path.c 34.3 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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#include "object-store.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 const char *cleanup_path(const char *path)
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{
	/* Clean it up */
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	if (skip_prefix(path, "./", &path)) {
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		while (*path == '/')
			path++;
	}
	return path;
}

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static void strbuf_cleanup_path(struct strbuf *sb)
{
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	const char *path = cleanup_path(sb->buf);
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	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;
	}
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	return (char *)cleanup_path(buf);
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}

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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" },
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	{ 0, 1, 0, "common" },
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	{ 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, 1, "logs/refs/rewritten" },
	{ 0, 1, 1, "logs/refs/worktree" },
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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, 1, "refs/rewritten" },
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	{ 0, 1, 1, "refs/worktree" },
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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.
		 */
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		child = xmalloc(sizeof(*child));
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		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->objects->odb->path);
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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;
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	char buffer[256];
	const char *refname;
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	struct object_id oid;
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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);

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

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	/*
	 * Is it a symbolic ref?
	 */
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	if (skip_prefix(buffer, "ref:", &refname)) {
		while (isspace(*refname))
			refname++;
		if (starts_with(refname, "refs/"))
682 683 684 685 686 687
			return 0;
	}

	/*
	 * Is this a detached HEAD?
	 */
688
	if (!get_oid_hex(buffer, &oid))
689
		return 0;
690

691 692 693
	return -1;
}

694
static struct passwd *getpw_str(const char *username, size_t len)
695
{
696
	struct passwd *pw;
697
	char *username_z = xmemdupz(username, len);
698 699 700 701
	pw = getpwnam(username_z);
	free(username_z);
	return pw;
}
702

703 704 705 706
/*
 * 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.
707 708
 *
 * If real_home is true, real_path($HOME) is used in the expansion.
709
 */
710
char *expand_user_path(const char *path, int real_home)
711 712 713 714 715 716 717
{
	struct strbuf user_path = STRBUF_INIT;
	const char *to_copy = path;

	if (path == NULL)
		goto return_null;
	if (path[0] == '~') {
718
		const char *first_slash = strchrnul(path, '/');
719 720
		const char *username = path + 1;
		size_t username_len = first_slash - username;
721 722
		if (username_len == 0) {
			const char *home = getenv("HOME");
723 724
			if (!home)
				goto return_null;
725
			if (real_home)
726
				strbuf_add_real_path(&user_path, home);
727 728
			else
				strbuf_addstr(&user_path, home);
729 730 731
#ifdef GIT_WINDOWS_NATIVE
			convert_slashes(user_path.buf);
#endif
732 733 734 735
		} else {
			struct passwd *pw = getpw_str(username, username_len);
			if (!pw)
				goto return_null;
736
			strbuf_addstr(&user_path, pw->pw_dir);
737
		}
738
		to_copy = first_slash;
739
	}
740
	strbuf_addstr(&user_path, to_copy);
741 742 743 744
	return strbuf_detach(&user_path, NULL);
return_null:
	strbuf_release(&user_path);
	return NULL;
745 746
}

747 748 749 750 751 752 753 754 755 756
/*
 * 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.
 *
757 758 759
 * 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.
760 761 762 763 764 765
 *
 * 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.
 */
766
const char *enter_repo(const char *path, int strict)
767
{
768 769
	static struct strbuf validated_path = STRBUF_INIT;
	static struct strbuf used_path = STRBUF_INIT;
770 771

	if (!path)
772 773
		return NULL;

774 775
	if (!strict) {
		static const char *suffix[] = {
776
			"/.git", "", ".git/.git", ".git", NULL,
777
		};
778
		const char *gitfile;
779 780
		int len = strlen(path);
		int i;
781
		while ((1 < len) && (path[len-1] == '/'))
782
			len--;
783

784 785 786 787
		/*
		 * We can handle arbitrary-sized buffers, but this remains as a
		 * sanity check on untrusted input.
		 */
788
		if (PATH_MAX <= len)
789
			return NULL;
790

791 792 793 794 795 796
		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] == '~') {
797
			char *newpath = expand_user_path(used_path.buf, 0);
798
			if (!newpath)
799
				return NULL;
800 801
			strbuf_attach(&used_path, newpath, strlen(newpath),
				      strlen(newpath));
802 803
		}
		for (i = 0; suffix[i]; i++) {
804
			struct stat st;
805 806 807
			size_t baselen = used_path.len;
			strbuf_addstr(&used_path, suffix[i]);
			if (!stat(used_path.buf, &st) &&
808
			    (S_ISREG(st.st_mode) ||
809 810
			    (S_ISDIR(st.st_mode) && is_git_directory(used_path.buf)))) {
				strbuf_addstr(&validated_path, suffix[i]);
811 812
				break;
			}
813
			strbuf_setlen(&used_path, baselen);
814
		}
815 816
		if (!suffix[i])
			return NULL;
817
		gitfile = read_gitfile(used_path.buf);
818 819 820 821 822
		if (gitfile) {
			strbuf_reset(&used_path);
			strbuf_addstr(&used_path, gitfile);
		}
		if (chdir(used_path.buf))
823
			return NULL;
824
		path = validated_path.buf;
825
	}
826 827 828 829 830 831 832
	else {
		const char *gitfile = read_gitfile(path);
		if (gitfile)
			path = gitfile;
		if (chdir(path))
			return NULL;
	}
833

834
	if (is_git_directory(".")) {
René Scharfe's avatar
René Scharfe committed
835
		set_git_dir(".");
836
		check_repository_format();
837
		return path;
838 839 840 841
	}

	return NULL;
}
842

843
static int calc_shared_perm(int mode)
844
{
845
	int tweak;
846

847 848
	if (get_shared_repository() < 0)
		tweak = -get_shared_repository();
849
	else
850
		tweak = get_shared_repository();
851 852 853 854 855 856

	if (!(mode & S_IWUSR))
		tweak &= ~0222;
	if (mode & S_IXUSR)
		/* Copy read bits to execute bits */
		tweak |= (tweak & 0444) >> 2;
857
	if (get_shared_repository() < 0)
858 859
		mode = (mode & ~0777) | tweak;
	else
860
		mode |= tweak;
861

862 863 864 865 866 867 868 869
	return mode;
}


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

870
	if (!get_shared_repository())
871 872 873 874 875 876
		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)) {
877
		/* Copy read bits to execute bits */
878 879
		new_mode |= (new_mode & 0444) >> 2;
		new_mode |= FORCE_DIR_SET_GID;
880 881
	}

882 883
	if (((old_mode ^ new_mode) & ~S_IFMT) &&
			chmod(path, (new_mode & ~S_IFMT)) < 0)
884 885 886
		return -2;
	return 0;
}
887

888 889 890 891 892 893 894 895 896 897 898 899
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);
}

900 901 902 903 904 905 906 907 908 909
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);
}

910 911 912 913 914 915 916 917
/*
 * 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)
918
{
919 920 921 922
	int in_len = in ? strlen(in) : 0;
	int prefix_len = prefix ? strlen(prefix) : 0;
	int in_off = 0;
	int prefix_off = 0;
923 924
	int i = 0, j = 0;

925 926 927 928 929
	if (!in_len)
		return "./";
	else if (!prefix_len)
		return in;

930
	if (have_same_root(in, prefix))
931
		/* bypass dos_drive, for "c:" is identical to "C:" */
932 933
		i = j = has_dos_drive_prefix(in);
	else {
934 935 936
		return in;
	}

937 938 939
	while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
		if (is_dir_sep(prefix[i])) {
			while (is_dir_sep(prefix[i]))
940
				i++;
941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964
			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]))
965
				j++;
966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000
			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++;
1001 1002 1003 1004
			continue;
		}
		i++;
	}
1005 1006 1007 1008 1009 1010
	if (!is_dir_sep(prefix[prefix_len - 1]))
		strbuf_addstr(sb, "../");

	strbuf_addstr(sb, in);

	return sb->buf;
1011
}
1012

1013 1014 1015 1016 1017 1018 1019 1020 1021
/*
 * 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)
{
1022
	static struct strbuf buf = STRBUF_INIT;
1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050
	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++;
1051 1052

	strbuf_reset(&buf);
1053
	if (!in[j])
1054
		strbuf_addstr(&buf, ".");
1055
	else
1056 1057
		strbuf_addstr(&buf, in + j);
	return buf.buf;
1058 1059
}

1060
/*
1061
 * It is okay if dst == src, but they should not overlap otherwise.
1062
 *
1063 1064
 * Performs the following normalizations on src, storing the result in dst:
 * - Ensures that components are separated by '/' (Windows only)
1065
 * - Squashes sequences of '/' except "//server/share" on Windows
1066 1067
 * - Removes "." components.
 * - Removes ".." components, and the components the precede them.
1068 1069
 * Returns failure (non-zero) if a ".." component appears as first path
 * component anytime during the normalization. Otherwise, returns success (0).
1070 1071 1072
 *
 * Note that this function is purely textual.  It does not follow symlinks,
 * verify the existence of the path, or make any system calls.
1073 1074 1075 1076 1077 1078
 *
 * 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.
1079 1080 1081 1082 1083
 *
 * 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.
 *
1084
 */
1085
int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
1086
{
1087
	char *dst0;
1088
	const char *end;
1089

1090 1091 1092 1093 1094 1095 1096 1097 1098 1099
	/*
	 * 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;
	}
1100
	dst0 = dst;
1101

1102 1103
	while (is_dir_sep(*src))
		src++;
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 1135 1136 1137 1138 1139

	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;
				}
			}
		}
1140

1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157
		/* 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.
		 */
1158 1159
		dst--;	/* go to trailing '/' */
		if (dst <= dst0)
1160
			return -1;
1161 1162 1163
		/* Windows: dst[-1] cannot be backslash anymore */
		while (dst0 < dst && dst[-1] != '/')
			dst--;
1164 1165
		if (prefix_len && *prefix_len > dst - dst0)
			*prefix_len = dst - dst0;
1166
	}
1167
	*dst = '\0';
1168
	return 0;
1169
}
1170

1171 1172 1173 1174 1175
int normalize_path_copy(char *dst, const char *src)
{
	return normalize_path_copy_len(dst, src, NULL);
}

1176 1177
/*
 * path = Canonical absolute path
1178 1179
 * prefixes = string_list containing normalized, absolute paths without
 * trailing slashes (except for the root directory, which is denoted by "/").
1180
 *
1181
 * Determines, for each path in prefixes, whether the "prefix"
1182 1183
 * is an ancestor directory of path.  Returns the length of the longest
 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
1184 1185
 * is an ancestor.  (Note that this means 0 is returned if prefixes is
 * ["/"].) "/foo" is not considered an ancestor of "/foobar".  Directories
1186 1187
 * are not considered to be their own ancestors.  path must be in a
 * canonical form: empty components, or "." or ".." components are not
1188
 * allowed.
1189
 */
1190
int longest_ancestor_length(const char *path, struct string_list *prefixes)
1191
{
1192
	int i, max_len = -1;
1193

1194
	if (!strcmp(path, "/"))
1195 1196
		return -1;

1197 1198
	for (i = 0; i < prefixes->nr; i++) {
		const char *ceil = prefixes->items[i].string;
1199 1200
		int len = strlen(ceil);

1201 1202 1203 1204 1205 1206
		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 */
1207

1208
		if (len > max_len)
1209 1210 1211 1212 1213
			max_len = len;
	}

	return max_len;
}
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 1245 1246 1247 1248 1249

/* 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));
}
1250 1251 1252 1253 1254 1255 1256 1257

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()
1258
	 * does not do getcwd() based path canonicalization.
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 1292 1293 1294 1295 1296
	 *
	 * 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;
		}
	}
}
1297

1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313
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)
{
1314
	size_t len;
1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329

	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;
		}
}
1330

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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 = 1;
		} else if (i >= 6)
			return 0;
1377
		else if (name[i] & 0x80) {
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			/*
			 * We know our needles contain only ASCII, so we clamp
			 * here to make the results of tolower() sane.
			 */
			return 0;
		} else if (tolower(name[i]) != dotgit_ntfs_shortname_prefix[i])
			return 0;

	goto only_spaces_and_periods;
}

/*
 * Inline helper to make sure compiler resolves strlen() on literals at
 * compile time.
 */
static inline int is_ntfs_dot_str(const char *name, const char *dotgit_name,
				  const char *dotgit_ntfs_shortname_prefix)
{
	return is_ntfs_dot_generic(name, dotgit_name, strlen(dotgit_name),
				   dotgit_ntfs_shortname_prefix);
}

int is_ntfs_dotgitmodules(const char *name)
{
	return is_ntfs_dot_str(name, "gitmodules", "gi7eba");
}

int is_ntfs_dotgitignore(const char *name)
{
	return is_ntfs_dot_str(name, "gitignore", "gi250a");
}

int is_ntfs_dotgitattributes(const char *name)
{
	return is_ntfs_dot_str(name, "gitattributes", "gi7d29");
}

1415 1416 1417 1418 1419
int looks_like_command_line_option(const char *str)
{
	return str && str[0] == '-';
}

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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;
}
1434

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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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REPO_GIT_PATH_FUNC(cherry_pick_head, "CHERRY_PICK_HEAD")
REPO_GIT_PATH_FUNC(revert_head, "REVERT_HEAD")
REPO_GIT_PATH_FUNC(squash_msg, "SQUASH_MSG")
REPO_GIT_PATH_FUNC(merge_msg, "MERGE_MSG")
REPO_GIT_PATH_FUNC(merge_rr, "MERGE_RR")
REPO_GIT_PATH_FUNC(merge_mode, "MERGE_MODE")
REPO_GIT_PATH_FUNC(merge_head, "MERGE_HEAD")
REPO_GIT_PATH_FUNC(fetch_head, "FETCH_HEAD")
REPO_GIT_PATH_FUNC(shallow, "shallow")