Do not allow gasTokens to be managed by hard asset manager

contracts/ForkableBridge.sol

@@ -62,6 +62,9 @@ contract ForkableBridge is
         if (to != children[0] && to != children[1]) {
             revert InvalidDestinationForHardAsset();
         }
+        if (token == gasTokenAddress) {
+            revert GasTokenIsNotHardAsset();
+        }
         IERC20(token).transfer(to, amount);
     }
 
@@ -178,8 +181,12 @@ contract ForkableBridge is
      * @dev Allows aynone to take out their forkonomic tokens
      * and send them to the children-bridge contracts
      * Notice that forkonomic tokens are special, as they their main contract
-     * is on L1, but they are still forkable tokens as all the tokens from
+     * is on L1, but they are still forkable tokens, as their contract is forked as well.
+     * We allow to send tokens only to one child, just in case the one child contract
+     * was updated shortly after the fork and contains an error (e.g. reverts on sending)
+     * @param amount Amount of tokens to be sent to the children-bridge contracts
      * @param useFirstChild boolean indicating for which child the operation should be run
+     * @param useChildTokenAllowance boolean indicating if the child token allowance (previously burned tokens) should be used
      */
     function sendForkonomicTokensToChild(
         uint256 amount,

contracts/interfaces/IForkableBridge.sol

@@ -11,6 +11,8 @@ interface IForkableBridge is IForkableStructure, IPolygonZkEVMBridge {
     error NotAuthorized();
     /// @dev Error thrown when trying to send bridged tokens to a child contract
     error InvalidDestinationForHardAsset();
+    /// @dev Error thrown when hardasset manager tries to send gas token to a child contract
+    error GasTokenIsNotHardAsset();
 
     /**
      * @dev Function to initialize the contract

test/ForkableBridge.t.sol

@@ -504,6 +504,13 @@ contract ForkableBridgeTest is Test {
             to
         );
 
+        vm.expectRevert(IForkableBridge.GasTokenIsNotHardAsset.selector);
+        vm.prank(hardAssetManger);
+        forkableBridge.transferHardAssetsToChild(
+            address(gasTokenAddress),
+            amount,
+            child2
+        );
         vm.expectRevert(
             IForkableBridge.InvalidDestinationForHardAsset.selector
         );