[Bug libstdc++/47921] New: pbump will overflow when input n is larger than 2G-1

[RobertPython at 163 dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47921

           Summary: pbump will overflow when input n is larger than 2G-1
           Product: gcc
           Version: 4.1.2
            Status: UNCONFIRMED
          Severity: critical
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: RobertPython@163.com
            Target: x86_64-redhat-linux
             Build: gcc version 4.1.2 20071124 (Red Hat 4.1.2-42)


in function int basic_streambuf::pbump(int n), n is a int which is easily
overflow in 64bit environment, especially when it is called in overflow
function.