Make sure all methods of KeyCombination copy args

I'm not sure how nessesary this is but better safe than sorry and
better explicit of intention

1 files changed, 10 insertions, 3 deletions

diff --git a/keyboardpython/key.py b/keyboardpython/key.py
index eb315b5..ec5f32b 100644
--- a/keyboardpython/key.py
+++ b/keyboardpython/key.py
@@ -50,8 +50,10 @@ class KeyCombination:
     def add_key(self,_key):
         ''' add _key to this combination '''
         assert isinstance(_key,Key)
+        import copy
         if self.contains_key(_key): return
-        self.keys.append(_key)
+        to_add = copy.deepcopy(_key)
+        self.keys.append(to_add)
         self.keys = list(set(self.keys))
         self.string = self.__string()
 
@@ -66,17 +68,22 @@ class KeyCombination:
     def add_keyCombination(self,key_comb):
         ''' add each key from key_comb to this combination '''
         assert isinstance(key_comb,KeyCombination)
-        for _key in key_comb.keys: self.keys.append(_key)
+        import copy
+        for _key in key_comb.keys:
+            to_add = copy.deepcopy(_key)
+            self.keys.append(to_add)
         self.keys = list(set(self.keys))
         self.string = self.__string()
 
     def diff(self,key_comb):
         ''' return keys in key_comb that aren't in this combination '''
         assert isinstance(key_comb,KeyCombination)
+        import copy
         to_return = KeyCombination()
         for _key in key_comb.keys:
             if not self.contains_key(_key):
-                to_return.keys.append(_key)
+                to_add = copy.deepcopy(_key)
+                to_return.keys.append(to_add)
         to_return.keys.sort(key=lambda x: x.name)
         return to_return