Disallow 0 address for l1 token when creating l2 standard token

packages/contracts/contracts/optimistic-ethereum/OVM/bridge/tokens/OVM_L2StandardTokenFactory.sol

@@ -30,6 +30,8 @@ contract OVM_L2StandardTokenFactory {
     )
         external
     {
+        require (_l1Token != address(0), "Must provide L1 token address");
+
         L2StandardERC20 l2Token = new L2StandardERC20(
             Lib_PredeployAddresses.L2_STANDARD_BRIDGE,
             _l1Token,

packages/contracts/test/contracts/OVM/bridge/assets/OVM_L2StandardTokenFactory.spec.ts

@@ -7,7 +7,6 @@ import { smoddit } from '@eth-optimism/smock'
 import { getContractInterface } from '@eth-optimism/contracts'
 
 /* Internal Imports */
-import { NON_NULL_BYTES32, NON_ZERO_ADDRESS } from '../../../../helpers'
 import { predeploys } from '../../../../../src'
 
 describe('OVM_L2StandardTokenFactory', () => {
@@ -54,5 +53,13 @@ describe('OVM_L2StandardTokenFactory', () => {
       expect(await l2Token.name()).to.equal('L2ERC20')
       expect(await l2Token.symbol()).to.equal('ERC')
     })
+
+    it('should not be able to create a standard token with a 0 address for l1 token', async () => {
+      await expect(OVM_L2StandardTokenFactory.createStandardL2Token(
+        ethers.constants.AddressZero,
+        'L2ERC20',
+        'ERC'
+      )).to.be.revertedWith('Must provide L1 token address')
+    })
   })
 })