no double postUpgradeInit

Author: godzillaba

src/L2ArbitrumToken.sol

@@ -77,13 +77,17 @@ contract L2ArbitrumToken is
         _transferOwnership(_owner);
     }
 
-    /// @notice Called at proposal #1
+    /// @notice Called after upgrade to set the initial total delegation estimate
     ///         The initial estimate may be manipulable with artificial delegation/undelegation prior to the upgrade.
     ///         Since this value is only used for quorum calculation, and the quroum is clamped by the governors to an acceptable range,
     ///         the risk/impact of manipulation is low.
     /// @param  initialTotalDelegation The initial total delegation at the time of upgrade proposal creation.
     ///         This is an estimate since it is chosen at proposal creation time and not effective until the proposal is executed.
     function postUpgradeInit(uint256 initialTotalDelegation) external onlyOwner {
+        require(
+            _totalDelegationHistory._checkpoints.length == 0,
+            "ARB: POST_UPGRADE_INIT_ALREADY_CALLED"
+        );
         _totalDelegationHistory.push(initialTotalDelegation);
     }
 

test/L2ArbitrumToken.t.sol

@@ -49,6 +49,20 @@ contract L2ArbitrumTokenTest is Test {
         );
     }
 
+    // test no double init
+    function testNoDoublePostUpgradeInit() public {
+        L2ArbitrumToken l2Token = deployAndInit();
+
+        // set an initial estimate
+        vm.prank(owner);
+        l2Token.postUpgradeInit(10);
+
+        // try to set it again
+        vm.prank(owner);
+        vm.expectRevert("ARB: POST_UPGRADE_INIT_ALREADY_CALLED");
+        l2Token.postUpgradeInit(20);
+    }
+
     // test adjustment
     function testDvpAdjustment(
         uint64 initialEstimate,