1/*
2 * Utilities for paths and pathnames
3 */
4#include "cache.h"
5#include "strbuf.h"
6#include "string-list.h"
7#include "dir.h"
8static int get_st_mode_bits(const char *path, int *mode)
10{
11 struct stat st;
12 if (lstat(path, &st) < 0)
13 return -1;
14 *mode = st.st_mode;
15 return 0;
16}
17static char bad_path[] = "/bad-path/";
19static struct strbuf *get_pathname(void)
21{
22 static struct strbuf pathname_array[4] = {
23 STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
24 };
25 static int index;
26 struct strbuf *sb = &pathname_array[3 & ++index];
27 strbuf_reset(sb);
28 return sb;
29}
30static char *cleanup_path(char *path)
32{
33 /* Clean it up */
34 if (!memcmp(path, "./", 2)) {
35 path += 2;
36 while (*path == '/')
37 path++;
38 }
39 return path;
40}
41static void strbuf_cleanup_path(struct strbuf *sb)
43{
44 char *path = cleanup_path(sb->buf);
45 if (path > sb->buf)
46 strbuf_remove(sb, 0, path - sb->buf);
47}
48char *mksnpath(char *buf, size_t n, const char *fmt, ...)
50{
51 va_list args;
52 unsigned len;
53 va_start(args, fmt);
55 len = vsnprintf(buf, n, fmt, args);
56 va_end(args);
57 if (len >= n) {
58 strlcpy(buf, bad_path, n);
59 return buf;
60 }
61 return cleanup_path(buf);
62}
63static int dir_prefix(const char *buf, const char *dir)
65{
66 int len = strlen(dir);
67 return !strncmp(buf, dir, len) &&
68 (is_dir_sep(buf[len]) || buf[len] == '\0');
69}
70/* $buf =~ m|$dir/+$file| but without regex */
72static int is_dir_file(const char *buf, const char *dir, const char *file)
73{
74 int len = strlen(dir);
75 if (strncmp(buf, dir, len) || !is_dir_sep(buf[len]))
76 return 0;
77 while (is_dir_sep(buf[len]))
78 len++;
79 return !strcmp(buf + len, file);
80}
81static void replace_dir(struct strbuf *buf, int len, const char *newdir)
83{
84 int newlen = strlen(newdir);
85 int need_sep = (buf->buf[len] && !is_dir_sep(buf->buf[len])) &&
86 !is_dir_sep(newdir[newlen - 1]);
87 if (need_sep)
88 len--; /* keep one char, to be replaced with '/' */
89 strbuf_splice(buf, 0, len, newdir, newlen);
90 if (need_sep)
91 buf->buf[newlen] = '/';
92}
93static const char *common_list[] = {
95 "/branches", "/hooks", "/info", "!/logs", "/lost-found",
96 "/objects", "/refs", "/remotes", "/worktrees", "/rr-cache", "/svn",
97 "config", "!gc.pid", "packed-refs", "shallow",
98 NULL
99};
100static void update_common_dir(struct strbuf *buf, int git_dir_len)
102{
103 char *base = buf->buf + git_dir_len;
104 const char **p;
105 if (is_dir_file(base, "logs", "HEAD") ||
107 is_dir_file(base, "info", "sparse-checkout"))
108 return; /* keep this in $GIT_DIR */
109 for (p = common_list; *p; p++) {
110 const char *path = *p;
111 int is_dir = 0;
112 if (*path == '!')
113 path++;
114 if (*path == '/') {
115 path++;
116 is_dir = 1;
117 }
118 if (is_dir && dir_prefix(base, path)) {
119 replace_dir(buf, git_dir_len, get_git_common_dir());
120 return;
121 }
122 if (!is_dir && !strcmp(base, path)) {
123 replace_dir(buf, git_dir_len, get_git_common_dir());
124 return;
125 }
126 }
127}
128void report_linked_checkout_garbage(void)
130{
131 struct strbuf sb = STRBUF_INIT;
132 const char **p;
133 int len;
134 if (!git_common_dir_env)
136 return;
137 strbuf_addf(&sb, "%s/", get_git_dir());
138 len = sb.len;
139 for (p = common_list; *p; p++) {
140 const char *path = *p;
141 if (*path == '!')
142 continue;
143 strbuf_setlen(&sb, len);
144 strbuf_addstr(&sb, path);
145 if (file_exists(sb.buf))
146 report_garbage("unused in linked checkout", sb.buf);
147 }
148 strbuf_release(&sb);
149}
150static void adjust_git_path(struct strbuf *buf, int git_dir_len)
152{
153 const char *base = buf->buf + git_dir_len;
154 if (git_graft_env && is_dir_file(base, "info", "grafts"))
155 strbuf_splice(buf, 0, buf->len,
156 get_graft_file(), strlen(get_graft_file()));
157 else if (git_index_env && !strcmp(base, "index"))
158 strbuf_splice(buf, 0, buf->len,
159 get_index_file(), strlen(get_index_file()));
160 else if (git_db_env && dir_prefix(base, "objects"))
161 replace_dir(buf, git_dir_len + 7, get_object_directory());
162 else if (git_common_dir_env)
163 update_common_dir(buf, git_dir_len);
164}
165static void do_git_path(struct strbuf *buf, const char *fmt, va_list args)
167{
168 int gitdir_len;
169 strbuf_addstr(buf, get_git_dir());
170 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
171 strbuf_addch(buf, '/');
172 gitdir_len = buf->len;
173 strbuf_vaddf(buf, fmt, args);
174 adjust_git_path(buf, gitdir_len);
175 strbuf_cleanup_path(buf);
176}
177void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
179{
180 va_list args;
181 va_start(args, fmt);
182 do_git_path(sb, fmt, args);
183 va_end(args);
184}
185const char *git_path(const char *fmt, ...)
187{
188 struct strbuf *pathname = get_pathname();
189 va_list args;
190 va_start(args, fmt);
191 do_git_path(pathname, fmt, args);
192 va_end(args);
193 return pathname->buf;
194}
195char *git_pathdup(const char *fmt, ...)
197{
198 struct strbuf path = STRBUF_INIT;
199 va_list args;
200 va_start(args, fmt);
201 do_git_path(&path, fmt, args);
202 va_end(args);
203 return strbuf_detach(&path, NULL);
204}
205char *mkpathdup(const char *fmt, ...)
207{
208 struct strbuf sb = STRBUF_INIT;
209 va_list args;
210 va_start(args, fmt);
211 strbuf_vaddf(&sb, fmt, args);
212 va_end(args);
213 strbuf_cleanup_path(&sb);
214 return strbuf_detach(&sb, NULL);
215}
216const char *mkpath(const char *fmt, ...)
218{
219 va_list args;
220 struct strbuf *pathname = get_pathname();
221 va_start(args, fmt);
222 strbuf_vaddf(pathname, fmt, args);
223 va_end(args);
224 return cleanup_path(pathname->buf);
225}
226static void do_submodule_path(struct strbuf *buf, const char *path,
228 const char *fmt, va_list args)
229{
230 const char *git_dir;
231 strbuf_addstr(buf, path);
233 if (buf->len && buf->buf[buf->len - 1] != '/')
234 strbuf_addch(buf, '/');
235 strbuf_addstr(buf, ".git");
236 git_dir = read_gitfile(buf->buf);
238 if (git_dir) {
239 strbuf_reset(buf);
240 strbuf_addstr(buf, git_dir);
241 }
242 strbuf_addch(buf, '/');
243 strbuf_vaddf(buf, fmt, args);
245 strbuf_cleanup_path(buf);
246}
247const char *git_path_submodule(const char *path, const char *fmt, ...)
249{
250 va_list args;
251 struct strbuf *buf = get_pathname();
252 va_start(args, fmt);
253 do_submodule_path(buf, path, fmt, args);
254 va_end(args);
255 return buf->buf;
256}
257char *git_pathdup_submodule(const char *path, const char *fmt, ...)
259{
260 va_list args;
261 struct strbuf buf = STRBUF_INIT;
262 va_start(args, fmt);
263 do_submodule_path(&buf, path, fmt, args);
264 va_end(args);
265 return strbuf_detach(&buf, NULL);
266}
267void strbuf_git_path_submodule(struct strbuf *buf, const char *path,
269 const char *fmt, ...)
270{
271 va_list args;
272 va_start(args, fmt);
273 do_submodule_path(buf, path, fmt, args);
274 va_end(args);
275}
276int validate_headref(const char *path)
278{
279 struct stat st;
280 char *buf, buffer[256];
281 unsigned char sha1[20];
282 int fd;
283 ssize_t len;
284 if (lstat(path, &st) < 0)
286 return -1;
287 /* Make sure it is a "refs/.." symlink */
289 if (S_ISLNK(st.st_mode)) {
290 len = readlink(path, buffer, sizeof(buffer)-1);
291 if (len >= 5 && !memcmp("refs/", buffer, 5))
292 return 0;
293 return -1;
294 }
295 /*
297 * Anything else, just open it and try to see if it is a symbolic ref.
298 */
299 fd = open(path, O_RDONLY);
300 if (fd < 0)
301 return -1;
302 len = read_in_full(fd, buffer, sizeof(buffer)-1);
303 close(fd);
304 /*
306 * Is it a symbolic ref?
307 */
308 if (len < 4)
309 return -1;
310 if (!memcmp("ref:", buffer, 4)) {
311 buf = buffer + 4;
312 len -= 4;
313 while (len && isspace(*buf))
314 buf++, len--;
315 if (len >= 5 && !memcmp("refs/", buf, 5))
316 return 0;
317 }
318 /*
320 * Is this a detached HEAD?
321 */
322 if (!get_sha1_hex(buffer, sha1))
323 return 0;
324 return -1;
326}
327static struct passwd *getpw_str(const char *username, size_t len)
329{
330 struct passwd *pw;
331 char *username_z = xmemdupz(username, len);
332 pw = getpwnam(username_z);
333 free(username_z);
334 return pw;
335}
336/*
338 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
339 * then it is a newly allocated string. Returns NULL on getpw failure or
340 * if path is NULL.
341 */
342char *expand_user_path(const char *path)
343{
344 struct strbuf user_path = STRBUF_INIT;
345 const char *to_copy = path;
346 if (path == NULL)
348 goto return_null;
349 if (path[0] == '~') {
350 const char *first_slash = strchrnul(path, '/');
351 const char *username = path + 1;
352 size_t username_len = first_slash - username;
353 if (username_len == 0) {
354 const char *home = getenv("HOME");
355 if (!home)
356 goto return_null;
357 strbuf_addstr(&user_path, home);
358 } else {
359 struct passwd *pw = getpw_str(username, username_len);
360 if (!pw)
361 goto return_null;
362 strbuf_addstr(&user_path, pw->pw_dir);
363 }
364 to_copy = first_slash;
365 }
366 strbuf_addstr(&user_path, to_copy);
367 return strbuf_detach(&user_path, NULL);
368return_null:
369 strbuf_release(&user_path);
370 return NULL;
371}
372/*
374 * First, one directory to try is determined by the following algorithm.
375 *
376 * (0) If "strict" is given, the path is used as given and no DWIM is
377 * done. Otherwise:
378 * (1) "~/path" to mean path under the running user's home directory;
379 * (2) "~user/path" to mean path under named user's home directory;
380 * (3) "relative/path" to mean cwd relative directory; or
381 * (4) "/absolute/path" to mean absolute directory.
382 *
383 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
384 * in this order. We select the first one that is a valid git repository, and
385 * chdir() to it. If none match, or we fail to chdir, we return NULL.
386 *
387 * If all goes well, we return the directory we used to chdir() (but
388 * before ~user is expanded), avoiding getcwd() resolving symbolic
389 * links. User relative paths are also returned as they are given,
390 * except DWIM suffixing.
391 */
392const char *enter_repo(const char *path, int strict)
393{
394 static char used_path[PATH_MAX];
395 static char validated_path[PATH_MAX];
396 if (!path)
398 return NULL;
399 if (!strict) {
401 static const char *suffix[] = {
402 "/.git", "", ".git/.git", ".git", NULL,
403 };
404 const char *gitfile;
405 int len = strlen(path);
406 int i;
407 while ((1 < len) && (path[len-1] == '/'))
408 len--;
409 if (PATH_MAX <= len)
411 return NULL;
412 strncpy(used_path, path, len); used_path[len] = 0 ;
413 strcpy(validated_path, used_path);
414 if (used_path[0] == '~') {
416 char *newpath = expand_user_path(used_path);
417 if (!newpath || (PATH_MAX - 10 < strlen(newpath))) {
418 free(newpath);
419 return NULL;
420 }
421 /*
422 * Copy back into the static buffer. A pity
423 * since newpath was not bounded, but other
424 * branches of the if are limited by PATH_MAX
425 * anyway.
426 */
427 strcpy(used_path, newpath); free(newpath);
428 }
429 else if (PATH_MAX - 10 < len)
430 return NULL;
431 len = strlen(used_path);
432 for (i = 0; suffix[i]; i++) {
433 struct stat st;
434 strcpy(used_path + len, suffix[i]);
435 if (!stat(used_path, &st) &&
436 (S_ISREG(st.st_mode) ||
437 (S_ISDIR(st.st_mode) && is_git_directory(used_path)))) {
438 strcat(validated_path, suffix[i]);
439 break;
440 }
441 }
442 if (!suffix[i])
443 return NULL;
444 gitfile = read_gitfile(used_path) ;
445 if (gitfile)
446 strcpy(used_path, gitfile);
447 if (chdir(used_path))
448 return NULL;
449 path = validated_path;
450 }
451 else if (chdir(path))
452 return NULL;
453 if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
455 validate_headref("HEAD") == 0) {
456 set_git_dir(".");
457 check_repository_format();
458 return path;
459 }
460 return NULL;
462}
463static int calc_shared_perm(int mode)
465{
466 int tweak;
467 if (shared_repository < 0)
469 tweak = -shared_repository;
470 else
471 tweak = shared_repository;
472 if (!(mode & S_IWUSR))
474 tweak &= ~0222;
475 if (mode & S_IXUSR)
476 /* Copy read bits to execute bits */
477 tweak |= (tweak & 0444) >> 2;
478 if (shared_repository < 0)
479 mode = (mode & ~0777) | tweak;
480 else
481 mode |= tweak;
482 return mode;
484}
485int adjust_shared_perm(const char *path)
488{
489 int old_mode, new_mode;
490 if (!shared_repository)
492 return 0;
493 if (get_st_mode_bits(path, &old_mode) < 0)
494 return -1;
495 new_mode = calc_shared_perm(old_mode);
497 if (S_ISDIR(old_mode)) {
498 /* Copy read bits to execute bits */
499 new_mode |= (new_mode & 0444) >> 2;
500 new_mode |= FORCE_DIR_SET_GID;
501 }
502 if (((old_mode ^ new_mode) & ~S_IFMT) &&
504 chmod(path, (new_mode & ~S_IFMT)) < 0)
505 return -2;
506 return 0;
507}
508static int have_same_root(const char *path1, const char *path2)
510{
511 int is_abs1, is_abs2;
512 is_abs1 = is_absolute_path(path1);
514 is_abs2 = is_absolute_path(path2);
515 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
516 (!is_abs1 && !is_abs2);
517}
518/*
520 * Give path as relative to prefix.
521 *
522 * The strbuf may or may not be used, so do not assume it contains the
523 * returned path.
524 */
525const char *relative_path(const char *in, const char *prefix,
526 struct strbuf *sb)
527{
528 int in_len = in ? strlen(in) : 0;
529 int prefix_len = prefix ? strlen(prefix) : 0;
530 int in_off = 0;
531 int prefix_off = 0;
532 int i = 0, j = 0;
533 if (!in_len)
535 return "./";
536 else if (!prefix_len)
537 return in;
538 if (have_same_root(in, prefix)) {
540 /* bypass dos_drive, for "c:" is identical to "C:" */
541 if (has_dos_drive_prefix(in)) {
542 i = 2;
543 j = 2;
544 }
545 } else {
546 return in;
547 }
548 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
550 if (is_dir_sep(prefix[i])) {
551 while (is_dir_sep(prefix[i]))
552 i++;
553 while (is_dir_sep(in[j]))
554 j++;
555 prefix_off = i;
556 in_off = j;
557 } else {
558 i++;
559 j++;
560 }
561 }
562 if (
564 /* "prefix" seems like prefix of "in" */
565 i >= prefix_len &&
566 /*
567 * but "/foo" is not a prefix of "/foobar"
568 * (i.e. prefix not end with '/')
569 */
570 prefix_off < prefix_len) {
571 if (j >= in_len) {
572 /* in="/a/b", prefix="/a/b" */
573 in_off = in_len;
574 } else if (is_dir_sep(in[j])) {
575 /* in="/a/b/c", prefix="/a/b" */
576 while (is_dir_sep(in[j]))
577 j++;
578 in_off = j;
579 } else {
580 /* in="/a/bbb/c", prefix="/a/b" */
581 i = prefix_off;
582 }
583 } else if (
584 /* "in" is short than "prefix" */
585 j >= in_len &&
586 /* "in" not end with '/' */
587 in_off < in_len) {
588 if (is_dir_sep(prefix[i])) {
589 /* in="/a/b", prefix="/a/b/c/" */
590 while (is_dir_sep(prefix[i]))
591 i++;
592 in_off = in_len;
593 }
594 }
595 in += in_off;
596 in_len -= in_off;
597 if (i >= prefix_len) {
599 if (!in_len)
600 return "./";
601 else
602 return in;
603 }
604 strbuf_reset(sb);
606 strbuf_grow(sb, in_len);
607 while (i < prefix_len) {
609 if (is_dir_sep(prefix[i])) {
610 strbuf_addstr(sb, "../");
611 while (is_dir_sep(prefix[i]))
612 i++;
613 continue;
614 }
615 i++;
616 }
617 if (!is_dir_sep(prefix[prefix_len - 1]))
618 strbuf_addstr(sb, "../");
619 strbuf_addstr(sb, in);
621 return sb->buf;
623}
624/*
626 * A simpler implementation of relative_path
627 *
628 * Get relative path by removing "prefix" from "in". This function
629 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
630 * to increase performance when traversing the path to work_tree.
631 */
632const char *remove_leading_path(const char *in, const char *prefix)
633{
634 static char buf[PATH_MAX + 1];
635 int i = 0, j = 0;
636 if (!prefix || !prefix[0])
638 return in;
639 while (prefix[i]) {
640 if (is_dir_sep(prefix[i])) {
641 if (!is_dir_sep(in[j]))
642 return in;
643 while (is_dir_sep(prefix[i]))
644 i++;
645 while (is_dir_sep(in[j]))
646 j++;
647 continue;
648 } else if (in[j] != prefix[i]) {
649 return in;
650 }
651 i++;
652 j++;
653 }
654 if (
655 /* "/foo" is a prefix of "/foo" */
656 in[j] &&
657 /* "/foo" is not a prefix of "/foobar" */
658 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
659 )
660 return in;
661 while (is_dir_sep(in[j]))
662 j++;
663 if (!in[j])
664 strcpy(buf, ".");
665 else
666 strcpy(buf, in + j);
667 return buf;
668}
669/*
671 * It is okay if dst == src, but they should not overlap otherwise.
672 *
673 * Performs the following normalizations on src, storing the result in dst:
674 * - Ensures that components are separated by '/' (Windows only)
675 * - Squashes sequences of '/'.
676 * - Removes "." components.
677 * - Removes ".." components, and the components the precede them.
678 * Returns failure (non-zero) if a ".." component appears as first path
679 * component anytime during the normalization. Otherwise, returns success (0).
680 *
681 * Note that this function is purely textual. It does not follow symlinks,
682 * verify the existence of the path, or make any system calls.
683 *
684 * prefix_len != NULL is for a specific case of prefix_pathspec():
685 * assume that src == dst and src[0..prefix_len-1] is already
686 * normalized, any time "../" eats up to the prefix_len part,
687 * prefix_len is reduced. In the end prefix_len is the remaining
688 * prefix that has not been overridden by user pathspec.
689 */
690int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
691{
692 char *dst0;
693 if (has_dos_drive_prefix(src)) {
695 *dst++ = *src++;
696 *dst++ = *src++;
697 }
698 dst0 = dst;
699 if (is_dir_sep(*src)) {
701 *dst++ = '/';
702 while (is_dir_sep(*src))
703 src++;
704 }
705 for (;;) {
707 char c = *src;
708 /*
710 * A path component that begins with . could be
711 * special:
712 * (1) "." and ends -- ignore and terminate.
713 * (2) "./" -- ignore them, eat slash and continue.
714 * (3) ".." and ends -- strip one and terminate.
715 * (4) "../" -- strip one, eat slash and continue.
716 */
717 if (c == '.') {
718 if (!src[1]) {
719 /* (1) */
720 src++;
721 } else if (is_dir_sep(src[1])) {
722 /* (2) */
723 src += 2;
724 while (is_dir_sep(*src))
725 src++;
726 continue;
727 } else if (src[1] == '.') {
728 if (!src[2]) {
729 /* (3) */
730 src += 2;
731 goto up_one;
732 } else if (is_dir_sep(src[2])) {
733 /* (4) */
734 src += 3;
735 while (is_dir_sep(*src))
736 src++;
737 goto up_one;
738 }
739 }
740 }
741 /* copy up to the next '/', and eat all '/' */
743 while ((c = *src++) != '\0' && !is_dir_sep(c))
744 *dst++ = c;
745 if (is_dir_sep(c)) {
746 *dst++ = '/';
747 while (is_dir_sep(c))
748 c = *src++;
749 src--;
750 } else if (!c)
751 break;
752 continue;
753 up_one:
755 /*
756 * dst0..dst is prefix portion, and dst[-1] is '/';
757 * go up one level.
758 */
759 dst--; /* go to trailing '/' */
760 if (dst <= dst0)
761 return -1;
762 /* Windows: dst[-1] cannot be backslash anymore */
763 while (dst0 < dst && dst[-1] != '/')
764 dst--;
765 if (prefix_len && *prefix_len > dst - dst0)
766 *prefix_len = dst - dst0;
767 }
768 *dst = '\0';
769 return 0;
770}
771int normalize_path_copy(char *dst, const char *src)
773{
774 return normalize_path_copy_len(dst, src, NULL);
775}
776/*
778 * path = Canonical absolute path
779 * prefixes = string_list containing normalized, absolute paths without
780 * trailing slashes (except for the root directory, which is denoted by "/").
781 *
782 * Determines, for each path in prefixes, whether the "prefix"
783 * is an ancestor directory of path. Returns the length of the longest
784 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
785 * is an ancestor. (Note that this means 0 is returned if prefixes is
786 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
787 * are not considered to be their own ancestors. path must be in a
788 * canonical form: empty components, or "." or ".." components are not
789 * allowed.
790 */
791int longest_ancestor_length(const char *path, struct string_list *prefixes)
792{
793 int i, max_len = -1;
794 if (!strcmp(path, "/"))
796 return -1;
797 for (i = 0; i < prefixes->nr; i++) {
799 const char *ceil = prefixes->items[i].string;
800 int len = strlen(ceil);
801 if (len == 1 && ceil[0] == '/')
803 len = 0; /* root matches anything, with length 0 */
804 else if (!strncmp(path, ceil, len) && path[len] == '/')
805 ; /* match of length len */
806 else
807 continue; /* no match */
808 if (len > max_len)
810 max_len = len;
811 }
812 return max_len;
814}
815/* strip arbitrary amount of directory separators at end of path */
817static inline int chomp_trailing_dir_sep(const char *path, int len)
818{
819 while (len && is_dir_sep(path[len - 1]))
820 len--;
821 return len;
822}
823/*
825 * If path ends with suffix (complete path components), returns the
826 * part before suffix (sans trailing directory separators).
827 * Otherwise returns NULL.
828 */
829char *strip_path_suffix(const char *path, const char *suffix)
830{
831 int path_len = strlen(path), suffix_len = strlen(suffix);
832 while (suffix_len) {
834 if (!path_len)
835 return NULL;
836 if (is_dir_sep(path[path_len - 1])) {
838 if (!is_dir_sep(suffix[suffix_len - 1]))
839 return NULL;
840 path_len = chomp_trailing_dir_sep(path, path_len);
841 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
842 }
843 else if (path[--path_len] != suffix[--suffix_len])
844 return NULL;
845 }
846 if (path_len && !is_dir_sep(path[path_len - 1]))
848 return NULL;
849 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
850}
851int daemon_avoid_alias(const char *p)
853{
854 int sl, ndot;
855 /*
857 * This resurrects the belts and suspenders paranoia check by HPA
858 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
859 * does not do getcwd() based path canonicalization.
860 *
861 * sl becomes true immediately after seeing '/' and continues to
862 * be true as long as dots continue after that without intervening
863 * non-dot character.
864 */
865 if (!p || (*p != '/' && *p != '~'))
866 return -1;
867 sl = 1; ndot = 0;
868 p++;
869 while (1) {
871 char ch = *p++;
872 if (sl) {
873 if (ch == '.')
874 ndot++;
875 else if (ch == '/') {
876 if (ndot < 3)
877 /* reject //, /./ and /../ */
878 return -1;
879 ndot = 0;
880 }
881 else if (ch == 0) {
882 if (0 < ndot && ndot < 3)
883 /* reject /.$ and /..$ */
884 return -1;
885 return 0;
886 }
887 else
888 sl = ndot = 0;
889 }
890 else if (ch == 0)
891 return 0;
892 else if (ch == '/') {
893 sl = 1;
894 ndot = 0;
895 }
896 }
897}
898static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
900{
901 if (len < skip)
902 return 0;
903 len -= skip;
904 path += skip;
905 while (len-- > 0) {
906 char c = *(path++);
907 if (c != ' ' && c != '.')
908 return 0;
909 }
910 return 1;
911}
912int is_ntfs_dotgit(const char *name)
914{
915 int len;
916 for (len = 0; ; len++)
918 if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
919 if (only_spaces_and_periods(name, len, 4) &&
920 !strncasecmp(name, ".git", 4))
921 return 1;
922 if (only_spaces_and_periods(name, len, 5) &&
923 !strncasecmp(name, "git~1", 5))
924 return 1;
925 if (name[len] != '\\')
926 return 0;
927 name += len + 1;
928 len = -1;
929 }
930}
931char *xdg_config_home(const char *filename)
933{
934 const char *home, *config_home;
935 assert(filename);
937 config_home = getenv("XDG_CONFIG_HOME");
938 if (config_home && *config_home)
939 return mkpathdup("%s/git/%s", config_home, filename);
940 home = getenv("HOME");
942 if (home)
943 return mkpathdup("%s/.config/git/%s", home, filename);
944 return NULL;
945}