timestamp_t: a new data type for timestamps
[gitweb.git] / config.c
index 1bdef44a3ad315ecc4cdfa879e9c0881bd82722b..3247bfaa0205eaab4ad6282e4661ed1a637215f0 100644 (file)
--- a/config.c
+++ b/config.c
  *
  */
 #include "cache.h"
-#include <regex.h>
+#include "lockfile.h"
+#include "exec_cmd.h"
+#include "strbuf.h"
+#include "quote.h"
+#include "hashmap.h"
+#include "string-list.h"
+#include "utf8.h"
+#include "dir.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;
+       int die_on_error;
+       int linenr;
+       int eof;
+       struct strbuf value;
+       struct strbuf var;
+
+       int (*do_fgetc)(struct config_source *c);
+       int (*do_ungetc)(int c, struct config_source *conf);
+       long (*do_ftell)(struct config_source *c);
+};
 
-#define MAXNAME (256)
+/*
+ * 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;
 
-static FILE *config_file;
-static const char *config_file_name;
-static int config_linenr;
-static int get_next_char(void)
+/*
+ * 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 core_compression_seen;
+static int pack_compression_seen;
+static int zlib_compression_seen;
+
+/*
+ * Default config_set that contains key-value pairs from the usual set of config
+ * config files (i.e repo specific .git/config, user wide ~/.gitconfig, XDG
+ * config file and the global /etc/gitconfig)
+ */
+static struct config_set the_config_set;
+
+static int config_file_fgetc(struct config_source *conf)
 {
-       int c;
-       FILE *f;
+       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)
+                       die("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;
+}
+
+#define MAX_INCLUDE_DEPTH 10
+static const char include_depth_advice[] =
+"exceeded maximum include depth (%d) while including\n"
+"      %s\n"
+"from\n"
+"      %s\n"
+"Do you have 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 = expand_user_path(path);
+       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)
+                       return error("relative config includes must come from files");
+
+               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--;
+       }
+       strbuf_release(&buf);
+       free(expanded);
+       return ret;
+}
+
+static int prepare_include_condition_pattern(struct strbuf *pat)
+{
+       struct strbuf path = STRBUF_INIT;
+       char *expanded;
+       int prefix = 0;
+
+       expanded = expand_user_path(pat->buf);
+       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_add_absolute_path(&path, cf->path);
+               slash = find_last_dir_sep(path.buf);
+               if (!slash)
+                       die("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_insert(pat, 0, "**/", 3);
+
+       if (pat->len && is_dir_sep(pat->buf[pat->len - 1]))
+               strbuf_addstr(pat, "**");
+
+       strbuf_release(&path);
+       return prefix;
+}
+
+static int include_by_gitdir(const char *cond, size_t cond_len, int icase)
+{
+       struct strbuf text = STRBUF_INIT;
+       struct strbuf pattern = STRBUF_INIT;
+       int ret = 0, prefix;
+
+       strbuf_add_absolute_path(&text, get_git_dir());
+       strbuf_add(&pattern, cond, cond_len);
+       prefix = prepare_include_condition_pattern(&pattern);
+
+       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,
+                        icase ? WM_CASEFOLD : 0, NULL);
+
+done:
+       strbuf_release(&pattern);
+       strbuf_release(&text);
+       return ret;
+}
+
+static int include_condition_is_true(const char *cond, size_t cond_len)
+{
+
+       if (skip_prefix_mem(cond, cond_len, "gitdir:", &cond, &cond_len))
+               return include_by_gitdir(cond, cond_len, 0);
+       else if (skip_prefix_mem(cond, cond_len, "gitdir/i:", &cond, &cond_len))
+               return include_by_gitdir(cond, cond_len, 1);
+
+       /* unknown conditionals are always false */
+       return 0;
+}
+
+int git_config_include(const char *var, const char *value, void *data)
+{
+       struct config_include_data *inc = data;
+       const char *cond, *key;
+       int 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(cond, cond_len)) &&
+           !strcmp(key, "path"))
+               ret = handle_path_include(value, inc);
+
+       return ret;
+}
+
+void git_config_push_parameter(const char *text)
+{
+       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, text);
+       setenv(CONFIG_DATA_ENVIRONMENT, env.buf, 1);
+       strbuf_release(&env);
+}
+
+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 int which will hold the length of the
+ *           section + subsection part, can be NULL
+ */
+static int git_config_parse_key_1(const char *key, char **store_key, int *baselen_, int quiet)
+{
+       int i, dot, baselen;
+       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) {
+               if (!quiet)
+                       error("key does not contain a section: %s", key);
+               return -CONFIG_NO_SECTION_OR_NAME;
+       }
+
+       if (!last_dot[1]) {
+               if (!quiet)
+                       error("key does not contain variable name: %s", key);
+               return -CONFIG_NO_SECTION_OR_NAME;
+       }
 
-       c = '\n';
-       if ((f = config_file) != NULL) {
-               c = fgetc(f);
-               if (c == '\r') {
-                       /* DOS like systems */
-                       c = fgetc(f);
-                       if (c != '\n') {
-                               ungetc(c, f);
-                               c = '\r';
+       baselen = last_dot - key;
+       if (baselen_)
+               *baselen_ = baselen;
+
+       /*
+        * Validate the key and while at it, lower case it for matching.
+        */
+       if (store_key)
+               *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))) {
+                               if (!quiet)
+                                       error("invalid key: %s", key);
+                               goto out_free_ret_1;
                        }
+                       c = tolower(c);
+               } else if (c == '\n') {
+                       if (!quiet)
+                               error("invalid key (newline): %s", key);
+                       goto out_free_ret_1;
                }
-               if (c == '\n')
-                       config_linenr++;
-               if (c == EOF) {
-                       config_file = NULL;
-                       c = '\n';
+               if (store_key)
+                       (*store_key)[i] = c;
+       }
+
+       return 0;
+
+out_free_ret_1:
+       if (store_key) {
+               free(*store_key);
+               *store_key = NULL;
+       }
+       return -CONFIG_INVALID_KEY;
+}
+
+int git_config_parse_key(const char *key, char **store_key, int *baselen)
+{
+       return git_config_parse_key_1(key, store_key, baselen, 0);
+}
+
+int git_config_key_is_valid(const char *key)
+{
+       return !git_config_parse_key_1(key, NULL, NULL, 1);
+}
+
+int git_config_parse_parameter(const char *text,
+                              config_fn_t fn, void *data)
+{
+       const char *value;
+       char *canonical_name;
+       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);
+       }
+
+       if (git_config_parse_key(pair[0]->buf, &canonical_name, NULL)) {
+               ret = -1;
+       } else {
+               ret = (fn(canonical_name, value, data) < 0) ? -1 : 0;
+               free(canonical_name);
+       }
+       strbuf_list_free(pair);
+       return ret;
+}
+
+int git_config_from_parameters(config_fn_t fn, void *data)
+{
+       const char *env = getenv(CONFIG_DATA_ENVIRONMENT);
+       int ret = 0;
+       char *envw;
+       const char **argv = NULL;
+       int nr = 0, alloc = 0;
+       int i;
+       struct config_source source;
+
+       if (!env)
+               return 0;
+
+       memset(&source, 0, sizeof(source));
+       source.prev = cf;
+       source.origin_type = CONFIG_ORIGIN_CMDLINE;
+       cf = &source;
+
+       /* sq_dequote will write over it */
+       envw = xstrdup(env);
+
+       if (sq_dequote_to_argv(envw, &argv, &nr, &alloc) < 0) {
+               ret = error("bogus format in " CONFIG_DATA_ENVIRONMENT);
+               goto out;
+       }
+
+       for (i = 0; i < nr; i++) {
+               if (git_config_parse_parameter(argv[i], fn, data) < 0) {
+                       ret = -1;
+                       goto out;
+               }
+       }
+
+out:
+       free(argv);
+       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 == '\n')
+               cf->linenr++;
+       if (c == EOF) {
+               cf->eof = 1;
+               cf->linenr++;
+               c = '\n';
+       }
        return c;
 }
 
 static char *parse_value(void)
 {
-       static char value[1024];
-       int quote = 0, comment = 0, len = 0, space = 0;
+       int quote = 0, comment = 0, space = 0;
 
+       strbuf_reset(&cf->value);
        for (;;) {
                int c = get_next_char();
-               if (len >= sizeof(value))
-                       return NULL;
                if (c == '\n') {
-                       if (quote)
+                       if (quote) {
+                               cf->linenr--;
                                return NULL;
-                       value[len] = 0;
-                       return value;
+                       }
+                       return cf->value.buf;
                }
                if (comment)
                        continue;
                if (isspace(c) && !quote) {
-                       space = 1;
+                       if (cf->value.len)
+                               space++;
                        continue;
                }
                if (!quote) {
@@ -66,11 +510,8 @@ static char *parse_value(void)
                                continue;
                        }
                }
-               if (space) {
-                       if (len)
-                               value[len++] = ' ';
-                       space = 0;
-               }
+               for (; space; space--)
+                       strbuf_addch(&cf->value, ' ');
                if (c == '\\') {
                        c = get_next_char();
                        switch (c) {
@@ -92,39 +533,33 @@ static char *parse_value(void)
                        default:
                                return NULL;
                        }
-                       value[len++] = c;
+                       strbuf_addch(&cf->value, c);
                        continue;
                }
                if (c == '"') {
                        quote = 1-quote;
                        continue;
                }
-               value[len++] = c;
+               strbuf_addch(&cf->value, c);
        }
 }
 
-static inline int iskeychar(int c)
-{
-       return isalnum(c) || c == '-';
-}
-
-static int get_value(config_fn_t fn, char *name, unsigned int len)
+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 (c == EOF)
+               if (cf->eof)
                        break;
                if (!iskeychar(c))
                        break;
-               name[len++] = tolower(c);
-               if (len >= MAXNAME)
-                       return -1;
+               strbuf_addch(name, tolower(c));
        }
-       name[len] = 0;
+
        while (c == ' ' || c == '\t')
                c = get_next_char();
 
@@ -136,75 +571,99 @@ static int get_value(config_fn_t fn, char *name, unsigned int len)
                if (!value)
                        return -1;
        }
-       return fn(name, value);
+       /*
+        * 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);
+       cf->linenr++;
+       return ret;
 }
 
-static int get_extended_base_var(char *name, int baselen, int c)
+static int get_extended_base_var(struct strbuf *name, int c)
 {
        do {
                if (c == '\n')
-                       return -1;
+                       goto error_incomplete_line;
                c = get_next_char();
        } while (isspace(c));
 
        /* We require the format to be '[base "extension"]' */
        if (c != '"')
                return -1;
-       name[baselen++] = '.';
+       strbuf_addch(name, '.');
 
        for (;;) {
                int c = get_next_char();
                if (c == '\n')
-                       return -1;
+                       goto error_incomplete_line;
                if (c == '"')
                        break;
                if (c == '\\') {
                        c = get_next_char();
                        if (c == '\n')
-                               return -1;
+                               goto error_incomplete_line;
                }
-               name[baselen++] = c;
-               if (baselen > MAXNAME / 2)
-                       return -1;
+               strbuf_addch(name, c);
        }
 
        /* Final ']' */
        if (get_next_char() != ']')
                return -1;
-       return baselen;
+       return 0;
+error_incomplete_line:
+       cf->linenr--;
+       return -1;
 }
 
-static int get_base_var(char *name)
+static int get_base_var(struct strbuf *name)
 {
-       int baselen = 0;
-
        for (;;) {
                int c = get_next_char();
-               if (c == EOF)
+               if (cf->eof)
                        return -1;
                if (c == ']')
-                       return baselen;
+                       return 0;
                if (isspace(c))
-                       return get_extended_base_var(name, baselen, c);
+                       return get_extended_base_var(name, c);
                if (!iskeychar(c) && c != '.')
                        return -1;
-               if (baselen > MAXNAME / 2)
-                       return -1;
-               name[baselen++] = tolower(c);
+               strbuf_addch(name, tolower(c));
        }
 }
 
-static int git_parse_file(config_fn_t fn)
+static int git_parse_source(config_fn_t fn, void *data)
 {
        int comment = 0;
        int baselen = 0;
-       static char var[MAXNAME];
+       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 (;;) {
                int 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') {
-                       /* EOF? */
-                       if (!config_file)
+                       if (cf->eof)
                                return 0;
                        comment = 0;
                        continue;
@@ -216,287 +675,1535 @@ static int git_parse_file(config_fn_t fn)
                        continue;
                }
                if (c == '[') {
-                       baselen = get_base_var(var);
-                       if (baselen <= 0)
+                       /* Reset prior to determining a new stem */
+                       strbuf_reset(var);
+                       if (get_base_var(var) < 0 || var->len < 1)
                                break;
-                       var[baselen++] = '.';
-                       var[baselen] = 0;
+                       strbuf_addch(var, '.');
+                       baselen = var->len;
                        continue;
                }
                if (!isalpha(c))
                        break;
-               var[baselen] = tolower(c);
-               if (get_value(fn, var, baselen+1) < 0)
+               /*
+                * 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;
        }
-       die("bad config file line %d in %s", config_linenr, config_file_name);
+
+       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);
+       }
+
+       if (cf->die_on_error)
+               die("%s", error_msg);
+       else
+               error_return = error("%s", error_msg);
+
+       free(error_msg);
+       return error_return;
+}
+
+static int parse_unit_factor(const char *end, uintmax_t *val)
+{
+       if (!*end)
+               return 1;
+       else if (!strcasecmp(end, "k")) {
+               *val *= 1024;
+               return 1;
+       }
+       else if (!strcasecmp(end, "m")) {
+               *val *= 1024 * 1024;
+               return 1;
+       }
+       else if (!strcasecmp(end, "g")) {
+               *val *= 1024 * 1024 * 1024;
+               return 1;
+       }
+       return 0;
+}
+
+static int git_parse_signed(const char *value, intmax_t *ret, intmax_t max)
+{
+       if (value && *value) {
+               char *end;
+               intmax_t val;
+               uintmax_t uval;
+               uintmax_t factor = 1;
+
+               errno = 0;
+               val = strtoimax(value, &end, 0);
+               if (errno == ERANGE)
+                       return 0;
+               if (!parse_unit_factor(end, &factor)) {
+                       errno = EINVAL;
+                       return 0;
+               }
+               uval = labs(val);
+               uval *= factor;
+               if (uval > max || labs(val) > uval) {
+                       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 oldval;
+
+               errno = 0;
+               val = strtoumax(value, &end, 0);
+               if (errno == ERANGE)
+                       return 0;
+               oldval = val;
+               if (!parse_unit_factor(end, &val)) {
+                       errno = EINVAL;
+                       return 0;
+               }
+               if (val > max || oldval > val) {
+                       errno = ERANGE;
+                       return 0;
+               }
+               *ret = val;
+               return 1;
+       }
+       errno = EINVAL;
+       return 0;
+}
+
+static 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;
+}
+
+NORETURN
+static void die_bad_number(const char *name, const char *value)
+{
+       const char * error_type = (errno == ERANGE)? _("out of range"):_("invalid unit");
+
+       if (!value)
+               value = "";
+
+       if (!(cf && cf->name))
+               die(_("bad numeric config value '%s' for '%s': %s"),
+                   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;
+}
+
+int git_parse_maybe_bool(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;
+}
+
+int git_config_maybe_bool(const char *name, const char *value)
+{
+       int v = git_parse_maybe_bool(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(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 discard;
+       return !!git_config_bool_or_int(name, value, &discard);
+}
+
+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 = expand_user_path(value);
+       if (!*dest)
+               die(_("failed to expand user dir in: '%s'"), value);
+       return 0;
+}
+
+static int git_default_core_config(const char *var, const char *value)
+{
+       /* 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 {
+                       int abbrev = git_config_int(var, value);
+                       if (abbrev < minimum_abbrev || abbrev > 40)
+                               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);
+               core_compression_level = level;
+               core_compression_seen = 1;
+               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")) {
+               if (value && !strcasecmp(value, "warn")) {
+                       safe_crlf = SAFE_CRLF_WARN;
+                       return 0;
+               }
+               safe_crlf = git_config_bool(var, value);
+               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.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.fsyncobjectfiles")) {
+               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.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.hidedotfiles")) {
+               if (value && !strcasecmp(value, "dotgitonly"))
+                       hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
+               else
+                       hide_dotfiles = git_config_bool(var, value);
+               return 0;
+       }
+
+       /* Add other config variables here and to Documentation/config.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 && !strcasecmp(value, "always")) {
+                       git_branch_track = BRANCH_TRACK_ALWAYS;
+                       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 *dummy)
+{
+       if (starts_with(var, "core."))
+               return git_default_core_config(var, value);
+
+       if (starts_with(var, "user."))
+               return git_ident_config(var, value, dummy);
+
+       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."))
+               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;
+       }
+
+       /* 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)
+{
+       int ret;
+
+       /* push config-file parsing state stack */
+       top->prev = cf;
+       top->linenr = 1;
+       top->eof = 0;
+       strbuf_init(&top->value, 1024);
+       strbuf_init(&top->var, 1024);
+       cf = top;
+
+       ret = git_parse_source(fn, data);
+
+       /* 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)
+{
+       struct config_source top;
+
+       top.u.file = f;
+       top.origin_type = origin_type;
+       top.name = name;
+       top.path = path;
+       top.die_on_error = 1;
+       top.do_fgetc = config_file_fgetc;
+       top.do_ungetc = config_file_ungetc;
+       top.do_ftell = config_file_ftell;
+
+       return do_config_from(&top, fn, data);
+}
+
+static int git_config_from_stdin(config_fn_t fn, void *data)
+{
+       return do_config_from_file(fn, CONFIG_ORIGIN_STDIN, "", NULL, stdin, data);
+}
+
+int git_config_from_file(config_fn_t fn, const char *filename, void *data)
+{
+       int ret = -1;
+       FILE *f;
+
+       f = fopen(filename, "r");
+       if (f) {
+               flockfile(f);
+               ret = do_config_from_file(fn, CONFIG_ORIGIN_FILE, filename, filename, f, data);
+               funlockfile(f);
+               fclose(f);
+       }
+       return ret;
+}
+
+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)
+{
+       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.die_on_error = 0;
+       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);
+}
+
+int git_config_from_blob_sha1(config_fn_t fn,
+                             const char *name,
+                             const unsigned char *sha1,
+                             void *data)
+{
+       enum object_type type;
+       char *buf;
+       unsigned long size;
+       int ret;
+
+       buf = read_sha1_file(sha1, &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);
+       free(buf);
+
+       return ret;
+}
+
+static int git_config_from_blob_ref(config_fn_t fn,
+                                   const char *name,
+                                   void *data)
+{
+       unsigned char sha1[20];
+
+       if (get_sha1(name, sha1) < 0)
+               return error("unable to resolve config blob '%s'", name);
+       return git_config_from_blob_sha1(fn, name, sha1, data);
+}
+
+const char *git_etc_gitconfig(void)
+{
+       static const char *system_wide;
+       if (!system_wide)
+               system_wide = system_path(ETC_GITCONFIG);
+       return system_wide;
+}
+
+/*
+ * 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(config_fn_t fn, void *data)
+{
+       int ret = 0;
+       char *xdg_config = xdg_config_home("config");
+       char *user_config = expand_user_path("~/.gitconfig");
+       char *repo_config = have_git_dir() ? git_pathdup("config") : NULL;
+
+       current_parsing_scope = CONFIG_SCOPE_SYSTEM;
+       if (git_config_system() && !access_or_die(git_etc_gitconfig(), R_OK, 0))
+               ret += git_config_from_file(fn, git_etc_gitconfig(),
+                                           data);
+
+       current_parsing_scope = CONFIG_SCOPE_GLOBAL;
+       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_REPO;
+       if (repo_config && !access_or_die(repo_config, R_OK, 0))
+               ret += git_config_from_file(fn, repo_config, data);
+
+       current_parsing_scope = CONFIG_SCOPE_CMDLINE;
+       if (git_config_from_parameters(fn, data) < 0)
+               die(_("unable to parse command-line config"));
+
+       current_parsing_scope = CONFIG_SCOPE_UNKNOWN;
+       free(xdg_config);
+       free(user_config);
+       free(repo_config);
+       return ret;
+}
+
+int git_config_with_options(config_fn_t fn, void *data,
+                           struct git_config_source *config_source,
+                           int respect_includes)
+{
+       struct config_include_data inc = CONFIG_INCLUDE_INIT;
+
+       if (respect_includes) {
+               inc.fn = fn;
+               inc.data = data;
+               fn = git_config_include;
+               data = &inc;
+       }
+
+       /*
+        * If we have a specific filename, use it. Otherwise, follow the
+        * regular lookup sequence.
+        */
+       if (config_source && config_source->use_stdin)
+               return git_config_from_stdin(fn, data);
+       else if (config_source && config_source->file)
+               return git_config_from_file(fn, config_source->file, data);
+       else if (config_source && config_source->blob)
+               return git_config_from_blob_ref(fn, config_source->blob, data);
+
+       return do_git_config_sequence(fn, data);
+}
+
+static void git_config_raw(config_fn_t fn, void *data)
+{
+       if (git_config_with_options(fn, data, NULL, 1) < 0)
+               /*
+                * git_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 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 strbuf buf = STRBUF_INIT;
+
+       git_config_with_options(cb, data, NULL, 1);
+
+       /*
+        * 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).
+        */
+       if (!have_git_dir() && discover_git_directory(&buf)) {
+               struct git_config_source repo_config;
+
+               memset(&repo_config, 0, sizeof(repo_config));
+               strbuf_addstr(&buf, "/config");
+               repo_config.file = buf.buf;
+               git_config_with_options(cb, data, &repo_config, 1);
+       }
+       strbuf_release(&buf);
+}
+
+static void git_config_check_init(void);
+
+void git_config(config_fn_t fn, void *data)
+{
+       git_config_check_init();
+       configset_iter(&the_config_set, fn, data);
+}
+
+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, strhash(normalized_key));
+       k.key = normalized_key;
+       found_entry = hashmap_get(&cs->config_hash, &k, 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, strhash(key));
+               e->key = xstrdup(key);
+               string_list_init(&e->value_list, 1);
+               hashmap_add(&cs->config_hash, e);
+       }
+       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)
+               die("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 struct config_set_element *e1,
+                                const struct config_set_element *e2, const void *unused)
+{
+       return strcmp(e1->key, e2->key);
+}
+
+void git_configset_init(struct config_set *cs)
+{
+       hashmap_init(&cs->config_hash, (hashmap_cmp_fn)config_set_element_cmp, 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_iter_init(&cs->config_hash, &iter);
+       while ((entry = hashmap_iter_next(&iter))) {
+               free(entry->key);
+               string_list_clear(&entry->value_list, 1);
+       }
+       hashmap_free(&cs->config_hash, 1);
+       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_const(struct config_set *cs, const char *key, const char **dest)
+{
+       const char *value;
+       if (!git_configset_get_value(cs, key, &value))
+               return git_config_string(dest, key, value);
+       else
+               return 1;
+}
+
+int git_configset_get_string(struct config_set *cs, const char *key, char **dest)
+{
+       return git_configset_get_string_const(cs, key, (const char **)dest);
+}
+
+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_config_maybe_bool(key, 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;
+}
+
+static void git_config_check_init(void)
+{
+       if (the_config_set.hash_initialized)
+               return;
+       git_configset_init(&the_config_set);
+       git_config_raw(config_set_callback, &the_config_set);
+}
+
+void git_config_clear(void)
+{
+       if (!the_config_set.hash_initialized)
+               return;
+       git_configset_clear(&the_config_set);
+}
+
+int git_config_get_value(const char *key, const char **value)
+{
+       git_config_check_init();
+       return git_configset_get_value(&the_config_set, key, value);
+}
+
+const struct string_list *git_config_get_value_multi(const char *key)
+{
+       git_config_check_init();
+       return git_configset_get_value_multi(&the_config_set, key);
+}
+
+int git_config_get_string_const(const char *key, const char **dest)
+{
+       int ret;
+       git_config_check_init();
+       ret = git_configset_get_string_const(&the_config_set, key, dest);
+       if (ret < 0)
+               git_die_config(key, NULL);
+       return ret;
 }
 
-int git_config_int(const char *name, const char *value)
+int git_config_get_string(const char *key, char **dest)
 {
-       if (value && *value) {
-               char *end;
-               int val = strtol(value, &end, 0);
-               if (!*end)
-                       return val;
-       }
-       die("bad config value for '%s' in %s", name, config_file_name);
+       git_config_check_init();
+       return git_config_get_string_const(key, (const char **)dest);
 }
 
-int git_config_bool(const char *name, const char *value)
+int git_config_get_int(const char *key, int *dest)
 {
-       if (!value)
-               return 1;
-       if (!*value)
-               return 0;
-       if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
-               return 1;
-       if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
-               return 0;
-       return git_config_int(name, value) != 0;
+       git_config_check_init();
+       return git_configset_get_int(&the_config_set, key, dest);
 }
 
-int git_default_config(const char *var, const char *value)
+int git_config_get_ulong(const char *key, unsigned long *dest)
 {
-       /* This needs a better name */
-       if (!strcmp(var, "core.filemode")) {
-               trust_executable_bit = git_config_bool(var, value);
-               return 0;
-       }
+       git_config_check_init();
+       return git_configset_get_ulong(&the_config_set, key, dest);
+}
 
-       if (!strcmp(var, "core.ignorestat")) {
-               assume_unchanged = git_config_bool(var, value);
-               return 0;
-       }
+int git_config_get_bool(const char *key, int *dest)
+{
+       git_config_check_init();
+       return git_configset_get_bool(&the_config_set, key, dest);
+}
 
-       if (!strcmp(var, "core.prefersymlinkrefs")) {
-               prefer_symlink_refs = git_config_bool(var, value);
-               return 0;
-       }
+int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest)
+{
+       git_config_check_init();
+       return git_configset_get_bool_or_int(&the_config_set, key, is_bool, dest);
+}
 
-       if (!strcmp(var, "core.logallrefupdates")) {
-               log_all_ref_updates = git_config_bool(var, value);
-               return 0;
-       }
+int git_config_get_maybe_bool(const char *key, int *dest)
+{
+       git_config_check_init();
+       return git_configset_get_maybe_bool(&the_config_set, key, dest);
+}
 
-       if (!strcmp(var, "core.warnambiguousrefs")) {
-               warn_ambiguous_refs = git_config_bool(var, value);
-               return 0;
-       }
+int git_config_get_pathname(const char *key, const char **dest)
+{
+       int ret;
+       git_config_check_init();
+       ret = git_configset_get_pathname(&the_config_set, key, dest);
+       if (ret < 0)
+               git_die_config(key, NULL);
+       return ret;
+}
 
-       if (!strcmp(var, "core.legacyheaders")) {
-               use_legacy_headers = git_config_bool(var, value);
-               return 0;
+int git_config_get_expiry(const char *key, const char **output)
+{
+       int ret = git_config_get_string_const(key, 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;
+}
 
-       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);
-               zlib_compression_level = level;
-               return 0;
-       }
+int git_config_get_untracked_cache(void)
+{
+       int val = -1;
+       const char *v;
 
-       if (!strcmp(var, "user.name")) {
-               strlcpy(git_default_name, value, sizeof(git_default_name));
-               return 0;
-       }
+       /* Hack for test programs like test-dump-untracked-cache */
+       if (ignore_untracked_cache_config)
+               return -1;
 
-       if (!strcmp(var, "user.email")) {
-               strlcpy(git_default_email, value, sizeof(git_default_email));
-               return 0;
-       }
+       if (!git_config_get_maybe_bool("core.untrackedcache", &val))
+               return val;
 
-       if (!strcmp(var, "i18n.commitencoding")) {
-               strlcpy(git_commit_encoding, value, sizeof(git_commit_encoding));
-               return 0;
-       }
+       if (!git_config_get_value("core.untrackedcache", &v)) {
+               if (!strcasecmp(v, "keep"))
+                       return -1;
 
-       if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
-               pager_use_color = git_config_bool(var,value);
-               return 0;
+               error(_("unknown core.untrackedCache value '%s'; "
+                       "using 'keep' default value"), v);
+               return -1;
        }
 
-       /* Add other config variables here and to Documentation/config.txt. */
-       return 0;
+       return -1; /* default value */
 }
 
-int git_config_from_file(config_fn_t fn, const char *filename)
+int git_config_get_split_index(void)
 {
-       int ret;
-       FILE *f = fopen(filename, "r");
+       int val;
 
-       ret = -1;
-       if (f) {
-               config_file = f;
-               config_file_name = filename;
-               config_linenr = 1;
-               ret = git_parse_file(fn);
-               fclose(f);
-               config_file_name = NULL;
-       }
-       return ret;
+       if (!git_config_get_maybe_bool("core.splitindex", &val))
+               return val;
+
+       return -1; /* default value */
 }
 
-int git_config(config_fn_t fn)
+int git_config_get_max_percent_split_change(void)
 {
-       int ret = 0;
-       char *repo_config = NULL;
-       const char *home = NULL, *filename;
+       int val = -1;
 
-       /* $GIT_CONFIG makes git read _only_ the given config file,
-        * $GIT_CONFIG_LOCAL will make it process it in addition to the
-        * global config file, the same way it would the per-repository
-        * config file otherwise. */
-       filename = getenv("GIT_CONFIG");
-       if (!filename) {
-               home = getenv("HOME");
-               filename = getenv("GIT_CONFIG_LOCAL");
-               if (!filename)
-                       filename = repo_config = xstrdup(git_path("config"));
-       }
+       if (!git_config_get_int("splitindex.maxpercentchange", &val)) {
+               if (0 <= val && val <= 100)
+                       return val;
 
-       if (home) {
-               char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
-               if (!access(user_config, R_OK))
-                       ret = git_config_from_file(fn, user_config);
-               free(user_config);
+               return error(_("splitIndex.maxPercentChange value '%d' "
+                              "should be between 0 and 100"), val);
        }
 
-       ret += git_config_from_file(fn, filename);
-       free(repo_config);
-       return ret;
+       return -1; /* default value */
+}
+
+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;
+
+       if (err) {
+               va_list params;
+               va_start(params, err);
+               vreportf("error: ", 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.
  */
 
-#define MAX_MATCHES 512
-
 static struct {
        int baselen;
-       charkey;
+       char *key;
        int do_not_match;
-       regex_tvalue_regex;
+       regex_t *value_regex;
        int multi_replace;
-       off_t offset[MAX_MATCHES];
+       size_t *offset;
+       unsigned int offset_alloc;
        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
        int seen;
 } store;
 
-static int matches(const char* key, const char* value)
+static int matches(const char *key, const char *value)
 {
-       return !strcmp(key, store.key) &&
-               (store.value_regex == NULL ||
-                (store.do_not_match ^
-                 !regexec(store.value_regex, value, 0, NULL, 0)));
+       if (strcmp(key, store.key))
+               return 0; /* not ours */
+       if (!store.value_regex)
+               return 1; /* always matches */
+       if (store.value_regex == CONFIG_REGEX_NONE)
+               return 0; /* never matches */
+
+       return store.do_not_match ^
+               (value && !regexec(store.value_regex, value, 0, NULL, 0));
 }
 
-static int store_aux(const char* key, const char* value)
+static int store_aux(const char *key, const char *value, void *cb)
 {
+       const char *ep;
+       size_t section_len;
+
        switch (store.state) {
        case KEY_SEEN:
                if (matches(key, value)) {
                        if (store.seen == 1 && store.multi_replace == 0) {
-                               fprintf(stderr,
-                                       "Warning: %s has multiple values\n",
-                                       key);
-                       } else if (store.seen >= MAX_MATCHES) {
-                               fprintf(stderr, "Too many matches\n");
-                               return 1;
+                               warning(_("%s has multiple values"), key);
                        }
 
-                       store.offset[store.seen] = ftell(config_file);
+                       ALLOC_GROW(store.offset, store.seen + 1,
+                                  store.offset_alloc);
+
+                       store.offset[store.seen] = cf->do_ftell(cf);
                        store.seen++;
                }
                break;
        case SECTION_SEEN:
-               if (strncmp(key, store.key, store.baselen+1)) {
+               /*
+                * What we are looking for is in store.key (both
+                * section and var), and its section part is baselen
+                * long.  We found key (again, both section and var).
+                * We would want to know if this key is in the same
+                * section as what we are looking for.  We already
+                * know we are in the same section as what should
+                * hold store.key.
+                */
+               ep = strrchr(key, '.');
+               section_len = ep - key;
+
+               if ((section_len != store.baselen) ||
+                   memcmp(key, store.key, section_len+1)) {
                        store.state = SECTION_END_SEEN;
                        break;
-               } else
-                       /* do not increment matches: this is no match */
-                       store.offset[store.seen] = ftell(config_file);
+               }
+
+               /*
+                * Do not increment matches: this is no match, but we
+                * just made sure we are in the desired section.
+                */
+               ALLOC_GROW(store.offset, store.seen + 1,
+                          store.offset_alloc);
+               store.offset[store.seen] = cf->do_ftell(cf);
                /* fallthru */
        case SECTION_END_SEEN:
        case START:
                if (matches(key, value)) {
-                       store.offset[store.seen] = ftell(config_file);
+                       ALLOC_GROW(store.offset, store.seen + 1,
+                                  store.offset_alloc);
+                       store.offset[store.seen] = cf->do_ftell(cf);
                        store.state = KEY_SEEN;
                        store.seen++;
                } else {
                        if (strrchr(key, '.') - key == store.baselen &&
                              !strncmp(key, store.key, store.baselen)) {
                                        store.state = SECTION_SEEN;
-                                       store.offset[store.seen] = ftell(config_file);
+                                       ALLOC_GROW(store.offset,
+                                                  store.seen + 1,
+                                                  store.offset_alloc);
+                                       store.offset[store.seen] = cf->do_ftell(cf);
                        }
                }
        }
        return 0;
 }
 
-static void store_write_section(int fd, const char* key)
+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 int store_write_section(int fd, const char *key)
 {
-       const char *dot = strchr(key, '.');
-       int len1 = store.baselen, len2 = -1;
+       const char *dot;
+       int i, success;
+       struct strbuf sb = STRBUF_INIT;
 
-       dot = strchr(key, '.');
+       dot = memchr(key, '.', store.baselen);
        if (dot) {
-               int dotlen = dot - key;
-               if (dotlen < len1) {
-                       len2 = len1 - dotlen - 1;
-                       len1 = dotlen;
+               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_addf(&sb, "[%.*s]\n", store.baselen, key);
        }
 
-       write(fd, "[", 1);
-       write(fd, key, len1);
-       if (len2 >= 0) {
-               write(fd, " \"", 2);
-               while (--len2 >= 0) {
-                       unsigned char c = *++dot;
-                       if (c == '"')
-                               write(fd, "\\", 1);
-                       write(fd, &c, 1);
-               }
-               write(fd, "\"", 1);
-       }
-       write(fd, "]\n", 2);
+       success = write_in_full(fd, sb.buf, sb.len) == sb.len;
+       strbuf_release(&sb);
+
+       return success;
 }
 
-static void store_write_pair(int fd, const char* key, const char* value)
+static int store_write_pair(int fd, const char *key, const char *value)
 {
-       int i;
+       int i, success;
+       int length = strlen(key + store.baselen + 1);
+       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",
+                   length, key + store.baselen + 1, quote);
 
-       write(fd, "\t", 1);
-       write(fd, key+store.baselen+1,
-               strlen(key+store.baselen+1));
-       write(fd, " = ", 3);
        for (i = 0; value[i]; i++)
                switch (value[i]) {
-               case '\n': write(fd, "\\n", 2); break;
-               case '\t': write(fd, "\\t", 2); break;
-               case '"': case '\\': write(fd, "\\", 1);
-               default: write(fd, value+i, 1);
-       }
-       write(fd, "\n", 1);
+               case '\n':
+                       strbuf_addstr(&sb, "\\n");
+                       break;
+               case '\t':
+                       strbuf_addstr(&sb, "\\t");
+                       break;
+               case '"':
+               case '\\':
+                       strbuf_addch(&sb, '\\');
+               default:
+                       strbuf_addch(&sb, value[i]);
+                       break;
+               }
+       strbuf_addf(&sb, "%s\n", quote);
+
+       success = write_in_full(fd, sb.buf, sb.len) == sb.len;
+       strbuf_release(&sb);
+
+       return success;
 }
 
-static int find_beginning_of_line(const char* contents, int size,
-       int offset_, int* found_bracket)
+static ssize_t find_beginning_of_line(const char *contents, size_t size,
+       size_t offset_, int *found_bracket)
 {
-       int equal_offset = size, bracket_offset = size;
-       int offset;
+       size_t equal_offset = size, bracket_offset = size;
+       ssize_t offset;
 
-       for (offset = offset_-2; offset > 0 
+contline:
+       for (offset = offset_-2; offset > 0
                        && contents[offset] != '\n'; offset--)
                switch (contents[offset]) {
                        case '=': equal_offset = offset; break;
                        case ']': bracket_offset = offset; break;
                }
+       if (offset > 0 && contents[offset-1] == '\\') {
+               offset_ = offset;
+               goto contline;
+       }
        if (bracket_offset < equal_offset) {
                *found_bracket = 1;
                offset = bracket_offset+1;
@@ -506,14 +2213,33 @@ static int find_beginning_of_line(const char* contents, int size,
        return offset;
 }
 
-int git_config_set(const char* key, const char* value)
+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);
+}
+
+void git_config_set(const char *key, const char *value)
 {
-       return git_config_set_multivar(key, value, NULL, 0);
+       git_config_set_multivar(key, value, NULL, 0);
 }
 
 /*
  * If value==NULL, unset in (remove from) config,
  * if value_regex!=NULL, disregard key/value pairs where value does not match.
+ * if value_regex==CONFIG_REGEX_NONE, do not match any existing values
+ *     (only add a new one)
  * if multi_replace==0, nothing, or only one matching key/value is replaced,
  *     else all matching key/values (regardless how many) are removed,
  *     before the new pair is written.
@@ -534,71 +2260,38 @@ int git_config_set(const char* key, const char* value)
  * - the config file is removed and the lock file rename()d to it.
  *
  */
-int git_config_set_multivar(const char* key, const char* value,
-       const char* value_regex, int multi_replace)
+int git_config_set_multivar_in_file_gently(const char *config_filename,
+                                          const char *key, const char *value,
+                                          const char *value_regex,
+                                          int multi_replace)
 {
-       int i, dot;
-       int fd = -1, in_fd;
+       int fd = -1, in_fd = -1;
        int ret;
-       char* config_filename;
-       char* lock_file;
-       const char* last_dot = strrchr(key, '.');
-
-       config_filename = getenv("GIT_CONFIG");
-       if (!config_filename) {
-               config_filename = getenv("GIT_CONFIG_LOCAL");
-               if (!config_filename)
-                       config_filename  = git_path("config");
-       }
-       config_filename = xstrdup(config_filename);
-       lock_file = xstrdup(mkpath("%s.lock", config_filename));
-
-       /*
-        * 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) {
-               fprintf(stderr, "key does not contain a section: %s\n", key);
-               ret = 2;
+       struct lock_file *lock = NULL;
+       char *filename_buf = NULL;
+       char *contents = NULL;
+       size_t contents_sz;
+
+       /* 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.baselen = last_dot - key;
 
        store.multi_replace = multi_replace;
 
-       /*
-        * Validate the key and while at it, lower case it for matching.
-        */
-       store.key = xmalloc(strlen(key) + 1);
-       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 > store.baselen) {
-                       if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
-                               fprintf(stderr, "invalid key: %s\n", key);
-                               free(store.key);
-                               ret = 1;
-                               goto out_free;
-                       }
-                       c = tolower(c);
-               }
-               store.key[i] = c;
-       }
-       store.key[i] = 0;
+       if (!config_filename)
+               config_filename = filename_buf = git_pathdup("config");
 
        /*
-        * The lock_file serves a purpose in addition to locking: the new
+        * The lock serves a purpose in addition to locking: the new
         * contents of .git/config will be written into it.
         */
-       fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
-       if (fd < 0 || adjust_shared_perm(lock_file)) {
-               fprintf(stderr, "could not lock config file\n");
+       lock = xcalloc(1, sizeof(struct lock_file));
+       fd = hold_lock_file_for_update(lock, config_filename, 0);
+       if (fd < 0) {
+               error_errno("could not lock config file %s", config_filename);
                free(store.key);
-               ret = -1;
+               ret = CONFIG_NO_LOCK;
                goto out_free;
        }
 
@@ -610,27 +2303,29 @@ int git_config_set_multivar(const char* key, const char* value,
                free(store.key);
 
                if ( ENOENT != errno ) {
-                       error("opening %s: %s", config_filename,
-                             strerror(errno));
-                       ret = 3; /* same as "invalid config file" */
+                       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 == NULL) {
-                       ret = 5;
+                       ret = CONFIG_NOTHING_SET;
                        goto out_free;
                }
 
-               store.key = (char*)key;
-               store_write_section(fd, key);
-               store_write_pair(fd, key, value);
-       } else{
+               store.key = (char *)key;
+               if (!store_write_section(fd, key) ||
+                   !store_write_pair(fd, key, value))
+                       goto write_err_out;
+       } else {
                struct stat st;
-               char* contents;
-               int i, copy_begin, copy_end, new_line = 0;
+               size_t copy_begin, copy_end;
+               int i, new_line = 0;
 
                if (value_regex == NULL)
                        store.value_regex = NULL;
+               else if (value_regex == CONFIG_REGEX_NONE)
+                       store.value_regex = CONFIG_REGEX_NONE;
                else {
                        if (value_regex[0] == '!') {
                                store.do_not_match = 1;
@@ -641,14 +2336,14 @@ int git_config_set_multivar(const char* key, const char* value,
                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
                        if (regcomp(store.value_regex, value_regex,
                                        REG_EXTENDED)) {
-                               fprintf(stderr, "Invalid pattern: %s\n",
-                                       value_regex);
+                               error("invalid pattern: %s", value_regex);
                                free(store.value_regex);
-                               ret = 6;
+                               ret = CONFIG_INVALID_PATTERN;
                                goto out_free;
                        }
                }
 
+               ALLOC_GROW(store.offset, 1, store.offset_alloc);
                store.offset[0] = 0;
                store.state = START;
                store.seen = 0;
@@ -659,19 +2354,21 @@ int git_config_set_multivar(const char* key, const char* value,
                 * As a side effect, we make sure to transform only a valid
                 * existing config file.
                 */
-               if (git_config_from_file(store_aux, config_filename)) {
-                       fprintf(stderr, "invalid config file\n");
+               if (git_config_from_file(store_aux, config_filename, NULL)) {
+                       error("invalid config file %s", config_filename);
                        free(store.key);
-                       if (store.value_regex != NULL) {
+                       if (store.value_regex != NULL &&
+                           store.value_regex != CONFIG_REGEX_NONE) {
                                regfree(store.value_regex);
                                free(store.value_regex);
                        }
-                       ret = 3;
+                       ret = CONFIG_INVALID_FILE;
                        goto out_free;
                }
 
                free(store.key);
-               if (store.value_regex != NULL) {
+               if (store.value_regex != NULL &&
+                   store.value_regex != CONFIG_REGEX_NONE) {
                        regfree(store.value_regex);
                        free(store.value_regex);
                }
@@ -679,71 +2376,398 @@ int git_config_set_multivar(const char* key, const char* value,
                /* if nothing to unset, or too many matches, error out */
                if ((store.seen == 0 && value == NULL) ||
                                (store.seen > 1 && multi_replace == 0)) {
-                       ret = 5;
+                       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;
                }
 
-               fstat(in_fd, &st);
-               contents = mmap(NULL, st.st_size, PROT_READ,
-                       MAP_PRIVATE, in_fd, 0);
+               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'", config_filename);
+                       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 == 0)
                        store.seen = 1;
 
                for (i = 0, copy_begin = 0; i < store.seen; i++) {
                        if (store.offset[i] == 0) {
-                               store.offset[i] = copy_end = st.st_size;
+                               store.offset[i] = copy_end = contents_sz;
                        } else if (store.state != KEY_SEEN) {
                                copy_end = store.offset[i];
                        } else
                                copy_end = find_beginning_of_line(
-                                       contents, st.st_size,
+                                       contents, contents_sz,
                                        store.offset[i]-2, &new_line);
 
+                       if (copy_end > 0 && contents[copy_end-1] != '\n')
+                               new_line = 1;
+
                        /* write the first part of the config */
                        if (copy_end > copy_begin) {
-                               write(fd, contents + copy_begin,
-                               copy_end - copy_begin);
-                               if (new_line)
-                                       write(fd, "\n", 1);
+                               if (write_in_full(fd, contents + copy_begin,
+                                                 copy_end - copy_begin) <
+                                   copy_end - copy_begin)
+                                       goto write_err_out;
+                               if (new_line &&
+                                   write_str_in_full(fd, "\n") != 1)
+                                       goto write_err_out;
                        }
                        copy_begin = store.offset[i];
                }
 
                /* write the pair (value == NULL means unset) */
                if (value != NULL) {
-                       if (store.state == START)
-                               store_write_section(fd, key);
-                       store_write_pair(fd, key, value);
+                       if (store.state == START) {
+                               if (!store_write_section(fd, key))
+                                       goto write_err_out;
+                       }
+                       if (!store_write_pair(fd, key, value))
+                               goto write_err_out;
                }
 
                /* write the rest of the config */
-               if (copy_begin < st.st_size)
-                       write(fd, contents + copy_begin,
-                               st.st_size - copy_begin);
-
-               munmap(contents, st.st_size);
-               unlink(config_filename);
+               if (copy_begin < contents_sz)
+                       if (write_in_full(fd, contents + copy_begin,
+                                         contents_sz - copy_begin) <
+                           contents_sz - copy_begin)
+                               goto write_err_out;
+
+               munmap(contents, contents_sz);
+               contents = NULL;
        }
 
-       if (rename(lock_file, config_filename) < 0) {
-               fprintf(stderr, "Could not rename the lock file?\n");
-               ret = 4;
+       if (commit_lock_file(lock) < 0) {
+               error_errno("could not write config file %s", config_filename);
+               ret = CONFIG_NO_WRITE;
+               lock = NULL;
                goto out_free;
        }
 
+       /*
+        * lock is committed, so don't try to roll it back below.
+        * NOTE: Since lockfile.c keeps a linked list of all created
+        * lock_file structures, it isn't safe to free(lock).  It's
+        * better to just leave it hanging around.
+        */
+       lock = NULL;
        ret = 0;
 
+       /* Invalidate the config cache */
+       git_config_clear();
+
 out_free:
-       if (0 <= fd)
-               close(fd);
-       free(config_filename);
-       if (lock_file) {
-               unlink(lock_file);
-               free(lock_file);
+       if (lock)
+               rollback_lock_file(lock);
+       free(filename_buf);
+       if (contents)
+               munmap(contents, contents_sz);
+       if (in_fd >= 0)
+               close(in_fd);
+       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_regex, int multi_replace)
+{
+       if (!git_config_set_multivar_in_file_gently(config_filename, key, value,
+                                                   value_regex, multi_replace))
+               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_regex, int multi_replace)
+{
+       return git_config_set_multivar_in_file_gently(NULL, key, value, value_regex,
+                                                     multi_replace);
+}
+
+void git_config_set_multivar(const char *key, const char *value,
+                            const char *value_regex, int multi_replace)
+{
+       git_config_set_multivar_in_file(NULL, key, value, value_regex,
+                                       multi_replace);
+}
+
+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 */
+int git_config_rename_section_in_file(const char *config_filename,
+                                     const char *old_name, const char *new_name)
+{
+       int ret = 0, remove = 0;
+       char *filename_buf = NULL;
+       struct lock_file *lock;
+       int out_fd;
+       char buf[1024];
+       FILE *config_file;
+       struct stat st;
+
+       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");
+
+       lock = xcalloc(1, sizeof(struct lock_file));
+       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"))) {
+               /* 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)) {
+               int i;
+               int length;
+               char *output = buf;
+               for (i = 0; buf[i] && isspace(buf[i]); i++)
+                       ; /* do nothing */
+               if (buf[i] == '[') {
+                       /* it's a section */
+                       int offset = section_name_match(&buf[i], old_name);
+                       if (offset > 0) {
+                               ret++;
+                               if (new_name == NULL) {
+                                       remove = 1;
+                                       continue;
+                               }
+                               store.baselen = strlen(new_name);
+                               if (!store_write_section(out_fd, new_name)) {
+                                       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';
+                               }
+                       }
+                       remove = 0;
+               }
+               if (remove)
+                       continue;
+               length = strlen(output);
+               if (write_in_full(out_fd, output, length) != length) {
+                       ret = write_error(get_lock_file_path(lock));
+                       goto out;
+               }
        }
+       fclose(config_file);
+commit_and_out:
+       if (commit_lock_file(lock) < 0)
+               ret = error_errno("could not write config file %s",
+                                 config_filename);
+out:
+       rollback_lock_file(lock);
+out_no_rollback:
+       free(filename_buf);
        return ret;
 }
 
+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);
+}
+
+/*
+ * 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, int *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
+               die("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:
+               die("BUG: unknown config origin type");
+       }
+}
+
+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
+               die("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;
+}