FIX BUG: accommodate tellg() returning -1 at end of string.
FIX BUG: accommodate tellg() returning -1 at end of string.

planetmarshall/GeographicLib,planetmarshall/GeographicLib,planetmarshall/GeographicLib,planetmarshall/GeographicLib,planetmarshall/GeographicLib,planetmarshall/GeographicLib,planetmarshall/GeographicLib,planetmarshall/GeographicLib,planetmarshall/GeographicLib