Merge pull request #381 from python/bugfix/entry-points-unique-normal…

…ized

Fix expectation on unique packages to include normalization.

CHANGES.rst

@@ -3,6 +3,10 @@ v4.11.4
 
 * #377: In ``PathDistribution._name_from_stem``, avoid including
   parts of the extension in the result.
+# #381: In ``PathDistribution._normalized_name``, ensure names
+  loaded from the stem of the filename are also normalized, ensuring
+  duplicate entry points by packages varying only by non-normalized
+  name are hidden.
 
 v4.11.3
 =======

importlib_metadata/__init__.py

@@ -956,7 +956,10 @@ def _normalized_name(self):
         normalized name from the file system path.
         """
         stem = os.path.basename(str(self._path))
-        return self._name_from_stem(stem) or super()._normalized_name
+        return (
+            pass_none(Prepared.normalize)(self._name_from_stem(stem))
+            or super()._normalized_name
+        )
 
     @staticmethod
     def _name_from_stem(stem):

tests/test_api.py

@@ -89,15 +89,15 @@ def test_entry_points_distribution(self):
             self.assertIn(ep.dist.name, ('distinfo-pkg', 'egginfo-pkg'))
             self.assertEqual(ep.dist.version, "1.0.0")
 
-    def test_entry_points_unique_packages(self):
+    def test_entry_points_unique_packages_normalized(self):
         """
         Entry points should only be exposed for the first package
-        on sys.path with a given name.
+        on sys.path with a given name (even when normalized).
         """
         alt_site_dir = self.fixtures.enter_context(fixtures.tempdir())
         self.fixtures.enter_context(self.add_sys_path(alt_site_dir))
         alt_pkg = {
-            "distinfo_pkg-1.1.0.dist-info": {
+            "DistInfo_pkg-1.1.0.dist-info": {
                 "METADATA": """
                 Name: distinfo-pkg
                 Version: 1.1.0