SliverAppBar FlexibleSpaceBar title overflow issue

sliver_app_bar.dart

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: HomePage(),
    );
  }
}

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: CustomScrollView(
        slivers: <Widget>[
          SliverAppBar(
            leading: IconButton(icon: Icon(Icons.arrow_back), onPressed: () {}),
            expandedHeight: 256.0,
            pinned: true,
            flexibleSpace: FlexibleSpaceBar(
              centerTitle: true,
              title: Text(
                'Minions ipsum bee do bee do bee do baboiii '
                    'pepete butt potatoooo poulet tikka ',
                overflow: TextOverflow.ellipsis,
              ),
            ),
            backgroundColor: Colors.red,
          ),
          SliverList(
            delegate: SliverChildListDelegate([
              _getLongText(),
            ]),
          )
        ],
      ),
    );
  }

  Widget _getLongText() {
    return Text(
      'Minions ipsum bee do bee do bee do baboiii pepete butt '
          'potatoooo poulet tikka masala. Tatata bala tu tatata bala tu chasy '
          'aaaaaah. Gelatooo jeje poulet tikka masala aaaaaah me want bananaaa! '
          'Chasy bee do bee do bee do pepete baboiii jiji butt. Jiji po kass '
          'bappleees chasy aaaaaah bananaaaa underweaaar tank yuuu! Tank yuuu! '
          'Para tú butt. Hana dul sae poulet tikka masala '
          'baboiii tatata bala tu hana dul sae jiji tatata bala tu. Aaaaaah ti '
          'aamoo! La bodaaa belloo! Pepete chasy pepete.'
          'Minions ipsum bee do bee do bee do baboiii pepete butt '
          'potatoooo poulet tikka masala. Tatata bala tu tatata bala tu chasy '
          'aaaaaah. Gelatooo jeje poulet tikka masala aaaaaah me want bananaaa! '
          'Chasy bee do bee do bee do pepete baboiii jiji butt. Jiji po kass '
          'bappleees chasy aaaaaah bananaaaa underweaaar tank yuuu! Tank yuuu! '
          'Para tú butt. Hana dul sae poulet tikka masala '
          'baboiii tatata bala tu hana dul sae jiji tatata bala tu. Aaaaaah ti '
          'aamoo! La bodaaa belloo! Pepete chasy pepete.'
          'Minions ipsum bee do bee do bee do baboiii pepete butt '
          'potatoooo poulet tikka masala. Tatata bala tu tatata bala tu chasy '
          'aaaaaah. Gelatooo jeje poulet tikka masala aaaaaah me want bananaaa! '
          'Chasy bee do bee do bee do pepete baboiii jiji butt. Jiji po kass '
          'bappleees chasy aaaaaah bananaaaa underweaaar tank yuuu! Tank yuuu! '
          'Para tú butt. Hana dul sae poulet tikka masala '
          'baboiii tatata bala tu hana dul sae jiji tatata bala tu. Aaaaaah ti '
          'aamoo! La bodaaa belloo! Pepete chasy pepete.'
          'Minions ipsum bee do bee do bee do baboiii pepete butt '
          'potatoooo poulet tikka masala. Tatata bala tu tatata bala tu chasy '
          'aaaaaah. Gelatooo jeje poulet tikka masala aaaaaah me want bananaaa! ',
      style: TextStyle(fontSize: 24.0),
    );
  }
}

PR: flutter/flutter#20339