Fix sleeping on older Minecraft server versions (#2049)

BED_POSITION is enough to trigger sleep.

connector/src/main/java/org/geysermc/connector/entity/Entity.java

@@ -331,15 +331,12 @@ public class Entity {
             case 6: // Pose change
                 if (entityMetadata.getValue().equals(Pose.SLEEPING)) {
                     metadata.getFlags().setFlag(EntityFlag.SLEEPING, true);
-                    // Has to be a byte or it does not work
-                    metadata.put(EntityData.PLAYER_FLAGS, (byte) 2);
                     metadata.put(EntityData.BOUNDING_BOX_WIDTH, 0.2f);
                     metadata.put(EntityData.BOUNDING_BOX_HEIGHT, 0.2f);
                 } else if (metadata.getFlags().getFlag(EntityFlag.SLEEPING)) {
                     metadata.getFlags().setFlag(EntityFlag.SLEEPING, false);
                     metadata.put(EntityData.BOUNDING_BOX_WIDTH, getEntityType().getWidth());
                     metadata.put(EntityData.BOUNDING_BOX_HEIGHT, getEntityType().getHeight());
-                    metadata.put(EntityData.PLAYER_FLAGS, (byte) 0);
                 }
                 break;
         }

connector/src/main/java/org/geysermc/connector/entity/LivingEntity.java

@@ -99,6 +99,13 @@ public class LivingEntity extends Entity {
                         // Bed has to be updated, or else player is floating in the air
                         ChunkUtils.updateBlock(session, bed, bedPosition);
                     }
+                    // Indicate that the player should enter the sleep cycle
+                    // Has to be a byte or it does not work
+                    // (Bed position is what actually triggers sleep - "pose" is only optional)
+                    metadata.put(EntityData.PLAYER_FLAGS, (byte) 2);
+                } else {
+                    // Player is no longer sleeping
+                    metadata.put(EntityData.PLAYER_FLAGS, (byte) 0);
                 }
                 break;
         }

connector/src/main/java/org/geysermc/connector/network/translators/java/entity/JavaEntityMetadataTranslator.java

@@ -39,9 +39,11 @@ public class JavaEntityMetadataTranslator extends PacketTranslator<ServerEntityM
 
     @Override
     public void translate(ServerEntityMetadataPacket packet, GeyserSession session) {
-        Entity entity = session.getEntityCache().getEntityByJavaId(packet.getEntityId());
+        Entity entity;
         if (packet.getEntityId() == session.getPlayerEntity().getEntityId()) {
             entity = session.getPlayerEntity();
+        } else {
+            entity = session.getEntityCache().getEntityByJavaId(packet.getEntityId());
         }
         if (entity == null) return;