fix: edge case with unprocessable requests

packages/chain/mempool/mempool.go

@@ -649,6 +649,10 @@ func (mpi *mempoolImpl) handleReceiveOnLedgerRequest(request isc.OnLedgerRequest
 		mpi.log.Warnf("dropping request, because it has ReturnAmount, ID=%v", requestID)
 		return
 	}
+	if request.SenderAccount() == nil {
+		// do not process requests without the sender feature
+		return
+	}
 	//
 	// Check, maybe mempool already has it.
 	if mpi.onLedgerPool.Has(requestRef) || mpi.timePool.Has(requestRef) {

packages/chain/mempool/mempool_test.go

@@ -779,7 +779,7 @@ func getRequestsOnLedger(t *testing.T, chainAddress iotago.Address, amount int,
 		}
 		output := transaction.BasicOutputFromPostData(
 			tpkg.RandEd25519Address(),
-			isc.Hn("dummySenderContract"),
+			0,
 			requestParams,
 		)
 		outputID := tpkg.RandOutputID(uint16(i))

packages/solo/mempool.go

@@ -49,6 +49,9 @@ func (mi *mempoolImpl) ReceiveRequests(reqs ...isc.Request) {
 	mi.mu.Lock()
 	defer mi.mu.Unlock()
 	for _, req := range reqs {
+		if req.SenderAccount() == nil {
+			continue // ignore requests without a sender
+		}
 		if _, ok := mi.requests[req.ID()]; !ok {
 			mi.info.TotalPool++
 			mi.info.InPoolCounter++

packages/vm/core/blocklog/unprocessable.go

@@ -130,7 +130,8 @@ func retryUnprocessable(ctx isc.Sandbox) dict.Dict {
 	if err != nil {
 		panic(ErrUnprocessableUnexpected)
 	}
-	if !rec.SenderAccount().Equals(ctx.Request().SenderAccount()) {
+	recSender := rec.SenderAccount()
+	if rec.SenderAccount() == nil || !recSender.Equals(ctx.Request().SenderAccount()) {
 		panic(ErrUnprocessableWrongSender)
 	}
 	ctx.Privileged().RetryUnprocessable(rec, outputID)

packages/vm/core/testcore/custom_onledger_requests_test.go

@@ -106,7 +106,7 @@ func TestNoSenderFeature(t *testing.T) {
 
 	reqs, err := ch.Env.RequestsForChain(tx, ch.ChainID)
 	require.NoError(ch.Env.T, err)
-	results := ch.RunRequestsSync(reqs, "post")
+	results := ch.RunRequestsSync(reqs, "post") // under normal circumstances this request won't reach the mempool
 	require.Len(t, results, 1)
 	require.NotNil(t, results[0].Receipt.Error)
 	err = ch.ResolveVMError(results[0].Receipt.Error)

packages/vm/gas/feepolicy.go

@@ -60,6 +60,9 @@ func (p *FeePolicy) FeeFromGas(gasUnits uint64) uint64 {
 }
 
 func (p *FeePolicy) MinFee() uint64 {
+	if p.GasPerToken.A == 0 {
+		return 0
+	}
 	return p.FeeFromGas(BurnCodeMinimumGasPerRequest1P.Cost())
 }
 

packages/vm/vmimpl/internal.go

@@ -184,6 +184,9 @@ func (vmctx *vmContext) storeUnprocessable(chainState kv.KVStore, unprocessable
 
 	withContractState(chainState, blocklog.Contract, func(s kv.KVStore) {
 		for _, r := range unprocessable {
+			if r.SenderAccount() == nil {
+				continue
+			}
 			txsnapshot := vmctx.createTxBuilderSnapshot()
 			err := panicutil.CatchPanic(func() {
 				position := vmctx.txbuilder.ConsumeUnprocessable(r)

packages/vm/vmimpl/runreq.go

@@ -98,15 +98,16 @@ func (reqctx *requestContext) creditAssetsToChain() {
 	storageDepositNeeded := reqctx.vm.txbuilder.Consume(req)
 
 	// if sender is specified, all assets goes to sender's sender
-	// Otherwise it all goes to the common sender and panics is logged in the SC call
+	// Otherwise it all goes to the common sender and panic is logged in the SC call
 	sender := req.SenderAccount()
 	if sender == nil {
+		if storageDepositNeeded > req.Assets().BaseTokens {
+			panic(vmexceptions.ErrNotEnoughFundsForSD) // if sender is not specified, and extra tokens are needed to pay for SD, the request cannot be processed.
+		}
 		// onleger request with no sender, send all assets to the payoutAddress
 		payoutAgentID := reqctx.vm.payoutAgentID()
 		creditNFTToAccount(reqctx.uncommittedState, payoutAgentID, req)
 		creditToAccount(reqctx.uncommittedState, payoutAgentID, req.Assets())
-
-		// debit any SD required for accounting UTXOs
 		if storageDepositNeeded > 0 {
 			debitFromAccount(reqctx.uncommittedState, payoutAgentID, isc.NewAssetsBaseTokens(storageDepositNeeded))
 		}
@@ -115,7 +116,8 @@ func (reqctx *requestContext) creditAssetsToChain() {
 
 	senderBaseTokens := req.Assets().BaseTokens + reqctx.GetBaseTokensBalance(sender)
 
-	if senderBaseTokens < storageDepositNeeded {
+	minReqCost := reqctx.ChainInfo().GasFeePolicy.MinFee()
+	if senderBaseTokens < storageDepositNeeded+minReqCost {
 		// user doesn't have enough funds to pay for the SD needs of this request
 		panic(vmexceptions.ErrNotEnoughFundsForSD)
 	}