Wallet migration includes rescan #930
Description
Users may want to migrate legacy wallets they haven't used in years. The migration itself is typically very quick, but it's followed by a rescan (if the wallet is behind).
Depending on whether the user has -blockfilterindex enabled, this rescan takes somewhere between long and really really long.
There's no visual indication, only the logs show what's going on:
Ideally the migration should finish and then prompt the user that a rescan is about to happen. That way the user can abort the rescan and resume it some other time if it takes too long.
Alternatively, the migrate wallet dialog could at least warn that a rescan is (or may be) happening and could take a while.
Fun aside: block filters don't work on legacy wallets, so it's much faster to first migrate and then rescan.