Add DoctestScope

Author: jayvdb

pyflakes/checker.py

@@ -240,6 +240,10 @@ class ModuleScope(Scope):
     pass
 
 
+class DoctestScope(ModuleScope):
+    pass
+
+
 # Globally defined names which are not attributes of the builtins module, or
 # are only present on some platforms.
 _MAGIC_GLOBALS = ['__file__', '__builtins__', 'WindowsError']
@@ -625,7 +629,7 @@ def handleDoctests(self, node):
         if not examples:
             return
         node_offset = self.offset or (0, 0)
-        self.pushScope()
+        self.pushScope(DoctestScope)
         underscore_in_builtins = '_' in self.builtIns
         if not underscore_in_builtins:
             self.builtIns.add('_')
@@ -681,9 +685,14 @@ def GLOBAL(self, node):
         """
         Keep track of globals declarations.
         """
-        # In doctests, the global scope is an anonymous function at index 1.
-        global_scope_index = 1 if self.withDoctest else 0
-        global_scope = self.scopeStack[global_scope_index]
+        for i, scope in enumerate(self.scopeStack):
+            if isinstance(scope, DoctestScope):
+                global_scope_index = i
+                global_scope = scope
+                break
+        else:
+            global_scope_index = 0
+            global_scope = self.scopeStack[0]
 
         # Ignore 'global' statement in global scope.
         if self.scope is not global_scope: