Prevent InputDecorator from supplying its descendants with non-normalized constraints (#130460)

Fixes flutter/flutter#129611

Author: LongCatIsLooong

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

@@ -964,7 +964,7 @@ class _RenderDecoration extends RenderBox with SlottedContainerRenderObjectMixin
     boxToBaseline[prefixIcon] = _layoutLineBox(prefixIcon, containerConstraints);
     boxToBaseline[suffixIcon] = _layoutLineBox(suffixIcon, containerConstraints);
     final BoxConstraints contentConstraints = containerConstraints.copyWith(
-      maxWidth: containerConstraints.maxWidth - contentPadding.horizontal,
+      maxWidth: math.max(0.0, containerConstraints.maxWidth - contentPadding.horizontal),
     );
     boxToBaseline[prefix] = _layoutLineBox(prefix, contentConstraints);
     boxToBaseline[suffix] = _layoutLineBox(suffix, contentConstraints);
@@ -1093,7 +1093,7 @@ class _RenderDecoration extends RenderBox with SlottedContainerRenderObjectMixin
     final double minContainerHeight = decoration.isDense! || decoration.isCollapsed || expands
       ? 0.0
       : kMinInteractiveDimension;
-    final double maxContainerHeight = boxConstraints.maxHeight - bottomHeight;
+    final double maxContainerHeight = math.max(0.0, boxConstraints.maxHeight - bottomHeight);
     final double containerHeight = expands
       ? maxContainerHeight
       : math.min(math.max(contentHeight, minContainerHeight), maxContainerHeight);

packages/flutter/test/material/input_decorator_test.dart

@@ -158,7 +158,11 @@ TextStyle? getIconStyle(WidgetTester tester, IconData icon) {
 }
 
 void main() {
-  for (final bool useMaterial3 in  <bool>[true, false]){
+  runAllTests(useMaterial3: true);
+  runAllTests(useMaterial3: false);
+}
+
+void runAllTests({ required bool useMaterial3 }) {
   testWidgets('InputDecorator input/label text layout', (WidgetTester tester) async {
     // The label appears above the input text
     await tester.pumpWidget(
@@ -1796,7 +1800,7 @@ void main() {
           ),
         );
     await tester.pumpWidget(
-       MaterialApp(
+      MaterialApp(
         theme: theme,
         home: Material(
           child: TextField(
@@ -2011,9 +2015,9 @@ void main() {
 
     // Overall height for this InputDecorator is 48dps because the prefix icon's minimum size
     // is 48x48 and the rest of the elements only require 40dps:
-     //   12 - top padding
-     //   16 - input text (font size 16dps)
-     //   12 - bottom padding
+    //   12 - top padding
+    //   16 - input text (font size 16dps)
+    //   12 - bottom padding
 
     expect(tester.getSize(find.byType(InputDecorator)), const Size(800.0, 48.0));
     expect(tester.getSize(find.text('text')).height, 16.0);
@@ -2085,10 +2089,10 @@ void main() {
     );
 
     // Overall height for this InputDecorator is 48dps because the prefix icon's minimum size
-     // is 48x48 and the rest of the elements only require 40dps:
-     //   12 - top padding
-     //   16 - input text (font size 16dps)
-     //   12 - bottom padding
+    // is 48x48 and the rest of the elements only require 40dps:
+    //   12 - top padding
+    //   16 - input text (font size 16dps)
+    //   12 - bottom padding
 
     expect(tester.getSize(find.byType(InputDecorator)), const Size(800.0, 48.0));
     expect(tester.getSize(find.byKey(prefixKey)).height, 16.0);
@@ -2303,9 +2307,9 @@ void main() {
 
     // Overall height for this InputDecorator is 100dps because the prefix icon's size
     // is 100x100 and the rest of the elements only require 40dps:
-     //   12 - top padding
-     //   16 - input text (font size 16dps)
-     //   12 - bottom padding
+    //   12 - top padding
+    //   16 - input text (font size 16dps)
+    //   12 - bottom padding
 
     expect(tester.getSize(find.byType(InputDecorator)), const Size(800.0, 100.0));
     expect(tester.getSize(find.byKey(prefixKey)).height, 100.0);
@@ -5487,7 +5491,7 @@ void main() {
     );
   }, skip: isBrowser); // https://github.com/flutter/flutter/issues/55317
 
- testWidgets('OutlineInputBorder with BorderRadius.zero should draw a rectangular border', (WidgetTester tester) async {
+testWidgets('OutlineInputBorder with BorderRadius.zero should draw a rectangular border', (WidgetTester tester) async {
     // Regression test for https://github.com/flutter/flutter/issues/78855
     const String labelText = 'Flutter';
 
@@ -6546,5 +6550,29 @@ void main() {
     // The prefix is inside the decorator.
     expect(decoratorRight, lessThanOrEqualTo(prefixRight));
   });
-}
+
+  testWidgets('InputDecorator with counter does not crash when given a 0 size', (WidgetTester tester) async {
+    // Regression test for https://github.com/flutter/flutter/issues/129611
+    const InputDecoration decoration = InputDecoration(
+      contentPadding: EdgeInsetsDirectional.all(99),
+      prefixIcon: Focus(child: Icon(Icons.search)),
+      counter: Text('COUNTER'),
+    );
+
+    await tester.pumpWidget(
+      Center(
+        child: SizedBox.square(
+          dimension: 0.0,
+          child: buildInputDecorator(
+            useMaterial3: useMaterial3,
+            decoration: decoration,
+          ),
+        ),
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    expect(find.byType(InputDecorator), findsOneWidget);
+    expect(tester.renderObject<RenderBox>(find.text('COUNTER')).size, Size.zero);
+  });
 }