Fix interface compositioning not working because of common interfaces

The issue is that any interface has the interfaces like
`org.freedesktop.DBus.Introspectable` or `org.freedesktop.DBus.Properties`.
The interface names and member names of those built-in interfaces
should not be checked for collisions.

Thank you @AndersBlomdell for testing NetworkManager binds against
development version.

src/sdbus/dbus_proxy_async_interface_base.py

@@ -97,6 +97,9 @@ def __new__(cls, name: str,
                     f"async interface: {attr_name!r}"
                 )
 
+            if not serving_enabled:
+                continue
+
             if isinstance(attr, DbusMethodAsync):
                 dbus_class_meta.dbus_member_to_python_attr[
                     attr.method_name] = attr_name

src/sdbus/dbus_proxy_sync_interface_base.py

@@ -46,7 +46,7 @@ def __new__(cls, name: str,
                 ) -> DbusInterfaceMetaSync:
 
         dbus_class_meta = DbusClassMeta()
-        if interface_name is not None:
+        if interface_name is not None and serving_enabled:
             dbus_class_meta.dbus_interfaces_names.add(interface_name)
 
         for attr_name, attr in namespace.items():
@@ -58,6 +58,9 @@ def __new__(cls, name: str,
                     f"Can't mix async methods in sync interface: {attr_name!r}"
                 )
 
+            if not serving_enabled:
+                continue
+
             if isinstance(attr, DbusMethodSync):
                 dbus_class_meta.dbus_member_to_python_attr[
                     attr.method_name] = attr_name

test/test_sdbus_async.py

@@ -350,12 +350,12 @@ def test_property_setter(self, var: str) -> None:
 
         with self.subTest('Test dbus to python mapping'):
             self.assertIn(
-                "PropertiesChanged",
+                "TestInt",
                 test_object._dbus_meta.dbus_member_to_python_attr,
             )
 
             self.assertIn(
-                "PropertiesChanged",
+                "TestInt",
                 test_subclass._dbus_meta.dbus_member_to_python_attr,
             )
 
@@ -887,3 +887,23 @@ async def catch_properties_changed() -> int:
             await wait_for(catch_changed_task, timeout=1),
             10,
         )
+
+    async def test_interface_composition(self) -> None:
+        class OneInterface(
+            DbusInterfaceCommonAsync,
+            interface_name="org.example.one",
+        ):
+            @dbus_method_async(result_signature="x")
+            async def one(self) -> int:
+                raise NotImplementedError
+
+        class TwoInterface(
+            DbusInterfaceCommonAsync,
+            interface_name="org.example.two",
+        ):
+            @dbus_method_async(result_signature="t")
+            async def two(self) -> int:
+                return 2
+
+        class CombinedInterface(OneInterface, TwoInterface):
+            ...

test/test_sdbus_block.py

@@ -26,6 +26,8 @@
 from sdbus.unittest import IsolatedDbusTestCase
 from sdbus_block.dbus_daemon import FreedesktopDbus
 
+from sdbus import DbusInterfaceCommon, dbus_method
+
 
 class TestSync(IsolatedDbusTestCase):
 
@@ -70,6 +72,26 @@ def test_docstring(self) -> None:
         with self.subTest('Property doc (through class dict)'):
             self.assertTrue(getdoc(s.__class__.__dict__['features']))
 
+    def test_interface_composition(self) -> None:
+        class OneInterface(
+            DbusInterfaceCommon,
+            interface_name="org.example.one",
+        ):
+            @dbus_method(result_signature="x")
+            def one(self) -> int:
+                raise NotImplementedError
+
+        class TwoInterface(
+            DbusInterfaceCommon,
+            interface_name="org.example.two",
+        ):
+            @dbus_method(result_signature="t")
+            def two(self) -> int:
+                raise NotImplementedError
+
+        class CombinedInterface(OneInterface, TwoInterface):
+            ...
+
 
 if __name__ == '__main__':
     main()