Minor improvements and fixes

networking/src/main/java/ch/dissem/bitmessage/networking/AbstractConnection.java

@@ -145,7 +145,7 @@ public abstract class AbstractConnection {
         updateIvCache(inv.getInventory());
         List<InventoryVector> missing = ctx.getInventory().getMissing(inv.getInventory(), streams);
         missing.removeAll(commonRequestedObjects);
-        LOG.debug("Received inventory with " + originalSize + " elements, of which are "
+        LOG.trace("Received inventory with " + originalSize + " elements, of which are "
             + missing.size() + " missing.");
         send(new GetData.Builder().inventory(missing).build());
     }

networking/src/main/java/ch/dissem/bitmessage/networking/nio/ConnectionInfo.java

@@ -135,6 +135,7 @@ public class ConnectionInfo extends AbstractConnection {
             reader.cleanup();
             reader = null;
         }
+        payloadOut = null;
     }
 
     public boolean isSyncFinished() {

networking/src/main/java/ch/dissem/bitmessage/networking/nio/NioNetworkHandler.java

@@ -239,8 +239,8 @@ public class NioNetworkHandler implements NetworkHandler, InternalContext.Contex
                             }
                             e.getValue().cancel();
                             e.getValue().attach(null);
-                            it.remove();
                             e.getKey().disconnect();
+                            it.remove();
                         }
                     }
                     try {
@@ -387,12 +387,20 @@ public class NioNetworkHandler implements NetworkHandler, InternalContext.Contex
                 distribution.put(connection, new LinkedList<InventoryVector>());
             }
         }
+        if (distribution.isEmpty()){
+            return;
+        }
         InventoryVector next = iterator.next();
         ConnectionInfo previous = null;
         do {
             for (ConnectionInfo connection : distribution.keySet()) {
                 if (connection == previous || previous == null) {
-                    next = iterator.next();
+                    if (iterator.hasNext()) {
+                        previous = connection;
+                        next = iterator.next();
+                    } else {
+                        break;
+                    }
                 }
                 if (connection.knowsOf(next)) {
                     List<InventoryVector> ivs = distribution.get(connection);