GH-102700: allow built-in modules to be submodules (GH-103162)

Lib/importlib/_bootstrap.py

@@ -887,8 +887,6 @@ class BuiltinImporter:
 
     @classmethod
     def find_spec(cls, fullname, path=None, target=None):
-        if path is not None:
-            return None
         if _imp.is_builtin(fullname):
             return spec_from_loader(fullname, cls, origin=cls._ORIGIN)
         else:

Lib/test/test_importlib/builtin/test_finder.py

@@ -37,13 +37,6 @@ class FindSpecTests(abc.FinderTests):
         spec = self.machinery.BuiltinImporter.find_spec(name)
         self.assertIsNone(spec)
 
-    def test_ignore_path(self):
-        # The value for 'path' should always trigger a failed import.
-        with util.uncache(util.BUILTINS.good_name):
-            spec = self.machinery.BuiltinImporter.find_spec(util.BUILTINS.good_name,
-                                                            ['pkg'])
-            self.assertIsNone(spec)
-
 
 (Frozen_FindSpecTests,
  Source_FindSpecTests
@@ -77,16 +70,6 @@ class FinderTests(abc.FinderTests):
             loader = self.machinery.BuiltinImporter.find_module('importlib')
         self.assertIsNone(loader)
 
-    def test_ignore_path(self):
-        # The value for 'path' should always trigger a failed import.
-        with util.uncache(util.BUILTINS.good_name):
-            with warnings.catch_warnings():
-                warnings.simplefilter("ignore", DeprecationWarning)
-                loader = self.machinery.BuiltinImporter.find_module(
-                                                        util.BUILTINS.good_name,
-                                                        ['pkg'])
-            self.assertIsNone(loader)
-
 
 (Frozen_FinderTests,
  Source_FinderTests

Misc/NEWS.d/next/Core and Builtins/2023-04-01-00-46-31.gh-issue-102700.493NB4.rst

@@ -0,0 +1 @@
+Allow built-in modules to be submodules. This allows submodules to be statically linked into a CPython binary.