libstdc++/9563: ostream::sentry returns true after a failed preparation

[paolo@gcc.gnu.org]

Synopsis: ostream::sentry returns true after a failed preparation

Responsible-Changed-From-To: unassigned->paolo
Responsible-Changed-By: paolo
Responsible-Changed-When: Wed Feb 12 13:00:51 2003
Responsible-Changed-Why:
    Patching.
State-Changed-From-To: open->analyzed
State-Changed-By: paolo
State-Changed-When: Wed Feb 12 13:00:51 2003
State-Changed-Why:
    Confirmed. Seems easy to fix: just move over the logic already
    present in istream::sentry.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=9563