- case 1: in version 4.4.1, 4.4.2, the qml GUI wizard allowed creating multisig wallets with an old_mpk as cosigner.
- case 2: in version 4.4.0, 4.4.1, 4.4.2, the qml GUI wizard allowed creating multisig wallets with mixed xpub/Ypub/Zpub.
The corresponding missing input validation was a bug in the wizard, it was unintended behaviour. Validation was added in d2cf21fc2b. Note however that there might be users who created such wallet files.
Re case 1 wallet files: there is no version of Electrum that allows spending from such a wallet. Coins received at addresses are not burned, however it is technically challenging to spend them. (unless the multisig can spend without needing the old_mpk cosigner in the quorum).
Re case 2 wallet files: it is possible to create a corresponding spending wallet for such a multisig, however it is a bit tricky. The script type for the addresses in such a heterogeneous xpub wallet is based on the xpub_type of the first keystore. So e.g. given a wallet file [Yprv1, Zpub2] it will have sh(wsh()) scripts, and the cosigner should create a wallet file [Ypub1, Zprv2] (same order).
Technically case 2 wallet files could be "fixed" automatically by converting the xpub types as part of a wallet_db upgrade. However if the wallet files also contain seeds, those cannot be converted ("standard" vs "segwit" electrum seed).
Case 1 wallet files are not possible to "fix" automatically as the cosigner using the old_mpk is not bip32 based.
It is unclear if there are *any* users out there affected by this. I suspect for case 1 it is very likely there are none (not many people have pre-2.0 electrum seeds which were never supported as part of a multisig who would also now try to create a multisig using them); for case 2 however there might be.
This commit breaks both case 1 and case 2 wallets: these wallet files can no longer be opened in new Electrum, an error message is shown and the crash reporter opens. If any potential users opt to send crash reports, at least we will know they exist and can help them recover.
given a bip21 uri that has both onchain addr and bolt11,
if we have LN enabled but no LN channels, auto-fallback to paying onchain
we will have to clean up and unify this logic between GUIs. becoming spaghetti :/
rumour has it, Thomas has a branch? :P
