1 files changed, 40 insertions, 15 deletions
diff --git a/Lib/test/test_importlib/import_/test___package__.py b/Lib/test/test_importlib/import_/test___package__.py
index c7d3a2a204..7f64548748 100644
--- a/Lib/test/test_importlib/import_/test___package__.py
+++ b/Lib/test/test_importlib/import_/test___package__.py
@@ -5,6 +5,7 @@ of using the typical __path__/__name__ test).
 
 """
 import unittest
+import warnings
 from .. import util
 
 
@@ -33,31 +34,50 @@ class Using__package__:
 
     """
 
-    def test_using___package__(self):
-        # [__package__]
+    def import_module(self, globals_):
         with self.mock_modules('pkg.__init__', 'pkg.fake') as importer:
             with util.import_state(meta_path=[importer]):
                 self.__import__('pkg.fake')
                 module = self.__import__('',
-                                            globals={'__package__': 'pkg.fake'},
-                                            fromlist=['attr'], level=2)
+                                         globals=globals_,
+                                         fromlist=['attr'], level=2)
+        return module
+
+    def test_using___package__(self):
+        # [__package__]
+        module = self.import_module({'__package__': 'pkg.fake'})
         self.assertEqual(module.__name__, 'pkg')
 
-    def test_using___name__(self, package_as_None=False):
+    def test_using___name__(self):
         # [__name__]
-        globals_ = {'__name__': 'pkg.fake', '__path__': []}
-        if package_as_None:
-            globals_['__package__'] = None
-        with self.mock_modules('pkg.__init__', 'pkg.fake') as importer:
-            with util.import_state(meta_path=[importer]):
-                self.__import__('pkg.fake')
-                module = self.__import__('', globals= globals_,
-                                                fromlist=['attr'], level=2)
-            self.assertEqual(module.__name__, 'pkg')
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore")
+            module = self.import_module({'__name__': 'pkg.fake',
+                                         '__path__': []})
+        self.assertEqual(module.__name__, 'pkg')
+
+    def test_warn_when_using___name__(self):
+        with self.assertWarns(ImportWarning):
+            self.import_module({'__name__': 'pkg.fake', '__path__': []})
 
     def test_None_as___package__(self):
         # [None]
-        self.test_using___name__(package_as_None=True)
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore")
+            module = self.import_module({
+                '__name__': 'pkg.fake', '__path__': [], '__package__': None })
+        self.assertEqual(module.__name__, 'pkg')
+
+    def test_spec_fallback(self):
+        # If __package__ isn't defined, fall back on __spec__.parent.
+        module = self.import_module({'__spec__': FakeSpec('pkg.fake')})
+        self.assertEqual(module.__name__, 'pkg')
+
+    def test_warn_when_package_and_spec_disagree(self):
+        # Raise an ImportWarning if __package__ != __spec__.parent.
+        with self.assertWarns(ImportWarning):
+            self.import_module({'__package__': 'pkg.fake',
+                                '__spec__': FakeSpec('pkg.fakefake')})
 
     def test_bad__package__(self):
         globals = {'__package__': '<not real>'}
@@ -70,6 +90,11 @@ class Using__package__:
             self.__import__('', globals, {}, ['relimport'], 1)
 
 
+class FakeSpec:
+    def __init__(self, parent):
+        self.parent = parent
+
+
 class Using__package__PEP302(Using__package__):
     mock_modules = util.mock_modules