Fixes #4740 - RangeError: Maximum call stack size exceeded while upda…

…ting organizations.

Co-authored-by: Florian Liebe <fl@zammad.com>

app/assets/javascripts/application.js

@@ -68,14 +68,19 @@ Date.prototype.getWeek = function() {
   return Math.ceil((((this - onejan) / 86400000) + onejan.getDay()+1)/7);
 }
 
-function difference(object1, object2) {
+function difference(object1, object2, depth = 0, maxDepth = 10) {
   object1 = object1 || {};
   object2 = object2 || {};
   var changes = {};
+
+  if (depth > maxDepth) {
+    return changes;
+  }
+
   _.uniq(Object.keys(object1).concat(Object.keys(object2))).forEach(function(name) {
     if (name in object1 && name in object2) {
       if (_.isObject(object1[name]) && !_.isArray(object1[name]) && _.isObject(object2[name]) && !_.isArray(object2[name])) {
-        var diff = difference(object1[name], object2[name]);
+        var diff = difference(object1[name], object2[name], depth + 1, maxDepth);
         if (!_.isEmpty(diff)) {
             changes[name] = diff;
         }

public/assets/tests/qunit/core.js

@@ -657,6 +657,16 @@ QUnit.test('difference', assert => {
 
   item = difference(undefined, {})
   assert.deepEqual(item, {})
+
+  try {
+    a = { a: { a: 1 } }
+    b = { b: { b: a } }
+    a.a.a = b
+    item = difference(a, a)
+    assert.deepEqual(item, {})
+  } catch(error) {
+    assert.deepEqual(false, true, 'recursion failed: ' + error)
+  }
 });
 
 QUnit.test('auth - not existing user', assert => {