path.c 32.2 KB
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/*
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 * Utilities for paths and pathnames
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 */
#include "cache.h"
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#include "repository.h"
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#include "strbuf.h"
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#include "string-list.h"
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#include "dir.h"
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#include "worktree.h"
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#include "submodule-config.h"
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#include "path.h"
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#include "packfile.h"
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static int get_st_mode_bits(const char *path, int *mode)
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{
	struct stat st;
	if (lstat(path, &st) < 0)
		return -1;
	*mode = st.st_mode;
	return 0;
}

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

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static struct strbuf *get_pathname(void)
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{
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	static struct strbuf pathname_array[4] = {
		STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
	};
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	static int index;
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	struct strbuf *sb = &pathname_array[index];
	index = (index + 1) % ARRAY_SIZE(pathname_array);
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	strbuf_reset(sb);
	return sb;
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}

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static char *cleanup_path(char *path)
{
	/* Clean it up */
	if (!memcmp(path, "./", 2)) {
		path += 2;
		while (*path == '/')
			path++;
	}
	return path;
}

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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);
}

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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) {
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		strlcpy(buf, bad_path, n);
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		return buf;
	}
	return cleanup_path(buf);
}

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static int dir_prefix(const char *buf, const char *dir)
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{
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	int len = strlen(dir);
	return !strncmp(buf, dir, len) &&
		(is_dir_sep(buf[len]) || buf[len] == '\0');
}
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/* $buf =~ m|$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] = '/';
}

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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" },
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	{ 0, 1, 1, "logs/refs/bisect" },
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	{ 0, 1, 0, "lost-found" },
	{ 0, 1, 0, "objects" },
	{ 0, 1, 0, "refs" },
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	{ 0, 1, 1, "refs/bisect" },
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	{ 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 }
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};

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/*
 * 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
 *
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 * The trie would look like:
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 * 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)
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{
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	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;
}
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/*
 * 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);
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		}
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		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;
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		}
	}
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	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;
}

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static void update_common_dir(struct strbuf *buf, int git_dir_len,
			      const char *common_dir)
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{
	char *base = buf->buf + git_dir_len;
	init_common_trie();
	if (trie_find(&common_trie, base, check_common, NULL) > 0)
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		replace_dir(buf, git_dir_len, common_dir);
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}

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void report_linked_checkout_garbage(void)
{
	struct strbuf sb = STRBUF_INIT;
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	const struct common_dir *p;
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	int len;

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	if (!the_repository->different_commondir)
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		return;
	strbuf_addf(&sb, "%s/", get_git_dir());
	len = sb.len;
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	for (p = common_list; p->dirname; p++) {
		const char *path = p->dirname;
		if (p->ignore_garbage)
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			continue;
		strbuf_setlen(&sb, len);
		strbuf_addstr(&sb, path);
		if (file_exists(sb.buf))
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			report_garbage(PACKDIR_FILE_GARBAGE, sb.buf);
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	}
	strbuf_release(&sb);
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}

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static void adjust_git_path(const struct repository *repo,
			    struct strbuf *buf, int git_dir_len)
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{
	const char *base = buf->buf + git_dir_len;
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	if (is_dir_file(base, "info", "grafts"))
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		strbuf_splice(buf, 0, buf->len,
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			      repo->graft_file, strlen(repo->graft_file));
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	else if (!strcmp(base, "index"))
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		strbuf_splice(buf, 0, buf->len,
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			      repo->index_file, strlen(repo->index_file));
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	else if (dir_prefix(base, "objects"))
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		replace_dir(buf, git_dir_len + 7, repo->objectdir);
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	else if (git_hooks_path && dir_prefix(base, "hooks"))
		replace_dir(buf, git_dir_len + 5, git_hooks_path);
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	else if (repo->different_commondir)
		update_common_dir(buf, git_dir_len, repo->commondir);
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}

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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,
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			const char *fmt, va_list args)
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{
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	int gitdir_len;
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	strbuf_worktree_gitdir(buf, repo, wt);
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	if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
		strbuf_addch(buf, '/');
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	gitdir_len = buf->len;
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	strbuf_vaddf(buf, fmt, args);
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	if (!wt)
		adjust_git_path(repo, buf, gitdir_len);
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	strbuf_cleanup_path(buf);
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}

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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);
}

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char *git_path_buf(struct strbuf *buf, const char *fmt, ...)
{
	va_list args;
	strbuf_reset(buf);
	va_start(args, fmt);
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	do_git_path(the_repository, NULL, buf, fmt, args);
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	va_end(args);
	return buf->buf;
}

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

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

char *git_pathdup(const char *fmt, ...)
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{
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	struct strbuf path = STRBUF_INIT;
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	va_list args;
	va_start(args, fmt);
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	do_git_path(the_repository, NULL, &path, fmt, args);
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	va_end(args);
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	return strbuf_detach(&path, NULL);
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}

char *mkpathdup(const char *fmt, ...)
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{
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	struct strbuf sb = STRBUF_INIT;
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	va_list args;
	va_start(args, fmt);
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	strbuf_vaddf(&sb, fmt, args);
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	va_end(args);
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	strbuf_cleanup_path(&sb);
	return strbuf_detach(&sb, NULL);
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}

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const char *mkpath(const char *fmt, ...)
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{
	va_list args;
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	struct strbuf *pathname = get_pathname();
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	va_start(args, fmt);
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	strbuf_vaddf(pathname, fmt, args);
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	va_end(args);
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	return cleanup_path(pathname->buf);
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}
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const char *worktree_git_path(const struct worktree *wt, const char *fmt, ...)
{
	struct strbuf *pathname = get_pathname();
	va_list args;
	va_start(args, fmt);
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	do_git_path(the_repository, wt, pathname, fmt, args);
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	va_end(args);
	return pathname->buf;
}

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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);
}

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/* Returns 0 on success, negative on failure. */
static int do_submodule_path(struct strbuf *buf, const char *path,
			     const char *fmt, va_list args)
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{
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	struct strbuf git_submodule_common_dir = STRBUF_INIT;
	struct strbuf git_submodule_dir = STRBUF_INIT;
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	int ret;
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	ret = submodule_to_gitdir(&git_submodule_dir, path);
	if (ret)
		goto cleanup;
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	strbuf_complete(&git_submodule_dir, '/');
	strbuf_addbuf(buf, &git_submodule_dir);
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	strbuf_vaddf(buf, fmt, args);
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	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);

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	strbuf_cleanup_path(buf);
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cleanup:
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	strbuf_release(&git_submodule_dir);
	strbuf_release(&git_submodule_common_dir);
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	return ret;
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}

char *git_pathdup_submodule(const char *path, const char *fmt, ...)
{
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	int err;
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	va_list args;
	struct strbuf buf = STRBUF_INIT;
	va_start(args, fmt);
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	err = do_submodule_path(&buf, path, fmt, args);
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	va_end(args);
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	if (err) {
		strbuf_release(&buf);
		return NULL;
	}
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	return strbuf_detach(&buf, NULL);
}

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int strbuf_git_path_submodule(struct strbuf *buf, const char *path,
			      const char *fmt, ...)
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{
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	int err;
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	va_list args;
	va_start(args, fmt);
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	err = do_submodule_path(buf, path, fmt, args);
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	va_end(args);
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	return err;
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}

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static void do_git_common_path(const struct repository *repo,
			       struct strbuf *buf,
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			       const char *fmt,
			       va_list args)
{
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	strbuf_addstr(buf, repo->commondir);
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	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);
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	do_git_common_path(the_repository, pathname, fmt, args);
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	va_end(args);
	return pathname->buf;
}

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

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int validate_headref(const char *path)
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{
	struct stat st;
	char *buf, buffer[256];
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	unsigned char sha1[20];
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	int fd;
	ssize_t len;
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	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);
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		if (len >= 5 && !memcmp("refs/", buffer, 5))
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			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;
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	len = read_in_full(fd, buffer, sizeof(buffer)-1);
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	close(fd);

	/*
	 * Is it a symbolic ref?
	 */
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	if (len < 4)
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		return -1;
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	if (!memcmp("ref:", buffer, 4)) {
		buf = buffer + 4;
		len -= 4;
		while (len && isspace(*buf))
			buf++, len--;
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		if (len >= 5 && !memcmp("refs/", buf, 5))
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			return 0;
	}

	/*
	 * Is this a detached HEAD?
	 */
	if (!get_sha1_hex(buffer, sha1))
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		return 0;
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685 686 687
	return -1;
}

688
static struct passwd *getpw_str(const char *username, size_t len)
689
{
690
	struct passwd *pw;
691
	char *username_z = xmemdupz(username, len);
692 693 694 695
	pw = getpwnam(username_z);
	free(username_z);
	return pw;
}
696

697 698 699 700
/*
 * 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.
701 702
 *
 * If real_home is true, real_path($HOME) is used in the expansion.
703
 */
704
char *expand_user_path(const char *path, int real_home)
705 706 707 708 709 710 711
{
	struct strbuf user_path = STRBUF_INIT;
	const char *to_copy = path;

	if (path == NULL)
		goto return_null;
	if (path[0] == '~') {
712
		const char *first_slash = strchrnul(path, '/');
713 714
		const char *username = path + 1;
		size_t username_len = first_slash - username;
715 716
		if (username_len == 0) {
			const char *home = getenv("HOME");
717 718
			if (!home)
				goto return_null;
719 720 721 722
			if (real_home)
				strbuf_addstr(&user_path, real_path(home));
			else
				strbuf_addstr(&user_path, home);
723 724 725
#ifdef GIT_WINDOWS_NATIVE
			convert_slashes(user_path.buf);
#endif
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		} else {
			struct passwd *pw = getpw_str(username, username_len);
			if (!pw)
				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);
735 736 737 738
	return strbuf_detach(&user_path, NULL);
return_null:
	strbuf_release(&user_path);
	return NULL;
739 740
}

741 742 743 744 745 746 747 748 749 750
/*
 * 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.
 *
751 752 753
 * 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.
754 755 756 757 758 759
 *
 * 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.
 */
760
const char *enter_repo(const char *path, int strict)
761
{
762 763
	static struct strbuf validated_path = STRBUF_INIT;
	static struct strbuf used_path = STRBUF_INIT;
764 765

	if (!path)
766 767
		return NULL;

768 769
	if (!strict) {
		static const char *suffix[] = {
770
			"/.git", "", ".git/.git", ".git", NULL,
771
		};
772
		const char *gitfile;
773 774
		int len = strlen(path);
		int i;
775
		while ((1 < len) && (path[len-1] == '/'))
776
			len--;
777

778 779 780 781
		/*
		 * We can handle arbitrary-sized buffers, but this remains as a
		 * sanity check on untrusted input.
		 */
782
		if (PATH_MAX <= len)
783
			return NULL;
784

785 786 787 788 789 790
		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] == '~') {
791
			char *newpath = expand_user_path(used_path.buf, 0);
792
			if (!newpath)
793
				return NULL;
794 795
			strbuf_attach(&used_path, newpath, strlen(newpath),
				      strlen(newpath));
796 797
		}
		for (i = 0; suffix[i]; i++) {
798
			struct stat st;
799 800 801
			size_t baselen = used_path.len;
			strbuf_addstr(&used_path, suffix[i]);
			if (!stat(used_path.buf, &st) &&
802
			    (S_ISREG(st.st_mode) ||
803 804
			    (S_ISDIR(st.st_mode) && is_git_directory(used_path.buf)))) {
				strbuf_addstr(&validated_path, suffix[i]);
805 806
				break;
			}
807
			strbuf_setlen(&used_path, baselen);
808
		}
809 810
		if (!suffix[i])
			return NULL;
811
		gitfile = read_gitfile(used_path.buf);
812 813 814 815 816
		if (gitfile) {
			strbuf_reset(&used_path);
			strbuf_addstr(&used_path, gitfile);
		}
		if (chdir(used_path.buf))
817
			return NULL;
818
		path = validated_path.buf;
819
	}
820 821 822 823 824 825 826
	else {
		const char *gitfile = read_gitfile(path);
		if (gitfile)
			path = gitfile;
		if (chdir(path))
			return NULL;
	}
827

828
	if (is_git_directory(".")) {
René Scharfe's avatar
René Scharfe committed
829
		set_git_dir(".");
830
		check_repository_format();
831
		return path;
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	}

	return NULL;
}
836

837
static int calc_shared_perm(int mode)
838
{
839
	int tweak;
840

841 842
	if (get_shared_repository() < 0)
		tweak = -get_shared_repository();
843
	else
844
		tweak = get_shared_repository();
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	if (!(mode & S_IWUSR))
		tweak &= ~0222;
	if (mode & S_IXUSR)
		/* Copy read bits to execute bits */
		tweak |= (tweak & 0444) >> 2;
851
	if (get_shared_repository() < 0)
852 853
		mode = (mode & ~0777) | tweak;
	else
854
		mode |= tweak;
855

856 857 858 859 860 861 862 863
	return mode;
}


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

864
	if (!get_shared_repository())
865 866 867 868 869 870
		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)) {
871
		/* Copy read bits to execute bits */
872 873
		new_mode |= (new_mode & 0444) >> 2;
		new_mode |= FORCE_DIR_SET_GID;
874 875
	}

876 877
	if (((old_mode ^ new_mode) & ~S_IFMT) &&
			chmod(path, (new_mode & ~S_IFMT)) < 0)
878 879 880
		return -2;
	return 0;
}
881

882 883 884 885 886 887 888 889 890 891 892 893
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);
}

894 895 896 897 898 899 900 901 902 903
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);
}

904 905 906 907 908 909 910 911
/*
 * 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)
912
{
913 914 915 916
	int in_len = in ? strlen(in) : 0;
	int prefix_len = prefix ? strlen(prefix) : 0;
	int in_off = 0;
	int prefix_off = 0;
917 918
	int i = 0, j = 0;

919 920 921 922 923
	if (!in_len)
		return "./";
	else if (!prefix_len)
		return in;

924
	if (have_same_root(in, prefix))
925
		/* bypass dos_drive, for "c:" is identical to "C:" */
926 927
		i = j = has_dos_drive_prefix(in);
	else {
928 929 930
		return in;
	}

931 932 933
	while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
		if (is_dir_sep(prefix[i])) {
			while (is_dir_sep(prefix[i]))
934
				i++;
935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958
			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]))
959
				j++;
960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994
			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++;
995 996 997 998
			continue;
		}
		i++;
	}
999 1000 1001 1002 1003 1004
	if (!is_dir_sep(prefix[prefix_len - 1]))
		strbuf_addstr(sb, "../");

	strbuf_addstr(sb, in);

	return sb->buf;
1005
}
1006

1007 1008 1009 1010 1011 1012 1013 1014 1015
/*
 * 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)
{
1016
	static struct strbuf buf = STRBUF_INIT;
1017 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
	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++;
1045 1046

	strbuf_reset(&buf);
1047
	if (!in[j])
1048
		strbuf_addstr(&buf, ".");
1049
	else
1050 1051
		strbuf_addstr(&buf, in + j);
	return buf.buf;
1052 1053
}

1054
/*
1055
 * It is okay if dst == src, but they should not overlap otherwise.
1056
 *
1057 1058
 * Performs the following normalizations on src, storing the result in dst:
 * - Ensures that components are separated by '/' (Windows only)
1059
 * - Squashes sequences of '/' except "//server/share" on Windows
1060 1061
 * - Removes "." components.
 * - Removes ".." components, and the components the precede them.
1062 1063
 * Returns failure (non-zero) if a ".." component appears as first path
 * component anytime during the normalization. Otherwise, returns success (0).
1064 1065 1066
 *
 * Note that this function is purely textual.  It does not follow symlinks,
 * verify the existence of the path, or make any system calls.
1067 1068 1069 1070 1071 1072
 *
 * 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.
1073 1074 1075 1076 1077
 *
 * 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.
 *
1078
 */
1079
int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
1080
{
1081
	char *dst0;
1082
	const char *end;
1083

1084 1085 1086 1087 1088 1089 1090 1091 1092 1093
	/*
	 * 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;
	}
1094
	dst0 = dst;
1095

1096 1097
	while (is_dir_sep(*src))
		src++;
1098 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

	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;
				}
			}
		}
1134

1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151
		/* 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.
		 */
1152 1153
		dst--;	/* go to trailing '/' */
		if (dst <= dst0)
1154
			return -1;
1155 1156 1157
		/* Windows: dst[-1] cannot be backslash anymore */
		while (dst0 < dst && dst[-1] != '/')
			dst--;
1158 1159
		if (prefix_len && *prefix_len > dst - dst0)
			*prefix_len = dst - dst0;
1160
	}
1161
	*dst = '\0';
1162
	return 0;
1163
}
1164

1165 1166 1167 1168 1169
int normalize_path_copy(char *dst, const char *src)
{
	return normalize_path_copy_len(dst, src, NULL);
}

1170 1171
/*
 * path = Canonical absolute path
1172 1173
 * prefixes = string_list containing normalized, absolute paths without
 * trailing slashes (except for the root directory, which is denoted by "/").
1174
 *
1175
 * Determines, for each path in prefixes, whether the "prefix"
1176 1177
 * is an ancestor directory of path.  Returns the length of the longest
 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
1178 1179
 * is an ancestor.  (Note that this means 0 is returned if prefixes is
 * ["/"].) "/foo" is not considered an ancestor of "/foobar".  Directories
1180 1181
 * are not considered to be their own ancestors.  path must be in a
 * canonical form: empty components, or "." or ".." components are not
1182
 * allowed.
1183
 */
1184
int longest_ancestor_length(const char *path, struct string_list *prefixes)
1185
{
1186
	int i, max_len = -1;
1187

1188
	if (!strcmp(path, "/"))
1189 1190
		return -1;

1191 1192
	for (i = 0; i < prefixes->nr; i++) {
		const char *ceil = prefixes->items[i].string;
1193 1194
		int len = strlen(ceil);

1195 1196 1197 1198 1199 1200
		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 */
1201

1202
		if (len > max_len)
1203 1204 1205 1206 1207
			max_len = len;
	}

	return max_len;
}
1208 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

/* 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));
}
1244 1245 1246 1247 1248 1249 1250 1251

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()
1252
	 * does not do getcwd() based path canonicalization.
1253 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
	 *
	 * 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;
		}
	}
}
1291

1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323
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;
		}
}
1324

1325 1326 1327 1328 1329
int looks_like_command_line_option(const char *str)
{
	return str && str[0] == '-';
}

1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343
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;
}
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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;
}

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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")