updated for version 7.4.462
Problem:    Setting the local value of 'backupcopy' empty gives an error.
	    (Peter Mattern)
Solution:   When using an empty value set the flags to zero. (Hirohito
	    Higashi)
Added tag v7-4-462 for changeset c0d93d67572b
updated for version 7.4.463
Problem:    Test 86 and 87 may hang on MS-Windows.
Solution:   Call inputrestore() after inputsave(). (Ken Takata)
Added tag v7-4-463 for changeset 6f80b9a773db