Opening the trading GUI while holding items causes one to consume, charge or use it

The bug

Having items in your main hand or offhand will consume, charge or use that item when opening the trading GUI with a villager.

How to reproduce

1. Summon a villager

   /summon villager ~ ~1 ~ {NoAI:1,Offers:{Recipes:[{buy:{id:air,Count:0},sell:{id:air,Count:0}}]}}
   

2. Run /effect give @s minecraft:hunger 5 255 (Only needed for food items)
3. Pick an item from "Affected Items"
4. Right click the summoned villager
5. Wait (If the item is a food or potion)
   → You will consume, charge or use the item

Affected Items

• Food and potions (Causes you to consume the item)
• Fishing rod in main hand or offhand (Causes you to use the fishing rod)
• Trident in offhand (Causes you to charge the trident)
• Bow in offhand (Causes you to charge the bow)

See Minecraft 1.14 2019-04-26 01-12-38.mp4 if you have trouble reproducing.