See attached 'test' file with some non-ASCII chars.

$ cat test
a�-�-

Then;

$ sed -i "s|.*|allgone|" test && cat test
allgone�-�-

Or (using fresh copy of 'test');

$ sed -i "s|.*|allgone|gi" test && cat test
allgone�allgone�allgone

Expected output in both cases would seem to be "allgone" on the line and
nothing else?

God Bless,
Roel