Hunger saturation depletes on peaceful difficulty

Confirmed
Harder to reproduce since Hunger is restoring now, but still an issue.

Is this still an issue in 1.9 or 1.9.1-pre3?

Ticket resolved as incomplete, because no answer in a reasonable amount of time (1+ year), if it still happens, please update the ticket.

Can confirm that this issue is still present in 1.18.1. Since the current reproduction steps are quite unreliable, below, I've provided a consistent method of recreating this problem. Just for clarification purposes, when reproducing this, the hunger bar will remain full and will not visually change, but will shake very subtly.

Steps to Reproduce:

• Change the difficulty to peaceful and run /kill to reset all player stats.

/difficulty peaceful
/kill

• Take lots of fall damage by teleporting yourself high up in the air.

/tp @s ~ ~23 ~

• Watch your hunger bar closely.

• Take note as to whether or not the hunger bar shakes (hunger saturation depletes) whilst playing on peaceful difficulty.

Here's a code analysis of this issue.

Code Analysis:

The following is based on a decompiled version of Minecraft 1.19.2 using MCP-Reborn.

net.minecraft.world.entity.player.Player.java

public abstract class Player extends LivingEntity {
   ...
   public void aiStep() {
      ...
      if (this.level.getDifficulty() == Difficulty.PEACEFUL && this.level.getGameRules().getBoolean(GameRules.RULE_NATURAL_REGENERATION)) {
         if (this.getHealth() < this.getMaxHealth() && this.tickCount % 20 == 0) {
            this.heal(1.0F);
         }

         if (this.foodData.needsFood() && this.tickCount % 10 == 0) {
            this.foodData.setFoodLevel(this.foodData.getFoodLevel() + 1);
         }
      }
      ...

If we look at the above class, we can see that when in peaceful mode, players will regenerate 1 health every 20 ticks if their health is not currently full and will additionally regenerate 1 hunger every 10 ticks if their hunger is not currently full as well. The game doesn't replenish the player's saturation level when in peaceful difficulty, causing it to be able to decrease, and upon it reaching 0, the hunger bar starts shaking.

Can confirm in 1.18.2.

@Avoma already stated a potential fix, although with a very minor code syntax error.

Can confirm in 1.18.2.