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}
226const char *git_path_submodule(const char *path, const char *fmt, ...)
228{
229 struct strbuf *buf = get_pathname();
230 const char *git_dir;
231 va_list args;
232 strbuf_addstr(buf, path);
234 if (buf->len && buf->buf[buf->len - 1] != '/')
235 strbuf_addch(buf, '/');
236 strbuf_addstr(buf, ".git");
237 git_dir = read_gitfile(buf->buf);
239 if (git_dir) {
240 strbuf_reset(buf);
241 strbuf_addstr(buf, git_dir);
242 }
243 strbuf_addch(buf, '/');
244 va_start(args, fmt);
246 strbuf_vaddf(buf, fmt, args);
247 va_end(args);
248 strbuf_cleanup_path(buf);
249 return buf->buf;
250}
251int validate_headref(const char *path)
253{
254 struct stat st;
255 char *buf, buffer[256];
256 unsigned char sha1[20];
257 int fd;
258 ssize_t len;
259 if (lstat(path, &st) < 0)
261 return -1;
262 /* Make sure it is a "refs/.." symlink */
264 if (S_ISLNK(st.st_mode)) {
265 len = readlink(path, buffer, sizeof(buffer)-1);
266 if (len >= 5 && !memcmp("refs/", buffer, 5))
267 return 0;
268 return -1;
269 }
270 /*
272 * Anything else, just open it and try to see if it is a symbolic ref.
273 */
274 fd = open(path, O_RDONLY);
275 if (fd < 0)
276 return -1;
277 len = read_in_full(fd, buffer, sizeof(buffer)-1);
278 close(fd);
279 /*
281 * Is it a symbolic ref?
282 */
283 if (len < 4)
284 return -1;
285 if (!memcmp("ref:", buffer, 4)) {
286 buf = buffer + 4;
287 len -= 4;
288 while (len && isspace(*buf))
289 buf++, len--;
290 if (len >= 5 && !memcmp("refs/", buf, 5))
291 return 0;
292 }
293 /*
295 * Is this a detached HEAD?
296 */
297 if (!get_sha1_hex(buffer, sha1))
298 return 0;
299 return -1;
301}
302static struct passwd *getpw_str(const char *username, size_t len)
304{
305 struct passwd *pw;
306 char *username_z = xmemdupz(username, len);
307 pw = getpwnam(username_z);
308 free(username_z);
309 return pw;
310}
311/*
313 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
314 * then it is a newly allocated string. Returns NULL on getpw failure or
315 * if path is NULL.
316 */
317char *expand_user_path(const char *path)
318{
319 struct strbuf user_path = STRBUF_INIT;
320 const char *to_copy = path;
321 if (path == NULL)
323 goto return_null;
324 if (path[0] == '~') {
325 const char *first_slash = strchrnul(path, '/');
326 const char *username = path + 1;
327 size_t username_len = first_slash - username;
328 if (username_len == 0) {
329 const char *home = getenv("HOME");
330 if (!home)
331 goto return_null;
332 strbuf_addstr(&user_path, home);
333 } else {
334 struct passwd *pw = getpw_str(username, username_len);
335 if (!pw)
336 goto return_null;
337 strbuf_addstr(&user_path, pw->pw_dir);
338 }
339 to_copy = first_slash;
340 }
341 strbuf_addstr(&user_path, to_copy);
342 return strbuf_detach(&user_path, NULL);
343return_null:
344 strbuf_release(&user_path);
345 return NULL;
346}
347/*
349 * First, one directory to try is determined by the following algorithm.
350 *
351 * (0) If "strict" is given, the path is used as given and no DWIM is
352 * done. Otherwise:
353 * (1) "~/path" to mean path under the running user's home directory;
354 * (2) "~user/path" to mean path under named user's home directory;
355 * (3) "relative/path" to mean cwd relative directory; or
356 * (4) "/absolute/path" to mean absolute directory.
357 *
358 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
359 * in this order. We select the first one that is a valid git repository, and
360 * chdir() to it. If none match, or we fail to chdir, we return NULL.
361 *
362 * If all goes well, we return the directory we used to chdir() (but
363 * before ~user is expanded), avoiding getcwd() resolving symbolic
364 * links. User relative paths are also returned as they are given,
365 * except DWIM suffixing.
366 */
367const char *enter_repo(const char *path, int strict)
368{
369 static char used_path[PATH_MAX];
370 static char validated_path[PATH_MAX];
371 if (!path)
373 return NULL;
374 if (!strict) {
376 static const char *suffix[] = {
377 "/.git", "", ".git/.git", ".git", NULL,
378 };
379 const char *gitfile;
380 int len = strlen(path);
381 int i;
382 while ((1 < len) && (path[len-1] == '/'))
383 len--;
384 if (PATH_MAX <= len)
386 return NULL;
387 strncpy(used_path, path, len); used_path[len] = 0 ;
388 strcpy(validated_path, used_path);
389 if (used_path[0] == '~') {
391 char *newpath = expand_user_path(used_path);
392 if (!newpath || (PATH_MAX - 10 < strlen(newpath))) {
393 free(newpath);
394 return NULL;
395 }
396 /*
397 * Copy back into the static buffer. A pity
398 * since newpath was not bounded, but other
399 * branches of the if are limited by PATH_MAX
400 * anyway.
401 */
402 strcpy(used_path, newpath); free(newpath);
403 }
404 else if (PATH_MAX - 10 < len)
405 return NULL;
406 len = strlen(used_path);
407 for (i = 0; suffix[i]; i++) {
408 struct stat st;
409 strcpy(used_path + len, suffix[i]);
410 if (!stat(used_path, &st) &&
411 (S_ISREG(st.st_mode) ||
412 (S_ISDIR(st.st_mode) && is_git_directory(used_path)))) {
413 strcat(validated_path, suffix[i]);
414 break;
415 }
416 }
417 if (!suffix[i])
418 return NULL;
419 gitfile = read_gitfile(used_path) ;
420 if (gitfile)
421 strcpy(used_path, gitfile);
422 if (chdir(used_path))
423 return NULL;
424 path = validated_path;
425 }
426 else if (chdir(path))
427 return NULL;
428 if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
430 validate_headref("HEAD") == 0) {
431 set_git_dir(".");
432 check_repository_format();
433 return path;
434 }
435 return NULL;
437}
438static int calc_shared_perm(int mode)
440{
441 int tweak;
442 if (shared_repository < 0)
444 tweak = -shared_repository;
445 else
446 tweak = shared_repository;
447 if (!(mode & S_IWUSR))
449 tweak &= ~0222;
450 if (mode & S_IXUSR)
451 /* Copy read bits to execute bits */
452 tweak |= (tweak & 0444) >> 2;
453 if (shared_repository < 0)
454 mode = (mode & ~0777) | tweak;
455 else
456 mode |= tweak;
457 return mode;
459}
460int adjust_shared_perm(const char *path)
463{
464 int old_mode, new_mode;
465 if (!shared_repository)
467 return 0;
468 if (get_st_mode_bits(path, &old_mode) < 0)
469 return -1;
470 new_mode = calc_shared_perm(old_mode);
472 if (S_ISDIR(old_mode)) {
473 /* Copy read bits to execute bits */
474 new_mode |= (new_mode & 0444) >> 2;
475 new_mode |= FORCE_DIR_SET_GID;
476 }
477 if (((old_mode ^ new_mode) & ~S_IFMT) &&
479 chmod(path, (new_mode & ~S_IFMT)) < 0)
480 return -2;
481 return 0;
482}
483static int have_same_root(const char *path1, const char *path2)
485{
486 int is_abs1, is_abs2;
487 is_abs1 = is_absolute_path(path1);
489 is_abs2 = is_absolute_path(path2);
490 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
491 (!is_abs1 && !is_abs2);
492}
493/*
495 * Give path as relative to prefix.
496 *
497 * The strbuf may or may not be used, so do not assume it contains the
498 * returned path.
499 */
500const char *relative_path(const char *in, const char *prefix,
501 struct strbuf *sb)
502{
503 int in_len = in ? strlen(in) : 0;
504 int prefix_len = prefix ? strlen(prefix) : 0;
505 int in_off = 0;
506 int prefix_off = 0;
507 int i = 0, j = 0;
508 if (!in_len)
510 return "./";
511 else if (!prefix_len)
512 return in;
513 if (have_same_root(in, prefix)) {
515 /* bypass dos_drive, for "c:" is identical to "C:" */
516 if (has_dos_drive_prefix(in)) {
517 i = 2;
518 j = 2;
519 }
520 } else {
521 return in;
522 }
523 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
525 if (is_dir_sep(prefix[i])) {
526 while (is_dir_sep(prefix[i]))
527 i++;
528 while (is_dir_sep(in[j]))
529 j++;
530 prefix_off = i;
531 in_off = j;
532 } else {
533 i++;
534 j++;
535 }
536 }
537 if (
539 /* "prefix" seems like prefix of "in" */
540 i >= prefix_len &&
541 /*
542 * but "/foo" is not a prefix of "/foobar"
543 * (i.e. prefix not end with '/')
544 */
545 prefix_off < prefix_len) {
546 if (j >= in_len) {
547 /* in="/a/b", prefix="/a/b" */
548 in_off = in_len;
549 } else if (is_dir_sep(in[j])) {
550 /* in="/a/b/c", prefix="/a/b" */
551 while (is_dir_sep(in[j]))
552 j++;
553 in_off = j;
554 } else {
555 /* in="/a/bbb/c", prefix="/a/b" */
556 i = prefix_off;
557 }
558 } else if (
559 /* "in" is short than "prefix" */
560 j >= in_len &&
561 /* "in" not end with '/' */
562 in_off < in_len) {
563 if (is_dir_sep(prefix[i])) {
564 /* in="/a/b", prefix="/a/b/c/" */
565 while (is_dir_sep(prefix[i]))
566 i++;
567 in_off = in_len;
568 }
569 }
570 in += in_off;
571 in_len -= in_off;
572 if (i >= prefix_len) {
574 if (!in_len)
575 return "./";
576 else
577 return in;
578 }
579 strbuf_reset(sb);
581 strbuf_grow(sb, in_len);
582 while (i < prefix_len) {
584 if (is_dir_sep(prefix[i])) {
585 strbuf_addstr(sb, "../");
586 while (is_dir_sep(prefix[i]))
587 i++;
588 continue;
589 }
590 i++;
591 }
592 if (!is_dir_sep(prefix[prefix_len - 1]))
593 strbuf_addstr(sb, "../");
594 strbuf_addstr(sb, in);
596 return sb->buf;
598}
599/*
601 * A simpler implementation of relative_path
602 *
603 * Get relative path by removing "prefix" from "in". This function
604 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
605 * to increase performance when traversing the path to work_tree.
606 */
607const char *remove_leading_path(const char *in, const char *prefix)
608{
609 static char buf[PATH_MAX + 1];
610 int i = 0, j = 0;
611 if (!prefix || !prefix[0])
613 return in;
614 while (prefix[i]) {
615 if (is_dir_sep(prefix[i])) {
616 if (!is_dir_sep(in[j]))
617 return in;
618 while (is_dir_sep(prefix[i]))
619 i++;
620 while (is_dir_sep(in[j]))
621 j++;
622 continue;
623 } else if (in[j] != prefix[i]) {
624 return in;
625 }
626 i++;
627 j++;
628 }
629 if (
630 /* "/foo" is a prefix of "/foo" */
631 in[j] &&
632 /* "/foo" is not a prefix of "/foobar" */
633 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
634 )
635 return in;
636 while (is_dir_sep(in[j]))
637 j++;
638 if (!in[j])
639 strcpy(buf, ".");
640 else
641 strcpy(buf, in + j);
642 return buf;
643}
644/*
646 * It is okay if dst == src, but they should not overlap otherwise.
647 *
648 * Performs the following normalizations on src, storing the result in dst:
649 * - Ensures that components are separated by '/' (Windows only)
650 * - Squashes sequences of '/'.
651 * - Removes "." components.
652 * - Removes ".." components, and the components the precede them.
653 * Returns failure (non-zero) if a ".." component appears as first path
654 * component anytime during the normalization. Otherwise, returns success (0).
655 *
656 * Note that this function is purely textual. It does not follow symlinks,
657 * verify the existence of the path, or make any system calls.
658 *
659 * prefix_len != NULL is for a specific case of prefix_pathspec():
660 * assume that src == dst and src[0..prefix_len-1] is already
661 * normalized, any time "../" eats up to the prefix_len part,
662 * prefix_len is reduced. In the end prefix_len is the remaining
663 * prefix that has not been overridden by user pathspec.
664 */
665int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
666{
667 char *dst0;
668 if (has_dos_drive_prefix(src)) {
670 *dst++ = *src++;
671 *dst++ = *src++;
672 }
673 dst0 = dst;
674 if (is_dir_sep(*src)) {
676 *dst++ = '/';
677 while (is_dir_sep(*src))
678 src++;
679 }
680 for (;;) {
682 char c = *src;
683 /*
685 * A path component that begins with . could be
686 * special:
687 * (1) "." and ends -- ignore and terminate.
688 * (2) "./" -- ignore them, eat slash and continue.
689 * (3) ".." and ends -- strip one and terminate.
690 * (4) "../" -- strip one, eat slash and continue.
691 */
692 if (c == '.') {
693 if (!src[1]) {
694 /* (1) */
695 src++;
696 } else if (is_dir_sep(src[1])) {
697 /* (2) */
698 src += 2;
699 while (is_dir_sep(*src))
700 src++;
701 continue;
702 } else if (src[1] == '.') {
703 if (!src[2]) {
704 /* (3) */
705 src += 2;
706 goto up_one;
707 } else if (is_dir_sep(src[2])) {
708 /* (4) */
709 src += 3;
710 while (is_dir_sep(*src))
711 src++;
712 goto up_one;
713 }
714 }
715 }
716 /* copy up to the next '/', and eat all '/' */
718 while ((c = *src++) != '\0' && !is_dir_sep(c))
719 *dst++ = c;
720 if (is_dir_sep(c)) {
721 *dst++ = '/';
722 while (is_dir_sep(c))
723 c = *src++;
724 src--;
725 } else if (!c)
726 break;
727 continue;
728 up_one:
730 /*
731 * dst0..dst is prefix portion, and dst[-1] is '/';
732 * go up one level.
733 */
734 dst--; /* go to trailing '/' */
735 if (dst <= dst0)
736 return -1;
737 /* Windows: dst[-1] cannot be backslash anymore */
738 while (dst0 < dst && dst[-1] != '/')
739 dst--;
740 if (prefix_len && *prefix_len > dst - dst0)
741 *prefix_len = dst - dst0;
742 }
743 *dst = '\0';
744 return 0;
745}
746int normalize_path_copy(char *dst, const char *src)
748{
749 return normalize_path_copy_len(dst, src, NULL);
750}
751/*
753 * path = Canonical absolute path
754 * prefixes = string_list containing normalized, absolute paths without
755 * trailing slashes (except for the root directory, which is denoted by "/").
756 *
757 * Determines, for each path in prefixes, whether the "prefix"
758 * is an ancestor directory of path. Returns the length of the longest
759 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
760 * is an ancestor. (Note that this means 0 is returned if prefixes is
761 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
762 * are not considered to be their own ancestors. path must be in a
763 * canonical form: empty components, or "." or ".." components are not
764 * allowed.
765 */
766int longest_ancestor_length(const char *path, struct string_list *prefixes)
767{
768 int i, max_len = -1;
769 if (!strcmp(path, "/"))
771 return -1;
772 for (i = 0; i < prefixes->nr; i++) {
774 const char *ceil = prefixes->items[i].string;
775 int len = strlen(ceil);
776 if (len == 1 && ceil[0] == '/')
778 len = 0; /* root matches anything, with length 0 */
779 else if (!strncmp(path, ceil, len) && path[len] == '/')
780 ; /* match of length len */
781 else
782 continue; /* no match */
783 if (len > max_len)
785 max_len = len;
786 }
787 return max_len;
789}
790/* strip arbitrary amount of directory separators at end of path */
792static inline int chomp_trailing_dir_sep(const char *path, int len)
793{
794 while (len && is_dir_sep(path[len - 1]))
795 len--;
796 return len;
797}
798/*
800 * If path ends with suffix (complete path components), returns the
801 * part before suffix (sans trailing directory separators).
802 * Otherwise returns NULL.
803 */
804char *strip_path_suffix(const char *path, const char *suffix)
805{
806 int path_len = strlen(path), suffix_len = strlen(suffix);
807 while (suffix_len) {
809 if (!path_len)
810 return NULL;
811 if (is_dir_sep(path[path_len - 1])) {
813 if (!is_dir_sep(suffix[suffix_len - 1]))
814 return NULL;
815 path_len = chomp_trailing_dir_sep(path, path_len);
816 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
817 }
818 else if (path[--path_len] != suffix[--suffix_len])
819 return NULL;
820 }
821 if (path_len && !is_dir_sep(path[path_len - 1]))
823 return NULL;
824 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
825}
826int daemon_avoid_alias(const char *p)
828{
829 int sl, ndot;
830 /*
832 * This resurrects the belts and suspenders paranoia check by HPA
833 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
834 * does not do getcwd() based path canonicalization.
835 *
836 * sl becomes true immediately after seeing '/' and continues to
837 * be true as long as dots continue after that without intervening
838 * non-dot character.
839 */
840 if (!p || (*p != '/' && *p != '~'))
841 return -1;
842 sl = 1; ndot = 0;
843 p++;
844 while (1) {
846 char ch = *p++;
847 if (sl) {
848 if (ch == '.')
849 ndot++;
850 else if (ch == '/') {
851 if (ndot < 3)
852 /* reject //, /./ and /../ */
853 return -1;
854 ndot = 0;
855 }
856 else if (ch == 0) {
857 if (0 < ndot && ndot < 3)
858 /* reject /.$ and /..$ */
859 return -1;
860 return 0;
861 }
862 else
863 sl = ndot = 0;
864 }
865 else if (ch == 0)
866 return 0;
867 else if (ch == '/') {
868 sl = 1;
869 ndot = 0;
870 }
871 }
872}
873static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
875{
876 if (len < skip)
877 return 0;
878 len -= skip;
879 path += skip;
880 while (len-- > 0) {
881 char c = *(path++);
882 if (c != ' ' && c != '.')
883 return 0;
884 }
885 return 1;
886}
887int is_ntfs_dotgit(const char *name)
889{
890 int len;
891 for (len = 0; ; len++)
893 if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
894 if (only_spaces_and_periods(name, len, 4) &&
895 !strncasecmp(name, ".git", 4))
896 return 1;
897 if (only_spaces_and_periods(name, len, 5) &&
898 !strncasecmp(name, "git~1", 5))
899 return 1;
900 if (name[len] != '\\')
901 return 0;
902 name += len + 1;
903 len = -1;
904 }
905}
906char *xdg_config_home(const char *filename)
908{
909 const char *home, *config_home;
910 assert(filename);
912 config_home = getenv("XDG_CONFIG_HOME");
913 if (config_home && *config_home)
914 return mkpathdup("%s/git/%s", config_home, filename);
915 home = getenv("HOME");
917 if (home)
918 return mkpathdup("%s/.config/git/%s", home, filename);
919 return NULL;
920}