Different behavior of isql when redirecting stdin in Windows and Linux

[Noremos]

There is some strange statement in isql source code: https://github.com/FirebirdSQL/firebird/blob/682853e827bbc4ce1c9be643fee46c83dcb1229e/src/isql/isql.epp#L9340-L9341 in fucntion static bool stdin_redirected() As a result, when isql is called the same way, in Linux stdin_redirected returns true, but in Widnows it returns false.

So, is it correct behavor?