freshlybakedca.ke
Git fork
1/*
2 * Utilities for paths and pathnames
3 */
4
5#include "git-compat-util.h"
6#include "abspath.h"
7#include "environment.h"
8#include "gettext.h"
9#include "repository.h"
10#include "strbuf.h"
11#include "string-list.h"
12#include "dir.h"
13#include "worktree.h"
14#include "setup.h"
15#include "submodule-config.h"
16#include "path.h"
17#include "packfile.h"
18#include "odb.h"
19#include "lockfile.h"
20#include "exec-cmd.h"
21
22static int get_st_mode_bits(const char *path, int *mode)
23{
24 struct stat st;
25 if (lstat(path, &st) < 0)
26 return -1;
27 *mode = st.st_mode;
28 return 0;
29}
30
31static struct strbuf *get_pathname(void)
32{
33 static struct strbuf pathname_array[4] = {
34 STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
35 };
36 static int index;
37 struct strbuf *sb = &pathname_array[index];
38 index = (index + 1) % ARRAY_SIZE(pathname_array);
39 strbuf_reset(sb);
40 return sb;
41}
42
43static const char *cleanup_path(const char *path)
44{
45 /* Clean it up */
46 if (skip_prefix(path, "./", &path)) {
47 while (*path == '/')
48 path++;
49 }
50 return path;
51}
52
53static void strbuf_cleanup_path(struct strbuf *sb)
54{
55 const char *path = cleanup_path(sb->buf);
56 if (path > sb->buf)
57 strbuf_remove(sb, 0, path - sb->buf);
58}
59
60static int dir_prefix(const char *buf, const char *dir)
61{
62 int len = strlen(dir);
63 return !strncmp(buf, dir, len) &&
64 (is_dir_sep(buf[len]) || buf[len] == '\0');
65}
66
67/* $buf =~ m|$dir/+$file| but without regex */
68static int is_dir_file(const char *buf, const char *dir, const char *file)
69{
70 int len = strlen(dir);
71 if (strncmp(buf, dir, len) || !is_dir_sep(buf[len]))
72 return 0;
73 while (is_dir_sep(buf[len]))
74 len++;
75 return !strcmp(buf + len, file);
76}
77
78static void replace_dir(struct strbuf *buf, int len, const char *newdir)
79{
80 int newlen = strlen(newdir);
81 int need_sep = (buf->buf[len] && !is_dir_sep(buf->buf[len])) &&
82 !is_dir_sep(newdir[newlen - 1]);
83 if (need_sep)
84 len--; /* keep one char, to be replaced with '/' */
85 strbuf_splice(buf, 0, len, newdir, newlen);
86 if (need_sep)
87 buf->buf[newlen] = '/';
88}
89
90struct common_dir {
91 /* Not considered garbage for report_linked_checkout_garbage */
92 unsigned ignore_garbage:1;
93 unsigned is_dir:1;
94 /* Belongs to the common dir, though it may contain paths that don't */
95 unsigned is_common:1;
96 const char *path;
97};
98
99static struct common_dir common_list[] = {
100 { 0, 1, 1, "branches" },
101 { 0, 1, 1, "common" },
102 { 0, 1, 1, "hooks" },
103 { 0, 1, 1, "info" },
104 { 0, 0, 0, "info/sparse-checkout" },
105 { 1, 1, 1, "logs" },
106 { 1, 0, 0, "logs/HEAD" },
107 { 0, 1, 0, "logs/refs/bisect" },
108 { 0, 1, 0, "logs/refs/rewritten" },
109 { 0, 1, 0, "logs/refs/worktree" },
110 { 0, 1, 1, "lost-found" },
111 { 0, 1, 1, "objects" },
112 { 0, 1, 1, "refs" },
113 { 0, 1, 0, "refs/bisect" },
114 { 0, 1, 0, "refs/rewritten" },
115 { 0, 1, 0, "refs/worktree" },
116 { 0, 1, 1, "remotes" },
117 { 0, 1, 1, "worktrees" },
118 { 0, 1, 1, "rr-cache" },
119 { 0, 1, 1, "svn" },
120 { 0, 0, 1, "config" },
121 { 1, 0, 1, "gc.pid" },
122 { 0, 0, 1, "packed-refs" },
123 { 0, 0, 1, "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 */
147struct trie {
148 struct trie *children[256];
149 int len;
150 char *contents;
151 void *value;
152};
153
154static 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 */
170static 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 = xmalloc(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
229typedef int (*match_fn)(const char *unmatched, void *value, 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. If there is
234 * no such prefix, return -1. Otherwise call fn with the unmatched
235 * portion of the key and the found value. If fn returns 0 or
236 * positive, then return its return value. If fn returns negative,
237 * then call fn with the next-longest /-terminated prefix of the key
238 * (i.e. a parent directory) for which the trie contains a value, and
239 * handle its return value the same way. If there is no shorter
240 * /-terminated prefix with a value left, then return the negative
241 * return value of the most recent fn invocation.
242 *
243 * The key is partially normalized: consecutive slashes are skipped.
244 *
245 * For example, consider the trie containing only [logs,
246 * logs/refs/bisect], both with values, but not logs/refs.
247 *
248 * | key | unmatched | prefix to node | return value |
249 * |--------------------|----------------|------------------|--------------|
250 * | a | not called | n/a | -1 |
251 * | logstore | not called | n/a | -1 |
252 * | logs | \0 | logs | as per fn |
253 * | logs/ | / | logs | as per fn |
254 * | logs/refs | /refs | logs | as per fn |
255 * | logs/refs/ | /refs/ | logs | as per fn |
256 * | logs/refs/b | /refs/b | logs | as per fn |
257 * | logs/refs/bisected | /refs/bisected | logs | as per fn |
258 * | logs/refs/bisect | \0 | logs/refs/bisect | as per fn |
259 * | logs/refs/bisect/ | / | logs/refs/bisect | as per fn |
260 * | logs/refs/bisect/a | /a | logs/refs/bisect | as per fn |
261 * | (If fn in the previous line returns -1, then fn is called once more:) |
262 * | logs/refs/bisect/a | /refs/bisect/a | logs | as per fn |
263 * |--------------------|----------------|------------------|--------------|
264 */
265static int trie_find(struct trie *root, const char *key, match_fn fn,
266 void *baton)
267{
268 int i;
269 int result;
270 struct trie *child;
271
272 if (!*key) {
273 /* we have reached the end of the key */
274 if (root->value && !root->len)
275 return fn(key, root->value, baton);
276 else
277 return -1;
278 }
279
280 for (i = 0; i < root->len; i++) {
281 /* Partial path normalization: skip consecutive slashes. */
282 if (key[i] == '/' && key[i+1] == '/') {
283 key++;
284 continue;
285 }
286 if (root->contents[i] != key[i])
287 return -1;
288 }
289
290 /* Matched the entire compressed section */
291 key += i;
292 if (!*key) {
293 /* End of key */
294 if (root->value)
295 return fn(key, root->value, baton);
296 else
297 return -1;
298 }
299
300 /* Partial path normalization: skip consecutive slashes */
301 while (key[0] == '/' && key[1] == '/')
302 key++;
303
304 child = root->children[(unsigned char)*key];
305 if (child)
306 result = trie_find(child, key + 1, fn, baton);
307 else
308 result = -1;
309
310 if (result >= 0 || (*key != '/' && *key != 0))
311 return result;
312 if (root->value)
313 return fn(key, root->value, baton);
314 else
315 return -1;
316}
317
318static struct trie common_trie;
319static int common_trie_done_setup;
320
321static void init_common_trie(void)
322{
323 struct common_dir *p;
324
325 if (common_trie_done_setup)
326 return;
327
328 for (p = common_list; p->path; p++)
329 add_to_trie(&common_trie, p->path, p);
330
331 common_trie_done_setup = 1;
332}
333
334/*
335 * Helper function for update_common_dir: returns 1 if the dir
336 * prefix is common.
337 */
338static int check_common(const char *unmatched, void *value,
339 void *baton UNUSED)
340{
341 struct common_dir *dir = value;
342
343 if (dir->is_dir && (unmatched[0] == 0 || unmatched[0] == '/'))
344 return dir->is_common;
345
346 if (!dir->is_dir && unmatched[0] == 0)
347 return dir->is_common;
348
349 return 0;
350}
351
352static void update_common_dir(struct strbuf *buf, int git_dir_len,
353 const char *common_dir)
354{
355 char *base = buf->buf + git_dir_len;
356 int has_lock_suffix = strbuf_strip_suffix(buf, LOCK_SUFFIX);
357
358 init_common_trie();
359 if (trie_find(&common_trie, base, check_common, NULL) > 0)
360 replace_dir(buf, git_dir_len, common_dir);
361
362 if (has_lock_suffix)
363 strbuf_addstr(buf, LOCK_SUFFIX);
364}
365
366void report_linked_checkout_garbage(struct repository *r)
367{
368 struct strbuf sb = STRBUF_INIT;
369 const struct common_dir *p;
370 int len;
371
372 if (!r->different_commondir)
373 return;
374 strbuf_addf(&sb, "%s/", r->gitdir);
375 len = sb.len;
376 for (p = common_list; p->path; p++) {
377 const char *path = p->path;
378 if (p->ignore_garbage)
379 continue;
380 strbuf_setlen(&sb, len);
381 strbuf_addstr(&sb, path);
382 if (file_exists(sb.buf))
383 report_garbage(PACKDIR_FILE_GARBAGE, sb.buf);
384 }
385 strbuf_release(&sb);
386}
387
388static void adjust_git_path(struct repository *repo,
389 struct strbuf *buf, int git_dir_len)
390{
391 const char *base = buf->buf + git_dir_len;
392
393 if (is_dir_file(base, "info", "grafts"))
394 strbuf_splice(buf, 0, buf->len,
395 repo->graft_file, strlen(repo->graft_file));
396 else if (!strcmp(base, "index"))
397 strbuf_splice(buf, 0, buf->len,
398 repo->index_file, strlen(repo->index_file));
399 else if (dir_prefix(base, "objects"))
400 replace_dir(buf, git_dir_len + 7, repo->objects->sources->path);
401 else if (repo_settings_get_hooks_path(repo) && dir_prefix(base, "hooks"))
402 replace_dir(buf, git_dir_len + 5, repo_settings_get_hooks_path(repo));
403 else if (repo->different_commondir)
404 update_common_dir(buf, git_dir_len, repo->commondir);
405}
406
407static void strbuf_worktree_gitdir(struct strbuf *buf,
408 const struct repository *repo,
409 const struct worktree *wt)
410{
411 if (!wt)
412 strbuf_addstr(buf, repo->gitdir);
413 else if (!wt->id)
414 strbuf_addstr(buf, repo->commondir);
415 else
416 repo_common_path_append(repo, buf, "worktrees/%s", wt->id);
417}
418
419static void repo_git_pathv(struct repository *repo,
420 const struct worktree *wt, struct strbuf *buf,
421 const char *fmt, va_list args)
422{
423 int gitdir_len;
424 strbuf_worktree_gitdir(buf, repo, wt);
425 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
426 strbuf_addch(buf, '/');
427 gitdir_len = buf->len;
428 strbuf_vaddf(buf, fmt, args);
429 if (!wt)
430 adjust_git_path(repo, buf, gitdir_len);
431 strbuf_cleanup_path(buf);
432}
433
434char *repo_git_path(struct repository *repo,
435 const char *fmt, ...)
436{
437 struct strbuf path = STRBUF_INIT;
438 va_list args;
439 va_start(args, fmt);
440 repo_git_pathv(repo, NULL, &path, fmt, args);
441 va_end(args);
442 return strbuf_detach(&path, NULL);
443}
444
445const char *repo_git_path_append(struct repository *repo,
446 struct strbuf *sb,
447 const char *fmt, ...)
448{
449 va_list args;
450 va_start(args, fmt);
451 repo_git_pathv(repo, NULL, sb, fmt, args);
452 va_end(args);
453 return sb->buf;
454}
455
456const char *repo_git_path_replace(struct repository *repo,
457 struct strbuf *sb,
458 const char *fmt, ...)
459{
460 va_list args;
461 strbuf_reset(sb);
462 va_start(args, fmt);
463 repo_git_pathv(repo, NULL, sb, fmt, args);
464 va_end(args);
465 return sb->buf;
466}
467
468char *mkpathdup(const char *fmt, ...)
469{
470 struct strbuf sb = STRBUF_INIT;
471 va_list args;
472 va_start(args, fmt);
473 strbuf_vaddf(&sb, fmt, args);
474 va_end(args);
475 strbuf_cleanup_path(&sb);
476 return strbuf_detach(&sb, NULL);
477}
478
479const char *mkpath(const char *fmt, ...)
480{
481 va_list args;
482 struct strbuf *pathname = get_pathname();
483 va_start(args, fmt);
484 strbuf_vaddf(pathname, fmt, args);
485 va_end(args);
486 return cleanup_path(pathname->buf);
487}
488
489const char *worktree_git_path(struct repository *r,
490 const struct worktree *wt, const char *fmt, ...)
491{
492 struct strbuf *pathname = get_pathname();
493 va_list args;
494
495 if (wt && wt->repo != r)
496 BUG("worktree not connected to expected repository");
497
498 va_start(args, fmt);
499 repo_git_pathv(r, wt, pathname, fmt, args);
500 va_end(args);
501 return pathname->buf;
502}
503
504static void do_worktree_path(const struct repository *repo,
505 struct strbuf *buf,
506 const char *fmt, va_list args)
507{
508 strbuf_addstr(buf, repo->worktree);
509 if(buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
510 strbuf_addch(buf, '/');
511
512 strbuf_vaddf(buf, fmt, args);
513 strbuf_cleanup_path(buf);
514}
515
516char *repo_worktree_path(const struct repository *repo, const char *fmt, ...)
517{
518 struct strbuf path = STRBUF_INIT;
519 va_list args;
520
521 va_start(args, fmt);
522 do_worktree_path(repo, &path, fmt, args);
523 va_end(args);
524
525 return strbuf_detach(&path, NULL);
526}
527
528const char *repo_worktree_path_append(const struct repository *repo,
529 struct strbuf *sb,
530 const char *fmt, ...)
531{
532 va_list args;
533
534 if (!repo->worktree)
535 return NULL;
536
537 va_start(args, fmt);
538 do_worktree_path(repo, sb, fmt, args);
539 va_end(args);
540
541 return sb->buf;
542}
543
544const char *repo_worktree_path_replace(const struct repository *repo,
545 struct strbuf *sb,
546 const char *fmt, ...)
547{
548 va_list args;
549
550 strbuf_reset(sb);
551 if (!repo->worktree)
552 return NULL;
553
554 va_start(args, fmt);
555 do_worktree_path(repo, sb, fmt, args);
556 va_end(args);
557
558 return sb->buf;
559}
560
561/* Returns 0 on success, negative on failure. */
562static int do_submodule_path(struct repository *repo,
563 struct strbuf *buf, const char *path,
564 const char *fmt, va_list args)
565{
566 struct strbuf git_submodule_common_dir = STRBUF_INIT;
567 struct strbuf git_submodule_dir = STRBUF_INIT;
568 int ret;
569
570 ret = submodule_to_gitdir(repo, &git_submodule_dir, path);
571 if (ret)
572 goto cleanup;
573
574 strbuf_complete(&git_submodule_dir, '/');
575 strbuf_addbuf(buf, &git_submodule_dir);
576 strbuf_vaddf(buf, fmt, args);
577
578 if (get_common_dir_noenv(&git_submodule_common_dir, git_submodule_dir.buf))
579 update_common_dir(buf, git_submodule_dir.len, git_submodule_common_dir.buf);
580
581 strbuf_cleanup_path(buf);
582
583cleanup:
584 strbuf_release(&git_submodule_dir);
585 strbuf_release(&git_submodule_common_dir);
586 return ret;
587}
588
589char *repo_submodule_path(struct repository *repo,
590 const char *path, const char *fmt, ...)
591{
592 int err;
593 va_list args;
594 struct strbuf buf = STRBUF_INIT;
595 va_start(args, fmt);
596 err = do_submodule_path(repo, &buf, path, fmt, args);
597 va_end(args);
598 if (err) {
599 strbuf_release(&buf);
600 return NULL;
601 }
602 return strbuf_detach(&buf, NULL);
603}
604
605const char *repo_submodule_path_append(struct repository *repo,
606 struct strbuf *buf,
607 const char *path,
608 const char *fmt, ...)
609{
610 int err;
611 va_list args;
612 va_start(args, fmt);
613 err = do_submodule_path(repo, buf, path, fmt, args);
614 va_end(args);
615 if (err)
616 return NULL;
617 return buf->buf;
618}
619
620const char *repo_submodule_path_replace(struct repository *repo,
621 struct strbuf *buf,
622 const char *path,
623 const char *fmt, ...)
624{
625 int err;
626 va_list args;
627 strbuf_reset(buf);
628 va_start(args, fmt);
629 err = do_submodule_path(repo, buf, path, fmt, args);
630 va_end(args);
631 if (err)
632 return NULL;
633 return buf->buf;
634}
635
636static void repo_common_pathv(const struct repository *repo,
637 struct strbuf *sb,
638 const char *fmt,
639 va_list args)
640{
641 strbuf_addstr(sb, repo->commondir);
642 if (sb->len && !is_dir_sep(sb->buf[sb->len - 1]))
643 strbuf_addch(sb, '/');
644 strbuf_vaddf(sb, fmt, args);
645 strbuf_cleanup_path(sb);
646}
647
648char *repo_common_path(const struct repository *repo,
649 const char *fmt, ...)
650{
651 struct strbuf sb = STRBUF_INIT;
652 va_list args;
653 va_start(args, fmt);
654 repo_common_pathv(repo, &sb, fmt, args);
655 va_end(args);
656 return strbuf_detach(&sb, NULL);
657}
658
659const char *repo_common_path_append(const struct repository *repo,
660 struct strbuf *sb,
661 const char *fmt, ...)
662{
663 va_list args;
664 va_start(args, fmt);
665 repo_common_pathv(repo, sb, fmt, args);
666 va_end(args);
667 return sb->buf;
668}
669
670const char *repo_common_path_replace(const struct repository *repo,
671 struct strbuf *sb,
672 const char *fmt, ...)
673{
674 va_list args;
675 strbuf_reset(sb);
676 va_start(args, fmt);
677 repo_common_pathv(repo, sb, fmt, args);
678 va_end(args);
679 return sb->buf;
680}
681
682static struct passwd *getpw_str(const char *username, size_t len)
683{
684 struct passwd *pw;
685 char *username_z = xmemdupz(username, len);
686 pw = getpwnam(username_z);
687 free(username_z);
688 return pw;
689}
690
691/*
692 * Return a string with ~ and ~user expanded via getpw*. Returns NULL on getpw
693 * failure or if path is NULL.
694 *
695 * If real_home is true, strbuf_realpath($HOME) is used in the `~/` expansion.
696 *
697 * If the path starts with `%(prefix)/`, the remainder is interpreted as
698 * relative to where Git is installed, and expanded to the absolute path.
699 */
700char *interpolate_path(const char *path, int real_home)
701{
702 struct strbuf user_path = STRBUF_INIT;
703 const char *to_copy = path;
704
705 if (!path)
706 goto return_null;
707
708 if (skip_prefix(path, "%(prefix)/", &path))
709 return system_path(path);
710
711 if (path[0] == '~') {
712 const char *first_slash = strchrnul(path, '/');
713 const char *username = path + 1;
714 size_t username_len = first_slash - username;
715 if (username_len == 0) {
716 const char *home = getenv("HOME");
717 if (!home)
718 goto return_null;
719 if (real_home)
720 strbuf_add_real_path(&user_path, home);
721 else
722 strbuf_addstr(&user_path, home);
723#ifdef GIT_WINDOWS_NATIVE
724 convert_slashes(user_path.buf);
725#endif
726 } else {
727 struct passwd *pw = getpw_str(username, username_len);
728 if (!pw)
729 goto return_null;
730 strbuf_addstr(&user_path, pw->pw_dir);
731 }
732 to_copy = first_slash;
733 }
734 strbuf_addstr(&user_path, to_copy);
735 return strbuf_detach(&user_path, NULL);
736return_null:
737 strbuf_release(&user_path);
738 return NULL;
739}
740
741/*
742 * First, one directory to try is determined by the following algorithm.
743 *
744 * (0) If "strict" is given, the path is used as given and no DWIM is
745 * done. Otherwise:
746 * (1) "~/path" to mean path under the running user's home directory;
747 * (2) "~user/path" to mean path under named user's home directory;
748 * (3) "relative/path" to mean cwd relative directory; or
749 * (4) "/absolute/path" to mean absolute directory.
750 *
751 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
752 * in this order. We select the first one that is a valid git repository, and
753 * chdir() to it. If none match, or we fail to chdir, we return NULL.
754 *
755 * If all goes well, we return the directory we used to chdir() (but
756 * before ~user is expanded), avoiding getcwd() resolving symbolic
757 * links. User relative paths are also returned as they are given,
758 * except DWIM suffixing.
759 */
760const char *enter_repo(const char *path, unsigned flags)
761{
762 static struct strbuf validated_path = STRBUF_INIT;
763 static struct strbuf used_path = STRBUF_INIT;
764
765 if (!path)
766 return NULL;
767
768 if (!(flags & ENTER_REPO_STRICT)) {
769 static const char *suffix[] = {
770 "/.git", "", ".git/.git", ".git", NULL,
771 };
772 const char *gitfile;
773 int len = strlen(path);
774 int i;
775 while ((1 < len) && (path[len-1] == '/'))
776 len--;
777
778 /*
779 * We can handle arbitrary-sized buffers, but this remains as a
780 * sanity check on untrusted input.
781 */
782 if (PATH_MAX <= len)
783 return NULL;
784
785 strbuf_reset(&used_path);
786 strbuf_reset(&validated_path);
787 strbuf_add(&used_path, path, len);
788 strbuf_add(&validated_path, path, len);
789
790 if (used_path.buf[0] == '~') {
791 char *newpath = interpolate_path(used_path.buf, 0);
792 if (!newpath)
793 return NULL;
794 strbuf_attach(&used_path, newpath, strlen(newpath),
795 strlen(newpath));
796 }
797 for (i = 0; suffix[i]; i++) {
798 struct stat st;
799 size_t baselen = used_path.len;
800 strbuf_addstr(&used_path, suffix[i]);
801 if (!stat(used_path.buf, &st) &&
802 (S_ISREG(st.st_mode) ||
803 (S_ISDIR(st.st_mode) && is_git_directory(used_path.buf)))) {
804 strbuf_addstr(&validated_path, suffix[i]);
805 break;
806 }
807 strbuf_setlen(&used_path, baselen);
808 }
809 if (!suffix[i])
810 return NULL;
811 gitfile = read_gitfile(used_path.buf);
812 if (!(flags & ENTER_REPO_ANY_OWNER_OK))
813 die_upon_dubious_ownership(gitfile, NULL, used_path.buf);
814 if (gitfile) {
815 strbuf_reset(&used_path);
816 strbuf_addstr(&used_path, gitfile);
817 }
818 if (chdir(used_path.buf))
819 return NULL;
820 path = validated_path.buf;
821 }
822 else {
823 const char *gitfile = read_gitfile(path);
824 if (!(flags & ENTER_REPO_ANY_OWNER_OK))
825 die_upon_dubious_ownership(gitfile, NULL, path);
826 if (gitfile)
827 path = gitfile;
828 if (chdir(path))
829 return NULL;
830 }
831
832 if (is_git_directory(".")) {
833 set_git_dir(".", 0);
834 check_repository_format(NULL);
835 return path;
836 }
837
838 return NULL;
839}
840
841int calc_shared_perm(struct repository *repo,
842 int mode)
843{
844 int tweak;
845
846 if (repo_settings_get_shared_repository(repo) < 0)
847 tweak = -repo_settings_get_shared_repository(repo);
848 else
849 tweak = repo_settings_get_shared_repository(repo);
850
851 if (!(mode & S_IWUSR))
852 tweak &= ~0222;
853 if (mode & S_IXUSR)
854 /* Copy read bits to execute bits */
855 tweak |= (tweak & 0444) >> 2;
856 if (repo_settings_get_shared_repository(repo) < 0)
857 mode = (mode & ~0777) | tweak;
858 else
859 mode |= tweak;
860
861 return mode;
862}
863
864int adjust_shared_perm(struct repository *repo,
865 const char *path)
866{
867 int old_mode, new_mode;
868
869 if (!repo_settings_get_shared_repository(repo))
870 return 0;
871 if (get_st_mode_bits(path, &old_mode) < 0)
872 return -1;
873
874 new_mode = calc_shared_perm(repo, old_mode);
875 if (S_ISDIR(old_mode)) {
876 /* Copy read bits to execute bits */
877 new_mode |= (new_mode & 0444) >> 2;
878
879 /*
880 * g+s matters only if any extra access is granted
881 * based on group membership.
882 */
883 if (FORCE_DIR_SET_GID && (new_mode & 060))
884 new_mode |= FORCE_DIR_SET_GID;
885 }
886
887 if (((old_mode ^ new_mode) & ~S_IFMT) &&
888 chmod(path, (new_mode & ~S_IFMT)) < 0)
889 return -2;
890 return 0;
891}
892
893void safe_create_dir(struct repository *repo, const char *dir, int share)
894{
895 if (mkdir(dir, 0777) < 0) {
896 if (errno != EEXIST) {
897 perror(dir);
898 exit(1);
899 }
900 }
901 else if (share && adjust_shared_perm(repo, dir))
902 die(_("Could not make %s writable by group"), dir);
903}
904
905int safe_create_dir_in_gitdir(struct repository *repo, const char *path)
906{
907 if (mkdir(path, 0777)) {
908 int saved_errno = errno;
909 struct stat st;
910 struct strbuf sb = STRBUF_INIT;
911
912 if (errno != EEXIST)
913 return -1;
914 /*
915 * Are we looking at a path in a symlinked worktree
916 * whose original repository does not yet have it?
917 * e.g. .git/rr-cache pointing at its original
918 * repository in which the user hasn't performed any
919 * conflict resolution yet?
920 */
921 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
922 strbuf_readlink(&sb, path, st.st_size) ||
923 !is_absolute_path(sb.buf) ||
924 mkdir(sb.buf, 0777)) {
925 strbuf_release(&sb);
926 errno = saved_errno;
927 return -1;
928 }
929 strbuf_release(&sb);
930 }
931 return adjust_shared_perm(repo, path);
932}
933
934static enum scld_error safe_create_leading_directories_1(struct repository *repo,
935 char *path)
936{
937 char *next_component = path + offset_1st_component(path);
938 enum scld_error ret = SCLD_OK;
939
940 while (ret == SCLD_OK && next_component) {
941 struct stat st;
942 char *slash = next_component, slash_character;
943
944 while (*slash && !is_dir_sep(*slash))
945 slash++;
946
947 if (!*slash)
948 break;
949
950 next_component = slash + 1;
951 while (is_dir_sep(*next_component))
952 next_component++;
953 if (!*next_component)
954 break;
955
956 slash_character = *slash;
957 *slash = '\0';
958 if (!stat(path, &st)) {
959 /* path exists */
960 if (!S_ISDIR(st.st_mode)) {
961 errno = ENOTDIR;
962 ret = SCLD_EXISTS;
963 }
964 } else if (mkdir(path, 0777)) {
965 if (errno == EEXIST &&
966 !stat(path, &st) && S_ISDIR(st.st_mode))
967 ; /* somebody created it since we checked */
968 else if (errno == ENOENT)
969 /*
970 * Either mkdir() failed because
971 * somebody just pruned the containing
972 * directory, or stat() failed because
973 * the file that was in our way was
974 * just removed. Either way, inform
975 * the caller that it might be worth
976 * trying again:
977 */
978 ret = SCLD_VANISHED;
979 else
980 ret = SCLD_FAILED;
981 } else if (repo && adjust_shared_perm(repo, path)) {
982 ret = SCLD_PERMS;
983 }
984 *slash = slash_character;
985 }
986 return ret;
987}
988
989enum scld_error safe_create_leading_directories(struct repository *repo,
990 char *path)
991{
992 return safe_create_leading_directories_1(repo, path);
993}
994
995enum scld_error safe_create_leading_directories_no_share(char *path)
996{
997 return safe_create_leading_directories_1(NULL, path);
998}
999
1000enum scld_error safe_create_leading_directories_const(struct repository *repo,
1001 const char *path)
1002{
1003 int save_errno;
1004 /* path points to cache entries, so xstrdup before messing with it */
1005 char *buf = xstrdup(path);
1006 enum scld_error result = safe_create_leading_directories(repo, buf);
1007
1008 save_errno = errno;
1009 free(buf);
1010 errno = save_errno;
1011 return result;
1012}
1013
1014int safe_create_file_with_leading_directories(struct repository *repo,
1015 const char *path)
1016{
1017 int fd;
1018
1019 fd = open(path, O_RDWR|O_CREAT|O_EXCL, 0600);
1020 if (0 <= fd)
1021 return fd;
1022
1023 /* slow path */
1024 safe_create_leading_directories_const(repo, path);
1025 return open(path, O_RDWR|O_CREAT|O_EXCL, 0600);
1026}
1027
1028static int have_same_root(const char *path1, const char *path2)
1029{
1030 int is_abs1, is_abs2;
1031
1032 is_abs1 = is_absolute_path(path1);
1033 is_abs2 = is_absolute_path(path2);
1034 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
1035 (!is_abs1 && !is_abs2);
1036}
1037
1038/*
1039 * Give path as relative to prefix.
1040 *
1041 * The strbuf may or may not be used, so do not assume it contains the
1042 * returned path.
1043 */
1044const char *relative_path(const char *in, const char *prefix,
1045 struct strbuf *sb)
1046{
1047 int in_len = in ? strlen(in) : 0;
1048 int prefix_len = prefix ? strlen(prefix) : 0;
1049 int in_off = 0;
1050 int prefix_off = 0;
1051 int i = 0, j = 0;
1052
1053 if (!in_len)
1054 return "./";
1055 else if (!prefix_len)
1056 return in;
1057
1058 if (have_same_root(in, prefix))
1059 /* bypass dos_drive, for "c:" is identical to "C:" */
1060 i = j = has_dos_drive_prefix(in);
1061 else {
1062 return in;
1063 }
1064
1065 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
1066 if (is_dir_sep(prefix[i])) {
1067 while (is_dir_sep(prefix[i]))
1068 i++;
1069 while (is_dir_sep(in[j]))
1070 j++;
1071 prefix_off = i;
1072 in_off = j;
1073 } else {
1074 i++;
1075 j++;
1076 }
1077 }
1078
1079 if (
1080 /* "prefix" seems like prefix of "in" */
1081 i >= prefix_len &&
1082 /*
1083 * but "/foo" is not a prefix of "/foobar"
1084 * (i.e. prefix not end with '/')
1085 */
1086 prefix_off < prefix_len) {
1087 if (j >= in_len) {
1088 /* in="/a/b", prefix="/a/b" */
1089 in_off = in_len;
1090 } else if (is_dir_sep(in[j])) {
1091 /* in="/a/b/c", prefix="/a/b" */
1092 while (is_dir_sep(in[j]))
1093 j++;
1094 in_off = j;
1095 } else {
1096 /* in="/a/bbb/c", prefix="/a/b" */
1097 i = prefix_off;
1098 }
1099 } else if (
1100 /* "in" is short than "prefix" */
1101 j >= in_len &&
1102 /* "in" not end with '/' */
1103 in_off < in_len) {
1104 if (is_dir_sep(prefix[i])) {
1105 /* in="/a/b", prefix="/a/b/c/" */
1106 while (is_dir_sep(prefix[i]))
1107 i++;
1108 in_off = in_len;
1109 }
1110 }
1111 in += in_off;
1112 in_len -= in_off;
1113
1114 if (i >= prefix_len) {
1115 if (!in_len)
1116 return "./";
1117 else
1118 return in;
1119 }
1120
1121 strbuf_reset(sb);
1122 strbuf_grow(sb, in_len);
1123
1124 while (i < prefix_len) {
1125 if (is_dir_sep(prefix[i])) {
1126 strbuf_addstr(sb, "../");
1127 while (is_dir_sep(prefix[i]))
1128 i++;
1129 continue;
1130 }
1131 i++;
1132 }
1133 if (!is_dir_sep(prefix[prefix_len - 1]))
1134 strbuf_addstr(sb, "../");
1135
1136 strbuf_addstr(sb, in);
1137
1138 return sb->buf;
1139}
1140
1141/*
1142 * A simpler implementation of relative_path
1143 *
1144 * Get relative path by removing "prefix" from "in". This function
1145 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
1146 * to increase performance when traversing the path to work_tree.
1147 */
1148const char *remove_leading_path(const char *in, const char *prefix)
1149{
1150 static struct strbuf buf = STRBUF_INIT;
1151 int i = 0, j = 0;
1152
1153 if (!prefix || !prefix[0])
1154 return in;
1155 while (prefix[i]) {
1156 if (is_dir_sep(prefix[i])) {
1157 if (!is_dir_sep(in[j]))
1158 return in;
1159 while (is_dir_sep(prefix[i]))
1160 i++;
1161 while (is_dir_sep(in[j]))
1162 j++;
1163 continue;
1164 } else if (in[j] != prefix[i]) {
1165 return in;
1166 }
1167 i++;
1168 j++;
1169 }
1170 if (
1171 /* "/foo" is a prefix of "/foo" */
1172 in[j] &&
1173 /* "/foo" is not a prefix of "/foobar" */
1174 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
1175 )
1176 return in;
1177 while (is_dir_sep(in[j]))
1178 j++;
1179
1180 strbuf_reset(&buf);
1181 if (!in[j])
1182 strbuf_addstr(&buf, ".");
1183 else
1184 strbuf_addstr(&buf, in + j);
1185 return buf.buf;
1186}
1187
1188/*
1189 * It is okay if dst == src, but they should not overlap otherwise.
1190 * The "dst" buffer must be at least as long as "src"; normalizing may shrink
1191 * the size of the path, but will never grow it.
1192 *
1193 * Performs the following normalizations on src, storing the result in dst:
1194 * - Ensures that components are separated by '/' (Windows only)
1195 * - Squashes sequences of '/' except "//server/share" on Windows
1196 * - Removes "." components.
1197 * - Removes ".." components, and the components the precede them.
1198 * Returns failure (non-zero) if a ".." component appears as first path
1199 * component anytime during the normalization. Otherwise, returns success (0).
1200 *
1201 * Note that this function is purely textual. It does not follow symlinks,
1202 * verify the existence of the path, or make any system calls.
1203 *
1204 * prefix_len != NULL is for a specific case of prefix_pathspec():
1205 * assume that src == dst and src[0..prefix_len-1] is already
1206 * normalized, any time "../" eats up to the prefix_len part,
1207 * prefix_len is reduced. In the end prefix_len is the remaining
1208 * prefix that has not been overridden by user pathspec.
1209 *
1210 * NEEDSWORK: This function doesn't perform normalization w.r.t. trailing '/'.
1211 * For everything but the root folder itself, the normalized path should not
1212 * end with a '/', then the callers need to be fixed up accordingly.
1213 *
1214 */
1215int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
1216{
1217 char *dst0;
1218 const char *end;
1219
1220 /*
1221 * Copy initial part of absolute path: "/", "C:/", "//server/share/".
1222 */
1223 end = src + offset_1st_component(src);
1224 while (src < end) {
1225 char c = *src++;
1226 if (is_dir_sep(c))
1227 c = '/';
1228 *dst++ = c;
1229 }
1230 dst0 = dst;
1231
1232 while (is_dir_sep(*src))
1233 src++;
1234
1235 for (;;) {
1236 char c = *src;
1237
1238 /*
1239 * A path component that begins with . could be
1240 * special:
1241 * (1) "." and ends -- ignore and terminate.
1242 * (2) "./" -- ignore them, eat slash and continue.
1243 * (3) ".." and ends -- strip one and terminate.
1244 * (4) "../" -- strip one, eat slash and continue.
1245 */
1246 if (c == '.') {
1247 if (!src[1]) {
1248 /* (1) */
1249 src++;
1250 } else if (is_dir_sep(src[1])) {
1251 /* (2) */
1252 src += 2;
1253 while (is_dir_sep(*src))
1254 src++;
1255 continue;
1256 } else if (src[1] == '.') {
1257 if (!src[2]) {
1258 /* (3) */
1259 src += 2;
1260 goto up_one;
1261 } else if (is_dir_sep(src[2])) {
1262 /* (4) */
1263 src += 3;
1264 while (is_dir_sep(*src))
1265 src++;
1266 goto up_one;
1267 }
1268 }
1269 }
1270
1271 /* copy up to the next '/', and eat all '/' */
1272 while ((c = *src++) != '\0' && !is_dir_sep(c))
1273 *dst++ = c;
1274 if (is_dir_sep(c)) {
1275 *dst++ = '/';
1276 while (is_dir_sep(c))
1277 c = *src++;
1278 src--;
1279 } else if (!c)
1280 break;
1281 continue;
1282
1283 up_one:
1284 /*
1285 * dst0..dst is prefix portion, and dst[-1] is '/';
1286 * go up one level.
1287 */
1288 dst--; /* go to trailing '/' */
1289 if (dst <= dst0)
1290 return -1;
1291 /* Windows: dst[-1] cannot be backslash anymore */
1292 while (dst0 < dst && dst[-1] != '/')
1293 dst--;
1294 if (prefix_len && *prefix_len > dst - dst0)
1295 *prefix_len = dst - dst0;
1296 }
1297 *dst = '\0';
1298 return 0;
1299}
1300
1301int normalize_path_copy(char *dst, const char *src)
1302{
1303 return normalize_path_copy_len(dst, src, NULL);
1304}
1305
1306int strbuf_normalize_path(struct strbuf *src)
1307{
1308 struct strbuf dst = STRBUF_INIT;
1309
1310 strbuf_grow(&dst, src->len);
1311 if (normalize_path_copy(dst.buf, src->buf) < 0) {
1312 strbuf_release(&dst);
1313 return -1;
1314 }
1315
1316 /*
1317 * normalize_path does not tell us the new length, so we have to
1318 * compute it by looking for the new NUL it placed
1319 */
1320 strbuf_setlen(&dst, strlen(dst.buf));
1321 strbuf_swap(src, &dst);
1322 strbuf_release(&dst);
1323 return 0;
1324}
1325
1326/*
1327 * path = Canonical absolute path
1328 * prefixes = string_list containing normalized, absolute paths without
1329 * trailing slashes (except for the root directory, which is denoted by "/").
1330 *
1331 * Determines, for each path in prefixes, whether the "prefix"
1332 * is an ancestor directory of path. Returns the length of the longest
1333 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
1334 * is an ancestor. (Note that this means 0 is returned if prefixes is
1335 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
1336 * are not considered to be their own ancestors. path must be in a
1337 * canonical form: empty components, or "." or ".." components are not
1338 * allowed.
1339 */
1340int longest_ancestor_length(const char *path, struct string_list *prefixes)
1341{
1342 int max_len = -1;
1343
1344 if (!strcmp(path, "/"))
1345 return -1;
1346
1347 for (size_t i = 0; i < prefixes->nr; i++) {
1348 const char *ceil = prefixes->items[i].string;
1349 int len = strlen(ceil);
1350
1351 /*
1352 * For root directories (`/`, `C:/`, `//server/share/`)
1353 * adjust the length to exclude the trailing slash.
1354 */
1355 if (len > 0 && ceil[len - 1] == '/')
1356 len--;
1357
1358 if (strncmp(path, ceil, len) ||
1359 path[len] != '/' || !path[len + 1])
1360 continue; /* no match */
1361
1362 if (len > max_len)
1363 max_len = len;
1364 }
1365
1366 return max_len;
1367}
1368
1369/* strip arbitrary amount of directory separators at end of path */
1370static inline int chomp_trailing_dir_sep(const char *path, int len)
1371{
1372 while (len && is_dir_sep(path[len - 1]))
1373 len--;
1374 return len;
1375}
1376
1377/*
1378 * If path ends with suffix (complete path components), returns the offset of
1379 * the last character in the path before the suffix (sans trailing directory
1380 * separators), and -1 otherwise.
1381 */
1382static ssize_t stripped_path_suffix_offset(const char *path, const char *suffix)
1383{
1384 int path_len = strlen(path), suffix_len = strlen(suffix);
1385
1386 while (suffix_len) {
1387 if (!path_len)
1388 return -1;
1389
1390 if (is_dir_sep(path[path_len - 1])) {
1391 if (!is_dir_sep(suffix[suffix_len - 1]))
1392 return -1;
1393 path_len = chomp_trailing_dir_sep(path, path_len);
1394 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
1395 }
1396 else if (path[--path_len] != suffix[--suffix_len])
1397 return -1;
1398 }
1399
1400 if (path_len && !is_dir_sep(path[path_len - 1]))
1401 return -1;
1402 return chomp_trailing_dir_sep(path, path_len);
1403}
1404
1405/*
1406 * Returns true if the path ends with components, considering only complete path
1407 * components, and false otherwise.
1408 */
1409int ends_with_path_components(const char *path, const char *components)
1410{
1411 return stripped_path_suffix_offset(path, components) != -1;
1412}
1413
1414/*
1415 * If path ends with suffix (complete path components), returns the
1416 * part before suffix (sans trailing directory separators).
1417 * Otherwise returns NULL.
1418 */
1419char *strip_path_suffix(const char *path, const char *suffix)
1420{
1421 ssize_t offset = stripped_path_suffix_offset(path, suffix);
1422
1423 return offset == -1 ? NULL : xstrndup(path, offset);
1424}
1425
1426int daemon_avoid_alias(const char *p)
1427{
1428 int sl, ndot;
1429
1430 /*
1431 * This resurrects the belts and suspenders paranoia check by HPA
1432 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
1433 * does not do getcwd() based path canonicalization.
1434 *
1435 * sl becomes true immediately after seeing '/' and continues to
1436 * be true as long as dots continue after that without intervening
1437 * non-dot character.
1438 */
1439 if (!p || (*p != '/' && *p != '~'))
1440 return -1;
1441 sl = 1; ndot = 0;
1442 p++;
1443
1444 while (1) {
1445 char ch = *p++;
1446 if (sl) {
1447 if (ch == '.')
1448 ndot++;
1449 else if (ch == '/') {
1450 if (ndot < 3)
1451 /* reject //, /./ and /../ */
1452 return -1;
1453 ndot = 0;
1454 }
1455 else if (ch == 0) {
1456 if (0 < ndot && ndot < 3)
1457 /* reject /.$ and /..$ */
1458 return -1;
1459 return 0;
1460 }
1461 else
1462 sl = ndot = 0;
1463 }
1464 else if (ch == 0)
1465 return 0;
1466 else if (ch == '/') {
1467 sl = 1;
1468 ndot = 0;
1469 }
1470 }
1471}
1472
1473/*
1474 * On NTFS, we need to be careful to disallow certain synonyms of the `.git/`
1475 * directory:
1476 *
1477 * - For historical reasons, file names that end in spaces or periods are
1478 * automatically trimmed. Therefore, `.git . . ./` is a valid way to refer
1479 * to `.git/`.
1480 *
1481 * - For other historical reasons, file names that do not conform to the 8.3
1482 * format (up to eight characters for the basename, three for the file
1483 * extension, certain characters not allowed such as `+`, etc) are associated
1484 * with a so-called "short name", at least on the `C:` drive by default.
1485 * Which means that `git~1/` is a valid way to refer to `.git/`.
1486 *
1487 * Note: Technically, `.git/` could receive the short name `git~2` if the
1488 * short name `git~1` were already used. In Git, however, we guarantee that
1489 * `.git` is the first item in a directory, therefore it will be associated
1490 * with the short name `git~1` (unless short names are disabled).
1491 *
1492 * - For yet other historical reasons, NTFS supports so-called "Alternate Data
1493 * Streams", i.e. metadata associated with a given file, referred to via
1494 * `<filename>:<stream-name>:<stream-type>`. There exists a default stream
1495 * type for directories, allowing `.git/` to be accessed via
1496 * `.git::$INDEX_ALLOCATION/`.
1497 *
1498 * When this function returns 1, it indicates that the specified file/directory
1499 * name refers to a `.git` file or directory, or to any of these synonyms, and
1500 * Git should therefore not track it.
1501 *
1502 * For performance reasons, _all_ Alternate Data Streams of `.git/` are
1503 * forbidden, not just `::$INDEX_ALLOCATION`.
1504 *
1505 * This function is intended to be used by `git fsck` even on platforms where
1506 * the backslash is a regular filename character, therefore it needs to handle
1507 * backlash characters in the provided `name` specially: they are interpreted
1508 * as directory separators.
1509 */
1510int is_ntfs_dotgit(const char *name)
1511{
1512 char c;
1513
1514 /*
1515 * Note that when we don't find `.git` or `git~1` we end up with `name`
1516 * advanced partway through the string. That's okay, though, as we
1517 * return immediately in those cases, without looking at `name` any
1518 * further.
1519 */
1520 c = *(name++);
1521 if (c == '.') {
1522 /* .git */
1523 if (((c = *(name++)) != 'g' && c != 'G') ||
1524 ((c = *(name++)) != 'i' && c != 'I') ||
1525 ((c = *(name++)) != 't' && c != 'T'))
1526 return 0;
1527 } else if (c == 'g' || c == 'G') {
1528 /* git ~1 */
1529 if (((c = *(name++)) != 'i' && c != 'I') ||
1530 ((c = *(name++)) != 't' && c != 'T') ||
1531 *(name++) != '~' ||
1532 *(name++) != '1')
1533 return 0;
1534 } else
1535 return 0;
1536
1537 for (;;) {
1538 c = *(name++);
1539 if (!c || is_xplatform_dir_sep(c) || c == ':')
1540 return 1;
1541 if (c != '.' && c != ' ')
1542 return 0;
1543 }
1544}
1545
1546static int is_ntfs_dot_generic(const char *name,
1547 const char *dotgit_name,
1548 size_t len,
1549 const char *dotgit_ntfs_shortname_prefix)
1550{
1551 int saw_tilde;
1552 size_t i;
1553
1554 if ((name[0] == '.' && !strncasecmp(name + 1, dotgit_name, len))) {
1555 i = len + 1;
1556only_spaces_and_periods:
1557 for (;;) {
1558 char c = name[i++];
1559 if (!c || c == ':')
1560 return 1;
1561 if (c != ' ' && c != '.')
1562 return 0;
1563 }
1564 }
1565
1566 /*
1567 * Is it a regular NTFS short name, i.e. shortened to 6 characters,
1568 * followed by ~1, ... ~4?
1569 */
1570 if (!strncasecmp(name, dotgit_name, 6) && name[6] == '~' &&
1571 name[7] >= '1' && name[7] <= '4') {
1572 i = 8;
1573 goto only_spaces_and_periods;
1574 }
1575
1576 /*
1577 * Is it a fall-back NTFS short name (for details, see
1578 * https://en.wikipedia.org/wiki/8.3_filename?
1579 */
1580 for (i = 0, saw_tilde = 0; i < 8; i++)
1581 if (name[i] == '\0')
1582 return 0;
1583 else if (saw_tilde) {
1584 if (name[i] < '0' || name[i] > '9')
1585 return 0;
1586 } else if (name[i] == '~') {
1587 if (name[++i] < '1' || name[i] > '9')
1588 return 0;
1589 saw_tilde = 1;
1590 } else if (i >= 6)
1591 return 0;
1592 else if (name[i] & 0x80) {
1593 /*
1594 * We know our needles contain only ASCII, so we clamp
1595 * here to make the results of tolower() sane.
1596 */
1597 return 0;
1598 } else if (tolower(name[i]) != dotgit_ntfs_shortname_prefix[i])
1599 return 0;
1600
1601 goto only_spaces_and_periods;
1602}
1603
1604/*
1605 * Inline helper to make sure compiler resolves strlen() on literals at
1606 * compile time.
1607 */
1608static inline int is_ntfs_dot_str(const char *name, const char *dotgit_name,
1609 const char *dotgit_ntfs_shortname_prefix)
1610{
1611 return is_ntfs_dot_generic(name, dotgit_name, strlen(dotgit_name),
1612 dotgit_ntfs_shortname_prefix);
1613}
1614
1615int is_ntfs_dotgitmodules(const char *name)
1616{
1617 return is_ntfs_dot_str(name, "gitmodules", "gi7eba");
1618}
1619
1620int is_ntfs_dotgitignore(const char *name)
1621{
1622 return is_ntfs_dot_str(name, "gitignore", "gi250a");
1623}
1624
1625int is_ntfs_dotgitattributes(const char *name)
1626{
1627 return is_ntfs_dot_str(name, "gitattributes", "gi7d29");
1628}
1629
1630int is_ntfs_dotmailmap(const char *name)
1631{
1632 return is_ntfs_dot_str(name, "mailmap", "maba30");
1633}
1634
1635int looks_like_command_line_option(const char *str)
1636{
1637 return str && str[0] == '-';
1638}
1639
1640char *xdg_config_home_for(const char *subdir, const char *filename)
1641{
1642 const char *home, *config_home;
1643
1644 assert(subdir);
1645 assert(filename);
1646 config_home = getenv("XDG_CONFIG_HOME");
1647 if (config_home && *config_home)
1648 return mkpathdup("%s/%s/%s", config_home, subdir, filename);
1649
1650 home = getenv("HOME");
1651 if (home)
1652 return mkpathdup("%s/.config/%s/%s", home, subdir, filename);
1653
1654 return NULL;
1655}
1656
1657char *xdg_config_home(const char *filename)
1658{
1659 return xdg_config_home_for("git", filename);
1660}
1661
1662char *xdg_cache_home(const char *filename)
1663{
1664 const char *home, *cache_home;
1665
1666 assert(filename);
1667 cache_home = getenv("XDG_CACHE_HOME");
1668 if (cache_home && *cache_home)
1669 return mkpathdup("%s/git/%s", cache_home, filename);
1670
1671 home = getenv("HOME");
1672 if (home)
1673 return mkpathdup("%s/.cache/git/%s", home, filename);
1674 return NULL;
1675}
1676
1677REPO_GIT_PATH_FUNC(squash_msg, "SQUASH_MSG")
1678REPO_GIT_PATH_FUNC(merge_msg, "MERGE_MSG")
1679REPO_GIT_PATH_FUNC(merge_rr, "MERGE_RR")
1680REPO_GIT_PATH_FUNC(merge_mode, "MERGE_MODE")
1681REPO_GIT_PATH_FUNC(merge_head, "MERGE_HEAD")
1682REPO_GIT_PATH_FUNC(fetch_head, "FETCH_HEAD")
1683REPO_GIT_PATH_FUNC(shallow, "shallow")