path.c 30.2 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 "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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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();
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	if (!common_dir)
		common_dir = get_git_common_dir();
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	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;

	if (!git_common_dir_env)
		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(struct strbuf *buf, int git_dir_len)
{
	const char *base = buf->buf + git_dir_len;
	if (git_graft_env && is_dir_file(base, "info", "grafts"))
		strbuf_splice(buf, 0, buf->len,
			      get_graft_file(), strlen(get_graft_file()));
	else if (git_index_env && !strcmp(base, "index"))
		strbuf_splice(buf, 0, buf->len,
			      get_index_file(), strlen(get_index_file()));
	else if (git_db_env && dir_prefix(base, "objects"))
		replace_dir(buf, git_dir_len + 7, get_object_directory());
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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 (git_common_dir_env)
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		update_common_dir(buf, git_dir_len, NULL);
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}

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static void do_git_path(const struct worktree *wt, struct strbuf *buf,
			const char *fmt, va_list args)
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{
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	int gitdir_len;
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	strbuf_addstr(buf, get_worktree_git_dir(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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	adjust_git_path(buf, gitdir_len);
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	strbuf_cleanup_path(buf);
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}

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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(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(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(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(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);
	do_git_path(wt, pathname, fmt, args);
	va_end(args);
	return pathname->buf;
}

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/* Returns 0 on success, negative on failure. */
#define SUBMODULE_PATH_ERR_NOT_CONFIGURED -1
static int do_submodule_path(struct strbuf *buf, const char *path,
			     const char *fmt, va_list args)
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{
	const char *git_dir;
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	struct strbuf git_submodule_common_dir = STRBUF_INIT;
	struct strbuf git_submodule_dir = STRBUF_INIT;
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	const struct submodule *sub;
	int err = 0;
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	strbuf_addstr(buf, path);
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	strbuf_complete(buf, '/');
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	strbuf_addstr(buf, ".git");
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	git_dir = read_gitfile(buf->buf);
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	if (git_dir) {
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		strbuf_reset(buf);
		strbuf_addstr(buf, git_dir);
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	}
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	if (!is_git_directory(buf->buf)) {
		gitmodules_config();
		sub = submodule_from_path(null_sha1, path);
		if (!sub) {
			err = SUBMODULE_PATH_ERR_NOT_CONFIGURED;
			goto cleanup;
		}
		strbuf_reset(buf);
		strbuf_git_path(buf, "%s/%s", "modules", sub->name);
	}

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	strbuf_addch(buf, '/');
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	strbuf_addbuf(&git_submodule_dir, buf);
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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 err;
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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(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);
}

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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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	return -1;
}

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static struct passwd *getpw_str(const char *username, size_t len)
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{
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	struct passwd *pw;
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	char *username_z = xmemdupz(username, len);
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	pw = getpwnam(username_z);
	free(username_z);
	return pw;
}
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/*
 * 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.
 */
char *expand_user_path(const char *path)
{
	struct strbuf user_path = STRBUF_INIT;
	const char *to_copy = path;

	if (path == NULL)
		goto return_null;
	if (path[0] == '~') {
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		const char *first_slash = strchrnul(path, '/');
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		const char *username = path + 1;
		size_t username_len = first_slash - username;
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		if (username_len == 0) {
			const char *home = getenv("HOME");
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			if (!home)
				goto return_null;
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			strbuf_addstr(&user_path, home);
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#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;
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			strbuf_addstr(&user_path, pw->pw_dir);
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		}
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		to_copy = first_slash;
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	}
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	strbuf_addstr(&user_path, to_copy);
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	return strbuf_detach(&user_path, NULL);
return_null:
	strbuf_release(&user_path);
	return NULL;
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}

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/*
 * 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.
 *
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 * 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.
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 *
 * 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.
 */
695
const char *enter_repo(const char *path, int strict)
696
{
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	static struct strbuf validated_path = STRBUF_INIT;
	static struct strbuf used_path = STRBUF_INIT;
699 700

	if (!path)
701 702
		return NULL;

703 704
	if (!strict) {
		static const char *suffix[] = {
705
			"/.git", "", ".git/.git", ".git", NULL,
706
		};
707
		const char *gitfile;
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		int len = strlen(path);
		int i;
710
		while ((1 < len) && (path[len-1] == '/'))
711
			len--;
712

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		/*
		 * We can handle arbitrary-sized buffers, but this remains as a
		 * sanity check on untrusted input.
		 */
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		if (PATH_MAX <= len)
718
			return NULL;
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		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] == '~') {
			char *newpath = expand_user_path(used_path.buf);
			if (!newpath)
728
				return NULL;
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			strbuf_attach(&used_path, newpath, strlen(newpath),
				      strlen(newpath));
731 732
		}
		for (i = 0; suffix[i]; i++) {
733
			struct stat st;
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			size_t baselen = used_path.len;
			strbuf_addstr(&used_path, suffix[i]);
			if (!stat(used_path.buf, &st) &&
737
			    (S_ISREG(st.st_mode) ||
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			    (S_ISDIR(st.st_mode) && is_git_directory(used_path.buf)))) {
				strbuf_addstr(&validated_path, suffix[i]);
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				break;
			}
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			strbuf_setlen(&used_path, baselen);
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		}
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		if (!suffix[i])
			return NULL;
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		gitfile = read_gitfile(used_path.buf);
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		if (gitfile) {
			strbuf_reset(&used_path);
			strbuf_addstr(&used_path, gitfile);
		}
		if (chdir(used_path.buf))
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			return NULL;
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		path = validated_path.buf;
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	}
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	else {
		const char *gitfile = read_gitfile(path);
		if (gitfile)
			path = gitfile;
		if (chdir(path))
			return NULL;
	}
762

763
	if (is_git_directory(".")) {
René Scharfe's avatar
René Scharfe committed
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		set_git_dir(".");
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		check_repository_format();
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		return path;
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	}

	return NULL;
}
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static int calc_shared_perm(int mode)
773
{
774
	int tweak;
775

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	if (get_shared_repository() < 0)
		tweak = -get_shared_repository();
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	else
779
		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;
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	if (get_shared_repository() < 0)
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		mode = (mode & ~0777) | tweak;
	else
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		mode |= tweak;
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	return mode;
}


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

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	if (!get_shared_repository())
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		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)) {
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		/* Copy read bits to execute bits */
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		new_mode |= (new_mode & 0444) >> 2;
		new_mode |= FORCE_DIR_SET_GID;
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	}

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	if (((old_mode ^ new_mode) & ~S_IFMT) &&
			chmod(path, (new_mode & ~S_IFMT)) < 0)
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		return -2;
	return 0;
}
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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);
}

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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);
}

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/*
 * 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)
847
{
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	int in_len = in ? strlen(in) : 0;
	int prefix_len = prefix ? strlen(prefix) : 0;
	int in_off = 0;
	int prefix_off = 0;
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	int i = 0, j = 0;

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	if (!in_len)
		return "./";
	else if (!prefix_len)
		return in;

859
	if (have_same_root(in, prefix))
860
		/* bypass dos_drive, for "c:" is identical to "C:" */
861 862
		i = j = has_dos_drive_prefix(in);
	else {
863 864 865
		return in;
	}

866 867 868
	while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
		if (is_dir_sep(prefix[i])) {
			while (is_dir_sep(prefix[i]))
869
				i++;
870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893
			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]))
894
				j++;
895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929
			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++;
930 931 932 933
			continue;
		}
		i++;
	}
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	if (!is_dir_sep(prefix[prefix_len - 1]))
		strbuf_addstr(sb, "../");

	strbuf_addstr(sb, in);

	return sb->buf;
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}
941

942 943 944 945 946 947 948 949 950
/*
 * 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)
{
951
	static struct strbuf buf = STRBUF_INIT;
952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979
	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++;
980 981

	strbuf_reset(&buf);
982
	if (!in[j])
983
		strbuf_addstr(&buf, ".");
984
	else
985 986
		strbuf_addstr(&buf, in + j);
	return buf.buf;
987 988
}

989
/*
990
 * It is okay if dst == src, but they should not overlap otherwise.
991
 *
992 993
 * Performs the following normalizations on src, storing the result in dst:
 * - Ensures that components are separated by '/' (Windows only)
994
 * - Squashes sequences of '/' except "//server/share" on Windows
995 996
 * - Removes "." components.
 * - Removes ".." components, and the components the precede them.
997 998
 * Returns failure (non-zero) if a ".." component appears as first path
 * component anytime during the normalization. Otherwise, returns success (0).
999 1000 1001
 *
 * Note that this function is purely textual.  It does not follow symlinks,
 * verify the existence of the path, or make any system calls.
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 *
 * 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.
1008 1009 1010 1011 1012
 *
 * 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.
 *
1013
 */
1014
int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
1015
{
1016
	char *dst0;
1017
	const char *end;
1018

1019 1020 1021 1022 1023 1024 1025 1026 1027 1028
	/*
	 * 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;
	}
1029
	dst0 = dst;
1030

1031 1032
	while (is_dir_sep(*src))
		src++;
1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068

	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;
				}
			}
		}
1069

1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086
		/* 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.
		 */
1087 1088
		dst--;	/* go to trailing '/' */
		if (dst <= dst0)
1089
			return -1;
1090 1091 1092
		/* Windows: dst[-1] cannot be backslash anymore */
		while (dst0 < dst && dst[-1] != '/')
			dst--;
1093 1094
		if (prefix_len && *prefix_len > dst - dst0)
			*prefix_len = dst - dst0;
1095
	}
1096
	*dst = '\0';
1097
	return 0;
1098
}
1099

1100 1101 1102 1103 1104
int normalize_path_copy(char *dst, const char *src)
{
	return normalize_path_copy_len(dst, src, NULL);
}

1105 1106
/*
 * path = Canonical absolute path
1107 1108
 * prefixes = string_list containing normalized, absolute paths without
 * trailing slashes (except for the root directory, which is denoted by "/").
1109
 *
1110
 * Determines, for each path in prefixes, whether the "prefix"
1111 1112
 * is an ancestor directory of path.  Returns the length of the longest
 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
1113 1114
 * is an ancestor.  (Note that this means 0 is returned if prefixes is
 * ["/"].) "/foo" is not considered an ancestor of "/foobar".  Directories
1115 1116
 * are not considered to be their own ancestors.  path must be in a
 * canonical form: empty components, or "." or ".." components are not
1117
 * allowed.
1118
 */
1119
int longest_ancestor_length(const char *path, struct string_list *prefixes)
1120
{
1121
	int i, max_len = -1;
1122

1123
	if (!strcmp(path, "/"))
1124 1125
		return -1;

1126 1127
	for (i = 0; i < prefixes->nr; i++) {
		const char *ceil = prefixes->items[i].string;
1128 1129
		int len = strlen(ceil);

1130 1131 1132 1133 1134 1135
		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 */
1136

1137
		if (len > max_len)
1138 1139 1140 1141 1142
			max_len = len;
	}

	return max_len;
}
1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178

/* 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));
}
1179 1180 1181 1182 1183 1184 1185 1186

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()
1187
	 * does not do getcwd() based path canonicalization.
1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225
	 *
	 * 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;
		}
	}
}
1226

1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258
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;
		}
}
1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273

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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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")