deadlock with wrong system date/time and non-empty wallet

[hebasto]

I have encountered a deadlock in bitcoin-qt on Manjaro Linux IF you have a wrong system date (enough to trigger this message - "Please check that your computer's date and time are correct!") AND if your wallet is not empty. It seems it tries to read transactions in:

TransactionRecord *index(interfaces::Wallet& wallet, int idx)
{
...
            if (wallet.tryGetTxStatus(rec->hash, wtx, numBlocks, adjustedTime) && rec->statusUpdateNeeded(numBlocks)) {
                rec->updateStatus(wtx, numBlocks, adjustedTime);
}

while displaying the warning message box and somehow deadlocks cs_nTimeOffset. The effect is that the message box pop-ups but you cannot click it and program does not react in any way.

Moved from bitcoin/bitcoin#15598.