handle TALER_EXCHANGEDB_RO_EXCHANGE_TO_BANK in DB balance calulations

src/exchange/taler-exchange-httpd_db.c

@@ -781,6 +781,23 @@ execute_reserve_withdraw_transaction (struct MHD_Connection *connection,
         }
       res |= 1;
       break;
+
+    case TALER_EXCHANGEDB_RO_EXCHANGE_TO_BANK:
+      if (0 == (res & 2))
+        withdraw_total = pos->details.bank->amount;
+      else
+        if (GNUNET_OK !=
+            TALER_amount_add (&withdraw_total,
+                              &withdraw_total,
+                              &pos->details.bank->amount))
+        {
+          TEH_plugin->rollback (TEH_plugin->cls,
+                                session);
+          return TEH_RESPONSE_reply_internal_db_error (connection,
+						       TALER_EC_WITHDRAW_AMOUNT_WITHDRAWALS_OVERFLOW);
+        }
+      res |= 2;
+      break;
     }
   }
   if (0 == (res & 1))