Handle panics when calling the RPCHandler instead of dying (#488)

Added a wrapper around the callRPCHandler function to recover from panic and translate that to and error so that the RPC thread doesn't just die when something malformed comes in. This should keep the Jet flying.

jsonrpc.go

@@ -466,7 +466,31 @@ func rpcSetTLSState(state TLSState) error {
 	return nil
 }
 
-func callRPCHandler(handler RPCHandler, params map[string]interface{}) (interface{}, error) {
+type RPCHandler struct {
+	Func   interface{}
+	Params []string
+}
+
+// call the handler but recover from a panic to ensure our RPC thread doesn't collapse on malformed calls
+func callRPCHandler(handler RPCHandler, params map[string]interface{}) (result interface{}, err error) {
+	// Use defer to recover from a panic
+	defer func() {
+		if r := recover(); r != nil {
+			// Convert the panic to an error
+			if e, ok := r.(error); ok {
+				err = e
+			} else {
+				err = fmt.Errorf("panic occurred: %v", r)
+			}
+		}
+	}()
+
+	// Call the handler
+	result, err = riskyCallRPCHandler(handler, params)
+	return result, err
+}
+
+func riskyCallRPCHandler(handler RPCHandler, params map[string]interface{}) (interface{}, error) {
 	handlerValue := reflect.ValueOf(handler.Func)
 	handlerType := handlerValue.Type()
 
@@ -563,11 +587,6 @@ func callRPCHandler(handler RPCHandler, params map[string]interface{}) (interfac
 	return nil, errors.New("unexpected return values from handler")
 }
 
-type RPCHandler struct {
-	Func   interface{}
-	Params []string
-}
-
 func rpcSetMassStorageMode(mode string) (string, error) {
 	logger.Info().Str("mode", mode).Msg("Setting mass storage mode")
 	var cdrom bool