Unexpected change in RPM behavior

Issue

• We've noted a change in the behavior of the RPM program.
• In RHEL 5 and earlier if rpm --import <gpg-key> is called and the key has already been imported rpm creates duplicate and returns zero exit code.
• In RHEL 6 if --import <gpg-key> is called and the key has already been imported rpm doesn't create duplicate but exits with an error "error: /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release: key 1 import failed." and a non-zero exit code.

$ rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

error: /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release: key 1 import failed.
error: /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release: key 2 import failed