Postgres 9.6.1 accepts connections from not allowed Ip addresses

Hi, I wanted to report a bug that I found while using postgres 9.6.1.

Summary: The database accepts connections from addresses that were previous=
ly allowed but later on have been excluded in the  postgresql.conf & pg_hba=
.conf files.

Step by step

1.       Set up an environment where the postgresql.conf file is set to "li=
sten_addresses =3D '*'" and pg_hba.conf includes the following line "host  =
  all             all             0.0.0.0/0            md5" (This is just a=
n example, the issue can be reproduced with a range of other ip addresses, =
like your local host).

2.       Connect your application to the database and make sure everything =
is up and running.

3.       Exclude the ip-address that is connected to the database from pg_h=
ba.conf or listen_addresses. Eg if your application users ip address 192.16=
8.1.1, comment (add a # or remove the entire row) the row you added in step=
 1 in the pg_hba.conf file and/or change listen_addresses to 'localhost'. R=
estart the service postgresql-x64-9.6 to be sure that the new settings are =
active.

4.       The application is still connected to the database even though the=
 access should be denied. As a matter of fact you are still able to write d=
ata to the database. Only when the remote application shuts its connection =
down and re-connects it is rejected by postgres.

This issue cannot be reproduced on postgres 9.3
OS: Windows 10

Best Regards Jan Ogrodowczyk, if you have any questions do not hesitate to =
ask.