date_popup_input_value incorrectly handles auto_complete

The description of date_popup_input_value lists this parameter:
@param autocomplete -- Should we add a time value to complete the date if there is no time?

That parameter is defined with a default value of FALSE, but the parameter is never used anywhere in the function. As a result, the always time is filled into the date.

There is a trivial fix for this -- the last "if" clause of the function is what accomplishes the auto completion, and hence it could be skipped if auto_complete == FALSE. However, since that is the default value, many things may break because they depend on the buggy behavior.

I suppose that a third parameter could be introduced to the function, and the second parameter renamed to unused or something. Is there a better way to fix that?