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