SelectBox: should not throw an error if its detached template is re-mounted by a framework (T1178295)

js/ui/drop_down_editor/ui.drop_down_editor.js

@@ -337,8 +337,6 @@ const DropDownEditor = TextBox.inherit({
     },
 
     _renderTemplatedField: function(fieldTemplate, data) {
-        this._fieldRenderQueueLength = (this._fieldRenderQueueLength ?? 0) + 1;
-
         const isFocused = focused(this._input());
         const $container = this._$container;
 
@@ -354,8 +352,9 @@ const DropDownEditor = TextBox.inherit({
             model: data,
             container: getPublicElement($templateWrapper),
             onRendered: () => {
-                this._fieldRenderQueueLength--;
-                if(this._fieldRenderQueueLength !== 0) {
+                const isRenderedInRoot = !!this.$element().find($templateWrapper).length;
+
+                if(!isRenderedInRoot) {
                     return;
                 }
 

testing/tests/DevExpress.ui.widgets.editors/dropDownEditor.tests.js

@@ -13,6 +13,7 @@ import { isRenderer } from 'core/utils/type';
 import caretWorkaround from './textEditorParts/caretWorkaround.js';
 import resizeCallbacks from 'core/utils/resize_callbacks';
 import dxButton from 'ui/button';
+import domAdapter from 'core/dom_adapter';
 
 import 'generic_light.css!';
 QUnit.testStart(function() {
@@ -923,6 +924,42 @@ QUnit.module('Templates', () => {
         }
     });
 
+    QUnit.test('should not raise error if onRendered is received for a removed template (T1178295, T1059261)', function(assert) {
+        const clock = sinon.useFakeTimers();
+
+        const dropDownEditor = $('#dropDownEditorLazy').dxDropDownEditor({
+            fieldTemplate: 'field',
+            templatesRenderAsynchronously: true,
+            integrationOptions: {
+                templates: {
+                    field: {
+                        render: function({ container, onRendered }) {
+                            const $input = $('<div>').appendTo(container);
+
+                            setTimeout(() => {
+                                $input.dxTextBox();
+                                onRendered();
+                                domAdapter.removeElement(container);
+                                domAdapter.removeElement($input);
+                                dropDownEditor.repaint();
+                                onRendered();
+                            }, 100);
+                        }
+                    }
+                }
+            },
+        }).dxDropDownEditor('instance');
+
+        try {
+            clock.tick(110);
+        } catch(e) {
+            assert.ok(false, `error is raised: ${e.message}`);
+        } finally {
+            clock.restore();
+            assert.ok(true);
+        }
+    });
+
     QUnit.test('onValueChanged should be fired for each change by keyboard when fieldTemplate is used', function(assert) {
         const valueChangedSpy = sinon.spy();