     func wmf_deleteBackward(_ sender: UITextField) {
         guard
             displayMode == .shortNumeric,
-            (sender.text ?? "").characters.count == 0
+            sender.text.wmf_safeCharacterCount == 0
         else {
             return
         }

        enableProgressiveButton(areRequiredFieldsPopulated())
        guard
            displayMode == .shortNumeric,
            let text = sender.text,
            text.characters.count > 0
        else {
            return
        }

        }
        
        // Enforce max count.
        let countIfAllowed = textField.text.wmf_safeCharacterCount + string.characters.count
        return (countIfAllowed <= maxTextFieldCharacterCount())
    }
    
    func textFieldDidBeginEditing(_ textField: UITextField) {
