When a block reward is spent together with other outputs in the wallet and that block reward is later orphaned, the wallet does not show the other funds as available anymore.  Even a `-rescan` is not enough - only `-zapwallettxes` or an explicit `abandontransaction` "recovers" the funds.  I prepared a [test case](https://github.com/domob1812/bitcoin/blob/wallet-bug-invalidated-block-rewards/test/functional/wallet_bug.py) that shows this behaviour.

Is this a known issue or the expected behaviour?  While this situation is something that will presumably not occur in practice (as it requires a long reorg), I wonder if that transaction should be automatically abandoned as it seems clear it won't be able to be confirmed anymore.
{
public:
    template<typename Stream>
    void Unserialize(Stream& s)
    {
        CTransactionRef tx;
        uint256 hashBlock;
        std::vector<uint256> vMerkleBranch;
        int nIndex;
        s >> tx >> hashBlock >> vMerkleBranch >> nIndex;
    }
};
/**
 * A transaction with a bunch of additional info that only the owner cares about.
 * It includes any unrecorded transactions needed to link it back to the block chain.
 */
class CWalletTx