Luau segmentation fault on FromLuaConversionError #674
Description
Using mlua with Luau causes a segmentation fault when FromLua implementation of UserDataRef fails. Minimal reproducible example:
use mlua::{Lua, Result, UserData, UserDataMethods, UserDataRef};
fn main() -> Result<()> {
let lua = Lua::new();
struct MyUserData(i32);
impl UserData for MyUserData {
fn add_methods<M: UserDataMethods<Self>>(methods: &mut M) {
methods.add_method_mut("add", |_, this, other: UserDataRef<MyUserData>| {
this.0 += other.0;
Ok(())
});
}
}
lua.globals().set("myobject", MyUserData(1))?;
lua.load("myobject:add(2)").exec()?;
Ok(())
}This returns a proper error with vendored Lua 5.1:
$ cargo run
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.02s
Running `target/debug/tmp`
Error: CallbackError { traceback: "stack traceback:\n\t[C]: in method 'add'\n\tsrc/main.rs:19:1: in main chunk", cause: BadArgument { to: Some("MyUserData.add"), pos: 2, name: None, cause: FromLuaConversionError { from: "number", to: "userdata", message: Some("expected userdata of type 'MyUserData'") } } }
But terminates with a segfault when luau is enabled:
cargo run
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.01s
Running `target/debug/tmp`
Error: CallbackError { traceback: "stack traceback:\n\t[C]: in ?\n\tsrc/main.rs:19:1: in function <src/main.rs:19:1>", cause: BadArgument { to: Some("MyUserData.add"), pos: 2, name: None, cause: FromLuaConversionError { from: "Error: nu::shell::terminated_by_signal
× External command was terminated by a signal
╭─[entry #55:1:1]
1 │ cargo run
· ──┬──
· ╰── terminated by SIGSEGV (11)
╰────