[Material] Parent checkbox in DataTable should deselect all, if children...

[Material] Parent checkbox in DataTable should deselect all, if children checkboxes are disabled or selected  (#67938)

packages/flutter/lib/src/material/data_table.dart

@@ -868,9 +868,10 @@ class DataTable extends StatelessWidget {
     );
     final bool anyRowSelectable = rows.any((DataRow row) => row.onSelectChanged != null);
     final bool displayCheckboxColumn = showCheckboxColumn && anyRowSelectable;
-    final Iterable<DataRow> rowsChecked = displayCheckboxColumn ?
-      rows.where((DataRow row) => row.onSelectChanged != null && row.selected) : <DataRow>[];
-    final bool allChecked = displayCheckboxColumn && rowsChecked.length == rows.length;
+    final Iterable<DataRow> rowsWithCheckbox = displayCheckboxColumn ?
+      rows.where((DataRow row) => row.onSelectChanged != null) : <DataRow>[];
+    final Iterable<DataRow> rowsChecked = rowsWithCheckbox.where((DataRow row) => row.selected);
+    final bool allChecked = displayCheckboxColumn && rowsChecked.length == rowsWithCheckbox.length;
     final bool anyChecked = displayCheckboxColumn && rowsChecked.isNotEmpty;
     final bool someChecked = anyChecked && !allChecked;
     final double effectiveHorizontalMargin = horizontalMargin

packages/flutter/test/material/data_table_test.dart

@@ -107,7 +107,7 @@ void main() {
   testWidgets('DataTable control test - tristate', (WidgetTester tester) async {
     final List<String> log = <String>[];
     const int numItems = 3;
-    Widget buildTable(List<bool> selected) {
+    Widget buildTable(List<bool> selected, {int? disabledIndex}) {
       return DataTable(
         onSelectAll: (bool? value) {
           log.add('select-all: $value');
@@ -123,7 +123,7 @@ void main() {
           (int index) => DataRow(
             cells: <DataCell>[DataCell(Text('Row $index'))],
             selected: selected[index],
-            onSelectChanged: (bool? value) {
+            onSelectChanged: index == disabledIndex ? null : (bool? value) {
               log.add('row-selected: $index');
             },
           ),
@@ -157,6 +157,21 @@ void main() {
 
     expect(log, <String>['select-all: false']);
     log.clear();
+
+    // Tapping the parent checkbox when all rows are selected and one is
+    // disabled, deselects all.
+    await tester.pumpWidget(MaterialApp(
+      home: Material(
+        child: buildTable(
+          <bool>[true, true, false],
+          disabledIndex: 2,
+        ),
+      ),
+    ));
+    await tester.tap(find.byType(Checkbox).first);
+
+    expect(log, <String>['select-all: false']);
+    log.clear();
   });
 
   testWidgets('DataTable control test - no checkboxes', (WidgetTester tester) async {