Adding upstream version 1:2.39.2.upstream/1%2.39.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3854 insertions, 0 deletions

diff --git a/config.c b/config.c
new file mode 100644
index 0000000..27f3828
--- /dev/null
+++ b/config.c
@@ -0,0 +1,3854 @@
+/*
+ * GIT - The information manager from hell
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ * Copyright (C) Johannes Schindelin, 2005
+ *
+ */
+#include "cache.h"
+#include "date.h"
+#include "branch.h"
+#include "config.h"
+#include "environment.h"
+#include "repository.h"
+#include "lockfile.h"
+#include "exec-cmd.h"
+#include "strbuf.h"
+#include "quote.h"
+#include "hashmap.h"
+#include "string-list.h"
+#include "object-store.h"
+#include "utf8.h"
+#include "dir.h"
+#include "color.h"
+#include "refs.h"
+#include "worktree.h"
+
+struct config_source {
+	struct config_source *prev;
+	union {
+		FILE *file;
+		struct config_buf {
+			const char *buf;
+			size_t len;
+			size_t pos;
+		} buf;
+	} u;
+	enum config_origin_type origin_type;
+	const char *name;
+	const char *path;
+	enum config_error_action default_error_action;
+	int linenr;
+	int eof;
+	size_t total_len;
+	struct strbuf value;
+	struct strbuf var;
+	unsigned subsection_case_sensitive : 1;
+
+	int (*do_fgetc)(struct config_source *c);
+	int (*do_ungetc)(int c, struct config_source *conf);
+	long (*do_ftell)(struct config_source *c);
+};
+
+/*
+ * These variables record the "current" config source, which
+ * can be accessed by parsing callbacks.
+ *
+ * The "cf" variable will be non-NULL only when we are actually parsing a real
+ * config source (file, blob, cmdline, etc).
+ *
+ * The "current_config_kvi" variable will be non-NULL only when we are feeding
+ * cached config from a configset into a callback.
+ *
+ * They should generally never be non-NULL at the same time. If they are both
+ * NULL, then we aren't parsing anything (and depending on the function looking
+ * at the variables, it's either a bug for it to be called in the first place,
+ * or it's a function which can be reused for non-config purposes, and should
+ * fall back to some sane behavior).
+ */
+static struct config_source *cf;
+static struct key_value_info *current_config_kvi;
+
+/*
+ * Similar to the variables above, this gives access to the "scope" of the
+ * current value (repo, global, etc). For cached values, it can be found via
+ * the current_config_kvi as above. During parsing, the current value can be
+ * found in this variable. It's not part of "cf" because it transcends a single
+ * file (i.e., a file included from .git/config is still in "repo" scope).
+ */
+static enum config_scope current_parsing_scope;
+
+static int pack_compression_seen;
+static int zlib_compression_seen;
+
+/*
+ * Config that comes from trusted scopes, namely:
+ * - CONFIG_SCOPE_SYSTEM (e.g. /etc/gitconfig)
+ * - CONFIG_SCOPE_GLOBAL (e.g. $HOME/.gitconfig, $XDG_CONFIG_HOME/git)
+ * - CONFIG_SCOPE_COMMAND (e.g. "-c" option, environment variables)
+ *
+ * This is declared here for code cleanliness, but unlike the other
+ * static variables, this does not hold config parser state.
+ */
+static struct config_set protected_config;
+
+static int config_file_fgetc(struct config_source *conf)
+{
+	return getc_unlocked(conf->u.file);
+}
+
+static int config_file_ungetc(int c, struct config_source *conf)
+{
+	return ungetc(c, conf->u.file);
+}
+
+static long config_file_ftell(struct config_source *conf)
+{
+	return ftell(conf->u.file);
+}
+
+
+static int config_buf_fgetc(struct config_source *conf)
+{
+	if (conf->u.buf.pos < conf->u.buf.len)
+		return conf->u.buf.buf[conf->u.buf.pos++];
+
+	return EOF;
+}
+
+static int config_buf_ungetc(int c, struct config_source *conf)
+{
+	if (conf->u.buf.pos > 0) {
+		conf->u.buf.pos--;
+		if (conf->u.buf.buf[conf->u.buf.pos] != c)
+			BUG("config_buf can only ungetc the same character");
+		return c;
+	}
+
+	return EOF;
+}
+
+static long config_buf_ftell(struct config_source *conf)
+{
+	return conf->u.buf.pos;
+}
+
+struct config_include_data {
+	int depth;
+	config_fn_t fn;
+	void *data;
+	const struct config_options *opts;
+	struct git_config_source *config_source;
+
+	/*
+	 * All remote URLs discovered when reading all config files.
+	 */
+	struct string_list *remote_urls;
+};
+#define CONFIG_INCLUDE_INIT { 0 }
+
+static int git_config_include(const char *var, const char *value, void *data);
+
+#define MAX_INCLUDE_DEPTH 10
+static const char include_depth_advice[] = N_(
+"exceeded maximum include depth (%d) while including\n"
+"	%s\n"
+"from\n"
+"	%s\n"
+"This might be due to circular includes.");
+static int handle_path_include(const char *path, struct config_include_data *inc)
+{
+	int ret = 0;
+	struct strbuf buf = STRBUF_INIT;
+	char *expanded;
+
+	if (!path)
+		return config_error_nonbool("include.path");
+
+	expanded = interpolate_path(path, 0);
+	if (!expanded)
+		return error(_("could not expand include path '%s'"), path);
+	path = expanded;
+
+	/*
+	 * Use an absolute path as-is, but interpret relative paths
+	 * based on the including config file.
+	 */
+	if (!is_absolute_path(path)) {
+		char *slash;
+
+		if (!cf || !cf->path) {
+			ret = error(_("relative config includes must come from files"));
+			goto cleanup;
+		}
+
+		slash = find_last_dir_sep(cf->path);
+		if (slash)
+			strbuf_add(&buf, cf->path, slash - cf->path + 1);
+		strbuf_addstr(&buf, path);
+		path = buf.buf;
+	}
+
+	if (!access_or_die(path, R_OK, 0)) {
+		if (++inc->depth > MAX_INCLUDE_DEPTH)
+			die(_(include_depth_advice), MAX_INCLUDE_DEPTH, path,
+			    !cf ? "<unknown>" :
+			    cf->name ? cf->name :
+			    "the command line");
+		ret = git_config_from_file(git_config_include, path, inc);
+		inc->depth--;
+	}
+cleanup:
+	strbuf_release(&buf);
+	free(expanded);
+	return ret;
+}
+
+static void add_trailing_starstar_for_dir(struct strbuf *pat)
+{
+	if (pat->len && is_dir_sep(pat->buf[pat->len - 1]))
+		strbuf_addstr(pat, "**");
+}
+
+static int prepare_include_condition_pattern(struct strbuf *pat)
+{
+	struct strbuf path = STRBUF_INIT;
+	char *expanded;
+	int prefix = 0;
+
+	expanded = interpolate_path(pat->buf, 1);
+	if (expanded) {
+		strbuf_reset(pat);
+		strbuf_addstr(pat, expanded);
+		free(expanded);
+	}
+
+	if (pat->buf[0] == '.' && is_dir_sep(pat->buf[1])) {
+		const char *slash;
+
+		if (!cf || !cf->path)
+			return error(_("relative config include "
+				       "conditionals must come from files"));
+
+		strbuf_realpath(&path, cf->path, 1);
+		slash = find_last_dir_sep(path.buf);
+		if (!slash)
+			BUG("how is this possible?");
+		strbuf_splice(pat, 0, 1, path.buf, slash - path.buf);
+		prefix = slash - path.buf + 1 /* slash */;
+	} else if (!is_absolute_path(pat->buf))
+		strbuf_insertstr(pat, 0, "**/");
+
+	add_trailing_starstar_for_dir(pat);
+
+	strbuf_release(&path);
+	return prefix;
+}
+
+static int include_by_gitdir(const struct config_options *opts,
+			     const char *cond, size_t cond_len, int icase)
+{
+	struct strbuf text = STRBUF_INIT;
+	struct strbuf pattern = STRBUF_INIT;
+	int ret = 0, prefix;
+	const char *git_dir;
+	int already_tried_absolute = 0;
+
+	if (opts->git_dir)
+		git_dir = opts->git_dir;
+	else
+		goto done;
+
+	strbuf_realpath(&text, git_dir, 1);
+	strbuf_add(&pattern, cond, cond_len);
+	prefix = prepare_include_condition_pattern(&pattern);
+
+again:
+	if (prefix < 0)
+		goto done;
+
+	if (prefix > 0) {
+		/*
+		 * perform literal matching on the prefix part so that
+		 * any wildcard character in it can't create side effects.
+		 */
+		if (text.len < prefix)
+			goto done;
+		if (!icase && strncmp(pattern.buf, text.buf, prefix))
+			goto done;
+		if (icase && strncasecmp(pattern.buf, text.buf, prefix))
+			goto done;
+	}
+
+	ret = !wildmatch(pattern.buf + prefix, text.buf + prefix,
+			 WM_PATHNAME | (icase ? WM_CASEFOLD : 0));
+
+	if (!ret && !already_tried_absolute) {
+		/*
+		 * We've tried e.g. matching gitdir:~/work, but if
+		 * ~/work is a symlink to /mnt/storage/work
+		 * strbuf_realpath() will expand it, so the rule won't
+		 * match. Let's match against a
+		 * strbuf_add_absolute_path() version of the path,
+		 * which'll do the right thing
+		 */
+		strbuf_reset(&text);
+		strbuf_add_absolute_path(&text, git_dir);
+		already_tried_absolute = 1;
+		goto again;
+	}
+done:
+	strbuf_release(&pattern);
+	strbuf_release(&text);
+	return ret;
+}
+
+static int include_by_branch(const char *cond, size_t cond_len)
+{
+	int flags;
+	int ret;
+	struct strbuf pattern = STRBUF_INIT;
+	const char *refname = !the_repository->gitdir ?
+		NULL : resolve_ref_unsafe("HEAD", 0, NULL, &flags);
+	const char *shortname;
+
+	if (!refname || !(flags & REF_ISSYMREF)	||
+			!skip_prefix(refname, "refs/heads/", &shortname))
+		return 0;
+
+	strbuf_add(&pattern, cond, cond_len);
+	add_trailing_starstar_for_dir(&pattern);
+	ret = !wildmatch(pattern.buf, shortname, WM_PATHNAME);
+	strbuf_release(&pattern);
+	return ret;
+}
+
+static int add_remote_url(const char *var, const char *value, void *data)
+{
+	struct string_list *remote_urls = data;
+	const char *remote_name;
+	size_t remote_name_len;
+	const char *key;
+
+	if (!parse_config_key(var, "remote", &remote_name, &remote_name_len,
+			      &key) &&
+	    remote_name &&
+	    !strcmp(key, "url"))
+		string_list_append(remote_urls, value);
+	return 0;
+}
+
+static void populate_remote_urls(struct config_include_data *inc)
+{
+	struct config_options opts;
+
+	struct config_source *store_cf = cf;
+	struct key_value_info *store_kvi = current_config_kvi;
+	enum config_scope store_scope = current_parsing_scope;
+
+	opts = *inc->opts;
+	opts.unconditional_remote_url = 1;
+
+	cf = NULL;
+	current_config_kvi = NULL;
+	current_parsing_scope = 0;
+
+	inc->remote_urls = xmalloc(sizeof(*inc->remote_urls));
+	string_list_init_dup(inc->remote_urls);
+	config_with_options(add_remote_url, inc->remote_urls, inc->config_source, &opts);
+
+	cf = store_cf;
+	current_config_kvi = store_kvi;
+	current_parsing_scope = store_scope;
+}
+
+static int forbid_remote_url(const char *var, const char *value UNUSED,
+			     void *data UNUSED)
+{
+	const char *remote_name;
+	size_t remote_name_len;
+	const char *key;
+
+	if (!parse_config_key(var, "remote", &remote_name, &remote_name_len,
+			      &key) &&
+	    remote_name &&
+	    !strcmp(key, "url"))
+		die(_("remote URLs cannot be configured in file directly or indirectly included by includeIf.hasconfig:remote.*.url"));
+	return 0;
+}
+
+static int at_least_one_url_matches_glob(const char *glob, int glob_len,
+					 struct string_list *remote_urls)
+{
+	struct strbuf pattern = STRBUF_INIT;
+	struct string_list_item *url_item;
+	int found = 0;
+
+	strbuf_add(&pattern, glob, glob_len);
+	for_each_string_list_item(url_item, remote_urls) {
+		if (!wildmatch(pattern.buf, url_item->string, WM_PATHNAME)) {
+			found = 1;
+			break;
+		}
+	}
+	strbuf_release(&pattern);
+	return found;
+}
+
+static int include_by_remote_url(struct config_include_data *inc,
+		const char *cond, size_t cond_len)
+{
+	if (inc->opts->unconditional_remote_url)
+		return 1;
+	if (!inc->remote_urls)
+		populate_remote_urls(inc);
+	return at_least_one_url_matches_glob(cond, cond_len,
+					     inc->remote_urls);
+}
+
+static int include_condition_is_true(struct config_include_data *inc,
+				     const char *cond, size_t cond_len)
+{
+	const struct config_options *opts = inc->opts;
+
+	if (skip_prefix_mem(cond, cond_len, "gitdir:", &cond, &cond_len))
+		return include_by_gitdir(opts, cond, cond_len, 0);
+	else if (skip_prefix_mem(cond, cond_len, "gitdir/i:", &cond, &cond_len))
+		return include_by_gitdir(opts, cond, cond_len, 1);
+	else if (skip_prefix_mem(cond, cond_len, "onbranch:", &cond, &cond_len))
+		return include_by_branch(cond, cond_len);
+	else if (skip_prefix_mem(cond, cond_len, "hasconfig:remote.*.url:", &cond,
+				   &cond_len))
+		return include_by_remote_url(inc, cond, cond_len);
+
+	/* unknown conditionals are always false */
+	return 0;
+}
+
+static int git_config_include(const char *var, const char *value, void *data)
+{
+	struct config_include_data *inc = data;
+	const char *cond, *key;
+	size_t cond_len;
+	int ret;
+
+	/*
+	 * Pass along all values, including "include" directives; this makes it
+	 * possible to query information on the includes themselves.
+	 */
+	ret = inc->fn(var, value, inc->data);
+	if (ret < 0)
+		return ret;
+
+	if (!strcmp(var, "include.path"))
+		ret = handle_path_include(value, inc);
+
+	if (!parse_config_key(var, "includeif", &cond, &cond_len, &key) &&
+	    cond && include_condition_is_true(inc, cond, cond_len) &&
+	    !strcmp(key, "path")) {
+		config_fn_t old_fn = inc->fn;
+
+		if (inc->opts->unconditional_remote_url)
+			inc->fn = forbid_remote_url;
+		ret = handle_path_include(value, inc);
+		inc->fn = old_fn;
+	}
+
+	return ret;
+}
+
+static void git_config_push_split_parameter(const char *key, const char *value)
+{
+	struct strbuf env = STRBUF_INIT;
+	const char *old = getenv(CONFIG_DATA_ENVIRONMENT);
+	if (old && *old) {
+		strbuf_addstr(&env, old);
+		strbuf_addch(&env, ' ');
+	}
+	sq_quote_buf(&env, key);
+	strbuf_addch(&env, '=');
+	if (value)
+		sq_quote_buf(&env, value);
+	setenv(CONFIG_DATA_ENVIRONMENT, env.buf, 1);
+	strbuf_release(&env);
+}
+
+void git_config_push_parameter(const char *text)
+{
+	const char *value;
+
+	/*
+	 * When we see:
+	 *
+	 *   section.subsection=with=equals.key=value
+	 *
+	 * we cannot tell if it means:
+	 *
+	 *   [section "subsection=with=equals"]
+	 *   key = value
+	 *
+	 * or:
+	 *
+	 *   [section]
+	 *   subsection = with=equals.key=value
+	 *
+	 * We parse left-to-right for the first "=", meaning we'll prefer to
+	 * keep the value intact over the subsection. This is historical, but
+	 * also sensible since values are more likely to contain odd or
+	 * untrusted input than a section name.
+	 *
+	 * A missing equals is explicitly allowed (as a bool-only entry).
+	 */
+	value = strchr(text, '=');
+	if (value) {
+		char *key = xmemdupz(text, value - text);
+		git_config_push_split_parameter(key, value + 1);
+		free(key);
+	} else {
+		git_config_push_split_parameter(text, NULL);
+	}
+}
+
+void git_config_push_env(const char *spec)
+{
+	char *key;
+	const char *env_name;
+	const char *env_value;
+
+	env_name = strrchr(spec, '=');
+	if (!env_name)
+		die(_("invalid config format: %s"), spec);
+	key = xmemdupz(spec, env_name - spec);
+	env_name++;
+	if (!*env_name)
+		die(_("missing environment variable name for configuration '%.*s'"),
+		    (int)(env_name - spec - 1), spec);
+
+	env_value = getenv(env_name);
+	if (!env_value)
+		die(_("missing environment variable '%s' for configuration '%.*s'"),
+		    env_name, (int)(env_name - spec - 1), spec);
+
+	git_config_push_split_parameter(key, env_value);
+	free(key);
+}
+
+static inline int iskeychar(int c)
+{
+	return isalnum(c) || c == '-';
+}
+
+/*
+ * Auxiliary function to sanity-check and split the key into the section
+ * identifier and variable name.
+ *
+ * Returns 0 on success, -1 when there is an invalid character in the key and
+ * -2 if there is no section name in the key.
+ *
+ * store_key - pointer to char* which will hold a copy of the key with
+ *             lowercase section and variable name
+ * baselen - pointer to size_t which will hold the length of the
+ *           section + subsection part, can be NULL
+ */
+int git_config_parse_key(const char *key, char **store_key, size_t *baselen_)
+{
+	size_t i, baselen;
+	int dot;
+	const char *last_dot = strrchr(key, '.');
+
+	/*
+	 * Since "key" actually contains the section name and the real
+	 * key name separated by a dot, we have to know where the dot is.
+	 */
+
+	if (last_dot == NULL || last_dot == key) {
+		error(_("key does not contain a section: %s"), key);
+		return -CONFIG_NO_SECTION_OR_NAME;
+	}
+
+	if (!last_dot[1]) {
+		error(_("key does not contain variable name: %s"), key);
+		return -CONFIG_NO_SECTION_OR_NAME;
+	}
+
+	baselen = last_dot - key;
+	if (baselen_)
+		*baselen_ = baselen;
+
+	/*
+	 * Validate the key and while at it, lower case it for matching.
+	 */
+	*store_key = xmallocz(strlen(key));
+
+	dot = 0;
+	for (i = 0; key[i]; i++) {
+		unsigned char c = key[i];
+		if (c == '.')
+			dot = 1;
+		/* Leave the extended basename untouched.. */
+		if (!dot || i > baselen) {
+			if (!iskeychar(c) ||
+			    (i == baselen + 1 && !isalpha(c))) {
+				error(_("invalid key: %s"), key);
+				goto out_free_ret_1;
+			}
+			c = tolower(c);
+		} else if (c == '\n') {
+			error(_("invalid key (newline): %s"), key);
+			goto out_free_ret_1;
+		}
+		(*store_key)[i] = c;
+	}
+
+	return 0;
+
+out_free_ret_1:
+	FREE_AND_NULL(*store_key);
+	return -CONFIG_INVALID_KEY;
+}
+
+static int config_parse_pair(const char *key, const char *value,
+			  config_fn_t fn, void *data)
+{
+	char *canonical_name;
+	int ret;
+
+	if (!strlen(key))
+		return error(_("empty config key"));
+	if (git_config_parse_key(key, &canonical_name, NULL))
+		return -1;
+
+	ret = (fn(canonical_name, value, data) < 0) ? -1 : 0;
+	free(canonical_name);
+	return ret;
+}
+
+int git_config_parse_parameter(const char *text,
+			       config_fn_t fn, void *data)
+{
+	const char *value;
+	struct strbuf **pair;
+	int ret;
+
+	pair = strbuf_split_str(text, '=', 2);
+	if (!pair[0])
+		return error(_("bogus config parameter: %s"), text);
+
+	if (pair[0]->len && pair[0]->buf[pair[0]->len - 1] == '=') {
+		strbuf_setlen(pair[0], pair[0]->len - 1);
+		value = pair[1] ? pair[1]->buf : "";
+	} else {
+		value = NULL;
+	}
+
+	strbuf_trim(pair[0]);
+	if (!pair[0]->len) {
+		strbuf_list_free(pair);
+		return error(_("bogus config parameter: %s"), text);
+	}
+
+	ret = config_parse_pair(pair[0]->buf, value, fn, data);
+	strbuf_list_free(pair);
+	return ret;
+}
+
+static int parse_config_env_list(char *env, config_fn_t fn, void *data)
+{
+	char *cur = env;
+	while (cur && *cur) {
+		const char *key = sq_dequote_step(cur, &cur);
+		if (!key)
+			return error(_("bogus format in %s"),
+				     CONFIG_DATA_ENVIRONMENT);
+
+		if (!cur || isspace(*cur)) {
+			/* old-style 'key=value' */
+			if (git_config_parse_parameter(key, fn, data) < 0)
+				return -1;
+		}
+		else if (*cur == '=') {
+			/* new-style 'key'='value' */
+			const char *value;
+
+			cur++;
+			if (*cur == '\'') {
+				/* quoted value */
+				value = sq_dequote_step(cur, &cur);
+				if (!value || (cur && !isspace(*cur))) {
+					return error(_("bogus format in %s"),
+						     CONFIG_DATA_ENVIRONMENT);
+				}
+			} else if (!*cur || isspace(*cur)) {
+				/* implicit bool: 'key'= */
+				value = NULL;
+			} else {
+				return error(_("bogus format in %s"),
+					     CONFIG_DATA_ENVIRONMENT);
+			}
+
+			if (config_parse_pair(key, value, fn, data) < 0)
+				return -1;
+		}
+		else {
+			/* unknown format */
+			return error(_("bogus format in %s"),
+				     CONFIG_DATA_ENVIRONMENT);
+		}
+
+		if (cur) {
+			while (isspace(*cur))
+				cur++;
+		}
+	}
+	return 0;
+}
+
+int git_config_from_parameters(config_fn_t fn, void *data)
+{
+	const char *env;
+	struct strbuf envvar = STRBUF_INIT;
+	struct strvec to_free = STRVEC_INIT;
+	int ret = 0;
+	char *envw = NULL;
+	struct config_source source;
+
+	memset(&source, 0, sizeof(source));
+	source.prev = cf;
+	source.origin_type = CONFIG_ORIGIN_CMDLINE;
+	cf = &source;
+
+	env = getenv(CONFIG_COUNT_ENVIRONMENT);
+	if (env) {
+		unsigned long count;
+		char *endp;
+		int i;
+
+		count = strtoul(env, &endp, 10);
+		if (*endp) {
+			ret = error(_("bogus count in %s"), CONFIG_COUNT_ENVIRONMENT);
+			goto out;
+		}
+		if (count > INT_MAX) {
+			ret = error(_("too many entries in %s"), CONFIG_COUNT_ENVIRONMENT);
+			goto out;
+		}
+
+		for (i = 0; i < count; i++) {
+			const char *key, *value;
+
+			strbuf_addf(&envvar, "GIT_CONFIG_KEY_%d", i);
+			key = getenv_safe(&to_free, envvar.buf);
+			if (!key) {
+				ret = error(_("missing config key %s"), envvar.buf);
+				goto out;
+			}
+			strbuf_reset(&envvar);
+
+			strbuf_addf(&envvar, "GIT_CONFIG_VALUE_%d", i);
+			value = getenv_safe(&to_free, envvar.buf);
+			if (!value) {
+				ret = error(_("missing config value %s"), envvar.buf);
+				goto out;
+			}
+			strbuf_reset(&envvar);
+
+			if (config_parse_pair(key, value, fn, data) < 0) {
+				ret = -1;
+				goto out;
+			}
+		}
+	}
+
+	env = getenv(CONFIG_DATA_ENVIRONMENT);
+	if (env) {
+		/* sq_dequote will write over it */
+		envw = xstrdup(env);
+		if (parse_config_env_list(envw, fn, data) < 0) {
+			ret = -1;
+			goto out;
+		}
+	}
+
+out:
+	strbuf_release(&envvar);
+	strvec_clear(&to_free);
+	free(envw);
+	cf = source.prev;
+	return ret;
+}
+
+static int get_next_char(void)
+{
+	int c = cf->do_fgetc(cf);
+
+	if (c == '\r') {
+		/* DOS like systems */
+		c = cf->do_fgetc(cf);
+		if (c != '\n') {
+			if (c != EOF)
+				cf->do_ungetc(c, cf);
+			c = '\r';
+		}
+	}
+
+	if (c != EOF && ++cf->total_len > INT_MAX) {
+		/*
+		 * This is an absurdly long config file; refuse to parse
+		 * further in order to protect downstream code from integer
+		 * overflows. Note that we can't return an error specifically,
+		 * but we can mark EOF and put trash in the return value,
+		 * which will trigger a parse error.
+		 */
+		cf->eof = 1;
+		return 0;
+	}
+
+	if (c == '\n')
+		cf->linenr++;
+	if (c == EOF) {
+		cf->eof = 1;
+		cf->linenr++;
+		c = '\n';
+	}
+	return c;
+}
+
+static char *parse_value(void)
+{
+	int quote = 0, comment = 0, space = 0;
+
+	strbuf_reset(&cf->value);
+	for (;;) {
+		int c = get_next_char();
+		if (c == '\n') {
+			if (quote) {
+				cf->linenr--;
+				return NULL;
+			}
+			return cf->value.buf;
+		}
+		if (comment)
+			continue;
+		if (isspace(c) && !quote) {
+			if (cf->value.len)
+				space++;
+			continue;
+		}
+		if (!quote) {
+			if (c == ';' || c == '#') {
+				comment = 1;
+				continue;
+			}
+		}
+		for (; space; space--)
+			strbuf_addch(&cf->value, ' ');
+		if (c == '\\') {
+			c = get_next_char();
+			switch (c) {
+			case '\n':
+				continue;
+			case 't':
+				c = '\t';
+				break;
+			case 'b':
+				c = '\b';
+				break;
+			case 'n':
+				c = '\n';
+				break;
+			/* Some characters escape as themselves */
+			case '\\': case '"':
+				break;
+			/* Reject unknown escape sequences */
+			default:
+				return NULL;
+			}
+			strbuf_addch(&cf->value, c);
+			continue;
+		}
+		if (c == '"') {
+			quote = 1-quote;
+			continue;
+		}
+		strbuf_addch(&cf->value, c);
+	}
+}
+
+static int get_value(config_fn_t fn, void *data, struct strbuf *name)
+{
+	int c;
+	char *value;
+	int ret;
+
+	/* Get the full name */
+	for (;;) {
+		c = get_next_char();
+		if (cf->eof)
+			break;
+		if (!iskeychar(c))
+			break;
+		strbuf_addch(name, tolower(c));
+	}
+
+	while (c == ' ' || c == '\t')
+		c = get_next_char();
+
+	value = NULL;
+	if (c != '\n') {
+		if (c != '=')
+			return -1;
+		value = parse_value();
+		if (!value)
+			return -1;
+	}
+	/*
+	 * We already consumed the \n, but we need linenr to point to
+	 * the line we just parsed during the call to fn to get
+	 * accurate line number in error messages.
+	 */
+	cf->linenr--;
+	ret = fn(name->buf, value, data);
+	if (ret >= 0)
+		cf->linenr++;
+	return ret;
+}
+
+static int get_extended_base_var(struct strbuf *name, int c)
+{
+	cf->subsection_case_sensitive = 0;
+	do {
+		if (c == '\n')
+			goto error_incomplete_line;
+		c = get_next_char();
+	} while (isspace(c));
+
+	/* We require the format to be '[base "extension"]' */
+	if (c != '"')
+		return -1;
+	strbuf_addch(name, '.');
+
+	for (;;) {
+		int c = get_next_char();
+		if (c == '\n')
+			goto error_incomplete_line;
+		if (c == '"')
+			break;
+		if (c == '\\') {
+			c = get_next_char();
+			if (c == '\n')
+				goto error_incomplete_line;
+		}
+		strbuf_addch(name, c);
+	}
+
+	/* Final ']' */
+	if (get_next_char() != ']')
+		return -1;
+	return 0;
+error_incomplete_line:
+	cf->linenr--;
+	return -1;
+}
+
+static int get_base_var(struct strbuf *name)
+{
+	cf->subsection_case_sensitive = 1;
+	for (;;) {
+		int c = get_next_char();
+		if (cf->eof)
+			return -1;
+		if (c == ']')
+			return 0;
+		if (isspace(c))
+			return get_extended_base_var(name, c);
+		if (!iskeychar(c) && c != '.')
+			return -1;
+		strbuf_addch(name, tolower(c));
+	}
+}
+
+struct parse_event_data {
+	enum config_event_t previous_type;
+	size_t previous_offset;
+	const struct config_options *opts;
+};
+
+static int do_event(enum config_event_t type, struct parse_event_data *data)
+{
+	size_t offset;
+
+	if (!data->opts || !data->opts->event_fn)
+		return 0;
+
+	if (type == CONFIG_EVENT_WHITESPACE &&
+	    data->previous_type == type)
+		return 0;
+
+	offset = cf->do_ftell(cf);
+	/*
+	 * At EOF, the parser always "inserts" an extra '\n', therefore
+	 * the end offset of the event is the current file position, otherwise
+	 * we will already have advanced to the next event.
+	 */
+	if (type != CONFIG_EVENT_EOF)
+		offset--;
+
+	if (data->previous_type != CONFIG_EVENT_EOF &&
+	    data->opts->event_fn(data->previous_type, data->previous_offset,
+				 offset, data->opts->event_fn_data) < 0)
+		return -1;
+
+	data->previous_type = type;
+	data->previous_offset = offset;
+
+	return 0;
+}
+
+static int git_parse_source(config_fn_t fn, void *data,
+			    const struct config_options *opts)
+{
+	int comment = 0;
+	size_t baselen = 0;
+	struct strbuf *var = &cf->var;
+	int error_return = 0;
+	char *error_msg = NULL;
+
+	/* U+FEFF Byte Order Mark in UTF8 */
+	const char *bomptr = utf8_bom;
+
+	/* For the parser event callback */
+	struct parse_event_data event_data = {
+		CONFIG_EVENT_EOF, 0, opts
+	};
+
+	for (;;) {
+		int c;
+
+		c = get_next_char();
+		if (bomptr && *bomptr) {
+			/* We are at the file beginning; skip UTF8-encoded BOM
+			 * if present. Sane editors won't put this in on their
+			 * own, but e.g. Windows Notepad will do it happily. */
+			if (c == (*bomptr & 0377)) {
+				bomptr++;
+				continue;
+			} else {
+				/* Do not tolerate partial BOM. */
+				if (bomptr != utf8_bom)
+					break;
+				/* No BOM at file beginning. Cool. */
+				bomptr = NULL;
+			}
+		}
+		if (c == '\n') {
+			if (cf->eof) {
+				if (do_event(CONFIG_EVENT_EOF, &event_data) < 0)
+					return -1;
+				return 0;
+			}
+			if (do_event(CONFIG_EVENT_WHITESPACE, &event_data) < 0)
+				return -1;
+			comment = 0;
+			continue;
+		}
+		if (comment)
+			continue;
+		if (isspace(c)) {
+			if (do_event(CONFIG_EVENT_WHITESPACE, &event_data) < 0)
+					return -1;
+			continue;
+		}
+		if (c == '#' || c == ';') {
+			if (do_event(CONFIG_EVENT_COMMENT, &event_data) < 0)
+					return -1;
+			comment = 1;
+			continue;
+		}
+		if (c == '[') {
+			if (do_event(CONFIG_EVENT_SECTION, &event_data) < 0)
+					return -1;
+
+			/* Reset prior to determining a new stem */
+			strbuf_reset(var);
+			if (get_base_var(var) < 0 || var->len < 1)
+				break;
+			strbuf_addch(var, '.');
+			baselen = var->len;
+			continue;
+		}
+		if (!isalpha(c))
+			break;
+
+		if (do_event(CONFIG_EVENT_ENTRY, &event_data) < 0)
+			return -1;
+
+		/*
+		 * Truncate the var name back to the section header
+		 * stem prior to grabbing the suffix part of the name
+		 * and the value.
+		 */
+		strbuf_setlen(var, baselen);
+		strbuf_addch(var, tolower(c));
+		if (get_value(fn, data, var) < 0)
+			break;
+	}
+
+	if (do_event(CONFIG_EVENT_ERROR, &event_data) < 0)
+		return -1;
+
+	switch (cf->origin_type) {
+	case CONFIG_ORIGIN_BLOB:
+		error_msg = xstrfmt(_("bad config line %d in blob %s"),
+				      cf->linenr, cf->name);
+		break;
+	case CONFIG_ORIGIN_FILE:
+		error_msg = xstrfmt(_("bad config line %d in file %s"),
+				      cf->linenr, cf->name);
+		break;
+	case CONFIG_ORIGIN_STDIN:
+		error_msg = xstrfmt(_("bad config line %d in standard input"),
+				      cf->linenr);
+		break;
+	case CONFIG_ORIGIN_SUBMODULE_BLOB:
+		error_msg = xstrfmt(_("bad config line %d in submodule-blob %s"),
+				       cf->linenr, cf->name);
+		break;
+	case CONFIG_ORIGIN_CMDLINE:
+		error_msg = xstrfmt(_("bad config line %d in command line %s"),
+				       cf->linenr, cf->name);
+		break;
+	default:
+		error_msg = xstrfmt(_("bad config line %d in %s"),
+				      cf->linenr, cf->name);
+	}
+
+	switch (opts && opts->error_action ?
+		opts->error_action :
+		cf->default_error_action) {
+	case CONFIG_ERROR_DIE:
+		die("%s", error_msg);
+		break;
+	case CONFIG_ERROR_ERROR:
+		error_return = error("%s", error_msg);
+		break;
+	case CONFIG_ERROR_SILENT:
+		error_return = -1;
+		break;
+	case CONFIG_ERROR_UNSET:
+		BUG("config error action unset");
+	}
+
+	free(error_msg);
+	return error_return;
+}
+
+static uintmax_t get_unit_factor(const char *end)
+{
+	if (!*end)
+		return 1;
+	else if (!strcasecmp(end, "k"))
+		return 1024;
+	else if (!strcasecmp(end, "m"))
+		return 1024 * 1024;
+	else if (!strcasecmp(end, "g"))
+		return 1024 * 1024 * 1024;
+	return 0;
+}
+
+static int git_parse_signed(const char *value, intmax_t *ret, intmax_t max)
+{
+	if (value && *value) {
+		char *end;
+		intmax_t val;
+		intmax_t factor;
+
+		if (max < 0)
+			BUG("max must be a positive integer");
+
+		errno = 0;
+		val = strtoimax(value, &end, 0);
+		if (errno == ERANGE)
+			return 0;
+		if (end == value) {
+			errno = EINVAL;
+			return 0;
+		}
+		factor = get_unit_factor(end);
+		if (!factor) {
+			errno = EINVAL;
+			return 0;
+		}
+		if ((val < 0 && -max / factor > val) ||
+		    (val > 0 && max / factor < val)) {
+			errno = ERANGE;
+			return 0;
+		}
+		val *= factor;
+		*ret = val;
+		return 1;
+	}
+	errno = EINVAL;
+	return 0;
+}
+
+static int git_parse_unsigned(const char *value, uintmax_t *ret, uintmax_t max)
+{
+	if (value && *value) {
+		char *end;
+		uintmax_t val;
+		uintmax_t factor;
+
+		/* negative values would be accepted by strtoumax */
+		if (strchr(value, '-')) {
+			errno = EINVAL;
+			return 0;
+		}
+		errno = 0;
+		val = strtoumax(value, &end, 0);
+		if (errno == ERANGE)
+			return 0;
+		if (end == value) {
+			errno = EINVAL;
+			return 0;
+		}
+		factor = get_unit_factor(end);
+		if (!factor) {
+			errno = EINVAL;
+			return 0;
+		}
+		if (unsigned_mult_overflows(factor, val) ||
+		    factor * val > max) {
+			errno = ERANGE;
+			return 0;
+		}
+		val *= factor;
+		*ret = val;
+		return 1;
+	}
+	errno = EINVAL;
+	return 0;
+}
+
+int git_parse_int(const char *value, int *ret)
+{
+	intmax_t tmp;
+	if (!git_parse_signed(value, &tmp, maximum_signed_value_of_type(int)))
+		return 0;
+	*ret = tmp;
+	return 1;
+}
+
+static int git_parse_int64(const char *value, int64_t *ret)
+{
+	intmax_t tmp;
+	if (!git_parse_signed(value, &tmp, maximum_signed_value_of_type(int64_t)))
+		return 0;
+	*ret = tmp;
+	return 1;
+}
+
+int git_parse_ulong(const char *value, unsigned long *ret)
+{
+	uintmax_t tmp;
+	if (!git_parse_unsigned(value, &tmp, maximum_unsigned_value_of_type(long)))
+		return 0;
+	*ret = tmp;
+	return 1;
+}
+
+int git_parse_ssize_t(const char *value, ssize_t *ret)
+{
+	intmax_t tmp;
+	if (!git_parse_signed(value, &tmp, maximum_signed_value_of_type(ssize_t)))
+		return 0;
+	*ret = tmp;
+	return 1;
+}
+
+NORETURN
+static void die_bad_number(const char *name, const char *value)
+{
+	const char *error_type = (errno == ERANGE) ?
+		N_("out of range") : N_("invalid unit");
+	const char *bad_numeric = N_("bad numeric config value '%s' for '%s': %s");
+
+	if (!value)
+		value = "";
+
+	if (!(cf && cf->name))
+		die(_(bad_numeric), value, name, _(error_type));
+
+	switch (cf->origin_type) {
+	case CONFIG_ORIGIN_BLOB:
+		die(_("bad numeric config value '%s' for '%s' in blob %s: %s"),
+		    value, name, cf->name, _(error_type));
+	case CONFIG_ORIGIN_FILE:
+		die(_("bad numeric config value '%s' for '%s' in file %s: %s"),
+		    value, name, cf->name, _(error_type));
+	case CONFIG_ORIGIN_STDIN:
+		die(_("bad numeric config value '%s' for '%s' in standard input: %s"),
+		    value, name, _(error_type));
+	case CONFIG_ORIGIN_SUBMODULE_BLOB:
+		die(_("bad numeric config value '%s' for '%s' in submodule-blob %s: %s"),
+		    value, name, cf->name, _(error_type));
+	case CONFIG_ORIGIN_CMDLINE:
+		die(_("bad numeric config value '%s' for '%s' in command line %s: %s"),
+		    value, name, cf->name, _(error_type));
+	default:
+		die(_("bad numeric config value '%s' for '%s' in %s: %s"),
+		    value, name, cf->name, _(error_type));
+	}
+}
+
+int git_config_int(const char *name, const char *value)
+{
+	int ret;
+	if (!git_parse_int(value, &ret))
+		die_bad_number(name, value);
+	return ret;
+}
+
+int64_t git_config_int64(const char *name, const char *value)
+{
+	int64_t ret;
+	if (!git_parse_int64(value, &ret))
+		die_bad_number(name, value);
+	return ret;
+}
+
+unsigned long git_config_ulong(const char *name, const char *value)
+{
+	unsigned long ret;
+	if (!git_parse_ulong(value, &ret))
+		die_bad_number(name, value);
+	return ret;
+}
+
+ssize_t git_config_ssize_t(const char *name, const char *value)
+{
+	ssize_t ret;
+	if (!git_parse_ssize_t(value, &ret))
+		die_bad_number(name, value);
+	return ret;
+}
+
+static int git_parse_maybe_bool_text(const char *value)
+{
+	if (!value)
+		return 1;
+	if (!*value)
+		return 0;
+	if (!strcasecmp(value, "true")
+	    || !strcasecmp(value, "yes")
+	    || !strcasecmp(value, "on"))
+		return 1;
+	if (!strcasecmp(value, "false")
+	    || !strcasecmp(value, "no")
+	    || !strcasecmp(value, "off"))
+		return 0;
+	return -1;
+}
+
+static const struct fsync_component_name {
+	const char *name;
+	enum fsync_component component_bits;
+} fsync_component_names[] = {
+	{ "loose-object", FSYNC_COMPONENT_LOOSE_OBJECT },
+	{ "pack", FSYNC_COMPONENT_PACK },
+	{ "pack-metadata", FSYNC_COMPONENT_PACK_METADATA },
+	{ "commit-graph", FSYNC_COMPONENT_COMMIT_GRAPH },
+	{ "index", FSYNC_COMPONENT_INDEX },
+	{ "objects", FSYNC_COMPONENTS_OBJECTS },
+	{ "reference", FSYNC_COMPONENT_REFERENCE },
+	{ "derived-metadata", FSYNC_COMPONENTS_DERIVED_METADATA },
+	{ "committed", FSYNC_COMPONENTS_COMMITTED },
+	{ "added", FSYNC_COMPONENTS_ADDED },
+	{ "all", FSYNC_COMPONENTS_ALL },
+};
+
+static enum fsync_component parse_fsync_components(const char *var, const char *string)
+{
+	enum fsync_component current = FSYNC_COMPONENTS_PLATFORM_DEFAULT;
+	enum fsync_component positive = 0, negative = 0;
+
+	while (string) {
+		int i;
+		size_t len;
+		const char *ep;
+		int negated = 0;
+		int found = 0;
+
+		string = string + strspn(string, ", \t\n\r");
+		ep = strchrnul(string, ',');
+		len = ep - string;
+		if (!strcmp(string, "none")) {
+			current = FSYNC_COMPONENT_NONE;
+			goto next_name;
+		}
+
+		if (*string == '-') {
+			negated = 1;
+			string++;
+			len--;
+			if (!len)
+				warning(_("invalid value for variable %s"), var);
+		}
+
+		if (!len)
+			break;
+
+		for (i = 0; i < ARRAY_SIZE(fsync_component_names); ++i) {
+			const struct fsync_component_name *n = &fsync_component_names[i];
+
+			if (strncmp(n->name, string, len))
+				continue;
+
+			found = 1;
+			if (negated)
+				negative |= n->component_bits;
+			else
+				positive |= n->component_bits;
+		}
+
+		if (!found) {
+			char *component = xstrndup(string, len);
+			warning(_("ignoring unknown core.fsync component '%s'"), component);
+			free(component);
+		}
+
+next_name:
+		string = ep;
+	}
+
+	return (current & ~negative) | positive;
+}
+
+int git_parse_maybe_bool(const char *value)
+{
+	int v = git_parse_maybe_bool_text(value);
+	if (0 <= v)
+		return v;
+	if (git_parse_int(value, &v))
+		return !!v;
+	return -1;
+}
+
+int git_config_bool_or_int(const char *name, const char *value, int *is_bool)
+{
+	int v = git_parse_maybe_bool_text(value);
+	if (0 <= v) {
+		*is_bool = 1;
+		return v;
+	}
+	*is_bool = 0;
+	return git_config_int(name, value);
+}
+
+int git_config_bool(const char *name, const char *value)
+{
+	int v = git_parse_maybe_bool(value);
+	if (v < 0)
+		die(_("bad boolean config value '%s' for '%s'"), value, name);
+	return v;
+}
+
+int git_config_string(const char **dest, const char *var, const char *value)
+{
+	if (!value)
+		return config_error_nonbool(var);
+	*dest = xstrdup(value);
+	return 0;
+}
+
+int git_config_pathname(const char **dest, const char *var, const char *value)
+{
+	if (!value)
+		return config_error_nonbool(var);
+	*dest = interpolate_path(value, 0);
+	if (!*dest)
+		die(_("failed to expand user dir in: '%s'"), value);
+	return 0;
+}
+
+int git_config_expiry_date(timestamp_t *timestamp, const char *var, const char *value)
+{
+	if (!value)
+		return config_error_nonbool(var);
+	if (parse_expiry_date(value, timestamp))
+		return error(_("'%s' for '%s' is not a valid timestamp"),
+			     value, var);
+	return 0;
+}
+
+int git_config_color(char *dest, const char *var, const char *value)
+{
+	if (!value)
+		return config_error_nonbool(var);
+	if (color_parse(value, dest) < 0)
+		return -1;
+	return 0;
+}
+
+static int git_default_core_config(const char *var, const char *value, void *cb)
+{
+	/* This needs a better name */
+	if (!strcmp(var, "core.filemode")) {
+		trust_executable_bit = git_config_bool(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "core.trustctime")) {
+		trust_ctime = git_config_bool(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "core.checkstat")) {
+		if (!strcasecmp(value, "default"))
+			check_stat = 1;
+		else if (!strcasecmp(value, "minimal"))
+			check_stat = 0;
+	}
+
+	if (!strcmp(var, "core.quotepath")) {
+		quote_path_fully = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.symlinks")) {
+		has_symlinks = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.ignorecase")) {
+		ignore_case = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.attributesfile"))
+		return git_config_pathname(&git_attributes_file, var, value);
+
+	if (!strcmp(var, "core.hookspath"))
+		return git_config_pathname(&git_hooks_path, var, value);
+
+	if (!strcmp(var, "core.bare")) {
+		is_bare_repository_cfg = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.ignorestat")) {
+		assume_unchanged = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.prefersymlinkrefs")) {
+		prefer_symlink_refs = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.logallrefupdates")) {
+		if (value && !strcasecmp(value, "always"))
+			log_all_ref_updates = LOG_REFS_ALWAYS;
+		else if (git_config_bool(var, value))
+			log_all_ref_updates = LOG_REFS_NORMAL;
+		else
+			log_all_ref_updates = LOG_REFS_NONE;
+		return 0;
+	}
+
+	if (!strcmp(var, "core.warnambiguousrefs")) {
+		warn_ambiguous_refs = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.abbrev")) {
+		if (!value)
+			return config_error_nonbool(var);
+		if (!strcasecmp(value, "auto"))
+			default_abbrev = -1;
+		else if (!git_parse_maybe_bool_text(value))
+			default_abbrev = the_hash_algo->hexsz;
+		else {
+			int abbrev = git_config_int(var, value);
+			if (abbrev < minimum_abbrev || abbrev > the_hash_algo->hexsz)
+				return error(_("abbrev length out of range: %d"), abbrev);
+			default_abbrev = abbrev;
+		}
+		return 0;
+	}
+
+	if (!strcmp(var, "core.disambiguate"))
+		return set_disambiguate_hint_config(var, value);
+
+	if (!strcmp(var, "core.loosecompression")) {
+		int level = git_config_int(var, value);
+		if (level == -1)
+			level = Z_DEFAULT_COMPRESSION;
+		else if (level < 0 || level > Z_BEST_COMPRESSION)
+			die(_("bad zlib compression level %d"), level);
+		zlib_compression_level = level;
+		zlib_compression_seen = 1;
+		return 0;
+	}
+
+	if (!strcmp(var, "core.compression")) {
+		int level = git_config_int(var, value);
+		if (level == -1)
+			level = Z_DEFAULT_COMPRESSION;
+		else if (level < 0 || level > Z_BEST_COMPRESSION)
+			die(_("bad zlib compression level %d"), level);
+		if (!zlib_compression_seen)
+			zlib_compression_level = level;
+		if (!pack_compression_seen)
+			pack_compression_level = level;
+		return 0;
+	}
+
+	if (!strcmp(var, "core.packedgitwindowsize")) {
+		int pgsz_x2 = getpagesize() * 2;
+		packed_git_window_size = git_config_ulong(var, value);
+
+		/* This value must be multiple of (pagesize * 2) */
+		packed_git_window_size /= pgsz_x2;
+		if (packed_git_window_size < 1)
+			packed_git_window_size = 1;
+		packed_git_window_size *= pgsz_x2;
+		return 0;
+	}
+
+	if (!strcmp(var, "core.bigfilethreshold")) {
+		big_file_threshold = git_config_ulong(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.packedgitlimit")) {
+		packed_git_limit = git_config_ulong(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.deltabasecachelimit")) {
+		delta_base_cache_limit = git_config_ulong(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.autocrlf")) {
+		if (value && !strcasecmp(value, "input")) {
+			auto_crlf = AUTO_CRLF_INPUT;
+			return 0;
+		}
+		auto_crlf = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.safecrlf")) {
+		int eol_rndtrp_die;
+		if (value && !strcasecmp(value, "warn")) {
+			global_conv_flags_eol = CONV_EOL_RNDTRP_WARN;
+			return 0;
+		}
+		eol_rndtrp_die = git_config_bool(var, value);
+		global_conv_flags_eol = eol_rndtrp_die ?
+			CONV_EOL_RNDTRP_DIE : 0;
+		return 0;
+	}
+
+	if (!strcmp(var, "core.eol")) {
+		if (value && !strcasecmp(value, "lf"))
+			core_eol = EOL_LF;
+		else if (value && !strcasecmp(value, "crlf"))
+			core_eol = EOL_CRLF;
+		else if (value && !strcasecmp(value, "native"))
+			core_eol = EOL_NATIVE;
+		else
+			core_eol = EOL_UNSET;
+		return 0;
+	}
+
+	if (!strcmp(var, "core.checkroundtripencoding")) {
+		check_roundtrip_encoding = xstrdup(value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.notesref")) {
+		notes_ref_name = xstrdup(value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.editor"))
+		return git_config_string(&editor_program, var, value);
+
+	if (!strcmp(var, "core.commentchar")) {
+		if (!value)
+			return config_error_nonbool(var);
+		else if (!strcasecmp(value, "auto"))
+			auto_comment_line_char = 1;
+		else if (value[0] && !value[1]) {
+			comment_line_char = value[0];
+			auto_comment_line_char = 0;
+		} else
+			return error(_("core.commentChar should only be one character"));
+		return 0;
+	}
+
+	if (!strcmp(var, "core.askpass"))
+		return git_config_string(&askpass_program, var, value);
+
+	if (!strcmp(var, "core.excludesfile"))
+		return git_config_pathname(&excludes_file, var, value);
+
+	if (!strcmp(var, "core.whitespace")) {
+		if (!value)
+			return config_error_nonbool(var);
+		whitespace_rule_cfg = parse_whitespace_rule(value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.fsync")) {
+		if (!value)
+			return config_error_nonbool(var);
+		fsync_components = parse_fsync_components(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.fsyncmethod")) {
+		if (!value)
+			return config_error_nonbool(var);
+		if (!strcmp(value, "fsync"))
+			fsync_method = FSYNC_METHOD_FSYNC;
+		else if (!strcmp(value, "writeout-only"))
+			fsync_method = FSYNC_METHOD_WRITEOUT_ONLY;
+		else if (!strcmp(value, "batch"))
+			fsync_method = FSYNC_METHOD_BATCH;
+		else
+			warning(_("ignoring unknown core.fsyncMethod value '%s'"), value);
+
+	}
+
+	if (!strcmp(var, "core.fsyncobjectfiles")) {
+		if (fsync_object_files < 0)
+			warning(_("core.fsyncObjectFiles is deprecated; use core.fsync instead"));
+		fsync_object_files = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.preloadindex")) {
+		core_preload_index = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.createobject")) {
+		if (!strcmp(value, "rename"))
+			object_creation_mode = OBJECT_CREATION_USES_RENAMES;
+		else if (!strcmp(value, "link"))
+			object_creation_mode = OBJECT_CREATION_USES_HARDLINKS;
+		else
+			die(_("invalid mode for object creation: %s"), value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.sparsecheckout")) {
+		core_apply_sparse_checkout = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.sparsecheckoutcone")) {
+		core_sparse_checkout_cone = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.precomposeunicode")) {
+		precomposed_unicode = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.protecthfs")) {
+		protect_hfs = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.protectntfs")) {
+		protect_ntfs = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "core.usereplacerefs")) {
+		read_replace_refs = git_config_bool(var, value);
+		return 0;
+	}
+
+	/* Add other config variables here and to Documentation/config.txt. */
+	return platform_core_config(var, value, cb);
+}
+
+static int git_default_sparse_config(const char *var, const char *value)
+{
+	if (!strcmp(var, "sparse.expectfilesoutsideofpatterns")) {
+		sparse_expect_files_outside_of_patterns = git_config_bool(var, value);
+		return 0;
+	}
+
+	/* Add other config variables here and to Documentation/config/sparse.txt. */
+	return 0;
+}
+
+static int git_default_i18n_config(const char *var, const char *value)
+{
+	if (!strcmp(var, "i18n.commitencoding"))
+		return git_config_string(&git_commit_encoding, var, value);
+
+	if (!strcmp(var, "i18n.logoutputencoding"))
+		return git_config_string(&git_log_output_encoding, var, value);
+
+	/* Add other config variables here and to Documentation/config.txt. */
+	return 0;
+}
+
+static int git_default_branch_config(const char *var, const char *value)
+{
+	if (!strcmp(var, "branch.autosetupmerge")) {
+		if (value && !strcmp(value, "always")) {
+			git_branch_track = BRANCH_TRACK_ALWAYS;
+			return 0;
+		} else if (value && !strcmp(value, "inherit")) {
+			git_branch_track = BRANCH_TRACK_INHERIT;
+			return 0;
+		} else if (value && !strcmp(value, "simple")) {
+			git_branch_track = BRANCH_TRACK_SIMPLE;
+			return 0;
+		}
+		git_branch_track = git_config_bool(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "branch.autosetuprebase")) {
+		if (!value)
+			return config_error_nonbool(var);
+		else if (!strcmp(value, "never"))
+			autorebase = AUTOREBASE_NEVER;
+		else if (!strcmp(value, "local"))
+			autorebase = AUTOREBASE_LOCAL;
+		else if (!strcmp(value, "remote"))
+			autorebase = AUTOREBASE_REMOTE;
+		else if (!strcmp(value, "always"))
+			autorebase = AUTOREBASE_ALWAYS;
+		else
+			return error(_("malformed value for %s"), var);
+		return 0;
+	}
+
+	/* Add other config variables here and to Documentation/config.txt. */
+	return 0;
+}
+
+static int git_default_push_config(const char *var, const char *value)
+{
+	if (!strcmp(var, "push.default")) {
+		if (!value)
+			return config_error_nonbool(var);
+		else if (!strcmp(value, "nothing"))
+			push_default = PUSH_DEFAULT_NOTHING;
+		else if (!strcmp(value, "matching"))
+			push_default = PUSH_DEFAULT_MATCHING;
+		else if (!strcmp(value, "simple"))
+			push_default = PUSH_DEFAULT_SIMPLE;
+		else if (!strcmp(value, "upstream"))
+			push_default = PUSH_DEFAULT_UPSTREAM;
+		else if (!strcmp(value, "tracking")) /* deprecated */
+			push_default = PUSH_DEFAULT_UPSTREAM;
+		else if (!strcmp(value, "current"))
+			push_default = PUSH_DEFAULT_CURRENT;
+		else {
+			error(_("malformed value for %s: %s"), var, value);
+			return error(_("must be one of nothing, matching, simple, "
+				       "upstream or current"));
+		}
+		return 0;
+	}
+
+	/* Add other config variables here and to Documentation/config.txt. */
+	return 0;
+}
+
+static int git_default_mailmap_config(const char *var, const char *value)
+{
+	if (!strcmp(var, "mailmap.file"))
+		return git_config_pathname(&git_mailmap_file, var, value);
+	if (!strcmp(var, "mailmap.blob"))
+		return git_config_string(&git_mailmap_blob, var, value);
+
+	/* Add other config variables here and to Documentation/config.txt. */
+	return 0;
+}
+
+int git_default_config(const char *var, const char *value, void *cb)
+{
+	if (starts_with(var, "core."))
+		return git_default_core_config(var, value, cb);
+
+	if (starts_with(var, "user.") ||
+	    starts_with(var, "author.") ||
+	    starts_with(var, "committer."))
+		return git_ident_config(var, value, cb);
+
+	if (starts_with(var, "i18n."))
+		return git_default_i18n_config(var, value);
+
+	if (starts_with(var, "branch."))
+		return git_default_branch_config(var, value);
+
+	if (starts_with(var, "push."))
+		return git_default_push_config(var, value);
+
+	if (starts_with(var, "mailmap."))
+		return git_default_mailmap_config(var, value);
+
+	if (starts_with(var, "advice.") || starts_with(var, "color.advice"))
+		return git_default_advice_config(var, value);
+
+	if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
+		pager_use_color = git_config_bool(var,value);
+		return 0;
+	}
+
+	if (!strcmp(var, "pack.packsizelimit")) {
+		pack_size_limit_cfg = git_config_ulong(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "pack.compression")) {
+		int level = git_config_int(var, value);
+		if (level == -1)
+			level = Z_DEFAULT_COMPRESSION;
+		else if (level < 0 || level > Z_BEST_COMPRESSION)
+			die(_("bad pack compression level %d"), level);
+		pack_compression_level = level;
+		pack_compression_seen = 1;
+		return 0;
+	}
+
+	if (starts_with(var, "sparse."))
+		return git_default_sparse_config(var, value);
+
+	/* Add other config variables here and to Documentation/config.txt. */
+	return 0;
+}
+
+/*
+ * All source specific fields in the union, die_on_error, name and the callbacks
+ * fgetc, ungetc, ftell of top need to be initialized before calling
+ * this function.
+ */
+static int do_config_from(struct config_source *top, config_fn_t fn, void *data,
+			  const struct config_options *opts)
+{
+	int ret;
+
+	/* push config-file parsing state stack */
+	top->prev = cf;
+	top->linenr = 1;
+	top->eof = 0;
+	top->total_len = 0;
+	strbuf_init(&top->value, 1024);
+	strbuf_init(&top->var, 1024);
+	cf = top;
+
+	ret = git_parse_source(fn, data, opts);
+
+	/* pop config-file parsing state stack */
+	strbuf_release(&top->value);
+	strbuf_release(&top->var);
+	cf = top->prev;
+
+	return ret;
+}
+
+static int do_config_from_file(config_fn_t fn,
+		const enum config_origin_type origin_type,
+		const char *name, const char *path, FILE *f,
+		void *data, const struct config_options *opts)
+{
+	struct config_source top;
+	int ret;
+
+	top.u.file = f;
+	top.origin_type = origin_type;
+	top.name = name;
+	top.path = path;
+	top.default_error_action = CONFIG_ERROR_DIE;
+	top.do_fgetc = config_file_fgetc;
+	top.do_ungetc = config_file_ungetc;
+	top.do_ftell = config_file_ftell;
+
+	flockfile(f);
+	ret = do_config_from(&top, fn, data, opts);
+	funlockfile(f);
+	return ret;
+}
+
+static int git_config_from_stdin(config_fn_t fn, void *data)
+{
+	return do_config_from_file(fn, CONFIG_ORIGIN_STDIN, "", NULL, stdin,
+				   data, NULL);
+}
+
+int git_config_from_file_with_options(config_fn_t fn, const char *filename,
+				      void *data,
+				      const struct config_options *opts)
+{
+	int ret = -1;
+	FILE *f;
+
+	if (!filename)
+		BUG("filename cannot be NULL");
+	f = fopen_or_warn(filename, "r");
+	if (f) {
+		ret = do_config_from_file(fn, CONFIG_ORIGIN_FILE, filename,
+					  filename, f, data, opts);
+		fclose(f);
+	}
+	return ret;
+}
+
+int git_config_from_file(config_fn_t fn, const char *filename, void *data)
+{
+	return git_config_from_file_with_options(fn, filename, data, NULL);
+}
+
+int git_config_from_mem(config_fn_t fn,
+			const enum config_origin_type origin_type,
+			const char *name, const char *buf, size_t len,
+			void *data, const struct config_options *opts)
+{
+	struct config_source top;
+
+	top.u.buf.buf = buf;
+	top.u.buf.len = len;
+	top.u.buf.pos = 0;
+	top.origin_type = origin_type;
+	top.name = name;
+	top.path = NULL;
+	top.default_error_action = CONFIG_ERROR_ERROR;
+	top.do_fgetc = config_buf_fgetc;
+	top.do_ungetc = config_buf_ungetc;
+	top.do_ftell = config_buf_ftell;
+
+	return do_config_from(&top, fn, data, opts);
+}
+
+int git_config_from_blob_oid(config_fn_t fn,
+			      const char *name,
+			      struct repository *repo,
+			      const struct object_id *oid,
+			      void *data)
+{
+	enum object_type type;
+	char *buf;
+	unsigned long size;
+	int ret;
+
+	buf = repo_read_object_file(repo, oid, &type, &size);
+	if (!buf)
+		return error(_("unable to load config blob object '%s'"), name);
+	if (type != OBJ_BLOB) {
+		free(buf);
+		return error(_("reference '%s' does not point to a blob"), name);
+	}
+
+	ret = git_config_from_mem(fn, CONFIG_ORIGIN_BLOB, name, buf, size,
+				  data, NULL);
+	free(buf);
+
+	return ret;
+}
+
+static int git_config_from_blob_ref(config_fn_t fn,
+				    struct repository *repo,
+				    const char *name,
+				    void *data)
+{
+	struct object_id oid;
+
+	if (repo_get_oid(repo, name, &oid) < 0)
+		return error(_("unable to resolve config blob '%s'"), name);
+	return git_config_from_blob_oid(fn, name, repo, &oid, data);
+}
+
+char *git_system_config(void)
+{
+	char *system_config = xstrdup_or_null(getenv("GIT_CONFIG_SYSTEM"));
+	if (!system_config)
+		system_config = system_path(ETC_GITCONFIG);
+	normalize_path_copy(system_config, system_config);
+	return system_config;
+}
+
+void git_global_config(char **user_out, char **xdg_out)
+{
+	char *user_config = xstrdup_or_null(getenv("GIT_CONFIG_GLOBAL"));
+	char *xdg_config = NULL;
+
+	if (!user_config) {
+		user_config = interpolate_path("~/.gitconfig", 0);
+		xdg_config = xdg_config_home("config");
+	}
+
+	*user_out = user_config;
+	*xdg_out = xdg_config;
+}
+
+/*
+ * Parse environment variable 'k' as a boolean (in various
+ * possible spellings); if missing, use the default value 'def'.
+ */
+int git_env_bool(const char *k, int def)
+{
+	const char *v = getenv(k);
+	return v ? git_config_bool(k, v) : def;
+}
+
+/*
+ * Parse environment variable 'k' as ulong with possibly a unit
+ * suffix; if missing, use the default value 'val'.
+ */
+unsigned long git_env_ulong(const char *k, unsigned long val)
+{
+	const char *v = getenv(k);
+	if (v && !git_parse_ulong(v, &val))
+		die(_("failed to parse %s"), k);
+	return val;
+}
+
+int git_config_system(void)
+{
+	return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
+}
+
+static int do_git_config_sequence(const struct config_options *opts,
+				  config_fn_t fn, void *data)
+{
+	int ret = 0;
+	char *system_config = git_system_config();
+	char *xdg_config = NULL;
+	char *user_config = NULL;
+	char *repo_config;
+	enum config_scope prev_parsing_scope = current_parsing_scope;
+
+	if (opts->commondir)
+		repo_config = mkpathdup("%s/config", opts->commondir);
+	else if (opts->git_dir)
+		BUG("git_dir without commondir");
+	else
+		repo_config = NULL;
+
+	current_parsing_scope = CONFIG_SCOPE_SYSTEM;
+	if (git_config_system() && system_config &&
+	    !access_or_die(system_config, R_OK,
+			   opts->system_gently ? ACCESS_EACCES_OK : 0))
+		ret += git_config_from_file(fn, system_config, data);
+
+	current_parsing_scope = CONFIG_SCOPE_GLOBAL;
+	git_global_config(&user_config, &xdg_config);
+
+	if (xdg_config && !access_or_die(xdg_config, R_OK, ACCESS_EACCES_OK))
+		ret += git_config_from_file(fn, xdg_config, data);
+
+	if (user_config && !access_or_die(user_config, R_OK, ACCESS_EACCES_OK))
+		ret += git_config_from_file(fn, user_config, data);
+
+	current_parsing_scope = CONFIG_SCOPE_LOCAL;
+	if (!opts->ignore_repo && repo_config &&
+	    !access_or_die(repo_config, R_OK, 0))
+		ret += git_config_from_file(fn, repo_config, data);
+
+	current_parsing_scope = CONFIG_SCOPE_WORKTREE;
+	if (!opts->ignore_worktree && repository_format_worktree_config) {
+		char *path = git_pathdup("config.worktree");
+		if (!access_or_die(path, R_OK, 0))
+			ret += git_config_from_file(fn, path, data);
+		free(path);
+	}
+
+	current_parsing_scope = CONFIG_SCOPE_COMMAND;
+	if (!opts->ignore_cmdline && git_config_from_parameters(fn, data) < 0)
+		die(_("unable to parse command-line config"));
+
+	current_parsing_scope = prev_parsing_scope;
+	free(system_config);
+	free(xdg_config);
+	free(user_config);
+	free(repo_config);
+	return ret;
+}
+
+int config_with_options(config_fn_t fn, void *data,
+			struct git_config_source *config_source,
+			const struct config_options *opts)
+{
+	struct config_include_data inc = CONFIG_INCLUDE_INIT;
+	int ret;
+
+	if (opts->respect_includes) {
+		inc.fn = fn;
+		inc.data = data;
+		inc.opts = opts;
+		inc.config_source = config_source;
+		fn = git_config_include;
+		data = &inc;
+	}
+
+	if (config_source)
+		current_parsing_scope = config_source->scope;
+
+	/*
+	 * If we have a specific filename, use it. Otherwise, follow the
+	 * regular lookup sequence.
+	 */
+	if (config_source && config_source->use_stdin) {
+		ret = git_config_from_stdin(fn, data);
+	} else if (config_source && config_source->file) {
+		ret = git_config_from_file(fn, config_source->file, data);
+	} else if (config_source && config_source->blob) {
+		struct repository *repo = config_source->repo ?
+			config_source->repo : the_repository;
+		ret = git_config_from_blob_ref(fn, repo, config_source->blob,
+						data);
+	} else {
+		ret = do_git_config_sequence(opts, fn, data);
+	}
+
+	if (inc.remote_urls) {
+		string_list_clear(inc.remote_urls, 0);
+		FREE_AND_NULL(inc.remote_urls);
+	}
+	return ret;
+}
+
+static void configset_iter(struct config_set *cs, config_fn_t fn, void *data)
+{
+	int i, value_index;
+	struct string_list *values;
+	struct config_set_element *entry;
+	struct configset_list *list = &cs->list;
+
+	for (i = 0; i < list->nr; i++) {
+		entry = list->items[i].e;
+		value_index = list->items[i].value_index;
+		values = &entry->value_list;
+
+		current_config_kvi = values->items[value_index].util;
+
+		if (fn(entry->key, values->items[value_index].string, data) < 0)
+			git_die_config_linenr(entry->key,
+					      current_config_kvi->filename,
+					      current_config_kvi->linenr);
+
+		current_config_kvi = NULL;
+	}
+}
+
+void read_early_config(config_fn_t cb, void *data)
+{
+	struct config_options opts = {0};
+	struct strbuf commondir = STRBUF_INIT;
+	struct strbuf gitdir = STRBUF_INIT;
+
+	opts.respect_includes = 1;
+
+	if (have_git_dir()) {
+		opts.commondir = get_git_common_dir();
+		opts.git_dir = get_git_dir();
+	/*
+	 * When setup_git_directory() was not yet asked to discover the
+	 * GIT_DIR, we ask discover_git_directory() to figure out whether there
+	 * is any repository config we should use (but unlike
+	 * setup_git_directory_gently(), no global state is changed, most
+	 * notably, the current working directory is still the same after the
+	 * call).
+	 */
+	} else if (!discover_git_directory(&commondir, &gitdir)) {
+		opts.commondir = commondir.buf;
+		opts.git_dir = gitdir.buf;
+	}
+
+	config_with_options(cb, data, NULL, &opts);
+
+	strbuf_release(&commondir);
+	strbuf_release(&gitdir);
+}
+
+/*
+ * Read config but only enumerate system and global settings.
+ * Omit any repo-local, worktree-local, or command-line settings.
+ */
+void read_very_early_config(config_fn_t cb, void *data)
+{
+	struct config_options opts = { 0 };
+
+	opts.respect_includes = 1;
+	opts.ignore_repo = 1;
+	opts.ignore_worktree = 1;
+	opts.ignore_cmdline = 1;
+	opts.system_gently = 1;
+
+	config_with_options(cb, data, NULL, &opts);
+}
+
+static struct config_set_element *configset_find_element(struct config_set *cs, const char *key)
+{
+	struct config_set_element k;
+	struct config_set_element *found_entry;
+	char *normalized_key;
+	/*
+	 * `key` may come from the user, so normalize it before using it
+	 * for querying entries from the hashmap.
+	 */
+	if (git_config_parse_key(key, &normalized_key, NULL))
+		return NULL;
+
+	hashmap_entry_init(&k.ent, strhash(normalized_key));
+	k.key = normalized_key;
+	found_entry = hashmap_get_entry(&cs->config_hash, &k, ent, NULL);
+	free(normalized_key);
+	return found_entry;
+}
+
+static int configset_add_value(struct config_set *cs, const char *key, const char *value)
+{
+	struct config_set_element *e;
+	struct string_list_item *si;
+	struct configset_list_item *l_item;
+	struct key_value_info *kv_info = xmalloc(sizeof(*kv_info));
+
+	e = configset_find_element(cs, key);
+	/*
+	 * Since the keys are being fed by git_config*() callback mechanism, they
+	 * are already normalized. So simply add them without any further munging.
+	 */
+	if (!e) {
+		e = xmalloc(sizeof(*e));
+		hashmap_entry_init(&e->ent, strhash(key));
+		e->key = xstrdup(key);
+		string_list_init_dup(&e->value_list);
+		hashmap_add(&cs->config_hash, &e->ent);
+	}
+	si = string_list_append_nodup(&e->value_list, xstrdup_or_null(value));
+
+	ALLOC_GROW(cs->list.items, cs->list.nr + 1, cs->list.alloc);
+	l_item = &cs->list.items[cs->list.nr++];
+	l_item->e = e;
+	l_item->value_index = e->value_list.nr - 1;
+
+	if (!cf)
+		BUG("configset_add_value has no source");
+	if (cf->name) {
+		kv_info->filename = strintern(cf->name);
+		kv_info->linenr = cf->linenr;
+		kv_info->origin_type = cf->origin_type;
+	} else {
+		/* for values read from `git_config_from_parameters()` */
+		kv_info->filename = NULL;
+		kv_info->linenr = -1;
+		kv_info->origin_type = CONFIG_ORIGIN_CMDLINE;
+	}
+	kv_info->scope = current_parsing_scope;
+	si->util = kv_info;
+
+	return 0;
+}
+
+static int config_set_element_cmp(const void *cmp_data UNUSED,
+				  const struct hashmap_entry *eptr,
+				  const struct hashmap_entry *entry_or_key,
+				  const void *keydata UNUSED)
+{
+	const struct config_set_element *e1, *e2;
+
+	e1 = container_of(eptr, const struct config_set_element, ent);
+	e2 = container_of(entry_or_key, const struct config_set_element, ent);
+
+	return strcmp(e1->key, e2->key);
+}
+
+void git_configset_init(struct config_set *cs)
+{
+	hashmap_init(&cs->config_hash, config_set_element_cmp, NULL, 0);
+	cs->hash_initialized = 1;
+	cs->list.nr = 0;
+	cs->list.alloc = 0;
+	cs->list.items = NULL;
+}
+
+void git_configset_clear(struct config_set *cs)
+{
+	struct config_set_element *entry;
+	struct hashmap_iter iter;
+	if (!cs->hash_initialized)
+		return;
+
+	hashmap_for_each_entry(&cs->config_hash, &iter, entry,
+				ent /* member name */) {
+		free(entry->key);
+		string_list_clear(&entry->value_list, 1);
+	}
+	hashmap_clear_and_free(&cs->config_hash, struct config_set_element, ent);
+	cs->hash_initialized = 0;
+	free(cs->list.items);
+	cs->list.nr = 0;
+	cs->list.alloc = 0;
+	cs->list.items = NULL;
+}
+
+static int config_set_callback(const char *key, const char *value, void *cb)
+{
+	struct config_set *cs = cb;
+	configset_add_value(cs, key, value);
+	return 0;
+}
+
+int git_configset_add_file(struct config_set *cs, const char *filename)
+{
+	return git_config_from_file(config_set_callback, filename, cs);
+}
+
+int git_configset_get_value(struct config_set *cs, const char *key, const char **value)
+{
+	const struct string_list *values = NULL;
+	/*
+	 * Follows "last one wins" semantic, i.e., if there are multiple matches for the
+	 * queried key in the files of the configset, the value returned will be the last
+	 * value in the value list for that key.
+	 */
+	values = git_configset_get_value_multi(cs, key);
+
+	if (!values)
+		return 1;
+	assert(values->nr > 0);
+	*value = values->items[values->nr - 1].string;
+	return 0;
+}
+
+const struct string_list *git_configset_get_value_multi(struct config_set *cs, const char *key)
+{
+	struct config_set_element *e = configset_find_element(cs, key);
+	return e ? &e->value_list : NULL;
+}
+
+int git_configset_get_string(struct config_set *cs, const char *key, char **dest)
+{
+	const char *value;
+	if (!git_configset_get_value(cs, key, &value))
+		return git_config_string((const char **)dest, key, value);
+	else
+		return 1;
+}
+
+static int git_configset_get_string_tmp(struct config_set *cs, const char *key,
+					const char **dest)
+{
+	const char *value;
+	if (!git_configset_get_value(cs, key, &value)) {
+		if (!value)
+			return config_error_nonbool(key);
+		*dest = value;
+		return 0;
+	} else {
+		return 1;
+	}
+}
+
+int git_configset_get_int(struct config_set *cs, const char *key, int *dest)
+{
+	const char *value;
+	if (!git_configset_get_value(cs, key, &value)) {
+		*dest = git_config_int(key, value);
+		return 0;
+	} else
+		return 1;
+}
+
+int git_configset_get_ulong(struct config_set *cs, const char *key, unsigned long *dest)
+{
+	const char *value;
+	if (!git_configset_get_value(cs, key, &value)) {
+		*dest = git_config_ulong(key, value);
+		return 0;
+	} else
+		return 1;
+}
+
+int git_configset_get_bool(struct config_set *cs, const char *key, int *dest)
+{
+	const char *value;
+	if (!git_configset_get_value(cs, key, &value)) {
+		*dest = git_config_bool(key, value);
+		return 0;
+	} else
+		return 1;
+}
+
+int git_configset_get_bool_or_int(struct config_set *cs, const char *key,
+				int *is_bool, int *dest)
+{
+	const char *value;
+	if (!git_configset_get_value(cs, key, &value)) {
+		*dest = git_config_bool_or_int(key, value, is_bool);
+		return 0;
+	} else
+		return 1;
+}
+
+int git_configset_get_maybe_bool(struct config_set *cs, const char *key, int *dest)
+{
+	const char *value;
+	if (!git_configset_get_value(cs, key, &value)) {
+		*dest = git_parse_maybe_bool(value);
+		if (*dest == -1)
+			return -1;
+		return 0;
+	} else
+		return 1;
+}
+
+int git_configset_get_pathname(struct config_set *cs, const char *key, const char **dest)
+{
+	const char *value;
+	if (!git_configset_get_value(cs, key, &value))
+		return git_config_pathname(dest, key, value);
+	else
+		return 1;
+}
+
+/* Functions use to read configuration from a repository */
+static void repo_read_config(struct repository *repo)
+{
+	struct config_options opts = { 0 };
+
+	opts.respect_includes = 1;
+	opts.commondir = repo->commondir;
+	opts.git_dir = repo->gitdir;
+
+	if (!repo->config)
+		CALLOC_ARRAY(repo->config, 1);
+	else
+		git_configset_clear(repo->config);
+
+	git_configset_init(repo->config);
+
+	if (config_with_options(config_set_callback, repo->config, NULL, &opts) < 0)
+		/*
+		 * config_with_options() normally returns only
+		 * zero, as most errors are fatal, and
+		 * non-fatal potential errors are guarded by "if"
+		 * statements that are entered only when no error is
+		 * possible.
+		 *
+		 * If we ever encounter a non-fatal error, it means
+		 * something went really wrong and we should stop
+		 * immediately.
+		 */
+		die(_("unknown error occurred while reading the configuration files"));
+}
+
+static void git_config_check_init(struct repository *repo)
+{
+	if (repo->config && repo->config->hash_initialized)
+		return;
+	repo_read_config(repo);
+}
+
+static void repo_config_clear(struct repository *repo)
+{
+	if (!repo->config || !repo->config->hash_initialized)
+		return;
+	git_configset_clear(repo->config);
+}
+
+void repo_config(struct repository *repo, config_fn_t fn, void *data)
+{
+	git_config_check_init(repo);
+	configset_iter(repo->config, fn, data);
+}
+
+int repo_config_get_value(struct repository *repo,
+			  const char *key, const char **value)
+{
+	git_config_check_init(repo);
+	return git_configset_get_value(repo->config, key, value);
+}
+
+const struct string_list *repo_config_get_value_multi(struct repository *repo,
+						      const char *key)
+{
+	git_config_check_init(repo);
+	return git_configset_get_value_multi(repo->config, key);
+}
+
+int repo_config_get_string(struct repository *repo,
+			   const char *key, char **dest)
+{
+	int ret;
+	git_config_check_init(repo);
+	ret = git_configset_get_string(repo->config, key, dest);
+	if (ret < 0)
+		git_die_config(key, NULL);
+	return ret;
+}
+
+int repo_config_get_string_tmp(struct repository *repo,
+			       const char *key, const char **dest)
+{
+	int ret;
+	git_config_check_init(repo);
+	ret = git_configset_get_string_tmp(repo->config, key, dest);
+	if (ret < 0)
+		git_die_config(key, NULL);
+	return ret;
+}
+
+int repo_config_get_int(struct repository *repo,
+			const char *key, int *dest)
+{
+	git_config_check_init(repo);
+	return git_configset_get_int(repo->config, key, dest);
+}
+
+int repo_config_get_ulong(struct repository *repo,
+			  const char *key, unsigned long *dest)
+{
+	git_config_check_init(repo);
+	return git_configset_get_ulong(repo->config, key, dest);
+}
+
+int repo_config_get_bool(struct repository *repo,
+			 const char *key, int *dest)
+{
+	git_config_check_init(repo);
+	return git_configset_get_bool(repo->config, key, dest);
+}
+
+int repo_config_get_bool_or_int(struct repository *repo,
+				const char *key, int *is_bool, int *dest)
+{
+	git_config_check_init(repo);
+	return git_configset_get_bool_or_int(repo->config, key, is_bool, dest);
+}
+
+int repo_config_get_maybe_bool(struct repository *repo,
+			       const char *key, int *dest)
+{
+	git_config_check_init(repo);
+	return git_configset_get_maybe_bool(repo->config, key, dest);
+}
+
+int repo_config_get_pathname(struct repository *repo,
+			     const char *key, const char **dest)
+{
+	int ret;
+	git_config_check_init(repo);
+	ret = git_configset_get_pathname(repo->config, key, dest);
+	if (ret < 0)
+		git_die_config(key, NULL);
+	return ret;
+}
+
+/* Read values into protected_config. */
+static void read_protected_config(void)
+{
+	struct config_options opts = {
+		.respect_includes = 1,
+		.ignore_repo = 1,
+		.ignore_worktree = 1,
+		.system_gently = 1,
+	};
+	git_configset_init(&protected_config);
+	config_with_options(config_set_callback, &protected_config,
+			    NULL, &opts);
+}
+
+void git_protected_config(config_fn_t fn, void *data)
+{
+	if (!protected_config.hash_initialized)
+		read_protected_config();
+	configset_iter(&protected_config, fn, data);
+}
+
+/* Functions used historically to read configuration from 'the_repository' */
+void git_config(config_fn_t fn, void *data)
+{
+	repo_config(the_repository, fn, data);
+}
+
+void git_config_clear(void)
+{
+	repo_config_clear(the_repository);
+}
+
+int git_config_get_value(const char *key, const char **value)
+{
+	return repo_config_get_value(the_repository, key, value);
+}
+
+const struct string_list *git_config_get_value_multi(const char *key)
+{
+	return repo_config_get_value_multi(the_repository, key);
+}
+
+int git_config_get_string(const char *key, char **dest)
+{
+	return repo_config_get_string(the_repository, key, dest);
+}
+
+int git_config_get_string_tmp(const char *key, const char **dest)
+{
+	return repo_config_get_string_tmp(the_repository, key, dest);
+}
+
+int git_config_get_int(const char *key, int *dest)
+{
+	return repo_config_get_int(the_repository, key, dest);
+}
+
+int git_config_get_ulong(const char *key, unsigned long *dest)
+{
+	return repo_config_get_ulong(the_repository, key, dest);
+}
+
+int git_config_get_bool(const char *key, int *dest)
+{
+	return repo_config_get_bool(the_repository, key, dest);
+}
+
+int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest)
+{
+	return repo_config_get_bool_or_int(the_repository, key, is_bool, dest);
+}
+
+int git_config_get_maybe_bool(const char *key, int *dest)
+{
+	return repo_config_get_maybe_bool(the_repository, key, dest);
+}
+
+int git_config_get_pathname(const char *key, const char **dest)
+{
+	return repo_config_get_pathname(the_repository, key, dest);
+}
+
+int git_config_get_expiry(const char *key, const char **output)
+{
+	int ret = git_config_get_string(key, (char **)output);
+	if (ret)
+		return ret;
+	if (strcmp(*output, "now")) {
+		timestamp_t now = approxidate("now");
+		if (approxidate(*output) >= now)
+			git_die_config(key, _("Invalid %s: '%s'"), key, *output);
+	}
+	return ret;
+}
+
+int git_config_get_expiry_in_days(const char *key, timestamp_t *expiry, timestamp_t now)
+{
+	const char *expiry_string;
+	intmax_t days;
+	timestamp_t when;
+
+	if (git_config_get_string_tmp(key, &expiry_string))
+		return 1; /* no such thing */
+
+	if (git_parse_signed(expiry_string, &days, maximum_signed_value_of_type(int))) {
+		const int scale = 86400;
+		*expiry = now - days * scale;
+		return 0;
+	}
+
+	if (!parse_expiry_date(expiry_string, &when)) {
+		*expiry = when;
+		return 0;
+	}
+	return -1; /* thing exists but cannot be parsed */
+}
+
+int git_config_get_split_index(void)
+{
+	int val;
+
+	if (!git_config_get_maybe_bool("core.splitindex", &val))
+		return val;
+
+	return -1; /* default value */
+}
+
+int git_config_get_max_percent_split_change(void)
+{
+	int val = -1;
+
+	if (!git_config_get_int("splitindex.maxpercentchange", &val)) {
+		if (0 <= val && val <= 100)
+			return val;
+
+		return error(_("splitIndex.maxPercentChange value '%d' "
+			       "should be between 0 and 100"), val);
+	}
+
+	return -1; /* default value */
+}
+
+int git_config_get_index_threads(int *dest)
+{
+	int is_bool, val;
+
+	val = git_env_ulong("GIT_TEST_INDEX_THREADS", 0);
+	if (val) {
+		*dest = val;
+		return 0;
+	}
+
+	if (!git_config_get_bool_or_int("index.threads", &is_bool, &val)) {
+		if (is_bool)
+			*dest = val ? 0 : 1;
+		else
+			*dest = val;
+		return 0;
+	}
+
+	return 1;
+}
+
+NORETURN
+void git_die_config_linenr(const char *key, const char *filename, int linenr)
+{
+	if (!filename)
+		die(_("unable to parse '%s' from command-line config"), key);
+	else
+		die(_("bad config variable '%s' in file '%s' at line %d"),
+		    key, filename, linenr);
+}
+
+NORETURN __attribute__((format(printf, 2, 3)))
+void git_die_config(const char *key, const char *err, ...)
+{
+	const struct string_list *values;
+	struct key_value_info *kv_info;
+	report_fn error_fn = get_error_routine();
+
+	if (err) {
+		va_list params;
+		va_start(params, err);
+		error_fn(err, params);
+		va_end(params);
+	}
+	values = git_config_get_value_multi(key);
+	kv_info = values->items[values->nr - 1].util;
+	git_die_config_linenr(key, kv_info->filename, kv_info->linenr);
+}
+
+/*
+ * Find all the stuff for git_config_set() below.
+ */
+
+struct config_store_data {
+	size_t baselen;
+	char *key;
+	int do_not_match;
+	const char *fixed_value;
+	regex_t *value_pattern;
+	int multi_replace;
+	struct {
+		size_t begin, end;
+		enum config_event_t type;
+		int is_keys_section;
+	} *parsed;
+	unsigned int parsed_nr, parsed_alloc, *seen, seen_nr, seen_alloc;
+	unsigned int key_seen:1, section_seen:1, is_keys_section:1;
+};
+
+static void config_store_data_clear(struct config_store_data *store)
+{
+	free(store->key);
+	if (store->value_pattern != NULL &&
+	    store->value_pattern != CONFIG_REGEX_NONE) {
+		regfree(store->value_pattern);
+		free(store->value_pattern);
+	}
+	free(store->parsed);
+	free(store->seen);
+	memset(store, 0, sizeof(*store));
+}
+
+static int matches(const char *key, const char *value,
+		   const struct config_store_data *store)
+{
+	if (strcmp(key, store->key))
+		return 0; /* not ours */
+	if (store->fixed_value)
+		return !strcmp(store->fixed_value, value);
+	if (!store->value_pattern)
+		return 1; /* always matches */
+	if (store->value_pattern == CONFIG_REGEX_NONE)
+		return 0; /* never matches */
+
+	return store->do_not_match ^
+		(value && !regexec(store->value_pattern, value, 0, NULL, 0));
+}
+
+static int store_aux_event(enum config_event_t type,
+			   size_t begin, size_t end, void *data)
+{
+	struct config_store_data *store = data;
+
+	ALLOC_GROW(store->parsed, store->parsed_nr + 1, store->parsed_alloc);
+	store->parsed[store->parsed_nr].begin = begin;
+	store->parsed[store->parsed_nr].end = end;
+	store->parsed[store->parsed_nr].type = type;
+
+	if (type == CONFIG_EVENT_SECTION) {
+		int (*cmpfn)(const char *, const char *, size_t);
+
+		if (cf->var.len < 2 || cf->var.buf[cf->var.len - 1] != '.')
+			return error(_("invalid section name '%s'"), cf->var.buf);
+
+		if (cf->subsection_case_sensitive)
+			cmpfn = strncasecmp;
+		else
+			cmpfn = strncmp;
+
+		/* Is this the section we were looking for? */
+		store->is_keys_section =
+			store->parsed[store->parsed_nr].is_keys_section =
+			cf->var.len - 1 == store->baselen &&
+			!cmpfn(cf->var.buf, store->key, store->baselen);
+		if (store->is_keys_section) {
+			store->section_seen = 1;
+			ALLOC_GROW(store->seen, store->seen_nr + 1,
+				   store->seen_alloc);
+			store->seen[store->seen_nr] = store->parsed_nr;
+		}
+	}
+
+	store->parsed_nr++;
+
+	return 0;
+}
+
+static int store_aux(const char *key, const char *value, void *cb)
+{
+	struct config_store_data *store = cb;
+
+	if (store->key_seen) {
+		if (matches(key, value, store)) {
+			if (store->seen_nr == 1 && store->multi_replace == 0) {
+				warning(_("%s has multiple values"), key);
+			}
+
+			ALLOC_GROW(store->seen, store->seen_nr + 1,
+				   store->seen_alloc);
+
+			store->seen[store->seen_nr] = store->parsed_nr;
+			store->seen_nr++;
+		}
+	} else if (store->is_keys_section) {
+		/*
+		 * Do not increment matches yet: this may not be a match, but we
+		 * are in the desired section.
+		 */
+		ALLOC_GROW(store->seen, store->seen_nr + 1, store->seen_alloc);
+		store->seen[store->seen_nr] = store->parsed_nr;
+		store->section_seen = 1;
+
+		if (matches(key, value, store)) {
+			store->seen_nr++;
+			store->key_seen = 1;
+		}
+	}
+
+	return 0;
+}
+
+static int write_error(const char *filename)
+{
+	error(_("failed to write new configuration file %s"), filename);
+
+	/* Same error code as "failed to rename". */
+	return 4;
+}
+
+static struct strbuf store_create_section(const char *key,
+					  const struct config_store_data *store)
+{
+	const char *dot;
+	size_t i;
+	struct strbuf sb = STRBUF_INIT;
+
+	dot = memchr(key, '.', store->baselen);
+	if (dot) {
+		strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
+		for (i = dot - key + 1; i < store->baselen; i++) {
+			if (key[i] == '"' || key[i] == '\\')
+				strbuf_addch(&sb, '\\');
+			strbuf_addch(&sb, key[i]);
+		}
+		strbuf_addstr(&sb, "\"]\n");
+	} else {
+		strbuf_addch(&sb, '[');
+		strbuf_add(&sb, key, store->baselen);
+		strbuf_addstr(&sb, "]\n");
+	}
+
+	return sb;
+}
+
+static ssize_t write_section(int fd, const char *key,
+			     const struct config_store_data *store)
+{
+	struct strbuf sb = store_create_section(key, store);
+	ssize_t ret;
+
+	ret = write_in_full(fd, sb.buf, sb.len);
+	strbuf_release(&sb);
+
+	return ret;
+}
+
+static ssize_t write_pair(int fd, const char *key, const char *value,
+			  const struct config_store_data *store)
+{
+	int i;
+	ssize_t ret;
+	const char *quote = "";
+	struct strbuf sb = STRBUF_INIT;
+
+	/*
+	 * Check to see if the value needs to be surrounded with a dq pair.
+	 * Note that problematic characters are always backslash-quoted; this
+	 * check is about not losing leading or trailing SP and strings that
+	 * follow beginning-of-comment characters (i.e. ';' and '#') by the
+	 * configuration parser.
+	 */
+	if (value[0] == ' ')
+		quote = "\"";
+	for (i = 0; value[i]; i++)
+		if (value[i] == ';' || value[i] == '#')
+			quote = "\"";
+	if (i && value[i - 1] == ' ')
+		quote = "\"";
+
+	strbuf_addf(&sb, "\t%s = %s", key + store->baselen + 1, quote);
+
+	for (i = 0; value[i]; i++)
+		switch (value[i]) {
+		case '\n':
+			strbuf_addstr(&sb, "\\n");
+			break;
+		case '\t':
+			strbuf_addstr(&sb, "\\t");
+			break;
+		case '"':
+		case '\\':
+			strbuf_addch(&sb, '\\');
+			/* fallthrough */
+		default:
+			strbuf_addch(&sb, value[i]);
+			break;
+		}
+	strbuf_addf(&sb, "%s\n", quote);
+
+	ret = write_in_full(fd, sb.buf, sb.len);
+	strbuf_release(&sb);
+
+	return ret;
+}
+
+/*
+ * If we are about to unset the last key(s) in a section, and if there are
+ * no comments surrounding (or included in) the section, we will want to
+ * extend begin/end to remove the entire section.
+ *
+ * Note: the parameter `seen_ptr` points to the index into the store.seen
+ * array.  * This index may be incremented if a section has more than one
+ * entry (which all are to be removed).
+ */
+static void maybe_remove_section(struct config_store_data *store,
+				 size_t *begin_offset, size_t *end_offset,
+				 int *seen_ptr)
+{
+	size_t begin;
+	int i, seen, section_seen = 0;
+
+	/*
+	 * First, ensure that this is the first key, and that there are no
+	 * comments before the entry nor before the section header.
+	 */
+	seen = *seen_ptr;
+	for (i = store->seen[seen]; i > 0; i--) {
+		enum config_event_t type = store->parsed[i - 1].type;
+
+		if (type == CONFIG_EVENT_COMMENT)
+			/* There is a comment before this entry or section */
+			return;
+		if (type == CONFIG_EVENT_ENTRY) {
+			if (!section_seen)
+				/* This is not the section's first entry. */
+				return;
+			/* We encountered no comment before the section. */
+			break;
+		}
+		if (type == CONFIG_EVENT_SECTION) {
+			if (!store->parsed[i - 1].is_keys_section)
+				break;
+			section_seen = 1;
+		}
+	}
+	begin = store->parsed[i].begin;
+
+	/*
+	 * Next, make sure that we are removing the last key(s) in the section,
+	 * and that there are no comments that are possibly about the current
+	 * section.
+	 */
+	for (i = store->seen[seen] + 1; i < store->parsed_nr; i++) {
+		enum config_event_t type = store->parsed[i].type;
+
+		if (type == CONFIG_EVENT_COMMENT)
+			return;
+		if (type == CONFIG_EVENT_SECTION) {
+			if (store->parsed[i].is_keys_section)
+				continue;
+			break;
+		}
+		if (type == CONFIG_EVENT_ENTRY) {
+			if (++seen < store->seen_nr &&
+			    i == store->seen[seen])
+				/* We want to remove this entry, too */
+				continue;
+			/* There is another entry in this section. */
+			return;
+		}
+	}
+
+	/*
+	 * We are really removing the last entry/entries from this section, and
+	 * there are no enclosed or surrounding comments. Remove the entire,
+	 * now-empty section.
+	 */
+	*seen_ptr = seen;
+	*begin_offset = begin;
+	if (i < store->parsed_nr)
+		*end_offset = store->parsed[i].begin;
+	else
+		*end_offset = store->parsed[store->parsed_nr - 1].end;
+}
+
+int git_config_set_in_file_gently(const char *config_filename,
+				  const char *key, const char *value)
+{
+	return git_config_set_multivar_in_file_gently(config_filename, key, value, NULL, 0);
+}
+
+void git_config_set_in_file(const char *config_filename,
+			    const char *key, const char *value)
+{
+	git_config_set_multivar_in_file(config_filename, key, value, NULL, 0);
+}
+
+int git_config_set_gently(const char *key, const char *value)
+{
+	return git_config_set_multivar_gently(key, value, NULL, 0);
+}
+
+int repo_config_set_worktree_gently(struct repository *r,
+				    const char *key, const char *value)
+{
+	/* Only use worktree-specific config if it is is already enabled. */
+	if (repository_format_worktree_config) {
+		char *file = repo_git_path(r, "config.worktree");
+		int ret = git_config_set_multivar_in_file_gently(
+					file, key, value, NULL, 0);
+		free(file);
+		return ret;
+	}
+	return repo_config_set_multivar_gently(r, key, value, NULL, 0);
+}
+
+void git_config_set(const char *key, const char *value)
+{
+	git_config_set_multivar(key, value, NULL, 0);
+
+	trace2_cmd_set_config(key, value);
+}
+
+/*
+ * If value==NULL, unset in (remove from) config,
+ * if value_pattern!=NULL, disregard key/value pairs where value does not match.
+ * if value_pattern==CONFIG_REGEX_NONE, do not match any existing values
+ *     (only add a new one)
+ * if flags contains the CONFIG_FLAGS_MULTI_REPLACE flag, all matching
+ *     key/values are removed before a single new pair is written. If the
+ *     flag is not present, then replace only the first match.
+ *
+ * Returns 0 on success.
+ *
+ * This function does this:
+ *
+ * - it locks the config file by creating ".git/config.lock"
+ *
+ * - it then parses the config using store_aux() as validator to find
+ *   the position on the key/value pair to replace. If it is to be unset,
+ *   it must be found exactly once.
+ *
+ * - the config file is mmap()ed and the part before the match (if any) is
+ *   written to the lock file, then the changed part and the rest.
+ *
+ * - the config file is removed and the lock file rename()d to it.
+ *
+ */
+int git_config_set_multivar_in_file_gently(const char *config_filename,
+					   const char *key, const char *value,
+					   const char *value_pattern,
+					   unsigned flags)
+{
+	int fd = -1, in_fd = -1;
+	int ret;
+	struct lock_file lock = LOCK_INIT;
+	char *filename_buf = NULL;
+	char *contents = NULL;
+	size_t contents_sz;
+	struct config_store_data store;
+
+	memset(&store, 0, sizeof(store));
+
+	/* parse-key returns negative; flip the sign to feed exit(3) */
+	ret = 0 - git_config_parse_key(key, &store.key, &store.baselen);
+	if (ret)
+		goto out_free;
+
+	store.multi_replace = (flags & CONFIG_FLAGS_MULTI_REPLACE) != 0;
+
+	if (!config_filename)
+		config_filename = filename_buf = git_pathdup("config");
+
+	/*
+	 * The lock serves a purpose in addition to locking: the new
+	 * contents of .git/config will be written into it.
+	 */
+	fd = hold_lock_file_for_update(&lock, config_filename, 0);
+	if (fd < 0) {
+		error_errno(_("could not lock config file %s"), config_filename);
+		ret = CONFIG_NO_LOCK;
+		goto out_free;
+	}
+
+	/*
+	 * If .git/config does not exist yet, write a minimal version.
+	 */
+	in_fd = open(config_filename, O_RDONLY);
+	if ( in_fd < 0 ) {
+		if ( ENOENT != errno ) {
+			error_errno(_("opening %s"), config_filename);
+			ret = CONFIG_INVALID_FILE; /* same as "invalid config file" */
+			goto out_free;
+		}
+		/* if nothing to unset, error out */
+		if (!value) {
+			ret = CONFIG_NOTHING_SET;
+			goto out_free;
+		}
+
+		free(store.key);
+		store.key = xstrdup(key);
+		if (write_section(fd, key, &store) < 0 ||
+		    write_pair(fd, key, value, &store) < 0)
+			goto write_err_out;
+	} else {
+		struct stat st;
+		size_t copy_begin, copy_end;
+		int i, new_line = 0;
+		struct config_options opts;
+
+		if (!value_pattern)
+			store.value_pattern = NULL;
+		else if (value_pattern == CONFIG_REGEX_NONE)
+			store.value_pattern = CONFIG_REGEX_NONE;
+		else if (flags & CONFIG_FLAGS_FIXED_VALUE)
+			store.fixed_value = value_pattern;
+		else {
+			if (value_pattern[0] == '!') {
+				store.do_not_match = 1;
+				value_pattern++;
+			} else
+				store.do_not_match = 0;
+
+			store.value_pattern = (regex_t*)xmalloc(sizeof(regex_t));
+			if (regcomp(store.value_pattern, value_pattern,
+					REG_EXTENDED)) {
+				error(_("invalid pattern: %s"), value_pattern);
+				FREE_AND_NULL(store.value_pattern);
+				ret = CONFIG_INVALID_PATTERN;
+				goto out_free;
+			}
+		}
+
+		ALLOC_GROW(store.parsed, 1, store.parsed_alloc);
+		store.parsed[0].end = 0;
+
+		memset(&opts, 0, sizeof(opts));
+		opts.event_fn = store_aux_event;
+		opts.event_fn_data = &store;
+
+		/*
+		 * After this, store.parsed will contain offsets of all the
+		 * parsed elements, and store.seen will contain a list of
+		 * matches, as indices into store.parsed.
+		 *
+		 * As a side effect, we make sure to transform only a valid
+		 * existing config file.
+		 */
+		if (git_config_from_file_with_options(store_aux,
+						      config_filename,
+						      &store, &opts)) {
+			error(_("invalid config file %s"), config_filename);
+			ret = CONFIG_INVALID_FILE;
+			goto out_free;
+		}
+
+		/* if nothing to unset, or too many matches, error out */
+		if ((store.seen_nr == 0 && value == NULL) ||
+		    (store.seen_nr > 1 && !store.multi_replace)) {
+			ret = CONFIG_NOTHING_SET;
+			goto out_free;
+		}
+
+		if (fstat(in_fd, &st) == -1) {
+			error_errno(_("fstat on %s failed"), config_filename);
+			ret = CONFIG_INVALID_FILE;
+			goto out_free;
+		}
+
+		contents_sz = xsize_t(st.st_size);
+		contents = xmmap_gently(NULL, contents_sz, PROT_READ,
+					MAP_PRIVATE, in_fd, 0);
+		if (contents == MAP_FAILED) {
+			if (errno == ENODEV && S_ISDIR(st.st_mode))
+				errno = EISDIR;
+			error_errno(_("unable to mmap '%s'%s"),
+					config_filename, mmap_os_err());
+			ret = CONFIG_INVALID_FILE;
+			contents = NULL;
+			goto out_free;
+		}
+		close(in_fd);
+		in_fd = -1;
+
+		if (chmod(get_lock_file_path(&lock), st.st_mode & 07777) < 0) {
+			error_errno(_("chmod on %s failed"), get_lock_file_path(&lock));
+			ret = CONFIG_NO_WRITE;
+			goto out_free;
+		}
+
+		if (store.seen_nr == 0) {
+			if (!store.seen_alloc) {
+				/* Did not see key nor section */
+				ALLOC_GROW(store.seen, 1, store.seen_alloc);
+				store.seen[0] = store.parsed_nr
+					- !!store.parsed_nr;
+			}
+			store.seen_nr = 1;
+		}
+
+		for (i = 0, copy_begin = 0; i < store.seen_nr; i++) {
+			size_t replace_end;
+			int j = store.seen[i];
+
+			new_line = 0;
+			if (!store.key_seen) {
+				copy_end = store.parsed[j].end;
+				/* include '\n' when copying section header */
+				if (copy_end > 0 && copy_end < contents_sz &&
+				    contents[copy_end - 1] != '\n' &&
+				    contents[copy_end] == '\n')
+					copy_end++;
+				replace_end = copy_end;
+			} else {
+				replace_end = store.parsed[j].end;
+				copy_end = store.parsed[j].begin;
+				if (!value)
+					maybe_remove_section(&store,
+							     &copy_end,
+							     &replace_end, &i);
+				/*
+				 * Swallow preceding white-space on the same
+				 * line.
+				 */
+				while (copy_end > 0 ) {
+					char c = contents[copy_end - 1];
+
+					if (isspace(c) && c != '\n')
+						copy_end--;
+					else
+						break;
+				}
+			}
+
+			if (copy_end > 0 && contents[copy_end-1] != '\n')
+				new_line = 1;
+
+			/* write the first part of the config */
+			if (copy_end > copy_begin) {
+				if (write_in_full(fd, contents + copy_begin,
+						  copy_end - copy_begin) < 0)
+					goto write_err_out;
+				if (new_line &&
+				    write_str_in_full(fd, "\n") < 0)
+					goto write_err_out;
+			}
+			copy_begin = replace_end;
+		}
+
+		/* write the pair (value == NULL means unset) */
+		if (value) {
+			if (!store.section_seen) {
+				if (write_section(fd, key, &store) < 0)
+					goto write_err_out;
+			}
+			if (write_pair(fd, key, value, &store) < 0)
+				goto write_err_out;
+		}
+
+		/* write the rest of the config */
+		if (copy_begin < contents_sz)
+			if (write_in_full(fd, contents + copy_begin,
+					  contents_sz - copy_begin) < 0)
+				goto write_err_out;
+
+		munmap(contents, contents_sz);
+		contents = NULL;
+	}
+
+	if (commit_lock_file(&lock) < 0) {
+		error_errno(_("could not write config file %s"), config_filename);
+		ret = CONFIG_NO_WRITE;
+		goto out_free;
+	}
+
+	ret = 0;
+
+	/* Invalidate the config cache */
+	git_config_clear();
+
+out_free:
+	rollback_lock_file(&lock);
+	free(filename_buf);
+	if (contents)
+		munmap(contents, contents_sz);
+	if (in_fd >= 0)
+		close(in_fd);
+	config_store_data_clear(&store);
+	return ret;
+
+write_err_out:
+	ret = write_error(get_lock_file_path(&lock));
+	goto out_free;
+
+}
+
+void git_config_set_multivar_in_file(const char *config_filename,
+				     const char *key, const char *value,
+				     const char *value_pattern, unsigned flags)
+{
+	if (!git_config_set_multivar_in_file_gently(config_filename, key, value,
+						    value_pattern, flags))
+		return;
+	if (value)
+		die(_("could not set '%s' to '%s'"), key, value);
+	else
+		die(_("could not unset '%s'"), key);
+}
+
+int git_config_set_multivar_gently(const char *key, const char *value,
+				   const char *value_pattern, unsigned flags)
+{
+	return repo_config_set_multivar_gently(the_repository, key, value,
+					       value_pattern, flags);
+}
+
+int repo_config_set_multivar_gently(struct repository *r, const char *key,
+				    const char *value,
+				    const char *value_pattern, unsigned flags)
+{
+	char *file = repo_git_path(r, "config");
+	int res = git_config_set_multivar_in_file_gently(file,
+							 key, value,
+							 value_pattern,
+							 flags);
+	free(file);
+	return res;
+}
+
+void git_config_set_multivar(const char *key, const char *value,
+			     const char *value_pattern, unsigned flags)
+{
+	git_config_set_multivar_in_file(git_path("config"),
+					key, value, value_pattern,
+					flags);
+}
+
+static int section_name_match (const char *buf, const char *name)
+{
+	int i = 0, j = 0, dot = 0;
+	if (buf[i] != '[')
+		return 0;
+	for (i = 1; buf[i] && buf[i] != ']'; i++) {
+		if (!dot && isspace(buf[i])) {
+			dot = 1;
+			if (name[j++] != '.')
+				break;
+			for (i++; isspace(buf[i]); i++)
+				; /* do nothing */
+			if (buf[i] != '"')
+				break;
+			continue;
+		}
+		if (buf[i] == '\\' && dot)
+			i++;
+		else if (buf[i] == '"' && dot) {
+			for (i++; isspace(buf[i]); i++)
+				; /* do_nothing */
+			break;
+		}
+		if (buf[i] != name[j++])
+			break;
+	}
+	if (buf[i] == ']' && name[j] == 0) {
+		/*
+		 * We match, now just find the right length offset by
+		 * gobbling up any whitespace after it, as well
+		 */
+		i++;
+		for (; buf[i] && isspace(buf[i]); i++)
+			; /* do nothing */
+		return i;
+	}
+	return 0;
+}
+
+static int section_name_is_ok(const char *name)
+{
+	/* Empty section names are bogus. */
+	if (!*name)
+		return 0;
+
+	/*
+	 * Before a dot, we must be alphanumeric or dash. After the first dot,
+	 * anything goes, so we can stop checking.
+	 */
+	for (; *name && *name != '.'; name++)
+		if (*name != '-' && !isalnum(*name))
+			return 0;
+	return 1;
+}
+
+/* if new_name == NULL, the section is removed instead */
+static int git_config_copy_or_rename_section_in_file(const char *config_filename,
+				      const char *old_name,
+				      const char *new_name, int copy)
+{
+	int ret = 0, remove = 0;
+	char *filename_buf = NULL;
+	struct lock_file lock = LOCK_INIT;
+	int out_fd;
+	char buf[1024];
+	FILE *config_file = NULL;
+	struct stat st;
+	struct strbuf copystr = STRBUF_INIT;
+	struct config_store_data store;
+
+	memset(&store, 0, sizeof(store));
+
+	if (new_name && !section_name_is_ok(new_name)) {
+		ret = error(_("invalid section name: %s"), new_name);
+		goto out_no_rollback;
+	}
+
+	if (!config_filename)
+		config_filename = filename_buf = git_pathdup("config");
+
+	out_fd = hold_lock_file_for_update(&lock, config_filename, 0);
+	if (out_fd < 0) {
+		ret = error(_("could not lock config file %s"), config_filename);
+		goto out;
+	}
+
+	if (!(config_file = fopen(config_filename, "rb"))) {
+		ret = warn_on_fopen_errors(config_filename);
+		if (ret)
+			goto out;
+		/* no config file means nothing to rename, no error */
+		goto commit_and_out;
+	}
+
+	if (fstat(fileno(config_file), &st) == -1) {
+		ret = error_errno(_("fstat on %s failed"), config_filename);
+		goto out;
+	}
+
+	if (chmod(get_lock_file_path(&lock), st.st_mode & 07777) < 0) {
+		ret = error_errno(_("chmod on %s failed"),
+				  get_lock_file_path(&lock));
+		goto out;
+	}
+
+	while (fgets(buf, sizeof(buf), config_file)) {
+		unsigned i;
+		int length;
+		int is_section = 0;
+		char *output = buf;
+		for (i = 0; buf[i] && isspace(buf[i]); i++)
+			; /* do nothing */
+		if (buf[i] == '[') {
+			/* it's a section */
+			int offset;
+			is_section = 1;
+
+			/*
+			 * When encountering a new section under -c we
+			 * need to flush out any section we're already
+			 * coping and begin anew. There might be
+			 * multiple [branch "$name"] sections.
+			 */
+			if (copystr.len > 0) {
+				if (write_in_full(out_fd, copystr.buf, copystr.len) < 0) {
+					ret = write_error(get_lock_file_path(&lock));
+					goto out;
+				}
+				strbuf_reset(&copystr);
+			}
+
+			offset = section_name_match(&buf[i], old_name);
+			if (offset > 0) {
+				ret++;
+				if (!new_name) {
+					remove = 1;
+					continue;
+				}
+				store.baselen = strlen(new_name);
+				if (!copy) {
+					if (write_section(out_fd, new_name, &store) < 0) {
+						ret = write_error(get_lock_file_path(&lock));
+						goto out;
+					}
+					/*
+					 * We wrote out the new section, with
+					 * a newline, now skip the old
+					 * section's length
+					 */
+					output += offset + i;
+					if (strlen(output) > 0) {
+						/*
+						 * More content means there's
+						 * a declaration to put on the
+						 * next line; indent with a
+						 * tab
+						 */
+						output -= 1;
+						output[0] = '\t';
+					}
+				} else {
+					copystr = store_create_section(new_name, &store);
+				}
+			}
+			remove = 0;
+		}
+		if (remove)
+			continue;
+		length = strlen(output);
+
+		if (!is_section && copystr.len > 0) {
+			strbuf_add(&copystr, output, length);
+		}
+
+		if (write_in_full(out_fd, output, length) < 0) {
+			ret = write_error(get_lock_file_path(&lock));
+			goto out;
+		}
+	}
+
+	/*
+	 * Copy a trailing section at the end of the config, won't be
+	 * flushed by the usual "flush because we have a new section
+	 * logic in the loop above.
+	 */
+	if (copystr.len > 0) {
+		if (write_in_full(out_fd, copystr.buf, copystr.len) < 0) {
+			ret = write_error(get_lock_file_path(&lock));
+			goto out;
+		}
+		strbuf_reset(&copystr);
+	}
+
+	fclose(config_file);
+	config_file = NULL;
+commit_and_out:
+	if (commit_lock_file(&lock) < 0)
+		ret = error_errno(_("could not write config file %s"),
+				  config_filename);
+out:
+	if (config_file)
+		fclose(config_file);
+	rollback_lock_file(&lock);
+out_no_rollback:
+	free(filename_buf);
+	config_store_data_clear(&store);
+	return ret;
+}
+
+int git_config_rename_section_in_file(const char *config_filename,
+				      const char *old_name, const char *new_name)
+{
+	return git_config_copy_or_rename_section_in_file(config_filename,
+					 old_name, new_name, 0);
+}
+
+int git_config_rename_section(const char *old_name, const char *new_name)
+{
+	return git_config_rename_section_in_file(NULL, old_name, new_name);
+}
+
+int git_config_copy_section_in_file(const char *config_filename,
+				      const char *old_name, const char *new_name)
+{
+	return git_config_copy_or_rename_section_in_file(config_filename,
+					 old_name, new_name, 1);
+}
+
+int git_config_copy_section(const char *old_name, const char *new_name)
+{
+	return git_config_copy_section_in_file(NULL, old_name, new_name);
+}
+
+/*
+ * Call this to report error for your variable that should not
+ * get a boolean value (i.e. "[my] var" means "true").
+ */
+#undef config_error_nonbool
+int config_error_nonbool(const char *var)
+{
+	return error(_("missing value for '%s'"), var);
+}
+
+int parse_config_key(const char *var,
+		     const char *section,
+		     const char **subsection, size_t *subsection_len,
+		     const char **key)
+{
+	const char *dot;
+
+	/* Does it start with "section." ? */
+	if (!skip_prefix(var, section, &var) || *var != '.')
+		return -1;
+
+	/*
+	 * Find the key; we don't know yet if we have a subsection, but we must
+	 * parse backwards from the end, since the subsection may have dots in
+	 * it, too.
+	 */
+	dot = strrchr(var, '.');
+	*key = dot + 1;
+
+	/* Did we have a subsection at all? */
+	if (dot == var) {
+		if (subsection) {
+			*subsection = NULL;
+			*subsection_len = 0;
+		}
+	}
+	else {
+		if (!subsection)
+			return -1;
+		*subsection = var + 1;
+		*subsection_len = dot - *subsection;
+	}
+
+	return 0;
+}
+
+const char *current_config_origin_type(void)
+{
+	int type;
+	if (current_config_kvi)
+		type = current_config_kvi->origin_type;
+	else if(cf)
+		type = cf->origin_type;
+	else
+		BUG("current_config_origin_type called outside config callback");
+
+	switch (type) {
+	case CONFIG_ORIGIN_BLOB:
+		return "blob";
+	case CONFIG_ORIGIN_FILE:
+		return "file";
+	case CONFIG_ORIGIN_STDIN:
+		return "standard input";
+	case CONFIG_ORIGIN_SUBMODULE_BLOB:
+		return "submodule-blob";
+	case CONFIG_ORIGIN_CMDLINE:
+		return "command line";
+	default:
+		BUG("unknown config origin type");
+	}
+}
+
+const char *config_scope_name(enum config_scope scope)
+{
+	switch (scope) {
+	case CONFIG_SCOPE_SYSTEM:
+		return "system";
+	case CONFIG_SCOPE_GLOBAL:
+		return "global";
+	case CONFIG_SCOPE_LOCAL:
+		return "local";
+	case CONFIG_SCOPE_WORKTREE:
+		return "worktree";
+	case CONFIG_SCOPE_COMMAND:
+		return "command";
+	case CONFIG_SCOPE_SUBMODULE:
+		return "submodule";
+	default:
+		return "unknown";
+	}
+}
+
+const char *current_config_name(void)
+{
+	const char *name;
+	if (current_config_kvi)
+		name = current_config_kvi->filename;
+	else if (cf)
+		name = cf->name;
+	else
+		BUG("current_config_name called outside config callback");
+	return name ? name : "";
+}
+
+enum config_scope current_config_scope(void)
+{
+	if (current_config_kvi)
+		return current_config_kvi->scope;
+	else
+		return current_parsing_scope;
+}
+
+int current_config_line(void)
+{
+	if (current_config_kvi)
+		return current_config_kvi->linenr;
+	else
+		return cf->linenr;
+}
+
+int lookup_config(const char **mapping, int nr_mapping, const char *var)
+{
+	int i;
+
+	for (i = 0; i < nr_mapping; i++) {
+		const char *name = mapping[i];
+
+		if (name && !strcasecmp(var, name))
+			return i;
+	}
+	return -1;
+}