refs: split filesystem-based refs code into a new file
[git/git.git] / path.c
CommitLineData
26c8a533 1/*
3a429d3b 2 * Utilities for paths and pathnames
26c8a533
LT
3 */
4#include "cache.h"
395de250 5#include "strbuf.h"
a5ccdbe4 6#include "string-list.h"
77a6d840 7#include "dir.h"
26c8a533 8
f66450ae 9static int get_st_mode_bits(const char *path, int *mode)
0117c2f0
TB
10{
11 struct stat st;
12 if (lstat(path, &st) < 0)
13 return -1;
14 *mode = st.st_mode;
15 return 0;
16}
0117c2f0 17
26c8a533
LT
18static char bad_path[] = "/bad-path/";
19
4ef9caf5 20static struct strbuf *get_pathname(void)
e7676d2f 21{
4ef9caf5
NTND
22 static struct strbuf pathname_array[4] = {
23 STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
24 };
e7676d2f 25 static int index;
4ef9caf5
NTND
26 struct strbuf *sb = &pathname_array[3 & ++index];
27 strbuf_reset(sb);
28 return sb;
e7676d2f
LT
29}
30
26c8a533
LT
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
4ef9caf5
NTND
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
108bebea
AR
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) {
9db56f71 58 strlcpy(buf, bad_path, n);
108bebea
AR
59 return buf;
60 }
61 return cleanup_path(buf);
62}
63
557bd833 64static int dir_prefix(const char *buf, const char *dir)
fe2d7776 65{
557bd833
NTND
66 int len = strlen(dir);
67 return !strncmp(buf, dir, len) &&
68 (is_dir_sep(buf[len]) || buf[len] == '\0');
69}
fe2d7776 70
557bd833
NTND
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
0701530c
DT
94struct 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
103static 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" },
ce414b33 110 { 0, 1, 1, "logs/refs/bisect" },
0701530c
DT
111 { 0, 1, 0, "lost-found" },
112 { 0, 1, 0, "objects" },
113 { 0, 1, 0, "refs" },
ce414b33 114 { 0, 1, 1, "refs/bisect" },
0701530c
DT
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 }
c7b3a3d2
NTND
124};
125
4e09cf2a
DT
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 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 */
146struct trie {
147 struct trie *children[256];
148 int len;
149 char *contents;
150 void *value;
151};
152
153static struct trie *make_trie_node(const char *key, void *value)
c7b3a3d2 154{
4e09cf2a
DT
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}
c7b3a3d2 164
4e09cf2a
DT
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 */
169static 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);
c7b3a3d2 197 }
4e09cf2a
DT
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;
c7b3a3d2
NTND
220 }
221 }
4e09cf2a
DT
222
223 old = root->value;
224 root->value = value;
225 return old;
226}
227
228typedef 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 */
253static 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
302static struct trie common_trie;
303static int common_trie_done_setup;
304
305static 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 */
322static 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
1c630bad
JH
338static void update_common_dir(struct strbuf *buf, int git_dir_len,
339 const char *common_dir)
4e09cf2a
DT
340{
341 char *base = buf->buf + git_dir_len;
342 init_common_trie();
1c630bad
JH
343 if (!common_dir)
344 common_dir = get_git_common_dir();
4e09cf2a 345 if (trie_find(&common_trie, base, check_common, NULL) > 0)
1c630bad 346 replace_dir(buf, git_dir_len, common_dir);
c7b3a3d2
NTND
347}
348
77a6d840
NTND
349void report_linked_checkout_garbage(void)
350{
351 struct strbuf sb = STRBUF_INIT;
0701530c 352 const struct common_dir *p;
77a6d840
NTND
353 int len;
354
355 if (!git_common_dir_env)
356 return;
357 strbuf_addf(&sb, "%s/", get_git_dir());
358 len = sb.len;
0701530c
DT
359 for (p = common_list; p->dirname; p++) {
360 const char *path = p->dirname;
361 if (p->ignore_garbage)
77a6d840
NTND
362 continue;
363 strbuf_setlen(&sb, len);
364 strbuf_addstr(&sb, path);
365 if (file_exists(sb.buf))
366 report_garbage("unused in linked checkout", sb.buf);
367 }
368 strbuf_release(&sb);
fe2d7776
AR
369}
370
557bd833
NTND
371static 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());
c7b3a3d2 382 else if (git_common_dir_env)
11f9dd71 383 update_common_dir(buf, git_dir_len, NULL);
557bd833
NTND
384}
385
8afdaf39 386static void do_git_path(struct strbuf *buf, const char *fmt, va_list args)
fe2d7776 387{
557bd833
NTND
388 int gitdir_len;
389 strbuf_addstr(buf, get_git_dir());
4ef9caf5
NTND
390 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
391 strbuf_addch(buf, '/');
557bd833 392 gitdir_len = buf->len;
4ef9caf5 393 strbuf_vaddf(buf, fmt, args);
557bd833 394 adjust_git_path(buf, gitdir_len);
4ef9caf5 395 strbuf_cleanup_path(buf);
fe2d7776
AR
396}
397
bb3788ce
JK
398char *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
1a83c240 408void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
aba13e7c
AR
409{
410 va_list args;
411 va_start(args, fmt);
8afdaf39 412 do_git_path(sb, fmt, args);
aba13e7c 413 va_end(args);
aba13e7c
AR
414}
415
57a23b77 416const char *git_path(const char *fmt, ...)
aba13e7c 417{
57a23b77 418 struct strbuf *pathname = get_pathname();
aba13e7c
AR
419 va_list args;
420 va_start(args, fmt);
57a23b77 421 do_git_path(pathname, fmt, args);
aba13e7c 422 va_end(args);
57a23b77 423 return pathname->buf;
aba13e7c
AR
424}
425
aba13e7c 426char *git_pathdup(const char *fmt, ...)
21cf3227 427{
4ef9caf5 428 struct strbuf path = STRBUF_INIT;
21cf3227 429 va_list args;
21cf3227 430 va_start(args, fmt);
8afdaf39 431 do_git_path(&path, fmt, args);
21cf3227 432 va_end(args);
4ef9caf5 433 return strbuf_detach(&path, NULL);
21cf3227
HKNN
434}
435
21cf3227 436char *mkpathdup(const char *fmt, ...)
26c8a533 437{
21cf3227 438 struct strbuf sb = STRBUF_INIT;
26c8a533 439 va_list args;
26c8a533 440 va_start(args, fmt);
21cf3227 441 strbuf_vaddf(&sb, fmt, args);
26c8a533 442 va_end(args);
4ef9caf5
NTND
443 strbuf_cleanup_path(&sb);
444 return strbuf_detach(&sb, NULL);
26c8a533
LT
445}
446
dcf69262 447const char *mkpath(const char *fmt, ...)
26c8a533 448{
26c8a533 449 va_list args;
4ef9caf5 450 struct strbuf *pathname = get_pathname();
26c8a533 451 va_start(args, fmt);
4ef9caf5 452 strbuf_vaddf(pathname, fmt, args);
26c8a533 453 va_end(args);
4ef9caf5 454 return cleanup_path(pathname->buf);
26c8a533 455}
f2db68ed 456
f5895fd3
JK
457static void do_submodule_path(struct strbuf *buf, const char *path,
458 const char *fmt, va_list args)
0bad611b 459{
0bad611b 460 const char *git_dir;
11f9dd71
MK
461 struct strbuf git_submodule_common_dir = STRBUF_INIT;
462 struct strbuf git_submodule_dir = STRBUF_INIT;
0bad611b 463
4ef9caf5 464 strbuf_addstr(buf, path);
00b6c178 465 strbuf_complete(buf, '/');
4ef9caf5 466 strbuf_addstr(buf, ".git");
0bad611b 467
4ef9caf5 468 git_dir = read_gitfile(buf->buf);
0bad611b 469 if (git_dir) {
4ef9caf5
NTND
470 strbuf_reset(buf);
471 strbuf_addstr(buf, git_dir);
0bad611b 472 }
4ef9caf5 473 strbuf_addch(buf, '/');
11f9dd71 474 strbuf_addstr(&git_submodule_dir, buf->buf);
0bad611b 475
4ef9caf5 476 strbuf_vaddf(buf, fmt, args);
11f9dd71
MK
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
4ef9caf5 481 strbuf_cleanup_path(buf);
11f9dd71
MK
482
483 strbuf_release(&git_submodule_dir);
484 strbuf_release(&git_submodule_common_dir);
f5895fd3
JK
485}
486
f5895fd3
JK
487char *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
497void 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
c847f537 506int validate_headref(const char *path)
0870ca7f
JH
507{
508 struct stat st;
509 char *buf, buffer[256];
c847f537 510 unsigned char sha1[20];
0104ca09
HO
511 int fd;
512 ssize_t len;
0870ca7f
JH
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);
222b1673 520 if (len >= 5 && !memcmp("refs/", buffer, 5))
0870ca7f
JH
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;
93d26e4c 531 len = read_in_full(fd, buffer, sizeof(buffer)-1);
0870ca7f
JH
532 close(fd);
533
534 /*
535 * Is it a symbolic ref?
536 */
c847f537 537 if (len < 4)
0870ca7f 538 return -1;
c847f537
JH
539 if (!memcmp("ref:", buffer, 4)) {
540 buf = buffer + 4;
541 len -= 4;
542 while (len && isspace(*buf))
543 buf++, len--;
222b1673 544 if (len >= 5 && !memcmp("refs/", buf, 5))
c847f537
JH
545 return 0;
546 }
547
548 /*
549 * Is this a detached HEAD?
550 */
551 if (!get_sha1_hex(buffer, sha1))
0870ca7f 552 return 0;
c847f537 553
0870ca7f
JH
554 return -1;
555}
556
395de250 557static struct passwd *getpw_str(const char *username, size_t len)
54f4b874 558{
d79374c7 559 struct passwd *pw;
5c0b13f8 560 char *username_z = xmemdupz(username, len);
395de250
MM
561 pw = getpwnam(username_z);
562 free(username_z);
563 return pw;
564}
54f4b874 565
395de250
MM
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 */
571char *expand_user_path(const char *path)
572{
573 struct strbuf user_path = STRBUF_INIT;
395de250
MM
574 const char *to_copy = path;
575
576 if (path == NULL)
577 goto return_null;
578 if (path[0] == '~') {
53ec551c 579 const char *first_slash = strchrnul(path, '/');
395de250
MM
580 const char *username = path + 1;
581 size_t username_len = first_slash - username;
df2a79f4
MM
582 if (username_len == 0) {
583 const char *home = getenv("HOME");
79bf1490
JN
584 if (!home)
585 goto return_null;
cedc61a9 586 strbuf_addstr(&user_path, home);
df2a79f4
MM
587 } else {
588 struct passwd *pw = getpw_str(username, username_len);
589 if (!pw)
590 goto return_null;
cedc61a9 591 strbuf_addstr(&user_path, pw->pw_dir);
54f4b874 592 }
395de250 593 to_copy = first_slash;
d79374c7 594 }
cedc61a9 595 strbuf_addstr(&user_path, to_copy);
395de250
MM
596 return strbuf_detach(&user_path, NULL);
597return_null:
598 strbuf_release(&user_path);
599 return NULL;
54f4b874
AE
600}
601
d79374c7
JH
602/*
603 * First, one directory to try is determined by the following algorithm.
604 *
605 * (0) If "strict" is given, the path is used as given and no DWIM is
606 * done. Otherwise:
607 * (1) "~/path" to mean path under the running user's home directory;
608 * (2) "~user/path" to mean path under named user's home directory;
609 * (3) "relative/path" to mean cwd relative directory; or
610 * (4) "/absolute/path" to mean absolute directory.
611 *
c8c3f1d0
PT
612 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
613 * in this order. We select the first one that is a valid git repository, and
614 * chdir() to it. If none match, or we fail to chdir, we return NULL.
d79374c7
JH
615 *
616 * If all goes well, we return the directory we used to chdir() (but
617 * before ~user is expanded), avoiding getcwd() resolving symbolic
618 * links. User relative paths are also returned as they are given,
619 * except DWIM suffixing.
620 */
1c64b48e 621const char *enter_repo(const char *path, int strict)
54f4b874 622{
e9ba6781
JK
623 static struct strbuf validated_path = STRBUF_INIT;
624 static struct strbuf used_path = STRBUF_INIT;
d79374c7
JH
625
626 if (!path)
54f4b874
AE
627 return NULL;
628
d79374c7
JH
629 if (!strict) {
630 static const char *suffix[] = {
b3256eb8 631 "/.git", "", ".git/.git", ".git", NULL,
d79374c7 632 };
03106768 633 const char *gitfile;
d79374c7
JH
634 int len = strlen(path);
635 int i;
1c64b48e 636 while ((1 < len) && (path[len-1] == '/'))
d79374c7 637 len--;
1c64b48e 638
e9ba6781
JK
639 /*
640 * We can handle arbitrary-sized buffers, but this remains as a
641 * sanity check on untrusted input.
642 */
d79374c7 643 if (PATH_MAX <= len)
54f4b874 644 return NULL;
1c64b48e 645
e9ba6781
JK
646 strbuf_reset(&used_path);
647 strbuf_reset(&validated_path);
648 strbuf_add(&used_path, path, len);
649 strbuf_add(&validated_path, path, len);
650
651 if (used_path.buf[0] == '~') {
652 char *newpath = expand_user_path(used_path.buf);
653 if (!newpath)
d79374c7 654 return NULL;
e9ba6781
JK
655 strbuf_attach(&used_path, newpath, strlen(newpath),
656 strlen(newpath));
d79374c7 657 }
d79374c7 658 for (i = 0; suffix[i]; i++) {
b3256eb8 659 struct stat st;
e9ba6781
JK
660 size_t baselen = used_path.len;
661 strbuf_addstr(&used_path, suffix[i]);
662 if (!stat(used_path.buf, &st) &&
b3256eb8 663 (S_ISREG(st.st_mode) ||
e9ba6781
JK
664 (S_ISDIR(st.st_mode) && is_git_directory(used_path.buf)))) {
665 strbuf_addstr(&validated_path, suffix[i]);
d79374c7
JH
666 break;
667 }
e9ba6781 668 strbuf_setlen(&used_path, baselen);
d79374c7 669 }
03106768
PH
670 if (!suffix[i])
671 return NULL;
78891795 672 gitfile = read_gitfile(used_path.buf);
e9ba6781
JK
673 if (gitfile) {
674 strbuf_reset(&used_path);
675 strbuf_addstr(&used_path, gitfile);
676 }
677 if (chdir(used_path.buf))
0870ca7f 678 return NULL;
e9ba6781 679 path = validated_path.buf;
0870ca7f 680 }
1f5fbe1f
NTND
681 else {
682 const char *gitfile = read_gitfile(path);
683 if (gitfile)
684 path = gitfile;
685 if (chdir(path))
686 return NULL;
687 }
54f4b874 688
0f64cc40 689 if (is_git_directory(".")) {
717c3972 690 set_git_dir(".");
1644162a 691 check_repository_format();
d79374c7 692 return path;
54f4b874
AE
693 }
694
695 return NULL;
696}
138086a7 697
cbe43b84 698static int calc_shared_perm(int mode)
138086a7 699{
cbe43b84 700 int tweak;
138086a7 701
5a688fe4 702 if (shared_repository < 0)
cbe43b84 703 tweak = -shared_repository;
5a688fe4 704 else
cbe43b84 705 tweak = shared_repository;
5a688fe4
JH
706
707 if (!(mode & S_IWUSR))
708 tweak &= ~0222;
709 if (mode & S_IXUSR)
710 /* Copy read bits to execute bits */
711 tweak |= (tweak & 0444) >> 2;
712 if (shared_repository < 0)
713 mode = (mode & ~0777) | tweak;
714 else
8c6202d8 715 mode |= tweak;
06cbe855 716
cbe43b84
TB
717 return mode;
718}
719
720
721int adjust_shared_perm(const char *path)
722{
723 int old_mode, new_mode;
724
725 if (!shared_repository)
726 return 0;
727 if (get_st_mode_bits(path, &old_mode) < 0)
728 return -1;
729
730 new_mode = calc_shared_perm(old_mode);
731 if (S_ISDIR(old_mode)) {
06cbe855 732 /* Copy read bits to execute bits */
cbe43b84
TB
733 new_mode |= (new_mode & 0444) >> 2;
734 new_mode |= FORCE_DIR_SET_GID;
06cbe855
HO
735 }
736
cbe43b84
TB
737 if (((old_mode ^ new_mode) & ~S_IFMT) &&
738 chmod(path, (new_mode & ~S_IFMT)) < 0)
138086a7
JH
739 return -2;
740 return 0;
741}
e5392c51 742
7fbd4221
JX
743static int have_same_root(const char *path1, const char *path2)
744{
745 int is_abs1, is_abs2;
746
747 is_abs1 = is_absolute_path(path1);
748 is_abs2 = is_absolute_path(path2);
749 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
750 (!is_abs1 && !is_abs2);
751}
752
e02ca72f
JX
753/*
754 * Give path as relative to prefix.
755 *
756 * The strbuf may or may not be used, so do not assume it contains the
757 * returned path.
758 */
759const char *relative_path(const char *in, const char *prefix,
760 struct strbuf *sb)
044bbbcb 761{
e02ca72f
JX
762 int in_len = in ? strlen(in) : 0;
763 int prefix_len = prefix ? strlen(prefix) : 0;
764 int in_off = 0;
765 int prefix_off = 0;
288123f0
JH
766 int i = 0, j = 0;
767
e02ca72f
JX
768 if (!in_len)
769 return "./";
770 else if (!prefix_len)
771 return in;
772
7fbd4221
JX
773 if (have_same_root(in, prefix)) {
774 /* bypass dos_drive, for "c:" is identical to "C:" */
775 if (has_dos_drive_prefix(in)) {
776 i = 2;
777 j = 2;
778 }
779 } else {
780 return in;
781 }
782
e02ca72f
JX
783 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
784 if (is_dir_sep(prefix[i])) {
785 while (is_dir_sep(prefix[i]))
288123f0 786 i++;
e02ca72f
JX
787 while (is_dir_sep(in[j]))
788 j++;
789 prefix_off = i;
790 in_off = j;
791 } else {
792 i++;
793 j++;
794 }
795 }
796
797 if (
798 /* "prefix" seems like prefix of "in" */
799 i >= prefix_len &&
800 /*
801 * but "/foo" is not a prefix of "/foobar"
802 * (i.e. prefix not end with '/')
803 */
804 prefix_off < prefix_len) {
805 if (j >= in_len) {
806 /* in="/a/b", prefix="/a/b" */
807 in_off = in_len;
808 } else if (is_dir_sep(in[j])) {
809 /* in="/a/b/c", prefix="/a/b" */
810 while (is_dir_sep(in[j]))
288123f0 811 j++;
e02ca72f
JX
812 in_off = j;
813 } else {
814 /* in="/a/bbb/c", prefix="/a/b" */
815 i = prefix_off;
816 }
817 } else if (
818 /* "in" is short than "prefix" */
819 j >= in_len &&
820 /* "in" not end with '/' */
821 in_off < in_len) {
822 if (is_dir_sep(prefix[i])) {
823 /* in="/a/b", prefix="/a/b/c/" */
824 while (is_dir_sep(prefix[i]))
825 i++;
826 in_off = in_len;
827 }
828 }
829 in += in_off;
830 in_len -= in_off;
831
832 if (i >= prefix_len) {
833 if (!in_len)
834 return "./";
835 else
836 return in;
837 }
838
839 strbuf_reset(sb);
840 strbuf_grow(sb, in_len);
841
842 while (i < prefix_len) {
843 if (is_dir_sep(prefix[i])) {
844 strbuf_addstr(sb, "../");
845 while (is_dir_sep(prefix[i]))
846 i++;
288123f0 847 continue;
288123f0
JH
848 }
849 i++;
288123f0 850 }
e02ca72f
JX
851 if (!is_dir_sep(prefix[prefix_len - 1]))
852 strbuf_addstr(sb, "../");
853
854 strbuf_addstr(sb, in);
855
856 return sb->buf;
044bbbcb 857}
ae299be0 858
41894ae3
JX
859/*
860 * A simpler implementation of relative_path
861 *
862 * Get relative path by removing "prefix" from "in". This function
863 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
864 * to increase performance when traversing the path to work_tree.
865 */
866const char *remove_leading_path(const char *in, const char *prefix)
867{
46357688 868 static struct strbuf buf = STRBUF_INIT;
41894ae3
JX
869 int i = 0, j = 0;
870
871 if (!prefix || !prefix[0])
872 return in;
873 while (prefix[i]) {
874 if (is_dir_sep(prefix[i])) {
875 if (!is_dir_sep(in[j]))
876 return in;
877 while (is_dir_sep(prefix[i]))
878 i++;
879 while (is_dir_sep(in[j]))
880 j++;
881 continue;
882 } else if (in[j] != prefix[i]) {
883 return in;
884 }
885 i++;
886 j++;
887 }
888 if (
889 /* "/foo" is a prefix of "/foo" */
890 in[j] &&
891 /* "/foo" is not a prefix of "/foobar" */
892 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
893 )
894 return in;
895 while (is_dir_sep(in[j]))
896 j++;
46357688
JK
897
898 strbuf_reset(&buf);
41894ae3 899 if (!in[j])
46357688 900 strbuf_addstr(&buf, ".");
41894ae3 901 else
46357688
JK
902 strbuf_addstr(&buf, in + j);
903 return buf.buf;
41894ae3
JX
904}
905
ae299be0 906/*
f2a782b8 907 * It is okay if dst == src, but they should not overlap otherwise.
ae299be0 908 *
f2a782b8
JS
909 * Performs the following normalizations on src, storing the result in dst:
910 * - Ensures that components are separated by '/' (Windows only)
911 * - Squashes sequences of '/'.
ae299be0
DR
912 * - Removes "." components.
913 * - Removes ".." components, and the components the precede them.
f2a782b8
JS
914 * Returns failure (non-zero) if a ".." component appears as first path
915 * component anytime during the normalization. Otherwise, returns success (0).
ae299be0
DR
916 *
917 * Note that this function is purely textual. It does not follow symlinks,
918 * verify the existence of the path, or make any system calls.
645a29c4
NTND
919 *
920 * prefix_len != NULL is for a specific case of prefix_pathspec():
921 * assume that src == dst and src[0..prefix_len-1] is already
922 * normalized, any time "../" eats up to the prefix_len part,
923 * prefix_len is reduced. In the end prefix_len is the remaining
924 * prefix that has not been overridden by user pathspec.
b2a7123b
RD
925 *
926 * NEEDSWORK: This function doesn't perform normalization w.r.t. trailing '/'.
927 * For everything but the root folder itself, the normalized path should not
928 * end with a '/', then the callers need to be fixed up accordingly.
929 *
ae299be0 930 */
645a29c4 931int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
ae299be0 932{
f3cad0ad 933 char *dst0;
ae299be0 934
f3cad0ad
JS
935 if (has_dos_drive_prefix(src)) {
936 *dst++ = *src++;
937 *dst++ = *src++;
ae299be0 938 }
f3cad0ad 939 dst0 = dst;
ae299be0 940
f3cad0ad 941 if (is_dir_sep(*src)) {
ae299be0 942 *dst++ = '/';
f3cad0ad
JS
943 while (is_dir_sep(*src))
944 src++;
945 }
946
947 for (;;) {
948 char c = *src;
949
950 /*
951 * A path component that begins with . could be
952 * special:
953 * (1) "." and ends -- ignore and terminate.
954 * (2) "./" -- ignore them, eat slash and continue.
955 * (3) ".." and ends -- strip one and terminate.
956 * (4) "../" -- strip one, eat slash and continue.
957 */
958 if (c == '.') {
959 if (!src[1]) {
960 /* (1) */
961 src++;
962 } else if (is_dir_sep(src[1])) {
963 /* (2) */
964 src += 2;
965 while (is_dir_sep(*src))
966 src++;
967 continue;
968 } else if (src[1] == '.') {
969 if (!src[2]) {
970 /* (3) */
971 src += 2;
972 goto up_one;
973 } else if (is_dir_sep(src[2])) {
974 /* (4) */
975 src += 3;
976 while (is_dir_sep(*src))
977 src++;
978 goto up_one;
979 }
980 }
981 }
ae299be0 982
f3cad0ad
JS
983 /* copy up to the next '/', and eat all '/' */
984 while ((c = *src++) != '\0' && !is_dir_sep(c))
985 *dst++ = c;
986 if (is_dir_sep(c)) {
987 *dst++ = '/';
988 while (is_dir_sep(c))
989 c = *src++;
990 src--;
991 } else if (!c)
992 break;
993 continue;
994
995 up_one:
996 /*
997 * dst0..dst is prefix portion, and dst[-1] is '/';
998 * go up one level.
999 */
f42302b4
JS
1000 dst--; /* go to trailing '/' */
1001 if (dst <= dst0)
f3cad0ad 1002 return -1;
f42302b4
JS
1003 /* Windows: dst[-1] cannot be backslash anymore */
1004 while (dst0 < dst && dst[-1] != '/')
1005 dst--;
645a29c4
NTND
1006 if (prefix_len && *prefix_len > dst - dst0)
1007 *prefix_len = dst - dst0;
f3cad0ad 1008 }
ae299be0 1009 *dst = '\0';
f3cad0ad 1010 return 0;
ae299be0 1011}
0454dd93 1012
645a29c4
NTND
1013int normalize_path_copy(char *dst, const char *src)
1014{
1015 return normalize_path_copy_len(dst, src, NULL);
1016}
1017
0454dd93
DR
1018/*
1019 * path = Canonical absolute path
9e2326c7
MH
1020 * prefixes = string_list containing normalized, absolute paths without
1021 * trailing slashes (except for the root directory, which is denoted by "/").
0454dd93 1022 *
9e2326c7 1023 * Determines, for each path in prefixes, whether the "prefix"
0454dd93
DR
1024 * is an ancestor directory of path. Returns the length of the longest
1025 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
31171d9e
MH
1026 * is an ancestor. (Note that this means 0 is returned if prefixes is
1027 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
0454dd93
DR
1028 * are not considered to be their own ancestors. path must be in a
1029 * canonical form: empty components, or "." or ".." components are not
9e2326c7 1030 * allowed.
0454dd93 1031 */
31171d9e 1032int longest_ancestor_length(const char *path, struct string_list *prefixes)
0454dd93 1033{
a5ccdbe4 1034 int i, max_len = -1;
0454dd93 1035
31171d9e 1036 if (!strcmp(path, "/"))
0454dd93
DR
1037 return -1;
1038
31171d9e
MH
1039 for (i = 0; i < prefixes->nr; i++) {
1040 const char *ceil = prefixes->items[i].string;
a5ccdbe4
MH
1041 int len = strlen(ceil);
1042
9e2326c7
MH
1043 if (len == 1 && ceil[0] == '/')
1044 len = 0; /* root matches anything, with length 0 */
1045 else if (!strncmp(path, ceil, len) && path[len] == '/')
1046 ; /* match of length len */
1047 else
1048 continue; /* no match */
0454dd93 1049
9e2326c7 1050 if (len > max_len)
0454dd93 1051 max_len = len;
0454dd93
DR
1052 }
1053
1054 return max_len;
1055}
4fcc86b0
JS
1056
1057/* strip arbitrary amount of directory separators at end of path */
1058static inline int chomp_trailing_dir_sep(const char *path, int len)
1059{
1060 while (len && is_dir_sep(path[len - 1]))
1061 len--;
1062 return len;
1063}
1064
1065/*
1066 * If path ends with suffix (complete path components), returns the
1067 * part before suffix (sans trailing directory separators).
1068 * Otherwise returns NULL.
1069 */
1070char *strip_path_suffix(const char *path, const char *suffix)
1071{
1072 int path_len = strlen(path), suffix_len = strlen(suffix);
1073
1074 while (suffix_len) {
1075 if (!path_len)
1076 return NULL;
1077
1078 if (is_dir_sep(path[path_len - 1])) {
1079 if (!is_dir_sep(suffix[suffix_len - 1]))
1080 return NULL;
1081 path_len = chomp_trailing_dir_sep(path, path_len);
1082 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
1083 }
1084 else if (path[--path_len] != suffix[--suffix_len])
1085 return NULL;
1086 }
1087
1088 if (path_len && !is_dir_sep(path[path_len - 1]))
1089 return NULL;
1090 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
1091}
34b6cb8b
SP
1092
1093int daemon_avoid_alias(const char *p)
1094{
1095 int sl, ndot;
1096
1097 /*
1098 * This resurrects the belts and suspenders paranoia check by HPA
1099 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
9517e6b8 1100 * does not do getcwd() based path canonicalization.
34b6cb8b
SP
1101 *
1102 * sl becomes true immediately after seeing '/' and continues to
1103 * be true as long as dots continue after that without intervening
1104 * non-dot character.
1105 */
1106 if (!p || (*p != '/' && *p != '~'))
1107 return -1;
1108 sl = 1; ndot = 0;
1109 p++;
1110
1111 while (1) {
1112 char ch = *p++;
1113 if (sl) {
1114 if (ch == '.')
1115 ndot++;
1116 else if (ch == '/') {
1117 if (ndot < 3)
1118 /* reject //, /./ and /../ */
1119 return -1;
1120 ndot = 0;
1121 }
1122 else if (ch == 0) {
1123 if (0 < ndot && ndot < 3)
1124 /* reject /.$ and /..$ */
1125 return -1;
1126 return 0;
1127 }
1128 else
1129 sl = ndot = 0;
1130 }
1131 else if (ch == 0)
1132 return 0;
1133 else if (ch == '/') {
1134 sl = 1;
1135 ndot = 0;
1136 }
1137 }
1138}
4bb43de2 1139
1d1d69bc
JS
1140static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
1141{
1142 if (len < skip)
1143 return 0;
1144 len -= skip;
1145 path += skip;
1146 while (len-- > 0) {
1147 char c = *(path++);
1148 if (c != ' ' && c != '.')
1149 return 0;
1150 }
1151 return 1;
1152}
1153
1154int is_ntfs_dotgit(const char *name)
1155{
1156 int len;
1157
1158 for (len = 0; ; len++)
1159 if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
1160 if (only_spaces_and_periods(name, len, 4) &&
1161 !strncasecmp(name, ".git", 4))
1162 return 1;
1163 if (only_spaces_and_periods(name, len, 5) &&
1164 !strncasecmp(name, "git~1", 5))
1165 return 1;
1166 if (name[len] != '\\')
1167 return 0;
1168 name += len + 1;
1169 len = -1;
1170 }
1171}
ea19289b
PT
1172
1173char *xdg_config_home(const char *filename)
1174{
1175 const char *home, *config_home;
1176
1177 assert(filename);
1178 config_home = getenv("XDG_CONFIG_HOME");
1179 if (config_home && *config_home)
1180 return mkpathdup("%s/git/%s", config_home, filename);
1181
1182 home = getenv("HOME");
1183 if (home)
1184 return mkpathdup("%s/.config/git/%s", home, filename);
1185 return NULL;
1186}
f932729c
JK
1187
1188GIT_PATH_FUNC(git_path_cherry_pick_head, "CHERRY_PICK_HEAD")
1189GIT_PATH_FUNC(git_path_revert_head, "REVERT_HEAD")
1190GIT_PATH_FUNC(git_path_squash_msg, "SQUASH_MSG")
1191GIT_PATH_FUNC(git_path_merge_msg, "MERGE_MSG")
1192GIT_PATH_FUNC(git_path_merge_rr, "MERGE_RR")
1193GIT_PATH_FUNC(git_path_merge_mode, "MERGE_MODE")
1194GIT_PATH_FUNC(git_path_merge_head, "MERGE_HEAD")
1195GIT_PATH_FUNC(git_path_fetch_head, "FETCH_HEAD")
1196GIT_PATH_FUNC(git_path_shallow, "shallow")