Issue 1:
Steps to Reproduce

I am using onGenerateRoute to perform navigation. My onGenerateRoute method creates MaterialPageRoute objects with maintainState: false. When navigating backwards, TextField widgets can no longer be focused and edited. This Gist produces the issue. When the home page first loads, its TextField can be edited. When you navigate to Next and then go back, the TextField can no longer be edited.

Flutter Doctor

✓] Flutter (on Mac OS X 10.13.3 17D47, locale en-US, channel master)
• Flutter version 0.1.3-pre.46 at /Users/tlarsen/flutter
• Framework revision f914e701c5 (4 days ago), 2018-02-19 21:12:17 +0000
• Engine revision 13cf22c284
• Dart version 2.0.0-dev.27.0-flutter-0d5cf900b0

[✓] Android toolchain - develop for Android devices (Android SDK 26.0.2)
• Android SDK at /Users/tlarsen/Library/Android/sdk
• Android NDK location not configured (optional; useful for native profiling support)
• Platform android-26, build-tools 26.0.2
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-915-b08)

[✓] iOS toolchain - develop for iOS devices (Xcode 9.2)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 9.2, Build version 9C40b
• ios-deploy 1.9.2
• CocoaPods version 1.3.1

[✓] Android Studio (version 3.0)
• Android Studio at /Applications/Android Studio.app/Contents
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-915-b08)

[✓] IntelliJ IDEA Community Edition (version 2017.3.4)
• Flutter plugin version 21.2.3
• Dart plugin version 173.4548.30

[✓] Connected devices
• iPhone 7 • B3ECB1A2-524B-4C57-801A-C34AE83D617E • ios • iOS 11.2 (simulator)

• No issues found!

Issue 2:
Steps to Reproduce

Navigate to search screen.

Enter search term and tap on a result.

Navigate away from search screen.

Return to search screen using the back button.

Search text field becomes unresponsive.

Reproduced here: https://gist.github.com/JordanADavies/c7b630681aa81940d254876078a2f7a0

flutter doctor -v
[✓] Flutter (Channel beta, v0.9.4, on Mac OS X 10.14.1 18B75, locale en-GB)
• Flutter version 0.9.4 at /Users/jordandavies/Documents/development/flutter
• Framework revision f37c235c32 (5 weeks ago), 2018-09-25 17:45:40 -0400
• Engine revision 74625aed32
• Dart version 2.1.0-dev.5.0.flutter-a2eb050044

[✓] Android toolchain - develop for Android devices (Android SDK 28.0.3)
• Android SDK at /Users/jordandavies/Library/Android/sdk
• Android NDK location not configured (optional; useful for native profiling support)
• Platform android-28, build-tools 28.0.3
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)
• All Android licenses accepted.

[✓] iOS toolchain - develop for iOS devices (Xcode 10.1)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 10.1, Build version 10B61
• ios-deploy 2.0.0
• CocoaPods version 1.5.3

[✓] Android Studio (version 3.2)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin version 29.1.1
• Dart plugin version 181.5656
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)

[✓] Connected devices (1 available)
• iPhone XR • 4018CC7F-D913-4181-8CF3-C29A87529EA2 • ios • iOS 12.1 (simulator)

• No issues found!