The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/10/bug-reporting.html
Description:
The initial value returned when current_setting() is passed an unset
parameter is '<NULL>'.
After a SET and a RESET, the value returned by current_setting() is ''.
This causes an invalid cast when the value is cast to an integer, as it is
expected to be.
Tested on Postgres 10 in Linux.