Ocpp: add workarounds for Enercab Smart (ELEDIO - EVCC01) (#13990)

* allow enercab smart (ELEDIO / EVCC01) sending file:// and not ip/name as origin string when switching to websocket
* allow enercab smart (ELEDIO / EVCC01) sending space padded numerical values of small numbers
* accept old pending stop message during startup
* Accept stopping unknown txn

charger/ocpp/connector_core.go

@@ -1,6 +1,7 @@
 package ocpp
 
 import (
+	"strings"
 	"time"
 
 	"github.com/lorenzodonini/ocpp-go/ocpp1.6/core"
@@ -60,6 +61,7 @@ func (conn *Connector) MeterValues(request *core.MeterValuesRequest) (*core.Mete
 		// ignore old meter value requests
 		if meterValue.Timestamp.Time.After(conn.meterUpdated) {
 			for _, sample := range meterValue.SampledValue {
+				sample.Value = strings.TrimSpace(sample.Value)
 				conn.measurements[getSampleKey(sample)] = sample
 				conn.meterUpdated = conn.clock.Now()
 			}

charger/ocpp/cp_core.go

@@ -111,7 +111,13 @@ func (cp *CP) StopTransaction(request *core.StopTransactionRequest) (*core.StopT
 
 	conn := cp.connectorByTransactionID(request.TransactionId)
 	if conn == nil {
-		return nil, ErrInvalidTransaction
+		res := &core.StopTransactionConfirmation{
+			IdTagInfo: &types.IdTagInfo{
+				Status: types.AuthorizationStatusAccepted, // accept old pending stop message during startup
+			},
+		}
+
+		return res, nil
 	}
 
 	return conn.StopTransaction(request)

charger/ocpp/instance.go

@@ -1,6 +1,7 @@
 package ocpp
 
 import (
+	"net/http"
 	"sync"
 	"time"
 
@@ -31,6 +32,7 @@ func Instance() *CS {
 
 		server := ws.NewServer()
 		server.SetTimeoutConfig(timeoutConfig)
+		server.SetCheckOriginHandler(func(r *http.Request) bool { return true })
 
 		dispatcher := ocppj.NewDefaultServerDispatcher(ocppj.NewFIFOQueueMap(0))
 		dispatcher.SetTimeout(time.Minute)

charger/ocpp_test.go

@@ -126,8 +126,9 @@ func (suite *ocppTestSuite) TestConnect() {
 	{
 		expectedTxn := 99
 
+		// always accept stopping unknown transaction, see https://github.com/evcc-io/evcc/pull/13990
 		_, err := cp1.StopTransaction(0, types.NewDateTime(suite.clock.Now()), expectedTxn)
-		suite.Require().Error(err)
+		suite.Require().NoError(err)
 
 		_, err = cp1.MeterValues(1, []types.MeterValue{
 			{