bpo-35899: Fix Enum handling of empty and weird strings (GH-11891)

Co-authored-by: Maxwell <maxwellpxt@gmail.com>
Co-authored-by: Stéphane Wirtel <stephane@wirtel.be>





https://bugs.python.org/issue35899

1 files changed, 9 insertions, 8 deletions

diff --git a/Lib/enum.py b/Lib/enum.py
index a958ed8..6ef17c7 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -19,18 +19,19 @@ def _is_descriptor(obj):
 
 def _is_dunder(name):
     """Returns True if a __dunder__ name, False otherwise."""
-    return (name[:2] == name[-2:] == '__' and
-            name[2:3] != '_' and
-            name[-3:-2] != '_' and
-            len(name) > 4)
+    return (len(name) > 4 and
+            name[:2] == name[-2:] == '__' and
+            name[2] != '_' and
+            name[-3] != '_')
 
 
 def _is_sunder(name):
     """Returns True if a _sunder_ name, False otherwise."""
-    return (name[0] == name[-1] == '_' and
+    return (len(name) > 2 and
+            name[0] == name[-1] == '_' and
             name[1:2] != '_' and
-            name[-2:-1] != '_' and
-            len(name) > 2)
+            name[-2:-1] != '_')
+
 
 def _make_class_unpicklable(cls):
     """Make the given class un-picklable."""
@@ -150,7 +151,7 @@ class EnumMeta(type):
         _order_ = classdict.pop('_order_', None)
 
         # check for illegal enum names (any others?)
-        invalid_names = set(enum_members) & {'mro', }
+        invalid_names = set(enum_members) & {'mro', ''}
         if invalid_names:
             raise ValueError('Invalid enum member name: {0}'.format(
                 ','.join(invalid_names)))