Is this a bug ?

[jfreiberg]

The program allows me to castle through check. Here is a simple game that illustrates the issue:
1. e4 e5 2. Nf3 b6 3. Ba6 Bxa6 4. O-O

I know some chess programs have a setting to allow illegal moves, but COW doesn't allow me to castle into or out of check. It only allows me to castle through check, which it shouldn't.

Sometimes it correctly prevents castling, but I can't see a pattern of when it allows it and when it doesn't.

I get the same issue running COW on my Windows 10 machine and also on my Android tablet.

[MikeAtBookup]

COW uses the same code on all platforms so if it allows castling through check in isolated cases, it will allow it in all versions.

Probably no harm in this bug. It's rare anyone tries to make an illegal move with COW though.