Fixed https://github.com/surveyjs/survey-creator/issues/3916 - 'Apply' button in Edit Totals popup causes console error 'Cannot read properties of null

src/question_matrixdropdownbase.ts

@@ -2305,10 +2305,10 @@ export class QuestionMatrixDropdownModelBase extends QuestionMatrixBaseModel<Mat
     return this.SurveyModel.getMatrixCellTemplateData(cell);
   }
   public getCellWrapperComponentName(cell: MatrixDropdownCell) {
-    return this.SurveyModel.getElementWrapperComponentName(cell, "cell");
+    return this.SurveyModel.getElementWrapperComponentName(cell, cell.row instanceof MatrixDropdownTotalRowModel ? "row-footer" : "cell");
   }
   public getCellWrapperComponentData(cell: MatrixDropdownCell) {
-    return this.SurveyModel.getElementWrapperComponentData(cell, "cell");
+    return this.SurveyModel.getElementWrapperComponentData(cell, cell.row instanceof MatrixDropdownTotalRowModel ? "row-footer" : "cell");
   }
   public getColumnHeaderWrapperComponentName(cell: MatrixDropdownCell) {
     return this.SurveyModel.getElementWrapperComponentName(

src/react/reactquestion.tsx

@@ -424,7 +424,7 @@ export class SurveyQuestionAndErrorsCell extends SurveyQuestionAndErrorsWrapped
     const survey: SurveyModel = this.question.survey as SurveyModel;
     let wrapper: JSX.Element | null = null;
     if (survey) {
-      wrapper = ReactSurveyElementsWrapper.wrapMatrixCell(survey, element, cell);
+      wrapper = ReactSurveyElementsWrapper.wrapMatrixCell(survey, element, cell, this.props.reason);
     }
     return wrapper ?? element;
   }

src/react/reactquestion_matrixdropdownbase.tsx

@@ -113,7 +113,8 @@ export class SurveyQuestionMatrixDropdownBase extends SurveyQuestionElementBase
     var row = this.renderRow(
       "footer",
       table.footerRow,
-      this.question.cssClasses
+      this.question.cssClasses,
+      "row-footer"
     );
     return <tfoot>{row}</tfoot>;
   }
@@ -131,13 +132,14 @@ export class SurveyQuestionMatrixDropdownBase extends SurveyQuestionElementBase
   renderRow(
     keyValue: any,
     row: QuestionMatrixDropdownRenderedRow,
-    cssClasses: any
+    cssClasses: any,
+    reason?: string
   ): JSX.Element {
     var matrixrow:Array<JSX.Element> = [];
     var cells = row.cells;
 
     for (var i = 0; i < cells.length; i++) {
-      matrixrow.push(this.renderCell(cells[i], i, cssClasses));
+      matrixrow.push(this.renderCell(cells[i], i, cssClasses, reason));
     }
     var key = "row" + keyValue;
 
@@ -151,7 +153,8 @@ export class SurveyQuestionMatrixDropdownBase extends SurveyQuestionElementBase
   renderCell(
     cell: QuestionMatrixDropdownRenderedCell,
     index: number,
-    cssClasses: any
+    cssClasses: any,
+    reason?: string
   ): JSX.Element {
     var key = "cell" + index;
     if (cell.hasQuestion) {
@@ -161,11 +164,15 @@ export class SurveyQuestionMatrixDropdownBase extends SurveyQuestionElementBase
           cssClasses={cssClasses}
           cell={cell}
           creator={this.creator}
+          reason={reason}
         />
       );
     }
-    let reason = cell.hasTitle ? "row-header" : "";
-    var cellContent = this.renderCellContent(cell, reason, cssClasses);
+    let calcReason = reason;
+    if(!calcReason) {
+      calcReason = cell.hasTitle ? "row-header" : "";
+    }
+    var cellContent = this.renderCellContent(cell, calcReason, cssClasses);
     var cellStyle: any = null;
     if (!!cell.width || !!cell.minWidth) {
       cellStyle = {};

tests/question_matrixdropdownbasetests.ts

@@ -400,4 +400,53 @@ QUnit.test("Check matrixdropdown cells cssClasses with showInMultipleColumns", f
   assert.equal(columnName, "col1", "The event raised correctly");
   matrix.columns.push(new MatrixDropdownColumn("col2"));
   assert.equal(columnName, "col2", "The event raised correctly on adding into array");
-});
+});
+
+class TestElementWrapperSurveyModel extends SurveyModel {
+  constructor(json: any) {
+    super(json);
+  }
+  public getElementWrapperComponentName(element: any, reason?: string): string {
+    this.reason = "name->" + reason;
+    return super.getElementWrapperComponentName(element, reason);
+  }
+  public getElementWrapperComponentData(element: any, reason?: string): string {
+    this.reason = "data->" + reason;
+    return super.getElementWrapperComponentData(element, reason);
+  }
+  public reason?: string;
+}
+
+QUnit.test("getCellWrapper name and data", function (assert) {
+  var json = {
+    elements: [
+      {
+        type: "matrixdynamic",
+        name: "q1",
+        columns: [
+          {
+            name: "Column 1",
+            totalType: "sum",
+          },
+        ],
+        rows: ["First"]
+      },
+    ],
+  };
+  var survey = new TestElementWrapperSurveyModel(json);
+  var matrix = <QuestionMatrixDropdownModelBase>survey.getQuestionByName("q1");
+
+  var totalRow = matrix.visibleTotalRow;
+  var totalCell = totalRow.cells[0];
+  matrix.getCellWrapperComponentName(totalCell);
+  assert.equal(survey.reason, "name->row-footer", "Total cell component name");
+  matrix.getCellWrapperComponentData(totalCell);
+  assert.equal(survey.reason, "data->row-footer", "Total cell component data");
+
+  var ordinaryRow = matrix.visibleRows[0];
+  var ordinaryCell = ordinaryRow.cells[0];
+  matrix.getCellWrapperComponentName(ordinaryCell);
+  assert.equal(survey.reason, "name->cell", "Ordinary cell component name");
+  matrix.getCellWrapperComponentData(ordinaryCell);
+  assert.equal(survey.reason, "data->cell", "Ordinary cell component data");
+});