[Python-checkins] r74586 - in python/branches/release31-maint: Lib/importlib/_bootstrap.py Lib/importlib/test/import_/test_caching.py Misc/NEWS

[brett.cannon]

Author: brett.cannon
Date: Sun Aug 30 06:29:47 2009
New Revision: 74586

Log:
Merged revisions 74584 via svnmerge from 
svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  r74584 | brett.cannon | 2009-08-29 20:47:36 -0700 (Sat, 29 Aug 2009) | 3 lines
  
  Have importlib raise ImportError if None is found in sys.modules. This matches
  current import semantics.
........


Modified:
   python/branches/release31-maint/   (props changed)
   python/branches/release31-maint/Lib/importlib/_bootstrap.py
   python/branches/release31-maint/Lib/importlib/test/import_/test_caching.py
   python/branches/release31-maint/Misc/NEWS

Modified: python/branches/release31-maint/Lib/importlib/_bootstrap.py
==============================================================================
--- python/branches/release31-maint/Lib/importlib/_bootstrap.py	(original)
+++ python/branches/release31-maint/Lib/importlib/_bootstrap.py	Sun Aug 30 06:29:47 2009
@@ -860,7 +860,12 @@
             name = package[:dot]
     with _ImportLockContext():
         try:
-            return sys.modules[name]
+            module = sys.modules[name]
+            if module is None:
+                message = ("import of {} halted; "
+                            "None in sys.modules".format(name))
+                raise ImportError(message)
+            return module
         except KeyError:
             pass
         parent = name.rpartition('.')[0]

Modified: python/branches/release31-maint/Lib/importlib/test/import_/test_caching.py
==============================================================================
--- python/branches/release31-maint/Lib/importlib/test/import_/test_caching.py	(original)
+++ python/branches/release31-maint/Lib/importlib/test/import_/test_caching.py	Sun Aug 30 06:29:47 2009
@@ -17,15 +17,25 @@
     loader returns) [from cache on return]. This also applies to imports of
     things contained within a package and thus get assigned as an attribute
     [from cache to attribute] or pulled in thanks to a fromlist import
-    [from cache for fromlist].
+    [from cache for fromlist]. But if sys.modules contains None then
+    ImportError is raised [None in cache].
 
     """
     def test_using_cache(self):
         # [use cache]
         module_to_use = "some module found!"
-        sys.modules['some_module'] = module_to_use
-        module = import_util.import_('some_module')
-        self.assertEqual(id(module_to_use), id(module))
+        with util.uncache(module_to_use):
+            sys.modules['some_module'] = module_to_use
+            module = import_util.import_('some_module')
+            self.assertEqual(id(module_to_use), id(module))
+
+    def test_None_in_cache(self):
+        #[None in cache]
+        name = 'using_None'
+        with util.uncache(name):
+            sys.modules[name] = None
+            with self.assertRaises(ImportError):
+                import_util.import_(name)
 
     def create_mock(self, *names, return_=None):
         mock = util.mock_modules(*names)

Modified: python/branches/release31-maint/Misc/NEWS
==============================================================================
--- python/branches/release31-maint/Misc/NEWS	(original)
+++ python/branches/release31-maint/Misc/NEWS	Sun Aug 30 06:29:47 2009
@@ -50,6 +50,9 @@
 Library
 -------
 
+- Have importlib raise ImportError if None is found in sys.modules for a
+  module.
+
 - Issue #6794: Fix Decimal.compare_total and Decimal.compare_total_mag: NaN
   payloads are now ordered by integer value rather than lexicographically.