Allow closures in cdef functions.

Cython/Compiler/Nodes.py

@@ -2388,8 +2388,8 @@ class CFuncDefNode(FuncDefNode):
     def generate_argument_parsing_code(self, env, code):
         i = 0
         used = 0
-        if self.type.optional_arg_count:
         scope = self.local_scope
+        if self.type.optional_arg_count:
             code.putln('if (%s) {' % Naming.optional_args_cname)
             for arg in self.args:
                 if arg.default:
@@ -2410,6 +2410,16 @@ class CFuncDefNode(FuncDefNode):
                 code.putln('}')
             code.putln('}')
 
+        # Move arguments into closure if required
+        def put_into_closure(entry):
+            if entry.in_closure and not arg.default:
+                code.putln('%s = %s;' % (entry.cname, entry.original_cname))
+                code.put_var_incref(entry)
+                code.put_var_giveref(entry)
+        for arg in self.args:
+            put_into_closure(scope.lookup_here(arg.name))
+
+
     def generate_argument_conversion_code(self, code):
         pass
 

Cython/Compiler/ParseTreeTransforms.py

@@ -2261,8 +2261,8 @@ class MarkClosureVisitor(CythonTransform):
 
     def visit_CFuncDefNode(self, node):
         self.visit_FuncDefNode(node)
-        if node.needs_closure:
-            error(node.pos, "closures inside cdef functions not yet supported")
+        if node.needs_closure and node.overridable:
+            error(node.pos, "closures inside cpdef functions not yet supported")
         return node
 
     def visit_LambdaNode(self, node):
@@ -2400,10 +2400,6 @@ class CreateClosureClasses(CythonTransform):
         self.visitchildren(node)
         return node
 
-    def visit_CFuncDefNode(self, node):
-        self.visitchildren(node)
-        return node
-
 
 class GilCheck(VisitorTransform):
     """