path.c 34.2 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"
Brandon Williams's avatar
Brandon Williams committed
11
#include "path.h"
12
#include "packfile.h"
13
#include "object-store.h"
14

15
static int get_st_mode_bits(const char *path, int *mode)
16 17 18 19 20 21 22 23
{
	struct stat st;
	if (lstat(path, &st) < 0)
		return -1;
	*mode = st.st_mode;
	return 0;
}

24 25
static char bad_path[] = "/bad-path/";

26
static struct strbuf *get_pathname(void)
27
{
28 29 30
	static struct strbuf pathname_array[4] = {
		STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
	};
31
	static int index;
32 33
	struct strbuf *sb = &pathname_array[index];
	index = (index + 1) % ARRAY_SIZE(pathname_array);
34 35
	strbuf_reset(sb);
	return sb;
36 37
}

38
static const char *cleanup_path(const char *path)
39 40
{
	/* Clean it up */
41
	if (skip_prefix(path, "./", &path)) {
42 43 44 45 46 47
		while (*path == '/')
			path++;
	}
	return path;
}

48 49
static void strbuf_cleanup_path(struct strbuf *sb)
{
50
	const char *path = cleanup_path(sb->buf);
51 52 53 54
	if (path > sb->buf)
		strbuf_remove(sb, 0, path - sb->buf);
}

55 56 57 58 59 60 61 62 63
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) {
64
		strlcpy(buf, bad_path, n);
65 66
		return buf;
	}
67
	return (char *)cleanup_path(buf);
68 69
}

70
static int dir_prefix(const char *buf, const char *dir)
71
{
72 73 74 75
	int len = strlen(dir);
	return !strncmp(buf, dir, len) &&
		(is_dir_sep(buf[len]) || buf[len] == '\0');
}
76

77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
/* $buf =~ m|$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
100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115
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" },
116
	{ 0, 1, 1, "logs/refs/bisect" },
David Turner's avatar
David Turner committed
117 118 119
	{ 0, 1, 0, "lost-found" },
	{ 0, 1, 0, "objects" },
	{ 0, 1, 0, "refs" },
120
	{ 0, 1, 1, "refs/bisect" },
David Turner's avatar
David Turner committed
121 122 123 124 125 126 127 128 129
	{ 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 }
130 131
};

132 133 134 135 136 137 138 139 140 141 142
/*
 * 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
 *
143
 * The trie would look like:
144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159
 * 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)
160
{
161 162 163 164 165 166 167 168 169
	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;
}
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
/*
 * 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.
		 */
196
		child = xmalloc(sizeof(*child));
197 198 199 200 201 202
		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);
203
		}
204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225
		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;
226 227
		}
	}
228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343

	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;
}

344 345
static void update_common_dir(struct strbuf *buf, int git_dir_len,
			      const char *common_dir)
346 347 348 349
{
	char *base = buf->buf + git_dir_len;
	init_common_trie();
	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
static void adjust_git_path(const struct repository *repo,
			    struct strbuf *buf, int git_dir_len)
377 378
{
	const char *base = buf->buf + git_dir_len;
379
	if (is_dir_file(base, "info", "grafts"))
380
		strbuf_splice(buf, 0, buf->len,
381
			      repo->graft_file, strlen(repo->graft_file));
382
	else if (!strcmp(base, "index"))
383
		strbuf_splice(buf, 0, buf->len,
384
			      repo->index_file, strlen(repo->index_file));
385
	else if (dir_prefix(base, "objects"))
386
		replace_dir(buf, git_dir_len + 7, repo->objects->objectdir);
387 388
	else if (git_hooks_path && dir_prefix(base, "hooks"))
		replace_dir(buf, git_dir_len + 5, git_hooks_path);
389 390
	else if (repo->different_commondir)
		update_common_dir(buf, git_dir_len, repo->commondir);
391 392
}

393 394 395 396 397 398 399 400 401 402 403 404 405 406
static void strbuf_worktree_gitdir(struct strbuf *buf,
				   const struct repository *repo,
				   const struct worktree *wt)
{
	if (!wt)
		strbuf_addstr(buf, repo->gitdir);
	else if (!wt->id)
		strbuf_addstr(buf, repo->commondir);
	else
		strbuf_git_common_path(buf, repo, "worktrees/%s", wt->id);
}

static void do_git_path(const struct repository *repo,
			const struct worktree *wt, struct strbuf *buf,
407
			const char *fmt, va_list args)
408
{
409
	int gitdir_len;
410
	strbuf_worktree_gitdir(buf, repo, wt);
411 412
	if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
		strbuf_addch(buf, '/');
413
	gitdir_len = buf->len;
414
	strbuf_vaddf(buf, fmt, args);
415 416
	if (!wt)
		adjust_git_path(repo, buf, gitdir_len);
417
	strbuf_cleanup_path(buf);
418 419
}

420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440
char *repo_git_path(const struct repository *repo,
		    const char *fmt, ...)
{
	struct strbuf path = STRBUF_INIT;
	va_list args;
	va_start(args, fmt);
	do_git_path(repo, NULL, &path, fmt, args);
	va_end(args);
	return strbuf_detach(&path, NULL);
}

void strbuf_repo_git_path(struct strbuf *sb,
			  const struct repository *repo,
			  const char *fmt, ...)
{
	va_list args;
	va_start(args, fmt);
	do_git_path(repo, NULL, sb, fmt, args);
	va_end(args);
}

Jeff King's avatar
Jeff King committed
441 442 443 444 445
char *git_path_buf(struct strbuf *buf, const char *fmt, ...)
{
	va_list args;
	strbuf_reset(buf);
	va_start(args, fmt);
446
	do_git_path(the_repository, NULL, buf, fmt, args);
Jeff King's avatar
Jeff King committed
447 448 449 450
	va_end(args);
	return buf->buf;
}

451
void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
452 453 454
{
	va_list args;
	va_start(args, fmt);
455
	do_git_path(the_repository, NULL, sb, fmt, args);
456 457 458
	va_end(args);
}

459
const char *git_path(const char *fmt, ...)
460
{
461
	struct strbuf *pathname = get_pathname();
462 463
	va_list args;
	va_start(args, fmt);
464
	do_git_path(the_repository, NULL, pathname, fmt, args);
465
	va_end(args);
466
	return pathname->buf;
467 468 469
}

char *git_pathdup(const char *fmt, ...)
470
{
471
	struct strbuf path = STRBUF_INIT;
472 473
	va_list args;
	va_start(args, fmt);
474
	do_git_path(the_repository, NULL, &path, fmt, args);
475
	va_end(args);
476
	return strbuf_detach(&path, NULL);
477 478 479
}

char *mkpathdup(const char *fmt, ...)
480
{
481
	struct strbuf sb = STRBUF_INIT;
482 483
	va_list args;
	va_start(args, fmt);
484
	strbuf_vaddf(&sb, fmt, args);
485
	va_end(args);
486 487
	strbuf_cleanup_path(&sb);
	return strbuf_detach(&sb, NULL);
488 489
}

490
const char *mkpath(const char *fmt, ...)
491 492
{
	va_list args;
493
	struct strbuf *pathname = get_pathname();
494
	va_start(args, fmt);
495
	strbuf_vaddf(pathname, fmt, args);
496
	va_end(args);
497
	return cleanup_path(pathname->buf);
498
}
499

500 501 502 503 504
const char *worktree_git_path(const struct worktree *wt, const char *fmt, ...)
{
	struct strbuf *pathname = get_pathname();
	va_list args;
	va_start(args, fmt);
505
	do_git_path(the_repository, wt, pathname, fmt, args);
506 507 508 509
	va_end(args);
	return pathname->buf;
}

510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550
static void do_worktree_path(const struct repository *repo,
			     struct strbuf *buf,
			     const char *fmt, va_list args)
{
	strbuf_addstr(buf, repo->worktree);
	if(buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
		strbuf_addch(buf, '/');

	strbuf_vaddf(buf, fmt, args);
	strbuf_cleanup_path(buf);
}

char *repo_worktree_path(const struct repository *repo, const char *fmt, ...)
{
	struct strbuf path = STRBUF_INIT;
	va_list args;

	if (!repo->worktree)
		return NULL;

	va_start(args, fmt);
	do_worktree_path(repo, &path, fmt, args);
	va_end(args);

	return strbuf_detach(&path, NULL);
}

void strbuf_repo_worktree_path(struct strbuf *sb,
			       const struct repository *repo,
			       const char *fmt, ...)
{
	va_list args;

	if (!repo->worktree)
		return;

	va_start(args, fmt);
	do_worktree_path(repo, sb, fmt, args);
	va_end(args);
}

551 552 553
/* Returns 0 on success, negative on failure. */
static int do_submodule_path(struct strbuf *buf, const char *path,
			     const char *fmt, va_list args)
554
{
555 556
	struct strbuf git_submodule_common_dir = STRBUF_INIT;
	struct strbuf git_submodule_dir = STRBUF_INIT;
557
	int ret;
558

559 560 561
	ret = submodule_to_gitdir(&git_submodule_dir, path);
	if (ret)
		goto cleanup;
562

563 564
	strbuf_complete(&git_submodule_dir, '/');
	strbuf_addbuf(buf, &git_submodule_dir);
565
	strbuf_vaddf(buf, fmt, args);
566 567 568 569

	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);

570
	strbuf_cleanup_path(buf);
571

572
cleanup:
573 574
	strbuf_release(&git_submodule_dir);
	strbuf_release(&git_submodule_common_dir);
575
	return ret;
576 577 578 579
}

char *git_pathdup_submodule(const char *path, const char *fmt, ...)
{
580
	int err;
581 582 583
	va_list args;
	struct strbuf buf = STRBUF_INIT;
	va_start(args, fmt);
584
	err = do_submodule_path(&buf, path, fmt, args);
585
	va_end(args);
586 587 588 589
	if (err) {
		strbuf_release(&buf);
		return NULL;
	}
590 591 592
	return strbuf_detach(&buf, NULL);
}

593 594
int strbuf_git_path_submodule(struct strbuf *buf, const char *path,
			      const char *fmt, ...)
595
{
596
	int err;
597 598
	va_list args;
	va_start(args, fmt);
599
	err = do_submodule_path(buf, path, fmt, args);
600
	va_end(args);
601 602

	return err;
603 604
}

605 606
static void do_git_common_path(const struct repository *repo,
			       struct strbuf *buf,
607 608 609
			       const char *fmt,
			       va_list args)
{
610
	strbuf_addstr(buf, repo->commondir);
611 612 613 614 615 616 617 618 619 620 621
	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);
622
	do_git_common_path(the_repository, pathname, fmt, args);
623 624 625 626
	va_end(args);
	return pathname->buf;
}

627 628 629
void strbuf_git_common_path(struct strbuf *sb,
			    const struct repository *repo,
			    const char *fmt, ...)
630 631 632
{
	va_list args;
	va_start(args, fmt);
633
	do_git_common_path(repo, sb, fmt, args);
634 635 636
	va_end(args);
}

637
int validate_headref(const char *path)
638 639
{
	struct stat st;
640 641
	char buffer[256];
	const char *refname;
642
	struct object_id oid;
643 644
	int fd;
	ssize_t len;
645 646 647 648 649 650 651

	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);
652
		if (len >= 5 && !memcmp("refs/", buffer, 5))
653 654 655 656 657 658 659 660 661 662
			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;
663
	len = read_in_full(fd, buffer, sizeof(buffer)-1);
664 665
	close(fd);

666 667 668 669
	if (len < 0)
		return -1;
	buffer[len] = '\0';

670 671 672
	/*
	 * Is it a symbolic ref?
	 */
673 674 675 676
	if (skip_prefix(buffer, "ref:", &refname)) {
		while (isspace(*refname))
			refname++;
		if (starts_with(refname, "refs/"))
677 678 679 680 681 682
			return 0;
	}

	/*
	 * Is this a detached HEAD?
	 */
683
	if (!get_oid_hex(buffer, &oid))
684
		return 0;
685

686 687 688
	return -1;
}

689
static struct passwd *getpw_str(const char *username, size_t len)
690
{
691
	struct passwd *pw;
692
	char *username_z = xmemdupz(username, len);
693 694 695 696
	pw = getpwnam(username_z);
	free(username_z);
	return pw;
}
697

698 699 700 701
/*
 * 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.
702 703
 *
 * If real_home is true, real_path($HOME) is used in the expansion.
704
 */
705
char *expand_user_path(const char *path, int real_home)
706 707 708 709 710 711 712
{
	struct strbuf user_path = STRBUF_INIT;
	const char *to_copy = path;

	if (path == NULL)
		goto return_null;
	if (path[0] == '~') {
713
		const char *first_slash = strchrnul(path, '/');
714 715
		const char *username = path + 1;
		size_t username_len = first_slash - username;
716 717
		if (username_len == 0) {
			const char *home = getenv("HOME");
718 719
			if (!home)
				goto return_null;
720
			if (real_home)
721
				strbuf_add_real_path(&user_path, home);
722 723
			else
				strbuf_addstr(&user_path, home);
724 725 726
#ifdef GIT_WINDOWS_NATIVE
			convert_slashes(user_path.buf);
#endif
727 728 729 730
		} else {
			struct passwd *pw = getpw_str(username, username_len);
			if (!pw)
				goto return_null;
731
			strbuf_addstr(&user_path, pw->pw_dir);
732
		}
733
		to_copy = first_slash;
734
	}
735
	strbuf_addstr(&user_path, to_copy);
736 737 738 739
	return strbuf_detach(&user_path, NULL);
return_null:
	strbuf_release(&user_path);
	return NULL;
740 741
}

742 743 744 745 746 747 748 749 750 751
/*
 * 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.
 *
752 753 754
 * 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.
755 756 757 758 759 760
 *
 * 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.
 */
761
const char *enter_repo(const char *path, int strict)
762
{
763 764
	static struct strbuf validated_path = STRBUF_INIT;
	static struct strbuf used_path = STRBUF_INIT;
765 766

	if (!path)
767 768
		return NULL;

769 770
	if (!strict) {
		static const char *suffix[] = {
771
			"/.git", "", ".git/.git", ".git", NULL,
772
		};
773
		const char *gitfile;
774 775
		int len = strlen(path);
		int i;
776
		while ((1 < len) && (path[len-1] == '/'))
777
			len--;
778

779 780 781 782
		/*
		 * We can handle arbitrary-sized buffers, but this remains as a
		 * sanity check on untrusted input.
		 */
783
		if (PATH_MAX <= len)
784
			return NULL;
785

786 787 788 789 790 791
		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] == '~') {
792
			char *newpath = expand_user_path(used_path.buf, 0);
793
			if (!newpath)
794
				return NULL;
795 796
			strbuf_attach(&used_path, newpath, strlen(newpath),
				      strlen(newpath));
797 798
		}
		for (i = 0; suffix[i]; i++) {
799
			struct stat st;
800 801 802
			size_t baselen = used_path.len;
			strbuf_addstr(&used_path, suffix[i]);
			if (!stat(used_path.buf, &st) &&
803
			    (S_ISREG(st.st_mode) ||
804 805
			    (S_ISDIR(st.st_mode) && is_git_directory(used_path.buf)))) {
				strbuf_addstr(&validated_path, suffix[i]);
806 807
				break;
			}
808
			strbuf_setlen(&used_path, baselen);
809
		}
810 811
		if (!suffix[i])
			return NULL;
812
		gitfile = read_gitfile(used_path.buf);
813 814 815 816 817
		if (gitfile) {
			strbuf_reset(&used_path);
			strbuf_addstr(&used_path, gitfile);
		}
		if (chdir(used_path.buf))
818
			return NULL;
819
		path = validated_path.buf;
820
	}
821 822 823 824 825 826 827
	else {
		const char *gitfile = read_gitfile(path);
		if (gitfile)
			path = gitfile;
		if (chdir(path))
			return NULL;
	}
828

829
	if (is_git_directory(".")) {
René Scharfe's avatar
René Scharfe committed
830
		set_git_dir(".");
831
		check_repository_format();
832
		return path;
833 834 835 836
	}

	return NULL;
}
837

838
static int calc_shared_perm(int mode)
839
{
840
	int tweak;
841

842 843
	if (get_shared_repository() < 0)
		tweak = -get_shared_repository();
844
	else
845
		tweak = get_shared_repository();
846 847 848 849 850 851

	if (!(mode & S_IWUSR))
		tweak &= ~0222;
	if (mode & S_IXUSR)
		/* Copy read bits to execute bits */
		tweak |= (tweak & 0444) >> 2;
852
	if (get_shared_repository() < 0)
853 854
		mode = (mode & ~0777) | tweak;
	else
855
		mode |= tweak;
856

857 858 859 860 861 862 863 864
	return mode;
}


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

865
	if (!get_shared_repository())
866 867 868 869 870 871
		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)) {
872
		/* Copy read bits to execute bits */
873 874
		new_mode |= (new_mode & 0444) >> 2;
		new_mode |= FORCE_DIR_SET_GID;
875 876
	}

877 878
	if (((old_mode ^ new_mode) & ~S_IFMT) &&
			chmod(path, (new_mode & ~S_IFMT)) < 0)
879 880 881
		return -2;
	return 0;
}
882

883 884 885 886 887 888 889 890 891 892 893 894
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);
}

895 896 897 898 899 900 901 902 903 904
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);
}

905 906 907 908 909 910 911 912
/*
 * 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)
913
{
914 915 916 917
	int in_len = in ? strlen(in) : 0;
	int prefix_len = prefix ? strlen(prefix) : 0;
	int in_off = 0;
	int prefix_off = 0;
918 919
	int i = 0, j = 0;

920 921 922 923 924
	if (!in_len)
		return "./";
	else if (!prefix_len)
		return in;

925
	if (have_same_root(in, prefix))
926
		/* bypass dos_drive, for "c:" is identical to "C:" */
927 928
		i = j = has_dos_drive_prefix(in);
	else {
929 930 931
		return in;
	}

932 933 934
	while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
		if (is_dir_sep(prefix[i])) {
			while (is_dir_sep(prefix[i]))
935
				i++;
936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959
			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]))
960
				j++;
961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995
			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++;
996 997 998 999
			continue;
		}
		i++;
	}
1000 1001 1002 1003 1004 1005
	if (!is_dir_sep(prefix[prefix_len - 1]))
		strbuf_addstr(sb, "../");

	strbuf_addstr(sb, in);

	return sb->buf;
1006
}
1007

1008 1009 1010 1011 1012 1013 1014 1015 1016
/*
 * 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)
{
1017
	static struct strbuf buf = STRBUF_INIT;
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
	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++;
1046 1047

	strbuf_reset(&buf);
1048
	if (!in[j])
1049
		strbuf_addstr(&buf, ".");
1050
	else
1051 1052
		strbuf_addstr(&buf, in + j);
	return buf.buf;
1053 1054
}

1055
/*
1056
 * It is okay if dst == src, but they should not overlap otherwise.
1057
 *
1058 1059
 * Performs the following normalizations on src, storing the result in dst:
 * - Ensures that components are separated by '/' (Windows only)
1060
 * - Squashes sequences of '/' except "//server/share" on Windows
1061 1062
 * - Removes "." components.
 * - Removes ".." components, and the components the precede them.
1063 1064
 * Returns failure (non-zero) if a ".." component appears as first path
 * component anytime during the normalization. Otherwise, returns success (0).
1065 1066 1067
 *
 * Note that this function is purely textual.  It does not follow symlinks,
 * verify the existence of the path, or make any system calls.
1068 1069 1070 1071 1072 1073
 *
 * 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.
1074 1075 1076 1077 1078
 *
 * 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.
 *
1079
 */
1080
int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
1081
{
1082
	char *dst0;
1083
	const char *end;
1084

1085 1086 1087 1088 1089 1090 1091 1092 1093 1094
	/*
	 * 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;
	}
1095
	dst0 = dst;
1096

1097 1098
	while (is_dir_sep(*src))
		src++;
1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134

	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;
				}
			}
		}
1135

1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152
		/* 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.
		 */
1153 1154
		dst--;	/* go to trailing '/' */
		if (dst <= dst0)
1155
			return -1;
1156 1157 1158
		/* Windows: dst[-1] cannot be backslash anymore */
		while (dst0 < dst && dst[-1] != '/')
			dst--;
1159 1160
		if (prefix_len && *prefix_len > dst - dst0)
			*prefix_len = dst - dst0;
1161
	}
1162
	*dst = '\0';
1163
	return 0;
1164
}
1165

1166 1167 1168 1169 1170
int normalize_path_copy(char *dst, const char *src)
{
	return normalize_path_copy_len(dst, src, NULL);
}

1171 1172
/*
 * path = Canonical absolute path
1173 1174
 * prefixes = string_list containing normalized, absolute paths without
 * trailing slashes (except for the root directory, which is denoted by "/").
1175
 *
1176
 * Determines, for each path in prefixes, whether the "prefix"
1177 1178
 * is an ancestor directory of path.  Returns the length of the longest
 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
1179 1180
 * is an ancestor.  (Note that this means 0 is returned if prefixes is
 * ["/"].) "/foo" is not considered an ancestor of "/foobar".  Directories
1181 1182
 * are not considered to be their own ancestors.  path must be in a
 * canonical form: empty components, or "." or ".." components are not
1183
 * allowed.
1184
 */
1185
int longest_ancestor_length(const char *path, struct string_list *prefixes)
1186
{
1187
	int i, max_len = -1;
1188

1189
	if (!strcmp(path, "/"))
1190 1191
		return -1;

1192 1193
	for (i = 0; i < prefixes->nr; i++) {
		const char *ceil = prefixes->items[i].string;
1194 1195
		int len = strlen(ceil);

1196 1197 1198 1199 1200 1201
		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 */
1202

1203
		if (len > max_len)
1204 1205 1206 1207 1208
			max_len = len;
	}

	return max_len;
}
1209 1210 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 1244

/* 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));
}
1245 1246 1247 1248 1249 1250 1251 1252

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

	/*
	 * This resurrects the belts and suspenders paranoia check by HPA
	 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
1253
	 * does not do getcwd() based path canonicalization.
1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291
	 *
	 * 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;
		}
	}
}
1292

1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308
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)
{
1309
	size_t len;
1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324

	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;
		}
}
1325

1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409
static int is_ntfs_dot_generic(const char *name,
			       const char *dotgit_name,
			       size_t len,
			       const char *dotgit_ntfs_shortname_prefix)
{
	int saw_tilde;
	size_t i;

	if ((name[0] == '.' && !strncasecmp(name + 1, dotgit_name, len))) {
		i = len + 1;
only_spaces_and_periods:
		for (;;) {
			char c = name[i++];
			if (!c)
				return 1;
			if (c != ' ' && c != '.')
				return 0;
		}
	}

	/*
	 * Is it a regular NTFS short name, i.e. shortened to 6 characters,
	 * followed by ~1, ... ~4?
	 */
	if (!strncasecmp(name, dotgit_name, 6) && name[6] == '~' &&
	    name[7] >= '1' && name[7] <= '4') {
		i = 8;
		goto only_spaces_and_periods;
	}

	/*
	 * Is it a fall-back NTFS short name (for details, see
	 * https://en.wikipedia.org/wiki/8.3_filename?
	 */
	for (i = 0, saw_tilde = 0; i < 8; i++)
		if (name[i] == '\0')
			return 0;
		else if (saw_tilde) {
			if (name[i] < '0' || name[i] > '9')
				return 0;
		} else if (name[i] == '~') {
			if (name[++i] < '1' || name[i] > '9')
				return 0;
			saw_tilde</