--- a/util/set.lua Wed Jan 15 21:16:08 2020 +0100
+++ b/util/set.lua Wed Jan 15 21:18:30 2020 +0100
@@ -8,6 +8,7 @@
local ipairs, pairs, setmetatable, next, tostring =
ipairs, pairs, setmetatable, next, tostring;
+local getmetatable = getmetatable;
local t_concat = table.concat;
local _ENV = nil;
@@ -146,6 +147,11 @@
return new_set;
end
function set_mt.__eq(set1, set2)
+ if getmetatable(set1) ~= set_mt or getmetatable(set2) ~= set_mt then
+ -- Lua 5.3+ calls this if both operands are tables, even if metatables differ
+ return false;
+ end
+
set1, set2 = set1._items, set2._items;
for item in pairs(set1) do
if not set2[item] then