protection against wrong word hash length

see http://www.yacy-forum.de/viewtopic.php?p=35657#35657

git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@3723 6c8d7289-2bf4-0310-a012-ef5d649a1542

source/de/anomic/plasma/plasmaWordIndex.java

@@ -54,6 +54,7 @@ import de.anomic.plasma.urlPattern.plasmaURLPattern;
 import de.anomic.server.logging.serverLog;
 import de.anomic.server.serverMemory;
 import de.anomic.yacy.yacyDHTAction;
+import de.anomic.yacy.yacySeedDB;
 
 public final class plasmaWordIndex implements indexRI {
 
@@ -323,6 +324,10 @@ public final class plasmaWordIndex implements indexRI {
     }
     
     public indexContainer getContainer(String wordHash, Set urlselection, long maxTime) {
+        if ((wordHash == null) || (wordHash.length() != yacySeedDB.commonHashLength)) {
+            // wrong input
+            return null;
+        }
         
         // get from cache
         indexContainer container;