fix for http://forum.yacy-websuche.de/viewtopic.php?f=6&t=1915&hilit=&p=13249#p13249

git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@5684 6c8d7289-2bf4-0310-a012-ef5d649a1542

source/de/anomic/kelondro/text/IndexCache.java

@@ -305,6 +305,7 @@ public final class IndexCache implements Index, IndexReader, Iterable<ReferenceC
     }
 
     public synchronized void addEntry(final String wordHash, final ReferenceRow newEntry, final long updateTime, final boolean dhtCase) {
+        if (heap == null) return; // there was already a shutdown
         heap.addEntry(wordHash, newEntry);
         hashScore.incScore(wordHash);
         hashDate.setScore(wordHash, intTime(updateTime));