In 0.12, a wallet tx thats not in the mempool does not free up its inputs.  So if a tx spends the same inputs as a conflict tx included in a new block, its inputs are explicitly marked dirty so they will be recalculated as spendable again due to having no non-conflicted spends.  However if the in-block conflict is reorged out, the wallet txs inputs should now be market spent again according to the 0.12 regime, but they are not marked dirty as the tx itself is not notified it is no longer conflicted.

This has the odd effect that the cached value is incorrect and so randomly they will be spendable or not depending on whether they have been recalculated.

This is easy enough to fix by marking all inputs of all txs in SyncTransaction dirty regardless of whether AddToWalletIfInvolvingMe returns true or false.  But I'm not sure the performance impact this will have, so I'm not proposing that change now.

It's a minor issue, but I just thought I'd document that that the cached credit available in wallet txs may not always be correct.

For reference, in 0.11, whenever a tx left the mempool it's inputs were respendable.  So if a tx was removed due to a conflict in a block, any remaining inputs would be spendable again.  If the in-block conflict was later reorged out, the wallet txs inputs would remain spendable unless and until the wallet tx reentered the mempool.

if (wtx.isAbandoned()) return false;
    // Don't try to submit coinbase transactions. These would fail anyway but would
    // cause log spam.
    if (wtx.IsCoinBase()) return false;
    // Don't try to submit conflicted or confirmed transactions.
    if (GetTxDepthInMainChain(wtx) != 0) return false;
    // Submit transaction to mempool for relay
    WalLogPrintf("Submitting wtx %s to mempool for relay\n", wtx.GetHash().ToString());
    // We must set TxStateInMempool here. Even though it will also be set later by the
    // entered-mempool callback, if we did not there would be a race where a
    // user could call sendmoney in a loop and hit spurious out of funds errors
    // because we think that this newly generated transaction's change is
    // unavailable as we're not yet aware that it is in the mempool.
    //
    //  broadcast fails for any reason, trying to set wtx.m_state here would be incorrect.
    //  transaction was previously in the mempool, it should be updated when
    // TransactionRemovedFromMempool fires.
    bool ret = chain().broadcastTransaction(wtx.tx, m_default_max_tx_fee, relay, err_string);
    if (ret) wtx.m_state = TxStateInMempool{};
    return ret;
}
stdset<uint256> CWalGetTxConflicts(const CWalTx& wtx) const
{
    AssertLockHeld(cs_wal);
    const uint256 myHash{wtx.GetHash()};
    stdset<uint256> result{GetConflicts(myHash)};
    result.erase(myHash);
    return result;
}
bool CWalShouldResend() const