Invalid characters for a wallet name, e.g. `bitcoin-qt -wallet=你好` used to result in an error like this

<img width="494" alt="schermafbeelding 2018-07-24 om 17 46 37" src="https://user-images.githubusercontent.com/10217/43150553-7bdf598a-8f6a-11e8-8972-44c311a57e56.png">

But now it just crashes:

<img width="509" alt="schermafbeelding 2018-07-24 om 17 43 26" src="https://user-images.githubusercontent.com/10217/43150605-9cf32192-8f6a-11e8-9333-87d074c8dd35.png">

I didn't do a `git bisect`, but it broke somewhere this year :-)
{
    nTimeCreated = (nExpires ? GetTime() : 0);
    nTimeExpires = nExpires;
}
void CMerkleTx::SetMerkleBranch(const CBlockIndex* pindex, int posInBlock)
{
    
    hashBlock = pindex->GetBlockHash();
    
    nIndex = posInBlock;
}
int CMerkleTx::GetDepthInMainChain() const
{
    if (hashUnset())
        return 0;
    AssertLockHeld(cs_main);
    
    CBlockIndex* pindex = LookupBlockIndex(hashBlock);
    if (!pindex || !chainActive.Contains(pindex))
        return 0;
    return ((nIndex == -1) ? (-1) : 1) * (chainActive.Height() - pindex->nHeight + 1);
}
int CMerkleTx::GetBlocksToMaturity() const
{
    if (!IsCoinBase())
        return 0;
    return std::max(0, (COINBASE_MATURITY+1) - GetDepthInMainChain());
}
bool CWalletTx::AcceptToMemoryPool(const CAmount& nAbsurdFee, CValidationState& state)