4818da809f wallet: fix rescanning inconsistency (Martin Zumsande)
Pull request description:
If the chain advances during a rescan, ScanForWalletTransactions would previously process the new blocks without adjusting `m_last_processed_block`, which would leave the wallet in an inconsistent state temporarily, and could lead to crashes in the GUI reported in #31474.
Fix this by not rescanning blocks beyond `m_last_processed_block` - for all blocks beyond that height, there will be pending BlockConnected notifications that will process them after the rescan is finished.
This means that if rescanning was triggered with `cs_wallet` permanently held (`AttachChain`), additional blocks that were connected during the rescan will only be processed with the pending `blockConnected` notifications after the lock is released.
If rescanning without a permanent `cs_wallet` lock (`RescanFromTime`), additional blocks that were connected during the rescan can be re-processed here because `m_last_processed_block` was already updated by `blockConnected`.
Fixes#31474
ACKs for top commit:
psgreco:
Not that it matters much, but UTACK 4818da809f
achow101:
ACK 4818da809f
furszy:
utACK 4818da809f
Tree-SHA512: 8e7dbc9e00019aef4f80a11776f3089cd671e0eadd3c548cc6267b5c722433f80339a9b2b338ff9b611863de75ed0a817a845e1668e729b71af70c9038b075af