diff --git a/src/main/org/apache/tools/ant/taskdefs/optional/extension/ExtensionAdapter.java b/src/main/org/apache/tools/ant/taskdefs/optional/extension/ExtensionAdapter.java
index 0f00b557e..c9f548e99 100644
--- a/src/main/org/apache/tools/ant/taskdefs/optional/extension/ExtensionAdapter.java
+++ b/src/main/org/apache/tools/ant/taskdefs/optional/extension/ExtensionAdapter.java
@@ -160,23 +160,6 @@ public class ExtensionAdapter extends DataType {
             || null != implementationURL) {
             throw tooManyAttributes();
         }
-        // change this to get the objects from the other reference
-        Object o = reference.getReferencedObject(getProject());
-        if (o instanceof ExtensionAdapter) {
-            final ExtensionAdapter other = (ExtensionAdapter) o;
-            extensionName = other.extensionName;
-            specificationVersion = other.specificationVersion;
-            specificationVendor = other.specificationVendor;
-            implementationVersion = other.implementationVersion;
-            implementationVendorID = other.implementationVendorID;
-            implementationVendor = other.implementationVendor;
-            implementationURL = other.implementationURL;
-        } else {
-            final String message =
-                reference.getRefId() + " doesn\'t refer to a Extension";
-            throw new BuildException(message);
-        }
-
         super.setRefid(reference);
     }
 
@@ -194,6 +177,10 @@ public class ExtensionAdapter extends DataType {
      */
     Extension toExtension()
         throws BuildException {
+        if (isReference()) {
+            return ((ExtensionAdapter) getCheckedRef()).toExtension();
+        }
+        dieOnCircularReference();
         if (null == extensionName) {
             final String message = "Extension is missing name.";
             throw new BuildException(message);
diff --git a/src/main/org/apache/tools/ant/taskdefs/optional/extension/ExtensionSet.java b/src/main/org/apache/tools/ant/taskdefs/optional/extension/ExtensionSet.java
index 069f095fa..743edd95e 100644
--- a/src/main/org/apache/tools/ant/taskdefs/optional/extension/ExtensionSet.java
+++ b/src/main/org/apache/tools/ant/taskdefs/optional/extension/ExtensionSet.java
@@ -19,6 +19,8 @@ package org.apache.tools.ant.taskdefs.optional.extension;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Iterator;
+import java.util.Stack;
 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.Project;
 import org.apache.tools.ant.types.DataType;
@@ -49,6 +51,10 @@ public class ExtensionSet
      * @param extensionAdapter an extension that this library requires.
      */
     public void addExtension(final ExtensionAdapter extensionAdapter) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         extensions.add(extensionAdapter);
     }
 
@@ -58,6 +64,10 @@ public class ExtensionSet
      * @param fileSet a set of files about which extensions data will be extracted.
      */
     public void addLibfileset(final LibFileSet fileSet) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         extensionsFilesets.add(fileSet);
     }
 
@@ -67,6 +77,10 @@ public class ExtensionSet
      * @param fileSet a set of files about which extensions data will be extracted.
      */
     public void addFileset(final FileSet fileSet) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         extensionsFilesets.add(fileSet);
     }
 
@@ -79,6 +93,10 @@ public class ExtensionSet
      */
     public Extension[] toExtensions(final Project proj)
         throws BuildException {
+        if (isReference()) {
+            return ((ExtensionSet) getCheckedRef()).toExtensions(proj);
+        }
+        dieOnCircularReference();
         final ArrayList extensionsList = ExtensionUtil.toExtensions(extensions);
         ExtensionUtil.extractExtensions(proj, extensionsList, extensionsFilesets);
         return (Extension[]) extensionsList.toArray(new Extension[extensionsList.size()]);
@@ -99,20 +117,26 @@ public class ExtensionSet
         if (!extensions.isEmpty() || !extensionsFilesets.isEmpty()) {
             throw tooManyAttributes();
         }
-        // change this to get the objects from the other reference
-        final Object object =
-            reference.getReferencedObject(getProject());
-        if (object instanceof ExtensionSet) {
-            final ExtensionSet other = (ExtensionSet) object;
-            extensions.addAll(other.extensions);
-            extensionsFilesets.addAll(other.extensionsFilesets);
+        super.setRefid(reference);
+    }
+
+    protected synchronized void dieOnCircularReference(Stack stk, Project p)
+        throws BuildException {
+        if (isChecked()) {
+            return;
+        }
+        if (isReference()) {
+            super.dieOnCircularReference(stk, p);
         } else {
-            final String message =
-                reference.getRefId() + " doesn\'t refer to a ExtensionSet";
-            throw new BuildException(message);
+            for (Iterator i = extensions.iterator(); i.hasNext(); ) {
+                pushAndInvokeCircularReferenceCheck((ExtensionAdapter) i.next(),
+                                                    stk, p);
+            }
+            for (Iterator i = extensionsFilesets.iterator(); i.hasNext(); ) {
+                pushAndInvokeCircularReferenceCheck((FileSet) i.next(), stk, p);
+            }
+            setChecked(true);
         }
-
-        super.setRefid(reference);
     }
 
     /**
diff --git a/src/main/org/apache/tools/ant/taskdefs/optional/junit/FailureRecorder.java b/src/main/org/apache/tools/ant/taskdefs/optional/junit/FailureRecorder.java
index 0a131187c..cf40922de 100644
--- a/src/main/org/apache/tools/ant/taskdefs/optional/junit/FailureRecorder.java
+++ b/src/main/org/apache/tools/ant/taskdefs/optional/junit/FailureRecorder.java
@@ -36,7 +36,7 @@ import org.apache.tools.ant.BuildEvent;
 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.BuildListener;
 import org.apache.tools.ant.Project;
-import org.apache.tools.ant.types.DataType;
+import org.apache.tools.ant.ProjectComponent;
 import org.apache.tools.ant.util.FileUtils;
 
 /**
@@ -67,7 +67,7 @@ import org.apache.tools.ant.util.FileUtils;
  *
  * @since Ant 1.8.0
  */
-public class FailureRecorder extends DataType implements JUnitResultFormatter, BuildListener {
+public class FailureRecorder extends ProjectComponent implements JUnitResultFormatter, BuildListener {
 
     /**
      * This is the name of a magic System property ({@value}). The value of this
diff --git a/src/main/org/apache/tools/ant/types/AbstractFileSet.java b/src/main/org/apache/tools/ant/types/AbstractFileSet.java
index c1d04c0d9..10e5816cc 100644
--- a/src/main/org/apache/tools/ant/types/AbstractFileSet.java
+++ b/src/main/org/apache/tools/ant/types/AbstractFileSet.java
@@ -18,8 +18,10 @@
 package org.apache.tools.ant.types;
 
 import java.io.File;
-import java.util.Vector;
 import java.util.Enumeration;
+import java.util.Iterator;
+import java.util.Stack;
+import java.util.Vector;
 
 import org.apache.tools.ant.Project;
 import org.apache.tools.ant.FileScanner;
@@ -147,7 +149,11 @@ public abstract class AbstractFileSet extends DataType
      * @return <code>File</code>.
      */
     public synchronized File getDir(Project p) {
-        return (isReference()) ? getRef(p).getDir(p) : dir;
+        if (isReference()) {
+            return getRef(p).getDir(p);
+        }
+        dieOnCircularReference();
+        return dir;
     }
 
     /**
@@ -342,8 +348,11 @@ public abstract class AbstractFileSet extends DataType
      * @since Ant 1.6.3
      */
     public synchronized boolean getDefaultexcludes() {
-        return (isReference())
-            ? getRef(getProject()).getDefaultexcludes() : useDefaultExcludes;
+        if (isReference()) {
+            return getRef(getProject()).getDefaultexcludes();
+        }
+        dieOnCircularReference();
+        return useDefaultExcludes;
     }
 
     /**
@@ -368,8 +377,11 @@ public abstract class AbstractFileSet extends DataType
      * @since Ant 1.7
      */
     public synchronized boolean isCaseSensitive() {
-        return (isReference())
-            ? getRef(getProject()).isCaseSensitive() : caseSensitive;
+        if (isReference()) {
+            return getRef(getProject()).isCaseSensitive();
+        }
+        dieOnCircularReference();
+        return caseSensitive;
     }
 
     /**
@@ -394,8 +406,11 @@ public abstract class AbstractFileSet extends DataType
      * @since Ant 1.6
      */
     public synchronized boolean isFollowSymlinks() {
-        return (isReference())
-            ? getRef(getProject()).isFollowSymlinks() : followSymlinks;
+        if (isReference()) {
+            return getRef(getProject()).isCaseSensitive();
+        }
+        dieOnCircularReference();
+        return followSymlinks;
     }
 
     /**
@@ -435,6 +450,7 @@ public abstract class AbstractFileSet extends DataType
         if (isReference()) {
             return getRef(p).getDirectoryScanner(p);
         }
+        dieOnCircularReference();
         DirectoryScanner ds = null;
         synchronized (this) {
             if (directoryScanner != null && p == getProject()) {
@@ -484,6 +500,7 @@ public abstract class AbstractFileSet extends DataType
             getRef(p).setupDirectoryScanner(ds, p);
             return;
         }
+        dieOnCircularReference(p);
         if (ds == null) {
             throw new IllegalArgumentException("ds cannot be null");
         }
@@ -523,8 +540,11 @@ public abstract class AbstractFileSet extends DataType
      * @return whether any selectors are in this container.
      */
     public synchronized boolean hasSelectors() {
-        return (isReference() && getProject() != null)
-            ? getRef(getProject()).hasSelectors() : !(selectors.isEmpty());
+        if (isReference()) {
+            return getRef(getProject()).hasSelectors();
+        }
+        dieOnCircularReference();
+        return !(selectors.isEmpty());
     }
 
     /**
@@ -536,6 +556,7 @@ public abstract class AbstractFileSet extends DataType
         if (isReference() && getProject() != null) {
             return getRef(getProject()).hasPatterns();
         }
+        dieOnCircularReference();
         if (defaultPatterns.hasPatterns(getProject())) {
             return true;
         }
@@ -555,8 +576,11 @@ public abstract class AbstractFileSet extends DataType
      * @return the number of selectors in this container as an <code>int</code>.
      */
     public synchronized int selectorCount() {
-        return (isReference() && getProject() != null)
-            ? getRef(getProject()).selectorCount() : selectors.size();
+        if (isReference()) {
+            return getRef(getProject()).selectorCount();
+        }
+        dieOnCircularReference();
+        return selectors.size();
     }
 
     /**
@@ -565,8 +589,11 @@ public abstract class AbstractFileSet extends DataType
      * @return a <code>FileSelector[]</code> of the selectors in this container.
      */
     public synchronized FileSelector[] getSelectors(Project p) {
-        return (isReference())
-            ? getRef(p).getSelectors(p) : (FileSelector[]) (selectors.toArray(
+        if (isReference()) {
+            return getRef(getProject()).getSelectors(p);
+        }
+        dieOnCircularReference(p);
+        return (FileSelector[]) (selectors.toArray(
             new FileSelector[selectors.size()]));
     }
 
@@ -576,8 +603,11 @@ public abstract class AbstractFileSet extends DataType
      * @return an <code>Enumeration</code> of selectors.
      */
     public synchronized Enumeration selectorElements() {
-        return (isReference() && getProject() != null)
-            ? getRef(getProject()).selectorElements() : selectors.elements();
+        if (isReference()) {
+            return getRef(getProject()).selectorElements();
+        }
+        dieOnCircularReference();
+        return selectors.elements();
     }
 
     /**
@@ -591,6 +621,7 @@ public abstract class AbstractFileSet extends DataType
         }
         selectors.addElement(selector);
         directoryScanner = null;
+        setChecked(false);
     }
 
     /* Methods below all add specific selectors */
@@ -763,6 +794,10 @@ public abstract class AbstractFileSet extends DataType
      * @return a <code>String</code> of included filenames.
      */
     public String toString() {
+        if (isReference()) {
+            return getRef(getProject()).toString();
+        }
+        dieOnCircularReference();
         DirectoryScanner ds = getDirectoryScanner(getProject());
         String[] files = ds.getIncludedFiles();
         StringBuffer sb = new StringBuffer();
@@ -840,6 +875,7 @@ public abstract class AbstractFileSet extends DataType
         if (isReference()) {
             return getRef(p).mergePatterns(p);
         }
+        dieOnCircularReference();
         PatternSet ps = (PatternSet) defaultPatterns.clone();
         final int count = additionalPatterns.size();
         for (int i = 0; i < count; i++) {
@@ -849,4 +885,21 @@ public abstract class AbstractFileSet extends DataType
         return ps;
     }
 
+    protected synchronized void dieOnCircularReference(Stack stk, Project p)
+        throws BuildException {
+        if (isChecked()) {
+            return;
+        }
+        if (isReference()) {
+            super.dieOnCircularReference(stk, p);
+        } else {
+            for (Iterator i = selectors.iterator(); i.hasNext(); ) {
+                Object o = i.next();
+                if (o instanceof DataType) {
+                    pushAndInvokeCircularReferenceCheck((DataType) o, stk, p);
+                }
+            }
+            setChecked(true);
+        }
+    }
 }
diff --git a/src/main/org/apache/tools/ant/types/AntFilterReader.java b/src/main/org/apache/tools/ant/types/AntFilterReader.java
index 737bcec68..64f6f027e 100644
--- a/src/main/org/apache/tools/ant/types/AntFilterReader.java
+++ b/src/main/org/apache/tools/ant/types/AntFilterReader.java
@@ -17,8 +17,10 @@
  */
 package org.apache.tools.ant.types;
 
+import java.util.Stack;
 import java.util.Vector;
 import org.apache.tools.ant.BuildException;
+import org.apache.tools.ant.Project;
 
 /**
  * An AntFilterReader is a wrapper class that encloses the classname
@@ -39,6 +41,9 @@ public final class AntFilterReader
      * @param className a <code>String</code> value
      */
     public void setClassName(final String className) {
+        if (isReference()) {
+            throw tooManyAttributes();
+        }
         this.className = className;
     }
 
@@ -48,6 +53,10 @@ public final class AntFilterReader
      * @return a <code>String</code> value
      */
     public String getClassName() {
+        if (isReference()) {
+            return ((AntFilterReader) getCheckedRef()).getClassName();
+        }
+        dieOnCircularReference();
         return className;
     }
 
@@ -57,6 +66,9 @@ public final class AntFilterReader
      * @param param a <code>Parameter</code> value
      */
     public void addParam(final Parameter param) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
         parameters.addElement(param);
     }
 
@@ -73,6 +85,7 @@ public final class AntFilterReader
         } else {
             this.classpath.append(classpath);
         }
+        setChecked(false);
     }
 
     /**
@@ -86,6 +99,7 @@ public final class AntFilterReader
         if (this.classpath == null) {
             this.classpath = new Path(getProject());
         }
+        setChecked(false);
         return this.classpath.createPath();
     }
 
@@ -94,6 +108,10 @@ public final class AntFilterReader
      * @return the classpath
      */
     public Path getClasspath() {
+        if (isReference()) {
+            ((AntFilterReader) getCheckedRef()).getClasspath();
+        }
+        dieOnCircularReference();
         return classpath;
     }
 
@@ -115,6 +133,10 @@ public final class AntFilterReader
      * @return a <code>Parameter[]</code> value
      */
     public Parameter[] getParams() {
+        if (isReference()) {
+            ((AntFilterReader) getCheckedRef()).getParams();
+        }
+        dieOnCircularReference();
         Parameter[] params = new Parameter[parameters.size()];
         parameters.copyInto(params);
         return params;
@@ -135,23 +157,21 @@ public final class AntFilterReader
                 || classpath != null) {
             throw tooManyAttributes();
         }
-        // change this to get the objects from the other reference
-        Object o = r.getReferencedObject(getProject());
-        if (o instanceof AntFilterReader) {
-            AntFilterReader afr = (AntFilterReader) o;
-            setClassName(afr.getClassName());
-            setClasspath(afr.getClasspath());
-            Parameter[] p = afr.getParams();
-            if (p != null) {
-                for (int i = 0; i < p.length; i++) {
-                    addParam(p[i]);
-                }
-            }
+        super.setRefid(r);
+    }
+
+    protected synchronized void dieOnCircularReference(Stack stk, Project p)
+        throws BuildException {
+        if (isChecked()) {
+            return;
+        }
+        if (isReference()) {
+            super.dieOnCircularReference(stk, p);
         } else {
-            String msg = r.getRefId() + " doesn\'t refer to a FilterReader";
-            throw new BuildException(msg);
+            if (classpath != null) {
+                pushAndInvokeCircularReferenceCheck(classpath, stk, p);
+            }
+            setChecked(true);
         }
-
-        super.setRefid(r);
     }
 }
diff --git a/src/main/org/apache/tools/ant/types/FilterChain.java b/src/main/org/apache/tools/ant/types/FilterChain.java
index 82999b605..ebfc1531a 100644
--- a/src/main/org/apache/tools/ant/types/FilterChain.java
+++ b/src/main/org/apache/tools/ant/types/FilterChain.java
@@ -17,9 +17,12 @@
  */
 package org.apache.tools.ant.types;
 
+import java.util.Iterator;
+import java.util.Stack;
 import java.util.Vector;
 
 import org.apache.tools.ant.BuildException;
+import org.apache.tools.ant.Project;
 import org.apache.tools.ant.filters.ChainableReader;
 import org.apache.tools.ant.filters.ClassConstants;
 import org.apache.tools.ant.filters.EscapeUnicode;
@@ -52,6 +55,10 @@ public class FilterChain extends DataType
      * @param filterReader an <code>AntFilterReader</code> value
      */
     public void addFilterReader(final AntFilterReader filterReader) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(filterReader);
     }
 
@@ -61,6 +68,10 @@ public class FilterChain extends DataType
      * @return a <code>Vector</code> value containing the filters
      */
     public Vector getFilterReaders() {
+        if (isReference()) {
+            return ((FilterChain) getCheckedRef()).getFilterReaders();
+        }
+        dieOnCircularReference();
         return filterReaders;
     }
 
@@ -70,6 +81,10 @@ public class FilterChain extends DataType
      * @param classConstants a <code>ClassConstants</code> value
      */
     public void addClassConstants(final ClassConstants classConstants) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(classConstants);
     }
 
@@ -79,6 +94,10 @@ public class FilterChain extends DataType
      * @param expandProperties an <code>ExpandProperties</code> value
      */
     public void addExpandProperties(final ExpandProperties expandProperties) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(expandProperties);
     }
 
@@ -88,6 +107,10 @@ public class FilterChain extends DataType
      * @param headFilter a <code>HeadFilter</code> value
      */
     public void addHeadFilter(final HeadFilter headFilter) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(headFilter);
     }
 
@@ -97,6 +120,10 @@ public class FilterChain extends DataType
      * @param lineContains a <code>LineContains</code> value
      */
     public void addLineContains(final LineContains lineContains) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(lineContains);
     }
 
@@ -107,6 +134,10 @@ public class FilterChain extends DataType
      */
     public void addLineContainsRegExp(final LineContainsRegExp
                                                 lineContainsRegExp) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(lineContainsRegExp);
     }
 
@@ -116,6 +147,10 @@ public class FilterChain extends DataType
      * @param prefixLines a <code>PrefixLines</code> value
      */
     public void addPrefixLines(final PrefixLines prefixLines) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(prefixLines);
     }
 
@@ -125,6 +160,10 @@ public class FilterChain extends DataType
      * @param replaceTokens a <code>ReplaceTokens</code> value
      */
     public void addReplaceTokens(final ReplaceTokens replaceTokens) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(replaceTokens);
     }
 
@@ -135,6 +174,10 @@ public class FilterChain extends DataType
      */
     public void addStripJavaComments(final StripJavaComments
                                                 stripJavaComments) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(stripJavaComments);
     }
 
@@ -145,6 +188,10 @@ public class FilterChain extends DataType
      */
     public void addStripLineBreaks(final StripLineBreaks
                                                 stripLineBreaks) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(stripLineBreaks);
     }
 
@@ -155,6 +202,10 @@ public class FilterChain extends DataType
      */
     public void addStripLineComments(final StripLineComments
                                                 stripLineComments) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(stripLineComments);
     }
 
@@ -164,6 +215,10 @@ public class FilterChain extends DataType
      * @param tabsToSpaces a <code>TabsToSpaces</code> value
      */
     public void addTabsToSpaces(final TabsToSpaces tabsToSpaces) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(tabsToSpaces);
     }
 
@@ -173,6 +228,10 @@ public class FilterChain extends DataType
      * @param tailFilter a <code>TailFilter</code> value
      */
     public void addTailFilter(final TailFilter tailFilter) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(tailFilter);
     }
 
@@ -183,6 +242,10 @@ public class FilterChain extends DataType
      * @since Ant 1.6
      */
     public void addEscapeUnicode(final EscapeUnicode escapeUnicode) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(escapeUnicode);
     }
 
@@ -193,6 +256,10 @@ public class FilterChain extends DataType
      * @since Ant 1.6
      */
     public void addTokenFilter(final TokenFilter tokenFilter) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(tokenFilter);
     }
 
@@ -203,6 +270,10 @@ public class FilterChain extends DataType
      * @since Ant 1.6
      */
     public void addDeleteCharacters(TokenFilter.DeleteCharacters filter) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(filter);
     }
 
@@ -213,6 +284,10 @@ public class FilterChain extends DataType
      * @since Ant 1.6
      */
     public void addContainsRegex(TokenFilter.ContainsRegex filter) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(filter);
     }
 
@@ -222,6 +297,10 @@ public class FilterChain extends DataType
      * @param filter a <code>TokenFilter.ReplaceRegex</code> value
      */
     public void addReplaceRegex(TokenFilter.ReplaceRegex filter) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(filter);
     }
 
@@ -232,6 +311,10 @@ public class FilterChain extends DataType
      * @since Ant 1.6
      */
     public void addTrim(TokenFilter.Trim filter) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(filter);
     }
 
@@ -243,6 +326,10 @@ public class FilterChain extends DataType
      */
     public void addReplaceString(
         TokenFilter.ReplaceString filter) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(filter);
     }
 
@@ -254,6 +341,10 @@ public class FilterChain extends DataType
      */
     public void addIgnoreBlank(
         TokenFilter.IgnoreBlank filter) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(filter);
     }
 
@@ -272,16 +363,6 @@ public class FilterChain extends DataType
         if (!filterReaders.isEmpty()) {
             throw tooManyAttributes();
         }
-        // change this to get the objects from the other reference
-        Object o = r.getReferencedObject(getProject());
-        if (o instanceof FilterChain) {
-            FilterChain fc = (FilterChain) o;
-            filterReaders = fc.getFilterReaders();
-        } else {
-            String msg = r.getRefId() + " doesn\'t refer to a FilterChain";
-            throw new BuildException(msg);
-        }
-
         super.setRefid(r);
     }
 
@@ -293,7 +374,28 @@ public class FilterChain extends DataType
      */
 
     public void add(ChainableReader filter) {
+        if (isReference()) {
+            throw noChildrenAllowed();
+        }
+        setChecked(false);
         filterReaders.addElement(filter);
     }
 
+    protected synchronized void dieOnCircularReference(Stack stk, Project p)
+        throws BuildException {
+        if (isChecked()) {
+            return;
+        }
+        if (isReference()) {
+            super.dieOnCircularReference(stk, p);
+        } else {
+            for (Iterator i = filterReaders.iterator(); i.hasNext(); ) {
+                Object o = i.next();
+                if (o instanceof DataType) {
+                    pushAndInvokeCircularReferenceCheck((DataType) o, stk, p);
+                }
+            }
+            setChecked(true);
+        }
+    }
 }
diff --git a/src/main/org/apache/tools/ant/types/FilterSet.java b/src/main/org/apache/tools/ant/types/FilterSet.java
index ee322d974..55cd6191f 100644
--- a/src/main/org/apache/tools/ant/types/FilterSet.java
+++ b/src/main/org/apache/tools/ant/types/FilterSet.java
@@ -218,6 +218,7 @@ public class FilterSet extends DataType implements Cloneable {
         if (isReference()) {
             return getRef().getFilters();
         }
+        dieOnCircularReference();
         //silly hack to avoid stack overflow...
         if (!readingFiles) {
             readingFiles = true;
@@ -245,6 +246,10 @@ public class FilterSet extends DataType implements Cloneable {
      * @return   The hash of the tokens and values for quick lookup.
      */
     public synchronized Hashtable getFilterHash() {
+        if (isReference()) {
+            return getRef().getFilterHash();
+        }
+        dieOnCircularReference();
         if (filterHash == null) {
             filterHash = new Hashtable(getFilters().size());
             for (Enumeration e = getFilters().elements(); e.hasMoreElements();) {
diff --git a/src/main/org/apache/tools/ant/types/PropertySet.java b/src/main/org/apache/tools/ant/types/PropertySet.java
index c39776001..2ac084398 100644
--- a/src/main/org/apache/tools/ant/types/PropertySet.java
+++ b/src/main/org/apache/tools/ant/types/PropertySet.java
@@ -23,6 +23,7 @@ import java.util.Iterator;
 import java.util.Map;
 import java.util.HashSet;
 import java.util.Set;
+import java.util.Stack;
 import java.util.TreeMap;
 import java.util.Hashtable;
 import java.util.Properties;
@@ -181,6 +182,7 @@ public class PropertySet extends DataType implements ResourceCollection {
      */
     public void addPropertyref(PropertyRef ref) {
         assertNotReference();
+        setChecked(false);
         ptyRefs.addElement(ref);
     }
 
@@ -190,6 +192,7 @@ public class PropertySet extends DataType implements ResourceCollection {
      */
     public void addPropertyset(PropertySet ref) {
         assertNotReference();
+        setChecked(false);
         setRefs.addElement(ref);
     }
 
@@ -203,6 +206,7 @@ public class PropertySet extends DataType implements ResourceCollection {
             throw new BuildException("Too many <mapper>s!");
         }
         mapper = new Mapper(getProject());
+        setChecked(false);
         return mapper;
     }
 
@@ -245,7 +249,11 @@ public class PropertySet extends DataType implements ResourceCollection {
      * @return true if the property set is to be evalulated each time it is used.
      */
     public boolean getDynamic() {
-        return isReference() ? getRef().dynamic : dynamic;
+        if (isReference()) {
+            return getRef().dynamic;
+        }
+        dieOnCircularReference();
+        return dynamic;
     }
 
     /**
@@ -253,7 +261,11 @@ public class PropertySet extends DataType implements ResourceCollection {
      * @return the mapper attribute.
      */
     public Mapper getMapper() {
-        return isReference() ? getRef().mapper : mapper;
+        if (isReference()) {
+            return getRef().mapper;
+        }
+        dieOnCircularReference();
+        return mapper;
     }
 
     /**
@@ -279,6 +291,7 @@ public class PropertySet extends DataType implements ResourceCollection {
         if (isReference()) {
             return getRef().getProperties();
         }
+        dieOnCircularReference();
         Set names = null;
         Project prj = getProject();
         Hashtable props =
@@ -343,6 +356,10 @@ public class PropertySet extends DataType implements ResourceCollection {
      *         avoid needless duplication of the Hashtable during recursion.
      */
     private void addPropertyNames(Set names, Hashtable properties) {
+        if (isReference()) {
+            getRef().addPropertyNames(names, properties);
+        }
+        dieOnCircularReference();
         // Add this PropertySet's property names.
         for (Enumeration e = ptyRefs.elements(); e.hasMoreElements();) {
             PropertyRef r = (PropertyRef) e.nextElement();
@@ -453,6 +470,10 @@ public class PropertySet extends DataType implements ResourceCollection {
      * @return a string rep of this object.
      */
     public String toString() {
+        if (isReference()) {
+            return getRef().toString();
+        }
+        dieOnCircularReference();
         StringBuffer b = new StringBuffer();
         TreeMap sorted = new TreeMap(getProperties());
         for (Iterator i = sorted.entrySet().iterator(); i.hasNext();) {
@@ -473,6 +494,10 @@ public class PropertySet extends DataType implements ResourceCollection {
      * @since Ant 1.7
      */
     public Iterator iterator() {
+        if (isReference()) {
+            return getRef().iterator();
+        }
+        dieOnCircularReference();
         final Enumeration e = getProperties().propertyNames();
         return new Iterator() {
             public boolean hasNext() {
@@ -500,7 +525,30 @@ public class PropertySet extends DataType implements ResourceCollection {
      * @return whether this is a filesystem-only resource collection.
      */
     public boolean isFilesystemOnly() {
-        return isReference() && getRef().isFilesystemOnly();
+        if (isReference()) {
+            return getRef().isFilesystemOnly();
+        }
+        dieOnCircularReference();
+        return false;
+    }
+
+    protected synchronized void dieOnCircularReference(Stack stk, Project p)
+        throws BuildException {
+        if (isChecked()) {
+            return;
+        }
+        if (isReference()) {
+            super.dieOnCircularReference(stk, p);
+        } else {
+            if (mapper != null) {
+                pushAndInvokeCircularReferenceCheck(mapper, stk, p);
+            }
+            for (Iterator i = setRefs.iterator(); i.hasNext(); ) {
+                pushAndInvokeCircularReferenceCheck((PropertySet) i.next(), stk,
+                                                    p);
+            }
+            setChecked(true);
+        }
     }
 
 }
diff --git a/src/main/org/apache/tools/ant/types/RedirectorElement.java b/src/main/org/apache/tools/ant/types/RedirectorElement.java
index 507fbe2f1..479ff2a70 100755
--- a/src/main/org/apache/tools/ant/types/RedirectorElement.java
+++ b/src/main/org/apache/tools/ant/types/RedirectorElement.java
@@ -592,9 +592,7 @@ public class RedirectorElement extends DataType {
                 if (v[i] != null) {
                     for (Iterator fci = v[i].iterator(); fci.hasNext();) {
                         FilterChain fc = (FilterChain) fci.next();
-                        stk.push(fc);
-                        fc.dieOnCircularReference(stk, p);
-                        stk.pop();
+                        pushAndInvokeCircularReferenceCheck(fc, stk, p);
                     }
                 }
             }