Merge pull request #1450 from gustavo-grieco/fix-event-decoding-crash

Fixed event decoding crash

Author: elopez

lib/Echidna/Events.hs

@@ -17,9 +17,10 @@ import Data.Text (pack, Text)
 import Data.Tree (flatten)
 import Data.Tree.Zipper (fromForest, TreePos, Empty)
 import Data.Vector (fromList)
+import Data.Vector qualified as V
 
 import EVM (traceForest)
-import EVM.ABI (Event(..), Indexed(..), decodeAbiValue, getAbi, AbiType(..), AbiValue(..))
+import EVM.ABI (Event(..), Indexed(..), decodeAbiValue, getAbiSeq, AbiType(..), AbiValue(..))
 import EVM.Dapp (DappContext(..), DappInfo(..))
 import EVM.Expr (maybeLitWordSimp)
 import EVM.Format (showValues, showError, contractNamePart)
@@ -91,10 +92,12 @@ extractEventValues dappInfo vm vm' =
       LogEntry _addr (ConcreteBuf bs) (sigHash : _) ->
         case Map.lookup (forceWord sigHash) dappInfo.eventMap of
           Just (Event _ _ params) ->
-            [ (ty, val)
-            | (_, ty, NotIndexed) <- params
-            , Right (_, _, val) <- [ runGetOrFail (getAbi ty) (fromStrict bs) ]
-            ]
+            let
+              types = [ t | (_, t, NotIndexed) <- params ]
+            in
+              case runGetOrFail (getAbiSeq (length types) types) (fromStrict bs) of
+                Right (_, _, vals) -> zip types (V.toList vals)
+                _ -> []
           Nothing -> []
       _ -> []
 

tests/solidity/values/events.sol

@@ -1,10 +1,10 @@
 contract EventAssert {
     bytes32 private hash;
-    event Secret(bytes32);
+    event Secret(uint256, string, bytes32);
     function reset(uint seed) public {
         require(hash == 0);
 	bytes32 secret = keccak256(abi.encodePacked(seed));
-	emit Secret(secret);
+	emit Secret(1, "abc", secret);
         hash = keccak256(abi.encodePacked(secret));
     }
     function check(bytes32 seed) public {