Merge pull request #77 from euler-xyz/gulp-fix

cap gulp without reverts
euler-xyz · Mar 27, 2024 · 2065d38 · 2065d38
2 parents 7d2408d + c6bd456
commit 2065d38
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Showing 2 changed files with 10 additions and 5 deletions.
diff --git a/src/Synths/EulerSavingsRate.sol b/src/Synths/EulerSavingsRate.sol
@@ -29,7 +29,6 @@ contract EulerSavingsRate is EVCUtil, ERC4626 {
     uint256 totalAssetsDeposited;
 
     error Reentrancy();
-    error E_GulpTooMuch();
 
     /// @notice Modifier to require an account status check on the EVC.
     /// @dev Calls `requireAccountStatusCheck` function from EVC for the specified account after the function body.
@@ -133,10 +132,12 @@ contract EulerSavingsRate is EVCUtil, ERC4626 {
         uint256 assetBalance = IERC20(asset()).balanceOf(address(this));
         uint256 toGulp = assetBalance - totalAssetsDeposited - esrSlotCache.interestLeft;
 
-        if (toGulp > type(uint168).max - esrSlotCache.interestLeft) revert E_GulpTooMuch();
+        uint256 maxGulp = type(uint168).max - esrSlotCache.interestLeft;
+        if (toGulp > maxGulp) toGulp = maxGulp; // cap interest, allowing the vault to function
 
         esrSlotCache.interestSmearEnd = uint40(block.timestamp + INTEREST_SMEAR);
-        esrSlotCache.interestLeft += uint168(toGulp);
+        esrSlotCache.interestLeft += uint168(toGulp); // toGulp <= maxGulp <= max uint168
+
         // write esrSlotCache back to storage in a single SSTORE
         esrSlot = esrSlotCache;
     }

diff --git a/test/unit/esr/ESR.Fuzz.t.sol b/test/unit/esr/ESR.Fuzz.t.sol
@@ -35,15 +35,19 @@ contract ESRFuzzTest is ESRTest {
     // this tests shows that when you have a very small deposit and a very large interestAmount minted to the contract
     function testFuzz_gulp_under_uint168(uint256 interestAmount, uint256 depositAmount, uint256 timePassed) public {
         depositAmount = bound(depositAmount, 0, type(uint112).max);
-        interestAmount = bound(interestAmount, 0, type(uint112).max - depositAmount); // this makes sure that the mint won't cause overflow
+        interestAmount = bound(interestAmount, 0, type(uint256).max - depositAmount); // this makes sure that the mint won't cause overflow
         timePassed = bound(timePassed, block.timestamp, type(uint40).max);
         asset.mint(address(esr), interestAmount);
 
         doDeposit(user, depositAmount);
         esr.gulp();
 
         EulerSavingsRate.ESRSlot memory esrSlot = esr.updateInterestAndReturnESRSlotCache();
-        assertEq(esrSlot.interestLeft, interestAmount);
+        if (interestAmount <= type(uint168).max - depositAmount) {
+            assertEq(esrSlot.interestLeft, interestAmount);
+        } else {
+            assertEq(esrSlot.interestLeft, type(uint168).max);
+        }
     }
 
     // fuzz test that any deposits added are added to the totalAssetsDeposited