Fix InputDecorator intrinsic height reporting (#55408)

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

@@ -1243,11 +1243,16 @@ class _RenderDecoration extends RenderBox {
     double subtextHeight = _lineHeight(width, <RenderBox>[helperError, counter]);
     if (subtextHeight > 0.0)
       subtextHeight += subtextGap;
-    return contentPadding.top
+    final Offset densityOffset = decoration.visualDensity.baseSizeAdjustment;
+    final double containerHeight = contentPadding.top
       + (label == null ? 0.0 : decoration.floatingLabelHeight)
       + _lineHeight(width, <RenderBox>[prefix, input, suffix])
       + subtextHeight
       + contentPadding.bottom;
+    final double minContainerHeight = decoration.isDense || expands
+      ? 0.0
+      : kMinInteractiveDimension + densityOffset.dy;
+    return math.max(containerHeight, minContainerHeight);
   }
 
   @override

packages/flutter/test/material/text_field_test.dart

@@ -7417,6 +7417,48 @@ void main() {
       final RenderBox renderBox = tester.renderObject(find.byType(TextField));
       expect(renderBox.size.height, lessThan(kMinInteractiveDimension));
     });
+
+    group('intrinsics', () {
+      Widget _buildTest({ bool isDense }) {
+        return MaterialApp(
+          home: Scaffold(
+            body: CustomScrollView(
+              slivers: <Widget>[
+                SliverFillRemaining(
+                  hasScrollBody: false,
+                  child: Column(
+                    children: <Widget>[
+                      TextField(
+                        decoration: InputDecoration(
+                          isDense: isDense,
+                        )
+                      ),
+                      Container(
+                        height: 1000,
+                      ),
+                    ],
+                  )
+                )
+              ],
+            )
+          )
+        );
+      }
+
+      testWidgets('By default, intrinsic height is at least kMinInteractiveDimension high', (WidgetTester tester) async {
+        // Regression test for https://github.com/flutter/flutter/issues/54729
+        // If the intrinsic height does not match that of the height after
+        // performLayout, this will fail.
+        tester.pumpWidget(_buildTest(isDense: false));
+      });
+
+      testWidgets('When isDense, intrinsic height can go below kMinInteractiveDimension height', (WidgetTester tester) async {
+        // Regression test for https://github.com/flutter/flutter/issues/54729
+        // If the intrinsic height does not match that of the height after
+        // performLayout, this will fail.
+        tester.pumpWidget(_buildTest(isDense: true));
+      });
+    });
   });
   testWidgets("Arrow keys don't move input focus", (WidgetTester tester) async {
     final TextEditingController controller1 = TextEditingController();