Perl 5.6.0 (on Linux) getpwuid() leave /etc/shadow opened

I'm not sure how serious this issue is, but I think it may cause problems in some environments. The system is Linux, RedHat 7.0, Perl 5.6.0, glibc 2.2.4, latest updates. Recently I run 'lsof' on unprivileged Apache httpd process running modperl application and was pretty surprised to see...