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Date:: Mon Mar 11 14:03:28 2019 UTC
Message:: implement got_ref_write()
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1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@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 
17 #include <sys/types.h>
18 #include <sys/queue.h>
19 #include <sys/stat.h>
20 
21 #include <ctype.h>
22 #include <dirent.h>
23 #include <sha1.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <util.h>
28 #include <zlib.h>
29 #include <time.h>
30 
31 #include "got_error.h"
32 #include "got_object.h"
33 #include "got_repository.h"
34 #include "got_reference.h"
35 #include "got_opentemp.h"
36 
37 #include "got_lib_sha1.h"
38 #include "got_lib_path.h"
39 #include "got_lib_delta.h"
40 #include "got_lib_inflate.h"
41 #include "got_lib_object.h"
42 #include "got_lib_lockfile.h"
43 
44 #ifndef nitems
45 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
46 #endif
47 
48 #define GOT_REF_HEADS	"heads"
49 #define GOT_REF_TAGS	"tags"
50 #define GOT_REF_REMOTES	"remotes"
51 
52 /* A symbolic reference. */
53 struct got_symref {
54 	char *name;
55 	char *ref;
56 };
57 
58 /* A non-symbolic reference (there is no better designation). */
59 struct got_ref {
60 	char *name;
61 	u_int8_t sha1[SHA1_DIGEST_LENGTH];
62 };
63 
64 /* A reference which points to an arbitrary object. */
65 struct got_reference {
66 	unsigned int flags;
67 #define GOT_REF_IS_SYMBOLIC	0x01
68 
69 	union {
70 		struct got_ref ref;
71 		struct got_symref symref;
72 	} ref;
73 };
74 
75 static const struct got_error *
76 parse_symref(struct got_reference **ref, const char *name, const char *line)
77 {
78 	struct got_symref *symref;
79 	char *symref_name;
80 	char *symref_ref;
81 
82 	if (line[0] == '\0')
83 		return got_error(GOT_ERR_BAD_REF_DATA);
84 
85 	symref_name = strdup(name);
86 	if (symref_name == NULL)
87 		return got_error_from_errno();
88 	symref_ref = strdup(line);
89 	if (symref_ref == NULL) {
90 		const struct got_error *err = got_error_from_errno();
91 		free(symref_name);
92 		return err;
93 	}
94 
95 	*ref = calloc(1, sizeof(**ref));
96 	if (*ref == NULL)
97 		return got_error_from_errno();
98 	(*ref)->flags |= GOT_REF_IS_SYMBOLIC;
99 	symref = &((*ref)->ref.symref);
100 	symref->name = symref_name;
101 	symref->ref = symref_ref;
102 	return NULL;
103 }
104 
105 static const struct got_error *
106 parse_ref_line(struct got_reference **ref, const char *name, const char *line)
107 {
108 	struct got_object_id id;
109 
110 	if (strncmp(line, "ref: ", 5) == 0) {
111 		line += 5;
112 		return parse_symref(ref, name, line);
113 	}
114 
115 	if (!got_parse_sha1_digest(id.sha1, line))
116 		return got_error(GOT_ERR_BAD_REF_DATA);
117 
118 	return got_ref_alloc(ref, name, &id);
119 }
120 
121 static const struct got_error *
122 parse_ref_file(struct got_reference **ref, const char *name,
123     const char *abspath)
124 {
125 	const struct got_error *err = NULL;
126 	FILE *f = fopen(abspath, "rb");
127 	char *line;
128 	size_t len;
129 	const char delim[3] = {'\0', '\0', '\0'};
130 
131 	if (f == NULL)
132 		return NULL;
133 
134 	line = fparseln(f, &len, NULL, delim, 0);
135 	if (line == NULL) {
136 		err = got_error(GOT_ERR_BAD_REF_DATA);
137 		goto done;
138 	}
139 
140 	err = parse_ref_line(ref, name, line);
141 done:
142 	free(line);
143 	if (fclose(f) != 0 && err == NULL)
144 		err = got_error_from_errno();
145 	return err;
146 }
147 
148 static int
149 is_well_known_ref(const char *refname)
150 {
151 	return (strcmp(refname, GOT_REF_HEAD) == 0 ||
152 	    strcmp(refname, GOT_REF_ORIG_HEAD) == 0 ||
153 	    strcmp(refname, GOT_REF_MERGE_HEAD) == 0 ||
154 	    strcmp(refname, GOT_REF_FETCH_HEAD) == 0);
155 }
156 
157 static char *
158 get_refs_dir_path(struct got_repository *repo, const char *refname)
159 {
160 	if (is_well_known_ref(refname) || strncmp(refname, "refs/", 5) == 0)
161 		return strdup(got_repo_get_path_git_dir(repo));
162 
163 	return got_repo_get_path_refs(repo);
164 }
165 
166 static int
167 is_valid_ref_name(const char *name)
168 {
169 	const char *s, *slash, *seg;
170 	const char forbidden[] = { ' ', '~', '^', ':', '?', '*', '[' , '\\' };
171 	const char *forbidden_seq[] = { "//", "..", "@{" };
172 	const char *lfs = GOT_LOCKFILE_SUFFIX;
173 	const size_t lfs_len = sizeof(GOT_LOCKFILE_SUFFIX) - 1;
174 	int i;
175 
176 	if (name[0] == '@' && name[1] == '\0')
177 		return 0;
178 
179 	slash = strchr(name, '/');
180 	if (slash == NULL)
181 		return 0;
182 
183 	s = name;
184 	seg = s;
185 	if (seg[0] == '\0' || seg[0] == '.' || seg[0] == '/')
186 		return 0;
187 	while (*s) {
188 		for (i = 0; i < nitems(forbidden); i++) {
189 			if (*s == forbidden[i])
190 				return 0;
191 		}
192 		for (i = 0; i < nitems(forbidden_seq); i++) {
193 			if (s[0] == forbidden_seq[i][0] &&
194 			    s[1] == forbidden_seq[i][1])
195 				return 0;
196 		}
197 		if (iscntrl((unsigned char)s[0]))
198 			return 0;
199 		if (s[0] == '.' && s[1] == '\0')
200 			return 0;
201 		if (*s == '/') {
202 			const char *nextseg = s + 1;
203 			if (nextseg[0] == '\0' || nextseg[0] == '.' ||
204 			    nextseg[0] == '/')
205 				return 0;
206 			if (seg <= s - lfs_len &&
207 			    strncmp(s - lfs_len, lfs, lfs_len) == 0)
208 				return 0;
209 			seg = nextseg;
210 		}
211 		s++;
212 	}
213 
214 	if (seg <= s - lfs_len &&
215 	    strncmp(s - lfs_len, lfs, lfs_len) == 0)
216 		return 0;
217 
218 	return 1;
219 }
220 
221 const struct got_error *
222 got_ref_alloc(struct got_reference **ref, const char *name,
223     struct got_object_id *id)
224 {
225 	const struct got_error *err = NULL;
226 
227 	if (!is_valid_ref_name(name))
228 		return got_error(GOT_ERR_BAD_REF_NAME);
229 
230 	*ref = calloc(1, sizeof(**ref));
231 	if (*ref == NULL)
232 		return got_error_from_errno();
233 
234 	memcpy(&(*ref)->ref.ref.sha1, id->sha1, SHA1_DIGEST_LENGTH);
235 	(*ref)->ref.ref.name = strdup(name);
236 	if ((*ref)->ref.ref.name == NULL) {
237 		err = got_error_from_errno();
238 		free(*ref);
239 		*ref = NULL;
240 	}
241 	return err;
242 }
243 
244 static const struct got_error *
245 parse_packed_ref_line(struct got_reference **ref, const char *abs_refname,
246     const char *line)
247 {
248 	struct got_object_id id;
249 	const char *name;
250 
251 	*ref = NULL;
252 
253 	if (line[0] == '#' || line[0] == '^')
254 		return NULL;
255 
256 	if (!got_parse_sha1_digest(id.sha1, line))
257 		return got_error(GOT_ERR_BAD_REF_DATA);
258 
259 	if (abs_refname) {
260 		if (strcmp(line + SHA1_DIGEST_STRING_LENGTH, abs_refname) != 0)
261 			return NULL;
262 		name = abs_refname;
263 	} else
264 		name = line + SHA1_DIGEST_STRING_LENGTH;
265 
266 	return got_ref_alloc(ref, name, &id);
267 }
268 
269 static const struct got_error *
270 open_packed_ref(struct got_reference **ref, FILE *f, const char **subdirs,
271     int nsubdirs, const char *refname)
272 {
273 	const struct got_error *err = NULL;
274 	char *abs_refname;
275 	char *line;
276 	size_t len;
277 	const char delim[3] = {'\0', '\0', '\0'};
278 	int i, ref_is_absolute = (strncmp(refname, "refs/", 5) == 0);
279 
280 	*ref = NULL;
281 
282 	if (ref_is_absolute)
283 		abs_refname = (char *)refname;
284 	do {
285 		line = fparseln(f, &len, NULL, delim, 0);
286 		if (line == NULL)
287 			break;
288 		for (i = 0; i < nsubdirs; i++) {
289 			if (!ref_is_absolute &&
290 			    asprintf(&abs_refname, "refs/%s/%s", subdirs[i],
291 			    refname) == -1)
292 				return got_error_from_errno();
293 			err = parse_packed_ref_line(ref, abs_refname, line);
294 			if (!ref_is_absolute)
295 				free(abs_refname);
296 			if (err || *ref != NULL)
297 				break;
298 		}
299 		free(line);
300 		if (err)
301 			break;
302 	} while (*ref == NULL);
303 
304 	return err;
305 }
306 
307 static const struct got_error *
308 open_ref(struct got_reference **ref, const char *path_refs, const char *subdir,
309     const char *name)
310 {
311 	const struct got_error *err = NULL;
312 	char *path = NULL;
313 	char *normpath = NULL;
314 	char *absname = NULL;
315 	int ref_is_absolute = (strncmp(name, "refs/", 5) == 0);
316 	int ref_is_well_known = is_well_known_ref(name);
317 
318 	*ref = NULL;
319 
320 	if (ref_is_absolute || ref_is_well_known) {
321 		if (asprintf(&path, "%s/%s", path_refs, name) == -1)
322 			return got_error_from_errno();
323 		absname = (char *)name;
324 	} else {
325 		if (asprintf(&path, "%s/%s/%s", path_refs, subdir, name) == -1)
326 			return got_error_from_errno();
327 
328 		if (asprintf(&absname, "refs/%s/%s", subdir, name) == -1) {
329 			err = got_error_from_errno();
330 			goto done;
331 		}
332 	}
333 
334 	normpath = got_path_normalize(path);
335 	if (normpath == NULL) {
336 		err = got_error_from_errno();
337 		goto done;
338 	}
339 
340 	err = parse_ref_file(ref, absname, normpath);
341 done:
342 	if (!ref_is_absolute && !ref_is_well_known)
343 		free(absname);
344 	free(path);
345 	free(normpath);
346 	return err;
347 }
348 
349 const struct got_error *
350 got_ref_open(struct got_reference **ref, struct got_repository *repo,
351    const char *refname)
352 {
353 	const struct got_error *err = NULL;
354 	char *path_refs = NULL;
355 	const char *subdirs[] = {
356 	    GOT_REF_HEADS, GOT_REF_TAGS, GOT_REF_REMOTES
357 	};
358 	int i, well_known = is_well_known_ref(refname);
359 
360 	*ref = NULL;
361 
362 	path_refs = get_refs_dir_path(repo, refname);
363 	if (path_refs == NULL) {
364 		err = got_error_from_errno();
365 		goto done;
366 	}
367 
368 	if (!well_known) {
369 		char *packed_refs_path;
370 		FILE *f;
371 
372 		/* Search on-disk refs before packed refs! */
373 		for (i = 0; i < nitems(subdirs); i++) {
374 			err = open_ref(ref, path_refs, subdirs[i], refname);
375 			if (err || *ref)
376 				goto done;
377 		}
378 
379 		packed_refs_path = got_repo_get_path_packed_refs(repo);
380 		if (packed_refs_path == NULL) {
381 			err = got_error_from_errno();
382 			goto done;
383 		}
384 
385 		f = fopen(packed_refs_path, "rb");
386 		free(packed_refs_path);
387 		if (f != NULL) {
388 			err = open_packed_ref(ref, f, subdirs, nitems(subdirs),
389 			    refname);
390 			if (fclose(f) != 0 && err == NULL)
391 				err = got_error_from_errno();
392 			if (err || *ref)
393 				goto done;
394 		}
395 	}
396 
397 	err = open_ref(ref, path_refs, "", refname);
398 	if (err)
399 		goto done;
400 done:
401 	if (*ref == NULL)
402 		err = got_error_not_ref(refname);
403 	free(path_refs);
404 	return err;
405 }
406 
407 void
408 got_ref_close(struct got_reference *ref)
409 {
410 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
411 		free(ref->ref.symref.name);
412 	else
413 		free(ref->ref.ref.name);
414 	free(ref);
415 }
416 
417 struct got_reference *
418 got_ref_dup(struct got_reference *ref)
419 {
420 	struct got_reference *ret;
421 
422 	ret = calloc(1, sizeof(*ret));
423 	if (ret == NULL)
424 		return NULL;
425 
426 	ret->flags = ref->flags;
427 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
428 		ret->ref.symref.name = strdup(ref->ref.symref.name);
429 		if (ret->ref.symref.name == NULL) {
430 			free(ret);
431 			return NULL;
432 		}
433 		ret->ref.symref.ref = strdup(ref->ref.symref.ref);
434 		if (ret->ref.symref.ref == NULL) {
435 			free(ret->ref.symref.name);
436 			free(ret);
437 			return NULL;
438 		}
439 	} else {
440 		ref->ref.ref.name = strdup(ref->ref.ref.name);
441 		if (ref->ref.ref.name == NULL) {
442 			free(ret);
443 			return NULL;
444 		}
445 		memcpy(ret->ref.ref.sha1, ref->ref.ref.sha1,
446 		    SHA1_DIGEST_LENGTH);
447 	}
448 
449 	return ret;
450 }
451 
452 static const struct got_error *
453 resolve_symbolic_ref(struct got_reference **resolved,
454     struct got_repository *repo, struct got_reference *ref)
455 {
456 	struct got_reference *nextref;
457 	const struct got_error *err;
458 
459 	err = got_ref_open(&nextref, repo, ref->ref.symref.ref);
460 	if (err)
461 		return err;
462 
463 	if (nextref->flags & GOT_REF_IS_SYMBOLIC)
464 		err = resolve_symbolic_ref(resolved, repo, nextref);
465 	else
466 		*resolved = got_ref_dup(nextref);
467 
468 	got_ref_close(nextref);
469 	return err;
470 }
471 
472 const struct got_error *
473 got_ref_resolve(struct got_object_id **id, struct got_repository *repo,
474     struct got_reference *ref)
475 {
476 	const struct got_error *err;
477 
478 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
479 		struct got_reference *resolved = NULL;
480 		err = resolve_symbolic_ref(&resolved, repo, ref);
481 		if (err == NULL)
482 			err = got_ref_resolve(id, repo, resolved);
483 		free(resolved);
484 		return err;
485 	}
486 
487 	*id = calloc(1, sizeof(**id));
488 	if (*id == NULL)
489 		return got_error_from_errno();
490 	memcpy((*id)->sha1, ref->ref.ref.sha1, SHA1_DIGEST_LENGTH);
491 	return NULL;
492 }
493 
494 char *
495 got_ref_to_str(struct got_reference *ref)
496 {
497 	char *str;
498 
499 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
500 		return strdup(ref->ref.symref.ref);
501 
502 	str = malloc(SHA1_DIGEST_STRING_LENGTH);
503 	if (str == NULL)
504 		return NULL;
505 
506 	if (got_sha1_digest_to_str(ref->ref.ref.sha1, str,
507 	    SHA1_DIGEST_STRING_LENGTH) == NULL) {
508 		free(str);
509 		return NULL;
510 	}
511 
512 	return str;
513 }
514 
515 const char *
516 got_ref_get_name(struct got_reference *ref)
517 {
518 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
519 		return ref->ref.symref.name;
520 
521 	return ref->ref.ref.name;
522 }
523 
524 static const struct got_error *
525 insert_ref(struct got_reflist_head *refs, struct got_reference *ref,
526     struct got_repository *repo)
527 {
528 	const struct got_error *err;
529 	struct got_object_id *id;
530 	struct got_reflist_entry *new, *re, *prev;
531 	int cmp;
532 
533 	err = got_ref_resolve(&id, repo, ref);
534 	if (err)
535 		return err;
536 
537 	new = malloc(sizeof(*re));
538 	if (new == NULL) {
539 		free(id);
540 		return got_error_from_errno();
541 	}
542 	new->ref = ref;
543 	new->id = id;
544 
545 	/*
546 	 * We must de-duplicate entries on insert because packed-refs may
547 	 * contain redundant entries. On-disk refs take precedence.
548 	 * This code assumes that on-disk revs are read before packed-refs.
549 	 * We're iterating the list anyway, so insert elements sorted by name.
550 	 */
551 	re = SIMPLEQ_FIRST(refs);
552 	while (re) {
553 		cmp = got_path_cmp(got_ref_get_name(re->ref),
554 		    got_ref_get_name(ref));
555 		if (cmp == 0) {
556 			free(ref); /* duplicate */
557 			return NULL;
558 		} else if (cmp > 0) {
559 			if (prev)
560 				SIMPLEQ_INSERT_AFTER(refs, prev, new, entry);
561 			else
562 				SIMPLEQ_INSERT_HEAD(refs, new, entry);
563 			return NULL;
564 		} else {
565 			prev = re;
566 			re = SIMPLEQ_NEXT(re, entry);
567 		}
568 	}
569 
570 	SIMPLEQ_INSERT_TAIL(refs, new, entry);
571 	return NULL;
572 }
573 
574 static const struct got_error *
575 gather_on_disk_refs(struct got_reflist_head *refs, const char *path_refs,
576     const char *subdir, struct got_repository *repo)
577 {
578 	const struct got_error *err = NULL;
579 	DIR *d = NULL;
580 	char *path_subdir;
581 
582 	if (asprintf(&path_subdir, "%s/%s", path_refs, subdir) == -1)
583 		return got_error_from_errno();
584 
585 	d = opendir(path_subdir);
586 	if (d == NULL)
587 		goto done;
588 
589 	while (1) {
590 		struct dirent *dent;
591 		struct got_reference *ref;
592 		char *child;
593 
594 		dent = readdir(d);
595 		if (dent == NULL)
596 			break;
597 
598 		if (strcmp(dent->d_name, ".") == 0 ||
599 		    strcmp(dent->d_name, "..") == 0)
600 			continue;
601 
602 		switch (dent->d_type) {
603 		case DT_REG:
604 			err = open_ref(&ref, path_refs, subdir, dent->d_name);
605 			if (err)
606 				goto done;
607 			if (ref) {
608 				err = insert_ref(refs, ref, repo);
609 				if (err)
610 					goto done;
611 			}
612 			break;
613 		case DT_DIR:
614 			if (asprintf(&child, "%s%s%s", subdir,
615 			    subdir[0] == '\0' ? "" : "/", dent->d_name) == -1) {
616 				err = got_error_from_errno();
617 				break;
618 			}
619 			err = gather_on_disk_refs(refs, path_refs, child, repo);
620 			free(child);
621 			break;
622 		default:
623 			break;
624 		}
625 	}
626 done:
627 	if (d)
628 		closedir(d);
629 	free(path_subdir);
630 	return err;
631 }
632 
633 const struct got_error *
634 got_ref_list(struct got_reflist_head *refs, struct got_repository *repo)
635 {
636 	const struct got_error *err;
637 	char *packed_refs_path, *path_refs = NULL;
638 	FILE *f = NULL;
639 	struct got_reference *ref;
640 
641 	/* HEAD ref should always exist. */
642 	path_refs = get_refs_dir_path(repo, GOT_REF_HEAD);
643 	if (path_refs == NULL) {
644 		err = got_error_from_errno();
645 		goto done;
646 	}
647 	err = open_ref(&ref, path_refs, "", GOT_REF_HEAD);
648 	if (err)
649 		goto done;
650 	err = insert_ref(refs, ref, repo);
651 	if (err)
652 		goto done;
653 
654 	/* Gather on-disk refs before parsing packed-refs. */
655 	free(path_refs);
656 	path_refs = get_refs_dir_path(repo, "");
657 	if (path_refs == NULL) {
658 		err = got_error_from_errno();
659 		goto done;
660 	}
661 	err = gather_on_disk_refs(refs, path_refs, "", repo);
662 	if (err)
663 		goto done;
664 
665 	/*
666 	 * The packed-refs file may contain redundant entries, in which
667 	 * case on-disk refs take precedence.
668 	 */
669 	packed_refs_path = got_repo_get_path_packed_refs(repo);
670 	if (packed_refs_path == NULL) {
671 		err = got_error_from_errno();
672 		goto done;
673 	}
674 
675 	f = fopen(packed_refs_path, "r");
676 	free(packed_refs_path);
677 	if (f) {
678 		char *line;
679 		size_t len;
680 		const char delim[3] = {'\0', '\0', '\0'};
681 		while (1) {
682 			line = fparseln(f, &len, NULL, delim, 0);
683 			if (line == NULL)
684 				break;
685 			err = parse_packed_ref_line(&ref, NULL, line);
686 			if (err)
687 				goto done;
688 			if (ref) {
689 				err = insert_ref(refs, ref, repo);
690 				if (err)
691 					goto done;
692 			}
693 		}
694 	}
695 done:
696 	free(path_refs);
697 	if (f && fclose(f) != 0 && err == NULL)
698 		err = got_error_from_errno();
699 	return err;
700 }
701 
702 const struct got_error *
703 got_ref_write(struct got_reference *ref, struct got_repository *repo)
704 {
705 	const struct got_error *err = NULL, *unlock_err = NULL;
706 	const char *name = got_ref_get_name(ref);
707 	char *path_refs = NULL, *path = NULL, *tmppath = NULL;
708 	struct got_lockfile *lf = NULL;
709 	FILE *f = NULL;
710 	size_t n;
711 	struct stat sb;
712 
713 	path_refs = get_refs_dir_path(repo, name);
714 	if (path_refs == NULL) {
715 		err = got_error_from_errno();
716 		goto done;
717 	}
718 
719 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
720 		err = got_error_from_errno();
721 		goto done;
722 	}
723 
724 	err = got_opentemp_named(&tmppath, &f, path);
725 	if (f == NULL) {
726 		err = got_error_from_errno();
727 		goto done;
728 	}
729 
730 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
731 		n = fprintf(f, "ref: %s\n", ref->ref.symref.ref);
732 		if (n != strlen(ref->ref.symref.ref) + 6) {
733 			err = got_ferror(f, GOT_ERR_IO);
734 			goto done;
735 		}
736 	} else {
737 		char hex[SHA1_DIGEST_STRING_LENGTH];
738 		if (got_sha1_digest_to_str(ref->ref.ref.sha1, hex,
739 		    sizeof(hex)) == NULL) {
740 			err = got_error(GOT_ERR_BAD_REF_DATA);
741 			goto done;
742 		}
743 		n = fprintf(f, "%s\n", hex);
744 		if (n != sizeof(hex) + 1) {
745 			err = got_ferror(f, GOT_ERR_IO);
746 			goto done;
747 		}
748 	}
749 
750 	err = got_lockfile_lock(&lf, path);
751 	if (err)
752 		goto done;
753 
754 	/* XXX: check if old content matches our expectations? */
755 
756 	if (stat(path, &sb) != 0) {
757 		err = got_error_from_errno();
758 		goto done;
759 	}
760 
761 	if (rename(tmppath, path) != 0) {
762 		err = got_error_from_errno();
763 		goto done;
764 	}
765 	free(tmppath);
766 	tmppath = NULL;
767 
768 	if (chmod(path, sb.st_mode) != 0) {
769 		err = got_error_from_errno();
770 		goto done;
771 	}
772 done:
773 	if (lf)
774 		unlock_err = got_lockfile_unlock(lf);
775 	if (f) {
776 		if (fclose(f) != 0 && err == NULL)
777 			err = got_error_from_errno();
778 	}
779 	free(path_refs);
780 	free(path);
781 	if (tmppath) {
782 		if (unlink(tmppath) != 0 && err == NULL)
783 			err = got_error_from_errno();
784 		free(tmppath);
785 	}
786 	return err ? err : unlock_err;
787 }