id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
5340,Patch to support concrete base classes becomming abstract classes,Aaron Barany <akb825@…>,Robert Ramey,"If you are serializing a pointer to a polymorphic object as a pointer to its base class, and that base class is concrete, it will fail to load if that base class later becomes abstract. That is because the serializer for the base class is automatically registered if it is concrete, but not if it is abstract, making a mismatch in the class id for the object. I have attached a patch that detects this case and registers the serializer for the abstract class if it occurs.

This patch contains multiple pieces. Fist, basic_iarchive.cpp is patched in load_pointer() to detect that mismatch in class ids and register the serializer. Second, iserializer.hpp is patched so that register_type() for abstract classes returns the proper pointer serializer. (though it isn't directly registered) Third, pointer_iserializer::load_object_pointer() now uses templates to split into two implementations: one for abstract and one for non-abstract classes. The abstract implementation throws an archive_exception, to which an abstract_class_error field has been added.

This patch does not handle going from an abstract base class to a concrete base class, as that would break backwards compatibility. However, it should be more common to go from concrete to abstract than the other way around, and having this support can solve a lot of debugging headaches when it comes up. (headaches that prompted me adding this support)

I have tried to keep consistent with your coding style and techniques to make it as seamless to patch as possible.",Patches,new,To Be Determined,serialization,Boost 1.47.0,Showstopper,,serialization abstract concrete,