1 files changed, 789 insertions, 0 deletions
diff --git a/setup.c b/setup.c
new file mode 100644
index 000000000..6c3f85ff7
--- /dev/null
+++ b/setup.c
@@ -0,0 +1,789 @@
+#include "cache.h"
+#include "dir.h"
+#include "string-list.h"
+
+static int inside_git_dir = -1;
+static int inside_work_tree = -1;
+
+/*
+ * Normalize "path", prepending the "prefix" for relative paths. If
+ * remaining_prefix is not NULL, return the actual prefix still
+ * remains in the path. For example, prefix = sub1/sub2/ and path is
+ *
+ *  foo          -> sub1/sub2/foo  (full prefix)
+ *  ../foo       -> sub1/foo       (remaining prefix is sub1/)
+ *  ../../bar    -> bar            (no remaining prefix)
+ *  ../../sub1/sub2/foo -> sub1/sub2/foo (but no remaining prefix)
+ *  `pwd`/../bar -> sub1/bar       (no remaining prefix)
+ */
+char *prefix_path_gently(const char *prefix, int len,
+			 int *remaining_prefix, const char *path)
+{
+	const char *orig = path;
+	char *sanitized;
+	if (is_absolute_path(orig)) {
+		const char *temp = real_path(path);
+		sanitized = xmalloc(len + strlen(temp) + 1);
+		strcpy(sanitized, temp);
+		if (remaining_prefix)
+			*remaining_prefix = 0;
+	} else {
+		sanitized = xmalloc(len + strlen(path) + 1);
+		if (len)
+			memcpy(sanitized, prefix, len);
+		strcpy(sanitized + len, path);
+		if (remaining_prefix)
+			*remaining_prefix = len;
+	}
+	if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix))
+		goto error_out;
+	if (is_absolute_path(orig)) {
+		size_t root_len, len, total;
+		const char *work_tree = get_git_work_tree();
+		if (!work_tree)
+			goto error_out;
+		len = strlen(work_tree);
+		root_len = offset_1st_component(work_tree);
+		total = strlen(sanitized) + 1;
+		if (strncmp(sanitized, work_tree, len) ||
+		    (len > root_len && sanitized[len] != '\0' && sanitized[len] != '/')) {
+		error_out:
+			free(sanitized);
+			return NULL;
+		}
+		if (sanitized[len] == '/')
+			len++;
+		memmove(sanitized, sanitized + len, total - len);
+	}
+	return sanitized;
+}
+
+char *prefix_path(const char *prefix, int len, const char *path)
+{
+	char *r = prefix_path_gently(prefix, len, NULL, path);
+	if (!r)
+		die("'%s' is outside repository", path);
+	return r;
+}
+
+int path_inside_repo(const char *prefix, const char *path)
+{
+	int len = prefix ? strlen(prefix) : 0;
+	char *r = prefix_path_gently(prefix, len, NULL, path);
+	if (r) {
+		free(r);
+		return 1;
+	}
+	return 0;
+}
+
+int check_filename(const char *prefix, const char *arg)
+{
+	const char *name;
+	struct stat st;
+
+	if (starts_with(arg, ":/")) {
+		if (arg[2] == '\0') /* ":/" is root dir, always exists */
+			return 1;
+		name = arg + 2;
+	} else if (prefix)
+		name = prefix_filename(prefix, strlen(prefix), arg);
+	else
+		name = arg;
+	if (!lstat(name, &st))
+		return 1; /* file exists */
+	if (errno == ENOENT || errno == ENOTDIR)
+		return 0; /* file does not exist */
+	die_errno("failed to stat '%s'", arg);
+}
+
+static void NORETURN die_verify_filename(const char *prefix,
+					 const char *arg,
+					 int diagnose_misspelt_rev)
+{
+	if (!diagnose_misspelt_rev)
+		die("%s: no such path in the working tree.\n"
+		    "Use 'git <command> -- <path>...' to specify paths that do not exist locally.",
+		    arg);
+	/*
+	 * Saying "'(icase)foo' does not exist in the index" when the
+	 * user gave us ":(icase)foo" is just stupid.  A magic pathspec
+	 * begins with a colon and is followed by a non-alnum; do not
+	 * let maybe_die_on_misspelt_object_name() even trigger.
+	 */
+	if (!(arg[0] == ':' && !isalnum(arg[1])))
+		maybe_die_on_misspelt_object_name(arg, prefix);
+
+	/* ... or fall back the most general message. */
+	die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
+	    "Use '--' to separate paths from revisions, like this:\n"
+	    "'git <command> [<revision>...] -- [<file>...]'", arg);
+
+}
+
+/*
+ * Verify a filename that we got as an argument for a pathspec
+ * entry. Note that a filename that begins with "-" never verifies
+ * as true, because even if such a filename were to exist, we want
+ * it to be preceded by the "--" marker (or we want the user to
+ * use a format like "./-filename")
+ *
+ * The "diagnose_misspelt_rev" is used to provide a user-friendly
+ * diagnosis when dying upon finding that "name" is not a pathname.
+ * If set to 1, the diagnosis will try to diagnose "name" as an
+ * invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis
+ * will only complain about an inexisting file.
+ *
+ * This function is typically called to check that a "file or rev"
+ * argument is unambiguous. In this case, the caller will want
+ * diagnose_misspelt_rev == 1 when verifying the first non-rev
+ * argument (which could have been a revision), and
+ * diagnose_misspelt_rev == 0 for the next ones (because we already
+ * saw a filename, there's not ambiguity anymore).
+ */
+void verify_filename(const char *prefix,
+		     const char *arg,
+		     int diagnose_misspelt_rev)
+{
+	if (*arg == '-')
+		die("bad flag '%s' used after filename", arg);
+	if (check_filename(prefix, arg))
+		return;
+	die_verify_filename(prefix, arg, diagnose_misspelt_rev);
+}
+
+/*
+ * Opposite of the above: the command line did not have -- marker
+ * and we parsed the arg as a refname.  It should not be interpretable
+ * as a filename.
+ */
+void verify_non_filename(const char *prefix, const char *arg)
+{
+	if (!is_inside_work_tree() || is_inside_git_dir())
+		return;
+	if (*arg == '-')
+		return; /* flag */
+	if (!check_filename(prefix, arg))
+		return;
+	die("ambiguous argument '%s': both revision and filename\n"
+	    "Use '--' to separate paths from revisions, like this:\n"
+	    "'git <command> [<revision>...] -- [<file>...]'", arg);
+}
+
+
+/*
+ * Test if it looks like we're at a git directory.
+ * We want to see:
+ *
+ *  - either an objects/ directory _or_ the proper
+ *    GIT_OBJECT_DIRECTORY environment variable
+ *  - a refs/ directory
+ *  - either a HEAD symlink or a HEAD file that is formatted as
+ *    a proper "ref:", or a regular file HEAD that has a properly
+ *    formatted sha1 object name.
+ */
+int is_git_directory(const char *suspect)
+{
+	char path[PATH_MAX];
+	size_t len = strlen(suspect);
+
+	if (PATH_MAX <= len + strlen("/objects"))
+		die("Too long path: %.*s", 60, suspect);
+	strcpy(path, suspect);
+	if (getenv(DB_ENVIRONMENT)) {
+		if (access(getenv(DB_ENVIRONMENT), X_OK))
+			return 0;
+	}
+	else {
+		strcpy(path + len, "/objects");
+		if (access(path, X_OK))
+			return 0;
+	}
+
+	strcpy(path + len, "/refs");
+	if (access(path, X_OK))
+		return 0;
+
+	strcpy(path + len, "/HEAD");
+	if (validate_headref(path))
+		return 0;
+
+	return 1;
+}
+
+int is_inside_git_dir(void)
+{
+	if (inside_git_dir < 0)
+		inside_git_dir = is_inside_dir(get_git_dir());
+	return inside_git_dir;
+}
+
+int is_inside_work_tree(void)
+{
+	if (inside_work_tree < 0)
+		inside_work_tree = is_inside_dir(get_git_work_tree());
+	return inside_work_tree;
+}
+
+void setup_work_tree(void)
+{
+	const char *work_tree, *git_dir;
+	static int initialized = 0;
+
+	if (initialized)
+		return;
+	work_tree = get_git_work_tree();
+	git_dir = get_git_dir();
+	if (!is_absolute_path(git_dir))
+		git_dir = real_path(get_git_dir());
+	if (!work_tree || chdir(work_tree))
+		die("This operation must be run in a work tree");
+
+	/*
+	 * Make sure subsequent git processes find correct worktree
+	 * if $GIT_WORK_TREE is set relative
+	 */
+	if (getenv(GIT_WORK_TREE_ENVIRONMENT))
+		setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
+
+	set_git_dir(remove_leading_path(git_dir, work_tree));
+	initialized = 1;
+}
+
+static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
+{
+	char repo_config[PATH_MAX+1];
+
+	/*
+	 * git_config() can't be used here because it calls git_pathdup()
+	 * to get $GIT_CONFIG/config. That call will make setup_git_env()
+	 * set git_dir to ".git".
+	 *
+	 * We are in gitdir setup, no git dir has been found useable yet.
+	 * Use a gentler version of git_config() to check if this repo
+	 * is a good one.
+	 */
+	snprintf(repo_config, PATH_MAX, "%s/config", gitdir);
+	git_config_early(check_repository_format_version, NULL, repo_config);
+	if (GIT_REPO_VERSION < repository_format_version) {
+		if (!nongit_ok)
+			die ("Expected git repo version <= %d, found %d",
+			     GIT_REPO_VERSION, repository_format_version);
+		warning("Expected git repo version <= %d, found %d",
+			GIT_REPO_VERSION, repository_format_version);
+		warning("Please upgrade Git");
+		*nongit_ok = -1;
+		return -1;
+	}
+	return 0;
+}
+
+/*
+ * Try to read the location of the git directory from the .git file,
+ * return path to git directory if found.
+ */
+const char *read_gitfile(const char *path)
+{
+	char *buf;
+	char *dir;
+	const char *slash;
+	struct stat st;
+	int fd;
+	ssize_t len;
+
+	if (stat(path, &st))
+		return NULL;
+	if (!S_ISREG(st.st_mode))
+		return NULL;
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		die_errno("Error opening '%s'", path);
+	buf = xmalloc(st.st_size + 1);
+	len = read_in_full(fd, buf, st.st_size);
+	close(fd);
+	if (len != st.st_size)
+		die("Error reading %s", path);
+	buf[len] = '\0';
+	if (!starts_with(buf, "gitdir: "))
+		die("Invalid gitfile format: %s", path);
+	while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
+		len--;
+	if (len < 9)
+		die("No path in gitfile: %s", path);
+	buf[len] = '\0';
+	dir = buf + 8;
+
+	if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
+		size_t pathlen = slash+1 - path;
+		size_t dirlen = pathlen + len - 8;
+		dir = xmalloc(dirlen + 1);
+		strncpy(dir, path, pathlen);
+		strncpy(dir + pathlen, buf + 8, len - 8);
+		dir[dirlen] = '\0';
+		free(buf);
+		buf = dir;
+	}
+
+	if (!is_git_directory(dir))
+		die("Not a git repository: %s", dir);
+	path = real_path(dir);
+
+	free(buf);
+	return path;
+}
+
+static const char *setup_explicit_git_dir(const char *gitdirenv,
+					  char *cwd, int len,
+					  int *nongit_ok)
+{
+	const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
+	const char *worktree;
+	char *gitfile;
+	int offset;
+
+	if (PATH_MAX - 40 < strlen(gitdirenv))
+		die("'$%s' too big", GIT_DIR_ENVIRONMENT);
+
+	gitfile = (char*)read_gitfile(gitdirenv);
+	if (gitfile) {
+		gitfile = xstrdup(gitfile);
+		gitdirenv = gitfile;
+	}
+
+	if (!is_git_directory(gitdirenv)) {
+		if (nongit_ok) {
+			*nongit_ok = 1;
+			free(gitfile);
+			return NULL;
+		}
+		die("Not a git repository: '%s'", gitdirenv);
+	}
+
+	if (check_repository_format_gently(gitdirenv, nongit_ok)) {
+		free(gitfile);
+		return NULL;
+	}
+
+	/* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
+	if (work_tree_env)
+		set_git_work_tree(work_tree_env);
+	else if (is_bare_repository_cfg > 0) {
+		if (git_work_tree_cfg) /* #22.2, #30 */
+			die("core.bare and core.worktree do not make sense");
+
+		/* #18, #26 */
+		set_git_dir(gitdirenv);
+		free(gitfile);
+		return NULL;
+	}
+	else if (git_work_tree_cfg) { /* #6, #14 */
+		if (is_absolute_path(git_work_tree_cfg))
+			set_git_work_tree(git_work_tree_cfg);
+		else {
+			char core_worktree[PATH_MAX];
+			if (chdir(gitdirenv))
+				die_errno("Could not chdir to '%s'", gitdirenv);
+			if (chdir(git_work_tree_cfg))
+				die_errno("Could not chdir to '%s'", git_work_tree_cfg);
+			if (!getcwd(core_worktree, PATH_MAX))
+				die_errno("Could not get directory '%s'", git_work_tree_cfg);
+			if (chdir(cwd))
+				die_errno("Could not come back to cwd");
+			set_git_work_tree(core_worktree);
+		}
+	}
+	else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
+		/* #16d */
+		set_git_dir(gitdirenv);
+		free(gitfile);
+		return NULL;
+	}
+	else /* #2, #10 */
+		set_git_work_tree(".");
+
+	/* set_git_work_tree() must have been called by now */
+	worktree = get_git_work_tree();
+
+	/* both get_git_work_tree() and cwd are already normalized */
+	if (!strcmp(cwd, worktree)) { /* cwd == worktree */
+		set_git_dir(gitdirenv);
+		free(gitfile);
+		return NULL;
+	}
+
+	offset = dir_inside_of(cwd, worktree);
+	if (offset >= 0) {	/* cwd inside worktree? */
+		set_git_dir(real_path(gitdirenv));
+		if (chdir(worktree))
+			die_errno("Could not chdir to '%s'", worktree);
+		cwd[len++] = '/';
+		cwd[len] = '\0';
+		free(gitfile);
+		return cwd + offset;
+	}
+
+	/* cwd outside worktree */
+	set_git_dir(gitdirenv);
+	free(gitfile);
+	return NULL;
+}
+
+static const char *setup_discovered_git_dir(const char *gitdir,
+					    char *cwd, int offset, int len,
+					    int *nongit_ok)
+{
+	if (check_repository_format_gently(gitdir, nongit_ok))
+		return NULL;
+
+	/* --work-tree is set without --git-dir; use discovered one */
+	if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
+		if (offset != len && !is_absolute_path(gitdir))
+			gitdir = xstrdup(real_path(gitdir));
+		if (chdir(cwd))
+			die_errno("Could not come back to cwd");
+		return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
+	}
+
+	/* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
+	if (is_bare_repository_cfg > 0) {
+		set_git_dir(offset == len ? gitdir : real_path(gitdir));
+		if (chdir(cwd))
+			die_errno("Could not come back to cwd");
+		return NULL;
+	}
+
+	/* #0, #1, #5, #8, #9, #12, #13 */
+	set_git_work_tree(".");
+	if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
+		set_git_dir(gitdir);
+	inside_git_dir = 0;
+	inside_work_tree = 1;
+	if (offset == len)
+		return NULL;
+
+	/* Make "offset" point to past the '/', and add a '/' at the end */
+	offset++;
+	cwd[len++] = '/';
+	cwd[len] = 0;
+	return cwd + offset;
+}
+
+/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
+static const char *setup_bare_git_dir(char *cwd, int offset, int len, int *nongit_ok)
+{
+	int root_len;
+
+	if (check_repository_format_gently(".", nongit_ok))
+		return NULL;
+
+	setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
+
+	/* --work-tree is set without --git-dir; use discovered one */
+	if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
+		const char *gitdir;
+
+		gitdir = offset == len ? "." : xmemdupz(cwd, offset);
+		if (chdir(cwd))
+			die_errno("Could not come back to cwd");
+		return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
+	}
+
+	inside_git_dir = 1;
+	inside_work_tree = 0;
+	if (offset != len) {
+		if (chdir(cwd))
+			die_errno("Cannot come back to cwd");
+		root_len = offset_1st_component(cwd);
+		cwd[offset > root_len ? offset : root_len] = '\0';
+		set_git_dir(cwd);
+	}
+	else
+		set_git_dir(".");
+	return NULL;
+}
+
+static const char *setup_nongit(const char *cwd, int *nongit_ok)
+{
+	if (!nongit_ok)
+		die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
+	if (chdir(cwd))
+		die_errno("Cannot come back to cwd");
+	*nongit_ok = 1;
+	return NULL;
+}
+
+static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
+{
+	struct stat buf;
+	if (stat(path, &buf)) {
+		die_errno("failed to stat '%*s%s%s'",
+				prefix_len,
+				prefix ? prefix : "",
+				prefix ? "/" : "", path);
+	}
+	return buf.st_dev;
+}
+
+/*
+ * A "string_list_each_func_t" function that canonicalizes an entry
+ * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
+ * discards it if unusable.  The presence of an empty entry in
+ * GIT_CEILING_DIRECTORIES turns off canonicalization for all
+ * subsequent entries.
+ */
+static int canonicalize_ceiling_entry(struct string_list_item *item,
+				      void *cb_data)
+{
+	int *empty_entry_found = cb_data;
+	char *ceil = item->string;
+
+	if (!*ceil) {
+		*empty_entry_found = 1;
+		return 0;
+	} else if (!is_absolute_path(ceil)) {
+		return 0;
+	} else if (*empty_entry_found) {
+		/* Keep entry but do not canonicalize it */
+		return 1;
+	} else {
+		const char *real_path = real_path_if_valid(ceil);
+		if (!real_path)
+			return 0;
+		free(item->string);
+		item->string = xstrdup(real_path);
+		return 1;
+	}
+}
+
+/*
+ * We cannot decide in this function whether we are in the work tree or
+ * not, since the config can only be read _after_ this function was called.
+ */
+static const char *setup_git_directory_gently_1(int *nongit_ok)
+{
+	const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
+	struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
+	static char cwd[PATH_MAX + 1];
+	const char *gitdirenv, *ret;
+	char *gitfile;
+	int len, offset, offset_parent, ceil_offset = -1;
+	dev_t current_device = 0;
+	int one_filesystem = 1;
+
+	/*
+	 * Let's assume that we are in a git repository.
+	 * If it turns out later that we are somewhere else, the value will be
+	 * updated accordingly.
+	 */
+	if (nongit_ok)
+		*nongit_ok = 0;
+
+	if (!getcwd(cwd, sizeof(cwd) - 1))
+		die_errno("Unable to read current working directory");
+	offset = len = strlen(cwd);
+
+	/*
+	 * If GIT_DIR is set explicitly, we're not going
+	 * to do any discovery, but we still do repository
+	 * validation.
+	 */
+	gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
+	if (gitdirenv)
+		return setup_explicit_git_dir(gitdirenv, cwd, len, nongit_ok);
+
+	if (env_ceiling_dirs) {
+		int empty_entry_found = 0;
+
+		string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
+		filter_string_list(&ceiling_dirs, 0,
+				   canonicalize_ceiling_entry, &empty_entry_found);
+		ceil_offset = longest_ancestor_length(cwd, &ceiling_dirs);
+		string_list_clear(&ceiling_dirs, 0);
+	}
+
+	if (ceil_offset < 0 && has_dos_drive_prefix(cwd))
+		ceil_offset = 1;
+
+	/*
+	 * Test in the following order (relative to the cwd):
+	 * - .git (file containing "gitdir: <path>")
+	 * - .git/
+	 * - ./ (bare)
+	 * - ../.git
+	 * - ../.git/
+	 * - ../ (bare)
+	 * - ../../.git/
+	 *   etc.
+	 */
+	one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
+	if (one_filesystem)
+		current_device = get_device_or_die(".", NULL, 0);
+	for (;;) {
+		gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
+		if (gitfile)
+			gitdirenv = gitfile = xstrdup(gitfile);
+		else {
+			if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
+				gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
+		}
+
+		if (gitdirenv) {
+			ret = setup_discovered_git_dir(gitdirenv,
+						       cwd, offset, len,
+						       nongit_ok);
+			free(gitfile);
+			return ret;
+		}
+		free(gitfile);
+
+		if (is_git_directory("."))
+			return setup_bare_git_dir(cwd, offset, len, nongit_ok);
+
+		offset_parent = offset;
+		while (--offset_parent > ceil_offset && cwd[offset_parent] != '/');
+		if (offset_parent <= ceil_offset)
+			return setup_nongit(cwd, nongit_ok);
+		if (one_filesystem) {
+			dev_t parent_device = get_device_or_die("..", cwd, offset);
+			if (parent_device != current_device) {
+				if (nongit_ok) {
+					if (chdir(cwd))
+						die_errno("Cannot come back to cwd");
+					*nongit_ok = 1;
+					return NULL;
+				}
+				cwd[offset] = '\0';
+				die("Not a git repository (or any parent up to mount point %s)\n"
+				"Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).", cwd);
+			}
+		}
+		if (chdir("..")) {
+			cwd[offset] = '\0';
+			die_errno("Cannot change to '%s/..'", cwd);
+		}
+		offset = offset_parent;
+	}
+}
+
+const char *setup_git_directory_gently(int *nongit_ok)
+{
+	const char *prefix;
+
+	prefix = setup_git_directory_gently_1(nongit_ok);
+	if (prefix)
+		setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
+	else
+		setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
+
+	if (startup_info) {
+		startup_info->have_repository = !nongit_ok || !*nongit_ok;
+		startup_info->prefix = prefix;
+	}
+	return prefix;
+}
+
+int git_config_perm(const char *var, const char *value)
+{
+	int i;
+	char *endptr;
+
+	if (value == NULL)
+		return PERM_GROUP;
+
+	if (!strcmp(value, "umask"))
+		return PERM_UMASK;
+	if (!strcmp(value, "group"))
+		return PERM_GROUP;
+	if (!strcmp(value, "all") ||
+	    !strcmp(value, "world") ||
+	    !strcmp(value, "everybody"))
+		return PERM_EVERYBODY;
+
+	/* Parse octal numbers */
+	i = strtol(value, &endptr, 8);
+
+	/* If not an octal number, maybe true/false? */
+	if (*endptr != 0)
+		return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
+
+	/*
+	 * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
+	 * a chmod value to restrict to.
+	 */
+	switch (i) {
+	case PERM_UMASK:               /* 0 */
+		return PERM_UMASK;
+	case OLD_PERM_GROUP:           /* 1 */
+		return PERM_GROUP;
+	case OLD_PERM_EVERYBODY:       /* 2 */
+		return PERM_EVERYBODY;
+	}
+
+	/* A filemode value was given: 0xxx */
+
+	if ((i & 0600) != 0600)
+		die("Problem with core.sharedRepository filemode value "
+		    "(0%.3o).\nThe owner of files must always have "
+		    "read and write permissions.", i);
+
+	/*
+	 * Mask filemode value. Others can not get write permission.
+	 * x flags for directories are handled separately.
+	 */
+	return -(i & 0666);
+}
+
+int check_repository_format_version(const char *var, const char *value, void *cb)
+{
+	if (strcmp(var, "core.repositoryformatversion") == 0)
+		repository_format_version = git_config_int(var, value);
+	else if (strcmp(var, "core.sharedrepository") == 0)
+		shared_repository = git_config_perm(var, value);
+	else if (strcmp(var, "core.bare") == 0) {
+		is_bare_repository_cfg = git_config_bool(var, value);
+		if (is_bare_repository_cfg == 1)
+			inside_work_tree = -1;
+	} else if (strcmp(var, "core.worktree") == 0) {
+		if (!value)
+			return config_error_nonbool(var);
+		free(git_work_tree_cfg);
+		git_work_tree_cfg = xstrdup(value);
+		inside_work_tree = -1;
+	}
+	return 0;
+}
+
+int check_repository_format(void)
+{
+	return check_repository_format_gently(get_git_dir(), NULL);
+}
+
+/*
+ * Returns the "prefix", a path to the current working directory
+ * relative to the work tree root, or NULL, if the current working
+ * directory is not a strict subdirectory of the work tree root. The
+ * prefix always ends with a '/' character.
+ */
+const char *setup_git_directory(void)
+{
+	return setup_git_directory_gently(NULL);
+}
+
+const char *resolve_gitdir(const char *suspect)
+{
+	if (is_git_directory(suspect))
+		return suspect;
+	return read_gitfile(suspect);
+}
+
+/* if any standard file descriptor is missing open it to /dev/null */
+void sanitize_stdfds(void)
+{
+	int fd = open("/dev/null", O_RDWR, 0);
+	while (fd != -1 && fd < 2)
+		fd = dup(fd);
+	if (fd == -1)
+		die_errno("open /dev/null or dup failed");
+	if (fd > 2)
+		close(fd);
+}