Remove tokudb_dir_cmd variable

The feature is too dangerous for a stable version.

storage/tokudb/tokudb_sysvars.cc

@@ -43,7 +43,6 @@ namespace sysvars {
 #define TOKUDB_VERSION_STR NULL
 #endif
 
-const size_t error_buffer_max_size = 1024;
 
 ulonglong   cache_size = 0;
 uint        cachetable_pool_threads = 0;
@@ -923,73 +922,6 @@ static MYSQL_THDVAR_BOOL(
     true);
 #endif
 
-static int dir_cmd_check(THD* thd, struct st_mysql_sys_var* var,
-                         void* save, struct st_mysql_value* value) ;
-
-static MYSQL_THDVAR_INT(dir_cmd_last_error,
-    PLUGIN_VAR_THDLOCAL,
-    "error from the last dir command. 0 is success",
-    NULL, NULL, 0, 0, 0, 1);
-
-static MYSQL_THDVAR_STR(dir_cmd_last_error_string,
-    PLUGIN_VAR_THDLOCAL + PLUGIN_VAR_MEMALLOC,
-    "error string from the last dir command",
-    NULL, NULL, NULL);
-
-static MYSQL_THDVAR_STR(dir_cmd,
-    PLUGIN_VAR_THDLOCAL + PLUGIN_VAR_MEMALLOC,
-    "name of the directory where the backup is stored",
-    dir_cmd_check, NULL, NULL);
-
-static void dir_cmd_set_error(THD *thd,
-                              int error,
-                              const char *error_fmt,
-                              ...) {
-    char   buff[error_buffer_max_size];
-    va_list varargs;
-
-    assert(thd);
-    assert(error_fmt);
-
-    va_start(varargs, error_fmt);
-    vsnprintf(buff, sizeof(buff), error_fmt, varargs);
-    va_end(varargs);
-
-#if 0  // Disable macros unavailable in MariaDB.
-    THDVAR_SET(thd, dir_cmd_last_error, &error);
-    THDVAR_SET(thd, dir_cmd_last_error_string, buff);
-#endif
-}
-
-static int dir_cmd_check(THD* thd, struct st_mysql_sys_var* var,
-                         void* save, struct st_mysql_value* value) {
-    int error = 0;
-    dir_cmd_set_error(thd, error, "");
-
-    if (check_global_access(thd, SUPER_ACL)) {
-        return 1;
-    }
-
-    char buff[STRING_BUFFER_USUAL_SIZE];
-    int length = sizeof(buff);
-    const char *str = value->val_str(value, buff, &length);
-    if (str) {
-        str = thd->strmake(str, length);
-        *(const char**)save = str;
-    }
-
-    if (str) {
-        dir_cmd_callbacks callbacks { .set_error = dir_cmd_set_error };
-        process_dir_cmd(thd, str, callbacks);
-
-        error = THDVAR(thd, dir_cmd_last_error);
-    } else {
-        error = EINVAL;
-    }
-
-    return error;
-}
-
 //******************************************************************************
 // all system variables
 //******************************************************************************
@@ -1077,9 +1009,6 @@ st_mysql_sys_var* system_variables[] = {
 #if TOKUDB_DEBUG
    MYSQL_SYSVAR(debug_pause_background_job_manager),
 #endif // TOKUDB_DEBUG
-    MYSQL_SYSVAR(dir_cmd_last_error),
-    MYSQL_SYSVAR(dir_cmd_last_error_string),
-    MYSQL_SYSVAR(dir_cmd),
 
     NULL
 };