Gotweb

Blob

Date:: Mon Jun 27 18:47:02 2022 UTC
Message:: handle blob ids without corresponding blob ids ok stsp@
Actions:: History | Blame | Raw File
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_repository.h"
46 #include "got_opentemp.h"
47 #include "got_patch.h"
48 
49 #include "got_lib_delta.h"
50 #include "got_lib_diff.h"
51 #include "got_lib_object.h"
52 #include "got_lib_privsep.h"
53 #include "got_lib_sha1.h"
54 
55 #define MIN(a, b) ((a) < (b) ? (a) : (b))
56 
57 struct got_patch_hunk {
58 	STAILQ_ENTRY(got_patch_hunk) entries;
59 	const struct got_error *err;
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 const struct got_error *
404 test_hunk(FILE *orig, struct got_patch_hunk *h)
405 {
406 	const struct got_error *err = NULL;
407 	char *line = NULL;
408 	size_t linesize = 0, i = 0;
409 	ssize_t linelen;
410 
411 	for (i = 0; i < h->len; ++i) {
412 		switch (*h->lines[i]) {
413 		case '+':
414 			continue;
415 		case ' ':
416 		case '-':
417 			linelen = getline(&line, &linesize, orig);
418 			if (linelen == -1) {
419 				if (ferror(orig))
420 					err = got_error_from_errno("getline");
421 				else
422 					err = got_error(
423 					    GOT_ERR_HUNK_FAILED);
424 				goto done;
425 			}
426 			if (line[linelen - 1] == '\n')
427 				line[linelen - 1] = '\0';
428 			if (strcmp(h->lines[i] + 1, line)) {
429 				err = got_error(GOT_ERR_HUNK_FAILED);
430 				goto done;
431 			}
432 			break;
433 		}
434 	}
435 
436 done:
437 	free(line);
438 	return err;
439 }
440 
441 static const struct got_error *
442 apply_hunk(FILE *tmp, struct got_patch_hunk *h, int *lineno)
443 {
444 	size_t i, new = 0;
445 
446 	for (i = 0; i < h->len; ++i) {
447 		switch (*h->lines[i]) {
448 		case ' ':
449 			if (fprintf(tmp, "%s\n", h->lines[i] + 1) < 0)
450 				return got_error_from_errno("fprintf");
451 			/* fallthrough */
452 		case '-':
453 			(*lineno)++;
454 			break;
455 		case '+':
456 			new++;
457 			if (fprintf(tmp, "%s", h->lines[i] + 1) < 0)
458 				return got_error_from_errno("fprintf");
459 			if (new != h->new_lines || !h->new_nonl) {
460 				if (fprintf(tmp, "\n") < 0)
461 					return got_error_from_errno(
462 					    "fprintf");
463 			}
464 			break;
465 		}
466 	}
467 	return NULL;
468 }
469 
470 static const struct got_error *
471 patch_file(struct got_patch *p, FILE *orig, FILE *tmp, mode_t *mode)
472 {
473 	const struct got_error *err = NULL;
474 	struct got_patch_hunk *h;
475 	struct stat sb;
476 	int lineno = 0;
477 	off_t copypos, pos;
478 	char *line = NULL;
479 	size_t linesize = 0;
480 	ssize_t linelen;
481 
482 	if (p->old == NULL) {				/* create */
483 		h = STAILQ_FIRST(&p->head);
484 		if (h == NULL || STAILQ_NEXT(h, entries) != NULL)
485 			return got_error(GOT_ERR_PATCH_MALFORMED);
486 		return apply_hunk(tmp, h, &lineno);
487 	}
488 
489 	if (fstat(fileno(orig), &sb) == -1)
490 		return got_error_from_errno("fstat");
491 	*mode = sb.st_mode;
492 
493 	copypos = 0;
494 	STAILQ_FOREACH(h, &p->head, entries) {
495 	tryagain:
496 		err = locate_hunk(orig, h, &pos, &lineno);
497 		if (err != NULL && err->code == GOT_ERR_HUNK_FAILED)
498 			h->err = err;
499 		if (err != NULL)
500 			return err;
501 		err = copy(tmp, orig, copypos, pos);
502 		if (err != NULL)
503 			return err;
504 		copypos = pos;
505 
506 		err = test_hunk(orig, h);
507 		if (err != NULL && err->code == GOT_ERR_HUNK_FAILED) {
508 			/*
509 			 * try to apply the hunk again starting the search
510 			 * after the previous partial match.
511 			 */
512 			if (fseeko(orig, pos, SEEK_SET) == -1)
513 				return got_error_from_errno("fseeko");
514 			linelen = getline(&line, &linesize, orig);
515 			if (linelen == -1)
516 				return got_error_from_errno("getline");
517 			lineno++;
518 			goto tryagain;
519 		}
520 		if (err != NULL)
521 			return err;
522 
523 		if (lineno + 1 != h->old_from)
524 			h->offset = lineno + 1 - h->old_from;
525 
526 		err = apply_hunk(tmp, h, &lineno);
527 		if (err != NULL)
528 			return err;
529 
530 		copypos = ftello(orig);
531 		if (copypos == -1)
532 			return got_error_from_errno("ftello");
533 	}
534 
535 	if (p->new == NULL && sb.st_size != copypos) {
536 		h = STAILQ_FIRST(&p->head);
537 		h->err = got_error(GOT_ERR_HUNK_FAILED);
538 		err = h->err;
539 	} else if (!feof(orig))
540 		err = copy(tmp, orig, copypos, -1);
541 
542 	return err;
543 }
544 
545 static const struct got_error *
546 report_progress(struct patch_args *pa, const char *old, const char *new,
547     unsigned char status, const struct got_error *orig_error)
548 {
549 	const struct got_error *err;
550 	struct got_patch_hunk *h;
551 
552 	err = pa->progress_cb(pa->progress_arg, old, new, status,
553 	    orig_error, 0, 0, 0, 0, 0, NULL);
554 	if (err)
555 		return err;
556 
557 	STAILQ_FOREACH(h, pa->head, entries) {
558 		if (h->offset == 0 && h->err == NULL)
559 			continue;
560 
561 		err = pa->progress_cb(pa->progress_arg, old, new, 0, NULL,
562 		    h->old_from, h->old_lines, h->new_from, h->new_lines,
563 		    h->offset, h->err);
564 		if (err)
565 			return err;
566 	}
567 
568 	return NULL;
569 }
570 
571 static const struct got_error *
572 patch_delete(void *arg, unsigned char status, unsigned char staged_status,
573     const char *path)
574 {
575 	return report_progress(arg, path, NULL, status, NULL);
576 }
577 
578 static const struct got_error *
579 patch_add(void *arg, unsigned char status, const char *path)
580 {
581 	return report_progress(arg, NULL, path, status, NULL);
582 }
583 
584 static const struct got_error *
585 open_blob(char **path, FILE **fp, const char *blobid,
586     struct got_repository *repo)
587 {
588 	const struct got_error *err = NULL;
589 	struct got_blob_object *blob = NULL;
590 	struct got_object_id id;
591 
592 	*fp = NULL;
593 	*path = NULL;
594 
595 	if (!got_parse_sha1_digest(id.sha1, blobid))
596 		return got_error(GOT_ERR_BAD_OBJ_ID_STR);
597 
598 	err = got_object_open_as_blob(&blob, repo, &id, 8192);
599 	if (err)
600 		goto done;
601 
602 	err = got_opentemp_named(path, fp, GOT_TMPDIR_STR "/got-patch-blob");
603 	if (err)
604 		goto done;
605 
606 	err = got_object_blob_dump_to_file(NULL, NULL, NULL, *fp, blob);
607 	if (err)
608 		goto done;
609 
610 done:
611 	if (blob)
612 		got_object_blob_close(blob);
613 	if (err) {
614 		if (*fp != NULL)
615 			fclose(*fp);
616 		if (*path != NULL)
617 			unlink(*path);
618 		free(*path);
619 		*fp = NULL;
620 		*path = NULL;
621 	}
622 	return err;
623 }
624 
625 static const struct got_error *
626 apply_patch(int *overlapcnt, struct got_worktree *worktree,
627     struct got_repository *repo, struct got_fileindex *fileindex,
628     const char *old, const char *new, struct got_patch *p, int nop,
629     struct patch_args *pa, got_cancel_cb cancel_cb, void *cancel_arg)
630 {
631 	const struct got_error *err = NULL;
632 	int do_merge = 0, file_renamed = 0;
633 	char *oldlabel = NULL, *newlabel = NULL, *anclabel = NULL;
634 	char *oldpath = NULL, *newpath = NULL;
635 	char *tmppath = NULL, *template = NULL, *parent = NULL;
636 	char *apath = NULL, *mergepath = NULL;
637 	FILE *oldfile = NULL, *tmpfile = NULL, *afile = NULL, *mergefile = NULL;
638 	int outfd;
639 	const char *outpath;
640 	mode_t mode = GOT_DEFAULT_FILE_MODE;
641 
642 	*overlapcnt = 0;
643 
644 	/* don't run the diff3 merge on creations/deletions */
645 	if (*p->blob != '\0' && p->old != NULL && p->new != NULL) {
646 		err = open_blob(&apath, &afile, p->blob, repo);
647 		/*
648 		 * ignore failures to open this blob, we might have
649 		 * parsed gibberish.
650 		 */
651 		if (err && !(err->code == GOT_ERR_ERRNO && errno == ENOENT))
652 			return err;
653 		else if (err == NULL)
654 			do_merge = 1;
655 		err = NULL;
656 	}
657 
658 	if (asprintf(&oldpath, "%s/%s", got_worktree_get_root_path(worktree),
659 	    old) == -1) {
660 		err = got_error_from_errno("asprintf");
661 		goto done;
662 	}
663 
664 	if (asprintf(&newpath, "%s/%s", got_worktree_get_root_path(worktree),
665 	    new) == -1) {
666 		err = got_error_from_errno("asprintf");
667 		goto done;
668 	}
669 
670 	file_renamed = strcmp(oldpath, newpath);
671 
672 	if (asprintf(&template, "%s/got-patch",
673 	    got_worktree_get_root_path(worktree)) == -1) {
674 		err = got_error_from_errno(template);
675 		goto done;
676 	}
677 
678 	if (p->old != NULL && (oldfile = fopen(oldpath, "r")) == NULL) {
679 		err = got_error_from_errno2("open", oldpath);
680 		goto done;
681 	}
682 
683 	err = got_opentemp_named(&tmppath, &tmpfile, template);
684 	if (err)
685 		goto done;
686 	outpath = tmppath;
687 	outfd = fileno(tmpfile);
688 	err = patch_file(p, afile != NULL ? afile : oldfile, tmpfile, &mode);
689 	if (err)
690 		goto done;
691 
692 	if (do_merge) {
693 		const char *type, *id;
694 
695 		if (fseeko(afile, 0, SEEK_SET) == -1 ||
696 		    fseeko(oldfile, 0, SEEK_SET) == -1 ||
697 		    fseeko(tmpfile, 0, SEEK_SET) == -1) {
698 			err = got_error_from_errno("fseeko");
699 			goto done;
700 		}
701 
702 		if (asprintf(&oldlabel, "--- %s", p->old) == -1) {
703 			err = got_error_from_errno("asprintf");
704 			oldlabel = NULL;
705 			goto done;
706 		}
707 
708 		if (asprintf(&newlabel, "+++ %s", p->new) == -1) {
709 			err = got_error_from_errno("asprintf");
710 			newlabel = NULL;
711 			goto done;
712 		}
713 
714 		if (*p->cid != '\0') {
715 			type = "commit";
716 			id = p->cid;
717 		} else {
718 			type = "blob";
719 			id = p->blob;
720 		}
721 
722 		if (asprintf(&anclabel, "%s %s", type, id) == -1) {
723 			err = got_error_from_errno("asprintf");
724 			anclabel = NULL;
725 			goto done;
726 		}
727 
728 		err = got_opentemp_named(&mergepath, &mergefile, template);
729 		if (err)
730 			goto done;
731 		outpath = mergepath;
732 		outfd = fileno(mergefile);
733 
734 		err = got_merge_diff3(overlapcnt, outfd, tmpfile, afile,
735 		    oldfile, oldlabel, anclabel, newlabel,
736 		    GOT_DIFF_ALGORITHM_PATIENCE);
737 		if (err)
738 			goto done;
739 	}
740 
741 	if (nop)
742 		goto done;
743 
744 	if (p->old != NULL && p->new == NULL) {
745 		err = got_worktree_patch_schedule_rm(old, repo, worktree,
746 		    fileindex, patch_delete, pa);
747 		goto done;
748 	}
749 
750 	if (fchmod(outfd, mode) == -1) {
751 		err = got_error_from_errno2("chmod", tmppath);
752 		goto done;
753 	}
754 
755 	if (rename(outpath, newpath) == -1) {
756 		if (errno != ENOENT) {
757 			err = got_error_from_errno3("rename", outpath,
758 			    newpath);
759 			goto done;
760 		}
761 
762 		err = got_path_dirname(&parent, newpath);
763 		if (err != NULL)
764 			goto done;
765 		err = got_path_mkdir(parent);
766 		if (err != NULL)
767 			goto done;
768 		if (rename(outpath, newpath) == -1) {
769 			err = got_error_from_errno3("rename", outpath,
770 			    newpath);
771 			goto done;
772 		}
773 	}
774 
775 	if (file_renamed) {
776 		err = got_worktree_patch_schedule_rm(old, repo, worktree,
777 		    fileindex, patch_delete, pa);
778 		if (err == NULL)
779 			err = got_worktree_patch_schedule_add(new, repo,
780 			    worktree, fileindex, patch_add,
781 			    pa);
782 		if (err)
783 			unlink(newpath);
784 	} else if (p->old == NULL) {
785 		err = got_worktree_patch_schedule_add(new, repo, worktree,
786 		    fileindex, patch_add, pa);
787 		if (err)
788 			unlink(newpath);
789 	} else if (*overlapcnt != 0)
790 		err = report_progress(pa, old, new, GOT_STATUS_CONFLICT, NULL);
791 	else if (do_merge)
792 		err = report_progress(pa, old, new, GOT_STATUS_MERGE, NULL);
793 	else
794 		err = report_progress(pa, old, new, GOT_STATUS_MODIFY, NULL);
795 
796 done:
797 	free(parent);
798 	free(template);
799 
800 	if (tmppath != NULL)
801 		unlink(tmppath);
802 	if (tmpfile != NULL && fclose(tmpfile) == EOF && err == NULL)
803 		err = got_error_from_errno("fclose");
804 	free(tmppath);
805 
806 	free(oldpath);
807 	if (oldfile != NULL && fclose(oldfile) == EOF && err == NULL)
808 		err = got_error_from_errno("fclose");
809 
810 	if (apath != NULL)
811 		unlink(apath);
812 	if (afile != NULL && fclose(afile) == EOF && err == NULL)
813 		err = got_error_from_errno("fclose");
814 	free(apath);
815 
816 	if (mergepath != NULL)
817 		unlink(mergepath);
818 	if (mergefile != NULL && fclose(mergefile) == EOF && err == NULL)
819 		err = got_error_from_errno("fclose");
820 	free(mergepath);
821 
822 	free(newpath);
823 	free(oldlabel);
824 	free(newlabel);
825 	free(anclabel);
826 	return err;
827 }
828 
829 static void
830 reverse_patch(struct got_patch *p)
831 {
832 	struct got_patch_hunk *h;
833 	size_t i;
834 	int tmp;
835 
836 	STAILQ_FOREACH(h, &p->head, entries) {
837 		tmp = h->old_from;
838 		h->old_from = h->new_from;
839 		h->new_from = tmp;
840 
841 		tmp = h->old_lines;
842 		h->old_lines = h->new_lines;
843 		h->new_lines = tmp;
844 
845 		tmp = h->old_nonl;
846 		h->old_nonl = h->new_nonl;
847 		h->new_nonl = tmp;
848 
849 		for (i = 0; i < h->len; ++i) {
850 			if (*h->lines[i] == '+')
851 				*h->lines[i] = '-';
852 			else if (*h->lines[i] == '-')
853 				*h->lines[i] = '+';
854 		}
855 	}
856 }
857 
858 const struct got_error *
859 got_patch(int fd, struct got_worktree *worktree, struct got_repository *repo,
860     int nop, int strip, int reverse, got_patch_progress_cb progress_cb,
861     void *progress_arg, got_cancel_cb cancel_cb, void *cancel_arg)
862 {
863 	const struct got_error *err = NULL, *complete_err = NULL;
864 	struct got_fileindex *fileindex = NULL;
865 	char *fileindex_path = NULL;
866 	char *oldpath, *newpath;
867 	struct imsgbuf *ibuf;
868 	int imsg_fds[2] = {-1, -1};
869 	int overlapcnt, done = 0, failed = 0;
870 	pid_t pid;
871 
872 	ibuf = calloc(1, sizeof(*ibuf));
873 	if (ibuf == NULL) {
874 		err = got_error_from_errno("calloc");
875 		goto done;
876 	}
877 
878 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
879 		err = got_error_from_errno("socketpair");
880 		goto done;
881 	}
882 
883 	pid = fork();
884 	if (pid == -1) {
885 		err = got_error_from_errno("fork");
886 		goto done;
887 	} else if (pid == 0) {
888 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PATCH,
889 		    NULL);
890 		/* not reached */
891 	}
892 
893 	if (close(imsg_fds[1]) == -1) {
894 		err = got_error_from_errno("close");
895 		goto done;
896 	}
897 	imsg_fds[1] = -1;
898 	imsg_init(ibuf, imsg_fds[0]);
899 
900 	err = send_patch(ibuf, fd);
901 	fd = -1;
902 	if (err)
903 		goto done;
904 
905 	err = got_worktree_patch_prepare(&fileindex, &fileindex_path,
906 	    worktree);
907 	if (err)
908 		goto done;
909 
910 	while (!done && err == NULL) {
911 		struct got_patch p;
912 		struct patch_args pa;
913 
914 		pa.progress_cb = progress_cb;
915 		pa.progress_arg = progress_arg;
916 		pa.head = &p.head;
917 
918 		err = recv_patch(ibuf, &done, &p, strip);
919 		if (err || done)
920 			break;
921 
922 		if (reverse)
923 			reverse_patch(&p);
924 
925 		err = got_worktree_patch_check_path(p.old, p.new, &oldpath,
926 		    &newpath, worktree, repo, fileindex);
927 		if (err == NULL)
928 			err = apply_patch(&overlapcnt, worktree, repo,
929 			    fileindex, oldpath, newpath, &p, nop, &pa,
930 			    cancel_cb, cancel_arg);
931 		if (err != NULL) {
932 			failed = 1;
933 			/* recoverable errors */
934 			if (err->code == GOT_ERR_FILE_STATUS ||
935 			    (err->code == GOT_ERR_ERRNO && errno == ENOENT))
936 				err = report_progress(&pa, p.old, p.new,
937 				    GOT_STATUS_CANNOT_UPDATE, err);
938 			else if (err->code == GOT_ERR_HUNK_FAILED)
939 				err = report_progress(&pa, p.old, p.new,
940 				    GOT_STATUS_CANNOT_UPDATE, NULL);
941 		}
942 		if (overlapcnt != 0)
943 			failed = 1;
944 
945 		free(oldpath);
946 		free(newpath);
947 		patch_free(&p);
948 
949 		if (err)
950 			break;
951 	}
952 
953 done:
954 	if (fileindex != NULL)
955 		complete_err = got_worktree_patch_complete(fileindex,
956 		    fileindex_path);
957 	if (complete_err && err == NULL)
958 		err = complete_err;
959 	free(fileindex_path);
960 	if (fd != -1 && close(fd) == -1 && err == NULL)
961 		err = got_error_from_errno("close");
962 	if (ibuf != NULL)
963 		imsg_clear(ibuf);
964 	if (imsg_fds[0] != -1 && close(imsg_fds[0]) == -1 && err == NULL)
965 		err = got_error_from_errno("close");
966 	if (imsg_fds[1] != -1 && close(imsg_fds[1]) == -1 && err == NULL)
967 		err = got_error_from_errno("close");
968 	if (err == NULL && failed)
969 		err = got_error(GOT_ERR_PATCH_FAILED);
970 	return err;
971 }