bpo-36412: fix a possible crash in dictobject.c's new_dict() (GH-12519)

diff --git a/Misc/NEWS.d/next/Core and Builtins/2019-03-23-19-51-09.bpo-36412.C7acGn.rst b/Misc/NEWS.d/next/Core and Builtins/2019-03-23-19-51-09.bpo-36412.C7acGn.rst
new file mode 100644
index 0000000..0146988
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2019-03-23-19-51-09.bpo-36412.C7acGn.rst
@@ -0,0 +1 @@
+Fix a possible crash when creating a new dictionary.
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 524ff67..e2603e1 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -604,7 +604,9 @@
         mp = PyObject_GC_New(PyDictObject, &PyDict_Type);
         if (mp == NULL) {
             dictkeys_decref(keys);
-            free_values(values);
+            if (values != empty_values) {
+                free_values(values);
+            }
             return NULL;
         }
     }