Add cycle detection when converting lua values to dynamic

Cargo.lock

@@ -2021,7 +2021,6 @@ dependencies = [
  "bstr 0.2.17",
  "log",
  "mlua",
- "strsim 0.10.0",
  "wezterm-dynamic",
 ]
 
@@ -2229,9 +2228,8 @@ dependencies = [
 
 [[package]]
 name = "mlua"
-version = "0.7.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "29e2194305aa8301d5da9c1c98640047f4219f6b95c190f6860338ab9872b686"
+version = "0.8.0-beta.4"
+source = "git+https://github.com/wez/mlua?branch=table_to_pointer#7884481691169044c18a77ec495886db0d02bee9"
 dependencies = [
  "bstr 0.2.17",
  "cc",

Cargo.toml

@@ -24,3 +24,4 @@ split-debuginfo = "unpacked"
 
 [patch.crates-io]
 xcb = {version="1.1", git="https://github.com/wez/rust-xcb", branch="ffi"}
+mlua = {version="0.8.0-beta.4", git="https://github.com/wez/mlua", branch="table_to_pointer"}

config/Cargo.toml

@@ -25,7 +25,7 @@ lazy_static = "1.4"
 libc = "0.2"
 log = "0.4"
 luahelper = { path = "../luahelper" }
-mlua = {version="0.7", features=["vendored", "lua54", "async", "send"]}
+mlua = {version="0.8.0-beta.4", features=["vendored", "lua54", "async", "send"]}
 # file change notification
 notify = "4.0"
 open = "2.0"

config/src/config.rs

@@ -705,7 +705,7 @@ impl Config {
                 // file. Note that we can't catch this happening for files that are
                 // imported via the lua require function.
                 lua.load(s.trim_start_matches('\u{FEFF}'))
-                    .set_name(p.to_string_lossy().as_bytes())?
+                    .set_name(p.to_string_lossy())?
                     .eval_async(),
             )?;
             let config = Self::apply_overrides_to(&lua, config)?;

luahelper/Cargo.toml

@@ -9,6 +9,5 @@ edition = "2018"
 [dependencies]
 bstr = "0.2"
 log = "0.4"
-mlua = "0.7"
-strsim = "0.10"
+mlua = "0.8.0-beta.4"
 wezterm-dynamic = { path = "../wezterm-dynamic" }

luahelper/src/lib.rs

@@ -2,7 +2,7 @@
 
 pub use mlua;
 use mlua::{ToLua, Value as LuaValue};
-use std::collections::BTreeMap;
+use std::collections::{BTreeMap, HashSet};
 use wezterm_dynamic::{FromDynamic, ToDynamic, Value as DynValue};
 
 /// Implement lua conversion traits for a type.
@@ -76,8 +76,15 @@ pub fn dynamic_to_lua_value<'lua>(
     })
 }
 
-/// FIXME: lua_value_to_dynamic should detect and avoid cycles in the underlying lua object
 pub fn lua_value_to_dynamic(value: LuaValue) -> mlua::Result<DynValue> {
+    let mut visited = HashSet::new();
+    lua_value_to_dynamic_impl(value, &mut visited)
+}
+
+fn lua_value_to_dynamic_impl(
+    value: LuaValue,
+    visited: &mut HashSet<usize>,
+) -> mlua::Result<DynValue> {
     Ok(match value {
         LuaValue::Nil => DynValue::Null,
         LuaValue::String(s) => DynValue::String(s.to_str()?.to_string()),
@@ -107,6 +114,14 @@ pub fn lua_value_to_dynamic(value: LuaValue) -> mlua::Result<DynValue> {
         }
         LuaValue::Error(e) => return Err(e),
         LuaValue::Table(table) => {
+            let ptr = table.to_pointer() as usize;
+            if visited.contains(&ptr) {
+                // Skip this one, as we've seen it before.
+                // Treat it as a Null value.
+                return Ok(DynValue::Null);
+            }
+            visited.insert(ptr);
+
             if let Ok(true) = table.contains_key(1) {
                 let mut array = vec![];
                 for value in table.sequence_values() {

mux/Cargo.toml

@@ -22,7 +22,7 @@ libc = "0.2"
 log = "0.4"
 luahelper = { path = "../luahelper" }
 metrics = { version="0.17", features=["std"]}
-mlua = "0.7"
+mlua = "0.8.0-beta.4"
 names = { version = "0.12", default-features = false }
 percent-encoding = "2"
 portable-pty = { path = "../pty", features = ["serde_support"]}

wezterm-gui/Cargo.toml

@@ -42,7 +42,7 @@ log = "0.4"
 lru = "0.7"
 luahelper = { path = "../luahelper" }
 metrics = { version="0.17", features=["std"]}
-mlua = "0.7"
+mlua = "0.8.0-beta.4"
 mux = { path = "../mux" }
 open = "2.0"
 ordered-float = "3.0"