Image picker crashed - invoke interface method 'void MethodChannel$Result.success(java.lang.Object)' on a null object

[sleith]

Hi,
I found my app crashed on some devices. It crashed on Image picker.
I'm using version 0.4.12.
Please find the crash log:

Caused by java.lang.NullPointerException: Attempt to invoke interface method 'void io.flutter.plugin.common.MethodChannel$Result.success(java.lang.Object)' on a null object reference
       at io.flutter.plugins.imagepicker.ImagePickerDelegate.finishWithSuccess(Unknown Source:2)
       at io.flutter.plugins.imagepicker.ImagePickerDelegate.handleCaptureImageResult(Unknown Source:17)
       at io.flutter.plugins.imagepicker.ImagePickerDelegate.onActivityResult(Unknown Source:10)
       at io.flutter.app.FlutterPluginRegistry.onActivityResult(Unknown Source:18)
       at io.flutter.app.FlutterActivityDelegate.onActivityResult(Unknown Source:6)
       at io.flutter.app.FlutterActivity.onActivityResult(Unknown Source:2)
       at android.app.Activity.dispatchActivityResult(Activity.java:7454)
       at android.app.ActivityThread.deliverResults(ActivityThread.java:4375)
       at android.app.ActivityThread.handleSendResult(ActivityThread.java:4424)
       at android.app.servertransaction.ActivityResultItem.execute(ActivityResultItem.java:49)
       at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
       at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1818)
       at android.os.Handler.dispatchMessage(Handler.java:106)
       at android.os.Looper.loop(Looper.java:193)
       at android.app.ActivityThread.main(ActivityThread.java:6762)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

My flutter doctor:

[✓] Flutter (Channel beta, v1.0.0, on Mac OS X 10.13.6 17G65, locale en-ID)
    • Flutter version 1.0.0 at /Users/raymond.rulin/flutter
    • Framework revision 5391447fae (7 weeks ago), 2018-11-29 19:41:26 -0800
    • Engine revision 7375a0f414
    • Dart version 2.1.0 (build 2.1.0-dev.9.4 f9ebf21297)
[✓] Android toolchain - develop for Android devices (Android SDK 28.0.3)
    • Android SDK at /Users/raymond.rulin/Library/Android/sdk
    • Android NDK at /Users/raymond.rulin/Library/Android/sdk/ndk-bundle
    • 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-1024-b01)
    • All Android licenses accepted.
[✓] Android Studio (version 3.1)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 28.0.1
    • Dart plugin version 173.4700
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b01)

It crashed many times on many devices. Here's the devices report from fabric:

Thank you

[zgosalvez]

I'm getting a flutter: PlatformException(multiple_request, Cancelled by a second request, null) error on the iOS simulator. Related?

[davidmartos96]

Maybe this is related?
flutter-team-archive/plugins#1089

[wouterhardeman]

I probably found the issue. So when the image_picker is called before another call is finished it should return an error with the MethodResult object that came with the last method call. But instead it uses the MethodResult object from the first method call. When finishing up the first method call, the pendingResult (MethodResult object of the first call) property will already be set to null.

Relevant code: https://github.com/flutter/plugins/blob/82bab678d76c69e56456f97879452eebd4ea66da/packages/image_picker/android/src/main/java/io/flutter/plugins/imagepicker/ImagePickerDelegate.java#L490

[cyanglaz]

Hi @sleith, have you turned on the "don't keep activities" option in setting? There is a similar crash described here when "don't keep activities" is on.
If you have the option on, could you try to turn it off and see if it is still crashing?
#26676

[sleith]

Hi @cyanglaz ,
The crash happened on client's phone (production) :)
I also tried to turn on 'don't keep activities', indeed it crashed with the same exact log.
So it means their activities was destroyed? this happened on 78 users which is quite weird.

Meanwhile I'm trying to contact the user to know more details.
Thank you :)

[wouterhardeman]

I was able to reproduce this error. I will try to fix it and send a pull request over the weekend.

[cyanglaz]

@wouterhardeman
Could you share a detailed step to how to reproduce the issue?

I'm getting a flutter: PlatformException(multiple_request, Cancelled by a second request, null) error on the iOS simulator. Related?