Fix BottomNavigationBar MediaQuery padding (#75360)

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

@@ -1018,9 +1018,7 @@ class _BottomNavigationBarState extends State<BottomNavigationBar> with TickerPr
     assert(Overlay.of(context, debugRequiredFor: widget) != null);
 
     final BottomNavigationBarThemeData bottomTheme = BottomNavigationBarTheme.of(context);
-
-    // Labels apply up to _bottomMargin padding. Remainder is media padding.
-    final double additionalBottomPadding = math.max(MediaQuery.of(context).padding.bottom - widget.selectedFontSize / 2.0, 0.0);
+    final double additionalBottomPadding = MediaQuery.of(context).padding.bottom;
     Color? backgroundColor;
     switch (_effectiveType) {
       case BottomNavigationBarType.fixed:

packages/flutter/test/material/bottom_navigation_bar_test.dart

@@ -721,9 +721,35 @@ void main() {
       ),
     );
 
-    const double labelBottomMargin = 7.0; // 7 == defaulted selectedFontSize / 2.0.
-    const double additionalPadding = 40.0 - labelBottomMargin;
-    const double expectedHeight = kBottomNavigationBarHeight + additionalPadding;
+    const double expectedHeight = kBottomNavigationBarHeight + 40.0;
+    expect(tester.getSize(find.byType(BottomNavigationBar)).height, expectedHeight);
+  });
+
+  testWidgets('BottomNavigationBar adds bottom padding to height with a custom font size', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        home: MediaQuery(
+          data: const MediaQueryData(padding: EdgeInsets.only(bottom: 40.0)),
+          child: Scaffold(
+            bottomNavigationBar: BottomNavigationBar(
+              selectedFontSize: 8,
+              items: const <BottomNavigationBarItem>[
+                BottomNavigationBarItem(
+                  icon: Icon(Icons.ac_unit),
+                  label: 'AC',
+                ),
+                BottomNavigationBarItem(
+                  icon: Icon(Icons.access_alarm),
+                  label: 'Alarm',
+                ),
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+
+    const double expectedHeight = kBottomNavigationBarHeight + 40.0;
     expect(tester.getSize(find.byType(BottomNavigationBar)).height, expectedHeight);
   });
 

packages/flutter/test/material/floating_action_button_location_test.dart

@@ -684,7 +684,7 @@ void main() {
       const double keyboardHeight = 200.0;
       const double viewPadding = 50.0;
       final Key floatingActionButton = UniqueKey();
-      const double bottomNavHeight = 99.0;
+      const double bottomNavHeight = 106.0;
       // Default
       await tester.pumpWidget(_buildTest(
         location,
@@ -929,7 +929,7 @@ void main() {
     testWidgets('startFloat', (WidgetTester tester) async {
       const Rect defaultRect = Rect.fromLTRB(16.0, 478.0, 72.0, 534.0);
       // Positioned relative to BottomNavigationBar
-      const Rect bottomNavigationBarRect = Rect.fromLTRB(16.0, 429.0, 72.0, 485.0);
+      const Rect bottomNavigationBarRect = Rect.fromLTRB(16.0, 422.0, 72.0, 478.0);
       // Position relative to BottomSheet
       const Rect bottomSheetRect = Rect.fromLTRB(16.0, 472.0, 72.0, 528.0);
       // Positioned relative to SnackBar
@@ -947,7 +947,7 @@ void main() {
     testWidgets('miniStartFloat', (WidgetTester tester) async {
       const Rect defaultRect = Rect.fromLTRB(12.0, 490.0, 60.0, 538.0);
       // Positioned relative to BottomNavigationBar
-      const Rect bottomNavigationBarRect = Rect.fromLTRB(12.0, 441.0, 60.0, 489.0);
+      const Rect bottomNavigationBarRect = Rect.fromLTRB(12.0, 434.0, 60.0, 482.0);
       // Positioned relative to BottomSheet
       const Rect bottomSheetRect = Rect.fromLTRB(12.0, 480.0, 60.0, 528.0);
       // Positioned relative to SnackBar
@@ -966,7 +966,7 @@ void main() {
     testWidgets('centerFloat', (WidgetTester tester) async {
       const Rect defaultRect = Rect.fromLTRB(372.0, 478.0, 428.0, 534.0);
       // Positioned relative to BottomNavigationBar
-      const Rect bottomNavigationBarRect = Rect.fromLTRB(372.0, 429.0, 428.0, 485.0);
+      const Rect bottomNavigationBarRect = Rect.fromLTRB(372.0, 422.0, 428.0, 478.0);
       // Positioned relative to BottomSheet
       const Rect bottomSheetRect = Rect.fromLTRB(372.0, 472.0, 428.0, 528.0);
       // Positioned relative to SnackBar
@@ -984,7 +984,7 @@ void main() {
     testWidgets('miniCenterFloat', (WidgetTester tester) async {
       const Rect defaultRect = Rect.fromLTRB(376.0, 490.0, 424.0, 538.0);
       // Positioned relative to BottomNavigationBar
-      const Rect bottomNavigationBarRect = Rect.fromLTRB(376.0, 441.0, 424.0, 489.0);
+      const Rect bottomNavigationBarRect = Rect.fromLTRB(376.0, 434.0, 424.0, 482.0);
       // Positioned relative to BottomSheet
       const Rect bottomSheetRect = Rect.fromLTRB(376.0, 480.0, 424.0, 528.0);
       // Positioned relative to SnackBar
@@ -1003,7 +1003,7 @@ void main() {
     testWidgets('endFloat', (WidgetTester tester) async {
       const Rect defaultRect = Rect.fromLTRB(728.0, 478.0, 784.0, 534.0);
       // Positioned relative to BottomNavigationBar
-      const Rect bottomNavigationBarRect = Rect.fromLTRB(728.0, 429.0, 784.0, 485.0);
+      const Rect bottomNavigationBarRect = Rect.fromLTRB(728.0, 422.0, 784.0, 478.0);
       // Positioned relative to BottomSheet
       const Rect bottomSheetRect = Rect.fromLTRB(728.0, 472.0, 784.0, 528.0);
       // Positioned relative to SnackBar
@@ -1021,7 +1021,7 @@ void main() {
     testWidgets('miniEndFloat', (WidgetTester tester) async {
       const Rect defaultRect = Rect.fromLTRB(740.0, 490.0, 788.0, 538.0);
       // Positioned relative to BottomNavigationBar
-      const Rect bottomNavigationBarRect = Rect.fromLTRB(740.0, 441.0, 788.0, 489.0);
+      const Rect bottomNavigationBarRect = Rect.fromLTRB(740.0, 434.0, 788.0, 482.0);
       // Positioned relative to BottomSheet
       const Rect bottomSheetRect = Rect.fromLTRB(740.0, 480.0, 788.0, 528.0);
       // Positioned relative to SnackBar
@@ -1056,7 +1056,7 @@ void main() {
     }) async  {
       const double keyboardHeight = 200.0;
       const double viewPadding = 50.0;
-      const double bottomNavHeight = 99.0;
+      const double bottomNavHeight = 106.0;
       final Key floatingActionButton = UniqueKey();
       final double fabHeight = mini ? 48.0 : 56.0;
       // Default
@@ -1269,9 +1269,9 @@ void main() {
     testWidgets('startDocked', (WidgetTester tester) async {
       const Rect defaultRect = Rect.fromLTRB(16.0, 494.0, 72.0, 550.0);
       // Positioned relative to BottomNavigationBar
-      const Rect bottomNavigationBarRect = Rect.fromLTRB(16.0, 473.0, 72.0, 529.0);
+      const Rect bottomNavigationBarRect = Rect.fromLTRB(16.0, 466.0, 72.0, 522.0);
       // Positioned relative to BottomNavigationBar & BottomSheet
-      const Rect bottomSheetRect = Rect.fromLTRB(16.0, 373.0, 72.0, 429.0);
+      const Rect bottomSheetRect = Rect.fromLTRB(16.0, 366.0, 72.0, 422.0);
       // Positioned relative to SnackBar
       const Rect snackBarRect = Rect.fromLTRB(16.0, 486.0, 72.0, 542.0);
       await _runDockedTests(
@@ -1287,9 +1287,9 @@ void main() {
     testWidgets('miniStartDocked', (WidgetTester tester) async {
       const Rect defaultRect = Rect.fromLTRB(12.0, 502.0, 60.0, 550.0);
       // Positioned relative to BottomNavigationBar
-      const Rect bottomNavigationBarRect = Rect.fromLTRB(12.0, 477.0, 60.0, 525.0);
+      const Rect bottomNavigationBarRect = Rect.fromLTRB(12.0, 470.0, 60.0, 518.0);
       // Positioned relative to BottomNavigationBar & BottomSheet
-      const Rect bottomSheetRect = Rect.fromLTRB(12.0, 377.0, 60.0, 425.0);
+      const Rect bottomSheetRect = Rect.fromLTRB(12.0, 370.0, 60.0, 418.0);
       // Positioned relative to SnackBar
       const Rect snackBarRect = Rect.fromLTRB(12.0, 494.0, 60.0, 542.0);
       await _runDockedTests(
@@ -1306,9 +1306,9 @@ void main() {
     testWidgets('centerDocked', (WidgetTester tester) async {
       const Rect defaultRect = Rect.fromLTRB(372.0, 494.0, 428.0, 550.0);
       // Positioned relative to BottomNavigationBar
-      const Rect bottomNavigationBarRect = Rect.fromLTRB(372.0, 473.0, 428.0, 529.0);
+      const Rect bottomNavigationBarRect = Rect.fromLTRB(372.0, 466.0, 428.0, 522.0);
       // Positioned relative to BottomNavigationBar & BottomSheet
-      const Rect bottomSheetRect = Rect.fromLTRB(372.0, 373.0, 428.0, 429.0);
+      const Rect bottomSheetRect = Rect.fromLTRB(372.0, 366.0, 428.0, 422.0);
       // Positioned relative to SnackBar
       const Rect snackBarRect = Rect.fromLTRB(372.0, 486.0, 428.0, 542.0);
       await _runDockedTests(
@@ -1324,9 +1324,9 @@ void main() {
     testWidgets('miniCenterDocked', (WidgetTester tester) async {
       const Rect defaultRect = Rect.fromLTRB(376.0, 502.0, 424.0, 550.0);
       // Positioned relative to BottomNavigationBar
-      const Rect bottomNavigationBarRect = Rect.fromLTRB(376.0, 477.0, 424.0, 525.0);
+      const Rect bottomNavigationBarRect = Rect.fromLTRB(376.0, 470.0, 424.0, 518.0);
       // Positioned relative to BottomNavigationBar & BottomSheet
-      const Rect bottomSheetRect = Rect.fromLTRB(376.0, 377.0, 424.0, 425.0);
+      const Rect bottomSheetRect = Rect.fromLTRB(376.0, 370.0, 424.0, 418.0);
       // Positioned relative to SnackBar
       const Rect snackBarRect = Rect.fromLTRB(376.0, 494.0, 424.0, 542.0);
       await _runDockedTests(
@@ -1343,9 +1343,9 @@ void main() {
     testWidgets('endDocked', (WidgetTester tester) async {
       const Rect defaultRect = Rect.fromLTRB(728.0, 494.0, 784.0, 550.0);
       // Positioned relative to BottomNavigationBar
-      const Rect bottomNavigationBarRect = Rect.fromLTRB(728.0, 473.0, 784.0, 529.0);
+      const Rect bottomNavigationBarRect = Rect.fromLTRB(728.0, 466.0, 784.0, 522.0);
       // Positioned relative to BottomNavigationBar & BottomSheet
-      const Rect bottomSheetRect = Rect.fromLTRB(728.0, 373.0, 784.0, 429.0);
+      const Rect bottomSheetRect = Rect.fromLTRB(728.0, 366.0, 784.0, 422.0);
       // Positioned relative to SnackBar
       const Rect snackBarRect = Rect.fromLTRB(728.0, 486.0, 784.0, 542.0);
       await _runDockedTests(
@@ -1361,9 +1361,9 @@ void main() {
     testWidgets('miniEndDocked', (WidgetTester tester) async {
       const Rect defaultRect = Rect.fromLTRB(740.0, 502.0, 788.0, 550.0);
       // Positioned relative to BottomNavigationBar
-      const Rect bottomNavigationBarRect = Rect.fromLTRB(740.0, 477.0, 788.0, 525.0);
+      const Rect bottomNavigationBarRect = Rect.fromLTRB(740.0, 470.0, 788.0, 518.0);
       // Positioned relative to BottomNavigationBar & BottomSheet
-      const Rect bottomSheetRect = Rect.fromLTRB(740.0, 377.0, 788.0, 425.0);
+      const Rect bottomSheetRect = Rect.fromLTRB(740.0, 370.0, 788.0, 418.0);
       // Positioned relative to SnackBar
       const Rect snackBarRect = Rect.fromLTRB(740.0, 494.0, 788.0, 542.0);
       await _runDockedTests(