`ScanForWalletTransactions()` has the following comment about its return value:

```
 * Returns null if scan was successful. Otherwise, if a complete rescan was not
 * possible (due to pruning or corruption), returns pointer to the most recent
 * block that could not be scanned.
```

This is not strictly true. If `abortrescan` is called, then `ScanForWalletTransactions()` will return `nullptr`, even though the scan wasn't successful to the tip.

This in turn causes a minor bug in `importmulti`, where the call doesn't return the correct error and warning about potentially not finding transactions if `abortrescan` was called.

I think the correct fix is for `ScanForWalletTransactions()` to inform the caller that the rescan was aborted.
LOCK(cs_wallet);
    auto it = mapWallet.find(ptx->GetHash());
    if (it != mapWallet.end()) {
        it->second.fInMempool = false;
    }
}
void CWallet::BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex *pindex, const std::vector<CTransactionRef>& vtxConflicted) {
    auto locked_chain = chain().lock();
    LOCK(cs_wallet);
    
    
    
    
    
    
    
    for (const CTransactionRef& ptx : vtxConflicted) {
        SyncTransaction(ptx);
        TransactionRemovedFromMempool(ptx);
    }
    for (size_t i = 0; i < pblock->vtx.size(); i++) {
        SyncTransaction(pblock->vtx[i], pindex, i);
        TransactionRemovedFromMempool(pblock->vtx[i]);
    }
    m_last_block_processed = pindex;
}
void CWallet::BlockDisconnected(const std::shared_ptr<const CBlock>& pblock) {