The bug

When a experience orb is summoned with negative experience value, this experience doesn't decrease player's experience. Despite that gear enchanted with Mending entchantment does lose it's durability.

How to reproduce

• Do summon minecraft:experience_orb ~ ~ ~ {Value:-60}on a repeating command block and activate it
• Watch your experience bar 

Notice how your experience doesn't decrease but it stays the same

Observed behavior

Experience orbs with negative value doesn't decrease player's experience

Expected behavior

Experience orbs with negative value does decrease player's experience