From 34098ab9da64b314b430d82b3530035670039f79 Mon Sep 17 00:00:00 2001 From: Kim Alvefur Date: Wed, 15 Jan 2020 21:08:01 +0100 Subject: util.array: Fix equality metamethod in Lua 5.3 Lua 5.2 only used the __eq metamethod if both operands have the same __eq, but Lua 5.3 will pick one from either operands that has one as long as both are tables. This results in array() == {} and all sorts of odd behavior, including array() == util.json.null. I think [array() == {}] should have the same semantics as {} == {} --- util/array.lua | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'util') diff --git a/util/array.lua b/util/array.lua index 0b60a4fd..32d2d6a5 100644 --- a/util/array.lua +++ b/util/array.lua @@ -10,6 +10,7 @@ local t_insert, t_sort, t_remove, t_concat = table.insert, table.sort, table.remove, table.concat; local setmetatable = setmetatable; +local getmetatable = getmetatable; local math_random = math.random; local math_floor = math.floor; local pairs, ipairs = pairs, ipairs; @@ -40,6 +41,10 @@ function array_mt.__add(a1, a2) end function array_mt.__eq(a, b) + if getmetatable(a) ~= array_mt or getmetatable(b) ~= array_mt then + -- Lua 5.3+ calls this if both operands are tables, even if metatables differ + return false; + end if #a == #b then for i = 1, #a do if a[i] ~= b[i] then -- cgit v1.2.3