diff --git a/core/src/main/java/org/springframework/security/ui/AbstractProcessingFilter.java b/core/src/main/java/org/springframework/security/ui/AbstractProcessingFilter.java
index e653e6417e..001da04b8a 100644
--- a/core/src/main/java/org/springframework/security/ui/AbstractProcessingFilter.java
+++ b/core/src/main/java/org/springframework/security/ui/AbstractProcessingFilter.java
@@ -127,8 +127,7 @@ import javax.servlet.http.HttpSession;
  * is true.
  *
  * @author Ben Alex
- * @version $Id: AbstractProcessingFilter.java 1909 2007-06-19 04:08:19Z
- * vishalpuri $
+ * @version $Id$
  */
 public abstract class AbstractProcessingFilter extends SpringSecurityFilter implements InitializingBean,
         ApplicationEventPublisherAware, MessageSourceAware {
@@ -364,45 +363,46 @@ public abstract class AbstractProcessingFilter extends SpringSecurityFilter impl
     private void startNewSessionIfRequired(HttpServletRequest request) {
         HttpSession session = request.getSession(false);
 
-        if (session != null) {
+        if (session == null) {
+            return;
+        }
 
-            if (!migrateInvalidatedSessionAttributes) {
+        if (!migrateInvalidatedSessionAttributes) {
 
-                if (logger.isDebugEnabled()) {
-                    logger.debug("Invalidating session without migrating attributes.");
-                }
+            if (logger.isDebugEnabled()) {
+                logger.debug("Invalidating session without migrating attributes.");
+            }
 
-                session.invalidate();
-                session = null;
+            session.invalidate();
+            session = null;
 
-                // this is probably not necessary, but seems cleaner since
-                // there already was a session going.
-                request.getSession(true);
+            // this is probably not necessary, but seems cleaner since
+            // there already was a session going.
+            request.getSession(true);
 
-            } else {
+        } else {
 
-                if (logger.isDebugEnabled()) {
-                    logger.debug("Invalidating session and migrating attributes.");
-                }
+            if (logger.isDebugEnabled()) {
+                logger.debug("Invalidating session and migrating attributes.");
+            }
 
-                HashMap migratedAttributes = new HashMap();
+            HashMap migratedAttributes = new HashMap();
 
-                Enumeration enumer = session.getAttributeNames();
+            Enumeration enumer = session.getAttributeNames();
 
-                while (enumer.hasMoreElements()) {
-                    String key = (String) enumer.nextElement();
-                    migratedAttributes.put(key, session.getAttribute(key));
-                }
+            while (enumer.hasMoreElements()) {
+                String key = (String) enumer.nextElement();
+                migratedAttributes.put(key, session.getAttribute(key));
+            }
 
-                session.invalidate();
-                session = request.getSession(true); // we now have a new session
+            session.invalidate();
+            session = request.getSession(true); // we now have a new session
 
-                Iterator iter = migratedAttributes.entrySet().iterator();
+            Iterator iter = migratedAttributes.entrySet().iterator();
 
-                while (iter.hasNext()) {
-                    Map.Entry entry = (Map.Entry) iter.next();
-                    session.setAttribute((String) entry.getKey(), entry.getValue());
-                }
+            while (iter.hasNext()) {
+                Map.Entry entry = (Map.Entry) iter.next();
+                session.setAttribute((String) entry.getKey(), entry.getValue());
             }
         }
     }
@@ -558,5 +558,4 @@ public abstract class AbstractProcessingFilter extends SpringSecurityFilter impl
 	public void setUseRelativeContext(boolean useRelativeContext) {
 		this.useRelativeContext = useRelativeContext;
 	}
-
 }
diff --git a/core/src/test/java/org/springframework/security/ui/AbstractProcessingFilterTests.java b/core/src/test/java/org/springframework/security/ui/AbstractProcessingFilterTests.java
index c0ec89342c..64039a9c0a 100644
--- a/core/src/test/java/org/springframework/security/ui/AbstractProcessingFilterTests.java
+++ b/core/src/test/java/org/springframework/security/ui/AbstractProcessingFilterTests.java
@@ -31,6 +31,7 @@ import org.springframework.security.util.PortResolverImpl;
 import org.springframework.mock.web.MockFilterConfig;
 import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.mock.web.MockHttpServletResponse;
+import org.springframework.mock.web.MockHttpSession;
 
 import javax.servlet.Filter;
 import javax.servlet.FilterChain;
@@ -40,6 +41,7 @@ import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpSession;
 import java.io.IOException;
 import java.util.Properties;
 
@@ -254,6 +256,7 @@ public class AbstractProcessingFilterTests extends TestCase {
     public void testNormalOperationWithDefaultFilterProcessesUrl() throws Exception {
         // Setup our HTTP request
         MockHttpServletRequest request = createMockRequest();
+        HttpSession sessionPreAuth = request.getSession();
 
         // Setup our filter configuration
         MockFilterConfig config = new MockFilterConfig(null, null);
@@ -275,6 +278,8 @@ public class AbstractProcessingFilterTests extends TestCase {
         assertEquals("/mycontext/logged_in.jsp", response.getRedirectedUrl());
         assertNotNull(SecurityContextHolder.getContext().getAuthentication());
         assertEquals("test", SecurityContextHolder.getContext().getAuthentication().getPrincipal().toString());
+        // Should still have the same session
+        assertEquals(sessionPreAuth, request.getSession());
     }
 
     public void testStartupDetectsInvalidAuthenticationFailureUrl() throws Exception {
@@ -373,7 +378,7 @@ public class AbstractProcessingFilterTests extends TestCase {
     }
 
     public void testSuccessfulAuthenticationButWithAlwaysUseDefaultTargetUrlCausesRedirectToDefaultTargetUrl()
-        throws Exception {
+            throws Exception {
         // Setup our HTTP request
         MockHttpServletRequest request = createMockRequest();
         request.getSession().setAttribute(AbstractProcessingFilter.SPRING_SECURITY_SAVED_REQUEST_KEY, makeSavedRequestForUrl());
@@ -433,7 +438,6 @@ public class AbstractProcessingFilterTests extends TestCase {
 
         // Setup our test object, to grant access
         MockAbstractProcessingFilter filter = new MockAbstractProcessingFilter(true);
-        filter.setFilterProcessesUrl("/j_mock_post");
         filter.setDefaultTargetUrl("http://monkeymachine.co.uk/");
         filter.setAlwaysUseDefaultTargetUrl(true);
 
@@ -442,6 +446,48 @@ public class AbstractProcessingFilterTests extends TestCase {
         assertNotNull(SecurityContextHolder.getContext().getAuthentication());
     }
 
+    public void testNewSessionIsCreatedIfInvalidateSessionOnSuccessfulAuthenticationIsSet() throws Exception {
+        MockHttpServletRequest request = createMockRequest();
+        HttpSession oldSession = request.getSession();
+        oldSession.setAttribute("test","test");
+        MockFilterConfig config = new MockFilterConfig(null, null);
+
+        MockFilterChain chain = new MockFilterChain(true);
+        MockHttpServletResponse response = new MockHttpServletResponse();
+
+        // Setup our test object, to grant access
+        MockAbstractProcessingFilter filter = new MockAbstractProcessingFilter(true);
+        filter.setInvalidateSessionOnSuccessfulAuthentication(true);
+        filter.setDefaultTargetUrl("http://monkeymachine.co.uk/");
+
+        executeFilterInContainerSimulator(config, filter, request, response, chain);
+
+        HttpSession newSession = request.getSession();
+        assertFalse(newSession.getId().equals(oldSession.getId()));
+        assertEquals("test", newSession.getAttribute("test"));
+    }
+
+    public void testAttributesAreNotMigratedToNewlyCreatedSessionIfMigrateAttributesIsFalse() throws Exception {
+        MockHttpServletRequest request = createMockRequest();
+        HttpSession oldSession = request.getSession();
+        MockFilterConfig config = new MockFilterConfig(null, null);
+
+        MockFilterChain chain = new MockFilterChain(true);
+        MockHttpServletResponse response = new MockHttpServletResponse();
+
+        // Setup our test object, to grant access
+        MockAbstractProcessingFilter filter = new MockAbstractProcessingFilter(true);
+        filter.setInvalidateSessionOnSuccessfulAuthentication(true);
+        filter.setMigrateInvalidatedSessionAttributes(false);
+        filter.setDefaultTargetUrl("http://monkeymachine.co.uk/");
+
+        executeFilterInContainerSimulator(config, filter, request, response, chain);
+
+        HttpSession newSession = request.getSession();
+        assertFalse(newSession.getId().equals(oldSession.getId()));
+        assertNull(newSession.getAttribute("test"));
+    }
+
     //~ Inner Classes ==================================================================================================
 
     private class MockAbstractProcessingFilter extends AbstractProcessingFilter {