fix(5.0): handle the utf-8 conversion correctly for loadstring

Author: YoRyan

scripts/build.sh

@@ -20,7 +20,7 @@ cd ../..
 if [[ "$1" == "lua-5.0.3" ]]; then
     emcc -Ithirdparty/$1 thirdparty/$1/lib/liblua.a thirdparty/$1/lib/liblualib.a \
         -s WASM=1 -O3 -o dist/glue/glue-$1.js \
-        -s EXPORTED_RUNTIME_METHODS="['cwrap']" \
+        -s EXPORTED_RUNTIME_METHODS="['cwrap', 'allocateUTF8', 'lengthBytesUTF8']" \
         -s MODULARIZE=1 \
         -s ALLOW_TABLE_GROWTH \
         -s EXPORT_NAME="glue" \

src/binding-factory.ts

@@ -165,12 +165,14 @@ const lauxBindings: Record<string, lauxBindingFactoryFunc> = {
                 return (this as LauxLib).luaL_loadstring(L, s) || lua.lua_pcall(L, 0, LUA_MULTRET, 0);
             },
             luaL_loadstring: function(L: LuaState, s: string) {
-                return (this as LauxLib).luaL_loadbuffer(L, s, s.length, s);
+                const ptr = luaGlue.allocateUTF8(s) as unknown;
+                return (this as LauxLib).luaL_loadbuffer(L, ptr as string, luaGlue.lengthBytesUTF8(s), s);
             },
+            luaL_loadbuffer: luaGlue.cwrap("luaL_loadbuffer", "number", ["number", "number", "number", "string"]),
             luaL_newstate: luaGlue.cwrap("lua_open", "number", []),
         }
     },
-    "<=5.1.x": function(luaGlue: LuaEmscriptenModule, _lua: Lua) {
+    "5.1.x": function(luaGlue: LuaEmscriptenModule, _lua: Lua) {
         return {
             luaL_loadbuffer: luaGlue.cwrap("luaL_loadbuffer", "number", ["number", "string", "number", "string"]),
         }

src/glue/glue.ts

@@ -1,4 +1,6 @@
 export interface LuaEmscriptenModule extends EmscriptenModule {
+    allocateUTF8: typeof allocateUTF8;
+    lengthBytesUTF8: typeof lengthBytesUTF8;
     cwrap: typeof cwrap;
 }