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"
8
9static 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}
17
18static char bad_path[] = "/bad-path/";
19
20static 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}
30
31static 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}
41
42static 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}
48
49char *mksnpath(char *buf, size_t n, const char *fmt, ...)
50{
51 va_list args;
52 unsigned len;
53
54 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}
63
64static 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
71/* $buf =~ m|$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}
81
82static 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}
93
94static 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};
100
101static 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
106 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}
128
129void report_linked_checkout_garbage(void)
130{
131 struct strbuf sb = STRBUF_INIT;
132 const char **p;
133 int len;
134
135 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}
150
151static 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}
165
166static 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}
177
178void 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}
185
186const 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}
195
196char *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}
205
206char *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}
216
217const 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}
226
227static void do_submodule_path(struct strbuf *buf, const char *path,
228 const char *fmt, va_list args)
229{
230 const char *git_dir;
231
232 strbuf_addstr(buf, path);
233 if (buf->len && buf->buf[buf->len - 1] != '/')
234 strbuf_addch(buf, '/');
235 strbuf_addstr(buf, ".git");
236
237 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
244 strbuf_vaddf(buf, fmt, args);
245 strbuf_cleanup_path(buf);
246}
247
248char *git_pathdup_submodule(const char *path, const char *fmt, ...)
249{
250 va_list args;
251 struct strbuf buf = STRBUF_INIT;
252 va_start(args, fmt);
253 do_submodule_path(&buf, path, fmt, args);
254 va_end(args);
255 return strbuf_detach(&buf, NULL);
256}
257
258void strbuf_git_path_submodule(struct strbuf *buf, const char *path,
259 const char *fmt, ...)
260{
261 va_list args;
262 va_start(args, fmt);
263 do_submodule_path(buf, path, fmt, args);
264 va_end(args);
265}
266
267int validate_headref(const char *path)
268{
269 struct stat st;
270 char *buf, buffer[256];
271 unsigned char sha1[20];
272 int fd;
273 ssize_t len;
274
275 if (lstat(path, &st) < 0)
276 return -1;
277
278 /* Make sure it is a "refs/.." symlink */
279 if (S_ISLNK(st.st_mode)) {
280 len = readlink(path, buffer, sizeof(buffer)-1);
281 if (len >= 5 && !memcmp("refs/", buffer, 5))
282 return 0;
283 return -1;
284 }
285
286 /*
287 * Anything else, just open it and try to see if it is a symbolic ref.
288 */
289 fd = open(path, O_RDONLY);
290 if (fd < 0)
291 return -1;
292 len = read_in_full(fd, buffer, sizeof(buffer)-1);
293 close(fd);
294
295 /*
296 * Is it a symbolic ref?
297 */
298 if (len < 4)
299 return -1;
300 if (!memcmp("ref:", buffer, 4)) {
301 buf = buffer + 4;
302 len -= 4;
303 while (len && isspace(*buf))
304 buf++, len--;
305 if (len >= 5 && !memcmp("refs/", buf, 5))
306 return 0;
307 }
308
309 /*
310 * Is this a detached HEAD?
311 */
312 if (!get_sha1_hex(buffer, sha1))
313 return 0;
314
315 return -1;
316}
317
318static struct passwd *getpw_str(const char *username, size_t len)
319{
320 struct passwd *pw;
321 char *username_z = xmemdupz(username, len);
322 pw = getpwnam(username_z);
323 free(username_z);
324 return pw;
325}
326
327/*
328 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
329 * then it is a newly allocated string. Returns NULL on getpw failure or
330 * if path is NULL.
331 */
332char *expand_user_path(const char *path)
333{
334 struct strbuf user_path = STRBUF_INIT;
335 const char *to_copy = path;
336
337 if (path == NULL)
338 goto return_null;
339 if (path[0] == '~') {
340 const char *first_slash = strchrnul(path, '/');
341 const char *username = path + 1;
342 size_t username_len = first_slash - username;
343 if (username_len == 0) {
344 const char *home = getenv("HOME");
345 if (!home)
346 goto return_null;
347 strbuf_addstr(&user_path, home);
348 } else {
349 struct passwd *pw = getpw_str(username, username_len);
350 if (!pw)
351 goto return_null;
352 strbuf_addstr(&user_path, pw->pw_dir);
353 }
354 to_copy = first_slash;
355 }
356 strbuf_addstr(&user_path, to_copy);
357 return strbuf_detach(&user_path, NULL);
358return_null:
359 strbuf_release(&user_path);
360 return NULL;
361}
362
363/*
364 * First, one directory to try is determined by the following algorithm.
365 *
366 * (0) If "strict" is given, the path is used as given and no DWIM is
367 * done. Otherwise:
368 * (1) "~/path" to mean path under the running user's home directory;
369 * (2) "~user/path" to mean path under named user's home directory;
370 * (3) "relative/path" to mean cwd relative directory; or
371 * (4) "/absolute/path" to mean absolute directory.
372 *
373 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
374 * in this order. We select the first one that is a valid git repository, and
375 * chdir() to it. If none match, or we fail to chdir, we return NULL.
376 *
377 * If all goes well, we return the directory we used to chdir() (but
378 * before ~user is expanded), avoiding getcwd() resolving symbolic
379 * links. User relative paths are also returned as they are given,
380 * except DWIM suffixing.
381 */
382const char *enter_repo(const char *path, int strict)
383{
384 static char used_path[PATH_MAX];
385 static char validated_path[PATH_MAX];
386
387 if (!path)
388 return NULL;
389
390 if (!strict) {
391 static const char *suffix[] = {
392 "/.git", "", ".git/.git", ".git", NULL,
393 };
394 const char *gitfile;
395 int len = strlen(path);
396 int i;
397 while ((1 < len) && (path[len-1] == '/'))
398 len--;
399
400 if (PATH_MAX <= len)
401 return NULL;
402 strncpy(used_path, path, len); used_path[len] = 0 ;
403 strcpy(validated_path, used_path);
404
405 if (used_path[0] == '~') {
406 char *newpath = expand_user_path(used_path);
407 if (!newpath || (PATH_MAX - 10 < strlen(newpath))) {
408 free(newpath);
409 return NULL;
410 }
411 /*
412 * Copy back into the static buffer. A pity
413 * since newpath was not bounded, but other
414 * branches of the if are limited by PATH_MAX
415 * anyway.
416 */
417 strcpy(used_path, newpath); free(newpath);
418 }
419 else if (PATH_MAX - 10 < len)
420 return NULL;
421 len = strlen(used_path);
422 for (i = 0; suffix[i]; i++) {
423 struct stat st;
424 strcpy(used_path + len, suffix[i]);
425 if (!stat(used_path, &st) &&
426 (S_ISREG(st.st_mode) ||
427 (S_ISDIR(st.st_mode) && is_git_directory(used_path)))) {
428 strcat(validated_path, suffix[i]);
429 break;
430 }
431 }
432 if (!suffix[i])
433 return NULL;
434 gitfile = read_gitfile(used_path);
435 if (gitfile)
436 strcpy(used_path, gitfile);
437 if (chdir(used_path))
438 return NULL;
439 path = validated_path;
440 }
441 else {
442 const char *gitfile = read_gitfile(path);
443 if (gitfile)
444 path = gitfile;
445 if (chdir(path))
446 return NULL;
447 }
448
449 if (is_git_directory(".")) {
450 set_git_dir(".");
451 check_repository_format();
452 return path;
453 }
454
455 return NULL;
456}
457
458static int calc_shared_perm(int mode)
459{
460 int tweak;
461
462 if (shared_repository < 0)
463 tweak = -shared_repository;
464 else
465 tweak = shared_repository;
466
467 if (!(mode & S_IWUSR))
468 tweak &= ~0222;
469 if (mode & S_IXUSR)
470 /* Copy read bits to execute bits */
471 tweak |= (tweak & 0444) >> 2;
472 if (shared_repository < 0)
473 mode = (mode & ~0777) | tweak;
474 else
475 mode |= tweak;
476
477 return mode;
478}
479
480
481int adjust_shared_perm(const char *path)
482{
483 int old_mode, new_mode;
484
485 if (!shared_repository)
486 return 0;
487 if (get_st_mode_bits(path, &old_mode) < 0)
488 return -1;
489
490 new_mode = calc_shared_perm(old_mode);
491 if (S_ISDIR(old_mode)) {
492 /* Copy read bits to execute bits */
493 new_mode |= (new_mode & 0444) >> 2;
494 new_mode |= FORCE_DIR_SET_GID;
495 }
496
497 if (((old_mode ^ new_mode) & ~S_IFMT) &&
498 chmod(path, (new_mode & ~S_IFMT)) < 0)
499 return -2;
500 return 0;
501}
502
503static int have_same_root(const char *path1, const char *path2)
504{
505 int is_abs1, is_abs2;
506
507 is_abs1 = is_absolute_path(path1);
508 is_abs2 = is_absolute_path(path2);
509 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
510 (!is_abs1 && !is_abs2);
511}
512
513/*
514 * Give path as relative to prefix.
515 *
516 * The strbuf may or may not be used, so do not assume it contains the
517 * returned path.
518 */
519const char *relative_path(const char *in, const char *prefix,
520 struct strbuf *sb)
521{
522 int in_len = in ? strlen(in) : 0;
523 int prefix_len = prefix ? strlen(prefix) : 0;
524 int in_off = 0;
525 int prefix_off = 0;
526 int i = 0, j = 0;
527
528 if (!in_len)
529 return "./";
530 else if (!prefix_len)
531 return in;
532
533 if (have_same_root(in, prefix)) {
534 /* bypass dos_drive, for "c:" is identical to "C:" */
535 if (has_dos_drive_prefix(in)) {
536 i = 2;
537 j = 2;
538 }
539 } else {
540 return in;
541 }
542
543 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
544 if (is_dir_sep(prefix[i])) {
545 while (is_dir_sep(prefix[i]))
546 i++;
547 while (is_dir_sep(in[j]))
548 j++;
549 prefix_off = i;
550 in_off = j;
551 } else {
552 i++;
553 j++;
554 }
555 }
556
557 if (
558 /* "prefix" seems like prefix of "in" */
559 i >= prefix_len &&
560 /*
561 * but "/foo" is not a prefix of "/foobar"
562 * (i.e. prefix not end with '/')
563 */
564 prefix_off < prefix_len) {
565 if (j >= in_len) {
566 /* in="/a/b", prefix="/a/b" */
567 in_off = in_len;
568 } else if (is_dir_sep(in[j])) {
569 /* in="/a/b/c", prefix="/a/b" */
570 while (is_dir_sep(in[j]))
571 j++;
572 in_off = j;
573 } else {
574 /* in="/a/bbb/c", prefix="/a/b" */
575 i = prefix_off;
576 }
577 } else if (
578 /* "in" is short than "prefix" */
579 j >= in_len &&
580 /* "in" not end with '/' */
581 in_off < in_len) {
582 if (is_dir_sep(prefix[i])) {
583 /* in="/a/b", prefix="/a/b/c/" */
584 while (is_dir_sep(prefix[i]))
585 i++;
586 in_off = in_len;
587 }
588 }
589 in += in_off;
590 in_len -= in_off;
591
592 if (i >= prefix_len) {
593 if (!in_len)
594 return "./";
595 else
596 return in;
597 }
598
599 strbuf_reset(sb);
600 strbuf_grow(sb, in_len);
601
602 while (i < prefix_len) {
603 if (is_dir_sep(prefix[i])) {
604 strbuf_addstr(sb, "../");
605 while (is_dir_sep(prefix[i]))
606 i++;
607 continue;
608 }
609 i++;
610 }
611 if (!is_dir_sep(prefix[prefix_len - 1]))
612 strbuf_addstr(sb, "../");
613
614 strbuf_addstr(sb, in);
615
616 return sb->buf;
617}
618
619/*
620 * A simpler implementation of relative_path
621 *
622 * Get relative path by removing "prefix" from "in". This function
623 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
624 * to increase performance when traversing the path to work_tree.
625 */
626const char *remove_leading_path(const char *in, const char *prefix)
627{
628 static char buf[PATH_MAX + 1];
629 int i = 0, j = 0;
630
631 if (!prefix || !prefix[0])
632 return in;
633 while (prefix[i]) {
634 if (is_dir_sep(prefix[i])) {
635 if (!is_dir_sep(in[j]))
636 return in;
637 while (is_dir_sep(prefix[i]))
638 i++;
639 while (is_dir_sep(in[j]))
640 j++;
641 continue;
642 } else if (in[j] != prefix[i]) {
643 return in;
644 }
645 i++;
646 j++;
647 }
648 if (
649 /* "/foo" is a prefix of "/foo" */
650 in[j] &&
651 /* "/foo" is not a prefix of "/foobar" */
652 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
653 )
654 return in;
655 while (is_dir_sep(in[j]))
656 j++;
657 if (!in[j])
658 strcpy(buf, ".");
659 else
660 strcpy(buf, in + j);
661 return buf;
662}
663
664/*
665 * It is okay if dst == src, but they should not overlap otherwise.
666 *
667 * Performs the following normalizations on src, storing the result in dst:
668 * - Ensures that components are separated by '/' (Windows only)
669 * - Squashes sequences of '/'.
670 * - Removes "." components.
671 * - Removes ".." components, and the components the precede them.
672 * Returns failure (non-zero) if a ".." component appears as first path
673 * component anytime during the normalization. Otherwise, returns success (0).
674 *
675 * Note that this function is purely textual. It does not follow symlinks,
676 * verify the existence of the path, or make any system calls.
677 *
678 * prefix_len != NULL is for a specific case of prefix_pathspec():
679 * assume that src == dst and src[0..prefix_len-1] is already
680 * normalized, any time "../" eats up to the prefix_len part,
681 * prefix_len is reduced. In the end prefix_len is the remaining
682 * prefix that has not been overridden by user pathspec.
683 */
684int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
685{
686 char *dst0;
687
688 if (has_dos_drive_prefix(src)) {
689 *dst++ = *src++;
690 *dst++ = *src++;
691 }
692 dst0 = dst;
693
694 if (is_dir_sep(*src)) {
695 *dst++ = '/';
696 while (is_dir_sep(*src))
697 src++;
698 }
699
700 for (;;) {
701 char c = *src;
702
703 /*
704 * A path component that begins with . could be
705 * special:
706 * (1) "." and ends -- ignore and terminate.
707 * (2) "./" -- ignore them, eat slash and continue.
708 * (3) ".." and ends -- strip one and terminate.
709 * (4) "../" -- strip one, eat slash and continue.
710 */
711 if (c == '.') {
712 if (!src[1]) {
713 /* (1) */
714 src++;
715 } else if (is_dir_sep(src[1])) {
716 /* (2) */
717 src += 2;
718 while (is_dir_sep(*src))
719 src++;
720 continue;
721 } else if (src[1] == '.') {
722 if (!src[2]) {
723 /* (3) */
724 src += 2;
725 goto up_one;
726 } else if (is_dir_sep(src[2])) {
727 /* (4) */
728 src += 3;
729 while (is_dir_sep(*src))
730 src++;
731 goto up_one;
732 }
733 }
734 }
735
736 /* copy up to the next '/', and eat all '/' */
737 while ((c = *src++) != '\0' && !is_dir_sep(c))
738 *dst++ = c;
739 if (is_dir_sep(c)) {
740 *dst++ = '/';
741 while (is_dir_sep(c))
742 c = *src++;
743 src--;
744 } else if (!c)
745 break;
746 continue;
747
748 up_one:
749 /*
750 * dst0..dst is prefix portion, and dst[-1] is '/';
751 * go up one level.
752 */
753 dst--; /* go to trailing '/' */
754 if (dst <= dst0)
755 return -1;
756 /* Windows: dst[-1] cannot be backslash anymore */
757 while (dst0 < dst && dst[-1] != '/')
758 dst--;
759 if (prefix_len && *prefix_len > dst - dst0)
760 *prefix_len = dst - dst0;
761 }
762 *dst = '\0';
763 return 0;
764}
765
766int normalize_path_copy(char *dst, const char *src)
767{
768 return normalize_path_copy_len(dst, src, NULL);
769}
770
771/*
772 * path = Canonical absolute path
773 * prefixes = string_list containing normalized, absolute paths without
774 * trailing slashes (except for the root directory, which is denoted by "/").
775 *
776 * Determines, for each path in prefixes, whether the "prefix"
777 * is an ancestor directory of path. Returns the length of the longest
778 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
779 * is an ancestor. (Note that this means 0 is returned if prefixes is
780 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
781 * are not considered to be their own ancestors. path must be in a
782 * canonical form: empty components, or "." or ".." components are not
783 * allowed.
784 */
785int longest_ancestor_length(const char *path, struct string_list *prefixes)
786{
787 int i, max_len = -1;
788
789 if (!strcmp(path, "/"))
790 return -1;
791
792 for (i = 0; i < prefixes->nr; i++) {
793 const char *ceil = prefixes->items[i].string;
794 int len = strlen(ceil);
795
796 if (len == 1 && ceil[0] == '/')
797 len = 0; /* root matches anything, with length 0 */
798 else if (!strncmp(path, ceil, len) && path[len] == '/')
799 ; /* match of length len */
800 else
801 continue; /* no match */
802
803 if (len > max_len)
804 max_len = len;
805 }
806
807 return max_len;
808}
809
810/* strip arbitrary amount of directory separators at end of path */
811static inline int chomp_trailing_dir_sep(const char *path, int len)
812{
813 while (len && is_dir_sep(path[len - 1]))
814 len--;
815 return len;
816}
817
818/*
819 * If path ends with suffix (complete path components), returns the
820 * part before suffix (sans trailing directory separators).
821 * Otherwise returns NULL.
822 */
823char *strip_path_suffix(const char *path, const char *suffix)
824{
825 int path_len = strlen(path), suffix_len = strlen(suffix);
826
827 while (suffix_len) {
828 if (!path_len)
829 return NULL;
830
831 if (is_dir_sep(path[path_len - 1])) {
832 if (!is_dir_sep(suffix[suffix_len - 1]))
833 return NULL;
834 path_len = chomp_trailing_dir_sep(path, path_len);
835 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
836 }
837 else if (path[--path_len] != suffix[--suffix_len])
838 return NULL;
839 }
840
841 if (path_len && !is_dir_sep(path[path_len - 1]))
842 return NULL;
843 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
844}
845
846int daemon_avoid_alias(const char *p)
847{
848 int sl, ndot;
849
850 /*
851 * This resurrects the belts and suspenders paranoia check by HPA
852 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
853 * does not do getcwd() based path canonicalization.
854 *
855 * sl becomes true immediately after seeing '/' and continues to
856 * be true as long as dots continue after that without intervening
857 * non-dot character.
858 */
859 if (!p || (*p != '/' && *p != '~'))
860 return -1;
861 sl = 1; ndot = 0;
862 p++;
863
864 while (1) {
865 char ch = *p++;
866 if (sl) {
867 if (ch == '.')
868 ndot++;
869 else if (ch == '/') {
870 if (ndot < 3)
871 /* reject //, /./ and /../ */
872 return -1;
873 ndot = 0;
874 }
875 else if (ch == 0) {
876 if (0 < ndot && ndot < 3)
877 /* reject /.$ and /..$ */
878 return -1;
879 return 0;
880 }
881 else
882 sl = ndot = 0;
883 }
884 else if (ch == 0)
885 return 0;
886 else if (ch == '/') {
887 sl = 1;
888 ndot = 0;
889 }
890 }
891}
892
893static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
894{
895 if (len < skip)
896 return 0;
897 len -= skip;
898 path += skip;
899 while (len-- > 0) {
900 char c = *(path++);
901 if (c != ' ' && c != '.')
902 return 0;
903 }
904 return 1;
905}
906
907int is_ntfs_dotgit(const char *name)
908{
909 int len;
910
911 for (len = 0; ; len++)
912 if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
913 if (only_spaces_and_periods(name, len, 4) &&
914 !strncasecmp(name, ".git", 4))
915 return 1;
916 if (only_spaces_and_periods(name, len, 5) &&
917 !strncasecmp(name, "git~1", 5))
918 return 1;
919 if (name[len] != '\\')
920 return 0;
921 name += len + 1;
922 len = -1;
923 }
924}
925
926char *xdg_config_home(const char *filename)
927{
928 const char *home, *config_home;
929
930 assert(filename);
931 config_home = getenv("XDG_CONFIG_HOME");
932 if (config_home && *config_home)
933 return mkpathdup("%s/git/%s", config_home, filename);
934
935 home = getenv("HOME");
936 if (home)
937 return mkpathdup("%s/.config/git/%s", home, filename);
938 return NULL;
939}
940
941GIT_PATH_FUNC(git_path_cherry_pick_head, "CHERRY_PICK_HEAD")
942GIT_PATH_FUNC(git_path_revert_head, "REVERT_HEAD")
943GIT_PATH_FUNC(git_path_squash_msg, "SQUASH_MSG")
944GIT_PATH_FUNC(git_path_merge_msg, "MERGE_MSG")
945GIT_PATH_FUNC(git_path_merge_rr, "MERGE_RR")
946GIT_PATH_FUNC(git_path_merge_mode, "MERGE_MODE")
947GIT_PATH_FUNC(git_path_merge_head, "MERGE_HEAD")
948GIT_PATH_FUNC(git_path_fetch_head, "FETCH_HEAD")
949GIT_PATH_FUNC(git_path_shallow, "shallow")