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Date:: Mon Jul 4 09:15:23 2022 UTC
Message:: check for specific chars instead of using isspace(3) Reminded by naddy and stsp; it was missing a cast to unsigned char to prevent issues on archs with signed chars and was too broad anyway. While here, drop an extra check immediately after. 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/queue.h>
25 #include <sys/socket.h>
26 #include <sys/stat.h>
27 #include <sys/uio.h>
28 
29 #include <ctype.h>
30 #include <errno.h>
31 #include <limits.h>
32 #include <sha1.h>
33 #include <stdint.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <unistd.h>
38 #include <imsg.h>
39 
40 #include "got_error.h"
41 #include "got_object.h"
42 #include "got_path.h"
43 #include "got_reference.h"
44 #include "got_cancel.h"
45 #include "got_worktree.h"
46 #include "got_repository.h"
47 #include "got_opentemp.h"
48 #include "got_patch.h"
49 #include "got_diff.h"
50 
51 #include "got_lib_delta.h"
52 #include "got_lib_diff.h"
53 #include "got_lib_object.h"
54 #include "got_lib_privsep.h"
55 #include "got_lib_sha1.h"
56 
57 #define MIN(a, b) ((a) < (b) ? (a) : (b))
58 
59 struct got_patch_hunk {
60 	STAILQ_ENTRY(got_patch_hunk) entries;
61 	const struct got_error *err;
62 	int	ws_mangled;
63 	int	offset;
64 	int	old_nonl;
65 	int	new_nonl;
66 	int	old_from;
67 	int	old_lines;
68 	int	new_from;
69 	int	new_lines;
70 	size_t	len;
71 	size_t	cap;
72 	char	**lines;
73 };
74 
75 STAILQ_HEAD(got_patch_hunk_head, got_patch_hunk);
76 struct got_patch {
77 	char	*old;
78 	char	*new;
79 	char	 cid[41];
80 	char	 blob[41];
81 	struct got_patch_hunk_head head;
82 };
83 
84 struct patch_args {
85 	got_patch_progress_cb progress_cb;
86 	void	*progress_arg;
87 	struct got_patch_hunk_head *head;
88 };
89 
90 static const struct got_error *
91 send_patch(struct imsgbuf *ibuf, int fd)
92 {
93 	const struct got_error *err = NULL;
94 
95 	if (imsg_compose(ibuf, GOT_IMSG_PATCH_FILE, 0, 0, fd,
96 	    NULL, 0) == -1) {
97 		err = got_error_from_errno(
98 		    "imsg_compose GOT_IMSG_PATCH_FILE");
99 		close(fd);
100 		return err;
101 	}
102 
103 	if (imsg_flush(ibuf) == -1) {
104 		err = got_error_from_errno("imsg_flush");
105 		imsg_clear(ibuf);
106 	}
107 
108 	return err;
109 }
110 
111 static void
112 patch_free(struct got_patch *p)
113 {
114 	struct got_patch_hunk *h;
115 	size_t i;
116 
117 	while (!STAILQ_EMPTY(&p->head)) {
118 		h = STAILQ_FIRST(&p->head);
119 		STAILQ_REMOVE_HEAD(&p->head, entries);
120 
121 		for (i = 0; i < h->len; ++i)
122 			free(h->lines[i]);
123 		free(h->lines);
124 		free(h);
125 	}
126 
127 	free(p->new);
128 	free(p->old);
129 
130 	memset(p, 0, sizeof(*p));
131 	STAILQ_INIT(&p->head);
132 }
133 
134 static const struct got_error *
135 pushline(struct got_patch_hunk *h, const char *line)
136 {
137 	void 	*t;
138 	size_t	 newcap;
139 
140 	if (h->len == h->cap) {
141 		if ((newcap = h->cap * 1.5) == 0)
142 			newcap = 16;
143 		t = recallocarray(h->lines, h->cap, newcap,
144 		    sizeof(h->lines[0]));
145 		if (t == NULL)
146 			return got_error_from_errno("recallocarray");
147 		h->lines = t;
148 		h->cap = newcap;
149 	}
150 
151 	if ((t = strdup(line)) == NULL)
152 		return got_error_from_errno("strdup");
153 
154 	h->lines[h->len++] = t;
155 	return NULL;
156 }
157 
158 static const struct got_error *
159 recv_patch(struct imsgbuf *ibuf, int *done, struct got_patch *p, int strip)
160 {
161 	const struct got_error *err = NULL;
162 	struct imsg imsg;
163 	struct got_imsg_patch_hunk hdr;
164 	struct got_imsg_patch patch;
165 	struct got_patch_hunk *h = NULL;
166 	size_t datalen;
167 	int lastmode = -1;
168 
169 	memset(p, 0, sizeof(*p));
170 	STAILQ_INIT(&p->head);
171 
172 	err = got_privsep_recv_imsg(&imsg, ibuf, 0);
173 	if (err)
174 		return err;
175 	if (imsg.hdr.type == GOT_IMSG_PATCH_EOF) {
176 		*done = 1;
177 		goto done;
178 	}
179 	if (imsg.hdr.type != GOT_IMSG_PATCH) {
180 		err = got_error(GOT_ERR_PRIVSEP_MSG);
181 		goto done;
182 	}
183 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
184 	if (datalen != sizeof(patch)) {
185 		err = got_error(GOT_ERR_PRIVSEP_LEN);
186 		goto done;
187 	}
188 	memcpy(&patch, imsg.data, sizeof(patch));
189 
190 	if (patch.old[sizeof(patch.old)-1] != '\0' ||
191 	    patch.new[sizeof(patch.new)-1] != '\0' ||
192 	    patch.cid[sizeof(patch.cid)-1] != '\0' ||
193 	    patch.blob[sizeof(patch.blob)-1] != '\0') {
194 		err = got_error(GOT_ERR_PRIVSEP_LEN);
195 		goto done;
196 	}
197 
198 	if (*patch.cid != '\0')
199 		strlcpy(p->cid, patch.cid, sizeof(p->cid));
200 
201 	if (*patch.blob != '\0')
202 		strlcpy(p->blob, patch.blob, sizeof(p->blob));
203 
204 	/* automatically set strip=1 for git-style diffs */
205 	if (strip == -1 && patch.git &&
206 	    (*patch.old == '\0' || !strncmp(patch.old, "a/", 2)) &&
207 	    (*patch.new == '\0' || !strncmp(patch.new, "b/", 2)))
208 		strip = 1;
209 
210 	/* prefer the new name if not /dev/null for not git-style diffs */
211 	if (!patch.git && *patch.new != '\0' && *patch.old != '\0') {
212 		err = got_path_strip(&p->old, patch.new, strip);
213 		if (err)
214 			goto done;
215 	} else if (*patch.old != '\0') {
216 		err = got_path_strip(&p->old, patch.old, strip);
217 		if (err)
218 			goto done;
219 	}
220 
221 	if (*patch.new != '\0') {
222 		err = got_path_strip(&p->new, patch.new, strip);
223 		if (err)
224 			goto done;
225 	}
226 
227 	if (p->old == NULL && p->new == NULL) {
228 		err = got_error(GOT_ERR_PATCH_MALFORMED);
229 		goto done;
230 	}
231 
232 	imsg_free(&imsg);
233 
234 	for (;;) {
235 		char *t;
236 
237 		err = got_privsep_recv_imsg(&imsg, ibuf, 0);
238 		if (err) {
239 			patch_free(p);
240 			return err;
241 		}
242 
243 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
244 		switch (imsg.hdr.type) {
245 		case GOT_IMSG_PATCH_DONE:
246 			if (h != NULL && h->len == 0)
247 				err = got_error(GOT_ERR_PATCH_MALFORMED);
248 			goto done;
249 		case GOT_IMSG_PATCH_HUNK:
250 			if (h != NULL &&
251 			    (h->len == 0 || h->old_nonl || h->new_nonl)) {
252 				err = got_error(GOT_ERR_PATCH_MALFORMED);
253 				goto done;
254 			}
255 			lastmode = -1;
256 			if (datalen != sizeof(hdr)) {
257 				err = got_error(GOT_ERR_PRIVSEP_LEN);
258 				goto done;
259 			}
260 			memcpy(&hdr, imsg.data, sizeof(hdr));
261 			if (hdr.oldfrom < 0 || hdr.newfrom < 0) {
262 				err = got_error(GOT_ERR_PRIVSEP_LEN);
263 				goto done;
264 			}
265 			if ((h = calloc(1, sizeof(*h))) == NULL) {
266 				err = got_error_from_errno("calloc");
267 				goto done;
268 			}
269 			h->old_from = hdr.oldfrom;
270 			h->old_lines = hdr.oldlines;
271 			h->new_from = hdr.newfrom;
272 			h->new_lines = hdr.newlines;
273 			STAILQ_INSERT_TAIL(&p->head, h, entries);
274 			break;
275 		case GOT_IMSG_PATCH_LINE:
276 			if (h == NULL) {
277 				err = got_error(GOT_ERR_PRIVSEP_MSG);
278 				goto done;
279 			}
280 			t = imsg.data;
281 			/* at least one char */
282 			if (datalen < 2 || t[datalen-1] != '\0') {
283 				err = got_error(GOT_ERR_PRIVSEP_MSG);
284 				goto done;
285 			}
286 			if (*t != ' ' && *t != '-' && *t != '+' &&
287 			    *t != '\\') {
288 				err = got_error(GOT_ERR_PRIVSEP_MSG);
289 				goto done;
290 			}
291 
292 			if (*t != '\\')
293 				err = pushline(h, t);
294 			else if (lastmode == '-')
295 				h->old_nonl = 1;
296 			else if (lastmode == '+')
297 				h->new_nonl = 1;
298 			else
299 				err = got_error(GOT_ERR_PATCH_MALFORMED);
300 
301 			if (err)
302 				goto done;
303 
304 			lastmode = *t;
305 			break;
306 		default:
307 			err = got_error(GOT_ERR_PRIVSEP_MSG);
308 			goto done;
309 		}
310 
311 		imsg_free(&imsg);
312 	}
313 
314 done:
315 	if (err)
316 		patch_free(p);
317 
318 	imsg_free(&imsg);
319 	return err;
320 }
321 
322 /*
323  * Copy data from orig starting at copypos until pos into tmp.
324  * If pos is -1, copy until EOF.
325  */
326 static const struct got_error *
327 copy(FILE *tmp, FILE *orig, off_t copypos, off_t pos)
328 {
329 	char buf[BUFSIZ];
330 	size_t len, r, w;
331 
332 	if (fseeko(orig, copypos, SEEK_SET) == -1)
333 		return got_error_from_errno("fseeko");
334 
335 	while (pos == -1 || copypos < pos) {
336 		len = sizeof(buf);
337 		if (pos > 0)
338 			len = MIN(len, (size_t)pos - copypos);
339 		r = fread(buf, 1, len, orig);
340 		if (r != len && ferror(orig))
341 			return got_error_from_errno("fread");
342 		w = fwrite(buf, 1, r, tmp);
343 		if (w != r)
344 			return got_error_from_errno("fwrite");
345 		copypos += len;
346 		if (r != len && feof(orig)) {
347 			if (pos == -1)
348 				return NULL;
349 			return got_error(GOT_ERR_HUNK_FAILED);
350 		}
351 	}
352 	return NULL;
353 }
354 
355 static const struct got_error *
356 locate_hunk(FILE *orig, struct got_patch_hunk *h, off_t *pos, int *lineno)
357 {
358 	const struct got_error *err = NULL;
359 	char *line = NULL;
360 	char mode = *h->lines[0];
361 	size_t linesize = 0;
362 	ssize_t linelen;
363 	off_t match = -1;
364 	int match_lineno = -1;
365 
366 	for (;;) {
367 		linelen = getline(&line, &linesize, orig);
368 		if (linelen == -1) {
369 			if (ferror(orig))
370 				err = got_error_from_errno("getline");
371 			else if (match == -1)
372 				err = got_error(GOT_ERR_HUNK_FAILED);
373 			break;
374 		}
375 		if (line[linelen - 1] == '\n')
376 			line[linelen - 1] = '\0';
377 		(*lineno)++;
378 
379 		if ((mode == ' ' && !strcmp(h->lines[0] + 1, line)) ||
380 		    (mode == '-' && !strcmp(h->lines[0] + 1, line)) ||
381 		    (mode == '+' && *lineno == h->old_from)) {
382 			match = ftello(orig);
383 			if (match == -1) {
384 				err = got_error_from_errno("ftello");
385 				break;
386 			}
387 			match -= linelen;
388 			match_lineno = (*lineno)-1;
389 		}
390 
391 		if (*lineno >= h->old_from && match != -1)
392 			break;
393 	}
394 
395 	if (err == NULL) {
396 		*pos = match;
397 		*lineno = match_lineno;
398 		if (fseeko(orig, match, SEEK_SET) == -1)
399 			err = got_error_from_errno("fseeko");
400 	}
401 
402 	free(line);
403 	return err;
404 }
405 
406 static int
407 linecmp(const char *a, const char *b, int *mangled)
408 {
409 	int c;
410 
411 	*mangled = 0;
412 	c = strcmp(a, b);
413 	if (c == 0)
414 		return c;
415 
416 	*mangled = 1;
417 	for (;;) {
418 		while (*a == '\t' || *a == ' ' || *a == '\f')
419 			a++;
420 		while (*b == '\t' || *b == ' ' || *b == '\f')
421 			b++;
422 		if (*a == '\0' || *a != *b)
423 			break;
424 		a++, b++;
425 	}
426 
427 	return *a - *b;
428 }
429 
430 static const struct got_error *
431 test_hunk(FILE *orig, struct got_patch_hunk *h)
432 {
433 	const struct got_error *err = NULL;
434 	char *line = NULL;
435 	size_t linesize = 0, i = 0;
436 	ssize_t linelen;
437 	int mangled;
438 
439 	for (i = 0; i < h->len; ++i) {
440 		switch (*h->lines[i]) {
441 		case '+':
442 			continue;
443 		case ' ':
444 		case '-':
445 			linelen = getline(&line, &linesize, orig);
446 			if (linelen == -1) {
447 				if (ferror(orig))
448 					err = got_error_from_errno("getline");
449 				else
450 					err = got_error(
451 					    GOT_ERR_HUNK_FAILED);
452 				goto done;
453 			}
454 			if (line[linelen - 1] == '\n')
455 				line[linelen - 1] = '\0';
456 			if (linecmp(h->lines[i] + 1, line, &mangled)) {
457 				err = got_error(GOT_ERR_HUNK_FAILED);
458 				goto done;
459 			}
460 			if (mangled)
461 				h->ws_mangled = 1;
462 			break;
463 		}
464 	}
465 
466 done:
467 	free(line);
468 	return err;
469 }
470 
471 static const struct got_error *
472 apply_hunk(FILE *orig, FILE *tmp, struct got_patch_hunk *h, int *lineno,
473     off_t from)
474 {
475 	const struct got_error *err = NULL;
476 	const char *t;
477 	size_t linesize = 0, i, new = 0;
478 	char *line = NULL;
479 	char mode;
480 	ssize_t linelen;
481 
482 	if (orig != NULL && fseeko(orig, from, SEEK_SET) == -1)
483 		return got_error_from_errno("fseeko");
484 
485 	for (i = 0; i < h->len; ++i) {
486 		switch (mode = *h->lines[i]) {
487 		case '-':
488 		case ' ':
489 			(*lineno)++;
490 			if (orig != NULL) {
491 				linelen = getline(&line, &linesize, orig);
492 				if (linelen == -1) {
493 					err = got_error_from_errno("getline");
494 					goto done;
495 				}
496 				if (line[linelen - 1] == '\n')
497 					line[linelen - 1] = '\0';
498 				t = line;
499 			} else
500 				t = h->lines[i] + 1;
501 			if (mode == '-')
502 				continue;
503 			if (fprintf(tmp, "%s\n", t) < 0) {
504 				err = got_error_from_errno("fprintf");
505 				goto done;
506 			}
507 			break;
508 		case '+':
509 			new++;
510 			if (fprintf(tmp, "%s", h->lines[i] + 1) < 0) {
511 				err = got_error_from_errno("fprintf");
512 				goto done;
513 			}
514 			if (new != h->new_lines || !h->new_nonl) {
515 				if (fprintf(tmp, "\n") < 0) {
516 					err = got_error_from_errno("fprintf");
517 					goto done;
518 				}
519 			}
520 			break;
521 		}
522 	}
523 
524 done:
525 	free(line);
526 	return err;
527 }
528 
529 static const struct got_error *
530 patch_file(struct got_patch *p, FILE *orig, FILE *tmp)
531 {
532 	const struct got_error *err = NULL;
533 	struct got_patch_hunk *h;
534 	struct stat sb;
535 	int lineno = 0;
536 	off_t copypos, pos;
537 	char *line = NULL;
538 	size_t linesize = 0;
539 	ssize_t linelen;
540 
541 	if (p->old == NULL) {				/* create */
542 		h = STAILQ_FIRST(&p->head);
543 		if (h == NULL || STAILQ_NEXT(h, entries) != NULL)
544 			return got_error(GOT_ERR_PATCH_MALFORMED);
545 		return apply_hunk(orig, tmp, h, &lineno, 0);
546 	}
547 
548 	if (fstat(fileno(orig), &sb) == -1)
549 		return got_error_from_errno("fstat");
550 
551 	copypos = 0;
552 	STAILQ_FOREACH(h, &p->head, entries) {
553 	tryagain:
554 		err = locate_hunk(orig, h, &pos, &lineno);
555 		if (err != NULL && err->code == GOT_ERR_HUNK_FAILED)
556 			h->err = err;
557 		if (err != NULL)
558 			return err;
559 		err = copy(tmp, orig, copypos, pos);
560 		if (err != NULL)
561 			return err;
562 		copypos = pos;
563 
564 		err = test_hunk(orig, h);
565 		if (err != NULL && err->code == GOT_ERR_HUNK_FAILED) {
566 			/*
567 			 * try to apply the hunk again starting the search
568 			 * after the previous partial match.
569 			 */
570 			if (fseeko(orig, pos, SEEK_SET) == -1)
571 				return got_error_from_errno("fseeko");
572 			linelen = getline(&line, &linesize, orig);
573 			if (linelen == -1)
574 				return got_error_from_errno("getline");
575 			lineno++;
576 			goto tryagain;
577 		}
578 		if (err != NULL)
579 			return err;
580 
581 		if (lineno + 1 != h->old_from)
582 			h->offset = lineno + 1 - h->old_from;
583 
584 		err = apply_hunk(orig, tmp, h, &lineno, pos);
585 		if (err != NULL)
586 			return err;
587 
588 		copypos = ftello(orig);
589 		if (copypos == -1)
590 			return got_error_from_errno("ftello");
591 	}
592 
593 	if (p->new == NULL && sb.st_size != copypos) {
594 		h = STAILQ_FIRST(&p->head);
595 		h->err = got_error(GOT_ERR_HUNK_FAILED);
596 		err = h->err;
597 	} else if (!feof(orig))
598 		err = copy(tmp, orig, copypos, -1);
599 
600 	return err;
601 }
602 
603 static const struct got_error *
604 report_progress(struct patch_args *pa, const char *old, const char *new,
605     unsigned char status, const struct got_error *orig_error)
606 {
607 	const struct got_error *err;
608 	struct got_patch_hunk *h;
609 
610 	err = pa->progress_cb(pa->progress_arg, old, new, status,
611 	    orig_error, 0, 0, 0, 0, 0, 0, NULL);
612 	if (err)
613 		return err;
614 
615 	STAILQ_FOREACH(h, pa->head, entries) {
616 		if (h->offset == 0 && !h->ws_mangled && h->err == NULL)
617 			continue;
618 
619 		err = pa->progress_cb(pa->progress_arg, old, new, 0, NULL,
620 		    h->old_from, h->old_lines, h->new_from, h->new_lines,
621 		    h->offset, h->ws_mangled, h->err);
622 		if (err)
623 			return err;
624 	}
625 
626 	return NULL;
627 }
628 
629 static const struct got_error *
630 patch_delete(void *arg, unsigned char status, unsigned char staged_status,
631     const char *path)
632 {
633 	return report_progress(arg, path, NULL, status, NULL);
634 }
635 
636 static const struct got_error *
637 patch_add(void *arg, unsigned char status, const char *path)
638 {
639 	return report_progress(arg, NULL, path, status, NULL);
640 }
641 
642 static const struct got_error *
643 open_blob(char **path, FILE **fp, const char *blobid,
644     struct got_repository *repo)
645 {
646 	const struct got_error *err = NULL;
647 	struct got_blob_object *blob = NULL;
648 	struct got_object_id id, *idptr, *matched_id = NULL;
649 	int fd = -1;
650 
651 	*fp = NULL;
652 	*path = NULL;
653 
654 	if (strlen(blobid) != SHA1_DIGEST_STRING_LENGTH - 1) {
655 		err = got_repo_match_object_id(&matched_id, NULL, blobid,
656 		    GOT_OBJ_TYPE_BLOB, NULL /* do not resolve tags */,
657 		    repo);
658 		if (err)
659 			return err;
660 		idptr = matched_id;
661 	} else {
662 		if (!got_parse_sha1_digest(id.sha1, blobid))
663 			return got_error(GOT_ERR_BAD_OBJ_ID_STR);
664 		idptr = &id;
665 	}
666 
667 	fd = got_opentempfd();
668 	if (fd == -1) {
669 		err = got_error_from_errno("got_opentempfd");
670 		goto done;
671 	}
672 
673 	err = got_object_open_as_blob(&blob, repo, idptr, 8192, fd);
674 	if (err)
675 		goto done;
676 
677 	err = got_opentemp_named(path, fp, GOT_TMPDIR_STR "/got-patch-blob");
678 	if (err)
679 		goto done;
680 
681 	err = got_object_blob_dump_to_file(NULL, NULL, NULL, *fp, blob);
682 	if (err)
683 		goto done;
684 
685 done:
686 	if (fd != -1 && close(fd) == -1 && err == NULL)
687 		err = got_error_from_errno("close");
688 	if (blob)
689 		got_object_blob_close(blob);
690 	if (matched_id != NULL)
691 		free(matched_id);
692 	if (err) {
693 		if (*fp != NULL)
694 			fclose(*fp);
695 		if (*path != NULL)
696 			unlink(*path);
697 		free(*path);
698 		*fp = NULL;
699 		*path = NULL;
700 	}
701 	return err;
702 }
703 
704 static const struct got_error *
705 apply_patch(int *overlapcnt, struct got_worktree *worktree,
706     struct got_repository *repo, struct got_fileindex *fileindex,
707     const char *old, const char *new, struct got_patch *p, int nop,
708     struct patch_args *pa, got_cancel_cb cancel_cb, void *cancel_arg)
709 {
710 	const struct got_error *err = NULL;
711 	struct stat sb;
712 	int do_merge = 0, file_renamed = 0;
713 	char *oldlabel = NULL, *newlabel = NULL, *anclabel = NULL;
714 	char *oldpath = NULL, *newpath = NULL;
715 	char *tmppath = NULL, *template = NULL, *parent = NULL;
716 	char *apath = NULL, *mergepath = NULL;
717 	FILE *oldfile = NULL, *tmpfile = NULL, *afile = NULL, *mergefile = NULL;
718 	int outfd;
719 	const char *outpath;
720 	mode_t mode = GOT_DEFAULT_FILE_MODE;
721 
722 	*overlapcnt = 0;
723 
724 	/* don't run the diff3 merge on creations/deletions */
725 	if (*p->blob != '\0' && p->old != NULL && p->new != NULL) {
726 		err = open_blob(&apath, &afile, p->blob, repo);
727 		/*
728 		 * ignore failures to open this blob, we might have
729 		 * parsed gibberish.
730 		 */
731 		if (err && !(err->code == GOT_ERR_ERRNO && errno == ENOENT) &&
732 		    err->code != GOT_ERR_NO_OBJ)
733 			return err;
734 		else if (err == NULL)
735 			do_merge = 1;
736 		err = NULL;
737 	}
738 
739 	if (asprintf(&oldpath, "%s/%s", got_worktree_get_root_path(worktree),
740 	    old) == -1) {
741 		err = got_error_from_errno("asprintf");
742 		goto done;
743 	}
744 
745 	if (asprintf(&newpath, "%s/%s", got_worktree_get_root_path(worktree),
746 	    new) == -1) {
747 		err = got_error_from_errno("asprintf");
748 		goto done;
749 	}
750 
751 	file_renamed = strcmp(oldpath, newpath);
752 
753 	if (asprintf(&template, "%s/got-patch",
754 	    got_worktree_get_root_path(worktree)) == -1) {
755 		err = got_error_from_errno(template);
756 		goto done;
757 	}
758 
759 	if (p->old != NULL) {
760 		if ((oldfile = fopen(oldpath, "r")) == NULL) {
761 			err = got_error_from_errno2("open", oldpath);
762 			goto done;
763 		}
764 		if (fstat(fileno(oldfile), &sb) == -1) {
765 			err = got_error_from_errno2("fstat", oldpath);
766 			goto done;
767 		}
768 		mode = sb.st_mode;
769 	}
770 
771 	err = got_opentemp_named(&tmppath, &tmpfile, template);
772 	if (err)
773 		goto done;
774 	outpath = tmppath;
775 	outfd = fileno(tmpfile);
776 	err = patch_file(p, afile != NULL ? afile : oldfile, tmpfile);
777 	if (err)
778 		goto done;
779 
780 	if (do_merge) {
781 		const char *type, *id;
782 
783 		if (fseeko(afile, 0, SEEK_SET) == -1 ||
784 		    fseeko(oldfile, 0, SEEK_SET) == -1 ||
785 		    fseeko(tmpfile, 0, SEEK_SET) == -1) {
786 			err = got_error_from_errno("fseeko");
787 			goto done;
788 		}
789 
790 		if (asprintf(&oldlabel, "--- %s", p->old) == -1) {
791 			err = got_error_from_errno("asprintf");
792 			oldlabel = NULL;
793 			goto done;
794 		}
795 
796 		if (asprintf(&newlabel, "+++ %s", p->new) == -1) {
797 			err = got_error_from_errno("asprintf");
798 			newlabel = NULL;
799 			goto done;
800 		}
801 
802 		if (*p->cid != '\0') {
803 			type = "commit";
804 			id = p->cid;
805 		} else {
806 			type = "blob";
807 			id = p->blob;
808 		}
809 
810 		if (asprintf(&anclabel, "%s %s", type, id) == -1) {
811 			err = got_error_from_errno("asprintf");
812 			anclabel = NULL;
813 			goto done;
814 		}
815 
816 		err = got_opentemp_named(&mergepath, &mergefile, template);
817 		if (err)
818 			goto done;
819 		outpath = mergepath;
820 		outfd = fileno(mergefile);
821 
822 		err = got_merge_diff3(overlapcnt, outfd, tmpfile, afile,
823 		    oldfile, oldlabel, anclabel, newlabel,
824 		    GOT_DIFF_ALGORITHM_PATIENCE);
825 		if (err)
826 			goto done;
827 	}
828 
829 	if (nop)
830 		goto done;
831 
832 	if (p->old != NULL && p->new == NULL) {
833 		err = got_worktree_patch_schedule_rm(old, repo, worktree,
834 		    fileindex, patch_delete, pa);
835 		goto done;
836 	}
837 
838 	if (fchmod(outfd, mode) == -1) {
839 		err = got_error_from_errno2("chmod", tmppath);
840 		goto done;
841 	}
842 
843 	if (rename(outpath, newpath) == -1) {
844 		if (errno != ENOENT) {
845 			err = got_error_from_errno3("rename", outpath,
846 			    newpath);
847 			goto done;
848 		}
849 
850 		err = got_path_dirname(&parent, newpath);
851 		if (err != NULL)
852 			goto done;
853 		err = got_path_mkdir(parent);
854 		if (err != NULL)
855 			goto done;
856 		if (rename(outpath, newpath) == -1) {
857 			err = got_error_from_errno3("rename", outpath,
858 			    newpath);
859 			goto done;
860 		}
861 	}
862 
863 	if (file_renamed) {
864 		err = got_worktree_patch_schedule_rm(old, repo, worktree,
865 		    fileindex, patch_delete, pa);
866 		if (err == NULL)
867 			err = got_worktree_patch_schedule_add(new, repo,
868 			    worktree, fileindex, patch_add,
869 			    pa);
870 		if (err)
871 			unlink(newpath);
872 	} else if (p->old == NULL) {
873 		err = got_worktree_patch_schedule_add(new, repo, worktree,
874 		    fileindex, patch_add, pa);
875 		if (err)
876 			unlink(newpath);
877 	} else if (*overlapcnt != 0)
878 		err = report_progress(pa, old, new, GOT_STATUS_CONFLICT, NULL);
879 	else if (do_merge)
880 		err = report_progress(pa, old, new, GOT_STATUS_MERGE, NULL);
881 	else
882 		err = report_progress(pa, old, new, GOT_STATUS_MODIFY, NULL);
883 
884 done:
885 	free(parent);
886 	free(template);
887 
888 	if (tmppath != NULL)
889 		unlink(tmppath);
890 	if (tmpfile != NULL && fclose(tmpfile) == EOF && err == NULL)
891 		err = got_error_from_errno("fclose");
892 	free(tmppath);
893 
894 	free(oldpath);
895 	if (oldfile != NULL && fclose(oldfile) == EOF && err == NULL)
896 		err = got_error_from_errno("fclose");
897 
898 	if (apath != NULL)
899 		unlink(apath);
900 	if (afile != NULL && fclose(afile) == EOF && err == NULL)
901 		err = got_error_from_errno("fclose");
902 	free(apath);
903 
904 	if (mergepath != NULL)
905 		unlink(mergepath);
906 	if (mergefile != NULL && fclose(mergefile) == EOF && err == NULL)
907 		err = got_error_from_errno("fclose");
908 	free(mergepath);
909 
910 	free(newpath);
911 	free(oldlabel);
912 	free(newlabel);
913 	free(anclabel);
914 	return err;
915 }
916 
917 static void
918 reverse_patch(struct got_patch *p)
919 {
920 	struct got_patch_hunk *h;
921 	size_t i;
922 	int tmp;
923 
924 	STAILQ_FOREACH(h, &p->head, entries) {
925 		tmp = h->old_from;
926 		h->old_from = h->new_from;
927 		h->new_from = tmp;
928 
929 		tmp = h->old_lines;
930 		h->old_lines = h->new_lines;
931 		h->new_lines = tmp;
932 
933 		tmp = h->old_nonl;
934 		h->old_nonl = h->new_nonl;
935 		h->new_nonl = tmp;
936 
937 		for (i = 0; i < h->len; ++i) {
938 			if (*h->lines[i] == '+')
939 				*h->lines[i] = '-';
940 			else if (*h->lines[i] == '-')
941 				*h->lines[i] = '+';
942 		}
943 	}
944 }
945 
946 const struct got_error *
947 got_patch(int fd, struct got_worktree *worktree, struct got_repository *repo,
948     int nop, int strip, int reverse, got_patch_progress_cb progress_cb,
949     void *progress_arg, got_cancel_cb cancel_cb, void *cancel_arg)
950 {
951 	const struct got_error *err = NULL, *complete_err = NULL;
952 	struct got_fileindex *fileindex = NULL;
953 	char *fileindex_path = NULL;
954 	char *oldpath, *newpath;
955 	struct imsgbuf *ibuf;
956 	int imsg_fds[2] = {-1, -1};
957 	int overlapcnt, done = 0, failed = 0;
958 	pid_t pid;
959 
960 	ibuf = calloc(1, sizeof(*ibuf));
961 	if (ibuf == NULL) {
962 		err = got_error_from_errno("calloc");
963 		goto done;
964 	}
965 
966 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
967 		err = got_error_from_errno("socketpair");
968 		goto done;
969 	}
970 
971 	pid = fork();
972 	if (pid == -1) {
973 		err = got_error_from_errno("fork");
974 		goto done;
975 	} else if (pid == 0) {
976 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PATCH,
977 		    NULL);
978 		/* not reached */
979 	}
980 
981 	if (close(imsg_fds[1]) == -1) {
982 		err = got_error_from_errno("close");
983 		goto done;
984 	}
985 	imsg_fds[1] = -1;
986 	imsg_init(ibuf, imsg_fds[0]);
987 
988 	err = send_patch(ibuf, fd);
989 	fd = -1;
990 	if (err)
991 		goto done;
992 
993 	err = got_worktree_patch_prepare(&fileindex, &fileindex_path,
994 	    worktree);
995 	if (err)
996 		goto done;
997 
998 	while (!done && err == NULL) {
999 		struct got_patch p;
1000 		struct patch_args pa;
1001 
1002 		pa.progress_cb = progress_cb;
1003 		pa.progress_arg = progress_arg;
1004 		pa.head = &p.head;
1005 
1006 		err = recv_patch(ibuf, &done, &p, strip);
1007 		if (err || done)
1008 			break;
1009 
1010 		if (reverse)
1011 			reverse_patch(&p);
1012 
1013 		err = got_worktree_patch_check_path(p.old, p.new, &oldpath,
1014 		    &newpath, worktree, repo, fileindex);
1015 		if (err == NULL)
1016 			err = apply_patch(&overlapcnt, worktree, repo,
1017 			    fileindex, oldpath, newpath, &p, nop, &pa,
1018 			    cancel_cb, cancel_arg);
1019 		if (err != NULL) {
1020 			failed = 1;
1021 			/* recoverable errors */
1022 			if (err->code == GOT_ERR_FILE_STATUS ||
1023 			    (err->code == GOT_ERR_ERRNO && errno == ENOENT))
1024 				err = report_progress(&pa, p.old, p.new,
1025 				    GOT_STATUS_CANNOT_UPDATE, err);
1026 			else if (err->code == GOT_ERR_HUNK_FAILED)
1027 				err = report_progress(&pa, p.old, p.new,
1028 				    GOT_STATUS_CANNOT_UPDATE, NULL);
1029 		}
1030 		if (overlapcnt != 0)
1031 			failed = 1;
1032 
1033 		free(oldpath);
1034 		free(newpath);
1035 		patch_free(&p);
1036 
1037 		if (err)
1038 			break;
1039 	}
1040 
1041 done:
1042 	if (fileindex != NULL)
1043 		complete_err = got_worktree_patch_complete(fileindex,
1044 		    fileindex_path);
1045 	if (complete_err && err == NULL)
1046 		err = complete_err;
1047 	free(fileindex_path);
1048 	if (fd != -1 && close(fd) == -1 && err == NULL)
1049 		err = got_error_from_errno("close");
1050 	if (ibuf != NULL)
1051 		imsg_clear(ibuf);
1052 	if (imsg_fds[0] != -1 && close(imsg_fds[0]) == -1 && err == NULL)
1053 		err = got_error_from_errno("close");
1054 	if (imsg_fds[1] != -1 && close(imsg_fds[1]) == -1 && err == NULL)
1055 		err = got_error_from_errno("close");
1056 	if (err == NULL && failed)
1057 		err = got_error(GOT_ERR_PATCH_FAILED);
1058 	return err;
1059 }