`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.
walletInstance->WalletLogPrintf("Wallet completed loading in %15dms\n", GetTimeMillis() - nStart);
    
    walletInstance->TopUpKeyPool();
    LockAnnotation lock(::cs_main); 
    auto locked_chain = chain.lock();
    LOCK(walletInstance->cs_wallet);
    CBlockIndex *pindexRescan = chainActive.Genesis();
    if (!gArgs.GetBoolArg("-rescan", false))
    {
        WalletBatch batch(*walletInstance->database);
        CBlockLocator locator;
        if (batch.ReadBestBlock(locator))
            pindexRescan = FindForkInGlobalIndex(chainActive, locator);
    }
    walletInstance->m_last_block_processed = chainActive.Tip();
    if (chainActive.Tip() && chainActive.Tip() != pindexRescan)
    {
        
        
        
        if (fPruneMode)
        {
            CBlockIndex *block = chainActive.Tip();
            while (block && block->pprev && (block->pprev->nStatus & BLOCK_HAVE_DATA) && block->pprev->nTx > 0 && pindexRescan != block)
                block = block->pprev;
            if (pindexRescan != block) {
                InitError(_("Prune: last wallet synchronisation goes beyond pruned data. You need to -reindex (download the whole blockchain again in case of pruned node)"));
                return nullptr;
            }
        }