libstdc++/9423: filebuf::pubsetbuf(0, 0) doesn't turn off buffering if called after open

[paolo@gcc.gnu.org]

Synopsis: filebuf::pubsetbuf(0, 0) doesn't turn off buffering if called after open

Responsible-Changed-From-To: unassigned->paolo
Responsible-Changed-By: paolo
Responsible-Changed-When: Sun Mar  2 18:39:15 2003
Responsible-Changed-Why:
    Patching.
State-Changed-From-To: open->analyzed
State-Changed-By: paolo
State-Changed-When: Sun Mar  2 18:39:15 2003
State-Changed-Why:
    Confirmed. Should be rather easy to fix changing
    basic_filebuf::setbuf to _M_destroy_internal_buffer() even
    if this->is_open().

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=9423