;
446 	struct stat sb;
447 	long lineno = 0;
448 	FILE *orig;
449 	off_t copypos, pos;
450 	char *line = NULL;
451 	size_t linesize = 0;
452 	ssize_t linelen;
453 
454 	if (p->old == NULL) {				/* create */
455 		h = STAILQ_FIRST(&p->head);
456 		if (h == NULL || STAILQ_NEXT(h, entries) != NULL)
457 			return got_error(GOT_ERR_PATCH_MALFORMED);
458 		if (nop)
459 			return NULL;
460 		return apply_hunk(tmp, h, &lineno);
461 	}
462 
463 	if ((orig = fopen(path, "r")) == NULL) {
464 		err = got_error_from_errno2("fopen", path);
465 		goto done;
466 	}
467 
468 	if (fstat(fileno(orig), &sb) == -1) {
469 		err = got_error_from_errno("fstat");
470 		goto done;
471 	}
472 	*mode = sb.st_mode;
473 
474 	copypos = 0;
475 	STAILQ_FOREACH(h, &p->head, entries) {
476 	tryagain:
477 		err = locate_hunk(orig, h, &pos, &lineno);
478 		if (err != NULL && err->code == GOT_ERR_HUNK_FAILED)
479 			h->err = err;
480 		if (err != NULL)
481 			goto done;
482 		if (!nop)
483 			err = copy(tmp, orig, copypos, pos);
484 		if (err != NULL)
485 			goto done;
486 		copypos = pos;
487 
488 		err = test_hunk(orig, h);
489 		if (err != NULL && err->code == GOT_ERR_HUNK_FAILED) {
490 			/*
491 			 * try to apply the hunk again starting the search
492 			 * after the previous partial match.
493 			 */
494 			if (fseeko(orig, pos, SEEK_SET) == -1) {
495 				err = got_error_from_errno("fseeko");
496 				goto done;
497 			}
498 			linelen = getline(&line, &linesize, orig);
499 			if (linelen == -1) {
500 				err = got_error_from_errno("getline");
501 				goto done;
502 			}
503 			lineno++;
504 			goto tryagain;
505 		}
506 		if (err != NULL)
507 			goto done;
508 
509 		if (lineno + 1 != h->old_from)
510 			h->offset = lineno + 1 - h->old_from;
511 
512 		if (!nop)
513 			err = apply_hunk(tmp, h, &lineno);
514 		if (err != NULL)
515 			goto done;
516 
517 		copypos = ftello(orig);
518 		if (copypos == -1) {
519 			err = got_error_from_errno("ftello");
520 			goto done;
521 		}
522 	}
523 
524 	if (p->new == NULL && sb.st_size != copypos) {
525 		h = STAILQ_FIRST(&p->head);
526 		h->err = got_error(GOT_ERR_HUNK_FAILED);
527 		err = h->err;
528 	} else if (!nop && !feof(orig))
529 		err = copy(tmp, orig, copypos, -1);
530 
531 done:
532 	if (orig != NULL)
533 		fclose(orig);
534 	return err;
535 }
536 
537 static const struct got_error *
538 report_progress(struct patch_args *pa, const char *old, const char *new,
539     unsigned char status, const struct got_error *orig_error)
540 {
541 	const struct got_error *err;
542 	struct got_patch_hunk *h;
543 
544 	err = pa->progress_cb(pa->progress_arg, old, new, status,
545 	    orig_error, 0, 0, 0, 0, 0, NULL);
546 	if (err)
547 		return err;
548 
549 	STAILQ_FOREACH(h, pa->head, entries) {
550 		if (h->offset == 0 && h->err == NULL)
551 			continue;
552 
553 		err = pa->progress_cb(pa->progress_arg, old, new, 0, NULL,
554 		    h->old_from, h->old_lines, h->new_from, h->new_lines,
555 		    h->offset, h->err);
556 		if (err)
557 			return err;
558 	}
559 
560 	return NULL;
561 }
562 
563 static const struct got_error *
564 patch_delete(void *arg, unsigned char status, unsigned char staged_status,
565     const char *path)
566 {
567 	return report_progress(arg, path, NULL, status, NULL);
568 }
569 
570 static const struct got_error *
571 patch_add(void *arg, unsigned char status, const char *path)
572 {
573 	return report_progress(arg, NULL, path, status, NULL);
574 }
575 
576 static const struct got_error *
577 apply_patch(struct got_worktree *worktree, struct got_repository *repo,
578     struct got_fileindex *fileindex, const char *old, const char *new,
579     struct got_patch *p, int nop, struct patch_args *pa,
580     got_cancel_cb cancel_cb, void *cancel_arg)
581 {
582 	const struct got_error *err = NULL;
583 	int file_renamed = 0;
584 	char *oldpath = NULL, *newpath = NULL;
585 	char *tmppath = NULL, *template = NULL, *parent = NULL;;
586 	FILE *tmp = NULL;
587 	mode_t mode = GOT_DEFAULT_FILE_MODE;
588 
589 	if (asprintf(&oldpath, "%s/%s", got_worktree_get_root_path(worktree),
590 	    old) == -1) {
591 		err = got_error_from_errno("asprintf");
592 		goto done;
593 	}
594 
595 	if (asprintf(&newpath, "%s/%s", got_worktree_get_root_path(worktree),
596 	    new) == -1) {
597 		err = got_error_from_errno("asprintf");
598 		goto done;
599 	}
600 
601 	file_renamed = strcmp(oldpath, newpath);
602 
603 	if (asprintf(&template, "%s/got-patch",
604 	    got_worktree_get_root_path(worktree)) == -1) {
605 		err = got_error_from_errno(template);
606 		goto done;
607 	}
608 
609 	if (!nop)
610 		err = got_opentemp_named(&tmppath, &tmp, template);
611 	if (err)
612 		goto done;
613 	err = patch_file(p, oldpath, tmp, nop, &mode);
614 	if (err)
615 		goto done;
616 
617 	if (nop)
618 		goto done;
619 
620 	if (p->old != NULL && p->new == NULL) {
621 		err = got_worktree_patch_schedule_rm(old, repo, worktree,
622 		    fileindex, patch_delete, pa);
623 		goto done;
624 	}
625 
626 	if (fchmod(fileno(tmp), mode) == -1) {
627 		err = got_error_from_errno2("chmod", tmppath);
628 		goto done;
629 	}
630 
631 	if (rename(tmppath, newpath) == -1) {
632 		if (errno != ENOENT) {
633 			err = got_error_from_errno3("rename", tmppath,
634 			    newpath);
635 			goto done;
636 		}
637 
638 		err = got_path_dirname(&parent, newpath);
639 		if (err != NULL)
640 			goto done;
641 		err = got_path_mkdir(parent);
642 		if (err != NULL)
643 			goto done;
644 		if (rename(tmppath, newpath) == -1) {
645 			err = got_error_from_errno3("rename", tmppath,
646 			    newpath);
647 			goto done;
648 		}
649 	}
650 
651 	if (file_renamed) {
652 		err = got_worktree_patch_schedule_rm(old, repo, worktree,
653 		    fileindex, patch_delete, pa);
654 		if (err == NULL)
655 			err = got_worktree_patch_schedule_add(new, repo,
656 			    worktree, fileindex, patch_add,
657 			    pa);
658 		if (err)
659 			unlink(newpath);
660 	} else if (p->old == NULL) {
661 		err = got_worktree_patch_schedule_add(new, repo, worktree,
662 		    fileindex, patch_add, pa);
663 		if (err)
664 			unlink(newpath);
665 	} else
666 		err = report_progress(pa, old, new, GOT_STATUS_MODIFY, NULL);
667 
668 done:
669 	free(parent);
670 	free(template);
671 	if (tmppath != NULL)
672 		unlink(tmppath);
673 	free(tmppath);
674 	free(oldpath);
675 	free(newpath);
676 	return err;
677 }
678 
679 static void
680 reverse_patch(struct got_patch *p)
681 {
682 	struct got_patch_hunk *h;
683 	size_t i;
684 	long tmp;
685 
686 	STAILQ_FOREACH(h, &p->head, entries) {
687 		tmp = h->old_from;
688 		h->old_from = h->new_from;
689 		h->new_from = tmp;
690 
691 		tmp = h->old_lines;
692 		h->old_lines = h->new_lines;
693 		h->new_lines = tmp;
694 
695 		tmp = h->old_nonl;
696 		h->old_nonl = h->new_nonl;
697 		h->new_nonl = tmp;
698 
699 		for (i = 0; i < h->len; ++i) {
700 			if (*h->lines[i] == '+')
701 				*h->lines[i] = '-';
702 			else if (*h->lines[i] == '-')
703 				*h->lines[i] = '+';
704 		}
705 	}
706 }
707 
708 const struct got_error *
709 got_patch(int fd, struct got_worktree *worktree, struct got_repository *repo,
710     int nop, int strip, int reverse, got_patch_progress_cb progress_cb,
711     void *progress_arg, got_cancel_cb cancel_cb, void *cancel_arg)
712 {
713 	const struct got_error *err = NULL, *complete_err = NULL;
714 	struct got_fileindex *fileindex = NULL;
715 	char *fileindex_path = NULL;
716 	char *oldpath, *newpath;
717 	struct imsgbuf *ibuf;
718 	int imsg_fds[2] = {-1, -1};
719 	int done = 0, failed = 0;
720 	pid_t pid;
721 
722 	ibuf = calloc(1, sizeof(*ibuf));
723 	if (ibuf == NULL) {
724 		err = got_error_from_errno("calloc");
725 		goto done;
726 	}
727 
728 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
729 		err = got_error_from_errno("socketpair");
730 		goto done;
731 	}
732 
733 	pid = fork();
734 	if (pid == -1) {
735 		err = got_error_from_errno("fork");
736 		goto done;
737 	} else if (pid == 0) {
738 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PATCH,
739 		    NULL);
740 		/* not reached */
741 	}
742 
743 	if (close(imsg_fds[1]) == -1) {
744 		err = got_error_from_errno("close");
745 		goto done;
746 	}
747 	imsg_fds[1] = -1;
748 	imsg_init(ibuf, imsg_fds[0]);
749 
750 	err = send_patch(ibuf, fd);
751 	fd = -1;
752 	if (err)
753 		goto done;
754 
755 	err = got_worktree_patch_prepare(&fileindex, &fileindex_path,
756 	    worktree);
757 	if (err)
758 		goto done;
759 
760 	while (!done && err == NULL) {
761 		struct got_patch p;
762 		struct patch_args pa;
763 
764 		pa.progress_cb = progress_cb;
765 		pa.progress_arg = progress_arg;
766 		pa.head = &p.head;
767 
768 		err = recv_patch(ibuf, &done, &p, strip);
769 		if (err || done)
770 			break;
771 
772 		if (reverse)
773 			reverse_patch(&p);
774 
775 		err = got_worktree_patch_check_path(p.old, p.new, &oldpath,
776 		    &newpath, worktree, repo, fileindex);
777 		if (err == NULL)
778 			err = apply_patch(worktree, repo, fileindex, oldpath,
779 			    newpath, &p, nop, &pa, cancel_cb, cancel_arg);
780 		if (err != NULL) {
781 			failed = 1;
782 			/* recoverable errors */
783 			if (err->code == GOT_ERR_FILE_STATUS ||
784 			    (err->code == GOT_ERR_ERRNO && errno == ENOENT))
785 				err = report_progress(&pa, p.old, p.new,
786 				    GOT_STATUS_CANNOT_UPDATE, err);
787 			else if (err->code == GOT_ERR_HUNK_FAILED)
788 				err = report_progress(&pa, p.old, p.new,
789 				    GOT_STATUS_CANNOT_UPDATE, NULL);
790 		}
791 
792 		free(oldpath);
793 		free(newpath);
794 		patch_free(&p);
795 
796 		if (err)
797 			break;
798 	}
799 
800 done:
801 	if (fileindex != NULL)
802 		complete_err = got_worktree_patch_complete(fileindex,
803 		    fileindex_path);
804 	if (complete_err && err == NULL)
805 		err = complete_err;
806 	free(fileindex_path);
807 	if (fd != -1 && close(fd) == -1 && err == NULL)
808 		err = got_error_from_errno("close");
809 	if (ibuf != NULL)
810 		imsg_clear(ibuf);
811 	if (imsg_fds[0] != -1 && close(imsg_fds[0]) == -1 && err == NULL)
812 		err = got_error_from_errno("close");
813 	if (imsg_fds[1] != -1 && close(imsg_fds[1]) == -1 && err == NULL)
814 		err = got_error_from_errno("close");
815 	if (err == NULL && failed)
816 		err = got_error(GOT_ERR_PATCH_FAILED);
817 	return err;
818 }