fix: make sure ETH transfer call never reverts

src/ReservoirPriceOracle.sol

@@ -5,11 +5,7 @@ import { IERC20 } from "forge-std/interfaces/IERC20.sol";
 import { IERC4626 } from "forge-std/interfaces/IERC4626.sol";
 
 import { OracleErrors } from "src/libraries/OracleErrors.sol";
-import {
-    IReservoirPriceOracle,
-    OracleAverageQuery,
-    OracleLatestQuery
-} from "src/interfaces/IReservoirPriceOracle.sol";
+import { IReservoirPriceOracle, OracleAverageQuery, OracleLatestQuery } from "src/interfaces/IReservoirPriceOracle.sol";
 import { IPriceOracle } from "src/interfaces/IPriceOracle.sol";
 import { QueryProcessor, ReservoirPair, PriceType } from "src/libraries/QueryProcessor.sol";
 import { Utils } from "src/libraries/Utils.sol";
@@ -241,12 +237,10 @@ contract ReservoirPriceOracle is IPriceOracle, IReservoirPriceOracle, Owned(msg.
             lPayoutAmt = block.basefee * rewardGasAmount;
         }
 
-        if (lPayoutAmt <= address(this).balance) {
-            // REVIEW: This can still revert, rather than balance checking we
-            // could just try/catch or use Yul to ignore reverts?
-            payable(aRecipient).transfer(lPayoutAmt);
+        // does not revert even if transfer fails
+        assembly ("memory-safe") {
+            let result := call(gas(), aRecipient, lPayoutAmt, codesize(), 0x00, codesize(), 0x00)
         }
-        // do nothing if lPayoutAmt is greater than the balance
     }
 
     /// @return rRoute The route to determine the price between aToken0 and aToken1

test/mock/GasBuster.sol

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.0;
+
+contract GasBuster {
+    // Allow the contract to receive ETH
+    receive() external payable {
+        while(true) {
+            // This loop will continue until all gas is consumed
+        }
+    }
+}

test/unit/ReservoirPriceOracle.t.sol

@@ -20,6 +20,7 @@ import { EnumerableSetLib } from "lib/solady/src/utils/EnumerableSetLib.sol";
 import { Constants } from "src/libraries/Constants.sol";
 import { MockFallbackOracle } from "test/mock/MockFallbackOracle.sol";
 import { StubERC4626 } from "test/mock/StubERC4626.sol";
+import { GasBuster } from "test/mock/GasBuster.sol";
 
 contract ReservoirPriceOracleTest is BaseTest {
     using Utils for *;
@@ -621,6 +622,31 @@ contract ReservoirPriceOracleTest is BaseTest {
         assertEq(lPriceAB, 0); // composite price is not stored in the cache
     }
 
+    function testUpdatePrice_RecipientOutOfGas() external {
+        // arrange
+        GasBuster lGasBuster = new GasBuster();
+
+        _writePriceCache(address(_tokenA), address(_tokenB), 5e18);
+        deal(address(_oracle), 1 ether);
+
+        skip(1);
+        _pair.sync();
+        skip(_oracle.twapPeriod() * 2);
+        _tokenA.mint(address(_pair), 2e18);
+        _pair.swap(2e18, true, address(this), "");
+
+        // act
+        _oracle.updatePrice(address(_tokenB), address(_tokenA), address(lGasBuster));
+
+        // assert
+        (uint256 lPrice,) = _oracle.priceCache(address(_tokenA), address(_tokenB));
+        assertEq(lPrice, 98_918_868_099_219_913_512);
+        (lPrice,) = _oracle.priceCache(address(_tokenB), address(_tokenA));
+        assertEq(lPrice, 0);
+        assertEq(address(this).balance, block.basefee * _oracle.rewardGasAmount());
+        assertEq(address(_oracle).balance, 1 ether - block.basefee * _oracle.rewardGasAmount());
+    }
+
     function testSetRoute() public {
         // arrange
         address lToken0 = address(_tokenB);