Merge #23722 from 3.6

1 files changed, 6 insertions, 2 deletions

diff --git a/Python/compile.c b/Python/compile.c
index 62f1c3f..76f08da 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -1967,8 +1967,9 @@ compiler_class(struct compiler *c, stmt_ty s)
             compiler_exit_scope(c);
             return 0;
         }
+        /* Return __classcell__ if it is referenced, otherwise return None */
         if (c->u->u_ste->ste_needs_class_closure) {
-            /* store __classcell__ into class namespace */
+            /* Store __classcell__ into class namespace & return it */
             str = PyUnicode_InternFromString("__class__");
             if (str == NULL) {
                 compiler_exit_scope(c);
@@ -1983,6 +1984,7 @@ compiler_class(struct compiler *c, stmt_ty s)
             assert(i == 0);
 
             ADDOP_I(c, LOAD_CLOSURE, i);
+            ADDOP(c, DUP_TOP);
             str = PyUnicode_InternFromString("__classcell__");
             if (!str || !compiler_nameop(c, str, Store)) {
                 Py_XDECREF(str);
@@ -1992,9 +1994,11 @@ compiler_class(struct compiler *c, stmt_ty s)
             Py_DECREF(str);
         }
         else {
-            /* This happens when nobody references the cell. */
+            /* No methods referenced __class__, so just return None */
             assert(PyDict_Size(c->u->u_cellvars) == 0);
+            ADDOP_O(c, LOAD_CONST, Py_None, consts);
         }
+        ADDOP_IN_SCOPE(c, RETURN_VALUE);
         /* create the code object */
         co = assemble(c, 1);
     }