Matrix dynamic with editing object doesn't work correctly on adding a…

src/question_matrixdynamic.ts

@@ -787,7 +787,7 @@ export class QuestionMatrixDynamicModel extends QuestionMatrixDropdownModelBase
     const lastDelRow = this.lastDeletedRow;
     this.lastDeletedRow = undefined;
     const rows = this.generatedVisibleRows;
-    if(!Array.isArray(val) || Math.abs(rows.length - val.length) > 1) return false;
+    if(!Array.isArray(val) || Math.abs(rows.length - val.length) > 1 || rows.length === val.length) return false;
     const index = this.getInsertedDeletedIndex(rows, val);
     if(rows.length > val.length) {
       this.lastDeletedRow = rows[index];

tests/editingObjectTests.ts

@@ -16,6 +16,7 @@ import { QuestionMultipleTextModel } from "../src/question_multipletext";
 import { QuestionMatrixModel } from "../src/question_matrix";
 import { Question } from "../src/question";
 import { QuestionCheckboxModel } from "../src/question_checkbox";
+import { SurveyTriggerComplete } from "../src/trigger";
 
 export default QUnit.module("Survey.editingObj Tests");
 
@@ -1472,3 +1473,31 @@ QUnit.test("Allow to set empty string into localization string & string property
   assert.strictEqual(q2.placeholder, "", "q2.placeholder value is empty");
   assert.strictEqual(q2.minWidth, "", "q2.minWidth value is empty");
 });
+QUnit.test("Edit triggers array", function (assert) {
+  const survey = new SurveyModel();
+
+  const editSurvey = new SurveyModel({
+    elements: [
+      {
+        type: "matrixdynamic",
+        name: "triggers",
+        columns: [{ cellType: "text", name: "type" }],
+        rowCount: 0,
+      },
+    ],
+  });
+  editSurvey.onMatrixCellCreated.add((sender, options) => {
+    const obj = options.row.editingObj;
+    if(obj) {
+      options.cell.value = obj.getType();
+    }
+  });
+  const matrix = <QuestionMatrixDynamicModel>(
+    editSurvey.getQuestionByName("triggers")
+  );
+  editSurvey.editingObj = survey;
+  assert.equal(matrix.visibleRows.length, 0, "There is no triggers");
+  survey.triggers.push(new SurveyTriggerComplete());
+  assert.equal(matrix.visibleRows.length, 1, "There is one trigger");
+  assert.equal(matrix.visibleRows[0].cells[0].value, "completetrigger", "correct trigger type");
+});