LMS-1783 bug revealed in system tests fixed

SVN: 19126

openbis/source/java/ch/systemsx/cisd/openbis/generic/client/web/client/application/ui/TypedTableGrid.java

@@ -84,7 +84,7 @@ public abstract class TypedTableGrid<T extends ISerializable>
 
         public String tryGetLink(T entity, final ISerializableComparable value)
         {
-            if (value == null)
+            if (value == null || value.toString().length() == 0)
             {
                 return null;
             }