backends/bluezdbus/manager: Release resources on bus restart

Call disconnect() on the old bus object if we have to reconnect to the
D-Bus system bus. This ensures that file handles are released and we
don't leak them.

Author: dlech

CHANGELOG.rst

@@ -21,6 +21,7 @@ Changed
 
 Fixed
 -----
+* Fixed file handle leak in BlueZ backend when D-Bus connection is lost and re-established.
 * Fixed crash in CoreBluetooth backend if an ObjC delegate callback is called after the asyncio run loop stops.
 * Fixed possible deadlock when starting scanning on Windows when Bluetooth is turned off.
 * Fixed "Bluetooth device is turned off" Exception on macOS, when a Bluetooth permission request popup is shown to the user by the OS.

bleak/backends/bluezdbus/manager.py

@@ -361,6 +361,11 @@ async def async_init(self) -> None:
                 bus.disconnect()
                 raise
 
+            if self._bus:
+                # Even if we are disconnected, still need to call this to
+                # release file handles.
+                self._bus.disconnect()
+
             # Everything is setup, so save the bus
             self._bus = bus