From 140d942634f9f1bba191aafa948df57812c0f3fe Mon Sep 17 00:00:00 2001 From: S3RK <1466284+S3RK@users.noreply.github.com> Date: Tue, 5 Apr 2022 08:23:49 +0200 Subject: wallet: don't add change fee to target if subtracting fees from output --- src/wallet/spend.cpp | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'src') diff --git a/src/wallet/spend.cpp b/src/wallet/spend.cpp index 81055a5a1a..1d22d0993e 100644 --- a/src/wallet/spend.cpp +++ b/src/wallet/spend.cpp @@ -397,10 +397,13 @@ std::optional AttemptSelection(const CWallet& wallet, const CAm // 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 all_groups = GroupOutputs(wallet, 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 as well, as we are expecting to create a change output. - if (auto knapsack_result{KnapsackSolver(all_groups, nTargetValue + coin_selection_params.m_change_fee, - coin_selection_params.m_min_change_target, coin_selection_params.rng_fast)}) { + // 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)}) { knapsack_result->ComputeAndSetWaste(coin_selection_params.m_cost_of_change); results.push_back(*knapsack_result); } @@ -409,7 +412,7 @@ std::optional AttemptSelection(const CWallet& wallet, const CAm // 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 = nTargetValue + coin_selection_params.m_change_fee + CHANGE_LOWER; + const CAmount srd_target = target_with_change + CHANGE_LOWER; if (auto srd_result{SelectCoinsSRD(positive_groups, srd_target, coin_selection_params.rng_fast)}) { srd_result->ComputeAndSetWaste(coin_selection_params.m_cost_of_change); results.push_back(*srd_result); -- cgit v1.2.3