fix crash

Author: codemodify

command.go

@@ -53,10 +53,12 @@ func (thisRef *Command) parseAndExecute(execute bool) error {
 
 	// 2. find root and ask to parse flags
 	commandToExecute := thisRef.getLastSubcommandFlagedForExecute()
-	if execute && helpsIsWanted {
-		commandToExecute.showUsage()
-	} else if execute && commandToExecute.Handler != nil {
-		commandToExecute.Handler(commandToExecute)
+	if commandToExecute != nil {
+		if execute && helpsIsWanted {
+			commandToExecute.showUsage()
+		} else if execute && commandToExecute.Handler != nil {
+			commandToExecute.Handler(commandToExecute)
+		}
 	}
 
 	return nil