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Date:: Thu Jul 7 22:16:43 2022 UTC
Message:: use got_privsep_flush_imsg instead of reinventing it ok stsp@
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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/socket.h>
25 #include <sys/stat.h>
26 #include <sys/uio.h>
27 
28 #include <ctype.h>
29 #include <errno.h>
30 #include <limits.h>
31 #include <stdint.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <unistd.h>
36 
37 #include "got_error.h"
38 #include "got_object.h"
39 #include "got_path.h"
40 #include "got_reference.h"
41 #include "got_cancel.h"
42 #include "got_worktree.h"
43 #include "got_repository.h"
44 #include "got_opentemp.h"
45 #include "got_patch.h"
46 #include "got_diff.h"
47 
48 #include "got_lib_delta.h"
49 #include "got_lib_diff.h"
50 #include "got_lib_object.h"
51 #include "got_lib_privsep.h"
52 #include "got_lib_sha1.h"
53 
54 #define MIN(a, b) ((a) < (b) ? (a) : (b))
55 
56 struct got_patch_hunk {
57 	STAILQ_ENTRY(got_patch_hunk) entries;
58 	const struct got_error *err;
59 	int	ws_mangled;
60 	int	offset;
61 	int	old_nonl;
62 	int	new_nonl;
63 	int	old_from;
64 	int	old_lines;
65 	int	new_from;
66 	int	new_lines;
67 	size_t	len;
68 	size_t	cap;
69 	char	**lines;
70 };
71 
72 STAILQ_HEAD(got_patch_hunk_head, got_patch_hunk);
73 struct got_patch {
74 	char	*old;
75 	char	*new;
76 	char	 cid[41];
77 	char	 blob[41];
78 	struct got_patch_hunk_head head;
79 };
80 
81 struct patch_args {
82 	got_patch_progress_cb progress_cb;
83 	void	*progress_arg;
84 	struct got_patch_hunk_head *head;
85 };
86 
87 static const struct got_error *
88 send_patch(struct imsgbuf *ibuf, int fd)
89 {
90 	const struct got_error *err = NULL;
91 
92 	if (imsg_compose(ibuf, GOT_IMSG_PATCH_FILE, 0, 0, fd,
93 	    NULL, 0) == -1) {
94 		err = got_error_from_errno(
95 		    "imsg_compose GOT_IMSG_PATCH_FILE");
96 		close(fd);
97 		return err;
98 	}
99 
100 	return got_privsep_flush_imsg(ibuf);
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 	    patch.cid[sizeof(patch.cid)-1] != '\0' ||
185 	    patch.blob[sizeof(patch.blob)-1] != '\0') {
186 		err = got_error(GOT_ERR_PRIVSEP_LEN);
187 		goto done;
188 	}
189 
190 	if (*patch.cid != '\0')
191 		strlcpy(p->cid, patch.cid, sizeof(p->cid));
192 
193 	if (*patch.blob != '\0')
194 		strlcpy(p->blob, patch.blob, sizeof(p->blob));
195 
196 	/* automatically set strip=1 for git-style diffs */
197 	if (strip == -1 && patch.git &&
198 	    (*patch.old == '\0' || !strncmp(patch.old, "a/", 2)) &&
199 	    (*patch.new == '\0' || !strncmp(patch.new, "b/", 2)))
200 		strip = 1;
201 
202 	/* prefer the new name if not /dev/null for not git-style diffs */
203 	if (!patch.git && *patch.new != '\0' && *patch.old != '\0') {
204 		err = got_path_strip(&p->old, patch.new, strip);
205 		if (err)
206 			goto done;
207 	} else if (*patch.old != '\0') {
208 		err = got_path_strip(&p->old, patch.old, strip);
209 		if (err)
210 			goto done;
211 	}
212 
213 	if (*patch.new != '\0') {
214 		err = got_path_strip(&p->new, patch.new, strip);
215 		if (err)
216 			goto done;
217 	}
218 
219 	if (p->old == NULL && p->new == NULL) {
220 		err = got_error(GOT_ERR_PATCH_MALFORMED);
221 		goto done;
222 	}
223 
224 	imsg_free(&imsg);
225 
226 	for (;;) {
227 		char *t;
228 
229 		err = got_privsep_recv_imsg(&imsg, ibuf, 0);
230 		if (err) {
231 			patch_free(p);
232 			return err;
233 		}
234 
235 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
236 		switch (imsg.hdr.type) {
237 		case GOT_IMSG_PATCH_DONE:
238 			if (h != NULL && h->len == 0)
239 				err = got_error(GOT_ERR_PATCH_MALFORMED);
240 			goto done;
241 		case GOT_IMSG_PATCH_HUNK:
242 			if (h != NULL &&
243 			    (h->len == 0 || h->old_nonl || h->new_nonl)) {
244 				err = got_error(GOT_ERR_PATCH_MALFORMED);
245 				goto done;
246 			}
247 			lastmode = -1;
248 			if (datalen != sizeof(hdr)) {
249 				err = got_error(GOT_ERR_PRIVSEP_LEN);
250 				goto done;
251 			}
252 			memcpy(&hdr, imsg.data, sizeof(hdr));
253 			if (hdr.oldfrom < 0 || hdr.newfrom < 0) {
254 				err = got_error(GOT_ERR_PRIVSEP_LEN);
255 				goto done;
256 			}
257 			if ((h = calloc(1, sizeof(*h))) == NULL) {
258 				err = got_error_from_errno("calloc");
259 				goto done;
260 			}
261 			h->old_from = hdr.oldfrom;
262 			h->old_lines = hdr.oldlines;
263 			h->new_from = hdr.newfrom;
264 			h->new_lines = hdr.newlines;
265 			STAILQ_INSERT_TAIL(&p->head, h, entries);
266 			break;
267 		case GOT_IMSG_PATCH_LINE:
268 			if (h == NULL) {
269 				err = got_error(GOT_ERR_PRIVSEP_MSG);
270 				goto done;
271 			}
272 			t = imsg.data;
273 			/* at least one char */
274 			if (datalen < 2 || t[datalen-1] != '\0') {
275 				err = got_error(GOT_ERR_PRIVSEP_MSG);
276 				goto done;
277 			}
278 			if (*t != ' ' && *t != '-' && *t != '+' &&
279 			    *t != '\\') {
280 				err = got_error(GOT_ERR_PRIVSEP_MSG);
281 				goto done;
282 			}
283 
284 			if (*t != '\\')
285 				err = pushline(h, t);
286 			else if (lastmode == '-')
287 				h->old_nonl = 1;
288 			else if (lastmode == '+')
289 				h->new_nonl = 1;
290 			else
291 				err = got_error(GOT_ERR_PATCH_MALFORMED);
292 
293 			if (err)
294 				goto done;
295 
296 			lastmode = *t;
297 			break;
298 		default:
299 			err = got_error(GOT_ERR_PRIVSEP_MSG);
300 			goto done;
301 		}
302 
303 		imsg_free(&imsg);
304 	}
305 
306 done:
307 	if (err)
308 		patch_free(p);
309 
310 	imsg_free(&imsg);
311 	return err;
312 }
313 
314 /*
315  * Copy data from orig starting at copypos until pos into tmp.
316  * If pos is -1, copy until EOF.
317  */
318 static const struct got_error *
319 copy(FILE *tmp, FILE *orig, off_t copypos, off_t pos)
320 {
321 	char buf[BUFSIZ];
322 	size_t len, r, w;
323 
324 	if (fseeko(orig, copypos, SEEK_SET) == -1)
325 		return got_error_from_errno("fseeko");
326 
327 	while (pos == -1 || copypos < pos) {
328 		len = sizeof(buf);
329 		if (pos > 0)
330 			len = MIN(len, (size_t)pos - copypos);
331 		r = fread(buf, 1, len, orig);
332 		if (r != len && ferror(orig))
333 			return got_error_from_errno("fread");
334 		w = fwrite(buf, 1, r, tmp);
335 		if (w != r)
336 			return got_error_from_errno("fwrite");
337 		copypos += len;
338 		if (r != len && feof(orig)) {
339 			if (pos == -1)
340 				return NULL;
341 			return got_error(GOT_ERR_HUNK_FAILED);
342 		}
343 	}
344 	return NULL;
345 }
346 
347 static const struct got_error *
348 locate_hunk(FILE *orig, struct got_patch_hunk *h, off_t *pos, int *lineno)
349 {
350 	const struct got_error *err = NULL;
351 	char *line = NULL;
352 	char mode = *h->lines[0];
353 	size_t linesize = 0;
354 	ssize_t linelen;
355 	off_t match = -1;
356 	int match_lineno = -1;
357 
358 	for (;;) {
359 		linelen = getline(&line, &linesize, orig);
360 		if (linelen == -1) {
361 			if (ferror(orig))
362 				err = got_error_from_errno("getline");
363 			else if (match == -1)
364 				err = got_error(GOT_ERR_HUNK_FAILED);
365 			break;
366 		}
367 		if (line[linelen - 1] == '\n')
368 			line[linelen - 1] = '\0';
369 		(*lineno)++;
370 
371 		if ((mode == ' ' && !strcmp(h->lines[0] + 1, line)) ||
372 		    (mode == '-' && !strcmp(h->lines[0] + 1, line)) ||
373 		    (mode == '+' && *lineno == h->old_from)) {
374 			match = ftello(orig);
375 			if (match == -1) {
376 				err = got_error_from_errno("ftello");
377 				break;
378 			}
379 			match -= linelen;
380 			match_lineno = (*lineno)-1;
381 		}
382 
383 		if (*lineno >= h->old_from && match != -1)
384 			break;
385 	}
386 
387 	if (err == NULL) {
388 		*pos = match;
389 		*lineno = match_lineno;
390 		if (fseeko(orig, match, SEEK_SET) == -1)
391 			err = got_error_from_errno("fseeko");
392 	}
393 
394 	free(line);
395 	return err;
396 }
397 
398 static int
399 linecmp(const char *a, const char *b, int *mangled)
400 {
401 	int c;
402 
403 	*mangled = 0;
404 	c = strcmp(a, b);
405 	if (c == 0)
406 		return c;
407 
408 	*mangled = 1;
409 	for (;;) {
410 		while (*a == '\t' || *a == ' ' || *a == '\f')
411 			a++;
412 		while (*b == '\t' || *b == ' ' || *b == '\f')
413 			b++;
414 		if (*a == '\0' || *a != *b)
415 			break;
416 		a++, b++;
417 	}
418 
419 	return *a - *b;
420 }
421 
422 static const struct got_error *
423 test_hunk(FILE *orig, struct got_patch_hunk *h)
424 {
425 	const struct got_error *err = NULL;
426 	char *line = NULL;
427 	size_t linesize = 0, i = 0;
428 	ssize_t linelen;
429 	int mangled;
430 
431 	for (i = 0; i < h->len; ++i) {
432 		switch (*h->lines[i]) {
433 		case '+':
434 			continue;
435 		case ' ':
436 		case '-':
437 			linelen = getline(&line, &linesize, orig);
438 			if (linelen == -1) {
439 				if (ferror(orig))
440 					err = got_error_from_errno("getline");
441 				else
442 					err = got_error(
443 					    GOT_ERR_HUNK_FAILED);
444 				goto done;
445 			}
446 			if (line[linelen - 1] == '\n')
447 				line[linelen - 1] = '\0';
448 			if (linecmp(h->lines[i] + 1, line, &mangled)) {
449 				err = got_error(GOT_ERR_HUNK_FAILED);
450 				goto done;
451 			}
452 			if (mangled)
453 				h->ws_mangled = 1;
454 			break;
455 		}
456 	}
457 
458 done:
459 	free(line);
460 	return err;
461 }
462 
463 static const struct got_error *
464 apply_hunk(FILE *orig, FILE *tmp, struct got_patch_hunk *h, int *lineno,
465     off_t from)
466 {
467 	const struct got_error *err = NULL;
468 	const char *t;
469 	size_t linesize = 0, i, new = 0;
470 	char *line = NULL;
471 	char mode;
472 	ssize_t linelen;
473 
474 	if (orig != NULL && fseeko(orig, from, SEEK_SET) == -1)
475 		return got_error_from_errno("fseeko");
476 
477 	for (i = 0; i < h->len; ++i) {
478 		switch (mode = *h->lines[i]) {
479 		case '-':
480 		case ' ':
481 			(*lineno)++;
482 			if (orig != NULL) {
483 				linelen = getline(&line, &linesize, orig);
484 				if (linelen == -1) {
485 					err = got_error_from_errno("getline");
486 					goto done;
487 				}
488 				if (line[linelen - 1] == '\n')
489 					line[linelen - 1] = '\0';
490 				t = line;
491 			} else
492 				t = h->lines[i] + 1;
493 			if (mode == '-')
494 				continue;
495 			if (fprintf(tmp, "%s\n", t) < 0) {
496 				err = got_error_from_errno("fprintf");
497 				goto done;
498 			}
499 			break;
500 		case '+':
501 			new++;
502 			if (fprintf(tmp, "%s", h->lines[i] + 1) < 0) {
503 				err = got_error_from_errno("fprintf");
504 				goto done;
505 			}
506 			if (new != h->new_lines || !h->new_nonl) {
507 				if (fprintf(tmp, "\n") < 0) {
508 					err = got_error_from_errno("fprintf");
509 					goto done;
510 				}
511 			}
512 			break;
513 		}
514 	}
515 
516 done:
517 	free(line);
518 	return err;
519 }
520 
521 static const struct got_error *
522 patch_file(struct got_patch *p, FILE *orig, FILE *tmp)
523 {
524 	const struct got_error *err = NULL;
525 	struct got_patch_hunk *h;
526 	struct stat sb;
527 	int lineno = 0;
528 	off_t copypos, pos;
529 	char *line = NULL;
530 	size_t linesize = 0;
531 	ssize_t linelen;
532 
533 	if (p->old == NULL) {				/* create */
534 		h = STAILQ_FIRST(&p->head);
535 		if (h == NULL || STAILQ_NEXT(h, entries) != NULL)
536 			return got_error(GOT_ERR_PATCH_MALFORMED);
537 		return apply_hunk(orig, tmp, h, &lineno, 0);
538 	}
539 
540 	if (fstat(fileno(orig), &sb) == -1)
541 		return got_error_from_errno("fstat");
542 
543 	copypos = 0;
544 	STAILQ_FOREACH(h, &p->head, entries) {
545 	tryagain:
546 		err = locate_hunk(orig, h, &pos, &lineno);
547 		if (err != NULL && err->code == GOT_ERR_HUNK_FAILED)
548 			h->err = err;
549 		if (err != NULL)
550 			return err;
551 		err = copy(tmp, orig, copypos, pos);
552 		if (err != NULL)
553 			return err;
554 		copypos = pos;
555 
556 		err = test_hunk(orig, h);
557 		if (err != NULL && err->code == GOT_ERR_HUNK_FAILED) {
558 			/*
559 			 * try to apply the hunk again starting the search
560 			 * after the previous partial match.
561 			 */
562 			if (fseeko(orig, pos, SEEK_SET) == -1)
563 				return got_error_from_errno("fseeko");
564 			linelen = getline(&line, &linesize, orig);
565 			if (linelen == -1)
566 				return got_error_from_errno("getline");
567 			lineno++;
568 			goto tryagain;
569 		}
570 		if (err != NULL)
571 			return err;
572 
573 		if (lineno + 1 != h->old_from)
574 			h->offset = lineno + 1 - h->old_from;
575 
576 		err = apply_hunk(orig, tmp, h, &lineno, pos);
577 		if (err != NULL)
578 			return err;
579 
580 		copypos = ftello(orig);
581 		if (copypos == -1)
582 			return got_error_from_errno("ftello");
583 	}
584 
585 	if (p->new == NULL && sb.st_size != copypos) {
586 		h = STAILQ_FIRST(&p->head);
587 		h->err = got_error(GOT_ERR_HUNK_FAILED);
588 		err = h->err;
589 	} else if (!feof(orig))
590 		err = copy(tmp, orig, copypos, -1);
591 
592 	return err;
593 }
594 
595 static const struct got_error *
596 report_progress(struct patch_args *pa, const char *old, const char *new,
597     unsigned char status, const struct got_error *orig_error)
598 {
599 	const struct got_error *err;
600 	struct got_patch_hunk *h;
601 
602 	err = pa->progress_cb(pa->progress_arg, old, new, status,
603 	    orig_error, 0, 0, 0, 0, 0, 0, NULL);
604 	if (err)
605 		return err;
606 
607 	STAILQ_FOREACH(h, pa->head, entries) {
608 		if (h->offset == 0 && !h->ws_mangled && h->err == NULL)
609 			continue;
610 
611 		err = pa->progress_cb(pa->progress_arg, old, new, 0, NULL,
612 		    h->old_from, h->old_lines, h->new_from, h->new_lines,
613 		    h->offset, h->ws_mangled, h->err);
614 		if (err)
615 			return err;
616 	}
617 
618 	return NULL;
619 }
620 
621 static const struct got_error *
622 patch_delete(void *arg, unsigned char status, unsigned char staged_status,
623     const char *path)
624 {
625 	return report_progress(arg, path, NULL, status, NULL);
626 }
627 
628 static const struct got_error *
629 patch_add(void *arg, unsigned char status, const char *path)
630 {
631 	return report_progress(arg, NULL, path, status, NULL);
632 }
633 
634 static const struct got_error *
635 open_blob(char **path, FILE **fp, const char *blobid,
636     struct got_repository *repo)
637 {
638 	const struct got_error *err = NULL;
639 	struct got_blob_object *blob = NULL;
640 	struct got_object_id id, *idptr, *matched_id = NULL;
641 	int fd = -1;
642 
643 	*fp = NULL;
644 	*path = NULL;
645 
646 	if (strlen(blobid) != SHA1_DIGEST_STRING_LENGTH - 1) {
647 		err = got_repo_match_object_id(&matched_id, NULL, blobid,
648 		    GOT_OBJ_TYPE_BLOB, NULL /* do not resolve tags */,
649 		    repo);
650 		if (err)
651 			return err;
652 		idptr = matched_id;
653 	} else {
654 		if (!got_parse_sha1_digest(id.sha1, blobid))
655 			return got_error(GOT_ERR_BAD_OBJ_ID_STR);
656 		idptr = &id;
657 	}
658 
659 	fd = got_opentempfd();
660 	if (fd == -1) {
661 		err = got_error_from_errno("got_opentempfd");
662 		goto done;
663 	}
664 
665 	err = got_object_open_as_blob(&blob, repo, idptr, 8192, fd);
666 	if (err)
667 		goto done;
668 
669 	err = got_opentemp_named(path, fp, GOT_TMPDIR_STR "/got-patch-blob");
670 	if (err)
671 		goto done;
672 
673 	err = got_object_blob_dump_to_file(NULL, NULL, NULL, *fp, blob);
674 	if (err)
675 		goto done;
676 
677 done:
678 	if (fd != -1 && close(fd) == -1 && err == NULL)
679 		err = got_error_from_errno("close");
680 	if (blob)
681 		got_object_blob_close(blob);
682 	if (matched_id != NULL)
683 		free(matched_id);
684 	if (err) {
685 		if (*fp != NULL)
686 			fclose(*fp);
687 		if (*path != NULL)
688 			unlink(*path);
689 		free(*path);
690 		*fp = NULL;
691 		*path = NULL;
692 	}
693 	return err;
694 }
695 
696 static const struct got_error *
697 apply_patch(int *overlapcnt, struct got_worktree *worktree,
698     struct got_repository *repo, struct got_fileindex *fileindex,
699     const char *old, const char *new, struct got_patch *p, int nop,
700     struct patch_args *pa, got_cancel_cb cancel_cb, void *cancel_arg)
701 {
702 	const struct got_error *err = NULL;
703 	struct stat sb;
704 	int do_merge = 0, file_renamed = 0;
705 	char *oldlabel = NULL, *newlabel = NULL, *anclabel = NULL;
706 	char *oldpath = NULL, *newpath = NULL;
707 	char *tmppath = NULL, *template = NULL, *parent = NULL;
708 	char *apath = NULL, *mergepath = NULL;
709 	FILE *oldfile = NULL, *tmpfile = NULL, *afile = NULL, *mergefile = NULL;
710 	int outfd;
711 	const char *outpath;
712 	mode_t mode = GOT_DEFAULT_FILE_MODE;
713 
714 	*overlapcnt = 0;
715 
716 	/* don't run the diff3 merge on creations/deletions */
717 	if (*p->blob != '\0' && p->old != NULL && p->new != NULL) {
718 		err = open_blob(&apath, &afile, p->blob, repo);
719 		/*
720 		 * ignore failures to open this blob, we might have
721 		 * parsed gibberish.
722 		 */
723 		if (err && !(err->code == GOT_ERR_ERRNO && errno == ENOENT) &&
724 		    err->code != GOT_ERR_NO_OBJ)
725 			return err;
726 		else if (err == NULL)
727 			do_merge = 1;
728 		err = NULL;
729 	}
730 
731 	if (asprintf(&oldpath, "%s/%s", got_worktree_get_root_path(worktree),
732 	    old) == -1) {
733 		err = got_error_from_errno("asprintf");
734 		goto done;
735 	}
736 
737 	if (asprintf(&newpath, "%s/%s", got_worktree_get_root_path(worktree),
738 	    new) == -1) {
739 		err = got_error_from_errno("asprintf");
740 		goto done;
741 	}
742 
743 	file_renamed = strcmp(oldpath, newpath);
744 
745 	if (asprintf(&template, "%s/got-patch",
746 	    got_worktree_get_root_path(worktree)) == -1) {
747 		err = got_error_from_errno(template);
748 		goto done;
749 	}
750 
751 	if (p->old != NULL) {
752 		if ((oldfile = fopen(oldpath, "r")) == NULL) {
753 			err = got_error_from_errno2("open", oldpath);
754 			goto done;
755 		}
756 		if (fstat(fileno(oldfile), &sb) == -1) {
757 			err = got_error_from_errno2("fstat", oldpath);
758 			goto done;
759 		}
760 		mode = sb.st_mode;
761 	}
762 
763 	err = got_opentemp_named(&tmppath, &tmpfile, template);
764 	if (err)
765 		goto done;
766 	outpath = tmppath;
767 	outfd = fileno(tmpfile);
768 	err = patch_file(p, afile != NULL ? afile : oldfile, tmpfile);
769 	if (err)
770 		goto done;
771 
772 	if (do_merge) {
773 		const char *type, *id;
774 
775 		if (fseeko(afile, 0, SEEK_SET) == -1 ||
776 		    fseeko(oldfile, 0, SEEK_SET) == -1 ||
777 		    fseeko(tmpfile, 0, SEEK_SET) == -1) {
778 			err = got_error_from_errno("fseeko");
779 			goto done;
780 		}
781 
782 		if (asprintf(&oldlabel, "--- %s", p->old) == -1) {
783 			err = got_error_from_errno("asprintf");
784 			oldlabel = NULL;
785 			goto done;
786 		}
787 
788 		if (asprintf(&newlabel, "+++ %s", p->new) == -1) {
789 			err = got_error_from_errno("asprintf");
790 			newlabel = NULL;
791 			goto done;
792 		}
793 
794 		if (*p->cid != '\0') {
795 			type = "commit";
796 			id = p->cid;
797 		} else {
798 			type = "blob";
799 			id = p->blob;
800 		}
801 
802 		if (asprintf(&anclabel, "%s %s", type, id) == -1) {
803 			err = got_error_from_errno("asprintf");
804 			anclabel = NULL;
805 			goto done;
806 		}
807 
808 		err = got_opentemp_named(&mergepath, &mergefile, template);
809 		if (err)
810 			goto done;
811 		outpath = mergepath;
812 		outfd = fileno(mergefile);
813 
814 		err = got_merge_diff3(overlapcnt, outfd, tmpfile, afile,
815 		    oldfile, oldlabel, anclabel, newlabel,
816 		    GOT_DIFF_ALGORITHM_PATIENCE);
817 		if (err)
818 			goto done;
819 	}
820 
821 	if (nop)
822 		goto done;
823 
824 	if (p->old != NULL && p->new == NULL) {
825 		err = got_worktree_patch_schedule_rm(old, repo, worktree,
826 		    fileindex, patch_delete, pa);
827 		goto done;
828 	}
829 
830 	if (fchmod(outfd, mode) == -1) {
831 		err = got_error_from_errno2("chmod", tmppath);
832 		goto done;
833 	}
834 
835 	if (rename(outpath, newpath) == -1) {
836 		if (errno != ENOENT) {
837 			err = got_error_from_errno3("rename", outpath,
838 			    newpath);
839 			goto done;
840 		}
841 
842 		err = got_path_dirname(&parent, newpath);
843 		if (err != NULL)
844 			goto done;
845 		err = got_path_mkdir(parent);
846 		if (err != NULL)
847 			goto done;
848 		if (rename(outpath, newpath) == -1) {
849 			err = got_error_from_errno3("rename", outpath,
850 			    newpath);
851 			goto done;
852 		}
853 	}
854 
855 	if (file_renamed) {
856 		err = got_worktree_patch_schedule_rm(old, repo, worktree,
857 		    fileindex, patch_delete, pa);
858 		if (err == NULL)
859 			err = got_worktree_patch_schedule_add(new, repo,
860 			    worktree, fileindex, patch_add,
861 			    pa);
862 		if (err)
863 			unlink(newpath);
864 	} else if (p->old == NULL) {
865 		err = got_worktree_patch_schedule_add(new, repo, worktree,
866 		    fileindex, patch_add, pa);
867 		if (err)
868 			unlink(newpath);
869 	} else if (*overlapcnt != 0)
870 		err = report_progress(pa, old, new, GOT_STATUS_CONFLICT, NULL);
871 	else if (do_merge)
872 		err = report_progress(pa, old, new, GOT_STATUS_MERGE, NULL);
873 	else
874 		err = report_progress(pa, old, new, GOT_STATUS_MODIFY, NULL);
875 
876 done:
877 	free(parent);
878 	free(template);
879 
880 	if (tmppath != NULL)
881 		unlink(tmppath);
882 	if (tmpfile != NULL && fclose(tmpfile) == EOF && err == NULL)
883 		err = got_error_from_errno("fclose");
884 	free(tmppath);
885 
886 	free(oldpath);
887 	if (oldfile != NULL && fclose(oldfile) == EOF && err == NULL)
888 		err = got_error_from_errno("fclose");
889 
890 	if (apath != NULL)
891 		unlink(apath);
892 	if (afile != NULL && fclose(afile) == EOF && err == NULL)
893 		err = got_error_from_errno("fclose");
894 	free(apath);
895 
896 	if (mergepath != NULL)
897 		unlink(mergepath);
898 	if (mergefile != NULL && fclose(mergefile) == EOF && err == NULL)
899 		err = got_error_from_errno("fclose");
900 	free(mergepath);
901 
902 	free(newpath);
903 	free(oldlabel);
904 	free(newlabel);
905 	free(anclabel);
906 	return err;
907 }
908 
909 static void
910 reverse_patch(struct got_patch *p)
911 {
912 	struct got_patch_hunk *h;
913 	size_t i;
914 	int tmp;
915 
916 	STAILQ_FOREACH(h, &p->head, entries) {
917 		tmp = h->old_from;
918 		h->old_from = h->new_from;
919 		h->new_from = tmp;
920 
921 		tmp = h->old_lines;
922 		h->old_lines = h->new_lines;
923 		h->new_lines = tmp;
924 
925 		tmp = h->old_nonl;
926 		h->old_nonl = h->new_nonl;
927 		h->new_nonl = tmp;
928 
929 		for (i = 0; i < h->len; ++i) {
930 			if (*h->lines[i] == '+')
931 				*h->lines[i] = '-';
932 			else if (*h->lines[i] == '-')
933 				*h->lines[i] = '+';
934 		}
935 	}
936 }
937 
938 const struct got_error *
939 got_patch(int fd, struct got_worktree *worktree, struct got_repository *repo,
940     int nop, int strip, int reverse, got_patch_progress_cb progress_cb,
941     void *progress_arg, got_cancel_cb cancel_cb, void *cancel_arg)
942 {
943 	const struct got_error *err = NULL, *complete_err = NULL;
944 	struct got_fileindex *fileindex = NULL;
945 	char *fileindex_path = NULL;
946 	char *oldpath, *newpath;
947 	struct imsgbuf *ibuf;
948 	int imsg_fds[2] = {-1, -1};
949 	int overlapcnt, done = 0, failed = 0;
950 	pid_t pid;
951 
952 	ibuf = calloc(1, sizeof(*ibuf));
953 	if (ibuf == NULL) {
954 		err = got_error_from_errno("calloc");
955 		goto done;
956 	}
957 
958 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
959 		err = got_error_from_errno("socketpair");
960 		goto done;
961 	}
962 
963 	pid = fork();
964 	if (pid == -1) {
965 		err = got_error_from_errno("fork");
966 		goto done;
967 	} else if (pid == 0) {
968 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PATCH,
969 		    NULL);
970 		/* not reached */
971 	}
972 
973 	if (close(imsg_fds[1]) == -1) {
974 		err = got_error_from_errno("close");
975 		goto done;
976 	}
977 	imsg_fds[1] = -1;
978 	imsg_init(ibuf, imsg_fds[0]);
979 
980 	err = send_patch(ibuf, fd);
981 	fd = -1;
982 	if (err)
983 		goto done;
984 
985 	err = got_worktree_patch_prepare(&fileindex, &fileindex_path,
986 	    worktree);
987 	if (err)
988 		goto done;
989 
990 	while (!done && err == NULL) {
991 		struct got_patch p;
992 		struct patch_args pa;
993 
994 		pa.progress_cb = progress_cb;
995 		pa.progress_arg = progress_arg;
996 		pa.head = &p.head;
997 
998 		err = recv_patch(ibuf, &done, &p, strip);
999 		if (err || done)
1000 			break;
1001 
1002 		if (reverse)
1003 			reverse_patch(&p);
1004 
1005 		err = got_worktree_patch_check_path(p.old, p.new, &oldpath,
1006 		    &newpath, worktree, repo, fileindex);
1007 		if (err == NULL)
1008 			err = apply_patch(&overlapcnt, worktree, repo,
1009 			    fileindex, oldpath, newpath, &p, nop, &pa,
1010 			    cancel_cb, cancel_arg);
1011 		if (err != NULL) {
1012 			failed = 1;
1013 			/* recoverable errors */
1014 			if (err->code == GOT_ERR_FILE_STATUS ||
1015 			    (err->code == GOT_ERR_ERRNO && errno == ENOENT))
1016 				err = report_progress(&pa, p.old, p.new,
1017 				    GOT_STATUS_CANNOT_UPDATE, err);
1018 			else if (err->code == GOT_ERR_HUNK_FAILED)
1019 				err = report_progress(&pa, p.old, p.new,
1020 				    GOT_STATUS_CANNOT_UPDATE, NULL);
1021 		}
1022 		if (overlapcnt != 0)
1023 			failed = 1;
1024 
1025 		free(oldpath);
1026 		free(newpath);
1027 		patch_free(&p);
1028 
1029 		if (err)
1030 			break;
1031 	}
1032 
1033 done:
1034 	if (fileindex != NULL)
1035 		complete_err = got_worktree_patch_complete(fileindex,
1036 		    fileindex_path);
1037 	if (complete_err && err == NULL)
1038 		err = complete_err;
1039 	free(fileindex_path);
1040 	if (fd != -1 && close(fd) == -1 && err == NULL)
1041 		err = got_error_from_errno("close");
1042 	if (ibuf != NULL)
1043 		imsg_clear(ibuf);
1044 	if (imsg_fds[0] != -1 && close(imsg_fds[0]) == -1 && err == NULL)
1045 		err = got_error_from_errno("close");
1046 	if (imsg_fds[1] != -1 && close(imsg_fds[1]) == -1 && err == NULL)
1047 		err = got_error_from_errno("close");
1048 	if (err == NULL && failed)
1049 		err = got_error(GOT_ERR_PATCH_FAILED);
1050 	return err;
1051 }