From fca21d56d38fd0ee394114074d980bdf7e06ff7f Mon Sep 17 00:00:00 2001
From: Alex Orlenko <zxteam@protonmail.com>
Date: Sun, 13 Jun 2021 23:28:41 +0100
Subject: [PATCH] Check stack in entrypoint1 before pushing value to a stack

---
 src/lua.rs | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/lua.rs b/src/lua.rs
index a9f6b5b..6b50be8 100644
--- a/src/lua.rs
+++ b/src/lua.rs
@@ -536,14 +536,18 @@ impl Lua {
         F: 'static + MaybeSend + Fn(&'callback Lua) -> Result<R>,
     {
         let cb = self.create_callback(Box::new(move |lua, _| func(lua)?.to_lua_multi(lua)))?;
-        match cb.call(()) {
-            Ok(res) => unsafe { self.push_value(res)? },
-            Err(err) => unsafe {
-                self.push_value(Value::Error(err))?;
-                // This longjmp is undesired, but we cannot wrap it to a C
-                ffi::lua_error(self.state)
-            },
-        }
+        let res = cb.call(());
+        unsafe {
+            check_stack(self.state, 2)?;
+            match res {
+                Ok(res) => self.push_value(res)?,
+                Err(err) => {
+                    self.push_value(Value::Error(err))?;
+                    // This longjmp is undesired, but we cannot wrap it to a C
+                    ffi::lua_error(self.state)
+                }
+            }
+        };
         Ok(1)
     }