use new token update methods (#4599)

Author: pjfanning

src/main/java/com/fasterxml/jackson/databind/node/TreeTraversingParser.java

@@ -92,7 +92,7 @@ public void close() throws IOException
         if (!_closed) {
             _closed = true;
             _nodeCursor = null;
-            _currToken = null;
+            _updateTokenToNull();
         }
     }
 
@@ -105,7 +105,7 @@ public void close() throws IOException
     @Override
     public JsonToken nextToken() throws IOException
     {
-        _currToken = _nodeCursor.nextToken();
+        _updateToken(_nodeCursor.nextToken());
         if (_currToken == null) {
             _closed = true; // if not already set
             return null;
@@ -133,10 +133,10 @@ public JsonParser skipChildren() throws IOException
     {
         if (_currToken == JsonToken.START_OBJECT) {
             _nodeCursor = _nodeCursor.getParent();
-            _currToken = JsonToken.END_OBJECT;
+            _updateToken(JsonToken.END_OBJECT);
         } else if (_currToken == JsonToken.START_ARRAY) {
             _nodeCursor = _nodeCursor.getParent();
-            _currToken = JsonToken.END_ARRAY;
+            _updateToken(JsonToken.END_ARRAY);
         }
         return this;
     }

src/main/java/com/fasterxml/jackson/databind/util/TokenBuffer.java

@@ -1641,7 +1641,7 @@ public JsonToken nextToken() throws IOException
                     return null;
                 }
             }
-            _currToken = _segment.type(_segmentPtr);
+            _updateToken(_segment.type(_segmentPtr));
             // Field name? Need to update context
             if (_currToken == JsonToken.FIELD_NAME) {
                 Object ob = _currentObject();
@@ -1672,7 +1672,7 @@ public String nextFieldName() throws IOException
             int ptr = _segmentPtr+1;
             if ((ptr < Segment.TOKENS_PER_SEGMENT) && (_segment.type(ptr) == JsonToken.FIELD_NAME)) {
                 _segmentPtr = ptr;
-                _currToken = JsonToken.FIELD_NAME;
+                _updateToken(JsonToken.FIELD_NAME);
                 Object ob = _segment.get(ptr); // inlined _currentObject();
                 String name = (ob instanceof String) ? ((String) ob) : ob.toString();
                 _parsingContext.setCurrentName(name);