The cause of the bug turned out to be a strange idiosyncrasy with the way the van location is tracked - the van's current node in the code is marked as the square it's about to cross, so a cow and van are marked as being on the same node if the van is right in front of the cow. This will require a longer term fix as well, but for now this bug fix just changes the way the cow check works for vans that are waiting in front of a cow. (Note that waiting also includes other blocks like increment where the van doesn't move)
The cause of the bug turned out to be a strange idiosyncrasy with the way the van location is tracked - the van's current node in the code is marked as the square it's about to cross, so a cow and van are marked as being on the same node if the van is right in front of the cow. This will require a longer term fix as well, but for now this bug fix just changes the way the cow check works for vans that are waiting in front of a cow. (Note that waiting also includes other blocks like increment where the van doesn't move)
This change is