Making a 4xx response body available in the error handlers.

[milancermak]

Some web services send a body on 4xx responses containing data about the error, how to fix it, etc. I need to access the response body in the error handlers. This patch allows that.

[MugunthKumar]

I would recommend overriding MKNetworkOperation for doing custom error handling.

[milancermak]

Fair enough.

[sspencer]

For future reference, I created a gist for overriding MKNetworkOperation here: https://gist.github.com/3222686

[Rupert-RR]

Obviously we can override the MKNetworkOperation, but this should be included in the core - as far as I am aware, according to the HTTP protocol, 4xx responses are supposed to return a body that contains information about the error so it is a standard requirement to be able to read the response body.
Personally I would favour returning the operation object as part of the error block, but that is an implementation detail.