Description of problem:

I've noticed a strange interaction with custom ports and booleans. After setting a boolean, the list of ports for a particular type (which has been customized) shows duplicate entries.

Example:

  $ semanage port -a -t http_port_t -p tcp 12345
  $ semanage port -l | grep http_port_t
  http_port_t                    tcp      12345, 80, 81, ...
  $ setsebool -P zebra_write_config false
  $ semanage port -l | grep http_port_t
  http_port_t                    tcp      12345, 12345, 80, 81, ...
  $ setsebool -P zebra_write_config false
  $ semanage port -l | grep http_port_t
  http_port_t                    tcp      12345, 12345, 12345, 80, 81, ...

As can be seen, each time a boolean is set persistently (it doesn't matter which boolean or which state), the custom port 12345 is duplicated. Running "semodule -B" clears the duplicates.

However, if only the local customizations are listed, the port is always listed only once:

  $ semanage port -l -C
  SELinux Port Type              Proto    Port Number
  http_port_t                    tcp      12345

Version-Release number of selected component (if applicable):
libselinux-2.5-13.fc25.x86_64
(Originally found this on CentOS 7.3's "libselinux-2.5-6.el7.x86_64").

How reproducible:
Always

I've submitted this upstream here: https://github.com/SELinuxProject/selinux/issues/50