libstdc++/9875: filebuf doesn't handle codecvt::encoding() > 1

[paolo@gcc.gnu.org]

Synopsis: filebuf doesn't handle codecvt::encoding() > 1

State-Changed-From-To: closed->analyzed
State-Changed-By: paolo
State-Changed-When: Sat Mar  1 10:44:16 2003
State-Changed-Why:
    Mistakenly closed ;)
    
    Anyway, I have a patch for it, quite simple indeed, which
    already passes all your tests.
    
    The underflow bits are still missing, however. Are you
    willing to provide some tests for it too?
    
    Thanks, Paolo.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=9875