What I expected to happen was...:
Pressing q while hovering over my hot bar inventory stack would throw one item out onto the game field regardless of the selected inventory page.
What actually happened was...:
Stack inventory count was decreased, even to zero, but no objects were created in the actual game.
Steps to Reproduce:
1. In Creative mode, have some items in your hot bar.
2. Make sure you are on any inventory page except 'Survival Inventory' or 'Search'.
3. Hover your mouse over the items in your hot bar and press q.
4. Notice that the item count in your hot bar decreases, but no items fly from you into the world around you.
Interestingly, you can hold down q and quickly make all your items disappear into nothing. I don't remember if holding down q was an option previously, but I do like it as a feature. I just wish the items actually were tossed out appropriately.
Related issues
is duplicated by
Comments
Confirmed for 14w19a.

Confirmed for 14w32d.
May be related to MC-5415

Confirmed for:
Minecraft 1.8-pre 2

Confirmed for 1.8. Also if you press Q several times (in non search or survival inventory) and then press Q in the survival inventory and pick it up, you will get 2 items back for each item dropped in the survival inventory (regardless of type).

Confirmed for 1.8.1 and 1.8.2-pre1. Your hand moves up and down (like when you normally throw items), but the items simply get deleted instead of thrown out.
still present in 1.9

Attempting to drop an item when in creative will result in that "dropped" item being dropped back into the unlimited items which I think is actually normal because when you take an item from the creative inventory and try to drop it in said inventory, it does delete the item anyway. To drop an item to the ground from the creative inventory you would have to click on your inventory and ctrl+q but there is a bug where if you do this the items double here MC-5415 . As far as the item not showing up on the ground, i think this is actually not really a bug. But perhaps as qmagnet suggested, these two tickets might actually be related in some way?
Confirmed for:
1.10-pre1
1.10-pre2
Confirmed for 1.10
Confirmed.