prevent changing user of an UserPreferences instance

basetheme_bootstrap/__init__.py

-VERSION = '1.8.6'
\ No newline at end of file
+VERSION = '1.8.7'
\ No newline at end of file

basetheme_bootstrap/admin.py

@@ -61,6 +61,11 @@ class UserPreferencesAdmin(admin.ModelAdmin):
         else get_user_preference_class()._meta.get_fields()
     ) if field.many_to_many]
 
+    def get_readonly_fields(self, request, obj=None):
+        if obj:
+            return self.readonly_fields + ('user',)
+        return self.readonly_fields
+
     def username(self, obj):
         return mark_safe("<i>default preferences</i>") if obj.user is None else obj.user