@0x/contracts-dev-utils: Rebase.

contracts/dev-utils/contracts/src/OrderValidationUtils.sol

@@ -118,22 +118,14 @@ contract OrderValidationUtils is
             transferableTakerAssetAmount
         );
 
-        // Execute the maker transfers.
-        fillableTakerAssetAmount = LibOrderTransferSimulation.getSimulatedOrderMakerTransferResults(
-            exchangeAddress,
-            order,
-            order.takerAddress,
-            fillableTakerAssetAmount
-        ) == LibOrderTransferSimulation.OrderTransferResults.TransfersSuccessful ? fillableTakerAssetAmount : 0;
-
-        if (!_isAssetDataValid(order.takerAssetData)) {
-            fillableTakerAssetAmount = 0;
-        }
-
-        if (order.takerFee != 0 && !_isAssetDataValid(order.takerFeeAssetData)) {
+        // Ensure that all of the asset data is valid. Fee asset data only needs
+        // to be valid if the fees are nonzero.
+        if (!_areOrderAssetDatasValid(order)) {
             fillableTakerAssetAmount = 0;
         }
 
+        // If the order is not fillable, then the fillable taker asset amount is
+        // zero by definition.
         if (orderInfo.orderStatus != LibOrder.OrderStatus.FILLABLE) {
             fillableTakerAssetAmount = 0;
         }
@@ -210,6 +202,21 @@ contract OrderValidationUtils is
         return LibSafeMath.min256(transferableAssetAmount, order.makerAssetAmount);
     }
 
+    /// @dev Checks that the asset data contained in a ZeroEx is valid and returns
+    /// a boolean that indicates whether or not the asset data was found to be valid.
+    /// @param order A ZeroEx order to validate.
+    /// @return The validatity of the asset data.
+    function _areOrderAssetDatasValid(LibOrder.Order memory order)
+        internal
+        pure
+        returns (bool)
+    {
+        return _isAssetDataValid(order.makerAssetData) &&
+            (order.makerFee == 0 || _isAssetDataValid(order.makerFeeAssetData)) &&
+            _isAssetDataValid(order.takerAssetData) &&
+            (order.takerFee == 0 || _isAssetDataValid(order.takerFeeAssetData));
+    }
+
     /// @dev This function handles the edge cases around taker validation. This function
     ///      currently attempts to find duplicate ERC721 token's in the taker
     ///      multiAssetData.