simplify returnData logic

nimbus/vm/computation.nim

@@ -293,14 +293,9 @@ proc addChildComputation*(c, child: Computation) =
         child.vmState.touchedAccounts.incl child.msg.contractAddress
 
   if child.isError:
-    if child.shouldBurnGas:
-      c.returnData = @[]
-    else:
-      c.returnData = child.output
+    c.returnData = child.output
   else:
-    if child.msg.isCreate:
-      c.returnData = @[]
-    else:
+    if not child.msg.isCreate:
       c.returnData = child.output
       child.touchedAccounts.incl child.msg.contractAddress
     c.logEntries.add child.logEntries

nimbus/vm/interpreter/opcodes_impl.nim

@@ -561,7 +561,8 @@ proc canTransfer(c: Computation, memPos, memLen: int, value: Uint256, opCode: st
 
   c.gasMeter.consumeGas(gasCost, reason = reason)
   c.memory.extend(memPos, memLen)
-
+  c.returnData.setLen(0)
+  
   # the sender is childmsg sender, not parent msg sender
   # perhaps we need to move this code somewhere else
   # to avoid confusion