Dust rounding on claimReward

uniswapfoundation · Apr 10, 2024 · c8a2d84 · c8a2d84
1 parent de35d2d
commit c8a2d84
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/src/UniStaker.sol b/src/UniStaker.sol
@@ -802,7 +802,9 @@ contract UniStaker is INotifiableRewardReceiver, Multicall, EIP712, Nonces {
 
     uint256 _reward = scaledUnclaimedRewardCheckpoint[_beneficiary] / SCALE_FACTOR;
     if (_reward == 0) return;
-    scaledUnclaimedRewardCheckpoint[_beneficiary] = 0;
+    // retain sub-wei dust that would be left due to the precision loss
+    scaledUnclaimedRewardCheckpoint[_beneficiary] =
+      scaledUnclaimedRewardCheckpoint[_beneficiary] - (_reward * SCALE_FACTOR);
     emit RewardClaimed(_beneficiary, _reward);
 
     SafeERC20.safeTransfer(REWARD_TOKEN, _beneficiary, _reward);