core/state: fix bug in copy of copy State

core/state/statedb.go

@@ -474,6 +474,16 @@ func (self *StateDB) Copy() *StateDB {
 		state.stateObjects[addr] = self.stateObjects[addr].deepCopy(state)
 		state.stateObjectsDirty[addr] = struct{}{}
 	}
+	// Above, we don't copy the actual journal. This means that if the copy is copied, the
+	// loop above will be a no-op, since the copy's journal is empty.
+	// Thus, here we iterate over stateObjects, to enable copies of copies
+	for addr := range self.stateObjectsDirty {
+		if _, exist := state.stateObjects[addr]; !exist {
+			state.stateObjects[addr] = self.stateObjects[addr].deepCopy(state)
+			state.stateObjectsDirty[addr] = struct{}{}
+		}
+	}
+
 	for hash, logs := range self.logs {
 		state.logs[hash] = make([]*types.Log, len(logs))
 		copy(state.logs[hash], logs)