When in the inventory, you have to drag items by holding onto the mouse where as in previous versions before 1.8.4, you could do this without holding onto the mouse.
MC-80676
Dragging items in the inventory
Resolved
Duplicate
0
Misha Higham
(Unassigned)
Unconfirmed
Minecraft 1.8.4, Minecraft 1.8.5, Minecraft 1.8.6
Retrieved
Disable touchscreen mode in the settings.