When exporting a tx as qr code, the prev txs are omitted to save space.
This causes problems with offline signers: software electrum signers will
just warn and then proceed, but hw devices will typically error.
If checked, we download prev (parent) txs from the network, asynchronously.
This allows calculating the fee and showing "input addresses".
We could also SPV-verify the tx, to fill in missing tx_mined_status
(block height, blockhash, timestamp, short ids), but this is not done currently.
Note that there is no clean way to do this with electrum protocol 1.4:
`blockchain.transaction.get_merkle(tx_hash, height)` requires knowledge of the block height.
Loosely based on 6112fe0e51
- wallet.add_input_info() previously had a fallback to download parent
prev txs from the network (after a lookup in wallet.db failed).
wallet.add_input_info() is not async, so the network request cannot
be done cleanly there and was really just a hack.
- tx.add_info_from_wallet() calls wallet.add_input_info() on each txin,
in which case these network requests were done sequentially, not concurrently
- the network part of wallet.add_input_info() is now split out into new method:
txin.add_info_from_network()
- in addition to tx.add_info_from_wallet(), there is now also tx.add_info_from_network()
- callers of old tx.add_info_from_wallet() should now called either
- tx.add_info_from_wallet(), then tx.add_info_from_network(), preferably in that order
- tx.add_info_from_wallet() alone is sufficient if the tx is complete,
or typically when not in a signing context
- callers of wallet.bump_fee and wallet.dscancel are now expected to have already
called tx.add_info_from_network(), as it cannot be done in a non-async context
(but for the common case of all-inputs-are-ismine, bump_fee/dscancel should work regardless)
- PartialTxInput.utxo was moved to the baseclass, TxInput.utxo
(this somehow escaped attention before, as most objects usually don't have multiple instances,
unless multiple wallets are open at the same time.)
Also, move all signal declarations, class constants and variables to the top of class definitions.