do not allow arbitrary calls to Zora.cancelAuction() unless it is t…

…he last call in sequence (#154)

contracts/proposals/ArbitraryCallsProposal.sol

@@ -7,6 +7,7 @@ import "../tokens/IERC721Receiver.sol";
 import "../tokens/ERC1155Receiver.sol";
 import "../utils/LibSafeERC721.sol";
 import "../utils/LibAddress.sol";
+import "../vendor/markets/IZoraAuctionHouse.sol";
 import "./vendor/IOpenseaExchange.sol";
 
 import "./LibProposal.sol";
@@ -39,6 +40,12 @@ contract ArbitraryCallsProposal {
 
     event ArbitraryCallExecuted(uint256 proposalId, uint256 idx, uint256 count);
 
+    IZoraAuctionHouse private immutable _ZORA;
+
+    constructor(IZoraAuctionHouse zora) {
+        _ZORA = zora;
+    }
+
     function _executeArbitraryCalls(
         IProposalExecutionEngine.ExecuteProposalParams memory params
     )
@@ -67,7 +74,7 @@ contract ArbitraryCallsProposal {
             // Execute an arbitrary call.
             _executeSingleArbitraryCall(
                 i,
-                calls[i],
+                calls,
                 params.preciousTokens,
                 params.preciousTokenIds,
                 isUnanimous,
@@ -101,16 +108,24 @@ contract ArbitraryCallsProposal {
 
     function _executeSingleArbitraryCall(
         uint256 idx,
-        ArbitraryCall memory call,
+        ArbitraryCall[] memory calls,
         IERC721[] memory preciousTokens,
         uint256[] memory preciousTokenIds,
         bool isUnanimous,
         uint256 ethAvailable
     )
         private
     {
+        ArbitraryCall memory call = calls[idx];
         // Check that the call is not prohibited.
-        if (!_isCallAllowed(call, isUnanimous, preciousTokens, preciousTokenIds)) {
+        if (!_isCallAllowed(
+            call,
+            isUnanimous,
+            idx,
+            calls.length,
+            preciousTokens,
+            preciousTokenIds))
+        {
             revert CallProhibitedError(call.target, call.data);
         }
         // Check that we have enough ETH to execute the call.
@@ -151,6 +166,8 @@ contract ArbitraryCallsProposal {
     function _isCallAllowed(
         ArbitraryCall memory call,
         bool isUnanimous,
+        uint256 callIndex,
+        uint256 callsCount,
         IERC721[] memory preciousTokens,
         uint256[] memory preciousTokenIds
     )
@@ -197,6 +214,12 @@ contract ArbitraryCallsProposal {
                     if (isApproved) {
                         return !LibProposal.isTokenPrecious(IERC721(call.target), preciousTokens);
                     }
+                // Can only call cancelAuction on the zora AH if it's the last call
+                // in the sequence.
+                } else if (selector == IZoraAuctionHouse.cancelAuction.selector) {
+                    if (call.target == address(_ZORA)) {
+                        return callIndex + 1 == callsCount;
+                    }
                 }
             }
             // Can never call receive hooks on any target.

contracts/proposals/ProposalExecutionEngine.sol

@@ -88,6 +88,7 @@ contract ProposalExecutionEngine is
         ListOnOpenseaProposal(globals, seaport, seaportConduitController)
         ListOnZoraProposal(globals, zoraAuctionHouse)
         FractionalizeProposal(fractionalVaultFactory)
+        ArbitraryCallsProposal(zoraAuctionHouse)
     {
         _GLOBALS = globals;
     }

sol-tests/crowdfund/Crowdfund.t.sol

@@ -1022,7 +1022,6 @@ contract CrowdfundTest is Test, TestUtils {
     function test_canReuseContributionEntry() external {
         TestableCrowdfund cf = _createCrowdfund(0);
         address contributor = _randomAddress();
-        address payable badERC721Receiver = payable(new BadERC721Receiver());
         // Contributor contributes twice back-to-back.
         vm.deal(contributor, 3);
         vm.prank(contributor);
@@ -1039,7 +1038,6 @@ contract CrowdfundTest is Test, TestUtils {
         TestableCrowdfund cf = _createCrowdfund(0);
         address contributor1 = _randomAddress();
         address contributor2 = _randomAddress();
-        address payable badERC721Receiver = payable(new BadERC721Receiver());
         // contributor1 sandwiches contributor2.
         vm.deal(contributor1, 3);
         vm.deal(contributor2, 10);

sol-tests/proposals/ArbitraryCallsProposal.t.sol

@@ -11,6 +11,9 @@ import "../TestUtils.sol";
 import "../DummyERC721.sol";
 
 contract TestableArbitraryCallsProposal is ArbitraryCallsProposal {
+
+    constructor(IZoraAuctionHouse zora) ArbitraryCallsProposal(zora) {}
+
     function execute(
         IProposalExecutionEngine.ExecuteProposalParams calldata params
     )
@@ -66,6 +69,10 @@ contract ArbitraryCallTarget {
     }
 }
 
+contract FakeZora {
+    function cancelAuction(uint256 auctionId) external {}
+}
+
 contract ArbitraryCallsProposalTest is
     Test,
     TestUtils,
@@ -80,7 +87,9 @@ contract ArbitraryCallsProposalTest is
     event ArbitraryCallExecuted(uint256 proposalId, uint256 idx, uint256 count);
 
     ArbitraryCallTarget target = new ArbitraryCallTarget();
-    TestableArbitraryCallsProposal testContract = new TestableArbitraryCallsProposal();
+    FakeZora zora = new FakeZora();
+    TestableArbitraryCallsProposal testContract =
+        new TestableArbitraryCallsProposal(IZoraAuctionHouse(address(zora)));
     IERC721[] preciousTokens;
     uint256[] preciousTokenIds;
 
@@ -615,6 +624,44 @@ contract ArbitraryCallsProposalTest is
         testContract.execute(prop);
     }
 
+    function test_cannotCallCancelAuctionOnZoraIfNotLastCall() external {
+        (
+            ArbitraryCallsProposal.ArbitraryCall[] memory calls,
+        ) = _createSimpleCalls(2, false);
+        calls[0].target = payable(address(zora));
+        calls[0].data = abi.encodeCall(
+            IZoraAuctionHouse.cancelAuction,
+            (_randomUint256()) // params don't matter
+        );
+        IProposalExecutionEngine.ExecuteProposalParams memory prop =
+            _createTestProposal(calls);
+        vm.expectRevert(abi.encodeWithSelector(
+            ArbitraryCallsProposal.CallProhibitedError.selector,
+            calls[0].target,
+            calls[0].data
+        ));
+        testContract.execute(prop);
+    }
+
+    function test_canCallCancelAuctionOnZoraIfLastCall() external {
+        (
+            ArbitraryCallsProposal.ArbitraryCall[] memory calls,
+        ) = _createSimpleCalls(2, false);
+        calls[1].target = payable(address(zora));
+        calls[1].data = abi.encodeCall(
+            IZoraAuctionHouse.cancelAuction,
+            (_randomUint256()) // params don't matter
+        );
+        IProposalExecutionEngine.ExecuteProposalParams memory prop =
+            _createTestProposal(calls);
+        _expectEmit0();
+        emit ArbitraryCallExecuted(prop.proposalId, 0, 2);
+        _expectEmit0();
+        emit ArbitraryCallExecuted(prop.proposalId, 1, 2);
+        testContract.execute(prop);
+    }
+
+
     function test_cannotExecuteShortApproveCallData() external {
         (
             ArbitraryCallsProposal.ArbitraryCall[] memory calls,