I would just like to ask what would happen if Walock uses Lvl7 Snatch(1hr) on a target with buff that lasts for 30mins only. Would the stolen buff last for 1hr on the warlock?

If yes, the stolen buff would last on warlock for 1hr, how about if the warlock Snatches a buff the lasts 15 secs of the target, (those short durations buffs). Would it last 1hr on the warlock or just 15 secs?

If it is 15 secs on this example, and on the other scenario it lasts 1hr (from stolen 30 min buff), it appears it is not consistent. How would we know, if a buff would last as 1hr, or just use the real duration of the buff?