Added virtual descriptor to DoublyLinkedListImpl, PackageSymlink and PackageDirectory
|Reported by:||Ezodev||Owned by:||nobody|
|Has a Patch:||yes||Platform:||All|
empty virtual destructor in DoublyLinkedListImpl:
There is some derivatives, such as PackageNode. If someone assign ptr to PackageNode to DoublyLinkedListImpl<PackageNode>* there will be memleak.
Virtual destructors in PackegeSymlink and PackageDirectory: I don't know if they have childs, but they could have.
I've fount this in Coverity CID:1108472, wanted to fix it but it seems someone was faster, and there is virtual destructor in PackageNode class.