device: Handle composite IntFlag.name on Python < 3.11 (#3187)

* Handle composite IntFlag.name on Python < 3.11

On Python < 3.11, IntFlag.name returns None for composite flags
(e.g. NotificationFlag(0x000900) = SOFTWARE_PRESENT|WIRELESS).

The previous fix (#3184) returns an empty list in this case, losing
the flag names. This commit decomposes composite flags manually by
iterating over enum members, producing correct results on all
supported Python versions (>= 3.8 as declared in setup.py).

Add regression tests covering composite flags and None input.

Tested on:
- Python 3.9.2 (Debian 11): 56/56 passed
- Python 3.11.15 (pyenv): 56/56 passed

Refs #3184

* Fix line length style violation (E501)

Move comment above the parametrize entry to stay under 127 chars.

---------

Co-authored-by: avercelli <avercelli@vulog.com>

lib/logitech_receiver/hidpp10_constants.py

@@ -91,9 +91,12 @@ class NotificationFlag(IntFlag):
     @classmethod
     def flag_names(cls, flags) -> List[str]:
         """Extract the names of the flags from the integer."""
-        if flags is None or flags.name is None:
+        if flags is None:
             return []
-        return flags.name.replace("_", " ").lower().split("|")
+        if flags.name is not None:
+            return flags.name.replace("_", " ").lower().split("|")
+        # Python < 3.11: .name is None for composite flags, decompose manually
+        return [m.name.replace("_", " ").lower() for m in cls if m.value and m in flags]
 
     NUMPAD_NUMERICAL_KEYS = 0x800000
     F_LOCK_STATUS = 0x400000

tests/logitech_receiver/test_hidpp10.py

@@ -296,6 +296,32 @@ def test_notification_flag_str(flag_bits, expected_names):
     assert flag_names == expected_names
 
 
+@pytest.mark.parametrize(
+    "flags, expected",
+    [
+        (None, []),
+        # composite flag, .name is None on Python < 3.11
+        (hidpp10_constants.NotificationFlag(0x000900), ["software present", "wireless"]),
+        (hidpp10_constants.NotificationFlag(0x100000), ["battery status"]),
+        (hidpp10_constants.NotificationFlag(0x080000), ["mouse extra buttons"]),
+    ],
+)
+def test_notification_flag_names(flags, expected):
+    result = hidpp10_constants.NotificationFlag.flag_names(flags)
+    assert result == expected
+
+
+def test_notification_flag_names_none_does_not_crash():
+    """Regression test for #3184: flag_names crashes with AttributeError when
+    flags.name is None, which happens with certain receiver firmware versions
+    (e.g. Nano C52F reporting 0x000900)."""
+    flags_with_none_name = hidpp10_constants.NotificationFlag(0x000900)
+    result = hidpp10_constants.NotificationFlag.flag_names(flags_with_none_name)
+    assert "software present" in result
+    assert "wireless" in result
+    assert isinstance(result, list)
+
+
 def test_get_device_features():
     result = _hidpp10.get_device_features(device_standard)