PreserveReferences uses GetHashCode?

[IB38]

Hi,

Does automapper use GetHashCode for unique object identification?
I've run into some unexpected behavior when using automapper to map classes with overriden GetHashCode with PreserveReferences option.
Perhaps using RuntimeHelpers.GetHashCode would be a better option?

[lbargaoanu]

Other than the custom GetHashCode being broken, why wouldn't we call it virtually?

[IB38]

Using GetHashCode for object identification is not recommended, but i dont think there is any other way other than using Object.GetHashCode.

Object.GetHashCode result being based on reference is just an effect of implementation. When GetHashCode and Equals are overriden, often its done to use property/field/etc equality instead of reference equality. In this case, AutoMapper calling GetHashCode virtually is incorrent, because the intent is to get some representation of reference to use as key in object dictionary for PreserveReferences. Something like that.

[lbargaoanu]

If you override Equals, that seems to me like a reasonable result and some people might rely on that, but I see your point too.