Fix changing the mapper to (none) if other mappers are defined

classes/window/main_window.xml

@@ -665,7 +665,9 @@
                                     result.add("(none)")
                                     self.allowed_mappers = list(result)
                                     global current_mapper
-                                    if current_mapper not in result:
+                                    if current_mapper is None:
+                                        current_mapper = None
+                                    elif current_mapper not in result:
                                         current_mapper = next(iter(result))
                                         if current_mapper == "(none)":
                                             current_mapper = None

frontend.py

@@ -1,7 +1,7 @@
 """
 Generated by Statechart compiler by Glenn De Jonghe, Joeri Exelmans, Simon Van Mierlo, and Yentl Van Tendeloo (for the inspiration)
 
-Date:   Mon Jan 29 15:30:36 2018
+Date:   Mon Mar  5 08:55:17 2018
 
 Model author: Yentl Van Tendeloo
 Model name:   Modelverse Visual Editor - Tkinter Version 
@@ -3439,13 +3439,13 @@ class Modelverse(RuntimeClassBase):
         return self.expect_response_partial('Success: ', pop=False)
     
     def _initialized_behaviour_operations_read_association_source_0_exec(self, parameters):
-        self.raiseInternalEvent(Event("result", None, [self.split_response(self.responses.pop(0))[0]]))
+        self.raiseInternalEvent(Event("result", None, [self.split_response(self.responses.pop(0))]))
     
     def _initialized_behaviour_operations_read_association_source_0_guard(self, parameters):
         return self.expect_response_partial('Success: ', pop=False)
     
     def _initialized_behaviour_operations_read_association_destination_0_exec(self, parameters):
-        self.raiseInternalEvent(Event("result", None, [self.split_response(self.responses.pop(0))[0]]))
+        self.raiseInternalEvent(Event("result", None, [self.split_response(self.responses.pop(0))]))
     
     def _initialized_behaviour_operations_read_association_destination_0_guard(self, parameters):
         return self.expect_response_partial('Success: ', pop=False)
@@ -6346,7 +6346,9 @@ class MainWindow(RuntimeClassBase, tk.Toplevel, SCCDWidget):
         result.add("(none)")
         self.allowed_mappers = list(result)
         global current_mapper
-        if current_mapper not in result:
+        if current_mapper is None:
+            current_mapper = None
+        elif current_mapper not in result:
             current_mapper = next(iter(result))
             if current_mapper == "(none)":
                 current_mapper = None