device: be defensive when getting device id

lib/logitech_receiver/device.py

@@ -218,7 +218,9 @@ class Device(object):
     def unitId(self):
         if not self._unitId:
             if self.online and self.protocol >= 2.0:
-                self._unitId, self._modelId, self._tid_map = _hidpp20.get_ids(self)
+                ids = _hidpp20.get_ids(self)
+                if ids:
+                    self._unitId, self._modelId, self._tid_map = ids
                     if _log.isEnabledFor(_INFO) and self._serial and self._serial != self._unitId:
                         _log.info('%s: unitId %s does not match serial %s', self, self._unitId, self._serial)
         return self._unitId
@@ -227,6 +229,8 @@ class Device(object):
     def modelId(self):
         if not self._modelId:
             if self.online and self.protocol >= 2.0:
+                ids = _hidpp20.get_ids(self)
+                if ids:
                     self._unitId, self._modelId, self._tid_map = _hidpp20.get_ids(self)
         return self._modelId
 
@@ -234,6 +238,8 @@ class Device(object):
     def tid_map(self):
         if not self._tid_map:
             if self.online and self.protocol >= 2.0:
+                ids = _hidpp20.get_ids(self)
+                if ids:
                     self._unitId, self._modelId, self._tid_map = _hidpp20.get_ids(self)
         return self._tid_map
 

lib/logitech_receiver/hidpp20.py

@@ -1054,6 +1054,7 @@ def get_firmware(device):
 def get_ids(device):
     """Reads a device's ids (unit and model numbers)"""
     ids = feature_request(device, FEATURE.DEVICE_FW_VERSION)
+    if ids:
         unitId = ids[1:5]
         modelId = ids[7:13]
         transport_bits = ord(ids[6:7])

lib/solaar/cli/show.py

@@ -208,7 +208,9 @@ def _print_device(dev, num=None):
                 for fw in _hidpp20.get_firmware(dev):
                     extras = _strhex(fw.extras) if fw.extras else ''
                     print('            Firmware: %s %s %s %s' % (fw.kind, fw.name, fw.version, extras))
-                unitId, modelId, tid_map = _hidpp20.get_ids(dev)
+                ids = _hidpp20.get_ids(dev)
+                if ids:
+                    unitId, modelId, tid_map = ids
                     print('            Unit ID: %s  Model ID: %s  Transport IDs: %s' % (unitId, modelId, tid_map))
             elif feature == _hidpp20.FEATURE.REPORT_RATE:
                 print('            Polling Rate (ms): %d' % _hidpp20.get_polling_rate(dev))