Proper fix for #2270

Fixes #2270

docs/changelog.rst

@@ -16,6 +16,8 @@ To update |kitty|, :doc:`follow the instructions <binary>`.
 - Add a :opt:`resize_in_steps` option that can be used to resize the OS window
   in steps as large as character cells (:pull:`2131`)
 
+- Fix a segfault when using :opt:`--debug-config` with maps (:iss:`2270`)
+
 
 0.15.1 [2019-12-21]
 --------------------

kitty/glfw.c

@@ -840,6 +840,9 @@ static PyObject*
 glfw_get_key_name(PyObject UNUSED *self, PyObject *args) {
     int key, native_key;
     if (!PyArg_ParseTuple(args, "ii", &key, &native_key)) return NULL;
+    if (!glfwGetKeyName) {
+        return PyUnicode_FromFormat("key: %d native_key: %d", key, native_key);
+    }
     return Py_BuildValue("z", glfwGetKeyName(key, native_key));
 }