Affects Version/s: Minecraft 16w44a
Fix Version/s: Minecraft 1.11 Pre-Release 1
Mac OS Sierra
Go into minecraft (creative, survival also affected but just for ease)
grab an item (single item) and swing your cursor left and right while trying to drop an item off into a slot in your inventory
in 16w44a the item does not get dropped from the mouse.
in 16w43a it did drop into the correct slot from the mouse.
This shows the new and old behaviour