The function push_val in Lua.xs was only checking for reference types (like code references) if the underlying Perl variable was an integer, which is incorrect. It needs to check for references before it checks for any other scalar type.

Author: ItsMeForLua

Lua.xs

@@ -221,43 +221,42 @@ void
 push_val (lua_State *L, SV *val) {
 
     if (is_lua_nil(val)) {
-	lua_pushnil(L);
-	return;
+        lua_pushnil(L);
+        return;
     }
 
     if (!val || val == &PL_sv_undef || !SvOK(val)) {
-	if (!UNDEF || UNDEF == &PL_sv_undef || !SvOK(UNDEF))
-	    lua_pushnil(L);
-	else
-	    /* otherwise we can safely call push_val again
-	     * because Inline::Lua::_undef is defined */
-	    push_val(L, UNDEF);
-	return;
+        if (!UNDEF || UNDEF == &PL_sv_undef || !SvOK(UNDEF))
+            lua_pushnil(L);
+        else
+            push_val(L, UNDEF);
+        return;
+    }
+
+    if (SvROK(val)) {
+        push_ref(L, val);
+        return;
     }
 
     switch (SvTYPE(val)) {
-	case SVt_IV:
-            if(SvROK(val)) {
-                push_ref(L, val);
-            } else {
+        case SVt_IV:
 #if LUA_VERSION_NUM < 503
-                lua_pushnumber(L, (lua_Number)SvIV(val));
+            lua_pushnumber(L, (lua_Number)SvIV(val));
 #else
-                lua_pushinteger(L, (lua_Integer)SvIV(val));
+            lua_pushinteger(L, (lua_Integer)SvIV(val));
 #endif
+            return;
+        case SVt_NV:
+            lua_pushnumber(L, (lua_Number)SvNV(val));
+            return;
+        case SVt_PV: case SVt_PVIV:
+        case SVt_PVNV: case SVt_PVMG:
+            {
+                STRLEN n_a;
+                char *cval = SvPV(val, n_a);
+                lua_pushlstring(L, cval, n_a);
+                return;
             }
-	    return;
-	case SVt_NV:
-	    lua_pushnumber(L, (lua_Number)SvNV(val));
-	    return;
-	case SVt_PV: case SVt_PVIV:
-	case SVt_PVNV: case SVt_PVMG:
-	    {
-		STRLEN n_a;
-		char *cval = SvPV(val, n_a);
-		lua_pushlstring(L, cval, n_a);
-		return;
-	    }
     }
 }