Git 2.8.6
[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 struct common_dir {
95 /* Not considered garbage for report_linked_checkout_garbage */
96 unsigned ignore_garbage:1;
97 unsigned is_dir:1;
98 /* Not common even though its parent is */
99 unsigned exclude:1;
100 const char *dirname;
101 };
102
103 static struct common_dir common_list[] = {
104 { 0, 1, 0, "branches" },
105 { 0, 1, 0, "hooks" },
106 { 0, 1, 0, "info" },
107 { 0, 0, 1, "info/sparse-checkout" },
108 { 1, 1, 0, "logs" },
109 { 1, 1, 1, "logs/HEAD" },
110 { 0, 1, 1, "logs/refs/bisect" },
111 { 0, 1, 0, "lost-found" },
112 { 0, 1, 0, "objects" },
113 { 0, 1, 0, "refs" },
114 { 0, 1, 1, "refs/bisect" },
115 { 0, 1, 0, "remotes" },
116 { 0, 1, 0, "worktrees" },
117 { 0, 1, 0, "rr-cache" },
118 { 0, 1, 0, "svn" },
119 { 0, 0, 0, "config" },
120 { 1, 0, 0, "gc.pid" },
121 { 0, 0, 0, "packed-refs" },
122 { 0, 0, 0, "shallow" },
123 { 0, 0, 0, NULL }
124 };
125
126 /*
127 * A compressed trie. A trie node consists of zero or more characters that
128 * are common to all elements with this prefix, optionally followed by some
129 * children. If value is not NULL, the trie node is a terminal node.
130 *
131 * For example, consider the following set of strings:
132 * abc
133 * def
134 * definite
135 * definition
136 *
137 * The trie would look like:
138 * root: len = 0, children a and d non-NULL, value = NULL.
139 * a: len = 2, contents = bc, value = (data for "abc")
140 * d: len = 2, contents = ef, children i non-NULL, value = (data for "def")
141 * i: len = 3, contents = nit, children e and i non-NULL, value = NULL
142 * e: len = 0, children all NULL, value = (data for "definite")
143 * i: len = 2, contents = on, children all NULL,
144 * value = (data for "definition")
145 */
146 struct trie {
147 struct trie *children[256];
148 int len;
149 char *contents;
150 void *value;
151 };
152
153 static struct trie *make_trie_node(const char *key, void *value)
154 {
155 struct trie *new_node = xcalloc(1, sizeof(*new_node));
156 new_node->len = strlen(key);
157 if (new_node->len) {
158 new_node->contents = xmalloc(new_node->len);
159 memcpy(new_node->contents, key, new_node->len);
160 }
161 new_node->value = value;
162 return new_node;
163 }
164
165 /*
166 * Add a key/value pair to a trie. The key is assumed to be \0-terminated.
167 * If there was an existing value for this key, return it.
168 */
169 static void *add_to_trie(struct trie *root, const char *key, void *value)
170 {
171 struct trie *child;
172 void *old;
173 int i;
174
175 if (!*key) {
176 /* we have reached the end of the key */
177 old = root->value;
178 root->value = value;
179 return old;
180 }
181
182 for (i = 0; i < root->len; i++) {
183 if (root->contents[i] == key[i])
184 continue;
185
186 /*
187 * Split this node: child will contain this node's
188 * existing children.
189 */
190 child = malloc(sizeof(*child));
191 memcpy(child->children, root->children, sizeof(root->children));
192
193 child->len = root->len - i - 1;
194 if (child->len) {
195 child->contents = xstrndup(root->contents + i + 1,
196 child->len);
197 }
198 child->value = root->value;
199 root->value = NULL;
200 root->len = i;
201
202 memset(root->children, 0, sizeof(root->children));
203 root->children[(unsigned char)root->contents[i]] = child;
204
205 /* This is the newly-added child. */
206 root->children[(unsigned char)key[i]] =
207 make_trie_node(key + i + 1, value);
208 return NULL;
209 }
210
211 /* We have matched the entire compressed section */
212 if (key[i]) {
213 child = root->children[(unsigned char)key[root->len]];
214 if (child) {
215 return add_to_trie(child, key + root->len + 1, value);
216 } else {
217 child = make_trie_node(key + root->len + 1, value);
218 root->children[(unsigned char)key[root->len]] = child;
219 return NULL;
220 }
221 }
222
223 old = root->value;
224 root->value = value;
225 return old;
226 }
227
228 typedef int (*match_fn)(const char *unmatched, void *data, void *baton);
229
230 /*
231 * Search a trie for some key. Find the longest /-or-\0-terminated
232 * prefix of the key for which the trie contains a value. Call fn
233 * with the unmatched portion of the key and the found value, and
234 * return its return value. If there is no such prefix, return -1.
235 *
236 * The key is partially normalized: consecutive slashes are skipped.
237 *
238 * For example, consider the trie containing only [refs,
239 * refs/worktree] (both with values).
240 *
241 * | key | unmatched | val from node | return value |
242 * |-----------------|------------|---------------|--------------|
243 * | a | not called | n/a | -1 |
244 * | refs | \0 | refs | as per fn |
245 * | refs/ | / | refs | as per fn |
246 * | refs/w | /w | refs | as per fn |
247 * | refs/worktree | \0 | refs/worktree | as per fn |
248 * | refs/worktree/ | / | refs/worktree | as per fn |
249 * | refs/worktree/a | /a | refs/worktree | as per fn |
250 * |-----------------|------------|---------------|--------------|
251 *
252 */
253 static int trie_find(struct trie *root, const char *key, match_fn fn,
254 void *baton)
255 {
256 int i;
257 int result;
258 struct trie *child;
259
260 if (!*key) {
261 /* we have reached the end of the key */
262 if (root->value && !root->len)
263 return fn(key, root->value, baton);
264 else
265 return -1;
266 }
267
268 for (i = 0; i < root->len; i++) {
269 /* Partial path normalization: skip consecutive slashes. */
270 if (key[i] == '/' && key[i+1] == '/') {
271 key++;
272 continue;
273 }
274 if (root->contents[i] != key[i])
275 return -1;
276 }
277
278 /* Matched the entire compressed section */
279 key += i;
280 if (!*key)
281 /* End of key */
282 return fn(key, root->value, baton);
283
284 /* Partial path normalization: skip consecutive slashes */
285 while (key[0] == '/' && key[1] == '/')
286 key++;
287
288 child = root->children[(unsigned char)*key];
289 if (child)
290 result = trie_find(child, key + 1, fn, baton);
291 else
292 result = -1;
293
294 if (result >= 0 || (*key != '/' && *key != 0))
295 return result;
296 if (root->value)
297 return fn(key, root->value, baton);
298 else
299 return -1;
300 }
301
302 static struct trie common_trie;
303 static int common_trie_done_setup;
304
305 static void init_common_trie(void)
306 {
307 struct common_dir *p;
308
309 if (common_trie_done_setup)
310 return;
311
312 for (p = common_list; p->dirname; p++)
313 add_to_trie(&common_trie, p->dirname, p);
314
315 common_trie_done_setup = 1;
316 }
317
318 /*
319 * Helper function for update_common_dir: returns 1 if the dir
320 * prefix is common.
321 */
322 static int check_common(const char *unmatched, void *value, void *baton)
323 {
324 struct common_dir *dir = value;
325
326 if (!dir)
327 return 0;
328
329 if (dir->is_dir && (unmatched[0] == 0 || unmatched[0] == '/'))
330 return !dir->exclude;
331
332 if (!dir->is_dir && unmatched[0] == 0)
333 return !dir->exclude;
334
335 return 0;
336 }
337
338 static void update_common_dir(struct strbuf *buf, int git_dir_len,
339 const char *common_dir)
340 {
341 char *base = buf->buf + git_dir_len;
342 init_common_trie();
343 if (!common_dir)
344 common_dir = get_git_common_dir();
345 if (trie_find(&common_trie, base, check_common, NULL) > 0)
346 replace_dir(buf, git_dir_len, common_dir);
347 }
348
349 void report_linked_checkout_garbage(void)
350 {
351 struct strbuf sb = STRBUF_INIT;
352 const struct common_dir *p;
353 int len;
354
355 if (!git_common_dir_env)
356 return;
357 strbuf_addf(&sb, "%s/", get_git_dir());
358 len = sb.len;
359 for (p = common_list; p->dirname; p++) {
360 const char *path = p->dirname;
361 if (p->ignore_garbage)
362 continue;
363 strbuf_setlen(&sb, len);
364 strbuf_addstr(&sb, path);
365 if (file_exists(sb.buf))
366 report_garbage(PACKDIR_FILE_GARBAGE, sb.buf);
367 }
368 strbuf_release(&sb);
369 }
370
371 static void adjust_git_path(struct strbuf *buf, int git_dir_len)
372 {
373 const char *base = buf->buf + git_dir_len;
374 if (git_graft_env && is_dir_file(base, "info", "grafts"))
375 strbuf_splice(buf, 0, buf->len,
376 get_graft_file(), strlen(get_graft_file()));
377 else if (git_index_env && !strcmp(base, "index"))
378 strbuf_splice(buf, 0, buf->len,
379 get_index_file(), strlen(get_index_file()));
380 else if (git_db_env && dir_prefix(base, "objects"))
381 replace_dir(buf, git_dir_len + 7, get_object_directory());
382 else if (git_common_dir_env)
383 update_common_dir(buf, git_dir_len, NULL);
384 }
385
386 static void do_git_path(struct strbuf *buf, const char *fmt, va_list args)
387 {
388 int gitdir_len;
389 strbuf_addstr(buf, get_git_dir());
390 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
391 strbuf_addch(buf, '/');
392 gitdir_len = buf->len;
393 strbuf_vaddf(buf, fmt, args);
394 adjust_git_path(buf, gitdir_len);
395 strbuf_cleanup_path(buf);
396 }
397
398 char *git_path_buf(struct strbuf *buf, const char *fmt, ...)
399 {
400 va_list args;
401 strbuf_reset(buf);
402 va_start(args, fmt);
403 do_git_path(buf, fmt, args);
404 va_end(args);
405 return buf->buf;
406 }
407
408 void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
409 {
410 va_list args;
411 va_start(args, fmt);
412 do_git_path(sb, fmt, args);
413 va_end(args);
414 }
415
416 const char *git_path(const char *fmt, ...)
417 {
418 struct strbuf *pathname = get_pathname();
419 va_list args;
420 va_start(args, fmt);
421 do_git_path(pathname, fmt, args);
422 va_end(args);
423 return pathname->buf;
424 }
425
426 char *git_pathdup(const char *fmt, ...)
427 {
428 struct strbuf path = STRBUF_INIT;
429 va_list args;
430 va_start(args, fmt);
431 do_git_path(&path, fmt, args);
432 va_end(args);
433 return strbuf_detach(&path, NULL);
434 }
435
436 char *mkpathdup(const char *fmt, ...)
437 {
438 struct strbuf sb = STRBUF_INIT;
439 va_list args;
440 va_start(args, fmt);
441 strbuf_vaddf(&sb, fmt, args);
442 va_end(args);
443 strbuf_cleanup_path(&sb);
444 return strbuf_detach(&sb, NULL);
445 }
446
447 const char *mkpath(const char *fmt, ...)
448 {
449 va_list args;
450 struct strbuf *pathname = get_pathname();
451 va_start(args, fmt);
452 strbuf_vaddf(pathname, fmt, args);
453 va_end(args);
454 return cleanup_path(pathname->buf);
455 }
456
457 static void do_submodule_path(struct strbuf *buf, const char *path,
458 const char *fmt, va_list args)
459 {
460 const char *git_dir;
461 struct strbuf git_submodule_common_dir = STRBUF_INIT;
462 struct strbuf git_submodule_dir = STRBUF_INIT;
463
464 strbuf_addstr(buf, path);
465 strbuf_complete(buf, '/');
466 strbuf_addstr(buf, ".git");
467
468 git_dir = read_gitfile(buf->buf);
469 if (git_dir) {
470 strbuf_reset(buf);
471 strbuf_addstr(buf, git_dir);
472 }
473 strbuf_addch(buf, '/');
474 strbuf_addstr(&git_submodule_dir, buf->buf);
475
476 strbuf_vaddf(buf, fmt, args);
477
478 if (get_common_dir_noenv(&git_submodule_common_dir, git_submodule_dir.buf))
479 update_common_dir(buf, git_submodule_dir.len, git_submodule_common_dir.buf);
480
481 strbuf_cleanup_path(buf);
482
483 strbuf_release(&git_submodule_dir);
484 strbuf_release(&git_submodule_common_dir);
485 }
486
487 char *git_pathdup_submodule(const char *path, const char *fmt, ...)
488 {
489 va_list args;
490 struct strbuf buf = STRBUF_INIT;
491 va_start(args, fmt);
492 do_submodule_path(&buf, path, fmt, args);
493 va_end(args);
494 return strbuf_detach(&buf, NULL);
495 }
496
497 void strbuf_git_path_submodule(struct strbuf *buf, const char *path,
498 const char *fmt, ...)
499 {
500 va_list args;
501 va_start(args, fmt);
502 do_submodule_path(buf, path, fmt, args);
503 va_end(args);
504 }
505
506 int validate_headref(const char *path)
507 {
508 struct stat st;
509 char *buf, buffer[256];
510 unsigned char sha1[20];
511 int fd;
512 ssize_t len;
513
514 if (lstat(path, &st) < 0)
515 return -1;
516
517 /* Make sure it is a "refs/.." symlink */
518 if (S_ISLNK(st.st_mode)) {
519 len = readlink(path, buffer, sizeof(buffer)-1);
520 if (len >= 5 && !memcmp("refs/", buffer, 5))
521 return 0;
522 return -1;
523 }
524
525 /*
526 * Anything else, just open it and try to see if it is a symbolic ref.
527 */
528 fd = open(path, O_RDONLY);
529 if (fd < 0)
530 return -1;
531 len = read_in_full(fd, buffer, sizeof(buffer)-1);
532 close(fd);
533
534 /*
535 * Is it a symbolic ref?
536 */
537 if (len < 4)
538 return -1;
539 if (!memcmp("ref:", buffer, 4)) {
540 buf = buffer + 4;
541 len -= 4;
542 while (len && isspace(*buf))
543 buf++, len--;
544 if (len >= 5 && !memcmp("refs/", buf, 5))
545 return 0;
546 }
547
548 /*
549 * Is this a detached HEAD?
550 */
551 if (!get_sha1_hex(buffer, sha1))
552 return 0;
553
554 return -1;
555 }
556
557 static struct passwd *getpw_str(const char *username, size_t len)
558 {
559 struct passwd *pw;
560 char *username_z = xmemdupz(username, len);
561 pw = getpwnam(username_z);
562 free(username_z);
563 return pw;
564 }
565
566 /*
567 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
568 * then it is a newly allocated string. Returns NULL on getpw failure or
569 * if path is NULL.
570 */
571 char *expand_user_path(const char *path)
572 {
573 struct strbuf user_path = STRBUF_INIT;
574 const char *to_copy = path;
575
576 if (path == NULL)
577 goto return_null;
578 if (path[0] == '~') {
579 const char *first_slash = strchrnul(path, '/');
580 const char *username = path + 1;
581 size_t username_len = first_slash - username;
582 if (username_len == 0) {
583 const char *home = getenv("HOME");
584 if (!home)
585 goto return_null;
586 strbuf_addstr(&user_path, home);
587 #ifdef GIT_WINDOWS_NATIVE
588 convert_slashes(user_path.buf);
589 #endif
590 } else {
591 struct passwd *pw = getpw_str(username, username_len);
592 if (!pw)
593 goto return_null;
594 strbuf_addstr(&user_path, pw->pw_dir);
595 }
596 to_copy = first_slash;
597 }
598 strbuf_addstr(&user_path, to_copy);
599 return strbuf_detach(&user_path, NULL);
600 return_null:
601 strbuf_release(&user_path);
602 return NULL;
603 }
604
605 /*
606 * First, one directory to try is determined by the following algorithm.
607 *
608 * (0) If "strict" is given, the path is used as given and no DWIM is
609 * done. Otherwise:
610 * (1) "~/path" to mean path under the running user's home directory;
611 * (2) "~user/path" to mean path under named user's home directory;
612 * (3) "relative/path" to mean cwd relative directory; or
613 * (4) "/absolute/path" to mean absolute directory.
614 *
615 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
616 * in this order. We select the first one that is a valid git repository, and
617 * chdir() to it. If none match, or we fail to chdir, we return NULL.
618 *
619 * If all goes well, we return the directory we used to chdir() (but
620 * before ~user is expanded), avoiding getcwd() resolving symbolic
621 * links. User relative paths are also returned as they are given,
622 * except DWIM suffixing.
623 */
624 const char *enter_repo(const char *path, int strict)
625 {
626 static struct strbuf validated_path = STRBUF_INIT;
627 static struct strbuf used_path = STRBUF_INIT;
628
629 if (!path)
630 return NULL;
631
632 if (!strict) {
633 static const char *suffix[] = {
634 "/.git", "", ".git/.git", ".git", NULL,
635 };
636 const char *gitfile;
637 int len = strlen(path);
638 int i;
639 while ((1 < len) && (path[len-1] == '/'))
640 len--;
641
642 /*
643 * We can handle arbitrary-sized buffers, but this remains as a
644 * sanity check on untrusted input.
645 */
646 if (PATH_MAX <= len)
647 return NULL;
648
649 strbuf_reset(&used_path);
650 strbuf_reset(&validated_path);
651 strbuf_add(&used_path, path, len);
652 strbuf_add(&validated_path, path, len);
653
654 if (used_path.buf[0] == '~') {
655 char *newpath = expand_user_path(used_path.buf);
656 if (!newpath)
657 return NULL;
658 strbuf_attach(&used_path, newpath, strlen(newpath),
659 strlen(newpath));
660 }
661 for (i = 0; suffix[i]; i++) {
662 struct stat st;
663 size_t baselen = used_path.len;
664 strbuf_addstr(&used_path, suffix[i]);
665 if (!stat(used_path.buf, &st) &&
666 (S_ISREG(st.st_mode) ||
667 (S_ISDIR(st.st_mode) && is_git_directory(used_path.buf)))) {
668 strbuf_addstr(&validated_path, suffix[i]);
669 break;
670 }
671 strbuf_setlen(&used_path, baselen);
672 }
673 if (!suffix[i])
674 return NULL;
675 gitfile = read_gitfile(used_path.buf);
676 if (gitfile) {
677 strbuf_reset(&used_path);
678 strbuf_addstr(&used_path, gitfile);
679 }
680 if (chdir(used_path.buf))
681 return NULL;
682 path = validated_path.buf;
683 }
684 else {
685 const char *gitfile = read_gitfile(path);
686 if (gitfile)
687 path = gitfile;
688 if (chdir(path))
689 return NULL;
690 }
691
692 if (is_git_directory(".")) {
693 set_git_dir(".");
694 check_repository_format();
695 return path;
696 }
697
698 return NULL;
699 }
700
701 static int calc_shared_perm(int mode)
702 {
703 int tweak;
704
705 if (get_shared_repository() < 0)
706 tweak = -get_shared_repository();
707 else
708 tweak = get_shared_repository();
709
710 if (!(mode & S_IWUSR))
711 tweak &= ~0222;
712 if (mode & S_IXUSR)
713 /* Copy read bits to execute bits */
714 tweak |= (tweak & 0444) >> 2;
715 if (get_shared_repository() < 0)
716 mode = (mode & ~0777) | tweak;
717 else
718 mode |= tweak;
719
720 return mode;
721 }
722
723
724 int adjust_shared_perm(const char *path)
725 {
726 int old_mode, new_mode;
727
728 if (!get_shared_repository())
729 return 0;
730 if (get_st_mode_bits(path, &old_mode) < 0)
731 return -1;
732
733 new_mode = calc_shared_perm(old_mode);
734 if (S_ISDIR(old_mode)) {
735 /* Copy read bits to execute bits */
736 new_mode |= (new_mode & 0444) >> 2;
737 new_mode |= FORCE_DIR_SET_GID;
738 }
739
740 if (((old_mode ^ new_mode) & ~S_IFMT) &&
741 chmod(path, (new_mode & ~S_IFMT)) < 0)
742 return -2;
743 return 0;
744 }
745
746 void safe_create_dir(const char *dir, int share)
747 {
748 if (mkdir(dir, 0777) < 0) {
749 if (errno != EEXIST) {
750 perror(dir);
751 exit(1);
752 }
753 }
754 else if (share && adjust_shared_perm(dir))
755 die(_("Could not make %s writable by group"), dir);
756 }
757
758 static int have_same_root(const char *path1, const char *path2)
759 {
760 int is_abs1, is_abs2;
761
762 is_abs1 = is_absolute_path(path1);
763 is_abs2 = is_absolute_path(path2);
764 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
765 (!is_abs1 && !is_abs2);
766 }
767
768 /*
769 * Give path as relative to prefix.
770 *
771 * The strbuf may or may not be used, so do not assume it contains the
772 * returned path.
773 */
774 const char *relative_path(const char *in, const char *prefix,
775 struct strbuf *sb)
776 {
777 int in_len = in ? strlen(in) : 0;
778 int prefix_len = prefix ? strlen(prefix) : 0;
779 int in_off = 0;
780 int prefix_off = 0;
781 int i = 0, j = 0;
782
783 if (!in_len)
784 return "./";
785 else if (!prefix_len)
786 return in;
787
788 if (have_same_root(in, prefix))
789 /* bypass dos_drive, for "c:" is identical to "C:" */
790 i = j = has_dos_drive_prefix(in);
791 else {
792 return in;
793 }
794
795 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
796 if (is_dir_sep(prefix[i])) {
797 while (is_dir_sep(prefix[i]))
798 i++;
799 while (is_dir_sep(in[j]))
800 j++;
801 prefix_off = i;
802 in_off = j;
803 } else {
804 i++;
805 j++;
806 }
807 }
808
809 if (
810 /* "prefix" seems like prefix of "in" */
811 i >= prefix_len &&
812 /*
813 * but "/foo" is not a prefix of "/foobar"
814 * (i.e. prefix not end with '/')
815 */
816 prefix_off < prefix_len) {
817 if (j >= in_len) {
818 /* in="/a/b", prefix="/a/b" */
819 in_off = in_len;
820 } else if (is_dir_sep(in[j])) {
821 /* in="/a/b/c", prefix="/a/b" */
822 while (is_dir_sep(in[j]))
823 j++;
824 in_off = j;
825 } else {
826 /* in="/a/bbb/c", prefix="/a/b" */
827 i = prefix_off;
828 }
829 } else if (
830 /* "in" is short than "prefix" */
831 j >= in_len &&
832 /* "in" not end with '/' */
833 in_off < in_len) {
834 if (is_dir_sep(prefix[i])) {
835 /* in="/a/b", prefix="/a/b/c/" */
836 while (is_dir_sep(prefix[i]))
837 i++;
838 in_off = in_len;
839 }
840 }
841 in += in_off;
842 in_len -= in_off;
843
844 if (i >= prefix_len) {
845 if (!in_len)
846 return "./";
847 else
848 return in;
849 }
850
851 strbuf_reset(sb);
852 strbuf_grow(sb, in_len);
853
854 while (i < prefix_len) {
855 if (is_dir_sep(prefix[i])) {
856 strbuf_addstr(sb, "../");
857 while (is_dir_sep(prefix[i]))
858 i++;
859 continue;
860 }
861 i++;
862 }
863 if (!is_dir_sep(prefix[prefix_len - 1]))
864 strbuf_addstr(sb, "../");
865
866 strbuf_addstr(sb, in);
867
868 return sb->buf;
869 }
870
871 /*
872 * A simpler implementation of relative_path
873 *
874 * Get relative path by removing "prefix" from "in". This function
875 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
876 * to increase performance when traversing the path to work_tree.
877 */
878 const char *remove_leading_path(const char *in, const char *prefix)
879 {
880 static struct strbuf buf = STRBUF_INIT;
881 int i = 0, j = 0;
882
883 if (!prefix || !prefix[0])
884 return in;
885 while (prefix[i]) {
886 if (is_dir_sep(prefix[i])) {
887 if (!is_dir_sep(in[j]))
888 return in;
889 while (is_dir_sep(prefix[i]))
890 i++;
891 while (is_dir_sep(in[j]))
892 j++;
893 continue;
894 } else if (in[j] != prefix[i]) {
895 return in;
896 }
897 i++;
898 j++;
899 }
900 if (
901 /* "/foo" is a prefix of "/foo" */
902 in[j] &&
903 /* "/foo" is not a prefix of "/foobar" */
904 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
905 )
906 return in;
907 while (is_dir_sep(in[j]))
908 j++;
909
910 strbuf_reset(&buf);
911 if (!in[j])
912 strbuf_addstr(&buf, ".");
913 else
914 strbuf_addstr(&buf, in + j);
915 return buf.buf;
916 }
917
918 /*
919 * It is okay if dst == src, but they should not overlap otherwise.
920 *
921 * Performs the following normalizations on src, storing the result in dst:
922 * - Ensures that components are separated by '/' (Windows only)
923 * - Squashes sequences of '/'.
924 * - Removes "." components.
925 * - Removes ".." components, and the components the precede them.
926 * Returns failure (non-zero) if a ".." component appears as first path
927 * component anytime during the normalization. Otherwise, returns success (0).
928 *
929 * Note that this function is purely textual. It does not follow symlinks,
930 * verify the existence of the path, or make any system calls.
931 *
932 * prefix_len != NULL is for a specific case of prefix_pathspec():
933 * assume that src == dst and src[0..prefix_len-1] is already
934 * normalized, any time "../" eats up to the prefix_len part,
935 * prefix_len is reduced. In the end prefix_len is the remaining
936 * prefix that has not been overridden by user pathspec.
937 *
938 * NEEDSWORK: This function doesn't perform normalization w.r.t. trailing '/'.
939 * For everything but the root folder itself, the normalized path should not
940 * end with a '/', then the callers need to be fixed up accordingly.
941 *
942 */
943 int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
944 {
945 char *dst0;
946 int i;
947
948 for (i = has_dos_drive_prefix(src); i > 0; i--)
949 *dst++ = *src++;
950 dst0 = dst;
951
952 if (is_dir_sep(*src)) {
953 *dst++ = '/';
954 while (is_dir_sep(*src))
955 src++;
956 }
957
958 for (;;) {
959 char c = *src;
960
961 /*
962 * A path component that begins with . could be
963 * special:
964 * (1) "." and ends -- ignore and terminate.
965 * (2) "./" -- ignore them, eat slash and continue.
966 * (3) ".." and ends -- strip one and terminate.
967 * (4) "../" -- strip one, eat slash and continue.
968 */
969 if (c == '.') {
970 if (!src[1]) {
971 /* (1) */
972 src++;
973 } else if (is_dir_sep(src[1])) {
974 /* (2) */
975 src += 2;
976 while (is_dir_sep(*src))
977 src++;
978 continue;
979 } else if (src[1] == '.') {
980 if (!src[2]) {
981 /* (3) */
982 src += 2;
983 goto up_one;
984 } else if (is_dir_sep(src[2])) {
985 /* (4) */
986 src += 3;
987 while (is_dir_sep(*src))
988 src++;
989 goto up_one;
990 }
991 }
992 }
993
994 /* copy up to the next '/', and eat all '/' */
995 while ((c = *src++) != '\0' && !is_dir_sep(c))
996 *dst++ = c;
997 if (is_dir_sep(c)) {
998 *dst++ = '/';
999 while (is_dir_sep(c))
1000 c = *src++;
1001 src--;
1002 } else if (!c)
1003 break;
1004 continue;
1005
1006 up_one:
1007 /*
1008 * dst0..dst is prefix portion, and dst[-1] is '/';
1009 * go up one level.
1010 */
1011 dst--; /* go to trailing '/' */
1012 if (dst <= dst0)
1013 return -1;
1014 /* Windows: dst[-1] cannot be backslash anymore */
1015 while (dst0 < dst && dst[-1] != '/')
1016 dst--;
1017 if (prefix_len && *prefix_len > dst - dst0)
1018 *prefix_len = dst - dst0;
1019 }
1020 *dst = '\0';
1021 return 0;
1022 }
1023
1024 int normalize_path_copy(char *dst, const char *src)
1025 {
1026 return normalize_path_copy_len(dst, src, NULL);
1027 }
1028
1029 /*
1030 * path = Canonical absolute path
1031 * prefixes = string_list containing normalized, absolute paths without
1032 * trailing slashes (except for the root directory, which is denoted by "/").
1033 *
1034 * Determines, for each path in prefixes, whether the "prefix"
1035 * is an ancestor directory of path. Returns the length of the longest
1036 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
1037 * is an ancestor. (Note that this means 0 is returned if prefixes is
1038 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
1039 * are not considered to be their own ancestors. path must be in a
1040 * canonical form: empty components, or "." or ".." components are not
1041 * allowed.
1042 */
1043 int longest_ancestor_length(const char *path, struct string_list *prefixes)
1044 {
1045 int i, max_len = -1;
1046
1047 if (!strcmp(path, "/"))
1048 return -1;
1049
1050 for (i = 0; i < prefixes->nr; i++) {
1051 const char *ceil = prefixes->items[i].string;
1052 int len = strlen(ceil);
1053
1054 if (len == 1 && ceil[0] == '/')
1055 len = 0; /* root matches anything, with length 0 */
1056 else if (!strncmp(path, ceil, len) && path[len] == '/')
1057 ; /* match of length len */
1058 else
1059 continue; /* no match */
1060
1061 if (len > max_len)
1062 max_len = len;
1063 }
1064
1065 return max_len;
1066 }
1067
1068 /* strip arbitrary amount of directory separators at end of path */
1069 static inline int chomp_trailing_dir_sep(const char *path, int len)
1070 {
1071 while (len && is_dir_sep(path[len - 1]))
1072 len--;
1073 return len;
1074 }
1075
1076 /*
1077 * If path ends with suffix (complete path components), returns the
1078 * part before suffix (sans trailing directory separators).
1079 * Otherwise returns NULL.
1080 */
1081 char *strip_path_suffix(const char *path, const char *suffix)
1082 {
1083 int path_len = strlen(path), suffix_len = strlen(suffix);
1084
1085 while (suffix_len) {
1086 if (!path_len)
1087 return NULL;
1088
1089 if (is_dir_sep(path[path_len - 1])) {
1090 if (!is_dir_sep(suffix[suffix_len - 1]))
1091 return NULL;
1092 path_len = chomp_trailing_dir_sep(path, path_len);
1093 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
1094 }
1095 else if (path[--path_len] != suffix[--suffix_len])
1096 return NULL;
1097 }
1098
1099 if (path_len && !is_dir_sep(path[path_len - 1]))
1100 return NULL;
1101 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
1102 }
1103
1104 int daemon_avoid_alias(const char *p)
1105 {
1106 int sl, ndot;
1107
1108 /*
1109 * This resurrects the belts and suspenders paranoia check by HPA
1110 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
1111 * does not do getcwd() based path canonicalization.
1112 *
1113 * sl becomes true immediately after seeing '/' and continues to
1114 * be true as long as dots continue after that without intervening
1115 * non-dot character.
1116 */
1117 if (!p || (*p != '/' && *p != '~'))
1118 return -1;
1119 sl = 1; ndot = 0;
1120 p++;
1121
1122 while (1) {
1123 char ch = *p++;
1124 if (sl) {
1125 if (ch == '.')
1126 ndot++;
1127 else if (ch == '/') {
1128 if (ndot < 3)
1129 /* reject //, /./ and /../ */
1130 return -1;
1131 ndot = 0;
1132 }
1133 else if (ch == 0) {
1134 if (0 < ndot && ndot < 3)
1135 /* reject /.$ and /..$ */
1136 return -1;
1137 return 0;
1138 }
1139 else
1140 sl = ndot = 0;
1141 }
1142 else if (ch == 0)
1143 return 0;
1144 else if (ch == '/') {
1145 sl = 1;
1146 ndot = 0;
1147 }
1148 }
1149 }
1150
1151 static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
1152 {
1153 if (len < skip)
1154 return 0;
1155 len -= skip;
1156 path += skip;
1157 while (len-- > 0) {
1158 char c = *(path++);
1159 if (c != ' ' && c != '.')
1160 return 0;
1161 }
1162 return 1;
1163 }
1164
1165 int is_ntfs_dotgit(const char *name)
1166 {
1167 int len;
1168
1169 for (len = 0; ; len++)
1170 if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
1171 if (only_spaces_and_periods(name, len, 4) &&
1172 !strncasecmp(name, ".git", 4))
1173 return 1;
1174 if (only_spaces_and_periods(name, len, 5) &&
1175 !strncasecmp(name, "git~1", 5))
1176 return 1;
1177 if (name[len] != '\\')
1178 return 0;
1179 name += len + 1;
1180 len = -1;
1181 }
1182 }
1183
1184 int looks_like_command_line_option(const char *str)
1185 {
1186 return str && str[0] == '-';
1187 }
1188
1189 char *xdg_config_home(const char *filename)
1190 {
1191 const char *home, *config_home;
1192
1193 assert(filename);
1194 config_home = getenv("XDG_CONFIG_HOME");
1195 if (config_home && *config_home)
1196 return mkpathdup("%s/git/%s", config_home, filename);
1197
1198 home = getenv("HOME");
1199 if (home)
1200 return mkpathdup("%s/.config/git/%s", home, filename);
1201 return NULL;
1202 }
1203
1204 GIT_PATH_FUNC(git_path_cherry_pick_head, "CHERRY_PICK_HEAD")
1205 GIT_PATH_FUNC(git_path_revert_head, "REVERT_HEAD")
1206 GIT_PATH_FUNC(git_path_squash_msg, "SQUASH_MSG")
1207 GIT_PATH_FUNC(git_path_merge_msg, "MERGE_MSG")
1208 GIT_PATH_FUNC(git_path_merge_rr, "MERGE_RR")
1209 GIT_PATH_FUNC(git_path_merge_mode, "MERGE_MODE")
1210 GIT_PATH_FUNC(git_path_merge_head, "MERGE_HEAD")
1211 GIT_PATH_FUNC(git_path_fetch_head, "FETCH_HEAD")
1212 GIT_PATH_FUNC(git_path_shallow, "shallow")