Index: main/org/apache/tools/ant/taskdefs/Filter.java
===================================================================
RCS file: /home/cvspublic/jakarta-ant/src/main/org/apache/tools/ant/taskdefs/Filter.java,v
retrieving revision 1.2
diff -u -r1.2 Filter.java
--- main/org/apache/tools/ant/taskdefs/Filter.java	2000/09/14 07:19:52	1.2
+++ main/org/apache/tools/ant/taskdefs/Filter.java	2000/09/16 17:48:45
@@ -76,6 +76,10 @@
     }
 
     public void execute() throws BuildException {
+        if (token == null || value == null) {
+            throw new BuildException("token and value are required", location);
+        }
+
         project.addFilter(token, value);
     }
 }