make table discovery work

storage/xpand/ha_xpand.cc

@@ -1467,10 +1467,13 @@ static int xpand_discover_table_names(handlerton *hton, LEX_CSTRING *db,
 {
   xpand_connection *xpand_net = new xpand_connection();
   int error_code = xpand_net->connect();
-  if (error_code)
+  if (error_code) {
+    if (error_code == HA_ERR_NO_CONNECTION)
+      error_code = 0;
     goto err;
+  }
 
-  xpand_net->populate_table_list(db, result);
+  error_code = xpand_net->populate_table_list(db, result);
 
 err:
   delete xpand_net;
@@ -1481,8 +1484,11 @@ int xpand_discover_table(handlerton *hton, THD *thd, TABLE_SHARE *share)
 {
   xpand_connection *xpand_net = new xpand_connection();
   int error_code = xpand_net->connect();
-  if (error_code)
+  if (error_code) {
+    if (error_code == HA_ERR_NO_CONNECTION)
+      error_code = HA_ERR_NO_SUCH_TABLE;
     goto err;
+  }
 
   error_code = xpand_net->discover_table_details(&share->db, &share->table_name,
                                                  thd, share);

storage/xpand/xpand_connection.cc

@@ -141,7 +141,7 @@ int xpand_connection::connect()
   mysql_rwlock_rdlock(&xpand_hosts_lock);
 
   //search for available host
-  int error_code = ER_BAD_HOST_ERROR;
+  int error_code = HA_ERR_NO_CONNECTION;
   for (int i = 0; i < xpand_hosts->hosts_len; i++) {
     char *host = xpand_hosts->hosts[(start + i) % xpand_hosts->hosts_len];
     error_code = connect_direct(host);
@@ -196,12 +196,9 @@ int xpand_connection::connect_direct(char *host)
                           NULL, xpand_port, xpand_socket,
                           CLIENT_MULTI_STATEMENTS))
   {
-    error_code = mysql_errno(&xpand_net);
+    sql_print_error("Error connecting to xpand: %s", mysql_error(&xpand_net));
     disconnect();
-  }
-
-  if (error_code && error_code != ER_CON_COUNT_ERROR) {
-    error_code = ER_CONNECT_TO_FOREIGN_DATA_SOURCE;
+    error_code = HA_ERR_NO_CONNECTION;
   }
 
   DBUG_RETURN(error_code);