Proper disabling of unticked KML files.

Fix #1866

mslib/msui/kmloverlay_dockwidget.py

@@ -337,7 +337,8 @@ def __init__(self, parent=None, view=None):
 
     def update(self):
         for entry in self.dict_files.values():
-            entry["patch"].update()
+            if entry["patch"] is not None:
+                entry["patch"].update()
 
     def save_settings(self):
         for entry in self.dict_files.values():
@@ -525,6 +526,7 @@ def remove_file(self):  # removes checked files
                     self.listWidget.item(index).checkState() == QtCore.Qt.Checked):  # if file is checked
                 if self.dict_files[self.listWidget.item(index).text()]["patch"] is not None:
                     self.dict_files[self.listWidget.item(index).text()]["patch"].remove()  # remove patch object
+                    self.dict_files[self.listWidget.item(index).text()]["patch"] = None  # remove patch object
                 del self.dict_files[self.listWidget.item(index).text()]  # del the checked files from dictionary
                 self.listWidget.takeItem(index)  # remove file item from ListWidget
                 self.remove_file()  # recursively since count of for loop changes every iteration due to del of items))
@@ -542,6 +544,7 @@ def load_file(self):
         for entry in self.dict_files.values():  # removes all patches from map, but not from dict_flighttrack
             if entry["patch"] is not None:  # since newly initialized files will have patch:None
                 entry["patch"].remove()
+                entry["patch"] = None
 
         for index in range(self.listWidget.count()):
             if hasattr(self.listWidget.item(index), "checkState") and (