Add deprecation warning about setting list safety

chirp/settings.py

@@ -14,6 +14,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import logging
+import warnings
 
 from chirp import chirp_common
 
@@ -226,6 +227,14 @@ class RadioSettingValueList(RadioSettingValue):
     def __init__(self, options, current=None, current_index=0):
         RadioSettingValue.__init__(self)
         self._options = list(options)
+        if current is not None:
+            # Using current_index is safer than using current because we can
+            # gracefully handle out-of-range values without crashing. All new
+            # code should use current_index and old code should be fixed.
+            warnings.warn(
+                'RadioSettingValueList should be provided with '
+                'current_index instead of current (value) for '
+                'safety', FutureWarning, stacklevel=2)
         self.queue_current(current if current is not None
                            else int(current_index))