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Date:: Thu Jul 7 13:40:32 2022 UTC
Message:: use got_privsep_flush_imsg instead of reinventing it ok stsp@
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1 /*
2  * Copyright (c) 2022 Omar Polo <op@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  *
16  * Apply patches.
17  *
18  * Things that we may want to support:
19  *     + support indented patches?
20  *     + support other kinds of patches?
21  */
22 
23 #include <sys/types.h>
24 #include <sys/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 	return got_privsep_flush_imsg(ibuf);
104 }
105 
106 static void
107 patch_free(struct got_patch *p)
108 {
109 	struct got_patch_hunk *h;
110 	size_t i;
111 
112 	while (!STAILQ_EMPTY(&p->head)) {
113 		h = STAILQ_FIRST(&p->head);
114 		STAILQ_REMOVE_HEAD(&p->head, entries);
115 
116 		for (i = 0; i < h->len; ++i)
117 			free(h->lines[i]);
118 		free(h->lines);
119 		free(h);
120 	}
121 
122 	free(p->new);
123 	free(p->old);
124 
125 	memset(p, 0, sizeof(*p));
126 	STAILQ_INIT(&p->head);
127 }
128 
129 static const struct got_error *
130 pushline(struct got_patch_hunk *h, const char *line)
131 {
132 	void 	*t;
133 	size_t	 newcap;
134 
135 	if (h->len == h->cap) {
136 		if ((newcap = h->cap * 1.5) == 0)
137 			newcap = 16;
138 		t = recallocarray(h->lines, h->cap, newcap,
139 		    sizeof(h->lines[0]));
140 		if (t == NULL)
141 			return got_error_from_errno("recallocarray");
142 		h->lines = t;
143 		h->cap = newcap;
144 	}
145 
146 	if ((t = strdup(line)) == NULL)
147 		return got_error_from_errno("strdup");
148 
149 	h->lines[h->len++] = t;
150 	return NULL;
151 }
152 
153 static const struct got_error *
154 recv_patch(struct imsgbuf *ibuf, int *done, struct got_patch *p, int strip)
155 {
156 	const struct got_error *err = NULL;
157 	struct imsg imsg;
158 	struct got_imsg_patch_hunk hdr;
159 	struct got_imsg_patch patch;
160 	struct got_patch_hunk *h = NULL;
161 	size_t datalen;
162 	int lastmode = -1;
163 
164 	memset(p, 0, sizeof(*p));
165 	STAILQ_INIT(&p->head);
166 
167 	err = got_privsep_recv_imsg(&imsg, ibuf, 0);
168 	if (err)
169 		return err;
170 	if (imsg.hdr.type == GOT_IMSG_PATCH_EOF) {
171 		*done = 1;
172 		goto done;
173 	}
174 	if (imsg.hdr.type != GOT_IMSG_PATCH) {
175 		err = got_error(GOT_ERR_PRIVSEP_MSG);
176 		goto done;
177 	}
178 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
179 	if (datalen != sizeof(patch)) {
180 		err = got_error(GOT_ERR_PRIVSEP_LEN);
181 		goto done;
182 	}
183 	memcpy(&patch, imsg.data, sizeof(patch));
184 
185 	if (patch.old[sizeof(patch.old)-1] != '\0' ||
186 	    patch.new[sizeof(patch.new)-1] != '\0' ||
187 	    patch.cid[sizeof(patch.cid)-1] != '\0' ||
188 	    patch.blob[sizeof(patch.blob)-1] != '\0') {
189 		err = got_error(GOT_ERR_PRIVSEP_LEN);
190 		goto done;
191 	}
192 
193 	if (*patch.cid != '\0')
194 		strlcpy(p->cid, patch.cid, sizeof(p->cid));
195 
196 	if (*patch.blob != '\0')
197 		strlcpy(p->blob, patch.blob, sizeof(p->blob));
198 
199 	/* automatically set strip=1 for git-style diffs */
200 	if (strip == -1 && patch.git &&
201 	    (*patch.old == '\0' || !strncmp(patch.old, "a/", 2)) &&
202 	    (*patch.new == '\0' || !strncmp(patch.new, "b/", 2)))
203 		strip = 1;
204 
205 	/* prefer the new name if not /dev/null for not git-style diffs */
206 	if (!patch.git && *patch.new != '\0' && *patch.old != '\0') {
207 		err = got_path_strip(&p->old, patch.new, strip);
208 		if (err)
209 			goto done;
210 	} else if (*patch.old != '\0') {
211 		err = got_path_strip(&p->old, patch.old, strip);
212 		if (err)
213 			goto done;
214 	}
215 
216 	if (*patch.new != '\0') {
217 		err = got_path_strip(&p->new, patch.new, strip);
218 		if (err)
219 			goto done;
220 	}
221 
222 	if (p->old == NULL && p->new == NULL) {
223 		err = got_error(GOT_ERR_PATCH_MALFORMED);
224 		goto done;
225 	}
226 
227 	imsg_free(&imsg);
228 
229 	for (;;) {
230 		char *t;
231 
232 		err = got_privsep_recv_imsg(&imsg, ibuf, 0);
233 		if (err) {
234 			patch_free(p);
235 			return err;
236 		}
237 
238 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
239 		switch (imsg.hdr.type) {
240 		case GOT_IMSG_PATCH_DONE:
241 			if (h != NULL && h->len == 0)
242 				err = got_error(GOT_ERR_PATCH_MALFORMED);
243 			goto done;
244 		case GOT_IMSG_PATCH_HUNK:
245 			if (h != NULL &&
246 			    (h->len == 0 || h->old_nonl || h->new_nonl)) {
247 				err = got_error(GOT_ERR_PATCH_MALFORMED);
248 				goto done;
249 			}
250 			lastmode = -1;
251 			if (datalen != sizeof(hdr)) {
252 				err = got_error(GOT_ERR_PRIVSEP_LEN);
253 				goto done;
254 			}
255 			memcpy(&hdr, imsg.data, sizeof(hdr));
256 			if (hdr.oldfrom < 0 || hdr.newfrom < 0) {
257 				err = got_error(GOT_ERR_PRIVSEP_LEN);
258 				goto done;
259 			}
260 			if ((h = calloc(1, sizeof(*h))) == NULL) {
261 				err = got_error_from_errno("calloc");
262 				goto done;
263 			}
264 			h->old_from = hdr.oldfrom;
265 			h->old_lines = hdr.oldlines;
266 			h->new_from = hdr.newfrom;
267 			h->new_lines = hdr.newlines;
268 			STAILQ_INSERT_TAIL(&p->head, h, entries);
269 			break;
270 		case GOT_IMSG_PATCH_LINE:
271 			if (h == NULL) {
272 				err = got_error(GOT_ERR_PRIVSEP_MSG);
273 				goto done;
274 			}
275 			t = imsg.data;
276 			/* at least one char */
277 			if (datalen < 2 || t[datalen-1] != '\0') {
278 				err = got_error(GOT_ERR_PRIVSEP_MSG);
279 				goto done;
280 			}
281 			if (*t != ' ' && *t != '-' && *t != '+' &&
282 			    *t != '\\') {
283 				err = got_error(GOT_ERR_PRIVSEP_MSG);
284 				goto done;
285 			}
286 
287 			if (*t != '\\')
288 				err = pushline(h, t);
289 			else if (lastmode == '-')
290 				h->old_nonl = 1;
291 			else if (lastmode == '+')
292 				h->new_nonl = 1;
293 			else
294 				err = got_error(GOT_ERR_PATCH_MALFORMED);
295 
296 			if (err)
297 				goto done;
298 
299 			lastmode = *t;
300 			break;
301 		default:
302 			err = got_error(GOT_ERR_PRIVSEP_MSG);
303 			goto done;
304 		}
305 
306 		imsg_free(&imsg);
307 	}
308 
309 done:
310 	if (err)
311 		patch_free(p);
312 
313 	imsg_free(&imsg);
314 	return err;
315 }
316 
317 /*
318  * Copy data from orig starting at copypos until pos into tmp.
319  * If pos is -1, copy until EOF.
320  */
321 static const struct got_error *
322 copy(FILE *tmp, FILE *orig, off_t copypos, off_t pos)
323 {
324 	char buf[BUFSIZ];
325 	size_t len, r, w;
326 
327 	if (fseeko(orig, copypos, SEEK_SET) == -1)
328 		return got_error_from_errno("fseeko");
329 
330 	while (pos == -1 || copypos < pos) {
331 		len = sizeof(buf);
332 		if (pos > 0)
333 			len = MIN(len, (size_t)pos - copypos);
334 		r = fread(buf, 1, len, orig);
335 		if (r != len && ferror(orig))
336 			return got_error_from_errno("fread");
337 		w = fwrite(buf, 1, r, tmp);
338 		if (w != r)
339 			return got_error_from_errno("fwrite");
340 		copypos += len;
341 		if (r != len && feof(orig)) {
342 			if (pos == -1)
343 				return NULL;
344 			return got_error(GOT_ERR_HUNK_FAILED);
345 		}
346 	}
347 	return NULL;
348 }
349 
350 static const struct got_error *
351 locate_hunk(FILE *orig, struct got_patch_hunk *h, off_t *pos, int *lineno)
352 {
353 	const struct got_error *err = NULL;
354 	char *line = NULL;
355 	char mode = *h->lines[0];
356 	size_t linesize = 0;
357 	ssize_t linelen;
358 	off_t match = -1;
359 	int match_lineno = -1;
360 
361 	for (;;) {
362 		linelen = getline(&line, &linesize, orig);
363 		if (linelen == -1) {
364 			if (ferror(orig))
365 				err = got_error_from_errno("getline");
366 			else if (match == -1)
367 				err = got_error(GOT_ERR_HUNK_FAILED);
368 			break;
369 		}
370 		if (line[linelen - 1] == '\n')
371 			line[linelen - 1] = '\0';
372 		(*lineno)++;
373 
374 		if ((mode == ' ' && !strcmp(h->lines[0] + 1, line)) ||
375 		    (mode == '-' && !strcmp(h->lines[0] + 1, line)) ||
376 		    (mode == '+' && *lineno == h->old_from)) {
377 			match = ftello(orig);
378 			if (match == -1) {
379 				err = got_error_from_errno("ftello");
380 				break;
381 			}
382 			match -= linelen;
383 			match_lineno = (*lineno)-1;
384 		}
385 
386 		if (*lineno >= h->old_from && match != -1)
387 			break;
388 	}
389 
390 	if (err == NULL) {
391 		*pos = match;
392 		*lineno = match_lineno;
393 		if (fseeko(orig, match, SEEK_SET) == -1)
394 			err = got_error_from_errno("fseeko");
395 	}
396 
397 	free(line);
398 	return err;
399 }
400 
401 static int
402 linecmp(const char *a, const char *b, int *mangled)
403 {
404 	int c;
405 
406 	*mangled = 0;
407 	c = strcmp(a, b);
408 	if (c == 0)
409 		return c;
410 
411 	*mangled = 1;
412 	for (;;) {
413 		while (*a == '\t' || *a == ' ' || *a == '\f')
414 			a++;
415 		while (*b == '\t' || *b == ' ' || *b == '\f')
416 			b++;
417 		if (*a == '\0' || *a != *b)
418 			break;
419 		a++, b++;
420 	}
421 
422 	return *a - *b;
423 }
424 
425 static const struct got_error *
426 test_hunk(FILE *orig, struct got_patch_hunk *h)
427 {
428 	const struct got_error *err = NULL;
429 	char *line = NULL;
430 	size_t linesize = 0, i = 0;
431 	ssize_t linelen;
432 	int mangled;
433 
434 	for (i = 0; i < h->len; ++i) {
435 		switch (*h->lines[i]) {
436 		case '+':
437 			continue;
438 		case ' ':
439 		case '-':
440 			linelen = getline(&line, &linesize, orig);
441 			if (linelen == -1) {
442 				if (ferror(orig))
443 					err = got_error_from_errno("getline");
444 				else
445 					err = got_error(
446 					    GOT_ERR_HUNK_FAILED);
447 				goto done;
448 			}
449 			if (line[linelen - 1] == '\n')
450 				line[linelen - 1] = '\0';
451 			if (linecmp(h->lines[i] + 1, line, &mangled)) {
452 				err = got_error(GOT_ERR_HUNK_FAILED);
453 				goto done;
454 			}
455 			if (mangled)
456 				h->ws_mangled = 1;
457 			break;
458 		}
459 	}
460 
461 done:
462 	free(line);
463 	return err;
464 }
465 
466 static const struct got_error *
467 apply_hunk(FILE *orig, FILE *tmp, struct got_patch_hunk *h, int *lineno,
468     off_t from)
469 {
470 	const struct got_error *err = NULL;
471 	const char *t;
472 	size_t linesize = 0, i, new = 0;
473 	char *line = NULL;
474 	char mode;
475 	ssize_t linelen;
476 
477 	if (orig != NULL && fseeko(orig, from, SEEK_SET) == -1)
478 		return got_error_from_errno("fseeko");
479 
480 	for (i = 0; i < h->len; ++i) {
481 		switch (mode = *h->lines[i]) {
482 		case '-':
483 		case ' ':
484 			(*lineno)++;
485 			if (orig != NULL) {
486 				linelen = getline(&line, &linesize, orig);
487 				if (linelen == -1) {
488 					err = got_error_from_errno("getline");
489 					goto done;
490 				}
491 				if (line[linelen - 1] == '\n')
492 					line[linelen - 1] = '\0';
493 				t = line;
494 			} else
495 				t = h->lines[i] + 1;
496 			if (mode == '-')
497 				continue;
498 			if (fprintf(tmp, "%s\n", t) < 0) {
499 				err = got_error_from_errno("fprintf");
500 				goto done;
501 			}
502 			break;
503 		case '+':
504 			new++;
505 			if (fprintf(tmp, "%s", h->lines[i] + 1) < 0) {
506 				err = got_error_from_errno("fprintf");
507 				goto done;
508 			}
509 			if (new != h->new_lines || !h->new_nonl) {
510 				if (fprintf(tmp, "\n") < 0) {
511 					err = got_error_from_errno("fprintf");
512 					goto done;
513 				}
514 			}
515 			break;
516 		}
517 	}
518 
519 done:
520 	free(line);
521 	return err;
522 }
523 
524 static const struct got_error *
525 patch_file(struct got_patch *p, FILE *orig, FILE *tmp)
526 {
527 	const struct got_error *err = NULL;
528 	struct got_patch_hunk *h;
529 	struct stat sb;
530 	int lineno = 0;
531 	off_t copypos, pos;
532 	char *line = NULL;
533 	size_t linesize = 0;
534 	ssize_t linelen;
535 
536 	if (p->old == NULL) {				/* create */
537 		h = STAILQ_FIRST(&p->head);
538 		if (h == NULL || STAILQ_NEXT(h, entries) != NULL)
539 			return got_error(GOT_ERR_PATCH_MALFORMED);
540 		return apply_hunk(orig, tmp, h, &lineno, 0);
541 	}
542 
543 	if (fstat(fileno(orig), &sb) == -1)
544 		return got_error_from_errno("fstat");
545 
546 	copypos = 0;
547 	STAILQ_FOREACH(h, &p->head, entries) {
548 	tryagain:
549 		err = locate_hunk(orig, h, &pos, &lineno);
550 		if (err != NULL && err->code == GOT_ERR_HUNK_FAILED)
551 			h->err = err;
552 		if (err != NULL)
553 			return err;
554 		err = copy(tmp, orig, copypos, pos);
555 		if (err != NULL)
556 			return err;
557 		copypos = pos;
558 
559 		err = test_hunk(orig, h);
560 		if (err != NULL && err->code == GOT_ERR_HUNK_FAILED) {
561 			/*
562 			 * try to apply the hunk again starting the search
563 			 * after the previous partial match.
564 			 */
565 			if (fseeko(orig, pos, SEEK_SET) == -1)
566 				return got_error_from_errno("fseeko");
567 			linelen = getline(&line, &linesize, orig);
568 			if (linelen == -1)
569 				return got_error_from_errno("getline");
570 			lineno++;
571 			goto tryagain;
572 		}
573 		if (err != NULL)
574 			return err;
575 
576 		if (lineno + 1 != h->old_from)
577 			h->offset = lineno + 1 - h->old_from;
578 
579 		err = apply_hunk(orig, tmp, h, &lineno, pos);
580 		if (err != NULL)
581 			return err;
582 
583 		copypos = ftello(orig);
584 		if (copypos == -1)
585 			return got_error_from_errno("ftello");
586 	}
587 
588 	if (p->new == NULL && sb.st_size != copypos) {
589 		h = STAILQ_FIRST(&p->head);
590 		h->err = got_error(GOT_ERR_HUNK_FAILED);
591 		err = h->err;
592 	} else if (!feof(orig))
593 		err = copy(tmp, orig, copypos, -1);
594 
595 	return err;
596 }
597 
598 static const struct got_error *
599 report_progress(struct patch_args *pa, const char *old, const char *new,
600     unsigned char status, const struct got_error *orig_error)
601 {
602 	const struct got_error *err;
603 	struct got_patch_hunk *h;
604 
605 	err = pa->progress_cb(pa->progress_arg, old, new, status,
606 	    orig_error, 0, 0, 0, 0, 0, 0, NULL);
607 	if (err)
608 		return err;
609 
610 	STAILQ_FOREACH(h, pa->head, entries) {
611 		if (h->offset == 0 && !h->ws_mangled && h->err == NULL)
612 			continue;
613 
614 		err = pa->progress_cb(pa->progress_arg, old, new, 0, NULL,
615 		    h->old_from, h->old_lines, h->new_from, h->new_lines,
616 		    h->offset, h->ws_mangled, h->err);
617 		if (err)
618 			return err;
619 	}
620 
621 	return NULL;
622 }
623 
624 static const struct got_error *
625 patch_delete(void *arg, unsigned char status, unsigned char staged_status,
626     const char *path)
627 {
628 	return report_progress(arg, path, NULL, status, NULL);
629 }
630 
631 static const struct got_error *
632 patch_add(void *arg, unsigned char status, const char *path)
633 {
634 	return report_progress(arg, NULL, path, status, NULL);
635 }
636 
637 static const struct got_error *
638 open_blob(char **path, FILE **fp, const char *blobid,
639     struct got_repository *repo)
640 {
641 	const struct got_error *err = NULL;
642 	struct got_blob_object *blob = NULL;
643 	struct got_object_id id, *idptr, *matched_id = NULL;
644 	int fd = -1;
645 
646 	*fp = NULL;
647 	*path = NULL;
648 
649 	if (strlen(blobid) != SHA1_DIGEST_STRING_LENGTH - 1) {
650 		err = got_repo_match_object_id(&matched_id, NULL, blobid,
651 		    GOT_OBJ_TYPE_BLOB, NULL /* do not resolve tags */,
652 		    repo);
653 		if (err)
654 			return err;
655 		idptr = matched_id;
656 	} else {
657 		if (!got_parse_sha1_digest(id.sha1, blobid))
658 			return got_error(GOT_ERR_BAD_OBJ_ID_STR);
659 		idptr = &id;
660 	}
661 
662 	fd = got_opentempfd();
663 	if (fd == -1) {
664 		err = got_error_from_errno("got_opentempfd");
665 		goto done;
666 	}
667 
668 	err = got_object_open_as_blob(&blob, repo, idptr, 8192, fd);
669 	if (err)
670 		goto done;
671 
672 	err = got_opentemp_named(path, fp, GOT_TMPDIR_STR "/got-patch-blob");
673 	if (err)
674 		goto done;
675 
676 	err = got_object_blob_dump_to_file(NULL, NULL, NULL, *fp, blob);
677 	if (err)
678 		goto done;
679 
680 done:
681 	if (fd != -1 && close(fd) == -1 && err == NULL)
682 		err = got_error_from_errno("close");
683 	if (blob)
684 		got_object_blob_close(blob);
685 	if (matched_id != NULL)
686 		free(matched_id);
687 	if (err) {
688 		if (*fp != NULL)
689 			fclose(*fp);
690 		if (*path != NULL)
691 			unlink(*path);
692 		free(*path);
693 		*fp = NULL;
694 		*path = NULL;
695 	}
696 	return err;
697 }
698 
699 static const struct got_error *
700 apply_patch(int *overlapcnt, struct got_worktree *worktree,
701     struct got_repository *repo, struct got_fileindex *fileindex,
702     const char *old, const char *new, struct got_patch *p, int nop,
703     struct patch_args *pa, got_cancel_cb cancel_cb, void *cancel_arg)
704 {
705 	const struct got_error *err = NULL;
706 	struct stat sb;
707 	int do_merge = 0, file_renamed = 0;
708 	char *oldlabel = NULL, *newlabel = NULL, *anclabel = NULL;
709 	char *oldpath = NULL, *newpath = NULL;
710 	char *tmppath = NULL, *template = NULL, *parent = NULL;
711 	char *apath = NULL, *mergepath = NULL;
712 	FILE *oldfile = NULL, *tmpfile = NULL, *afile = NULL, *mergefile = NULL;
713 	int outfd;
714 	const char *outpath;
715 	mode_t mode = GOT_DEFAULT_FILE_MODE;
716 
717 	*overlapcnt = 0;
718 
719 	/* don't run the diff3 merge on creations/deletions */
720 	if (*p->blob != '\0' && p->old != NULL && p->new != NULL) {
721 		err = open_blob(&apath, &afile, p->blob, repo);
722 		/*
723 		 * ignore failures to open this blob, we might have
724 		 * parsed gibberish.
725 		 */
726 		if (err && !(err->code == GOT_ERR_ERRNO && errno == ENOENT) &&
727 		    err->code != GOT_ERR_NO_OBJ)
728 			return err;
729 		else if (err == NULL)
730 			do_merge = 1;
731 		err = NULL;
732 	}
733 
734 	if (asprintf(&oldpath, "%s/%s", got_worktree_get_root_path(worktree),
735 	    old) == -1) {
736 		err = got_error_from_errno("asprintf");
737 		goto done;
738 	}
739 
740 	if (asprintf(&newpath, "%s/%s", got_worktree_get_root_path(worktree),
741 	    new) == -1) {
742 		err = got_error_from_errno("asprintf");
743 		goto done;
744 	}
745 
746 	file_renamed = strcmp(oldpath, newpath);
747 
748 	if (asprintf(&template, "%s/got-patch",
749 	    got_worktree_get_root_path(worktree)) == -1) {
750 		err = got_error_from_errno(template);
751 		goto done;
752 	}
753 
754 	if (p->old != NULL) {
755 		if ((oldfile = fopen(oldpath, "r")) == NULL) {
756 			err = got_error_from_errno2("open", oldpath);
757 			goto done;
758 		}
759 		if (fstat(fileno(oldfile), &sb) == -1) {
760 			err = got_error_from_errno2("fstat", oldpath);
761 			goto done;
762 		}
763 		mode = sb.st_mode;
764 	}
765 
766 	err = got_opentemp_named(&tmppath, &tmpfile, template);
767 	if (err)
768 		goto done;
769 	outpath = tmppath;
770 	outfd = fileno(tmpfile);
771 	err = patch_file(p, afile != NULL ? afile : oldfile, tmpfile);
772 	if (err)
773 		goto done;
774 
775 	if (do_merge) {
776 		const char *type, *id;
777 
778 		if (fseeko(afile, 0, SEEK_SET) == -1 ||
779 		    fseeko(oldfile, 0, SEEK_SET) == -1 ||
780 		    fseeko(tmpfile, 0, SEEK_SET) == -1) {
781 			err = got_error_from_errno("fseeko");
782 			goto done;
783 		}
784 
785 		if (asprintf(&oldlabel, "--- %s", p->old) == -1) {
786 			err = got_error_from_errno("asprintf");
787 			oldlabel = NULL;
788 			goto done;
789 		}
790 
791 		if (asprintf(&newlabel, "+++ %s", p->new) == -1) {
792 			err = got_error_from_errno("asprintf");
793 			newlabel = NULL;
794 			goto done;
795 		}
796 
797 		if (*p->cid != '\0') {
798 			type = "commit";
799 			id = p->cid;
800 		} else {
801 			type = "blob";
802 			id = p->blob;
803 		}
804 
805 		if (asprintf(&anclabel, "%s %s", type, id) == -1) {
806 			err = got_error_from_errno("asprintf");
807 			anclabel = NULL;
808 			goto done;
809 		}
810 
811 		err = got_opentemp_named(&mergepath, &mergefile, template);
812 		if (err)
813 			goto done;
814 		outpath = mergepath;
815 		outfd = fileno(mergefile);
816 
817 		err = got_merge_diff3(overlapcnt, outfd, tmpfile, afile,
818 		    oldfile, oldlabel, anclabel, newlabel,
819 		    GOT_DIFF_ALGORITHM_PATIENCE);
820 		if (err)
821 			goto done;
822 	}
823 
824 	if (nop)
825 		goto done;
826 
827 	if (p->old != NULL && p->new == NULL) {
828 		err = got_worktree_patch_schedule_rm(old, repo, worktree,
829 		    fileindex, patch_delete, pa);
830 		goto done;
831 	}
832 
833 	if (fchmod(outfd, mode) == -1) {
834 		err = got_error_from_errno2("chmod", tmppath);
835 		goto done;
836 	}
837 
838 	if (rename(outpath, newpath) == -1) {
839 		if (errno != ENOENT) {
840 			err = got_error_from_errno3("rename", outpath,
841 			    newpath);
842 			goto done;
843 		}
844 
845 		err = got_path_dirname(&parent, newpath);
846 		if (err != NULL)
847 			goto done;
848 		err = got_path_mkdir(parent);
849 		if (err != NULL)
850 			goto done;
851 		if (rename(outpath, newpath) == -1) {
852 			err = got_error_from_errno3("rename", outpath,
853 			    newpath);
854 			goto done;
855 		}
856 	}
857 
858 	if (file_renamed) {
859 		err = got_worktree_patch_schedule_rm(old, repo, worktree,
860 		    fileindex, patch_delete, pa);
861 		if (err == NULL)
862 			err = got_worktree_patch_schedule_add(new, repo,
863 			    worktree, fileindex, patch_add,
864 			    pa);
865 		if (err)
866 			unlink(newpath);
867 	} else if (p->old == NULL) {
868 		err = got_worktree_patch_schedule_add(new, repo, worktree,
869 		    fileindex, patch_add, pa);
870 		if (err)
871 			unlink(newpath);
872 	} else if (*overlapcnt != 0)
873 		err = report_progress(pa, old, new, GOT_STATUS_CONFLICT, NULL);
874 	else if (do_merge)
875 		err = report_progress(pa, old, new, GOT_STATUS_MERGE, NULL);
876 	else
877 		err = report_progress(pa, old, new, GOT_STATUS_MODIFY, NULL);
878 
879 done:
880 	free(parent);
881 	free(template);
882 
883 	if (tmppath != NULL)
884 		unlink(tmppath);
885 	if (tmpfile != NULL && fclose(tmpfile) == EOF && err == NULL)
886 		err = got_error_from_errno("fclose");
887 	free(tmppath);
888 
889 	free(oldpath);
890 	if (oldfile != NULL && fclose(oldfile) == EOF && err == NULL)
891 		err = got_error_from_errno("fclose");
892 
893 	if (apath != NULL)
894 		unlink(apath);
895 	if (afile != NULL && fclose(afile) == EOF && err == NULL)
896 		err = got_error_from_errno("fclose");
897 	free(apath);
898 
899 	if (mergepath != NULL)
900 		unlink(mergepath);
901 	if (mergefile != NULL && fclose(mergefile) == EOF && err == NULL)
902 		err = got_error_from_errno("fclose");
903 	free(mergepath);
904 
905 	free(newpath);
906 	free(oldlabel);
907 	free(newlabel);
908 	free(anclabel);
909 	return err;
910 }
911 
912 static void
913 reverse_patch(struct got_patch *p)
914 {
915 	struct got_patch_hunk *h;
916 	size_t i;
917 	int tmp;
918 
919 	STAILQ_FOREACH(h, &p->head, entries) {
920 		tmp = h->old_from;
921 		h->old_from = h->new_from;
922 		h->new_from = tmp;
923 
924 		tmp = h->old_lines;
925 		h->old_lines = h->new_lines;
926 		h->new_lines = tmp;
927 
928 		tmp = h->old_nonl;
929 		h->old_nonl = h->new_nonl;
930 		h->new_nonl = tmp;
931 
932 		for (i = 0; i < h->len; ++i) {
933 			if (*h->lines[i] == '+')
934 				*h->lines[i] = '-';
935 			else if (*h->lines[i] == '-')
936 				*h->lines[i] = '+';
937 		}
938 	}
939 }
940 
941 const struct got_error *
942 got_patch(int fd, struct got_worktree *worktree, struct got_repository *repo,
943     int nop, int strip, int reverse, got_patch_progress_cb progress_cb,
944     void *progress_arg, got_cancel_cb cancel_cb, void *cancel_arg)
945 {
946 	const struct got_error *err = NULL, *complete_err = NULL;
947 	struct got_fileindex *fileindex = NULL;
948 	char *fileindex_path = NULL;
949 	char *oldpath, *newpath;
950 	struct imsgbuf *ibuf;
951 	int imsg_fds[2] = {-1, -1};
952 	int overlapcnt, done = 0, failed = 0;
953 	pid_t pid;
954 
955 	ibuf = calloc(1, sizeof(*ibuf));
956 	if (ibuf == NULL) {
957 		err = got_error_from_errno("calloc");
958 		goto done;
959 	}
960 
961 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
962 		err = got_error_from_errno("socketpair");
963 		goto done;
964 	}
965 
966 	pid = fork();
967 	if (pid == -1) {
968 		err = got_error_from_errno("fork");
969 		goto done;
970 	} else if (pid == 0) {
971 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PATCH,
972 		    NULL);
973 		/* not reached */
974 	}
975 
976 	if (close(imsg_fds[1]) == -1) {
977 		err = got_error_from_errno("close");
978 		goto done;
979 	}
980 	imsg_fds[1] = -1;
981 	imsg_init(ibuf, imsg_fds[0]);
982 
983 	err = send_patch(ibuf, fd);
984 	fd = -1;
985 	if (err)
986 		goto done;
987 
988 	err = got_worktree_patch_prepare(&fileindex, &fileindex_path,
989 	    worktree);
990 	if (err)
991 		goto done;
992 
993 	while (!done && err == NULL) {
994 		struct got_patch p;
995 		struct patch_args pa;
996 
997 		pa.progress_cb = progress_cb;
998 		pa.progress_arg = progress_arg;
999 		pa.head = &p.head;
1000 
1001 		err = recv_patch(ibuf, &done, &p, strip);
1002 		if (err || done)
1003 			break;
1004 
1005 		if (reverse)
1006 			reverse_patch(&p);
1007 
1008 		err = got_worktree_patch_check_path(p.old, p.new, &oldpath,
1009 		    &newpath, worktree, repo, fileindex);
1010 		if (err == NULL)
1011 			err = apply_patch(&overlapcnt, worktree, repo,
1012 			    fileindex, oldpath, newpath, &p, nop, &pa,
1013 			    cancel_cb, cancel_arg);
1014 		if (err != NULL) {
1015 			failed = 1;
1016 			/* recoverable errors */
1017 			if (err->code == GOT_ERR_FILE_STATUS ||
1018 			    (err->code == GOT_ERR_ERRNO && errno == ENOENT))
1019 				err = report_progress(&pa, p.old, p.new,
1020 				    GOT_STATUS_CANNOT_UPDATE, err);
1021 			else if (err->code == GOT_ERR_HUNK_FAILED)
1022 				err = report_progress(&pa, p.old, p.new,
1023 				    GOT_STATUS_CANNOT_UPDATE, NULL);
1024 		}
1025 		if (overlapcnt != 0)
1026 			failed = 1;
1027 
1028 		free(oldpath);
1029 		free(newpath);
1030 		patch_free(&p);
1031 
1032 		if (err)
1033 			break;
1034 	}
1035 
1036 done:
1037 	if (fileindex != NULL)
1038 		complete_err = got_worktree_patch_complete(fileindex,
1039 		    fileindex_path);
1040 	if (complete_err && err == NULL)
1041 		err = complete_err;
1042 	free(fileindex_path);
1043 	if (fd != -1 && close(fd) == -1 && err == NULL)
1044 		err = got_error_from_errno("close");
1045 	if (ibuf != NULL)
1046 		imsg_clear(ibuf);
1047 	if (imsg_fds[0] != -1 && close(imsg_fds[0]) == -1 && err == NULL)
1048 		err = got_error_from_errno("close");
1049 	if (imsg_fds[1] != -1 && close(imsg_fds[1]) == -1 && err == NULL)
1050 		err = got_error_from_errno("close");
1051 	if (err == NULL && failed)
1052 		err = got_error(GOT_ERR_PATCH_FAILED);
1053 	return err;
1054 }