fix: add storage padding in L1GasPriceOracle (#164)

Author: Thegaram

src/L2/predeploys/L1GasPriceOracle.sol

@@ -117,6 +117,9 @@ contract L1GasPriceOracle is OwnableBase, IL1GasPriceOracle {
     /// @notice Indicates whether the network has gone through the Feynman upgrade.
     bool public isFeynman;
 
+    /// @dev Gap added to ensure that `isGalileo` is in the next storage slot.
+    uint248 private __gap;
+
     /// @notice Indicates whether the network has gone through the Galileo upgrade.
     bool public isGalileo;
 

src/test/L1GasPriceOracle.t.sol

@@ -312,4 +312,19 @@ contract L1GasPriceOracleTest is DSTestPlus {
 
         assertEq(oracle.getL1Fee(_data), (_baseTerm + _penaltyTerm) / PRECISION);
     }
+
+    function testSetStorageDuringUpgrade() external {
+        assertFalse(oracle.isFeynman());
+        assertFalse(oracle.isGalileo());
+
+        // Feynman upgrade
+        hevm.store(address(oracle), bytes32(uint256(11)), bytes32(uint256(1)));
+        assertTrue(oracle.isFeynman());
+        assertFalse(oracle.isGalileo());
+
+        // GalileoV2 upgrade
+        hevm.store(address(oracle), bytes32(uint256(12)), bytes32(uint256(1)));
+        assertTrue(oracle.isFeynman());
+        assertTrue(oracle.isGalileo());
+    }
 }