To reproduce, simply open your inventory, open the recipe interface, and click an item to pick it up. Move your cursor over to the recipe interface and right-click (or left-click). The item will be dropped.
The expected behavior is that nothing would happen, because right/left-clicking in similar areas inside the normal part of the GUI do not drop the item.
tryashtar
migrated
Whoa, this report isn't about clicking on buttons also dropping things, this report is about the fact that items can be dropped anywhere in the recipe interface – even with right-click when you aren't interacting with any buttons.
EDIT: If you think they're similar enough to be merged, would you mind adding this information to the description of MC-115025?