Handle connection error in pool:get()

[Totktonada]

See the code:

mysql/mysql/init.lua

Lines 31 to 46 in 9ca113b

	-- get connection from pool
	local function conn_get(pool, timeout)
	local mysql_conn = pool.queue:get(timeout)
	-- A timeout was reached.
	if mysql_conn == nil then return nil end
	local status
	if mysql_conn == POOL_EMPTY_SLOT then
	status, mysql_conn = driver.connect(pool.host, pool.port or 0,
	pool.user, pool.pass,
	pool.db, pool.use_numeric_result)
	if status < 0 then
	return error(mysql_conn)
	end
	end

When we got POOL_EMPTY_SLOT from the pool and a connection error occurs, we don't return the slot back to the pool.