fix: Remove panic for unexpected tx response in resCbRecheck (#394)

* fix: Remove panic for unexpected tx response in `resCbRecheck`

* fix: Add a log when tx could not be loaded and changed the level to `Debug` level

mempool/clist_mempool.go

@@ -537,20 +537,23 @@ func (mem *CListMempool) resCbFirstTime(
 func (mem *CListMempool) resCbRecheck(req *abci.Request, res *abci.Response) {
  switch r := res.Value.(type) {
  case *abci.Response_CheckTx:
- tx := req.GetCheckTx().Tx
- txHash := TxKey(tx)
- if e, ok := mem.txsMap.Load(txHash); ok {
- celem := e.(*clist.CElement)
- if r.CheckTx.Code == abci.CodeTypeOK {
-  // Good, nothing to do.
- } else {
+ if r.CheckTx.Code == abci.CodeTypeOK {
+  // Good, nothing to do.
+ } else {
+ tx := req.GetCheckTx().Tx
+ txHash := TxKey(tx)
+ if e, ok := mem.txsMap.Load(txHash); ok {
+  celem := e.(*clist.CElement)
  // Tx became invalidated due to newly committed block.
  mem.logger.Debug("tx is no longer valid", "tx", txID(tx), "res", r)
  // NOTE: we remove tx from the cache because it might be good later
  mem.removeTx(tx, celem, true)
+ } else {
+ mem.logger.Debug(
+ "re-CheckTx transaction does not exist",
+ "expected", types.Tx(tx),
+ )
  }
- } else {
- panic(fmt.Sprintf("unexpected tx response from proxy during recheck\ntxHash=%X, tx=%X", txHash, tx))
  }
  default:
  // ignore other messages