It is ignoring the invalid columns in subquery,Instead of throwing the error 'Column does not exist'.
(eg): select * from emp where (empname,empid,empno) in(selec emname,emid,emno from em_details)
Note:There is no emno in em_details table.
Note: just user, not developer.
I tried to duplicate your error in PostgreSQL 9.5.5 on Fedora Linux 25, 64 bit. I got the expected "column does not exist". Can you try version 9.5 or even 9.6 to see if the bug is squashed in a later Windows version?
--
There’s no obfuscated Perl contest because it’s pointless.