Fix arbitrum L1 to L2 crosschain call detection (#3578)

* Fix arbitrum L1 to L2 crosschain call detection

* fix BridgeArbitrumL2Mock

* update changelog

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>

CHANGELOG.md

@@ -17,6 +17,10 @@
 
 ERC-721 integrators that interpret contract state from events should make sure that they implement the clearing of approval that is implicit in every transfer according to the EIP. Previous versions of OpenZeppellin Contracts emitted an explicit `Approval` event even though it was not required by the specification, and this is no longer the case.
 
+## 4.7.2
+
+ * `LibArbitrumL2`, `CrossChainEnabledArbitrumL2`: Fixed detection of cross-chain calls for EOAs. Previously, calls from EOAs would be classified as cross-chain calls. ([#3578](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3578))
+
 ## 4.7.1
 
  * `SignatureChecker`: Fix an issue that causes `isValidSignatureNow` to revert when the target contract returns ill-encoded data. ([#3552](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3552))

contracts/crosschain/arbitrum/LibArbitrumL2.sol

@@ -21,7 +21,7 @@ library LibArbitrumL2 {
     address public constant ARBSYS = 0x0000000000000000000000000000000000000064;
 
     function isCrossChain(address arbsys) internal view returns (bool) {
-        return ArbitrumL2_Bridge(arbsys).isTopLevelCall();
+        return ArbitrumL2_Bridge(arbsys).wasMyCallersAddressAliased();
     }
 
     /**
@@ -35,9 +35,6 @@ library LibArbitrumL2 {
     function crossChainSender(address arbsys) internal view returns (address) {
         if (!isCrossChain(arbsys)) revert NotCrossChainCall();
 
-        return
-            ArbitrumL2_Bridge(arbsys).wasMyCallersAddressAliased()
-                ? ArbitrumL2_Bridge(arbsys).myCallersAddressWithoutAliasing()
-                : msg.sender;
+        return ArbitrumL2_Bridge(arbsys).myCallersAddressWithoutAliasing();
     }
 }

contracts/mocks/crosschain/bridges.sol

@@ -70,14 +70,10 @@ contract BridgeArbitrumL1Outbox {
 }
 
 contract BridgeArbitrumL2Mock is BaseRelayMock {
-    function isTopLevelCall() public view returns (bool) {
+    function wasMyCallersAddressAliased() public view returns (bool) {
         return _currentSender != address(0);
     }
 
-    function wasMyCallersAddressAliased() public pure returns (bool) {
-        return true;
-    }
-
     function myCallersAddressWithoutAliasing() public view returns (address) {
         return _currentSender;
     }