Bug Report: NullPointerException in FilePicker on Android API 35

[vicajilau]

Summary

The app crashes when invoking the saveFile method from FilePicker on a device running Android API 35. The crash occurs due to a NullPointerException when attempting to write to a file.

Steps to Reproduce

1. Use a device or emulator running Android API 35.
2. Call the following method:

   return await FilePicker.platform.saveFile(
       dialogTitle: 'Please select an output file:',
       fileName: 'output-file.maso',
       initialDirectory: '/data/user/0/com.example.maso/cache/file_picker/1735558385877/example.maso');
   

3. Select a file in the file picker dialog.

Expected Behavior

The file picker should successfully allow the user to save the file without crashing the app.

Actual Behavior

The app crashes with the following stack trace:

E/AndroidRuntime( 6271): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=43700, result=-1, data=Intent { dat=content://com.android.providers.downloads.documents/... flg=0x43 }} to activity {com.example.maso/com.example.maso.MainActivity}: java.lang.NullPointerException: Attempt to get length of null array
E/AndroidRuntime( 6271): 	at android.app.ActivityThread.deliverResults(ActivityThread.java:5878)
E/AndroidRuntime( 6271): 	at android.app.ActivityThread.handleSendResult(ActivityThread.java:5917)
E/AndroidRuntime( 6271): 	at android.app.servertransaction.ActivityResultItem.execute(ActivityResultItem.java:69)
E/AndroidRuntime( 6271): 	at android.app.servertransaction.ActivityTransactionItem.execute(ActivityTransactionItem.java:60)
E/AndroidRuntime( 6271): 	at android.app.servertransaction.TransactionExecutor.executeNonLifecycleItem(TransactionExecutor.java:174)
E/AndroidRuntime( 6271): 	at android.app.servertransaction.TransactionExecutor.executeTransactionItems(TransactionExecutor.java:109)
E/AndroidRuntime( 6271): 	at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:81)
E/AndroidRuntime( 6271): 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2636)
E/AndroidRuntime( 6271): 	at android.os.Handler.dispatchMessage(Handler.java:107)
E/AndroidRuntime( 6271): 	at android.os.Looper.loopOnce(Looper.java:232)
E/AndroidRuntime( 6271): 	at android.os.Looper.loop(Looper.java:317)
E/AndroidRuntime( 6271): 	at android.app.ActivityThread.main(ActivityThread.java:8705)
E/AndroidRuntime( 6271): 	at java.lang.reflect.Method.invoke(Native Method)
E/AndroidRuntime( 6271): 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:580)
E/AndroidRuntime( 6271): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:886)
E/AndroidRuntime( 6271): Caused by: java.lang.NullPointerException: Attempt to get length of null array
E/AndroidRuntime( 6271): 	at java.io.FileOutputStream.write(FileOutputStream.java:409)
E/AndroidRuntime( 6271): 	at com.mr.flutter.plugin.filepicker.FilePickerDelegate.onActivityResult(FilePickerDelegate.java:84)
E/AndroidRuntime( 6271): 	at io.flutter.embedding.engine.FlutterEngineConnectionRegistry$FlutterEngineActivityPluginBinding.onActivityResult(FlutterEngineConnectionRegistry.java:774)
E/AndroidRuntime( 6271): 	at io.flutter.embedding.engine.FlutterEngineConnectionRegistry.onActivityResult(FlutterEngineConnectionRegistry.java:422)
E/AndroidRuntime( 6271): 	at io.flutter.embedding.android.FlutterActivityAndFragmentDelegate.onActivityResult(FlutterActivityAndFragmentDelegate.java:964)
E/AndroidRuntime( 6271): 	at io.flutter.embedding.android.FlutterActivity.onActivityResult(FlutterActivity.java:911)
E/AndroidRuntime( 6271): 	at android.app.Activity.onActivityResult(Activity.java:7494)
E/AndroidRuntime( 6271): 	at android.app.Activity.internalDispatchActivityResult(Activity.java:9379)
E/AndroidRuntime( 6271): 	at android.app.Activity.dispatchActivityResult(Activity.java:9356)
E/AndroidRuntime( 6271): 	at android.app.ActivityThread.deliverResults(ActivityThread.java:5867)
E/AndroidRuntime( 6271): 	... 14 more

[vicajilau]

Bug found, it happens when you don't send the bytes parameter. That means null is sent. PR on its way...