Merge branch 'release/4.9.1' into master

docs/main/changelog.rst

@@ -7,6 +7,12 @@ that were made in every particular version.
 From version 0.7.6 *Dependency Injector* framework strictly 
 follows `Semantic versioning`_
 
+4.9.1
+-----
+- Fix a bug in the ``Configuration`` provider to correctly handle undefined values.
+  See issue `#358 <https://github.com/ets-labs/python-dependency-injector/issues/358>`_.
+  Many thanks to `Stefano Frazzetto <https://github.com/StefanoFrazzetto>`_ for reporting the issue.
+
 4.9.0
 -----
 - Add ``.dependencies`` attribute to the ``DeclarativeContainer`` and ``DynamicContainer``.

src/dependency_injector/__init__.py

@@ -1,6 +1,6 @@
 """Top-level package."""
 
-__version__ = '4.9.0'
+__version__ = '4.9.1'
 """Version number.
 
 :type: str

src/dependency_injector/providers.pyx

@@ -1462,6 +1462,9 @@ cdef class Configuration(Object):
         keys = selector.split('.')
         value = self.__call__()
 
+        if value is None:
+            return None
+
         while len(keys) > 0:
             key = keys.pop(0)
             value = value.get(key)
@@ -1507,8 +1510,6 @@ cdef class Configuration(Object):
         :return: Overriding context.
         :rtype: :py:class:`OverridingContext`
         """
-        if provider is None:
-            provider = {}
         context = super().override(provider)
         self.reset_cache()
         return context