FIX: lost focus on unchanged cell in structure editor clearing neighbor, close #315

media/js/discipline/editStructure.js

@@ -276,6 +276,11 @@ $(document).ready(function () {
         e => setNewRateAndControl($(e.target).turnOff(), oldMaxRate));
 
     function setNewRateAndControl($rateInput, oldMaxRate) {
+        // http://gitlab.mmcs.sfedu.ru/it-lab/grade/issues/315
+        if ($rateInput.val() === oldMaxRate) {
+            $rateInput.turnOn();
+            return;
+        }
         let $moduleHeads = $('.moduleHead'),
             currentControl = $moduleHeads.children('.currentControl').sum(true),
             landmarkControl = $moduleHeads.children('.landmarkControl').sum(true);