Fix rare dimension switch inconsistencies

Fixes #3161

core/src/main/java/org/geysermc/geyser/session/GeyserSession.java

@@ -155,7 +155,6 @@ import org.geysermc.geyser.inventory.recipe.GeyserStonecutterData;
 import org.geysermc.geyser.level.JavaDimension;
 import org.geysermc.geyser.level.WorldManager;
 import org.geysermc.geyser.level.physics.CollisionManager;
-import org.geysermc.geyser.network.GameProtocol;
 import org.geysermc.geyser.network.netty.LocalSession;
 import org.geysermc.geyser.registry.Registries;
 import org.geysermc.geyser.registry.type.BlockMappings;

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

@@ -83,11 +83,8 @@ public class JavaRespawnTranslator extends PacketTranslator<ClientboundRespawnPa
 
         String newDimension = packet.getDimension();
         if (!session.getDimension().equals(newDimension) || !packet.getWorldName().equals(session.getWorldName())) {
-            // Switching to a new world (based off the world name change); send a fake dimension change
-            if (!packet.getWorldName().equals(session.getWorldName()) && (session.getDimension().equals(newDimension)
-                    // Ensure that the player never ever dimension switches to the same dimension - BAD
-                    // Can likely be removed if the Above Bedrock Nether Building option can be removed
-                    || DimensionUtils.javaToBedrock(session.getDimension()) == DimensionUtils.javaToBedrock(newDimension))) {
+            // Switching to a new world (based off the world name change or new dimension); send a fake dimension change
+            if (DimensionUtils.javaToBedrock(session.getDimension()) == DimensionUtils.javaToBedrock(newDimension)) {
                 String fakeDim = DimensionUtils.getTemporaryDimension(session.getDimension(), newDimension);
                 DimensionUtils.switchDimension(session, fakeDim);
             }

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

@@ -208,7 +208,9 @@ public class DimensionUtils {
             // Prevents rare instances of Bedrock locking up
             return javaToBedrock(newDimension) == 2 ? OVERWORLD : NETHER;
         }
-        return currentDimension.equals(OVERWORLD) ? NETHER : OVERWORLD;
+        // Check current Bedrock dimension and not just the Java dimension.
+        // Fixes rare instances like https://github.com/GeyserMC/Geyser/issues/3161
+        return javaToBedrock(currentDimension) == 0 ? NETHER : OVERWORLD;
     }
 
     public static boolean isCustomBedrockNetherId() {