Flutter: GestureDetector behavior depends on internal Container property

Steps to Reproduce

There are two GestureDetectors include a Container with padding,
the only difference is whether the internal Container has color property or not.

Tap space around icons, that is, tap the area of padding:

• Container has color: onTap is called
• Container has not color : onTap is not called

import 'package:flutter/foundation.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/material.dart';

void main() {
  final GlobalKey<ScaffoldState> _key = new GlobalKey<ScaffoldState>();
  runApp(new MaterialApp(
    title: 'GestureDetector Test',
    home: new Builder(builder: (BuildContext context) {
      return new Scaffold(
        key: _key,
        appBar: new AppBar(title: new Text("GestureDetector Test")),
        body: new Column(
          children: <Widget>[
            new Container(
              child: new GestureDetector(
                onTap: () {
                  _key.currentState.showSnackBar(new SnackBar(content: new Text("Foo!")));
                },
                child: new Container(
                  color: Colors.blue,
                  padding: const EdgeInsets.all(16.0),
                  child: const Icon(Icons.star, size: 32.0),
                ),
              )
            ),
            new Container(
              child: new GestureDetector(
                onTap: () {
                  _key.currentState.showSnackBar(new SnackBar(content: new Text("Bar!")));
                },
                child: new Container(
                  //color: Colors.blue, // no color
                  padding: const EdgeInsets.all(16.0),
                  child: const Icon(Icons.star, size: 32.0),
                ),
              )
            ),
          ],
        ),
      );
    }),
  ));
}

Tap the icon itself, both onTap will be call.

Flutter Doctor

alpha 0.0.20

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