replace lua error

error may cause c stack overflow
https://github.com/aarzilli/golua/issues/24

README.md

@@ -93,6 +93,7 @@ Choosing a store database to use is very simple, you have two ways:
 
 + You must known that changing store database runtime is very dangerous, LedisDB will not guarantee the data validation if you do it.
 + Begin a transaction will block any other write operators before you call `commit` or `rollback`. Don't use long-time transaction. 
++ `pcall` and `xpcall` are not supported in lua, you can see the readme in [golua](https://github.com/aarzilli/golua).
 
 ## Configuration
 

server/script.go

@@ -159,6 +159,8 @@ func (app *App) openScript() {
 	l.OpenTable()
 	l.OpenPackage()
 
+	l.Register("error", luaErrorHandler)
+
 	s.l = l
 	s.c = newClient(app)
 	s.c.db = nil
@@ -223,6 +225,11 @@ func delMapState(l *lua.State) {
 	delete(mapState, l)
 }
 
+func luaErrorHandler(l *lua.State) int {
+	msg := l.ToString(1)
+	panic(fmt.Errorf(msg))
+}
+
 func luaCall(l *lua.State) int {
 	return luaCallGenericCommand(l)
 }