Ok, so most of us know and loathe the guild bank's lack of a stacking system. Further, most of us know that this feature was removed because of an item duplication glitch involving multiple players modifying the guild bank simultaneously. This is an extremely common problem in threaded programming, one that is solved using mutually exclusive access and locks.
As a possible solution to this problem, I suggest the addition of a bank stacking feature which would "lock" the bank to everybody except the guild leader (as there can only be ONE guild leader). Clearly, this feature would only be available to the guild leader. That way the guild leader can then stack the items in the bank (with one click) without ZOS having to worry about anybody simultaneously modifying the bank at the same time, thus eliminating the possibility of a duplication. Then the bank could be unlocked and access restored to other guild members.
A good thing about this solution is that it doesn't require any changes to the way the way the items are fetched from the database, so it shouldn't require modifying any, or much, pre-existing code. This limits the chances of breaking already working code and makes the change very easy to undo should it prove to cause issues. It's at little bulky, but it's nothing compared to the horrible bandage of a fix we currently are dealing with. This feature could even be packaged tidily into a single stack button which would lock the bank, kick out other members currently accessing it, stack the items, and then unlock the bank.
Any response from ZOS on whether this would be a viable solution or whether any other real solution to the problem is in works would be greatly appreciated.