util.signal: Fix signalfd closure on non-Linux systems The loop was incorrect for 0-indexed arrays. It started at signalfd_num, which is the total number of signalfds, and decremented to 1 (condition was >0). So if 1 signalfd was registered, it would check only signalfds[1]. At capacity (32 signalfds) it would read past the end of the array. In every case, it would always skip the entry at position [0], leading to a leak. The swap-with-tail removal of the matched item used the post-decrement operator, leading to accessing the array slot just beyond the tail. Finally, it didn't break after finding a match. Probably harmless, but there isn't expected to be more than a single entry per fd, as far as I can tell.

-- Enables SQL query logging
--
-- luacheck: ignore 213/uri

module:set_global();

local engines = module:shared("/*/sql/connections");

for uri, engine in pairs(engines) do
	engine:debug(true);
end

setmetatable(engines, {
	__newindex = function (t, uri, engine)
		engine:debug(true);
		rawset(t, uri, engine);
	end
});

function module.unload()
	setmetatable(engines, nil);
	for uri, engine in pairs(engines) do
		engine:debug(false);
	end
end