Fix: Bedrock players being able to always eat food while in peaceful difficulty (#4904)

core/src/main/java/org/geysermc/geyser/translator/protocol/bedrock/BedrockServerSettingsRequestTranslator.java

@@ -27,12 +27,14 @@ package org.geysermc.geyser.translator.protocol.bedrock;
 
 import org.cloudburstmc.protocol.bedrock.packet.ServerSettingsRequestPacket;
 import org.cloudburstmc.protocol.bedrock.packet.ServerSettingsResponsePacket;
+import org.cloudburstmc.protocol.bedrock.packet.SetDifficultyPacket;
 import org.geysermc.cumulus.form.CustomForm;
 import org.geysermc.cumulus.form.impl.FormDefinitions;
 import org.geysermc.geyser.session.GeyserSession;
 import org.geysermc.geyser.translator.protocol.PacketTranslator;
 import org.geysermc.geyser.translator.protocol.Translator;
 import org.geysermc.geyser.util.SettingsUtils;
+import org.geysermc.mcprotocollib.protocol.data.game.setting.Difficulty;
 
 import java.util.concurrent.TimeUnit;
 
@@ -47,6 +49,14 @@ public class BedrockServerSettingsRequestTranslator extends PacketTranslator<Ser
             return;
         }
 
+        // Peaceful difficulty allows always eating food - hence, we just do not send it to Bedrock.
+        // However, in order for server settings to show it properly, let's revert while we are in the menu!
+        if (session.getWorldCache().getDifficulty() == Difficulty.PEACEFUL) {
+            SetDifficultyPacket setDifficultyPacket = new SetDifficultyPacket();
+            setDifficultyPacket.setDifficulty(Difficulty.PEACEFUL.ordinal());
+            session.sendUpstreamPacket(setDifficultyPacket);
+        }
+
         CustomForm form = SettingsUtils.buildForm(session);
         int formId = session.getFormCache().addForm(form);
 

core/src/main/java/org/geysermc/geyser/translator/protocol/java/JavaChangeDifficultyTranslator.java

@@ -25,21 +25,29 @@
 
 package org.geysermc.geyser.translator.protocol.java;
 
-import org.geysermc.mcprotocollib.protocol.packet.ingame.clientbound.ClientboundChangeDifficultyPacket;
 import org.cloudburstmc.protocol.bedrock.packet.SetDifficultyPacket;
 import org.geysermc.geyser.session.GeyserSession;
 import org.geysermc.geyser.translator.protocol.PacketTranslator;
 import org.geysermc.geyser.translator.protocol.Translator;
+import org.geysermc.mcprotocollib.protocol.data.game.setting.Difficulty;
+import org.geysermc.mcprotocollib.protocol.packet.ingame.clientbound.ClientboundChangeDifficultyPacket;
 
 @Translator(packet = ClientboundChangeDifficultyPacket.class)
 public class JavaChangeDifficultyTranslator extends PacketTranslator<ClientboundChangeDifficultyPacket> {
 
     @Override
     public void translate(GeyserSession session, ClientboundChangeDifficultyPacket packet) {
+        Difficulty difficulty = packet.getDifficulty();
+        session.getWorldCache().setDifficulty(difficulty);
+
+        // Peaceful difficulty allows always eating food - hence, we just do not send it to Bedrock.
+        if (difficulty == Difficulty.PEACEFUL) {
+            difficulty = Difficulty.EASY;
+        }
+
         SetDifficultyPacket setDifficultyPacket = new SetDifficultyPacket();
-        setDifficultyPacket.setDifficulty(packet.getDifficulty().ordinal());
+        setDifficultyPacket.setDifficulty(difficulty.ordinal());
         session.sendUpstreamPacket(setDifficultyPacket);
 
-        session.getWorldCache().setDifficulty(packet.getDifficulty());
     }
 }

core/src/main/java/org/geysermc/geyser/util/SettingsUtils.java

@@ -25,6 +25,7 @@
 
 package org.geysermc.geyser.util;
 
+import org.cloudburstmc.protocol.bedrock.packet.SetDifficultyPacket;
 import org.geysermc.cumulus.component.DropdownComponent;
 import org.geysermc.cumulus.form.CustomForm;
 import org.geysermc.geyser.GeyserImpl;
@@ -33,6 +34,7 @@ import org.geysermc.geyser.level.WorldManager;
 import org.geysermc.geyser.session.GeyserSession;
 import org.geysermc.geyser.text.GeyserLocale;
 import org.geysermc.geyser.text.MinecraftLocale;
+import org.geysermc.mcprotocollib.protocol.data.game.setting.Difficulty;
 
 public class SettingsUtils {
     /**
@@ -96,6 +98,7 @@ public class SettingsUtils {
         }
 
         builder.validResultHandler((response) -> {
+            applyDifficultyFix(session);
             if (showClientSettings) {
                 // Client can only see its coordinates if reducedDebugInfo is disabled and coordinates are enabled in geyser config.
                 if (showCoordinates) {
@@ -134,9 +137,21 @@ public class SettingsUtils {
             }
         });
 
+        builder.closedOrInvalidResultHandler($ -> applyDifficultyFix(session));
+
         return builder.build();
     }
 
+    private static void applyDifficultyFix(GeyserSession session) {
+        // Peaceful difficulty allows always eating food - hence, we just do not send it to Bedrock.
+        // Since we sent the real difficulty before opening the server settings form, let's restore it to our workaround here
+        if (session.getWorldCache().getDifficulty() == Difficulty.PEACEFUL) {
+            SetDifficultyPacket setDifficultyPacket = new SetDifficultyPacket();
+            setDifficultyPacket.setDifficulty(Difficulty.EASY.ordinal());
+            session.sendUpstreamPacket(setDifficultyPacket);
+        }
+    }
+
     private static String translateEntry(String key, String locale) {
         if (key.startsWith("%")) {
             // Bedrock will translate