use strbuf_complete to conditionally append slash
[git/git.git] / path.c
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
9 static 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
18 static char bad_path[] = "/bad-path/";
19
20 static 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
31 static 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
42 static 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
49 char *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
64 static 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 */
72 static 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
82 static 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
94 static 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
101 static 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
129 void 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
151 static 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
166 static 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
178 char *git_path_buf(struct strbuf *buf, const char *fmt, ...)
179 {
180 va_list args;
181 strbuf_reset(buf);
182 va_start(args, fmt);
183 do_git_path(buf, fmt, args);
184 va_end(args);
185 return buf->buf;
186 }
187
188 void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
189 {
190 va_list args;
191 va_start(args, fmt);
192 do_git_path(sb, fmt, args);
193 va_end(args);
194 }
195
196 const char *git_path(const char *fmt, ...)
197 {
198 struct strbuf *pathname = get_pathname();
199 va_list args;
200 va_start(args, fmt);
201 do_git_path(pathname, fmt, args);
202 va_end(args);
203 return pathname->buf;
204 }
205
206 char *git_pathdup(const char *fmt, ...)
207 {
208 struct strbuf path = STRBUF_INIT;
209 va_list args;
210 va_start(args, fmt);
211 do_git_path(&path, fmt, args);
212 va_end(args);
213 return strbuf_detach(&path, NULL);
214 }
215
216 char *mkpathdup(const char *fmt, ...)
217 {
218 struct strbuf sb = STRBUF_INIT;
219 va_list args;
220 va_start(args, fmt);
221 strbuf_vaddf(&sb, fmt, args);
222 va_end(args);
223 strbuf_cleanup_path(&sb);
224 return strbuf_detach(&sb, NULL);
225 }
226
227 const char *mkpath(const char *fmt, ...)
228 {
229 va_list args;
230 struct strbuf *pathname = get_pathname();
231 va_start(args, fmt);
232 strbuf_vaddf(pathname, fmt, args);
233 va_end(args);
234 return cleanup_path(pathname->buf);
235 }
236
237 static void do_submodule_path(struct strbuf *buf, const char *path,
238 const char *fmt, va_list args)
239 {
240 const char *git_dir;
241
242 strbuf_addstr(buf, path);
243 strbuf_complete(buf, '/');
244 strbuf_addstr(buf, ".git");
245
246 git_dir = read_gitfile(buf->buf);
247 if (git_dir) {
248 strbuf_reset(buf);
249 strbuf_addstr(buf, git_dir);
250 }
251 strbuf_addch(buf, '/');
252
253 strbuf_vaddf(buf, fmt, args);
254 strbuf_cleanup_path(buf);
255 }
256
257 char *git_pathdup_submodule(const char *path, const char *fmt, ...)
258 {
259 va_list args;
260 struct strbuf buf = STRBUF_INIT;
261 va_start(args, fmt);
262 do_submodule_path(&buf, path, fmt, args);
263 va_end(args);
264 return strbuf_detach(&buf, NULL);
265 }
266
267 void strbuf_git_path_submodule(struct strbuf *buf, const char *path,
268 const char *fmt, ...)
269 {
270 va_list args;
271 va_start(args, fmt);
272 do_submodule_path(buf, path, fmt, args);
273 va_end(args);
274 }
275
276 int validate_headref(const char *path)
277 {
278 struct stat st;
279 char *buf, buffer[256];
280 unsigned char sha1[20];
281 int fd;
282 ssize_t len;
283
284 if (lstat(path, &st) < 0)
285 return -1;
286
287 /* Make sure it is a "refs/.." symlink */
288 if (S_ISLNK(st.st_mode)) {
289 len = readlink(path, buffer, sizeof(buffer)-1);
290 if (len >= 5 && !memcmp("refs/", buffer, 5))
291 return 0;
292 return -1;
293 }
294
295 /*
296 * Anything else, just open it and try to see if it is a symbolic ref.
297 */
298 fd = open(path, O_RDONLY);
299 if (fd < 0)
300 return -1;
301 len = read_in_full(fd, buffer, sizeof(buffer)-1);
302 close(fd);
303
304 /*
305 * Is it a symbolic ref?
306 */
307 if (len < 4)
308 return -1;
309 if (!memcmp("ref:", buffer, 4)) {
310 buf = buffer + 4;
311 len -= 4;
312 while (len && isspace(*buf))
313 buf++, len--;
314 if (len >= 5 && !memcmp("refs/", buf, 5))
315 return 0;
316 }
317
318 /*
319 * Is this a detached HEAD?
320 */
321 if (!get_sha1_hex(buffer, sha1))
322 return 0;
323
324 return -1;
325 }
326
327 static struct passwd *getpw_str(const char *username, size_t len)
328 {
329 struct passwd *pw;
330 char *username_z = xmemdupz(username, len);
331 pw = getpwnam(username_z);
332 free(username_z);
333 return pw;
334 }
335
336 /*
337 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
338 * then it is a newly allocated string. Returns NULL on getpw failure or
339 * if path is NULL.
340 */
341 char *expand_user_path(const char *path)
342 {
343 struct strbuf user_path = STRBUF_INIT;
344 const char *to_copy = path;
345
346 if (path == NULL)
347 goto return_null;
348 if (path[0] == '~') {
349 const char *first_slash = strchrnul(path, '/');
350 const char *username = path + 1;
351 size_t username_len = first_slash - username;
352 if (username_len == 0) {
353 const char *home = getenv("HOME");
354 if (!home)
355 goto return_null;
356 strbuf_addstr(&user_path, home);
357 } else {
358 struct passwd *pw = getpw_str(username, username_len);
359 if (!pw)
360 goto return_null;
361 strbuf_addstr(&user_path, pw->pw_dir);
362 }
363 to_copy = first_slash;
364 }
365 strbuf_addstr(&user_path, to_copy);
366 return strbuf_detach(&user_path, NULL);
367 return_null:
368 strbuf_release(&user_path);
369 return NULL;
370 }
371
372 /*
373 * First, one directory to try is determined by the following algorithm.
374 *
375 * (0) If "strict" is given, the path is used as given and no DWIM is
376 * done. Otherwise:
377 * (1) "~/path" to mean path under the running user's home directory;
378 * (2) "~user/path" to mean path under named user's home directory;
379 * (3) "relative/path" to mean cwd relative directory; or
380 * (4) "/absolute/path" to mean absolute directory.
381 *
382 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
383 * in this order. We select the first one that is a valid git repository, and
384 * chdir() to it. If none match, or we fail to chdir, we return NULL.
385 *
386 * If all goes well, we return the directory we used to chdir() (but
387 * before ~user is expanded), avoiding getcwd() resolving symbolic
388 * links. User relative paths are also returned as they are given,
389 * except DWIM suffixing.
390 */
391 const char *enter_repo(const char *path, int strict)
392 {
393 static struct strbuf validated_path = STRBUF_INIT;
394 static struct strbuf used_path = STRBUF_INIT;
395
396 if (!path)
397 return NULL;
398
399 if (!strict) {
400 static const char *suffix[] = {
401 "/.git", "", ".git/.git", ".git", NULL,
402 };
403 const char *gitfile;
404 int len = strlen(path);
405 int i;
406 while ((1 < len) && (path[len-1] == '/'))
407 len--;
408
409 /*
410 * We can handle arbitrary-sized buffers, but this remains as a
411 * sanity check on untrusted input.
412 */
413 if (PATH_MAX <= len)
414 return NULL;
415
416 strbuf_reset(&used_path);
417 strbuf_reset(&validated_path);
418 strbuf_add(&used_path, path, len);
419 strbuf_add(&validated_path, path, len);
420
421 if (used_path.buf[0] == '~') {
422 char *newpath = expand_user_path(used_path.buf);
423 if (!newpath)
424 return NULL;
425 strbuf_attach(&used_path, newpath, strlen(newpath),
426 strlen(newpath));
427 }
428 for (i = 0; suffix[i]; i++) {
429 struct stat st;
430 size_t baselen = used_path.len;
431 strbuf_addstr(&used_path, suffix[i]);
432 if (!stat(used_path.buf, &st) &&
433 (S_ISREG(st.st_mode) ||
434 (S_ISDIR(st.st_mode) && is_git_directory(used_path.buf)))) {
435 strbuf_addstr(&validated_path, suffix[i]);
436 break;
437 }
438 strbuf_setlen(&used_path, baselen);
439 }
440 if (!suffix[i])
441 return NULL;
442 gitfile = read_gitfile(used_path.buf) ;
443 if (gitfile) {
444 strbuf_reset(&used_path);
445 strbuf_addstr(&used_path, gitfile);
446 }
447 if (chdir(used_path.buf))
448 return NULL;
449 path = validated_path.buf;
450 }
451 else if (chdir(path))
452 return NULL;
453
454 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
461 return NULL;
462 }
463
464 static int calc_shared_perm(int mode)
465 {
466 int tweak;
467
468 if (shared_repository < 0)
469 tweak = -shared_repository;
470 else
471 tweak = shared_repository;
472
473 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
483 return mode;
484 }
485
486
487 int adjust_shared_perm(const char *path)
488 {
489 int old_mode, new_mode;
490
491 if (!shared_repository)
492 return 0;
493 if (get_st_mode_bits(path, &old_mode) < 0)
494 return -1;
495
496 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
503 if (((old_mode ^ new_mode) & ~S_IFMT) &&
504 chmod(path, (new_mode & ~S_IFMT)) < 0)
505 return -2;
506 return 0;
507 }
508
509 static int have_same_root(const char *path1, const char *path2)
510 {
511 int is_abs1, is_abs2;
512
513 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
519 /*
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 */
525 const 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
534 if (!in_len)
535 return "./";
536 else if (!prefix_len)
537 return in;
538
539 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
549 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
563 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
598 if (i >= prefix_len) {
599 if (!in_len)
600 return "./";
601 else
602 return in;
603 }
604
605 strbuf_reset(sb);
606 strbuf_grow(sb, in_len);
607
608 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
620 strbuf_addstr(sb, in);
621
622 return sb->buf;
623 }
624
625 /*
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 */
632 const char *remove_leading_path(const char *in, const char *prefix)
633 {
634 static struct strbuf buf = STRBUF_INIT;
635 int i = 0, j = 0;
636
637 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
664 strbuf_reset(&buf);
665 if (!in[j])
666 strbuf_addstr(&buf, ".");
667 else
668 strbuf_addstr(&buf, in + j);
669 return buf.buf;
670 }
671
672 /*
673 * It is okay if dst == src, but they should not overlap otherwise.
674 *
675 * Performs the following normalizations on src, storing the result in dst:
676 * - Ensures that components are separated by '/' (Windows only)
677 * - Squashes sequences of '/'.
678 * - Removes "." components.
679 * - Removes ".." components, and the components the precede them.
680 * Returns failure (non-zero) if a ".." component appears as first path
681 * component anytime during the normalization. Otherwise, returns success (0).
682 *
683 * Note that this function is purely textual. It does not follow symlinks,
684 * verify the existence of the path, or make any system calls.
685 *
686 * prefix_len != NULL is for a specific case of prefix_pathspec():
687 * assume that src == dst and src[0..prefix_len-1] is already
688 * normalized, any time "../" eats up to the prefix_len part,
689 * prefix_len is reduced. In the end prefix_len is the remaining
690 * prefix that has not been overridden by user pathspec.
691 */
692 int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
693 {
694 char *dst0;
695
696 if (has_dos_drive_prefix(src)) {
697 *dst++ = *src++;
698 *dst++ = *src++;
699 }
700 dst0 = dst;
701
702 if (is_dir_sep(*src)) {
703 *dst++ = '/';
704 while (is_dir_sep(*src))
705 src++;
706 }
707
708 for (;;) {
709 char c = *src;
710
711 /*
712 * A path component that begins with . could be
713 * special:
714 * (1) "." and ends -- ignore and terminate.
715 * (2) "./" -- ignore them, eat slash and continue.
716 * (3) ".." and ends -- strip one and terminate.
717 * (4) "../" -- strip one, eat slash and continue.
718 */
719 if (c == '.') {
720 if (!src[1]) {
721 /* (1) */
722 src++;
723 } else if (is_dir_sep(src[1])) {
724 /* (2) */
725 src += 2;
726 while (is_dir_sep(*src))
727 src++;
728 continue;
729 } else if (src[1] == '.') {
730 if (!src[2]) {
731 /* (3) */
732 src += 2;
733 goto up_one;
734 } else if (is_dir_sep(src[2])) {
735 /* (4) */
736 src += 3;
737 while (is_dir_sep(*src))
738 src++;
739 goto up_one;
740 }
741 }
742 }
743
744 /* copy up to the next '/', and eat all '/' */
745 while ((c = *src++) != '\0' && !is_dir_sep(c))
746 *dst++ = c;
747 if (is_dir_sep(c)) {
748 *dst++ = '/';
749 while (is_dir_sep(c))
750 c = *src++;
751 src--;
752 } else if (!c)
753 break;
754 continue;
755
756 up_one:
757 /*
758 * dst0..dst is prefix portion, and dst[-1] is '/';
759 * go up one level.
760 */
761 dst--; /* go to trailing '/' */
762 if (dst <= dst0)
763 return -1;
764 /* Windows: dst[-1] cannot be backslash anymore */
765 while (dst0 < dst && dst[-1] != '/')
766 dst--;
767 if (prefix_len && *prefix_len > dst - dst0)
768 *prefix_len = dst - dst0;
769 }
770 *dst = '\0';
771 return 0;
772 }
773
774 int normalize_path_copy(char *dst, const char *src)
775 {
776 return normalize_path_copy_len(dst, src, NULL);
777 }
778
779 /*
780 * path = Canonical absolute path
781 * prefixes = string_list containing normalized, absolute paths without
782 * trailing slashes (except for the root directory, which is denoted by "/").
783 *
784 * Determines, for each path in prefixes, whether the "prefix"
785 * is an ancestor directory of path. Returns the length of the longest
786 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
787 * is an ancestor. (Note that this means 0 is returned if prefixes is
788 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
789 * are not considered to be their own ancestors. path must be in a
790 * canonical form: empty components, or "." or ".." components are not
791 * allowed.
792 */
793 int longest_ancestor_length(const char *path, struct string_list *prefixes)
794 {
795 int i, max_len = -1;
796
797 if (!strcmp(path, "/"))
798 return -1;
799
800 for (i = 0; i < prefixes->nr; i++) {
801 const char *ceil = prefixes->items[i].string;
802 int len = strlen(ceil);
803
804 if (len == 1 && ceil[0] == '/')
805 len = 0; /* root matches anything, with length 0 */
806 else if (!strncmp(path, ceil, len) && path[len] == '/')
807 ; /* match of length len */
808 else
809 continue; /* no match */
810
811 if (len > max_len)
812 max_len = len;
813 }
814
815 return max_len;
816 }
817
818 /* strip arbitrary amount of directory separators at end of path */
819 static inline int chomp_trailing_dir_sep(const char *path, int len)
820 {
821 while (len && is_dir_sep(path[len - 1]))
822 len--;
823 return len;
824 }
825
826 /*
827 * If path ends with suffix (complete path components), returns the
828 * part before suffix (sans trailing directory separators).
829 * Otherwise returns NULL.
830 */
831 char *strip_path_suffix(const char *path, const char *suffix)
832 {
833 int path_len = strlen(path), suffix_len = strlen(suffix);
834
835 while (suffix_len) {
836 if (!path_len)
837 return NULL;
838
839 if (is_dir_sep(path[path_len - 1])) {
840 if (!is_dir_sep(suffix[suffix_len - 1]))
841 return NULL;
842 path_len = chomp_trailing_dir_sep(path, path_len);
843 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
844 }
845 else if (path[--path_len] != suffix[--suffix_len])
846 return NULL;
847 }
848
849 if (path_len && !is_dir_sep(path[path_len - 1]))
850 return NULL;
851 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
852 }
853
854 int daemon_avoid_alias(const char *p)
855 {
856 int sl, ndot;
857
858 /*
859 * This resurrects the belts and suspenders paranoia check by HPA
860 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
861 * does not do getcwd() based path canonicalization.
862 *
863 * sl becomes true immediately after seeing '/' and continues to
864 * be true as long as dots continue after that without intervening
865 * non-dot character.
866 */
867 if (!p || (*p != '/' && *p != '~'))
868 return -1;
869 sl = 1; ndot = 0;
870 p++;
871
872 while (1) {
873 char ch = *p++;
874 if (sl) {
875 if (ch == '.')
876 ndot++;
877 else if (ch == '/') {
878 if (ndot < 3)
879 /* reject //, /./ and /../ */
880 return -1;
881 ndot = 0;
882 }
883 else if (ch == 0) {
884 if (0 < ndot && ndot < 3)
885 /* reject /.$ and /..$ */
886 return -1;
887 return 0;
888 }
889 else
890 sl = ndot = 0;
891 }
892 else if (ch == 0)
893 return 0;
894 else if (ch == '/') {
895 sl = 1;
896 ndot = 0;
897 }
898 }
899 }
900
901 static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
902 {
903 if (len < skip)
904 return 0;
905 len -= skip;
906 path += skip;
907 while (len-- > 0) {
908 char c = *(path++);
909 if (c != ' ' && c != '.')
910 return 0;
911 }
912 return 1;
913 }
914
915 int is_ntfs_dotgit(const char *name)
916 {
917 int len;
918
919 for (len = 0; ; len++)
920 if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
921 if (only_spaces_and_periods(name, len, 4) &&
922 !strncasecmp(name, ".git", 4))
923 return 1;
924 if (only_spaces_and_periods(name, len, 5) &&
925 !strncasecmp(name, "git~1", 5))
926 return 1;
927 if (name[len] != '\\')
928 return 0;
929 name += len + 1;
930 len = -1;
931 }
932 }
933
934 char *xdg_config_home(const char *filename)
935 {
936 const char *home, *config_home;
937
938 assert(filename);
939 config_home = getenv("XDG_CONFIG_HOME");
940 if (config_home && *config_home)
941 return mkpathdup("%s/git/%s", config_home, filename);
942
943 home = getenv("HOME");
944 if (home)
945 return mkpathdup("%s/.config/git/%s", home, filename);
946 return NULL;
947 }
948
949 GIT_PATH_FUNC(git_path_cherry_pick_head, "CHERRY_PICK_HEAD")
950 GIT_PATH_FUNC(git_path_revert_head, "REVERT_HEAD")
951 GIT_PATH_FUNC(git_path_squash_msg, "SQUASH_MSG")
952 GIT_PATH_FUNC(git_path_merge_msg, "MERGE_MSG")
953 GIT_PATH_FUNC(git_path_merge_rr, "MERGE_RR")
954 GIT_PATH_FUNC(git_path_merge_mode, "MERGE_MODE")
955 GIT_PATH_FUNC(git_path_merge_head, "MERGE_HEAD")
956 GIT_PATH_FUNC(git_path_fetch_head, "FETCH_HEAD")
957 GIT_PATH_FUNC(git_path_shallow, "shallow")