UDP fixes: we can only stop transmitting the mappings sent in the

acknowledged datagram (not the ones before it, which may or may 
not have been received).  Also, make sure we don't throw an 
ArrayIndexOutOfBounds exception when retrieving a bogus class 
mapping (so that we show the correct error logging information).


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5751 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/io/ObjectInputStream.java

@@ -143,7 +143,7 @@ public class ObjectInputStream extends DataInputStream
             return mapClass(code, cname);
 
         } else {
-            ClassMapping cmap = _classmap.get(code);
+            ClassMapping cmap = (code < _classmap.size()) ? _classmap.get(code) : null;
 
             // sanity check
             if (cmap == null) {

src/java/com/threerings/presents/util/DatagramSequencer.java

@@ -101,7 +101,7 @@ public class DatagramSequencer
                 break;
             }
             remove++;
-            if (sendrec.mappedClasses != null) {
+            if (sendrec.number == received && sendrec.mappedClasses != null) {
                 _uout.noteMappingsReceived(sendrec.mappedClasses);
             }
         }