diff --git a/src/main/org/apache/tools/ant/taskdefs/Java.java b/src/main/org/apache/tools/ant/taskdefs/Java.java
index 9f947c03a..f491f9e3d 100644
--- a/src/main/org/apache/tools/ant/taskdefs/Java.java
+++ b/src/main/org/apache/tools/ant/taskdefs/Java.java
@@ -329,6 +329,19 @@ public class Java extends Task {
         cmdl.createArgument().setLine(s);
     }
 
+    /**
+     * If set, system properties will be copied to the cloned VM - as
+     * well as the bootclasspath unless you have explicitly specified
+     * a bootclaspath.
+     *
+     * <p>Doesn't have any effect unless fork is true.</p>
+     *
+     * @since Ant 1.7
+     */
+    public void setCloneVm(boolean cloneVm) {
+        cmdl.setCloneVm(cloneVm);
+    }
+
     /**
      * Adds a command-line argument.
      *
diff --git a/src/main/org/apache/tools/ant/taskdefs/optional/junit/JUnitTask.java b/src/main/org/apache/tools/ant/taskdefs/optional/junit/JUnitTask.java
index 4fa47e038..99ba7dd3a 100644
--- a/src/main/org/apache/tools/ant/taskdefs/optional/junit/JUnitTask.java
+++ b/src/main/org/apache/tools/ant/taskdefs/optional/junit/JUnitTask.java
@@ -587,6 +587,19 @@ public class JUnitTask extends Task {
         return perm;
     }
 
+    /**
+     * If set, system properties will be copied to the cloned VM - as
+     * well as the bootclasspath unless you have explicitly specified
+     * a bootclaspath.
+     *
+     * <p>Doesn't have any effect unless fork is true.</p>
+     *
+     * @since Ant 1.7
+     */
+    public void setCloneVm(boolean cloneVm) {
+        commandline.setCloneVm(cloneVm);
+    }
+
     /**
      * Creates a new JUnitRunner and enables fork of a new Java VM.
      *
diff --git a/src/main/org/apache/tools/ant/types/CommandlineJava.java b/src/main/org/apache/tools/ant/types/CommandlineJava.java
index 3bd58fb6b..52bf7d312 100644
--- a/src/main/org/apache/tools/ant/types/CommandlineJava.java
+++ b/src/main/org/apache/tools/ant/types/CommandlineJava.java
@@ -104,6 +104,12 @@ public class CommandlineJava implements Cloneable {
      */
      private boolean executeJar = false;
 
+    /**
+     * Whether system properties and bootclasspath shall be cloned.
+     * @since Ant 1.7
+     */
+    private boolean cloneVm = false;
+
     /**
      * Specialized Environment class for System properties
      */
@@ -294,6 +300,15 @@ public class CommandlineJava implements Cloneable {
         vmVersion = value;
     }
 
+    /**
+     * If set, system properties will be copied to the cloned VM - as
+     * well as the bootclasspath unless you have explicitly specified
+     * a bootclaspath.
+     * @since Ant 1.7
+     */
+    public void setCloneVm(boolean cloneVm) {
+        this.cloneVm = cloneVm;
+    }
 
     /**
      * get the current assertions
@@ -397,10 +412,26 @@ public class CommandlineJava implements Cloneable {
         getActualVMCommand().addCommandToList(listIterator);
         // properties are part of the vm options...
         sysProperties.addDefinitionsToList(listIterator);
+
+        if (isCloneVm()) {
+            SysProperties clonedSysProperties = new SysProperties();
+            PropertySet ps = new PropertySet();
+            PropertySet.BuiltinPropertySetName sys =
+                new PropertySet.BuiltinPropertySetName();
+            sys.setValue("system");
+            ps.appendBuiltin(sys);
+            clonedSysProperties.addSyspropertyset(ps);
+            clonedSysProperties.addDefinitionsToList(listIterator);
+        }
+        
         //boot classpath
         if (haveBootclasspath(true)) {
             listIterator.add("-Xbootclasspath:" + bootclasspath.toString());
+        } else if (cloneBootclasspath()) {
+            listIterator.add("-Xbootclasspath:" + 
+                             Path.systemBootClasspath.toString());
         }
+        
         //main classpath
         if (haveClasspath()) {
             listIterator.add("-classpath");
@@ -489,13 +520,19 @@ public class CommandlineJava implements Cloneable {
      * @deprecated please dont use this -it effectively creates the entire command.
      */
     public int size() {
-        int size = getActualVMCommand().size() + javaCommand.size() + sysProperties.size();
+        int size = getActualVMCommand().size() + javaCommand.size() 
+            + sysProperties.size();
+        // cloned system properties
+        if (isCloneVm()) {
+            size += System.getProperties().size();
+        }
+        
         // classpath is "-classpath <classpath>" -> 2 args
         if (haveClasspath()) {
             size += 2;
         }
         // bootclasspath is "-Xbootclasspath:<classpath>" -> 1 arg
-        if (haveBootclasspath(true)) {
+        if (haveBootclasspath(true) || cloneBootclasspath()) {
             size++;
         }
         // jar execution requires an additional -jar option
@@ -648,4 +685,23 @@ public class CommandlineJava implements Cloneable {
         return false;
     }
 
+    /**
+     * Should a bootclasspath argument be created to clone the current
+     * VM settings?
+     *
+     * @since Ant 1.7
+     */
+    private boolean cloneBootclasspath() {
+        return isCloneVm() && !vmVersion.startsWith("1.1")
+            && Path.systemBootClasspath.size() > 0;
+    }
+        
+    /**
+     * Has the cloneVm attribute or the magic property build.clonevm been set?
+     *
+     * @since 1.7
+     */
+    private boolean isCloneVm() {
+        return cloneVm || "true".equals(System.getProperty("build.clonevm"));
+    }
 }
diff --git a/src/main/org/apache/tools/ant/types/Path.java b/src/main/org/apache/tools/ant/types/Path.java
index c922651b5..60c67761d 100644
--- a/src/main/org/apache/tools/ant/types/Path.java
+++ b/src/main/org/apache/tools/ant/types/Path.java
@@ -104,6 +104,15 @@ public class Path extends DataType implements Cloneable {
         new Path(null, System.getProperty("java.class.path"));
 
 
+    /** 
+     * The system bootclassspath as a Path object.
+     *
+     * @since Ant 1.7
+     */
+    public static Path systemBootClasspath =
+        new Path(null, System.getProperty("sun.boot.class.path"));
+
+
     /**
      * Helper class, holds the nested <code>&lt;pathelement&gt;</code> values.
      */
@@ -404,7 +413,7 @@ public class Path extends DataType implements Cloneable {
     public static String[] translatePath(Project project, String source) {
         final Vector result = new Vector();
         if (source == null) {
-          return new String[0];
+            return new String[0];
         }
 
         PathTokenizer tok = new PathTokenizer(source);
diff --git a/src/main/org/apache/tools/ant/types/PropertySet.java b/src/main/org/apache/tools/ant/types/PropertySet.java
index 485be383c..c50906dfb 100644
--- a/src/main/org/apache/tools/ant/types/PropertySet.java
+++ b/src/main/org/apache/tools/ant/types/PropertySet.java
@@ -194,13 +194,15 @@ public class PropertySet extends DataType {
     public Properties getProperties() {
         Vector names = null;
         Project prj = getProject();
+        Hashtable props = 
+            prj == null ? System.getProperties() : prj.getProperties();
 
         if (getDynamic() || cachedNames == null) {
             names = new Vector(); // :TODO: should be a Set!
             if (isReference()) {
-                getRef().addPropertyNames(names, prj.getProperties());
+                getRef().addPropertyNames(names, props);
             } else {
-                addPropertyNames(names, prj.getProperties());
+                addPropertyNames(names, props);
             }
 
             if (!getDynamic()) {
@@ -218,7 +220,7 @@ public class PropertySet extends DataType {
         Properties properties = new Properties();
         for (Enumeration e = names.elements(); e.hasMoreElements();) {
             String name = (String) e.nextElement();
-            String value = prj.getProperty(name);
+            String value = (String) props.get(name);
             if (mapper != null) {
                 String[] newname = mapper.mapFileName(name);
                 if (newname != null) {
@@ -243,7 +245,7 @@ public class PropertySet extends DataType {
         for (Enumeration e = ptyRefs.elements(); e.hasMoreElements();) {
             PropertyRef ref = (PropertyRef) e.nextElement();
             if (ref.name != null) {
-                if (prj.getProperty(ref.name) != null) {
+                if (prj != null && prj.getProperty(ref.name) != null) {
                     names.addElement(ref.name);
                 }
             } else if (ref.prefix != null) {