The combination of right click to place an item in a frame and left click to pop off the item frame appears to cause items to permanently disappear from my inventory without being placed or dropped anywhere.

What I expected to happen was...:
I expect the item to be placed in the item frame and immediately popped back off... or, the item frame to pop off first and I keep my item.

What actually happened was...:
If you press left and right at around the same time, the item is removed from my inventory, and instead of popping off the item, the whole item frame pops off instead.

Additionally, the item is completely destroyed (not in inventory os as inventory). I can confirm this with the following test:

1. /gamerule doMobLoot false (prevent chicken eggs from messing us up)
2. /kill @e
3. Respawn
4. /kill @e[type=Item]
5. Place item frame and press both buttons as described
6. Pick up the item frame
7. /tp @p @e[type=Item] -> Gives an error since no Item entities exist.
8. Relog and notice that the item is still gone (not a client side error)

Steps to Reproduce:

1. Open a new singleplayer survival world with cheats.
2. /give @p minecraft:item_frame
3. /give @p minecraft:bucket (or your favorite item)
4. place the item frame on a wall.
5. With the bucket, press both mouse buttons with the right button pressed slightly earlier than the left.
6. If the item did not place, or if the item pops out the timing was off. It may take a few tries to get it.