[bug] Dropdown 'Clear' button always visible

[sendf]

When enabling 'AllowClear' for a DropDown, the 'X' icon never disappears, even when there is no value to clear anymore.

Here is an example (correct):

After clicking the 'X', the icon should also be cleared along with the value, since there is nothing else to clear anymore:

[enchev]

Here is what I see