Normally localed would do an approximate parsing of the Xorg config file
to determine the XKB keyboard layout.  This doesn't make sense on Guix
where there's no such file in /etc, and where the keyboard layout is
known statically at configuration time.

This patch removes the XOrg configuration parsing and expects to read the
configuration from environment variables instead.  It also removes the
stateful bits that would write configuration to /etc/vconsole.conf
and /etc/X11, which are unused in Guix anyway.

Patch by Ludovic Courtès <ludo@gnu.org>.

diff --git a/src/locale/keymap-util.c b/src/locale/keymap-util.c
index 6b6b32a591..46aab472b0 100644
--- a/src/locale/keymap-util.c
+++ b/src/locale/keymap-util.c
@@ -174,32 +174,16 @@ int vconsole_read_data(Context *c, sd_bus_message *m) {
                 c->vc_cache = sd_bus_message_ref(m);
         }
 
-        if (stat("/etc/vconsole.conf", &st) < 0) {
-                if (errno != ENOENT)
-                        return -errno;
-
-                c->vc_mtime = USEC_INFINITY;
-                context_free_vconsole(c);
-                return 0;
-        }
-
-        /* If mtime is not changed, then we do not need to re-read */
-        t = timespec_load(&st.st_mtim);
-        if (c->vc_mtime != USEC_INFINITY && t == c->vc_mtime)
-                return 0;
-
-        c->vc_mtime = t;
+        c->vc_mtime = USEC_INFINITY;
         context_free_vconsole(c);
-
-        r = parse_env_file(NULL, "/etc/vconsole.conf",
-                           "KEYMAP",        &c->vc_keymap,
-                           "KEYMAP_TOGGLE", &c->vc_keymap_toggle);
-        if (r < 0)
-                return r;
-
         return 0;
 }
 
+static char *getenv_strdup(const char *variable) {
+        const char *value = getenv(variable);
+        return value == NULL ? NULL : strdup(value);
+}
+
 int x11_read_data(Context *c, sd_bus_message *m) {
         _cleanup_fclose_ FILE *f = NULL;
         bool in_section = false;
@@ -216,258 +200,27 @@ int x11_read_data(Context *c, sd_bus_message *m) {
                 c->x11_cache = sd_bus_message_ref(m);
         }
 
-        if (stat("/etc/X11/xorg.conf.d/00-keyboard.conf", &st) < 0) {
-                if (errno != ENOENT)
-                        return -errno;
-
-                c->x11_mtime = USEC_INFINITY;
-                context_free_x11(c);
-                return 0;
-        }
-
-        /* If mtime is not changed, then we do not need to re-read */
-        t = timespec_load(&st.st_mtim);
-        if (c->x11_mtime != USEC_INFINITY && t == c->x11_mtime)
-                return 0;
-
-        c->x11_mtime = t;
+        c->x11_mtime = 0;
         context_free_x11(c);
 
-        f = fopen("/etc/X11/xorg.conf.d/00-keyboard.conf", "re");
-        if (!f)
-                return -errno;
-
-        for (;;) {
-                _cleanup_free_ char *line = NULL;
-                char *l;
-
-                r = read_line(f, LONG_LINE_MAX, &line);
-                if (r < 0)
-                        return r;
-                if (r == 0)
-                        break;
-
-                l = strstrip(line);
-                if (IN_SET(l[0], 0, '#'))
-                        continue;
-
-                if (in_section && first_word(l, "Option")) {
-                        _cleanup_strv_free_ char **a = NULL;
-
-                        r = strv_split_extract(&a, l, WHITESPACE, EXTRACT_QUOTES);
-                        if (r < 0)
-                                return r;
-
-                        if (strv_length(a) == 3) {
-                                char **p = NULL;
-
-                                if (streq(a[1], "XkbLayout"))
-                                        p = &c->x11_layout;
-                                else if (streq(a[1], "XkbModel"))
-                                        p = &c->x11_model;
-                                else if (streq(a[1], "XkbVariant"))
-                                        p = &c->x11_variant;
-                                else if (streq(a[1], "XkbOptions"))
-                                        p = &c->x11_options;
-
-                                if (p) {
-                                        free_and_replace(*p, a[2]);
-                                }
-                        }
-
-                } else if (!in_section && first_word(l, "Section")) {
-                        _cleanup_strv_free_ char **a = NULL;
-
-                        r = strv_split_extract(&a, l, WHITESPACE, EXTRACT_QUOTES);
-                        if (r < 0)
-                                return -ENOMEM;
-
-                        if (strv_length(a) == 2 && streq(a[1], "InputClass"))
-                                in_section = true;
-
-                } else if (in_section && first_word(l, "EndSection"))
-                        in_section = false;
-        }
+        c->x11_layout = getenv_strdup("GUIX_XKB_LAYOUT");
+        c->x11_model = getenv_strdup("GUIX_XKB_MODEL");
+        c->x11_variant = getenv_strdup("GUIX_XKB_VARIANT");
+        c->x11_options = getenv_strdup("GUIX_XKB_OPTIONS");
 
         return 0;
 }
 
 int locale_write_data(Context *c, char ***settings) {
-        _cleanup_strv_free_ char **l = NULL;
-        struct stat st;
-        int r, p;
-
-        /* Set values will be returned as strv in *settings on success. */
-
-        for (p = 0; p < _VARIABLE_LC_MAX; p++) {
-                _cleanup_free_ char *t = NULL;
-                char **u;
-                const char *name;
-
-                name = locale_variable_to_string(p);
-                assert(name);
-
-                if (isempty(c->locale[p]))
-                        continue;
-
-                if (asprintf(&t, "%s=%s", name, c->locale[p]) < 0)
-                        return -ENOMEM;
-
-                u = strv_env_set(l, t);
-                if (!u)
-                        return -ENOMEM;
-
-                strv_free_and_replace(l, u);
-        }
-
-        if (strv_isempty(l)) {
-                if (unlink("/etc/locale.conf") < 0)
-                        return errno == ENOENT ? 0 : -errno;
-
-                c->locale_mtime = USEC_INFINITY;
-                return 0;
-        }
-
-        r = write_env_file_label("/etc/locale.conf", l);
-        if (r < 0)
-                return r;
-
-        *settings = TAKE_PTR(l);
-
-        if (stat("/etc/locale.conf", &st) >= 0)
-                c->locale_mtime = timespec_load(&st.st_mtim);
-
-        return 0;
+        return -ENOSYS;
 }
 
 int vconsole_write_data(Context *c) {
-        _cleanup_strv_free_ char **l = NULL;
-        struct stat st;
-        int r;
-
-        r = load_env_file(NULL, "/etc/vconsole.conf", &l);
-        if (r < 0 && r != -ENOENT)
-                return r;
-
-        if (isempty(c->vc_keymap))
-                l = strv_env_unset(l, "KEYMAP");
-        else {
-                _cleanup_free_ char *s = NULL;
-                char **u;
-
-                s = strappend("KEYMAP=", c->vc_keymap);
-                if (!s)
-                        return -ENOMEM;
-
-                u = strv_env_set(l, s);
-                if (!u)
-                        return -ENOMEM;
-
-                strv_free_and_replace(l, u);
-        }
-
-        if (isempty(c->vc_keymap_toggle))
-                l = strv_env_unset(l, "KEYMAP_TOGGLE");
-        else  {
-                _cleanup_free_ char *s = NULL;
-                char **u;
-
-                s = strappend("KEYMAP_TOGGLE=", c->vc_keymap_toggle);
-                if (!s)
-                        return -ENOMEM;
-
-                u = strv_env_set(l, s);
-                if (!u)
-                        return -ENOMEM;
-
-                strv_free_and_replace(l, u);
-        }
-
-        if (strv_isempty(l)) {
-                if (unlink("/etc/vconsole.conf") < 0)
-                        return errno == ENOENT ? 0 : -errno;
-
-                c->vc_mtime = USEC_INFINITY;
-                return 0;
-        }
-
-        r = write_env_file_label("/etc/vconsole.conf", l);
-        if (r < 0)
-                return r;
-
-        if (stat("/etc/vconsole.conf", &st) >= 0)
-                c->vc_mtime = timespec_load(&st.st_mtim);
-
-        return 0;
+        return -ENOSYS;
 }
 
 int x11_write_data(Context *c) {
-        _cleanup_fclose_ FILE *f = NULL;
-        _cleanup_free_ char *temp_path = NULL;
-        struct stat st;
-        int r;
-
-        if (isempty(c->x11_layout) &&
-            isempty(c->x11_model) &&
-            isempty(c->x11_variant) &&
-            isempty(c->x11_options)) {
-
-                if (unlink("/etc/X11/xorg.conf.d/00-keyboard.conf") < 0)
-                        return errno == ENOENT ? 0 : -errno;
-
-                c->vc_mtime = USEC_INFINITY;
-                return 0;
-        }
-
-        mkdir_p_label("/etc/X11/xorg.conf.d", 0755);
-
-        r = fopen_temporary("/etc/X11/xorg.conf.d/00-keyboard.conf", &f, &temp_path);
-        if (r < 0)
-                return r;
-
-        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
-        (void) fchmod(fileno(f), 0644);
-
-        fputs("# Written by systemd-localed(8), read by systemd-localed and Xorg. It's\n"
-              "# probably wise not to edit this file manually. Use localectl(1) to\n"
-              "# instruct systemd-localed to update it.\n"
-              "Section \"InputClass\"\n"
-              "        Identifier \"system-keyboard\"\n"
-              "        MatchIsKeyboard \"on\"\n", f);
-
-        if (!isempty(c->x11_layout))
-                fprintf(f, "        Option \"XkbLayout\" \"%s\"\n", c->x11_layout);
-
-        if (!isempty(c->x11_model))
-                fprintf(f, "        Option \"XkbModel\" \"%s\"\n", c->x11_model);
-
-        if (!isempty(c->x11_variant))
-                fprintf(f, "        Option \"XkbVariant\" \"%s\"\n", c->x11_variant);
-
-        if (!isempty(c->x11_options))
-                fprintf(f, "        Option \"XkbOptions\" \"%s\"\n", c->x11_options);
-
-        fputs("EndSection\n", f);
-
-        r = fflush_sync_and_check(f);
-        if (r < 0)
-                goto fail;
-
-        if (rename(temp_path, "/etc/X11/xorg.conf.d/00-keyboard.conf") < 0) {
-                r = -errno;
-                goto fail;
-        }
-
-        if (stat("/etc/X11/xorg.conf.d/00-keyboard.conf", &st) >= 0)
-                c->x11_mtime = timespec_load(&st.st_mtim);
-
-        return 0;
-
-fail:
-        if (temp_path)
-                (void) unlink(temp_path);
-
-        return r;
+        return -ENOSYS;
 }
 
 static int read_next_mapping(const char* filename,