fix #1409: cell variables were not initialized,

when the value comes from a keyword-only parameter.

Lib/test/test_scope.py

@@ -166,6 +166,17 @@ class ScopeTests(unittest.TestCase):
         self.assertEqual(t.method_and_var(), "method")
         self.assertEqual(t.actual_global(), "global")
 
+    def testCellIsKwonlyArg(self):
+        # Issue 1409: Initialisation of a cell value,
+        # when it comes from a keyword-only parameter
+        def foo(*, a=17):
+            def bar():
+                return a + 5
+            return bar() + 3
+
+        self.assertEqual(foo(a=42), 50)
+        self.assertEqual(foo(), 25)
+
     def testRecursion(self):
 
         def f(x):

Python/ceval.c

@@ -2708,7 +2708,7 @@ PyEval_EvalCodeEx(PyCodeObject *co, PyObject *globals, PyObject *locals,
 		Py_UNICODE *cellname, *argname;
 		PyObject *c;
 
-		nargs = co->co_argcount;
+		nargs = co->co_argcount + co->co_kwonlyargcount;
 		if (co->co_flags & CO_VARARGS)
 			nargs++;
 		if (co->co_flags & CO_VARKEYWORDS)