I believe this is inventory tweak's realm, but I am not sure. The feature I am talking about is picking up a stack and moving it to another inventory and holding shift when you place the stack down. It moves all of the same item into the inventory.

I love this feature but it is really really unreliable, no matter how much I make sure my cursor is perfectly centered in the inventory slot 50% of the time it throws all of the items on the ground instead of transferring them. Whenever I attempt this the inventory slot I am moving to is always highlighted under my cursor and the item stackk yet it still tosses all of the items on the ground randomly instead of moving them.

Not inventory tweaks -- no plain shift shortcut, and none of them trigger while clicking an empty slot.

The 'move all of an item' shortcut is either ctrl+shift or space by default, and works when you click that item type in the source area, not while trying to place it.