Merge branch 'rs/use-strbuf-addbuf'
[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 #include "worktree.h"
9
10 static int get_st_mode_bits(const char *path, int *mode)
11 {
12 struct stat st;
13 if (lstat(path, &st) < 0)
14 return -1;
15 *mode = st.st_mode;
16 return 0;
17 }
18
19 static char bad_path[] = "/bad-path/";
20
21 static struct strbuf *get_pathname(void)
22 {
23 static struct strbuf pathname_array[4] = {
24 STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
25 };
26 static int index;
27 struct strbuf *sb = &pathname_array[3 & ++index];
28 strbuf_reset(sb);
29 return sb;
30 }
31
32 static char *cleanup_path(char *path)
33 {
34 /* Clean it up */
35 if (!memcmp(path, "./", 2)) {
36 path += 2;
37 while (*path == '/')
38 path++;
39 }
40 return path;
41 }
42
43 static void strbuf_cleanup_path(struct strbuf *sb)
44 {
45 char *path = cleanup_path(sb->buf);
46 if (path > sb->buf)
47 strbuf_remove(sb, 0, path - sb->buf);
48 }
49
50 char *mksnpath(char *buf, size_t n, const char *fmt, ...)
51 {
52 va_list args;
53 unsigned len;
54
55 va_start(args, fmt);
56 len = vsnprintf(buf, n, fmt, args);
57 va_end(args);
58 if (len >= n) {
59 strlcpy(buf, bad_path, n);
60 return buf;
61 }
62 return cleanup_path(buf);
63 }
64
65 static int dir_prefix(const char *buf, const char *dir)
66 {
67 int len = strlen(dir);
68 return !strncmp(buf, dir, len) &&
69 (is_dir_sep(buf[len]) || buf[len] == '\0');
70 }
71
72 /* $buf =~ m|$dir/+$file| but without regex */
73 static int is_dir_file(const char *buf, const char *dir, const char *file)
74 {
75 int len = strlen(dir);
76 if (strncmp(buf, dir, len) || !is_dir_sep(buf[len]))
77 return 0;
78 while (is_dir_sep(buf[len]))
79 len++;
80 return !strcmp(buf + len, file);
81 }
82
83 static void replace_dir(struct strbuf *buf, int len, const char *newdir)
84 {
85 int newlen = strlen(newdir);
86 int need_sep = (buf->buf[len] && !is_dir_sep(buf->buf[len])) &&
87 !is_dir_sep(newdir[newlen - 1]);
88 if (need_sep)
89 len--; /* keep one char, to be replaced with '/' */
90 strbuf_splice(buf, 0, len, newdir, newlen);
91 if (need_sep)
92 buf->buf[newlen] = '/';
93 }
94
95 struct common_dir {
96 /* Not considered garbage for report_linked_checkout_garbage */
97 unsigned ignore_garbage:1;
98 unsigned is_dir:1;
99 /* Not common even though its parent is */
100 unsigned exclude:1;
101 const char *dirname;
102 };
103
104 static struct common_dir common_list[] = {
105 { 0, 1, 0, "branches" },
106 { 0, 1, 0, "hooks" },
107 { 0, 1, 0, "info" },
108 { 0, 0, 1, "info/sparse-checkout" },
109 { 1, 1, 0, "logs" },
110 { 1, 1, 1, "logs/HEAD" },
111 { 0, 1, 1, "logs/refs/bisect" },
112 { 0, 1, 0, "lost-found" },
113 { 0, 1, 0, "objects" },
114 { 0, 1, 0, "refs" },
115 { 0, 1, 1, "refs/bisect" },
116 { 0, 1, 0, "remotes" },
117 { 0, 1, 0, "worktrees" },
118 { 0, 1, 0, "rr-cache" },
119 { 0, 1, 0, "svn" },
120 { 0, 0, 0, "config" },
121 { 1, 0, 0, "gc.pid" },
122 { 0, 0, 0, "packed-refs" },
123 { 0, 0, 0, "shallow" },
124 { 0, 0, 0, NULL }
125 };
126
127 /*
128 * A compressed trie. A trie node consists of zero or more characters that
129 * are common to all elements with this prefix, optionally followed by some
130 * children. If value is not NULL, the trie node is a terminal node.
131 *
132 * For example, consider the following set of strings:
133 * abc
134 * def
135 * definite
136 * definition
137 *
138 * The trie would look like:
139 * root: len = 0, children a and d non-NULL, value = NULL.
140 * a: len = 2, contents = bc, value = (data for "abc")
141 * d: len = 2, contents = ef, children i non-NULL, value = (data for "def")
142 * i: len = 3, contents = nit, children e and i non-NULL, value = NULL
143 * e: len = 0, children all NULL, value = (data for "definite")
144 * i: len = 2, contents = on, children all NULL,
145 * value = (data for "definition")
146 */
147 struct trie {
148 struct trie *children[256];
149 int len;
150 char *contents;
151 void *value;
152 };
153
154 static struct trie *make_trie_node(const char *key, void *value)
155 {
156 struct trie *new_node = xcalloc(1, sizeof(*new_node));
157 new_node->len = strlen(key);
158 if (new_node->len) {
159 new_node->contents = xmalloc(new_node->len);
160 memcpy(new_node->contents, key, new_node->len);
161 }
162 new_node->value = value;
163 return new_node;
164 }
165
166 /*
167 * Add a key/value pair to a trie. The key is assumed to be \0-terminated.
168 * If there was an existing value for this key, return it.
169 */
170 static void *add_to_trie(struct trie *root, const char *key, void *value)
171 {
172 struct trie *child;
173 void *old;
174 int i;
175
176 if (!*key) {
177 /* we have reached the end of the key */
178 old = root->value;
179 root->value = value;
180 return old;
181 }
182
183 for (i = 0; i < root->len; i++) {
184 if (root->contents[i] == key[i])
185 continue;
186
187 /*
188 * Split this node: child will contain this node's
189 * existing children.
190 */
191 child = malloc(sizeof(*child));
192 memcpy(child->children, root->children, sizeof(root->children));
193
194 child->len = root->len - i - 1;
195 if (child->len) {
196 child->contents = xstrndup(root->contents + i + 1,
197 child->len);
198 }
199 child->value = root->value;
200 root->value = NULL;
201 root->len = i;
202
203 memset(root->children, 0, sizeof(root->children));
204 root->children[(unsigned char)root->contents[i]] = child;
205
206 /* This is the newly-added child. */
207 root->children[(unsigned char)key[i]] =
208 make_trie_node(key + i + 1, value);
209 return NULL;
210 }
211
212 /* We have matched the entire compressed section */
213 if (key[i]) {
214 child = root->children[(unsigned char)key[root->len]];
215 if (child) {
216 return add_to_trie(child, key + root->len + 1, value);
217 } else {
218 child = make_trie_node(key + root->len + 1, value);
219 root->children[(unsigned char)key[root->len]] = child;
220 return NULL;
221 }
222 }
223
224 old = root->value;
225 root->value = value;
226 return old;
227 }
228
229 typedef int (*match_fn)(const char *unmatched, void *data, void *baton);
230
231 /*
232 * Search a trie for some key. Find the longest /-or-\0-terminated
233 * prefix of the key for which the trie contains a value. Call fn
234 * with the unmatched portion of the key and the found value, and
235 * return its return value. If there is no such prefix, return -1.
236 *
237 * The key is partially normalized: consecutive slashes are skipped.
238 *
239 * For example, consider the trie containing only [refs,
240 * refs/worktree] (both with values).
241 *
242 * | key | unmatched | val from node | return value |
243 * |-----------------|------------|---------------|--------------|
244 * | a | not called | n/a | -1 |
245 * | refs | \0 | refs | as per fn |
246 * | refs/ | / | refs | as per fn |
247 * | refs/w | /w | refs | as per fn |
248 * | refs/worktree | \0 | refs/worktree | as per fn |
249 * | refs/worktree/ | / | refs/worktree | as per fn |
250 * | refs/worktree/a | /a | refs/worktree | as per fn |
251 * |-----------------|------------|---------------|--------------|
252 *
253 */
254 static int trie_find(struct trie *root, const char *key, match_fn fn,
255 void *baton)
256 {
257 int i;
258 int result;
259 struct trie *child;
260
261 if (!*key) {
262 /* we have reached the end of the key */
263 if (root->value && !root->len)
264 return fn(key, root->value, baton);
265 else
266 return -1;
267 }
268
269 for (i = 0; i < root->len; i++) {
270 /* Partial path normalization: skip consecutive slashes. */
271 if (key[i] == '/' && key[i+1] == '/') {
272 key++;
273 continue;
274 }
275 if (root->contents[i] != key[i])
276 return -1;
277 }
278
279 /* Matched the entire compressed section */
280 key += i;
281 if (!*key)
282 /* End of key */
283 return fn(key, root->value, baton);
284
285 /* Partial path normalization: skip consecutive slashes */
286 while (key[0] == '/' && key[1] == '/')
287 key++;
288
289 child = root->children[(unsigned char)*key];
290 if (child)
291 result = trie_find(child, key + 1, fn, baton);
292 else
293 result = -1;
294
295 if (result >= 0 || (*key != '/' && *key != 0))
296 return result;
297 if (root->value)
298 return fn(key, root->value, baton);
299 else
300 return -1;
301 }
302
303 static struct trie common_trie;
304 static int common_trie_done_setup;
305
306 static void init_common_trie(void)
307 {
308 struct common_dir *p;
309
310 if (common_trie_done_setup)
311 return;
312
313 for (p = common_list; p->dirname; p++)
314 add_to_trie(&common_trie, p->dirname, p);
315
316 common_trie_done_setup = 1;
317 }
318
319 /*
320 * Helper function for update_common_dir: returns 1 if the dir
321 * prefix is common.
322 */
323 static int check_common(const char *unmatched, void *value, void *baton)
324 {
325 struct common_dir *dir = value;
326
327 if (!dir)
328 return 0;
329
330 if (dir->is_dir && (unmatched[0] == 0 || unmatched[0] == '/'))
331 return !dir->exclude;
332
333 if (!dir->is_dir && unmatched[0] == 0)
334 return !dir->exclude;
335
336 return 0;
337 }
338
339 static void update_common_dir(struct strbuf *buf, int git_dir_len,
340 const char *common_dir)
341 {
342 char *base = buf->buf + git_dir_len;
343 init_common_trie();
344 if (!common_dir)
345 common_dir = get_git_common_dir();
346 if (trie_find(&common_trie, base, check_common, NULL) > 0)
347 replace_dir(buf, git_dir_len, common_dir);
348 }
349
350 void report_linked_checkout_garbage(void)
351 {
352 struct strbuf sb = STRBUF_INIT;
353 const struct common_dir *p;
354 int len;
355
356 if (!git_common_dir_env)
357 return;
358 strbuf_addf(&sb, "%s/", get_git_dir());
359 len = sb.len;
360 for (p = common_list; p->dirname; p++) {
361 const char *path = p->dirname;
362 if (p->ignore_garbage)
363 continue;
364 strbuf_setlen(&sb, len);
365 strbuf_addstr(&sb, path);
366 if (file_exists(sb.buf))
367 report_garbage(PACKDIR_FILE_GARBAGE, sb.buf);
368 }
369 strbuf_release(&sb);
370 }
371
372 static void adjust_git_path(struct strbuf *buf, int git_dir_len)
373 {
374 const char *base = buf->buf + git_dir_len;
375 if (git_graft_env && is_dir_file(base, "info", "grafts"))
376 strbuf_splice(buf, 0, buf->len,
377 get_graft_file(), strlen(get_graft_file()));
378 else if (git_index_env && !strcmp(base, "index"))
379 strbuf_splice(buf, 0, buf->len,
380 get_index_file(), strlen(get_index_file()));
381 else if (git_db_env && dir_prefix(base, "objects"))
382 replace_dir(buf, git_dir_len + 7, get_object_directory());
383 else if (git_common_dir_env)
384 update_common_dir(buf, git_dir_len, NULL);
385 }
386
387 static void do_git_path(const struct worktree *wt, struct strbuf *buf,
388 const char *fmt, va_list args)
389 {
390 int gitdir_len;
391 strbuf_addstr(buf, get_worktree_git_dir(wt));
392 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
393 strbuf_addch(buf, '/');
394 gitdir_len = buf->len;
395 strbuf_vaddf(buf, fmt, args);
396 adjust_git_path(buf, gitdir_len);
397 strbuf_cleanup_path(buf);
398 }
399
400 char *git_path_buf(struct strbuf *buf, const char *fmt, ...)
401 {
402 va_list args;
403 strbuf_reset(buf);
404 va_start(args, fmt);
405 do_git_path(NULL, buf, fmt, args);
406 va_end(args);
407 return buf->buf;
408 }
409
410 void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
411 {
412 va_list args;
413 va_start(args, fmt);
414 do_git_path(NULL, sb, fmt, args);
415 va_end(args);
416 }
417
418 const char *git_path(const char *fmt, ...)
419 {
420 struct strbuf *pathname = get_pathname();
421 va_list args;
422 va_start(args, fmt);
423 do_git_path(NULL, pathname, fmt, args);
424 va_end(args);
425 return pathname->buf;
426 }
427
428 char *git_pathdup(const char *fmt, ...)
429 {
430 struct strbuf path = STRBUF_INIT;
431 va_list args;
432 va_start(args, fmt);
433 do_git_path(NULL, &path, fmt, args);
434 va_end(args);
435 return strbuf_detach(&path, NULL);
436 }
437
438 char *mkpathdup(const char *fmt, ...)
439 {
440 struct strbuf sb = STRBUF_INIT;
441 va_list args;
442 va_start(args, fmt);
443 strbuf_vaddf(&sb, fmt, args);
444 va_end(args);
445 strbuf_cleanup_path(&sb);
446 return strbuf_detach(&sb, NULL);
447 }
448
449 const char *mkpath(const char *fmt, ...)
450 {
451 va_list args;
452 struct strbuf *pathname = get_pathname();
453 va_start(args, fmt);
454 strbuf_vaddf(pathname, fmt, args);
455 va_end(args);
456 return cleanup_path(pathname->buf);
457 }
458
459 const char *worktree_git_path(const struct worktree *wt, const char *fmt, ...)
460 {
461 struct strbuf *pathname = get_pathname();
462 va_list args;
463 va_start(args, fmt);
464 do_git_path(wt, pathname, fmt, args);
465 va_end(args);
466 return pathname->buf;
467 }
468
469 static void do_submodule_path(struct strbuf *buf, const char *path,
470 const char *fmt, va_list args)
471 {
472 const char *git_dir;
473 struct strbuf git_submodule_common_dir = STRBUF_INIT;
474 struct strbuf git_submodule_dir = STRBUF_INIT;
475
476 strbuf_addstr(buf, path);
477 strbuf_complete(buf, '/');
478 strbuf_addstr(buf, ".git");
479
480 git_dir = read_gitfile(buf->buf);
481 if (git_dir) {
482 strbuf_reset(buf);
483 strbuf_addstr(buf, git_dir);
484 }
485 strbuf_addch(buf, '/');
486 strbuf_addbuf(&git_submodule_dir, buf);
487
488 strbuf_vaddf(buf, fmt, args);
489
490 if (get_common_dir_noenv(&git_submodule_common_dir, git_submodule_dir.buf))
491 update_common_dir(buf, git_submodule_dir.len, git_submodule_common_dir.buf);
492
493 strbuf_cleanup_path(buf);
494
495 strbuf_release(&git_submodule_dir);
496 strbuf_release(&git_submodule_common_dir);
497 }
498
499 char *git_pathdup_submodule(const char *path, const char *fmt, ...)
500 {
501 va_list args;
502 struct strbuf buf = STRBUF_INIT;
503 va_start(args, fmt);
504 do_submodule_path(&buf, path, fmt, args);
505 va_end(args);
506 return strbuf_detach(&buf, NULL);
507 }
508
509 void strbuf_git_path_submodule(struct strbuf *buf, const char *path,
510 const char *fmt, ...)
511 {
512 va_list args;
513 va_start(args, fmt);
514 do_submodule_path(buf, path, fmt, args);
515 va_end(args);
516 }
517
518 static void do_git_common_path(struct strbuf *buf,
519 const char *fmt,
520 va_list args)
521 {
522 strbuf_addstr(buf, get_git_common_dir());
523 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
524 strbuf_addch(buf, '/');
525 strbuf_vaddf(buf, fmt, args);
526 strbuf_cleanup_path(buf);
527 }
528
529 const char *git_common_path(const char *fmt, ...)
530 {
531 struct strbuf *pathname = get_pathname();
532 va_list args;
533 va_start(args, fmt);
534 do_git_common_path(pathname, fmt, args);
535 va_end(args);
536 return pathname->buf;
537 }
538
539 void strbuf_git_common_path(struct strbuf *sb, const char *fmt, ...)
540 {
541 va_list args;
542 va_start(args, fmt);
543 do_git_common_path(sb, fmt, args);
544 va_end(args);
545 }
546
547 int validate_headref(const char *path)
548 {
549 struct stat st;
550 char *buf, buffer[256];
551 unsigned char sha1[20];
552 int fd;
553 ssize_t len;
554
555 if (lstat(path, &st) < 0)
556 return -1;
557
558 /* Make sure it is a "refs/.." symlink */
559 if (S_ISLNK(st.st_mode)) {
560 len = readlink(path, buffer, sizeof(buffer)-1);
561 if (len >= 5 && !memcmp("refs/", buffer, 5))
562 return 0;
563 return -1;
564 }
565
566 /*
567 * Anything else, just open it and try to see if it is a symbolic ref.
568 */
569 fd = open(path, O_RDONLY);
570 if (fd < 0)
571 return -1;
572 len = read_in_full(fd, buffer, sizeof(buffer)-1);
573 close(fd);
574
575 /*
576 * Is it a symbolic ref?
577 */
578 if (len < 4)
579 return -1;
580 if (!memcmp("ref:", buffer, 4)) {
581 buf = buffer + 4;
582 len -= 4;
583 while (len && isspace(*buf))
584 buf++, len--;
585 if (len >= 5 && !memcmp("refs/", buf, 5))
586 return 0;
587 }
588
589 /*
590 * Is this a detached HEAD?
591 */
592 if (!get_sha1_hex(buffer, sha1))
593 return 0;
594
595 return -1;
596 }
597
598 static struct passwd *getpw_str(const char *username, size_t len)
599 {
600 struct passwd *pw;
601 char *username_z = xmemdupz(username, len);
602 pw = getpwnam(username_z);
603 free(username_z);
604 return pw;
605 }
606
607 /*
608 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
609 * then it is a newly allocated string. Returns NULL on getpw failure or
610 * if path is NULL.
611 */
612 char *expand_user_path(const char *path)
613 {
614 struct strbuf user_path = STRBUF_INIT;
615 const char *to_copy = path;
616
617 if (path == NULL)
618 goto return_null;
619 if (path[0] == '~') {
620 const char *first_slash = strchrnul(path, '/');
621 const char *username = path + 1;
622 size_t username_len = first_slash - username;
623 if (username_len == 0) {
624 const char *home = getenv("HOME");
625 if (!home)
626 goto return_null;
627 strbuf_addstr(&user_path, home);
628 #ifdef GIT_WINDOWS_NATIVE
629 convert_slashes(user_path.buf);
630 #endif
631 } else {
632 struct passwd *pw = getpw_str(username, username_len);
633 if (!pw)
634 goto return_null;
635 strbuf_addstr(&user_path, pw->pw_dir);
636 }
637 to_copy = first_slash;
638 }
639 strbuf_addstr(&user_path, to_copy);
640 return strbuf_detach(&user_path, NULL);
641 return_null:
642 strbuf_release(&user_path);
643 return NULL;
644 }
645
646 /*
647 * First, one directory to try is determined by the following algorithm.
648 *
649 * (0) If "strict" is given, the path is used as given and no DWIM is
650 * done. Otherwise:
651 * (1) "~/path" to mean path under the running user's home directory;
652 * (2) "~user/path" to mean path under named user's home directory;
653 * (3) "relative/path" to mean cwd relative directory; or
654 * (4) "/absolute/path" to mean absolute directory.
655 *
656 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
657 * in this order. We select the first one that is a valid git repository, and
658 * chdir() to it. If none match, or we fail to chdir, we return NULL.
659 *
660 * If all goes well, we return the directory we used to chdir() (but
661 * before ~user is expanded), avoiding getcwd() resolving symbolic
662 * links. User relative paths are also returned as they are given,
663 * except DWIM suffixing.
664 */
665 const char *enter_repo(const char *path, int strict)
666 {
667 static struct strbuf validated_path = STRBUF_INIT;
668 static struct strbuf used_path = STRBUF_INIT;
669
670 if (!path)
671 return NULL;
672
673 if (!strict) {
674 static const char *suffix[] = {
675 "/.git", "", ".git/.git", ".git", NULL,
676 };
677 const char *gitfile;
678 int len = strlen(path);
679 int i;
680 while ((1 < len) && (path[len-1] == '/'))
681 len--;
682
683 /*
684 * We can handle arbitrary-sized buffers, but this remains as a
685 * sanity check on untrusted input.
686 */
687 if (PATH_MAX <= len)
688 return NULL;
689
690 strbuf_reset(&used_path);
691 strbuf_reset(&validated_path);
692 strbuf_add(&used_path, path, len);
693 strbuf_add(&validated_path, path, len);
694
695 if (used_path.buf[0] == '~') {
696 char *newpath = expand_user_path(used_path.buf);
697 if (!newpath)
698 return NULL;
699 strbuf_attach(&used_path, newpath, strlen(newpath),
700 strlen(newpath));
701 }
702 for (i = 0; suffix[i]; i++) {
703 struct stat st;
704 size_t baselen = used_path.len;
705 strbuf_addstr(&used_path, suffix[i]);
706 if (!stat(used_path.buf, &st) &&
707 (S_ISREG(st.st_mode) ||
708 (S_ISDIR(st.st_mode) && is_git_directory(used_path.buf)))) {
709 strbuf_addstr(&validated_path, suffix[i]);
710 break;
711 }
712 strbuf_setlen(&used_path, baselen);
713 }
714 if (!suffix[i])
715 return NULL;
716 gitfile = read_gitfile(used_path.buf);
717 if (gitfile) {
718 strbuf_reset(&used_path);
719 strbuf_addstr(&used_path, gitfile);
720 }
721 if (chdir(used_path.buf))
722 return NULL;
723 path = validated_path.buf;
724 }
725 else {
726 const char *gitfile = read_gitfile(path);
727 if (gitfile)
728 path = gitfile;
729 if (chdir(path))
730 return NULL;
731 }
732
733 if (is_git_directory(".")) {
734 set_git_dir(".");
735 check_repository_format();
736 return path;
737 }
738
739 return NULL;
740 }
741
742 static int calc_shared_perm(int mode)
743 {
744 int tweak;
745
746 if (get_shared_repository() < 0)
747 tweak = -get_shared_repository();
748 else
749 tweak = get_shared_repository();
750
751 if (!(mode & S_IWUSR))
752 tweak &= ~0222;
753 if (mode & S_IXUSR)
754 /* Copy read bits to execute bits */
755 tweak |= (tweak & 0444) >> 2;
756 if (get_shared_repository() < 0)
757 mode = (mode & ~0777) | tweak;
758 else
759 mode |= tweak;
760
761 return mode;
762 }
763
764
765 int adjust_shared_perm(const char *path)
766 {
767 int old_mode, new_mode;
768
769 if (!get_shared_repository())
770 return 0;
771 if (get_st_mode_bits(path, &old_mode) < 0)
772 return -1;
773
774 new_mode = calc_shared_perm(old_mode);
775 if (S_ISDIR(old_mode)) {
776 /* Copy read bits to execute bits */
777 new_mode |= (new_mode & 0444) >> 2;
778 new_mode |= FORCE_DIR_SET_GID;
779 }
780
781 if (((old_mode ^ new_mode) & ~S_IFMT) &&
782 chmod(path, (new_mode & ~S_IFMT)) < 0)
783 return -2;
784 return 0;
785 }
786
787 void safe_create_dir(const char *dir, int share)
788 {
789 if (mkdir(dir, 0777) < 0) {
790 if (errno != EEXIST) {
791 perror(dir);
792 exit(1);
793 }
794 }
795 else if (share && adjust_shared_perm(dir))
796 die(_("Could not make %s writable by group"), dir);
797 }
798
799 static int have_same_root(const char *path1, const char *path2)
800 {
801 int is_abs1, is_abs2;
802
803 is_abs1 = is_absolute_path(path1);
804 is_abs2 = is_absolute_path(path2);
805 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
806 (!is_abs1 && !is_abs2);
807 }
808
809 /*
810 * Give path as relative to prefix.
811 *
812 * The strbuf may or may not be used, so do not assume it contains the
813 * returned path.
814 */
815 const char *relative_path(const char *in, const char *prefix,
816 struct strbuf *sb)
817 {
818 int in_len = in ? strlen(in) : 0;
819 int prefix_len = prefix ? strlen(prefix) : 0;
820 int in_off = 0;
821 int prefix_off = 0;
822 int i = 0, j = 0;
823
824 if (!in_len)
825 return "./";
826 else if (!prefix_len)
827 return in;
828
829 if (have_same_root(in, prefix))
830 /* bypass dos_drive, for "c:" is identical to "C:" */
831 i = j = has_dos_drive_prefix(in);
832 else {
833 return in;
834 }
835
836 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
837 if (is_dir_sep(prefix[i])) {
838 while (is_dir_sep(prefix[i]))
839 i++;
840 while (is_dir_sep(in[j]))
841 j++;
842 prefix_off = i;
843 in_off = j;
844 } else {
845 i++;
846 j++;
847 }
848 }
849
850 if (
851 /* "prefix" seems like prefix of "in" */
852 i >= prefix_len &&
853 /*
854 * but "/foo" is not a prefix of "/foobar"
855 * (i.e. prefix not end with '/')
856 */
857 prefix_off < prefix_len) {
858 if (j >= in_len) {
859 /* in="/a/b", prefix="/a/b" */
860 in_off = in_len;
861 } else if (is_dir_sep(in[j])) {
862 /* in="/a/b/c", prefix="/a/b" */
863 while (is_dir_sep(in[j]))
864 j++;
865 in_off = j;
866 } else {
867 /* in="/a/bbb/c", prefix="/a/b" */
868 i = prefix_off;
869 }
870 } else if (
871 /* "in" is short than "prefix" */
872 j >= in_len &&
873 /* "in" not end with '/' */
874 in_off < in_len) {
875 if (is_dir_sep(prefix[i])) {
876 /* in="/a/b", prefix="/a/b/c/" */
877 while (is_dir_sep(prefix[i]))
878 i++;
879 in_off = in_len;
880 }
881 }
882 in += in_off;
883 in_len -= in_off;
884
885 if (i >= prefix_len) {
886 if (!in_len)
887 return "./";
888 else
889 return in;
890 }
891
892 strbuf_reset(sb);
893 strbuf_grow(sb, in_len);
894
895 while (i < prefix_len) {
896 if (is_dir_sep(prefix[i])) {
897 strbuf_addstr(sb, "../");
898 while (is_dir_sep(prefix[i]))
899 i++;
900 continue;
901 }
902 i++;
903 }
904 if (!is_dir_sep(prefix[prefix_len - 1]))
905 strbuf_addstr(sb, "../");
906
907 strbuf_addstr(sb, in);
908
909 return sb->buf;
910 }
911
912 /*
913 * A simpler implementation of relative_path
914 *
915 * Get relative path by removing "prefix" from "in". This function
916 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
917 * to increase performance when traversing the path to work_tree.
918 */
919 const char *remove_leading_path(const char *in, const char *prefix)
920 {
921 static struct strbuf buf = STRBUF_INIT;
922 int i = 0, j = 0;
923
924 if (!prefix || !prefix[0])
925 return in;
926 while (prefix[i]) {
927 if (is_dir_sep(prefix[i])) {
928 if (!is_dir_sep(in[j]))
929 return in;
930 while (is_dir_sep(prefix[i]))
931 i++;
932 while (is_dir_sep(in[j]))
933 j++;
934 continue;
935 } else if (in[j] != prefix[i]) {
936 return in;
937 }
938 i++;
939 j++;
940 }
941 if (
942 /* "/foo" is a prefix of "/foo" */
943 in[j] &&
944 /* "/foo" is not a prefix of "/foobar" */
945 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
946 )
947 return in;
948 while (is_dir_sep(in[j]))
949 j++;
950
951 strbuf_reset(&buf);
952 if (!in[j])
953 strbuf_addstr(&buf, ".");
954 else
955 strbuf_addstr(&buf, in + j);
956 return buf.buf;
957 }
958
959 /*
960 * It is okay if dst == src, but they should not overlap otherwise.
961 *
962 * Performs the following normalizations on src, storing the result in dst:
963 * - Ensures that components are separated by '/' (Windows only)
964 * - Squashes sequences of '/'.
965 * - Removes "." components.
966 * - Removes ".." components, and the components the precede them.
967 * Returns failure (non-zero) if a ".." component appears as first path
968 * component anytime during the normalization. Otherwise, returns success (0).
969 *
970 * Note that this function is purely textual. It does not follow symlinks,
971 * verify the existence of the path, or make any system calls.
972 *
973 * prefix_len != NULL is for a specific case of prefix_pathspec():
974 * assume that src == dst and src[0..prefix_len-1] is already
975 * normalized, any time "../" eats up to the prefix_len part,
976 * prefix_len is reduced. In the end prefix_len is the remaining
977 * prefix that has not been overridden by user pathspec.
978 *
979 * NEEDSWORK: This function doesn't perform normalization w.r.t. trailing '/'.
980 * For everything but the root folder itself, the normalized path should not
981 * end with a '/', then the callers need to be fixed up accordingly.
982 *
983 */
984 int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
985 {
986 char *dst0;
987 int i;
988
989 for (i = has_dos_drive_prefix(src); i > 0; i--)
990 *dst++ = *src++;
991 dst0 = dst;
992
993 if (is_dir_sep(*src)) {
994 *dst++ = '/';
995 while (is_dir_sep(*src))
996 src++;
997 }
998
999 for (;;) {
1000 char c = *src;
1001
1002 /*
1003 * A path component that begins with . could be
1004 * special:
1005 * (1) "." and ends -- ignore and terminate.
1006 * (2) "./" -- ignore them, eat slash and continue.
1007 * (3) ".." and ends -- strip one and terminate.
1008 * (4) "../" -- strip one, eat slash and continue.
1009 */
1010 if (c == '.') {
1011 if (!src[1]) {
1012 /* (1) */
1013 src++;
1014 } else if (is_dir_sep(src[1])) {
1015 /* (2) */
1016 src += 2;
1017 while (is_dir_sep(*src))
1018 src++;
1019 continue;
1020 } else if (src[1] == '.') {
1021 if (!src[2]) {
1022 /* (3) */
1023 src += 2;
1024 goto up_one;
1025 } else if (is_dir_sep(src[2])) {
1026 /* (4) */
1027 src += 3;
1028 while (is_dir_sep(*src))
1029 src++;
1030 goto up_one;
1031 }
1032 }
1033 }
1034
1035 /* copy up to the next '/', and eat all '/' */
1036 while ((c = *src++) != '\0' && !is_dir_sep(c))
1037 *dst++ = c;
1038 if (is_dir_sep(c)) {
1039 *dst++ = '/';
1040 while (is_dir_sep(c))
1041 c = *src++;
1042 src--;
1043 } else if (!c)
1044 break;
1045 continue;
1046
1047 up_one:
1048 /*
1049 * dst0..dst is prefix portion, and dst[-1] is '/';
1050 * go up one level.
1051 */
1052 dst--; /* go to trailing '/' */
1053 if (dst <= dst0)
1054 return -1;
1055 /* Windows: dst[-1] cannot be backslash anymore */
1056 while (dst0 < dst && dst[-1] != '/')
1057 dst--;
1058 if (prefix_len && *prefix_len > dst - dst0)
1059 *prefix_len = dst - dst0;
1060 }
1061 *dst = '\0';
1062 return 0;
1063 }
1064
1065 int normalize_path_copy(char *dst, const char *src)
1066 {
1067 return normalize_path_copy_len(dst, src, NULL);
1068 }
1069
1070 /*
1071 * path = Canonical absolute path
1072 * prefixes = string_list containing normalized, absolute paths without
1073 * trailing slashes (except for the root directory, which is denoted by "/").
1074 *
1075 * Determines, for each path in prefixes, whether the "prefix"
1076 * is an ancestor directory of path. Returns the length of the longest
1077 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
1078 * is an ancestor. (Note that this means 0 is returned if prefixes is
1079 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
1080 * are not considered to be their own ancestors. path must be in a
1081 * canonical form: empty components, or "." or ".." components are not
1082 * allowed.
1083 */
1084 int longest_ancestor_length(const char *path, struct string_list *prefixes)
1085 {
1086 int i, max_len = -1;
1087
1088 if (!strcmp(path, "/"))
1089 return -1;
1090
1091 for (i = 0; i < prefixes->nr; i++) {
1092 const char *ceil = prefixes->items[i].string;
1093 int len = strlen(ceil);
1094
1095 if (len == 1 && ceil[0] == '/')
1096 len = 0; /* root matches anything, with length 0 */
1097 else if (!strncmp(path, ceil, len) && path[len] == '/')
1098 ; /* match of length len */
1099 else
1100 continue; /* no match */
1101
1102 if (len > max_len)
1103 max_len = len;
1104 }
1105
1106 return max_len;
1107 }
1108
1109 /* strip arbitrary amount of directory separators at end of path */
1110 static inline int chomp_trailing_dir_sep(const char *path, int len)
1111 {
1112 while (len && is_dir_sep(path[len - 1]))
1113 len--;
1114 return len;
1115 }
1116
1117 /*
1118 * If path ends with suffix (complete path components), returns the
1119 * part before suffix (sans trailing directory separators).
1120 * Otherwise returns NULL.
1121 */
1122 char *strip_path_suffix(const char *path, const char *suffix)
1123 {
1124 int path_len = strlen(path), suffix_len = strlen(suffix);
1125
1126 while (suffix_len) {
1127 if (!path_len)
1128 return NULL;
1129
1130 if (is_dir_sep(path[path_len - 1])) {
1131 if (!is_dir_sep(suffix[suffix_len - 1]))
1132 return NULL;
1133 path_len = chomp_trailing_dir_sep(path, path_len);
1134 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
1135 }
1136 else if (path[--path_len] != suffix[--suffix_len])
1137 return NULL;
1138 }
1139
1140 if (path_len && !is_dir_sep(path[path_len - 1]))
1141 return NULL;
1142 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
1143 }
1144
1145 int daemon_avoid_alias(const char *p)
1146 {
1147 int sl, ndot;
1148
1149 /*
1150 * This resurrects the belts and suspenders paranoia check by HPA
1151 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
1152 * does not do getcwd() based path canonicalization.
1153 *
1154 * sl becomes true immediately after seeing '/' and continues to
1155 * be true as long as dots continue after that without intervening
1156 * non-dot character.
1157 */
1158 if (!p || (*p != '/' && *p != '~'))
1159 return -1;
1160 sl = 1; ndot = 0;
1161 p++;
1162
1163 while (1) {
1164 char ch = *p++;
1165 if (sl) {
1166 if (ch == '.')
1167 ndot++;
1168 else if (ch == '/') {
1169 if (ndot < 3)
1170 /* reject //, /./ and /../ */
1171 return -1;
1172 ndot = 0;
1173 }
1174 else if (ch == 0) {
1175 if (0 < ndot && ndot < 3)
1176 /* reject /.$ and /..$ */
1177 return -1;
1178 return 0;
1179 }
1180 else
1181 sl = ndot = 0;
1182 }
1183 else if (ch == 0)
1184 return 0;
1185 else if (ch == '/') {
1186 sl = 1;
1187 ndot = 0;
1188 }
1189 }
1190 }
1191
1192 static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
1193 {
1194 if (len < skip)
1195 return 0;
1196 len -= skip;
1197 path += skip;
1198 while (len-- > 0) {
1199 char c = *(path++);
1200 if (c != ' ' && c != '.')
1201 return 0;
1202 }
1203 return 1;
1204 }
1205
1206 int is_ntfs_dotgit(const char *name)
1207 {
1208 int len;
1209
1210 for (len = 0; ; len++)
1211 if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
1212 if (only_spaces_and_periods(name, len, 4) &&
1213 !strncasecmp(name, ".git", 4))
1214 return 1;
1215 if (only_spaces_and_periods(name, len, 5) &&
1216 !strncasecmp(name, "git~1", 5))
1217 return 1;
1218 if (name[len] != '\\')
1219 return 0;
1220 name += len + 1;
1221 len = -1;
1222 }
1223 }
1224
1225 char *xdg_config_home(const char *filename)
1226 {
1227 const char *home, *config_home;
1228
1229 assert(filename);
1230 config_home = getenv("XDG_CONFIG_HOME");
1231 if (config_home && *config_home)
1232 return mkpathdup("%s/git/%s", config_home, filename);
1233
1234 home = getenv("HOME");
1235 if (home)
1236 return mkpathdup("%s/.config/git/%s", home, filename);
1237 return NULL;
1238 }
1239
1240 GIT_PATH_FUNC(git_path_cherry_pick_head, "CHERRY_PICK_HEAD")
1241 GIT_PATH_FUNC(git_path_revert_head, "REVERT_HEAD")
1242 GIT_PATH_FUNC(git_path_squash_msg, "SQUASH_MSG")
1243 GIT_PATH_FUNC(git_path_merge_msg, "MERGE_MSG")
1244 GIT_PATH_FUNC(git_path_merge_rr, "MERGE_RR")
1245 GIT_PATH_FUNC(git_path_merge_mode, "MERGE_MODE")
1246 GIT_PATH_FUNC(git_path_merge_head, "MERGE_HEAD")
1247 GIT_PATH_FUNC(git_path_fetch_head, "FETCH_HEAD")
1248 GIT_PATH_FUNC(git_path_shallow, "shallow")