Cannot flush QBluetoothSocket or specify message length in RFCOMM

I'm developing a Qt application on Linux that uses a classical Bluetooth server via RFCOMM to communicate with an Android 5.1 device.

As it turns out, this specific Android 5.1 device has a bug in the RFCOMM parser which makes it impossible to decode messages longer than 127 bytes.

Therefore, I wish that I could specify in Qt a maximal message length of 127 bytes or have the option to flush the QBluetoothSocket and implement the buffer myself.

As far as I know, this is not possible right now:

1. There is of course no flush in QIODevice
2. The buffer size in qbluetoothsocket_bluez.cpp is currently hard-coded to be 1024 bytes.
3. QBluetoothServer just provides an instantiated QBluetoohSocket and there is no way to open the connection as QIODevice::Unbuffered.