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 	memset(p, 0, sizeof(*p));
123 	STAILQ_INIT(&p->head);
124 }
125 
126 static const struct got_error *
127 pushline(struct got_patch_hunk *h, const char *line)
128 {
129 	void 	*t;
130 	size_t	 newcap;
131 
132 	if (h->len == h->cap) {
133 		if ((newcap = h->cap * 1.5) == 0)
134 			newcap = 16;
135 		t = recallocarray(h->lines, h->cap, newcap,
136 		    sizeof(h->lines[0]));
137 		if (t == NULL)
138 			return got_error_from_errno("recallocarray");
139 		h->lines = t;
140 		h->cap = newcap;
141 	}
142 
143 	if ((t = strdup(line)) == NULL)
144 		return got_error_from_errno("strdup");
145 
146 	h->lines[h->len++] = t;
147 	return NULL;
148 }
149 
150 static const struct got_error *
151 recv_patch(struct imsgbuf *ibuf, int *done, struct got_patch *p, int strip)
152 {
153 	const struct got_error *err = NULL;
154 	struct imsg imsg;
155 	struct got_imsg_patch_hunk hdr;
156 	struct got_imsg_patch patch;
157 	struct got_patch_hunk *h = NULL;
158 	size_t datalen;
159 	int lastmode = -1;
160 
161 	memset(p, 0, sizeof(*p));
162 	STAILQ_INIT(&p->head);
163 
164 	err = got_privsep_recv_imsg(&imsg, ibuf, 0);
165 	if (err)
166 		return err;
167 	if (imsg.hdr.type == GOT_IMSG_PATCH_EOF) {
168 		*done = 1;
169 		goto done;
170 	}
171 	if (imsg.hdr.type != GOT_IMSG_PATCH) {
172 		err = got_error(GOT_ERR_PRIVSEP_MSG);
173 		goto done;
174 	}
175 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
176 	if (datalen != sizeof(patch)) {
177 		err = got_error(GOT_ERR_PRIVSEP_LEN);
178 		goto done;
179 	}
180 	memcpy(&patch, imsg.data, sizeof(patch));
181 
182 	if (patch.old[sizeof(patch.old)-1] != '\0' ||
183 	    patch.new[sizeof(patch.new)-1] != '\0') {
184 		err = got_error(GOT_ERR_PRIVSEP_LEN);
185 		goto done;
186 	}
187 
188 	/* automatically set strip=1 for git-style diffs */
189 	if (strip == -1 && patch.git &&
190 	    (*patch.old == '\0' || !strncmp(patch.old, "a/", 2)) &&
191 	    (*patch.new == '\0' || !strncmp(patch.new, "b/", 2)))
192 		strip = 1;
193 
194 	/* prefer the new name if not /dev/null for not git-style diffs */
195 	if (!patch.git && *patch.new != '\0' && *patch.old != '\0') {
196 		err = got_path_strip(&p->old, patch.new, strip);
197 		if (err)
198 			goto done;
199 	} else if (*patch.old != '\0') {
200 		err = got_path_strip(&p->old, patch.old, strip);
201 		if (err)
202 			goto done;
203 	}
204 
205 	if (*patch.new != '\0') {
206 		err = got_path_strip(&p->new, patch.new, strip);
207 		if (err)
208 			goto done;
209 	}
210 
211 	if (p->old == NULL && p->new == NULL) {
212 		err = got_error(GOT_ERR_PATCH_MALFORMED);
213 		goto done;
214 	}
215 
216 	imsg_free(&imsg);
217 
218 	for (;;) {
219 		char *t;
220 
221 		err = got_privsep_recv_imsg(&imsg, ibuf, 0);
222 		if (err) {
223 			patch_free(p);
224 			return err;
225 		}
226 
227 		switch (imsg.hdr.type) {
228 		case GOT_IMSG_PATCH_DONE:
229 			if (h != NULL && h->len == 0)
230 				err = got_error(GOT_ERR_PATCH_MALFORMED);
231 			goto done;
232 		case GOT_IMSG_PATCH_HUNK:
233 			if (h != NULL &&
234 			    (h->len == 0 || h->old_nonl || h->new_nonl)) {
235 				err = got_error(GOT_ERR_PATCH_MALFORMED);
236 				goto done;
237 			}
238 			lastmode = -1;
239 			datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
240 			if (datalen != sizeof(hdr)) {
241 				err = got_error(GOT_ERR_PRIVSEP_LEN);
242 				goto done;
243 			}
244 			memcpy(&hdr, imsg.data, sizeof(hdr));
245 			if ((h = calloc(1, sizeof(*h))) == NULL) {
246 				err = got_error_from_errno("calloc");
247 				goto done;
248 			}
249 			if (h->old_from < 0 || h->new_from < 0) {
250 				err = got_error(GOT_ERR_PRIVSEP_LEN);
251 				goto done;
252 			}
253 			h->old_from = hdr.oldfrom;
254 			h->old_lines = hdr.oldlines;
255 			h->new_from = hdr.newfrom;
256 			h->new_lines = hdr.newlines;
257 			STAILQ_INSERT_TAIL(&p->head, h, entries);
258 			break;
259 		case GOT_IMSG_PATCH_LINE:
260 			if (h == NULL) {
261 				err = got_error(GOT_ERR_PRIVSEP_MSG);
262 				goto done;
263 			}
264 			datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
265 			t = imsg.data;
266 			/* at least one char */
267 			if (datalen < 2 || t[datalen-1] != '\0') {
268 				err = got_error(GOT_ERR_PRIVSEP_MSG);
269 				goto done;
270 			}
271 			if (*t != ' ' && *t != '-' && *t != '+' &&
272 			    *t != '\\') {
273 				err = got_error(GOT_ERR_PRIVSEP_MSG);
274 				goto done;
275 			}
276 
277 			if (*t != '\\')
278 				err = pushline(h, t);
279 			else if (lastmode == '-')
280 				h->old_nonl = 1;
281 			else if (lastmode == '+')
282 				h->new_nonl = 1;
283 			else
284 				err = got_error(GOT_ERR_PATCH_MALFORMED);
285 
286 			if (err)
287 				goto done;
288 
289 			lastmode = *t;
290 			break;
291 		default:
292 			err = got_error(GOT_ERR_PRIVSEP_MSG);
293 			goto done;
294 		}
295 
296 		imsg_free(&imsg);
297 	}
298 
299 done:
300 	if (err)
301 		patch_free(p);
302 
303 	imsg_free(&imsg);
304 	return err;
305 }
306 
307 /*
308  * Copy data from orig starting at copypos until pos into tmp.
309  * If pos is -1, copy until EOF.
310  */
311 static const struct got_error *
312 copy(FILE *tmp, FILE *orig, off_t copypos, off_t pos)
313 {
314 	char buf[BUFSIZ];
315 	size_t len, r, w;
316 
317 	if (fseeko(orig, copypos, SEEK_SET) == -1)
318 		return got_error_from_errno("fseeko");
319 
320 	while (pos == -1 || copypos < pos) {
321 		len = sizeof(buf);
322 		if (pos > 0)
323 			len = MIN(len, (size_t)pos - copypos);
324 		r = fread(buf, 1, len, orig);
325 		if (r != len && ferror(orig))
326 			return got_error_from_errno("fread");
327 		w = fwrite(buf, 1, r, tmp);
328 		if (w != r)
329 			return got_error_from_errno("fwrite");
330 		copypos += len;
331 		if (r != len && feof(orig)) {
332 			if (pos == -1)
333 				return NULL;
334 			return got_error(GOT_ERR_HUNK_FAILED);
335 		}
336 	}
337 	return NULL;
338 }
339 
340 static const struct got_error *
341 locate_hunk(FILE *orig, struct got_patch_hunk *h, off_t *pos, long *lineno)
342 {
343 	const struct got_error *err = NULL;
344 	char *line = NULL;
345 	char mode = *h->lines[0];
346 	size_t linesize = 0;
347 	ssize_t linelen;
348 	off_t match = -1;
349 	long match_lineno = -1;
350 
351 	for (;;) {
352 		linelen = getline(&line, &linesize, orig);
353 		if (linelen == -1) {
354 			if (ferror(orig))
355 				err = got_error_from_errno("getline");
356 			else if (match == -1)
357 				err = got_error(GOT_ERR_HUNK_FAILED);
358 			break;
359 		}
360 		if (line[linelen - 1] == '\n')
361 			line[linelen - 1] = '\0';
362 		(*lineno)++;
363 
364 		if ((mode == ' ' && !strcmp(h->lines[0] + 1, line)) ||
365 		    (mode == '-' && !strcmp(h->lines[0] + 1, line)) ||
366 		    (mode == '+' && *lineno == h->old_from)) {
367 			match = ftello(orig);
368 			if (match == -1) {
369 				err = got_error_from_errno("ftello");
370 				break;
371 			}
372 			match -= linelen;
373 			match_lineno = (*lineno)-1;
374 		}
375 
376 		if (*lineno >= h->old_from && match != -1)
377 			break;
378 	}
379 
380 	if (err == NULL) {
381 		*pos = match;
382 		*lineno = match_lineno;
383 		if (fseeko(orig, match, SEEK_SET) == -1)
384 			err = got_error_from_errno("fseeko");
385 	}
386 
387 	free(line);
388 	return err;
389 }
390 
391 static const struct got_error *
392 test_hunk(FILE *orig, struct got_patch_hunk *h)
393 {
394 	const struct got_error *err = NULL;
395 	char *line = NULL;
396 	size_t linesize = 0, i = 0;
397 	ssize_t linelen;
398 
399 	for (i = 0; i < h->len; ++i) {
400 		switch (*h->lines[i]) {
401 		case '+':
402 			continue;
403 		case ' ':
404 		case '-':
405 			linelen = getline(&line, &linesize, orig);
406 			if (linelen == -1) {
407 				if (ferror(orig))
408 					err = got_error_from_errno("getline");
409 				else
410 					err = got_error(
411 					    GOT_ERR_HUNK_FAILED);
412 				goto done;
413 			}
414 			if (line[linelen - 1] == '\n')
415 				line[linelen - 1] = '\0';
416 			if (strcmp(h->lines[i] + 1, line)) {
417 				err = got_error(GOT_ERR_HUNK_FAILED);
418 				goto done;
419 			}
420 			break;
421 		}
422 	}
423 
424 done:
425 	free(line);
426 	return err;
427 }
428 
429 static const struct got_error *
430 apply_hunk(FILE *tmp, struct got_patch_hunk *h, long *lineno)
431 {
432 	size_t i, new = 0;
433 
434 	for (i = 0; i < h->len; ++i) {
435 		switch (*h->lines[i]) {
436 		case ' ':
437 			if (fprintf(tmp, "%s\n", h->lines[i] + 1) < 0)
438 				return got_error_from_errno("fprintf");
439 			/* fallthrough */
440 		case '-':
441 			(*lineno)++;
442 			break;
443 		case '+':
444 			new++;
445 			if (fprintf(tmp, "%s", h->lines[i] + 1) < 0)
446 				return got_error_from_errno("fprintf");
447 			if (new != h->new_lines || !h->new_nonl) {
448 				if (fprintf(tmp, "\n") < 0)
449 					return got_error_from_errno(
450 					    "fprintf");
451 			}
452 			break;
453 		}
454 	}
455 	return NULL;
456 }
457 
458 static const struct got_error *
459 patch_file(struct got_patch *p, const char *path, FILE *tmp, int nop,
460     mode_t *mode)
461 {
462 	const struct got_error *err = NULL;
463 	struct got_patch_hunk *h;
464 	struct stat sb;
465 	long lineno = 0;
466 	FILE *orig;
467 	off_t copypos, pos;
468 	char *line = NULL;
469 	size_t linesize = 0;
470 	ssize_t linelen;
471 
472 	if (p->old == NULL) {				/* create */
473 		h = STAILQ_FIRST(&p->head);
474 		if (h == NULL || STAILQ_NEXT(h, entries) != NULL)
475 			return got_error(GOT_ERR_PATCH_MALFORMED);
476 		if (nop)
477 			return NULL;
478 		return apply_hunk(tmp, h, &lineno);
479 	}
480 
481 	if ((orig = fopen(path, "r")) == NULL) {
482 		err = got_error_from_errno2("fopen", path);
483 		goto done;
484 	}
485 
486 	if (fstat(fileno(orig), &sb) == -1) {
487 		err = got_error_from_errno("fstat");
488 		goto done;
489 	}
490 	*mode = sb.st_mode;
491 
492 	copypos = 0;
493 	STAILQ_FOREACH(h, &p->head, entries) {
494 	tryagain:
495 		err = locate_hunk(orig, h, &pos, &lineno);
496 		if (err != NULL && err->code == GOT_ERR_HUNK_FAILED)
497 			h->err = err;
498 		if (err != NULL)
499 			goto done;
500 		if (!nop)
501 			err = copy(tmp, orig, copypos, pos);
502 		if (err != NULL)
503 			goto done;
504 		copypos = pos;
505 
506 		err = test_hunk(orig, h);
507 		if (err != NULL && err->code == GOT_ERR_HUNK_FAILED) {
508 			/*
509 			 * try to apply the hunk again starting the search
510 			 * after the previous partial match.
511 			 */
512 			if (fseeko(orig, pos, SEEK_SET) == -1) {
513 				err = got_error_from_errno("fseeko");
514 				goto done;
515 			}
516 			linelen = getline(&line, &linesize, orig);
517 			if (linelen == -1) {
518 				err = got_error_from_errno("getline");
519 				goto done;
520 			}
521 			lineno++;
522 			goto tryagain;
523 		}
524 		if (err != NULL)
525 			goto done;
526 
527 		if (lineno + 1 != h->old_from)
528 			h->offset = lineno + 1 - h->old_from;
529 
530 		if (!nop)
531 			err = apply_hunk(tmp, h, &lineno);
532 		if (err != NULL)
533 			goto done;
534 
535 		copypos = ftello(orig);
536 		if (copypos == -1) {
537 			err = got_error_from_errno("ftello");
538 			goto done;
539 		}
540 	}
541 
542 	if (p->new == NULL && sb.st_size != copypos) {
543 		h = STAILQ_FIRST(&p->head);
544 		h->err = got_error(GOT_ERR_HUNK_FAILED);
545 		err = h->err;
546 	} else if (!nop && !feof(orig))
547 		err = copy(tmp, orig, copypos, -1);
548 
549 done:
550 	if (orig != NULL)
551 		fclose(orig);
552 	return err;
553 }
554 
555 static const struct got_error *
556 report_progress(struct patch_args *pa, const char *old, const char *new,
557     unsigned char status, const struct got_error *orig_error)
558 {
559 	const struct got_error *err;
560 	struct got_patch_hunk *h;
561 
562 	err = pa->progress_cb(pa->progress_arg, old, new, status,
563 	    orig_error, 0, 0, 0, 0, 0, NULL);
564 	if (err)
565 		return err;
566 
567 	STAILQ_FOREACH(h, pa->head, entries) {
568 		if (h->offset == 0 && h->err == NULL)
569 			continue;
570 
571 		err = pa->progress_cb(pa->progress_arg, old, new, 0, NULL,
572 		    h->old_from, h->old_lines, h->new_from, h->new_lines,
573 		    h->offset, h->err);
574 		if (err)
575 			return err;
576 	}
577 
578 	return NULL;
579 }
580 
581 static const struct got_error *
582 patch_delete(void *arg, unsigned char status, unsigned char staged_status,
583     const char *path)
584 {
585 	return report_progress(arg, path, NULL, status, NULL);
586 }
587 
588 static const struct got_error *
589 patch_add(void *arg, unsigned char status, const char *path)
590 {
591 	return report_progress(arg, NULL, path, status, NULL);
592 }
593 
594 static const struct got_error *
595 apply_patch(struct got_worktree *worktree, struct got_repository *repo,
596     struct got_fileindex *fileindex, const char *old, const char *new,
597     struct got_patch *p, int nop, struct patch_args *pa,
598     got_cancel_cb cancel_cb, void *cancel_arg)
599 {
600 	const struct got_error *err = NULL;
601 	int file_renamed = 0;
602 	char *oldpath = NULL, *newpath = NULL;
603 	char *tmppath = NULL, *template = NULL, *parent = NULL;;
604 	FILE *tmp = NULL;
605 	mode_t mode = GOT_DEFAULT_FILE_MODE;
606 
607 	if (asprintf(&oldpath, "%s/%s", got_worktree_get_root_path(worktree),
608 	    old) == -1) {
609 		err = got_error_from_errno("asprintf");
610 		goto done;
611 	}
612 
613 	if (asprintf(&newpath, "%s/%s", got_worktree_get_root_path(worktree),
614 	    new) == -1) {
615 		err = got_error_from_errno("asprintf");
616 		goto done;
617 	}
618 
619 	file_renamed = strcmp(oldpath, newpath);
620 
621 	if (asprintf(&template, "%s/got-patch",
622 	    got_worktree_get_root_path(worktree)) == -1) {
623 		err = got_error_from_errno(template);
624 		goto done;
625 	}
626 
627 	if (!nop)
628 		err = got_opentemp_named(&tmppath, &tmp, template);
629 	if (err)
630 		goto done;
631 	err = patch_file(p, oldpath, tmp, nop, &mode);
632 	if (err)
633 		goto done;
634 
635 	if (nop)
636 		goto done;
637 
638 	if (p->old != NULL && p->new == NULL) {
639 		err = got_worktree_patch_schedule_rm(old, repo, worktree,
640 		    fileindex, patch_delete, pa);
641 		goto done;
642 	}
643 
644 	if (fchmod(fileno(tmp), mode) == -1) {
645 		err = got_error_from_errno2("chmod", tmppath);
646 		goto done;
647 	}
648 
649 	if (rename(tmppath, newpath) == -1) {
650 		if (errno != ENOENT) {
651 			err = got_error_from_errno3("rename", tmppath,
652 			    newpath);
653 			goto done;
654 		}
655 
656 		err = got_path_dirname(&parent, newpath);
657 		if (err != NULL)
658 			goto done;
659 		err = got_path_mkdir(parent);
660 		if (err != NULL)
661 			goto done;
662 		if (rename(tmppath, newpath) == -1) {
663 			err = got_error_from_errno3("rename", tmppath,
664 			    newpath);
665 			goto done;
666 		}
667 	}
668 
669 	if (file_renamed) {
670 		err = got_worktree_patch_schedule_rm(old, repo, worktree,
671 		    fileindex, patch_delete, pa);
672 		if (err == NULL)
673 			err = got_worktree_patch_schedule_add(new, repo,
674 			    worktree, fileindex, patch_add,
675 			    pa);
676 		if (err)
677 			unlink(newpath);
678 	} else if (p->old == NULL) {
679 		err = got_worktree_patch_schedule_add(new, repo, worktree,
680 		    fileindex, patch_add, pa);
681 		if (err)
682 			unlink(newpath);
683 	} else
684 		err = report_progress(pa, old, new, GOT_STATUS_MODIFY, NULL);
685 
686 done:
687 	free(parent);
688 	free(template);
689 	if (tmppath != NULL)
690 		unlink(tmppath);
691 	free(tmppath);
692 	free(oldpath);
693 	free(newpath);
694 	return err;
695 }
696 
697 static void
698 reverse_patch(struct got_patch *p)
699 {
700 	struct got_patch_hunk *h;
701 	size_t i;
702 	long tmp;
703 
704 	STAILQ_FOREACH(h, &p->head, entries) {
705 		tmp = h->old_from;
706 		h->old_from = h->new_from;
707 		h->new_from = tmp;
708 
709 		tmp = h->old_lines;
710 		h->old_lines = h->new_lines;
711 		h->new_lines = tmp;
712 
713 		tmp = h->old_nonl;
714 		h->old_nonl = h->new_nonl;
715 		h->new_nonl = tmp;
716 
717 		for (i = 0; i < h->len; ++i) {
718 			if (*h->lines[i] == '+')
719 				*h->lines[i] = '-';
720 			else if (*h->lines[i] == '-')
721 				*h->lines[i] = '+';
722 		}
723 	}
724 }
725 
726 const struct got_error *
727 got_patch(int fd, struct got_worktree *worktree, struct got_repository *repo,
728     int nop, int strip, int reverse, got_patch_progress_cb progress_cb,
729     void *progress_arg, got_cancel_cb cancel_cb, void *cancel_arg)
730 {
731 	const struct got_error *err = NULL, *complete_err = NULL;
732 	struct got_fileindex *fileindex = NULL;
733 	char *fileindex_path = NULL;
734 	char *oldpath, *newpath;
735 	struct imsgbuf *ibuf;
736 	int imsg_fds[2] = {-1, -1};
737 	int done = 0, failed = 0;
738 	pid_t pid;
739 
740 	ibuf = calloc(1, sizeof(*ibuf));
741 	if (ibuf == NULL) {
742 		err = got_error_from_errno("calloc");
743 		goto done;
744 	}
745 
746 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
747 		err = got_error_from_errno("socketpair");
748 		goto done;
749 	}
750 
751 	pid = fork();
752 	if (pid == -1) {
753 		err = got_error_from_errno("fork");
754 		goto done;
755 	} else if (pid == 0) {
756 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PATCH,
757 		    NULL);
758 		/* not reached */
759 	}
760 
761 	if (close(imsg_fds[1]) == -1) {
762 		err = got_error_from_errno("close");
763 		goto done;
764 	}
765 	imsg_fds[1] = -1;
766 	imsg_init(ibuf, imsg_fds[0]);
767 
768 	err = send_patch(ibuf, fd);
769 	fd = -1;
770 	if (err)
771 		goto done;
772 
773 	err = got_worktree_patch_prepare(&fileindex, &fileindex_path,
774 	    worktree);
775 	if (err)
776 		goto done;
777 
778 	while (!done && err == NULL) {
779 		struct got_patch p;
780 		struct patch_args pa;
781 
782 		pa.progress_cb = progress_cb;
783 		pa.progress_arg = progress_arg;
784 		pa.head = &p.head;
785 
786 		err = recv_patch(ibuf, &done, &p, strip);
787 		if (err || done)
788 			break;
789 
790 		if (reverse)
791 			reverse_patch(&p);
792 
793 		err = got_worktree_patch_check_path(p.old, p.new, &oldpath,
794 		    &newpath, worktree, repo, fileindex);
795 		if (err == NULL)
796 			err = apply_patch(worktree, repo, fileindex, oldpath,
797 			    newpath, &p, nop, &pa, cancel_cb, cancel_arg);
798 		if (err != NULL) {
799 			failed = 1;
800 			/* recoverable errors */
801 			if (err->code == GOT_ERR_FILE_STATUS ||
802 			    (err->code == GOT_ERR_ERRNO && errno == ENOENT))
803 				err = report_progress(&pa, p.old, p.new,
804 				    GOT_STATUS_CANNOT_UPDATE, err);
805 			else if (err->code == GOT_ERR_HUNK_FAILED)
806 				err = report_progress(&pa, p.old, p.new,
807 				    GOT_STATUS_CANNOT_UPDATE, NULL);
808 		}
809 
810 		free(oldpath);
811 		free(newpath);
812 		patch_free(&p);
813 
814 		if (err)
815 			break;
816 	}
817 
818 done:
819 	if (fileindex != NULL)
820 		complete_err = got_worktree_patch_complete(fileindex,
821 		    fileindex_path);
822 	if (complete_err && err == NULL)
823 		err = complete_err;
824 	free(fileindex_path);
825 	if (fd != -1 && close(fd) == -1 && err == NULL)
826 		err = got_error_from_errno("close");
827 	if (ibuf != NULL)
828 		imsg_clear(ibuf);
829 	if (imsg_fds[0] != -1 && close(imsg_fds[0]) == -1 && err == NULL)
830 		err = got_error_from_errno("close");
831 	if (imsg_fds[1] != -1 && close(imsg_fds[1]) == -1 && err == NULL)
832 		err = got_error_from_errno("close");
833 	if (err == NULL && failed)
834 		err = got_error(GOT_ERR_PATCH_FAILED);
835 	return err;
836 }