path.c 30.3 KB
Newer Older
1
/*
2
 * Utilities for paths and pathnames
3 4
 */
#include "cache.h"
5
#include "repository.h"
6
#include "strbuf.h"
7
#include "string-list.h"
8
#include "dir.h"
9
#include "worktree.h"
10
#include "submodule-config.h"
11

12
static int get_st_mode_bits(const char *path, int *mode)
13 14 15 16 17 18 19 20
{
	struct stat st;
	if (lstat(path, &st) < 0)
		return -1;
	*mode = st.st_mode;
	return 0;
}

21 22
static char bad_path[] = "/bad-path/";

23
static struct strbuf *get_pathname(void)
24
{
25 26 27
	static struct strbuf pathname_array[4] = {
		STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
	};
28
	static int index;
29 30
	struct strbuf *sb = &pathname_array[index];
	index = (index + 1) % ARRAY_SIZE(pathname_array);
31 32
	strbuf_reset(sb);
	return sb;
33 34
}

35 36 37 38 39 40 41 42 43 44 45
static char *cleanup_path(char *path)
{
	/* Clean it up */
	if (!memcmp(path, "./", 2)) {
		path += 2;
		while (*path == '/')
			path++;
	}
	return path;
}

46 47 48 49 50 51 52
static void strbuf_cleanup_path(struct strbuf *sb)
{
	char *path = cleanup_path(sb->buf);
	if (path > sb->buf)
		strbuf_remove(sb, 0, path - sb->buf);
}

53 54 55 56 57 58 59 60 61
char *mksnpath(char *buf, size_t n, const char *fmt, ...)
{
	va_list args;
	unsigned len;

	va_start(args, fmt);
	len = vsnprintf(buf, n, fmt, args);
	va_end(args);
	if (len >= n) {
62
		strlcpy(buf, bad_path, n);
63 64 65 66 67
		return buf;
	}
	return cleanup_path(buf);
}

68
static int dir_prefix(const char *buf, const char *dir)
69
{
70 71 72 73
	int len = strlen(dir);
	return !strncmp(buf, dir, len) &&
		(is_dir_sep(buf[len]) || buf[len] == '\0');
}
74

75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
/* $buf =~ m|$dir/+$file| but without regex */
static int is_dir_file(const char *buf, const char *dir, const char *file)
{
	int len = strlen(dir);
	if (strncmp(buf, dir, len) || !is_dir_sep(buf[len]))
		return 0;
	while (is_dir_sep(buf[len]))
		len++;
	return !strcmp(buf + len, file);
}

static void replace_dir(struct strbuf *buf, int len, const char *newdir)
{
	int newlen = strlen(newdir);
	int need_sep = (buf->buf[len] && !is_dir_sep(buf->buf[len])) &&
		!is_dir_sep(newdir[newlen - 1]);
	if (need_sep)
		len--;	 /* keep one char, to be replaced with '/'  */
	strbuf_splice(buf, 0, len, newdir, newlen);
	if (need_sep)
		buf->buf[newlen] = '/';
}

David Turner's avatar
David Turner committed
98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113
struct common_dir {
	/* Not considered garbage for report_linked_checkout_garbage */
	unsigned ignore_garbage:1;
	unsigned is_dir:1;
	/* Not common even though its parent is */
	unsigned exclude:1;
	const char *dirname;
};

static struct common_dir common_list[] = {
	{ 0, 1, 0, "branches" },
	{ 0, 1, 0, "hooks" },
	{ 0, 1, 0, "info" },
	{ 0, 0, 1, "info/sparse-checkout" },
	{ 1, 1, 0, "logs" },
	{ 1, 1, 1, "logs/HEAD" },
114
	{ 0, 1, 1, "logs/refs/bisect" },
David Turner's avatar
David Turner committed
115 116 117
	{ 0, 1, 0, "lost-found" },
	{ 0, 1, 0, "objects" },
	{ 0, 1, 0, "refs" },
118
	{ 0, 1, 1, "refs/bisect" },
David Turner's avatar
David Turner committed
119 120 121 122 123 124 125 126 127
	{ 0, 1, 0, "remotes" },
	{ 0, 1, 0, "worktrees" },
	{ 0, 1, 0, "rr-cache" },
	{ 0, 1, 0, "svn" },
	{ 0, 0, 0, "config" },
	{ 1, 0, 0, "gc.pid" },
	{ 0, 0, 0, "packed-refs" },
	{ 0, 0, 0, "shallow" },
	{ 0, 0, 0, NULL }
128 129
};

130 131 132 133 134 135 136 137 138 139 140
/*
 * A compressed trie.  A trie node consists of zero or more characters that
 * are common to all elements with this prefix, optionally followed by some
 * children.  If value is not NULL, the trie node is a terminal node.
 *
 * For example, consider the following set of strings:
 * abc
 * def
 * definite
 * definition
 *
141
 * The trie would look like:
142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157
 * root: len = 0, children a and d non-NULL, value = NULL.
 *    a: len = 2, contents = bc, value = (data for "abc")
 *    d: len = 2, contents = ef, children i non-NULL, value = (data for "def")
 *       i: len = 3, contents = nit, children e and i non-NULL, value = NULL
 *           e: len = 0, children all NULL, value = (data for "definite")
 *           i: len = 2, contents = on, children all NULL,
 *              value = (data for "definition")
 */
struct trie {
	struct trie *children[256];
	int len;
	char *contents;
	void *value;
};

static struct trie *make_trie_node(const char *key, void *value)
158
{
159 160 161 162 163 164 165 166 167
	struct trie *new_node = xcalloc(1, sizeof(*new_node));
	new_node->len = strlen(key);
	if (new_node->len) {
		new_node->contents = xmalloc(new_node->len);
		memcpy(new_node->contents, key, new_node->len);
	}
	new_node->value = value;
	return new_node;
}
168

169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200
/*
 * Add a key/value pair to a trie.  The key is assumed to be \0-terminated.
 * If there was an existing value for this key, return it.
 */
static void *add_to_trie(struct trie *root, const char *key, void *value)
{
	struct trie *child;
	void *old;
	int i;

	if (!*key) {
		/* we have reached the end of the key */
		old = root->value;
		root->value = value;
		return old;
	}

	for (i = 0; i < root->len; i++) {
		if (root->contents[i] == key[i])
			continue;

		/*
		 * Split this node: child will contain this node's
		 * existing children.
		 */
		child = malloc(sizeof(*child));
		memcpy(child->children, root->children, sizeof(root->children));

		child->len = root->len - i - 1;
		if (child->len) {
			child->contents = xstrndup(root->contents + i + 1,
						   child->len);
201
		}
202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223
		child->value = root->value;
		root->value = NULL;
		root->len = i;

		memset(root->children, 0, sizeof(root->children));
		root->children[(unsigned char)root->contents[i]] = child;

		/* This is the newly-added child. */
		root->children[(unsigned char)key[i]] =
			make_trie_node(key + i + 1, value);
		return NULL;
	}

	/* We have matched the entire compressed section */
	if (key[i]) {
		child = root->children[(unsigned char)key[root->len]];
		if (child) {
			return add_to_trie(child, key + root->len + 1, value);
		} else {
			child = make_trie_node(key + root->len + 1, value);
			root->children[(unsigned char)key[root->len]] = child;
			return NULL;
224 225
		}
	}
226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341

	old = root->value;
	root->value = value;
	return old;
}

typedef int (*match_fn)(const char *unmatched, void *data, void *baton);

/*
 * Search a trie for some key.  Find the longest /-or-\0-terminated
 * prefix of the key for which the trie contains a value.  Call fn
 * with the unmatched portion of the key and the found value, and
 * return its return value.  If there is no such prefix, return -1.
 *
 * The key is partially normalized: consecutive slashes are skipped.
 *
 * For example, consider the trie containing only [refs,
 * refs/worktree] (both with values).
 *
 * | key             | unmatched  | val from node | return value |
 * |-----------------|------------|---------------|--------------|
 * | a               | not called | n/a           | -1           |
 * | refs            | \0         | refs          | as per fn    |
 * | refs/           | /          | refs          | as per fn    |
 * | refs/w          | /w         | refs          | as per fn    |
 * | refs/worktree   | \0         | refs/worktree | as per fn    |
 * | refs/worktree/  | /          | refs/worktree | as per fn    |
 * | refs/worktree/a | /a         | refs/worktree | as per fn    |
 * |-----------------|------------|---------------|--------------|
 *
 */
static int trie_find(struct trie *root, const char *key, match_fn fn,
		     void *baton)
{
	int i;
	int result;
	struct trie *child;

	if (!*key) {
		/* we have reached the end of the key */
		if (root->value && !root->len)
			return fn(key, root->value, baton);
		else
			return -1;
	}

	for (i = 0; i < root->len; i++) {
		/* Partial path normalization: skip consecutive slashes. */
		if (key[i] == '/' && key[i+1] == '/') {
			key++;
			continue;
		}
		if (root->contents[i] != key[i])
			return -1;
	}

	/* Matched the entire compressed section */
	key += i;
	if (!*key)
		/* End of key */
		return fn(key, root->value, baton);

	/* Partial path normalization: skip consecutive slashes */
	while (key[0] == '/' && key[1] == '/')
		key++;

	child = root->children[(unsigned char)*key];
	if (child)
		result = trie_find(child, key + 1, fn, baton);
	else
		result = -1;

	if (result >= 0 || (*key != '/' && *key != 0))
		return result;
	if (root->value)
		return fn(key, root->value, baton);
	else
		return -1;
}

static struct trie common_trie;
static int common_trie_done_setup;

static void init_common_trie(void)
{
	struct common_dir *p;

	if (common_trie_done_setup)
		return;

	for (p = common_list; p->dirname; p++)
		add_to_trie(&common_trie, p->dirname, p);

	common_trie_done_setup = 1;
}

/*
 * Helper function for update_common_dir: returns 1 if the dir
 * prefix is common.
 */
static int check_common(const char *unmatched, void *value, void *baton)
{
	struct common_dir *dir = value;

	if (!dir)
		return 0;

	if (dir->is_dir && (unmatched[0] == 0 || unmatched[0] == '/'))
		return !dir->exclude;

	if (!dir->is_dir && unmatched[0] == 0)
		return !dir->exclude;

	return 0;
}

342 343
static void update_common_dir(struct strbuf *buf, int git_dir_len,
			      const char *common_dir)
344 345 346
{
	char *base = buf->buf + git_dir_len;
	init_common_trie();
347 348
	if (!common_dir)
		common_dir = get_git_common_dir();
349
	if (trie_find(&common_trie, base, check_common, NULL) > 0)
350
		replace_dir(buf, git_dir_len, common_dir);
351 352
}

353 354 355
void report_linked_checkout_garbage(void)
{
	struct strbuf sb = STRBUF_INIT;
David Turner's avatar
David Turner committed
356
	const struct common_dir *p;
357 358
	int len;

359
	if (!the_repository->different_commondir)
360 361 362
		return;
	strbuf_addf(&sb, "%s/", get_git_dir());
	len = sb.len;
David Turner's avatar
David Turner committed
363 364 365
	for (p = common_list; p->dirname; p++) {
		const char *path = p->dirname;
		if (p->ignore_garbage)
366 367 368 369
			continue;
		strbuf_setlen(&sb, len);
		strbuf_addstr(&sb, path);
		if (file_exists(sb.buf))
370
			report_garbage(PACKDIR_FILE_GARBAGE, sb.buf);
371 372
	}
	strbuf_release(&sb);
373 374
}

375 376 377
static void adjust_git_path(struct strbuf *buf, int git_dir_len)
{
	const char *base = buf->buf + git_dir_len;
378
	if (is_dir_file(base, "info", "grafts"))
379 380
		strbuf_splice(buf, 0, buf->len,
			      get_graft_file(), strlen(get_graft_file()));
381
	else if (!strcmp(base, "index"))
382 383
		strbuf_splice(buf, 0, buf->len,
			      get_index_file(), strlen(get_index_file()));
384
	else if (dir_prefix(base, "objects"))
385
		replace_dir(buf, git_dir_len + 7, get_object_directory());
386 387
	else if (git_hooks_path && dir_prefix(base, "hooks"))
		replace_dir(buf, git_dir_len + 5, git_hooks_path);
388
	else if (the_repository->different_commondir)
389
		update_common_dir(buf, git_dir_len, NULL);
390 391
}

392 393
static void do_git_path(const struct worktree *wt, struct strbuf *buf,
			const char *fmt, va_list args)
394
{
395
	int gitdir_len;
396
	strbuf_addstr(buf, get_worktree_git_dir(wt));
397 398
	if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
		strbuf_addch(buf, '/');
399
	gitdir_len = buf->len;
400
	strbuf_vaddf(buf, fmt, args);
401
	adjust_git_path(buf, gitdir_len);
402
	strbuf_cleanup_path(buf);
403 404
}

Jeff King's avatar
Jeff King committed
405 406 407 408 409
char *git_path_buf(struct strbuf *buf, const char *fmt, ...)
{
	va_list args;
	strbuf_reset(buf);
	va_start(args, fmt);
410
	do_git_path(NULL, buf, fmt, args);
Jeff King's avatar
Jeff King committed
411 412 413 414
	va_end(args);
	return buf->buf;
}

415
void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
416 417 418
{
	va_list args;
	va_start(args, fmt);
419
	do_git_path(NULL, sb, fmt, args);
420 421 422
	va_end(args);
}

423
const char *git_path(const char *fmt, ...)
424
{
425
	struct strbuf *pathname = get_pathname();
426 427
	va_list args;
	va_start(args, fmt);
428
	do_git_path(NULL, pathname, fmt, args);
429
	va_end(args);
430
	return pathname->buf;
431 432 433
}

char *git_pathdup(const char *fmt, ...)
434
{
435
	struct strbuf path = STRBUF_INIT;
436 437
	va_list args;
	va_start(args, fmt);
438
	do_git_path(NULL, &path, fmt, args);
439
	va_end(args);
440
	return strbuf_detach(&path, NULL);
441 442 443
}

char *mkpathdup(const char *fmt, ...)
444
{
445
	struct strbuf sb = STRBUF_INIT;
446 447
	va_list args;
	va_start(args, fmt);
448
	strbuf_vaddf(&sb, fmt, args);
449
	va_end(args);
450 451
	strbuf_cleanup_path(&sb);
	return strbuf_detach(&sb, NULL);
452 453
}

454
const char *mkpath(const char *fmt, ...)
455 456
{
	va_list args;
457
	struct strbuf *pathname = get_pathname();
458
	va_start(args, fmt);
459
	strbuf_vaddf(pathname, fmt, args);
460
	va_end(args);
461
	return cleanup_path(pathname->buf);
462
}
463

464 465 466 467 468 469 470 471 472 473
const char *worktree_git_path(const struct worktree *wt, const char *fmt, ...)
{
	struct strbuf *pathname = get_pathname();
	va_list args;
	va_start(args, fmt);
	do_git_path(wt, pathname, fmt, args);
	va_end(args);
	return pathname->buf;
}

474 475 476
/* Returns 0 on success, negative on failure. */
static int do_submodule_path(struct strbuf *buf, const char *path,
			     const char *fmt, va_list args)
477
{
478 479
	struct strbuf git_submodule_common_dir = STRBUF_INIT;
	struct strbuf git_submodule_dir = STRBUF_INIT;
480
	int ret;
481

482 483 484
	ret = submodule_to_gitdir(&git_submodule_dir, path);
	if (ret)
		goto cleanup;
485

486 487
	strbuf_complete(&git_submodule_dir, '/');
	strbuf_addbuf(buf, &git_submodule_dir);
488
	strbuf_vaddf(buf, fmt, args);
489 490 491 492

	if (get_common_dir_noenv(&git_submodule_common_dir, git_submodule_dir.buf))
		update_common_dir(buf, git_submodule_dir.len, git_submodule_common_dir.buf);

493
	strbuf_cleanup_path(buf);
494

495
cleanup:
496 497
	strbuf_release(&git_submodule_dir);
	strbuf_release(&git_submodule_common_dir);
498
	return ret;
499 500 501 502
}

char *git_pathdup_submodule(const char *path, const char *fmt, ...)
{
503
	int err;
504 505 506
	va_list args;
	struct strbuf buf = STRBUF_INIT;
	va_start(args, fmt);
507
	err = do_submodule_path(&buf, path, fmt, args);
508
	va_end(args);
509 510 511 512
	if (err) {
		strbuf_release(&buf);
		return NULL;
	}
513 514 515
	return strbuf_detach(&buf, NULL);
}

516 517
int strbuf_git_path_submodule(struct strbuf *buf, const char *path,
			      const char *fmt, ...)
518
{
519
	int err;
520 521
	va_list args;
	va_start(args, fmt);
522
	err = do_submodule_path(buf, path, fmt, args);
523
	va_end(args);
524 525

	return err;
526 527
}

528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556
static void do_git_common_path(struct strbuf *buf,
			       const char *fmt,
			       va_list args)
{
	strbuf_addstr(buf, get_git_common_dir());
	if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
		strbuf_addch(buf, '/');
	strbuf_vaddf(buf, fmt, args);
	strbuf_cleanup_path(buf);
}

const char *git_common_path(const char *fmt, ...)
{
	struct strbuf *pathname = get_pathname();
	va_list args;
	va_start(args, fmt);
	do_git_common_path(pathname, fmt, args);
	va_end(args);
	return pathname->buf;
}

void strbuf_git_common_path(struct strbuf *sb, const char *fmt, ...)
{
	va_list args;
	va_start(args, fmt);
	do_git_common_path(sb, fmt, args);
	va_end(args);
}

557
int validate_headref(const char *path)
558 559 560
{
	struct stat st;
	char *buf, buffer[256];
561
	unsigned char sha1[20];
562 563
	int fd;
	ssize_t len;
564 565 566 567 568 569 570

	if (lstat(path, &st) < 0)
		return -1;

	/* Make sure it is a "refs/.." symlink */
	if (S_ISLNK(st.st_mode)) {
		len = readlink(path, buffer, sizeof(buffer)-1);
571
		if (len >= 5 && !memcmp("refs/", buffer, 5))
572 573 574 575 576 577 578 579 580 581
			return 0;
		return -1;
	}

	/*
	 * Anything else, just open it and try to see if it is a symbolic ref.
	 */
	fd = open(path, O_RDONLY);
	if (fd < 0)
		return -1;
582
	len = read_in_full(fd, buffer, sizeof(buffer)-1);
583 584 585 586 587
	close(fd);

	/*
	 * Is it a symbolic ref?
	 */
588
	if (len < 4)
589
		return -1;
590 591 592 593 594
	if (!memcmp("ref:", buffer, 4)) {
		buf = buffer + 4;
		len -= 4;
		while (len && isspace(*buf))
			buf++, len--;
595
		if (len >= 5 && !memcmp("refs/", buf, 5))
596 597 598 599 600 601 602
			return 0;
	}

	/*
	 * Is this a detached HEAD?
	 */
	if (!get_sha1_hex(buffer, sha1))
603
		return 0;
604

605 606 607
	return -1;
}

608
static struct passwd *getpw_str(const char *username, size_t len)
609
{
610
	struct passwd *pw;
611
	char *username_z = xmemdupz(username, len);
612 613 614 615
	pw = getpwnam(username_z);
	free(username_z);
	return pw;
}
616

617 618 619 620
/*
 * Return a string with ~ and ~user expanded via getpw*.  If buf != NULL,
 * then it is a newly allocated string. Returns NULL on getpw failure or
 * if path is NULL.
621 622
 *
 * If real_home is true, real_path($HOME) is used in the expansion.
623
 */
624
char *expand_user_path(const char *path, int real_home)
625 626 627 628 629 630 631
{
	struct strbuf user_path = STRBUF_INIT;
	const char *to_copy = path;

	if (path == NULL)
		goto return_null;
	if (path[0] == '~') {
632
		const char *first_slash = strchrnul(path, '/');
633 634
		const char *username = path + 1;
		size_t username_len = first_slash - username;
635 636
		if (username_len == 0) {
			const char *home = getenv("HOME");
637 638
			if (!home)
				goto return_null;
639 640 641 642
			if (real_home)
				strbuf_addstr(&user_path, real_path(home));
			else
				strbuf_addstr(&user_path, home);
643 644 645
#ifdef GIT_WINDOWS_NATIVE
			convert_slashes(user_path.buf);
#endif
646 647 648 649
		} else {
			struct passwd *pw = getpw_str(username, username_len);
			if (!pw)
				goto return_null;
650
			strbuf_addstr(&user_path, pw->pw_dir);
651
		}
652
		to_copy = first_slash;
653
	}
654
	strbuf_addstr(&user_path, to_copy);
655 656 657 658
	return strbuf_detach(&user_path, NULL);
return_null:
	strbuf_release(&user_path);
	return NULL;
659 660
}

661 662 663 664 665 666 667 668 669 670
/*
 * First, one directory to try is determined by the following algorithm.
 *
 * (0) If "strict" is given, the path is used as given and no DWIM is
 *     done. Otherwise:
 * (1) "~/path" to mean path under the running user's home directory;
 * (2) "~user/path" to mean path under named user's home directory;
 * (3) "relative/path" to mean cwd relative directory; or
 * (4) "/absolute/path" to mean absolute directory.
 *
671 672 673
 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
 * in this order. We select the first one that is a valid git repository, and
 * chdir() to it. If none match, or we fail to chdir, we return NULL.
674 675 676 677 678 679
 *
 * If all goes well, we return the directory we used to chdir() (but
 * before ~user is expanded), avoiding getcwd() resolving symbolic
 * links.  User relative paths are also returned as they are given,
 * except DWIM suffixing.
 */
680
const char *enter_repo(const char *path, int strict)
681
{
682 683
	static struct strbuf validated_path = STRBUF_INIT;
	static struct strbuf used_path = STRBUF_INIT;
684 685

	if (!path)
686 687
		return NULL;

688 689
	if (!strict) {
		static const char *suffix[] = {
690
			"/.git", "", ".git/.git", ".git", NULL,
691
		};
692
		const char *gitfile;
693 694
		int len = strlen(path);
		int i;
695
		while ((1 < len) && (path[len-1] == '/'))
696
			len--;
697

698 699 700 701
		/*
		 * We can handle arbitrary-sized buffers, but this remains as a
		 * sanity check on untrusted input.
		 */
702
		if (PATH_MAX <= len)
703
			return NULL;
704

705 706 707 708 709 710
		strbuf_reset(&used_path);
		strbuf_reset(&validated_path);
		strbuf_add(&used_path, path, len);
		strbuf_add(&validated_path, path, len);

		if (used_path.buf[0] == '~') {
711
			char *newpath = expand_user_path(used_path.buf, 0);
712
			if (!newpath)
713
				return NULL;
714 715
			strbuf_attach(&used_path, newpath, strlen(newpath),
				      strlen(newpath));
716 717
		}
		for (i = 0; suffix[i]; i++) {
718
			struct stat st;
719 720 721
			size_t baselen = used_path.len;
			strbuf_addstr(&used_path, suffix[i]);
			if (!stat(used_path.buf, &st) &&
722
			    (S_ISREG(st.st_mode) ||
723 724
			    (S_ISDIR(st.st_mode) && is_git_directory(used_path.buf)))) {
				strbuf_addstr(&validated_path, suffix[i]);
725 726
				break;
			}
727
			strbuf_setlen(&used_path, baselen);
728
		}
729 730
		if (!suffix[i])
			return NULL;
731
		gitfile = read_gitfile(used_path.buf);
732 733 734 735 736
		if (gitfile) {
			strbuf_reset(&used_path);
			strbuf_addstr(&used_path, gitfile);
		}
		if (chdir(used_path.buf))
737
			return NULL;
738
		path = validated_path.buf;
739
	}
740 741 742 743 744 745 746
	else {
		const char *gitfile = read_gitfile(path);
		if (gitfile)
			path = gitfile;
		if (chdir(path))
			return NULL;
	}
747

748
	if (is_git_directory(".")) {
René Scharfe's avatar
René Scharfe committed
749
		set_git_dir(".");
750
		check_repository_format();
751
		return path;
752 753 754 755
	}

	return NULL;
}
756

757
static int calc_shared_perm(int mode)
758
{
759
	int tweak;
760

761 762
	if (get_shared_repository() < 0)
		tweak = -get_shared_repository();
763
	else
764
		tweak = get_shared_repository();
765 766 767 768 769 770

	if (!(mode & S_IWUSR))
		tweak &= ~0222;
	if (mode & S_IXUSR)
		/* Copy read bits to execute bits */
		tweak |= (tweak & 0444) >> 2;
771
	if (get_shared_repository() < 0)
772 773
		mode = (mode & ~0777) | tweak;
	else
774
		mode |= tweak;
775

776 777 778 779 780 781 782 783
	return mode;
}


int adjust_shared_perm(const char *path)
{
	int old_mode, new_mode;

784
	if (!get_shared_repository())
785 786 787 788 789 790
		return 0;
	if (get_st_mode_bits(path, &old_mode) < 0)
		return -1;

	new_mode = calc_shared_perm(old_mode);
	if (S_ISDIR(old_mode)) {
791
		/* Copy read bits to execute bits */
792 793
		new_mode |= (new_mode & 0444) >> 2;
		new_mode |= FORCE_DIR_SET_GID;
794 795
	}

796 797
	if (((old_mode ^ new_mode) & ~S_IFMT) &&
			chmod(path, (new_mode & ~S_IFMT)) < 0)
798 799 800
		return -2;
	return 0;
}
801

802 803 804 805 806 807 808 809 810 811 812 813
void safe_create_dir(const char *dir, int share)
{
	if (mkdir(dir, 0777) < 0) {
		if (errno != EEXIST) {
			perror(dir);
			exit(1);
		}
	}
	else if (share && adjust_shared_perm(dir))
		die(_("Could not make %s writable by group"), dir);
}

814 815 816 817 818 819 820 821 822 823
static int have_same_root(const char *path1, const char *path2)
{
	int is_abs1, is_abs2;

	is_abs1 = is_absolute_path(path1);
	is_abs2 = is_absolute_path(path2);
	return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
	       (!is_abs1 && !is_abs2);
}

824 825 826 827 828 829 830 831
/*
 * Give path as relative to prefix.
 *
 * The strbuf may or may not be used, so do not assume it contains the
 * returned path.
 */
const char *relative_path(const char *in, const char *prefix,
			  struct strbuf *sb)
832
{
833 834 835 836
	int in_len = in ? strlen(in) : 0;
	int prefix_len = prefix ? strlen(prefix) : 0;
	int in_off = 0;
	int prefix_off = 0;
837 838
	int i = 0, j = 0;

839 840 841 842 843
	if (!in_len)
		return "./";
	else if (!prefix_len)
		return in;

844
	if (have_same_root(in, prefix))
845
		/* bypass dos_drive, for "c:" is identical to "C:" */
846 847
		i = j = has_dos_drive_prefix(in);
	else {
848 849 850
		return in;
	}

851 852 853
	while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
		if (is_dir_sep(prefix[i])) {
			while (is_dir_sep(prefix[i]))
854
				i++;
855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878
			while (is_dir_sep(in[j]))
				j++;
			prefix_off = i;
			in_off = j;
		} else {
			i++;
			j++;
		}
	}

	if (
	    /* "prefix" seems like prefix of "in" */
	    i >= prefix_len &&
	    /*
	     * but "/foo" is not a prefix of "/foobar"
	     * (i.e. prefix not end with '/')
	     */
	    prefix_off < prefix_len) {
		if (j >= in_len) {
			/* in="/a/b", prefix="/a/b" */
			in_off = in_len;
		} else if (is_dir_sep(in[j])) {
			/* in="/a/b/c", prefix="/a/b" */
			while (is_dir_sep(in[j]))
879
				j++;
880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914
			in_off = j;
		} else {
			/* in="/a/bbb/c", prefix="/a/b" */
			i = prefix_off;
		}
	} else if (
		   /* "in" is short than "prefix" */
		   j >= in_len &&
		   /* "in" not end with '/' */
		   in_off < in_len) {
		if (is_dir_sep(prefix[i])) {
			/* in="/a/b", prefix="/a/b/c/" */
			while (is_dir_sep(prefix[i]))
				i++;
			in_off = in_len;
		}
	}
	in += in_off;
	in_len -= in_off;

	if (i >= prefix_len) {
		if (!in_len)
			return "./";
		else
			return in;
	}

	strbuf_reset(sb);
	strbuf_grow(sb, in_len);

	while (i < prefix_len) {
		if (is_dir_sep(prefix[i])) {
			strbuf_addstr(sb, "../");
			while (is_dir_sep(prefix[i]))
				i++;
915 916 917 918
			continue;
		}
		i++;
	}
919 920 921 922 923 924
	if (!is_dir_sep(prefix[prefix_len - 1]))
		strbuf_addstr(sb, "../");

	strbuf_addstr(sb, in);

	return sb->buf;
925
}
926

927 928 929 930 931 932 933 934 935
/*
 * A simpler implementation of relative_path
 *
 * Get relative path by removing "prefix" from "in". This function
 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
 * to increase performance when traversing the path to work_tree.
 */
const char *remove_leading_path(const char *in, const char *prefix)
{
936
	static struct strbuf buf = STRBUF_INIT;
937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964
	int i = 0, j = 0;

	if (!prefix || !prefix[0])
		return in;
	while (prefix[i]) {
		if (is_dir_sep(prefix[i])) {
			if (!is_dir_sep(in[j]))
				return in;
			while (is_dir_sep(prefix[i]))
				i++;
			while (is_dir_sep(in[j]))
				j++;
			continue;
		} else if (in[j] != prefix[i]) {
			return in;
		}
		i++;
		j++;
	}
	if (
	    /* "/foo" is a prefix of "/foo" */
	    in[j] &&
	    /* "/foo" is not a prefix of "/foobar" */
	    !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
	   )
		return in;
	while (is_dir_sep(in[j]))
		j++;
965 966

	strbuf_reset(&buf);
967
	if (!in[j])
968
		strbuf_addstr(&buf, ".");
969
	else
970 971
		strbuf_addstr(&buf, in + j);
	return buf.buf;
972 973
}

974
/*
975
 * It is okay if dst == src, but they should not overlap otherwise.
976
 *
977 978
 * Performs the following normalizations on src, storing the result in dst:
 * - Ensures that components are separated by '/' (Windows only)
979
 * - Squashes sequences of '/' except "//server/share" on Windows
980 981
 * - Removes "." components.
 * - Removes ".." components, and the components the precede them.
982 983
 * Returns failure (non-zero) if a ".." component appears as first path
 * component anytime during the normalization. Otherwise, returns success (0).
984 985 986
 *
 * Note that this function is purely textual.  It does not follow symlinks,
 * verify the existence of the path, or make any system calls.
987 988 989 990 991 992
 *
 * prefix_len != NULL is for a specific case of prefix_pathspec():
 * assume that src == dst and src[0..prefix_len-1] is already
 * normalized, any time "../" eats up to the prefix_len part,
 * prefix_len is reduced. In the end prefix_len is the remaining
 * prefix that has not been overridden by user pathspec.
993 994 995 996 997
 *
 * NEEDSWORK: This function doesn't perform normalization w.r.t. trailing '/'.
 * For everything but the root folder itself, the normalized path should not
 * end with a '/', then the callers need to be fixed up accordingly.
 *
998
 */
999
int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
1000
{
1001
	char *dst0;
1002
	const char *end;
1003

1004 1005 1006 1007 1008 1009 1010 1011 1012 1013
	/*
	 * Copy initial part of absolute path: "/", "C:/", "//server/share/".
	 */
	end = src + offset_1st_component(src);
	while (src < end) {
		char c = *src++;
		if (is_dir_sep(c))
			c = '/';
		*dst++ = c;
	}
1014
	dst0 = dst;
1015

1016 1017
	while (is_dir_sep(*src))
		src++;
1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053

	for (;;) {
		char c = *src;

		/*
		 * A path component that begins with . could be
		 * special:
		 * (1) "." and ends   -- ignore and terminate.
		 * (2) "./"           -- ignore them, eat slash and continue.
		 * (3) ".." and ends  -- strip one and terminate.
		 * (4) "../"          -- strip one, eat slash and continue.
		 */
		if (c == '.') {
			if (!src[1]) {
				/* (1) */
				src++;
			} else if (is_dir_sep(src[1])) {
				/* (2) */
				src += 2;
				while (is_dir_sep(*src))
					src++;
				continue;
			} else if (src[1] == '.') {
				if (!src[2]) {
					/* (3) */
					src += 2;
					goto up_one;
				} else if (is_dir_sep(src[2])) {
					/* (4) */
					src += 3;
					while (is_dir_sep(*src))
						src++;
					goto up_one;
				}
			}
		}
1054

1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071
		/* copy up to the next '/', and eat all '/' */
		while ((c = *src++) != '\0' && !is_dir_sep(c))
			*dst++ = c;
		if (is_dir_sep(c)) {
			*dst++ = '/';
			while (is_dir_sep(c))
				c = *src++;
			src--;
		} else if (!c)
			break;
		continue;

	up_one:
		/*
		 * dst0..dst is prefix portion, and dst[-1] is '/';
		 * go up one level.
		 */
1072 1073
		dst--;	/* go to trailing '/' */
		if (dst <= dst0)
1074
			return -1;
1075 1076 1077
		/* Windows: dst[-1] cannot be backslash anymore */
		while (dst0 < dst && dst[-1] != '/')
			dst--;
1078 1079
		if (prefix_len && *prefix_len > dst - dst0)
			*prefix_len = dst - dst0;
1080
	}
1081
	*dst = '\0';
1082
	return 0;
1083
}
1084

1085 1086 1087 1088 1089
int normalize_path_copy(char *dst, const char *src)
{
	return normalize_path_copy_len(dst, src, NULL);
}

1090 1091
/*
 * path = Canonical absolute path
1092 1093
 * prefixes = string_list containing normalized, absolute paths without
 * trailing slashes (except for the root directory, which is denoted by "/").
1094
 *
1095
 * Determines, for each path in prefixes, whether the "prefix"
1096 1097
 * is an ancestor directory of path.  Returns the length of the longest
 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
1098 1099
 * is an ancestor.  (Note that this means 0 is returned if prefixes is
 * ["/"].) "/foo" is not considered an ancestor of "/foobar".  Directories
1100 1101
 * are not considered to be their own ancestors.  path must be in a
 * canonical form: empty components, or "." or ".." components are not
1102
 * allowed.
1103
 */
1104
int longest_ancestor_length(const char *path, struct string_list *prefixes)
1105
{
1106
	int i, max_len = -1;
1107

1108
	if (!strcmp(path, "/"))
1109 1110
		return -1;

1111 1112
	for (i = 0; i < prefixes->nr; i++) {
		const char *ceil = prefixes->items[i].string;
1113 1114
		int len = strlen(ceil);

1115 1116 1117 1118 1119 1120
		if (len == 1 && ceil[0] == '/')
			len = 0; /* root matches anything, with length 0 */
		else if (!strncmp(path, ceil, len) && path[len] == '/')
			; /* match of length len */
		else
			continue; /* no match */
1121

1122
		if (len > max_len)
1123 1124 1125 1126 1127
			max_len = len;
	}

	return max_len;
}
1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163

/* strip arbitrary amount of directory separators at end of path */
static inline int chomp_trailing_dir_sep(const char *path, int len)
{
	while (len && is_dir_sep(path[len - 1]))
		len--;
	return len;
}

/*
 * If path ends with suffix (complete path components), returns the
 * part before suffix (sans trailing directory separators).
 * Otherwise returns NULL.
 */
char *strip_path_suffix(const char *path, const char *suffix)
{
	int path_len = strlen(path), suffix_len = strlen(suffix);

	while (suffix_len) {
		if (!path_len)
			return NULL;

		if (is_dir_sep(path[path_len - 1])) {
			if (!is_dir_sep(suffix[suffix_len - 1]))
				return NULL;
			path_len = chomp_trailing_dir_sep(path, path_len);
			suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
		}
		else if (path[--path_len] != suffix[--suffix_len])
			return NULL;
	}

	if (path_len && !is_dir_sep(path[path_len - 1]))
		return NULL;
	return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
}
1164 1165 1166 1167 1168 1169 1170 1171

int daemon_avoid_alias(const char *p)
{
	int sl, ndot;

	/*
	 * This resurrects the belts and suspenders paranoia check by HPA
	 * done in <[email protected]> thread, now enter_repo()
1172
	 * does not do getcwd() based path canonicalization.
1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210
	 *
	 * sl becomes true immediately after seeing '/' and continues to
	 * be true as long as dots continue after that without intervening
	 * non-dot character.
	 */
	if (!p || (*p != '/' && *p != '~'))
		return -1;
	sl = 1; ndot = 0;
	p++;

	while (1) {
		char ch = *p++;
		if (sl) {
			if (ch == '.')
				ndot++;
			else if (ch == '/') {
				if (ndot < 3)
					/* reject //, /./ and /../ */
					return -1;
				ndot = 0;
			}
			else if (ch == 0) {
				if (0 < ndot && ndot < 3)
					/* reject /.$ and /..$ */
					return -1;
				return 0;
			}
			else
				sl = ndot = 0;
		}
		else if (ch == 0)
			return 0;
		else if (ch == '/') {
			sl = 1;
			ndot = 0;
		}
	}
}
1211

1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243
static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
{
	if (len < skip)
		return 0;
	len -= skip;
	path += skip;
	while (len-- > 0) {
		char c = *(path++);
		if (c != ' ' && c != '.')
			return 0;
	}
	return 1;
}

int is_ntfs_dotgit(const char *name)
{
	int len;

	for (len = 0; ; len++)
		if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
			if (only_spaces_and_periods(name, len, 4) &&
					!strncasecmp(name, ".git", 4))
				return 1;
			if (only_spaces_and_periods(name, len, 5) &&
					!strncasecmp(name, "git~1", 5))
				return 1;
			if (name[len] != '\\')
				return 0;
			name += len + 1;
			len = -1;
		}
}
1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258

char *xdg_config_home(const char *filename)
{
	const char *home, *config_home;

	assert(filename);
	config_home = getenv("XDG_CONFIG_HOME");
	if (config_home && *config_home)
		return mkpathdup("%s/git/%s", config_home, filename);

	home = getenv("HOME");
	if (home)
		return mkpathdup("%s/.config/git/%s", home, filename);
	return NULL;
}
1259

Devin Lehmacher's avatar
Devin Lehmacher committed
1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274
char *xdg_cache_home(const char *filename)
{
	const char *home, *cache_home;

	assert(filename);
	cache_home = getenv("XDG_CACHE_HOME");
	if (cache_home && *cache_home)
		return mkpathdup("%s/git/%s", cache_home, filename);

	home = getenv("HOME");
	if (home)
		return mkpathdup("%s/.cache/git/%s", home, filename);
	return NULL;
}

1275 1276 1277 1278 1279 1280 1281 1282 1283
GIT_PATH_FUNC(git_path_cherry_pick_head, "CHERRY_PICK_HEAD")
GIT_PATH_FUNC(git_path_revert_head, "REVERT_HEAD")
GIT_PATH_FUNC(git_path_squash_msg, "SQUASH_MSG")
GIT_PATH_FUNC(git_path_merge_msg, "MERGE_MSG")
GIT_PATH_FUNC(git_path_merge_rr, "MERGE_RR")
GIT_PATH_FUNC(git_path_merge_mode, "MERGE_MODE")
GIT_PATH_FUNC(git_path_merge_head, "MERGE_HEAD")
GIT_PATH_FUNC(git_path_fetch_head, "FETCH_HEAD")
GIT_PATH_FUNC(git_path_shallow, "shallow")