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Date:: Sat Feb 4 13:58:38 2023 UTC
Message:: rename sha1.c to hash.c
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 <ctype.h>
30 #include <errno.h>
31 #include <limits.h>
32 #include <sha1.h>
33 #include <sha2.h>
34 #include <stdint.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <unistd.h>
39 #include <imsg.h>
40 
41 #include "got_error.h"
42 #include "got_object.h"
43 #include "got_path.h"
44 #include "got_reference.h"
45 #include "got_cancel.h"
46 #include "got_worktree.h"
47 #include "got_repository.h"
48 #include "got_opentemp.h"
49 #include "got_patch.h"
50 #include "got_diff.h"
51 
52 #include "got_lib_delta.h"
53 #include "got_lib_diff.h"
54 #include "got_lib_object.h"
55 #include "got_lib_privsep.h"
56 #include "got_lib_hash.h"
57 
58 #define MIN(a, b) ((a) < (b) ? (a) : (b))
59 
60 struct got_patch_hunk {
61 	STAILQ_ENTRY(got_patch_hunk) entries;
62 	const struct got_error *err;
63 	int	ws_mangled;
64 	int	offset;
65 	int	old_nonl;
66 	int	new_nonl;
67 	int	old_from;
68 	int	old_lines;
69 	int	new_from;
70 	int	new_lines;
71 	size_t	len;
72 	size_t	cap;
73 	char	**lines;
74 };
75 
76 STAILQ_HEAD(got_patch_hunk_head, got_patch_hunk);
77 struct got_patch {
78 	int	 xbit;
79 	char	*old;
80 	char	*new;
81 	char	 cid[41];
82 	char	 blob[41];
83 	struct got_patch_hunk_head head;
84 };
85 
86 struct patch_args {
87 	got_patch_progress_cb progress_cb;
88 	void	*progress_arg;
89 	struct got_patch_hunk_head *head;
90 };
91 
92 static mode_t
93 apply_umask(mode_t mode)
94 {
95 	mode_t um;
96 
97 	um = umask(000);
98 	umask(um);
99 	return mode & ~um;
100 }
101 
102 static const struct got_error *
103 send_patch(struct imsgbuf *ibuf, int fd)
104 {
105 	const struct got_error *err = NULL;
106 
107 	if (imsg_compose(ibuf, GOT_IMSG_PATCH_FILE, 0, 0, fd,
108 	    NULL, 0) == -1) {
109 		err = got_error_from_errno(
110 		    "imsg_compose GOT_IMSG_PATCH_FILE");
111 		close(fd);
112 		return err;
113 	}
114 
115 	return got_privsep_flush_imsg(ibuf);
116 }
117 
118 static void
119 patch_free(struct got_patch *p)
120 {
121 	struct got_patch_hunk *h;
122 	size_t i;
123 
124 	while (!STAILQ_EMPTY(&p->head)) {
125 		h = STAILQ_FIRST(&p->head);
126 		STAILQ_REMOVE_HEAD(&p->head, entries);
127 
128 		for (i = 0; i < h->len; ++i)
129 			free(h->lines[i]);
130 		free(h->lines);
131 		free(h);
132 	}
133 
134 	free(p->new);
135 	free(p->old);
136 
137 	memset(p, 0, sizeof(*p));
138 	STAILQ_INIT(&p->head);
139 }
140 
141 static const struct got_error *
142 pushline(struct got_patch_hunk *h, const char *line)
143 {
144 	void 	*t;
145 	size_t	 newcap;
146 
147 	if (h->len == h->cap) {
148 		if ((newcap = h->cap * 1.5) == 0)
149 			newcap = 16;
150 		t = recallocarray(h->lines, h->cap, newcap,
151 		    sizeof(h->lines[0]));
152 		if (t == NULL)
153 			return got_error_from_errno("recallocarray");
154 		h->lines = t;
155 		h->cap = newcap;
156 	}
157 
158 	if ((t = strdup(line)) == NULL)
159 		return got_error_from_errno("strdup");
160 
161 	h->lines[h->len++] = t;
162 	return NULL;
163 }
164 
165 static const struct got_error *
166 recv_patch(struct imsgbuf *ibuf, int *done, struct got_patch *p, int strip)
167 {
168 	const struct got_error *err = NULL;
169 	struct imsg imsg;
170 	struct got_imsg_patch_hunk hdr;
171 	struct got_imsg_patch patch;
172 	struct got_patch_hunk *h = NULL;
173 	size_t datalen;
174 	int lastmode = -1;
175 
176 	memset(p, 0, sizeof(*p));
177 	STAILQ_INIT(&p->head);
178 
179 	err = got_privsep_recv_imsg(&imsg, ibuf, 0);
180 	if (err)
181 		return err;
182 	if (imsg.hdr.type == GOT_IMSG_PATCH_EOF) {
183 		*done = 1;
184 		goto done;
185 	}
186 	if (imsg.hdr.type != GOT_IMSG_PATCH) {
187 		err = got_error(GOT_ERR_PRIVSEP_MSG);
188 		goto done;
189 	}
190 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
191 	if (datalen != sizeof(patch)) {
192 		err = got_error(GOT_ERR_PRIVSEP_LEN);
193 		goto done;
194 	}
195 	memcpy(&patch, imsg.data, sizeof(patch));
196 
197 	if (patch.old[sizeof(patch.old)-1] != '\0' ||
198 	    patch.new[sizeof(patch.new)-1] != '\0' ||
199 	    patch.cid[sizeof(patch.cid)-1] != '\0' ||
200 	    patch.blob[sizeof(patch.blob)-1] != '\0') {
201 		err = got_error(GOT_ERR_PRIVSEP_LEN);
202 		goto done;
203 	}
204 
205 	if (*patch.cid != '\0')
206 		strlcpy(p->cid, patch.cid, sizeof(p->cid));
207 
208 	if (*patch.blob != '\0')
209 		strlcpy(p->blob, patch.blob, sizeof(p->blob));
210 
211 	p->xbit = patch.xbit;
212 
213 	/* automatically set strip=1 for git-style diffs */
214 	if (strip == -1 && patch.git &&
215 	    (*patch.old == '\0' || !strncmp(patch.old, "a/", 2)) &&
216 	    (*patch.new == '\0' || !strncmp(patch.new, "b/", 2)))
217 		strip = 1;
218 
219 	/* prefer the new name if not /dev/null for not git-style diffs */
220 	if (!patch.git && *patch.new != '\0' && *patch.old != '\0') {
221 		err = got_path_strip(&p->old, patch.new, strip);
222 		if (err)
223 			goto done;
224 	} else if (*patch.old != '\0') {
225 		err = got_path_strip(&p->old, patch.old, strip);
226 		if (err)
227 			goto done;
228 	}
229 
230 	if (*patch.new != '\0') {
231 		err = got_path_strip(&p->new, patch.new, strip);
232 		if (err)
233 			goto done;
234 	}
235 
236 	if (p->old == NULL && p->new == NULL) {
237 		err = got_error(GOT_ERR_PATCH_MALFORMED);
238 		goto done;
239 	}
240 
241 	imsg_free(&imsg);
242 
243 	for (;;) {
244 		char *t;
245 
246 		err = got_privsep_recv_imsg(&imsg, ibuf, 0);
247 		if (err) {
248 			patch_free(p);
249 			return err;
250 		}
251 
252 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
253 		switch (imsg.hdr.type) {
254 		case GOT_IMSG_PATCH_DONE:
255 			if (h != NULL && h->len == 0)
256 				err = got_error(GOT_ERR_PATCH_MALFORMED);
257 			goto done;
258 		case GOT_IMSG_PATCH_HUNK:
259 			if (h != NULL &&
260 			    (h->len == 0 || h->old_nonl || h->new_nonl)) {
261 				err = got_error(GOT_ERR_PATCH_MALFORMED);
262 				goto done;
263 			}
264 			lastmode = -1;
265 			if (datalen != sizeof(hdr)) {
266 				err = got_error(GOT_ERR_PRIVSEP_LEN);
267 				goto done;
268 			}
269 			memcpy(&hdr, imsg.data, sizeof(hdr));
270 			if (hdr.oldfrom < 0 || hdr.newfrom < 0) {
271 				err = got_error(GOT_ERR_PRIVSEP_LEN);
272 				goto done;
273 			}
274 			if ((h = calloc(1, sizeof(*h))) == NULL) {
275 				err = got_error_from_errno("calloc");
276 				goto done;
277 			}
278 			h->old_from = hdr.oldfrom;
279 			h->old_lines = hdr.oldlines;
280 			h->new_from = hdr.newfrom;
281 			h->new_lines = hdr.newlines;
282 			STAILQ_INSERT_TAIL(&p->head, h, entries);
283 			break;
284 		case GOT_IMSG_PATCH_LINE:
285 			if (h == NULL) {
286 				err = got_error(GOT_ERR_PRIVSEP_MSG);
287 				goto done;
288 			}
289 			t = imsg.data;
290 			/* at least one char */
291 			if (datalen < 2 || t[datalen-1] != '\0') {
292 				err = got_error(GOT_ERR_PRIVSEP_MSG);
293 				goto done;
294 			}
295 			if (*t != ' ' && *t != '-' && *t != '+' &&
296 			    *t != '\\') {
297 				err = got_error(GOT_ERR_PRIVSEP_MSG);
298 				goto done;
299 			}
300 
301 			if (*t != '\\')
302 				err = pushline(h, t);
303 			else if (lastmode == '-')
304 				h->old_nonl = 1;
305 			else if (lastmode == '+')
306 				h->new_nonl = 1;
307 			else
308 				err = got_error(GOT_ERR_PATCH_MALFORMED);
309 
310 			if (err)
311 				goto done;
312 
313 			lastmode = *t;
314 			break;
315 		default:
316 			err = got_error(GOT_ERR_PRIVSEP_MSG);
317 			goto done;
318 		}
319 
320 		imsg_free(&imsg);
321 	}
322 
323 done:
324 	if (err)
325 		patch_free(p);
326 
327 	imsg_free(&imsg);
328 	return err;
329 }
330 
331 static void
332 reverse_patch(struct got_patch *p)
333 {
334 	struct got_patch_hunk *h;
335 	size_t i;
336 	int tmp;
337 
338 	STAILQ_FOREACH(h, &p->head, entries) {
339 		tmp = h->old_from;
340 		h->old_from = h->new_from;
341 		h->new_from = tmp;
342 
343 		tmp = h->old_lines;
344 		h->old_lines = h->new_lines;
345 		h->new_lines = tmp;
346 
347 		tmp = h->old_nonl;
348 		h->old_nonl = h->new_nonl;
349 		h->new_nonl = tmp;
350 
351 		for (i = 0; i < h->len; ++i) {
352 			if (*h->lines[i] == '+')
353 				*h->lines[i] = '-';
354 			else if (*h->lines[i] == '-')
355 				*h->lines[i] = '+';
356 		}
357 	}
358 }
359 
360 /*
361  * Copy data from orig starting at copypos until pos into tmp.
362  * If pos is -1, copy until EOF.
363  */
364 static const struct got_error *
365 copy(FILE *tmp, FILE *orig, off_t copypos, off_t pos)
366 {
367 	char buf[BUFSIZ];
368 	size_t len, r, w;
369 
370 	if (fseeko(orig, copypos, SEEK_SET) == -1)
371 		return got_error_from_errno("fseeko");
372 
373 	while (pos == -1 || copypos < pos) {
374 		len = sizeof(buf);
375 		if (pos > 0)
376 			len = MIN(len, (size_t)pos - copypos);
377 		r = fread(buf, 1, len, orig);
378 		if (r != len && ferror(orig))
379 			return got_error_from_errno("fread");
380 		w = fwrite(buf, 1, r, tmp);
381 		if (w != r)
382 			return got_error_from_errno("fwrite");
383 		copypos += len;
384 		if (r != len && feof(orig)) {
385 			if (pos == -1)
386 				return NULL;
387 			return got_error(GOT_ERR_HUNK_FAILED);
388 		}
389 	}
390 	return NULL;
391 }
392 
393 static int linecmp(const char *, const char *, int *);
394 
395 static const struct got_error *
396 locate_hunk(FILE *orig, struct got_patch_hunk *h, off_t *pos, int *lineno)
397 {
398 	const struct got_error *err = NULL;
399 	char *line = NULL;
400 	char mode = *h->lines[0];
401 	size_t linesize = 0;
402 	ssize_t linelen;
403 	off_t match = -1;
404 	int mangled = 0, match_lineno = -1;
405 
406 	for (;;) {
407 		linelen = getline(&line, &linesize, orig);
408 		if (linelen == -1) {
409 			if (ferror(orig))
410 				err = got_error_from_errno("getline");
411 			else if (match == -1)
412 				err = got_error(GOT_ERR_HUNK_FAILED);
413 			break;
414 		}
415 		if (line[linelen - 1] == '\n')
416 			line[linelen - 1] = '\0';
417 		(*lineno)++;
418 
419 		if ((mode == ' ' && !linecmp(h->lines[0] + 1, line, &mangled)) ||
420 		    (mode == '-' && !linecmp(h->lines[0] + 1, line, &mangled)) ||
421 		    (mode == '+' && *lineno == h->old_from)) {
422 			match = ftello(orig);
423 			if (match == -1) {
424 				err = got_error_from_errno("ftello");
425 				break;
426 			}
427 			match -= linelen;
428 			match_lineno = (*lineno)-1;
429 		}
430 
431 		if (*lineno >= h->old_from && match != -1) {
432 			if (mangled)
433 				h->ws_mangled = 1;
434 			break;
435 		}
436 	}
437 
438 	if (err == NULL) {
439 		*pos = match;
440 		*lineno = match_lineno;
441 		if (fseeko(orig, match, SEEK_SET) == -1)
442 			err = got_error_from_errno("fseeko");
443 	}
444 
445 	free(line);
446 	return err;
447 }
448 
449 static int
450 linecmp(const char *a, const char *b, int *mangled)
451 {
452 	int c;
453 
454 	*mangled = 0;
455 	c = strcmp(a, b);
456 	if (c == 0)
457 		return c;
458 
459 	*mangled = 1;
460 	for (;;) {
461 		while (*a == '\t' || *a == ' ' || *a == '\f')
462 			a++;
463 		while (*b == '\t' || *b == ' ' || *b == '\f')
464 			b++;
465 		if (*a == '\0' || *a != *b)
466 			break;
467 		a++, b++;
468 	}
469 
470 	return *a - *b;
471 }
472 
473 static const struct got_error *
474 test_hunk(FILE *orig, struct got_patch_hunk *h)
475 {
476 	const struct got_error *err = NULL;
477 	char *line = NULL;
478 	size_t linesize = 0, i = 0;
479 	ssize_t linelen;
480 	int mangled;
481 
482 	for (i = 0; i < h->len; ++i) {
483 		switch (*h->lines[i]) {
484 		case '+':
485 			continue;
486 		case ' ':
487 		case '-':
488 			linelen = getline(&line, &linesize, orig);
489 			if (linelen == -1) {
490 				if (ferror(orig))
491 					err = got_error_from_errno("getline");
492 				else
493 					err = got_error(
494 					    GOT_ERR_HUNK_FAILED);
495 				goto done;
496 			}
497 			if (line[linelen - 1] == '\n')
498 				line[linelen - 1] = '\0';
499 			if (linecmp(h->lines[i] + 1, line, &mangled)) {
500 				err = got_error(GOT_ERR_HUNK_FAILED);
501 				goto done;
502 			}
503 			if (mangled)
504 				h->ws_mangled = 1;
505 			break;
506 		}
507 	}
508 
509 done:
510 	free(line);
511 	return err;
512 }
513 
514 static const struct got_error *
515 apply_hunk(FILE *orig, FILE *tmp, struct got_patch_hunk *h, int *lineno,
516     off_t from)
517 {
518 	const struct got_error *err = NULL;
519 	const char *t;
520 	size_t linesize = 0, i, new = 0;
521 	char *line = NULL;
522 	char mode;
523 	ssize_t linelen;
524 
525 	if (orig != NULL && fseeko(orig, from, SEEK_SET) == -1)
526 		return got_error_from_errno("fseeko");
527 
528 	for (i = 0; i < h->len; ++i) {
529 		switch (mode = *h->lines[i]) {
530 		case '-':
531 		case ' ':
532 			(*lineno)++;
533 			if (orig != NULL) {
534 				linelen = getline(&line, &linesize, orig);
535 				if (linelen == -1) {
536 					err = got_error_from_errno("getline");
537 					goto done;
538 				}
539 				if (line[linelen - 1] == '\n')
540 					line[linelen - 1] = '\0';
541 				t = line;
542 			} else
543 				t = h->lines[i] + 1;
544 			if (mode == '-')
545 				continue;
546 			if (fprintf(tmp, "%s\n", t) < 0) {
547 				err = got_error_from_errno("fprintf");
548 				goto done;
549 			}
550 			break;
551 		case '+':
552 			new++;
553 			if (fprintf(tmp, "%s", h->lines[i] + 1) < 0) {
554 				err = got_error_from_errno("fprintf");
555 				goto done;
556 			}
557 			if (new != h->new_lines || !h->new_nonl) {
558 				if (fprintf(tmp, "\n") < 0) {
559 					err = got_error_from_errno("fprintf");
560 					goto done;
561 				}
562 			}
563 			break;
564 		}
565 	}
566 
567 done:
568 	free(line);
569 	return err;
570 }
571 
572 static const struct got_error *
573 patch_file(struct got_patch *p, FILE *orig, FILE *tmp)
574 {
575 	const struct got_error *err = NULL;
576 	struct got_patch_hunk *h;
577 	struct stat sb;
578 	int lineno = 0;
579 	off_t copypos, pos;
580 	char *line = NULL;
581 	size_t linesize = 0;
582 	ssize_t linelen;
583 
584 	if (p->old == NULL) {				/* create */
585 		h = STAILQ_FIRST(&p->head);
586 		if (h == NULL || STAILQ_NEXT(h, entries) != NULL)
587 			return got_error(GOT_ERR_PATCH_MALFORMED);
588 		return apply_hunk(orig, tmp, h, &lineno, 0);
589 	}
590 
591 	/* When deleting binary files there are no hunks to apply. */
592 	if (p->new == NULL && STAILQ_EMPTY(&p->head))
593 		return NULL;
594 
595 	if (fstat(fileno(orig), &sb) == -1)
596 		return got_error_from_errno("fstat");
597 
598 	copypos = 0;
599 	STAILQ_FOREACH(h, &p->head, entries) {
600 	tryagain:
601 		err = locate_hunk(orig, h, &pos, &lineno);
602 		if (err != NULL && err->code == GOT_ERR_HUNK_FAILED)
603 			h->err = err;
604 		if (err != NULL)
605 			return err;
606 		err = copy(tmp, orig, copypos, pos);
607 		if (err != NULL)
608 			return err;
609 		copypos = pos;
610 
611 		err = test_hunk(orig, h);
612 		if (err != NULL && err->code == GOT_ERR_HUNK_FAILED) {
613 			/*
614 			 * try to apply the hunk again starting the search
615 			 * after the previous partial match.
616 			 */
617 			if (fseeko(orig, pos, SEEK_SET) == -1)
618 				return got_error_from_errno("fseeko");
619 			linelen = getline(&line, &linesize, orig);
620 			if (linelen == -1)
621 				return got_error_from_errno("getline");
622 			lineno++;
623 			goto tryagain;
624 		}
625 		if (err != NULL)
626 			return err;
627 
628 		if (lineno + 1 != h->old_from)
629 			h->offset = lineno + 1 - h->old_from;
630 
631 		err = apply_hunk(orig, tmp, h, &lineno, pos);
632 		if (err != NULL)
633 			return err;
634 
635 		copypos = ftello(orig);
636 		if (copypos == -1)
637 			return got_error_from_errno("ftello");
638 	}
639 
640 	if (p->new == NULL && sb.st_size != copypos) {
641 		h = STAILQ_FIRST(&p->head);
642 		h->err = got_error(GOT_ERR_HUNK_FAILED);
643 		err = h->err;
644 	} else if (!feof(orig))
645 		err = copy(tmp, orig, copypos, -1);
646 
647 	return err;
648 }
649 
650 static const struct got_error *
651 report_progress(struct patch_args *pa, const char *old, const char *new,
652     unsigned char status, const struct got_error *orig_error)
653 {
654 	const struct got_error *err;
655 	struct got_patch_hunk *h;
656 
657 	err = pa->progress_cb(pa->progress_arg, old, new, status,
658 	    orig_error, 0, 0, 0, 0, 0, 0, NULL);
659 	if (err)
660 		return err;
661 
662 	STAILQ_FOREACH(h, pa->head, entries) {
663 		if (h->offset == 0 && !h->ws_mangled && h->err == NULL)
664 			continue;
665 
666 		err = pa->progress_cb(pa->progress_arg, old, new, 0, NULL,
667 		    h->old_from, h->old_lines, h->new_from, h->new_lines,
668 		    h->offset, h->ws_mangled, h->err);
669 		if (err)
670 			return err;
671 	}
672 
673 	return NULL;
674 }
675 
676 static const struct got_error *
677 patch_delete(void *arg, unsigned char status, unsigned char staged_status,
678     const char *path)
679 {
680 	return report_progress(arg, path, NULL, status, NULL);
681 }
682 
683 static const struct got_error *
684 patch_add(void *arg, unsigned char status, const char *path)
685 {
686 	return report_progress(arg, NULL, path, status, NULL);
687 }
688 
689 static const struct got_error *
690 open_blob(char **path, FILE **fp, const char *blobid,
691     struct got_repository *repo)
692 {
693 	const struct got_error *err = NULL;
694 	struct got_blob_object *blob = NULL;
695 	struct got_object_id id, *idptr, *matched_id = NULL;
696 	int fd = -1;
697 
698 	*fp = NULL;
699 	*path = NULL;
700 
701 	if (strlen(blobid) != SHA1_DIGEST_STRING_LENGTH - 1) {
702 		err = got_repo_match_object_id(&matched_id, NULL, blobid,
703 		    GOT_OBJ_TYPE_BLOB, NULL /* do not resolve tags */,
704 		    repo);
705 		if (err)
706 			return err;
707 		idptr = matched_id;
708 	} else {
709 		if (!got_parse_sha1_digest(id.hash, blobid))
710 			return got_error(GOT_ERR_BAD_OBJ_ID_STR);
711 		idptr = &id;
712 	}
713 
714 	fd = got_opentempfd();
715 	if (fd == -1) {
716 		err = got_error_from_errno("got_opentempfd");
717 		goto done;
718 	}
719 
720 	err = got_object_open_as_blob(&blob, repo, idptr, 8192, fd);
721 	if (err)
722 		goto done;
723 
724 	err = got_opentemp_named(path, fp, GOT_TMPDIR_STR "/got-patch-blob",
725 	    "");
726 	if (err)
727 		goto done;
728 
729 	err = got_object_blob_dump_to_file(NULL, NULL, NULL, *fp, blob);
730 	if (err)
731 		goto done;
732 
733 done:
734 	if (fd != -1 && close(fd) == -1 && err == NULL)
735 		err = got_error_from_errno("close");
736 	if (blob)
737 		got_object_blob_close(blob);
738 	if (matched_id != NULL)
739 		free(matched_id);
740 	if (err) {
741 		if (*fp != NULL)
742 			fclose(*fp);
743 		if (*path != NULL)
744 			unlink(*path);
745 		free(*path);
746 		*fp = NULL;
747 		*path = NULL;
748 	}
749 	return err;
750 }
751 
752 static const struct got_error *
753 prepare_merge(int *do_merge, char **apath, FILE **afile,
754     struct got_worktree *worktree, struct got_repository *repo,
755     struct got_patch *p, struct got_object_id *commit_id,
756     struct got_tree_object *tree, const char *path)
757 {
758 	const struct got_error *err = NULL;
759 
760 	*do_merge = 0;
761 	*apath = NULL;
762 	*afile = NULL;
763 
764 	/* don't run the diff3 merge on creations/deletions */
765 	if (p->old == NULL || p->new == NULL)
766 		return NULL;
767 
768 	if (commit_id) {
769 		struct got_object_id *id;
770 
771 		err = got_object_tree_find_path(&id, NULL, repo, tree, path);
772 		if (err)
773 			return err;
774 		got_sha1_digest_to_str(id->hash, p->blob, sizeof(p->blob));
775 		got_sha1_digest_to_str(commit_id->hash, p->cid, sizeof(p->cid));
776 		free(id);
777 		err = open_blob(apath, afile, p->blob, repo);
778 		*do_merge = err == NULL;
779 	} else if (*p->blob != '\0') {
780 		err = open_blob(apath, afile, p->blob, repo);
781 		/*
782 		 * ignore failures to open this blob, we might have
783 		 * parsed gibberish.
784 		 */
785 		if (err && !(err->code == GOT_ERR_ERRNO && errno == ENOENT) &&
786 		    err->code != GOT_ERR_NO_OBJ)
787 			return err;
788 		*do_merge = err == NULL;
789 		err = NULL;
790 	}
791 
792 	return err;
793 }
794 
795 static const struct got_error *
796 apply_patch(int *overlapcnt, struct got_worktree *worktree,
797     struct got_repository *repo, struct got_fileindex *fileindex,
798     const char *old, const char *new, struct got_patch *p, int nop,
799     int reverse, struct got_object_id *commit_id,
800     struct got_tree_object *tree, struct patch_args *pa,
801     got_cancel_cb cancel_cb, void *cancel_arg)
802 {
803 	const struct got_error *err = NULL;
804 	struct stat sb;
805 	int do_merge = 0, file_renamed = 0;
806 	char *oldlabel = NULL, *newlabel = NULL, *anclabel = NULL;
807 	char *oldpath = NULL, *newpath = NULL;
808 	char *tmppath = NULL, *template = NULL;
809 	char *apath = NULL, *mergepath = NULL;
810 	FILE *oldfile = NULL, *tmpfile = NULL, *afile = NULL, *mergefile = NULL;
811 	int outfd;
812 	mode_t mode = GOT_DEFAULT_FILE_MODE;
813 
814 	*overlapcnt = 0;
815 
816 	err = prepare_merge(&do_merge, &apath, &afile, worktree, repo, p,
817 	    commit_id, tree, old);
818 	if (err)
819 		return err;
820 
821 	if (reverse && !do_merge)
822 		reverse_patch(p);
823 
824 	if (asprintf(&oldpath, "%s/%s", got_worktree_get_root_path(worktree),
825 	    old) == -1) {
826 		err = got_error_from_errno("asprintf");
827 		goto done;
828 	}
829 
830 	if (asprintf(&newpath, "%s/%s", got_worktree_get_root_path(worktree),
831 	    new) == -1) {
832 		err = got_error_from_errno("asprintf");
833 		goto done;
834 	}
835 
836 	file_renamed = strcmp(oldpath, newpath);
837 
838 	if (asprintf(&template, "%s/got-patch",
839 	    got_worktree_get_root_path(worktree)) == -1) {
840 		err = got_error_from_errno(template);
841 		goto done;
842 	}
843 
844 	if (p->old != NULL) {
845 		if ((oldfile = fopen(oldpath, "r")) == NULL) {
846 			err = got_error_from_errno2("open", oldpath);
847 			goto done;
848 		}
849 		if (fstat(fileno(oldfile), &sb) == -1) {
850 			err = got_error_from_errno2("fstat", oldpath);
851 			goto done;
852 		}
853 		mode = sb.st_mode;
854 	} else if (p->xbit)
855 		mode |= (S_IXUSR | S_IXGRP | S_IXOTH);
856 
857 	err = got_opentemp_named(&tmppath, &tmpfile, template, "");
858 	if (err)
859 		goto done;
860 	outfd = fileno(tmpfile);
861 	err = patch_file(p, afile != NULL ? afile : oldfile, tmpfile);
862 	if (err)
863 		goto done;
864 
865 	if (do_merge) {
866 		const char *type, *id;
867 
868 		if (fseeko(afile, 0, SEEK_SET) == -1 ||
869 		    fseeko(oldfile, 0, SEEK_SET) == -1 ||
870 		    fseeko(tmpfile, 0, SEEK_SET) == -1) {
871 			err = got_error_from_errno("fseeko");
872 			goto done;
873 		}
874 
875 		if (asprintf(&oldlabel, "--- %s", p->old) == -1) {
876 			err = got_error_from_errno("asprintf");
877 			oldlabel = NULL;
878 			goto done;
879 		}
880 
881 		if (asprintf(&newlabel, "+++ %s", p->new) == -1) {
882 			err = got_error_from_errno("asprintf");
883 			newlabel = NULL;
884 			goto done;
885 		}
886 
887 		if (*p->cid != '\0') {
888 			type = "commit";
889 			id = p->cid;
890 		} else {
891 			type = "blob";
892 			id = p->blob;
893 		}
894 
895 		if (asprintf(&anclabel, "%s %s", type, id) == -1) {
896 			err = got_error_from_errno("asprintf");
897 			anclabel = NULL;
898 			goto done;
899 		}
900 
901 		if (reverse) {
902 			char *s;
903 			FILE *t;
904 
905 			s = anclabel;
906 			anclabel = newlabel;
907 			newlabel = s;
908 
909 			t = afile;
910 			afile = tmpfile;
911 			tmpfile = t;
912 		}
913 
914 		err = got_opentemp_named(&mergepath, &mergefile, template, "");
915 		if (err)
916 			goto done;
917 		outfd = fileno(mergefile);
918 
919 		err = got_merge_diff3(overlapcnt, outfd, tmpfile, afile,
920 		    oldfile, oldlabel, anclabel, newlabel,
921 		    GOT_DIFF_ALGORITHM_PATIENCE);
922 		if (err)
923 			goto done;
924 	}
925 
926 	if (nop)
927 		goto done;
928 
929 	if (p->old != NULL && p->new == NULL) {
930 		err = got_worktree_patch_schedule_rm(old, repo, worktree,
931 		    fileindex, patch_delete, pa);
932 		goto done;
933 	}
934 
935 	if (fchmod(outfd, apply_umask(mode)) == -1) {
936 		err = got_error_from_errno2("chmod", tmppath);
937 		goto done;
938 	}
939 
940 	if (mergepath) {
941 		err = got_path_move_file(mergepath, newpath);
942 		if (err)
943 			goto done;
944 		free(mergepath);
945 		mergepath = NULL;
946 	} else {
947 		err = got_path_move_file(tmppath, newpath);
948 		if (err)
949 			goto done;
950 		free(tmppath);
951 		tmppath = NULL;
952 	}
953 
954 	if (file_renamed) {
955 		err = got_worktree_patch_schedule_rm(old, repo, worktree,
956 		    fileindex, patch_delete, pa);
957 		if (err == NULL)
958 			err = got_worktree_patch_schedule_add(new, repo,
959 			    worktree, fileindex, patch_add,
960 			    pa);
961 		if (err)
962 			unlink(newpath);
963 	} else if (p->old == NULL) {
964 		err = got_worktree_patch_schedule_add(new, repo, worktree,
965 		    fileindex, patch_add, pa);
966 		if (err)
967 			unlink(newpath);
968 	} else if (*overlapcnt != 0)
969 		err = report_progress(pa, old, new, GOT_STATUS_CONFLICT, NULL);
970 	else if (do_merge)
971 		err = report_progress(pa, old, new, GOT_STATUS_MERGE, NULL);
972 	else
973 		err = report_progress(pa, old, new, GOT_STATUS_MODIFY, NULL);
974 
975 done:
976 	free(template);
977 
978 	if (tmppath != NULL && unlink(tmppath) == -1 && err == NULL)
979 		err = got_error_from_errno("unlink");
980 	if (tmpfile != NULL && fclose(tmpfile) == EOF && err == NULL)
981 		err = got_error_from_errno("fclose");
982 	free(tmppath);
983 
984 	free(oldpath);
985 	if (oldfile != NULL && fclose(oldfile) == EOF && err == NULL)
986 		err = got_error_from_errno("fclose");
987 
988 	if (apath != NULL && unlink(apath) == -1 && err == NULL)
989 		err = got_error_from_errno("unlink");
990 	if (afile != NULL && fclose(afile) == EOF && err == NULL)
991 		err = got_error_from_errno("fclose");
992 	free(apath);
993 
994 	if (mergepath != NULL && unlink(mergepath) == -1 && err == NULL)
995 		err = got_error_from_errno("unlink");
996 	if (mergefile != NULL && fclose(mergefile) == EOF && err == NULL)
997 		err = got_error_from_errno("fclose");
998 	free(mergepath);
999 
1000 	free(newpath);
1001 	free(oldlabel);
1002 	free(newlabel);
1003 	free(anclabel);
1004 	return err;
1005 }
1006 
1007 const struct got_error *
1008 got_patch(int fd, struct got_worktree *worktree, struct got_repository *repo,
1009     int nop, int strip, int reverse, struct got_object_id *commit_id,
1010     got_patch_progress_cb progress_cb, void *progress_arg,
1011     got_cancel_cb cancel_cb, void *cancel_arg)
1012 {
1013 	const struct got_error *err = NULL, *complete_err = NULL;
1014 	struct got_fileindex *fileindex = NULL;
1015 	struct got_commit_object *commit = NULL;
1016 	struct got_tree_object *tree = NULL;
1017 	char *fileindex_path = NULL;
1018 	char *oldpath, *newpath;
1019 	struct imsgbuf *ibuf;
1020 	int imsg_fds[2] = {-1, -1};
1021 	int overlapcnt, done = 0, failed = 0;
1022 	pid_t pid;
1023 
1024 	ibuf = calloc(1, sizeof(*ibuf));
1025 	if (ibuf == NULL) {
1026 		err = got_error_from_errno("calloc");
1027 		goto done;
1028 	}
1029 
1030 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1031 		err = got_error_from_errno("socketpair");
1032 		goto done;
1033 	}
1034 
1035 	pid = fork();
1036 	if (pid == -1) {
1037 		err = got_error_from_errno("fork");
1038 		goto done;
1039 	} else if (pid == 0) {
1040 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PATCH,
1041 		    NULL);
1042 		/* not reached */
1043 	}
1044 
1045 	if (close(imsg_fds[1]) == -1) {
1046 		err = got_error_from_errno("close");
1047 		goto done;
1048 	}
1049 	imsg_fds[1] = -1;
1050 	imsg_init(ibuf, imsg_fds[0]);
1051 
1052 	err = send_patch(ibuf, fd);
1053 	fd = -1;
1054 	if (err)
1055 		goto done;
1056 
1057 	err = got_worktree_patch_prepare(&fileindex, &fileindex_path,
1058 	    worktree);
1059 	if (err)
1060 		goto done;
1061 
1062 	if (commit_id) {
1063 		err = got_object_open_as_commit(&commit, repo, commit_id);
1064 		if (err)
1065 			goto done;
1066 
1067 		err = got_object_open_as_tree(&tree, repo, commit->tree_id);
1068 		if (err)
1069 			goto done;
1070 	}
1071 
1072 	while (!done && err == NULL) {
1073 		struct got_patch p;
1074 		struct patch_args pa;
1075 
1076 		pa.progress_cb = progress_cb;
1077 		pa.progress_arg = progress_arg;
1078 		pa.head = &p.head;
1079 
1080 		err = recv_patch(ibuf, &done, &p, strip);
1081 		if (err || done)
1082 			break;
1083 
1084 		err = got_worktree_patch_check_path(p.old, p.new, &oldpath,
1085 		    &newpath, worktree, repo, fileindex);
1086 		if (err == NULL)
1087 			err = apply_patch(&overlapcnt, worktree, repo,
1088 			    fileindex, oldpath, newpath, &p, nop, reverse,
1089 			    commit_id, tree, &pa, cancel_cb, cancel_arg);
1090 		if (err != NULL) {
1091 			failed = 1;
1092 			/* recoverable errors */
1093 			if (err->code == GOT_ERR_FILE_STATUS ||
1094 			    (err->code == GOT_ERR_ERRNO && errno == ENOENT))
1095 				err = report_progress(&pa, p.old, p.new,
1096 				    GOT_STATUS_CANNOT_UPDATE, err);
1097 			else if (err->code == GOT_ERR_HUNK_FAILED)
1098 				err = report_progress(&pa, p.old, p.new,
1099 				    GOT_STATUS_CANNOT_UPDATE, NULL);
1100 		}
1101 		if (overlapcnt != 0)
1102 			failed = 1;
1103 
1104 		free(oldpath);
1105 		free(newpath);
1106 		patch_free(&p);
1107 
1108 		if (err)
1109 			break;
1110 	}
1111 
1112 done:
1113 	if (fileindex != NULL)
1114 		complete_err = got_worktree_patch_complete(fileindex,
1115 		    fileindex_path);
1116 	if (complete_err && err == NULL)
1117 		err = complete_err;
1118 	free(fileindex_path);
1119 	if (tree)
1120 		got_object_tree_close(tree);
1121 	if (commit)
1122 		got_object_commit_close(commit);
1123 	if (fd != -1 && close(fd) == -1 && err == NULL)
1124 		err = got_error_from_errno("close");
1125 	if (ibuf != NULL)
1126 		imsg_clear(ibuf);
1127 	if (imsg_fds[0] != -1 && close(imsg_fds[0]) == -1 && err == NULL)
1128 		err = got_error_from_errno("close");
1129 	if (imsg_fds[1] != -1 && close(imsg_fds[1]) == -1 && err == NULL)
1130 		err = got_error_from_errno("close");
1131 	if (err == NULL && failed)
1132 		err = got_error(GOT_ERR_PATCH_FAILED);
1133 	return err;
1134 }