Fix shields not being for the right entity >.> and also print out value for metadata

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/metadata/MetadataRewriter.java

@@ -21,6 +21,7 @@ public class MetadataRewriter {
         for (Metadata entry : new ArrayList<>(list)) {
             MetaIndex metaIndex = MetaIndex.getIndex(type, entry.getId());
             try {
+                if (metaIndex != null) {
                     if (metaIndex.getNewType() != NewType.Discontinued) {
                         if (metaIndex.getNewType() != NewType.BlockID || id != -1 && data == -1 || id == -1 && data != -1) { // block ID is only written if we have both parts
                             entry.setId(metaIndex.getNewIndex());
@@ -135,6 +136,9 @@ public class MetadataRewriter {
                     } else {
                         list.remove(entry);
                     }
+                } else {
+                    throw new Exception("Could not find valid metadata");
+                }
             } catch (Exception e) {
                 list.remove(entry);
                 if (!((ViaVersionPlugin) ViaVersion.getInstance()).isSuppressMetadataErrors()) {
@@ -144,6 +148,7 @@ public class MetadataRewriter {
                     else
                         System.out.println("An error occurred with entity meta data for UNKNOWN_ENTITY OldID: " + entry.getId());
                     if (metaIndex != null) {
+                        System.out.println("Value: " + entry.getValue());
                         System.out.println("Old ID: " + metaIndex.getIndex() + " New ID: " + metaIndex.getNewIndex());
                         System.out.println("Old Type: " + metaIndex.getOldType() + " New Type: " + metaIndex.getNewType());
                     }

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/storage/EntityTracker.java

@@ -54,6 +54,10 @@ public class EntityTracker extends StoredObject {
     }
 
     public void setSecondHand(Item item) {
+        setSecondHand(entityID, item);
+    }
+
+    public void setSecondHand(int entityID, Item item) {
         PacketWrapper wrapper = new PacketWrapper(0x3C, null, getUser());
         wrapper.write(Type.VAR_INT, entityID);
         wrapper.write(Type.VAR_INT, 1); // slot
@@ -106,10 +110,10 @@ public class EntityTracker extends StoredObject {
                         if ((data & 0x10) == 0x10) {
                             if (validBlocking.contains(entityID)) {
                                 Item shield = new Item((short) 442, (byte) 1, (short) 0, null);
-                                setSecondHand(shield);
+                                setSecondHand(entityID, shield);
                             }
                         } else {
-                            setSecondHand(null);
+                            setSecondHand(entityID, null);
                         }
                     }
                 }