Moduli:table/getUnprotectedMetatable

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local _getmetatable = debug.getmetatable

-- For testing (and just in case it gets enabled). 
if _getmetatable ~= nil then
	-- Avoid debug.getmetatable() throwing an error if 0 arguments are passed,
	-- for parity with the other function.
	return function(t)
		return _getmetatable(t)
	end
end

_getmetatable = getmetatable
local pcall = pcall
local rawget = rawget
local setmetatable = setmetatable
local type = type

--[==[
Attempts to retrieve the input value's metatable, and returns it if found. If the value does not have a metatable, returns {nil}. If the input value does have a metatable, but that metatable is not possible to retrieve because it is protected with the `__metatable` metamethod, returns {false}.

This is a useful way to ensure that functions can reliably distinguish between objects that do not have metamethods, objects with known metamethods, and objects with unknown metamethods.]==]
return function(t)
	local mt = _getmetatable(t)
	-- If `mt` is nil, there's no metatable.
	if mt == nil then
		return nil
	-- If `mt` is not a table, the real metatable is protected and there's no
	-- way of retrieving it.
	elseif type(mt) ~= "table" then
		return false
	end
	-- Try setting `mt` as the metatable with `setmetatable`; if the metatable
	-- is protected, this will cause an error to be thrown (revealing it as
	-- protected), and if it isn't, then `mt` must be the real metatable anyway,
	-- so nothing has changed. Also make a special exception for data loaded via
	-- mw.loadData(), which sets each metatable at its own __metatable key as a
	-- way to stop the use of setmetatable() without actually hiding it. This is
	-- spoofable, but low-risk.
	return (pcall(setmetatable, t, mt) or rawget(mt, "mw_loadData") == true) and mt or false
end