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author | S3RK <1466284+S3RK@users.noreply.github.com> | 2022-07-06 08:51:22 +0200 |
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committer | S3RK <1466284+S3RK@users.noreply.github.com> | 2022-08-15 09:34:38 +0200 |
commit | 06f558e4e2164d1916f258c731efe4586728a23b (patch) | |
tree | b6331a743c0454d1120293f6ade842503714609e /src/wallet/spend.cpp | |
parent | c8cf08ea743e430c2bf3fe46439594257b0937e5 (diff) | |
download | bitcoin-06f558e4e2164d1916f258c731efe4586728a23b.tar.xz |
wallet: accurate SelectionResult::m_target
SelectionResult::m_target should be equal to actual selection target.
Selection target is the sum of all recipient amounts plus non input fees.
So we need to remove change_fee from the m_target. It's safe because change
target is always greater than the change fee, so we can always cover fees
if change output is created.
Diffstat (limited to 'src/wallet/spend.cpp')
-rw-r--r-- | src/wallet/spend.cpp | 20 |
1 files changed, 4 insertions, 16 deletions
diff --git a/src/wallet/spend.cpp b/src/wallet/spend.cpp index 9babb5e04e..aed6dc89d2 100644 --- a/src/wallet/spend.cpp +++ b/src/wallet/spend.cpp @@ -489,31 +489,19 @@ std::optional<SelectionResult> ChooseSelectionResult(const CWallet& wallet, cons // Vector of results. We will choose the best one based on waste. std::vector<SelectionResult> results; - // Note that unlike KnapsackSolver, we do not include the fee for creating a change output as BnB will not create a change output. - std::vector<OutputGroup> positive_groups = GroupOutputs(wallet, available_coins, coin_selection_params, eligibility_filter, true /* positive_only */); + std::vector<OutputGroup> positive_groups = GroupOutputs(wallet, available_coins, coin_selection_params, eligibility_filter, /*positive_only=*/true); if (auto bnb_result{SelectCoinsBnB(positive_groups, nTargetValue, coin_selection_params.m_cost_of_change)}) { results.push_back(*bnb_result); } // The knapsack solver has some legacy behavior where it will spend dust outputs. We retain this behavior, so don't filter for positive only here. - std::vector<OutputGroup> all_groups = GroupOutputs(wallet, available_coins, coin_selection_params, eligibility_filter, false /* positive_only */); - CAmount target_with_change = nTargetValue; - // While nTargetValue includes the transaction fees for non-input things, it does not include the fee for creating a change output. - // So we need to include that for KnapsackSolver and SRD as well, as we are expecting to create a change output. - if (!coin_selection_params.m_subtract_fee_outputs) { - target_with_change += coin_selection_params.m_change_fee; - } - if (auto knapsack_result{KnapsackSolver(all_groups, target_with_change, coin_selection_params.m_min_change_target, coin_selection_params.rng_fast)}) { + std::vector<OutputGroup> all_groups = GroupOutputs(wallet, available_coins, coin_selection_params, eligibility_filter, /*positive_only=*/false); + if (auto knapsack_result{KnapsackSolver(all_groups, nTargetValue, coin_selection_params.m_min_change_target, coin_selection_params.rng_fast)}) { knapsack_result->ComputeAndSetWaste(coin_selection_params.m_cost_of_change); results.push_back(*knapsack_result); } - // Include change for SRD as we want to avoid making really small change if the selection just - // barely meets the target. Just use the lower bound change target instead of the randomly - // generated one, since SRD will result in a random change amount anyway; avoid making the - // target needlessly large. - const CAmount srd_target = target_with_change + CHANGE_LOWER; - if (auto srd_result{SelectCoinsSRD(positive_groups, srd_target, coin_selection_params.rng_fast)}) { + if (auto srd_result{SelectCoinsSRD(positive_groups, nTargetValue, coin_selection_params.rng_fast)}) { srd_result->ComputeAndSetWaste(coin_selection_params.m_cost_of_change); results.push_back(*srd_result); } |