fix(grid): Guard dispatchEvent against an undefined position from getNextPosition

projects/igniteui-angular/grids/core/src/grid-navigation.service.ts

@@ -109,11 +109,15 @@ export class IgxGridNavigationService {
             this.grid.selectionService.keyboardStateOnKeydown(this.activeNode as ISelectionNode, shift, shift && key === 'tab');
         }
         const position = this.getNextPosition(this.activeNode.row, this.activeNode.column!, key, shift, ctrl, event);
+        // Keys without a target position (e.g. row-add keys without alt) need no further handling.
+        if (!position) {
+            return;
+        }
         const shouldNotifyVirtualizedKeyboardSelection =
-            this.shouldNotifyVirtualizedKeyboardSelection(key, position!.rowIndex, position!.colIndex);
+            this.shouldNotifyVirtualizedKeyboardSelection(key, position.rowIndex, position.colIndex);
         if (NAVIGATION_KEYS.has(key)) {
             event.preventDefault();
-            this.navigateInBody(position!.rowIndex, position!.colIndex, (obj) => {
+            this.navigateInBody(position.rowIndex, position.colIndex, (obj) => {
                 obj.target.activate(event);
                 if (shouldNotifyVirtualizedKeyboardSelection) {
                     this.grid.notifyChanges();

projects/igniteui-angular/grids/grid/src/grid-cell-editing.spec.ts

@@ -329,6 +329,28 @@ describe('IgxGrid - Cell Editing #grid', () => {
             expect((document.activeElement as HTMLInputElement).selectionEnd).toEqual(10)
         }));
 
+        it('should not throw or block typing + and = in the cell editor', fakeAsync(() => {
+            const cell = grid.gridAPI.get_cell_by_index(0, 'fullName');
+
+            UIInteractions.simulateDoubleClickAndSelectEvent(cell);
+            fixture.detectChanges();
+            tick(100);
+            expect(cell.editMode).toBe(true);
+
+            const editor = document.activeElement as HTMLInputElement;
+            expect(editor.nodeName).toEqual('INPUT');
+
+            ['+', '='].forEach(key => {
+                const event = new KeyboardEvent('keydown', { key, bubbles: true, cancelable: true });
+                expect(() => {
+                    editor.dispatchEvent(event);
+                    fixture.detectChanges();
+                }).not.toThrow();
+                expect(event.defaultPrevented).toBe(false);
+                expect(cell.editMode).toBe(true);
+            });
+        }));
+
         it('should work correct when not using ngModel but value and change event', fakeAsync(() => {
             fixture = TestBed.createComponent(CellEditingCustomEditorTestComponent);
             fixture.detectChanges();

projects/igniteui-angular/grids/grid/src/grid-keyBoardNav.spec.ts

@@ -254,6 +254,23 @@ describe('IgxGrid - Keyboard navigation #grid', () => {
             expect(selectedCell.value).toEqual('Company A');
             expect(selectedCell.column.field).toMatch('Company');
         });
+
+        it('should ignore + and = on a focused cell, with or without ctrl', () => {
+            GridFunctions.focusFirstCell(fix, grid);
+            fix.detectChanges();
+            const activeNode = { ...grid.navigation.activeNode };
+
+            ['+', '='].forEach(key => {
+                [false, true].forEach(ctrlKey => {
+                    const event = new KeyboardEvent('keydown', { key, ctrlKey, bubbles: true, cancelable: true });
+                    expect(() => grid.navigation.handleNavigation(event)).not.toThrow();
+                    fix.detectChanges();
+                    expect(event.defaultPrevented).toBe(false);
+                    expect(grid.navigation.activeNode.row).toBe(activeNode.row);
+                    expect(grid.navigation.activeNode.column).toBe(activeNode.column);
+                });
+            });
+        });
     });
 
     describe('in virtualized grid', () => {