exclusivity

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@537023 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/filters/StripLineComments.java

@@ -208,6 +208,9 @@ public final class StripLineComments
          * Must not be <code>null</code>.
          */
         public final void setValue(String comment) {
+            if (value != null) {
+                throw new IllegalStateException("Comment value already set.");
+            }
             value = comment;
         }
 

src/tests/antunit/filters/striplinecomments-test.xml

@@ -55,4 +55,14 @@ REMark
     </test>
   </target>
 
+  <target name="testExclusivity">
+    <au:expectfailure>
+      <filterchain>
+        <striplinecomments>
+          <comment value="#">#"</comment>
+        </striplinecomments>
+      </filterchain>
+    </au:expectfailure>
+  </target>
+
 </project>