Change ScanForWalletTransactions return value so it is possible to distinguish
scans that skip reading every block (due to the nTimeFirstKey optimization)
from scans that fail while reading the chainActive.Tip() block. Return value is
now non-null in the non-failing case.
This change doesn't affect any user-visible behavior, it is only an internal
API improvement. The only code currently using the ScanForWalletTransactions
return value is in importmulti, and importmulti always calls
ScanForWalletTransactions with a pindex pointing to the first block in
chainActive whose block time is >= (nLowestTimestamp - 7200), while
ScanForWalletTransactions would only return null without reading blocks when
pindex and every block after it had a block time < (nTimeFirstKey - 7200).
These conditions could never happen at the same time because nTimeFirstKey <=
nLowestTimestamp.
I'm planning to make a more substantial API improvement in the future (making
ScanForWalletTransactions private and exposing a higher level rescan method to
RPC code), but Matt Corallo <git@bluematt.me> pointed out this odd behavior
introduced by e2e2f4c "Return errors from importmulti if complete rescans are
not successful" yesterday, so I'm following up now to get rid of badness
introduced by that merge.
Warnings introduced by commit e2e2f4c "Return errors from importmulti if
complete rescans are not successful" and reported by Pavel Janík
<Pavel@Janik.cz> in https://github.com/bitcoin/bitcoin/pull/9773 and
https://github.com/bitcoin/bitcoin/pull/9827
wallet/test/wallet_tests.cpp: In member function ‘void wallet_tests::rescan::test_method()’:
wallet/test/wallet_tests.cpp:377:17: warning: declaration of ‘wallet’ shadows a global declaration [-Wshadow]
CWallet wallet;
cee1612 reduce number of lookups in TransactionWithinChainLimit (Gregory Sanders)
af9bedb Test for fix of txn chaining in wallet (Gregory Sanders)
5882c09 CreateTransaction: Don't return success with too-many-ancestor txn (Gregory Sanders)
0b2294a SelectCoinsMinConf: Prefer coins with fewer ancestors (Gregory Sanders)
This reverts PR #4906, "Coinselection prunes extraneous inputs from
ApproximateBestSubset".
Apparently the previous behavior of slightly over-estimating the set of
inputs was useful in cleaning up UTXOs.
See also #7664, #7657, as well as 2016-07-01 discussion on #bitcoin-core-dev IRC.
* Introduce new constant MIN_CHANGE and use it instead of the
hardcoded "CENT"
* Add test case for MIN_CHANGE
* Introduce new constant for -mintxfee default:
DEFAULT_TRANSACTION_MINFEE = 1000
