[BUG]: Characteristic read errors are not propagated from Android to dart

[jefflongo]

Requirements

• I've looked at the README 'Common Problems' section

Have you checked this problem on the example app?

No

FlutterBluePlus Version

1.32.13

Flutter Version

3.24.3

What OS?

Android

OS Version

Android 13

Bluetooth Module

ESP32C3

What is your problem?

To test if pairing is successful, I read an encrypted characteristic. If the bond was not successful (i.e. user dismissed PIN or entered wrong PIN), reading the characteristic will result in an authentication error. I expect to receive an exception on the Flutter side when this happens. Instead, the list [0] is returned.

The cause of this is this line: https://github.com/chipweinberger/flutter_blue_plus/blob/master/android/src/main/java/com/lib/flutter_blue_plus/FlutterBluePlusPlugin.java#L2294

Any error in the characteristic read (and notifications/indications, for that matter) on the Android side is logged and thrown away and treated as success in the dart side. If an encrypted characteristic is read without a successful bond, the status code is 137 (GATT_AUTH_FAIL). This status code is currently treated as UNKNOWN_GATT_ERROR. The real status code should be sent to onCharacteristicReceived instead of BluetoothGatt.GATT_SUCCESS, so the dart code can properly throw an exception.

Logs

E/[FBP-Android](31089): [FBP] onCharacteristicRead:
E/[FBP-Android](31089): [FBP]   chr: 827ebcc0-0d9a-521f-a336-39072e84edce
E/[FBP-Android](31089): [FBP]   status: UNKNOWN_GATT_ERROR (137) (137)
I/flutter (31089): [FBP] [[ OnCharacteristicReceived ]] result: {error_string: GATT_SUCCESS, service_uuid: e78333a3-57fb-5891-8ac2-fd83c79dea82, success: 1, remote_id: 10:91:A8:59:0F:9A, error_code: 0, characteristic_uuid: 827ebcc0-0d9a-521f-a336-39072e84edce, value: 00}

[chipweinberger]

thanks. you're right.

[chipweinberger]

fixed 1.33.0

[jefflongo]

Ah, you beat me to the PR. I posted mine anyway which adds the fix for notifications/indications and adds some more GATT error strings.