f20fe33e94 test: Add basic balance coverage to wallet_assumeutxo.py (Fabian Jahr)
037b101e80 test: Add coverage for best block locator write in wallet_backup (Fabian Jahr)
31c0df0389 wallet: migration, write best locator before unloading wallet (furszy)
7e3dbe4180 wallet: Write best block to disk before backup (Fabian Jahr)
Pull request description:
I discovered that we don't write the best block to disk when trying to explain the behavior described here: https://github.com/bitcoin/bitcoin/pull/30455#discussion_r1719951882
In the context of that test, the behavior is confusing and I think it also shows that one of the already existing tests in `wallet_assumeutxo.py` doesn't actually test what it says. It only fails because the best block isn't written and actually, the height of the backup that is loaded is at the snapshot height during backup. So it really shouldn't fail since it's past the background sync blocks already.
I'm not sure if this is super relevant in practice though so I am first looking for concept ACKs on the `BackupWallet` code change. Either way, I think this behavior should be documented better if it is left as is and the test should be changed.
ACKs for top commit:
achow101:
ACK f20fe33e94
furszy:
ACK f20fe33
Tree-SHA512: bb384a940df5c942fffe2eb06314ade4fc5d9b924012bfef3b1c456c4182a30825d1e137d8ae561d93d3a8a2f4d1c1ffe568132d20fa7d04844f1e289ab4a28b