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 			goto done;
219 		case GOT_IMSG_PATCH_HUNK:
220 			if (h != NULL && (h->old_nonl || h->new_nonl)) {
221 				err = got_error(GOT_ERR_PATCH_MALFORMED);
222 				goto done;
223 			}
224 			lastmode = -1;
225 			datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
226 			if (datalen != sizeof(hdr)) {
227 				err = got_error(GOT_ERR_PRIVSEP_LEN);
228 				goto done;
229 			}
230 			memcpy(&hdr, imsg.data, sizeof(hdr));
231 			if ((h = calloc(1, sizeof(*h))) == NULL) {
232 				err = got_error_from_errno("calloc");
233 				goto done;
234 			}
235 			h->old_from = hdr.oldfrom;
236 			h->old_lines = hdr.oldlines;
237 			h->new_from = hdr.newfrom;
238 			h->new_lines = hdr.newlines;
239 			STAILQ_INSERT_TAIL(&p->head, h, entries);
240 			break;
241 		case GOT_IMSG_PATCH_LINE:
242 			if (h == NULL) {
243 				err = got_error(GOT_ERR_PRIVSEP_MSG);
244 				goto done;
245 			}
246 			datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
247 			t = imsg.data;
248 			/* at least one char */
249 			if (datalen < 2 || t[datalen-1] != '\0') {
250 				err = got_error(GOT_ERR_PRIVSEP_MSG);
251 				goto done;
252 			}
253 			if (*t != ' ' && *t != '-' && *t != '+' &&
254 			    *t != '\\') {
255 				err = got_error(GOT_ERR_PRIVSEP_MSG);
256 				goto done;
257 			}
258 
259 			if (*t != '\\')
260 				err = pushline(h, t);
261 			else if (lastmode == '-')
262 				h->old_nonl = 1;
263 			else if (lastmode == '+')
264 				h->new_nonl = 1;
265 			else
266 				err = got_error(GOT_ERR_PATCH_MALFORMED);
267 
268 			if (err)
269 				goto done;
270 
271 			lastmode = *t;
272 			break;
273 		default:
274 			err = got_error(GOT_ERR_PRIVSEP_MSG);
275 			goto done;
276 		}
277 
278 		imsg_free(&imsg);
279 	}
280 
281 done:
282 	imsg_free(&imsg);
283 	return err;
284 }
285 
286 /*
287  * Copy data from orig starting at copypos until pos into tmp.
288  * If pos is -1, copy until EOF.
289  */
290 static const struct got_error *
291 copy(FILE *tmp, FILE *orig, off_t copypos, off_t pos)
292 {
293 	char buf[BUFSIZ];
294 	size_t len, r, w;
295 
296 	if (fseek(orig, copypos, SEEK_SET) == -1)
297 		return got_error_from_errno("fseek");
298 
299 	while (pos == -1 || copypos < pos) {
300 		len = sizeof(buf);
301 		if (pos > 0)
302 			len = MIN(len, (size_t)pos - copypos);
303 		r = fread(buf, 1, len, orig);
304 		if (r != len && ferror(orig))
305 			return got_error_from_errno("fread");
306 		w = fwrite(buf, 1, r, tmp);
307 		if (w != r)
308 			return got_error_from_errno("fwrite");
309 		copypos += len;
310 		if (r != len && feof(orig)) {
311 			if (pos == -1)
312 				return NULL;
313 			return got_error(GOT_ERR_HUNK_FAILED);
314 		}
315 	}
316 	return NULL;
317 }
318 
319 static const struct got_error *
320 locate_hunk(FILE *orig, struct got_patch_hunk *h, off_t *pos, long *lineno)
321 {
322 	const struct got_error *err = NULL;
323 	char *line = NULL;
324 	char mode = *h->lines[0];
325 	size_t linesize = 0;
326 	ssize_t linelen;
327 	off_t match = -1;
328 	long match_lineno = -1;
329 
330 	for (;;) {
331 		linelen = getline(&line, &linesize, orig);
332 		if (linelen == -1) {
333 			if (ferror(orig))
334 				err = got_error_from_errno("getline");
335 			else if (match == -1)
336 				err = got_error(GOT_ERR_HUNK_FAILED);
337 			break;
338 		}
339 		if (line[linelen - 1] == '\n')
340 			line[linelen - 1] = '\0';
341 		(*lineno)++;
342 
343 		if ((mode == ' ' && !strcmp(h->lines[0] + 1, line)) ||
344 		    (mode == '-' && !strcmp(h->lines[0] + 1, line)) ||
345 		    (mode == '+' && *lineno == h->old_from)) {
346 			match = ftello(orig);
347 			if (match == -1) {
348 				err = got_error_from_errno("ftello");
349 				break;
350 			}
351 			match -= linelen;
352 			match_lineno = (*lineno)-1;
353 		}
354 
355 		if (*lineno >= h->old_from && match != -1)
356 			break;
357 	}
358 
359 	if (err == NULL) {
360 		*pos = match;
361 		*lineno = match_lineno;
362 		if (fseek(orig, match, SEEK_SET) == -1)
363 			err = got_error_from_errno("fseek");
364 	}
365 
366 	free(line);
367 	return err;
368 }
369 
370 static const struct got_error *
371 test_hunk(FILE *orig, struct got_patch_hunk *h)
372 {
373 	const struct got_error *err = NULL;
374 	char *line = NULL;
375 	size_t linesize = 0, i = 0;
376 	ssize_t linelen;
377 
378 	for (i = 0; i < h->len; ++i) {
379 		switch (*h->lines[i]) {
380 		case '+':
381 			continue;
382 		case ' ':
383 		case '-':
384 			linelen = getline(&line, &linesize, orig);
385 			if (linelen == -1) {
386 				if (ferror(orig))
387 					err = got_error_from_errno("getline");
388 				else
389 					err = got_error(
390 					    GOT_ERR_HUNK_FAILED);
391 				goto done;
392 			}
393 			if (line[linelen - 1] == '\n')
394 				line[linelen - 1] = '\0';
395 			if (strcmp(h->lines[i] + 1, line)) {
396 				err = got_error(GOT_ERR_HUNK_FAILED);
397 				goto done;
398 			}
399 			break;
400 		}
401 	}
402 
403 done:
404 	free(line);
405 	return err;
406 }
407 
408 static const struct got_error *
409 apply_hunk(FILE *tmp, struct got_patch_hunk *h, long *lineno)
410 {
411 	size_t i, new = 0;
412 
413 	for (i = 0; i < h->len; ++i) {
414 		switch (*h->lines[i]) {
415 		case ' ':
416 			if (fprintf(tmp, "%s\n", h->lines[i] + 1) < 0)
417 				return got_error_from_errno("fprintf");
418 			/* fallthrough */
419 		case '-':
420 			(*lineno)++;
421 			break;
422 		case '+':
423 			new++;
424 			if (fprintf(tmp, "%s", h->lines[i] + 1) < 0)
425 				return got_error_from_errno("fprintf");
426 			if (new != h->new_lines || !h->new_nonl) {
427 				if (fprintf(tmp, "\n") < 0)
428 					return got_error_from_errno(
429 					    "fprintf");
430 			}
431 			break;
432 		}
433 	}
434 	return NULL;
435 }
436 
437 static const struct got_error *
438 patch_file(struct got_patch *p, const char *path, FILE *tmp, int nop,
439     mode_t *mode)
440 {
441 	const struct got_error *err = NULL;
442 	struct got_patch_hunk *h;
443 	struct stat sb;
444 	long lineno = 0;
445 	FILE *orig;
446 	off_t copypos, pos;
447 	char *line = NULL;
448 	size_t linesize = 0;
449 	ssize_t linelen;
450 
451 	if (p->old == NULL) {				/* create */
452 		h = STAILQ_FIRST(&p->head);
453 		if (h == NULL || STAILQ_NEXT(h, entries) != NULL)
454 			return got_error(GOT_ERR_PATCH_MALFORMED);
455 		if (nop)
456 			return NULL;
457 		return apply_hunk(tmp, h, &lineno);
458 	}
459 
460 	if ((orig = fopen(path, "r")) == NULL) {
461 		err = got_error_from_errno2("fopen", path);
462 		goto done;
463 	}
464 
465 	if (fstat(fileno(orig), &sb) == -1) {
466 		err = got_error_from_errno("fstat");
467 		goto done;
468 	}
469 	*mode = sb.st_mode;
470 
471 	copypos = 0;
472 	STAILQ_FOREACH(h, &p->head, entries) {
473 		if (h->lines == NULL)
474 			break;
475 
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 (fseek(orig, pos, SEEK_SET) == -1) {
495 				err = got_error_from_errno("fseek");
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     const char *old, const char *new, struct got_patch *p, int nop,
579     struct patch_args *pa, got_cancel_cb cancel_cb, void *cancel_arg)
580 {
581 	const struct got_error *err = NULL;
582 	struct got_pathlist_head oldpaths, newpaths;
583 	struct got_pathlist_entry *pe;
584 	int file_renamed = 0;
585 	char *oldpath = NULL, *newpath = NULL;
586 	char *tmppath = NULL, *template = NULL, *parent = NULL;;
587 	FILE *tmp = NULL;
588 	mode_t mode = GOT_DEFAULT_FILE_MODE;
589 
590 	TAILQ_INIT(&oldpaths);
591 	TAILQ_INIT(&newpaths);
592 
593 	err = got_pathlist_insert(&pe, &oldpaths, old, NULL);
594 	if (err)
595 		goto done;
596 	err = got_pathlist_insert(&pe, &newpaths, new, NULL);
597 	if (err)
598 		goto done;
599 
600 	if (asprintf(&oldpath, "%s/%s", got_worktree_get_root_path(worktree),
601 	    old) == -1) {
602 		err = got_error_from_errno("asprintf");
603 		goto done;
604 	}
605 
606 	if (asprintf(&newpath, "%s/%s", got_worktree_get_root_path(worktree),
607 	    new) == -1) {
608 		err = got_error_from_errno("asprintf");
609 		goto done;
610 	}
611 
612 	file_renamed = strcmp(oldpath, newpath);
613 
614 	if (asprintf(&template, "%s/got-patch",
615 	    got_worktree_get_root_path(worktree)) == -1) {
616 		err = got_error_from_errno(template);
617 		goto done;
618 	}
619 
620 	if (!nop)
621 		err = got_opentemp_named(&tmppath, &tmp, template);
622 	if (err)
623 		goto done;
624 	err = patch_file(p, oldpath, tmp, nop, &mode);
625 	if (err)
626 		goto done;
627 
628 	if (nop)
629 		goto done;
630 
631 	if (p->old != NULL && p->new == NULL) {
632 		err = got_worktree_schedule_delete(worktree, &oldpaths,
633 		    0, NULL, patch_delete, pa, repo, 0, 0);
634 		goto done;
635 	}
636 
637 	if (fchmod(fileno(tmp), mode) == -1) {
638 		err = got_error_from_errno2("chmod", tmppath);
639 		goto done;
640 	}
641 
642 	if (rename(tmppath, newpath) == -1) {
643 		if (errno != ENOENT) {
644 			err = got_error_from_errno3("rename", tmppath,
645 			    newpath);
646 			goto done;
647 		}
648 
649 		err = got_path_dirname(&parent, newpath);
650 		if (err != NULL)
651 			goto done;
652 		err = got_path_mkdir(parent);
653 		if (err != NULL)
654 			goto done;
655 		if (rename(tmppath, newpath) == -1) {
656 			err = got_error_from_errno3("rename", tmppath,
657 			    newpath);
658 			goto done;
659 		}
660 	}
661 
662 	if (file_renamed) {
663 		err = got_worktree_schedule_delete(worktree, &oldpaths,
664 		    0, NULL, patch_delete, pa, repo, 0, 0);
665 		if (err == NULL)
666 			err = got_worktree_schedule_add(worktree, &newpaths,
667 			    patch_add, pa, repo, 1);
668 		if (err)
669 			unlink(newpath);
670 	} else if (p->old == NULL) {
671 		err = got_worktree_schedule_add(worktree, &newpaths,
672 		    patch_add, pa, repo, 1);
673 		if (err)
674 			unlink(newpath);
675 	} else
676 		err = report_progress(pa, old, new, GOT_STATUS_MODIFY, NULL);
677 
678 done:
679 	got_pathlist_free(&oldpaths);
680 	got_pathlist_free(&newpaths);
681 	free(parent);
682 	free(template);
683 	if (tmppath != NULL)
684 		unlink(tmppath);
685 	free(tmppath);
686 	free(oldpath);
687 	free(newpath);
688 	return err;
689 }
690 
691 static void
692 reverse_patch(struct got_patch *p)
693 {
694 	struct got_patch_hunk *h;
695 	size_t i;
696 	long tmp;
697 
698 	STAILQ_FOREACH(h, &p->head, entries) {
699 		tmp = h->old_from;
700 		h->old_from = h->new_from;
701 		h->new_from = tmp;
702 
703 		tmp = h->old_lines;
704 		h->old_lines = h->new_lines;
705 		h->new_lines = tmp;
706 
707 		tmp = h->old_nonl;
708 		h->old_nonl = h->new_nonl;
709 		h->new_nonl = tmp;
710 
711 		for (i = 0; i < h->len; ++i) {
712 			if (*h->lines[i] == '+')
713 				*h->lines[i] = '-';
714 			else if (*h->lines[i] == '-')
715 				*h->lines[i] = '+';
716 		}
717 	}
718 }
719 
720 const struct got_error *
721 got_patch(int fd, struct got_worktree *worktree, struct got_repository *repo,
722     int nop, int strip, int reverse, got_patch_progress_cb progress_cb,
723     void *progress_arg, got_cancel_cb cancel_cb, void *cancel_arg)
724 {
725 	const struct got_error *err = NULL;
726 	struct got_fileindex *fileindex = NULL;
727 	char *oldpath, *newpath;
728 	struct imsgbuf *ibuf;
729 	int imsg_fds[2] = {-1, -1};
730 	int done = 0, failed = 0;
731 	pid_t pid;
732 
733 	ibuf = calloc(1, sizeof(*ibuf));
734 	if (ibuf == NULL) {
735 		err = got_error_from_errno("calloc");
736 		goto done;
737 	}
738 
739 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
740 		err = got_error_from_errno("socketpair");
741 		goto done;
742 	}
743 
744 	pid = fork();
745 	if (pid == -1) {
746 		err = got_error_from_errno("fork");
747 		goto done;
748 	} else if (pid == 0) {
749 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PATCH,
750 		    NULL);
751 		/* not reached */
752 	}
753 
754 	if (close(imsg_fds[1]) == -1) {
755 		err = got_error_from_errno("close");
756 		goto done;
757 	}
758 	imsg_fds[1] = -1;
759 	imsg_init(ibuf, imsg_fds[0]);
760 
761 	err = send_patch(ibuf, fd);
762 	fd = -1;
763 	if (err)
764 		goto done;
765 
766 	err = got_worktree_patch_prepare(&fileindex, worktree);
767 	if (err)
768 		goto done;
769 
770 	while (!done && err == NULL) {
771 		struct got_patch p;
772 		struct patch_args pa;
773 
774 		pa.progress_cb = progress_cb;
775 		pa.progress_arg = progress_arg;
776 		pa.head = &p.head;
777 
778 		err = recv_patch(ibuf, &done, &p, strip);
779 		if (err || done)
780 			break;
781 
782 		if (reverse)
783 			reverse_patch(&p);
784 
785 		err = got_worktree_patch_check_path(p.old, p.new, &oldpath,
786 		    &newpath, worktree, repo, fileindex);
787 		if (err == NULL)
788 			err = apply_patch(worktree, repo, oldpath, newpath,
789 			    &p, nop, &pa, cancel_cb, cancel_arg);
790 		if (err != NULL) {
791 			failed = 1;
792 			/* recoverable errors */
793 			if (err->code == GOT_ERR_FILE_STATUS ||
794 			    (err->code == GOT_ERR_ERRNO && errno == ENOENT))
795 				err = report_progress(&pa, p.old, p.new,
796 				    GOT_STATUS_CANNOT_UPDATE, err);
797 			else if (err->code == GOT_ERR_HUNK_FAILED)
798 				err = report_progress(&pa, p.old, p.new,
799 				    GOT_STATUS_CANNOT_UPDATE, NULL);
800 		}
801 
802 		free(oldpath);
803 		free(newpath);
804 		patch_free(&p);
805 
806 		if (err)
807 			break;
808 	}
809 
810 done:
811 	if (fileindex)
812 		got_worktree_patch_complete(fileindex);
813 	if (fd != -1 && close(fd) == -1 && err == NULL)
814 		err = got_error_from_errno("close");
815 	if (ibuf != NULL)
816 		imsg_clear(ibuf);
817 	if (imsg_fds[0] != -1 && close(imsg_fds[0]) == -1 && err == NULL)
818 		err = got_error_from_errno("close");
819 	if (imsg_fds[1] != -1 && close(imsg_fds[1]) == -1 && err == NULL)
820 		err = got_error_from_errno("close");
821 	if (err == NULL && failed)
822 		err = got_error(GOT_ERR_PATCH_FAILED);
823 	return err;
824 }