Index: src/main/org/apache/tools/ant/taskdefs/Ant.java
===================================================================
--- src/main/org/apache/tools/ant/taskdefs/Ant.java	(revision 424540)
+++ src/main/org/apache/tools/ant/taskdefs/Ant.java	(working copy)
@@ -1,5 +1,5 @@
 /*
- * Copyright  2000-2005 The Apache Software Foundation
+ * Copyright  2000-2006 The Apache Software Foundation
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -34,6 +34,7 @@
 import org.apache.tools.ant.Project;
 import org.apache.tools.ant.ProjectComponent;
 import org.apache.tools.ant.ProjectHelper;
+import org.apache.tools.ant.PropertyHelper;
 import org.apache.tools.ant.Target;
 import org.apache.tools.ant.Task;
 import org.apache.tools.ant.MagicNames;
@@ -140,6 +141,52 @@
     }
 
     /**
+     * Creates a clone of the property helper 
+     * if <var>inheritAll</var> is <code>true</code>.
+      */
+    private void correctPropertyHelper() {
+        // A new attribute inheritPropertyHelper or similar
+        // would be better. With default = false would
+        // be fully backward compatible. Using inheritAll
+        // instead causes problems to subclasses of
+        // PropertyHelper which don't expect to be cloned
+        // in the subbuild. Hopefully they don't exist.
+        if (!inheritAll) {
+            // not cloning the property helper
+            return;
+        }
+        PropertyHelper thisHelper = (PropertyHelper) getProject()
+                .getReference(MagicNames.REFID_PROPERTY_HELPER);
+        if (thisHelper == null) {
+            // no helper to clone
+            return;
+        }
+
+        PropertyHelper newHelper = null;
+        try {
+            newHelper = (PropertyHelper)thisHelper.clone();
+        } catch (CloneNotSupportedException cnse) {
+            //log("Couln't clone PropertyHelper", Project.MSG_VERBOSE);
+        }
+        if (newHelper != null) {
+            PropertyHelper tempHelper 
+                = PropertyHelper.getPropertyHelper(newProject);
+            newProject.addReference(MagicNames.REFID_PROPERTY_HELPER
+                    , newHelper);
+            // steal the properties
+            tempHelper.copyInheritedProperties(newProject);
+            tempHelper.copyUserProperties(newProject);
+            Hashtable props = tempHelper.getProperties();
+            Enumeration e = props.keys();
+            while (e.hasMoreElements()) {
+                String name = e.nextElement().toString();
+                Object value = props.get(name);
+                newProject.setNewProperty(name, value.toString());
+            }
+        }
+    }
+
+    /**
      * Creates a Project instance for the project to call.
      */
     public void init() {
@@ -286,6 +333,7 @@
             if (newProject == null) {
                 reinit();
             }
+            correctPropertyHelper();
 
             if ((dir == null) && (inheritAll)) {
                 dir = getProject().getBaseDir();