`_RenderScaledInlineWidget` constrains child size (#130648)

Fixes https://github.com/flutter/flutter/issues/130588

packages/flutter/lib/src/widgets/widget_span.dart

@@ -375,7 +375,7 @@ class _RenderScaledInlineWidget extends RenderBox with RenderObjectWithChildMixi
     // Only constrain the width to the maximum width of the paragraph.
     // Leave height unconstrained, which will overflow if expanded past.
     child.layout(BoxConstraints(maxWidth: constraints.maxWidth / scale), parentUsesSize: true);
-    size = child.size * scale;
+    size = constraints.constrain(child.size * scale);
   }
 
   @override

packages/flutter/test/widgets/text_test.dart

@@ -266,6 +266,23 @@ void main() {
     expect(renderText.size.height, singleLineHeight * textScaleFactor * 3);
   });
 
+  testWidgets("Inline widgets' scaled sizes are constrained", (WidgetTester tester) async {
+    // Regression test for https://github.com/flutter/flutter/issues/130588
+    await tester.pumpWidget(
+      const Directionality(
+        textDirection: TextDirection.ltr,
+        child: Center(
+          child: SizedBox(
+            width: 100.3,
+            child: Text.rich(WidgetSpan(child: Row()), textScaleFactor: 0.3),
+          ),
+        ),
+      ),
+    );
+
+    expect(tester.takeException(), isNull);
+  });
+
   testWidgets('semanticsLabel can override text label', (WidgetTester tester) async {
     final SemanticsTester semantics = SemanticsTester(tester);
     await tester.pumpWidget(