[Bug libstdc++/11603] New: Bad interaction between showmanyc and underflow on corrupt files.

[peturr02 at ru dot is]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11603

           Summary: Bad interaction between showmanyc and underflow on
                    corrupt files.
           Product: gcc
           Version: 3.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: peturr02 at ru dot is
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu

The return value of basic_filebuf::showmanyc is computed from the number of
bytes available, no attempt is made to convert the bytes. If underflow fails
to produce characters from those bytes, traits_type::eof() is returned,
which violates 27.5.2.4.3 p1.